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Biomedical subjects

D S Feingold

Publications and source records attributed to D S Feingold.

At least 73 records · Page 4Linked to original sources

Induction of colitis in hamsters by topical application of antibiotics.

Syrian hamsters are exquisitely sensitive to clindamycin; as little as 1 mg/kg of clindamycin given systemically causes a fatal colitis. Clindamycin and erythromycin were applied topically daily to the shaved backs of Syrian hamsters in a hydroalcoholic vehicle. A daily dose of 0.1 mg of clindamycin was lethal to more than half the hamsters and 1 mg to all the animals. The antibiotic-associated toxin from Clostridium difficile was present in their cecal material. Based on body surface areas and estimated usual volumes applied, the lethal dose in hamsters is not dissimilar to that given humans for acne. Oral tetracycline therapy protected the animals from clindamycin toxicity, but the animals died three days after stopping tetracycline if topical clindamycin applications were continued.

Administration, Topical↗

Dissociation between ion permeability and the lethal action of polyene antibiotics on Candida albicans.

Kinetic data on potassium release from and killing of Candida albicans by the four polyene antibiotics amphotericin B, amphotericin B methyl ester hydrochloride, nystatin, and nystatin methyl ester hydrochloride are presented. The nystatins were relatively more effective than the amphotericins in causing potassium release rather than killing. These data suggest that the aqueous channels or pores formed by the polyene antibiotics are not central to the lethal action of the drugs.

Amphotericin B↗

Activation of reticuloendothelial system macrophages and enhancement of host resistance to a transplantable osteogenic sarcoma in mice by an extract of Brucella abortus.

An aqueous-ether extract of Brucella abortus, Bru-Pel, enhanced resistance of mice to a transplantable osteogenic sarcoma (OGS). The results presented in this report suggest that Bru-Pel is an effective immunomodulator and that one mechanism through which it enhances host resistance is activation of phagocytic cells of the reticuloendothelial system. Peritoneal macrophages from mice inoculated with Bru-Pel 14 days previously were cytotoxic for OGS cells in vitro, limited the multiplication of vaccinia virus in cell cultures, and demonstrated increased chemiluminescence during phagocytosis. Furthermore, Bru-Pel enhanced host resistance to Listeria monocytogenes, in addition to viral infections and a transplantable tumor. These results support the hypothesis that Bru-Pel shares a number of characteristics with other recognized immunomodulating agents and suggest that further studies are warranted to better define the potential of Bru-Pel for immunotherapeutic regimens in man.

Animals↗

Overview of the activity of a Brucella abortus preparation, Bru-Pel.

The properties of a nonviable, aqueous ether-extracted Brucela abortus preparation, Bru-Pel, are described. In addition to inducing a "virus-type" interferon response and protecting mice against challenge with otherwise lethal doses of Semliki Forest virus, Bru-Pel is demonstrated to have potent antitumor properties in mice. These antitumor effects appear to be mediated by an increase in nonspecific resistance similar to that seen with other experimental antitumor agents.

Animals↗

Antitumor activity of a Brucella abortus preparation.

Mice injected intraperitoneally with sarcoma-180 cells develop ascites and eventually die. Intraperitoneal injection of a nonviable, aqueous... ether-extracted Brucella abortus preparation (BRU-PEL) as early as 7 days before or as late as 7 days after injection of tumor cells significantly inhibited development of ascites and protected against death. BRU-PEL was not effective if injected after ascites was grossly apparent. BRU-PEL was significantly more active than a Corynebacterium parvum preparation administered in the same way.

Animals↗

UDP-glucose dehydrogenase from Escherichia coli. Purification and subunit structure.

UDPglucose dehydrogenase from Escherichia coli has been purified 330-fold with an overall yield of 27%. A single homogeneous subunit was demonstrated by ultracentrifugation in 6 M guanidium chloride and by dodecyl sulfate-polyacrylamide gel electrophoresis. Since the molecular weight of the intact dehydrogenase is in the order of 86 000 and the subunit weight determined by the dodecyl sulfate-polyacrylamide gel electrophoresis is 47 000, the enzyme consists of two polypeptide chains. The sole amino terminal acid shown by the dansylation technique was arginine. Forty-four tryptic peptides were obtained by peptide mapping, in agreement with the number of arginine and lysine residues/mole protein [43] determined by amino acid analysis. The data are consistent with the presence of two identical or very similar polypeptide chains in E. coli UDPglucose dehydrogenase.

Alcohol Oxidoreductases↗

L-Rhamnose dehydrogenase of pullularia pullulans.

Growth of Pullularia pullulans on L-rhamnose induces formation of L-rhamnofuranose dehydrogenase, whichreversibly converts L-rhamnofuranose to L-rhamnono-gamma-lactone with the concomitant reduction of NAD, but not of NADP. The dehydrogenase was purified 100-fold by MnCl(2) treatment...

Alcohol Oxidoreductases↗

Antiviral activity of Brucella abortus preparations; separation of active components.

Injection into mice of heat-killed Brucella abortus or aqueous ether-extracted B. abortus (Bru-pel) induced a "virus-type" interferon response, with peak titers at 6.5 h. The animals also were protected against challenge with otherwise lethal doses of Semliki forest virus. Extraction of either heated B. abortus or BRU-PEL with a mixture of chloroform-methanol (2:1, vol/vol) (C-M( yielded an insoluble residue (extracted cells) and a C-M extract. Neither extracted cells nor C-M extract alone induced interferon or afforded protection against Semliki forest virus infection in mice. Full interferon-inducing and protective activity was restored when extracted cells were recombined with C-M extract. C-M extract from heat-killed Escherichia coli also was effective in restoring activity to extracted Brucella cells. Neither heat-killed E. coli nor its C-M extract was active, nor was C-M estracted E. coli recombined with the C-M extract from B. abortus. These results suggest that the interferon-inducing and antiviral protective properties of B. abortus are constituted of a C-M-extractable component that is common to B. abortus and E. coli and an unextractable component that is unique to B. abortus.

Animals↗

Interferon production in mice by components of Salmonella minnesota R595 lipid A.

The lipid A precipitate obtained by partial hydrolysis in 1% acetic acid of the glycolipid of a mutant strain of Salmonella minnesota (rough strain R595) was separated into a number of components by thin-layer chromatography. When tested as bovine serum albumin complexes, the minimal interferon-inducing dose in mice of the parent glycolipid was 0.1 mug, whereas that of lipid A was 1.0 mug. The minimal dose of the separated components ranged from 0.1 to 20 mug. The components did not differ significantly in regard to glucosamine-phosphate-fatty acid ratios. The results further emphasize that lipid A is a heterogeneous substance that contains a variety of components of differing biological activity.

Animals↗

Aerosol polymyxin and pneumonia in seriously ill patients.

Pneumonia caused by Pseudomonas aeruginosa occurs frequently in critically ill patients and is associated with a mortality rate of 70 per cent. An aerosol of polymyxin B was administered (2.5 mg per kilogram per day) to the upper airways of 292 patients in a respiratory-surgical intensive-care unit during a seven-month period, in an attempt to prevent Ps. aeruginosa pneumonia. Although only one of the patients studied acquired pneumonia due to Ps. aeruginosa, 10 others acquired pneumonia caused by a polymysinx-resistant organism. Seven pneumonias were caused by organisms not frequently pathogenic to man (flavobacteria, serratia and Streptococcus faecalis). The mortality rate for acquired pneumonia in this study, 64 per cent, is greater than that in previous studies in which either no polymyxin or cyclic polymyxin therapy was used. Continuous use of polymyxin B aerosol appears to be a dangerous form of therapy.

Aerosols↗