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Biomedical subjects

O S Morgan

Publications and source records attributed to O S Morgan.

17 recordsLinked to original sources

Myasthenia gravis and HLA phenotypes in Jamaicans.

We determined HLA-antigen frequencies and corresponding relative risks (RR) in 30 Jamaicans with myasthenia gravis (MG) and 40 normal controls. Using a microcytotoxicity assay and commercially prepared typing trays, we found that the strongest HLA associations with MG in Jamaicans were with HLA-A2 (RR = 6.15), HLA-B8 (RR = 3.4), HLA-B13 (RR = 7.76), and DQw4 (RR = 3.8). After correction of the P value for the number of antigens tested, only HLA-A2 was statistically significantly increased in MG patients. There was a statistically significant negative association between MG and HLA-DR2, as well as HLA-A9 and -B5. No correlation was observed between HLA phenotype, thymic disease, clinical grades, or disease course. HLA-A2 and sex were independent risk factors for MG, female patients having a higher risk (RR = 5.8). Further studies using larger patient and control groups, locally derived typing sera, and DNA probe analysis are indicated.

Adolescent

Arsenic: the forgotten poison?

Chronic arsenic poisoning is an uncommon cause of peripheral neuropathy in Jamaica. A patient with this disorder is described. The insidious nature of chronic arsenic poisoning, with its disabling complications, is emphasised.

Adult

Pregnancy outcome in paraplegic women.

Six cases of paraplegia in pregnancy are reviewed. The major medical complications were urinary tract infection and anaemia. The obstetrical problems were pre-term labour and one perinatal loss due to unattended birth.

Adolescent

Thymectomy in myasthenia gravis. The Jamaican experience.

Forty-five patients with myasthenia gravis (MG) were subjected to thymectomy by the median sternotomy technique and were followed up for 4,380 patient months. No operative deaths occurred and 93.3% of the patients benefited from surgery with 28.8% achieving remission. Forty patients (88.5%) showed improvement within one month, and 73% of those who achieved remission did so in the first 2 years. Outcome was not affected by thymic pathology except in one patient who had a thymoma removed. These results confirm the value of thymectomy in the management of MG patients with generalised disease and the efficacy of the simple median sternotomy procedure.

Adolescent

Thyrotoxic periodic paralysis in a Jamaican male patient.

A case of thyrotoxic periodic paralysis occurring in a Black Jamaican male patient is described. Diagnosis is based on history and confirmed by evaluation of serum electrolyte during attacks and thyroid function studies. The pathophysiology, associations, therapy and prognosis are discussed. It is important that clinicians recognise the condition as all forms of periodic paralysis are amenable to treatment, and progressive weakness can be prevented or even reversed.

Adult

Amyotrophic lateral sclerosis with antecedent poliomyelitis.

Motor neurone disease may occur in patients with antecedent, sometimes remote, paralytic poliomyelitis. A Jamaican patient with this sequence is described. Research exploring the relationship between the two diseases is giving a new insight into the aetiology of motor neurone disease.

Amyotrophic Lateral Sclerosis

Myasthenia gravis in Jamaica. Clinical, immunological and genetic studies.

Clinical, immunological and genetic parameters were studied in 73 Jamaican patients with myasthenia gravis (MG). The reported bimodal clinical distribution of females with early onset of disease and males with late onset was not observed. The female to male ratio was 2:1. The most frequent manifestations of disease were ptosis (84.9%), general muscle weakness (68.5%), bulbar symptoms (41.1%) and diplopia (32.9%). Unusual presenting features such as unilateral ptosis, recurrent chest infection and stumbling while walking resulted in diagnosis being missed in 5.8% of cases. The sensitivity of radioimmunoassay in detecting acetylcholine receptor antibody (AchR-Ab) in sera from a subgroup of 35 MG patients was 71.4% whilst that of the ELISA was only 14.2%. There was no correlation between concentration of AchR-Ab and severity of disease. Similarly, there was no association between HLA-type, thymic pathology and course of disease. HLTV-I could not be implicated in the pathogenesis of this disease. There was a paucity of other associated autoimmune conditions among MG patients. Thymectomy was an important therapeutic modality in that improvement was observed in 22 cases and remission in 11.

Adolescent

Screening for prolonged incubation of HTLV-I infection in British and Jamaican relatives of British patients with tropical spastic paraparesis.

OBJECTIVE: To compare the prevalence of antibody to and proviral DNA of the retrovirus HTLV-I in relatives of 11 British patients with tropical spastic paraparesis who had migrated from Jamaica before they developed symptoms, and to examine factors possibly related to transmission of HTLV-I. DESIGN: Migrant, family study. Antibody state was determined by several methods and confirmed by western blotting; the polymerase chain reaction was used to detect proviral DNA. SETTING: Britain and Jamaica. SUBJECTS: All available first degree relatives: those born and still resident in Jamaica (group 1); those born in Jamaica who migrated to Britain (group 2); and index patients' children who were born and resident in Britain (group 3). All had been breast fed and none had had blood transfusions. RESULTS: Of the 66 living relatives, 60 were traced. Seroprevalence among those born in Jamaica (irrespective of current residence) was 22% (10/46; 95% confidence limits 9 to 34%) compared with zero among British born offspring (0/14) and was higher in group 2 at 33% (7/21; 12 to 55%) than in group 1 at 12% (3/25; 0 to 25%). (Patients in group 1 had the greatest mean age.) Proviral DNA was not detected in any subject negative for HTLV-I antibody, making prolonged viral incubation in those negative for the antibody unlikely. CONCLUSION: In this sample factors related to place of birth and early residence were more important in transmission of HTLV-I than maternal or age effects. In areas with a low to moderate prevalence policies of preventing mothers who are carriers of the virus from breast feeding would be premature.

Base Sequence

Spinal cord compression in thalassaemia.

Two cases of spinal cord compression resulting from extramedullary haemopoiesis in patients with thalassaemia of intermediate clinical severity are reported. The association between mild thalassaemia with long survival and the risk of spinal cord compression from extramedullary haemopoietic deposits is emphasised.

Adult

Xanthogranulomatous pyelonephritis: a report of 2 cases.

Two cases of xanthogranulomatous pyelonephritis are reported in Negroes. The clinical findings are similar to those in previously reported cases. In 1 case nephrolithotomy was followed by the development of a perinephric abcess 8 months later. Late diagnosis has limited experience with more conservative management, which should be reserved for demonstrably focal disease.

Aged