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Biomedical subjects

T Kumamoto

Publications and source records attributed to T Kumamoto.

At least 109 records · Page 6Linked to original sources
PubMed1996

[A case of diaphragmatic paralysis following herpes zoster].

We report a case of diaphragmatic paralysis after herpes zoster. A 82-year-old woman developed shortness of breath on effort after about two months of a typical herpes zoster eruptions affecting the C4 and C5 dermatomic areas on the right side. A chest x-ray showed an elevated right diaphragm. The diaphragmatic evoked potential by stimulation of the right phrenic nerve at the posterior border of the sternocleidomastoid muscle was not elicited. Chest CT and cervical MRI were normal. The viral antibody titers of herpes zoster were elevated in the serum. Cervical herpes zoster should be considered as a possible cause of hemidiaphragmatic paralysis.

Aged↗
PubMed1995

Mitochondrial DNA mutation and muscle pathology in mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes.

We sought a relationship between abnormalities of mitochondrial DNA (mtDNA) and muscle pathology in patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) at the single fiber level, using histochemistry, in situ hybridization, and single fiber PCR. Most type 1 ragged-red fibers (RRF) showed positive cytochrome c oxidase (COX) activity at the subsarcolemmal region, while type 2 RRF showed little COX activity. However, there was no difference in the amount of total (mutant and wild-type) mtDNAs and the proportion of mutant mtDNA between type 1 RRF and type 2 RRF. These observations suggest that mitochondrial proliferation and nuclear factors affect muscle pathology, including COX activity, in MELAS. Total mtDNAs were greatly increased in RRF. The proportion of mutant mtDNA was significantly higher in RRF than in non-RRF. The amount of both wild-type and mutant mtDNAs was increased in RRF in MELAS, which fact does not support the contention of a replicative advantage of mutant mtDNA. The proportion of mutant mtDNA was significantly higher in the strongly succinate dehydrogenase-reactive blood vessels (SSV) than in non-SSV. The similar morphological behavior in these vessels and fibers suggests that increased mutant mtDNA is responsible for mitochondrial proliferation and dysfunction in both tissues. It seems likely that systemic vascular abnormalities involving cerebral vessels lead to the evolution of strokelike episodes in MELAS.

Arteries↗
PubMed1995

Immunohistochemical study of calpain and its endogenous inhibitor in the skeletal muscle of muscular dystrophy.

A calcium-dependent proteinase (calpain) has been suggested to play an important role in muscle degradation in Duchenne muscular dystrophy (DMD). In immunohistochemical studies, calpain and its endogenous inhibitor (calpastatin) were located exclusively in the cytoplasm in normal human muscles. The intensity of the staining was stronger in type 1 than in type 2 fibers. Quantitative immunohistochemical study showed an increase of calpain in biopsied muscles from the patients with DMD and Becker muscular dystrophy. Abnormal increases in calpain and calpastatin were demonstrated mainly in atrophic fibers, whereas necrotic fibers showed moderate or weak immunoreactions for the enzymes. Opaque fibers and hypertrophic fibers were negative. Not all dystrophin-deficient muscle fibers necessarily showed a strong reaction for calpain. We suggest that calpain may play an important role in muscle fiber degradation, especially in the early stage of muscle degradation in muscular dystrophy.

Adolescent↗
PubMed1995

Cytotoxic effects of irradiation and deoxyguanosine on fetal thymus.

Effects of irradiation and deoxyguanosine on the fetal thymus were examined both in vitro and in vivo. Fetal thymi (gestation day 15) of C57BL/6 mice that had been irradiated (0-25 Gy) or treated with various doses of deoxyguanosine (dGuo) were engrafted under the renal capsules of BALB/c nu/nu mice, and the differentiation of T cells was investigated in the engrafted thymi or spleens of these mice. After in vitro treatment of fetal thymi with 1.35 mM dGuo (which was previously reported to be an optimal dose), T cell precursors still remained in some cultures, whereas 1.80 mM dGuo was highly cytotoxic not only to T cell precursors but also to thymic epithelial cells. In contrast, 25 Gy irradiation totally eliminated the T cell precursors from the fetal thymi, though the capacity of epithelial cells to induce T cell differentiation was retained. Although irradiated thymi had the capacity to induce T cell differentiation when assayed in an in vitro organ culture system, long-term observation of thymi engrafted into BALB/c nu/nu mice revealed that, if they had been irradiated (9.5 Gy or 25 Gy), the thymi became scarred by 12 wks after their transplantation. Furthermore, the expression of cell interaction molecules such as ICAM-1 and MHC class II on the thymus stromal cells decreased after irradiation. The interaction molecules decreased 3 wks after 25 Gy irradiation and 7 wks after 9.5 Gy irradiation. The alteration in T cell subsets in the thymus (decreases in both double- and single- positive cells and an increase in double-negative cells) correlated with the decreases in the interaction molecules. This indicates that irradiation (even 9.5 Gy) impairs the T cell-induction capacity of the thymus stromal cells, resulting in an alteration of the T cell subsets followed by a change in the T cell counts in the thymus. Therefore, the long-term effects of irradiation of the thymus should be considered in cases of fetal thymus grafts or total body irradiation before bone marrow transplantation, particularly in the newborn.

Animals↗
PubMed1995

Characterization of Pseudomonas paucimobilis FP2001 which forms flagella depending upon the presence of rhamnose in liquid medium.

A bacterial strain FP2001 isolated from the exudate of land reclaimed for municipal waste was identified as Pseudomonas paucimobilis. Cells of strain FP2001 were mobile by means of polar monotrichous flagellum, only when rhamnose was added as a carbon source in the liquid medium. The replacement of rhamnose by arabinose, galactose, glucose or xylose did not lead to the formation of flagella.

Bacteriological Techniques↗
PubMed1995

Clinical manifestations associated with human herpesvirus 7 infection.

Twenty two cases of human herpesvirus 7 (HHV-7) infection are described. HHV-7 infection occurred later than human herpesvirus 6 (HHV-6) infection and induced exanthem subitum in 47.1% of the children. HHV-7 infection was associated with exanthem subitum and the other symptoms that were observed in HHV-6 infection.

Acute Disease↗
PubMed1995

Magnitudes of neurological disorders in a farming town in Kyushu, Japan: frequency of neurological symptoms and signs.

We examined 1,270 elderly residents aged 60 years and over in a cross-sectional study of a standardized clinical examination to determine the frequency of 'abnormal' neurological findings in 27 randomly selected communities in the town of Mifune, Japan. The survey showed one or more neurological symptoms in 89.1%, and one or more signs in 94.4% of the examined elderly. Most of the symptoms and signs increased with age, especially after 70 years, indicating the importance of neurological afflictions in the community health of the elderly.

Age Factors↗
PubMed1995

Neurologic features of chronic Minamata disease (organic mercury poisoning) certified at autopsy.

To better understand the neurologic events related to chronic Minamata disease (organic mercury poisoning), we studied data from 77 patients with Minamata disease as certified at autopsies performed from 1976 to 1994 (mean age: 72.3 years). Major neurologic findings included: sensory impairment in 80.5% of the patients which was limited to the extremities in 42.9%. Impairment of lower extremity coordination was present in 35.8% of the patients, constriction of the visual fields in 28.8%, and retrocochlear hearing loss in 15.3%. There was no correlation between the degree of cerebellar incoordination and the methylmercury concentration in the cerebellum. Compared with the classic type of Minamata disease, the incidence of major neurologic findings was markedly decreased. In light of these findings, supplemental examinations including brain computed tomography (CT), magnetic resonance imaging (MRI), short latency somatosensory evoked potential (SSEP), or tremogram may be necessary to clinically diagnose Minamata disease, especially in atypical or mild cases.

Adult↗
PubMed1995

[An autopsy case of immature teratoma with choriocarcinoma in the mediastinum].

The autopsy of a 28-year-old Japanese male patient, which revealed immature teratoma combined with choriocarcinoma in the mediastinum, is presented. The tumor, which was removed after chemotherapy, was localized in the superior-anterior mediastinum. Chemotherapy was performed several times after operation. However, HCG increased again, and a roentgenogram revealed metastatic shadows in both lungs. The metastatic tumors in the lungs showed only the choriocarcinoma.

Adult↗
PubMed1994

Structural requirement for recognition of the precursor proteins by the mitochondrial processing peptidase.

We examined the structural characteristics of the extension peptides responsible for the recognition by the mitochondrial processing peptidase by using preadrenodoxin, which has a long extension peptide of 58 amino acid residues, as the substrate. The deletion of various parts of the extension peptide of pre-adrenodoxin indicated that more than 40 amino acid residues and the presence of basic amino acid residues in the distal portion (20-40 amino acid residues upstream of the cleavage site) were necessary for the recognition of the precursor by the peptidase. The processing of preadrenodoxin was strongly inhibited by the synthetic peptide corresponding to the middle portion of the extension peptide, whereas the peptide corresponding to the amino-terminal portion exhibited weak inhibition of the processing. The replacement of arginine residues in the middle portion of the extension peptide with neutral amino acids resulted in a great decrease in the processing. We conclude that basic amino acids at a position distal to the cleavage site are necessary for the recognition of the precursor proteins by the processing peptidase and that basic amino acids required for the mitochondrial targeting and those for the recognition by the peptidase are separately located in the extension peptide of pre-adrenodoxin.

Adrenodoxin↗
PubMed1994

Changed affinity of apolipoprotein AII to high density lipoprotein (HDL) in patients with familial amyloidotic polyneuropathy (FAP) type I.

Patients with familial amyloidotic polyneuropathy (FAP) showed extremely low plasma apolipoprotein AII (apoAII) levels and apolipoprotein AII/AI (apoAII/AI) ratio while plasma levels of AI, B, CII, CIII, and E were all within normal ranges. To elucidate the reason for these phenomena, we investigated the percent of these proteins contained in high density lipoprotein (HDL) extracted from plasma of FAP patients by ultracentrifugation. The apoAII/AI ratio in extracted HDL was much lower in asymptomatic carriers of FAP as well as FAP patients than that in control subjects. Since a significant amount of apoAII as well as apoAI was recognized in the fraction of the density > 1.21 g/ml in the samples from asymptomatic carriers of FAP and FAP patients, decreased apoAII/AI ratio may result from the increased dissociation of apoAII from HDL during the process of the ultracentrifugation. Electrophoresis of HDL extracted by agarose gel revealed that HDL from asymptomatic carriers of FAP as well as FAP patients increased negative charge, suggesting that nature of HDL itself may change in these subjects. Although urinary excretion of apoAII was increased in carriers of FAP and FAP patients, there was no correlation between plasma and urinary apoAII levels and also no relationship between urinary total protein and apoAII levels. These results suggest that changed affinity of apoAII to HDL may cause the increased secretion of apoAII to the urine and the decreased plasma apoAII level in carriers of FAP and FAP patients.

Adult↗
PubMed1994

Single muscle fiber analysis of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS).

We examined muscle sections from 3 patients with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS), using single-fiber polymerase chain reaction, histochemistry, and in situ hybridization. Most type 1 ragged-red fibers showed positive cytochrome c oxidase activity at the subsarcolemmal region, while type 2 ragged-red fibers had little cytochrome c oxidase activity. However, there was no difference in the amount of total (mutant and wild-type) mitochondrial DNAs (mtDNAs) and the proportion of mutant mtDNA between type 1 and type 2 ragged-red fibers. These observations suggest that mitochondrial proliferation and nuclear factors affect muscle pathology, including cytochrome c oxidase activity, in MELAS. Total mtDNAs were greatly increased in ragged-red fibers (about 5-17 times over those in non-ragged-red fibers). The proportion of mutant mtDNA was significantly higher in ragged-red fibers (88.1 +/- 5.5%) than in non-ragged-red fibers (63.2 +/- 21.6%). Thus, the amount of wild-type mtDNA as well as mutant mtDNA was increased in ragged-red fibers in MELAS, failing to support the contention of a replicative advantage of mutant mtDNA. The proportion of mutant mtDNA was significantly higher in the strongly succinate dehydrogenase-reactive blood vessels (83.2 +/- 4.2%) than in non-succinate dehydrogenase-reactive blood vessels (38.8 +/- 16.2%). It seems likely that systemic vascular abnormalities involving cerebral vessels lead to the evolution of stroke-like episodes in MELAS.

Base Sequence↗
PubMed1994

Muscle fiber degradation in distal myopathy with rimmed vacuoles.

Late-onset distal myopathy showed numerous rimmed vacuoles with the same properties as autophagic vacuoles. Electron microscopy showed numerous degenerated mitochondria, glycogen, or cell membranes in rimmed vacuoles, but no evidence that these vacuoles engulfed and contained intact or partially disrupted myofibrils. Immunostaining for myosin, alpha-actinin, and actin, however, was sometimes positive within the vacuoles. Compared to the control muscle, there was increased staining activity by calpain around the rimmed vacuoles or in the cytoplasm of mainly atrophic fibers. The result seems to indicate an increase of calpain activity in these muscle fibers. We hypothesize that the myofibrils as well as mitochondria, glycogen, or cell membranes in this myopathy are degraded finally through a lysosomal autophagic process. However, the breakdown of the myofibrils may be not initiated by lysosomal activation; rather it may be the result of extralysosomal processes such as the calpain system.

Actinin↗
PubMed1994

Exonic trinucleotide repeats and expression of androgen receptor gene in spinal cord from X-linked spinal and bulbar muscular atrophy.

We studied exonic trinucleotide repeats and expression of androgen receptor (AR) gene in the spinal cord from an autopsied patient with X-linked spinal and bulbar muscular atrophy (SBMA). Forty-nine CAG triplet repeats were found in tissues from the spinal cord, cerebrum, cerebellum, cardiac muscle and bladder, while there were 20-24 CAG repeats in these tissues from control subjects, consisting of three patients with amyotrophic lateral sclerosis (ALS) and three patients with lung cancer. Thus, mitotic instability of the AR gene in SBMA may not occur at the level of somatic cells. To determine whether expression of the AR gene in the spinal cord of SBMA differs from that in control subjects, we used quantitative reverse transcriptase (RT)-PCR and Western blot. AR mRNA and protein were detected in the spinal cord from the patient with SBMA, but the levels of both AR mRNA and protein were less than those from the patients with ALS in whom the loss of motor neurons was similar to findings in the patient with SBMA. These findings suggest that structural alteration plus a reduced level of AR in the spinal cord are involved in the pathogenesis of SBMA, resulting in degeneration of motor neurons.

Adult↗
PubMed1994

A case report of placental hemangioma resulting in severe fetal distress.

A 30 year old female was admitted twice during her pregnancy for genital bleeding. An ultrasonography at 19 weeks gestation showed several nodules on the chorionic plate. Cardiotocography during labor at 37 weeks gestation indicated a non-reactive pattern. A 2230 g infant girl was delivered soon after rupture of membranes with asphyxia and hydrops fetalis. The placenta weighed 600 g with a maximal thickness of 6 cm. Nodules occupied about one-third of the placenta and were diagnosed as placental hemangiomas. Postnatal examination revealed that the infant had disseminated intravascular coagulation and cardiac failure. This baby recovered after treatment in the intensive care unit, and was discharged home on the 52nd day of life.

Adult↗
PubMed1994

[Additional palliative operation and staged definitive operation for pulmonary atresia with intact ventricular septum].

Between 1981 and 1992, 38 consecutive patients underwent initial operation for pulmonary atresia with intact ventricular septum. Transpulmonary valvotomy using balloon occlusion of RV outflow was carried out in 24 patients at a mean age of 20 days. An additional Blalock-Taussig shunt was required in 4 patients early in the series. Based on a retrospective review on the patients early in the series, initial palliative procedure had been decided in conformity with the value of an index of RV development (RVDI) = RVEDV% x TVD% x RVODmm/BSAm2 x 10(-5), and recent 3 patients with RVDI < 0.35 and patent RV outflow underwent concomitant valvotomy and Blalock-Taussig shunt. Fourteen patients with muscular atresia of RV outflow or major sinusoidal coronary artery communication underwent Blalock-Taussig shunt. There were 1 operative and 3 late deaths and second Blalock-Taussig shunt was required in 6 patients. Definitive repair was carried out in 20 patients between 1985 and 1994. Fifteen patients with RVEDV > 30% of normal had biventricular repair (partial closure of ASD in 6) and 5 underwent Fontan type repair. In terms of the definitive procedures, when the RV.TV index (= RVEDV% x TVD% x 10(-4)) is greater than 0.4, complete repair should be performed. When the index is between 0.2 and 0.4, the atrial septal defect should only be partially closed when the outflow tract is reconstructed. In those cases with an index of less than 0.2, the Fontan procedure seems to be a procedure of choice.

Humans↗
PubMed1993

Effect of denervation on overdevelopment of chloroquine-induced autophagic vacuoles in skeletal muscles.

We studied how denervation affects the overdevelopment of autophagic vacuoles in muscles of chloroquine-treated rats. The number of autophagic vacuoles increased significantly in the chloroquine-treated soleus muscles after denervation as compared to similarly treated contralateral, innervated muscles. No vacuoles were present in the denervated and innervated muscles of saline-treated rats. After denervation, the autophagic vacuoles in chloroquine-treated muscle contained numerous glycogen particles and various heterogeneous materials. A biochemical study showed no significant difference in the activities of lysosomal proteases and hydrolases in the chloroquine- and saline-treated muscles after denervation, although these activities were markedly increased in comparison to the same activities in the contralateral, innervated muscles. Chloroquine treatment by itself did not, but denervation with or without chloroquine treatment did enhance the biochemical activities of lysosomal enzymes in the animals. We speculate that denervation induces the marked accumulation of autophagic vacuoles in chloroquine-induced myopathy.

Animals↗