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Biomedical subjects

J Palace

Publications and source records attributed to J Palace.

9 recordsLinked to original sources
PubMed1996

Memory in myasthenia gravis: neuropsychological tests of central cholinergic function before and after effective immunologic treatment.

There are reports of central cholinergic deficits in myasthenia gravis (MG) describing impaired performance on a variety of tests of memory with varying benefits from plasmapheresis. We tested 11 patients with symptomatic MG at the start of a trial of immunosuppressive treatment (prednisolone plus azathioprine or placebo) and again when in remission. The tests included the Logical Memory and Design Reproduction parts of the Wechsler Memory Scale, the Rey Auditory Verbal Learning Test, Peterson-Peterson task, and an auditory vigilance task. Muscle strength improved significantly over the period of treatment, but overall performance on tests of memory or attention did not. These results fail to substantiate reports of functionally significant and reversible central deficits in myasthenia gravis.

Adolescent↗
PubMed1994

Immunogenicity of human recombinant acetylcholine receptor alpha subunit: cytoplasmic epitopes dominate the antibody response in four mouse strains.

In mysathenia gravis (MG) autoantibodies directed against acetylcholine receptors (AChR), at the neuromuscular junction lead to muscle weakness. These antibodies are directed against extracellular determinants, predominantly on the AChR alpha subunits. Similar antibodies can be induced in animals by immunisation with purified AChR, but immunisation of mice with recombinant human alpha subunit or its extracellular domain has produced conflicting results. To study further the immunogenicity of the human alpha subunit we immunised four inbred stains (C57B1/6, SJL, BALB/c, SWR) with almost full-length recombinant alpha subunit, r37-429, and looked at B cell epitopes by mapping with smaller recombinant fragments and synthetic peptides. The majority of anti-r37-429 antibodies bound to sequences within a region thought to be cytoplasmic, alpha 325-368, and reacted with human AChR. In two C57B1/6 sera, only, most antibodies were directed against an extracellular region, alpha 138-167, but the r37-429 used for immunisation of these two mice appeared to have lost the integrity of its cytoplasmic domain during preparation. Our results suggest that the antigenicity of the cytoplasmic region of the recombinant alpha subunit dominates the immune response in each of the four strains, and may even suppress the formation of antibodies to the extracellular domain. Moreover, although C57B1/6 and SJL mice were able to produce antibodies to alpha 138-167, these antibodies did not react with intact AChR, and none of the mice became weak.

Amino Acid Sequence↗
PubMed1991

3,4-Diaminopyridine in the treatment of congenital (hereditary) myasthenia.

Congenital or hereditary myasthenia describes a heterogeneous group of disorders in which the immune system is not implicated. Treatment has previously depended on anticholinesterase medication. The effectiveness of 3,4-diaminopyridine (3,4-DAP), a preparation that enhances acetylcholine release from motor nerve terminals, has been evaluated using a series of standardised strength measures. Sixteen patients (aged seven to 47 years) were studied in an open prospective trial, and four of them in a double blind crossover trial; existing anticholinesterase medication was continued. For the group as a whole, there was a highly significant increase in muscle strength (p less than 0.001; n = 16). In individual paired comparisons, 13 out of 16 showed significant improvement in the open trial and four out of four in the blind crossover trial. In conclusion, 3,4-DAP, either alone or combined with anticholinesterase medication, may be a useful additional treatment in congenital myasthenia.

4-Aminopyridine↗
PubMed1987

Cryptococcal choroidoretinitis and immunodeficiency.

A 30 year old man with Hodgkin's disease, clinically in remission, presented with blurred vision in one eye due to a choroiditis. He developed headaches 10 days after commencing oral steroids and was subsequently found to have cryptococcal meningitis. The meningitis and choroiditis resolved on antifungal medication. This is the first case of cryptococcal choroiditis recorded in the United Kingdom.

Adult↗