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Biomedical subjects

R H Hewlett

Publications and source records attributed to R H Hewlett.

15 recordsLinked to original sources
PubMed1998

Massive posterior fossa tuberculous abscess developing in a young child treated for miliary tuberculosis. Possible role of very rapid acetylation of isoniazid.

A 21-month-old infant presented with acute obstructive hydrocephalus due to a large tuberculous abscess in the posterior fossa 3 months after starting treatment for miliary tuberculosis. Insertion of a ventriculo-peritoneal shunt resulted in some clinical improvement but subsequent neurological deterioration occurred due to massive enlargement of the tuberculous abscess despite apparently adequate antituberculosis therapy. Repeated drainage procedures of the abscess eventually resulted in resolution and clinical improvement. As part of the workup for poor weight gain and the unusual clinical course, the patient's acetylation status for isoniazid was determined and found to be very rapid. Doubling the daily dose of isoniazid was followed by a dramatic weight increase and further clinical improvement. Decreasing the load of tuberculous antigen by draining the abscesses and increasing the pulse exposure of isoniazid is the best possible explanation for the clinical improvement finally seen in this patient.

Abscess↗
PubMed1995

Semiquantitative postembedding characterization of intermediate filaments in central nervous system lesions using immunoelectron microscopy.

Standardized postembedding immunoelectron microscopy was performed to demonstrate glial fibrillary acidic protein (GFAP) and vimentin in individual intermediate filaments to determine the diagnostic value of demonstrating ultrastructural and immunophenotypic characteristics of intermediate filaments in routine brain biopsy specimens. Dual expression of GFAP and vimentin was observed in the astroblastoma and astrocytes of Alexander's disease. The antigen availability for vimentin, however, was too low to allow reliable assessment of the GFAP:vimentin ratio in individual intermediate filaments and/or filament bundles. In meningioma, only vimentin positive intermediate filaments were found. GFAP positive intermediate filaments were present in all other specimens except the oligodendroglial components of the mixed glioma, which were devoid of intermediate filaments. GFAP positivity in the filamentous periphery and electron-dense core of Rosenthal fibers was demonstrated. Technical and tissue processing factors had a significant effect on particle density values obtained for individual specimens. Although the number, distribution, and density of glial intermediate filaments varies in different astroglial entities, correlation of particle density values determined by immunoelectron microscopy with relative GFAP concentrations in different lesions requires utmost caution. Nevertheless, application of the postembedding approach to routinely fixed biopsy specimens indicated an association of different entities with the exclusive presence of GFAP and/or vimentin in individual intermediate filaments, thus emphasizing the diagnostic value of intermediate filament typing for pathological characterization.

Adolescent↗
PubMed1987

Diagnostic problems of leptomeningeal lymphoma. A report of 3 cases.

Three cases are presented in which occult lymphoreticular malignant tumour spread to the spinal and cranial subarachnoid spaces inducing a problematic neurological illness characterised by poorly localised neuralgic pain, slowly progressive paresis and, in 2 patients, papilloedema with computed tomographic evidence of ventricular dilatation. Despite intensive investigations, diagnosis was only achieved at autopsy. A progressive disturbance of spinal and cranial nerve function should direct the attention of the clinician to the possibility of diffuse meningeal involvement by a malignant or inflammatory process.

Adolescent↗
PubMed1982

Correlative clinical, neuroradiological and pathological findings in subacute sclerosing panencephalitis: a report of 5 cases.

Changes in the brain in subacute sclerosing panencephalitis (SSPE) as detected on computed axial tomography (CT) have so far been insufficiently assessed. An attempt was therefore made to correlate the clinical, neuroradiological and pathological findings in 5 consecutive, unselected cases, 4 of which were somewhat atypical. It is concluded that within the context of a degenerative neurological disorder of childhood, the CT findings in SSPE correlate well with clinical staging, and also illuminate certain aspects of the pathogenesis and dynamics of the disease process.

Brain↗
PubMed1982

The spectrum of disease in weakness and wasting of the quadriceps muscles. Case reports.

Three patients who presented with weakness and wasting of the quadriceps muscles ('quadriceps myopathy'), are reported. In each, electrophysiological and biopsy studies revealed completely different pathological processes, including motor unit disease, polymyositis and muscular dystrophy. Double biopsies performed in 2 of the patients showed the disease process to involve upper as well as lower limbs. The diffuse and heterogeneous nature of this form of neuromuscular disease is confirmed.

Aged↗
PubMed1981

A study of a family with inherited disease of cardiac and skeletal muscle. Part II. Skeletal muscle morphology and mitochondrial oxidative phosphorylation.

Skeletal muscle morphology and mitochondrial oxidative phosphorylation capacity were examined in a family whose members showed very combinations of mental subnormality, cardiomyopathy and muscle weakness. Light and electron microscopic findings suggested a neuropathic process, while tests of mitochondrial function indicated a state of tight coupling of oxidative phosphorylation, a feature in marked contrast to those in biochemical studies so far reported.

Adenosine Triphosphate↗
PubMed1978

McArdle's disease--what limit to the age of onset?

A patient with McArdle's disease is reported in whome proximal muscle weakness began in the 7th decade. Other unusual features included the absence of muscle cramps at any stage, asymmetrical wasting of the shoulder girdle muscles and calf hypertrophy. Muscle biopsy revealed a vacuolar myopathy, absent phosphorylase staining and qualitatively low glycogen content.

Age Factors↗
PubMed1976

Chronic proximal muscular weakness in alcoholics.

In spite of the fact that peripheral neuropathy is very common in alcoholics, the chronic proximal muscular weakness and wasting found in alcoholics have been ascribed to myopathy. A clinical, biochemical, and histological study of 13 patients provided evidence for neuropathy. Enzymic histochemistry of muscle demonstrated selective type 2 neurogenic atrophy with evidence of reinnervation.

Adult↗
PubMed1976

Histiocytosis X of the cauda equina.

Laminectomy, performed on a 46-year-old woman because of weakness and paresthesias of the lower limbs, showed multiple discrete yellow nodules on the nerve roots of the cauda equina. One of these lesions was excised and proved to be a granuloma consistent with the diagnosis of histiocytosis X.

Cauda Equina↗
PubMed1975

Granulomatous myopathy: its relationship to sarcoidosis and polymyositis.

In three cases of generalized muscle weakness, muscle biopsy revealed well-defined, non-caseating epithelioid granulomata with giant cells. In one of these patients there was, in addition, a high serum CPK and histological evidence of widespread muscle cell degeneration and regeneration, apparently unrelated to the granulomatous process. In a re-examination of the histopathology of these cases, using biopsy material from a fourth case of proven sarcoidosis as a standard, it was concluded that there are no special features of the granulomatous/giant cell process which permit the separation of the case of presumed polymyositis. However, it appeared that granulomata per se do not exert a significant ill effect on surrounding muscle cells, and that evidence of widespread degeneration of muscle cells is the important point of distinction.

Adult↗
PubMedDate not supplied

DSM-III-R classification of psychiatric symptoms in systemic lupus erythematosus.

DSM-III-R criteria applied in the evaluation of 88 systemic lupus erythematosus patients revealed a point prevalence rate of 18.2% for psychiatric disorders, the most common diagnosis being adjustment disorder (11.4%). No patients had disorders compatible with a functional psychosis. Psychiatric morbidity was not associated with increased disease activity, corticosteroid use, brain magnetic resonance imaging abnormalities, or electroencephalogram abnormalities. High scores on a life event scale were associated with psychiatric disorders, suggesting that psychosocial stress is etiologically important. Cognitive testing showed that poor performance on the Stroop Colour-Word Inference Test was associated with psychiatric disorders.

Adolescent↗
PubMedDate not supplied

Acute stroke in a child with miliary tuberculosis.

Neurological symptoms in childhood miliary tuberculosis are generally caused by underlying tuberculous meningitis (TBM), since the 2 conditions commonly occur concurrently. Cerebral infarction, a well-recognized complication of TBM, usually results from tuberculous periarteritis and secondary thrombosis. Neuropathological studies have demonstrated that the anterior cerebral circulation is more commonly affected than the arteries of the vertebro-basilar system, and basilar artery occlusion as a presenting manifestation of childhood miliary tuberculosis or TBM has not been described before. We report a 13-month-old infant who presented with fever and convulsions, terminating in acute decerebration after a second prolonged seizure 1 week after the onset of symptoms. Magnetic resonance (MR) imaging demonstrated density changes compatible with acute vertebro-basilar ischemia as well as multiple cerebral granulomas. A chest radiograph showed diffuse miliary tuberculosis. Postmortem examination confirmed this diagnosis and revealed acute occlusion of the basilar artery by an infected (septic) thromboembolus showing granulomatous inflammation, which most likely arose from an endocardial vegetation with identical histology.

Cerebral Infarction↗