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Biomedical subjects

M E Levison

Publications and source records attributed to M E Levison.

At least 91 records · Page 5Linked to original sources
PubMed1977

Effect of aspirin on thrombogenesis and on production of experimental aortic valvular Streptococcus viridans endocarditis in rabbits.

Because thrombus formation at the site of endothelial injury has been thought to be a critical step in the pathogenesis of bacterial endocarditis, the effect of aspirin on experimental valvular thrombosis and bacterial endocarditis in rabbits was evaluated. Aortic valvular injury and thrombosis were induced in aspirin-treated and control rabbits with intracardiac catheters. A subsequent inoculation of Streptococcus viridans resulted in the development of infective endocarditis. Rabbits were sacrificed as early as 6 hr, and the effectiveness of aspirin was determined by the weight of the sterile vegetations and the quantitation of bacteria in the thrombotic vegetation. Aspirin, in levels in excess of 50 mg/dl did not attenuate the evolution of infective endocarditis, since the formation of sterile thrombotic vegetation and bacterial endocarditis in aspirin-treated rabbits was similar to those in controls.

Animals↗
PubMed1976

In vitro activity of josamycin and rosamicin against Bacteroides fragilis compared with clindamycin, erythromycin, and metronidazole.

The inhibitory and bactericidal activities of josamycin and rosamicin against 29 clinical isolates of Bacteroides fragilis were compared with those of clindamycin, erythromycin, and metronidazole by a broth dilution technique. Josamycin and rosamicin had similar inhibitory activity to metronidazole and clindamycin. Rosamicin had similar bactericidal activity to clindamycin but was less bactericidal than metronidazole (the most bactericidal agent tested). Josamycin was slightly more bactericidal than erythromycin (the least bactericidal agent tested), but less so than rosamicin and clindamycin.

Aminoglycosides↗
PubMed1976

A quantitative measurement of bacteremia and its relationship to plaque control.

Despite the improvement in the patients' oral hygiene, there was no significant decrease in the frequency of bacteremia. There was no significant difference in bacteremia between brushing, flossing, or deplaquing either before or after initial periodontal preparation and plaque control in 21 healthy subjects. Utilizing more sophisticated bacteriologic techniques for the cultivation of obligate anaerobes, a relatively high frequency of anaerobic bacteremia was found.

Bacteria↗
PubMed1976

Effect of indomethacin and sodium meclofenamate on the renal concentrating defect in experimental enterococcal pyelonephritis in rats.

The present studies have confirmed a severe urinary concentrating defect early in the course of experimental enterococcal pyelonephritis. This defect in maximum concentrating ability was almost completely reversed immediately following indomethacin or sodium meclofenamate intravenously. This effect of indomethacin and sodium meclofenamate was transient and was not associated with a fall in numbers of enterococci per gram of kidney. Injection of indomethacin or sodium meclofenamate in noninfected rats had no effect on maximum renal concentrating ability. The potential mechanisms by which indomethacin and sodium meclofenamate, inhibitors of renal prostaglandin synthesis, could reverse a defect in maximum urinary concentration are discussed.

Animals↗
PubMed1975

Sustained bacteremia and transvenous cardiac pacemakers.

Five patients with transvenous cardiac pacemakers had sustained staphylococcal bacteremia (defined as bacteremia for at least 12 hours) two weeks to ten months after pacemaker insertion. Three of the five patients had no evidence of an extravascular focus of infection at the time of stphylococcal bacteremia. An additional patient had a petechial rash, which is unusual in staphylococcal bacteremia, unless endocarditis is present. All patients were treated with antibiotics and drainage of the pacemaker packet when it was infected, removal of the pacemaker generator, or removal of the catheter electrode. One patient without evidence of pocket infection was treated successfully with antibiotic therapy alone.

Acute Disease↗
PubMed1975

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.

Adult↗
PubMed1975

Superiority of amphotericin over nystatin in Thayer-Martin medium.

Vaginal and cervical specimens taken for the detection of gonorrhea frequently contain Candida albicans. Thayer-Martin medium containing nystatin (VCTN) is unsatisfactory because nystatin fails to selectively inhibit C. albicans. Thayer-Martin medium containing no nystatin was prepared with varying concentrations of amphotericin (VCTA) added, and this latter medium was compared with VCTN for its ability to selectively inhibit varying numbers of C. albicans. The effect of amphotericin on the recovery of varying numbers of Neisseria gonorrhoeae was also studied. VCTN failed to inhibit 10(1) to 10(6)C. albicans. VCTA suppressed growth of up to 10(6)C. albicans. The optimal concentration of amphotericin B appeared to be 100 mug/ml. VCTA containing 100 mug of amphotericin B per ml (VCTA 100) was not inhibitory for N. gonorrhoeae when a dense population was applied with a replicator. However, it was slightly inhibitory when 10(1) to 10(2)N. gonorrhoeae were applied over the entire surface of an agar plate, although the colony count on VCTA 100 was more than 50% of the counts on chocolate agar and 75% of the counts on VCTN. These properties of VCTA 100, when stored at 4 C, were stable for up to 2 weeks.

Amphotericin B↗
PubMed1975

In vitro activity and pharmacokinetics in patients of cefamandole, a new cephalsoporin antibiotic.

Cefamandole nafate, a new cephalosporin for parenteral use, was evaluated in vitro against 231 recent clinical isolates and in 12 patients. Cefamandole had activity equivalent to cefazolin against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae. Cefamandole was more active than cephalothin or cefazolin against Proteus mirabilis. Both cefamandole and cefazolin were as active as cephalothin against S. aureus, were slightly more active against K. pneumoniae, and were considerably more active against E. coli. All strains of indole-positive Proteus sp. were inhibited by 6.3 mug of cefamandole per ml but only 20% were inhibited by 25 mug of cefazolin or cephalothin per ml. Eighty-eight percent of Enterobacter sp. was inhibited by 25 mug of cefamandole per ml, but only 20 and 5% were inhibited by the same concentration of cefazolin and cephalothin, respectively. Peak levels of cefamandole ranged from 6.0 to 110 mug/ml in serum and levels ranged from 440 to 16,800 mug/ml in a 4- to 6-h collection of urine after a 500-mg or 1-g intramuscular dose (6.1 to 17.3 mg/kg) in patients with endogenous creatinine clearances of >/=31 ml/min. These levels were done after the first dose, at mid-therapy, and at the end of therapy. There was no evidence of accumulation with the 500-mg or 1-g dose given every 4 to 6 h. The percentage of the dose excreted in the urine within the first 4 to 6 h after administration of cefamandole was >/=43%. The half-life of cefamandole in serum was 49 to 126 min.

Bacteria↗
PubMed1975

Experimental aspergillus endocarditis in rabbits.

Aspergillus endocarditis in man usually occurs on prosthetic cardiac valves and gives rise to large vegetations which embolize easily producing peripheral organ infarction and infection. Blood cultures are usually sterile and the disease is difficult to cure with antimicrobial agents. Aspergillus endocarditis was studied in rabbits to determine the course, degree of fungemia, and response to treatment with amphotericin B (A), 5 flucytosine (5 FC) or A + 5 FC. Polyethylene tubing was introduced into the left ventricle through the carotid artery and 24 hours later animals were inoculated with 10(4) to 10(7) spores of a strain of Aspergillus fumigatus. Large occlusive vegetations developed on the aortic valves. Spontaneous mortality reached 67 per cent after 3 days. Despite large aggregates of mycelia seen beneath a layer of amorphous material on microscopic sections, vegetations contained only 10(3) to 10(5) colony forming units (CFU) of aspergilli per gram, suggesting the aspergilli in tissues were clumped. Disseminated infection involving kidney, lung, liver, spleen, and brain occurred. Animals without intracardiac tubing which received the same inoculum of spores did not develop endocarditis, but showed evidence of disseminated infection. Blood after 24 hours of infection grew aspergilli only when large volumes were cultured and then only a small fraction of the total volume of blood obtained for culture yielded aspergilli, suggesting that the aspergilli in blood were clumped. Sterile vegetations in the absence of an intracardiac catheter were resistant to infection with aspergilli, but once established, infection with aspergilli persisted on vegetations despite removal of the catheter. Treatment of infected animals with A (1 mg. per kilogram), 5 FC (25 or 50 mg. per kilogram) or A + 5 FC daily intraperitoneally, significantly lowered the number of CFU per gram of vegetation.

Animals↗
PubMed1974

Treatment of anaerobic bacterial infections with clindamycin-2-phosphate.

Thirty-five patients with a variety of serious infections caused by anaerobic bacteria responded to clindamycin. Cure was achieved in 27 of the 32 patients with pleuropulmonary and intra-abdominal infections. Mean serum concentrations of clindamycin for the 8 h after intramuscular administration of clindamycin in these patients were at least 2.5 times the minimal inhibitory concentration of clindamycin for more than 90% of anaerobes. This experience suggests that clindamycin is an excellent and relatively safe antibiotic for treatment of infection caused by anaerobes when combined with surgery (when indicated) or other antibiotics active against aerobic gram-negative bacilli, if present.

Anaerobiosis↗
PubMed1974

Microbiological agar diffusion assay for metronidazole concentrations in serum.

An agar diffusion method using paper disks on plates seeded with Clostridium perfringens and incubated anaerobically to assay serum levels of metronidazole is described. The lowest serum metronidazole concentration that could be measured was 0.7 mug/ml, and the average error was 4% for 5 mug/ml. This assay could measure metronidazole in the presence of gentamicin or in the presence of penicillin, with the use of penicillinase incorporated into the assay plates, or in presence of penicillin, methicillin, and cephalothin with prior exposure of the specimen to beta-lactamase.

Adult↗
PubMed1974

Single-dose daily gentamicin therapy in urinary tract infection.

Patients with urinary tract infection were treated for 8 to 15 days with one daily intramuscular injection of 160 mg of gentamicin or 60 or 80 mg every 8 h. Ten of 11 patients treated with one injection daily were cured as compared with 8 of 10 patients treated with three injections daily. Urinary concentrations of gentamicin were 3.2 to 600 mug/ml in all 8-h collections in patients receiving one injection daily and were 22 to 440 mug/ml in all 8-h collections in patients receiving three injections daily. The group treated once daily demonstrated a significant but reversible increase in mean serum creatinine concentration and decrease in mean creatinine clearance during therapy as compared with no change in the group treated with three injections daily. Decreases in renal function were correlated with higher milligram per kilogram doses and higher 1-h serum concentrations.

Adult↗