Biomedical subjects

H Ishihara

Publications and source records attributed to H Ishihara.

At least 397 records · Page 22Linked to original sources

PubMed1992

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine. 14. Effect on epidural pressure].

We studied effect of total intravenous anesthesia using ketamine, fentanyl and droperidol (DFK) on epidural pressure as an index for cerebrospinal fluid pressure in six surgical patients who underwent gastrectomy. The epidural catheter was inserted on the previous day. The epidural puncture was made at Th7-12 and the tip of the catheter was located 5 cm cephalad. The epidural pressure was measured before, just after and 30 minutes after the induction. The induction dose of fentanyl was 5 micrograms.kg-1 and that of ketamine was 1 mg.kg-1. The epidural pressure at the induction decreased in significantly by 19% as compared with that before the induction. The result suggested that DFK would not increase cerebrospinal fluid pressure when the doses of ketamine and fentanyl were changed.

Adult↗

PubMed1992

[Clinical study on total intravenous anesthesia with droperidol, pentazocine and ketamine].

Fifty patients underwent various surgical procedures including abdominal, orthopedic, plastic and gynecological operations under total intravenous anesthesia with ketamine, pentazocine and droperidol. Neither nitrous oxide, inhaled anesthetics nor narcotics such as fentanyl were administered to the patients. Intraoperative muscle relaxation was achieved with vecuronium and the patients were ventilated manually throughout the surgical procedures. Thirty percent of the patients developed hypertension and tachycardia, but they were easily overcome with administration of calcium ion channel blocker. Their peripheral circulation as well as urine output was well maintained. No adverse effects on the liver and kidney were observed post-operatively. Their post-operative sedation and analgesia were evaluated excellent. A few patients had strange dream as if they might have missed their way into the "pink" tunnel. The data above described suggest that this anesthetic method would deserve further detailed clinical study.

Adult↗

PubMed1991

The role of N-glycosylation of GLUT1 for glucose transport activity.

To elucidate a functional role of N-glycosylation in glucose transporters, we introduced oligonucleotide-directed mutagenesis in GLUT1 cDNA to remove the possible site for N-linked glycosylation. The wild-type and the mutated GLUT1 cDNAs which induced a mutation of Asn at residue 45 to Asp, Tyr, or Gln were transfected and stably expressed into Chinese hamster ovary cells. The expressed wild-type and the mutated GLUT1 was demonstrated to be a broad band of a 45-60-kDa form and a sharp band of a 38-kDa form on Western blot analysis, respectively, indicating no glycosylation in the mutated GLUT1. Although the cell surface labeling of the glucose transporters demonstrated the presence of the glycosylation-defective glucose transporters on the cells surface, photoaffinity labeling of glycosylation-defective GLUT1 with [3H] cytochalasin B and a photoreactive mannose derivative, [3H]2-N-4-(1-azi-2,2,2,trifluoroethyl)benzoyl-1,3-bis(D-mannos+ ++-4-yloxy)-2- propylamine in the membranes was observed to be 40-70 and 15-30% of that of the wild-type GLUT1, respectively. The kinetic study of 2-deoxyglucose uptake revealed that the glycosylation-defective GLUT1 had a 2-2.5-fold greater Km value for 2-deoxyglucose uptake compared with the wild-type GLUT1. These observations strongly suggest that 1) N-glycosylation of GLUT1 glucose transporter is only on Asn 45 and 2) N-glycosylation plays an important role in maintaining a structure of glucose transporter with high affinity for glucose, thus, with high transport activity.

Affinity Labels↗

PubMed1991

Establishment and characterization of a mouse monoclonal anti-fucosylceramide antibody, PC47H.

A novel mouse monoclonal anti-fucosylceramide antibody was established by using neutral glycolipids from a human pancreas cancer tissue as the immunogen. Mice were immunized with the neutral glycolipids in the form of liposome-containing lipid A. Mouse monoclonal antibodies were screened with enzyme-linked immunosorbent assay and by thin layer chromatography-immunostaining. The latter technique showed that a mouse monoclonal antibody, designated PC47H, specifically reacts with a ceramide-monoglycoside fraction of the neutral glycolipids. The effects of various monosaccharides on the reactivity of PC47H with the neutral glycolipids were tested, and it was found that only fucose was able to inhibit the binding of PC47H to the neutral glycolipids. We also examined the direct binding activity of PC47H against galactosylceramide, glucosylceramide, fucosylceramide, and ceramide. This showed that the antigen specificity of PC47H was exclusively directed against fucosylceramide. In thin layer chromatography-immunostaining experiments with neutral glycolipids prepared from various human tissues, we observed that fucosylceramide was highly expressed in human colon and gastric cancer tissues. PC47H recognized the human adenocarcinoma cell lines of colon, stomach, pancreas, and lung but did not react with other tumor cells or with several nontumorous human cells.

Animals↗

PubMed1991

Expression of the GLUT1 glucose transporter increases thymidine uptake in Chinese hamster ovary cells at low glucose concentrations.

An increase in expression of the GLUT1 glucose transporter gene has been observed to be associated with an increase in glucose transport activity upon oncogenic transformation of the cells. Increased expression of this glucose transporter isoform has been also observed in fetal tissues. To investigate the consequences of this phenomenon on cellular metabolism and cell growth, an expression vector containing the GLUT1 glucose transporter complementary DNA was transfected into Chinese hamster ovary cells. Overexpression of this glucose transporter isoform resulted in an increase in not only glucose uptake and utilization but also thymidine uptake when cells were exposed to glucose-deficient conditions. This increase in glucose metabolism and DNA synthesis may play an important role on the growth and/or survival of cancer cells and fetal tissues.

3-O-Methylglucose↗

PubMed1991

Barbiturates enhance retinoic acid or 1,25-dihydroxyvitamin D3-induced differentiation of leukemia HL-60 cells.

In the presence of 1 nM retinoic acid (RA), pentobarbital markedly enhanced differentiation of HL-60 cells to granulocytic cells. In the absence of RA, pentobarbital by itself did not induce cell differentiation. Similarly, pentobarbital enhanced the action of 1,25-dihydroxyvitamin D3 to induce differentiation of HL-60 cells into monocyte/macrophage lineage. The potency of various barbiturates to enhance cell differentiation was closely correlated with their activity to inhibit protein kinase C of HL-60 cells. In contrast to staurosporine, however, barbiturates did not affect the action of differentiation inducers of other types such as dimethyl sulfoxide, dibutyryl cyclic AMP or actinomycin D.

Alkaloids↗

PubMed1991

Growth-associated changes in fatty acid compositions of nuclear phospholipids of liver cells.

To know the possible relationships between nuclear phospholipids and cell proliferation, we have extensively analyzed phospholipids extracted from the nuclei of rat hepatic cells at various growth states. The content of phospholipid in nuclei as well as its composition was similar among liver cells tested, i.e., the regenerating rat livers (28 h, post-hepatectomy), sham-operated or non-treated control livers, and rat ascites hepatoma, AH7974 cells. In contrast, the fatty acid compositions of phospholipids differed from each other among these cells. At the 2-position of phospholipids in the regenerating liver nuclei at 28 h after partial hepatectomy, 18:1 (oleic acid) increased transiently at the expense of 20:4 (arachidonic acid) and 22:6 (docosahexaenoic acid), compared with those in the sham-operated control nuclei. This change in fatty acid composition was commonly observed throughout all phospholipids analyzed, i.e., phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and phosphatidylserine (PS). On the other hand, the change at 1-position was rather limited: in the regenerating liver nuclei (28 h), 18:1 increased only in PC at the expense of 18:0 (stearic acid). The similar and more marked deviation at the 2-position was observed with AH7974 nuclei it contained approximately 2-times more of 18:1 in PC, PE and PI than regenerating liver nuclei (28 h), and the decreased levels of 20:4 and/or 22:6. It should be noted that there were significant differences in the fatty acid compositions of PE and PS between sham-operated and non-treated controls. So, the sham-operated rat is the appropriate control for proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Inhibitory effect of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8) in vascular smooth muscle.

The inhibitory effects of 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate (TMB-8) on vascular smooth muscle contraction and cytosolic Ca2+ level ([Ca2+]i) were examined using isolated rabbit aorta loaded with a fluorescent Ca2+ indicator, fura-2. TMB-8 (100 microM) decreased the high K(+)-induced increase in muscle tension, and [Ca2+]i and 45Ca2+ influx to their respective resting levels. TMB-8 (100 microM) almost completely inhibited the increase in [Ca2+]i and 45Ca2+ influx due to norepinephrine although muscle tension was only partially decreased. A higher concentration of TMB-8 (300 microM) inhibited the remaining portion of the contraction without additional decrease in [Ca2+]i. The inhibitory effect of TMB-8 on high K(+)-induced contraction, but not on the norepinephrine-induced contraction, was antagonized by the increase in external Ca2+ concentrations or by the Ca2+ channel activators, CGP 28,392 and by Bay K8644. In Ca(2+)-free solution, norepinephrine-induced transient increases in [Ca2+]i and muscle tension and 100 microM TMB-8 inhibited these changes. The caffeine-induced transient increases in [Ca2+]i and muscle tension were also inhibited by TMB-8 at concentrations higher than those needed to inhibit the norepinephrine-induced transient changes. In permeabilized smooth muscle, TMB-8 (300 microM) did not inhibit the Ca(2+)-induced contraction. These results suggest that TMB-8 inhibits vascular smooth muscle contractility by inhibiting Ca2+ influx, Ca2+ release and Ca2+ sensitization of contractile elements.

Animals↗

PubMed1991

The glucose transport activity of GLUT1 is markedly decreased by substitution of a single amino acid with a different charge at residue 415.

GLUT1 glucose transporter cDNA was modified to introduce a single amino acid substitution of aspartic acid for asparagine 415, which is conserved among all facilitative glucose transporter isoforms. Although a significant amount of the mutated transporter was expressed into plasma membranes of Chinese hamster ovary cells by transfection with expression vector, almost no increase in glucose transport activity was observed. Analysis of glucose uptake with Lineweaver-Burk plot depicts that the mutation induced a marked decrease (more than 5-fold) in turnover number and a slight increase (1.5-fold) in Km compared with the wild-type GLUT1. Results obtained with cytochalasin B and ethylidene glucose suggested that the inner but not outer glucose binding site was modulated. These results suggest that asparagine 415 is located close to the inner glucose binding site and the putative inner gate of GLUT1 glucose transporter and that an ionic charge in this domain might play an important role in the rate of conformational change between an inward-facing form and an outward-facing form of glucose transporter.

Animals↗

PubMed1991

Substitution of leucine for tryptophan 412 does not abolish cytochalasin B labeling but markedly decreases the intrinsic activity of GLUT1 glucose transporter.

GLUT1 glucose transporter cDNA was modified to introduce a single amino acid substitution of leucine for tryptophan 412, a putative cytochalasin B photo-affinity labeling site. Although the mutated transporter was expressed into plasma membranes of Chinese hamster ovary cells, glucose transport activity of the mutated transporter was observed to be only 15-30% of that of the wild-type GLUT1 when glucose transport activity was assessed by 2-deoxyglucose uptake at 0.1-10 mM concentrations. Analysis of glucose uptake kinetics depict that a mutation induced a 3-fold decrease in turnover number and a 2.5-fold increase in Km compared with the wild-type GLUT1. Importantly, cytochalasin B labeling was not abolished but decreased by 40%, and cytochalasin B binding was also decreased. In addition, the results obtained with side-specific glucose analogs suggested that the outer glucose binding site of the mutant appeared intact but the inner binding site was modulated. These results indicate 1) tryptophan 412 is not a cytochalasin B labeling site(s), although this residue is located in or close to the inner glucose binding site of the GLUT1 glucose transporter, 2) substitution of leucine for tryptophan 412 decreases the intrinsic activity of GLUT1 glucose transporter, which is definable as the turnover number/Km, to approximately 15% of that of the wild-type.

Affinity Labels↗

PubMed1991

Specific uptake of asialofetuin-tacked liposomes encapsulating interferon-gamma by human hepatoma cells and its inhibitory effect on hepatitis B virus replication.

Asialofetuin-tacked liposomes (AF-liposomes) encapsulating interferon (IFN)-gamma were bound and internalized into a human hepatoma cell line, HepG2 cells, selectively through asialoglycoprotein receptor, but not non-tacked liposomes (N-liposomes). AF-liposomal IFN-gamma was more effective for inhibition of viral DNA replication in hepatitis B virus (HBV)-producing clone from HepG2 cells transfected with HBV-DNA than N-liposomal IFN-gamma. AF-liposomes may increase the therapeutic potential of IFN-gamma through asialoglycoprotein receptor in treating HBV-infected hepatocytes.

Asialoglycoprotein Receptor↗

PubMed1991

Altered expression of glucose transporter isoforms with aging in rats--selective decrease in GluT4 in the fat tissue and skeletal muscle.

To elucidate the cellular mechanisms of glucose intolerance associated with aging, both the protein and mRNA levels of glucose transporter isoforms were studied in the various tissues of young (7-week-old) and aged (20-month-old) rats. GluT4 (adipose/muscle-type glucose transporter) protein, which is specifically expressed in insulin-responsive tissues, was selectively decreased per milligram of cellular membrane protein in both the epididymal fat tissues and the gastrocnemius muscle of the aged rats compared with the young rats. When the changes in total cellular membranes per gram of tissue are taken into account, a further decrease in GluT4 protein per gram of tissue was observed in the tissues of the aged rats compared with the young rats. The decreased amount of GluT4 protein in the fat tissues of the aged rats is probably due to the decreased protein synthesis rather than the stability, since GluT4 mRNA/micrograms of cellular total RNA was also decreased. In contrast, GluT4 mRNA in the gastrocnemius muscle was rather increased and a ratio of GluT4 protein/GluT4 mRNA was decreased by 70% in the aged rats, suggesting that the translational efficiency and/or stability of GluT4 protein is decreased in the skeletal muscle of the aged rats compared with the young rats. GluT2 (liver-type glucose transporter) protein and mRNA in the liver were also decreased in the aged rats, while no apparent decrease in GluT1 (HepG2/brain-type glucose transporter) protein/mg of cellular membrane protein was observed in the skeletal muscle and fat tissues of the aged rats compared with the young rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗

PubMed1991

Surgical repair of Wolff-Parkinson-White syndrome complicated with myocardial bridging.

Myocardial bridging causes myocardial ischemia during supraventricular tachycardia. We present a case of Wolff-Parkinson-White syndrome combined with myocardial bridging. The patient complained of angina pectoris during paroxysmal supraventricular tachycardia because of severe constriction of the left anterior descending coronary artery during systole. A myocardial scintigram revealed myocardial ischemia in the anteroseptal wall during paroxysmal supraventricular tachycardia. Myotomy to prevent myocardial bridging and interruption of the accessory conduction pathway was successfully accomplished in a one-stage operation.

Adult↗

PubMed1991

Solitary metastatic ovarian carcinoma of the spleen: a case report.

Carcinomatous metastatic involvement of the spleen usually indicates a widespread malignant disease. Solitary metastatic lesions in the spleen are exceedingly rare. The literature contains fewer than 16 cases. In this paper we report a case of a solitary metastatic lesion of the spleen arising from a serous cystadenocarcinoma of the ovary 5 years after the initial operation. A splenectomy was performed followed by smooth postoperative course.

Aclarubicin↗

PubMed1991

[Isolation trends on group A streptococci isolated from clinical specimens in hospitals in Saitama, 1979-1989].

On 4,864 group A streptococci isolated from throat culture of patients in hospitals in Saitama from 1979 to 1989, we have done an epidemiological analysis of the T-type detection rates and the T-type epidemic, the monthly isolation rates, and the isolation rates by sex and age of patients. 1. The T-type detection rates of 4,864 isolates of group A streptococci showed type T12 in 22.6%, type T4 in 16.4%, type T1 in 10.8%, type T13 in 8.5%, type T6 in 7.6%, type T28 in 6.9%, type T3 in 6.1% and type T18 in 5.3% etc, and the largest number of isolates was type T12 among 16 T-types. 2. The main epidemic T-type during the investigation was type T12, and it was at the top from 1980 to 1981 and from 1984 to 1985. The others, type T4 was at the top from 1982 to 1983 and from 1983 to 1989, type T3 was in 1986, type T6 was in 1987, and type T1 was in 1988, especially it has been suggested that there are the high epidemic T-types and low epidemic T-types among the T-types of throat group A streptococci. 3. Monthly epidemic pattern of throat group A streptococci in each year showed two small epidemic peaks on March and June, a large epidemic peak from November to December since a turn on August. Further, the monthly epidemic pattern has been repeated every year. 4. Throat group A streptococci isolated from patients occupied 87 per cent by the patients from 0 to 14 years, the peak of age distribution showed by age group from 5 to 7 years. The sexual ratio of male to female was in the ratio 1:0.9. Further, the throat group A streptococci isolated from patients of age greater than 15 years was occupied about 50 per cent by age group from 30 to 39 years. A sexual ratio of male to female in the age group was in the ratio 1:1.8.

Adult↗

PubMed1991

Prognosis of idiopathic pulmonary fibrosis in patients with mucous hypersecretion.

In order to determine the prognosis of patients with chronic idiopathic pulmonary fibrosis (IPF), we evaluated clinical, laboratory, and bronchoalveolar lavage (BAL) data at the onset of IPF in 25 patients who survived beyond 1 yr (nine women and 16 men, 59 +/- 3 yr of age, mean +/- SE). When the patients were divided into two groups according to whether they had or did not have mucous hypersecretion, 11 patients with hypersecretion (Group A) had a poorer survival rate (6 yr) than did 14 patients without hypersecretion (Group B) (10 yr) (p less than 0.01). Further, there was a significant negative correlation between sputum volume and the duration of survival in 25 patients (r = -0.55, p less than 0.01). Before glucocorticoid treatment, we also found significantly larger numbers of neutrophils (17%) and eosinophils (5%) in differential cell counts of bronchoalveolar lavage fluid (BALF) in Group A than in Group B (neutrophils, 1%; eosinophils, 0.6%) (p less than 0.05 each). Chest radiographic findings and other laboratory data including pulmonary function tests did not correlate with the survival rate. These findings suggest that mucous hypersecretion as well as neutrophils and eosinophils in BALF are among the determinants of prognosis in patients with chronic IPF.

Aged↗

PubMed1991

Neuropeptides and airway submucosal gland secretion.

Our study using feline tracheal isolated submucosal gland preparation has revealed that substance P (SP) produces an increase in submucosal gland secretion through the actions of both mucus ejection by glandular contraction and macromolecule secretion from secretory cells, and that the two actions are both mediated by a peripheral cholinergic action. In contrast, SP has no significant effect on macromolecule secretion from secretory cells in tracheal explants, probably because of epithelial suppression. Our study using an isolated gland preparation has also indicated that VIP potentiates mucous glycoprotein secretion induced by cholinergic stimulation through an interaction between muscarinic and VIP receptors in secretory cells. However, VIP failed to induce any significant glandular contraction or relaxation, indicating a lack of VIP receptors or a difference in the subtypes of muscarinic receptors in myoepithelial cells in submucosa glands.

Animals↗

PubMed1991

Interaction of recombinant human interferon-gamma with liposomes.

The interaction of recombinant human interferon-gamma (IFN) with egg phosphatidylcholine liposomes was studied. IFN which binds to liposomes was dependent on the liposomal charge and pH, and a preferential binding was observed in negatively charged liposomes at pH 7.4-10. Electron-microscopic observation showed that the increased liposomal turbidity induced by IFN was due to liposomal aggregation, and the increased turbidity could be decreased by the addition of NaCl. Thus, ionic binding may participate in this interaction. But, when the incubation time was longer, the liposomal aggregation was not decreased by the addition of NaCl, and the leakage of the entrapped marker, calcein, was observed. Electron-microscopic analysis showed that this leakage resulted from the morphological change of liposomes. From these findings, ionic binding may participate in the interaction between IFN and liposomes and then develop a morphological change in negatively charged liposomes under the neutral pH condition.

Fluoresceins↗