Biomedical subjects

N Murakami

Publications and source records attributed to N Murakami.

At least 343 records · Page 19Linked to original sources

PubMed1992

Basophilic inclusions in sporadic juvenile amyotrophic lateral sclerosis: an immunocytochemical and ultrastructural study.

This report concerns immunocytochemical and ultrastructural studies on the basophilic inclusions in two cases of sporadic juvenile amyotrophic lateral sclerosis (ALS). The inclusion had a globular, irregular-shaped, or sometimes fragmented appearance. Ultra-structurally, the inclusions consisted mainly of thick filamentous structures associated with granules. Focal neurofilamentous accumulations were occasionally observed among the granulofilamentous structures. The basophilic inclusions occasionally showed granular reaction product deposits with an antibody to ubiquitin. The inclusions did not react with antibodies to phosphorylated neurofilament and to tau protein.

Adult↗

PubMed1992

Effects of endurance training on myosin heavy-chain isoforms and enzyme activity in the rat diaphragm.

We investigated the effects of endurance training (20 m/min, 60 min/day, 5 days/week) on myosin heavy-chain (MHC) isoforms and succinic dehydrogenase (SDH) activity in rat crural and costal diaphragms, and plantaris muscles. Although the 4-week endurance training produced significant (P less than 0.05) increases, both in SDH activity and the percentage of isoform HCIIa in the plantaris of the trained rat compared with the sedentary control rat, these alterations did not occur in either the crural or costal diaphragms. After 10 weeks of endurance training, trained animals had significantly (P less than 0.05) higher SDH activity in the costal diaphragm and the plantaris. Moreover, a significant (P less than 0.05) decrease occurred in the percentage of HCIIb in the costal diaphragm, and a significant (P less than 0.01) decrease in the percentage of HCIIb concomitant with a significant (P less than 0.05) increase of HCIIa resulted in the plantaris. However, the crural diaphragm did not show any significant changes after 10 weeks of endurance training. These results indicate that endurance training induces an alteration in the expression of an MHC phenotype, in addition to causing an increase in oxidative enzyme activity. However, the alterations in response to endurance training are apparently not uniform, varying between regions and/or kinds of muscles.

Animals↗

PubMed1992

Ubiquitin-positive intraneuronal inclusions in the extramotor cortices of presenile dementia patients with motor neuron disease.

Ubiquitin-positive intraneuronal inclusions were found in the extramotor cortices of ten presenile dementia patients with motor neuron disease. There were inclusions in the hippocampal granular cells and in the small neurons of the superficial layers of the temporal and frontal cortices. Bunina bodies were present in the anterior horn cells in all cases. These results suggest that ubiquitin-related cytoskeletal abnormalities are common in cerebral non-motor small neurons in these patients.

Adult↗

PubMed1992

Pathological study of diffuse axonal injury patients who died shortly after impact.

It is generally considered that axonal injury is apparent only on electron microscopy in the very early stage after a closed head injury. To clarify the pathological findings in head injury patients dying very shortly after the impact, we analyzed 8 fatal cases of diffuse axonal injury (DAI) who underwent medicolegal autopsy at the Department of Forensic Medicine of Kyoto Prefectural University of Medicine. Seven cases died within one hour after injury and another one case died 3 days after injury. We studied these cases macroscopically, microscopically, and electron microscopically. Macroscopically all cases showed the typical findings of diffuse axonal injury. Microscopical study of the cases who died within one hour revealed no characteristic findings of DAI such as appearance of retraction balls or microglia. On the other hand, in the case who died only 3 days after injury it showed the typical retraction balls. Electron microscopic study showed the remarkable destruction of cytoskeletal structure of axons in all cases. From our results, it is reasonable to speculate that DAI may be common among head injury patients who die very soon after the impact.

Adolescent↗

PubMed1992

Changes in brain monoamine metabolism in rats with acute ischemic hepatic failure under artificial cardiopulmonary management.

A study was conducted to investigate changes in monoamine metabolism in the brain of rats with acute ischemic hepatic failure (AHF) induced by two-stage hepatic devascularization. Strict artificial cardiopulmonary management was used to exclude possible confounding effects of hypotension, hypothermia and hypoxemia that often appear in AHF. Rats were put in an incubator at 34 degrees C before the ligation of the hepatic artery (second stage operation), tracheotomized and ventilated artificially throughout the remaining experimental periods. No significant difference was observed in physiological parameters, including body temperature, pulse rate and systolic arterial blood pressure or PaO2 between AHF and sham operated rats. Brain levels of norepinephrine (NE) and its metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG), dopamine (DA) and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA), and serotonin (5-hydroxytryptamine, 5HT) and its metabolite 5-hydroxyindoleacetic acid (5HIAA) were determined by HPLC-voltametry. AHF rats showed significantly higher MHPG, DOPAC, 5HIAA and lower NE levels in the brain compared to controls. In addition, a significant negative correlation between NE and tyrosine (Tyr), a significant positive correlation between MHPG and Tyr or phenylalanine (Phe), and a significant positive correlation between DOPAC and Tyr or Phe were observed. In conclusion, the changes in monoamine metabolism in the brain of AHF rats are clearly induced specifically by hepatic failure itself, possibly through an altered metabolism of amino acids.

Animals↗

PubMed1992

Effects of running training on the blood glucose and lactate in rats during rest and swimming.

The purpose of this study was to examine the effect of physical training on the concentrations of glucose and lactate in the blood of rats during rest and after an acute bout of exercise. We used the following types and periods of training; (i) swimming for 4 weeks, (ii) running for 4 weeks, and (iii) running for 10 weeks. The results clearly show that the resting levels of blood glucose was significantly lower in groups trained by either swimming or running than untrained groups. In addition, after the acute exercise of swimming, animals trained by either running or swimming showed a lower increase in the blood lactate than untrained animals. Furthermore, the increases in the blood glucose after swimming were significantly lower in the group trained by swimming for 4 weeks and by running for 10 weeks than in untrained groups. These results suggest that after physical training by running, animals show an adaptation in the changes in the blood glucose and the blood lactate that are induced by a different type of physical stress, swimming.

Adaptation, Physiological↗

PubMed1992

Generation of lysoglyceroglycolipids in the cyanobacterium, Phormidium tenue.

Two kinds of lysoglycolipids, monogalactosyl 1-monoacylglycerol and digalactosyl 1-monoacylglycerol were generated in the cyanobacterium, Phormidium tenue, when it was stored at -20 degrees for more than 1 month. By comparison of the compositions of fatty acid residues between monogalactosyl 1-monoacylglycerol and monogalactosyl diacylglycerol, digalactosyl 1-monoacylglycerol and digalactosyl diacylglycerol, respectively, the 1-monoacylgalactolipids were presumed to be formed by regioselective deacylation at the sn-1 position with subsequent acyl-group migration from the sn-2 to the sn-1 position. In contrast, 1-monoacyl derivatives of sulphoquinovosyl diacylglycerol and phosphatidylglycerol, the other membrane lipids contained in cyanobacteria, were not formed.

Carbohydrate Sequence↗

PubMed1992

Myosin light chain patterns in histochemically typed single fibers of the rat skeletal muscle.

1. This study was conducted to investigate the relationship between histochemical fiber types and myosin light chain patterns in rat single muscle fibers. 2. The hybrid of fast and slow light chains was observed in type I and II fibers of the soleus and type II fibers of the red portion of lateral head of the gastrocnemius muscles. 3. We also observed 7 types of light chain composition. Of the 7 types, 5 types were explainable by assuming the coexistence of isomyosins with either fast or slow light chains. However, the other 2 types could not be accounted for without hypothesizing the presence of isomyosins with promiscuous light chain distribution.

Animals↗

PubMed1992

Does an increase in prostaglandin E2 in the blood circulation contribute to a febrile response in rabbits?

We investigated the effect of intravenous injection of human recombinant interleukin-1 beta (IL-1) on rectal temperature and prostaglandin E2 concentration in venous and arterial blood and in the push-pull perfusate in the third ventricle of rabbits. Changes in plasma prostaglandin E2 concentration in blood obtained from the marginal ear vein paralleled changes in body temperature during both monophasic and biphasic fevers. The plasma concentration of prostaglandin E2 in blood obtained from the jugular vein increased during the first phase of the biphasic fever. However, no increase in the prostaglandin E2 level in the carotid arterial blood was observed during the biphasic fever. The levels of prostaglandin E2 in the push-pull perfusate in the third ventricle were markedly elevated during both monophasic and biphasic fevers. Intracarotid infusion of prostaglandin E2 did not produce a fever nor result in a change in the prostaglandin E2 concentration of the push-pull perfusate in the third ventricle. The present results suggest that prostaglandin E2 from the blood circulation does not contribute to fever production in rabbits.

Animals↗

PubMed1992

Early and delayed imaging of Tc-99m HMPAO versus Tl-201 in benign and malignant thyroid tumors. Similar uptake but different retention.

The authors performed both Tc-99m HMPAO and Tl-201 scintigraphy in 30 patients with thyroid tumors (21 papillary adenocarcinoma, three solid follicular adenoma, six adenomatous goiter with cystic degeneration). Increased accumulation of both Tc-99m HMPAO and Tl-201 was seen in 14 patients with papillary adenocarcinoma and three with solid follicular adenoma, whereas two patients with papillar adenocarcinoma had low accumulation of both tracers. Of the six patients with adenomatous goiter with cystic degeneration, four had low accumulation of both Tc-99m HMPAO and Tl-201, and one patient had low accumulation of Tc-99m HMPAO only. Iso accumulation (same accumulation as the normal thyroid) of Tc-99m HMPAO was seen in five patients with papillary adenocarcinoma and one with adenomatous goiter. The distribution of Tc-99m HMPAO in the thyroid tumors and normal thyroid tissue was independent of time from 2 to 120 minutes after injection. The results of dynamic studies using Tc-99m HMPAO suggested that the accumulation of Tc-99m HMPAO in thyroid tumors reflected mainly tumor blood flow. The resultant Tc-99m HMPAO images were essentially similar to the Tl-201 images obtained 10 minutes after injection. Tc-99m HMPAO imaging can be a suitable substitute for Tl-201 imaging, and it may possibly be used to estimate tumor blood flow in patients with thyroid tumors.

Adenocarcinoma, Papillary↗

PubMed1992

Immunohistological study of nonfunctional parathyroid carcinoma. Report of a case.

The histological and immunohistological features of a non-functional parathyroid carcinoma obtained from a 56-year-old woman are reported. Macroscopically, the tumor consisted of many small hemorrhagic nodules and showed adhesion to the thyroid gland and esophageal wall. Histologically, the tumor cells resembled parathyroid chief cells, and showed an island-like or sheet-like arrangement, the former showing cystic degeneration and containing hemorrhagic fluid in the extracellular space. Tumor cells resembling water-clear cells and oxyphilic cells were also observed. Most of the tumor cells had glycogen in the cytoplasm. Immunohistologically, the tumor cells showed no staining with anti-thyroglobulin, JT-95 or anti-calcitonin antibodies. However, they were stained with antibodies against chromogranin A (Ch A) and the N-terminal portion of human parathyroid hormone (PTH (N)). The positive staining with anti-PTH (N) antibody disappeared when the antibody was absorbed with excess synthesized human PTH (N). Immunostaining for PTH (N) and Ch A was useful for differentiation of nonfunctional parathyroid carcinoma from thyroid carcinoma and thymoma.

Carcinoma↗

PubMed1992

Myosin heavy chain isoform transition in ageing fast and slow muscles of the rat.

Using gradient sodium dodecyl sulphate-polyacrylamide gel electrophoresis, myosin heavy chain (MHC) isoforms were studied in the extensor digitorum longus (EDL) and the soleus muscles of male Wistar rats at different ages (5, 10, 20 weeks, 1 and 2 years). In the EDL muscle, four types of MHC isoforms were observed in all age groups. There was an increase in the percentage of HCIId and a concomitant decrease in the percentage of HCIIb with increasing age. No significant difference was observed in the percentages of HCI and HCIIa isoforms in all the age groups. In contrast, the soleus muscle contained two MHC isoforms, HCI and HCIIa. There was an increase in the percentage of HCI and a concomitant decrease in the percentage of HCIIa with increasing age. These results suggest that age-related changes in the MHC isoforms in both the fast-twitch EDL and the slow-twitch soleus muscles are one factor underlying the age-related decrease in the speed of muscle contraction.

Aging↗

PubMed1992

Cardiovascular responses induced in free-moving rats by immune cytokines.

1. We investigated the effect of intraperitoneal (I.P.) injections of the immune cytokines, interleukin-1 beta (IL-1 beta) and tumour necrosis factor (TNF) on cardiovascular responses in free-moving rats, using a biotelemetry system. 2. The I.P. injection of a small dose of IL-1 beta (1 microgram/kg) induced a monophasic increase in the heart rate, and that of a large dose (10 micrograms/kg) induced biphasic increases in the blood pressure and heart rate. However, the I.P. injection of any of several doses of TNF (1, 10 and 50 micrograms/kg) had no effect on cardiovascular responses in rats. 3. Pre-treatment with I.P. injection of indomethacin (10 mg/kg), an inhibitor of cyclo-oxygenase, significantly suppressed the cardiovascular responses and the increase in the plasma noradrenaline (NA) concentration induced by I.P. injection of IL-1 beta. 4. Microinjection of IL-1 beta (1 and 10 ng) into the preoptic and anterior hypothalamic (PO-AH) region induced dose-dependent increases in the blood pressure and heart rate in rats. These responses were also suppressed by pretreatment with I.P. indomethacin (10 mg/kg). In addition, microinjection of prostaglandin E2 (20 and 100 ng) into the PO-AH region increased blood pressure and heart rate, but that of prostaglandin D2 (100 ng) had no effect. 5. The present results suggest that IL-1 beta stimulates the release of prostaglandins, presumably E series, near regions of the hypothalamus, which act on the hypothalamus to induce activation of the sympathetic nervous system. Subsequently, the blood pressure, heart rate and the plasma level of NA increase.

Animals↗

PubMed1992

Systemic injection of TNF-alpha attenuates fever due to IL-1 beta and LPS in rats.

The effect of tumor necrosis factor-alpha (TNF-alpha) on the febrile response to interleukin-1 beta (IL-1 beta) was investigated in rats. While both of these substances are capable of causing fever when injected into rats, an earlier study showed that the injection of antiserum against TNF-alpha enhanced endotoxin [lipopolysaccharide (LPS)] fever, suggesting that physiological levels of circulating TNF may act to limit the magnitude of fever. In the present study, the intraperitoneal injection of 1 microgram/kg of TNF-alpha significantly attenuated the fever due to the intraperitoneal injection of 10 micrograms/kg of IL-1 beta. Higher doses of TNF-alpha (10 and 50 micrograms/kg injected ip) slightly lowered the febrile response to this dose of IL-1 beta, but these changes were not significant. None of these doses of TNF-alpha alone significantly altered body temperature. The injection of 1 microgram/kg of TNF-alpha also significantly lowered the febrile response to the intraperitoneal injection of 10 micrograms/kg of LPS. The febrile responses to the preoptic area (POA) or intraperitoneal injection of IL-1 beta were not changed when a nonpyrogenic dose of TNF-alpha was simultaneously injected into the POA. Further studies are needed, however, before we can conclude that TNF does not act in the central nervous system to control the febrile response. These data support the hypothesis that nonpyrogenic levels of TNF act in the systemic circulation to suppress the development of fever.

Animals↗

PubMed1992

Regional differences in myosin heavy chain isoforms and enzyme activities of the rat diaphragm.

Myosin heavy chain isoforms and enzyme activities were compared between the costal and crural regions of the rat diaphragm. The percentage of heavy chain (HC) IIb in the crural region of the diaphragm was significantly (P less than 0.05) higher than that in the costal region (mean 7.3 vs. 3.0%), and the percentage of HCI was significantly lower in the crural than in the costal diaphragm (22.7 vs. 27.9%). The distributions of HCIIa and HCIId were relatively homogeneous in both regions. Succinate dehydrogenase activity in the costal diaphragm was 21% greater (P less than 0.01) than in the crural diaphragm. In contrast, there was no significant difference in the activity of phosphofructokinase in the crural and costal diaphragms. These results demonstrate that a difference in myosin heavy chain isoforms and oxidative capacity exists between the costal and crural regions of the rat diaphragm.

Animals↗

PubMed1992

Running training attenuates the ACTH responses in rats to swimming and cage-switch stress.

The present study was carried out to investigate the effect of running training on adrenocorticotrophic hormone (ACTH) response in rats to swimming or cage-switch stress to determine whether, after physical training, a cross-adaptation develops in the ACTH responses induced by different types of stresses. Rats were trained by two different kinds of exercises and for two different periods of training: 1) swimming for 4 wk (4W-swimming), 2) running for 4 wk (4W-running), and 3) running for 10 wk (10W-running). Remaining rats were used for control for 4 wk (4W-control) and 10 wk (10W-control). The ACTH response induced by swimming stress was reduced after training by swimming (62.4%) or by running (13.8-16.4%). These training periods also attenuated the ACTH response induced by cage-switch stress (62.4% in the swimming group, 23.8-34.6% in the running groups). After swimming stress, the 4W-swimming and 10W-running groups showed smaller increases in blood glucose than the control groups. In addition, the increased levels of blood lactate in all the trained rats were significantly smaller than those in the control groups, suggesting that an adaptation was achieved after physical training. These results suggest that after running training, cross-adaptation is developed in the ACTH response induced by different types of physical (swimming) or psychological (cage-switch) stresses.

Adrenocorticotropic Hormone↗

PubMed1992

Elevated ratio of late measles among subacute sclerosing panencephalitis patients in Karachi, Pakistan.

Subacute sclerosing panencephalitis (SSPE) in Western countries and Japan is found more often in early- than in late-measles sufferers. Recent SSPE findings in Karachi, however, present a different picture. Age at measles contraction was obtained and analyzed for 44 SSPE patients identified in Karachi between 1983 and 1988. The ratios of early- (< 2 years of age) and late- (> or = 2 years of age) measles sufferers among 36 of these patients who had experienced only one attack of measles were 0.33 and 0.67, respectively. This is in striking contrast to the predominance of early measles in the SSPE histories reported in Japan and an number of Western countries.

Age Factors↗

PubMed1992

Pure red cell aplasia following autoimmune haemolytic anaemia. Cell-mediated suppression of erythropoiesis as a possible pathogenesis of pure red cell aplasia.

We report here a rare case of pure red cell aplasia (PRCA) following autoimmune haemolytic anaemia (AIHA). After 4 years of AIHA, the patient developed anaemia with severe erythroid hypoplasia and was diagnosed as having PRCA. At this time, Coombs' test was negative and parvovirus infection was not recognized. The patient received azathioprine, and PRCA improved. To determine the pathogenesis of PRCA, in vitro culture studies of erythropoietic and granulopoietic precursors were performed. The patient's serum or IgG did not suppress the colony formation of bone marrow colony-forming units-erythroid (CFU-E) of normal subjects and the patient. In contrast, mononuclear cells in the peripheral blood of the patient significantly suppressed CFU-E of normal subjects. Media conditioned by the patient's mononuclear cells did not significantly suppress CFU-E. The significant production of suppressive cytokine such as tumour necrosis factor or gamma-interferon by the patient's mononuclear cells was not recognized. These findings suggest that the cytotoxic mononuclear cells affected directly the erythropoietic precursors and caused PRCA in this patient. The pathogenesis of PRCA was, therefore, considered to be different from that of the preceding AIHA.

Adult↗