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Biomedical subjects

H Matsui

Publications and source records attributed to H Matsui.

At least 19 recordsLinked to original sources
PubMed1996

Back muscle injury after posterior lumbar spine surgery. A histologic and enzymatic analysis.

STUDY DESIGN: Back muscle injury after posterior lumbar surgery was studied by muscle histology and serum creatine phosphokinase MM isoenzyme activity. OBJECTIVES: To investigate intraoperative factors influencing the magnitude of back muscle injury after posterior lumbar surgery. SUMMARY OF BACKGROUND DATA: The authors previously have reported iatrogenic back muscle injury in an animal model and in humans. Serious injury of the back muscle has been shown by short-term and long-term follow-up evaluation. METHODS: The retraction pressure was monitored, and the retraction pressure-time products were calculated in 24 patients. Early histologic changes of multifidus muscle, which were taken at completion of surgery, and serum creatine phosphokinase MM isoenzyme activity changes were examined. RESULTS: The magnitude of back muscle injury was significant as the pressure-time product increased. Creatine phosphokinase MM isoenzyme activity increased after surgery and reached a plateau 1 day after surgery, followed by recovery to the normal value 1 week after surgery. Creatine phosphokinase MM isoenzyme activity tended to be high in cases with multilevel exposure and with high pressure-time product. CONCLUSIONS: Back muscle injury occurs in all patients who underwent posterior lumbar surgery, and these injuries are related to the retraction pressure, time, and extent of exposure.

Adult↗
PubMed1996

Protective effect of vagus nerve stimulation on forebrain ischaemia in gerbil hippocampus.

The left vagus nerve was stimulated during transient forebrain ischaemia in gerbils. The animals were exposed to 3 min of forebrain ischaemic insult at 37.5 degrees C. On day 5 post-ischaemia, the animals were perfusion-fixed for qualitative and quantitative histopathological analyses. High current stimulation of the vagus nerve inhibited ischaemic neuronal damage in the hippocampal CA1 sector (p < 0.01), but low current stimulation did not (p < 0.01). These effects might have been due to inhibition of the effects of excitatory amino acids during ischaemia. These results indicate that vagus nerve stimulation might be protective to neurones subjected to ischaemic insult.

Animals↗
PubMed1996

Effects of neurotensin on neurons in the rat central amygdaloid nucleus in vitro.

The effects of neurotensin (NT) on neurons in the central amygdaloid nucleus (ACe) were investigated in rat brain slice preparations by adding the peptide to the perfusing medium. Of 115 ACe neurons, 69 cells (60%) showed excitatory responses and 10 cells (9%) showed inhibitory responses to application of NT. The excitatory response to NT was observed in a dose-dependent manner and the threshold concentration was approximately 3 x 10(-9) M. The excitatory effects of NT persisted under blockade of synaptic transmission. The NT fragment neurotensin 8-13 and the NT analogue neuromedin N showed effects similar to those of NT, whereas the NT fragment neurotensin 1-8 had no effect on ACe neurons. Of 43 neurons in the septal nucleus, 8 cells (19%) and 3 cells (7%) showed excitatory and inhibitory responses, respectively, to NT. The results suggest that NT exerts a potent excitatory effect on ACe neurons through a direct action on specific receptors, in which NT may play a role in amygdala-relevant functions.

Amygdala↗
PubMed1996

Comparative study of the metabolism of triphenyltin in hamsters and rats after a single oral treatment with triphenyltin chloride.

Our previous work has shown that triphenyltin compound induces the diabetogenic effects, such as hyperglycemia and hypertriglyceridemia, on hamsters, but not on rats. In the present study, it is examined whether the species differences in the metabolic fate of triphenyltin exist for susceptibility between hamsters and rats. Triphenyltin chloride was orally dosed to hamsters and rats, and triphenyltin and its metabolites, mono- and diphenyltin, and inorganic tin, in liver, kidney, pancreas, brain, and blood were determined by gas chromatography periodically for 96 h after the treatment. Triphenyltin levels in the tissues of both species were almost maxima within 24 h after treatment. Although there were relatively high levels of triphenyltin in the tissues of hamsters dosed with triphenyltin chloride, compared with those in the rats, the proportion of metabolites to triphenyltin were lower than those in the rats. In particular, hamsters were more susceptible than rats to the pancreatic accumulations of triphenyltin and good correlation exists between the tin concentrations in the pancreas and the plasma glucose levels in triphenyltin-treated hamsters. These findings suggest that the dearylation of absorbed triphenyltin in hamsters is slower than that in rats and that triphenyltin-induced hyperglycemic action depends upon the amount of tin compounds absorbed into the pancreas. Furthermore, most of the tin compounds in the brains of both species were triphenyltin. This result shows that the metabolism of triphenyltin in the brains of both species was different from that in other tissues.

Administration, Oral↗
PubMed1996

MB fraction of cumulative creatine kinase correlates with insulin secretion in patients with acute myocardial infarction: insulin as a possible determinant of myocardial MB creatine kinase.

To test whether insulin is a regulatory factor of myocardial MB creatine kinase content, we investigated the correlation between the ability of insulin secretion and the MB fraction of cumulative CK released in patients with acute myocardial infarction. We analyzed 18 patients who underwent successful direct angioplasty within 10 hours of the onset of their first myocardial infarction. Exclusion criteria were age more than 75 years, heart failure, severe obesity, multivessel disease, and history of diabetes mellitus. Cumulative activity of serum MB CK divided by that of total CK was defined as MB%, which was considered to represent myocardial MB CK content. Two weeks or more after the onset of myocardial infarction, 75 gm oral glucose tolerance test with serial determination of plasma glucose and serum insulin (0, 0.5, 1, 2, 3 hours) was done. Urinary and plasma catecholamines and echocardiographic left ventricular (LV) mass were measured. MB% significantly correlated with insulinogenic index (r = 0.564, p = 0.019), insulin area (r = 0.594, p = 0.012), insulin area/glucose area (r = 0.630, p = 0.007), and urinary adrenaline (r = -0.542, p = 0.025) and tended to correlate with plasma adrenaline (r = -0.431, p = 0.084). Age, body mass index, infarct size, glucose metabolism, and LV mass were not significant univariate predictors of MB%. Multivariate analysis showed that the ability of insulin secretion contributed to MB% more than catecholamines did and that insulin area/glucose area was the strongest independent predictor of MB% (t = 3.01, p = 0.015). Thus MB fraction of cumulative CK released, indicative of Myocardial MB CK distribution, strongly related to the ability of insulin secretion in subjects without overt insulin resistance. Regulation by insulin of myocardial MB CK is suggested.

Adrenergic Agonists↗
PubMed1996

Insulin increases distinct species of 1,2-diacylglycerol in isolated perfused rat heart.

Insulin and glucose increase the synthesis of 1,2-diacylglycerol (1,2-DAG), the physiological activator of protein kinase C (PKC) in a variety of tissues and cells. The effects of insulin and glucose on the abundance and fatty acid composition of 1,2-DAG were investigated in isolated perfused rat hearts with the use of capillary gas chromatography and 1,2-dipentadecanoin as an internal standard. A high concentration of insulin (25 mU/ mL) significantly increased cardiac contractility and reduced coronary flow. In addition, perfusion with 25 mU/mL insulin induced significant increases of 18.2% and 26.4% in 1,2-DAG mass after 5 and 30 minutes, respectively, in the presence of 8.6 mmol/L glucose, whereas there was no increase in 1,2-DAG with 2.5 mU/mL insulin. Analysis of the fatty acid composition of 1,2-DAG showed that only species containing specific fatty acids (16:0, 18:1, and 18:2) were increased in response to insulin. In contrast, an increase in glucose concentration in the perfusion medium from 3 to 17 mmol/L had no effect on the total mass or fatty acid composition of 1,2-DAG, cardiac contractility, or coronary flow. Addition of a high insulin concentration to the high-glucose medium increased the abundance of 1,2-DAG containing 16:0, 18:1, and 18:2 fatty acids, as well as cardiac contractility. It is concluded that the effect of insulin on cardiac contractility may be related to the associated increase in 1,2-DAG abundance.

Animals↗
PubMed1996

Enhanced expression of the protein kinase substrate annexin in human hepatocellular carcinoma.

Annexin (AX) constitutes a new family of Ca2+-dependent membrane-binding proteins; 13 of them have been described. Among these, annexin-1 (AX-I) has displayed many biological functions in vitro. Its actual role in vivo, however, remains unknown. We already reported that AX-I was expressed in proliferating (regenerating) hepatocytes at both protein and messenger RNA (mRNA) levels. The role of AX-I in human hepatocellular carcinoma (HCC) remains obscure. In this study, the amounts of AX-I at protein and mRNA levels, as well as its localization, have been determined in the normal human liver, chronic hepatitis liver, and nontumorous and tumorous portions of HCC. AX-I was rarely found in normal and chronic liver tissues, whereas it is overexpressed at both the transcriptional and translational levels in tumorous and nontumorous regions of HCC. In addition, more AX-I was expressed in the tumorous portion than the nontumorous portion of HCC. AX-I was present in the hepatocytes and HCC cells, localized mainly in the cytoplasm. AX-I was expressed in poorly differentiated cancer cells. Furthermore, AX-I was tyrosine-phosphorylated in HCC. We also found that some of the AX-I- positive hepatocytes in the nontumorous tissues were derived from a particular subset of parenchymal cells (stem or oval cells). These results indicate that AX-I plays an important role in the malignant transformation process leading to HCC and that it is closely related to the histological grade of HCC. HCC would offer a novel tool with which to study the function of AX-I in malignant transformation.

Annexin A1↗
PubMed1996

Presence of prostaglandin EP4 receptor gene expression in a rat gastric mucosal cell line.

RGM-1 is an epithelial cell line established from gastric mucosa of adult Wistar rats. In this study, we characterized this newly established cell line by Northern blot analysis. We also investigated deoxyribonucleic acid (DNA) synthesis and hexosamine production in RGM-1 by PGE2. Northern blot analysis did not detect any transcript of proton pump, gastrin receptor, histidine decarboxylase, somatostatin and pepsinogen 1, indicating the absence of characteristics of parietal, ECL, D and chief cells in RGM-1 cells. However, this periodic acid-Schiff (PAS)-positive cell line expressed prostaglandin EP4 receptor mRNA but not EP1 and EP3 receptor mRNAs. [3H]-thymidine incorporation into DNA of the cells was not increased by PGE2. In contrast, PGE2 increased hexosamine content in RGM-1 cells. These results suggest that RGM-1 may be a useful model of gastric mucosal cells and that PGE2 plays a role on mucin synthesis in RGM-1 cells possibly via EP4 receptors.

Animals↗
PubMed1996

Significance of serum laminin and type IV collagen levels for metastasis in murine RCT sarcoma.

We investigated in vivo the correlation between pulmonary metastasis and serum concentrations of laminin and type IV collagen in high-metastatic RCT(+) and low-metastatic RCT(-) clones established from poorly differentiated RCT sarcoma in C3H/He mice. The in vitro invasiveness of these cell clones through the extracellular matrix was also studied. In the in vitro invasion assay, high-metastatic RCT(+) cells showed significantly more invasiveness than low-metastatic RCT(-) cells. The different invasiveness of these cloned cells was associated with their different ability to attach to and degrade the matrix. In mice inoculated with RCT(+) cells, serum levels of laminin and type IV collagen rose with the increase in the number of pulmonary metastatic nodules. Serum levels of these extracellular matrix components started to rise when pulmonary metastatic nodules were macroscopically observed in the RCT(+) group. In mice bearing RCT(-) cells with lower metastatic ability, there were no significant increases in serum extracellular matrix levels. These findings suggested that serum concentrations of laminin and type IV collagen might be useful markers for the early detection of metastasis.

Animals↗
PubMed1996

Regulation and bioelectrical effects of cyclic adenosine monophosphate production in the ciliary epithelial bilayer.

PURPOSE: To determine whether the intact isolated ciliary epithelial bilayer retains the alpha-2 and beta adrenergic receptor activation and interaction described for whole ciliary processes and whether this pure epithelial bilayer displays bioelectric parameters sensitive to alterations in cyclic adenosine Monophosphate (cAMP) production induced by adrenergic compounds. METHODS: The intact ciliary epithelial bilayer of the rabbit eye isolated by perfusion was mounted in a specially constructed Ussing-type chamber. The transepithelial potential difference and short-circuit current were monitored for effects induced by agents that stimulated or blocked (some did both) caMP production. Using a radioimmunoassay, the latter were studied in the pure epithelial bilayers and in whole ciliary processes. RESULTS: A reproducible increase in cAMP production and an increase in the short-circuit current induced in the bilayer by isoproterenol, a nonspecific beta adrenergic agonist, were both blocked by pretreatment with either timolol, a nonspecific beta adrenergic blocking agent, or with para-aminoclonidine, an alpha-2 agonist. Maximal stimulation of cAMP with forskolin in this pure isolated epithelial preparation yields a response that is 60% of the value found in whole processes, indicating that the latter tissue contains responsive sites that are nonepithelial, probably vascular, or perhaps stromal. The degree of inhibition of the beta adrenergic receptor by alpha-2 agonists was not very different in the two preparations. On the other hand, inhibition of the epithelial vasointestinal peptide receptor by neuropeptide Y or alpha-2 agonism was considerably heightened in the pure bilayered epithelial preparation. CONCLUSIONS: The isolated intact ciliary epithelial bilayer, when stimulated with beta adrenergic receptor agonists, vasointestinal peptide, or forskolin, produces increased cAMP and its transepithelial potential becomes hyperpolarized. These chemical and bioelectrical effects are prevented by pretreatment with either alpha-2 adrenergic agonists or beta adrenergic blocking agents. The results obtained in the isolated intact purely epithelial ciliary bilayer confirm that the ciliary epithelium is the source of adrenergic receptor activation and interaction and support the hypothesis that aqueous humor production is regulated by interactions between epithelial alpha-2 and beta adrenergic receptors.

Adrenergic alpha-Agonists↗
PubMed1996

[System for registering gestational trophoblastic disease in Chiba Prefecture in the past 20 years].

From 1974 to 1993, a total of 3,203 patients with hydatidiform mole (HM), were registered in Chiba Prefecture. The incidence of HM during the study period was 2.8 per 1,000 live births or one per 357 live births, but it decreased to 1.5 per 1,000 live births in these 3 years. In the past 20 years, the incidence of invasive mole (IM) and choriocarcinoma was 8.8% (282/3,203) and 0.91% (29/3,203), respectively. In addition, 1,599 patients with HM have been diagnosed and registered as complete mole (CM) and partial mole (PM) patients on the basis of macroscopic findings since 1981. Of these classified patients, the incidence of IM following CM and PM was 12.5% (141/1,130) and 1.5% (7/469), respectively. Moreover, 19 (1.7%) patients with CM and one (0.2%) patient with PM developed CC. In this study, it is clear that gestational trophoblastic disease after the evacuation of PM definitely occurred and the management of PM should be similar to that of CM so long as macroscopic criteria are employed.

Adult↗
PubMed1996

Subchronic study of the metabolism of triphenyltin in hamsters.

In previous studies we investigated the metabolism of tin compounds in rats and hamsters following single oral treatments with triphenyltin. The objective of this study was to provide information on the metabolism of triphenyltin in hamsters subchronically treated with dietary triphenyltin for 180 d. Groups were fed diets containing 3 different triphenyltin concentrations: 1.28, 28.82 or 54.77 ppm. The 28.82 and 54.77 ppm groups gained less body weight than the control and 1.28 ppm groups. However, none of the animals showed characteristic symptoms. We detected triphenyltin and its metabolites in the tissues of dosed hamsters. Highest tin concentrations were in livers and kidneys, as diphenyltin and inorganic tin respectively; no significant amounts of triphenyltin were found. Triphenyltin was metabolized relatively rapidly in the hamsters. There was more tin relative to the administered triphenyltin in the livers of the low dietary group compared to the high dietary triphenyltin group. This suggests that low concentrations of triphenyltin are easily absorbed from the gastrointestinal tract. While we previously demonstrated that acutely dosed triphenyltin produced marked hyperglycemia in hamsters, this was not found in the hamsters repeatedly dosed with dietary triphenyltin in the present study.

Administration, Oral↗
PubMed1995

Quantification of the Na+/K(+)-pump in solubilized tissue by the ouabain binding method coupled with high-performance gel chromatography.

Membrane-bound Na+/K(+)-ATPase purified from dog kidney outer medulla was solubilized with octaethylene glycol n-dodecyl ether (C12E8) and incubated with [3H]ouabain in the presence of NaCl. ATP and MgCl2 for 10 min at 0 degrees C. The resulting enzyme was separated, by high-performance gel chromatography executed at 0.2 degrees C. Mainly into its (alpha beta)2-diprotomer and alpha beta-protomer, which both bound stoichiometrically to [3H]ouabain. The amounts of ouabain that bound to the tissue itself and its microsomes could be estimated in the same way, as [3H]ouabain was found to bind only to the diprotomer and protomer they possessed. The amounts of ouabain that bound to them in the solubilized state were at least 5-times higher than those that did so when they were non-solubilized, suggesting that the surfactant rendered the enzyme accessible to ouabain. When the solubilized tissue (138 mg ml-1 wet tissue) was reacted with ouabain in the presence of 0.1 M NaCl and 4.8 mM MgCl2 for 10 min at 0 degrees C, maximal ouabain binding was attained in the presence of 18.3 microM [3H]ouabain, 1.2 mM ATP and 3 to 5 mg ml-1 C12E8, which was common to the outer medulla and human colon cancer cells. The present method enabled the pump number in protein and tissue samples in the range 7.2 x 10(-9) (purified pump) to 1.5 x 10(-12) (cancer tissue) mol/mg protein to be estimated within 2 h.

Animals↗
PubMed1995

An isoform of the neuronal cyclin-dependent kinase 5 (Cdk5) activator.

Neuronal Cdc2-like kinase is a heterodimer of Cdk5 and a 25-kDa subunit that is derived from a 35-kDa brain- and neuron-specific protein called the neuronal Cdk5 activator (p35/p25nck5a) (Lew, J., Huang, Q.-Q., Qi, Z., Winkfein, R. J., Aebersold, R., Hunt, T., and Wang, J. H. (1994) Nature 371, 423-426; Tsai, L. H., Delalle, I., Caviness, V. S., Jr., Chae, T., and Harlow, E. (1994) Nature 371, 419-423). Upon screening of a human hippocampus library with a bovien Nck5a cDNA, we uncovered a distinct clone encoding a 39-kDa isoform of Nck5a. The isoform, designated the neuronal Cdk5 activator isoform (p39nck5ai), showed a high degree of sequence similarity to p35nck5a with 57% amino acid identity. Northern blot analysis detected its mRNA transcript in bovine and rat cerebrum and cerebellum, but not in any other rat tissues examined. In situ hybridization showed that Nck5ai was enriched in CA1 to CA3 of the hippocampus, but absent in the fimbria of hippocampal formation. Among seven cell lines in proliferating cultures, only PC12 and N2A, two cell lines capable of differentiating into neuron-like cells, were found to contain Nck5ai mRNA. A 30-kDa truncated form of Nck5ai expressed as a glutathione S-transferase fusion protein in Escherichia coli] was found to associate with Cdk5 to form an active Cdk5 kinase. Thus, the isoform shares many common characteristics with p35nck5a, including Ckd5 activating activity and brain- and neuron-specific expression. Both proteins show limited sequence homology to cyclins, suggesting that they define a new family of cyclin-dependent kinase-activating proteins.

Amino Acid Sequence↗
PubMed1995

Primer RNA synthesis by plasmid-specified Rep protein for initiation of ColE2 DNA replication.

Initiation of in vitro ColE2 DNA replication requires the plasmid-specified Rep protein and DNA polymerase I but not RNA polymerase and DnaG primase. The ColE2 Rep protein binds specifically to the origin where replication initiates. Leading-strand synthesis initiates at a unique site in the origin and lagging-strand DNA synthesis terminates at another unique site in the origin. Here we show that the primer RNA for leading-strand synthesis at the origin has a unique structure of 5'-ppApGpA. We reconstituted the initiation reaction of leading-strand DNA synthesis by using purified proteins, the ColE2 Rep protein, Escherichia coli DNA polymerase I and SSB, and we showed that the ColE2 Rep protein is a priming enzyme, primase, which is specific for the ColE2 origin. The ColE2 Rep protein is unique among other primases in that it recognizes the origin region and synthesizes the primer RNA at a fixed site in the origin region. Specific requirement for ADP as a substrate and its direct incorporation into the 5' end of the primer RNA are also unique properties of the ColE2 Rep protein.

Adenosine Diphosphate↗
PubMed1995

Tissue-type transglutaminase from red sea bream (Pagrus major). Sequence analysis of the cDNA and functional expression in Escherichia coli.

A cDNA clone encoding a tissue-type transglutaminase (TGase) was isolated from a cDNA library prepared from the liver of red sea bream (Pagrus major). The cDNA sequence had an open reading frame coding for a protein of 695 amino acids and showed 43% identity to the sequence of guinea pig liver TGase, revealing a relatively low overall similarity. However, the 25-amino-acid sequence containing the putative active site (Cys272) of the enzyme was completely conserved between the two species, and was also identical to the corresponding regions of human and bovine endothelial cell TGases. In addition, the critical residues (His332 and Asp355) thought to form the catalytic-center triad together with Cys272, were found in the highly conserved region. The red sea bream TGase had an extension of 11 amino acids in the C-terminal region and some differences in the N-terminal region when compared with guinea pig TGase. From the cloned cDNA, a semi-synthetic TGase gene suitable for overexpression in Escherichia coli was constructed (pTTG2-22). At a reduced temperature (28 degrees C), E. coli cells transformed with pTTG2-22 could produce soluble TGase which exhibited catalytic activity in the presence of calcium. E. coli extracts containing the recombinant red sea bream TGase induced gelation of actomyosin solutions, accompanied by a significant increase of epsilon-(gamma-glutamyl)lysine bonds, which are predominantly derived from the cross-linking of myosin heavy chains. These results indicate that this fish TGase should be useful for further analysis of TGase structure/function relationships and that it could also be employed to enhance the viscoelastic properties of proteinaceous materials.

Actomyosin↗