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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 415 records · Page 23Linked to original sources
PubMed1988

Treatment of persistent enuresis. Results of severing a tight filum terminale.

A tight filum terminale was severed in an attempt to treat intractable enuresis in 27 children. Urodynamic studies demonstrated pre-operative bladder instability in all cases. Although symptom scores for enuresis improved significantly 6 months after surgery, only 7 patients benefited clinically (3 were cured and enuresis was reduced in 4). An average of 26 months later, 12 patients were either dry or their enuresis was reduced, probably due to spontaneous cure rather than surgery. We found no clinical parameters able to predict a favourable outcome. It was concluded that although a tight filum terminale is a cause of intractable enuresis, transection of the filum is not recommended because of the low success rate.

Adolescent↗
PubMed1988

Relative contributions of the nervous system and hormones to CNS-mediated hyperglycemia.

We quantitatively determined the relative contributions of hormonal factors and the nervous system to the total glucose response after stimulation of the cholinergic neurons in the central nervous system of fed rats. Hepatic venous plasma glucose, glucagon, insulin, epinephrine, and norepinephrine were measured during 120 min after injection of neostigmine (5 X 10(-8) mol) into the third cerebral ventricle in rats subjected to bilateral adrenodemedullation (ADMX) to prevent epinephrine secretion (observed insulin secretion), with and without intravenous infusion of somatostatin to prevent glucagon and insulin secretion. Injection of neostigmine in intact rats resulted in increases in glucose, glucagon, epinephrine, and norepinephrine. Comparison of glucose areas suggests that 22% of the hyperglycemic response is due to the glucagon effect, that 29% is due to the epinephrine effect, and that an unknown factor other than epinephrine or glucagon, which may include activation through direct neural innervation of the liver via alpha-adrenergic receptor, contributes 49%. The suppressive effect of epinephrine on insulin secretion, which is potentially stimulated by direct neural activation of the pancreas, contributes 18% of the net hyperglycemia.

Adrenal Medulla↗
PubMed1988

Clinical and electrocardiographic characteristics of responders and nonresponders to class IA antiarrhythmic drugs.

A retrospective analysis of 44 patients was carried out to evaluate the efficacy of class IA antiarrhythmic drugs (disopyramide and/or procainamide), and of drugs of one or more other classes by means of 24-hour Holter recording. This study included only patients who exhibited 5000 or more ventricular premature complexes (VPCs) during a 24-hour pretrial baseline recording. The drugs that reduced the frequency of VPCs by at least 50% were considered effective. Eighteen patients (41%) responded to class IA drugs (responders) and 26 patients (59%) did not (nonresponders). There was a significant difference between the two groups in relation to the types of disease (p less than 0.01), but no significant difference with regard to other clinical and electrocardiographic characteristics. There was a significant discordance between trials of class IA drugs and class IC drugs (p less than 0.05). The efficacy of class IA drugs is very similar to that of class IB drugs, and only class IC drugs represent the highest efficacy in patients refractory to both class IA and class IB drugs. In conclusion, when ventricular arrhythmias do not respond to class IA or IB drugs, class IC drugs could be chosen as the next regimen.

Adult↗
PubMed1988

Effects of pentobarbital and cyproheptadine on brain ischemia induced by bilateral occlusions of carotid arteries and vertebral arteries of second cervical vertebra in rats.

The bilateral hemispheric ischemia in rats was induced by the occlusion of bilateral common carotid arteries after permanent electrocauterization of bilateral vertebral arteries at the level of the second cervical vertebra. In ischemic rats, (a) electroencephalograms became flat immediately after occlusion of carotid arteries, and (b) mortalities reached maximum levels at day 3 after recirculation. These results suggested that a constant level of cerebral ischemia was produced in this rat model. Pentobarbital markedly inhibited the mortality in these ischemic rats, whereas cyproheptadine did not.

Animals↗
PubMed1988

The roles of glucagon and adrenal epinephrine in mediating hyperglycemia induced by third cerebroventricular injection of bombesin.

The roles of glucagon and adrenal epinephrine in mediating bombesin-induced central hyperglycemia were further studied in anesthetized rats. Bombesin (10(-9) mol) injected into the third cerebral ventricle produced an increase in plasma concentrations of glucose, glucagon, and epinephrine. Prior bilateral adrenalectomy completely prevented the hyperglucagonemic and hyperglycemic responses to third cerebral ventricle injection of bombesin. These results support the view that bombesin-induced increases in plasma glucose and glucagon are fully dependent on adrenal epinephrine secretion. Furthermore, during constant intravenous infusion of somatostatin, the hyperglycemic response to third cerebral ventricle injection of bombesin was not significantly influenced despite complete inhibition of the increase in plasma glucagon. Therefore, it is suggested that bombesin-induced central hyperglycemia is mainly mediated by epinephrine itself rather than via epinephrine-stimulated glucagon secretion.

Animals↗
PubMed1988

Central versus peripheral effect of clonidine on hepatic venous plasma glucose concentrations in fasted rats.

To evaluate whether clonidine exerts its action within the central nervous system or outside the central nervous system to induce hyperglycemia, we compared the effects of clonidine injected into the third cerebral ventricle or intravenously on hepatic venous plasma glucose concentrations in fasted rats. Clonidine administration produced a dose-dependent hyperglycemia in each case. At all tested doses (5, 50, and 100 nmol) the hyperglycemic responses to clonidine injected intravenously were not significantly different from those to clonidine injected into the third cerebral ventricle. Intraperitoneal pretreatment with yohimbine (50 nmol) or phentolamine (50 nmol), both alpha-adrenergic antagonists, reduced the hyperglycemic response to clonidine (100 nmol) given intravenously, but these antagonists preinjected into the third cerebral ventricle did not reduce the response. Moreover, no significant differences in venous plasma clonidine concentrations were observed when intravenous and third cerebral ventricle injections of clonidine (100 nmol) were compared. These results suggest that clonidine-induced hyperglycemia is mainly mediated by the peripheral mechanism rather than through the central mechanism. To gain an insight into the peripheral mechanism for the hyperglycemic action of clonidine, we measured the plasma immunoreactive glucagon and insulin concentrations after intravenous clonidine (100 nmol). We found that plasma immunoreactive glucagon concentrations significantly increased, whereas plasma immunoreactive insulin concentrations did not change significantly despite hyperglycemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[A study on the DNA histogram pattern of hepatocellular carcinoma--application of a high resolution analytical system using a charge couple device (CCD)].

In 25 cases of primary hepatocellular carcinomas, the relationships between clinical, pathological features and DNA histogram patterns were investigated. Nuclear DNA histogram that represents cell cycle and indicates biological malignancy of carcinoma was analyzed by rapid image sensor analytical system scanning enable to measure the density, area and perimeter of nuclei even on thin tissue sections. Histograms of over 65 years old patients showed low ploidy pattern rather than that of less than 65 patients whose AFP values are over 1000 ng/ml showed statistically higher ploidy pattern compared to those of under 10 ng/ml. No significant relations were verified between pathological findings and DNA histogram patterns. But patients who died within 18 months after hepatectomy showed broad and high ploidy histogram patterns compared to patients who lived over 18 months. These results suggested that DNA histogram analysis is useful for evaluate the biological malignancy of primary hepatocellular carcinoma.

Adult↗
PubMed1988

Multiple donor allotransplantation. A new approach to pancreatic islet transplantation.

Currently it is not feasible to isolate sufficient numbers of islets from a single pancreas for clinical transplantation. We examined whether small numbers of islets obtained from multiple donors could be used for transplantation. Islets were isolated from four inbred strains of mice (DBA/2, DBA/1, C3H, and A.SW) by a stationary collagenase digestion and Ficoll separation and transplanted into the renal subcapsular space of streptozotocin-induced diabetic B6AF1 mice. At least 200 handpicked islets were required to produce normoglycemia in syngeneic and allogeneic diabetic recipient mice. None of the mice given 50 islets became normoglycemic within 2 weeks postgrafting. When various numbers of purified islets from a single donor were transplanted, the survival was significantly better for 200-islet allografts than for 800-islet and 400-islet allografts. When a 200-islet composite graft was prepared from four donors (50 fresh handpicked islets from each donor), the survival of the composite graft as measured by sustained normoglycemia in nonimmunosuppressed recipients was dramatic, with 17 of 18 recipients maintaining normoglycemia indefinitely (greater than 200 days). Similarly, when islets isolated from four donors and cultured for various periods were mixed and transplanted (200 islets/recipient) all recipient mice (n = 8) enjoyed indefinite graft survival. Use of higher numbers of purified islets or crude islets in a composite multiple-donor islet allograft was less effective in achieving indefinite graft survival. Thus, transplantation of a composite graft made up with subtherapeutic numbers of islets from multiple histoincompatible donors to provide adequate therapeutic numbers is a practical solution to the lack of islet availability. In addition, composite islet grafts appear to possess immunological advantages, with significantly prolonged survival over that produced by single-donor islet grafts.

Animals↗
PubMed1987

Effects of verapamil and sodium nitroprusside on acetylcholine-induced contraction of the rabbit detrusor muscle.

Effects of extracellular and intracellular Ca2+ on acetylcholine-induced contraction of the bladder detrusor muscle were studied in vitro, utilizing two types of Ca2+ antagonists of different mechanisms of action; verapamil and sodium nitroprusside (NP). Acetylcholine (10(-8) to 10(-2) M) caused dose-dependent contractions of the detrusor muscle strips. Pretreatment of the strips with verapamil (10(-7), 10(-6) M) significantly inhibited the acetylcholine-induced contraction in a dose-dependent manner, whereas NP (10(-7) to 10(-5) M) failed so suppress the contraction. The contraction of the strips once elicited by acetylcholine (10(-6) M) could be completely relaxed by verapamil (10(-5) M) addition, but only incompletely by NP (10(-5), 10(-4) M). In Ca2+-free solution containing 0.01 mM EGTA, replenishment of Ca2+ (2.5 mM) to the medium caused contractions of the strips. Addition of acetylcholine (10(-6) M) to the medium enhanced the Ca2+-induced contraction, which was significantly inhibited by pretreatment with verapamil (10(-6) M), but not affected by NP (10(-6) M). In Ca2+-free medium containing 0.1 mM EGTA, acetylcholine caused a slight degree of tension increase of the strips in a dose-dependent fashion, at higher concentrations exceeding 10(-6) M. These results suggest that the detrusor muscle contraction induced by acetylcholine is mostly dependent of extracellular Ca2+ influx both in its initiation and maintenance. It is also supposed, however, that intracellular Ca2+ fractions will partly participate in the acetylcholine-induced contraction and possibly in its maintenance.

Acetylcholine↗
PubMed1987

Elastic fibers in tunica propria of undescended and contralateral scrotal testes from cryptorchid patients.

Elastic fibers in the tunica propria of the testes from cryptorchid patients and normal fertile adults were examined by light (Weigert resorcin-fuchsin stain) and electron microscopic techniques. In the testes from normal fertile adults, elastic fibers were proved to exist in the tunica propria by light and electron microscopy, and were located in the fibrous and cellular layers of the tunica propria. In the undescended testes from the cryptorchid patients, during prepubertal and pubertal periods, elastic fibers could not be visualized in the tunica propria, but were found after puberty. The positive Weigert reaction of the tunica propria in the undescended testes from postpubertal cryptorchid patients, however, was markedly weaker than that in normal control patients, suggesting diminution of elastic fibers. This diminution of elastic fibers in the undescended testes from postpubertal cryptorchid patients was also substantiated by electron microscopy. However, in the contralateral scrotal testes, elastic fibers appeared during puberty and were observed after puberty in the same manner as in normal testes. Thus, the present study suggested retarded appearance of elastic fibers in puberty and impaired development of those fibers after puberty, in the undescended testes of cryptorchid patients.

Adolescent↗