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Biomedical subjects

W R Markesbery

Publications and source records attributed to W R Markesbery.

At least 199 records · Page 11Linked to original sources

Evidence for an altered physical state of membrane proteins in erythrocytes in Friedreich's ataxia.

Electron spin resonance, scanning electron microscopic, and SDS-polyacrylamide gel electrophoretic studies of erythrocytes in Friedreich's ataxia have been performed. No alteration in the physical state of membrane lipids, in morphology, or in the staining profile of erythrocytes in Friedreich's ataxia could be demonstrated. An altered conformation and/or organization of proteins in erythrocyte membranes in this disorder was suggested by spin labeling studies (P less than 0.025), favoring the possibility of a generalized membrane abnormality in Friedreich's ataxia. These findings are discussed in relation to other inherited neurological diseases where similar studies have been performed.

Electron Spin Resonance Spectroscopy↗

Lactic acidemia, mitochondrial myopathy, and basal ganglia calcification.

A 27-year-old man had limb weakness, short stature, neurosensory hearing loss, seizures, mild peripheral neuropathy, neurogenic bladder, elevated cerebrospinal fluid (CSF) protein content, primary lactic acidemia, and basal ganglia calcification. Muscle biopsy revealed numerous ragged-red fibers. On electronmicroscopy there were mitochondrial alterations, including many intramitochondrial inclusions. The mother of the patient had Vogt-Koyanagi-Harada syndrome, a combination of rare disorders in the same family that has not been previously described.

Adult↗

Treatment for patients with cerebral metastases.

To establish the effectiveness of treatment of patients with intracranial metastatic neoplasms, a retrospective study of survival of patients who had surgical excision, irradiation, or chemotherapy was compared with survival of patients who received no treatment. Our results indicate that although any form of therapy was superior to no treatment, no modality was clearly better than another. Furthermore, the prognosis for survival of patients with solitary lesions from a known primary was only slightly better than that of patients with numerous metastases. The prognosis was slightly improved when the cerebral lesion was detected before finding the primary site of origin. These observations should be considered when planning treatment for patients with brain metastases.

Adolescent↗

Huntington disease associated with Alzheimer disease.

The clinicopathological study of a case of Huntington disease with early severe dementia is presented. The pathological findings were those of Huntington disease (atrophy with neuronal loss and astrocytosis in the neostriatum) and Alzheimer disease (neuronal loss with numerous senile plaques and neurofibrillary tangles in the neocortex). Ultrastructural study of neurofibrillary tangles showed that they were composed of twisted tubules similar to those found in Alzheimer disease.

Alzheimer Disease↗

Increased sodium plus potassium adenosine triphosphatase activity in erythrocyte membranes in Huntington's disease.

Dopa-decarboxylase, acetylcholinesterase, sodium plus potassium stimulated adenosine triphosphatase (Na+ + K+-ATPase), and membrane-bound protein kinase were compared in the erythrocytes of patients with Huntington's disease and normal controls. All these enzymes also exist in the basal ganglia. The Na+ +K+-ATPase level was elevated (p less than 0.05) in Huntington's disease, while no significant changes were observed in the other enzymes. This finding is consistent with the concept that Huntington's disease is associated with a general membrane abnormality.

Acetylcholinesterase↗

Relationship of lymphocyte invasion and survival of brain tumor patients.

The length of survival of 149 patients harboring primary brain tumors was retrospectively correlated with the presence and location of lymphocytic infiltration. Mononuclear invasion of malignant gliomas confined to the perivascular spaces was the only histolgical finding that correlated significantly with survival. Patients with malignant gliomas containing perivascular infiltration live up to four months longer than those with no lymphocyte infiltration. The survival of patients with brain tumors who had lymphocyte invasion associated with areas of hemorrhage and necrosis beyond and separate from perivascular spaces was the same as far as for those with no lymphocyte involvement.

Astrocytoma↗

Juvenile amaurotic idiocy (neuronal ceroid lipofuscinosis) and lymphocyte fingerprint profiles.

Lymphocytes from 3 children with a form of juvenile amaurotic idiocy (characterized by retinal blindness, progressive dementia, and extrapyramidal motor disturbance) were studied by electron microscopy. Numerous fingerprint profiles (FP) were found in vacuolated lymphocytes from all 3 patients and an asymptomatic younger sibling of 1 patient who subsequently became symptomatic. We propose that the combination of this clinical picture and vacuolated lymphocytes with FP is sufficiently distinctive for clinical and research purposes until the biochemical defect is discovered. Wider utilization of ultrastructural study of lymphocytes should increase the number of children diagnosed and allow detection of asymptomatic patients.

Adolescent↗

Erythrocyte membrane alterations in Huntington disease: effects of gamma-aminobutyric acid.

The interaction of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) with erythrocyte membranes from patients with Huntington disease and normal controls has been studied by electron spin resonance. GABA affects the physical state of erythrocyte membrane proteins in control and Huntington disease differently. In addition, after exposure of spin-labeled Huntington disease erythrocyte membranes to 0.1 mM GABA, the relevant electron spin resonance parameters reflecting the physical state of membrane proteins are indistinguishable from those of untreated control membranes. These findings support the concept that this disease is associated with a generalized membrane defect.

Electron Spin Resonance Spectroscopy↗

Metabolic implications of distal atrophy. Carbohydrate metabolism in centronuclear myopathy.

Centronuclear myopathy, like myotonic dystrophy, is characterized by muscle wasting and type 1 fiber atrophy. To determine whether this disorder might include a derangement in carbohydrate metabolism similar to that in myotonic dystrophy, 3 comparably wasted patients with centronuclear myopathy, myotonic dystrophy, and neurogenic atrophy were investigated. The patient with centronuclear myopathy had mild glucose intolerance and hypoinsulinemia after oral glucose ingestion in bold contrast to the normal glucose tolerance and hyperinsulinemia observed in the myotonic dystrophy patient. No abnormality was seen in oral glucose tolerance in the patient with neurogenic atrophy, and all 3 patients had normal insulin tolerance. Forearm insulin infusion demonstrated normal stimulation of muscle glucose uptake in the patients with centronuclear myopathy and neurogenic atrophy in contrast to the markedly diminished response to insulin seen in the patient with myotonic dystrophy. These data indicate that neither distal wasting or type 1 fiber atrophy are responsible for the abnormalities in carbohydrate metabolism in myotonic dystrophy.

Adult↗

Lactic acidosis associated with cerebellar vermal atrophy and cardiomyopathy.

The association of fluctuating neurological signs and congestive cardiomyopathy with chronic lactic acidosis is described in a 5 1/2 year-old-boy who ultimately succumbed to congestive heart failure. The autopsy findings included severe atrophy of the anterior cerebellar vermis and a hypertrophied heart with left sided endocardial fibroelastosis. Skeletal and cardial muscle calcification was prominent and probably due to the effect of intracellular metabolic alterations associated with lactic acidosis. A review of the literature shows that the combination of cardiomyopathy, isolated atrophy of cerebellar vermis and muscle fiber calcification have not been reported in association with idiopathic lactic acidosis previously.

Acidosis↗

Infratentorial neuroepithelial cyst (colloid cyst). Case report.

An asymptomatic neuroepithelial cyst (colloid cyst) located in the leptomeninges between the inferior colliculus and the paravermal region of the superior cerebellum was an incidental postmortem finding. The cyst was lined by ciliated pseudostratified columnar epithelium of the respiratory tract type as lell as cuboidal epithelium of the ependymal type. Its developmental relationship to previously described colloid and paraphyseal cysts in the third ventricle is discussed.

Adolescent↗

General immunocompetence of rats bearing avian sarcoma virus-induced intracranial tumors.

The mitogenic responsiveness of spleen cells obtained from avian sarcoma virus-inoculated Fischer 344 rats was studied. Sixty % of the rats had astrocytomas, 13% had sarcomas, 7% had mixed gliosarcomas, and 20% had no evidence of tumors. Only spleen cells from rats bearing astrocytomas had significantly diminished responses to phytohemagglutinin and concanavalin A (Con A) when compared to control responses. The decreased responsiveness observed with phytohemagglutinin was limited to the optimal concentration range (10 and 20 microgram) while a broader concentration of Con A (0.01 to 50 microgram) induced significant suppression. Moreover, a more profound immunosuppression was observed with Con A. The results also demonstrated that spleen cells from rats with the largest astrocytomas exhibited the greatest suppression. From the results of this study, it appears the avian sarcoma virus-induced astrocytoma in rats is an immunological parallel of the human disease based on the loss of general immunological competence as assessed by responsiveness of lymphocytes to phytohemagglutinin and Con A.

Alpharetrovirus↗

Methyl bromide intoxication: neurologic features, including simulation of Reye syndrome.

Three family members intoxicated with methyl bromide presented with a variety of neuropsychiatric manifestations including coma, severe status epilepticus, hyporeflexia, and acute psychosis. The simulation of Reye syndrome in the child emphasizes the need for careful toxicologic screening of all children presenting with this syndrome. The initial diagnostic difficulty encountered in these cases emphasizes the need for heightened awareness of the toxic chemicals used in local industries and the clinical manifestations of their intoxication.

Adult↗