PubMed Health⌕ Search

Biomedical subjects

D M Simpson

Publications and source records attributed to D M Simpson.

At least 19 recordsLinked to original sources
PubMed1992

Neuromuscular complications of human immunodeficiency virus infection.

As the lifespan of patients with HIV infection is prolonged with more effective antiviral therapies, the prevalence of neuromuscular disorders is likely to increase. The understanding of the pathogenesis and optimal therapy of these illnesses has advanced during the past 5 years. However, there are still significant gaps in our knowledge. It is important that neurologists remain at the forefront of investigation and treatment of these complex disorders.

HIV Infections↗
PubMed1992

Peripheral neuropathies associated with human immunodeficiency virus infection.

In the 1990s, HIV has replaced syphilis as the "great masquerader." Virtually every level of the neuraxis may be affected in a patient with HIV infection. The superimposition of multiple levels of neuropathology further complicate the bedside neurologic diagnosis of an AIDS patient. This article has reviewed the variety of forms of peripheral neuropathy that may be associated with HIV infection and its treatment. Distal symmetrical polyneuropathy may be produced in patients with HIV infection by neurotoxic drugs (e.g., vincristine, INH, ddC, or ddI) or by vitamin B12 deficiency or may develop in the later stages of HIV infection without identifiable cause. GBS and CIDP occur with increased frequency in early HIV infection owing to presumed autoimmunity, and these IDPs respond to plasmapheresis or prednisone, similar to HIV-seronegative patients. A limited distribution of mononeuropathy simplex or multiplex occurs in patients with CD4 counts greater than 200; the neuropathy will usually spontaneously improve in these patients. Widespread mononeuropathy multiplex may occur in patients with AIDS and CD4 counts less than 50 and is then usually caused by CMV infections; those neuropathies are usually progressive unless antiviral treatment is given. Progressive polyradiculopathy usually occurs in patients with AIDS and low CD4 counts. If the cerebrospinal fluid has a polymorphonuclear pleocytosis, CMV infection is almost always present, and progression is expected unless ganciclovir therapy is promptly started. Finally, mild autonomic neuropathy is commonly present in HIV-infected patients. Protocols for the evaluation and therapy of cranial and peripheral neuropathies are presented (Figs. 6 and 7). It is unfortunate but likely that increasing numbers of "neuro-AIDS" patients will be encountered, not only in urban medical centers but also in general community practice. The pace at which research in the field of HIV research has proceeded is unprecedented. It is, therefore, important that neurologists stay at the forefront of investigation and clinical care of these complex disorders.

Autonomic Nervous System Diseases↗
PubMed1992

Involving the patient can free resources.

Involving the patient in the scheduling of theatres by a Diary Booking System improves patient choice and thus the quality of service offered. To assess the feasibility and cost effectiveness of such a system, a trial was conducted within ENT surgery. One consultant's theatre schedules were analysed before and after the introduction of a diary booking system. A second consultant's schedules, not using a diary booking system, were analysed to confirm the absence of seasonal variation or other factors. The trial consisted of three months' schedules before introduction and three months after introduction. The feasibility of the system was confirmed. The trial reduced cancellations by 32% and failures to attend by 68%. The introduction of the Diary Booking System increased the number of operations conducted by nearly one per session.

Appointments and Schedules↗
PubMed1991

Collagen cross-linking in bovine gingiva.

Tissue samples from 5 different sites of 6 bovine mandibles were used to quantify collagen cross-links as moles cross-link per mole of collagen. Gingiva contained primarily 3 reducible cross-links, deH-DHLNL, deH-HHMD, and deH-HLNL, and relatively small amounts of non-reducible cross-links. The cross-link density varied from site to site within the same mandible. DeH-DHLNL showed the most significant increase from anterior to posterior; the content in the retromolar region was 3-fold greater than in the anterior lingual site. Histologically, the posterior samples, especially the retromolar gingiva, contained less mature (thinner) collagen bundles. These findings suggest that the maturity of bovine mandibular gingival collagen varies at different sites.

Animals↗
PubMed1991

Human immunodeficiency virus infection in Northern Ireland 1980-1989.

To 31st December 1989, 71 persons are known to have attended medical practitioners in Northern Ireland with a diagnosis of Human Immunodeficiency Virus (HIV) infection. Twenty-one of these persons have had the diagnosis of Acquired Immune Deficiency Syndrome (AIDS) and 11 have died. The distribution of reports in the "at risk" categories of homosexual/bisexual males, injecting drug users, heterosexual males and females was significantly different (p less than 0.001) from those reported in the United Kingdom as a whole. Of tests for HIV infection carried out in patients attending the genitourinary medicine department of the Royal Victoria Hospital between 1987-1989, 0.16% have been positive. The prognostic value of the T4 lymphocyte count at presentation for the subsequent development of AIDS was significant (p = 0.0011). The commonest AIDS indicator disease diagnosed was Pneumocystis carinii pneumonia which was seen in seven of the 21 patients (33%).

Acquired Immunodeficiency Syndrome↗
PubMed1991

Pediatric emergency room visits: a risk factor for acquiring measles.

In recent years, measles outbreaks have occurred among unimmunized children in inner cities in the United States. From May 1988 through June 1989, 1214 measles cases were reported in Los Angeles, and from October 1988 through June 1989, 1730 cases were reported in Houston. More than half of cases were in children younger than 5 years of age, most of whom were unvaccinated. Of cases of measles in preschool-aged children, nearly one fourth in Los Angeles and more than one third in Houston were reported by one inner-city emergency room. To evaluate whether emergency room visits were a risk factor for acquiring measles, in Los Angeles, 35 measles patients and 109 control patients with illnesses other than measles, and in Houston, 49 measles patients and 128 control patients, who visited these emergency rooms, were enrolled in case-control studies. Control patients were matched to case patients for ethnicity, age, and week of visit. Records were reviewed to determine whether case patients had visited the emergency room during the period of potential measles exposure, which was defined as 10 to 18 days before rash onset, and whether control patients had visited 10 to 18 days before their enrollment visit. In Los Angeles, 23% of case patients and 5% of control patients (odds ratio = 5.2, 95% confidence interval = 1.7, 15.9; P less than .01), and in Houston, 41% of case patients and 6% of control patients (odds ratio = 8.4, 95% confidence interval = 3.3, 21.2; P less than .01), visited the emergency room during these periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Human immunodeficiency virus wasting syndrome may represent a treatable myopathy.

We evaluated 5 patients with the diagnosis of HIV wasting syndrome. None had severe diarrhea or other causes for malabsorption. All had myopathy by clinical, laboratory, and muscle biopsy criteria. Withdrawal of azidothymidine in 3 patients did not lead to improvement. Corticosteroid therapy was effective in 3 patients.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Clinical Q fever in Northern Ireland 1962-1989.

Q fever was diagnosed in 443 patients in Northern Ireland between 1962 and 1989. From 1986 onwards there was an increase, which peaked in 1989 with 107 cases of whom 47 were infected in Ballycastle, Co Antrim. There were three outbreaks and 21 clusters of patients with Q fever. Most cases were in April and May which correlated with the peak lambing and calving season. Q fever mainly affected males in the 40-49 year old age group. County Antrim had the highest prevalence rate of 40/100,000 population and also had the most sheep. The number of sheep in Northern Ireland has doubled in the past ten years. Q fever was strongly associated with occupation and animal contact. Eighty-seven patients (19.6%) drank unpasteurized milk. The commonest presenting illnesses were pneumonia (62.8%), influenza-like illness (24.6%), involvement of the heart (9.0%) and hepatitis (1.6%). Thirty-two patients (7.2%) had endocarditis, 20 of whom had prosthetic valves and three of whom died. Coxiella burnetii was present on valves removed from seven patients.

Adolescent↗
PubMed1989

Voluntary movement dysfunction in schizophrenics.

Several aspects of fine motor control were compared in schizophrenics and two control populations. The motor behavior analyzed was a button-press response in a forced choice paradigm. Three areas of abnormality were seen in schizophrenics: first, the interval preceding the motor response was characterized by reduced motor steadiness prior to the button-press response; second, the motor response was made with excessive force (hyperdynamia); and third, the agonist-antagonist synchrony (motor reversal) was impaired. Schizophrenics on and off neuroleptics did not differ on any measure of motor control, but schizophrenics with clinically observed tardive dyskinesia were found to have significantly less steadiness prior to the motor response than other schizophrenics.

Adult↗
PubMed1988

Human immunodeficiency virus-associated myopathy: analysis of 11 patients.

Neuromuscular disorders reported in association with human immunodeficiency virus (HIV) infection include several forms of peripheral neuropathy and polymyositis. We report 11 patients with HIV-associated myopathy. Five patients with acquired immunodeficiency syndrome (AIDS), 2 with AIDS-related complex, and 4 otherwise asymptomatic HIV-infected patients developed progressive proximal muscle weakness. Serum creatine phosphokinase levels were elevated and electromyography revealed abnormal spontaneous activity and myopathy in most patients. All 8 muscle biopsy specimens showed fiber necrosis. Four had inflammatory infiltrates, and nemaline rod bodies were prominent in 3. Immunosuppressant therapy in 5 patients resulted in improvement. Attempts at viral localization in 4 muscle biopsy specimens were unsuccessful. These findings suggest a distinct association between HIV infection and myopathy with features atypical for polymyositis.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Low and high molecular weight cytomegalovirus-specific immunoglobulin M antibody in renal transplant patients with cytomegalovirus infections.

Sera from 27 renal transplant patients with primary and recurrent CMV infections and which were known to contain CMV-specific IgM antibodies were investigated by indirect immunofluorescence for the presence of virus-specific high molecular weight IgM (19S IgM) and low molecular weight IgM (7S IgM). After sucrose gradient fractionation of the sera, 19S IgM was found in all 27 patients, whereas 7S IgM was present in 11 out of 19 (56%) patients with primary CMV infection and in 1 out of 8 (12%) patients with recurrent CMV infection. The presence of 7S IgM was unrelated to the titre of the virus-specific IgM in whole serum. The presence of IgM rheumatoid factor was monitored by a sensitive fluorescence assay using measles virus antigen/antibody complexes. The absorption of the serum fractions with heat-aggregated gamma globulin failed to remove the specific IgM staining indicating that it was not due to IgM rheumatoid factor. On the other hand adsorption with protein A/sepharose removed the specific IgM staining from the 7S IgM fractions but not from the 19S IgM fractions. This suggests that specific 19S and 7S IgM antibodies may belong to different subclasses of IgM.

Antibodies, Viral↗
PubMed1988

Spectral analysis of heart rate indicates reduced baroreceptor-related heart rate variability in elderly persons.

Spectral analysis of the cardiac interbeat interval was used to examine baroreceptor-related supine and standing heart rate variability (HRV) in young (less than 40 years of age) and elderly (greater than 60 years of age) healthy volunteers. Heart rates and blood pressures were examined also. When supine, average heart rate, systolic and diastolic blood pressure, and HRV for the young volunteers were 66.5 bpm, 113.0/64.3 mmHg, and 5.74 log units of relative power, respectively. The same values for the elderly group were 65.4 bpm, 126.3/74.0 mmHg, and 4.43 log units. Statistical analysis revealed that, compared to the young volunteers, supine elderly volunteers had similar heart rates, higher blood pressures, and lower baroreceptor HRV. There was little change in blood pressure in either group upon standing. However, upon standing, heart rate increased 17.7 bpm and baroreceptor HRV increased to 6.58 (+ 14.6%) in the younger volunteers. This was significantly different from the elderly volunteers, whose heart rate increased by only 10.9 bpm and their HRV to 4.72 (+ 6.5%). These results indicate that much of the reduction in HRV in old age results from decreases in baroreceptor modulation of heart rate. In addition, the difference between young and old persons is greatest in the standing position because elderly individuals exhibit less recruitment of baroreceptor activity with postural change.

Adult↗