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Biomedical subjects

M Osame

Publications and source records attributed to M Osame.

At least 325 records · Page 18Linked to original sources

Diseases among men living in human T-lymphotropic virus type I endemic areas in Japan.

The health effects of human T-lymphotropic virus type I (HTLV-I) were studied in HTLV-I endemic areas in Japan during the period from September 1990 to October 1991. The study subjects were 2,847 men living in the southern part of Kyushu and engaged in light work. Ages ranged from 19 to 79 years (47.8 +/- 7.2; mean +/- standard deviation). The prevalence of each disturbance was analyzed with a logistic model. The disturbances in which the prevalence showed a significant association with HTLV-I were old tuberculosis, ulcerative colitis and ossification of the posterior longitudinal ligament of the cervical spine (OPLL). The results of the present study suggest that HTLV-I may be a risk factor for these diseases and may indicate the necessity for a synthetic study on HTLV-I.

Adult↗

Computed tomography in fetal methylmercury poisoning.

Cerebral computed tomography was studied in eight patients with fetal methylmercury poisoning. All patients had evidence of prenatal exposure to methylmercury and showed psychomotor retardation. All of them had abnormal computed tomography findings. The most common finding was sulcal and ventricular enlargement, with or without cisternal enlargement. These findings indicated generalized cortical and subcortical maldevelopment. The distribution of sulcal and fissural enlargement did not show specific dominance in central sulcus, calcarine fissure or cerebellum. This distribution contrasts with the location of focal atrophy present in adult methylmercury poisoning. The computed tomography findings were relatively mild compared with the clinical features and were not distinct from those in cerebral palsy.

Activities of Daily Living↗

Nucleotide sequence analysis of HTLV-I isolate from a Korean patient with HAM/TSP.

Limited nucleotide sequences of human T-cell lymphotropic virus type I (HTLV-1) provirus isolated from the first case of a Korean patient with HTLV-I associated myelopathy and tropical spastic paraparesis (HAM/TSP) were analysed and compared with other isolates from different regions of the world. The sequences of the env, LTR regions (536bp, 690bp respectively) showed 98.7%, 99.3% homologies with the prototype HTLV-I, ATK-1, isolated from a Japanese Adult T-cell leukemia (ATL) patient. A comparison between other isolates from different geographical origins revealed that the Korean HTLV-I isolate is more closely related to Japanese isolates than to those from other geographical origins.

Adult↗

[Juvenile Binswanger-type encephalopathy with alopecia and spondylosis deformans--a case report].

The patient is a 33-year-old male and his parents are first cousins. He noticed his hair loss since about the age 14. At age 29, he manifested gait disturbance and urinary incontinence, which gradually progressed. Neurologically, he showed dementia (WAIS < 64), pyramidal and extrapyramidal signs, and pseudobulbar palsy. His blood pressure was normal. He also had dry skin with sclerema and marked cervical and lumbar spondylosis. His brain CT showed enlargement of the lateral ventricles and the periventricular low density areas. T2 weighted image of MRI showed diffuse high intensity in the periventricular white matter. Yamada et al presented a case progressive subcortical vascular encephalopathy (Binswanger type) with alopecia and spondylosis as a possible new syndrome, and this patient has the same syndrome. The etiology of this syndrome has not been known at the present time. The biopsied skin from the patient showed much hyaline deposits like glycoprotein in perivascular area of dermis. These morphological changes are very similar to those of lipoid proteinosis. These findings suggested that the pathological mechanism of this syndrome might be related to the biochemical disturbance in lipoid proteinosis.

Adult↗

[A case of Werner syndrome associated with spastic paraparesis and peripheral neuropathy].

A 33-year-old woman, whose parents were consanguineously married, was admitted to our hospital because of progressive difficulty in walking and hoarseness in speech. She had been in good health as a child, at age 16 ulcerations appeared on the skin of feet, and have been recurrent. AT age 22, bilateral cataracts were removed. From the age of 26 years, the deformities in the toes and fingers worsened and she had difficulty in walking. At age 32, hoarseness was noticed. The patient was a diminutive woman and the skin was dry, thin and hyperpigmented. The neurological examination revealed mental retardation, spastic paraparesis and polyneuropathy. Electrophysiological studies revealed a slowing of central and peripheral nerve conduction. Sural nerve biopsy revealed a significantly higher incidence of de- and remyelination and a loss of myelinated fibers. These data suggest that the central and peripheral nervous systems are affected in Werner syndrome.

Adult↗

Frequent clonal proliferation of human T-cell leukemia virus type 1 (HTLV-1)-infected T cells in HTLV-1-associated myelopathy (HAM-TSP).

Human T-cell leukemia virus type 1 (HTLV-1) integrates its proviruses into random sites in host chromosomal DNA. Random integration of the proviruses was observed in asymptomatic HTLV-1 carriers and patients with HTLV-1-associated myelopathy (HAM/TSP). However, clonal integration has been reported in patients with adult T-cell leukemia (ATL), including that in the smoldering, chronic, and acute states, indicating clonal expansion of infected cells. In this study, we found that about 20% of HAM/TSP patients and their seropositive family members harbored subpopulation(s) of clonally proliferated cells infected with HTLV-1, although they still maintained randomly infected cells as a major population. These clones were stable during examination periods of 4 months to 3 years. However, these carriers or HAM/TSP patients did not show any significant indication of ATL. This extremely high frequency of clonal expansion of HTLV-1-infected cells indicates that some clones of HTLV-1-infected cells have a tendency to proliferate more efficiently than the other population without malignant transformation.

Cell Division↗

A novel primer extension method to detect the number of CAG repeats in the androgen receptor gene in families with X-linked spinal and bulbar muscular atrophy.

X-linked spinal and bulbar muscular atrophy (SBMA), an adult-onset form of motor neuron disease, was recently reported to be caused by amplification of the CAG repeats in the androgen receptor gene. We report here a simple and rapid strategy to detect the precise number of the CAGs. After the DNA fragment containing the CAG repeats is amplified by the polymerase chain reaction, a primer extension is carried out; the extension of the end-labelled reverse primer adjacent to 3' end of CAG repeats stops at the first T after CAG repeats with the incorporation of dideoxy ATP in the reaction mixture. The resultant primer products are analysed by denaturing polyacrylamide gel electrophoresis and autoradiography. This method could be quite useful to detect not only CAG repeats in SBMA but also other polymorphic dinucleotide and trinucleotide repeats.

Adult↗

Failure to detect HTLV-I by in situ hybridization in the biopsied muscles of viral carriers with polymyositis.

Direct infection of muscle fibers by human T-lymphotropic virus type I (HTLV-I) has recently been reported in a patient with polymyositis infected with both HTLV-I and human immunodeficiency virus (HIV). Coinfections of these viruses are frequently found in the United States. In Kagoshima, Japan, patients with polymyositis have a significantly increased incidence of seropositivity to HTLV-I alone, when compared with the general population of Kagoshima. In this study, we examined muscle tissue from 6 HTLV-I-positive patients with polymyositis from Kagoshima. To detect HTLV-I products, sensitive immunohistochemistry and in situ hybridization analysis were performed. These were compared with muscle fibers from a well-characterized transgenic mouse model which expressed HTLV-I tax. No specific signals were detected in the biopsied muscles of patients with polymyositis infected with HTLV-I alone. HIV co-infection may, therefore, augment HTLV-I expression through either immunosuppression or direct viral interactions.

Adult↗

Cerebrotendinous xanthomatosis: cranial CT and MRI studies in eight patients.

We report the findings on cranial computed tomography (CT) and magnetic resonance imaging (MRI) and their correlation with the clinical manifestations, disease severity and biochemical abnormalities in eight patients with cerebrotendinous xanthomatosis. CT revealed cerebral atrophy in seven cases, cerebellar atrophy in four and focal low density lesions in the cerebral white matter in two. T2-weighted MRI showed high signal lesions in the cerebral white matter, focal in four cases and diffuse in one, and in the globus pallidus in three patients, two of whom also had lesions in the cerebellar white matter. While severely affected patients showed variable CT and MRI abnormalities, our cases did not show the dramatic findings expected from the neurological manifestations. Diffuse lesions in the cerebral and cerebellar white matter have been emphasized in previous reports, but in our study the focal lesions in the cerebral white matter were also present; the globus pallidus was frequently involved.

Achilles Tendon↗

Pathological changes in skeletal muscle in HTLV-I-associated myelopathy.

The main lesion site of HTLV-I-associated myelopathy or tropical spastic paraparesis (HAM/TSP) is the pyramidal tract. In some HAM patients, clinical symptoms and findings indicate neuromuscular involvement, such as muscular atrophy, fasciculation, elevated serum creatine kinase (CK) or significant electrophysiological data. Cases of HAM/TSP complicated with polymyositis or motor neuron disease have been reported. But no investigation has been directed to muscular pathology in many patients of HAM/TSP. We conducted muscle biopsies on 13 HAM patients. Four patients showed neurogenic changes. Six patients showed histological findings indicative of inflammatory myopathy. We investigated surface marker of invading cells in these 6 patients. In all patients, T lymphocytes were more predominant than B lymphocytes and in three of them T helper/inducer cells were more predominant than T suppressor cells. In 2 patients, only slight myopathic change could be seen, such as variation in fiber diameter and increase in the number of internal nuclei. In 1 patient, type 2 fiber atrophy was seen, and was possibly the result of disuse. Disturbance of secondary motor neurons or inflammatory myopathy is thus shown to be possibly associated with HAM/TSP.

Adult↗

Muscular involvement in lysosomal acid lipase deficiency in rats.

We investigated the pathological and biochemical changes of skeletal muscle in rats with lysosomal acid lipase deficiency, which is an animal counterpart of human Wolman's disease. In the affected rats, the acid lipase activity for three different substrates, 4-methylumbelliferyl-oleate (18.9% of the normal control level), [14C]cholesteryl oleate (23.5%), and [14C]triolein (26.9%), was similarly decreased in the lysosomal fraction of skeletal muscle which was obtained by differential centrifugation. Histochemical studies showed that acid phosphatase activity was high in the endomysium and perimysium and in some muscle fibers. Some fibers showed vacuolar degeneration resembling "rimmed vacuoles". Ultrastructural studies demonstrated many membrane-bound lipid droplets in the muscle fibers, especially in the subsarcolemmal space, indicating that a low density lipoprotein (LDL) uptake pathway apparently existed in the muscle cells. However, such lipid accumulation was much greater in the interstitial cells and the endothelial cells. This distribution also suggests that LDL/cholesterol is supplied to muscle cells predominantly through endothelial cells.

Animals↗

Experimental simvastatin-induced myopathy in rabbits.

We induced experimental myopathy in rabbits by giving simvastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor. After oral administration of simvastatin (50 mg/kg/day) for 2 weeks, serum CK was elevated in 5 of 7 rabbits; degenerating or necrotic fibers were seen in 3 rabbits. Using electromyography, myotonic discharges were found in the 2 rabbits examined. The combination of myotonic discharges, necrosis and raised serum CK levels suggests that the myopathy was induced by lesions of the muscle surface membrane.

Administration, Oral↗