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Biomedical subjects

N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 433 records · Page 24Linked to original sources
PubMed1993

[Epidural buprenorphine under nitrous oxide-oxygen-enflurane anesthesia in elderly patients].

The effects of epidural buprenorphine (Bn) under nitrous oxide-oxygen-enflurane (E) anesthesia in elderly patients were examined. The subjects were older than 65 years (n = 82) and scheduled for abdominal surgery. They were divided randomly into two groups according to epidural drugs used. The first group received epidural Bn 0.1-0.2 mg (group B, n = 41). The second group received epidural Bn 0.1-0.2mg + 1% lidocaine (group BL, n = 41). The enflurane concentration was 1.13% in group B, and it was significantly higher than 0.78% of group BL (P < 0.01). There was no intra-group difference in the highest systolic blood pressure during operation. The lowest systolic blood pressure during operation was 92.0 +/- 2.1 mmHg in group BL and it was significantly lower than 100.2 +/- 2.9 mmHg of group B (P < 0.05). The percentage of patients who needed vasoconstrictor drugs was 12% in group B, and it was significantly smaller than 42% of group BL (P < 0.01). On the other hand the percentage of patients who needed vasodilator drugs was 39% in group B, and it was significantly larger than 17% of group BL (P < 0.05). There was no intra-group difference in arousing time from anesthesia. Concerning the postoperative respiratory state, there was no intra-group difference in the respiratory rate, tidal volume and PaO2. But the PaCO2 value was 44.7 +/- 0.8 (mean +/- SE) mmHg in group BL, and it was significantly higher than 40.7 +/- 0.7 mmHg of group B (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1993

[Effects of high doses of beclomethasone dipropionate in bronchial asthma].

To evaluate the clinical efficacy of high dose inhaled steroids, we examined the effects of standard doses (400 micrograms/day) and high doses (800 micrograms/day) of inhaled beclomethasone dipropionate (BDP, Becotide Inhaler), and the dose for regular use (800 micrograms/day) of salbutamol (Salb. Asmidon Air) on pulmonary function, bronchial hyperresponsiveness and asthma attack score. The subjects were 17 out-patients with mild or moderate bronchial asthma who were not receiving any anti-allergics or steroids. The patients were randomly allocated into three groups i.e., Group I: BDP 400 micrograms/day, Group II: BDP 800 micrograms/day and Group III: Salb. 800 micrograms/day. The administration period was 8 weeks. Pulmonary function test were performed and bronchial hyperresponsiveness was examined before and after the 8 weeks of treatment and attack scores were recorded during this period. It was found that inhalations of 400 micrograms/day and 800 micrograms/day BDP improved FEV1.0% value, peak flow, F-V curve, Dmin. and SGrs/Grs cont. Particularly, inhalation of 800 micrograms/day of BDP significantly improved these values and reduced attack scores in the early stages of the 8 week treatment. In contrast, there was a trend for inhalation of Salbutamol to enhance bronchial hyperresponsiveness and not to improve pulmonary function and asthma attack score. In conclusion, 800 micrograms/day of inhaled BDP is considered to be useful in the treatment of mild or moderate bronchial asthma.

Adult↗
PubMed1993

Scintigraphic evaluation of gastroesophageal reflux following gastrectomy.

We used scintigraphy to detect and quantify gastro-esophageal reflux, and determined the sensitivity of this method for identifying patients with clinical symptoms and/or endoscopic evidence of reflux. Thirty gastrectomy patients with heartburn and regurgitation, and 8 healthy controls were studied. The gastro-esophageal reflux index, calculated from imaging data, correlated significantly with the symptom score of the subjects, and the index was significantly larger in the symptomatic patients group (7.07 +/- 1.21) than in the healthy control group (1.54 +/- 0.22) (p < 0.001). Our study suggests that scintiscanning is capable of detecting gastro-esophageal reflux accurately, rapidly, noninvasively, and with a high degree of sensitivity. In addition, scintiscanning can be employed to quantify reflux in gastrectomy patients.

Adult↗
PubMed1993

Malabsorption after small-bowel transplantation.

Following small intestinal transplantation for the short-bowel syndrome the absorptive capacity of the grafted bowel is markedly reduced in the early postoperative period. This impairment is thought to be due primarily to perioperative ischemic damage and complete denervation. To determine which of these was the more important factor, we compared three groups of mongrel dogs. A sham-operated group (n = 5), a denervation group (n = 4), and an autotransplantation group (n = 5). D-xylose absorption and graft tissue levels of substance P and ATP were measured at 4 and 5 weeks postoperatively. A significant reduction in the intestinal absorption of D-xylose was observed in the denervation and autotransplantation groups (P < 0.01, P < 0.05). In contrast, the denervation and autotransplantation groups had significantly higher substance P levels in small-bowel biopsy tissues than the control group (P < 0.01). However, the tissue ATP levels were similar in all three groups, suggesting that perioperative ischemic damage was reversible. These findings indicate that the impaired absorption following small-bowel autotransplantation was largely due to intestinal denervation.

Animals↗
PubMed1993

Analysis of hepatic encephalopathy after distal splenorenal shunt--PTP image and pancreatic hormone kinetics.

The Warren-Zeppa selective distal spleno-renal shunt is aimed at decompressing esophageal varices while at the same time ligating left gastric, gastroepiploic and umbilical veins. But in the long term follow-up loss of shunt selectivity was observed in a number of cases (7/76), with hepatic encephalopathy resulting in 9.3%. In this study, we carried out percutaneous transhepatic portography and investigated pancreatic hormone kinetics in portal blood after arginine load, mainly in cases of hepatic encephalopathy after distal splenorenal shunt compared with non-encephalopathy cases of LC + Varix. These data suggested that as a cause of encephalopathy after distal splenorenal shunt, (1) a marked decrease in portal blood flow due to portal systemic shunt via the pancreatic vein was considered from PTP image, (2) a marked decrease in I/G ratio was considered from pancreatic hormone kinetics in portal blood.

Blood Glucose↗
PubMed1993

[The circulatory and respiratory effects of methylprednisolone associated with catecholamine administration of a few hours].

We studied the circulatory and respiratory effects of methylprednisolone (MPS) associated with catecholamine administration of a few hours after cardiopulmonary bypass (CPB). Forty patients undergoing coronary artery bypass grafting were randomly divided into two groups. Twenty patients in group 1 [MPS (-) group] did not receive MPS and 20 patients in group 2 [MPS (+) group] received MPS 15 mg.kg-1 i.v. 60 minutes after CPB. The circulatory and respiratory parameters were measured 60 minutes after CPB, 30 minutes after MPS i.v. and 60 minutes after MPS i.v. The values in MPS (-) group were compared with those in MPS (+) group. CI and SVI decreased, and SVRI and PQR increased in MPS (-) group, but these values were unchanged in MPS (+) group. RAP, mPAP, PCWP and PVRI were unchanged in MPS (-) group. PCWP increased and the other values were unchanged in MPS (+) group. The blood gases and pulmonary alveolar function were not different between the two groups. The oxygen delivery decreased in MPS (-) group, but it was unchanged in MPS (+) group. The oxygen consumption was unchanged in the two groups. Blood cortisol increased and epinephrine and norepinephrine decreased in MPS (+) group. Methylprednisolone had an effect to improve the decreased CI and the increased SVRI, and no respiratory problems were observed in patients for coronary artery bypass grafting with catecholamine administration for a few hours after cardiopulmonary bypass.

Blood Circulation↗
PubMed1992

Differential regulation of mRNAs encoding three protein-tyrosine phosphatases by insulin and activation of protein kinase C.

Protein-tyrosine phosphatases (PTPases) play an essential role in the control of signalling through phosphotyrosine pathways. Since little is known about the regulation of these enzymes, we examined the effect of insulin and phorbol 12-myristate 13-acetate (PMA) treatment of well-differentiated rat hepatoma (Fao) cells on the expression of mRNAs encoding three major PTPase homologs in liver: PTPase1B, an intracellular enzyme with a single conserved PTPase domain, and two tandem-domain, transmembrane PTPases, known as LAR and LRP. Treatment of serum-deprived cells with 100 nM insulin increased the abundance of the 4.3 kb and 1.6 kb mRNAs encoding PTPase1B on Northern analysis by 1.6 and 3.1-fold, respectively (p < or = 0.02). Similarly, exposure to 100 ng/ml PMA increased the 4.3 and 1.6 kb PTPase1B mRNAs by 4.5 and 5.7-fold, respectively (p < or = 0.035). In contrast, treatment with insulin or PMA had no significant effect of the abundance of mRNA encoding either LAR or LRP. PMA appeared to have a transcriptional effect on the PTPase1B gene by a protein kinase C-mediated mechanism. The increase in PTPase1B mRNA expression by insulin and PMA suggests that this PTPase may provide feed-back regulation of signalling through the insulin action pathway as well as a potential link between the action of protein kinase C and the regulation of specific phosphotyrosine residues in cells.

Animals↗
PubMed1992

Insulin receptor protein-tyrosine phosphatases. Leukocyte common antigen-related phosphatase rapidly deactivates the insulin receptor kinase by preferential dephosphorylation of the receptor regulatory domain.

A number of protein-tyrosine phosphatase(s) (PTPases) have been shown to dephosphorylate the insulin receptor in vitro; however, it is not known whether any individual PTPase has specificity for certain phosphotyrosine residues of the receptor that regulate its intrinsic tyrosine kinase activity. We evaluated the deactivation of the insulin receptor kinase by three candidate enzymes that are expressed in insulin-sensitive rat tissues, including the receptor-like PTPases LAR and LRP, and the intracellular enzyme, PTPase1B. Purified insulin receptors were activated by insulin and receptor dephosphorylation, and kinase activity was quantitated after incubation with recombinant PTPases from an Escherichia coli expression system. When related to the level of overall receptor dephosphorylation, LAR deactivated the receptor kinase 3.1 and 2.1 times more rapidly than either PTPase1B or LRP, respectively (p less than 0.03). To assess whether these effects were associated with preferential dephosphorylation of the regulatory (Tyr-1150) domain of the receptor beta-subunit, we performed tryptic mapping of the insulin receptor beta-subunit after dephosphorylation by PTPases. Relative to the rate of initial loss of 32P from receptor C-terminal sites, LAR dephosphorylated the Tris-phosphorylated Tyr-1150 domain 3.5 and 3.7 times more rapidly than either PTPase1B or LRP, respectively (p less than 0.01). The accelerated deactivation of the insulin receptor kinase by LAR and its relative preference for regulatory phosphotyrosine residues further support a potential role for this transmembrane PTPase in the physiological regulation of insulin receptors in intact cells.

Animals↗
PubMed1992

Insulin receptor and epidermal growth factor receptor dephosphorylation by three major rat liver protein-tyrosine phosphatases expressed in a recombinant bacterial system.

Protein-tyrosine phosphatases (PTPases) play an essential role in the regulation of signal transduction mediated by reversible protein-tyrosine phosphorylation. In order to characterize individual rat hepatic PTPases that might have specificity for autophosphorylated receptor tyrosine kinases, we isolated cDNA segments encoding three PTPases (PTPase 1B, LAR and LRP) that are expressed in insulin-sensitive liver and skeletal muscle tissue, and evaluated their catalytic activity in vitro. The intrinsic PTPase activities of the full-length PTPase 1B protein and the cytoplasmic domains of LAR and LRP were studied by expression of recombinant cDNA constructs in the inducible bacterial vector pKK233-2 using extracts of a host strain of Escherichia coli that lacks endogenous PTPase activity. Each of the cloned cDNAs dephosphorylated a cognate phosphopeptide derived from the regulatory region of the insulin receptor. Despite having only 30-39% sequence identity in their catalytic domains, LAR and PTPase 1B had similar relative activities between the peptide substrate and intact insulin receptors, and also displayed similar initial rates of simultaneous dephosphorylation of insulin and epidermal growth factor (EGF) receptors. In contrast, LRP exhibited a higher rate of dephosphorylation of both intact receptors relative to the peptide substrate, and also dephosphorylated EGF receptors more rapidly than insulin receptors. These studies indicate that three PTPases with markedly divergent structures have the catalytic potential to dephosphorylate both insulin and EGF receptors in intact cells and that redundant PTPase activity may occur in vivo. For these PTPases to have specific physiological actions in intact cells, they must be influenced by steric effects of the additional protein segments of the native transmembrane enzymes, cellular compartmentalization and/or interactions with regulatory proteins.

Amino Acid Sequence↗
PubMed1992

Approaches to the molecular cloning of protein-tyrosine phosphatases in insulin-sensitive tissues.

The intrinsic tyrosyl kinase activity of the insulin receptor is regulated by a balance between insulin-induced receptor autophosphorylation, which stimulates the receptor kinase, and enzymatic dephosphorylation of the receptor, which deactivates its kinase activity. The cellular protein-tyrosine phosphatase (PTPase) enzymes responsible for reversing the activated state of the insulin receptor have not been characterized. Our laboratory is interested in identifying and cloning the specific PTPase(s) that regulate the phosphorylation state of the insulin receptor. This chapter will summarize the design and results of our initial molecular cloning studies to identify specific PTPases in insulin-sensitive tissues that may have a potential physiological role in insulin action and clinical insulin resistance.

Amino Acid Sequence↗
PubMed1992

Effect of nicardipine on haemodynamic response to stress in hypertension.

The effects of the calcium antagonist nicardipine on the pressor response to mental arithmetic, cold pressor and exercise tests have been studied in fifteen patients with established mild to moderate essential hypertension. Nicardipine 20 mg p.o. showed a hypotensive effect within 60 min, associated with a fall in total peripheral resistance and an increase in heart rate. As the pressor response to each stress was not affected by nicardipine, the peak blood pressure reached during each stress was lower. Nicardipine lowers blood pressure at rest as a result of arteriolar dilatation, associated with reflex tachycardia. The pressor responsiveness to various stresses was not affected by nicardipine.

Adult↗
PubMed1992

Abnormal messenger ribonucleic acid (mRNA) transcribed from a mutant insulin receptor gene in a patient with type A insulin resistance.

In a previous report on a 16-year-old Japanese girl with type A insulin resistance, we found that one allele of the insulin receptor gene was inherited from her mother and contained a 1.2 kilobase pair deletion which removed the 14th exon in the beta subunit. We extended investigation of the proband and found the deletion between two Alu sequences. To determine the effect of the deletion on the level of transcription and the splicing pattern of messenger ribonucleic acid (mRNA), we synthesized the complimentary DNA and used the polymerase chain reaction to amplify the region which included the deleted area. The deletion shifted the reading frame, resulting in a termination codon after amino acid 867 (Glu), thereby producing a truncated insulin receptor without a transmembrane region and cytoplasmic domain. We also sequenced each of 22 exons of the insulin receptor gene but found no mutation in exons of the insulin receptor gene, except for deletion of exon 14 of the maternal allele. Thus, the proband is a heterozygote for a single mutant allele. Abnormal mRNA transcribed from the mutant allele resulted in a decrease in insulin binding.

Adolescent↗
PubMed1992

Protective role of antigenic sites on the envelope protein of Hantaan virus defined by monoclonal antibodies.

To investigate the role of Hantaan virus envelope glycoprotein in infection, a panel of monoclonal antibodies (MAbs) was examined in vitro with several serological tests and in vivo by passive transfer experiments in mice. An antigenic site, specific for the inhibition of infected cell focus was detected with the focus inhibition neutralization test (FINT), in addition to the neutralization related antigenic sites, which were revealed by the ordinary focus reduction neutralization test (FRNT). Suckling mice were given the MAbs by passive transfer followed by lethal Hantaan virus challenge. All neutralizing MAbs detected by either FRNT or FINT protected all mice from lethal infection, confirming the importance of the antigenic sites as a protective antigen. Mice given non-neutralizing MAbs by passive transfer, however, began to die earlier than the control group; mean time to death (18.2 +/- 2.1 to 21.5 +/- 2.8 days) being significantly shorter than that of the control group (25.8 +/- 1.8, p less than 0.01, Mann-Whitney, U probability test). Virus titers in brains of mice which died early, were about 10 times higher than those of control mice. These results indicated the early death phenomenon of mice which was mediated by the anti-virus antibody.

Animals↗
PubMed1992

Antibody-dependent enhancement of hantavirus infection in macrophage cell lines.

Antibody-dependent enhancement (ADE) of hantavirus infections (strains Hantaan 76-118 and SR-11) was studied using macrophage-like cell lines (J774.1, P388D1, and U937). Significantly higher virus titers (1,000 to 4,000 FFU/ml) were obtained by pretreatment of the virus with immune serum as compared to normal serum (less than 20 FFU/ml). Monoclonal antibodies (MAbs) to strain Hantaan 76-118 were employed to determine the antigenic determinants responsible for the ADE activity. ADE of the infection occurred with MAbs to both G1 and G2 envelope glycoproteins, but not with MAbs to nucleocapsid protein. Antigenic determinants related to haemagglutination or virus neutralization were found to cause ADE of the infection.

Animals↗
PubMed1992

A nuclear extract, prepared from mass-isolated germinal vesicles, retains a factor able to sustain a cytoplasmic cycle of starfish oocytes.

The germinal vesicle (GV) of starfish oocytes contains a factor which is required to drive the cytoplasmic cycle of the meiotic division. Biochemical investigation of this factor has been difficult due to the small quantities of obtainable GV materials. To overcome this, we have developed a mass-isolation procedure for the GVs of starfish oocytes, which depends on the softening of the cortex of the oocytes by cytochalasins to enable the GVs to pass through the cortex by centrifugation. From the isolated GVs, we have prepared a soluble fraction which retains the activity to induce the cytoplasmic cycle in the meiotic division of oocytes. The factor was sensitive to both heat and papain, suggesting that it is a protein.

Animals↗
PubMed1992

A case of bovine sex cord tumour with annular tubules.

A case of sex cord tumour with annular tubules was found in the right ovary of a 17-month-old Holstein cow. The tumour was characterized by tubules encircling hyaline bodies, which were composed of concentric lamellae of basal lamina. Several irregular tubular structures and a small component of granulosa cell differentiation were seen. Immunohistochemically, the neoplastic cells stained positively for oestradiol or testosterone.

Animals↗