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1.  Prevention of Herpes Keratoconjunctivitis in Rabbits By Silver Sulfadiazine 
Silver sulfadiazine, at a concentration of 10 μg/ml when applied immediately after infection by Herpesvirus hominis, prevented the development of acute herpetic keratoconjunctivitis in rabbits. The efficacy was inversely related to the size of inoculum. Subclinical infections were observed in the drug-treated eyes.
PMCID: PMC429446  PMID: 1211919
2.  Comparison of Cefoxitin and Cephalothin Therapy of a Mixed Bacteroides fragilis and Fusobacterium necrophorum Infection in Mice 
Cefoxitin, a β-lactamase-resistant cephalosporin, was found to be more effective than cephalothin against an experimental mixed infection containing Bacteroides fragilis and Fusobacterium necrophorum.
PMCID: PMC429293  PMID: 1180547
3.  In Vitro Studies with Combinations of 5-Fluorocytosine and Amphotericin B 
Synergistic antifungal activity of 5-fluorocytosine (5-FC) and amphotericin B was studied using an abbreviated checkerboard titration scheme. 5-FC was titrated in twofold increments (100 to 0.05 μg/ml) in the absence and presence of graded increments of amphotericin B (1.0. 0.5, 0.1, 0.05, and 0.01 μg/ml) in buffered yeast nitrogen base. A limited number of experiments were performed using expanded dual titration checkerboard schemes and growth curve studies. Forty-eight isolates of yeastlike organisms were tested; two were inhibited by the buffer system. Evidence of synergy, as indicated by a fourfold or greater reduction of the minimal inhibitory concentration of 5-FC in the presence of subinhibitory concentrations of amphotericin B, was seen with 11 of 46 isolates, or 24%, at the fungistatic level and with three isolates, or 7% at the fungicidal level. Indifferent results were obtained for 44 and 74% of the isolates, respectively, at the fungistatic and fungicidal levels. Antagonism was observed with three isolates.
PMCID: PMC429277  PMID: 1101814
4.  Double-Blind Comparison of Phlebitis Produced by Cefazolin Versus Cephalothin 
In a double-blind study with each patient as his own control, 1 g of cefazolin and 2 g of cephalothin were administered intravenously every 6 h to 20 patients in opposite arms for a period of 48 h each. The degree of phlebitis was significantly more severe with cephalothin than with cefazolin (P < 0.05); however, neither the incidence of phlebitis nor the time of onset of phlebitis was significantly different between the two drugs.
PMCID: PMC429165  PMID: 1147583
5.  In Vitro Activity of Cinoxacin, an Organic Acid Antibacterial 
The activity of cinoxacin, a synthetic organic acid antimicrobial agent, was studied and found to have in vitro activity similar to that previously reported for nalidixic acid.
PMCID: PMC429140  PMID: 1137390
6.  Differences in Susceptibility of Enterobacteriaceae and Penicillin-Resistant Staphylococcus aureus to Tetracycline and Minocycline 
Two hundred strains of penicillin-resistant Staphylococcus aureus and 311 isolates of Enterobacteriaceae were compared for their susceptibility to tetracycline and minocycline. Thirteen and one-half percent of the staphylococcal isolates were resistant to tetracycline but susceptible to minocycline. Similarly, 24% of the enterobacterial isolates were found to be tetracycline resistant but susceptible to minocycline. Of a total of 511 recent clinical isolates, 14.5% were susceptible to minocycline but were tetracycline resistant.
PMCID: PMC429115  PMID: 1040464
7.  Simple Technique for the Assay of Antibiotic Synergism Against Enterococci 
A simple technique with antibiotic-impregnated disks has been developed to demonstrate the antibiotic synergism of penicillins and aminoglycosides against enterococci. The two antibiotic disks are placed on inoculated plates so that the distance between their centers is less than the sum of the two radii of their previously determined inhibitory zones. After 5 h of incubation, β-lactamase powder is dusted onto the susceptibility plate with a sterile cotton swab. After overnight incubation, the synergistic effect of the antibiotics is demonstrated by a clear area of no growth in between the two disks. There is good correlation between the synergism determined by this procedure and the susceptibility of the organisms to 2 mg of streptomycin per ml. This technique is simple and can be employed by any laboratory which performs Kirby-Bauer susceptibility procedures.
PMCID: PMC429077  PMID: 806260
8.  Properties of the Gentamicin Acetyltransferase Enzyme and Application to the Assay of Aminoglycoside Antibiotics 
The acetyltransferase technique of serum gentamicin assay was demonstrated to be specific for aminoglycoside antibiotics. The enzyme involved was isolated and stabilized by lyophilization.
PMCID: PMC429292  PMID: 1101816
9.  Triethyl-n-Hexylammonium Triethyl-n-Hexylboride: a New Antimicrobial Showing Activity Against Candida albicans and Gram-Positive Bacteria 
The organic salt triethyl-n-hexylammonium triethyl-n-hexylboride (N2226B2226) has biostatic effects against two gram-positive bacteria, Bacillus subtilis and Micrococcus luteus, and the yeast Candida albicans. Escherichia coli and chicken embryo fibroblasts grown in tissue culture are more refractory to this compound.
PMCID: PMC429384  PMID: 811160
10.  Viral Keratitis-Inhibitory Effect of 9-β-d-Arabinofuranosylhypoxanthine 5′-Monophosphate 
Topical application of 9-β-d-arabinofuranosylhypoxanthine 5′-monophosphate (ara-HxMP) significantly inhibited the development of keratitis induced by types 1 and 2 herpes simplex virus and vaccinia virus in the eyes of rabbits. Parameters for evaluation of efficacy were infectivity (corneal opacity, lesion size, and type), Draize (erythema, conjunctival swelling, and discharge), and reduction in titer of recoverable virus from the eye. When the relative efficacy of the related compounds 9-β-d-arabinofuranosyladenine (ara-A), ara-A 5′-monophosphate (ara-AMP), and ara-Hx was determined against type 1 herpes simplex virus in a parallel experiment, the more water-soluble compounds (ara-HxMP, ara-AMP) were the most effective. The relative efficacy of ara-A was also determined against type 2 herpes and vaccinia virus-induced keratitis. Mortality in rabbits due to central nervous system involvement caused by types 1 and 2 herpes simplex virus was inhibited. Ara-HxMP was not discernibly toxic to the eye at concentrations of at least 20%; efficacy was still discernible with a 0.1% solution.
PMCID: PMC429372  PMID: 1190753
11.  Enhancement by Nalidixic Acid of the Thermal Susceptibility of the Ts-7 Mutant of Escherichia Coli TAU-Bar 
Nadilidixic acid at 5 × 10−6 M produced a substantial increase in thermal susceptibility of Ts-7, suggesting either that the thermal and nalidixic acid targets are identical or closely interdependent.
PMCID: PMC429326  PMID: 1101825
12.  Antimicrobial Resistance of Shigella Isolated in New York City in 1973 
One hundred and two Shigella sonnei and fourteen S. flexneri strains isolated from individual patients in New York City hospitals were investigated for antibiotic resistance. The S. sonnei showed 60% resistance to ampicillin and 58% to tetracycline and streptomycin. S. flexneri showed no ampicillin resistance but 50% resistance to tetracycline. There were marked differences in resistance of S. sonnei between hospitals which were not explainable by ethnic or socio-economic differences in the patient populations.
PMCID: PMC429235  PMID: 1155925
13.  Artificial Elimination of Drug Resistance from Group A Beta-Hemolytic Streptococci 
Ten strains of beta-hemolytic streptococci were tested for elimination of resistance to macrolide antibiotics, tetracycline, and chloramphenicol. Six of the strains lost resistance after cultivation at 41 C or addition of acriflavine (0.2 μg/ml). These results suggest that determinants governing resistance to these antibiotics are located on extrachromosomal genetic elements (plasmids) that are widely distributed in streptococci.
PMCID: PMC429211  PMID: 1147599
14.  Effect of Actinomycin D and Oxygen on the Ribonucleic Acid Synthesis of an Anaerobic Gram-Negative Bacterium 
The synthesis of ribonucleic acid by whole cells of Bacteroides ruminicola is not sensitive to actinomycin D, but it is sensitive to actinomycin D in the presence of ethylenediaminetetraacetate. Ribonucleic acid synthesis by whole cells of this gram-negative anaerobic bacterium is also totally inhibited by oxygen.
PMCID: PMC429209  PMID: 1147598
15.  Comparison of Broth and Human Serum as the Diluent in the Serum Bactericidal Test 
The use of serum rather than broth as the diluent in the serum bactericidal test results in a significant decrease in the test level among patients receiving highly protein-bound semisynthetic penicillins.
PMCID: PMC429083  PMID: 1137355
16.  Antimicrobial Effect of Simple Lipids and the Effect of pH and Positive Ions 
Various branched fatty acids, particularly those of iso-configuration, have been shown to possess fungistatic and bacteriostatic properties. On the basis of their swelling effect on hyphae of Fusarium roseum it was suggested that this is due to an increase in the permeability of the plasma membrane. The solubilization of fatty acids in membranes should be expected to be influenced by the degree of dissociation and the presence of counter ions. Therefore, the effects of pH and K+, Na+, and Ca2+ ions were studied. It is demonstrated that the presence of the univalent ions, Na+ and K+, markedly enhances the fungistatic effect of iso-tetradecanoic acid, whereas the opposite effect is noted for the divalent ion, Ca2+. The effects are particularly pronounced at high pH. Furthermore, the antimicrobial effect obtained from the combination of fatty acid and tetramethylthiuramdisulfide is significantly enhanced in the presence of 0.1 and 0.2% KCl.
PMCID: PMC429455  PMID: 2099
17.  Prospective Double-Blind Evaluation of Topical Adenine Arabinoside in Male Herpes Progenitalis 
Thirty-four virologically proven episodes of herpes progenitalis in 32 men were treated in a prospective double-blind study with either adenine arabinoside ointment or an identical-appearing placebo for 7 days. Clinical evaluation and quantitative virological studies were done on days 1, 3, and 8. There was a highly significant correlation between clinical response and quantitative virology. There was no difference in clinical or virological response between drug and control groups. Primary attacks tended to have higher viral excretion over the period of observation. The level of complement-fixing antibody to herpes simplex virus type 2(<1:16 versus ≥1:16) in patients with recurrent disease did not appear to alter the course of viral excretion.
PMCID: PMC429450  PMID: 174489
18.  In Vitro Evaluation of a New Oral Cephalosporin, Cefatrizine (BL-S640) 
The activity of cefatrizine (BL-S640), a semisynthetic orally absorbed cephalosporin, was studied and found to have in vitro activity at least comparable to that previously reported for cephalexin.
PMCID: PMC429458  PMID: 813573
19.  Comparison of the Antiviral Effects of 5-Methoxymethyl-deoxyuridine with 5-Iododeoxyuridine, Cytosine Arabinoside, and Adenine Arabinoside 
The antiviral activity of 5-methoxymethyl-2′-deoxyuridine (MMUdR) was compared with that of 5-iodo-2′-deoxyuridine (IUdR), cytosine arabinoside (Ara-C), and adenine arabinoside (Ara-A). At concentrations of 2 to 4 μg/ml, MMUdR was inhibitory to herpes simplex virus type 1, but concentrations as high as 128 μg/ml were not inhibitory to three other herpesviruses tested (equine rhinopneumonitis virus, murine cytomegalovirus, and feline rhinopneumonitis virus) or to vaccinia virus. The other nucleosides, in contrast, were inhibitory at similar concentrations (1 to 8 μg/ml) against all viruses tested. The inhibition of HSV-1 by MMUdR appeared to be the result of interference with virus replication rather than the result of drug toxicity to host cells. The drug was not toxic to host cells at 100 times the antiviral concentrations, and pretreatment of host cells with high concentrations of MMUdR had no effect on subsequent virus replication. Combination of MMUdR with either IUdR, Ara-A, or Ara-C gave an enhanced antiviral effect, suggesting that the mechanism of action of MMUdR is different from that of the other three drugs. Antiviral indexes were calculated for each compound and were found to be >250, 80, 40, and 8 for MMUdR, IUdR, Ara-A, and Ara-C, respectively. These were defined as the minimum dose at which toxicity was observed microscopically divided by the dose which reduced plaque numbers by 50%.
PMCID: PMC429441  PMID: 1239978
20.  Stability of Frozen Rat Plasma Containing Different Antibiotics 
The antibiotic activity was determined at different intervals of time on plasma samples, taken from rats treated with a certain number of commonly used antibiotics, and kept at −20 C up to 8 weeks. The results of the microbiological assays demonstrate that the stability of the antibiotics in the frozen plasma decreases in the following order: oxytetracycline > cephalexin, streptomycin, erythromycin > demeclocycline > ampicillin, amoxycillin > penicillin G, cephaloridine, rolitetracycline, and tetracycline.
PMCID: PMC429439  PMID: 1211917
23.  Minimal Inhibitory Concentration of Dapsone for Mycobacterium leprae in Rats 
To define the minimal inhibitory concentration (MIC) of dapsone (DDS) for Mycobacterium leprae in rats, we determined the relationship between dietary and plasma levels of DDS in uninfected male and female Lewis rats. This knowledge was applied to the design of experiments using rats inoculated in the footpads with M. leprae. The MIC for DDS in male and female rats, respectively, was 1.5 to 4.0 ng and 1.8 to 3.0 ng of DDS/ml of plasma, even though the sexes exhibited markedly different concentrations of DDS when receiving the same dietary level of DDS. These values for the MIC of DDS for M. leprae in rats are nearly identical to the previously determined MIC of DDS for M. leprae in mice.
PMCID: PMC429419  PMID: 1108776
24.  Efficacy of 9-β-d-Arabinofuranosylhypoxanthine 5′-Monophosphate in Therapy of Equine Abortion Virus-Induced Hepatitis in Hamsters1 
Equine abortion virus (EAV)-induced hepatitis in hamsters presents an interesting animal model for the evaluation of drugs possessing anti-deoxyribonucleic acid virus activity. These experiments demonstrate that 9-β-d-arabinofuranosylhypoxanthine 5′-monophosphate (ara-HxMP), a new synthetic, water-soluble, antiviral agent, effectively controls this disease in hamsters with a therapeutic index of ∼60. Ara-HxMP prevented hepatitis-associated deaths in hamsters, reduced the titer of EAV developing in hamsters, and inhibited the increase of serum glutamic pyruvic transaminase in EAV-infected hamsters.
PMCID: PMC429375  PMID: 172009
25.  Inhibition of Experimental Deoxyribonucleic Acid Virus-Induced Encephalitis by 9-β-d-Arabinofuranosylhypoxanthine 5′-Monophosphate 
9-β-d-Arabinofuranosylhypoxanthine 5′-monophosphate (ara-HxMP) significantly controlled the development of encephalitis produced by deoxyribonucleic acid viruses in mice. In most experiments the activities of ara-HxMP and 9-β-d-arabinofuranosyladenine (ara-A) were determined simultaneously. In the intracerebral (target organ) and intravenous therapy experiments, ara-HxMP had a pronounced advantage over ara-A since the water solubility of ara-HxMP enabled it to be used in much higher concentrations. In experiments where the two drugs were administered intraperitoneally or orally they exhibited similar activity. In several intraperitoneal therapy experiments ara-HxMP was tested alone, using various treatment schedules and dosages. In these experiments, efficacy was observed in groups that had treatments initiated as late as 72 h after virus inoculation.
PMCID: PMC429374  PMID: 172008

Results 1-25 (297)