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Biomedical subjects

I Nachamkin

Publications and source records attributed to I Nachamkin.

79 records · Page 5Linked to original sources

Foreign body granulomatosis. Clinical and immunologic findings.

We studied the clinical and immunologic features of 10 patients with foreign body granulomatosis associated with injection of pentazocine. Five had typical micronodules on chest radiographs, 9 had abnormal 67Ga lung images, and 9 had elevated serum angiotensin-converting enzyme levels. Pulmonary function tests showed significant decreases in diffusing capacity in 8 subjects, but were otherwise normal. Bronchoalveolar lavage fluid had significantly (p less than 0.02) increased total cell numbers (13.8 +/- 7.5 x 10(7) and significantly lower percentages of lymphocytes (2 +/- 1) and neutrophils (2 +/- 1) (p less than 0.02) when compared with that from control subjects. Peripheral blood lymphocytes were normal when expressed as percentages of total leukocytes or as percent T-lymphocytes. Monoclonal antibody determinations of T-lymphocyte subsets (helper and suppressor) were similar to those in control subjects (p = NS). Lymphocyte transformation responses to a variety of antigens and skin test reactivity were normal. Foreign body granulomatosis contrasts with other interstitial lung diseases in its bronchoalveolar lavage cellular profile and in the absence of altered peripheral immunologic indexes.

Adult↗

Localization of distinct surface antigens on Chlamydia trachomatis HAR-13 by immune electron microscopy with monoclonal antibodies.

Monoclonal antibodies were produced against the HAR-13 strain (A) of Chlamydia trachomatis. By an indirect immunofluorescence technique, three clones (1-7, 2-8, 9F) were found to produce antibody that reacted only with serotype A strains. Clone 3-5 produced antibody that cross-reacted with serotypes A, C, H, I, and J. Using an indirect immunoferritin technique, we examined the binding of these antibodies to strain HAR-13 by electron microscopy. Antibodies from all four clones were shown to bind to the outer membrane surface of both reticulate and elementary bodies. Two distinct binding patterns were demonstrated. Antibodies from clones 1-7 and 9F bound to the outer membrane surface in a homogeneous pattern, whereas antibodies 2-8 and 3-5 bound to the outer membrane surface in an irregular, patchy distribution. There was a direct correlation between the distribution of antigen on the outer membrane surface and neutralization of C. trachomatis HAR-13 infectivity in vitro. Neutralization of HAR-13 infectivity by antibodies 1-7 and 9F was complement dependent, whereas antibodies 2-8 and 3-5 did not neutralize under any conditions.

Antibodies, Monoclonal↗

Evaluation of a rapid system for species identification of alpha-hemolytic streptococci.

A new 4-h commercial system (API 20S; Analytab Products, Plainview, N.Y.) for the identification of streptococci was compared with the conventional biochemical profile method in the species identification of alpha-hemolytic streptococci. A total of 194 clinical isolates (including 74 isolated from blood cultures, 64 isolated from wound cultures, and 56 isolated from respiratory cultures) and 20 reference strains were tested. Only 4 of the 20 reference strains were correctly identified to species level by the API 20S system. Six were identified to group level (viridans), four were incorrectly identified, and six did not conform to the identification key. Of the 194 clinical isolates tested, 79 (39%) were correctly identified to species level, 34 (17.5%) were identified to group level, 34 (17.5%) were incorrectly identified, and 50 (25.8%) did not conform to the identification key. Of the 12 different species of alpha-hemolytic streptococci isolated from clinical specimens, the API 20S system consistently identified Streptococcus faecalis and Streptococcus faecium, but consistently misidentified the other 10 species, especially Streptococcus mitis. Our results indicate that for identification to species level, the API 20S system is of little value for alpha-hemolytic streptococci other than enterococci.

Bacteriological Techniques↗

Monoclonal antibodies against Neisseria gonorrhoeae: production of antibodies directed against a strain-specific cell surface antigen.

Hybridomas secreting monoclonal antibodies against an apparent strain-specific cell surface antigen of Neisseria gonorrhoeae were produced. Spleen cells from BALB/c mice immunized with whole gonococci were fused with mouse myeloma cell line Sp2/0, and hybrid cells were selected in culture. One hybridoma that secreted antibodies reactive with the immunizing strain was cloned by limiting dilution to obtain cell lines secreting monoclonal antibodies. These antibodies reacted with purified outer membranes from the immunizing strain as well as with whole gonococci. Binding of antibodies to whole gonococci was highly strain specific, with most gonococcal strains showing less than 1% of the binding with the immunizing strain. Antibodies did not bind to the other Neisseria species tested. Binding of monoclonal antibodies to whole gonococci of the immunizing strain was not dependent on state of piliation. The extent of antibody binding did vary in different colonial variants of the immunizing strain. Antibody bound to cells from colonies that were transparent or of intermediate opacity, but did not bind to cells from deeply opaque colony variants.

Animals↗

Lipopolysaccharide induces expression of genes encoding pro-inflammatory cytokines and the elastin-degrading enzyme, cathepsin S, in human cervical smooth-muscle cells.

OBJECTIVE: Vaginal and amniotic infection with gram-negative bacteria is associated with preterm birth. We previously reported that human cervical smooth-muscle cells (CSMC) respond to pro-inflammatory cytokines by expressing enzymes that degrade the extracellular matrix. Our objective was to characterize the effects of lipopolysaccharide (LPS) from Escherichia coli (E coli), Bacteroides fragilis, (B frag)and Fusobacterium nucleatum (F nuc)on the expression of pro-inflammatory cytokines and the elastin-degrading enzyme, cathepsin S, in human CSMC. METHODS: Human CSMC were exposed to LPS and the expression of mRNAs encoding pro-inflammatory cytokines and cathepsin S, and selected matrix metalloproteinases (MMPs) was analyzed by Northern blotting. The effect of cytokine-neutralizing antibodies on LPS-induced cathepsin S mRNA expression also was determined. RESULTS: E coli LPS increased expression of cathepsin S 12.5-fold after 12 hours; MMP-1 and MMP-3 mRNAs also were increased 2.9- and 3.5-fold, respectively. Tumor necrosis factor (TNF)-alpha, interleukin (IL-1)alpha, and IL-1beta mRNAs were markedly up-regulated after 3 hours of LPS treatment. B frag and F nuc LPS also induced TNF-alpha and cathepsin S mRNAs. E coli LPS caused a sevenfold increase in TNF-alpha secretion after 5 to 8 hours. Antihuman TNF-alpha monoclonal antibody, but not a monoclonal antibody to the low-density lipoprotein receptor, reduced the LPS-induced increase in cathepsin S mRNA by 27%, whereas neutralizing antibodies against IL-1alpha and IL-1beta did not suppress the response. Human CSMC were shown to express the toll-like receptor (TLR-2) and TLR-4 genes, which mediate the action of LPS. TLR-2 mRNA was up-regulated by TNF-alpha. CONCLUSION: CSMC respond to LPS with increased expression of pro-inflammatory cytokines and cathepsin S. Increases in cathepsin S mRNA result only in part from the rapid induction of TNF-alpha gene expression. TNF-alpha may also augment the CSMC response to LPS by increasing expression of the LPS signaling receptor, TLR-2, which probably directly mediates LPS action. These observations provide a mechanism by which gram-negative bacteria can precipitate cervical changes associated with preterm birth.

Cathepsins↗

Quinolone and macrolide resistance in Campylobacter jejuni and C. coli: resistance mechanisms and trends in human isolates.

The incidence of human Campylobacter jejuni and C. coli infections has increased markedly in many parts of the world in the last decade as has the number of quinolone-resistant and, to a lesser extent, macrolide-resistant Campylobacter strains causing infections. We review macrolide and quinolone resistance in Campylobacter and track resistance trends in human clinical isolates in relation to use of these agents in food animals. Susceptibility data suggest that erythromycin and other macrolides should remain the drugs of choice in most regions, with systematic surveillance and control measures maintained, but fluoroquinolones may now be of limited use in the empiric treatment of Campylobacter infections in many regions.

Animal Diseases↗