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Biomedical subjects

M Fujishima

Publications and source records attributed to M Fujishima.

At least 487 records · Page 27Linked to original sources
PubMed1993

Altered cerebral hemodynamics and metabolism in Takayasu's arteritis with neurological deficits.

BACKGROUND AND PURPOSE: Takayasu's arteritis is a nonspecific arteritis involving major cerebral arteries. The aim of our study is to examine cerebral hemodynamics and metabolism in Takayasu's arteritis with neurologic symptoms. METHODS: We measured cerebral blood flow and metabolism using positron emission tomography in seven patients (14 to 59 years of age) with Takayasu's arteritis who developed transient ischemic attacks (2 patients), ischemic stroke (4) or putaminal hemorrhage with multiple brain infarction (1). RESULTS: All patients had severe stenosis or occlusion of one or more major cerebral arteries. There were no significant differences in the values of cerebral blood flow, oxygen extraction fraction, and cerebral blood volume in the infarcted and noninfarcted hemisphere. By contrast, the value of cerebral metabolic rate for oxygen in the infarcted hemisphere was markedly reduced (1.87 mL/100 mL per minute, P < .01) compared with controls. Mean transit time in the infarcted hemisphere was significantly greater than in the noninfarcted one, both in patients and controls (P < .01 and P < .05, respectively). CONCLUSIONS: Collateral blood flow to the hemisphere without brain damage may be relatively well developed in Takayasu's arteritis, although hemodynamic reserve as well as oxygen metabolism were impaired in the infarcted hemisphere with ischemic lesions.

Adolescent↗
PubMed1993

Angiotensin converting enzyme inhibitors attenuate ischemic brain metabolism in hypertensive rats.

BACKGROUND AND PURPOSE: Angiotensin converting enzyme (ACE) inhibitors are expected to modulate neuronal activities. The present study was designed to examine the beneficial effects of ACE inhibitors on microcirculation and metabolism in the ischemic brain. METHODS: Cerebral ischemia was developed for 60 minutes in spontaneously hypertensive rats (SHR, n = 35) by bilateral carotid artery occlusion. ACE inhibitor (0.1 or 10 mg/kg SQ 29,852 or captopril) were intravenously injected 15 minutes before cerebral ischemia. Cerebral blood flow to the parietal cortex was measured with the H2 clearance technique. Lactate, pyruvate, and ATP in the brain were estimated by the enzymatic method. RESULTS: Before cerebral ischemia, high doses of both SQ 29,852 and captopril significantly decreased mean arterial pressure by 15 to 25 mm Hg and reduced cerebral vascular resistance by 13% to 17% of the resting values. Cerebral blood flow and arterial pressure during ischemia were not altered by these ACE inhibitors. After 60 minutes of cerebral ischemia, tissue lactate in vehicle-treated SHR increased 6.6-fold and ATP decreased to 65% of the control values. Administration of SQ 29,852 or captopril significantly reduced the lactate levels to 1.6- to 3.1-fold and well preserved the ATP levels to 82% to 93% of the control. CONCLUSIONS: These results suggest that inhibition of ACE activities may be protective for cerebral metabolism against ischemic insult.

Adenosine Triphosphate↗
PubMed1993

Cerebral blood flow and ischemia-induced neurotransmitter release in the striatum of aged spontaneously hypertensive rats.

BACKGROUND AND PURPOSE: We found age-related vulnerability to cerebral ischemia in the hippocampus and striatum in spontaneously hypertensive rats. Further study revealed that ischemia-induced release of hippocampal taurine, an inhibitory amino acid, was reduced by 40% in aged rats compared with adult rats, which suggested an impaired inhibitory function against excitotoxicity in aged rats. The purpose of this study was to examine whether ischemia-induced neurotransmitter release is altered in the striatum of aged spontaneously hypertensive rats. METHODS: Five adult (5-6 months) and five aged (18-22 months) female spontaneously hypertensive rats were subjected to 20 minutes of cerebral ischemia induced by bilateral carotid artery occlusions and 120 minutes of recirculation under amobarbital anesthesia (100 mg/kg i.p.). Cerebral blood flow was determined using the hydrogen clearance method, and extracellular concentrations of neurotransmitters were determined with the brain dialysis technique in the striatum. RESULTS: During ischemia, cerebral blood flow in aged rats decreased to 8.7 +/- 1.2 (mean +/- SEM) mL/100 g per minute (11% of the resting), which was not different from 5.2 +/- 1.7 mL/100 g per minute (8% of the resting) in adult rats, and extracellular dopamine and amino acids (glutamate, aspartate, and taurine) increased by approximately 170- and 10-30-fold, respectively, and returned to baseline after 20-40 minutes of recirculation. These values of neurotransmitters, however, were not different between aged and adult rats during ischemia and reperfusion. CONCLUSIONS: It is unlikely that a presynaptic mechanism is involved in age-related vulnerability in the striatum of hypertensive rats.

Aging↗
PubMed1993

Decrease in cerebral blood flow with blood pressure reductions in patients with chronic stroke.

BACKGROUND AND PURPOSE: Possible effects of changes in blood pressure on the cerebral circulation were studied in patients with chronic stroke and age-matched nonstroke control subjects at 28 +/- 10 months (mean +/- SD) (range, 18 to 54 months) and 27 +/- 6 months (range, 19 to 44 months), respectively, after the first measurement. METHODS: Cerebral blood flow was measured by the 133Xe inhalation method in 55 patients (mean +/- SD age, 62 +/- 11 years; 39 with brain infarction and 16 with hemorrhage) and 10 control subjects (mean +/- SD age, 61 +/- 9 years). Correlations between changes in cerebral blood flow and blood pressure were evaluated. RESULTS: Among brain infarctions, average cerebral blood flow did not change from the first study; however, changes in cerebral blood flow in each individual were closely related to changes in systolic and mean arterial blood pressures (P < .01 and P < .05, respectively). Of these, in 10 patients with cerebral blood flow decreased more than 15% from the initial levels, systolic and mean arterial blood pressures decreased by 25 +/- 32 mm Hg and 16 +/- 14 mm Hg (P < .05 and P < .005, respectively). In contrast, in 29 patients with unchanged or increased cerebral blood flow, changes in systolic (0 +/- 19 or -2 +/- 12 mm Hg, respectively) and mean arterial blood pressures (3 +/- 22 or -1 +/- 11 mm Hg, respectively) were not significant, and their systolic blood pressure levels were maintained above 110 mm Hg. CONCLUSIONS: Blood pressure importantly correlates with cerebral circulatory changes among patients with chronic brain infarction. Early detection of cerebral hemodynamic changes should be useful for determining the most favorable levels of blood pressure and for selecting appropriate therapy.

Adult↗
PubMed1993

Massive spinal cord infarction with multiple paradoxical embolism: a case report.

A sixty-seven-year-old man suffered from acute anterior spinal artery syndrome at the level of T-10. Transverse myelopathy developed by the eighth day. Computed tomography of the brain on the thirteenth day demonstrated hemorrhagic infarction in the left occipital lobe and fresh ischemic infarction in the right cerebellar hemisphere. Respiratory distress was the cause of death on the fifteenth day. Autopsy study showed severe ischemic necrosis of the spinal cord below T-10, and multiple infarcted lesions in the brain, lung, kidney, and heart. Saddle thromboembolism of the bilateral trunk of the pulmonary artery was the major cause of his death. Deep venous thrombosis in the pelvis was disclosed to be the primary source of multiple paradoxical embolisms through the patent foramen ovale.

Acute Disease↗
PubMed1993

Renovascular hypertension caused by lymph node metastasis in a patient with uterine cervical cancer: case report.

Renovascular hypertension was found in a fifty-four-year-old woman who had been diagnosed as having uterine cervical cancer, stage Ib, six months before admission. Renal arteriography showed a stenosis of the right renal artery with a significant increase in renal vein renin level from the ipsilateral kidney. Abdominal computed tomographic scanning showed enlarged lymph nodes in the para-aortic region at the level of the right renal artery, which suggested metastasis of the carcinoma. Metastatic lymph node swellings probably caused compression of the right renal artery.

Female↗
PubMed1993

Idiopathic cerebral hemorrhage during delivery in normotensive women--case reports.

Two normotensive pregnant women who developed cerebral hemorrhage during delivery are reported. The hematoma was small and subcortical in one and large and putaminal in the other. They had no history of hypertension, cerebrovascular disorders, or eclampsia. Cerebral angiography studied in one case revealed no abnormalities. Idiopathic cerebral hemorrhage during delivery without any evidence of vascular risk factors is discussed.

Adult↗
PubMed1993

Invasive development of right atrial myxoma--a case report.

A thirty-nine-year-old man was admitted to the authors' department complaining of exertional dyspnea and high fever. An echocardiogram showed a mass in the right atrium, which was observed to move to the right atrium during the systolic phase and to the right ventricle during the diastolic phase. Magnetic resonance imaging showed that the mass developed from the right atrium to the superior vena cava. Intravenous digital subtraction angiography also showed a partial defect of the right atrium as well as obstructions of both the superior vena cava and the bilateral innominate veins. A pulmonary hemodynamic scintigram showed multiple defects at the mid and inferior areas of each lung, suggesting multiple pulmonary infarctions. The right atrial tumor was surgically removed. The superior vena cava and the innominate veins were found to be obstructed by organized thrombi, and the tumor had invasively grown into the right atrial wall. Histologic findings demonstrated that most of the tumor was composed of organized thrombi with scattered myxomatous tissue and was diagnosed as cardiac myxoma. These histologic findings suggest that the histogenesis of this right atrial myxoma might be thrombogenic.

Adult↗
PubMed1993

Multivariate analysis of magnetic resonance imaging of focal hepatic lesions.

A total of 124 lesions from 1 to 6cm in diameter, including 31 cavernous hemangiomas, 32 metastases and 61 hepatocellular carcinomas (HCC) were analyzed to study the usefulness of magnetic resonance imaging (MRI) at 0.5 Tesla to differentiate focal hepatic lesions on the basis of qualitative criteria. Each focal hepatic lesion was assessed for shape, internal architecture and signal intensity relative to normal liver parenchyma. While all cavernous hemangiomas and metastases except one lesion could be detected, detection rate of HCC was significantly inferior to that of the other two diseases. A tumor capsule and a hyperintense focus on T1-weighted images were demonstrated in only HCC lesions in strong contrast with the other two diseases; however, metastases with slow-growing characteristics or subacute hematoma may appear as similar images. Cavernous hemangiomas appeared markedly hyperintense on T2-weighted images in 23 of 31 lesions, but one metastasis and one HCC had similar images. A multivariate analysis of several MRI resulted in the following mean discriminant scores: cavernous hemangioma, -1.2652; metastasis, 0.1830; and HCC, 0.7138. It appeared to be possible to differentiate the three diseases with 84.4 percent accuracy.

Adult↗
PubMed1993

[Do blood glucose levels in the elderly have different metabolic significance than in non-elderly subjects?].

Diagnostic criteria of diabetes mellitus in elderly people are still controversial. The major questions are whether (1) effects of hyperglycemia in generating diabetic complications are the same as in younger diabetics, (2) too many diabetics might be diagnosed in the elderly by the criteria proposed by WHO and Japan Diabetes Society. To answer these questions, we carried out two studies. Blood glucose data were collected from population-based studies and from voluntary health check-up studies. Fasting blood glucose values were classified by sex and the age (-49, 50-64, 65-years old). Population-based studies showed no age-dependent change in blood glucose. However, data from health check-up studies showed an increase in median values from the group aged 50-64 and the 65 and older group. Two-hour values after glucose tolerance tests were classified by age and the fasting blood glucose (-99, 100-119, 120-139, and 140- mg/dl). The eldest and 140- mg/dl group showed the highest 2-hour values. Effects of hyperglycemia on the appearance of diabetic complications were studied in patients being follow-up in three diabetes clinics. Patients who has a history of one year or less and without any retinopathy on the first visit to the clinic were registered. Data were analyzed by the Kaplan-Meier method and the appearance of retinopathy was used as the end point. There were no difference in the rate of appearance of retinopathy between the age groups (-49, 50-64 and 65-years old). No age effect on the hyperglycemia-dependent appearance of retinopathy could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Hyperinsulinemia and hypertension in an elderly Japanese population--the Hisayama Study].

Hyperinsulinemia has been closely associated with hypertension in several epidemiological studies, but little is known about this condition in the elderly. The authors studied the relationship between serum insulin and blood pressure levels, and the prevalence of hypertension according to insulin levels in the elderly in a Japanese rural community, Hisayama. In 1988, 75 g oral glucose tolerance test was performed on 426 male and 567 female Hisayama residents aged 60 to 79 years. Fasting and 2 hr serum insulin values were measured by radioimmunoassay. In the subjects, excluding those receiving antihypertensive drugs, the sum of fasting and 2 hr postload insulin (sigma IRI) significantly correlated with systolic (r = 0.15 and 0.25 for males and females, respectively) and diastolic blood pressure (r = 0.20, 0.16). In multiple regression analyses, the correlation with systolic blood pressure remained significant in females after controlling for age, body mass index, alcohol intake, smoking habits, serum total cholesterol, HDL-cholesterol, triglycerides, and fasting plasma glucose. In contrast, sigma IRI did not remain as an independent variable relevant to blood pressure among males. The age-adjusted prevalence rates of hypertension (> or = 160/95 mmHg or receiving drug treatment) significantly increased with increasing quartiles of sigma IRI in females. The prevalence of hypertension which was not treated with drugs also increased significantly with increasing sigma IRI in females. However, no significant association was observed in males. In conclusion, the present study suggests that hyperinsulinemia can be related to hypertension in the female elderly in the general population of Japan.

Aged↗
PubMed1993

[Age-related changes in intracranial artery velocity measured by transcranial Doppler sonography in normotensive, hypertensive and diabetic patients].

We measured mean blood flow velocity (MFV) and Fourier pulsatility index (PI) of the M1 portion of the middle cerebral artery (MCA) by transcranial Doppler mapping technique (2 MHz, Trans-scan, EME Co., Ltd.). The correlations between these parameters and arteriosclerotic risk factors such as aging, hypertension and diabetes mellitus were examined. Healthy volunteers as well as patients suffering from hypertension and diabetes mellitus were studied. A total of 59 persons (85 MCAs) consisting of 30 males (mean age 54.4, 24-81 years) and 29 females (mean age 54.8, 20-75 years) were enrolled in this study. Some hypertensive or diabetic subjects had previous cerebrovascular disease, therefore cases who had only minor stroke or asymptomatic infarction without significant lesions in carotid artery system were included. After excluding brain embolism, these subjects were divided into three groups as normotensive/non diabetic group (NT/non DM), hypertensive group (HT) and diabetic group (DM). In each group, MFV decreased with aging, being more evident in the HT and DM groups than in the NT/non DM group. Fourier PI also showed a significant increase with aging, and the correlation was stronger than that between MFV and age. Moreover, these trends of age-Fourier PI relationship were more highly significant in HT and DM groups than NT/non DM group. In cases with HT or DM, age-related arterial changes appeared to be more severe than in those without. Fourier PI seemed valuable for detecting arterial lesions with aging, HT and DM.

Adult↗
PubMed1993

Acyclovir-resistant herpes zoster encephalitis successfully treated with vidarabine: a case report.

A 78-year-old man developed herpes zoster virus (HZV) encephalitis. Initially, treatment with aciclovir (750 mg per day) improved CSF cell count and protein level. During the treatment, however, encephalitis in the patient deteriorated in spite of the treatment with aciclovir, suggesting that HZV in the patient had become resistant to aciclovir. Subsequent treatment with vidarabine (600 mg per day, for 15 days) resulted in dramatic improvement in CSF pleocytosis. About two months after the discontinuation of vidarabine, the CSF cell count was normal. The patient became alert gradually, but his amnestic syndrome remained unchanged. Vidarabine may be recommended in the treatment of HZV encephalitis when aciclovir is not effective.

Acyclovir↗
PubMed1993

Effects of anti-hyperlipidaemic agent or dietary protein restriction on progressive renal deterioration in adriamycin-induced nephropathy in rats.

Hyperlipidaemia is strongly suggested to contribute to the pathogenesis of glomerular sclerosis. This study intends to clarify the effects of either a lipid lowering agent, lovastatin (LO) or protein restriction (PR) on adriamycin (ADR)-induced progressive glomerular sclerosis in rats. During the study period both serum cholesterol and triglyceride were significantly reduced in ADR-injected rats with either lovastatin administration (ADR-LO) or protein restriction (ADR-PR) compared to those without such treatment (ADR-NP). At week 22, urinary protein excretion, serum creatinine, blood urea nitrogen, glomerular sclerosis and tubulointestinal alterations, which were marked in ADR-NP, were ameliorated in both ADR-LO and ADR-PR rats. ADR-LO resulted in a body weight similar to that in ADR-NP while ADR-PR induced a marked weight loss. An antihyperlipidaemic agent, such as lovastatin, seems to be a useful tool for the prevention of renal deterioration.

Animals↗
PubMed1993

[Long-term efficacy of low residue diet for the maintenance of remission in patients with Crohn's disease].

The long term efficacy of low residue diet (LRD) for the maintenance of remission in patients with Crohn's disease was studied. The patients consisted of 60 with quiescent Crohn's disease who were given LRD (Clinimeal or Ensure Liquid) for maintenance therapy for more than one year (average 2.4 years) after discharge from our institute. On the basis of the quantity of LRD given per day, the patients were classified into three groups: A; O to 799 kcal a day, B; 800 to 1599 kcal a day and C; more than 1600 kcal a day. The remission rate and the avoidance rate of admission were calculated and compared among three groups. The remission rate in group C was significantly higher than those in groups A and B. The avoidance rates of admission in groups B and C were significantly higher than that in group A. These results suggest that drinking of LRD at home is useful for the maintenance of remission in patients with Crohn's disease and that the effect of LRD depends on the quantity of LRD given per day.

Adolescent↗