Biomedical subjects

H Ishihara

Publications and source records attributed to H Ishihara.

At least 379 records · Page 21Linked to original sources

PubMed1992

Studies on synthetic pathway of xylose-containing N-linked oligosaccharides deduced from substrate specificities of the processing enzymes in sycamore cells (Acer pseudoplatanus L.).

We measured the activities of alpha-1,3-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase, alpha-1,6-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase, beta-1,4-mannosyl-glycoprotein beta-1,2-xylosyltransferase and glycoprotein 3-alpha-L-fucosyltransferase in the Golgi fraction of suspension-cultured cells of sycamore (Acer pseudoplatanus L.) using fluorescence-labelled oligosaccharides as acceptor substrates for these transferase reactions. The structures of the pyridylaminated oligosaccharides produced by these reactions were analyzed by two-dimensional sugar mapping using high-performance liquid chromatography. We demonstrated that (formula; see text) was processed to produce by these in vitro reactions. On the basis of these results, we discuss a biosynthetic pathway for xylose containing N-linked oligosaccharides in plant glycoproteins.

Carbohydrate Sequence↗

PubMed1992

Extraperitoneal anterolateral discectomy for lumbar disc herniation: indications, techniques, and time-related clinical results.

We analyzed 80 consecutive cases of lumbar disc herniation who underwent an extraperitoneal anterolateral discectomy according to clinical and radiologic parameters. The average follow-up period was 5 1/2 years (range, 1-10 years). The results of 71 patients (89%) were satisfactory through the mid- and long-term follow-up periods, although a very slight decrease in subjective/objective scores and ADL score was found. Satisfactory results were obtained for adolescent and younger male adults and in isolated central or centrolateral herniations with a broad base. From an analysis of the nine reoperated cases, we determined that the contraindications of this technique are a sequestrated or extruded nucleus pulposus and disc protrusion accompanied by posterior dislocation of a vertebral edge fragment. The relative indications include a small, hard posterolateral herniation located just beneath the nerve roots, double-level herniation, disc herniation accompanied by narrow spinal canal, and bulged disc in elder patients. The absolute indications for this surgery are a centrally or centrolaterally protruded disc with a relatively broad base of herniation at single-disc level that is not accompanied by spinal stenosis in adolescent and younger male adults.

Adolescent↗

PubMed1992

Effects of continuous quantitative vibration on rheologic and biological behaviors of the intervertebral disc.

The authors attempted to investigate the effect of vibration on the physiologic behavior of the intervertebral disc from rheologic and biological responses. Using fresh disc-cartilaginous end plate complexes of porcine coccygeal vertebrae, the frequency characteristics of dynamic compressive elastic modulus and dissipated energy were monitored by means of a biomechanical spectrometer. The effect of vibration on proteoglycan synthetic rates and solute transport in the intervertebral disc were analyzed using a radioisotope. When the disc-cartilaginous plate complexes were subjected to sinusoidal vibration with a static load of 5 N and a vibratory load of 3 N, the elastic modulus decreased at 11 Hz compared with 3.5 Hz. After this, it increased again at 35 Hz. The dissipated energy increased rapidly with an increase in frequency. Proteoglycan synthetic rates did not change appreciably down to the inner and outer layers of the anulus fibrosus, but the rate in the nucleus pulposus alone decreased remarkably at 10 Hz and 35 Hz. Solute transport increased as a response to vibration, particularly in the nucleus pulposus. When the intervertebral disc is exposed to vibration for a long period of time, therefore, the proteoglycan content in the nucleus pulposus may be decreased, eventually resulting in disruption of matrix integrity.

Animals↗

PubMed1992

Autonomic innervation to feline tracheal submucosal glands for mucus glycoprotein secretion.

We examined the effect of electrical field stimulation (FS) on radiolabeled glycoconjugate released from feline tracheal isolated glands. Trichloroacetic acid precipitable [3H]-glycoconjugates released into the culture medium were counted, divided by the dry weight of sample, and data were expressed as percent of the release from the same animal that was unstimulated but otherwise received identical treatment. FS produced an increase in the glycoconjugate release that was dependent on the duration of stimulation, reaching a maximum response of 215% of nonstimulated sample for 30 min stimulation (10 Hz, 10 V). FS-evoked secretion was abolished by 10(-7) M tetrodotoxin but not altered by 10(-5) M hexamethonium. Atropine (10(-6) M) alone abolished the response to FS for 3 min or less. By contrast, a mixture of 10(-6) M atropine, 10(-5) M propranolol, and 10(-5) M phentolamine blocked only part of the response to FS for 15 min or more. The mixture of three antagonists reduced the response to FS for 30 min to 159% of control, which was significantly higher than control. Furthermore, 10(-6) M atropine, 10(-5) M propranolol, or 10(-5) M phentolamine significantly reduced the response to FS for 30 min to 162, 193, and 195%, respectively, from 215% of sample in the absence of blockers. Serotonin (10(-5) M) augmented FS-evoked response, which was abolished by 10(-6) M atropine or by 10(-5) M methysergide.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Endothelin regulation of mucus glycoprotein secretion from feline tracheal submucosal glands.

We examined the effects of endothelin on both the trichloroacetic acid precipitable 3H-labeled glycoconjugate release and intracellular Ca2+ concentration ([Ca2+]i]) measured by the usage of fura-2 in submucosal glands isolated from feline trachea. Endothelin-1 produced a significant increase in glycoconjugate release from the isolated glands in a dose-dependent fashion, reaching a response of 161% of the control at 10(-6) M. Atropine, propranolol, phentolamine, or indomethacin did not produce any significant alterations in the ET-1-evoked glycoconjugate secretion from the isolated glands. In contrast, in tracheal explants which contained epithelium, ET-1 produced a significant reduction in the glycoconjugate secretion in a dose-dependent fashion, reaching a response of 59% of the control at 10(-6) M. In the presence of cultured epithelial cells, ET-1 also produced a significant reduction in the glycoconjugate secretion from isolated glands. In isolated glands, ET-1 produced a sustained increase in the [Ca2+]i which was abolished by the removal of Ca2+ from the medium or by the presence of cultured epithelial cells. Pretreatment with indomethacin failed to alter the epithelial inhibitory action evoked by ET-1 in both the glycoconjugate secretion and the [Ca2+]i in isolated glands. ET-2 and ET-3 failed to produce significant alterations in the glycoconjugate secretion or [Ca2+]i. These findings indicate 1) that ET-1 induces mucus glycoprotein secretion via a Ca2+ influx and 2) that it possibly augments the an epithelial action inhibitory to the mucus glycoprotein secretion from airway submucosal glands.

Animals↗

PubMed1992

Muscarinic receptor subtypes in feline tracheal submucosal gland secretion.

To determine what muscarinic receptor subtype regulates [Ca2+]i mediating airway submucosal gland secretion, we examined the effects of atropine (Atr), pirenzepine (PZ), 11([2-(diethylamino)methyl-1-piperidinyl] acetyl)-5,11-dihydro-6H-pyrido (2,3-b)(1,4)-benzo-diazepin-6-one (AF-DX116) and 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP) on methacholine (MCh)-evoked [Ca2+]i rise in acinar cells, and compared this with mucus glycoprotein (MGP) and electrolyte secretion evoked by MCh from submucosal glands isolated from feline trachea. [Ca2+]i was measured with the Ca(2+)-sensitive fluorescent dye, fura 2. We determined MGP secretion by measuring TCA-precipitable 3H-labeled glycoconjugates and electrolyte secretion by the change in the rate constant of 22Na-efflux from isolated glands. Half-maximal inhibitory concentrations (IC50) of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked [Ca2+]i rise were 10(-7) M, 6 x 10(-6) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. IC50 of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked MGP secretion were 10(-6) M, 2 x 10(-5) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. MCh (10(-5) M)-evoked 22Na efflux was significantly inhibited by 10(-7) M 4-DAMP and 10(-7) M Atr (P less than 0.01, each) but not by 10(-7) M PZ. Receptor binding assays with [3H]quinuclidinyl benzilate showed that the Ki values for PZ, AF-D x 116, 4-DAMP and Atr were 2.2 x 10(-8) M, 6.6 x 10(-7) M, 6.2 x 10(-10) M, and 2.9 x 10(-10) M, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Endothelin-1 stimulates chloride secretion across canine tracheal epithelium.

Although much attention has been paid to the effect of endothelin on the bronchopulmonary system, there are few reports concerning the effect of endothelin on Cl- secretion across airway epithelium. We examined the effects of endothelin-1, -2 and -3 on bioelectric parameters of canine tracheal epithelium, a tissue in which Cl- is actively secreted and Na+ is absorbed. Potential difference (PD) and short-circuit current (SCC) were measured using an Ussing chamber with 0.5 cm2 of exposed area, and conductance (G) was calculated by dividing SCC by PD. Luminal endothelin-1 produced transient increases in PD and SCC, returning to baseline values within 5 min after stimulation in a dose-dependent fashion and reached mean responses of 123 and 126% of baseline PD and SCC, respectively, at 10(-6) M of endothelin-1, whereas submucosal endothelin-1 did not alter PD and SCC. G remained unchanged when stimulated by endothelin-1. Endothelin-2 and -3 did not produce any significant alterations in PD and SCC. Endothelin-1 evoked increases in PD and SCC, which were not altered by pretreatment with luminal amiloride (10(-4) M), or by treatment with submucosal propranolol (10(-5) M). Ionic substitution of Cl- with nontransported anions, iodide and gluconate, inhibited endothelin-1-induced increases in PD and SCC. Pretreatment with 10(-5) M indomethacin partially inhibited Endothelin-1-evoked increases in PD and SCC. These findings indicate that endothelin-1 stimulates Cl- secretion partially through the generation of cyclooxygenase products of arachidonic acid.

Amiloride↗

PubMed1992

Expression of glucose transporter isoforms with aging.

To elucidate the cellular mechanisms for impairment of glucose metabolism associated with aging, the facilitative glucose transporter protein and mRNA were studied in various tissues of young (7-week-old) and aged (20-month-old) rats. GLUT4 glucose transporter protein, a major glucose transporter isoform in the insulin-responsive tissues, was selectively decreased in the epididymal fat tissues of the aged rats compared with the young rats. This decrease is likely to be due to a decrease in protein synthesis rather than in protein stability, since GLUT4 mRNA per unit cellular total RNA was also decreased. GLUT4 mRNA in the skeletal muscle was rather increased in spite of the decreased level of GLUT4 protein 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. In contrast to these alterations in GLUT4 expression, no apparent decrease in the GLUT1 protein amount was observed in the fat tissues, skeletal muscle and brain of the aged rats compared with the young rats. Thus, the tissue and isoform-specific alterations in glucose transporter expression are associated with aging and may contribute to impairment of glucose metabolism observed with aging.

Adipose Tissue↗

PubMed1992

Upregulation of GLUT2 mRNA by glucose, mannose, and fructose in isolated rat hepatocytes.

Previously, demonstrated that GLUT2 mRNA and protein are increased in liver of streptozocin-induced diabetic rats. To examine the mechanisms whereby GLUT2 mRNA is regulated, we cultured isolated hepatocytes in the absence and presence of various concentrations of glucose. Culture of hepatocytes in high glucose concentration (27.8 mM) for 20 h induced a 3.2-fold increase in GLUT2 mRNA levels compared with hepatocytes cultured without D-glucose. Interestingly, D-mannose and D-fructose could substitute for D-glucose to elevate the GLUT2 mRNA level, whereas 3-O-methyl-D-glucose, 2-deoxy-D-glucose, and sucrose, which were not metabolized or taken up by the cells, were without effect. Insulin had no significant effect on GLUT2 mRNA levels in hepatocytes in the presence or absence of D-glucose. Therefore, the regulation of the GLUT2 gene by D-glucose in hepatocytes is contrary to that reported for GLUT1 and GLUT4 genes, which are downregulated by D-glucose. These results also suggest that the elevated GLUT2 mRNA level observed in diabetic rat liver is due to the high blood glucose concentration rather than to insulin deficiency.

3-O-Methylglucose↗

PubMed1992

Response rate and cell-cycle changes due to intra-arterial infusion chemotherapy with cisplatin and bleomycin for locally recurrent uterine cervical cancer.

Intra-arterial infusion with cisplatin (CDDP) and bleomycin (BLM) was carried out in 21 patients with locally recurrent uterine cervical cancer who were previously treated with irradiation alone. Patients were treated with a bolus infusion into both internal iliac arteries of 50 mg/m2 of CDDP and 30 mg/m2 of BLM. Two to four courses of the infusion therapy were given to each patient, and the response rate, the tumor and serum drug concentrations, and the cell kinetics in tumor tissue were evaluated. The response rate (CR+PR) was 71.4% according to the WHO criteria. There was no difference, in the tumor tissue concentrations of CDDP and BLM between responders and nonresponders. Although the DNA ploidy of tumor cells was not significantly different between the two groups before treatment, both the labeling index with BrdU and the proliferation index with flow cytometry significantly increased 24 hours after treatment in responding tumors but not in nonresponding tumors. These results show that intra-arterial infusion with CDDP and BLM improves the prognosis of recurrent cervical cancer and that labeling and proliferation indices may be useful for determining the response of cervical cancer to intra-arterial chemotherapy.

Adult↗

PubMed1992

[The role of muscarinic receptor subtypes in feline tracheal submucosal gland secretion].

To determine what muscarinic receptor subtype regulates the rise of intracellular calcium concentration ([Ca2+]i) and resultant airway submucosal gland secretion on muscarinic receptor stimulation, we examined the effects of atropine (ART), pirenzepine (PZ), 11([2-(diethylamino) methyl-1-piperidinyl] acetyl)-5,11-dihydro-6H-pirido (2,3-b)(1,4)-benzodiazepine-6-one (AF-DX116) and 4-diphenylacetoxy-N-methylpiperidine methiodode (4-DAMP) on methacholine (MCh)-evoked [Ca2+]i rise in acinar cells, mucus glycoprotein (MGP) secretion and electrolyte secretion from submucosal glands isolated from feline tracheae. [Ca2+]i was measured with the Ca(2+)-sensitive fluorescent dye, fura2. We determined MGP secretion by measuring trichloroacetic acid (TCA)-precipitable 3H-labeled glycoconjugates and electrolyte secretion by the change in the rate constant of 22Na-efflux from isolated glands. Half maximal inhibitory concentrations (IC50) of PZ, AF-DX116, 4-DAMP and ATR against MCh (10(-5) M)-evoked [Ca2+]i rise were 10(-7) M, 6 x 10(-6) M, 8 x 10(-9) M and 6 x 10(-9) M, respectively. IC50 values of these antagonists against MCh (10(-5) M)-evoked MGP secretion were 10(-6) M, 2 x 10(-5) M, 8 x 10(-9) M and 6 x 10(-9) M, respectively. MCh (10(-5) M)-evoked 22Na-efflux was significantly inhibited by 10(-7) M 4-DAMP and 10(-7) M ATR (p < 0.01, respectively), but the inhibitory effect of PZ (10(-7) M) was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Postoperative infection control in patients with hepatic, biliary tract, and pancreatic cancers].

Postoperative infection occurs more frequently in patients with malignant disease than in patients with benign disease. Postoperative infection control in patients with hepatic cancer, biliary tract cancer and pancreatic cancer is studied. Although in patients with jaundice due to malignancy the rate of positive bacterial culture of the bile collected at the time of PTCD was low, the rate of positive bile culture increased after 10 to 14 days of PTCD. The predominant strain was Enterococcus spp., followed by Klebsiella spp., Enterobacter spp. and E. coli in that order. These bacteria isolated from the bile were considered to be causative organisms of postoperative infection. Prophylactic antibiotics after the operation for jaundice due to malignancy should be chosen based on the results of bile culture. In patients undergoing hepatectomy, which is considered to be an aseptic operation, gram positive cocci such as S. aureus was the most frequently encountered organism. On the other hand, in patients undergoing hepatectomy and intestinal anastomosis, enteric bacteria were frequently isolated from the infectious foci. In this study there were 6 cases of methicillin-resistant S. aureus (MRSA) postoperative infection, 3 cases after pancreatoduodenectomy, and 3 cases after hepatectomy. Even after an aseptic operation, postoperative MRSA infection is likely to occur in patients undergoing a more invasive operation, so hospital infection control should be again emphasized.

Bacteria↗

PubMed1992

[A relationship between plasma ANP concentration and hemodynamics during PEEP--evaluation by transesophageal ECHO cardiography].

This study was undertaken to find which cardiac function indices as judged by transesophageal ECHO cardiography (TEE) would accurately predict the plasma ANP levels during PEEP. Fourteen patients who underwent orthopedic surgery were the subjects of the study. PEEP 10 cmH2O or 15 cmH2O was added with a PEEP valve during mechanical ventilation under general anesthesia. The cardiac function indices were measured using a 5 MHz TEE probe and plasma ANP levels were evaluated by radioimmunoassay. There were significant reductions in the left atrial diameter, cardiac output and pulmonary venous flow during PEEP, while A/R and CVP were significantly increased. The plasma ANP concentration decreased significantly from 39.2 +/- 4.8 pg.ml-1 at pre PEEP period to 26.8 +/- 3.1 pg.ml-1 at PEEP 15 cmH2O (mean +/- SE, P less than 0.05). However, we could not find any significant correlation between the cardiac function indices and ANP levels. The secretion of ANP from the heart is regulated mainly by stretch tension of the atrium. PEEP increases the pericardial pressure. Therefore, it seems to be difficult to predict the stretch tension of the atrium using TEE under PEEP.

Adult↗

PubMed1992

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--15. Application for cardiac anesthesia].

Total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK) was administered to 36 cardiac patients who underwent mostly coronary artery bypass graft or heart valve replacement. The induction and maintenance of anesthesia using this technique were almost satisfactory with little decrease in systolic blood pressure (SBP), although six patients among the early 21 patients developed hypotension below 90 mmHg (SBP) during the induction, and required vasopressors. Half of the patients had hypertensive episode of above 180 mmHg (SBP), from the start of operation to onset of cardiopulmonary bypass, which was safely and effectively overcome by a small dose of antihypertensive agents. Total intravenous anesthesia with DFK was accompanied with much more hypertensive episodes compared to anesthesia with moderate dose fentanyl (30 micrograms.kg-1) combined with enflurane. However, the incidence of cardiovascular complications following anesthesia was not statistically different between the two anesthesia groups. In addition, most of the patients with DFK showed a rapid awaking time with relatively good postoperative cardiovascular stability. These findings suggest that total intravenous anesthesia with DFK is accompanied with minimal hemodynamic changes during and after open heart surgery.

Aged↗

PubMed1992

[A case of rectus sheath hematoma].

The following is a rare case of rectus sheath hematoma. The patient was a 78-year-old man with a past history of axillo-femoral bypass operation. He contracted a cold, and when he coughed severely, acute lower abdominal pain occurred. Abdominal echography and CT scanning confirmed the presence of a hematoma in the rectus abdominis muscle. Before, patient was diagnosed as acute abdomen and surgery was performed. Recently, accurate diagnosis has been made easily by echography or CT.

Abdomen, Acute↗

PubMed1992

[Effects of sevoflurane anesthesia on dopamine metabolism in the rat brain].

To elucidate the mechanism of general anesthesia, effects of sevoflurane anesthesia on dopamine metabolism in rat brain were studied. Sevoflurane 3% was administered for 20 minutes to Wistar male rats weighing 230-270 g under spontaneous respiration. The rats were sacrificed by decapitation and the brains were rapidly removed. They were dissected into nine discrete regions, locus coeruleus, pons plus, medulla oblongata, hypothalamus, thalamus, basal ganglia, midbrain, hippocampus, amygdala and cerebral cortex. The contents of dopamine (DA) and its major metabolites, 3, 4-dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA) were measured by high performance liquid chromatography with the dual-cell coulometric detector before anesthesia, 20 minutes after the start of anesthesia and at the recovery from anesthesia. Significant increases in DA levels were observed in the pons, hypothalamus, thalamus and amygdala by sevoflurane anesthesia as compared with the control group. DOPAC levels increased significantly in the pons, hypothalamus, basal ganglia and cerebral cortex at the recovery from anesthesia. A significant increase in HVA levels was observed in amygdala by sevoflurane anesthesia, while an appreciable decrease in HVA levels was observed in hippocampus at recovery from anesthesia. It is concluded that DA metabolism is significantly suppressed in the pons, hypothalamus, thalamus, basal ganglia, midbrain and amygdala during sevoflurane anesthesia and this change in DA metabolism may be associated with the mechanism of sevoflurane anesthesia.

Anesthetics↗

PubMed1992

[Pharmacokinetics of ketamine and pentazocine during total intravenous anesthesia with droperidol, pentazocine and ketamine].

Pharmacokinetics was studied in ten surgical patients who underwent various operative procedures of about 4 hours under total intravenous anesthesia with droperidol, pentazocine and ketamine (DPK). Plasma levels of ketamine, its metabolites and pentazocine were determined thirteen times during and after DPK. During anesthesia, ketamine (KO) and norketamine (KMI) levels ranged from 0.7 to 1.0 micrograms.ml-1 and from 0.09 to 0.74 micrograms.ml-1, respectively. A small amount of dehydronorketamine (KM II) was detected only 90 min after the start of DPK anesthesia. Plasma half-lives of ketamine were calculated to be 33 min for distribution phase (alpha phase) and 60 min for elimination phase (beta phase), respectively. Pentazocine levels decreased 300 min after the induction of DPK to 10% of the control level measured 5 min after its injection. Plasma half-lives of pentazocine were 60 min for alpha phase and 140 min for beta phase, respectively. The data obtained in this clinical study show that pharmacokinetics of ketamine during DPK is almost similar to that of DFK.

Adolescent↗

PubMed1992

[Penetration of levofloxacin in bile].

The penetration into bile of a new pyridonecarboxylic acid derivative, levofloxacin (LVFX), was studied in a closs-over method with ofloxacin (OFLX) as the control drug in 6 post-operative patients. The lengths of time to the maximum concentrations in bile and the total areas under the curves were both almost the same for these 2 compounds, although the maximum bile concentration of LVFX was slightly lower than that of OFLX. A stability test for LVFX in human bile revealed that over 95.4% of the initial amount was recovered up to 24 hours after commencement of incubation at a room temperature, thus the stability in bile was similar to that in water. The penetration of LVFX which possesses twice as strong antibacterial activities as OFLX was similar to that of OFLX, suggesting that LVFX is useful against bile duct infections.

Aged↗