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Biomedical subjects

M Ryan

Publications and source records attributed to M Ryan.

At least 289 records · Page 16Linked to original sources
PubMed1987

Nucleic acid sequence relationships between enterovirus serotypes.

Forty-eight different enterovirus serotypes were analysed by a nucleic-acid hybridization test using probes derived from the 3' end of coxsackievirus A21 (CA21) and B3 (CB3), poliovirus 3 (P3) and enterovirus 70 (E70). More than 90% of the serotypes could be detected with this collection of reagents. The CB3 probe reacted with all the coxsackie B viruses, with all three poliovirus serotypes, and with almost all of the 30 ECHO virus types tested. In addition some of the coxsackie A viruses and the BrDr 73 strain of enterovirus 71 gave a positive signal with this probe. The P3 probe detected all the poliovirus strains and also some coxsackievirus A isolates but no coxsackie B or ECHO viruses. A similar hybridization pattern as with the P3 probe was obtained when the CA 21 probe was used. The E70 probe appeared to be strain-specific. The results indicate that nucleic-acid hybridization is a useful method for rapid detection and subgrouping of enteroviruses during virus isolation, and that the test could be further developed for typing of the strains.

Animals↗
PubMed1985

Colocalization of [3H]muscimol and antisera to GABA and glutamic acid decarboxylase within the same neurons in monkey retina.

Two procedures have been used to test for the colocalization of different neuroanatomical gamma-aminobutyric acid (GABA)ergic markers within the same neurons in primate retina. First, sequential immunocytochemical processing of sections was done using antisera to glutamic acid decarboxylase and to GABA, and these antisera were visualized by peroxidase-antiperoxidase and fluorescein isothiocyanate techniques respectively. Colocalization of both antisera was found within the same neuron cell bodies. In the second experiment, immunocytochemical staining using GABA antiserum was performed on retinal tissue that had been previously incubated in vitro for neuronal uptake of [3H]muscimol. Both markers colocalized in 70% of the labeled cell body population.

Animals↗
PubMed1985

Effects of spinal fusion on the proteoglycans of the canine intervertebral disc.

Posterior lumbar two-level spinal fusion was undertaken in 10 mature beagles. The animals were sacrificed 6 and 12 months later. Two months before sacrifice control and experimental animals received intravenously Na2(35)SO4 (1 mCi/kg). Discs encompassed by the fusion and those adjacent to it were dissected into the nucleus pulposus and annulus fibrosus (AF), which were analysed separately. Proteoglycans (PGs) were extracted with 4.0 M guanidine HCl and purified by CsCl density gradient ultracentrifugation. The hydrodynamic size and ability of the PG subunits to aggregate in the presence of hyaluronic acid were investigated by Sepharose CL-2B chromatography. The PG subunits were analysed for their galactosamine (galN), glucosamine (glcN), hexuronic acid, and protein content or were subjected to digestion with papain or chondroitin-ABC-lyase to establish the size of the chondroitin (CS) and keratan (KS) sulphate chains and the KS-PG core protein complex. Decreased ability to aggregate of PGs isolated from discs 6 and 12 months after surgery was demonstrated. While their hydrodynamic size after 6 months was generally the same or smaller than those in control tissues, the PG population present after 12 months was larger, particularly in the AF. Analysis of PG subunits from fusion discs afforded galN/glcN, galN/protein, and hexuronic acid/protein ratios that were compatible with the presence in these tissues of PGs in which the proportion of CS attached to core protein was greater than in control tissues. These studies provide the first experimental evidence that a metabolic response of discs in a fused segment may be accompanied by the biosynthesis of a new PG population whose structure is similar to that present in immature tissues.

Animals↗
PubMed1985

Cold reactive lymphocytotoxic activity in autoimmune thyroid disease.

An increased incidence of cold-reactive lymphocytotoxic activity (LCTA) has been demonstrated in the sera of patients with autoimmune thyroid disease. Twenty-six of 79 (33%) patients with Graves' disease and 9 of 21 (43%) patients with Hashimoto's thyroiditis had cold-reactive LCTA detected by microcytotoxicity assay compared to 6 of 42 (14%) normal controls. There was no correlation between LCTA and age, sex, MCHA titre or TGHA titre. A positive correlation with FTI and LCTA in Hashimoto's patients was demonstrated, but no such correlation was demonstrable in Graves' patients. The lymphocytotoxic activity was directed preferentially against B cells. There was no preferential lysis of T-cell subsets as defined by monoclonal antibodies, and the lymphocytotoxins were equally reactive with normal lymphocytes and toxic Graves' lymphocytes. The significance of cold-reactive lymphocytotoxic activity in the pathogenesis of autoimmune thyroid disease remains to be determined.

Adolescent↗