Search PubMed⌕ Search

Biomedical subjects

S Satoh

Publications and source records attributed to S Satoh.

At least 505 records · Page 28Linked to original sources
PubMed1993

Determinants of fasting hypertriglyceridemia in ventromedial hypothalamic obesity in rats.

The present study investigated the mechanism of fasting hypertriglyceridemia in ventromedial hypothalamic (VMH) obesity by measurement of post-heparin plasma lipoprotein lipase (LPL) activity, triglyceride secretion rate (TGSR), and plasma insulin. One week after VMH lesions, when the lesioned rats were gaining weight rapidly (the dynamic phase), they showed normal plasma triglyceride levels with increased plasma LPL activity and TGSR. There was a positive correlation between hyperinsulinemia and elevated plasma LPL activity or TGSR in VMH-lesioned rats, while no correlation was observed in control rats. Ten weeks after VMH lesions, when the rats had become obese and reached a steady-state weight gain (the static phase), they showed hypertriglyceridemia with increased plasma LPL activity and TGSR. There was, again, a positive correlation between hyperinsulinemia and elevated plasma LPL activity or TGSR in VMH-lesioned rats. These results suggest a possible mechanism of fasting hypertriglyceridemia in these rats; in the dynamic phase adipose tissue adequately takes up circulating triglyceride because the tissue has sufficient take-up capacity and hence hypertriglyceridemia does not develop. In the static phase the tissue cannot adequately take up circulating triglyceride because of a limitation of its capacity, resulting in hypertriglycemia despite enhanced triglyceride secretion and increased LPL activity in both phases.

Animals↗
PubMed1993

Tone-dependent coronary arterial-venous pressure differences at the cessation of venous outflow during long diastoles.

BACKGROUND: The origin and magnitude of the back pressure opposing diastolic coronary inflow remain controversial. The arterial pressure at which coronary inflow stops during a prolonged diastole, ie, "zero-flow pressure," is higher than coronary venous pressure. However, because of capacitive discharge as distending pressure falls, flow at the microcirculatory level exceeds inflow, and coronary outflow ceases later than inflow. If coronary arterial pressure continues to exceed venous pressure at the point of venous flow cessation, zero-flow pressure cannot be an artifact of capacitive discharge. METHODS AND RESULTS: Coronary inflow and outflow, arterial pressure, and right atrial pressure have been measured during long diastoles in closed-chest dogs chronically instrumented with volumetric flow probes on the great cardiac vein or coronary sinus as well as the circumflex artery. Although venous outflow continued for 1 to 4 seconds after arterial inflow ceased, coronary artery pressure at the point of venous flow cessation (Pfv = 0) always exceeded right atrial pressure (13 +/- 1.3 mm Hg [SEM] vs 6 +/- 0.7 mm Hg, P < .001). When vasomotor tone was augmented using vasopressin, the diastolic pressure-flow relation shifted to the right, with Pfv = 0 increasing to 21 +/- 2.4 mm Hg despite an unchanged right atrial pressure (6 +/- 0.5 mm Hg). CONCLUSIONS: Transcoronary pressure differences persist when venous outflow stops and are larger when vasomotor tone is augmented. Measurements of zero-flow pressure that exceed venous pressure cannot be considered an artifact of continuing capacitive discharge after the cessation of arterial inflow. Diastolic coronary back pressure exceeds right atrial pressure and is tone dependent.

Animals↗
PubMed1993

Modification of myogenic intrinsic tone and [Ca2+]i of rat isolated arterioles by ryanodine and cyclopiazonic acid.

The role of the sarcoplasmic reticulum (SR) in regulating myogenic tone and [Ca2+]i was examined with ryanodine and cyclopiazonic acid (CPA) in the rat skeletal muscle arteriole (A(sk)) and mesenteric arteriole (Ams). Arterioles were cannulated at both ends to control luminal pressure in a tissue bath. Luminal diameter was measured with a video-monitored microscopic system. Fura 2-AM was loaded to measure [Ca2+]i using the fluorescence intensity ratio at excitation wavelengths of 340 to 380 nm (F340/380). The myogenic response (luminal pressure was increased from 40 to 100 mm Hg) and the intrinsic tone at 40 mm Hg were observed in A(sk) but not in Ams. Ryanodine (10(-5) M decreased the steady-state diameter of A(sk) from 138 +/- 8 to 85 +/- 9 microns (P < .05) and increased the F340/380 ratio; these effects were reversed by nifedipine or Ca(2+)-free solution. Ryanodine shifted the [Ca2+]o-contraction response curve upward. CPA (10(-5) M) also decreased the steady-state diameter of A(sk) from 131 +/- 7 to 98 +/- 11 microns (P < .05). In contrast, Ams responded to neither ryanodine nor CPA. Caffeine-induced contractions were significantly reduced by either ryanodine or CPA in both arterioles. These results indicate that SR dysfunction increased the susceptibility of the arteriolar tone to [Ca2+]o and enhanced the tone of A(sk). In conclusion, the SR function may play a critical role in regulating [Ca2+]i and the intrinsic tone of A(sk) that was myogenically active at physiological luminal pressure.

Animals↗
PubMed1993

Regional differences in the vasodilator response to vasopressin in canine cerebral arteries in vivo.

BACKGROUND AND PURPOSE: The aim of this study was to investigate the regional differences in the in vivo vasodilator responses to vasopressin, which is thought to stimulate the release of nitric oxide from the endothelium, in canine cerebral arteries by angiography. METHODS: Angiograms were performed through a catheter inserted directly into the right vertebral artery and were taken periodically after the infusion of vasopressin. The diameters of various segments of the major arteries were measured using a computerized image analysis system. RESULTS: The bolus administration of vasopressin (10 pmol to 1 nmol) into the vertebral artery produced a long-lasting, dose-dependent vasodilation in the major cerebral arteries centering around the circle of Willis. One nanomole of vasopressin appeared to be the optimal dose for producing maximal vasodilation. The internal diameters of the basilar, posterior communicating, and internal carotid arteries experienced the most dilation (approximately 150% that of control) 2 minutes after the infusion of 1 nmol of vasopressin, followed by those of the middle cerebral, the intracranial portion of the vertebral, and the anterior spinal arteries (approximately 130% that of control). The extracranial portion of the vertebral artery (109.8 +/- 4.8% that of control, n = 4) was less sensitive to 1 nmol of vasopressin. Pretreatment with an intracisternal injection of 10 mumol of NG-monomethyl L-arginine suppressed the vasodilator effect of vasopressin and substance P, whereas it did not affect the response to vasoactive intestinal peptide. CONCLUSIONS: These results suggest that the arteries composing the circle of Willis at the base of the brain are more sensitive to nitric oxide release induced by vasopressin compared with other intracranial and extracranial arteries.

Angiography↗
PubMed1993

Glucoregulatory hormones in the immobilization stress-induced increase of plasma glucose in fasted and fed rats.

We investigated 1) the effect of immobilization stress on glucose metabolism in rats after sham operation (SHAM), adrenomedullectomy (ADMX), and adrenalectomy (ADX); and 2) the effect of glucoregulatory hormone infusion on plasma glucose using untreated normal fasted and fed rats under unanesthetized conditions. In immobilization stress, the plasma glucose concentration increased only in the SHAM group during fasting, while under fed conditions, all three groups showed significant increases (SHAM > ADMX > ADX). Plasma glucagon and norepinephrine significantly increased in all groups; plasma epinephrine increased only in the SHAM group, and plasma corticosterone increased in SHAM and ADMX groups under both conditions. The hepatic glycogen content in all fed groups significantly decreased after immobilization stress, while a very low content before stress and an undetectable level after stress were observed in all fasted groups. Only epinephrine infusion increased plasma glucose during fasting, while epinephrine and glucagon infusion increased it under fed conditions. Corticosterone infusion did not change it under either condition. These results suggest that in the fasted condition, only epinephrine plays an essential role, while under fed conditions, glucagon and corticosterone as well as epinephrine also act as synergistic factors in stress-induced hyperglycemia.

Adrenal Medulla↗
PubMed1993

Expandable metallic stents applied to benign bronchostenosis.

Tandem Gianturco expandable metallic stents (GEMSs) with barbs were inserted to dilate the left main bronchus of a 38-year-old man who had developed left bronchostenosis due to bronchial tuberculosis. Through the use of these GEMSs, ventilation in the left lung remarkably improved; however, the central airway resistance was found to be greater than that exhibited by the normal side and the mucociliary transport function was reduced.

Adult↗
PubMed1993

Prenatal evaluation and obstetrical management of fetuses at risk of developing lung hypoplasia.

The aim of this study was to measure the fetal lung area of normal human fetuses using ultrasound and them to test the predictive values of a nomogram in the identification of fetal lung hypoplasia. A nomogram for ultrasound-measured fetal lung area were constructed from 264 normal fetuses from 17 to 39 weeks of gestation. In 19 cases running the risk of developing lung hypoplasia, the sensitivity, specificity, and positive and negative predictive values of lung area measurements below the mean -2 SD were 75%, 100%, 94% and 100%, respectively, with total lung area showing a significant relation to the combined lung weight (Y = -1.05 + 2.06 X, r2 = 0.88). These results indicate that lung area measured by ultrasound is a good indicator of lung weight, and this nomogram of lung area may be useful in evaluating lung growth prenatally, as well as in the direct obstetrical management of fetuses at risk of developing lung hypoplasia.

Female↗
PubMed1993

Prevalence of hepatocellular carcinoma in patients with alcoholic cirrhosis and prior exposure to hepatitis C.

Sixty-three patients with alcoholic cirrhosis were retrospectively studied for the prevalence of antibodies to core (P22) and nonstructural (C100) region of hepatitis C virus (HCV). The prevalence rate of anti-P22 antibodies in patients with alcoholic cirrhosis was higher than that of anti-C100 antibodies (63.5% vs. 54.9%). The positivity rate of anti-C100 and/or anti-P22 antibodies was 73.0% (46/63) in alcoholic cirrhosis. We performed a multivariate analysis on the effects of age, sex, cumulative alcohol intake, anti-HCV antibodies, indocyanine green excretion test, and serum albumin on the development of hepatocellular carcinoma HCC in patients with cirrhosis, using Cox's proportional-hazards model, which revealed that anti-HCV positivity was the only independent prognostic variable for HCC in patients with alcoholic cirrhosis. The probability of HCC was significantly higher in the anti-HCV-positive patients than in the negative patients with alcoholic cirrhosis (p < 0.05). The 3-, 5- and 10-yr cumulative occurrence rate of HCC was, respectively, 13.3%, 41.3%, and 80.7% for anti-HCV-positive patients with alcoholic cirrhosis, compared with 0%, 8.3%, and 18.5% for anti-HCV-negative patients. In nonalcoholic patients with type C cirrhosis, the 3-, 5-, and 10-yr cumulative occurrence rate of HCC was 7.3%, 23.1%, and 56.5%, respectively. The follow-up studies indicate that hepatocarcinogenesis is hastened significantly in patients with alcoholic cirrhosis if they are positive for anti-HCV antibody, and that heavy alcohol consumption also is a risk factor for the development of HCC in patients with type C cirrhosis.

Adult↗
PubMed1993

Effects of nifedipine, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride and atrial natriuretic peptide on endothelin-induced antinatriuresis in dogs.

Nifedipine, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate hydrochloride (TMB-8) or atrial natriuretic peptide (ANP) was infused into the renal artery before and during intrarenal arterial infusion of endothelin-1 (ET) in anesthetized dogs. Before ET infusion, nifedipine (0.1 micrograms kg-1 min-1), TMB-8 (75 micrograms kg-1 min-1) or ANP (10 ng kg-1 min-1) increased the urine flow rate, urinary sodium excretion and fractional sodium excretion with little change in renal blood flow or glomerular filtration rate. ET (2 ng kg-1 min-1) reduced the basal renal blood flow, glomerular filtration rate, urine flow rate, urinary sodium excretion and fractional sodium excretion. Both nifedipine and TMB-8 induced natriuresis during ET infusion; but only TMB-8 completely reversed the ET-induced reduction in fractional sodium excretion and partially antagonized the reductions in urine flow rate and urinary sodium excretion. ANP did not induce substantial urinary responses during ET infusion. Neither nifedipine, TMB-8 nor ANP reversed the ET-induced decreases in renal blood flow and glomerular filtration rate. The present study suggests that in the dog kidney 1) the ET-induced antinatriuresis is caused in part by enhancement of tubular sodium reabsorption, 2) the tubular action of ET depends on TMB-8-sensitive calcium movements but not calcium influx through dihydropyridine-sensitive channels and 3) ANP cannot counteract the ET-induced antinatriuresis.

Animals↗
PubMed1993

[Studies of prognostic factor and chemotherapeutic effect of epithelial ovarian cancer using Cox's proportional hazard model].

To make clear the prognostic factor and chemotherapeutic effect of epithelial ovarian cancer, a multiple-center study involving 22 hospitals in Japan was conducted using Cox's proportional hazard model. A total of 1,181 cases were reviewed. Clinical stage, histologic type, and residual tumor diameter were significant prognostic factors, but the degree of tissue differentiation was not. The effect of remission induction chemotherapy was assessed with or without CDDP, and a distinct prognostic difference was noted. Among the patients receiving CDDP + ADM + other chemotherapeutic agents (PA group), CDDP + other chemotherapeutic agents (PO group) and CDDP only (P group), the prognosis of the PO group was better than for the P group. The long-term prognosis improving effect of chemotherapy was assessed. Neither maintenance chemotherapy based on oral administration of pyrimidine fluoride nor immunotherapy had any long-term prognosis improving effect, while intermittent chemotherapy based on CDDP resulted in improved prognosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1993

[Effect of continuous intravenous administration of midazolam and ketamine on respiratory pattern].

The purpose of the study was to investigate the effect of continuous IV administration of midazolam and ketamine on respiratory pattern in six adult volunteers. Midazolam 0.05 mg/kg and ketamine 0.5 mg/kg were given, and then 0.1 mg/kg/hr for midazolam and 1 mg/kg/hr for ketamine were administered continuously. We measured MV, RR and TV (OMR86036), and calculated duty ratio and mean inspiratory flow at the level of 0 and 5 cmH2O CPAP during spontaneous respiration of air with and without 5% CO2. Each parameter was obtained before and 1 hr after the start of IV administration of the drugs. With 5% CO2, MV decreased significantly from 15.5 +/- 1.5 l/min to 11.7 +/- 0.8 l/min at 0 cmH2O CPAP level and from 15.8 +/- 1.8 l/min to 12.6 +/- 1.5 l/min at 5 cmH2O CPAP level, and also mean inspiratory flow decreased significantly from 590 +/- 2 ml/sec to 421 +/- 30 ml/sec at 0 cmH2O CPAP level and from 606 +/- 53 ml/sec to 477 +/- 48 ml/sec at 5 cmH2O CPAP level. TV decreased significantly during sedation at both CPAP levels with or without 5% CO2, while RR and duty ratio tended to increase. It was thought that, when the respiration was stimulated with 5% CO2, the decrease in mean inspiratory flow greatly contributed to the fall in MV during administration of midazolam and ketamine.

Adult↗
PubMed1993

[Lower thoracic disc herniation with acutely developed vesicorectal dysfunction: case report].

Thoracic disc herniation is a rare and slowly progressive disease which most commonly occurs at the lower thoracic spine without any preceding trauma. We reported a case with acutely developed vesicorectal dysfunction due to a ruptured disc at Th 11-12. This symptom disappeared soon after disc removal via the transpedicular approach combined with transversectomy. This 45-year-old woman suddenly suffered, without previous trauma, from severe back pain radiating down to the posterior thighs. Since difficulty in urination and defecatory incontinence succeeded two days later, she was transferred to our hospital. Neurological examination on admission revealed anesthesia below S1, hypotonic bladder with almost perfectly preserved urinary sensation, complete lack of anal reflex, and only weak motor function in the lower extremities. Both knee and ankle jerks were diminished bilaterally. A herniated disc was initially suspected at L5-S1 on the MRI, but denied by both myelography and CT myelography. These studies showed a disc hernia compressing the cord at Th 11-12 on the left side. Since the hernia was located centrolaterally, we employed the transpedicular approach. To make removal of the more centrally located hernia easier, we further added transversectomy of the twelfth vertebra. This hernia was successfully removed under the operating microscope without further damage to the cord being incurred. We did not perform any instrumental fixation, because we thought preservation of the rib and costvertebral joint could contribute to the stability of the spine. Her vesicorectal symptom subsided immediately after the operation. She was free of any symptoms except for the remaining mild perianal numbness a year and seven months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Fecal Incontinence↗
PubMed1993

[The assessment of multiple coronary artery bypass with bilateral internal thoracic artery grafts].

From 1982 to March 1991, 68 patients underwent coronary artery bypass grafting (CABG) using bilateral internal thoracic arteries (ITA). There were 62 males (91.2%) and 6 females (8.8%) ranging from 33 to 74 years old (mean 58.5 +/- 9.2). Thirty four patients had old myocardial infarction (OMI) and left main trunk disease was seen in 8.5% of the patients. The number of grafts was 2 to 6 per patient with an average of 3.2 +/- 1.0. In bilateral ITA grafting the combinations of RITA to LAD and LITA to LCX were most frequently used. There were no operative deaths except for one death which occurred while at the hospital. The patency rates for the RITA and LITA were 98.3% and 96.7%, respectively. Postoperative complications included reexploration for bleeding and heart tamponade in 9 patients, and low output syndrome in 7 patients. The frequency of blood transfusion decreased with the use of cell saver. Routine bilateral ITA grafting for multiple CABG is considered safe, with the early patency being relatively better than with saphenous vein grafting.

Adult↗
PubMed1993

[Renal autotransplantation and graft replacement for DeBakey IIIb dissecting aneurysm--a case report].

A successfully repaired case, a 53-years old man, who suffered DeBakey IIIb type dissecting aneurysm and renal dysfunction was reported. The right kidney, of which artery was originated from the false lumen, was autotransplanted to the right iliac system to improve the renal blood circulation. Then the descending aorta was segmentally replaced with the prosthesis under profound hypothermia, circulatory arrest and retrograde cerebral perfusion without cross-clamping the aortic arch. Three months later, aortography and catheterization study suggested that the reperfused left kidney resulted in renin-dependent hypertension. Kidney, therefore, was resected to improve blood pressure control. Patient recovered successfully, with no evidence of neurological complication.

Aortic Dissection↗
PubMed1993

An intracellular calcium release inhibitor TMB-8 suppresses renal nerve stimulation-induced antinatriuresis in dogs.

Effects of nifedipine and TMB-8 on antinatriuresis induced by renal nerve stimulation (RNS) were examined in pentobarbital-anesthetized dogs. RNS (1 Hz) decreased urine flow rate, urinary sodium excretion rate and fractional excretion of sodium and increased renal norepinephrine efflux and renal venous plasma renin activity with little changes in renal hemodynamics. Intrarenal arterial infusion of nifedipine (0.1 microgram/kg/min) or TMB-8 (50 and 100 micrograms/kg/min) increased basal urine flow rate, urinary sodium excretion rate and fractional excretion of sodium without affecting renal venous plasma norepinephrine concentration or plasma renin activity. Neither nifedipine nor TMB-8 affected the RNS-induced increases in norepinephrine efflux and plasmin renin activity. The RNS-induced decreases in urinary sodium excretion rate and fractional excretion of sodium were suppressed during the TMB-8 infusion, whereas nifedipine failed to affect these urinary responses. These results raise the possibility that the release of intracellular calcium from TMB-8-sensitive stores, but not the influx of extracellular calcium through dihydropyridine-sensitive calcium channels, participates in neural control of tubular sodium reabsorption in the dog kidney.

Animals↗