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Biomedical subjects

K Fukiyama

Publications and source records attributed to K Fukiyama.

At least 91 records · Page 5Linked to original sources

Infected right atrial thrombus and pulmonary emboli associated with a perforated jejunal diverticulitis.

We describe a patient with an infected right atrial thrombus and pulmonary embolism who died suddenly. Jejunal diverticulitis, which was found at autopsy, was suspected to be the source of the bacterial thrombus. The 41-year-old female patient was admitted because of dyspnea and syncopal attacks. Physical examination on admission revealed an obese woman with a body temperature of 36.5 degrees C, systolic heart murmur and abnormal diastolic heart sound. Two-dimensional echocardiography revealed a strand-shaped mass in the right atrium. Lung blood perfusion scintigraphy revealed multiple perfusion defects in both lung fields. She suddenly developed severe dyspnea leading to death on the 6th hospital day. At autopsy, a strand-shaped organized thrombus was found in the right cardiac chambers. Microscopically, the thrombus was found to be infiltrated with numerous gram-positive cocci, leukocytes and a small number of gram-negative cocci. Most of the major pulmonary arterial branches were occluded by bacterial thromboemboli, and multiple pulmonary infarctions were found in both lungs. A perforating diverticulum with microabscess was found in the jejunal mucosa which was assumed to be the source of the bacterial thromboembolism.

Adult↗

Open clinical studies on a new angiotensin II receptor antagonist, TCV 116.

OBJECTIVES: The goals of these preliminary studies were to evaluate the effects of a new angiotensin II receptor antagonist, TCV 116, on the daytime blood pressure profile in hospital inpatients with essential hypertension, and to evaluate the clinical efficacy and safety of this agent in outpatients with essential hypertension. SUBJECTS: In study 1, daytime blood pressure changes were studied in 28 inpatients with mild to moderate essential hypertension (systolic blood pressure > or = 150 mmHg, diastolic blood pressure > or = 90 mmHg). In study 2, 55 outpatients with essential hypertension (systolic blood pressure > or = 160 mmHg, diastolic blood pressure > or = 95 mmHg) were enrolled in a dose-finding study. METHODS: In study 1, after a 1-week placebo run-in period, blood pressure and the pulse rate were measured every 2 h except at night. TCV 116 monotherapy was started at 1 mg/day and increased stepwise at 3- to 5-day intervals to 2, 4 and 8 mg/day until a predetermined reduction in blood pressure was achieved. The daytime profiles of blood pressure and the pulse rate were again monitored at the end of the treatment period. In study 2, after a 4-week placebo run-in period, TCV 116 alone was administered for 2 weeks at 1 mg/day. The dose was then increased to 2 mg/day and stepwise at 2-week intervals to 4 and 8 mg/day until a predetermined reduction in blood pressure was achieved. The total treatment period was 8-12 weeks. RESULTS: In study 1, a sufficient reduction in blood pressure was achieved in 19 of 28 patients (68%), with blood pressure significantly reduced at all measurement points, compared with the placebo run-in period. No differences were seen in the pulse rate. The only adverse reaction reported was a rash in one patient. In study 2, a sufficient reduction in blood pressure was achieved in 42 out of 55 patients (76%). The cumulative efficacy rate increased dose-dependently (15% at 1 mg/day, 38% at 2 mg/day, 60% at 4 mg/day and 76% at 8 mg/day). No differences were seen in the pulse rate. Adverse reactions were reported in three out of 55 patients (5.5%). No dry cough was reported by any of the patients. CONCLUSIONS: TCV 116, an angiotensin II receptor antagonist, has potential as an antihypertensive agent. A dose of 4-8 mg once per day appears to be appropriate for the treatment of patients with mild to moderate essential hypertension.

Benzimidazoles↗

Evidence for increased cancer deaths in chronic dialysis patients.

We analyzed longitudinal data on the cancer mortality rate in chronic dialysis patients and in the general population in Okinawa, Japan. In the general population from 1980 to 1990, the mortality rate has been stable at approximately 1.300 males and 0.897 females per thousand persons year, the male to female ratio being 1.45. In the period from 1971 to 1990, we found 91 (4.6%) patients with cancer in a group of 1,982 (824 females and 1,158 males) chronic dialysis patients; forty-nine of the 91 patient (53.8%) died by April 1, 1991. Using the standard mortality rate in the general population, which was obtained for each sex and age class (0 to 34 years, 35 to 44 years, 45 to 54 years, 55 to 64 years, and > or = 65 years), we calculated the relative risk of death from cancer in dialysis patients. The risk ratio in dialysis patients was significantly increased, being 2.48 (P < 0.05) for males and 3.99 (P < 0.05) for females. The mean (+/- SEM) age at the time of death from cancer in the dialysis group was 60.1 +/- 2.0 years in the males and 60.1 +/- 2.1 years in the females; the males were 6.3 years younger than the general population and the females were 9.3 years younger. The proportion of patients with colon cancer (both sexes) and cancer of the uterus and breast (females) was higher in the dialysis patients than in the general population.

Adolescent↗

Serum albumin is a strong predictor of death in chronic dialysis patients.

We examined the predictive value of various clinical variables in assessing survival in chronic hemodialysis patients (N = 1,243, 524 females, 719 males) who were under treatment with hemodialysis as of January 1991 in Okinawa, Japan and who were followed up until April 1992. Basal clinical data such as sex, starting date of dialysis, primary renal disease, blood pressure, blood chemistry values, and dialysis prescription data obtained just prior to dialysis were registered at the start of the study. As of the end of April 1992, 104 had died, 16 were transplant recipients, and five had been transferred. Those who died had significantly lower levels of total protein, serum albumin, total cholesterol, triglyceride, BUN, serum creatinine, body weight, body height, diastolic blood pressure, and duration of hemodialysis than those who survived. Older patients and those with diabetes mellitus had a poorer prognosis. A forward stepwise logistic procedure by SAS was used to determine the predictive value of the above clinical variables. With the addition of laboratory variables, the predictive value of diabetes was lost, as the diabetic patients had low serum levels of albumin and creatinine. The standardized coefficient was -0.380 (P = 0.0001) at age of entry, 0.316 (P = 0.0001) for serum albumin, 0.280 (P = 0.0001) for serum creatinine, 0.138 (P = 0.043) for body mass index (BMI), and -0.139 (P = 0.016) for male sex. The prescribed dialysis dose (M2 hr per week) was significantly correlated with serum creatinine (r = 0.48, P = 0.0001), serum albumin (r = 0.135, P = 0.0001) and BMI (r = 0.275, P = 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Evidence for high risk of cerebral hemorrhage in chronic dialysis patients.

One-half of the total deaths in chronic dialysis patients are due to cardiovascular disease; however, the precise incidence and relative risk of those compared to normals are not known. Therefore, we sought to determine the annual incidence of cardiovascular disease and relative risk of those on chronic dialysis to the general population. Both the general population (1.2 million, Census 1990) and chronic dialysis patients (N = 1,609) in Okinawa, Japan were studied prospectively from April, 1988, to March, 1991. Diagnosis of stroke was made by symptoms and brain CT scan, and acute myocardial infarction was done by changes in electrocardiogram and serum enzymes. The relative risk (observed/expected ratio) was calculated by using the standardized morbidity rate obtained in both sexes and age-class every 10 years in the general population. Forty-one stroke (8 cerebral infarction, 31 cerebral hemorrhage, and 2 subarachnoid hemorrhage) and four acute myocardial infarction cases were registered during the study period in chronic dialysis patients. The incidence per 1,000 person-year was 11.5 in stroke, 2.2 in cerebral infarction, 8.7 in cerebral hemorrhage, 0.6 in subarachnoid hemorrhage, and 1.1 in acute myocardial infarction. The relative risk compared to normals was 5.2 in stroke, 2.0 in cerebral infarction, 10.7 in cerebral hemorrhage, 4.0 in subarachnoid hemorrhage, and 2.1 in acute myocardial infarction. Cerebral hemorrhage occurred at 10 years younger than that of the general population (P < 0.001) and was associated with high prevalence of hypertension and low levels of serum albumin and cholesterol. Our results confirm the importance of blood pressure control and nutritional status in chronic dialysis patients.

Adolescent↗

Survival analysis of dialysis patients in Okinawa, Japan (1971-1990).

We analyzed longitudinal data obtained from the initiation of chronic dialysis in Okinawa, Japan. A total of 1,982 patients (824 females and 1,158 males) were registered in the Okinawa Dialysis Study (OKIDS) up to the end of 1990. The number of patients dying, undergoing renal transplantation, or being transferred was 605 (30.5%), 75 (3.8%), and 23 (1.2%), respectively. The mean acceptance rate per million population increased from 19.7 in 1971 to 1975 to 157.4 in 1986 to 1990. The percentage of diabetic patients and the annual gross mortality rate were, respectively 0% and 0.52 (1971 to 1975), 7.3% and 0.12 (1976 to 1980), 14.4% and 0.06 (1981 to 1985), and 24.6% and 0.07 (1986 to 1990). Cox proportional hazard analysis was used to determine the relative risk (RR) for sex, primary renal disease, age at entry, and the year of starting dialysis. The RR for males was 1.09 (1.00 for females) and the 95% confidence interval (CI) was 0.93 to 1.28. The RR for diabetics was 1.88 (95% CI; 1.55 to 2.28) when that for nondiabetics was set at 1.00. The RR (95% CI) for starting dialysis in 1976 to 1980, 1981 to 1985, and 1986 to 1990 was 0.65 (0.59 to 0.72), 0.43 (0.35 to 0.52), and 0.28 (0.20 to 0.38), respectively, when the RR in 1971 to 1975 was taken as 1.00. During the last two decades, the survival of chronic dialysis patients in Okinawa has continued to improve despite the large increase in acceptance rate, the older age of the new patients, and the increase in diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Carbamazepine-induced hyponatremia in a patient with partial central diabetes insipidus.

A 51-year-old Japanese man was referred for the evaluation of persistent hyponatremia. The serum sodium level remained around 120 mmol/l despite mild water restriction. His past history included chronic alcoholism, myocardial infarction and lumbar disc herniation. Carbamazepine (200 mg, b.i.d.) has been used for more than 8 years for low back pain. Serum sodium returned to normal after carbamazepine was stopped, and rechallenge produced acute symptomatic hyponatremia (117 mmol/l) on day 2 after a total dose of 600 mg. Hepatic, renal and endocrine function were within normal limits, and the response to a water load (20 ml/kg) was also normal. Partial central diabetes insipidus was diagnosed by his response to water restriction and nasal desmopressin administration. Polyuria and hypernatremia were not evident in this case, probably due to a combination of low solute intake and low, but not deficient, levels of plasma ADH. This case demonstrates that carbamazepine may cause acute hyponatremia even in central diabetes insipidus, probably by sensitizing the distal renal tubules.

Carbamazepine↗

Arterial pressure and its regulation in rats bred successively on low sodium diet.

To investigate the effects of long-term sodium restriction on mechanisms regulating cardiovascular function, Wistar rats at weaning (F0) were placed on a normal (0.4%) or low (0.05%) sodium diet. The first (F1) and second (F2) generations were derived from inbreeding within each group. The resting mean arterial pressure did not differ between the diet groups of F0 or F1 rats, but it was significantly lower in F2 rats on the low sodium diet. Plasma renin concentration was similar in the two groups in each generation, and the F2 rats on both diets responded to [Sar1, Ala8] angiotensin II with the same degree of decrease in arterial pressure. Plasma norepinephrine was not influenced by sodium intake in the F0 or F1 rats, but was significantly lower in F2 rats on the low sodium diet. The depressor response to hexamethonium was similar in the two F1 groups, while low sodium F2 rats exhibited a lesser response. These results suggest that rats bred successively on a low sodium diet have a suppressed sympathetic nerve function with no enhancement of the renin-angiotensin system, which in turn results in a lower arterial pressure.

Animals↗

Renin responses in patients with orthostatic hypotension: case reports.

In orthostatic hypotensive patients renin is reported to increase in response to head-up tilt unless the lesion involves postganglionic sympathetic efferent nerves. The authors examined responses of plasma renin activity (PRA) to acute blood pressure reduction in 4 patients with orthostatic hypotension. When the coexistence of normal plasma norepinephrine (PNE) and normal or high-normal pressor response to alpha stimulant is considered to be a sign of preserved function of postganglionic fibers, 2 of the patients had sympathetic lesions mainly confined to central and/or preganglionic fibers. They were diagnosed as having multiple system atrophy (MSA). The other 2 were diagnosed as having idiopathic orthostatic hypotension with possible postganglionic lesions. Although 1 MSA patient showed an increase in PRA from 2.0 to 4.7 ng/mL/hr in response to the tilt, the other MSA patient showed no PRA response to the tilt. The head-up tilt did not provoke an apparent PRA response in patients with idiopathic orthostatic hypotension. The authors infused sodium nitroprusside (SNP) in the 3 patients whose PRA did not respond to the head-up tilt. The infusion decreased blood pressure by 40 mmHg or more, but PRA responses were inappropriately small or suppressed. In all cases, PNE did not respond at all to the head-up tilt and to the infusion of SNP. These findings suggest that possible preservation of postganglionic fibers does not necessarily indicate an intact responsiveness of PRA. The PRA profiling may not be an accurate predictor for the site of the fiber degeneration in orthostatic hypotension.

Aged↗

Chronic hypovolemia associated with accelerated hypertension and orthostatic hypotension in a patient on continuous ambulatory peritoneal dialysis.

We report a patient with nondiabetic end-stage renal disease on continuous ambulatory peritoneal dialysis (CAPD) associated with chronic hypovolemia. Despite the administration of nilvadipine, the patient showed accelerated hypertension and concomitantly orthostatic hypotension. Plasma renin activity was markedly high, and blockade of angiotensin II action by captopril or an angiotension II antagonist decreased the supine blood pressure. This indicated that the enhanced activity of the renin-angiotensin system was the principal cause of the supine hypertension. The plasma concentration of norepinephrine was also very high. After correction of hypovolemia by blood transfusion, the enhancement of the renin-angiotensin system and high plasma norepinephrine level were reduced, and symptomatic orthostatic hypotension disappeared. The accelerated hypertension was easily controlled by the administration of low-dose captopril and nilvadipine. These findings suggest that chronic hypovolemia related to the intractable supine hypertension as well as orthostatic hypotension. Hypovolemia-induced enhancement of the renin-angiotensin system and sympathetic nerve activity may cause vasoconstrictive hypertension in patients on CAPD.

Blood Volume↗

A case of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) with low plasma concentrations of antidiuretic hormone.

A 66-year-old Japanese man presented with persistent hyponatremia without polydipsia and polyuria. Laboratory examination showed serum sodium of 117 mEq/l, plasma osmolality 239 mosm/kg, urine sodium 108 mEq/l, urine osmolality 577 mosm/kg, and normal levels (less than 2.0 pg/ml) of serum antidiuretic hormone (ADH). ADH release was regulated normally with changes in plasma osmolality. No obvious cause for the syndrome of inappropriate secretion of ADH (SIADH) could be detected. However, 20 months later, the patient had bouts of hematuria and was found to have cancer of the urinary bladder. Increased renal sensitivity to ADH was suspected as the underlying mechanism of SIADH.

Aged↗

Hypertension in an adult with unilateral renal dysplasia.

We report a 29-year-old Japanese female with severe hypertension and unilateral renal dysplasia, which is rarely found in adults. The involved kidney was surgically removed and then the blood pressure fell to borderline levels without any changes in plasma renin activity or plasma aldosterone concentration. Histological examinations revealed typical renal dysplasia without hyperplasia of the juxtaglomerular apparatus. Unilateral renal dysplasia may be a cause of secondary hypertension in adults, though the mechanisms are still unknown.

Adult↗

Acute effects of manidipine on renal blood flow and sympathetic nerve activity in conscious, spontaneously hypertensive rats.

To examine acute effects of manidipine hydrochloride, a new calcium antagonist, on renal blood flow (RBF) in spontaneously hypertensive rats, we recorded changes in RBF as the Doppler shift and a neurogram of renal sympathetic nerve activity (RSNA) simultaneously in a conscious and unrestrained state. An intravenous infusion of manidipine did not decrease RBF until mean arterial pressure (MAP) fell by 20 +/- 1 mmHg and RSNA increased by 98 +/- 18%. At the nadir of RBF (-25 +/- 2%, MAP: -31 +/- 2 mmHg, RSNA: +154 +/- 25%), percent increase in RSNA significantly correlated with percent decrease in RBF (r = -0.802, p < 0.02). On the other hand, the infusion of sodium nitroprusside did not decrease RBF significantly even at a nadir of MAP (-35 +/- 2 mmHg). Air jet stress increased both MAP and RSNA associated with a decrease in RBF. Responses of MAP and RBF were blunted after manidipine infusion while the stress evoked a similar degree of enhancement of RSNA to that of the control trial. Although manidipine may be less effective than nitroprusside in maintaining RBF during abrupt reductions of MAP, the results of this study suggest that antihypertensive treatment with manidipine may be clinically beneficial in maintaining RBF both at rest and during psychologically stressful conditions.

Air Pressure↗

Renal vascular responses in spontaneously hypertensive rats chronically treated with manidipine.

An enhanced renal vasoconstrictive response to emotional stress may be related to the pathogenesis of essential hypertension. We examined the effects of chronic manidipine treatment on renal blood flow (RBF) responses to air jet stress, angiotensin II (ANG II), and endothelin-3 (ET-3) in the conscious unrestrained spontaneously hypertensive rat (SHR). Male SHRs were placed on a control diet or one containing 0.05% of manidipine for 4 weeks. Age-matched Wistar-Kyoto (WKY) rats placed on a control diet served as normotensive controls. In comparison with control SHRs, manidipine reduced blood pressure (p < 0.01), increased urinary sodium excretion (p < 0.01), and reduced body weight (p < 0.01). Air jet stress elevated arterial pressure and increased RBF. The pressor response was enhanced more in the control SHRs than in the WKY rats (p < 0.01) and was not altered by manidipine. The percent fall in RBF in the manidipine-treated SHRs (-16%) was less than that in the control SHRs (-30%, p < 0.05) and similar to that in the WKY rats (-18%). In contrast, the pressor effect and the percent fall in RBF caused by ANG II (0.1 nmol/kg/min) were similar in the three groups. Intravenous ET-3 (1 nmol/kg) caused a transient fall, followed by a sustained increase in systemic blood pressure, both of which were associated with a decrease in RBF. The RBF response to ET-3 was blunted in SHRs compared to WKYs and was not altered by manidipine treatment. These results suggest that antihypertensive therapy with manidipine may be beneficial in maintaining RBF during emotional stress.

Air Pressure↗

A double-blind comparative study of doxazosin and prazosin in the treatment of essential hypertension.

Two hundred sixty-six patients took part in a multicenter comparative study of doxazosin and prazosin. Both drugs produced a significant reduction (p less than 0.001) in blood pressure and no increase in heart rate. Blood pressure was considered "markedly decreased" or "decreased" in 70.8% of patients treated with doxazosin and 70.0% of patients treated with prazosin. No statistically significant between-group differences in antihypertensive efficacy were observed. Both doxazosin and prazosin were well tolerated; seven patients (5.6%) in each group had the therapy withdrawn.

Antihypertensive Agents↗