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Biomedical subjects

L F Affronti

Publications and source records attributed to L F Affronti.

At least 19 recordsLinked to original sources
PubMed1994

Induction of mycobacterial proteins during phagocytosis and heat shock: a time interval analysis.

Mycobacterium tuberculosis survives macrophage bactericidal activities by mechanisms that may include induction of stress proteins. We sought to determine whether the synthesis of any mycobacterial proteins is increased during phagocytosis and whether any of these proteins are also up-regulated during heat shock. Protein synthesis by M. tuberculosis H37Ra during phagocytosis by the mouse macrophage cell line IC-21, and during heat shock at 45 and 48 degrees C, was monitored at various time intervals using 35S-labeled methionine/cysteine and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our data suggest the existence of certain common elements in the stress response of mycobacteria to the three stress stimuli. This apparent similarity was best characterized by the up-regulation of a 25-kDa protein after exposure to each of the stress conditions. Furthermore, this 25-kDa protein and a 37-kDa protein that was also synthesized during phagocytosis appeared to be extracellular because they were preferentially solubilized when infected macrophages were lysed with 0.5% NP-40.

Animals↗
PubMed1990

Trace elements incorporated into the culture medium of Mycobacterium tuberculosis promote the presence of tuberculoprotein C in the preparation of purified protein derivatives.

Two purified protein derivatives (PPDs) were prepared from Mycobacterium tuberculosis, H37Ra. One of the PPDs was prepared from the culture filtrate of organisms grown on Proskauer-Beck medium to which trace elements had been added. The other PPD was prepared from the culture filtrate of organisms grown on the same medium but without trace elements, and was used as the control. Comparative skin reactions in sensitized rabbits showed that the PPD prepared from organisms grown in the presence of trace elements was less potent than the control. Since it has long been recognized that of the many tuberculoproteins present in PPD, the C protein (a 44 to 66 kDa protein) was always the least potent fraction when tested in equivalent concentrations in both serological and skin test assays, the possibility existed that the PPD obtained from organisms grown in trace element medium had more of the C protein complex than the control. Comparative studies of these two PPDs in terms of their chemical composition, skin test responses, and electrophoretic profiles obtained by SDS-polyacrylamide gel electrophoresis provide support for this assumption.

Animals↗
PubMed1987

A protein preparation from Mycobacterium kansasii culture filtrate has biological activity similar to that of hCG and cholera toxin in human cell lines.

A protein preparation, from culture filtrates from a strain of Mycobacterium kansasii (MK precipitate), which cross reacts with antibodies to human chorionic gonadotropin (hCG) beta subunit and antibodies to cholera toxin beta subunit, has been isolated. A tissue culture assay was used to detect the ability of this preparation to affect the antiviral activity of interferons and to visualize changes in cell shape and cell-cell contact caused by this preparation. A cholera toxin containing precipitate (CT precipitate) from cultures of Vibrio cholerae and commercially prepared hCG were used for comparison. It was found that MK, CT, and hCG may cause reduction or apparent enhancement of interferon antiviral activity or may have no effect. The effect that is observed depends on which test protein the cells are treated with, the type of interferon used, and which cell line is employed in the assay. All three protein preparations had visible effects on the shapes of the cells and the way the cells interacted to form a monolayer.

Bacterial Proteins↗
PubMed1986

An evaluation of the polyacrylamide gel electrophoresis fractionation method for the production of Mycobacterium tuberculosis skin test preparations. I. Production, physiochemical characterization and serological analyses.

As a part of a cooperative inter-laboratory WHO supported project raw tuberculins were produced and purified protein derivative (PPD, 18.7 g protein) was prepared. Employing a multistage preparative polyacrylamide gel electrophoresis (PAGE) method the PPD was separated into four fractions corresponding to 15, 7, 4.75 and 3.5% gel concentrations. The PAGE procedure resulted in three lots of material--each representing 11 electrophoretic runs. Immunodiffusion analyses showed that the largest number of precipitinogens was found in the 15% fractions and that some precipitinogens cross-reacted with preparations of Mycobacterium bovis BCG, M. intracellulare, M. kansasii, M. smegmatis and M. vaccae.

Antibodies, Bacterial↗
PubMed1986

An evaluation of the polyacrylamide gel electrophoresis fractionation method for the production of Mycobacterium tuberculosis skin test preparations. II. Comparative skin testing on guinea-pigs.

As part of a cooperative inter-laboratory WHO supported project for the fractionation of Mycobacterium tuberculosis skin test preparations, four fractions (designated 15, 7, 4.75 and 3.5%) were evaluated by comparative skin tests on sensitized guinea-pigs. The 7% fraction was the most potent in both homologously and heterologously sensitized animals, and the 4.75% and 3.5% gel fractions showed the lowest activity. Significant levels of cross-reactivity in guinea-pigs immunized with M. bovis BCG, M. kansasii, M. avium and M. intracellulare were demonstrated for all fractions examined, thus reflecting the antigenic relationships among these mycobacteria. These four fractions may qualify as starting material for further studies aiming at a reduction of skin test cross-reactivity.

Animals↗
PubMed1986

Comparison between tuberculoproteins A and C in the serodiagnosis of tuberculosis by enzyme-linked immunosorbent assay.

Tuberculoproteins A and C obtained from culture filtrate of Mycobacterium tuberculosis by alcohol fractionation were utilized in an enzyme-linked immunosorbent assay to measure the amount of reactive IgG in the sera from advanced and moderately advanced tuberculosis patients, leprosy patients and normal individuals. The A-protein detected significant levels of IgG in the sera from both advanced and moderately-advanced tuberculosis patients and patients with leprosy as compared to the normal group. Employing the C-protein, only sera from the advanced tuberculosis patients group gave significantly positive results when compared with the normal control group. The data show that the A-protein is more potent than the C-protein and has a potential serodiagnostic value.

Bacterial Proteins↗
PubMed1986

Immunological detection of hCG-like substances in aerobic bacteria of both tumour and non-tumour origin.

Production of hormone-like substances by prokaryotes and unicellular eukaryotes, as well as the presence of a human chorionic gonadotropin-like substance in the serum of individuals with malignancies, have been previously established. To determine the presence and distribution of the production of human chorionic gonadotropin (hCG) among aerobic bacteria, fourteen strains of bacteria of both tumour and non-tumour origin were examined using enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and indirect immunoperoxidase techniques. Of the six bacterial strains tested, half of the tumour-isolates produced an hCG-like substance while non-tumour associated strains of the same species did not do so. Virulent strains of two mycobacterial species also gave high positive values while avirulent Mycobacterium tuberculosis strains (H37Ra) yielded low or negative values. The production of hCG-like substances by mycobacteria, for which no tumour association is known, indicates that tumour association is neither a prerequisite nor a requirement for production of hCG. It appears that the presence of hCG-like substances is a variable character among bacterial species, suggesting that it may have been conserved throughout evolutionary history.

Acinetobacter↗
PubMed1982

Isolation and partial characterization of the most immunologically reactive antigen from Mycobacterium tuberculosis H37Ra culture filtrate.

The culture filtrate of Mycobacterium tuberculosis H37Ra was fractionated by ammonium sulphate precipitation, diethyl aminoethyl (DEAE) cellulose-Sephadex A-50 column chromatography, preparative isoelectric focusing and polyacrylamide gel electrophoresis to isolate the most antigenic tuberculoprotein. One protein, designated P2, was isolated and determined by immunodiffusion to be the most immunologically reactive antigen present in H37Ra culture filtrate. This protein had a molecular weight of about 22 000, a sedimentation constant of 2.2S and was present in Seibert's A, B, and C proteins.

Antigens, Bacterial↗
PubMed1981

Tumor-associated bacteria capable of producing a human choriogonadotropin-like substance.

Aerobic microorganisms were isolated and identified from 9 of 10 malignant tissues aseptically obtained from surgical patients. The organisms isolated are species commonly associated with the flora of the human body. When these cancer-associated organisms were grown in Trypticase soy broth (BBL Microbiology Systems), a protein substance was isolated from the culture filtrates by acetone precipitation. The acetone precipitates of 12 of 14 organisms tested were positive when assayed by radioimmunoassay for the beta subunit of human chorionic gonadotropin (hCG). All but one of the bacterial isolates from the malignancies were capable of producing the hCG-like substance, but in varying quantities. Control organisms (not isolated from a malignancy) and uninoculated Trypticase soy broth were either completely negative in the radioimmunoassay for beta hCG or had levels of beta hCG near the limit of the sensitivity of the method. These results suggest the possibility that bacteria-tumor relationships do exist and are in agreement with the findings of other workers. Investigation of these relationships may have important and provocative implications in the study of neoplastic diseases.

Acinetobacter↗
PubMed1981

Persistence of protein, carbohydrate and was components of tubercle bacilli in dermal BCG lesions.

Dermal tuberculous lesions were produced in rabbits with Bacille Calmette Guèrin and biopsied on days 4, 14, 21, 35, and 56. Frozen sections prepared from the biopsy specimens were stained by the peroxidase-antiperoxidase immunocytochemical technique with antisera against whole tubercle bacilli and antisera against the protein B, polysaccharide I, and wax D fractions of tubercle bacilli. In the primary lesions, protein B was often undetectable at 21 days, and polysaccharide I was often undetectable at 35 days. Wax D disappeared more slowly than the other bacillary components evaluated, and some wax D was still found at 56 days (if the lesions had not completely healed). Antisera against intact tubercle bacilli produced results similar to those produced by antiserum against wax D. These studies suggest that the chronicity of tuberculous lesions is due, at least in part, to the persistence of the wax D-like component of tubercle bacilli.

Animals↗
PubMed1981

Proteolysis and recycling of Mycobacterium tuberculosis culture filtrate tuberculoproteins.

The culture filtrate of Mycobacterium tuberculosis H37Ra has proteolytic enzyme activity which can hydrolyse extracellular tuberculoproteins. Some of the released products are transported into the cells and are incorporated into cell protein, and finally reappear in the culture filtrate as constituents of secondary tuberculoproteins. Continued extracellular proteolysis and utilization of the resultant products could produce a cyclic source of culture filtrate tuberculoproteins.

Bacterial Proteins↗
PubMed1979

HLA-Bw15 and tuberculosis in a North American black population.

Peripheral blood lymphocytes from 60 black patients with Mycobacterium tuberculosis disease proved by culture and 100 healthy black persons were HLA phenotyped using a standard lymphocytotoxicity test. Statistical analysis of the results showed that only Bw15 antigen had a significantly increased frequency among patients with tuberculosis when they were compared to healthy persons. Furthermore, examination of disease manifestations among patients with tuberculosis demonstrated that patients with Bw15 had significantly more far-advanced pulmonary disease with cavitation than did patients without Bw15. These observations suggest that Bw15 may influence both susceptibility to tuberculosis and the course of the disease.

Adult↗
PubMed1978

Biological and physicochemical characteristics of four serotypes of Salmonella enteritidis.

Four serotypes of Salmonella enteritidis, Anatum ATCC 9270, Newbrunswick ATCC 1608, Oranienburg 200 E, and Pullorum RM, were studied to determine biological, chemical, or physical differences which might explain variations in Salmonella virulence as previously reported by McCullough and Eisele (J. Infect. Dis. 88:278-289, 1951; 89:259-265, 1951). These investigators found that serotype Pullorum was significantly less virulent than serotypes Newport, Derby, Barielly, Meleagridis and Anatum when fed to healthy humans. Results of our own experiments showed that serotype Pullorum RM had a generation time approximately twice that of serotype Anatum 9270. The volume of serotype Pullorum was approximately one-half the volume of the other serotypes used (Anatum 9270, Newbrunswick 1608, Oranienburg 200 E, Cubana 12007, and Meleagridis DR). The number of cells required to yield 1 g dry weight was substantially higher for serotype Pullorum RM than for serotypes Anatum 9270, Newbrunswick 1608, and Oranienburg 200 E. The yield of endotoxin per gram dry weight for serotype Pullorum RM averaged 22 mg/g, whereas yields of endotoxin for serotypes Anatum 9270, Newbrunswick 1608, and Oranienburg 200 E averaged 32 to 35 mg/g. The relative abundance of the four major fatty acids (measured by gas chromatography) also showed distinct differences among the serotypes. Pullorum RM contained less lauric and 3-hydroxymyristic acids and more myristic and palmitic acids than the other three serotypes. The identity of 3-hydroxymyristate was confirmed by mass spectroscopy. Serotype Pullorum RM required 10 times more lipopolysaccharides (endotoxin) to obtain a 50% lethal dose in mice than the other three serotypes. When the lipid part was separated from the polysaccharide and solubilized with bovine serum, the 50% lethal dose of serotype Pullorum RM was equal to that of the other three.

Endotoxins↗
PubMed1975

Preliminary observations on the effect of acupuncture on immune responses in sensitized rabbits and guinea pigs.

A preliminary report is presented on the possible effect of acupuncture on immune responses in rabbits injected with sheep RBC and in guinea pigs with an encephalitoenic antigen preparation. Results from acupuncturing experimental animals at four loci-Ta-Chu, Tsu-San-Li, Ch u-Chih-Shih-strongly suggest that acupuncture has an effect on the immune response. If these observations can be substantiated by more refined methods in subsequent experiments, a new avenue will be opened for acupuncture research.

Acupuncture Therapy↗