PubMed Health⌕ Search

Biomedical subjects

R D Meyer

Publications and source records attributed to R D Meyer.

At least 91 records · Page 5Linked to original sources
PubMed1983

Glycerol-3-phosphate dehydrogenase is induced by glucocorticoids in hepatocytes and hepatoma cells in vitro.

Previous studies have shown that cytosolic glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8) can be induced by glucocorticoids in mammalian brain, mammary gland, and thymus, but it was thought that no induction occurred in liver. We report here that GPDH is induced by glucocorticoids in several lines of hepatoma cells and in rat hepatocytes cultured in vitro. When rat hepatoma cells of clone FU5AH were exposed to 3 microM hydrocortisone (HC) for 3 days, GPDH specific activity increased greater than sixfold over control. The rate and extent of induction were similar in exponentially growing and stationary-phase cultures of cells. Four other hepatoma cell lines were inducible to a lesser extent, and three lines were not inducible. GPDH was also induced by glucocorticoids in cultures of hepatocytes isolated from livers of 6-day-old rats. The enzyme was induced three-to fourfold by the synthetic glucocorticoid, dexamethasone, in the presence of 1 nM insulin, but the induction was not observed in the absence of insulin.

Adrenalectomy↗
PubMed1983

In vitro activity of newer beta-lactam agents in combination with amikacin against Pseudomonas aeruginosa, Klebsiella pneumoniae, and Serratia marcescens.

The in vitro activity of cefoperazone, ceftazidime, ceftizoxime, moxalactam, and N-formimidoyl thienamycin was evaluated alone and in combination with amikacin to assess possible synergistic activity against isolates of amikacin-resistant Pseudomonas aeruginosa and multidrug-resistant Serratia marcescens and Klebsiella pneumoniae susceptible to amikacin (one S. marcescens isolate was also resistant to amikacin). The checkerboard agar dilution method was used. Ceftazidime and thienamycin followed by moxalactam and cefoperazone were the most active agents versus the P. aeruginosa alone and in combination testing. Ceftazidime, moxalactam, and thienamycin showed the greatest activity against S. marcescens, and all agents except cefoperazone were active against K. pneumoniae. The finding of synergy or partial synergy in combination testing was found in the majority with all three genera, including levels below the breakpoint for both amikacin and the beta-lactam agents. This wide in vitro activity indicates that clinical evaluation of these agents in treatment of multidrug-resistant infections is warranted.

Amikacin↗
PubMed1982

In vitro susceptibility of cephalothin-resistant Enterobacteriaceae and Pseudomonas aeruginosa to Amikacin and selected new beta-lactam agents.

Amikacin was evaluated in vitro by agar dilution testing against 148 different clinical isolates of cephalothin-resistant Enterobacteriaceae and Pseudomonas aeruginosa in parallel with cephalothin, cefoxitin, moxalactam, N-formimidoyl thienamycin, ceftriaxone, and cefmenoxime. Cefsulodin was also evaluated against 39 isolates of P. aeruginosa. More than 80% of all isolates tested were also gentamicin resistant, as determined by disk testing. Moxalactam and amikacin had comparable high activities against Proteus species, Escherichia coli, Serratia species, and Providencia species, and both amikacin and N-formimidoyl thienamycin had comparably high activities against the Klebsiella-Enterobacter group. N-Formimidoyl thienamycin was the most active agent against P. aeruginosa, followed by cefsulodin and amikacin.

Amikacin↗
PubMed1982

Clinical evaluation of moxalactam.

Moxalactam was administered intravenously or intramuscularly or both in doses of 1 to 12 g/day to 45 patients with clinically significant infections (17 soft tissue or bone, 9 pleuropulmonary, 9 septicemic, 6 urinary tract, and 4 intraabdominal infections). Mean 0.5-h postinfusion levels were 105 micrograms/ml for a 4.0-g dose, 44.7 micrograms/ml for a 2.0-g dose, and 18 micrograms/ml for a 1.0-g dose. We identified 28 isolates of Enterobacteriaceae, 10 Pseudomonas aeruginosa isolates, 9 Staphylococcus aureus isolates, and 15 anaerobic bacterial isolates. A total of 15 patients were clinically cured, 8 patients improved, 13 patients improved initially but suffered subsequent relapses or superinfections, and 10 patients failed therapy. Toxicity was generally minimal (reversible eosinophilia, and mild liver function abnormalities, and elevated prothrombin time). The selection or emergence of resistant organisms in 17 patients during treatment (particularly Pseudomonas, enterococci, and Candida) was a disturbing feature of therapy. Our results were generally favorable, considering the complicated underlying medical problems of this group of patients.

Adult↗
PubMed1982

Susceptibility of Legionella spp. to mycinamicin I and II and other macrolide antibiotics: effects of media composition and origin of organisms.

Thirty-three strains of Legionella spp., 29 of which were L. pneumophila, were tested for their susceptibilities to erythromycin (EM), rosaramicin, tylosin, mycinamicin I (Sch-27897), and mycinamicin II (Sch-27896). Testing was performed using an agar dilution method with two different types of media: buffered charcoal yeast extract medium supplemented with 0.1% alpha-ketoglutarate (BCYE alpha) and filter-sterilized yeast extract medium with 0.1% alpha-ketoglutarate (BYE alpha). The minimal inhibitory concentrations (MICs) of the drugs tested relative to the MICs of erythromycin were: rosaramicin, MIC approximately equal to 0.2 EM MIC; tylosin, MIC approximately equal to 2 EM MIC; mycinamicin I, MIC approximately equal to 0.5 EM MIC; and mycinamicin II, MIC approximately equal to EM MIC. Both types of media caused equivalent partial inactivation of the macrolides which was apparently due entirely to pH effect. MICs on BCYE alpha were one to five times more than those observed on BYE alpha; this may be due to poorer growth on BYE alpha.

Anti-Bacterial Agents↗
PubMed1981

Revision of the first web space: technics and results.

Between 1975 and 1980, 91 patients in our series with involvement of 103 webs had revision of a contracted first web space. The five main causes of impairment were burns, trauma, congenital defects, cerebral palsy, and cerebrovascular accident. Technics used were simple Z-plasty; four-flap Z-plasty; modified double-opposing Z-plasty; and rotational flaps from the dorsum of the thumb, index finger, or hand. No pedicled, tubed, or distant flaps were needed. Simple Z-plasty was sufficient for increases to 1 cm; for greater increases a modified double-opposing Z-plasty or local rotational flap was necessary. The modified double-opposing Z gave excellent depth. Release of all contracting elements and addition of sufficient supple skin to the web are required for success.

Burns↗
PubMed1981

Long-term followup of two patients with pulmonary cavitation caused by Legionella pneumophila.

Two patients with cavitary pneumonia caused by Legionella pneumophila were followed by several months. Both patients had positive sputum cultures for L. pneumophila; one patient had positive respiratory tract cultures for 18 days after initiation of erythromycin. Slow resolution of the cavities occurred in both patients after 1 to 2 months of antimicrobial therapy.

Fluorescent Antibody Technique↗
PubMed1981

Isolation of Legionella pneumophila from hospital shower heads.

Legionella pneumophila serogroup 6 was isolated from nine of 16 shower heads in a Chicago hospital ward where three patients had contracted Legionnaires' disease caused by serogroup 6 L. pneumophila. Each patient had showered there 2 to 10 days before the onset of disease symptoms. We also isolated the bacteria in two other hospitals, and found the same serogroups as had been causing Legionnaires' disease in those hospitals: serogroup 1 in Pittsburgh and serogroups 1 and 4 in Los Angeles. However, showers from hospital wards where no patients had contracted Legionnaires' disease also yielded L. pneumophila. Shower heads at the Chicago hospital were sterilized with ethylene oxide but rapidly became recontaminated, suggesting that the potable water at these hospitals may have contained the organism. The question of whether aerosols of shower water or other exposures to potable water containing L. pneumophila may cause nosocomial Legionnaires' disease has not been resolved but deserves further study.

Baths↗
PubMed1981

Amikacin.

Explore the source record for details and available documents.

Amikacin↗
PubMed1981

Coccidioidal meningitis. An analysis of thirty-one cases and review of the literature.

Clinical and laboratory features of 31 patients with coccidioidal meningitis seen from January 1964 through December 1976 with follow-up through 1979 are reported and data on 114 patients from the literature reviewed. History of exposure to C. immitis, a wide age range, and, in about one third, underlying conditions are noteworthy. Dissemination to the meninges usually occurs within the first few months although diagnosis is frequently delayed. Presenting symptoms and signs of coccidioidal meningitis are varied but signs of chronic meningitis or suggestion of hydrocephalus are prominent. Evidence of acute infection is unusual even with widespread disease. Diagnosis is usually made by demonstration of coccidioidal CF antibodies in the CSF although they are not found in all patients. Some show other direct evidence of C. immitis. Special diagnostic techniques such as CAT scanning for evidence of basilar meningitis or hydrocephalus are valuable. Amphotericin B remains the drug of choice despite the need for long-term therapy and the problems with intrathecal administration. Reservoirs are only occasionally useful but shunts are frequently lifesaving despite complications. Factors associated with a bad prognosis are hydrocephalus, non-Caucasian race, or presence of an underlying disease.

Adolescent↗
PubMed1980

Induction of both rat and mouse lactate dehydrogenase in hybrids between inducible rat glioma and uninducible mouse neuroblastoma cells.

The specific activity of lactate dehydrogenase (LDH; EC 1.1.1.27) is induced two-fold by l-norepinephrine (NE) in C6TK- rat glioma cells, but not in NA mouse neuroblastoma cells or various other nonglial cells. Previous reports have shown that the induction is mediated by cyclic AMP (cAMP) and possibly protein phosphorylation, and that it requires RNA and protein synthesis. To study the block to LDH induction in nonglial cells, we hybridized C6TK- cells with NA cells and isolated a hybrid clone in which LDH is inducible by NE. Mouse and rat LDH from hybrid cells were separated by electrophoresis and quantitated by two independent methods, and it was found that mouse and rat LDH were induced equally when cells were exposed to NE. The results suggest that inducibility of LDH is not determined by a cis-acting control at the gene level, but rather by the presence or absence of an earlier component in the cAMP-mediated induction system, and that the induction system acts indiscriminately on all active LDH gene copies in the cell.

Animals↗
PubMed1980

Immunologic diagnosis of Legionnaires' disease: cross-reactions with anaerobic and microaerophilic organisms and infections caused by them.

The hundred twenty-four isolates of anaerobic and microaerophilis organisms were examined with a polyvalent direct immunofluorescent antibody (DFA) reagent directed against Legionella pneumophila, serogroups (SG) I-IV. Three of 53 isolates of Bacteroides fragilis cross-reated with the SG I component of the reagent. Rabbit antisera to three SG I strains of L. pneumophila cross-reacted with these three B. fragilis isolates, and cross-reactivity was not due to preexisting rabbit antibodies; antisera to a fourth SG I strain did not cross-react with these isolates. Indirect fluorescent antibody (IFA) examinations of convalescent-phase sera from eight of 41 patients with B. fragilis group infections showed titers of greater than or equal to 1:128 or a fourfold or greater seroconversion against L. pneumophila, SG I. All eight patients had bacteremia due to B. fragilis, but five B. fragilis isolates available from these patients were DFA-negative. Thus, false-positive reactions may result from DFA as well as IFA examinations of sera from patients with B. fragilis infections.

Aerobiosis↗