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Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 199 records · Page 11Linked to original sources
PubMed1982

Renal handling of salt and water in the early stage of obstructive jaundice in rabbits.

Renal handling of salt and water in the early stage of obstructive jaundice was studied in rabbits 10 days after the ligation of the common bile duct (BDL). Sham-operated (SO) animals served as controls. No sodium retention was found in BDL rabbits, despite reduced renal perfusion and elevated plasma aldosterone level. A redistribution of intrarenal blood flow was not found. The filtration fraction did not change. A saline load resulted in decreases in arterial hematocrit and total serum proteins, and increases in urine output, urinary sodium excretion and osmolal clearance. Blood pressure, glomerular filtration rate (GFR), RPF, the filtration fraction and the intrarenal flow distribution were not significantly affected by the saline load. No significant difference was found in the natriuretic response to the saline load between the BDL and SO groups. After 60 h of water deprivation, there was no significant difference in urine-to-plasma osmolality ratios or renal tissue fluid osmolality between the BDL and SO animals. The findings indicate that renal handling of salt and water was well maintained in the early phase of obstructive jaundice in rabbits. The data also suggest the critical role of the redistribution of intrarenal blood flow rather than of GFR or aldosterone in determining sodium retention in obstructive jaundice.

Aldosterone↗
PubMed1982

Diurnal variation of urinary potassium excretion in chronic renal insufficiency.

Diurnal variation of urinary potassium excretion was examined on 10 adult patients with chronic renal insufficiency and 24 control subjects without cardiorenal functional disturbances. The daily cycle of potassium excretion, similar to that in controls, was present but less obvious in chronic renal insufficiency. In the controls, urinary potassium excretion reached a peak in the early morning (5.30 to 7.30) with a minimum in the night (21.00 to 5.30). The morning rise in potassium excretion was associated with increases in urinary sodium excretion, arterial blood pH, and plasma potassium and aldosterone concentrations. Creatinine clearance rate did not change significantly. In renal insufficiency, plasma potassium level and potassium excretion increased in the morning as compared with the night, whereas sodium excretion, the creatinine clearance rate, arterial blood pH and plasma aldosterone concentration did not change. 9 alpha-Fluorohydrocortisone gave rise to markedly enhanced potassium excretion. The findings suggest that the blunted cycle of potassium excretion in renal insufficiency is due, in part, to suppressed diurnal variations of sodium delivery to the distal tubule, acid-base balance and/or aldosterone secretion.

Adult↗
PubMed1982

Evidence for involvement of mast cells in tumor suppression in mice.

Mast cell-deficient W/Wv mice had an increased tumor incidence after subcutaneous treatment with 3-methylcholanthrene, compared with that in normal congenic mice treated in the same way. This increased tumor incidence was suppressed to the normal level when the carcinogen was given after the mast cell deficiency had been overcome by transplantation of bone marrow cells from normal congenic mice. The W/Wv mice, however, were not defective in natural killer and T-cell-mediated cytotoxic activities. These results support the hypothesis that mast cells are involved in tumor suppression.

Animals↗
PubMed1981

Involvement of ovarian innervation in steroid secretion.

The effects of electrical stimulation of the brain on the ovarian venous plasma concentrations of estradiol (E2) and progesterone (P) were investigated in female rats hypophysectomized and adrenalectomized at 1000 h on the day of proestrus. Stimulation was applied during the proestrous critical period under pentobarbital anesthesia, and contralateral ovarian venous blood was collected from 105-120 min after the stimulation E2 and P concentrations, estimated by RIA, were significantly increased by stimulation of the medial basal prechiasmatic area (PVA), ventromedial hypothalamus, and areas in the mesencephalon and decreased by stimulation of the dorsal hippocampus, lateral amygdala, and mesencephalic areas. Ovarian blood flow was not affected by these stimulations. Ovarian nervotomy in the proestrous rats abolished E2 secretion induced by PVA stimulation. In intact proestrous rats, electrochemical stimulation of the PVA but not the preoptic suprachiasmatic area increased E2 and P concentrations, although stimulation of both areas commonly potentiated gonadotropin secretion. Present findings suggest that the efferent neural system from the brain to the ovaries is supplementary to the brain-pituitary-ovarian hormonal mechanisms in the regulation of ovarian steroid secretion, and the system may be required for the adjustment of ovarian responsiveness and sensitivity to gonadotropins. In addition, evidence for neural feedback on basal FSH secretion in the ovarian-denervated proestrous rats is presented in this study.

Animals↗
PubMed1980

Surgical significance of dilatation of the common bile duct--with special reference to choledocholithiasis.

Diameter of the common bile duct was measured in 3,119 patients who underwent primary operation for gallstones, during the period from 1975 to 1978. Although dilatation of the common bile duct was most marked in patients with bilirubin stones in the bile duct alone, dilatation was also observed in patients with cholesterol stones in the gallbladder alone. Drip infusion cholangiograms of 84 healthy patients showed that the common bile duct dilated in parallel with aging. A review of patients with congenital choledochal cysts reported in the literature in Japan revealed that few had gallstones. Thus, it was difficult to determine whether common bile duct dilatation was the cause or result of gallstones, and it was suggested that the so-called drainage operation such as choledochoenterostomy should be done only under strict indications.

Adult↗
PubMed1980

Primary carcinoma of the remnant stomach--report of three cases.

Among the 318 patients operated on for gastric carcinoma during the last six years in our department, three patients were operated on for carcinoma which developed in the remnant stomach 25, 22 and 12 years respectively after partial gastrectomy for peptic ulcers. Their surgical results were uniformly poor because of far advanced malignant lesions. Another patient who developed adenomatous polyps near the stoma 23 years after gastrectomy for duodenal ulcer was treated by polypectomy through gastrotomy. Both from our experiences and from review of literatures, it was concluded that patients gastrectomized for benign lesions should be followed up regularly ten or more years after the surgery, especially by gastroscopy, in order to detect remnant stomach carcinoma as early as possible. And any physicians should always be aware of this disease and should not attribute any late appearing abdominal complaints to gastrectomy itself.

Adenocarcinoma↗
PubMed1980

Mechanisms of altered renal perfusion in the early stage of obstructive jaundice.

Mechanisms responsible for renal hemodynamic alterations were studied in jaundiced (by bile-duct ligation) rabbits (BDL) 10 days after ligation of the biliary tract, in comparison with sham-operated rabbits (SO). Arterial hematocrit, plasma volume, blood pressure, abdominal inferior vena cava pressure, and heart rate were not significantly different between the BDL and SO groups. Cardiac output in BDL rabbits decreased to approximately 73% of the value for SO rabbits. Renal blood flow and GFR were reduced to 64 and 61%, respectively. Reductions in blood pressure and renal blood flow, caused by bleeding (8 ml/kg of body wt), were more marked in the BDL group than they were in the SO group. In the BDL group, the recovery of blood pressure following blood infusion was slower and the mortality was higher, There was no significant increase in the renovascular sensitivity to exogenous noradrenaline or angiotensin II in the BDL group. The findings indicate that the early stage of obstructive jaundice in rabbits was characterized by altered renal perfusion partly due to reduced cardiac output and by incrased liability to hemorrhagic hypotension.

Animals↗
PubMed1980

Protein permeability and immune complex deposition in glomerular capillary walls of rats.

The effect of reduced glomerular anionic charge on immune complex deposition in the glomerular basement membrane was studied in rats with Heymann nephritis. A reduction of the anionic charge was induced by lysozyme administration. The animals were divided into the following four groups: normal controls (group A), group B treated with lysozyme, group C treated with lysozyme and immunized with autologous tubular antigen, and group D immunized with the antigen. Proteinuria was marked in groups B, C and D as compared with group A, especially in group D. Development of Heymann nephritis by the tubular antigen was suppressed in group C. Stainings of anionic substances in the glomerular capillary walls by cationic probes were weakened in groups B, C and D. Immune complex deposited in the subepithelial area of the capillary wall was also stained by cationic probes. The findings suggest that reduced glomerular anionic charge by polycations results in suppressed immune complex deposition in the basement membrane, partially due to increased permeation of macromolecules across the glomerular capillary walls in rats.

Animals↗
PubMed1980

Renal hemodynamics in oliguric and nonoliguric acute renal failure of rabbits.

The role of renal hemodynamic alterations in the curtailment of renal functions was studied in uranyl acetate-induced oliguric (ORF) and nonoliguric (NORF) renal failures of rabbits. 5 days after drug injection, renal functional and morphological changes were most remarkable. A depression of Cin and elevation of serum creatinine concentration were more marked in ORF than in NORF. Renal blood flow was high as compared to controls. Cortical blood flow redistributed to the inner cortex. There was no significant difference in renal blood flow or cortical flow distribution between renal failure models. The findings suggest the minor roles of renal blood flow and cortical flow distribution in maintaining renal failure in these nephrotoxic models. Prominent tubular necrosis was found in ORF but not in NORF. Arterial inulin concentration during retrograde ureteral infusion of 14C-inulin solution was significantly high in ORF as compared to controls and NORF. However, this inulin leakage was too small to explain severely curtailed inulin clearance.

Acute Kidney Injury↗
PubMed1980

Pathologic fracture of the mandible resulting from osteomyelitis: report of cases.

Two cases of pathologic fracture of the mandible resulting from chronic osteomyelitis are described. The first case was treated successfully by antibiotic therapy followed by resection of the affected bone and iliac bone grafting after six months of follow-up care. In the second case, a patient with a history of diabetes mellitus, a fracture of the condyloid process occurred because of extension of the Actinomyces infection after extraction of the third molar. Because antibiotics failed to prevent exacerbation of the disease, the patient was given human gamma globulin. Then, all the signs of inflammation disappeared gradually with no evidence of recurrence for more than a year. There was no spontaneous bony healing of the fractured site.

Adult↗
PubMed1980

Gallstones in Western Japan. Factors affecting the prevalence of intrahepatic gallstones.

In a study from 40 hospitals in Western Japan between 1975 and 1978, intrahepatic gallstones were identified at the first biliary tract operation in 106 patients (a 3.03% prevalence). These were predominantly bilirubin stones. The occurrence rate for patients with intrahepatic stones was the same as for patients with bilirubin stones solely in the common bile duct suggesting the pathogenetic similarity of these two conditions. The prevalence of intrahepatic stones was 1.5% at urban and 4.97% at rural hospitals (P less than 0.005). Rural patients were significantly older than urban patients (P less than 0.005), but both groups showed an increasing prevalence with age. However, patients with intrahepatic stones were younger than those with bilirubin stones solely in the common bile duct, reflecting the increase likelihood that stones obstructing the biliary tree in this location would cause hepatic damage, pain, and, fever or the possibility that congenital anomalies of the bile ducts migt lead to stone formation at an earlier age. Among the 106 patients, only 12% had stones in the intrahepatic ducts alone. The majority of patients with both bilirubin and cholesterol intrahepatic stones had stones throughout the biliary tree simultaneously. The decreasing prevalence of bilirubin stones in Japan may be related to multiple factors including eradication of parasites and westernization of the diet.

Adult↗