Biomedical subjects

T Mitsuma

Publications and source records attributed to T Mitsuma.

At least 73 records · Page 4Linked to original sources

PubMed1998

Distribution of Dopamine Transporter in the Rat: an Immunohistochemical Study.

OBJECTIVE: To investigate the organ distribution of dopamine transporter (DAT) in rats by immunohistochemical method. METHODS: Dopamine transporter (DAT) was identified immunohistochemically in the tissues using specific antipeptide antiserum raised in New Zealand white rabbits immunized with a conjugate of synthetic DAT peptide (29-45) with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method. RESULTS: DAT immunoreactivity was visualized in the neural perikarya, axons and dendrites of the central nervous system, retina, adrenal medulla, Auerbach's nervous branch and Meissner's nervous branch of the stomach, small intestine and colon, anterior pituitary, and lung. When using antiserum preincubated with synthetic DAT peptide (DAT, 29-45) or hypothalamus homogenate which contains DAT, no significant stain of neurons in the hypothalamus was detected. CONCLUSION: These findings suggest that DAT is widely distributed and that the method used is valuable in studying the distribution of DAT in rats.

Journal Article↗

PubMed1998

[Double filtration plasmapheresis (DFPP) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP)].

We studied the therapeutic characteristics of double filtration plasmapheresis (DFPP) in 14 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The patients were classified into 2 subgroups of the responders (7 patients) and the non-responders (7 patients) to DFPP. The responders to DFPP were designated as those showing the improvement 2 or more grades in measures the activity of daily living by the modified Rankin scale (MRS). All these patients underwent neurological assessment, CSF study, electrophysiological studies at the beginning and end of treatment. Sural nerve biopsy study was performed in 10 cases. Neurological function was assessed serially using a quantitative neurological disability score (NDS). At the beginning of treatment, there were no significant differences in various measurements between the responders and the non-responders except for the frequency of demyelination. In responders, significant improvement was found in mean changes in MRS, NDS, motor nerve conduction velocity, compound muscle action potential, distal motor latency, while in non-responders, all measures remained unchanged or worsened. Muscle wasting was seen in 3/7 responders and 4/7 non-responders, and denervation potentials in needle EMG were seen in 1/7 responders and 3/7 non-responders. Four patients of the responders were classified as chronic relapsing course, and 6 patients of the non-responders as chronic progressive course. We conclude that DFPP was useful for the subgroups of CIDP patients, but the underlying immuno-pathological background that determine the efficacy of plasmapheresis should be elucidated.

Activities of Daily Living↗

PubMed1998

[Cerebral infarction associated with nephrotic syndrome in a young adult: a case report].

We report a 19-year-old man who developed a cerebral infarction in the territory of the anterior choroidal artery and showed a hypercoagulable state and nephrotic syndrome after diarrhea and appetite loss. He had suffered from nephrotic syndrome from the age of three and had been treated for five years. MR-angiography showed an occlusion originating in the right internal carotid artery. The right anterior and middle cerebral arteries were imaged from the left internal carotid artery via the anterior communication artery. He showed symptoms of left hemiparesis, agnosia, loss of activity, anasarca and left hypacusis following his clinical course, but had recovered from all but left hemiparesis following medical treatments including steroid therapy. The histologic finding by a renal biopsy revealed focal glomerulosclerosis. In this case, we considered that when he was in a hypercoagulable state and had a second attack of nephrotic syndrome because of inflammation and dehydration due to diarrhea and appetite loss, his hypercoagulable state grew worse, and he then developed a cerebral infarction. When one see a patient with nephrotic syndrome, one should be attentive to the possibility of a complication of cerebral infarction.

Adult↗

PubMed1997

Impairment of calcitonin gene-related peptide-induced potentiation of cholinergic sweat secretion in patients with multiple system atrophy.

Loss of sweating is a characteristic feature of multiple system atrophy (MSA) with autonomic failure, and widespread anhidrosis may lead to hyperthermia and collapse in a hot environment. Calcitonin gene-related peptide (CGRP) is present in the periglandular nerves around sweat glands and is a strong stimulant of methacholine (MCH)-mediated cholinergic sweating. The present study evaluated CGRP-related regulation of cholinergic sweating in patients with MSA. CGRP-induced potentiation of MCH-mediated cholinergic sweating was significantly reduced in MSA patients as compared with normal age-matched controls. These results suggest that regulation of sweating is extensively affected in MSA as a consequence of peptidergic dysfunction.

Autonomic Nervous System Diseases↗

PubMed1997

The lateral corticospinal tract and spinal ventral horn in X-linked recessive spinal and bulbar muscular atrophy: a quantitative study.

A quantitative study was performed on spinal cord lesions in seven patients with X-linked recessive spinal and bulbar muscular atrophy. The myelinated fiber density of the lateral corticospinal tracts at the T7 cord level was well preserved for both large and small myelinated fibers. On the other hand, neurons in the L4 ventral horn were markedly depleted; marked loss was noted of the large alpha and medium-sized gamma motor neurons located in the lateral and medial nuclei as well as the small neurons in the intermediate zones of the ventral horn. These results suggest that myelinated fiber density and fiber-size distribution in the corticospinal tract are well preserved and that neuronal loss in the ventral horns is not restricted to alpha and gamma motoneurons but also involves small interneurons.

Aged↗

PubMed1997

Locations of crossover breakpoints within the CMT1A-REP repeat in Japanese patients with CMT1A and HNPP.

The crossover breakpoints for Charcot-Marie-Tooth disease type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsies (HNPP) are located in the CMT1A-REP repeat flanking a 1.5-Mb region of chromosome 17p11.2-12. The precise locations of the breakpoints are heterogeneous, and we analyzed the relative frequency distribution of breakpoints in 33 unrelated Japanese CMT1A and 3 unrelated HNPP families. The CMT1A-REP repeat region was divided into five regions, A, B, C, D and E, based on restriction site differences between the proximal and distal CMT1A-REP repeats. The frequency distribution of breakpoints within the CMT1A-REP repeat in the Japanese patients was 3% in region A, .78% in B/C and 19% in D, which is similar to that in Caucasian patients. This result also indicates that an 8-kb region defined by region B/C is a recombinational hotspot within the CMT1A-REP repeat in Japanese patients.

Asian People↗

PubMed1997

Amplification of BCR protein associated with oncogenesis in human hepatocellular carcinoma.

The BCR gene is located on human chromosome 22. The normal cellular BCR gene encodes a 160,000-dalton phosphoprotein associated with a serine/threonine kinase activity. The BCR protein is involved in signal transduction. We investigated the expression of the BCR protein in hepatocellular carcinoma (HCC), surrounding noncancerous liver tissue, liver cirrhosis (LC), chronic hepatitis (CH), and normal liver with immunohistochemistry and a western blot analysis. BCR immunoreactivity was detected using a monoclonal antibody. In normal liver, and both CH and LC without association of HCC, the immunoreactivity of the BCR protein was minimal. In contrast, 73% (22 of 30) of noncancerous liver tissue adjacent to the HCC and 40% (12 of 30) of HCC expressed BCR protein; this difference was statistically significant (P < 0.01). The expression of the BCR protein expression correlated with the degree of histological differentiation of HCC (P < 0.05). In addition, the amplification of BCR protein in noncancerous cells was supported by the detection of specific protein using a western blot analysis. In two cases, the expression of BCR protein occurred only in overtly malignant HCC cells. As a result, the expression of the BCR protein may be associated with oncogenesis in human HCC.

Aged↗

PubMed1997

Effects of gamma-butyric acid on the release of thyrotropin-releasing hormone from the rat retina in vitro.

Effects of gamma-butyric acid (GABA) on the release of thyrotropin-releasing hormone (TRH) from the rat retina in vitro were studied. The rat retina was incubated in medium 199 (pH 7.4) with 1.0 mg/ml of bacitracin and 100 micrograms/ml of ascorbic acid (medium). The amount of TRH release into the medium was measured by radioimmunoassay. The TRH release from the rat retina was inhibited significantly in a dose-related manner with the addition of GABA, but not with bicuculline. The inhibitory effect of GABA on TRH release from the retina was blocked by adding bicuculline to the medium. The findings suggest that the GABAergic system inhibits TRH release from the rat retina in vitro.

Animals↗

PubMed1997

Central facial weakness due to medial medullary infarction: the course of facial corticobulbar fibres.

Two patients are reported with contralateral hemiparesis including a face of supranuclear type, caused by an infarct of the unilateral ventromedial part of the upper medulla. Data from these patients support the hypothesis that part of the corticobulbar fibres supplying the lower facial muscles descend ipsilaterally in the ventromedial part of the upper medulla and then, after decussation, ascend rostrally to the contralateral facial nucleus.

Adult↗

PubMed1997

Skin sympathetic nerve activity in Guillain-Barré syndrome: a microneurographic study.

To assess autonomic dysfunction, skin sympathetic nerve activity (SSNA) of four patients with Guillain-Barré syndrome was microneurographically studied in the acute and remission phase. Autonomic symptoms such as sinus tachycardia, palmar hyperhidrosis, hypertension, and orthostatic hypotension were present in the acute phase, but all subsided during remission. Basal resting SSNA and the responses to various physical and mental stimuli were all increased in the acute phase and returned almost to normal during remission. Rate of response in sweat rate and blood flow against SSNA were kept proportionally constant during both the acute and remission phases. These findings suggest that some autonomic nerve symptoms of Guillain-Barré syndrome, particularly during the acute phase, are due to increased SSNA.

Acute Disease↗

PubMed1997

Upper motor neuron lesions in stroke patients do not induce anterograde transneuronal degeneration in spinal anterior horn cells.

BACKGROUND AND PURPOSE: To determine whether upper motor neuron lesions in stroke can cause transneuronal degeneration of lower motor neurons, we assessed spinal anterior horn cells in patients dying with poststroke hemiplegia. METHODS: Subjects were four stroke patients with severe left hemiplegia and four age-matched control subjects who died of nonneurological disease. After histological processing and staining, cytoarchitectonic assessment was made of all neurons in the ventral horns of the 4th lumbar segment of the spinal cord according to cell diameter and topography. RESULTS: In the four stroke patients, no differences were seen in anterior horn cell populations or diameter and size distribution patterns between affected and unaffected sides or between these patients and the control subjects. CONCLUSIONS: The present quantitative analysis provides no evidence of anterograde transneuronal degeneration of lower motor neurons after upper motor neuron damage in stroke patients.

Adult↗

PubMed1997

Axonal pathology in Japanese Guillain-Barré syndrome: a study of 15 autopsied cases.

We assessed the frequency and extent of axonal involvement in the ventral spinal roots in 15 Japanese autopsied patients with Guillain-Barré syndrome (GBS). Teased-fiber preparation revealed that five had predominantly axonal pathology with minimal segmental demyelination, seven had predominantly segmental demyelination with minimal axonal changes, two patients showed a mixture of both conditions, and one patient did not show any particular pathologic changes. We confirmed axon loss by immunohistochemical analysis of high-molecular-weight neurofilament protein. Macrophage invasion was a prominent feature in nerves with predominantly axonal changes. Two patients with severe axonal involvement and prolonged clinical courses exhibited motor neuron loss with astrogliosis in the ventral horns. These results suggest that autopsy-verified axonal involvement is more frequent among Japanese GBS patients than in Caucasian populations but less frequent than that reported from northern China.

Adult↗

PubMed1997

DISTRIBUTION OF SOMATOSTATIN RECEPTOR TYPE 3 IN THE RAT: IMMUNOHISTOCHEMICAL STUDY.

Somatostatin receptor type 3 (SSTR-3) was identified immunohistochemically in the rat tissues using specific anti-SSTR-3 serum which was raised in New Zealand white rabbits immunized with a conjugate of synthetic SSTR-3 peptide (28-41) with bovine serum albumin. Immunohistochemical analysis was performed by avidin-biotin complex method. SSTR-3 immunoreactivity was visualized in the central nervous system, anterior pituitary, gastric and duodenal mucosa, Auerbach's and Meissner's nervous branch of gastrointestinal tract, adrenal medulla, testis and pancreas. Significant staining was detected in neural perikarya, axons and dendrites. When using antiserum preincubated with synthetic SSTR-3 peptide (28-41) or rat anterior pituitary homogenate which contains SSTR-3 peptide, no significant stain of the anterior pituitary or neurons in the hypothalamus was detected. These findings suggest that SSTR-3 is widely distributed and that this method is valuable in studying the distribution of SSTR-3 in rats.

Journal Article↗

PubMed1997

Organ distribution of iodide transporter (symporter) in the rat: immunohistochemical study.

Iodide transporter/symporter (NIS) was identified immunohistochemically in rat tissues using specific antipeptide serum. Anti-NIS serum was raised in New Zealand white rabbits immunized with a conjugate of synthetic NIS peptide (39-53) with bovine serum albumin. Immunohistochemical analysis was performed by avidine-biotin complex method. NIS immunoreactivity was visualized in the thyroid gland, gastric and small intestine mucosa, anterior pituitary, adrenal medulla, pancreatic islets, kidney, chorioid plexus and several brain and spinal cord nuclei. When using antiserum preincubated with synthetic NIS peptide (39-53) or rat thyroid homogenate containing NIS, no significant stain of the thyroid gland was detected. These findings suggest that NIS is widely distributed and that the method used is suitable for studying the distribution of NIS in rats.

Journal Article↗

PubMed1997

[Heterogeneity in breakpoint location of duplication in Japanese Charcot-Marie-Tooth disease type 1A].

The crossover breakpoints for CMT1A are located in the CMT1A-REP repeat flanking a 1.5 Mb region of chromosome 17p11.2-12. We analysed the relationship between the breakpoint locations and clinical phenotypes in 21 Japanese patients with CMT1A duplication. The CMT1A-REP region was divided in 5 regions, A, B, C, D and E, based on restriction site differences between the proximal and distal CMT1A-REP repeats (Kiyosawa et al., HMG, 1995). The breakpoint location within the CMT1A-REP was heterogeneous, the frequency distribution of which was hightest in the B/C region and similar to that in Caucasian patients. The clinical phenotypes, such as foot deformity, muscular weakness and atrophy, sensory impairment and electrophysiologic finding, were extensively variable among the CMT1A patients with PMP22 gene duplication. The location of breakpoints was not related to the clinical phenotypes, suggesting that there is a factor other than the location of the crossover breakpoint, which influences phenotypic manifestation of CMT1A.

Adult↗

PubMed1997

[Locations of crossover breakpoints within the CMT 1 A-REP repeat in patients with hereditary neuropathy with liability to pressure palsy--detection by recombinant chromosome-specific polymerase chain reaction].

The crossover breakpoints for hereditary neuropathy with liability to pressure palsies (HNPP) are located in the CMT 1 A-REP repeat flanking a 1.5 Mb region of chromosome 17p11.2-12. Three-unrelated HNPP patients have breakpoints in a 3.2 kb novel fragment of recombinant chromosome in the CMT 1 A-REP repeat. The fragment is detected by recombinant chromosome-specific polymerase chain reaction (PCR). Further analysis of PCR demonstrated a 1.2 kb novel junction fragment in the 3.2 kb region in all HNPP patients. The precise mapping of the breakpoints indicated that 2 patients were localized in a 700 bp interval of the 1.2 kb fragment 1.3kb telomeric to a marier transposon-like element (Kiyosawa and Chance, HMG 5: 745-753, 1996), suggesting that this region is a recombinational "hotspot" within the CMT 1 A-REP repeat for HNPP as well as CMT 1 A.

Adult↗

PubMed1997

[Clinico-pathological significance of the immunostaining of myosin heavy chain isoforms in pathological human skeletal muscle].

Expression of the four myosin heavy chain isoforms (fast-twitch, slow-twitch, neonatal and embryonal isoforms) was immunohistochemically observed in 500 biopsied limb muscles of neuromuscular disorders. Fast-twitch isoform was expressed in type 2A, 2B and pathologic 2C fibers. Slow-twitch isoform was expressed in type 1 and 2C fibers. Embryonic isoform was expressed in regenerating type 2C fibers of active myopathies such as Duchenne dystrophy and polymyositis. Expression of neonatal isoform, which was longer positive than that of embryonic isoform, was noted in regenerating fibers, denervated fibers and highly atrophic fibers in chronic myopathies of limb-girdle dystrophy and myotonic dystrophy. In conclusion, the immunostaining of MHC isoforms are useful to make a clinico-pathological diagnosis to determine the stages in evolution of regeneration or degeneration of pathologic muscle fiber per se.

Humans↗

PubMed1996

Toxic effects of hexane derivatives on cultured rat Schwann cells.

The cytotoxic effects of the following five hexane-related compounds were examined on Schwann cell DNA synthesis: 2,5-hexanedione (2,5-HD), 2-hexanol (2-OH), 2-hexanone (MnBK), 2,5-dimethylfuran (DF) and gamma-valerolactone (VL). Schwann cells were isolated from the sciatic nerves of neonatal Sprague-Dawley rats and cultured. [(3)H]-thymidine incorporation into Schwann cell nuclei was measured by scintillation spectrometry and autoradiography when hexane derivatives were added to the culture medium. All of the hexane-related compounds suppressed [(3)H]-thymidine incorporation in a concentration-dependent manner. DF was the most cytotoxic for the inhibition of Schwann cell DNA synthesis among the compounds. The finding suggests that DF-mediated cytotoxicity should be taken into account as a possible additional mechanism of hexane intoxication, especially in the impairment of mitotic cells.

Animals↗