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Biomedical subjects

M E Klegerman

Publications and source records attributed to M E Klegerman.

8 recordsLinked to original sources
PubMed1992

Development of IgM antibody to group B Streptococcus type III in human infants.

An ELISA was developed to measure IgM antibody to albumin-coupled native capsular polysaccharide of type III group B streptococcus (GBS). The assay was standardized by two double-label methods that agreed within 33%. In quantitative assays, the range of IgM antibody to type III GBS in the sera of 94 adult pregnant women was 1.2-50.6 micrograms/ml (median, 5.4), while each of 38 cord serum samples contained less than 0.03 micrograms/ml IgM antibody. Neonatal rats were passively immunized with a serially diluted human serum containing 15 micrograms/ml IgM and undetectable IgG antibody to type III GBS. The rats were protected against lethal infection with an IgM antibody concentration of 0.5 micrograms/ml. In single serum samples from 31 healthy infants less than 2 years old and serial specimens from 5 infants with type III GBS infections, specific IgM antibody was detectable by 3 months of age. Levels greater than or equal to 0.5 micrograms/ml were present in all samples from infants greater than 7 months of age. The acquisition of specific IgM antibody is inversely correlated with the age-limited incidence of type III GBS infections in young children.

Aging↗
PubMed1992

Origins of BCG surface charge: effect of ionic strength and chemical modifications on zeta potential of Mycobacterium bovis BCG, Tice substrain, cells.

The zeta potential of washed Tice substrain BCG organisms was measured over a range of ionic strengths from I = 0.005 to 0.1 M. No change in the isoelectric point of 3.4-3.7 was evident. Proteolytic enzymes (trypsin/chymotrypsin, pepsin, papain and pronase) and fluorodinitrobenzene abolished the cationic charge, suggesting that this is substantially due to amino groups associated with protein. Neither hot HCI nor cold trichloroacetic acid affected the charge, indicating that ionic groups are not associated with extractable polysaccharides. Methanolysis, treatment with HF and carbodiimide, and cationic detergent (cetyltrimethylammonium bromide) binding indicated that the negative charge was provided by carboxylic acids, phosphoesters and strong acidic groups, possibly sulphates. Standardless quantitative X-ray microanalysis revealed the presence of phosphorus and sulphur on the surface of actively growing BCG colonies.

BCG Vaccine↗
PubMed1991

High-dose inhibition and low-dose enhancement of murine sarcoma growth exhibited by BCG vaccine.

An in vivo assay for BCG anti-cancer efficacy was developed, utilizing subcutaneous injection into CFW Swiss-Webster mice of cultured S180 sarcoma cells and mixed with freeze-dried TiceTM BCG vaccine. A BCG dose of 0.156-1.56 mg dry weight significantly inhibited tumor formation, but a BCG dose of 0.156-1.56 micrograms significantly enhanced tumor growth, evidenced by increased tumor incidence, volume and initial growth rate. These antagonistic activities may contribute to the high variability of BCG anti-cancer efficacy seen in animals and humans and indicate the need to exercise caution when employing even low doses of BCG for cancer immunotherapy.

Animals↗
PubMed1991

Surface morphology of Mycobacterium bovis BCG: relation to mechanisms of cellular aggregation.

Growing colonies of Mycobacterium bovis BCG, Tice and Glaxo substrains, and freshly ball milled and freeze-dried Tice BCG vaccines were examined by scanning and transmission electron microscopy (TEM) and by light microscopy after cytochemical staining. BCG organisms in colonies growing on agar were randomly oriented, despite colony morphology, and nearly completely covered by an amorphous material. Aggregates of organisms in vaccine suspensions were also covered with this material, but single cells were not covered. In TEM, the covering material was visualized between groups of cells as an electron-transparent area surrounded by a thin electron-dense layer. This material appeared to originate in the upper cell wall, between the cell wall skeleton and the outer dense layer. Staining of the covering material indicated the presence of protein, carbohydrate and acidic groups, but not exposed lipids. The covering material was absent from the ventral side of colonies, suggesting that its production is oxygen-dependent. These observations suggest that a mycobacterial exudate, previously observed and implicated as a virulence factor, may also bind the cells together, and accounts for the aggregative properties of the organisms in culture.

BCG Vaccine↗
PubMed1990

Cell mass of Mycobacterium bovis BCG estimated by gas chromatography.

The presence of additives and large cellular aggregates in freeze-dried BCG vaccines precludes accurate measurement of total cell content by traditional methods. The possibility that extraction and quantitation of a cell membrane fatty acid may provide a suitable means of cell mass determination was tested. The palmitic acid methyl ester peak area determined by gas chromatography was directly proportional to the wet weight of freshly grown Tice-, Pasteur-, and Glaxo-substrain BCG, as well as the dry weight of the ampoule contents after removal of soluble material. Extraction of palmitic acid from Tice BCG vaccine was not appreciably affected by lyophilization and the calculated dry cell mass values of freeze-dried vaccine samples correlated well with particle number. This method, therefore, may be useful in measuring BCG cell mass during all stages of vaccine manufacture and storage.

BCG Vaccine↗
PubMed1978

Behcet syndrome: with immunologic evaluation.

A case of Behcet syndrome with immunologic evaluation, including screening of a vulvar ulcer for IgG, IgM, IgA, and fibrinogen by direct fluorescent microscopy is presented. Attempts were made to demonstrate cellular and humoral immune responses to mucosal antigens by lymphoblast transformation in the presence of cadaver esophageal mucosal extracts and indirect immunofluorescence using autologous serum and mucosal tissue. Serial measurements of percentages of total T, active T, and B lymphocyte populations, and lymphocyte response to phytohemagglutinin (PHA) stimulation during the course of Behcet syndrome are also presented. Clinical evaluation, histology of a Behcet vulvar ulcer, and a 2-year followup with good response to chlorambucil are reviewed.

Adult↗
PubMedDate not supplied

Relative tumor inhibitory and stimulatory activities of BCG vaccine preparations, lots and substrains in a quantitative mouse sarcoma bioassay.

A quantitative in vivo assay for BCG anticancer efficacy was developed to maximize detection of tumor-antagonistic mechanisms. Cultured S180 sarcoma cells admixed with various quantities of Mycobacterium bovis-BCG organisms were injected subcutaneously into CFW Swiss-Webster mice and response was measured as tumor incidence 14 days after injection. Assay of various BCG substrains, lots and killed preparations revealed characteristic patterns of BCG dose-dependent tumor inhibition and enhancement that suggest the existence in the vaccine of multiple active components, the relative concentrations of which vary among cultures. Inhibition of tumor growth by high doses of BCG (greater than 10 micrograms dry weight) was found to be a function of total cell mass and not of the bacterial viability, suggesting that this activity is dependent upon one or more heat-stable components.

Animals↗