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Biomedical subjects

O S Morgan

Publications and source records attributed to O S Morgan.

At least 37 records · Page 2Linked to original sources
PubMed1993

Spirochetal antibodies in tropical spastic paraparesis: their significance.

The prevalence of antibodies to Treponema pallidum and Borrelia burgdorferi was investigated in Jamaicans with tropical spastic paraparesis (TSP). A significantly higher prevalence of reactive serologic tests for syphilis (STS) was found in TSP patients (35.0%) when compared with controls (14.5%; P < .001). Venereal Disease Research Laboratory (VDRL) test titers less than 1:8 were obtained in 88.4% of reactive sera from patients and in all reactive sera of controls. The biologic false-positive rate was also significantly higher in TSP patients (P < .05). A higher frequency of a reactive STS was observed in TSP patients (P < .01) and controls (P < .001) more than 40 years of age. The prevalence of reactive serologic tests for syphilis in TSP patients younger than 40 years was also higher than in controls in this age group (P < .1). The prevalence of positive immunofluorescent antibody tests and enzyme immunoassay for antibodies to B burgdorferi was similar in sera of TSP patients (12.5%) and healthy controls (10%). However, none of the sera was positive by Western immunoblot. Leptospiral antibodies were not present in any serum tested. This study's data do not support an etiologic role for treponemal disease in tropical spastic paraparesis, but rather suggest that the high prevalence of reactive STS in Jamaicans is multifactorial.

Adolescent↗
PubMed1993

Reactive serological tests for syphilis in tropical spastic paraparesis: a dilemma.

The prevalence of reactive serological tests for syphilis (STS) was investigated in 183 Jamaican patients with tropical spastic paraparesis (TSP) and 200 age and sex matched controls. A significantly higher prevalence of reactive STS was found in TSP patients (34.9%) compared with controls (14.0%, P < 0.001). The biological false positive (BFP) rate was also significantly higher in TSP patients (P < 0.01) as well as controls (P < 0.001) over 40 years of age. However, these findings do not imply a pathogenetic role for treponemal disease in TSP. The high prevalence of reactive STS in Jamaican TSP patients may be multifactorial, and include biological false positives (BFP), previous childhood yaws and concurrent syphilis.

Adult↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1992

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↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1989

HTLV-1 and polymyositis in Jamaica.

IgG antibodies to human T-cell lymphotropic virus (HTLV-1) were found in 11 of 13 (85%) Jamaican patients with idiopathic adult polymyositis. The association was first observed in 7 patients with polymyositis who were included in a control group of 100 patients with neurological and neuromuscular diseases in a serological investigation of the prevalence of HTLV-1 antibody in patients with tropical spastic paraparesis. All 7 patients with polymyositis were positive for the antibody by an enzyme-linked immunosorbent assay, confirmed by western blot. Because of this striking association a further 6 patients with polymyositis were identified and tested, 4 of whom were also seropositive for HTLV-1 antibody.

Adult↗
PubMed1989

Comparison of a human T-cell lymphotropic virus type I strain from cerebrospinal fluid of a Jamaican patient with tropical spastic paraparesis with a prototype human T-cell lymphotropic virus type I.

The isolation and characterization of a human T-cell lymphotropic retrovirus related to human T-cell lymphotropic virus type I (HTLV-I) from cerebrospinal fluid of a Jamaican patient with tropical spastic paraparesis is described. The virus isolate is a typical type C retrovirus as seen by electron microscopy and is related to prototype HTLV-I isolated from patients with adult T-cell leukemia but is not identical to this prototype HTLV-I as seen by restriction enzyme mapping.

Aged↗
PubMed1989

An assessment of the doctorate of medicine (internal medicine), University of the West Indies.

The outcome is described of 48 entrants to a postgraduate degree course (DM) in Internal Medicine established at the University of the West Indies in 1974. Contact by postal questionnaire was established in 96% of 26 graduates and 82% of 22 non-graduates. 22 of 25 DM graduate responders have remained in the Caribbean, working in six Caribbean territories. All graduate responders developed a subspecialty interest. The graduates' primary employers are the University (9) and the Government (12). However, failure to graduate did not necessarily preclude qualification as consultant physician (7 of 18 responders). Major difficulties with the DM programme included: (1) in practice, lack of recognition by contributing territories of individual DM (Internal Medicine) graduates; (2) incomplete regional coverage; (3) lack of adequate funding for the programme; (4) an inadequate research training input; and (5) difficulties with seniority for staff who trained in Jamaica to go to work in another territory. All these problems have solutions. Overall, the international recognition of the new degree programme has been satisfactory and the graduates' own assessment of the training was complimentary. At last a system has been devised that enables postgraduates to train as internal medicine specialists in the Caribbean to practise effectively within the Caribbean health system.

Adult↗
PubMed1988

The role of HTLV-I in tropical spastic paraparesis in Jamaica.

We report clinical and laboratory investigations of 47 native-born Jamaican patients with endemic tropical spastic paraparesis and of 1 patient with tropical ataxic neuropathy. Mean age at onset was 40 years, with a female-male preponderance (2.7:1). Neurological features of endemic tropical spastic paraparesis are predominantly those of a spastic paraparesis with variable degrees of proprioceptive and/or superficial sensory impairment. Using enzyme-linked immunoabsorbent assay (ELISA), IgG antibodies to human T-lymphotropic virus type I (HTLV-I) were present in 82% of sera and 77% of cerebrospinal fluids. On Western blot analysis, IgG antibodies detected the p19 and p24 gag-encoded core proteins in both serum and cerebrospinal fluid. Titers were tenfold higher by ELISA in serum than in cerebrospinal fluid, and some oligoclonal bands present in fluid were not seen in serum. Serum-cerebrospinal fluid albumin ratios were normal, and IgG indexes indicated intrathecal IgG synthesis. Histopathological changes showed a chronic inflammatory reaction with mononuclear cell infiltration, perivascular cuffing, and demyelination that was predominant in the lateral columns. In 1 patient, a retrovirus morphologically similar to HTLV-I on electron microscopy was isolated from spinal fluid. Our investigations show that endemic tropical spastic paraparesis in Jamaica is a retrovirus-associated myelopathy and that HTLV-I or an antigenically similar retrovirus is the causal agent.

Adolescent↗
PubMed1988

Seroprevalence of antibodies to HTLV-I in patients with chronic neurological disorders other than tropical spastic paraparesis.

Human T-lymphotropic virus type I (HTLV-I), the etiological agent of adult T-cell leukemia/lymphoma, also appears to be the cause of tropical spastic paraparesis, a chronic myelopathy reported in several different regions of the world. The prevalence of antibodies to HTLV-I in patients with chronic neurodegenerative disorders other than tropical spastic paraparesis and in patients with some muscle inflammatory disorders has been investigated. IgG antibodies to HTLV-I were measured in the sera and/or cerebrospinal fluid from 82 Guamanian patients with amyotrophic lateral sclerosis and parkinsonism-dementia, 164 Guamanian normal controls, 10 patients with kuru from the Eastern Highlands of Papua New Guinea, 4 patients with Viliuisk encephalomyelitis from the Iakut region of eastern Siberia, 45 Italian patients with multiple sclerosis, and 56 patients with polymyositis (49 from the United States and 7 from Jamaica). As determined by enzyme-linked immunosorbent assay, Western immunoblot, and gelatin particle agglutination techniques, serological evidence of HTLV-I infection was found in 1 patient with amyotrophic lateral sclerosis and 1 control subject from Guam, and in 1 patient from the United States and all 7 Jamaican patients with polymyositis. Except for the high seropositivity rate among the group of Jamaican patients with polymyositis, our data indicate that HTLV-I is an unlikely causative agent in the spectrum of the neurological diseases examined. The seropositivity of the 7 Jamaican patients with polymyositis requires further study.

Adult↗