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Biomedical subjects

S Morimoto

Publications and source records attributed to S Morimoto.

At least 631 records · Page 35Linked to original sources
PubMed1986

[Circadian rhythms of lithogenic and inhibitory substances in the urine].

The diurnal variations of urine composition with respect to urinary pH, volume, creatinine, calcium, magnesium, phosphate, uric acid, citrate and oxalate were studied in five healthy men. Generally, there was considerable variations in the excretion of the different urine constituents with meal related peaks except phosphate, which was most pronounced after dinner. The analysis of a 24-hour urine collection cannot account fully for the crystallization properties of urine and a fractionated urinalysis might be of value for therapeutic decisions. However, such procedures probably will not be possible in clinical practice and more reliable methods for evaluation of the crystallization propensity in whole 24-hour urine have to be developed.

Calcium↗
PubMed1986

[An experience of percutaneous nephro-ureterolithotomy].

Herein we report our experience of percutaneous nephro-ureterolithotomy on 18 renal or upper ureteral calculous patients between December, 1984 and May, 1985. Using an ultrasonic lithotrite and a nephroscope especially developed for the percutaneous disintegration and removal of upper urinary stones via a nephrostomy, 15 of the patients were successfully treated without open surgery.

Adult↗
PubMed1986

CT of intrathoracic neurogenic tumours.

Fifteen patients with primary intrathoracic neurogenic tumours were evaluated using computed tomography (CT) scans. Schwannomas were demonstrated as homogeneous or slightly inhomogeneous densities on plain CT images; 4 of 5 schwannomas showed rim enhancement with some enhancement in the central portion of the tumour on post-enhancement CT images. Neurofibromas and ganglioneuromas were visualized as homogeneous densities on plain CT images. Three of 5 ganglioneuromas revealed homogeneous contrast enhancement of post-contrast CT images. A ganglioneuroblastoma and 2 neuroblastomas manifested slightly inhomogeneous tumour density on plain CT images. The inhomogeneity of the tumours was accentuated on contrast enhancement CT images.

Adolescent↗
PubMed1986

[Pituitary abscess: report of two cases and a review].

Two cases of pituitary abscesses are reported. The first case was a 22-year-old female who was admitted with 14 months history of intermittent fever and headache followed by amenorrhea and polyuria. Plain craniograms showed no remarkable changes on the sella turcica. Direct coronal CT demonstrated a cystic lesion with a ring-like enhanced capsule in the pituitary complex with the apparent bulging of the pituitary top surface. On dynamic CT, the cystic lesion showed no remarkable increase in density. Transsphenoidal surgery was performed and a purulent materials was drained by cutting the underlying fibrous pituitary tissue. Pathological specimen revealed a marked inflammatory reaction around the degenerative pituitary gland. The second case was a 27-year-old female who underwent transsphenoidal excision of craniopharyngioma on May 12, 1983. Postoperatively she did well with the hormonal replacement therapy until 9 months after surgery when a follow up direct coronal CT revealed a cystic lesion with ring-like enhancement in the pituitary fossa. Purulent material was found at transsphenoidal surgery. Pathological specimen from the hard capsule was a chronic inflammatory fibrous tissue without tumorous component. Over seventy cases of pituitary abscesses have been reported previously, but the majority of them were secondary infections associated with systemic sepsis, chronic sphenoid sinusitis or pituitary tumors. Primary pituitary abscesses were rare and would be difficult to be diagnosed preoperatively without an aid of recent CT technology. Thirty cases in the literature since 1970 are reviewed and its clinical pictures and radiological findings are discussed.

Abscess↗
PubMed1986

[Renal oxalate excretion following oral oxalate load in patients with urinary calculus disease and healthy controls].

Oral oxalate loading using sodium oxalate or a vegetable juice was done to evaluate the intestinal absorption of exogenous oxalate in 30 patients with renal stones and 13 healthy controls. Fifteen calcium oxalate stone formers, 7 non-oxalate stone formers and 10 healthy volunteers were given an oral loading of sodium oxalate (500 mg). Urinary oxalate increased promptly, reaching a peak value within 4 to 8 hours after administration of a synthetic oxalate orally in a fasting state. In calcium oxalate stone formers, the mean increment of urinary oxalate and the bioavailability following oral sodium oxalate load were significantly higher than in the healthy controls and non-oxalate stone formers. Furthermore, intestinal hyperabsorption of oxalate in our criterion was defined in six patients with calcium oxalate stones (40%). On the other hand, eight calcium oxalate stone formers and three healthy controls were given vegetable juice. Urinary oxalate was increased only slightly after the ingestion, and there was no difference between calcium oxalate stone formers and normal controls. These results suggest that a certain hyperoxaluria might be induced by intestinal absorption of exogenous oxalate, and that the hyperabsorption might indicate a possible risk factor for calcium oxalate stone formation.

Administration, Oral↗
PubMed1985

(Ca2+ + Mg2+)-ATPase activity in plasma membrane of circulating mononuclear cells. Lack of a direct effect of vitamin D.

The in vivo effect of vitamin D on (Ca2+ + Mg2+)-ATPase activity was examined in a plasma membrane fraction of rat circulating mononuclear cells (MPM). Although there was no significant difference in the ATPase activities in red blood cell ghosts, (Ca2+ + Mg2+)-ATPase activity in MPM was significantly higher (p less than 0.05) in long-term vitamin D3-replete rats (100 IU/day for 6 months) than that in vitamin D-deplete rats (for 6 months). In rats maintained on vitamin D-deficient diets for 5-7 weeks, in vivo administration of either vitamin D3, 2,000 IU orally, 5 days prior to killing or 1,25-dihydroxyvitamin D3, 2.4 nmol, intraperitoneally, 24 h prior to killing failed to show any significant effect on (Ca2+ + Mg2+)-ATPase activity in MPM. (Ca2+ + Mg2+)-ATPase activity in MPM from rats maintained on vitamin D-deficient diet with high calcium content (1.8%) was significantly higher (p less than 0.05) than that from rats maintained on vitamin D-deficient diet with low calcium content (0.3%). Moreover, in vitro addition of vitamin D3 metabolites did not show any effect on (Ca2+ + Mg2+)-ATPase activity in MPM. These data suggest that decreased (Ca2+ + Mg2+)-ATPase activity in MPM from long-term vitamin D-deplete rats resulted from an adaptation to low extracellular calcium rather than vitamin D depletion.

Animals↗
PubMed1985

[Production of aldosterone and its precursor steroids by the adrenal zona glomerulosa in dextran sulfate-treated rats].

Heparin and heparinoids are known to produce selective aldosterone deficiency in man and experimental animals. To assess the nature of the hypoaldosteronism caused by heparin and heparinoids, we investigated the production of aldosterone and its precursor steroids in response to angiotensin II (AII), ACTH or potassium in adrenal zona glomerulosa cells from dextran sulfate-treated rats compared with that in the cells from vehicle-treated rats. Dextran sulfate-treated rats had a decrease in plasma aldosterone and a reduction in the width of the zona glomerulosa 4 weeks after the treatment (40 mg/day, intramuscularly). In these rats, PRA and plasma AII tended to be high, and plasma corticosterone was normal. Basal aldosterone production, when corrected to a uniform number of cells per group, was similar in cells from dextran sulfate- and vehicle-treated rats. The cells from dextran sulfate-treated rats had a less sensitive and lower response of aldosterone production to AII; an increase by 4 orders of magnitude in the threshold dose for AII and a decrease in the maximal AII-stimulated level. The maximal AII-stimulated levels, but not the basal levels, of pregnenolone, corticosterone and 18-hydroxycorticosterone production were low in the cells from dextran sulfate-treated rats. ACTH produced a similar stimulatory effect on aldosterone production in the cells from dextran sulfate- and vehicle-treated rats. The cells from dextran sulfate-treated rats had a less sensitive and lower response of aldosterone production to potassium; an increase by one order of magnitude in the threshold dose for potassium and a decrease in the maximum potassium-stimulated level, presumably because of the glomerulosa hyporesponsiveness to AII. These results suggest that long-term treatment with dextran sulfate in rats produces selective impairment of adrenal zona glomerulosa cells, involving the specific receptors and the aldosterone biosynthesis, to AII in addition to a reduction in the glomerulosa width.

Adrenal Cortex↗
PubMed1985

The calcium channel agonist, Bay K 8644, inhibits renin release from rat kidney cortical slices.

The effects of Bay K 8644 [methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl) -pyridine-5-carboxylate], a calcium channel agonist, on renin release in rat kidney cortical slices were examined. Bay K 8644 produced a dose-related inhibition of renin release in the presence of 15 mM potassium. The inhibitory effect of Bay K 8644 on this release was abolished when calcium was excluded from the incubation medium. Nifedipine exerted a concentration-dependent blocking action on the inhibition of renin release by Bay K 8644. These findings support the proposal that calcium influx into the renin secretory cells is an inhibitory signal for renin release.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1985

Activation of urinary inactive kallikrein by an extract from the rat kidney cortex.

Activation of purified urinary inactive kallikrein by an extract from the rat kidney cortex was investigated. The extract produced a dose-dependent activation of the inactive kallikrein and the optimum pH for this activation was 5.0. Marked depression of the activation was observed when the extract was pre-incubated with E-64, p-CMB and iodoacetate, but not with DFP, PMSF or pepstatin A. The molecular weight of the inactive kallikrein (Mr 44,000) was reduced to 38,000 by treatment with the extract, this molecular weight value being identical with that of urinary active kallikrein. These results indicate that the rat kidney cortex contains a protease catalyzing conversion of urinary inactive kallikrein into its active form, and that the protease has properties compatible with those of a thiol protease, but not of trypsin which has been used as a tool for the activation of urinary inactive kallikrein. The thiol protease is probably one of regulators of the kallikrein-kinin system in the kidney.

Animals↗
PubMed1985

Renin release from kidney cortical slices in response to isoproterenol and glucagon is decreased in vitamin E-deficient rats.

The effects of vitamin E (VE)-deficiency on renin release by various agents were examined using rat kidney cortical slices. Isoproterenol and glucagon in the presence or absence of theophylline increased renin release in the control group, while their stimulatory effects were attenuated by VE-deficiency. These decreased responses of renin release to isoproterenol and glucagon due to VE-deficiency were restored to the control level by dietary supplementation of dl-alpha-tocopheryl acetate or N,N'-diphenyl-p-phenylenediamine. The stimulatory effect of dibutyryl cyclic AMP or theophylline on renin release was not affected by VE-deficiency. These results suggest that in case of VE-deficiency, the response of renin release to stimuli is decreased via cyclic-AMP production.

Animals↗
PubMed1985

Prognosis of dilated cardiomyopathy. An integrated analysis including endomyocardial biopsy findings.

A long-term prognostic study of up to 15 years of dilated cardiomyopathy (DCM) was carried out in 65 cases. The 5-year survival rate after the onset of subjective symptoms was 40%, and the 10-year survival rate 22%. To evaluate the prognostic factor of DCM, the cardiothoracic ratio (CTR), ECG, hemodynamics, and histopathological contractility failure index (HCFI), which we constructed through right ventricular endomyocardial biopsy, were compared. Patients having malignant arrhythmias, such as short runs or multifocal ventricular premature beats with mild impaired cardiac status, mild cardiomegaly, and low HCFI, were more prone to sudden death. In patients with progressively deteriorating cardiac status, refractory cardiomegaly, supraventricular arrhythmias, left axis deviation, prolongation of QRS interval, low voltage, and high HCFI, the cause of death is more likely to be refractory heart failure.

Adult↗