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Biomedical subjects

N Taguchi

Publications and source records attributed to N Taguchi.

At least 55 records · Page 3Linked to original sources
PubMed1996

Hemodynamic effects of intravenous ephedrine in infants and children anesthetized with halothane and nitrous oxide.

The aim of this study was to evaluate the effect of age on the hemodynamic responses to intravenous (IV) ephedrine in pediatric patients anesthetized with halothane, nitrous oxide, and oxygen. One hundred ten pediatric patients, ranging in age from 0.1 to 15 yr, were assigned to receive 0.1 mg/kg (n = 55) or 0.2 mg/kg (n = 55) IV ephedrine. General anesthesia was maintained with 1.0 minimum alveolar anesthetic concentration (MAC) of halothane and 67% nitrous oxide in oxygen after tracheal intubation. Measurements of arterial blood pressure and heart rate were made at 1-min intervals for 10 min after ephedrine 0.1 or 0.2 mg/kg was injected IV as a bolus. Significant correlations were noted between age and changes in mean blood pressure (r = 0.37, P < 0.01 for the subjects receiving ephedrine 0.1 mg/kg; r = 0.63, P < 0.001 for the subjects receiving ephedrine 0.2 mg/kg), but not between age and changes in heart rate. The present results indicate that age correlates with the pressor but not the chronotropic effects of ephedrine in pediatric patients anesthetized with 1 MAC halothane and nitrous oxide.

Adolescent↗
PubMed1996

[Mast cell leukemia evolved from RAEB-T (5q-syndrome) in a 12 year-old girl].

A 12-year-old, female 5q- syndrome case of refractory anemia with excess of blasts in transformation (RAEB-T) evolving to mast cell leukemia is described. This case was admitted because of general fatigue, when her peripheral blood count revealed anemia and leukocytosis with basophil-like cells. RAEB-T was diagnosed based on the laboratory findings of her peripheral blood and bone marrow aspiration, which revealed over 10% peripheral blast cells and dysmyelopoietic changes in all three lineages. Chromosomal analysis of the bone marrow cells showed 46, XX, 5q-. Six months later, the RAEB-T phase evolved to acute leukemia, despite prednisolone, vitamin D3, oxymetholone and low-dose cytosine arabinoside treatment. She had remarkable pancytopenia, hemorrhage, and hepatosplenomegaly, which were not responsive to daunomycin, enocitabine, etoposide, and 6-mercaptopurine, and eventually died. This case was unique in that her karyotype changed to normal; 46, XX, and her blast cells were mast cell lineage during the overt leukemic phase. Interestingly, some blasts were intermediate cells possessing the ultrastructural features typical of both basophils and mast cells.

Anemia, Refractory, with Excess of Blasts↗
PubMed1995

Upper airway obstruction during midazolam sedation: modification by nasal CPAP.

We examined the depressant effect of midazolam on respiration in 21 healthy women undergoing lower abdominal surgery with spinal anaesthesia. Airway gas flow, airway pressure, and the sound of snoring were recorded together with arterial oxygen saturation (SpO2). After spinal anaesthesia was established, subjects were deeply sedated with pentazocine 15 mg followed by incremental doses of midazolam 1 mg i.v. up to 0.1 mg.kg-1. When SpO2 decreased to < 90% or snoring and/or apnoea was observed, continuous positive airway pressure applied through the nose (nasal CPAP) was increased until the respiratory deterioration was reversed. While one patient remained free of respiratory events, the other 20 patients were successfully treated with nasal CPAP restoring normal SpO2 (95.5 +/- 1.7%) without snoring. Stepwise reduction of nasal CPAP determined the minimally effective CPAP to prevent snoring to be 5.1 +/- 2.1 cm H2O. Further reduction of nasal CPAP induced snoring in 15 patients and obstructive apnoea in five patients with the latter accompanied by a severe reduction of SpO2 (87.4 +/- 6.1%). Patients with apnoea were older than those who snored (P < 0.05. We conclude that upper airway obstruction contributes considerably to decreases in SpO2 during midazolam sedation for spinal anaesthesia.

Abdomen↗
PubMed1995

Ketoacidosis-onset noninsulin dependent diabetes in Japanese subjects.

In 5 patients (2 women and 3 men, aged 16-36 years), diabetic ketoacidosis developed without precipitating illness. Pancreatic islet cell antibody was negative, and the duration of insulin dependency was shorter than 4 weeks. Hemoglobin A1c was < or = 6.3% for the mean period of 2.8 years thereafter, with diet therapy alone in 4 and with 5 mg glyburide in 1. Four were overweight before the development of diabetes, and 3 of them positive for family history of adult-onset, non-ketotic diabetes. Frequency of human leukocyte antigen B61 was increased significantly in the patients. In a patient not previously overweight, family history of diabetes was negative, and human leukocyte antigen haplotypes common in insulin-dependent diabetes mellitus were accumulated. Serum immunoreactive insulin was within normal range or supranormal with normal glucose tolerance after recovery. The patients closely resemble black Americans with ketoacidosis-onset non-insulin dependent diabetes.

Adolescent↗
PubMed1995

Mechanism of glucose-induced biphasic insulin release: physiological role of adenosine triphosphate-sensitive K+ channel-independent glucose action.

The mechanism of glucose-induced biphasic insulin release by the B cell was investigated using isolated rat pancreatic islets. In perifusion experiments, 16.7 mM glucose in combination with 25 mM K+ transformed the high K(+)-induced monophasic insulin release into a biphasic one in the presence of diazoxide (Dz), an ATP-sensitive K+ channel opener. Inclusion of Dz during the initial 6 min of glucose stimulation abolished the first phase, but was without effect on the second phase. In batch incubation experiments, fuels, including 16.7 mM glucose, 6 mM D-glyceraldehyde, and 10 mM 2-ketoisocaproate, but not sulfonylurea, caused time-dependent potentiation of the B cell so that the response to 25 mM K+, applied later, was increased in the fuel-primed islets. Inclusion of Dz or lowering extracellular Ca2+ (to micromolar range) during the priming, which eliminates the initiation of insulin release, did not eradicate the potentiation. We conclude that high glucose closes ATP-sensitive K+ channels, leading to membrane depolarization, Ca2+ influx, and initiation of insulin release (first phase), and subsequently self-augments insulin release in an ATP-sensitive K+ channel-independent manner (second phase), acting at steps distal to cytosolic Ca2+ elevation. The biphasic insulin release is thus generated by an interaction of ATP-sensitive K+ channel-dependent and -independent glucose actions.

Adenosine Triphosphate↗
PubMed1995

Prophylaxis of genetically determined diabetes by diazoxide: a study in a rat model of naturally occurring obese diabetes.

The study was carried out using a new rat model of naturally occurring obese, nonketotic diabetes, Otsuka Long-Evans Tokushima Fatty rat (Kawano et al., Diabetes 41: 1422-1428, 1992), which closely resembles obese noninsulin-dependent diabetes in human. At the age of 3.5 wk, body weight, glucose tolerance and plasma insulin level after glucose load were normal in Otsuka Long-Evans Tokushima Fatty rats, indicating the animals are at nonobese, prediabetic phase. At this age, however, glucose-stimulated insulin release by pancreatic islets in vitro was abnormally exaggerated whereas the islet insulin content and glucose metabolism by the islet cells were normal. Administration of diazoxide (0.2% in diet), an inhibitor of insulin secretion, to Otsuka Long-Evans Tokushima Fatty rats from the age of 4 to 12 wk completely prevented the development of obesity and insulin resistance, which was accompanied by marked improvement of glucose tolerance and disappearance of exaggerated B cell response to glucose in vitro. This is the first report of successful pharmacological prevention of genetically determined obese diabetes.

Animals↗
PubMed1994

Primary chemotherapy for children with rhabdomyosarcoma of the 'special pelvic' sites: is preservation of the bladder possible?

Twenty-one children with rhabdomyosarcoma involving the "special pelvic" sites, defined as such occurring in the bladder, prostate, vagina and uterus, were treated with primary surgery between 1969 and 1977, and with primary chemotherapy beginning in 1978. Among 11 patients in the latter group who were placed in Clinical Group III (according to the classification of the US Intergroup Rhabdomyosarcoma Study (IRS), six showed partial response (PR) and underwent tumorectomy by radical surgery an average of 6 months after the start of treatment, and three showed complete response (CR) and were treated with further chemotherapy in the hope that cystectomy could be avoided. However, in the latter group, the tumor recurred (39 months, 35 months, and 27 months later), and all eventually underwent total cystectomy. Seven of the nine long-term survivors underwent total cystectomy and have premanent urinary-cutaneous stomas. Two had tumor-free bladders, but function was impaired in one because of the effect of irradiation. Normal function was preserved in only one patient in the series, whose tumor was located at the dome of the bladder. To preserve bladder function in children with rhabdomyosarcoma in these sites, more effective forms of chemotherapy will be required.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Arteriovenous differences in PCO2 and cardiac output during CPR in the dog.

Using 14 mongrel dogs, we investigated the correlation between arteriovenous differences of PCO2 (AVD-CO2) and cardiac output (CO) during CPR. Ventricular fibrillation was induced by an electrical current and the respirator was stopped for 5 min. Cardiopulmonary resuscitation (CPR) was performed during the next 10 min and CO was measured with simultaneous arterial and venous blood gas analysis. CO was measured 26 times during CPR. The animals were divided into two groups according to the values of CO during CPR: low-CO group (CO < 0.3 l/min) and high-CO group (CO > or = 0.3 l/min). AVD-CO2 in the low CO group was 39.8 +/- 5.7 mmHg and that of the high group was 27.4 +/- 14.8 mmHg (mean +/- S.D., P < 0.05). In conclusion, AVD-CO2 showed an inverse result with the degree of CO during CPR.

Animals↗
PubMed1994

Identification and analysis of the Saccharomyces cerevisiae SYR1 gene reveals that ergosterol is involved in the action of syringomycin.

A 2.5 kb DNA fragment of the Saccharomyces cerevisiae SYR1 gene was cloned by complementation of the syr1 mutations that simultaneously lead to resistance to the phytotoxin syringomycin and sensitivity of growth to high Ca2+ concentrations. Sequencing of this fragment revealed a single open reading frame encoding a polypeptide of 365 amino acids. Four hydrophobic regions each separated by hydrophilic regions were present in the protein. SYR1 was identical to ERG3, which is suggested to encode C-5 sterol desaturase required for ergosterol biosynthesis. The protein product of SYR1 was identified by Western blot analysis as a protein of 40 kDa in the particulate fraction. Gene disruption experiments demonstrated that elimination of SYR1/ERG3 is not lethal, but results in membrane C-5 desaturated sterol deficiencies, resistance to syringomycin and sensitivity to high Ca2+. The syr1 mutant cells had significantly decreased ability for syringomycin binding. The results indicated that C-5 desaturated sterols are involved in the binding of syringomycin to the cell, and the lack of the sterols in the mutant membrane results in sensitivity to high Ca2+ and an increased rate of cellular Ca2+ influx.

Bacterial Proteins↗
PubMed1994

ATP-sensitive K+ channel-independent glucose action in rat pancreatic beta-cell.

The nature of ATP-sensitive K+ (K+ATP) channel-independent, insulinotropic action of glucose was investigated using non-glucose-primed pancreatic islets. When the beta-cell was depolarized with K+, glucose dose dependently stimulated insulin release despite inhibition of the K+ATP channel closure by diazoxide. K+ depolarization could be replaced with BAY K 8644, a calcium channel agonist. Prior fasting of rats and lowering ambient temperature greatly suppressed glucose oxidation and utilization by the islet cells and abolished insulin release in response to high glucose alone. However, under these conditions, the K+ATP channel-independent, glucose-induced insulin release was clearly demonstrable. p-Nitrophenyl-alpha-D-glucopyranoside (sweet taste inhibitor) but not its beta-isomer, neomycin (phospholipase C inhibitor) and staurosporine (C kinase blocker) inhibited the K+ATP channel-independent, insulinotropic action of glucose. For the K+ATP channel-independent glucose-induced insulin release 1) elevation of cytosolic calcium is required, 2) minute glucose metabolism is enough, if glucose metabolism is necessary, and 3) direct recognition of glucose molecule, phospholipase C, and protein kinase C appear to be involved.

Adenosine Triphosphate↗
PubMed1994

Determination of the distance between the laryngoscope blade and the upper incisors during direct laryngoscopy: comparisons of a curved, an angulated straight, and two straight blades.

We compared visibility and dental complications from a variety of blades during tracheal intubation. Ninety-eight patients who received tracheal intubation were enrolled. They were divided into two groups: Study 1 (n = 50) and Study 2 (n = 48). Four laryngoscopic evaluations were planned for each patient using Miller and Wisconsin straight blades with different heel heights, a Macintosh curved blade, and a Belscope angulated straight blade (Study 1: Miller No. 3, Wisconsin No. 3, Macintosh No. 4, and Belscope medium; and Study 2: Miller No. 2, Wisconsin No. 2, Macintosh No. 3, and Belscope medium, respectively). All laryngoscopies were performed by the same anesthesiologist. The distance between the blade and the upper central incisors was measured when the optimum visibility of the glottis was obtained. The visibility was determined according to the Cormack and Lehane grading. Analysis of the distance between the blade and upper incisors was performed using the results of the 44 patients (166 distances) in Study 1 and the 48 patients (181 distances) in Study 2 who had a visibility of two or better. The Belscope blade provided a significantly greater visual field than the other types of blade. Two patients sustained a fracture of the central incisor and subluxation of the central incisor, respectively, during laryngoscopy in which a Wisconsin blade was used. The average incidence of dental injury was 1/191. The Belscope blade may contribute to a reduced likelihood of upper dental injuries during laryngoscopy.

Adult↗
PubMed1994

Differential metabolic requirement for initiation and augmentation of insulin release by glucose: a study with rat pancreatic islets.

Insulin release, glucose utilization (3H2O formation from [5-3H]glucose), and glucose oxidation (14CO2 formation from [14C(U)]glucose) were determined in pancreatic islets from 96-h fasted rats at 37 degrees C and those from fed rats at 22 degrees C, using the islets from fed rats incubated at 37 degrees C as controls. In the islets from 96-h fasted rats and those from fed rats incubated at 22 degrees C, we could not demonstrate significant insulin release in response to high glucose concentrations of up to 16.7 mmol/l. However, 16.7 mmol/l glucose clearly augmented insulin release caused by a depolarizing concentration (50 mmol/l) of K+ in these islets: i.e. 16.7 mmol/l glucose plus 50 mmol/l K+ produced significantly greater insulin release than 50 mmol/l K+ alone. Glucose utilization and oxidation by the islet cells were suppressed by 96-h fasting of the rats or by lowering the incubation temperature to 22 degrees C, and depolarization with K+ at 50 mmol/l did not at all augment glucose utilization and oxidation by the islets. Thus we conclude that reduction of glucose metabolism in islets from fasted rats and in those incubated at low temperature eliminated initiation, but not augmentation, of insulin release by 16.7 mmol/l glucose. The data indicate that the metabolic threshold for the initiation of insulin release is significantly higher than it is for the augmentation of release by glucose.

Animals↗
PubMed1993

2-Buten-4-olide (2-B4O) inhibits type II collagen-induced arthritis in Lewis rats.

2-Buten-4-olide (2-B4O) is an endogenous substance which suppresses appetite and/or food intake. We studied its effect on type II collagen-induced arthritis (CIA) in Lewis rats, an animal model for human rheumatoid arthritis. Bovine type II collagen with incomplete Freund's adjuvant was injected intradermally into Lewis rats to induce CIA. 2-B4O (50 or 100 mg/kg) significantly inhibited the expression of the clinical symptoms when administered i.p. daily from day 1 to 21 after immunization. Furthermore, administration of 2-B4O daily from day 15 to 21 significantly reduced the severity of symptoms in established CIA. In addition, the progression of soft tissue swelling and articular bone erosions were suppressed by daily administration of 2-B4O. 2-B4O also significantly suppressed the delayed-type hypersensitivity (DTH) response to type II collagen at doses of 50 and 100 mg/kg. Finally 2-B4O significantly inhibited the formation of anti-type II collagen antibody at a dose of 100 mg/kg, but not at 50 mg/kg. These results suggest that 2-B4O has the strong inhibitory effects and therapeutic usefulness effects on CIA through the suppression of immune responses to type II collagen.

4-Butyrolactone↗
PubMed1993

Apnoea and oximetric desaturation in patients receiving epidural morphine after gastrectomy: a comparison of intermittent bolus and patient controlled administration.

The number of apnoeic episodes and arterial oxygen desaturations were measured preoperatively and for sixty hours postoperatively in twenty ASA status 1-2 patients scheduled for elective gastrectomy. Monitoring included continuous pulse oximetry, respiratory inductive plethysmography and repeated arterial blood gas analysis. The number and magnitude of apnoeas and desaturation episodes were compared between two postoperative analgesic regimens of epidural morphine; intermittent bolus injection (Group B, n = 10), and patient controlled administration with continuous infusion (Group P, n = 10). Morphine dose, P(a)CO2 and mean SpO2 values were similar between the two groups. Although the number of central apnoeas with SpO2 < 90% was greater in Group B, other episodes of apnoea or desaturation were similarly seen preoperatively. In the postoperative period, central apnoeas with SpO2 < 90% were significantly increased in Group B, while no change was seen in Group P. Apnoeas with SpO2 < 80% were only seen in Group B. We conclude from these results that postoperative apnoeas and episodic desaturations are greatly influenced by the different modes of opioid administration.

Adult↗
PubMed1993

Supramaximal second gas effect: more rapid rise of alveolar halothane concentration during ipsilateral lung N2O administration compared to bilateral administration.

To elucidate the mechanism of the second gas effect, we enhanced halothane uptake by a method other than by increasing the inspiratory concentration of N2O. We determined the effect of N2O elimination via the right lung, which is not receiving N2O (halothane and oxygen), on the halothane uptake in the left lung with N2O added to an inspiratory gas mixture during a differential ventilation using a double-lumen tube. Under the setting, some N2O which was absorbed in the left lung, and eventually eliminated via the right lung, decreased end-tidal (ET) N2O and thereby increased the inspired to end-tidal gradient for N2O in the left lung which was receiving N2O. The situation thus created was equivalent to administering N2O in a higher concentration than the initial concentration. This process enhanced the halothane uptake in the left lung. The study consisted of 15 patients assigned to three groups with five patients in each group. Control groups received a standard, single-lumen endotracheal tube using a gas mixture of O2 + halothane with and without N2O. The experimental group received a double-lumen tube for differential lung ventilation. A N2O + O2 + halothane mixture was administered to the left lung, and simultaneously O2 + halothane was administered to the right lung. On-line gas measurement was performed using Raman spectrometers. The second gas effect was observed between the control groups. N2O was detected in the exhaled gas from the right lung after 3 min of inhalation into the left lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Endotracheal↗