Short-term storage of six penicillins and cephalothin in microdilution trays for antimicrobial susceptibility tests.

To perform microdilution antimicrobial susceptibility tests efficiently, broth dilutions of the antimicrobial drugs should be prepared in large batches and stored frozen until needed. Studies were carried out to document the stability of ampicillin, benzylpenicillin, carbenicillin, methicillin, oxacillin, nafcillin, and cephalothin in microdilution trays during storage at -20 and -60 C. No significant deterioration was noted after 21 days of storage, as detected by bioassay and by replicate minimal inhibitory concentration determinations with control organisms. No significant differences were noted moreover between trays stored for three weeks at -20 C and those stored at -60 C. The microdilution technique was found to be a highly reproducible method for quantitative determination of antimicrobial susceptibility.


Influence of subtherapeutic levels of a combination of neomycin and oxytetracycline on Salmonella typhimurium in swine, calves, and chickens.

Subtherapeutic levels of oxytetracycline plus neomycin in animal feeds did not bring about increases in the quantity, prevalence, or shedding of Salmonella typhimurium in swine, calves, or chickens. In fact, the medication generally reduced the proportion of animals carrying S. typhimurium. The medicated groups were fed rations containing oxytetracycline plus neomycin commencing 5 days prior to oral inoculation with S. typhimurium and continuing through a 28-day postinoculation period. Colonization of S. typhimurium occurred in all three animal species, as evidenced by clinical signs of infection and/or colony counts in feces. Only from swine and on only one occasion was a single resistant colony isolated. It is concluded that no evidence has been obtained which would implicate the continuous low-level feeding of oxytetracycline and neomycin for a 4-week period to a potential increased incidence of disease in animals or as a hazard to humans.


In vitro effects of low concentrations of penicillin and sulfadiazine on Streptococcus mutans.

Investigations were conducted to determine the in vitro effects of low levels of penicillin and sulfadiazine on the growth, plaque formation, and agglutination of Streptococcus mutans and on the synthesis and activity of enzymes synthesizing extracellular polymers. The concentrations tested were equivalent to those expected in the saliva of subjects receiving oral therapy with the agents. Penicillin at 0.5 ng/ml and sulfadiazine at 1 mug/ml substantially inhibited in vitro plaque formation. At these concentrations, sulfadiazine but not penicillin also inhibited growth of the organism. Neither antimicrobial agent affected the agglutination of S. mutans with dextran or the synthesis or activity of enzymes synthesizing extracellular polymers. The effect of sulfadiazine on plaque formation was attributed, at least in part, to the inhibitory action of that agent on S. mutans growth.


Indirect method for assessing the penetration of beta-lactamase-nonsusceptible penicillins and cephalosporins in Escherichia coli strains.

Escherichia coli UB1005 and two mutants of this strain (DC2 and DC3) have been used to assess indirectly the relative ability of various beta-lactam antibiotics to penetrate the outer layers of E. coli. Benzylpenicillin, ampicillin, methicillin, cloxacillin, cephaloridine, cephalothin, and cephalexin have been examined. The results confirm those obtained with other methods and show that, among the compounds studied here, cephalosporins seem to penetrate more readily than penicillins.


Comparative study of seven cephalosporins: susceptibility to beta-lactamases and ability to penetrate the surface layers of Escherichia coli.

The properties of cefazolin, cefoxitin, cefamandole, and cefuroxime have been compared with those of cephaloridine, cephalothin, and cephalexin. The properties included for examination are the susceptibility to a range of beta-lactamases commonly encountered in gram-negative species and the ability of a beta-lactam antibiotic to penetrate the outer layers of Escherichia coli. Of the antibiotics tested, cefamandole was the most active in its antibiotic activity but had the disadvantage that it was sensitive to hydrolysis by type IVc beta-lactamase. Cefoxitin and cefuroxime were slightly less active than cefamandole but were effectively resistant to all the beta-lactamases used in the test.


Comparison of tetracycline action on Staphylococcus aureus and Escherichia coli by microbial kinetics.

Cultures of tetracycline-treated Staphylococcus aureus exhibited monophasic steady-state growth curves similar to that observed for tetracycline-treated Escherichia coli. Apparent growth rate constants of the respective drug-treated cultures showed the same formal dependence on drug concentration, which was linear at a low concentration but asymptotically approached zero at higher concentration levels and implied the saturation of a limited number of receptor sites engaged in microbial protein synthesis. The relative potency of tetracycline action of S. aureus/E. coli was 6.50:1 at 37.5 degrees C and pH 7.05. This is attributed to relative differences in drug permeation and/or binding affinity for biophase receptors in the respective organisms. It is concluded from kinetic dependencies of growth inhibition of the cultures that tetracycline has the same mode of action on S. aureus and E. coli. It is bacteriostatic at concentrations below the minimal inhibitory concentration level but bactericidal at the higher concentration levels.


Dual-action cephalosporin utilizing a novel therapeutic principle.

A new cephalosporin is described that overcomes, in a novel way, the general susceptibility of this group of agents to enterobacterial beta-lactamases. The new compound carries a substituent that is released on cleavage of the beta-lactam ring and then exhibits antibacterial activity in its own right. The possible therapeutic benefits of such an antibiotic are discussed.


Specific action of 4-nitropyridine 1-oxide on Excherichia coli K-12 pro+ strains leading to the isolation of proline-requiring mutants: isolation and characterization of pro-mutants.

A specific action of 4-nitropyridine 1-oxide on Escherichia coli K-12 Pro(+) strains leading to highly efficient, selective isolation of Pro(-) mutants is described. Incubation of Pro(+) cells with a sublethal concentration of 4-nitropyridine 1-oxide in Penassay broth gave Pro(-) mutants, which lacked either the biosynthetic pathway of proline from glutamic acid to glutamyl gamma-phosphate (proB(-)) or the pathway from glutamyl gamma-phosphate to glutamic gamma-semialdehyde (proA(-)) or both. Pro(-) mutants, which have the metabolic block between Delta(1) pyrroline-5-carboxylate (the cyclized dehydration product of glutamic gamma-semialdehyde) and proline (proC(-)) were not found among survivors. Treatment of Pro(+) cells with N-methyl-N'-nitro-N-nitrosoguanidine led to isolation of all three types of Pro(-) mutants, suggesting that the action of 4-nitropyridine 1-oxide on Pro(+) cells is apparently distinct from the action of N-methyl-N'-nitro-N-nitrosoguanidine. F-duction and interrupted mating experiments led to determination of the correlation between proline loci and the biosynthetic pathway of proline from glutamic acid.


Specific action of 4-nitropyridine 1-oxide on Escherichia coli K-12 Pro+ strains leading to the isolation of proline-requiring mutants: mechanism of action of 4-nitropyridine 1-oxide.

Possible mechanisms involved in the action of 4-nitropyridine 1-oxide (4NPO) on Escherichia coli K-12 pro(+) cells in Penassay broth leading to the selective isolation of proA(-) and/or proB(-) mutants but not proC(-) mutant were studied. Reconstruction experiments between pro(+) and pro(-) cells, together with experiments on the bactericidal action of 4NPO on pro(+) and pro(-) cells, indicated that 4NPO is more toxic for pro(+) and proC(-) cells than for proA(-) and proB(-) cells. These results, coupled with data indicating little mutagenicity of 4NPO on E. coli cells, led us to conclude that the selection of proA(-) and/or proB(-) cells that arose spontaneously in the pro(+) culture is a possible mechanism for the action of 4NPO. Examination of 4NPO sensitivity of pro(+) transductants derived from proA(-) and proB(-) cells with P1 vir phage and pro(+) cells as donor and of pro(+) spontaneous revertants derived from those pro(-) cells suggested that 4NPO-sensitive gene(s) should be on, or very close to, the proA and proB loci and that both products of proA and proB genes may be involved in the sensitivity of bacteria to 4NPO. The fact that the 4NPO-sensitive allele is dominant over the 4NPO-resistant allele further indicated the possible correlation between gene products of proA and proB and the 4NPO sensitivity of bacteria. Experiments on metabolic conversion of 4NPO with bacterial cells proved that the major metabolic pathway of the agent is reduction to (possibly via 4-nitroso-) 4-hydroxylamino- and 4-amino-pyridine 1-oxides, and then to 4-aminopyridine. Investigation of the effect of structural modification of 4NPO on the elective selection of Pro(-) mutants in Pro(+) culture further suggested that the structural feature indispensable for the action of the agent is the hydroxyl-amino or its more oxidized state at the 4 position and the N-oxide moiety at the 1 position on the pyridine skeleton. Action of 4NPO in minimal medium was found to be bacteriostatic on pro(+) cells but not on pro(-) cells, leading to the formation of long nonseptate multinucleate filament cells on pro(+) cells. Possible biochemical mechanisms of the selective toxicity of 4NPO for pro(+) and pro(-) cells are discussed.


Chloramphenicol: an enzymological microassay.

A new assay for chloramphenicol in biological fluids has been developed that offers sensitivity, specificity, precision, accuracy, economy, and ease of performance. The assay is based on the enzymological acetylation of chloramphenicol catalyzed by an R factor-mediated enzyme. [(14)C]acetyl coenzyme A serves as the donor of the labeled acetyl group, and the product, [(14)C]acetoxychloramphenicol, is separated from the labeled precursor by utilizing its preferential extraction into benzene. The product is then quantified by liquid scintillation counting. This assay measures chloramphenicol concentrations in both plasma and other biological specimens and in the presence of other antibiotics, hemolysis, or jaundice. Its rapidity and ease of performance are useful for clinical laboratories, and its sensitivity allows determinations on 10 mul of plasma.


Inhibition of the apparent rate of synthesis on the vacuolar glycoprotein carboxypeptidase Y and its protein antigen by tunicamycin in Saccharomyces cerevisiae.

Carboxypeptidase Y from Saccharomyces cerevisiae contains 14% mannose, the only neutral sugar present. An antiserum can be raised in rabbits which reacts with both the protein and the sugar moieties of the enzyme. This antiserum also precipitates yeast invertase and yeast cell wall mannan. Thus carboxypeptidase Y, which is known to be localized in yeast vacuoles, is very probably a mannoprotein. Tunicamycin inhibits the apparent formation of carboxypeptidase Y to a similar extent as that of the externally localized mannoprotein, invertase. No accumulation of an inactive nonglycosylated or partly glycosylated carboxypeptidase Y occurs as determined by the immunoprecipitation technique. Tunicamycin also inhibits the apparent formation of proteinase A, whereas it does not affect the increase in the activities of a number of other enzymes. It is suggested that in the synthesis of glycoproteins there exists a regulatory link between the synthesis of their polypeptide chains and the reactions involved in their glycosylation.


Reproducibility of control strains for antibiotic susceptibility testing.

Inter- and intralaboratory reproducibility of susceptibility testing requires stable control strains. The Food and Drug Administration diffusion procedure recommends the Seattle strains of Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922) for this purpose. It was of interest to determine the present reproducibility of control cultures maintained in various laboratories over several years. Fifteen cultures each of S. aureus and E. coli were obtained from laboratories in different parts of the country. Their performance was compared with strains directly derived from ATCC. Diffusion susceptibility tests using a modified overlay technique were made with four replicates. Seven of the eight statistically significant differences in responses of the staphylococci were to penicillin, methicillin, or cephalothin. One culture was a penicillinase producer with a zone 15 mm less than the standard strain. Eleven of the 15 cultures showed no significant deviations or differences greater than 2 mm from the results with the strain derived directly from ATCC. All except the penicillinase producer were of identical phage type. Among 150 organism-antibiotic combinations tested with E. coli, all but one reading were within 2 mm of the standard. Four of the six statistically significant differences were in a culture from one laboratory. The stability of the cultures appears to have been influenced by the method of storage. Cultures that were kept frozen during extended storage were remarkably stable. Significant differences were found in cultures from four of five laboratories that maintained cultures in refrigerators or at ambient temperature.


Comparison of thrombophlebitis associated with three cephalosporin antibiotics.

A double-blind study with volunteers was performed to determine the incidence and severity of thrombophlebitis associated with cephalothin, cephapirin, cefamandole, and a water control. Although there were no statistical differences in the incidence of thrombophlebitis, cephalothin resulted in significantly more severe thrombophlebitis compared with the other agents.


Antitrichomonad action, mutagenicity, and reduction of metronidazole and other nitroimidazoles.

Twelve 4- and 5-nitroimidazole derivatives, including metronidazole and two of its metabolites, tinidazole, dimetridazole, and nimorazole, were tested for antitrichomonad action on Tritrichomonas foetus (KV(1)) and Trichomonas vaginalis (ATCC 30001) for mutagenicity on a nitroreductase-positive (TA 100) and a nitroreductase-deficient (TA 100-FR(1)) strain of Salmonella typhimurium, as well as for the reducibility of the nitro group by T. foetus homogenates. Compounds with activity <1% of that of metronidazole are regarded as inactive. All antitrichomonad compounds induce mutations and can be reduced. S. typhimurium TA 100 gave mutations under both aerobiosis and anaerobiosis; TA 100-FR(1), however, gave mutations only under anaerobiosis. Certain compounds that are reducible, and the nonreducible derivatives, were inactive. Metronidazole and its inactive 4-nitro analogue were reduced in a four-electron process in ferredoxin- or methyl viologen-mediated reactions with the same velocity. The results underscore the role of the reduction of the nitro group in the antitrichomonad and in the mutagenic activity of nitroimidazoles.


Basis for the design of anticandidal agents from studies of peptide utilization in Canadida albicans.

The growth of Candida albicans WD 18-4, a methionine and lysine double auxotroph, on a variety of methionine- and lysine-containing peptides was determined. This yeast does not excrete extracellular peptidases. Thus, the growth response to peptides containing the required amino acid is a measure of peptide transport. A variety of methionine-containing peptides such as Met-Met, Met-Met-Met, and Met-Met-Met-Met-Met are transported. Acylation of the N-terminus of transported peptides does not affect their transport, but derivitization of the C-terminus prevents peptide uptake. In contrast, all lysine-containing peptides tested, except Lys-Gly, were not growth substrates. The inability of a peptide to substitute for the requisite amino acid was not due to the absence of cellular peptidases or to toxicity of the nonutilized peptides. Several potentially toxic amino acids were carried into Candida as a component of transported peptides. This establishes the peptide transport system as a possible tool for the design of antibiotics for Candida albicans.


In vitro synergistic effect of netilmicin, a new aminoglycoside antibiotic.

The combination of netilmicin (Sch 20569) with carbenicillin, cefazolin, chloramphenicol, and clindamycin was evaluated by in vitro tests against 91 clinical isolates of Pseudomonas, Klebsiella, and Escherichia coli. Combinations were considered to show synergy if there was a fourfold or greater reduction in minimal inhibitory concentration values of both antibiotics when combined. Synergy of netilmicin with carbenicillin could be demonstrated against 21 of 46 Pseudomonas isolates. Comparison of the synergy of carbenicillin with netilmicin or gentamicin showed that netilmicin was less active than gentamicin against Pseudomonas aeruginosa. However, at therapeutic concentrations of the antibiotics, significant differences were not observed. Synergy of netilmicin and cefazolin was demonstrated against only 1 of 21 Klebsiella strains tested, but partial synergy was found for 12 of 20 isolates. Synergy and antagonism were uncommon with the netilmicin-chloramphenicol and netilmicin-clindamycin combinations against E. coli and Pseudomonas.


Can mannitol reduce amphotericin B nephrotoxicity? Double-blind study and description of a new vascular lesion in kidneys.

Eleven patients with systemic mycotic infections were treated with amphotericin B, 1 mg/kg, on alternate days. Five patients also received mannitol (M), 1 g/kg, in the amphotericin infusion, while six served as controls (C). Renal function studies prior to therapy were repeated at a total cumulative amphotericin B dosage of 25 mg/kg; renal biopsies were obtained from 10 patients. Inulin and creatinine clearances decreased in both the C and M groups, significantly so in the latter. Urinary concentrating ability of five patients (2C, 3M) decreased as did the capacity of three (1C, 2M) to acidify urine after an acid load. Neither the peak and valley levels of amphotericin B in serum nor the urinary excretion thereof differed between the C and M groups. Striking vacuolization of smooth muscle cells, previously unrecognized, was observed in the media of arterioles and arteries in all renal biopsies. Tubular calcification was present in both groups. In summary, M therapy (1 g/kg) did not protect against the nephrotoxicity of amphotericin B. A unique lesion of the renal vasculature secondary to amphotericin B is described.


Kinetics of the actions of tetracyclines on Escherichia coli as studied by microcalorimetry.

Microcalorimetry was used to study the kinetics of the actions of various tetracyclines on a strain of Escherichia coli. Differences in the capacity to suppress the metabolism of this bacterium were observed. When the antibiotic was present from the start of the experiment, a heat production of 2.0 muW/ml was registered after 12.5 h using minocycline; the corresponding figures for doxycycline, oxytetracycline, and tetracycline were 7.3, 6.6, and 4.5 h, respectively. In these experiments, equal concentrations, i.e., half the minimum inhibitory concentration (MIC), of each drug were used. The MIC for all the tetracyclines tested, determined by the broth dilution technique, was 0.8 mug/ml. In other experiments, the antibiotic (concentration, 1.6 mug/ml = 2x MIC) was introduced into the growth vessel during the logarithmic growth phase of the organism. The extent and duration of the inhibitory effect on the metabolism, as judged from the decrease in heat production, varied with the different tetracyclines. Immediately after introduction, minocycline, doxycycline, oxytetracycline, and tetracycline decreased the heat production in decreasing order of potency. With tetracycline, the heat production rose after about 1 h, and with minocycline it rose after about 9 h. The heat production remained at a low level for at least 19 h when using doxycycline and oxytetracycline. The results indicate that microcalorimetry offers a means for studies of the kinetics of the antibacterial actions of antibiotics and provides information that cannot be obtained by conventional bacteriological techniques. This information may be of use, in conjunction with pharmacokinetic data, in establishing optimum doses and dose intervals in antibiotic therapy.


Effects of doxycycline in actively purging cholera patients: a double-blind clinical trial.

In 51 actively purging cholera patients the efficacy of doxycycline, a long-acting tetracycline, was compared with a placebo and tetracycline hydrochloride. Seventeen patients who were given doxycycline at the recommended dose of 2 mg/kg at the beginning of the study, at 12 h, and at the repeated dose once daily purged a mean volume of 5.1 liters of stool and received an average of 5.7 liters of intravenous fluid. Nineteen patients receiving the placebo purged 10.1 liters of stool and received 9.7 liters of fluid. Fifteen patients given tetracycline hydrochloride at 6-h intervals passed 4.8 liters of stool and received 5.5 liters of fluid. The durations of diarrhea calculated in 8-h periods were 3.5, 8.0, and 4.1 h in the respective groups receiving doxycycline, placebo, and tetracycline. The differences between the doxycycline and placebo treatments and the tetracycline and placebo treatments were statistically significant. Those receiving doxycycline became vibrio-free in about 3 days as compared with 2 days for those receiving tetracycline; the group given the placebo were vibrio positive for the duration of their hospitalization. The results show that in the treatment of cholera the administration of doxycycline once daily has effects equal to those when tetracycline is administered at 6-h intervals. This is a distinct advantage because it decreases the demand on nursing personnel in epidemics. Also, doxycycline may be safely administered in cases of suspected renal failure from prolonged shock in cholera.


Tirandamycin, an inhibitor of bacterial ribonucleic acid polymerase.

The antibiotic tirandamycin (a 3-acyltetramic acid structurally related to streptolydigin) specifically inhibits transcription by interfering with the function of bacterial ribonucleic acid polymerase. Ribonucleic acid polymerases from rat liver nuclei are not subject to tirandamycin inhibition. Qualitatively, the mode of action of the antibiotic is identical to that of streptolydigin in inhibiting chain initiation as well as chain elongation during the transcriptional process. However, tirandamycin is approximately 40 times less potent than streptolydigin. The structures of the 3-acyl groups of the two acyltetramic acid antibiotics tirandamycin and streptolydigin differ only slightly in the degree of oxidation of the terminal dioxabicyclo (3.1)nonane system and possess the same stereochemistry (D. J. Duchamp, A. R. Branfman, A. C. Button, and K. L. Rinehart, 1973). More significantly, major differences occur at the 1 and 5 positions of the tetramic acids. Tirandamycin contains no substituents; streptolydigin contains a substituted acetamide function at position 5 and a sugar moiety at position 1. The lack of substituents at the 1 and 5 positions of the tetramic acid portion in tirandamycin is probably responsible for the reduced biopotency of tirandamycin as compared with streptolydigin.


R-plasmid transfer in vivo in the absence of antibiotic selection pressure.

The persistence of an O18 Escherichia coli strain resistant to tetracycline, streptomycin, and sulfonamide has been followed in the fecal flora of a single individual over a period of 9 months. The strain in question carrying an R plasmid was detectable from the beginning of the survey, but it was only after a 10-day period of tetracycline therapy that it reached an all but permanent dominance in the fecal flora. No transfer of the R plasmid carried by the strain to any other coliform could be detected for 202 days after the end of tetracycline treatment. At this point, however, an O88 E. coli carrying the same plasmid as the O18 strain appeared briefly as a predominant component of the flora. The two plasmids isolated from the O18 and the O88 E. coli strains have been characterized in molecular terms and found to be similar. This suggests that R-plasmid transfer between two E. coli strains occurred in an individual who was living a normal daily life and who was not receiving antibiotics.


Correlation of resistance to proflavine and penicillin in Escherichia coli.

A number of proflavine (PF)-resistant mutants of Escherichia coli B were also resistant to penicillin and cephalothin. Mutants resistant to 1.0 mM PF were 10 times more penicillin resistant than were the PF-susceptible, wild-type cells. Single-step mutants selected for resistance to either PF or penicillin were also resistant to the other drug. None of the resistant mutants tested possessed beta-lactamase activity. These results suggest that resistance to PF and penicillin in E. coli B may be due to permeability changes in the cell envelope.


In vitro comparison of gentamicin, tobramycin, sisomicin, and netilmicin.

The antimicrobial activity of gentamicin, tobramycin, sisomicin, and netilmicin (Sch 20569) was compared against 150 strains of organisms. Netilmicin was shown to be the least effective against Pseudomonas strains but to have slightly better activity against Staphylococcus aureus and Escherichia coli than the other agents. The effect of calcium and magnesium in enhancing the differences in activity of these aminoglycosides against Pseudomonas strains was also demonstrated.


New medium for in vitro susceptibility studies with amphotericin B.

Antibiotic medium 20 FDA and antibiotic medium 3 FDA were compared to determine if antibiotic medium 3 would be suitable for in vitro susceptibility testing with amphotericin B.


The substrate constant for the ammonium ion of growing Saccharomyces cerevisiae.

The relation between ammonium concentration and growth rate was studied in steady state continuous cultures of Saccharomyces cerevisiae in nitrogen-limited glucose ammonium medium. This relation could be described by the Monod equation. A maximum specific growth rate of 0.41 h-1 and a substrate constant for ammonium of 5-11 muM were calculated. Ammonium was determined by a modification of the phenol hypochlorite method. A discussion of the results in view of literature data on the substrate constants for other nutrients is given.


Rapid detection of bacterial endotoxins in drinking water and renovated wastewater.

A pilot study was conducted to determine the feasibility of using the Limulus endotoxin assay to detect endotoxins in potable waters and from reclaimed advanced waste treatment (AWT) plant effluents. Water samples were tested using both Limulus lysates prepared in our laboratory and a commercial product, Difco Pyrotest. The Limulus assay procedure was easily adapted to the testing of water samples for endotoxin. Measured endotoxin concentrations varied from 0.78 ng/ml to 1,250 ng/ml. Levels of endotoxin were not predictable based on whether the water was drinking water or AWT water, i.e., some AWT water samples had less endotoxin activity than some samples of drinking water, and some AWT waters had greater endotoxin activity than drinking water. Only three of the water samples tested were free of any detectable endotoxin. Breakpoint chlorination procedures seemed to reduce measurable endotoxin content, whereas passage through activated carbon columns was associated with greater final endotoxin concentrations in test waters.


Subsampling technique for measuring growth of bacterial cultures under high hydrostatic pressure.

A method is presented for measuring growth of bacteria under high hydrostatic pressure in subsamples taken without pressure change in the incubation vessel. Subsamples may be withdrawn rapidly (5 s) and are not subjected to shear forces. Vice versa, nutrient media, labeled substrates, etc., may be introduced into the culture while under pressure. Chemical fixation of subsamples for electron microscopy or adenosine 5'-triphosphate determinations under pressure is also possible without affecting the growing culture. Data are given of growth experiments demonstrating the feasibility of the method. Problems of oxygen depletion are discussed.


Undecompressed microbial populations from the deep sea.

Metabolic transformations of glutamate and Casamino Acids by natural microbial populations collected from deep waters (1,600 to 3,100 m) were studied in decompressed and undecompressed samples. Pressure-retaining sampling/incubation vessels and appropriate subsampling/incubation vessels and appropriate subsampling techniques permitted time course experiments. In all cases the metabolic activity in undecompressed samples was lower than it was when incubated at 1 atm. Surface water controls showed a reduced activity upon compression. The processes involving substrate incorporation into cell material were more pressure sensitive than was respiration. The low utilization of substrates, previously found by in situ incubations for up to 12 months, was confirmed and demonstrated to consist of an initial phase of activity, in the range of 5 to 60 times lower than the controls, followed by a stationary phase of virtually no substrate utilization. No barophilic growth response (higher rates at elevated pressure than at 1 atm) was recorded; all populations observed exhibition various degrees of barotolerance.


Identification of thiobacilli by replica plating on thallous sulfide paper.

Colonies of Thiobacillus thioparus and T. thiooxidans grown on thiosulfate medium can be identified by replica plating on thallous sulfide paper.


Factors affecting catalase level and sensitivity to hydrogen peroxide in Escherichia coli.

Composition of the culture medium, growth phase, and temperature play important roles in the sensitivity of Escherichia coli to H2O2. The medium and growth phase affected the sensitivity of the cells to H2O2 by modifying the amount of catalase synthesized by them, whereas the effect of temperature was due to the thermolability of the enzyme. Since catalase is unstable in the presence of its substrate, the correlation between the catalase level in the cells and their sensitivity to H2O2 could be observed only when the H2O2 concentration was not excessive in proportion to the amount of catalase.


Determinants of the developing oral flora in normal newborns.

The ability of Streptococcus species to selectively adhere to the oral epithelial cells of newborns was studied in vitro. On day 1 of life, mucosal cells from normal infants demonstrated selective attraction for the natural distribution of streptococci that would soon colonize these surfaces. Streptococcus salivarius and Streptococcus mitis adhered well in vitro to scraped cells from cheek and tongue surfaces. Streptococcus mutans, on the other hand, exhibited feeble or no adherence to cheek or tongue cells. Adherence of Escherichia coli to oral epithelial cells was also studied. The ability of strains of E. coli to adhere to cheek and tongue cells correlated solely with the presence of cell surface substances, probably pili. These observations, made on infants at the critical moment of their developing flora, strengthen the hypothesis that the ability of bacteria to adhere to surfaces is an important determinant of their ecological place in the oral microflora.


Mercurial toxicity in yeast: evidence for catabolic pathway inhibition.

Evidence that the mechanism of mercurial toxicity is a blockage of catabolic metabolism is presented. Yeast cells (Saccharomyces cerevisiae) were found to cease respiratory activities within 1.5 min of contrast time with culture mercurials (as HgCl2). This cessation was followed by the rapid depletion of endogenous adenosine 5'-triphosphate (ATP) and a concomitant increase in phosphorylated hexoses. Levels of ATP in the culture medium remained essentially unchanged during this interval suggesting that the structural integrity of the membrane was not affected. Medium potassium concentrations did not increase until after endogenous ATP levels had begun to fall, suggesting that the loss of cellular potassium was the result of the inability of membrane ATPases to function because of the unavailability of sufficient substrate ATP to maintain this gradient.


Membrane filter method for recovery of fecal coliforms in chlorinated sewage effluents.

The standard one-step M-FC broth-membrane-filter procedure for recovery of fecal coliforms from chlorinated sewage effluents is much less effective than the multiple-tube (most-probable-number) technique. A two-step membrane-filter method, using a pre-enrichment technique with phenol red lactose broth and incubation at 35 degrees C for 4 h, followether 18+/-2 h, enhanced fecal coliform recovery from chlorinated effluents. The results of 126 comparisons using chlorinated effluents from five wastewater plants showed that fecal coliform recovery by using the two-step membrane-filter method is comparable to that using the multiple-tube procedure.


Role of L-proline in the biosynthesis of prodigiosin.

Nonproliferating cells of Serratia marcescens, wild-type strain Nima, synthesized the pigment, prodigiosin, when saline suspensions were incubated with aeration at 27 degrees C in the presence of proline or alanine. Mutants PutS1 and PutS2 derived from strain Nima formed prodigiosin from alanine, but not from proline, unless alanine also was added. Strain Nima utilized proline as a sole source of carbon and of nitrogen for growth, whereas Put mutants did not. Investigation of enzymes degrading proline showed that the wild-type strain contained proline oxidase, which was absent in Put mutants. The wild type, as well as the mutants, utilized alanine as the sole source of carbon and nitrogen for growth. Although nonproliferating cells of Put mutants failed to synthesize prodigiosin from proline, addition of L-[U-14C]proline to suspensions metabolizing and synthesizing the pigment because of addition of alanine resulted in the incorporation of radioactive label into prodigiosin, as well as into cellular protein. Since Put mutants could not catabolize proline, the incorporation of [14C]proline into the prodigiosin molecule indicated that proline was incorporated directly into the pigment.


Hepatitis B surface antigen in saliva, impetiginous lesions, and the environment in two remote Alaskan villages.

A study was conducted in an area of hepatitis B hyperendemicity to determin whether contact with infective bodily secretions or contaminated environmental surfaces could be involved in the transmission of the hepatitis B virus. Hepatitis B surface antigen was detected in gingival swab, saliva, and impetiginous lesion exudate samples from children. Hepatitis B surface antigen also was found in swab samples of surfaces frequently touched or placed in the mouth. In the absence of classical exposure to infectious blood or blood products, these findings suggested that, in a crowded home environment, saliva and cutaneous exudates containing hepatitis B virus may play a role in the transmission of hepatitis B.


Isoelectric focusing of mycoplasma proteins.

Polyacrylamide gel isoelectric focusing (PAGIF) in thin layer was used to resolve proteins of Mycoplasma spp., Acholeplasma spp., and eight strains of Ureaplasma urealyticum (T-strain). A mixture of urea, Triton X-100, and dithioerythritol was used to solubilize sonically disrupted cells. PAGIF was performed in the range of pH 3 to 10. Protein patterns were carefully compared, demonstrating resolved and distinguishable species-specific protein bands. The eight serotypes of U. urealyticum (T-strain) gave identical protein patterns in the pH 3 to 10 range. The characteristic "fingerprints" of a species appeared to correlate with the biochemical nature and not the habitat in each case. Arginine-hydrolyzing species seemed to show more diverse focusing than those that ferment glucose, or prefer an acid environment. Characterization and identification of highly resolved species-specific proteins, ease of performance, and reproducibility of this method suggest that PAGIF might be employed as a taxonomic aid.


Simplified thermonuclease test for rapid identification of Staphylococcus aureus recovered on agar media.

A simplified thermonuclease test that identifies colonies of Staphylococcus aureus 5 h after recovery on various agar media is described.


Linear transformation of standard curves for yeast turbidity.

Within a very serviceable range, light extinction plotted against yeast concentration follows a rectangular hyperbola. A linear transformation, which facilitates the determination of yeast concentration, is described.


Effect of potential water pollutants and enzyme inhibitors on an automated rapid test for Escherichia coli.

The effect of selected potential inhibitors that may be found in water or wastewater on the activity of glutamate decarboxylase (EC 4.1.1.5) from Escherichia coli was determined. Several classes of compounds inhibited the enzyme, but those expected to be most frequently encountered were the heavy metal ions, the phosphates, and possibly the sulfates. From the results, it was judged that these compounds should not adversely affect the routine usage of this enzyme in an automated rapid test for E. coli.


Determination of growth of Sphaerotilus discophorus in the presence of manganese.

Manganese interferes strongly with most chemical methods of biomass determination. However, the biomass of manganese-encrusted Sphaerotilus discophorus can be determined after removal of the MnO2 with trichloroacetic acid and oxalic acid. Evidence which indicates that manganese inhibits the heterotrophic growth of S. discophorus and that the cells only oxidize manganese late in the growth curve is presented.


Timed-release capsule method for coliform enumeration.

Wax-coated capsules containing selective ingredients (brilliant green and oxgall) were added at the time of inoculation of most-probable-number media (modified lactose broths). The inhibitory ingredients gradually diffused from the capsules into the nonselective media, imparting selectivity to the media. Concentrations of brilliant green did not reach inhibitory levels until 2 or more h had elapsed, which permitted repair of some injured cells. Resuscitation of heat-injured Escherichia coli B cells occurred in the capsule-containing media, but not in conventional brilliant green bile 2% broth or violet red bile agar. No statistically significant differences were noted between coliform counts obtained on two groups of water samples by using the capsule, most-probable-number, membrane filtration, and pour plate methods. The capsule method could be used, however, as a combined presumptive and confirmed test for the examination of water. Improvements are needed to adapt the capsule method to the analysis of some categories of food.


Chamber for bacterial chemotaxis experiments.

A design for a chemotaxis chamber and its use in bacterial chemotaxis experiments are described. Some of the advantages of the new design are discussed.


Herpes gestationis. A clinicopathologic study.

Herpes gestationis is a pruritic, blistering eruption of pregnancy and the puerperium. In three patients with immunologically verified disease, the clinical presentation consisted of widespread erythematous, edematous papules and plaques, grouped vesicles on erythematous bases, and tense bullae. Histologically, these lesions showed a moderately dense, mixed-inflammatory cell infiltrate around superficial and deep dermal blood vessels, and focal necrosis of epidermal basal cells. Papillary dermal edema, subepidermal bullae, and spongiosis were prominent. Eosinophils were frequently present in the subepidermal and intrepidermal vesicles. Differentiation of herpes gestationis from other blistering diseases and other dermatitides of pregnancy may be difficult.


Prednisone therapy for alopecia areata. A follow-up report.

Eighteen patients treated with prednisone on alternate days for varying degrees of alopecia areata (AA) were examined a mean of 15 months after discontinuation of the drug. Despite an initial response to the therapy, long-term benefit was not thought to be substantial. Numerous side effects related either to systemic corticosteroids or to AA were apparent during the course of therapy, as well as at the time of the evaluation reported herein. Acne, obesity, lenticular opacities, mild hypertension, and impaired adrenocorticotropic hormone (ACTH) reserve were among the findings noted. Long-term treatment was not accompanied by an obvious beneficial change in the natural course of AA. Because of the potentially serious side effects and the lack of substantial improvement in the eventual course, alternate-day prednisone therapy is not recommended for long-term use in AA.


Malignant atrophic papulosis of Degos. Report of a patient who failed to respond to fibrinolytic therapy.

A 21-year-old woman with eventually fatal malignant atrophic papulosis (Degos disease) was treated primarily with the fibrinolytic agents phenformin hydrochloride and ethylestrenol. In spite of therapy, primarily central nervous system manifestations led to the patient's death.


[Feulgencytophotometric DNA distribution patterns of well-differentiated (mature) and undifferentiated (less mature/immature) forms of primary skin-reticulosis].

33 tissue sections of cases of primary skin-reticulosis showing different degrees of maturity were analysed by means of Feulgen-cytophotometric methods in regard to their DNA-content. The measurements performed disclosed cytophotometric differences of DNA distribution patterns between mature and less mature/immature forms: Mature forms of reticulosis were characterized by predominantly diploid DNA distribution patterns, whereas less mature/immature forms showed a main distribution in the hyperdiploid-hypotetraploid range respectively atypically dispersed aneuploid values with increase of variation and mean DNA-content. Moreover in several cases distribution patterns were seen, which may be regarded as cytophotometric transition forms showing a diploid peak and a higher rate of cells with enhanced DNA-content. Those cases appeared histomorphologically mature with a slight tendency to immaturity.


Auranofin. New oral gold compound for treatment of rheumatoid arthritis.

Eight patients with rheumatoid arthritis were treated with SK & F D-39162 (auranofin), a new oral gold compound which was effective in suppressing adjuvant-induced arthritis in rats. Clinical and humoral parameters were studied during a 3-month period of drug administration followed by a 3-month period under placebo. The drug was absorbed, well tolerated, and its action was manifested by a drop in the mean IgG blood levels in the third week of treatment accompanied by clinical improvement after 5 weeks of oral gold intake. Together with IgG changes, an increase of the albumin ratio was observed, as well as a decrease of alpha2-globulin and rheumatoid factor titres. From a total number of 60 swollen joints found initially in the 8 patients only 17 were swollen at week 12 and 9 at week 15. Although the number of patients treated was too small to allow definite conclusions, a follow-up study under placebo of clinical and laboratory changes in the same patients during another 3-month period showed that IgG serum levels rapidly reverted preceding a flare up of disease activity after withdrawal of the drug. This confirmed a direct role in cause-effect relation played by the new oral gold compound.


Renal transplantation: a twenty-five year experience.

Boston has played a significant role in the development of renal transplantation. In Boston was performed the first successful isograft between identical twins (1954) the first successful allograft between fraternal twins (1959) and the first successful allograft from a cadaveric donor (1962). An immunosuppressive drug was also described in Boston by hematologists Schwartz and Dameschek (1959) and modified for renal transplantation in dogs (1961) and used for the first time in a human recipient in March 1962. By 1965 renal transplantation had become a clinical reality. Three hundred and ninety-eight of 589 recipients (68%) since 1950 are still alive, a remarkable figure  considering that it includes all the earliest experimental transplants. One hundred and ninety-five of 295 (68%) with living-related donor transplants still have functioning allografts; 104/265 (39%) with cadaveric donor transplants have functioning grafts currently. Since 1968 transplants from living-related donors have an 80% one year survival whereas cadaveric donor transplants have approximately a 50% one year survival. Seventy-nine per cent of all one year survivors have had excellent psycho-social rehabilitation.


Graft adherence to de-epithelialized surfaces: a comparative study.

Graft adherence may be divided into two distinct phases: Phase I, which is fibrin dependent and Phase II, which begins after 72 hours with fibro-vascular ingrowth or vascular anastomosis with the graft material. Adherence values for autograft, homograft, heterograft, silicone membrane and a modified collagen membrane were evaluated during the fibrin-dependent Phase I period at 5 and 72 hours on dermal, fascial and granulating surfaces on rats. Modified collagen membrane demonstrated a superior adherence at both times tested on dermal and fascial surfaces, while autograft and homograft were significantly more adherent on granulating surfaces at 72 hours. The inert silicone membrane was consistently the least adherent. Granulating surfaces produced the highest adherence values at 5 hours and fascial surfaces at 72 hours. The higher values found with collagen indicate that future research directed toward the production of a synthetic wound dressing or skin should be directed toward biologically derived materials, rather than inert materials. The data supports the concept of the role of fibrin as the bonding factor in Phase I adherence and implies that collagen, rather than elastin, is primarily responsible for early graft adherence.


A new technique for biliary drainage in orthotopic liver transplantation utilizing the gall bladder as a pedicle graft conduit between the donor and recipient common bile ducts.

A technique for biliary drainage in orthotopic liver transplantation has been developed in which the gall bladder is used as a pedicle graft between the donor and recipient common bile ducts. In 7 patients this technique has produced encouraging results. There has been no incidence of bile leakage or stenosis of the anastomoses. The gall bladder permits the widest possible anastomoses for obliquely cut ends of the donor and recipient common ducts. It eliminates tension and retains the advantage of the sphincter of Oddi. Although the followup is short, the incidence of biliary complications using other techniques has been so high that the procedure described here would appear to have distinct advantages.


Oxygen, politics and the American Revolution (with a note on the bicentennial of phlogiston).

In this bicentennial year, it seems appropriate that each discipline examine its heritage. Two centuries ago, Joseph Priestley isolated "dephlogisticated air." International diplomacy surrounding the American and early French Revolutions provided an opportunity for Benjamin Franklin and Antoine Lavoisier to witness Priestley's work. The combined efforts of these analytical minds converted an illogical phlogiston myth into a practical and therapeutic principle. Lavoisier subsequently coined the word "oxy-gène." In the ensuing centuries, this substance has gained a central role in rational surgical therapy. The interaction between these scientists, their ultimate fate and their relationship to their communities appear to provide lessons relevant to present day biomedical research funding and the peer review process. The surgical community can be justifiably proud of its past. By reflecting on these events, we may perhaps concentrate the benefits without condemning ourselves to the repetition of previous error.


Clinical evaluation of the Lillehei-Kaster pivoting-disc valve.

A four-year clinical evaluation of 133 patients with Lillehei-Kaster pivoting-disc valves has shown that patients with an aortic valve prosthesis have remained free from valve-related problems. Patients with a mitral valve implanted have a satisfactory survival record as calculated by actuarial methods; however, a 10% incidence of valve thrombosis was experienced. Analysis suggests that this may be related to inadequate anticoagulation or use of an inappropriate suturing technique or both. The patients enjoyed significant clinical improvement following operation, with no evidence of hemolysis. A history suggestive of postoperative embolization was present in only 1 patient in this series.


Management of the patient with a prosthetic heart valve.

Approximately 20,000 heart valve prostheses are inserted yearly in the United States. Even after successful heart operations, the patients who receive them cannot be regarded as healthy individuals but are a special group with special problems who need close medical attention for the rest of their lives. They are susceptible to many unusual complications because of their implanted foreign body, and it is a challenge to all physicians in contact with them to be aware of their peculiar problems in order to prevent complications if possible and to treat them immediately if they occur. General therapy, surgical complications, infection, and mechanical problems are reviewed, with means for management outlined. These difficulties can be dealt with only by careful follow-up and well-coordinated teamwork between the family physician and the institution where the operation was performed.


Kearns-Sayre syndrome. A review of a multisystem disorder of children and young adults.

The syndrome of a slowly progressive external ophthalmoplegia, pigment retinopathy, and disorder of cardiac conduction was described by Kearns and Sayre in 1958. In patients with this triad, other neurological deficits may occur with associated abnormalities of the electrocardiogram, electroencephalogram, audiogram, and an elevation of protein in cerebrospinal fluid. The onset of a potentially lethal cardiac dysrhythmia in a patient with this slowly progressive degeneration of the nervous system can be anticipated and prevented by the use of an artivicial cardiac pacemaker.


Serratia marcescens - caused arthritis with negative and positive birefrengent crystals.

We encountered an unusual case of arthritis caused by Serratia marcescens, with both positive and negative birefringent crystals in the same inflammatory synovial fluid. This combination of events is most likely to occur in men over 40 years old who have a predisposing illness or are receiving immunosuppressive drugs. This case shows the need to consider multiple pathological processes occurring in the same joint.


Inactivation by glucose of phosphoenolpyruvate carboxykinase from Saccharomyces cerevisiae.

Phosphoenolpyruvate carboxykinase showed high activity in Saccharomyces cerevisiae grown on gluconeogenic carbon sources. Addition of glucose to such cultures caused a rapid loss of the phosphoenolpyruvate carboxykinase activity. Fructose or mannose had the same effect as glucose, while 2-deoxyglucose or galactose were without effect. The inactivation was an irreversible process, since the regain of the activity was dependent of de novo protein synthesis. Cycloheximide did not prevent inactivation. All strains of the genus Saccharomyces tested showed inactivation of their phosphoenolpyruvate carboxykinase upon addition of glucose; this behaviour was not restricted to this genus.


[Mixed cultures of heterotrophic, sulfate-reducing and sulfur phototrophic bacteria (author's transl)].

In mixed cultures, carbon and electron sources for Desulfovibrio desulfuricans are excreted by Escherichia coli from glucose fermentation. Desulfovibrio produces substrates for Chlorobium strain.


[Fluorescence serologic studies for the detection of Trichinella spiralis].

Attempts were made to find out, if Trichinella (Tr.) spiralis could be detected by means of immunofluorescence. An applicable Trichinella antigen was prepared by applying pepsin digestion to trichinous muscular tissue of experimentally infected guinea pig. Different quantities of Trichinae were orally administered to guinea pig and rabbit, and even parenteral infection of rabbit was attempted, with the view to obtain immune sera. Oral infection was followed by the occurrence of antibody titres, between the tenth day from infection and the sixtieth day, when the experiment was disrupted. Highest antibody titres were established in the fourth through sixth weeks after infection. Titres in excess to 1:64 could not be recorded by means of indirect immunofluorescence.  No antibody were detected by fluorescence serology after parenteral immunisation. The detection of Trichinella spiralis by fluorescence microscopy was somewhat problematic. When the preparations were evaluated, some secondary fluorescence was observed. It had been caused by remnants of undigested muscular fibrils, contaminants, and cell detritus not removable by the authors' method of preparation and, therefore, also recorded. That secondary fluorescence, however, was eliminated by secondary staining, using methylen blue. Hence, fluorescence should not pose any obstacle to automatic reading of the reaction. Some five or six hours were required to detect by means of indirect immunofluorescence Trichinella antigen as extracted from test animals. Yet, in practice carcass processing would go on in that time. The above results, consequently, appear to suggest that for detection of Trichinella spiralis immunofluorescence cannot even replace trichinoscopy under the condition that the time of antigen preparation was shortened.


[The effect of Mecadox on the immune response and on various chicken lymphatic organs].

Through 35 days Mecadox was admixed to feed rations for chicken, 40 days of age, and inhibited immunogenesis which, generally, is reflected in lowering of antibody titre and gamma globulin level as well as in quantitative variation of the differential leucocyte count. Change of immune reactivity in chicken treated with Mecadox and deviation from the normal are attributable to changes in the organs which are responsible for immunological processes (thymus and bursa), such as reduction of ascorbic acid levels in the adrenal gland.


[Contributions to the study of properdin. 4. Report: in vitro model study on the effect of cattle properdin on Escherichia coli].

Light and electron microscopy were used in model experiments to study a high-titre "properdine-system" culture and its action in terms of altering E. coli bacteria. The reaction was altogether strongly predominated by the three following phases of lysis. 1. Onset of massive agglutination after few minutes; 2. Decomposition of bacterial structure by lysis after ten to twelve hours; 3. Terminal phase of lysis after two to three days (amorphous detritus).


[Bone marrow insufficiency in the child and androgen therapy. Preliminary results of a prospective schedule of examination and treatment].

The preliminary results of a prospective study of androgen therapy in the treatment of bone marrow insufficiency in children are reported. This study includes 11 children with the Fanconi syndrome, 21 idiopathic and 3 with toxic aplastic anaemia. Nine patients died early in the course of treatment. Impaired liver function was observed in 28% of patients and virilization in 37% of patients.


[Membranoproliferative glomerulonephritis and mycoplasma infection].

Two children presented with an acute mycoplasma infection associated with a significant increase of antistreptolysin level. A severe nephropathy occurred, rapidly resulting in renal failure with histologic lesions of membrano-proliferative glomerulonephritis. Both patients had persisting low complement levels with low C3 and normal C4. The relationship between mycoplasma and streptococcal infections and the abnormality of complement and the renal disease is discussed.


Platelet monamine oxidase in schizophrenia. An investigation in drug-free chronic hospitalized patients.

Platelet monoamine oxidase (MAO) activity was investigated in a series of 60 patients with chronic schizophrenic illnesses free from neuroleptic medication, and 70 normal controls. No significant differences in platelet MAO activity or in substrate preference were detected between patients and controls, using tryptamine and tyramine as substrates. Platelet MAO activity did not distinguish patients with positive symptoms from those with negative symptoms alone and did not show any relationship with severity of disease or with a number of clinical features. These findings suggest that low platelet MAO activity cannot be regarded as a genetic marker for schizophrenia. Important determinants of platelet MAO activity yet to be discovered may have contributed to the discrepancies in recent observations of platelet MAO activity in schizophrenia.


Pharmacological rebound: a tool in the evaluation of antispasticity drugs.

Twelve spastic patients with traumatic transverse myelopathies participated in a two-stage, double-blind crossover study using BA-34647 (a new experimental antispasticity drug by Ciba-Geigy) and placebo. Clinical measurements of spasticity were performed before, during and after each stage. Six patients had excellent results receiving a regimen of BA-34647 but not when receiving placebo. Four patients had fair-to-good results with both BA-34647 and placebo. One patient had no significant changes when receiving either drug or placebo, the effective dose not being reached due to excessive body weight. One patient had a shortened trial due to pain and diminished function caused by excessive spasticity. Abrupt changes in post-treatment symptomatology (increase in spasticity) occurred in all six patients who demonstrated excellent results and in all four patients with fair-to-good results. In each of these cases, the increase followed the discontinuation of BA-34647. In no case was there an increase of spasticity following discontinuation of placebo. The effectiveness of an antispasticity drug may be too subtle to be perceived subjectively and objectively. The rebound phenomenon is evidence that a pharmacodynamic effect, though minor, was present.


[Agreement between traditional and computer diagnosis in psychiatric outpatients (author's transl)].

Psychiatric diagnosis based on personal interviews with 100 clinic outpatients was made and the data thus obtained were documented in Spitzer's and Endicott's CAPPS (Current and Past Psychopathology Scales). Two clinicians and the computer program DIAL - a modification of the DIAGNO II program of the same authors - diagnosed the same patients independently of each other basing their diagnoses solely on the entries in the CAPPS. The diagnostic agreement between the different diagnoses was evaluated and results compared with earlier findings by Schmid et al. These authors had, however, used CAPPS data gathered from case histories and not from direct interviews of patients. The modification in the procedure of gathering the data resulted in a slight, but statistically insignificant improvement in diagnostic agreement. The possibility of improving diagnostic agreement by the use of another scale is discussed.


[Clinical double-blind study with two different dosages of maprotiline (150 and 225 mg per day) (author's transl)].

Effects and side-effects of 150 mg and 225 mg maprotiline per day were compared by means of a double-blind trial in 20 depressed inpatients. The first 2 days patients received a high initial dosage of 300 mg per day. Patients were examined on days 0, 2, 5, 10, 15, 20, and 30. Symptoms were evaluated by the AMP system and the Hamilton scale for depressions. Laboratory examinations were carried out on days 0, 10, 20, and 30. Exanthemas developed in five patients, three of whom were on the higher dosage. Moreover, the lower dosage caused less fine hand tremor. Coinciding with the beginning of treatment a linear decrease of depressive symptoms was noted. This demonstrates the rapid onset of the antidepressant effect. Moreover, contrary to what has been stated for antidepressants generally, the onset of action was frequently noted well before 10-20 days of treatment. Some patients improved within a few days while others needed more time. The time lag until antidepressants influence depressive symptoms shows pronounced individual differences. No significant difference between the two dosages was found. The profiles show a better antidepressant effect for the higher dosage; however, because of a higher incidence of side-effects on the higher dosage of maprotiline, it cannot be recommended as routine. On the other hand, depressive inpatients should receive a daily dosage of at least 150 mg. Our findings suggest a dose-effect relationship for maprotiline.


[Changes in delusional psychoses. A historical transcultural comparison (author's transl)].

A historical transcultural comparison of paranoid psychoses (ICD 295.3, 297. 0-9) was done by evaluating the data of 200 case histories (I: 100 from 1911, II: 100 from 1973). An interrater reliability test was performed. 1. Stable delusions were: delusions of reference, religious delusions, delusions of persecution. 2. There was a significant increase in hypochondriacal delusions. 3. Megalomania and erotomania decreased. 4. There is in the "old" and "new" group a significant correlation between megalomania and the male sex. 5. The significant correlation between erotomania and the female sex found in the "old" group could not be found in the "new" group. 6. Constancy and change of delusion is due to both sexes, differing in degree, in part contrarotating. 7. The decrease of "sex-specific" delusions (megalomania and erotomania) is due to the sex concerned. 8. With increasing age there is a reduction of delusion themes in group II: delusions of special descent, paranoid identity change, erotomania were not found after age 30. Querulant paranoia did not occur. In group I querulant paranoia did not appear before age 30. 9. There was a significant correlation between megalomania and the item "development in rural country". 10. In our material there was no correlation between delusion and intelligence and religious confession. 11. Paranoid ideas of hypochondriasis and persecution show changes in the thematics (organs, disease, means of persecution) subject to time. 12. A tendency to change of content of the main delusion is discussed.


Diagnosis of functional psychoses. Comparison of clinical and computerized classifications.

The results of a comparison between the clinical diagnoses of 115 probands with functional psychoses, made on the basis of careful clinical history-taking, interviewing and examinations, and those made by computerized evaluation (CATEGO) on the basis of the present state examination (PSE) were presented. The clinical diagnoses of the project psychiatrist and the provisional classification resulting from the application of the CATEGO program to the PSE symptom profiles were in an overall concordance of 82%. In a second step the 20 cases with differences in diagnoses were reevaluated on the basis of the full history and psychopathology and a syndrome checklist was completed. This reevaluation led to a practically full diagnostic agreement.


[Deanol in tardive dyskinesia: a double-blind study (author's transl)].

Tardive dyskinesia following long-term application of neuroleptics is resistant to treatment. According to the hypothesis of a relative central nervous system acetylcholine lack as the underlying mechanism 20 patients were treated with dimethylaminoethanol (Deanol) in a double-blind study. Deanol is known to be a direct precursor of intracerebral acetylcholine. For several reasons (which are discussed) the data of but 11 patients were statistically evaluated. The results suggest some therapeutic effect in some of the patients only (significant improvement of oral hyperkinesia).


[Hematopoietic  functions in hypokinesia].

Materials on the state of hemopoietic organs and peripheral blood of mice and rats kept under hypokinetic conditions for from 1 to 60 days are presented. The changes occurring in the lymphoid tissue (involution of thymo-lymphatic apparatus, lymphopenia and neutrophilosis) have been shown to result from the state of stress. In the bone marrow of animals there occurs activation of erythropoiesis (erythroblasts-polychromatophilic normoblasts) at early (up to 15 days) term of hypokinesia, followed by its inhibition on the 60th day of the experiment. The study of kinetics of the amount of hemopoietic stem cells in the spleen and bone marrow of the femur of mice kept under hypokinesia for 1-45 days suggests the amount of stem cells in the spleen to decrease exponentially while in the bone marrow it changes undulatorily with the maximum on the 1st-3d and 30th-45th days of hypokinesia. Shifts in the number of the stem cell population are accompanied by changes in the direction of their differentiation. The stem cells of the bone marrow manifest higher potencies to form colonies of the erythroid type as compared with the stem cells of intact animals. Possible mechanisms underlying the inhibition of lymph-and erythropoiesis and changes of the stem cell differentiation from the myeloid way to the erythroid way under conditions of hypokinesia are discussed.


[Motion picture study of the temporal and geometric parameters of ethanol fixation of an isolated neuron].

The work has employed a combination of microscopic observation, filming and computer processing of the data obtained. The proper time, rate and latent period of fixation with ethanol of different concentration were analyzed in the isolated surviving neuron. The temporal parameters of fixation were shown to depend on the size of the neuron and the concentration of the fixator. The authors describe the regularities and distinctions in changes of large and small diameters as well as the volumes in vegetative neurons of different size in frog. An attempt has been made to consider the fixation not only as a momentary action but also as a prolonged-in-time complex morphological process.


[Individual anatomic variability of Forel's field H].

The investigation was performed in serial frontal sections of 100 preparations of the diencephalon and midbrain made 1 mm from one another. The shape of Forel H field was found to be very variable, changing from the rectangular to triangular shape in pararubralparts, and from oval to semioval-in prerubral parts. The size and position of Forel H field proved to change in relation to intracerebral reference points: posterior comissure, medial and intercomissural planes used in stereotaxical technique.


[Early stages of myocardial infarct studied by opitcal methods].

The hearts of 45 dogs were investigated at times from 10 minutes to 24 hours following ligation of the anterior interventricular branch of the left coronary artery. The material was fixed in formalin and embedded in parafin. It was established that at early stages of experimental myocardial infarction in the zone of eschemia there took place eschemic zone various foms of contactural damages, lumpy decmposition, relaxation and sarcoplasmic matrix. By the polarizing microscope method in the peripheral area of the eshemic zone various forms of contractural damages, lumpy decomposition, relaxation and desaggregation of myofibrills, were noted. Phaso-contrast and interference microscopy investigations revealed in the damaged cells an induration of the sarcoplasmic matrix due to an increase in the dry matter concentration. The studies conducted with the help of polarizing, phaso-contrast, and interference microscopy methods showed that by using these methods it is possible at early periods to reveal the zone of myocardial infarction on stained and unstained preparations prepared by conventional methods.


[I.O. Siavtsillo--prominent pathologist of the Moscow school].

Summarized data on the life and scientific activity of physician I. O. Syavtsillo (1860-1907), a member of the Chair of General Pathology at the Faculty of Medicine, the Moscow University, a disciple of professor A. B. Fokht, are presented. The monographs by I. O. Syavtsillo (1887-1898) dedicated to the problem of odema are considered. The scientist's concepts concerning the role of hemodynamic changes and disorders of the nervous activity in pathogenesis of odematous states are set forth. Impairment of innervation of vessels, stimulation of vasodilators and vasoconstrictors in the development of odema are also considered. Results of the investigations carried out by I. O. Syavtsillo are collated with present-day findings.


Flavobacterium endophthalmitis following keratoplasty. Use of a tissue culture medium-stored cornea.

This case of Falvobacterium meningosepticum endophthalmitis in the immediate postoperative period following a penetrating keratoplasty represents the first known isolation of F meningosepticum from the eye and, also, our first encounter with bacterial endophthalmitis following keratoplasty. This case occurred soon after conversion from whole eye moist chamber storage to tissue culture storage (McCarey-Kaufman medium). This storage technique may predispose to development of postoperative endophthalmitis. We offer suggestions to minimize the possibility of such infection.


Reconstruction of the upper eyelid crease and fold.

For good cosmesis the upper eyelid creases and folds must be symmetric. The lid creases must be the same height above the upper lid margins. The skin below the crease must be smooth and firmly attached to the tarsus, or, in cases with a short tarsus, adherent to the short tarsus and levator muscle up to the crease. The skin above the crease must be loosely attached so that it forms symmetric folds over the crease. We have developed surgical procedures aimed at the following: (1) equalizing the upper lid creases and folds where they are asymmetric, (2) creating lid creases and folds where absent, as in Orientals, (3) removing excess unsightly skin folds, as in dermatochalasis, and (4) forming a lid fold by skin grafting where there is insufficient skin above the crease.


Silicone-loop repair of the torn canaliculus.

Internal splinting with silicone tubing is now a well-established principle of lacrimal canaliculus repair, but fixation of the tubing ends is often unsatisfactory. The use of an internal suture allows this tubing to be converted into a small, continuous loop that is inconspicuous, cannot be inadvertently pulled out, and can remain in position indefinitely.


McCarey-Kaufman technique of corneal storage before penetrating keratoplasties in rabbits. An evaluation.

The endothelial function of rabbit corneas stored in modified tissue culture medium (McCarey-Kaufman medium) for periods of 4, 8, or 12 days was studied after penetrating keratoplasty using the specular microscope and the response to temperature reversal. Our results indicate that rabbit donor corneas stored in McCarey-Kaufman (M-K) medium are suitable for penetrating keratoplasty after storage periods as long as 12 days. The limitations of using graft clarity or the morphologic appearance of the endothelium as an index of the success of a penetrating keratoplasty in the rabbit are discussed.


[History and present indications for corrective surgery of the acetabulum  in hip dysplasia (author's transl)].

F. König published the first shelf-operation above the dislocated femoral head, which could improve the function in 1891. In Europe only after 1920 the techniques of Spitzy and Lance grew popular and are still frequently performed with their different variations. Pelvic osteotomy with medialisation was published 25 years ago for special indications, some years later Salter's Innominate Osteotomy got very well known. Describing the history of these operations the actual indication for the different methods is analised.


[Mineral deposition in bone transplants and fracture callus of the mouse during healing (author's transl)].

85Sr uptake and ash-weights of the fracture callus of the tibia and of a heterotopic tibia graft in the same animal were measured in mice and followed up to 30 days after grafting and fracture. Growth and uptake of 85Sr was higher in the callus compared to the graft and reached a maximum at about 17 days post fracture. After this period 85Sr uptake of the callus decreased rapidly, whereas in the graft an initial increase of 85Sr uptake was followed by a slow decline after 17 days. Ash-weights of the grafts increased slightly up to day 11 und remained constant thereafter. A low 85Sr uptake of the uninjured tibia between days 2 and 4 post fracture compared to the data of the following period was assumed to be due to a transitory enhanced excretion of 85Sr along with Ca during this early period. Between 9 and 30 days the 85Sr uptake of the uninjured tibia remained unchanged. An influence of fracture repair or graft healing on the mineral uptake of the whole skeleton therefore cannot be confirmed by our data.


[Effect of ALS treatment in the uptake and release of 85sr by allogeneic bone transplants (author's transl)].

After a treatment of the recipients with antilymphocyte serum shortly before and after grafting of 85Sr uptake of bone grafts as well as the release of 85Sr from the grafted mineral was increased. The difference of these parameters between allogeneic grafts to untreated recipients and allogeneic grafts to ALS treated recipients was similar to that between allogeneic grafts in untreated recipients and syngeneic grafts. This finding indicates a marked improvement of mineral metabolism in allogeneic bone grafts by treatment with antilymphocyte serum.


Conservative face lift surgery.

Face lift surgery almost always is elective; and, because its purpose is to diminish aging problems, it most often is done in those who are aged. Local and general risks, therefore, should be minimized. Wide undermining dictates flaps dissected more deeply and wounds closed well short of the limits of stretch of skin. Less radical undermining described here produces much smaller total wounds, lessens hazards of hematoma, considerably shortens operative and anesthetic times, reduces risks to nerves and ducts, and allows snugger closures. Details of operative technique, including platysma plication, are demonstrated. Short- and long-term results are shown. They indicate improvement sufficient to justify expanded use of the suggested techniques, particularly in view of diminished morbidity and risks to the general condition of those in the older age group.


The bonded alumina crown. 1. The bonding of platinum to aluminous dental porcelain using tin oxide coatings.

A method has been evolved for bonding aluminous porcelain to pure platinum foil used for making porcelain crowns by the conventional 'tinner's joint' technique. It was found that good bonding was achieved when the platinum was coated with 0.2-2.0 mum of tin before firing on the porcelain. This paper describes experimental work for determining the optimum composition and thickness of the coating and the applicability of the technique to substrates other than platinum.


Sedation in dentistry.

A philosophy for the use of sedation and anxiety control in everyday dental practice is described. The need for greater education in basic sedation techniques is emphasized.


Heat treatment of cast restorations.

A survey of commercial dental laboratories in Brisbane indicates that hardening heat treatment of cast restorations, while not always prescribed by the dentist, is performed in most dental laboratories.


Mould-reaction with gypsum bonded refractory investments.

Three series of standard tensile test specimens were produced using the nickel-base Ticonium Premium  100 alloy cast into a gypsum-bonded investment. For the first series an average weight metal ingot was used and cast at the temperature determined by the sensing head of the casting machine. For the second series a larger ingot was used, whilst for the third an elevated casting temperature was employed. The degree of investment breakdown resulting from mould reaction was assessed visually and by sulphur determination.


A stucy of duplication variables related to partial denture castings.

A series of stone duplications of a standard impression die was produced, using a proprietary duplicating material, the various batches of which had been prepared differently. Two different sized duplicating vessels were also employed. The critical dimensions of the stone reproductions were compared with those of the original die. Specimens of each batch of duplicating material were tested to determine the degree of permanent deformation produced by a fixed strain and strain in compression.


The bonded alumina crown. 2. Construction using the twin foil technique.

A technique has been developed for making aluminous procelain crowns bonded to thin tin oxide coatings on platinum foil. These crowns require only very thin metal linings of less than 0.05 mm, thus reducing metal costs and considerably improving aesthetics. In addition, by using the "twin foil" technique, porcelain butt fits may be obtained without loss of fit.


Kidney transplantation.

Fifty patients per million per annum in Australia suffer from end stage renal failure and could be helped by dialysis and transplantation. At the present time, only half this number are being referred to renal units in Australia where we believe facilities are available to help all that could benefit from this treatment. This article discusses patient selection, the results and hazards of renal transplantation. As a result of this treatment programme, 50 per cent of patients can expect virtually a normal life with a kidney graft functioning five years or more.


Studies with the autotransplanted ovine pancreas: glucagon and insulin secretion.

Basic studies on the secretion of glucagon and insulin by the ovine pancreatic autotransplant in the neck are described. Of the 17 transplants in the series none failed to secrete glucagon and only three failed to secrete insulin in detectable amounts. The longest surviving transplant actively secreted both hormones 3 years after transplantation and five other transplants were functional and the animals healthy after 16 months. Exocrine secretion disappears shortly after transplantation. Sodium butyrate and alanine each promoted the secretion of both hormones by the transplant. Glucagon failed to promote insulin secretion by the transplant, although it apparently stimulated the ovine in situ pancreas. The immediate (presumably direct) effect of insulin was to inhibit transplant glucagon secretion. Hypoglycaemia induced by peripheral insulin administration failed to stimulate glucagon secretion by the transplant, although it did promote glucagon secretion by the ovine in situ pancreas. Heparin did not markedly suppress basal transplant secretion of either glucagon or insulin. Phasic response patterns occurred with both hormones during long butyrate perfusions, although first-phase responsiveness was not a constant feature. In one trial, first-phase responses fell off with repeated short butyrate infusions. Glucagon and insulin secretory patterns in response to butyrate were remarkably alike, suggesting a common mechanism. Loss of specific functions by the ovine pancreas after transplantation is discussed.


Studies on the zona pellucida of sheep ova: immune lysis and localization of antibodies in ova with, and without, zonae.

The susceptibility of fertilized sheep ova and oocytes, with and without zonae pellucidae, to lysis by complement plus antibodies in antisera raised against sheep ovaries, oocytes and sperm was examined in vitro. The presence of the zona reduced the proportion of ova lysed (8% v. 57%) and a large proportion of ova with zonae continued development in culture following exposure to antisera. Antisera to ovary and to oocytes lysed a higher proportion of ova than did antisera to sperm (51 and 56% v. 29%). There was no effect of age of fertilized ova (day 2, 4, 6; day 0 = day of oestrus) on susceptibility to lysis. Fluorescein-labelled antibodies from high-titre antisera to ovary and oocytes traversed the zona and attached to blastomeres. Following absorption of the antibody conjugates with sheep serum, fluorescein staining of ova with intact zonae was confined to the zona, whereas with zona-free ova the blastomeres were stained. It appears that the zona may protect embryos from lytic antibodies and it is suggested that the zona may be important in protecting the embryo from immunological attack in vivo.


Studies on the origin of false positive reactions to the complement-fixation test for contagious bovine pleuropneumonia.

Serums of cattle free from contagious bovine pleuropneumonia (CBPP) were tested in complement fixation (CF) tests using 3 antigens; these were the standard antigen (SA) used to test to CBPP in Australia, an ethanol extract antigen (EA) also prepared from Mycoplasma mycoides subsp. mycoides (M. mycoides) and an antigen prepared from a Group 7 bovine mycoplasma isolated from arthritis (AA). The serums included 146 which fixed complement with SA. Eighty percent of these false-positive serums reacted with AA but not with EA; the other 20% were positive at low titre with EA but gave no reaction with AA. Attempts were made to produce false-positive serums experimentally by inoculating 3 Group 7 mycoplasmas and 2 Mycoplasma bovigenitalium strains into cattle. Serums from 3 of 9 cattle inoculated with strain L2917 (Group 7) reacted with SA but differed from the false-positive serums of field cattle by reacting with all 3 antigens. Tests with serums from cattle experimentally infected with CBPP gave similar titres with SA and EA, but the results with AA were mostly negative or less than 10% of the titres obtained with SA and EA. The results of CF tests on serums from the experimental cattle, after absorptions with suspensions of the mycoplasmas, showed that there was a one-way serological relationship between strain L2917 and M. mycoides and between this Group 7 strain and M. bovigenitalium. The CF tests with 3 antigens have assisted in demonstrating the false-positive nature of the reacting field serums encountered in the course of routine CF tests for CBPP in cattle in Australia.


Prevention of experimental motion sickness by scopolamine absorbed through the skin.

A double-blind placebo-controlled study compared the efficacy of the antimotion sickness drug scopolamine when administered by oral or transdermal routes. A secondary purpose was to extend our bioassay involving fixed-dose combinations of the homergic drugs promethazine and ephedrine. After receiving 12 apparently identical drug-placebo treatments, eight normal male students were exposed to a slow rotation room to stressful accelerations generated by their execution of 40 head movements out of the plane of the room's rotation of 1 rpm and at 1-rpm increments until either symptoms were experienced (just short of frank motion sickness) or the 27-rpm ceiling on the test was reached. Efficacy of a drug was defined in terms of the placeborange and categorized as beneficial, inconsequential, or detrimental. The rank order of drugs with beneficial effects was: 1) promethazine 25 mg plus ephedrine 12.5 mg (86%); 2) scopolamine by mouth (75%); 3) scopolamine transdermally (63%); and 4) promethazine 12.5 mg plus ephedrine 25 mg (29%). The only detrimental effect was with scopolamine given orally. It is concluded that the advantages of the transdermal scopolamine, which include minimal side effects and prolonged effectiveness, deserve full exploitation.


A review of evidence for a genetic component in the determination of handedness.

Experimental evidence is marshalled in support of some arguments for a significant genetic component in the transmission of human handedness. Studies of infantile lateral asymmetries and their correlation with cerebral dominance, certain highly heritable traits, and handedness are discussed.


Recent studies on the pathophysiology of ischemic cell injury.

We can summarize the results of our studies as follows (Fig. 15). The critical cellular factors involved in the loss of reversibility following ischemia appear to be the mechanisms involved in the membrane function of energy transduction. Irreversibility appears to correlate with an irrepairable defect in energy transduction. This could involve both the mitochondrial energy transduction functions and those in the plasma membrane. The mechanisms involved in this transition are not presently clear but they are associated with increased leakiness or permeability of these membranes accompanied by changes in lipid content, alterations in membrane proteins, and presumably in lipid-protein interactions. There are two prominent theories to explain energy transduction. These are the "proton pump" hypothesis of Mitchell (1972) and the "paired moving charge" hypothesis of Blondin and Green (1975). Both of these hypotheses require integrated function of membrane components, i.e., lipid and protein. The hypothesis of Blondin and Green, however, can work even with discontinuous membrane sheets because it involves the concept of ribbons of protein embedded in the protein-lipid membrane matrix. The characteristic finding of our studies following ischemic injury, namely, the continuous electron flow well into the irreversible phase while the energy transduction is impaired, could be explained by both hypotheses. What do these observations have to say about theories of energy conservation? We have observed that the vectorial nature of the proton separation is stopped. Charge separation may not occur at this time across the membrane since proton gradient and possible membrane potential are abolished. Electron transport, however, continues indicating the generation of protons. Since the decline of P/O ratio, decline of proton gradient and the cellular "point-of-no-return" coincide, these observations point toward the important membrane defects acquired at that particular time. The "paired moving charge" model which involves moving ions encapsulated in endogenous ionophores such as lecithin and maintenance of magnesium is favpred by the observation that phosphatidyl choline and phosphatidyl ethanolamine are lost in correlation with irreversibility. Furthermore, the decrease in magnesium content of cells is closely associated with the loss of viability following ischemia. The "paired moving charge" hypothesis has the attractive feature in that it involves antagonistic effects of calcium and magnesium. During reflow, calcium may inhibit magnesium mediated transport of inorganic phosphate by lecithin. Also, according to this theory fatty acids or their cyclic anions which act as uncouplers may foster the loss of phosphorylation capacity.


Chemical carcinogenesis and experimental models using human tissues.

The majority of human cancer is caused by environmental agents including chemical carcinogens. These chemical carcinogens are both naturally-occurring compounds and products of an industrialized society. Most of the environmental chemical carcinogens require enzymatic activation into electrophilic metabolites which readily react with cellular macromolecules leading, in some cases, to malignant transformation of target epithelial cells. Model systems for studying carcinogenesis in human target tissues are being developed to link investigations using experimental animals with human cancer. Metabolism of chemical carcinogens is being studied in human tissues maintained in these model systems. For example, a marked variation among individuals in their capacity to metabolize carcinogenic polynuclear aromatic hydrocarbons has been observed. This inter-individual variation may, in part, be due to genetic factors. Model systems using human tissues should be useful in several areas of cancer research including: 1) identifying environmental carcinogens, their metabolic pathways and host factors determining susceptibility; and 2) testing new methods of prophylatic intervention in populations at high risk of developing cancer.


Immunofluorescent localisation of cathepsin D in trophoblastic cells in tissue culture.

Cathepsin D was localised by immunofluorescence within four different types of cells derived from human trophoblast in monolayer culture. Cells were stained with freshly reduced Fab' fragments of sheep anti-(human cathepsin D) antiserum followed by FITC conjugate of pig anti-(sheep Fab') Fab' fragments. The green fluorescence seen in cytoplasmic droplets were characteristic of the appearance of lysosomes in other cells.


[The significance of the columar structure of the stratum corneum for the effect of light on the skin].

Autologous full thickness skin autografts were carried out on 60 male guineapigs in such a way that the hair roots were destroyed. The light sensitivity of the skin towards UV B was then tested on the hairless skin by means of the Xenon lamp and the corresponding filter. Exploratory excisions were taken from another area of the graft and used to demonstrate the structure of the stratum corneum according to the method of Christophers. It could be shown that light erythema developed significantly less than when the columnar structure of the stratum cornuem was well developed.


Multiple diagnostic measures elicited during the stress ballistocardiogram.

Acceleration Bcgs were recorded on 22 subjects at rest and during acute elevation of blood pressure produced by isometric grip. Measurements on computer averaged graphic waveforms of H/I slope, I/J slope and I-J amplitude were made. The ratios of values during stress, to resting state, helped to select patients with 1,2 or 3 declines of 10% or more from the resting values. The method has the advantage of using each subject as his own control, and may help to elicit varying grades of myocardial pumping dysfunction not evident at rest.


Automatic determination of systolic time intervals.

Systolic time intervals (STI), measured non-invasively and during uninterrupted exercise, may contain information about cardiac function. A processing system was developed, which determines STI automatically from 8-sec recordings at each load level. A preprocessing unit provides automatic recording and optimal signal-to-noise ratios. One of the main tasks of the computer program, which is modular in structure and written in FORTRAN IV, is to recognize disturbances and artefacts in the signals. After selection of the complexes, usually with some kind of correlation method, a representative beat is found and the inclination points are localized. Besides these points, indicateions of possible errors are given. Preliminary results indicate that the system may be able to replace the human observer in estimating STI.


Characterization of upFc, a fragment of human immunoglobulin G1 produced by pepsin in urea.

The digestion of human IgG1/K myeloma proteins with pepsin in the presence of 8 M-urea produces fragments that differ from those produced by aqueous peptic digestion, and from other characteristic immunoglobulin fragments. Fb'2, the larger urea/pepsin fragment, was previously shown to consist of the constant regions of the light chains, and the CH1 domains and hinge regions of the heavy chains. The smaller fragment, upFc, has now been characterized. After reduction, three peptides were released from fragment upFc. Amino acid sequencing, N- and C-terminal determinations and amino acid compositions have enabled these peptides to be identified as residues Ile-253 to Leu-306, residues Thr-307 to Asp-376 and residues Thr-411 to Gly-446 of the heavy chain. Fragment upFc therefore contains the entire Fc region, beginning at residue Ile-253, except for a 34-residue section from within the CH3-domain disulphide loop. Peptic digestion of IgG1/K proteins in 8M-urea therefore provides a method for isolating from gamma1 heavy chains five homogeneous peptides in good yield, which account for almost the entire constant region. Characterization of fragments Fb'2 and upFc has shown that the action of pepsin in urea is entirely different from that of aqueous pepsin. Two gamma1 heavy chains have been shown to differ in sequence at three positions from the sequence reported for protein Eu.


An apparent lack of stereospecificity in the reaction catalysed by deoxyribose 5-phosphate aldolase due to methyl-group rotation and enolization before product release.

In the reaction catalysed by deoxyribose 5-phosphate aldolase (2-deoxy-D-ribose 5-phosphate acetaldehyde-lyase, EC 4.1.2.4) from Salmonella typhimurium, almost complete equilibration of the methyl-group protons of the product, acetaldehyde, occurs before its release from the enzyme surface. This phenomenon does not allow the stereo-chemical course of the reaction to be determined by using hydrogen-isotope labelling of the methyl group to generate a chiral centre.


A trypsin and chymotrypsin inhibitor from chick peas (Cicer arietinum).

1. A trypsin and chymotrypsin inhibitor was isolated by extraction of chick-pea meal at pH8.3, followed by (NH4)2SO4 precipitation and successive column chromatography on CM-cellulose and calcium phosphate (hydroxyapatite). 2. The inhibitor was pure by polyacrylamide-gel and cellulose acetate electrophoresis and by isoelectric focusing in polyacrylamide gels. 3. The inhibitor had a molecular weight of approx. 10000 as determined by ultracentrifugation and by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. A molecular weight of 8300 was resolved from its amino acid composition. 4. The inhibitor formed complexes with trypsin and chymotrypsin at molar ratios of 1:1. 5. Limited proteolysis of the inhibitor with trypsin at pH3.75 resulted in hydrolysis of a single-Lys-X-bond and in consequent loss of 85% of the trypsin inhibitory activity and 60% of the chymotrypsin inhibitory activity. Limited proteolysis of the inhibitor with chymotrypsin at pH3.75 resulted in hydrolysis of a single-Tyr-X-bond and in consequent loss of 70% of the trypsin inhibitory activity and in complete loss of the chymotrypsin inhibitory activity. 6. Cleavage of the inhibitor with CNBr followed by pepsin and consequent separation of the products on a Bio Gel P-10 column, yielded two active fragments, A and B. Fragment A inhibited trypsin but not chymotrypsin, and fragment B inhibited chymotrypsin but not trypsin. The specific trypsin inhibitory activity, on a molar ratio, of fragment A was twice that of the native inhibitor, suggesting the unmasking of another trypsin inhibitory site as a result of the cleavage. On the other hand, the specific chymotrypsin inhibitory activity of fragment B was about one-half of that of the native inhibitor, indicating the occurrence of a possible conformational change.


Polyamine and ornithine metabolism during the germination of conidia of Aspergillus nidulans.

1. The activities of ornithine decarboxylase, S-adenosylmethionine decarboxylase and ornithine-2-oxoglutarate aminotransferase were studied during the first 24 h of conidial germination in Aspergillus nidulans. 2. Increases (over 100-fold) in the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase occurred during the emergence of the germ-tube and before the doubling of DNA and this was followed by a sharp fall in the activities of both enzymes by 16h. 3. The increase in ornithine decarboxylase could be largely suppressed if 0.6 mM-putrescine was added to the growth medium. 4. Low concentrations of cycloheximide, which delayed germination by 2h, caused a corresponding delay in the changes in ornithine decarboxylase activity. 5. Ornithine-2-oxoglutarate aminotransferase activity increased steadily during the first 24h of germination. 6. Ornithine or arginine in the growth medium induced higher activity of ornithine-2-oxoglutarate aminotransferase, but did not affect ornithine decarboxylase activity. 7. The significance of these enzyme changes during germination is discussed.


The formation of exchangeable sulphite from adenosine 3'-phosphate 5'-sulphatophosphate in yeast.

A new low-molecular-weight bound sulphite was found in yeast enzyme reaction systems which convert the sulphur of 35S-labelled adenosine 3'-phosphate 5'-sulphatophosphate into exchangeable radioactive sulphite. This bound sulphite was separated from other components by paper electrophoresis and Sephadex G-25 chromatography, and shown to be a peptide with multiple thiol groups and an estimated mol.wt. of 1400. The labelled sulphur in this peptide is highly exchangeable with unlabelled sulphite, but exchangeability decreases with time and freeze-drying. The low-molecular-weight acceptor is tightly bound to enzyme B of the yeast system and, apparently, accepts the sulpho group of adenosine 3'-phosphate 5'-sulphatophosphate and is released as bound sulphite only in the presence of enzymically or chemically reduced fraction C. It is proposed that the low-molecular-weight acceptor is a carrier peptide which, after release of the reduced sulphur, becomes re-oxidized and returns to enzyme B. Fraction C appears to function as an obligatory reductant of the oxidized acceptor before it can accept another-SO-3-moiety from adenosine 3'-phosphate 5'-sulphatophosphate. These findings are consistent with mechanisms proposed for sulphate reduction in spinach and Chlorella, and suggest that fraction C is the natural thiol required in these systems. An improved column technique for the preparation of adenosine 3'-phosphate 5'-sulphatophosphate is described.


The composition of an unusual precursor of 50 S ribosomes in a mutant of Escherichia coli.

Escherichia coli strain 15--28 is a mutant which during exponential growth contains large amounts of a '47S' ribonucleoprotein precursor to 50S ribosomes. The '47S particles' are more sensitive to ribonuclease than are 50S ribosomes. The 23 S RNA of 47S particles may be slightly undermethylated, but cannot be distinguished from the 23S RNA of 50S ribosomes by sedimentation or electrophoresis. Isolated particles have 10--15% less protein than do 50S ribosomes; proteins L16, L28 and L33 are absent. Comparison with precursor particles studied by other workers in wild-type strains of E. coli suggests that the assembly of 50S ribosomes in strain 15--28 is atypical.