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Biomedical subjects

J Schachter

Publications and source records attributed to J Schachter.

At least 343 records · Page 19Linked to original sources

Plaque formation by Chlamydia in L cells.

Chlamydiae were found capable of producing plaques in several cell lines. Mouse fibroblast cells, L-929, proved the most sensitive to infection and yielded plaques of the highest clarity. Assay of chlamydial infectivity by plaque titration was at least as sensitive as egg ld(50) determination. Among chlamydial isolates of avian, mammalian, and human origin, only slow-growing trachoma-inclusion-conjunctivitis agents did not produce plaques. The plaque assay is highly sensitive, reproducible, and offers a potential tool for investigations requiring accurate measurement of small changes in chlamydial infectivity.

Journal Article↗

Protective effect of a synthetic polynucleotide complex (poly I: C) on ocular lesions produced by trachoma agent in rabbits.

Live trachoma agent (TE55) injected into the anterior chamber of the rabbit eye produced the following agent-specific ocular lesions: corneal opacity, corneal neovascularization, and iritis. Three intravenous injections of 1 mg of a potent interferon (IF) inducer, polyriboinosinic acid-polyribocytidylic acid complex (poly I:C), markedly suppressed the ocular lesions produced by the trachoma agent but failed to inhibit the growth of the agent in the ocular tissues. Furthermore, a single intravenous injection of 1 mg of polyriboinosinic acid or of polyribocytidylic acid was also protective, although each failed to induce any detectable circulating IF. These results indicate that a factor or factors other than IF may play a role in the suppression of the ocular lesions produced by trachoma agent in poly I:C-injected rabbits.

Journal Article↗

Plaque reduction technique for demonstrating neutralizing antibodies for Chlamydia.

Some members of the genus Chlamydia (Bedsonia or psittacosis-lymphogranuloma venereum-trachoma-inclusion conjunctivitis group of microorganisms) produce plaques in monolayers of mouse fibroblast (L-929) cells. Hyperimmune chicken antisera may be capable of specifically reducing plaque counts. When the test was applied to chlamydiae isolated from avian species, the results indicated that different isolates with a common source had similar antigenic reactivity. The plaque reduction test is a potentially useful method for serotyping chlamydiae. The difficult aspect of the method appears to be a readily reproducible means of producing neutralizing antiserum.

Journal Article↗

Lymphogranuloma venereum. II. Characterization of some recently isolated strains.

Five Bedsonia (Chlamydia) isolates from lymphogranuloma venereum (LGV) patients were tested for inclusion type, sulfonamide sensitivity, and mouse virulence. Two matched the classical description of LGV agents. Two were not virulent for mice by the intracerebral route, therefore fitting the description for trachoma-inclusion conjunctivitis agents. One was highly virulent for mice and sulfonamide-resistant, and produced inclusions that did not stain with iodine, all characteristics generally associated with avian bedsoniae. A sixth isolate could not be adequately tested due to poor infective yields. Because of this variety of properties within the Bedsonia group, the term LGV might more appropriately be reserved for clinical disease rather than to describe a particular bedsonial agent.

Animals↗