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Biomedical subjects

M Fujishima

Publications and source records attributed to M Fujishima.

At least 793 records · Page 44Linked to original sources

Pressor response to NaCl solution administered intracerebroventricularly or intracisternally to conscious normotensive and spontaneously hypertensive rats.

We examined the central action of NaCl on blood pressure using intracerebroventricular (i.c.v.) and intracisternal (i.c.) injections of hypertonic NaCl solution in conscious, unrestrained spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. The dose-dependent pressor response produced by i.c.v. hypertonic NaCl was greater in SHR than in WKY rats, while the dose-related pressor action produced by i.c. NaCl did not differ between the two strains. The hyperresponsiveness to i.c.v. NaCl in SHR was abolished by pretreatment with an i.c.v. injection of the angiotensin II (ANG II) analogue 1-Sar, 8-IIeu ANG II. Both ANG II and a combination of ANG II and NaCl given by i.c.v. injection had a greater pressor response in SHR than in WKY rats, although both ANG II and phenylephrine given intravenously elevated blood pressure to the same extent in both strains. Furthermore, i.c.v. ANG II both with and without hypertonic NaCl caused dipsogenic behaviour which lasted longer in SHR than in WKY rats. This response to i.c.v. hypertonic NaCl without ANG II was not substantially different between the two strains. Intracisternal hypertonic NaCl did not induce drinking behaviour. These observations suggest that in the SHR, the third ventricle rather than the brain stem is a more sensitive area to NaCl. The brain renin-angiotensin system in the SHR may play an important role in this accelerated pressor response and may be responsible, at least to some extent, for the enhanced reaction to chronic oral salt loading.

Angiotensin II↗

Ischemic colitis: serial changes in double-contrast barium enema examination.

Serial double-contrast barium enema examinations were performed in 40 patients with nongangrenous ischemic colitis, 15 with the stricturing form and 25 with the transient form. Thumb-printing was observed in 30 cases (75%); it appeared within 9 days after the onset of the disease in patients with the stricturing form and within 6 days in those with the transient form. Thumb-printing disappeared about 10 days after the onset, but it lasted considerably longer in two patients with the stricturing form (21 and 29 days, respectively). Longitudinal ulcers were observed in 24 patients (60%), and healing was confirmed on day 20 or later in patients with the stricturing form and on day 9 or later in those with the transient form. Eccentric deformity was found in 19 patients (48%), sacculation in 12 (30%), and transverse ridging in five (13%). These results indicate that longitudinal ulcers and thumb-printing are both characteristic findings of ischemic colitis. The double-contrast study is useful for visualization of the ulcer.

Adult↗

Glomerulocystic kidneys. Report of an adult case.

Glomerulocystic kidney characterized by dilatation of Bowman's space occurs primarily in infants and children. We treated a normally developed 29-year-old Japanese man for hypertension and renal failure, who had been well up to 6 months before admission. Extrarenal malformations were not determined. A biopsy of both kidneys was done at the time of interdialysis, and the histology revealed diffuse glomerular cystic lesions. Electron-dense deposits were also observed in the mesangial area. Radiological studies of the kidneys showed numerous minute cysts in the cortical area, a normal architecture of the arterial trees, and negative evidence of urinary tract obstruction. This may be the first documentation of glomerulocystic kidney in an adult, without extrarenal anomalies.

Adult↗

Effects of intravenous glycerol on cerebral blood flow and tissue metabolism in acute cerebral ischemia in spontaneously hypertensive rats.

The effects of antiedematous agent with intravenous 10% glycerol on cerebral blood flow (CBF) and metabolism were studied in acute cerebral ischemia experimentally induced by bilateral carotid artery occlusion in spontaneously hypertensive rats (SHR). CBF was measured by the hydrogen clearance technique and brain tissue metabolites such as lactate, pyruvate and ATP in the ischemic brain frozen in situ were determined by the enzymatic method. In comparison with saline-infused SHR, the reduction of CBF in the thalamus following carotid occlusion was significantly small in the glycerol treated SHR. Supratentorial ATP concentration in the 3 hr-ischemic brain was reduced in both groups of rats, but its reduction was significantly smaller in the glycerol-infused group than the other. Lactate and lactate/pyruvate ratio tended to be less increased in the glycerol rats, indicating that ischemic metabolism was restrained by the treatment. The present results strongly suggest that intravenous glycerol is effective against acute cerebral ischemia from the view point of cerebral hemodynamic and metabolism.

Acute Disease↗

Controlled trial of combined urokinase and dextran sulfate therapy in patients with acute cerebral infarction.

In this multiinstitute cooperative study, 143 patients were treated with either urokinase (UK) or combination of urokinase and dextran sulfate (UK-DS) within one to seven days following acute onset of cerebral thrombotic infarction. Of these, 81 randomized cases received a single dose of UK (2.83 X 10(5) units) by six-hour intravenous drip infusion and the remaining 62 received a combined dose of UK (2.84 X 10(5) units) and DS (3000 mg) for only one day. Moderate to marked clinical improvements assessed during the seven-day study period were observed in 30.9% of the patients treated with UK and in 61.3% of those with UK-DS, the latter being significantly higher. Hemorrhagic phenomena appeared in 3.2% of the cases treated with UK-DS and in none of those with UK alone, but mortality was 1.6% in the former and 2.5% in the latter. UK-DS produced a prompt and sustained increase in plasma fibrinolytic activity with transient and relatively minor disturbance of the blood coagulation system. The results indicate that combined therapy with UK and DS is more effective than UK alone for acute cerebral thrombotic infarction.

Acute Disease↗

Treatment of hyperthyroidism with a small single daily dose of methimazole.

The duration of action of methimazole (MMI) was studied in patients with hyperthyroidism due to Graves' disease. Perchlorate discharge tests performed 24 h after MMI administration revealed greater than 10% discharge in 77% of 53 patients who received a single dose of 15 mg MMI and in 74% of 23 patients who received 30 mg. The mean percent discharges were 41.5 +/- 26.4% (+/- SD) and 35.4 +/- 28.0, respectively. Based on these results, hyperthyroidism was treated with a single daily dose (SDD) of 15 mg in 43 patients and with 30 mg in 32 patients, and the results were compared with retrospective analysis of 50 patients who were treated with divided doses of MMI (10 mg, 3 times daily). Within 12 weeks, 93% of the patients treated with 15 mg SDD, 91% treated with 30 mg SDD, and 86% treated with divided doses were euthyroid. The mean times to achieve euthyroidism in these patients were 5.3 +/- 3.6 (+/- SD), 5.3 +/- 3.1, and 5.6 +/- 3.0 weeks, respectively. Side-effects occurred in 2 patients treated with 15 mg SDD and in 6 treated with 30 mg SDD. We conclude that a single daily dose of 15 mg MMI is not only effective in most patients with Graves' hyperthyroidism, but also less frequently causes adverse effects.

Adolescent↗

Long-term bromocriptine therapy and predictive tests in acromegaly.

The value of predictive tests in bromocriptine therapy and the effects of long-term bromocriptine therapy were investigated in acromegalic patients. In 72 acromegalic patients, there was a tendency for patients with a plasma GH response to TRH or with an elevated basal plasma PRL level, but without a plasma GH response to LHRH, to have a plasma GH response to bromocriptine, though statistical analysis did not reveal a significant difference. Acute and chronic effects of bromocriptine were significantly interrelated, while the chronic effect of bromocriptine and abnormal plasma GH response to TRH or elevated plasma PRL levels were not, in 18 acromegalic patients. These results suggest that the acute bromocriptine test is a better predictor than the TRH test and plasma PRL levels for evaluating the effects of chronic bromocriptine therapy. To maintain the low plasma GH levels, increasing doses of bromocriptine were needed in most patients, and failure to control the elevated GH level despite increasing doses was observed in 2 of 18 patients.

Acromegaly↗

Incidence of strokes and its prognosis in patients on maintenance hemodialysis.

The incidences of cerebral hemorrhage (CH), cerebral infarction (CI) and subarachnoid hemorrhage (SAH) were examined retrospectively in patients with chronic renal failure on maintenance hemodialysis, followed for 13 years in our 26 satellite dialysis centers. During 10,364 patient-years of experience (PYE), CH developed in 66, CI in 16, SAH in 3 and unclassified stroke in 5 cases. The incidence was 637 per 10(5) PYE for CH and 154 for CI, the former being approximately 5 times and the latter one third of the incidence of CH or CI in the general population in Japan. Forty-six percent of fatal CH cases died within 24 hours and 73% within 3 days after the onset, while 13% of CI deaths died within 24 hours and 26% within 3 days. These data suggest that factors such as the regular use of heparin as an anticoagulant in hemodialysis patients or other inherent factors in these patients may increase vulnerability to CH and decrease the probability of CI.

Adult↗

Brain renin angiotensin system contributes to the salt-induced enhancement of hypertension in SHR.

The study was performed to determine whether the brain renin angiotensin system may contribute to the acceleration in hypertension following long-term salt loading in spontaneously hypertensive rats (SHR). Five weeks old SHR and normotensive Wistar-Kyoto (WKY) were given 1% NaCl solution or plain tap water as drinking for 7 weeks. The salt treatment exaggerated the development of hypertension in SHR, but did not change the blood pressure (BP) in WKY. The hypotensive actions of intracerebroventricular (ICV) captopril was greater in SHR treated with salt than in those without treatment, whereas ICV AII increased BP to a similar degree between salt and control SHR. In WKY, the effects of ICV captopril and AII were not altered by the salt loading. The increases in BP induced by ICV hypertonic saline were not different between the rats with and without saline drinking in either SHR or WKY. The intravenous (IV) hexamethonium led to a greater fall in BP in SHR treated with saline than in those without salt, while it tended to produce a smaller decrease in BP in WKY with salt overload than in those without loading. Both duration and magnitude of the depressor effects of IV captopril were reduced by the chronic saline treatment in SHR. The plasma renin concentration (PRC) in both SHR and WKY was significantly suppressed by the salt load. The present results suggest that long-term salt overload may result in the enhanced activity of brain renin angiotensin system, which could be responsible for the exaggerated development of hypertension in SHR. Our observations also provide further evidence that the central renin angiotensin system is independent of the peripheral system.

Angiotensin II↗

Immune alterations in hemodialyzed patients. I. Effect of blood transfusion on T-lymphocyte subpopulations in hemodialyzed patients.

The immune status in 42 patients with end-stage renal failure on maintenance hemodialysis was studied by using monoclonal antibodies to lymphocyte subpopulations. Lymphopenia, reductions in the proportion of OKT4+ cells and OKT4+/OKT8+ cell ratio were observed in hemodialyzed patients. These alterations in immune status were observed in 34 transfused patients, but not in 8 patients without history of blood transfusion. The proportion of OKT8+ cells was increased in patients with history of blood transfusion. When transfused patients were divided according to the dose of blood transfused in the last 2 yr, the most serious change was observed in those who received greater than 10 u of transfusion. The dose of blood transfused in the last 2 yr correlated positively with the proportion of OKT8+ cells (p less than 0.01) and inversely with OKT4+/OKT8+ cell ratio (p less than 0.05). The duration of hemodialysis did not affect the alterations in immunoregulatory cells. These results indicate that alterations in immune features in hemodialyzed patients may be linked to the history of blood transfusion rather than that of uremia and/or hemodialysis.

Adolescent↗

Participation of the renin-angiotensin system in the captopril-induced worsening of anemia in chronic hemodialysis patients.

The study was aimed to show whether the renin-angiotensin system acts on erythropoiesis in chronic renal failure patients with hemodialysis, since captopril leads to the worsening of anemia in such patients. The average dose of captopril in 13 cases studied was 19.3 mg per day and duration of the administration was 48 days. Blood-pressure fall by captopril was accompanied with the worsening of anemia. There were significant decreases in hemoglobin (8.3%), hematocrit (7.3%), red blood cell count (7.6%) and reticulocyte count (43.7%). Angiotensin II was significantly decreased (15.7%) with significant reductions of plasma aldosterone concentration (15.2%) and angiotensin-I converting enzyme (45.7%), and with significant increases in plasma renin activity (158.6%) and in angiotensin I (238.3%). However, plasma erythropoietin concentration remained unchanged. Serum iron concentration was slightly but significantly increased after captopril. Reticulocyte count was significantly correlated with AII either before (r = 0.716, p less than 0.01) or after captopril (r = 0.658, p less than 0.05). There was significant correlation between angiotensin II and red blood cell count before captopril (r = 0.710, p less than 0.01). It is concluded from the present study that the reduction of angiotensin II by captopril might contribute to the worsening of anemia seen in chronic hemodialysis patients.

Acute Disease↗

Effect of blood pressure on the progress of renal deterioration in rats with renal mass reduction.

The effect of hypertension on the progress of renal deterioration with renal mass reduction was investigated in spontaneously hypertensive rats. Nephrectomies of five sixths, two thirds, and one third were performed. The antihypertensives guanethidine and hydralazine were given to half of the rats. Increase in urinary protein excretion and decreases in serum total protein and albumin were greater in rats with a larger nephrectomy. With the same extent of nephrectomy, these changes were severe in the group of rats with untreated hypertension, as compared with findings in rats given the antihypertensive drugs (AHD). Similar changes were obtained in BUN and creatinine levels. Only the animals with a five-sixths nephrectomy and hypertension became uremic. Glomerulosclerosis in five-sixths nephrectomized rats with hypertension was present in 71% of the glomeruli, whereas it was reduced to 34% in rats treated with AHD. The diameter of normal-appearing glomeruli increased significantly in rats with a large nephrectomy, but did not differ between the groups given or not given AHD. Medical thickening of the arterial walls, which increased with the reduction of renal mass, was significantly greater in five-sixths nephrectomized rats with hypertension than in those treated with AHD. These results indicate that a hyperdynamic state of the glomeruli, that is, a prominent urinary protein excretion and compensatory glomerular hypertrophy, may play a causative role in the progress of glomerulosclerosis in rats with extreme renal mass reduction. The hypertensive state may aggravate these renal dysfunctions.

Animals↗

Hyperbaric oxygen therapy in experimentally induced acute cerebral ischemia.

Effects of hyperbaric oxygen (HBO) on acute cerebral ischemia were studied in spontaneously hypertensive rats, which had the carotid artery bilaterally ligated. The animals were exposed to HBO (100% 02 at 2 ATA) for 30 min at 1 or 3 h after carotid ligation (treated group). Survival time and brain tissue metabolites were measured after HBO in these animals and compared with ischemic animals without HBO exposure (nontreated group). The animals treated at 3 h after ligation survived longer (6.5 +/- 0.7 h) than did nontreated ones (4.3 +/- 0.2 h) (P less than 0.05). The cerebral lactate increased much less in these treated animals (24.60 +/- 1.67 mM/kg) than in nontreated ones (31.78 +/- 1.68 mM/kg) (P less than 0.05). Cerebral ATP levels tended to decrease less in the former (0.66 +/- 0.17 mM/kg) than in the latter (0.59 +/- 0.07 mM/kg). When HBO started at 1 h after carotid ligation, however, there were no significant differences of survival time or brain metabolites between treated and nontreated groups of animals. The present results indicate that HBO administered at 3 h after brain ischemia prevents further increase in cerebral lactate and produces a slight but significant increase in survival time.

Adenosine Triphosphate↗