Search PubMed⌕ Search

Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 415 records · Page 23Linked to original sources
PubMed1995

Physiologic changes of nerve root during posterior lumbar discectomy.

STUDY DESIGN AND OBJECTIVES: The effects of nerve root retraction in posterior discectomy on pressure, blood flow, and electrophysiologic changes of the nerve root were investigated. OBJECTIVES: This study was performed to assess the effects of nerve root retraction in posterior discectomy on pressure, blood flow, and electrophysiologic changes of the nerve root. SUMMARY OF BACKGROUND DATA: The effects of compression on nerve tissue have been clinically studied mainly in peripheral nerves. The potential risk for lumbar nerve root injury has not been evaluated precisely in humans. METHODS: Among 31 patients with lumbar intervertebral disc herniation, the correlation between retraction pressure and changes in blood flow of the nerve root was evaluated. Retraction pressure was continuously monitored during the discectomy and the length of the discectomy procedure was measured. Threshold and amplitude of compound muscle action potentials were monitored before and after discectomy. The relationship between intraoperative data on nerve root physiology and postoperative neurologic change was analyzed. RESULTS: Nerve root blood flow was decreased to 18-30% of the initial value under the pressure around 70 g/cm2. An abrupt decrease in nerve root blood flow was observed even within 1 or 2 mm of retraction distance. The threshold of the nerve root before retraction was minimal in the nerve root of the asymptomatic side, but increased in the affected root demonstrating sensory loss only, and significantly increased in the root showing sensory/motor deficit. Amplitude of compound muscle action potentials evoked by the stimulation at distal from herniated mass was lowest in the nerve root showing sensory/motor deficit. In 4 of 31 patients, high retraction pressure (> 170 g/cm2) was required and they showed temporary sensory deterioration after surgery. The length of discectomy procedure in these 4 patients was 14.1 +/- 4.1 minutes, but it was 9.9 +/- 2.7 minutes in the remaining 27 patients. CONCLUSIONS: In posterior lumbar discectomy, nerve root ischemia usually occurs during retraction. The magnitude of pressure and time of retraction may be potential risk factors for nerve root injury.

Adolescent↗
PubMed1995

pp60c-src expression in rat spermatogenesis.

A fractionation of the membrane extract of rat testes revealed the existence of pp60c-src kinase activity. The expression of pp60c-src was examined in the developing rat testes. The immunecomplex kinase assay using a monoclonal antibody specific to pp60c-src (mAb327) showed that the expression of pp60c-src kinase activity increased during the development of rat testes and declined in the adult. The increase in pp60c-src kinase activity observed during the development of rat testes was accompanied with an increase in the amount of pp60c-src protein. The peak period in the increase of pp60c-src kinase activity well coincided with the timing, when the spermatogenesis by meiosis just began. The immunohistochemical staining of pp60c-src in rat testes demonstrated that pp60c-src is most abundantly expressed in the spermatids which are the spermatogenic cells in the post-meiotic phase of the spermatogenesis. These findings strongly suggest that pp60c-src is a developmentally regulated gene product which is involved in rat spermatogenesis.

Amino Acid Sequence↗
PubMed1995

Subaxial lesions in rheumatoid arthritis. Radiographic factors suggestive of lower cervical myelopathy.

STUDY DESIGN: The present study focused on the radiographic and clinical parameters that suggest lower cervical lesions directly or indirectly related to lower cervical myelopathy in rheumatoid arthritis. OBJECTIVES: The results provided the risk factor for predicting compressive myelopathy due to lower cervical spine lesions in patients with rheumatoid arthritis. SUMMARY OF BACKGROUND DATA: The clinical pathology and radiographic risk factor for upper cervical myelopathy in rheumatoid arthritis has been well documented, but the compressive factors for lower cervical myelopathy due to subaxial lesions remain unclear. METHODS: Radiographic analysis on the lateral radiographs (neutral, flexion, and extension) of the cervical spine and neurologic evaluation were carried out in 100 patients with rheumatoid arthritis. Fifty-eight of these patients were followed-up for 5 to 10 years (mean, 5.4 years) radiographically and clinically. A comparative study on the incidence of radiographic abnormalities also was performed in 100 patients with rheumatoid arthritis and in age- and sex-matched patients with cervical spondylosis. CONCLUSIONS: Among the radiographic parameters of the lesions related to lower cervical myelopathy, marked destruction of spinous processes, axial shortening, and narrow spinal canal may be important factors that suggest myelopathy. Time-related deterioration of lower cervical myelopathy can be predicted by progressions of anterior slip, axial shortening, spinous process erosion, apophysial joint erosion, and intervertebral disc collapse. Younger patient age, longer duration of disease, higher dose of corticosteroid administration, and higher stage or class of rheumatoid arthritis also are thought to be significant general factors for myelopathy.

Adrenal Cortex Hormones↗
PubMed1995

Posterior canal-activated vestibulocortical pathways in cats.

This study was undertaken to investigate vestibulothalamocortical pathways in anesthetized cats. Synaptic connections of posterior canal-activated excitatory vestibuloocular relay (PC) neurons to thalamic neurons were examined by a spike-triggered averaging technique. The averaged potentials evoked in the ventrobasal complex of the thalamus revealed a negative wave with latencies from 0.8 to 1.5 ms. Thirty-six thalamic neurons, which were activated by nose-up head rotation and by contralateral labyrinth stimulation, were mainly located in the ventrobasal complex. Thirteen of these neurons were antidromically activated from the anterior suprasylvian sulcus or postcruciate dimple of the cortex. These results suggest that the PC neurons participate, at least in part, in the vestibulocortical pathways contributing to spatial orientation.

Animals↗
PubMed1995

A complete hydatidiform mole coexisting with a normal fetus was confirmed by variable number tandem repeat (VNTR) polymorphism analysis using polymerase chain reaction.

The diagnosis of a complete hydatidiform mole coexisting with a live fetus is often difficult because of the morphological similarity to a partial mole, but it is crucial to management in the postmolar course. We present a recent case in which DNA polymorphism analysis clearly revealed a different genetic origin for the fetal and molar parts. DNA polymorphisms on three different variable number tandem repeat loci, which were detected by polymerase chain reaction, indicated that the cord/placenta and molar tissue were parental and androgenetic, respectively. Subsequently, the patient was admitted for chemotherapy of metastatic trophoblastic disease.

Adult↗
PubMed1995

A novel deletion mutation in the beta-myosin heavy chain gene found in Japanese patients with hypertrophic cardiomyopathy.

Mutations in the cardiac beta-myosin heavy chain (MHC) gene of 50 Japanese patients with hypertrophic cardiomyopathy (HCM) were investigated by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. A novel deletion mutation was detected in exon 3 of the cardiac beta-MHC gene in a Japanese family with HCM. Sequencing analysis revealed a three nucleotide deletion at codon 10 leading to a deletion of a glycine residue, which has been conserved in the myosin gene from birds to humans. Because this deletion mutation was not detected in other healthy family members, it was suggested that this 10Gly deletion is the cause of HCM in this family. The same deletion mutation has been found in three other unrelated patients with HCM. This is the first report of a one codon deletion in the beta-MHC gene in patients with HCM.

Adult↗
PubMed1995

Excitation-contraction coupling in ventricular myocytes: effects of angiotensin II.

The effects of the vasoactive peptide angiotensin II (AII) on contractility and excitation-contraction coupling in isolated adult rabbit ventricular myocytes were investigated. In most ventricular myocytes, AII (10(-8) M) induced a significant increase in fractional shortening which was not associated with an increase in the calcium transient measured with indo-1. AII did increase the intracellular pH by approximately 0.2 5 pH units coincident with the positive inotropic effect. Effects of AII on pH and contractility were blocked by inhibitors of Na+/H+ exchange. AII also increased the rate of pHi recovery from intracellular acidosis at pHi values above 6.9. AII was shown not to affect the L-type inward calcium current. However, in an occasional cell, AII was observed to cause a slight increase in the calcium transient. We hypothesize that this response may reflect an increase of calcium influx on the sodium calcium exchanger, as a consequence of an increase in subsarcolemmal sodium concentration resulting from enhanced Na(+)-H+ exchange.

Angiotensin II↗
PubMed1995

Laminectomy-induced arachnoradiculitis: a postoperative serial MRI study.

Time-related changes of laminectomy-induced cauda equina adhesions were investigated by MRI in ten patients with degenerative spinal disease who underwent posterior surgery to the lumbar spine; seven had disc herniations and three spinal stenosis. Axial MRI was performed before and 3, 7, 21 and 42 days after surgery. Cauda equina adhesions were most severe at the laminectomised levels L3-4, L4-5 and L5-S1 (n = 16); partial adhesions were found in 9 of 16 levels at 6 weeks after surgery. At the L3-4 or L5-S1 levels (n = 14), the area of laminar exposure without laminectomy, the cauda equina adhesions continued 1 week after surgery, but thereafter resolved; only partial adhesions were seen at 5 of 14 levels 6 weeks after surgery. Shrinkage of the arachnoid sac was also found at the level of the laminectomy, but it re-expanded 3 weeks after surgery in all cases. Cauda equina adhesions and shrinkage of the sac were correlated closely with laminectomy, with or without discectomy, suggesting that an inflammatory process of deep wound healing may be involved in the mechanism of a laminectomy-induced arachnoradiculitis which may be correlated with post-operative leg symptoms.

Adolescent↗
PubMed1995

Novel missense mutation in alpha-tropomyosin gene found in Japanese patients with hypertrophic cardiomyopathy.

We have searched for mutations in alpha-tropomyosin gene in 50 Japanese patients with hypertrophic cardiomyopathy (HCM) by means of polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) analysis. Two missense mutations of the alpha-tropomyosin gene were detected in Japanese patients with familial HCM. Sequencing analysis revealed a C to T transition at codon 63 leading to a replacement of Ala with Val residue, and a G to A transition with replacement of Asp by Asn at codon 175. These missense mutations were found at residues which were markedly conserved across the species, and have been reported to interact with troponin T. This is the first report on a mutant alpha-tropomyosin gene in a Japanese population. Familial HCM is a genetically heterogeneous disease in Japanese patients, similar to that reported in Caucasian kindreds.

Amino Acid Sequence↗
PubMed1995

Abnormal arachidonate distribution in low-density lipoprotein and thoracic aorta in hyperinsulinemia.

The mechanism by which hyperinsulinemia promotes atherogenesis is unknown. The effects of hyperinsulinemia on risk factors for atherosclerosis were investigated by subcutaneously injecting rats daily with an insulin-zinc suspension (20 U/kg) for 12 weeks. After this period, body mass and food consumption did not differ significantly between control and insulin-treated animals. Daily insulin injection significantly increased urinary excretion of epinephrine and decreased urinary excretion of norepinephrine and dopamine, but had no significant effect on blood pressure or heart rate. Although insulin decreased plasma triglyceride concentration by 44% (P < .01), the triglyceride to protein ratio in plasma low-density lipoprotein (LDL) was increased by 34% (P < .05) in insulin-treated rats; the cholesterol to protein and triglyceride to protein ratios remained unaffected, indicating a change in the quality of the LDL particle. Insulin also increased the percentage of arachidonic acid (20:4) in LDL triglycerides by 37% (P < .05). In contrast, cholesteryl esters and triglycerides in the thoracic aorta were significantly increased (49% and 91%, respectively) by insulin treatment. Insulin increased the percentage of monounsaturated fatty acids and decreased the percentage of n-6 fatty acids, including arachidonate, in aortic triglycerides. Insulin also increased the percentage of palmitoleic acid (16:1) and decreased the percentages of saturated fatty acids and n-6 fatty acids in aortic cholesteryl esters. These results indicate that insulin induced deposition of cholesteryl esters and triglycerides, especially those containing monounsaturated fatty acids, and abnormal arachidonate distribution in LDL and tissues. The data further suggest that the development of atherosclerosis in response to hyperinsulinemia may be associated with arachidonate-rich triglycerides in LDL.

Animals↗
PubMed1995

Developmental alteration and neuron-specific expression of bone morphogenetic protein-6 (BMP-6) mRNA in rodent brain.

Bone morphogenetic proteins (BMPs) are a group of proteins which induce bone formation from mesenchymal cells. The existence of BMPs in the nervous system as well as in bone tissue has recently been reported. In this study, we show that BMP-6 is neuron-specific, and describe the temporal and spatial expression patterns of BMP-6 mRNA in the developing rat and gerbil brain. Northern blot analysis showed that the BMP-6 transcript level was specifically high from newborn to 3 weeks after birth compared with those in fetal and adult rats. In situ hybridization showed that most of the neurons possessed high levels of BMP-6 mRNA in the neonatal brain, while in the adult brain, BMP-6 mRNA level was significantly decreased in most of the neurons except those in hippocampus which retained high levels. Furthermore, to show that the BMP-6 expression was specific to neurons, we induced delayed neuronal cell death and compensative glial cell proliferation in the gerbil hippocampus by transient ischemia. Our findings collectively suggest that BMP-6 is neuron-specific and may play important roles in neuronal maturation and synapse formation.

Animals↗
PubMed1995

Morphological changes in the hippocampus in amygdaloid kindled mouse.

To clarify the origin and maintenance of epileptogenesis, morphological changes in the hippocampus of amygdaloid-kindled mice were analyzed at different stages of kindling. The granule cell size in dentate gyrus and the pyramidal cell size in CA1 were clearly decreased depending on seizure stage. The cell size in CA2 was increased and density in dentate gyrus and CA2 was reduced, significantly. The morphological changes in hippocampus associated with kindling must be closely related to the acquisition and the maintenance of epileptogenesis. The results support the hypothesis that seizure-induced damage of neurons may lead to formation of new synaptic connections that produce abnormal hyperexitability and result in seizures.

Amygdala↗
PubMed1995

Tumor cell attachment to laminin promotes degradation of the extracellular matrix and cell migration in high-metastatic clone cells of RCT sarcoma in vitro.

We investigated the roles of extracellular matrix proteins, laminin and fibronectin, in promoting invasiveness through the extracellular matrix in high-metastatic [RCT(+)] clone cells established from poorly differentiated murine RCT sarcoma in C3H/He mice. Laminin stimulated the type IV collagenolytic activity of RCT(+) cells. After more than 6 h of incubation, the type IV collagenolysis of the cell-conditioned medium was significantly higher in laminin-treated groups compared with the control. The migration activity of RCT(+) cells was stimulated by laminin. However, fibronectin did not influence the type IV collagenolysis or cell migration in this clone cell. The amino acid sequence YIGSR, which is derived from laminin, inhibited the laminin-mediated cell attachment and the laminin-promoted type IV collagenolysis, as well as cell migration of RCT(+) cells. RGD derived from fibronectin did not influence the cell attachment to laminin or Matrigel in this clone. In the invasion assay employing a Matrigel coated filter in a Boyden chamber, YIGSR showed greater inhibition of invasion through the Matrigel than did RGD with RCT(+) cells. YIGSR might inhibit the promoted-matrix degradation and cell migration in response to the cell attachment to laminin by competing with laminin for binding to cell surface laminin receptor. We suggest that laminin-mediated cell attachment to the extracellular matrix may play a role in promoting the matrix degradation and cell migration during metastatic cascades.

Amino Acid Sequence↗
PubMed1995

Induction of differentiation into monocyte/macrophage cell lineage of a human eosinophilic leukaemia cell line EoL-1 by simultaneous stimulation with tumour necrosis factor-alpha and interferon-gamma.

Human myeloid leukaemia cell lines have been shown to differentiate into distinct cell lineages in vitro in response to several differentiation-inducing agents. A human eosinophilic leukaemia cell line, EoL-1, has been shown to differentiate into mature eosinophilic granulocytes by treatment with the culture supernatant of a human T-cell line, HIL-3. In this study we have studied whether the EoL-1 cell line has potential to differentiate into cell lineage other than eosinophils. We found that EoL-1 cells cultured in the presence of tumour necrosis factor (TNF)-alpha (10 u/ml) and interferon (IFN)-gamma (1000 u/ml) for 2-4 d differentiated into macrophage-like cells in morphology, and expressed CD14 antigen on their cell surface. It is possible that the small subpopulation of EoL-1 cells which contains non-specific esterase (NSE) activity may be preferentially differentiated by TNF-alpha and IFN-gamma. To clarify this issue, we have cloned the EoL-1 cell line and obtained NSE negative and positive sublines. Both EoL-1 sublines differentiated into monocyte/macrophage-like cells, because: (a) EoL-1 sublines were induced to express CD14 antigen, and (b) they attached firmly to the plastic wells; (c) after differentiation they became strongly positive for NSE staining, and secreted TNF-alpha in response to the stimulation with lipopolysaccharide; and (d) they exhibited potent phagocytic activity. Therefore, we found that the EoL-1 cell line has the ability to differentiate not only into mature eosinophilic cells but also into monocyte/macrophage cell lineage, suggesting that EoL-1 cells represent immature cells with ability to differentiate into multiple cell lineages.

CD11 Antigens↗
PubMed1995

Posthemorrhagic hydrocephalus in a fetus with severe tachycardia.

Although posthemorrhagic hydrocephalus has been observed in premature infants, few cases of its intrauterine occurrence in fetuses have been reported. We report a case of posthemorrhagic hydrocephalus in a fetus with severe tachycardia. This case indicates that its possible occurrence should be considered in a case of a preterm fetus with distress.

Adult↗
PubMed1995

Identification of Rap1 as a target for the Crk SH3 domain-binding guanine nucleotide-releasing factor C3G.

C3G, which was identified as a Crk SH3 domain-binding guanine nucleotide-releasing factor, shows sequence similarity to CDC25 and Sos family proteins (S. Tanaka, T. Morishita, Y. Hashimoto, S. Hattori, S. Nakamura, M. Shibuya, K. Matuoka, T. Takenawa, T. Kurata, K. Nagashima, and M. Matsuda, Proc. Natl. Acad. Sci. USA 91:3443-3447, 1994). The substrate specificity of C3G was examined by in vitro and in vivo experiments. C3G markedly stimulated dissociation of bound GDP from Rap1B but marginally affected the same reaction of other Ras family proteins (Ha-Ras, N-Ras, and RalA). C3G also stimulated binding of GTP-gamma S [guanosine 5'-3-O-(thio)triphosphate] to Rap1B. When C3G and Rap1A were expressed in COS7 cells, marked accumulation of the active GTP-bound form of Rap1A was observed, while Sos was not effective in the activation of Rap1A. These results clearly show that C3G is an activator for Rap1. Furthermore, expression of C3G with a membrane localization signal in a v-Ki-ras transformant, DT, induced a reversion of the cells to the flat form, possibly through the activation of endogenous Rap1.

Animals↗