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Biomedical subjects

S Faine

Publications and source records attributed to S Faine.

At least 37 records · Page 2Linked to original sources

Experimental syphilitic orchitis. Relationship between Treponema pallidum infection and testis synthesis of proteoglycans.

The relationship between Treponema pallidum infection and the synthesis of proteoglycans by organ cultures of rabbit testes was investigated. Two proteoglycan fractions, large (CL-6B Kav 0.05) and small (Kav 0.25), that were not synthesized at detectable levels by cultures from rabbits infected with T. pallidum for 0 or 5 days, were produced by cultures from 10-, 15- and 20-day infected rabbits. The small proteoglycan appeared to be synthesized first because greater amounts of this fraction were detected in extracts of cultures from 10-day infected animals. The large proteoglycan fraction may have been induced directly by T. pallidum because increased synthesis correlated with maximal treponemal numbers, 15 days after infection. In contrast, the induction of the smaller proteoglycan did not appear to be directly related to numbers of elutable organisms. The proteoglycans synthesized between 10 and 20 days after infection were analyzed for glycosaminoglycan (GAG) size and composition. The size of GAGs beta-eliminated from the proteoglycans generally increased over the 10-20-day infection period. Whereas the composition of the small proteoglycan fraction was largely unchanged during the 10-20-day period (45% chondroitin sulphate (CS), 55% dermatan sulphate (DS)), the amount of DS in the high molecular weight proteoglycan fraction decreased from 50-20% during this period (CS 50-80%). Autoradiography studies revealed that increased proteoglycan synthesis in T. pallidum-infected testes was localized to cells lining the seminiferous tubules and to fibroblasts infiltrating peritubular spaces.

Animals↗

Genus-specific antigens in Leptospira revealed by immunoblotting.

Immunoblotting of leptospiral sonicates with heterologous rabbit antisera revealed a distinct cross-reactive pattern which differed with respect to the pathogenic and non-pathogenic leptospiral serovars, and that all serovars tested from Leptospira interrogans, L. biflexa and L. illini contained a common 35 kilodalton (Kd) band. A leptospiral genus-specific antigen preparation produced by ethanol fractionation of L. biflexa serovar patoc reacted by enzyme immunoassay (EIA) with all heterologous serovars tested. Further purification using Sephacryl S-300 gel filtration revealed one major cross-reactive peak and several homologous peaks detectable by EIA. Gel electrophoresis of this peak revealed 3 major protein bands of 35, 34 and 29 Kd by Coomassie blue staining. This peak was further fractionated by high pressure liquid chromatography (HPLC), yielding 7 fractions, one of which cross-reacted. Rabbit antisera to this S-300/HPLC fraction reacted with all serovars tested. Immunoblotting revealed 2 distinct groups of cross-reactive antigens, a 33-35 Kd group that was proteinase K sensitive but not reduced by periodate oxidation, and a 14.4-26.5 Kd group whose activity was reduced by periodate but not proteinase K, indicating the presence of both protein and carbohydrate genus antigens. Immunoblotting L. interrogans serovar pomona flagella with S-300/HPLC antiserum suggested that the 35 Kd band found in all serovars tested was a flagellar component.

Animals↗

Opsonic monoclonal antibodies against lipopolysaccharide antigens of Leptospira interrogans serovar hardjo.

Six monoclonal antibodies produced from mice immunised with Leptospira interrogans serovar hardjo were directed against determinants in the leptospiral lipopolysaccharide, as indicated by immunodiffusion and enzyme immunoassay (EIA), and opsonised leptospires for phagocytosis by mouse macrophages. Their specificities were studied by agglutination and EIA. Five antibodies reacted with some, but not all, members of the Sejroe and Hebdomadis serogroups, and one antibody agglutinated exclusively members of the Sejroe group thus indentifying a serogroup-specific epitope. None of the six antibodies reacted with representative serovars of any other serogroup.

Animals↗

Ultrastructure and chemical composition of lipopolysaccharide extracted from Leptospira interrogans serovar copenhageni.

Lipopolysaccharide (LPS) from Leptospira interrogans serovar copenhageni was prepared from the aqueous phase of a phenol/water extract. Electron microscopic examination of negatively stained LPS showed a mixture of ribbon-like, round and ring structures. Carbohydrate analysis of the preparations revealed pentoses, hexoses, heptoses, hexosamines, and a 2-keto-3-deoxyonic acid which was chromatographically different from authentic 2-keto-3-deoxyoctonic acid (KDO). The major fatty acids of the LPS were hydroxylauric, palmitic and oleic acids. Although the leptospiral LPS preparations did not contain KDO or hydroxymyristic acid, they were otherwise morphologically and chemically similar to the LPS of other Gram-negative bacteria.

Chemical Phenomena↗

Glycolipoprotein cytotoxin from Leptospira interrogans serovar copenhageni.

Lipopolysaccharide (LPS), glycolipoprotein (GLP) and lipid extract were prepared from Leptospira interrogans serovar copenhageni. GLP, lipid extract or purified fatty acids from lipid extract produced cytotoxic effects seen as cell enzyme leakage followed by cytotoxic death when tested in mouse fibroblast L929 cells in tissue culture. All extracts also agglutinated mouse erythrocytes but purified LPS was not cytotoxic. Neither GLP nor LPS were pyrogenic but both gelled Limulus amoebocyte lysate. Specific anti-GLP IgG neutralized the cytotoxic and haemagglutinating effect of GLP; however, at higher concentrations it enhanced the cytotoxicity of GLP and mediated lysis of the erythrocytes. A high dose of leptospires (i.e. 10(10) organisms) killed weanling mice causing pathological changes similar to those seen in acute leptospirosis. Similar results were obtained with live, dead, pathogenic and saprophytic leptospires. The results suggest that toxicity is involved in leptospiral infection and that lipid components either of whole leptospires or of a leptospiral GLP may contribute to the pathogenesis of acute leptospirosis.

Animals↗

Interactions of virulent and avirulent leptospires with primary cultures of renal epithelial cells.

A primary culture system for the cells of mouse renal-tubular epithelium was established and used to observe the adhesion of leptospires. Virulent strains of serovars copenhageni and ballum attached themselves to epithelial cells within 3 h of infection whereas an avirulent variant of serovar copenhageni did not adhere to epithelial cells at all within the experimental period of 24 h. The saprophytic Leptospira biflexa serovar patoc became attached non-specifically to inert glass surfaces as well as to the cells. The adhesion of leptospires to epithelial cells was not inhibited by homologous antibody.

Adhesiveness↗

A monoclonal antibody reacting with a determinant on leptospiral lipopolysaccharide protects guinea pigs against leptospirosis.

An IgA monoclonal antibody (MUM/F1-1/copenhageni) was produced from a mouse immunised with Leptospira interrogans serovar copenhageni. The antibody showed partial serogroup specificity by agglutination and by reaction in enzyme immunoassay, and opsonised homologous leptospires for phagocytosis by cultured mouse macrophages. Immunodiffusion and Western-blotting experiments indicated that MUM/F1-1/copenhageni reacted with a carbohydrate determinant in the leptospiral lipopolysaccharide. Daily administration of purified MUM/F1-1/copenhageni IgA before and after challenge with 2 X 10(8) virulent homologous leptospires passively protected newborn guinea pigs against lethal leptospirosis.

Animals↗

Development of increased serum immunoblot reactivity against a 45,000-dalton polypeptide of Treponema pallidum (Nichols) correlates with establishment of chancre immunity in syphilitic rabbits.

Rabbits developed chancre immunity 5.0 to 7.5 weeks after intradermal infection with 10(3) Treponema pallidum (Nichols). The serological response against T. pallidum antigen during this 2.5-week period was examined by Western immunoblotting. Sera from rabbits infected for 5.0 weeks contained antibodies against 7 of 13 major T. pallidum immunogens, with strongest binding detected against a polypeptide of Mr 47,000. By 7.5 weeks of infection, syphilitic rabbit sera recognized 10 of 13 antigens; the most evident increase in serological reactivity was directed against a polypeptide of Mr 45,000, suggesting that the development of a strong serological response against this polypeptide correlated with the onset of chancre immunity.

Animals↗

Secondary lesions in rabbits experimentally infected with Treponema pallidum.

Thirty rabbits infected with 10(3) of either Nichols or Melbourne 1 strains of Treponema pallidum were observed for the development of secondary lesions, which appeared outside areas inoculated with viable treponemes. More rabbits infected with Melbourne 1 strain (eight of 15 rabbits) than were infected with the Nichols reference strain (three of 15 rabbits) developed secondary lesions. The mean (SD) incubation periods of secondary lesions were 52 (8) days for rabbits infected with Melbourne 1 and 56 (4) days for rabbits infected with Nichols strain. These mean incubation periods did not correlate with appreciably increased concentrations of immune complexes or glycosaminoglycans in the serum of infected rabbits.

Animals↗

Autoantibodies to creatine kinase in rabbits infected with Treponema pallidum.

Sera from rabbits infected intratesticularly with Treponema pallidum (Nichols) for 30 days were examined for autoantibody reactivity against muscle and testis extracts by Western immunoblotting. Syphilitic sera (30 day) reacted with an autoantigen of 43,000 daltons in muscle extracts. The antigen was shown to be creatine kinase (CK). Studies with the use of an anti-CK ELISA showed that the autoantibody to CK first appeared 3 wk after infection, declined by 7 wk infection, and was absent in rabbits "mock"-infected with heat-killed T. pallidum. CK activity was not detected in sonicated or intact, washed T. pallidum, suggesting that the antibody was not produced in response to treponemal CK.

Animals↗

Characterization of the proteoglycans synthesized by rabbit testis in response to infection by Treponema pallidum.

Organ cultures of syphilitic and normal rabbit testes were incubated with 35S-sulfate for labeling of proteoglycans. Syphilitic rabbit testes synthesized three macromolecular fractions (I, II, and III) which were not detected in extracts of normal uninfected tissue. The three fractions comprised a larger (approximately 10(6) mol wt) chondroitin sulfate/dermatan sulfate proteoglycan (Fraction I), a smaller (approximately 10(5) mol wt) chondroitin sulfate/dermatan sulfate proteoglycan (Fraction II), and a putative sulfated glycoprotein of Mr 40 kd (Fraction III). The glycosaminoglycan chains of both proteoglycans eluted with a Kav of 0.45 on Sepharose CL-6B, consistent with a molecular weight of 25,000. The smaller proteoglycan was not a cleavage product of the larger species. Erythromycin had no significant effect on the synthesis of any of the three macromolecules. In contrast, the synthesis of both proteoglycans was totally inhibited by a 2-hour preincubation with cycloheximide, which suggests that the constitutive "pools" of the two core proteins were small. The putative sulfated 40-kd glycoprotein was insensitive to a 2-hour preincubation with cycloheximide.

Animals↗

Enzymatic radioimmunoassay for detecting Leptospira interrogans serovar pomona in the urine of experimentally-infected pigs.

An enzymatic radioimmunoassay (ERIA) has been developed for detecting Leptospira interrogans serovar pomona in porcine urine. Four grower pigs were experimentally infected with serovar pomona. A total of 39 urine samples was collected, and ERIA was compared with dark ground microscopy (DGM) and culture for demonstrating leptospiruria. Of 20 samples positive by at least one technique, leptospires were detected by ERIA in 14, by culture in 16 and by DGM in 13. ERIA, unlike the other 2 methods, was suitable for use with urine which had been stored frozen for several months.

Animals↗

The immunoglobulin response of swine following experimental infection with Leptospira interrogans serovar pomona.

The antibody response of pigs following experimental infection with Leptospira interrogans serovar pomona was examined using enzyme immunoassay (EIA) and the microscopic agglutination test (MAT). Leptospires elicited the production of both IgM and IgG classes of antibody, with IgG levels persisting for much longer than IgM. A comparison of MAT and EIA indicated that the detection of specific IgM by EIA was potentially useful in distinguishing between past and recent infection in pigs. Agglutinins were also detected in the urine of infected animals but these antibodies could not be detected by EIA.

Animals↗