Deoxyribonucleic acid repair in Escherichia coli mutants deficient in the 5'----3' exonuclease activity of deoxyribonucleic acid polymerase I and exonuclease VII. A series of Escherichia coli strains deficient in the 5'----3' exonuclease activity associated with deoxyribonucleic acid (DNA) polymerase I (exonuclease VI) and exonuclease VII has been constructed. Both of these enzymes are capable of pyrimidine dimer excision in vitro. These strains were examined for conditional lethality, sensitivity to ultraviolet (UV) and X-irradiation, postirradiation DNA degradation, and ability to excise pyrimidine dimers. It was found that strains deficient in both exonuclease VI (polAex-) and exonuclease VII (xseA-) are significantly reduced in their ability to survive incubation at elevated temperature (43 degrees C) beyond the reduction previously observed for the polAex single mutants. The UV and X-ray sensitivity of the exonuclease VI-deficient strains was not increased by the addition of the xseA7 mutation. Mutants deficient in both enzymes are about as efficient as wild-type strains at excising dimers produced by up to 40 J/m2 UV. At higher doses strains containing only polAex- mutations show reduced ability to excise dimers; however, the interpretation of dimer excision data at these doses is complicated by extreme postirradiation DNA degradation in these strains. The additional deficiency in the polAex xseA7 double-mutant strains has no significant effect on either postirradiation DNA degradation or the apparent deficiency in dimer excision at high UV doses observed in polAex single mutants.


Mutations in the L-arabinose operon of Escherichia coli B/r with reduced initiator function. Partial reversion mutants derived from a strain containing a strongly polar initiator-defective mutation (araI1036) in the L-arabinose operon were found to have several characteristics expected of mutants with reduced initiator function. These reversion mutations are cotransduced with the ara region and are probably within the araI region. Furthermore, they permit induction of the L-arabinose operon to a level only one-third of the normal wild-type level. These partially functional initiator regions reduce the expression of structural genes in the cis position only; they function quite independently of wild-type or defective initiator regions in the trans position. These mutants exhibit a two- to threefold increase in the rate of expression of ara operon genes within one-tenth of a generation after a shift of the growth temperature from 28 to 42 degrees C. This suggests that the temperature optimum for initiation of operon expression is higher for the partial revertant strains than it is for strains containing a wild-type initiator region.


Deoxyribonucleic acid synthesis after inhibition of initiation of rounds of replication in Escherichia coli B/r. The theory describing the effect of inhibition of initiation of rounds of deoxyribonucleic acid (DNA) replication on the accumulation of DNA is derived, and an analysis is presented which allows the determination of the time C taken to replicate the bacterial chromosome from the kinetic changes in the accumulation of DNA. This analysis is applied to experiments in which inhibition of initiation was achieved by inhibiting protein or protein and ribonucleic acid synthesis with chloramphenicol or rifampin. The results for both antibiotics are identical and indicate that there is a delay of 6 to 11 min in the effect of the antibiotics on initiation of rounds of replication. If this delay is taken into account, then the value of the C period estimated from such experiments agrees with values obtained by other methods, whereas by conventional data evaluation of such experiments the C period would be overestimated. In the low thymine-requiring derivative of Escherichia coli B/r ATCC 12407 used here, the C period was found to be between 38 and 41 min for cultures growing with a mass doubling time of 29 min in glucose-amino acids medium, supplemented with 20 micrograms of thymine/ml.


Amino acid transport and metabolism in nitrogen-starved cells of Saccharomyces cerevisiae. Nitrogen-starved yeast derepress a general amino acid permease which transports basic and hydrophobic amino acids. Although both groups of amino acids are metabolized, the derivatives of the basic amino acids are retained by the cells, whereas those of the hydrophobic amino acids are released as acidic and neutral deaminated derivatives. The release of the deaminated derivatives of the hydrophobic amino acids only occurs in the presence of glucose, which presumably produces amino acceptors. The accumulation of intracellular amino acids results in trans-inhibition of the uptake of exogenous amino acids whether the intracellular amino acid is a basic amino acid or the product of intracellular transamination from a hydrophobic amino acid. Variation of permease and transaminase activity was measured during growth under repressed (ammonia-grown) and derepressed (proline-grown) conditions. Maximum levels for both activities occurs at the mid-exponential phase.


Cell division in Escherichia coli BS-12 is hypersensitive to deoxyribonucleic acid damage by ultraviolet light. Escherichia coli BS-12 uvrA lon is hypersensitive to ultraviolet light. On minimal agar plates at densities in excess of about 10(7) bacteria per plate, as few as one or two photoreversible pyrimidine dimers in the entire genome are sufficient to cause inhibition of cell division. Most of the resulting filaments are unable to divide or form a viable colony. Inhibition of cell division appears to be a rapid consequence of replication of deoxyribonucleic acid containing a pyrimidine dimer. Photoreversibility of the inhibition of cell division persists indefinitely, indicating that the continued presence of the pyrimidine dimers (or the continued generation of daughter strand gaps) is necessary to maintain the division-inhibited state. In view of the kinetics for the production of filamentation by ultraviolet light and the extremely low average inducing fluence (0.03 J/m2), it is concluded that the initiating signal is not the same as that causing other inducible phenomena such as prophage induction or Weigle reactivation.


Isolation and characterization of Saccharomyces cerevisiae glycolytic pathway mutants. Yeast strains carrying recessive mutations representing four different loci that cause defects in pyruvate kinase, pyruvate decarboxylase, 3-phosphoglycerate kinase, and 3-phosphoglycerate mutase were isolated and partially characterized. Cells carrying these mutations were unable to use glucose as a carbon source as measured in turbidimetric growth experiments. Tetrad analysis indicated that these mutations were not linked to each other; one of the mutations, that affecting phosphoglycerate kinase, was located on chromosome III.


Recovery of Saccharomyces cerevisiae mating-type a cells from G1 arrest by alpha factor. Mating-type a cells of the yeast Saccharomyces cerevisiae that had been specifically arrested in the G1 phase of the cell cycle by alpha factor, an oligopeptide pheromone made by alpha cells, recovered and resumed cell division after a period of inhibition which was dependent on the concentration of alpha factor used. These treated a cells were more resistant to alpha factor than untreated a cells, but lost their resistance upon further cell division. However, cells arrested for 6 h were no more resistant to alpha factor than cells arrested for only 2.5 h. Mating-type a strains could inactivate or remove alpha factor from the culture fluid, but two a sterile (nonmating) mutants and an a/alpha diploid strain could not. These results suggest that a cells have a mechanism, which may involve uptake or inactivation of alpha factor, for recovering from alpha factor arrest. However, the results do not distinguish between a recovery mechanism which is constitutive and one which is induced by alpha factor. The loss of alpha factor activity during recovery appeared to be primarily cell contact mediated, although an extracellular, diffusible inhibitor of alpha factor that is labile or that functions stoichiometrically could not be ruled out.


Iodination of Escherichia coli with chloramine T: selective labeling of the outer membrane lipoprotein. Iodination of Escherichia coli cells with chloramine T preferentially labels the free and murein-bound forms of the outer membrane lipoprotein. Iodination for 15 s at 15 degrees C labels the two forms of the lipoprotein almost exclusively, whereas iodination for 60 s at 25 degrees C also labels the other major outer membrane proteins. Chloramine T iodination is a rapid, simple technique for labeling the outer membrane lipoprotein.


Escherichia coli K-12 tolF mutants: alterations in protein composition of the outer membrane. Outer membrane materials prepared from three independently isolated spontaneous Escherichia coli tolF mutants contained no detectable protein Ia. The loss of this protein was nearly completely compensated for by an increase in other major outer membrane proteins, Ib and II. Thus, the major outer membrane proteins accounted for 40% of the total cell envelope protein in both tol+ and tolF strains. No changes were found in the levels of inner membrane proteins prepared from tolF strains when compared with similar preparations from the tol+ strain. Phage-resistant mutants were selected starting with a tolF strain by using either phage TuIb or phage PA2. These phage-resistant tolF strains contained neither protein Ia nor protein Ib. The mutation leading to the loss of protein Ib in these strains is independent of the tolF mutation and is located near malP on the E. coli genetic map.


Flagellar formation in Escherichia coli electron transport mutants. Mutants of Escherichia coli lacking ubiquinone or heme have been tested for motility and found to be essentially immotile. The loss of motility is identified with the loss of flagellum synthesis.


Regulatory changes in the fucose system associated with the evolution of a catabolic pathway for propanediol in Escherichia coli. Wild-type strains of Escherichia coli are unable to use L-1,2-propanediol as a carbon and energy source. Strain 3, a mutant selected for the ability to grow on this compound at progressively more rapid rates, synthesizes constitutively a nicotinamide adenine dinucleotide-linked propanediol oxidoreductase. This enzyme is normally synthesized during anaerobic growth on L-fucose when it functions as a lactaldehyde reductase. Propanediol, the end product of this fermentation process, escapes irretrievably into the medium. The propanediol-utilizing mutant can no longer grow on fucose in either the presence or absence of molecular oxygen. In the present study nine independent lines of propanediol-positive mutants were characterized. One mutant, strain 418, attained a propanediol growth rate close to that of strain 3 without loss of the ability to grow on fucose. In all cases examined, however, prolonged selection on propanediol did result in the emergence of fucose-negative mutants. All of these mutants had enzyme patterns similar to that of strain 3; namely, fucose permease, fucose isomerase, and fuculose kinase were noninducible, whereas fuculose 1-phosphate aldolase was constitutive. In strain 418 and in the fucose-positive predecessors of the other mutants, the first four enzymes in the pathway remained inducible, as in the wild-type strain. Improvements in the growth rate on propanediol appeared to reflect principally the increased activity level of the oxidoreductase during the early stages of evolution. According to transductional analysis, the mutations affecting the ability to grow on propanediol and those that affect the expression of the first enzymes in the fucose pathway were very closely linked. The loss of the ability to grow on fucose is thought to be a mechanistic consequence incidental to the remodeling of the regulatory system in favor of the utilization of the novel carbon source.


Area of 16S ribonucleic acid at or near the interface between 30S and 50S ribosomes of Escherichia coli. To determine the region of 16S ribonucleic acid (RNA) at the interface between 30 and 50S ribosomes of Escherichia coli, 30 and 70S ribosomes were treated with T1 ribonuclease (RNase). The accessibility of 16S RNA in the 5' half of the molecule is the same in 30 and 70S ribosomes. The interaction with 50S ribosomes decreases the sensitivity to T1 RNase of an area in the middle of 16S RNA. A large area near the 3' end of 16S RNA is completely protected in 70S ribosomes. The RNA near the 3' end of the molecule and an area of RNA in the middle of the molecule appear to be at the interface between 30 and 50S ribosomes. One site in 16S RNA, 13 to 15 nucleotides from the 3' end, normally inaccessible to T1 RNase in 30S ribosomes, becomes accessible to T1 RNase in 70S ribosomes. This indicates a conformational change at the 3' end of 16S RNA when 30S ribosomes are associated with 50S ribosomes.


Polysaccharide capsule of Escherichia coli: microscope study of its size, structure, and sites of synthesis. This report describes the structure, size, and shape of the uncollapsed polysaccharide capsule of Escherichia coli strain Bi 161/42 [O9:K29(A):H-], its ultrastructural preservation as well as the filamentous components of the isolated capsular material. In a temperature-sensitive mutant, sites were localized at which capsular polysaccharide is "exported" to the cell surface. The highly hydrated capsule of the wild-type cells was visible in the uncollapsed state after freeze-etching, whereas dehydration in greater than or equal to 50% acetone or alcohol caused the capsule to collapse into thick bundles. This was prevented by pretreatment of the cell with capsule-specific immunoglobulin G; the capsule appeared as a homogeneous layer of 250- to 300-nm thickness. The structural preservation depended on the concentration of the anti-capsular immunoglobulin G. Temperature-sensitive mutants, unable to produce capsular antigen at elevated temperatures, showed, 10 to 15 min after shift down to permissive temperature, polysaccharide strands with K29 specificity appearing at the cell surface at roughly 20 sites per cell; concomitantly, capsule-directed antibody started to agglutinate the bacteria. The sites at which the new antigen emerged were found in random distribution over the entire surface of the organism. Spreading of purified polysaccharide was achieved on air-water interfaces; after subsequent shadow casting with heavy metal, filamentous elements were observed with a smallest class of filaments measuring 250 nm in length and 3 to 6 nm in width. At one end these fibers revealed a knoblike structure of about 10-nm diameter. The slimelike polysaccharides from mutants produced filamentous bundles of greater than 100-microns length, with antigenic and phage-receptor properties indistinguishable from those of the wild-type K29 capsule antigen.


Stepwise selection of defective nitrogen-fixing phenotypes in Escherichia coli K-12 by dimethyl sulfoxide. Storage in dimethyl sulfoxide of Escherichia coli K-12 hybrids carrying Klebsiella pneumoniae nif+ genes can result in selection of a defective nitrogen-fixing phenotype. Dimethyl sulfoxide appears to affect particular inner membrane proteins associated with energy metabolism in E. coli K-12.


Fusion of yeast spheroplasts.

Fusion of yeast spheroplasts. Spheroplasts of two different auxotrophic strains of Saccharomyces cerevisiae, both of mating type a, were fused with the aid of polyethylene glycol and calcium ions. After reversion to vegetative cells in solid media, the resulting zygotes were shown to be diploid cells of mating type aa.


Multivalent regulation of isoleucine-valine transaminase in an Escherichia coli K-12 ilvA deletion strain. In a strain of Escherichia coli K-12 lacking threonine deaminase, the enzyme converting alpha-ketoisovalerate and alpha-keto-beta-methylvalerate to valine and isoleucine, respectively, was multivalently repressed by valine, isoleucine, and leucine. This activity was due to transaminase B, specified by the ilvE structural gene.


Coordinate control of the synthesis of ribonucleoside diphosphate reductase components in Escherichia coli. Ribonucleoside diphosphate reductase subunits B1 and B2 and ether-permeabilized cell activities of Escherichia coli increase in parallel during thymine deprivation. Thioredoxin and thioredoxin reductase activities are not affected by thymine deprivation.


Nucleoside triphosphate pools in minicells of Escherichia coli. The nucleoside triphosphate pools of Escherichia coli minicells are different from those in parental cells. The growth phase in which minicells accumulate significantly affects the pool sizes.


Transport of 3,4-dihydroxybutyl-1-phosphonate, an analogue of sn-glycerol 3-phosphate. 3,4-Dihydroxybutyl-1-phosphonate (DHBP), an analogue of glycerol 3-phosphate, is actively transported by the sn-glycerol 3-phosphate transport system of Escherichia coli strain 8. The Km for the transport of DHBP is 200 microM.


Wechsler Memory Scale: a selective review of the literature. Research on the Wechsler Memory Scale (WMS) is reviewed with respect to questions of its reliability, factor structure, construct validity, and utility. The relationship of Memory Quotient to Full Scale IQ is explored and the conditions under which disparity between the two scores may be clinically useful indicated. Despite its numerous limitations, the WMS has been a sensitive test of short-term verbal memory. As such, it may be helpful in identifying impairment of the dominant (left) temporal lobe and its medial hippocampal connections. The test is badly in need of re-standardization, however, and suggestions for improving the instrument are made.


Time-response analysis of the effect of stimulant medication on the learning ability of children referred for hyperactivity. This report introduces a method for obtaining behavioral time-response information for a short-acting psychotropic drug (methylphenidate [Ritalin]) that is widely used to treat behaviorally hyperactive children. We used a laboratory learning task to document that between one and two hours after the administration of a single dose of methylphenidate, the drug exerts its maximum effect on performance in a learning task in the laboratory. This effect on cognitive performance dissipates within the same day. This rapid and transient effect of methylphenidate makes it possible to classify patients in a single day into those who respond favorably and those who respond adversely to the drug in terms of its effect on cognitive behavior.


Pneumocystis carinii infection: evidence for high prevalence in normal and immunosuppressed children. Using Pneumocystis carinii organisms propagated through three passages in embryonic chick epithelial lung cultures, specific antigens and antisera were prepared for use in counterimmunoelectrophoresis and indirect immunofluorescent antibody techniques. These methods proved to be specific and sensitive for the detection of P. carinii antigen and antibody, respectively, in sera, and were applied to the study of cancer patients with P. carinii pneumonitis (PCP), cancer patients without pneumonitis, and normal children. Antigenemia was detected in 95% of patients with PCP, in 15% of cancer patients without pneumonitis, and in none of the normal children tested. In cross-sectional and longitudinal studies of normal infants and children, acquisition of serum antibody to P. carinii was demonstrated to occur progressively with increase in age. By 4 years of age two thirds of the normal children were found to have antibody to P. carinii in titers of 1:16 or greater. These studies indicate that subclinical P. carinii infection is highly prevalent in normal children, analogous to other opportunistic infections where active disease is manifest predominantly in the compromised host.


Modified agar dilution method for rapid antibiotic susceptibility testing of anaerobic bacteria. A simplified method has been developed for agar dilution antimicrobial susceptibility testing of anaerobic bacteria, designed to economize on time and money when only a few isolates need to be tested. The procedure is based on the principle of using filter paper disks as carriers of the antibiotic and 35- by 10-mm petri dishes which, when inoculated with the Steers replicator, can test up to four organisms per plate. The procedure was run in parallel with conventional agar dilution techniques and showed 95% agreement to within one dilution for all minimal inhibitory concentrations recorded on fresh anaerobic isolates from clinical specimens. The technique was further simplified by using commercially available antibiotic-containing disks, thereby alleviating the tedious and time-consuming procedure of preparing the disks. The data indicated that 48- to 72-h diffusion periods were sufficient to achieve a uniform concentration of the antibiotic in the petri plate and that the antibiotics were stable at room temperature for that period of time. In terms of applicability and relevance to the needs of the clinical microbiology laboratory, the modified agar dilution method for rapid antimicrobial susceptibility testing of individual anaerobic isolates was found to be superior to the broth dilution method since it was easier to read and required considerably less set up time.


Stepwise acquisition of multiple drug resistance by beta-hemolytic streptococci and difference in resistance pattern by type. We collected 1,353 strains of beta-hemolytic streptococci of groups A, B, C, and G (1,176 strains of which were group A) isolated in 26 institutions throughout Japan in 1972-1974. The strains were grouped and T-typed by our specific group-and T-factor sera, and the minimal inhibitory concentrations of 10 antibiotics were assayed by the standard method. Resistant strains from the above collection were classified according to group, T-type, and drug resistance pattern. Our data on T-types for 1964-1971 and on drug resistance for 1966-1971 were used to interpret the detected long-term variations in T-type and drug resistance. The stepwise acquisition of multiple drug resistance, the difference in resistance pattern between predominant T-types, and the rarity of single-macrolide resistance were demonstrated.


In vitro and in vivo studies with BL-S786, cefoxitin, and cefamandole. The in vitro antimicrobial activities of BL-S786, cefoxitin, and cefamandole against 90 isolates of Enterobacteriaceae, including Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter cloacae and E. aerogenes, were studied by using an agar dilution procedure. Comparison of geometric mean minimal inhibitory concentrations showed that BL-S786 was half as active as cefamandole against Enterobacter species, 2 to 4 times more active than cefamandole against all other species, and 4 to 25 times more active than cefoxitin against all species. In vivo experiments employed acute protection tests in infected mice, using five isolates each of the five genera. Drugs were administered intramuscularly in two doses 3 h apart at dosages of 2.5, 5, 10, 20, and 40 mg per mouse. In most instances, BL-S786 was the most efficacious drug, being some 1.3 to 9.1 times more active than cefoxitin in all experiments and 1.5 to 8.7 times more active than cefamandole in most experiments. BL-S786 and cefamandole were comparable in activity in experiments with E. aerogenes, whereas BL-S786 was superior in experiments with E. cloacae.


Protection by unsaturated lecithin against the imidazole antimycotics, clotrimazole and miconazole. The activity of egg lecithin in preventing the antifungal action of the two imidazole antimycotics, clotrimazole and miconazole, was confirmed. However, addition of this phospholipid could not relieve an existing imidazole inhibition. Compared with egg lecithin, reduced egg lecithin showed no such protective effect. The addition of egg lecithin to an aqueous suspension of the imidazole drugs changed the absorption profile of the imidazole, suggesting a low solubility and, consequently, a lower effective concentration; however, the addition of reduced egg lecithin did not produce any change in the adsorption. These results indicate that the preventive effect of egg lecithin on imidazole inhibition may be a consequence of preferential in vitro interaction of the drug with unsaturated phospholipid to form a hydrophobic complex.


Central nervous system chloramphenicol concentration in premature infants. Four premature infants under 1,500 g were treated with parenteral chloramphenicol for central nervous system infections due to organisms resistant to the penicillins. Serum, cerebrospinal fluid (CSF), and ventricular fluid concentrations of chloramphenicol were measured frequently during therapy and were used to maintain drug dosages in the safe and therapeutic range. Concentrations of chloramphenicol in the lumbar CSF and ventricular fluid had a mean of 23.3 +/- 7.7 micrograms/ml, consistently greater than 45% of peak serum levels. These data show that chloramphenicol enters the CSF in both ventricular and lumbar regions in therapeutic concentrations when administered intravenously. The clinical usefulness of this drug remains to be investigated. The importance of monitoring serum drug levels during therapy is emphasized.


Target substances of some antifungal agents in the cell membrane. Copiamycin, an antifungal antibiotic, exhibits antimicrobial activity against a few bacteria in addition to a wide variety of fungi. The methanol extract of Sarcina lutea, one of the most susceptible bacteria, was found to reverse the antimicrobial activity of copiamycin. The reversing activity was associated with the phospholipid fraction of the bacteria. The S. lutea phospholipids also reversed the activities of azalomycin F and miconazole, but not that of clotrimazole. The effects of authentic phospholipids and fatty acids were also investigated. As the antimicrobial activities of copiamycin and azalomycin F were most strongly reversed in the same manner by phospholipids with unsaturated fatty acids and basic hydrophilic groups, the sites on the cell membrane sensitive to both antibiotics are assumed to be identical. On the other hand, the activity of miconazole was affected by different phospholipids from those which affected these two antifungal antibiotics, and the activity of clotrimazole was not affected by any of the phospholipids and fatty acids. It was postulated that the sites on the cell membrane sensitive to miconazole and clotrimazole are different from those sensitive to copiamycin and azalomycin F.


Activity of flumequine against Escherichia coli: in vitro comparison with nalidixic and oxolinic acids. The in vitro activity of the new antibacterial agent, flumequine, against Escherichia coli was compared with those of oxolinic acid and nalidixic acid. As judged by turbidimetric criteria, flumequine was considerably more active than nalidixic acid and slightly less active than oxolinic acid against both nalidixic acid-susceptible and -resistant strains. Resistance to all three drugs could be easily induced in vitro. The comparative efficacy of flumequine, oxolinic acid, and nalidixic acid was also tested in an in vitro model of the treatment of bacterial cystitis. In this system, suppression of bacterial growth was obtained with markedly lower concentrations of flumequine and oxolinic acid than of nalidixic acid, but prevention of the emergence of bacterial populations that exhibited increased resistance to these compounds depended on the maintenance of adequate drug levels.


Comparative effects of sulfones and rifampin on growth of Mycobacterium lepraemurium in macrophage diffusion chamber cultures. A cell-impermeable diffusion chamber technique has been developed that lends itself to growth studies of Mycobacterium lepraemurium. This technique, in which the organism grows within macrophage cultures inside the chambers that are maintained on monolayer cultures of macrophages, provides a method for a strict in vitro evaluation of antileprosy drugs without the influence of a multiplicity of host factors. This system was used to compare the effect of three sulfone derivatives and rifampin on the growth of M. lepraemurium within these diffusion chamber cultures. Two sulfones, 4,4'-diaminodiphenyl sulfone and 4,4'-diacetamidodiphenyl sulfone, as well as rifampin, suppressed the growth of M. lepraemurium, but monoacetyl sulfone 4-amino-4'acetamidodiphenyl sulfone had no effect. The results indicate that the diffusion chamber technique can be used to evaluate the inhibitory effect of antileprosy drugs on the growth of M. lepraemurium. Also, the method provides for the first time a relatively rapid in vitro method for directly comparing the effects of drugs or their analogs when outside the metabolic influence of an animal host. This technique may be a useful tool for chemotherapy studies with other antileprosy compounds.


Mode of action of the Haemophilus bactericidal factor. Haemocin, a bacteriocin produced by Haemophilus influenzae b, caused pronounced cell elongation of the sensitive strains H. influenzae Rd and Escherichia coli CR34 thyA. In the sensitive strains, haemocin markedly inhibited the synthesis of deoxyribonucleic acid (DNA) but did not affect either ribonucleic acid or protein synthesis. The observed inhibition in synthesis of DNA was not due to degradation of preexisting DNA. The data suggest that haemocin may specifically inhibit DNA synthesis.


In vitro antimicrobial activity of some cyclic hydroxamic acids and related lactams. Against Enterobacter aerogenes 13048, Serratia marcescens 13880, Klebsiella pneumoniae 10031, Pseudomonas aeruginosa 10145, Escherichia coli 9723, Lactobacillus casei 7469, Lactobacillus plantarum 8014, Leuconostoc dextranicum 8086, and Streptococcus faecalis 8043, the mean minimal inhibitory concentrations of three cyclic hydroxamic acids, 3-amino-3,4-dihydro-1-hydroxycarbostyril, the 6-chloro analog, and the 7-chloro analog, were 0.6, 0.6, and 0.2 micrograms/ml, and those of the corresponding lactams, 3-amino-3,4-dihydrocarbostyril, the 6-chloro analog, and the 7-chloro analog, were 60, 60, and 6 micrograms/ml, respectively. Under the same assay conditions the mean minimal inhibitory concentrations of chloramphenicol and kanamycin were both 2 micrograms/ml. In addition, the cyclic hydroxamic acids but not the lactams inhibited the growth of Candida albicans at minimal inhibitory concentrations ranging from 20 to 200 micrograms/ml, at pH 7, as compared with that of amphotericin B, at 2 micrograms/ml.


Genetics of rheumatic diseases.

Genetics of rheumatic diseases. Evidence favoring genetic predisposition to each of the major classes of rheumatic diseases is reviewed, including juvenile-onset rheumatoid arthritis, rheumatic fever, ankylosing spondylitis and other syndromes associated with spondylitis, adult-onset rheumatoid arthritis, gout and pseudogout, and systemic lupus erythematosus. In addition, simply inherited genetic diseases that may present with arthritis are noted for purposes of differential diagnosis. The importance of heterogeneous causes and mechanisms within each major class of disease is emphasized, both for patient care and for clinical investigation.


Significance of histocompatibility genes in rheumatology. Because of the tremendous impact of recent findings of association between genes in the major histocompatibility system and certain rheumatic diseases, the genetics of this system and the methods of analyzing disease association are discussed in detail. These associations represent an important step forward in the search for basic causes and mechanisms of these diseases. Further analyses may permit better classification of diseases and increased understanding of the relationships between genetic and environmental factors in the susceptibility to specific disease.


Pathophysiology of rheumatic diseases.

Pathophysiology of rheumatic diseases. Current hypotheses regarding the pathophysiology of rheumatic disease are depicted in Figure 1. Susceptible individuals, when exposed to microorganisms and/or drugs, can start the events depicted in Figure 1; the ability of the individual to respond to these exogenous agents is influenced by genetic factors including inherited deficiencies of the host's immune defense mechanisms. Microorganisms may then infect and/or effect mononuclear cells with persistence, or may be activated by environmental factors including UV light or other infections. If cell lysis results, antibodies can then be made to the cell (lymphocytotoxic antibodies) or cell products (ANA, etc.). The antibodies-to-lymphocyte membranes may interfere with lymphocyte function in a number of ways, including immunosuppression, and may also cause reactivation of this cycle. The antibodies may combine with antigens to form immune complexes that can be efficiently cleared by macrophages, have a feedback role in lymphocyte regulation, or in susceptible individuals deposit in tissue with subsequent inflammation. All or some of these steps or pathways may be under the influence of genetic factors.


Müller's muscle-conjunctival resection ptosis procedure. The Müller's muscle-conjunctival resection procedure is a relatively simple means of relieving ptosis in patients whose upper eyelids elevate to a normal level with phenylephrine instillation. The Müller's muscle-conjunctival resection procedure has advantages over the Fasanella operation because tarsus is preserved, and over the levator aponeurosis advancement and tuck operation because the results are more predictable.


The effectiveness of the pigtail probe method of repairing canalicular lacerations. The pigtail probe method of repairing canalicular lacerations is a widely used technique, however its long-range effectiveness has never been documented. By evaluating statistical data on 51 canalicular lacerations, and then examining 30 patients who had been repaired by the pigtail probe we were able to conclude that: a left inferior canalicular laceration, in a young male, following assault is the most common presentation; that this method objectively yields a 36.6% patency rate with a 10% incidence of iatrogenic damage to the uninvolved side; that 73.3% of the failures remained asymptomatic; secondary to keratitis sicca, a functioning conjunctival canalicular fistula, or the patent remaining canaliculus; and that the inferior canaliculus appears to be symptomatically more important than the superior canaliculus. It is suggested that all canalicular lacerations be repaired, but that the pigtail probe method be abandoned.


Lower eyelid retraction: management.

Lower eyelid retraction: management. A surgical technique for the management of lower eyelid retraction caused by vertical shortening of the posterior layers of the lid is presented. This technique, developed during the course of our experience with 48 procedures on lower eyelids, is a modification of that originally proposed by Quickert and Dryden. Results have been satisfactory to date, with minimal morbidity and complications.


The Fasanella-Servat operation.

The Fasanella-Servat operation. Indications, complications, surgical anatomy and the author's method of performing the FSO have been described. The procedure is an excellent and predictable operation if the criteria which have been advocated by many authors are carefully followed.


A combined lateral and medial orbitotomy for exposure of the optic nerve and orbital apex. A technique for exposure and direct visualization of the optic nerve and medial apex of the orbit is presented. The technique involves an initial lateral orbitotomy or Krönlein procedure followed by a nasal conjunctival peritomy, detachment of the medial rectus muscle, and outward rotation of the globe to expose the optic nerve and apex of the orbit. With relaxing incisions in the conjunctiva, the globe can be rotated approximately 45 degrees with visualization of the optic nerve from its exit from the globe to its disappearance into the origin of the rectus muscles. This technique may be used for exposure of the optic nerve and orbital apex for the optic nerve decompression for chronic papilledema in indicated cases, biopsy of lesions of the orbital apex, or excisional biopsies of tumors of the optic nerve.


The pathogenesis of dialysis dementia.

The pathogenesis of dialysis dementia. There has been a recent increase in the number of literature reports describing a severe neurological syndrome (Dialysis Dementia) seen in a small number of dialysis patients. This article reviews the current literature on the disease and its possible causes.


Prevalence of Aspergillus and Candida precipitins in renal dialysis and transplant patients. Serum precipitin tests to Aspergillus and Candida antigens were used to define the rate of infectivity with these fungal organisms in patients on renal dialysis and after kidney transplantation. A total of 58 studies in 53 consecutive patients, of whom 41.5% were post-transplant an average of 14.6 months, failed to detect significantly more precipitin activity than in a normal population. The specificity of this non-immunoreactivity was supported by the absence of clinical or post-mortem evidence of fungal invasion. Since serum precipitins develop despite immunosuppressive therapy, and cases of fungal invasion in transplant recipients may occur sporadically in clusters, monitoring of renal transplant patients with these relatively simple tests should detect endemic occurrences of aspergillosis and candidiasis.


Determination of intraocular lens power: a comparison with and without ultrasound. Two consecutive and sequential series of 100 pseudophakic patients were compared. In the first series intraocular lens power was determined by clinical means. In the second series axial length, using an easily operated commercially available A-scan unit, keratometry, and estimation of anterior chamber depth data were entered into an electronic calculator programmed to determine intraocular lens power. In the first series 47% of patients had a residual refractive error of 1 diopter or less, whereas 72% were within this range in the second series. With clinical lens power determination, there were three cases of residual deviation from emmetropia of more than 4 diopters; there was none greater than 3 diopters in the group using the A-scan. Lens power determination is more accurate using ultrasonography and the presently available instrumentation can be incorporated easily into a busy private practice.


Supratarsal fixation in ophthalmic plastic surgery. The use of supratarsal fixation in ophthalmic plastic surgery is discussed. New anatomical terms for the external upper eyelid are described. Technique, complications, and illustrative cases are presented.


The McCarey-Kaufman medium and penicillin allergy. Thirty-four donor corneas previously stored in McCarey-Kaufman medium containing 100 u/ml of penicillin G were transplanted into 32 recipients with a given history of penicillin allergy. There were no early or late ocular or systemic postoperative complications that could be related to a history of penicillin allergy. Thirty-two of the 34 grafts were clear on long-term follow-up, and penicillin allergy appeared to play no role in the grafts, either success or failure.


Thermal denaturation of donor cornea: an unusual complication of penetrating keratoplasty. A most unusual complication of penetrating keratoplasty is the rapid thermal denaturation of a human donor cornea upon accidental exposure to temperature of 50 degrees to 60 degrees C, the result of inadequate cooling of a Teflon trephine block following autoclave sterilization.


Keratoplasty with primary and secondary lens implantation. Twenty-eight combined grafting and lens implantation operations were performed for patients with corneal disease plus cataract, or aphakia. Eighteen of these cases had cataract extraction at the time of surgery and ten had grafting, vitrectomy and secondary lens implantation in already aphakic eyes. The longest follow-up was forty-seven months; the shortest, six months with an average of 21 months. Complications included cystoid macular edema (five), transient rise in intraocular pressure, hemorrhage. One lens had to be removed, and one graft will have to be replaced with possible removal of the lens. Cystoid macular edema occurred in two cases of the 18 graft-cataract-implant cases (11%) and in three of the 10 cases of graft-vitrectomy-implant patients (30%), a total of 17.9%. Hemorrhage occurred in two cases (7%), and transient elevation of the intraocular pressure also in two cases (7%).


Neuromuscular circuits in affect-laden information processing. Substantial evidence has accrued indicating the involvement of neuromuscular circuits in covert information processing. The physiological systems imparting emotional tone to covert processing, however, are less well understood. Reviewed here are findings from a variety of methodologies which suggest that somatic patterns, particularly in the face, reflect moment by moment emotional reactions. These findings imply neuromuscular involvement in affect-laden information processing; less conclusive, though suggestive, are data indicating that the proprioceptive feedback from these phasic and specific patterns of response are integrated cortically and influence covert processing and overt responding.


Hyperprolactinemia and hypogonadism in the human female. Prolactin is a mammotropic hormone essential for the initiation of lactation. It also influences ovarian function; during hyperprolactinemia hypogonadism occurs. This is true for pathological forms of hyperprolactinemia but also for the early puerperium when there is physiological hyperprolactinemia. Amenorrhea is a better parameter of hyperprolactinemia than galactorrhea. The mechanisms by which prolactin disrupts ovarian function are not as yet fully understood; it probably alters hypothalamic neurotransmitter content through a direct feedback mechanism resulting in a decrease of Gn-RH. However, the direct effect of prolactin-producing pituitary tumors on the capacity of the gonadotrophs or a direct interference of prolactin at the gonadal level are also possibilities. Hyperprolactinemia can be treated very effectively with bromocriptine and this drug appears to have become the favorite form of treatment. In the case of obvious tumors hypophysectomy is indicated. When there are smaller tumors irradiation of the pituitary gland previous to bromocriptine treatment may prevent expansion of the gland during subsequent pregnancy.


Measuring the height of a cephalic presentation: an objective assessment of station. The authors have previously described a method of objectively assessing the height of the presentation, an ultrasonic echograph measuring the distance from the head to the sacral tip. They have now obtained 453 measurements made before and during labor; norms are given according to the clinical evaluation of the station. The usefulness of the method is discussed. It may make the Bishop's score more precise, permit a more accurate check of trial of labor and help to recognize a low station correctly before an application of forceps.


Fetal breathing movements in the normal and growth-retarded human fetus: a multiscan/M-mode echofetographic study. 52 women were examined, between the 25th and 40th wk of pregnancy, during the day-time, by the echographic multiscan/M-mode technique. Definitions of normal fetal breathing movements and singultus fetalis movements were determined. In normal pregnancies fetal breathing movements occurred during 12-19% of the total observation time before the 39th wk of pregnancy but only during 6-9% of the observation time in the 39th or 40th wk. In low birth weight pregnancies fetal breathing movements occurred during 8-13% of the total observation time, and the incidence was the same before and after the 39th wk. Singultus fetalis movements occurred in normal and low birth weight pregnancies.


Gray scale ultrasound for the investigation of early pregnancy. 73 early gestations (6-14 wk) were investigated with gray scale ultrasound. 7 of them ended in spontaneous first-trimester abortion, and in all of these the findings were characteristic for spontaneous interruption of pregnancy. The remaining 66 continued to term. Regression analysis was performed with respect to the diameter of the gestation sac, the fetal crown-rump length, and the placental surface and thickness. The method is considered appropriate for the diagnosis of early abortion and the study of placental morphology and morphometry. On the basis of the results obtained with gray scale techniques, various concepts derived from B-scan observations (e.g. implantation locus and early twin observation) will have to be corrected.


Ultrasound assessment of puerperal uterine involution. Echographic measurement of the early postpartum uterus was performed, mainly to investigate whether involution patterns correlate with parity, the administration of oxytocin during labor, and lactation. Our findings suggest that these factors do not have a marked effect on uterine involution.


Surfactant in the amniotic fluid and bromhexine metabolite VIII. The effect of metabolite VIII of bromhexine on surfactant content in the amniotic fluid was investigated in a double blind study. Administration of 100 and 200 mg NA-872 daily for 5 days to pregnant women ranging in gestational age from 196 to 243 days was not followed by a significant rise in the L/S ratio.


A study of indomethacin combined with ritodrine in threatened preterm labor. A prospective and double-blind study was undertaken to compare the effectiveness of two different treatments on two randomized groups of patients with threatened preterm labor. The first treatment consisted of the administration of ritodrine and a placebo; in the second, ritodrine was combined with indomethacin. 22 patients were evaluated in each group. The results obtained for gain in days, number of patients delivered at term, weight of newborns and number of recurrences in each group suggest that treatment with ritodrine and indomethacin is slightly but significantly more effective than treatment with ritodrine and placebo in prolonging pregnancy. No evidence has been found of possible unfavorable vascular effects of indomethacin in the fetus or the newborn.


Successful pregnancy after renal transplantation in a patient with a urinary diversion. A successful pregnancy is reported in a patient following renal transplantation and urinary diversion. The second half of pregnancy was complicated by hypertension, impaired renal function and obstruction of the ureter in the 35th wk. The latter complication required early termination of pregnancy by cesarean section. A healthy infant was delivered who survived without complications. Maternal renal function returned to pre-pregnancy levels following delivery.


Fetal deglutition: a study of the anencephalic fetus. The deglutition of amniotic fluid in utero by the anencephalic fetus is a controversial subject. We have studied 7 anencephalic pregnancies complicated by hydramnion in their third trimester of gestation. Fetographies revealed that 6 out of 7 anencephalic monsters showed signs of swallowing of the contrast material after only 3 h. The baby which was born dead could not swallow at all. The fact that the babies studied swallowed amniotic fluid shortly after injection of contrast media seems to confirm the opinion that fetal deglutition contributes only little to the mechanism of amniotic fluid volume regulation.


A new treatment of vaginal candidiasis: three-day treatment with econazole. From an open comparative multicentric trial it became clear that econazole was an active and well-tolerated agent for the treatment of vulvo-vaginal mycoses. Combined treatment with pessaries and econazole cream seems to be worthwhile in order to isolate the vagina from possible Candida reservoirs or to hasten symptomatic relief.


Metabolic effects of intravenous ritodrine infusion during pregnancy. The effect of intravenous administration of ritodrine on blood glucose, insulin, free fatty acids and electrolytes in 17 third-trimester gravidas was investigated. A highly significant increase in blood glucose, insulin and free fatty acids and a marked decrease in serum potassium levels were registered. No significant changes during ritodrine infusion were recorded in serum levels of sodium, chloride, calcium, phosphorus and magnesium. No cardiac arrhythmias or electrocardiographic deteriorations occurred. While intravenous ritodrine administration seems to be safe in normal pregnancy, there may be a risk in diabetic patients, digitalized cases and those patients being treated with diuretics.


A betamimetic drug and human fetal lung maturation. In a double-blind and randomized study the administration of a betamimetic drug to the mother from week 33 to 35 produces a significant increase in amniotic fluid palmitic acid levels. We suggest that the administration of a betamimetic drug during pregnancy to the mother can be useful in producing an acceleration of the fetal lung maturation.


Early human development and the chief sources of information on staged human embryos. In a brief historical survey, the importance of Wilhelm His, senior, to human embryology is emphasized. He provided the impetus to Mall to establish the Carnegie Embryological Collection, which serves as a 'Bureau of Standards' for early human development. The Carnegie system of 23 stages for the embryonic period proper (first 8 postovulatory wk) is outlined, and some common misusages are noted. Finally, because of the difficulty in tracking down data based on staged human embryos, an annotated list of more than 40 key references is provided.


Cellular hyperreactivity to placenta in toxemia of pregnancy. It is generally assumed that maternal immune response may be involved in some pathological conditions of pregnancy, such as toxemia. The activity of cell-mediated immunity to placenta was studied in women with gestosis. The leucocyte inhibition technique was employed to test reactivity of peripheral blood leucocytes from postpartum women. The results indicated that leucocyte migration was significantly inhibited in the presence of placental microsomal fraction when blood from toxemic women was used. Thus, about 87% out of 30 studied cases of toxemia showed positive results. At the same time, in only 22% of women with uncomplicated pregnancy was such a positive leucocyte migration inhibition test found. There was no correlation between the severity of the toxemic symptoms and the extent of inhibition. In further experiments the leucocyte migration inhibition test with the microsomal fraction antigens from cadaver kidneys was performed; only 1 out of 6 patients showed positive leucocyte migration inhibition. These findings may suggest that the normal status of the mother is altered towards cellular hyperreactivity to placental antigens in toxemic pregnancy.


Secondary cervical perforation by the Copper-T intrauterine device. Five cases of cervical perforation have been observed in women with a Copper-T IUCD, over a period of 5 yr. In all cases, the distal end of the stem (vertical limb) of the T had perforated through the cervical wall into one of the fornices of the vagina. Only 2 cases had symptoms leading to the discovery of the device, while the other 3 were discovered accidentally or on routine examination.


Regulation of mating in the cell cycle of Saccharomyces cerevisiae. The capacity of haploid a yeast cells to mate (fuse with a haploid strain of alpha mating type followed by nuclear fusion to produce a diploid cell) was assessed for a variety of temperature-sensitive cell division cycle (cdc) mutants at the permissive and restrictive temperatures. Asynchronous populations of some mutants do not mate at the restrictive temperature, and these mutants define genes (cdc 1, 4, 24, and 33) that are essential both for the cell cycle and for mating. For most cdc mutants, asynchronous populations mate well at the restrictive temperature while populations synchronized at the cdc block do not. Populations of a mutant carrying the cdc 28 mutation mate well at the restrictive temperature after synchronization at the cdc 28 step. These results suggest that mating can occur from the cdc 28 step, the same step at which mating factors arrest cell cycle progress. The cell cycle interval in which mating can occur may or may not extend to the immediately succeeding and diverging steps (cdc 4 and cdc 24). High frequency mating does not occur in the interval of the cell cycle extending from the step before the initiation of DNA synthesis (cdc 7) through DNA synthesis (cdc 2, 8, and 21), medial nuclear division (cdc 13), and late nuclear division (cdc 14 and 15).


Cryosurgery: theory and application to head and neck neoplasia. While surgery and radiation therapy remain the time-tested modalities for the treatment of cancer in the head and neck, recent experimental and clinical experience has documented the effectiveness of cryosurgery as an adjunct in the treatment of selected neoplasms in individual patients. A review is provided of the theory of freezing as a method of cell destruction, and experimental and clinical experience illustrate the principles and application of cryosurgery to head and neck tumors.


Unequal division in Saccharomyces cerevisiae and its implications for the control of cell division. The budding yeast, Saccharomyces cerevisiae, was grown exponentially at different rates in the presence of growth rate-limiting concentrations of a protein synthesis inhibitor, cycloheximide. The volumes of the parent cell and the bud were determined as were the intervals of the cell cycle devoted to the unbudded and budded periods. We found that S. cerevisiae cells divide unequally. The daughter cell (the cell produced at division by the bud of the previous cycle) is smaller and has a longer subsequent cell cycle than the parent cell which produced it. During the budded period most of the volume increase occurs in the bud and very little in the parent cell, while during the unbudded period both the daughter and the parent cell increase significantly in volume. The length of the budded interval of the cell cycle varies little as a function of population doubling time; the unbudded interval of the parent cell varies moderately; and the unbudded interval for the daughter cell varies greatly (in the latter case an increase of 100 min in population doubling time results in an increase of 124 min in the daughter cell's unbudded interval). All of the increase in the unbudded period occurs in that interval of G1 that precedes the point of cell cycle arrest by the S. cerevisiae alpha-mating factor. These results are qualitatively consistent with and support the model for the coordination of growth and division (Johnston, G. C., J. R. Pringle, and L. H. Hartwell. 1977. Exp. Cell. Res. 105:79-98.) This model states that growth and not the events of the DNA division cycle are rate limiting for cellular proliferation and that the attainment of a critical cell size is a necessary prerequisite for the "start" event in the DNA-division cycle, the event that requires the cdc 28 gene product, is inhibited by mating factor and results in duplication of the spindle pole body.


Electron microscope demonstration of tubulin in cilia and basal bodies of rat tracheal epithelium by the use of an antitubulin antibody. It has been previously demonstrated that both cytoplasmic microtubules and the microtubules of cilia, flagella, and sperm tail contain tubulin. Although the morphology of cytoplasmic microtubules and that of axonemes differs in cells from which they have been isolated, the tubulin of the two structures shares physical and chemical properties. In some mammalian tissues, such as tracheal epithelium, cilia and basal bodies are difficult to isolate and characterize. The use of an enzyme-labeled immunoglobulin probe would facilitate identification and in situ localization of such proteins. Tubulin prepared from porcine brain by ion-exchange chromatography and from rat brain by the method of cyclic polymerization and depolymerization with subsequent disk gel electrophoresis with SDS were injected intravenously into rabbits. The animals were intermittently bled and the antisera extracted. The specificity of the antisera was proved by indirect immunofluorescence staining of the mitotic spindle, specific blocking of spindle staining by purified tubulin and not by other proteins, staining of 3T3 cytoplasmic microtubules, single line on immunoelectrophoresis, failure of control antisera to show any of these, and precipitation of antibody with all tubulin preparations and not with actin. We have shown by electron microscopy of ciliated cells of the tracheal epithelium stained with antitubulin by the indirect enzyme-labeled antibody method that the basal bodies, outer doublets, and central pair of the cilia contain tubulin. This indicates that tubulin in microtubules of cilia and basal bodies of rat tracheal epithelium is antigenically similar to tubulin extracted from cytoplasmic neurotubules of brains from the same species and from a different mammalian species. No other axonemal structures stained with the antitubulin. Three different preparations of tubulin from pigs and rats were used to immunize rabbits. All elicited similar antisera which gave identical staining patterns. The specificity of the staining was demonstrated by the absence of staining with immune serum absorbed with purified tubulin, the absence of staining with preimmune serum, and the absence of staining if any of the reagents were omitted during the staining reaction.


Estrogens delay the postpartum recovery of the LH-RH-induced gonadotropin release. In 27 healthy postpartum women, who were neither lactating nor receiving any therapy, LH-RH stimulation tests (50 micrograms i.v.) were performed on days 7, 14, 21 and 28 of the puerperium. In a second group of 9 postpartum women an i.m. injection of 10 mg estradiol valerianate was administered within the 3rd postpartum day, and an LH-RH stimulation test was performed on days 14 and 21 of the puerperium. Blood was withdrawn at standard intervals and LH and FSH measured by radioimmunoassay. No significant FSH and LH response was found on day 7. On day 14 there was a significant release of FSH but no LH was released. On days 21 and 28 there was a significant release of FSH and LH but the magnitude of the FSH response was greater than that of the LH release. The administration of estrogens did inhibit the recovery of the pituitary from its refractoriness: on day 14 no release of LH and FSH was observed; on day 21, only a significant release of FSH could be detected in the second group of postpartum women. This emphasizes the major role played by steroids in the regulation of the hypothalamo-pituitary-gonadal function.


Ultrasound: an aid to diagnosing gallstones in the radiographically nonvisualized gallbladder. The accuracy and reproducibility of ultrasound as a modality to identify gallstones were evaluated. A credible result raises the possibility of the use of ultrasound to diagnose gallstones in the radiographically nonvisualized gallbladder.


Immunocytochemical identification of abnormal polymorphonuclear neutrophils in patients with leukemia. High titer, monospecific antibodies to human granulocyte myeloperoxidase, cathepsin G, elastase, lysozyme, and lactoferrin were conjugated with fluorescein and rhodamine and used for immunofluorescent staining of mature neutrophils obtained from 25 patients with acute and chronic leukemia. In 11 (44%) of the patients, two populations of mature neutrophils were detected. The abnormal cells were identified by complete deficiency of one or more markers and constituted 10%-100% of the total number of neutrophils. This immunocytochemical approach may permit recognition of mature cells derived from leukemic clones, and serial determinations of the ratio of normal to abnormal cells may be useful in the management of patients with leukemia.


Are cytotoxic T cells a common homeostatic mechanism in responses to viruses, homografts and tumours? Cytotoxic T cells (Tc) have been shown to be important in the rejection of histoincompatible tissue grafts. They are also generated in mice during infection with viruses that are known to express viral coded antigens at the infected cell surface, although their presence is much easier to demonstrate with some viral infections than with others. Cell-mediated lysis only occurs if the Tc and virus-infected target cells share gene products coded for in the K or D region of the H-2 complex. In the case of both ectromelia and influenza virus infection of mice, transfer of specific Tc to histocompatible, infected mice has been shown to significantly lower the virus titre in target organs (spleen and lungs respectively). In experimental animals with some tumours, there is increasingly good evidence for the expression of tumour specific transplantation antigens (TSTA) in the membrane of the malignant cells, yet there is little evidence for the presence of specific Tc which might control the growth of the tumour. Possible reasons for the lack of generation or expression of Tc in these situations are discussed.


Long-term preservation of canine bone marrow: in vitro studies. In vitro studies were performed on canine bone marrow frozen with DMSO and stored in liquid nitrogen for 2 to 6 months. The results are compared with previously reported parallel in vivo experiments that demonstrated no loss of stem cells. When studies were performed immediately after thawing, there was no substantial drop in the count of nucleated cells and, except for megakaryocytes, there was no alteration of the bone marrow morphology. After two washes, and removal of DMSO, the nucleated cell count dropped to 50% of its previous value. Optic and electron microscopy showed severe damage in mature myeloid elements. In some instances, the cells had a condensed nucleus similar to the red-purple inclusion body of LE cells (as observed in systemic lupus erythematosus), and electron microscopy showed heavy chromatin clumping. On the other hand, both optic and electron microscopy showed a good preservation of lymphocytes, plasmocytes, and erythroid precursors. Two-hour DNA synthesis slightly dropped after storage, and this drop appeared more consistent when related to a constant volume of bone marrow (50 microliters) rather than to a constant number of nucleated cells (10(6)). In five instances frozen and thawed bone marrow was grown in short-term cultures, and analysis of 98 metaphases showed no major aberrations of the chromosomes and only 2% of minor aberrations, such as breakages and fragments. These data, compared with the results of previous in vivo experiments that showed no loss of stem cells after 5 months storage, suggest that stem cells are less sensitive to freezing and thawing injury than myeloid elements and/or that it might be safer for the thawed bone marrow not to be manipulated before infusion.


External validity in the assessment of intellectual development in adulthood. The relation of intelligence and competence is discussed and external validity issues are examined for the dimensions of settings, measurement variables, treatment variables and experimental units. It is argued that external validity across situations and life stages cannot be obtained for any single measure of intellectual ability. External validity problems are exacerbated beyond young adulthood since single criterion goals comparable to that of educational aptitude in work with the young are not available, and tasks do not retain ecological validity when the situational context of the individual under study changes due to developmental progression and idiosyncratic modification of individual life situation and roles. External validity in adulthood must therefore be addressed by examining task-by-person-by-situation interfaces separately for different life stages and across cohort groupings. A major test construction and validation program is outlined, and examples are given showing how some of the aspects of such a program can be operationalized.


Methodological problems in the analysis of behavioral tolerance in toxicology. The analysis of selected data on differential behavioral tolerance to drugs and other chemicals leads to a series of tentative methodological proposals with potential interest for the purposes of toxicology. These data show a wide range of different relations between tolerance induced by continued exposure to treatment per se and tolerance dependent on specific treatment-behavior interactions, such as behavioral testing in the treatment state and unfavorable consequences on reinforcement density of response changes induced by treatment. Consequently, when tolerance phenomena occurring with a particular type of treatment deserve an in-depth analysis, a sequential strategy should assess (i) critical factors in short-term compensation for behavioral deficits (acute behaviorally augmented tolerance), (ii) relations between sensitization and tolerance phenomena (particularly in the case of agents with long-lasting and/or cumulative physiological-biochemical effects), with special regard to tolerance development in the absence of measurable changes in the lower dosage ranges, and (iii) factors responsible for behaviorally augmented tolerance in medium-and long-term experiments. The latter analysis may require the investigation of different relations between time of treatment and time of testing, and different treatment-induced changes in reinforcement density. Specific and non-specific transfer of coping responses across situations must also be considered, as well as changes in response topographies, interindividual differences in rate of tolerance development as a function of size and direction of the original treatment changes, and several other cues which can facilitate the understanding of the phenomena observed.(ABSTRACT TRUNCATED AT 250 WORDS)


Motor activity: a survey of methods with potential use in toxicity testing. Activity measurements are expected to have widespread use in toxicity testing. The multifaceted nature of motor activity will directly influence the selection of a measurement technique since the relative contribution of various motor acts to any particular measurement will depend upon the detection method. Because of the apparatus-dependent nature of motor activity measurements, it is recommended that consideration be given to how accurately the various devices measure locomotor activity. In the present paper, two types of body movement will be considered as locomotor activity: ambulation (horizontally directed movement) and rearing (vertically directed movement). Discussion focuses on the various methods currently used to record motor activity, the various components of motor activity which are likely to be recorded, and the advantages and disadvantages of these techniques for the measurement of locomotor activity. Finally, consideration is given to studies which have compared treatment effects on motor activity derived from two or more measurement techniques.


Reinforcing properties of inhaled substances. Inhaled substances can support behavior by acting as reinforcing stimulus events. The deliberate inhalation of volatile materials is attributable to the positively reinforcing properties of these substances and can induce profound toxicity. On the other hand, inhaled substances can also be aversive, e.g., corrosives, certain solvents, and combustion products. Both positive and negative reinforcing properties of inhaled materials can be used to support the behavior of laboratory animals. Several rules of evidence should be met, however, to demonstrate conclusively that an inhalant has such properties. Such properties should be considered in industrial hygiene and environmental quality decisions.


Myelography with metrizamide in occult spinal dysraphism. The initial experiences with metrizamide (Amipaque) in cases of spinal dysraphism are described. The technique, myelographic appearance and adverse reactions are discussed. The results have been promising and it is believed that this contrast medium will provide more accurate diagnostic information. However, further experience is necessary and in particular correlation with surgical findings.


Adverse effects of water-soluble contrast media in myelography, cisternography and ventriculography. A review with special reference to metrizamide. The adverse effects following lumbar myelography and ventriculography with meglumine iothalamate (Conray Meglumin), meglumine iocarmate (Dimer-X, Bis-Conray) and metrizamide (Amipaque), and after thoracic and cervical myelography and cisternography with metrizamide are reviewed. In addition to the published material information given to Nyegaard & Co. from several hospitals participating in clinical trials with metrizamide is also reported. The frequency of minor adverse effects (headache, nausea, vomiting) seems to be about the same with all the three water-soluble contrast media. Convulsions, either localized to the lower part of the body or generalized, may be a problem with meglumine iothalamate and meglumine iocarmate, while the epileptogenic effect is markedly lower with metrizamide. With a technique directed towards preventing contrast medium of high concentration from passing intracranially, the frequency of serious adverse effects may be kept at a very low level. Late adverse effects (adhesive arachnoiditis) occurring after all other water-soluble contrast media are a very minor problem after metrizamide. Serious complications have not been recorded following ventriculography and cisternography with metrizamide. Metrizamide is considered to be the water-soluble contrast medium best suited for use in the subarachnoid space and cerebral ventricles.


Angiography with metrizamide. Animal experiments and preliminary clinical experiences. The non-ionic contrast medium metrizamide (Amipaque) was compared in animal experiments with diatrizoate, iothalamate and metrizoate. Vasodilatory effects, acute intravenous toxicity and effects on red blood cells, pulmonary arterial pressure, endothelium and heart were all less after metrizamide than after the ionic media. This motivated clinical trial of metrizamide for angiography, which demonstrated that metrizamide produced less pain than the ionic monomeric media in femoral as well as in other types of angiography.


Metrizamide in cervical myelography. Survey and present state. The total number of patients examined with metrizamide (Amipaque) for cervical myelography up to 31 December 1976, exceeds 2,000. Review of this series under more detailed analysis of the 365 examinations performed at the Ullevål Sykehus indicate that such examinations can be performed safely and with excellent diagnostic results, provided the technique is satisfactory. Various techniques may be adequate. The injection of the contrast medium via a lateral C1-C2 puncture with the patient prone ensures optimum control of the contrast column to avoid intracranial flow, and therefore to give the lowest rate of side effects.


Experimental investigations with metrizamide with relevance to the myelographic use. Recent animal experiments with metrizamide (Amipaque) in the subarachnoid space have essentially substantiated the low toxicity previously demonstrated. The interaction with neuroleptic drugs has been confirmed. Whether clinical doses of metrizamide may induce adhesive arachnoiditis is still unsettled.


A study of the effect of ultraviolet light on the division potential of human diploid fibroblasts. Culture and UV (254 nm) irradiation conditions that are suggested as appropriate for a study of the effect of UV on the limited in vitro lifespan of a normal human diploid fibroblast (HDF) strain are first described. An inoculation density at each subcultivation of 1.8 x 10(4) viable cells/cm-2 permits the decline in proliferative capacity to occur with kinetics similar to that observed using a 1:2 split and prevents cell overlap at the time of irradiation. Doses of 5 and 10 J/m2 have only a slight effect on initial growth rates and little or no effect on cell density achieved at confluence. With these conditions populations can be irradiated several times throughout the in vitro lifespan. No effect of UV on the limited division potential was observed. In the extreme, a population irradiated 14 times, once every second passage starting at P-18 with doses of 5 or 10 J/m2 had the same lifespan as controls, as measured by lifespan determinations and thymidine labeling index. Transformed cells were not detected in the multi-irradiated populations. Evidently no accumulation in the populations of damage induced by UV that affected life span, thymidine labeling index, growth rates or confluent cell densities occurred. No selection of a population with altered sensitivity occurred. An argument that genome hits may not be a prime reason for the limited proliferative capacity of HDF populations is presented.


Failure of reactivation of chick erythrocytes after fusion with temperature-sensitive mutants of mammalian cells arrested in G1. Two temperature-sensitive (ts) mutants of mammalian cell lines (AF8 and cs4D3) that arrest in G1 at the nonpermissive temperature were fused with chick erythrocytes and the induction of DNA synthesis was studied in the resulting heterokaryons. While both AF8 and cs4D3 could induce DNA synthesis in chick nuclei at the permissive temperature, they both failed to do so when arrested in G1 at the nonpermissive temperature. When S phase AF8 cells were fused with chick erythrocytes, chick nuclei were reactivated even if the heterokaryons were incubated at the temperature nonpermissive for AF8. A third ts mutant, ts111, that is blocked in cytokinesis but continues to synthesize DNA, reactivated chick nuclei at both permissive and nonpermissive temperature. It is concluded that chick erythrocyte reactivation depends on the presence of S phase-specific factors.


Morphological differentiation of a murine neuroblastoma clone in monolayer culture induced by dexamethasone. Dexamethasone induces morphological differentiation in murine neuroblastoma cells in culture. The percentage of differentiated cells depends on the concentration of dexamethasone in the medium and duration of treatment. After drug removal (with or without replating), many cells maintain their differentiated phenotype. Dexamethasone-treated cells have larger soma and contain more protein. Dexamethasone also produces a concentration-dependent inhibition of population growth. Growth inhibition is complete by 2 days following treatment with dexamethasone 50 micrograms/ml. Complete growth inhibition is achieved prior to the complete expression of morphological differentiation. Androstenedione, testosterone, and 17-beta-estradiol--all steroids without glucocorticoid activity--have no differentiating effect, although they inhibit growth or cause cell death at higher concentrations.


An immunological approach to the isolation of factors with mitotic activity from the plasmodial stage of the myxomycete Physarum polycephalum. Nuclear divisions in plasmodia of Physarum polycephalum were advanced by applying immunologically purified plasmodial extracts of late G2 phase on the surface of plasmodia which were 1.5 h before the third mitosis. The purification of G2 extracts was achieved by interaction of antibodies prepared against the antigens of early S phase plasmodia with the antigens of late G2 plasmodia. There was no advancement of mitosis by extracts prepared from early S phase plasmodia. Untreated G2 extracts did not accelerate mitosis with the same effectiveness as did antibody purified G2 extracts.


Some aspects of mediastinal anatomy and radiology. High kilovoltage technique in chest radiography increases the visualization of the air-soft tissue boundaries of the mediastinum. The pulmonary-soft tissue interfaces account for pre- and paravertebral lines. The paravertebral and pleural-azygos-esophageal, central, posterior, and anterior lines of pleural contact are described, and displacement, deformities, and separation of the pleural reflections are illustrated.


Sequelae of stomach surgery.

Sequelae of stomach surgery. Gastric surgery has undergone continuous evolution since the 19th century. At present it is a highly sophisticated technique which provides symptomatic relief for the vast majority of patients operated upon for peptic ulcer disease. Although the overall incidence of complications has decreased, a variety of complications continues to occur and radiological examination plays a critical role in their detection, evaluation, and management. Knowledge of the variations in surgical terminology and commonly used eponyms provides the basic framework for discussion. Familiarity with the radiological appearance of the normal postoperative stomach together with an understanding of its physiology are essential prerequisites to the recognition of possible complications. Operative techniques may result in a radiographic appearance which simulates disease. Conditions as diverse as bezoars, afferent and efferent loop problems, marginal ulceration, anastomotic leakage, prolapse, and intussuception may all be characterized by distinct and highly specific radiographic changes. Physiologic problems such as dumping and malabsorption may also reflect their presence by X-ray changes. The radiographic features in a large number of surgical complications are discussed and illustrated. The importance of the radiographic examination in the postsurgical stomach is emphasized.


CNS 3-methoxy-4-hydroxyphenylglycol: its peripheral assessment by isotopic dilution and theoretical significance. An isotope dilution model for the peripheral measurement of CNS catecholamine metabolism was examined in rabbits. 3H-norepinephrine (3H-norepinephrine (3H-NE) infusions were performed on rabbits before and after central sympathectomy via intraventricular 6-hydroxydopamine (6-OHDA) treatment. Urine samples were obtained 72 hr after 3H-NE infusion and analysed for specific activities (SAs) of 3-methoxy-4-hydroxyphenylglycol (MHPG) and 3-methoxy-4-hydroxymandelic acid (VMA). The SA of MHPG was lower than that of VMA in all animals suggesting a source of unlabelled MHPG. The difference between the SAs of VMA and MHPG was abolished when the brain MHPG was markedly lowered by 6-OHDA injections. In animals which received 6-OHDA but retained moderate levels of brain MHPG, the difference between SAs of VMA and MHPG was maintained. The proposed model is able to predict and differentiate between rabbits that have severe depletion of CNS catecholamines and normal controls. The results suggest important relationships between CNS and peripheral NE metabolism and the compensatory capacity of the CNS to insult.


Simple template method for targeting brain loci in small animal stereotaxy. A simple and reliable method for stereotaxic approach at any angle is described. The presentation of the coordinate on a template replaces calculation of stereotaxic coordinates.


Method for effective rabbit head restraint during stereotaxic surgery. A method for rigid head restraint during stereotaxic surgical procedures is described. The method is based on modifications of a conventional rabbit stereotaxic head holder and provides reliable head fixation for accurate implantation of depth and surface electrodes, cannulae, microelectrode wells, etc.


Penetration of cefoxitin into cerebrospinal fluid and treatment of meningitis caused by gram-negative bacteria. Two patients with meningitis caused by antibiotic-resistant Escherichia coli and Klebsiella pneumoniae were treated successfully with intravenous cefoxitin plus oral probenecid. A total of 25 patients with central nervous system disorders that required a diagnostic spinal tap were also given cefoxitin, with or without probenecid, for determination of the degree of penetration into cerebrospinal fluid. In patients with uninflamed meninges, little or no cefoxitin entered after a single dose of 4-6 g. After three doses of 4 g each over a 6-8-hr period, penetration was considerable (average, 7% of the simultaneous serum level). In patients with inflamed meninges, a similar concentration was achieved rapidly after a single 2-g dose. After a day of therapy, cerebrospinal fluid levels equivalent to 30%-70% of the simultaneous serum levels were found; as the inflammation subsided, cerebrospinal fluid levels fell to around 15% of those in serum. Probenecid did not appear to influence greatly the degree of penetration.


Metabolism of potent enkephalin analogs (FK 33-824, D-Ala2, pentafluorophenylalanine-4-enkephalinamide and a dimer of D-Ala2-enkephalin) and D-amino acid substituted derivatives of human beta-endorphin. New analogs of the opiate peptides containing novel substitutions were compared in terms of their metabolic stability in the presence of an ultrafiltrate of mouse brain. The enkephalin analog FK 33-824 was more stable at short incubation periods (30 min) than Met-enkephalin but less stable than D-Ala2-enkephalinamide at longer periods (180 min) as shown by the complete release of N-terminal Tyr. In contrast, D-Ala2-enkephalinamide substituted in position 4 with pentafluorophenylalanine was completely stable at the time periods tested. A dimer of D-Ala2-enkephalin was relatively stable at short periods but subject to a 30% hydrolysis (vs. 100% for FK 33-824) in terms of Tyr release at longer periods of incubation. A doubly substituted human beta-endorphin (D-Leu17, D-Lys29-beta-endorphin) showed greater stability than the native peptide based on release of internal residues after incubation with the ultrafiltrate of brain. The presence of D-Leu17 blocked release of intermediate sized endorphins but did not affect liberation of Tyr. The additional presence of D-Thr in position 6 of a triply substituted beta-endorphin (D-Thr6, D-Leu17, D-Lys29-beta-endorphin) did not affect liberation of Tyr, indicating that formation of gamma-endorphin (cleavage of Leu17-Phe) and of enkephalin (cleavage of Met5-Thr) need not occur before the action of brain peptidases. The results demonstrate the feasibility of altering the resistance of analogs of enkephalin and endorphin to degradation by brain enzymes.


Treatment of uncomplicated gonococcal urethritis with cefoxitin: comparison with penicillin. Cefoxitin is a semisynthetic cephamycin with good in vitro activity against Neisseria gonorrhoeae. In a controlled clinical trial, 143 men with uncomplicated gonococcal urethritis received either cefoxitin (2.0 g intramuscularly [im] with 1.0 g of oral probenecid) or aqueous procaine penicillin G (4.8 x 10(6) units im with 1.0 g of oral probenecid). Of the 117 patients who returned for follow-up on days 3-13 after treatment, only 1.8% in the group given cefoxitin and 3.6% in the group given penicillin were not cured. The incidence of pain at the site of injection and rates of adverse reactions were similar for both groups. No hematologic, renal, or hepatic toxicity could be ascribed to either treatment regimen. Although none of the infections were due to beta-lactamase-producing gonococci, the results provide a basis for additional studies of the efficacy of cefoxitin in treatment of infections due to penicillinase-producing N. gonorrhoeae.


Intramuscular cefoxitin.

Intramuscular cefoxitin. Cefoxitin was administered by the intramuscular route to 102 patients who had infections of mild or moderate severity. The assessment of clinical and bacteriologic outcome was derived from data for 79 patients. Assessments of tolerance and safety were made for all patients who received 1 g of cefoxitin diluted in 1 ml of 0.5% or 1.0% lidocaine four times daily. Cure or improvement occurred in 45 of 47 patients with skin or soft tissue infections, in all of 16 patients with lower respiratory tract infections, and in 10 of 12 patients with urinary tract infections. One patient developed acute tubular necrosis. Eosinophilia was seen in 7% of patients treated with cefoxitin. The intramuscular preparation was not painful to 96% of the patients. Cefoxitin given by the intramuscular route can be used as an alternative to intravenous cefoxitin for treatment of mild or moderate infections, for continuation of treatment when the intravenous route is not appropriate, and for treatment of ulcers of polymicrobial etiology on ischemic extremities or on extremities of diabetic patients.


Comparative studies of cefoxitin and cephalothin: an overview. A comparative study of the efficacy and safety of cefoxitin and cephalothin in the treatment of serious infections was carried out by 21 investigators. A total of 320 patients were treated with cefoxitin, and 276 patients were treated with cephalothin. In each group 50% of patients could be evaluated. Patients were randomly allocated to groups in open fashion, and final analysis showed that the groups were comparable in terms of sex, age, severity of illness, and duration of therapy. The majority of pathogens isolated were susceptible to both agents, although 13% of gram-negative bacilli and anaerobes were susceptible to cefoxitin alone. The overall percentage of patients cured or improved by cephalothin was 93%; for cefoxitin the proportion was 91%. No statistical differences in response by type of organism or site of infection were shown. Cefoxitin was effective in treating infections and in eradicating the pathogenic bacteria. Cefoxitin was as well tolerated as cephalothin and produced no more adverse reactions or abnormal laboratory findings than did cephalothin. The results of this study demonstrate that cefoxitin is as effective in achieving bacteriologic and clinical cures as is cephalothin and also is effective in treatment of infections due to cephalothin-resistant bacteria.


Infections due to endemic, multiply resistant gram-negative rods: sensitivity to and therapy with cefoxitin. A nosocomial outbreak of infections due to bacteria resistant to multiple antibiotics evolved into an endemic prevalence of several antibiotic-resistant gram-negative rods. The resistance of these bacteria to available beta-lactam antibiotics, a variety of broad-spectrum agents, and available aminoglycosides other than amikacin led to an evaluation of cefoxitin, a beta-lactamase-resistant cephamycin. Most multiply resistant isolates of Klebsiella pneumoniae, Serratia marcescens, and Proteus mirabilis were sensitive to cefoxitin in vitro. Cefoxitin therapy of 11 severe nosocomial infections caused by multiply resistant K. pneumoniae resulted in clinical and bacteriologic cure in seven patients.


Safety of cefoxitin: an approach to the analysis of laboratory data. The safety of cefoxitin, in terms of values obtained in laboratory tests during and after therapy, was estimated by three methods for analysis of data derived from controlled clinical comparisons of cephalothin and cefoxitin. Both antibiotics were found to be safe with respect to hematologic, renal, and hepatic function and did not differ significantly from each other. Laboratory data confirmed by tests performed serially and by paired related tests were analyzed by a novel method of comparison.


General mechanisms of antimicrobial resistance. Bacteria can become resistant to antimicrobial agents by two routes, either by mutation or by the inheritance of new genetic information in the form of resistance plasmids. The mechanisms by which bacteria express resistance are manyfold, and five different biochemical mechanisms have been demonstrated in clinical isolates. The most important mechanisms are alteration of the drug target site, interference with the transport of the antimicrobial agent into the cell, and detoxification (inactivation) of the drug in the immediate environment of the cell.


Cefoxitin: an overview of clinical studies in the United States. Cefoxitin, a new cephamycin antibiotic that is active against aerobic and anaerobic bacteria, was studied by 35 investigators in the United States. Of 657 patients eligible for evaluation of efficacy of the compound, 69% were cured and 92% were cured or improved on clinical grounds. Bacteriologic response to therapy with cefoxitin was equally good for infections due to gram-positive cocci (94% cured), gram-negative bacilli (87% cured), and anaerobes (95% cured). Cefoxitin was effective clinically and bacteriologically in the eradication of infections due to organisms resistant to ampicillin, cephalothin, chloramphenicol, tetracycline, and aminoglycosides. Overall rates of favorable response to cefoxitin therapy by disease were: lower respiratory tract infections, 90%; urinary tract infections, 87%; intraabdominal infections, 90%; gynecologic infections, 94%; and septicemia, 84%. Cefoxitin was tolerated well, and major abnormalities of hematologic, hepatic, renal, or central nervous system function were encountered rarely. Resistance to cefoxitin did not develop among gram-negative cocci, anaerobes, or gram-negative bacilli in the medical centers in which the antibiotic was used.


Induction and effector phases of the immune response: physiological and pathophysiological features. A review is given on the current state of knowledge about the induction and effector phases of the immune response. Physiological and pathophysiological features of the regulation of the immune response are discussed comparatively for both man and animals.


Pseudotuberculosis in man: possible epidemiological role of the cats. Human infection by Malassez and Vignal's bacillus (Yersinia pseudotuberculosis) can take many clinical aspects, the most frequent of which is mesenteric adenitis with pseudoappendicular syndrome, but occasionally also appearing as a tumor of the right lower abdominal quadrant. In a subsequent stage this mesenteric adenitis is often accompanied by erythema nodosum. There also exist some septicemia-like forms, which have become more and more frequent of late, always appearing on a particular terrain (predisposed persons). These various forms all correspond to contamination via the digestive route. Other, more exceptional modes of contamination may result in much rarer forms, such as ocular or pulmonary forms. Diagnosis is based on: (a) demonstrating the presence of Yersinia pseudotuberculosis, (b) serodiagnosis, (c) a positive intradermal reaction, (d) the characteristic aspect of lymph node lesions. Pseudotuberculosis is extremely frequent in animals. Many species, most of them rodents or birds, can serve as healthy carriers. This is how cats, through their access to this natural "reservoir", get contaminated and thus act as a "conveyor belt" in transmitting the disease to man.


Mode of action of beta-lactam antibiotics. Biochemical investigations of the mode of action of beta-lactam antibiotics have focused on the interaction of these drugs with sensitive enzymes and penicillin-binding proteins in vitro and on the correlation of these data with physiological responses to the drugs. The classical response is inhibition of growth and cell death followed by lysis; however, the bacteriostatic response to penicillins, which is seen in certain bacterial species such as Streptococcus mutans and in mutants of species such as Streptococcus pneumoniae, is also described. The biochemical data remain consistent with the acyl-D-alanyl-D-alanine donor substrate analogue theory, but multiple targets with differential sensitivity to different beta-lactam antibiotics exist. The relationship of these targets to penicillin-binding proteins and their possible functions in cell growth and division are discussed.


Beta-lactam antibiotics and beta-lactamases: two sides of a continuing story. The period since the introduction of beta-lactam antibiotics for therapeutic purposes has been characterized by a number of phases during which the incidence of resistant bacteria causing clinical infections has been high. Initially, penicillin-resistant staphylococci were the problem; more recently, it has been the resistant gram-negative bacteria, including anaerobes, that have given cause for concern. Thus novel beta-lactam antibiotics with activity against the resistant organisms have been developed. For the staphylococci methicillin, oxacillin, and cloxacillin were introduced, and for gram-negative species, cefuroxime and cefoxitin. Cefoxitin is particularly useful for treatment of infections due to anaerobes and ampicillin-resistant isolates of Escherichia coli. In all cases the best way to achieve efficacy against resistant bacteria seems to have been to design antibiotics that are insensitive to hydrolysis by beta-lactamases.


The design of new drugs that resist microbial inactivation. Several possible strategems for overcoming the development of bacterial resistance are discussed. The design of new drugs that resist microbial inactivation is reviewed, with particular emphasis on the aminoglycoside and beta-lactam antibiotics. Examples of alteration of the inactivation site, decreased enzyme affinity, steric hindrance of enzymic inactivation, and semiempirical systematic modification of the parent antibiotic are presented. The role of the 7-alpha-methoxy group in cefoxitin and the cephamycins in conferring stability in the presence of beta-lactamase is best rationalized by its steric bulk. The effects of other 7-alpha-substituents are also discussed.


[Benign inoculation lymphoreticulosis or cat-scratch disease]. Discovered in 1950-51 by two great parisian medical teams, inoculation lymphoreticulosis, also called cat's scratch disease, is locoregional adenitis whose aetiology is imperfectly determined. Following, often bu not always, cat's scratch, it may evolve to suppuration. Pus is always aseptic. Attributed to Bedsonia's family micro-organism, no cultivation was possible up to date. Evolution is as a rule favourable, but disease is poorly accessible to tetracycline family's antibiotics. Diagnosis is possible by intradermoreaction. The antigen used is tyndallised pus of homologous infection. The role of the cat, still healthy, has not yet been explained.


Cefoxitin and cephamycins: microbiological studies. The cephamycins are a family of beta-lactam antibiotics that are produced by actinomycetes and are structurally similar to the cephalosporins. They are characterized by the presence of a 7-alpha-methoxyl group, which confers unusually high resistance to beta-lactamases. Cefoxitin, the first semisynthetic cephamycin, is resistant to almost all beta-lactamases. Cefoxitin retains the 3-carbamoyl group of cephamycin C and thus has excellent metabolic stability. Cefoxitin is bactericidal and almost devoid of any inoculum effect. Active against many cephalothin-resistant gram-negative bacteria, cefoxitin demonstrates a very broad spectrum that includes indole-positive Proteus and many strains of Serratia. In contrast to that of the cephalosporins, cefoxitin's spectrum of activity against anaerobic pathogens includes Bacteroides fragilis. The therapeutic effectiveness of cefoxitin in experimental infections in mice confirms the excellent characteristics of this semisynthetic cephamycin and indicates that it should be a very valuable agent for treatment of bacterial infections.


Yersinia enterocolitica among small wild mammals in France. A survey of Yersinia enterocolitica was made in two French areas (Indre and Alsace) in several components of the terrestrial ecosystem. Y. enterocolitica has been isolated from several habitats and from numerous species of small mammals. The trap line method enabled us to estimate the density of the two abundant small mammal species, Microtus arvalis and Apodemus sylvaticus, and the densities of Y. enterocolitica carriers. The frequency of isolation was high when temperatures were low, but did not seem to be in direct relationship with animal densities. Infectious lesions were never found in spleens or intestines of 1893 captured animals. Samples of fresh water, fresh-water fish, soil and earthworms were occasionally collected. A total of 163 strains were isolated. Of these, 99 were of biochemical type 1; 20 different 0 serogroups were found.


Glutamate dehydrogenase and aspartate aminotransferase in Trypanosoma cruzi. 1. The cultured, epimastigote-form of Trypanosoma cruzi contains NADP-linked glutamate dehydrogenase (EC 1.4.1.4), with a molecular weight of about 280,000, similar to the enzyme from Plasmodium chabaudi and different from the enzymes from higher animal sources. 2. T. cruzi also contains aspartate aminotransferase (EC 2.6.1.1), with properties similar to those of the enzyme from mammals. 3. The concerted action of the transaminase and glutamate dehydrogenase might be responsible for the production of NH3 which characterizes the protein catabolism in T. cruzi.


Comparative solubilities and electrophoresis of microtine hemoglobins. 1. The electrophoretic mobilities of the hemoglobins of 7 taxa of microtines were compared. Microtus oeconomus, M. pennsylvanicus pullatus and M. xanthognatus showed identical 2-band patterns on electrophoresis of their hemoglobins while M. pennsylvanicus tananaensis showed only a single hemoglobin corresponding to the major band of the others. Dicrostonyx rubricatus and D. stevensoni exhibited identical patterns different from the Microtus species. Lemmus sibiricus had a slow hemoglobin component with mobility slightly different from the slow ones of the Microtus species while the fast component appeared the same. 2. Electrophoresis of individual globin chains from hemolysates, purified hemoglobins, and isolated chains indicated a large degree of similarity between the species studied, although there were significant differences in hemoglobin patterns. 3. The minor hemoglobin band in Microtus seems to be the result of a second alpha chain locus as determined from the hemoglobins from hybrids of two subspecies. 4. Salting-out studies indicated differences between hemoglobins that were not detectable by electrophoresis of either whole hemoglobins or isolated chains. 5. M. xanthognathus hemolysate was considerably less soluble than those of M. oeconomus and M. pennsylvanicus pullatus which had essentially the same solubility. 6. The major hemoglobin components of M. pennsylvanicus pullatus and M. xanthognathus were considerably less soluble than either the corresponding unfractionated hemolysates or purified minor components.