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Biomedical subjects

M Fujishima

Publications and source records attributed to M Fujishima.

At least 271 records · Page 15Linked to original sources

Age-related changes in response of brain stem vessels to opening of ATP-sensitive potassium channels.

BACKGROUND AND PURPOSE: This study was designed to determine regional differences and age-related changes in the contribution of ATP-sensitive potassium (KATP) channels to vasodilator responses in the brain stem circulation in vivo. METHODS: Changes in diameter of the basilar artery (baseline diameter, 270 +/- 5 microns [mean +/- SEM]), its large branch (112 +/- 5 microns), and its small branch (49 +/- 2 microns) in response to KATP channel openers levcromakalim and Y-26763 were measured through a cranial window in anesthetized adult (4 to 6 months) and aged (24 to 26 months) Sprague-Dawley rats. RESULTS: Topical application of levcromakalim and Y-26763 produced concentration-dependent vasodilation that was similar among the three vessel groups in adult rats. In aged rats, dilator responses of the branches, but not of the basilar artery, to the KATP channel openers were smaller than those in adult rats (P < .05). Glibenclamide, a selective KATP channel blocker, almost abolished this vasodilation in both groups of rats. Vasodilator responses to sodium nitroprusside were preserved in aged rats. CONCLUSIONS: In adult rats, there is no regional heterogeneity in vasodilator response to KATP channel openers in the brain stem circulation in vivo. In aged rats, although KATP channels are also functional in the brain stem circulation, dilator response of the microvessels but not of the large arteries to direct activation of KATP channels is impaired.

Aging↗

Aortoiliac occlusion associated with the lupus anticoagulant. Report of two cases.

Aortoiliac occlusion due to atherosclerosis is known to occur in elderly people. Two unique cases are documented here in which aortoiliac occlusion was observed in young men. These patients had no identifiable risk factors for developing atherosclerotic thrombosis except for the lupus anticoagulant, an immunoglobulin associated with thromboembolic episodes. Although previously the lupus anticoagulant has been reported to cause thrombosis only in relatively small-sized arteries or veins, it may also be associated with aortoiliac atheromatous occlusion in young men.

Adult↗

Simultaneous multiple brain hemorrhage associated with migraine--a case report.

A fifty-five-year-old woman with a history of migraine suddenly developed an occipital headache and visual disturbance after a typical migrainous attack. On admission, she had a left homonymous hemianopsia, and computed tomography of the brain demonstrated intracranial hematomas in the occipital subcortices bilaterally. Cerebral arteriography revealed diffuse vasospasm of the intracranial arteries attributed to the migraine. The cystatin C concentration in the cerebrospinal fluid was low, which suggested the existence of cerebral amyloid angiopathy. According to the clinical course and angiographic findings, it is suggested that the vasospasm associated with migraine played an important role in developing multiple brain hemorrhage in this patient.

Cerebral Amyloid Angiopathy↗

Ambulatory blood pressure monitoring in diagnosing a pheochromocytoma of the urinary bladder. A case report.

A patient is presented in whom the preoperative diagnosis of an intravesical pheochromocytoma was facilitated by noninvasive ambulatory blood pressure monitoring. A fifty-two-year-old Japanese man suffered headache and palpitation after micturition. Cystoscopy revealed an intravesical tumor. To investigate whether his symptoms were associated with an elevation of blood pressure, the authors monitored his ambulatory blood pressure automatically for twenty-four hours. The patient was also instructed to activate the recording manually upon the onset of symptoms. As a result, elevations of blood pressure were apparent following micturition. The twenty-four-hour urinary excretion of norepinephrine was elevated on the day of the blood pressure monitoring. Pheochromocytoma was suspected and was confirmed by histopathologic studies following the operation. Thus, ambulatory blood pressure monitoring may be useful in detecting the transient hypertension induced by micturition, which can provide preoperative evidence of pheochromocytoma of the urinary bladder.

Blood Pressure Monitoring, Ambulatory↗

Ultrasonographic assessment of regional differences in atherosclerotic lesions in patients with hypertension, diabetes mellitus, or both.

We evaluated risk factors involved in regional differences in atherosclerotic lesions in patients with hypertension, diabetes mellitus, or both. Using ultrasonography, we examined the brachial, common carotid, and common femoral arteries in 65 hospitalized Japanese patients (15 controls, 18 patients with hypertension, 16 with diabetes mellitus, and 16 with both hypertension and diabetes mellitus). They ranged in age from 39 to 81 yr, mean 60.3 yr. The thickness of the intima-media complex of the far wall was measured, and the severity of atherosclerotic plaques was graded according to maximal lumen stenosis. The intima-media thickness in the carotid and femoral arteries was significantly greater in the hypertensive patients and the hypertensive patients with diabetes than in the controls. Severity of plaque was greater in the hypertensive patients with diabetes than in the controls. Plaque grades were higher in the carotid and femoral arteries than in the brachial artery. Multiple regression analysis revealed that age and mean blood pressure were strongly associated with the intima-media thickness in all three arteries. In the femoral artery, cigarette smoking and hyperglycemia also significantly correlated with the intima-media thickness. Plaque grades increased with age in the carotid and brachial arteries, while in the femoral artery the grade increased with cigarette smoking and serum cholesterol concentration. These findings suggest that the extent of atherosclerosis and its underlying risk factors differ among arterial sites. In addition, risk factors may partly differ according to the stage of atherosclerosis. To prevent or reverse atherosclerosis, the above differences should be taken into account.

Adult↗

Cloning and sequencing of gene coding for a periplasmic 5.4 kDa peptide of the macronucleus-specific symbiont Holospora obtusa of the ciliate Paramecium caudatum.

We purified a 5.4 kDa peptide which is present in the intermediate and infectious form, but not in the reproductive form of a symbiotic bacterium Holospora obtusa of the ciliate Paramecium caudatum. Sequencing of its gene revealed that it encodes a peptide composed of 49 amino acids, and that the peptide is preceded by a putative signal peptide of 19 amino acids. We determined the transcription start point for the gene by primer extension analysis, indicating that the transcription starts with a G nucleotide located 33 nucleotides upstream from the translational initiation codon. Northern blot hybridization showed that the gene is highly expressed in the intermediate form, a transitional stage from the reproductive to infectious form of the bacterium. Immunoelectron microscopy with anti-5.4 kDa peptide antiserum revealed that the 5.4 kDa peptide is localized in the periplasm of the infectious form.

Animals↗

Methicillin-resistant Staphylococcus aureus (MRSA) isolation from pharyngeal swab cultures of Japanese elderly at admission to a geriatric hospital.

The isolation rate of the methicillin-resistant Staphylococcus aureus(MRSA) from pharyngeal swab cultures in Japanese elderly was studied at admission to a geriatric hospital. The subjects were 233 consecutive patients admitted to Kitakyushu Tsuyazaki Hospital from April 1994 to March 1996. The isolation rate of MRSA was 3.0% in the patients admitted from their own homes, 9.7% in those transferred from nursing homes and 14.0% in those transferred from other hospitals. The patients from their own homes were younger than those from nursing homes, the latter being older than those transferring from other hospitals. The patients from their own homes had better activities of daily living(ADL), higher levels of hemoglobin and serum albumin than those from nursing homes or other hospitals. The white blood cell counts, and the proportion of patients with positive c-reactive protein or with fever did not differ among the three groups. Multiple logistic regression analysis revealed that fever and ADL disability were independent risk factors for the isolation of MRSA, and hypoalbuminemia was a risk factor for MRSA isolation in the model using serum albumin instead of ADL score. These results suggest that the lower isolation rate MRSA among patients from their own homes may be partly due to better ADL and nutritional status compared with those from nursing homes or other hospitals.

Aged↗

[Isolation of methicillin-resistant Staphylococcus aureus on admission to a geriatric hospital].

We studied the rate of isolation of methicillin-resistant Staphylococcus aureus (MRSA) from throat cultures obtained from elderly patients. The subjects were 151 consecutive patients admitted to Kitakyusyu Tsuyazaki Hospital from December 1994 to November 1995. MRSA was found more frequently in samples obtained from patients transferred from other hospitals or from nursing homes than in samples from those admitted from their own homes. Patients transferred from other hospitals or from nursing homes had lower levels of serum total protein, albumin, and hemoglobin, and also lower scores for activities of daily living than did those admitted from their own homes. Status prior to admission, nutrition, and the scores for activities of daily living may explain the differences in the rate of isolation of methicillin-resistant Staphylococcus aureus among patients admitted to geriatric hospitals.

Aged↗

[Glucose tolerance and insulin resistance in the elderly].

Glucose tolerance is reported to be impaired in the elderly, and this is said to be mainly due to a decrease in insulin sensitivity (insulin resistance). Insulin resistance is known to be associated with atherosclerosis and coronary artery disease. To clarify whether or not age-dependent changes in glucose tolerance and insulin sensitivity are risk factors for coronary artery disease, as they are in the case of the insulin resistance syndrome, we studied age-dependent changes in glucose tolerance, insulin sensitivity, blood pressure, and serum lipids in a large number of subjects who underwent annual health check-ups, and then studied the relationships between coronary artery disease and aging, insulin sensitivity, and other risk factors in subjects who underwent coronary angiography. Aging was associated with an increased prevalence of noninsulin-dependent diabetes mellitus and impaired glucose tolerance; even in subjects with normal glucose tolerance, plasma glucose levels during an oral glucose tolerance test were significantly higher in the elderly. Insulin sensitivity, as assessed by the ratio of the sum of the plasma glucose divided by the sum of the serum insulin during the test (sigma PG/sigma IRI), was significantly lower in subjects over 60 years old than in younger subjects. Age-dependent impairment of insulin sensitivity and glucose tolerance was associated with increased blood pressure and serum cholesterol levels, but not with changes in boy mass index or serum triglyceride levels. As an independent variable, aging, but not insulin sensitivity, was related to the severity of coronary artery disease. These data suggest that aging is associated with glucose intolerance, insulin resistance, and an increased risk of coronary artery disease, but that the effect of aging on coronary artery disease cannot be explained by insulin resistance alone. Other factors, such as glucose intolerance and increased blood pressure, in addition to insulin resistance, appear to be responsible of the increased risk for coronary artery disease in the elderly.

Aged↗

[Effect of body mass index on morbidity and mortality in a general Japanese population--the Hisayama study].

In order to investigate the effect of body mass index (BMI, kg/m2) on life expectancy, 2053 Hisayama residents, aged 40 years or older were studied for 13 years from 1974. During the follow-up period, 419 subjects died; of these, 39 deaths due to accident or suicide were excluded from further analysis. On initial examination, male subjects with BMI > or = 27 had significantly higher age-adjusted prevalence rates of hypertension, glucose intolerance, hypercholesterolemia, electrocardiogram abnormalities and proteinuria, as compared with those with 23-25 BMI. In contrast, the frequency of male smokers was inversely associated with BMI levels. Female prevalence rates of glucose intolerance, hypercholesterolemia and proteinuria were significantly higher in 25-27 BMI than in 23-25. Body Mass Index showed a U-shaped relationship with all cause mortality rates with the lowest rate in 23-27 BMI for men and in 23-25 BMI for women. These associations remained substantially unchanged, even after controlling for age, systolic blood pressure, glucose intolerance, serum cholesterol, proteinuria, electrocardiogram abnormalities, alcohol consumption, and smoking habits. When analyzing the BMI mortality relationship by cause of death, age- and sex-adjusted mortality rates from myocardial infarction and stroke significantly increased in subjects with BMI > or = 27 compared with those with 23-25 BMI. In contrast, there was a decreasing risk of death from malignant neoplasms with rising BMI levels, but the relationship was not significant. Mortality from pneumonia and other causes showed a U-shaped relationship with significantly higher rates seen in BMI < 19 than in 23-25 BMI. These data indicate that BMI has a U-shaped relationship with total mortality in the general Japanese population, which results from various associations between BMI and cause-specific mortality rates.

Adult↗

Fatty liver in a case with heterozygous familial hypobetalipoproteinemia.

We herein present a case of fatty liver in a patient with heterozygous familial hypobetalipoproteinemia. A 34-yr-old male presented with abnormally elevated levels of transaminases and a fatty liver. He was asymptomatic, and the physical examination showed nothing remarkable. The serum total cholesterol, triglyceride, LDL-cholesterol, and apolipoprotein B levels all ranged from low normal to one-half normal. His other laboratory data were all in the normal range. The patient's body mass index measured was 25.7 kg/m2, and he did not demonstrate obesity. He had no history of alcohol consumption. It was thus thought that the fatty liver in this case might be associated with heterozygous hypobetalipoproteinemia. Heterozygous hypobetalipoproteinemia with a bright liver by ultrasound was also found in several of the patient's family members. Based on these rare findings, heterozygous hypobetalipoproteinemia should thus be considered as a possible cause in patients presenting with an unexplained fatty liver.

Adult↗

Enhanced electrical activity in mesenteric arteries from salt-loaded Dahl salt-sensitive rats: actions of prostaglandin H2 on membrane channels.

Salt loading increases blood pressure in Dahl salt-sensitive (Dahl S) rats. We have previously shown that the mesenteric artery of salt-loaded Dahl S rats exhibits enhanced electrical activity that is corrected by a cycloxygenase inhibitor, indomethacin. Prostaglandin H2 (PGH2) is a product of cycloxygenase that is known as an intrinsic vasoconstricting factor in spontaneously hypertensive rats. Our hypothesis is that tissue production of PGH2 would be involved in the enhanced electrical activity of arteries from salt-loaded Dahl S rats. In the present study, to clarify this possibility, we evaluated the actions of PGH2 on membrane channels in arterial cells from Dahl S rats. Membrane currents were recorded by whole-cell voltage clamp technique in single smooth muscle cells from the mesenteric artery. Application of PGH2 evoked an inward current that was mainly dependent on extracellular Na+ in the physiological extracellular solution. When high Ba2+ solution was used for the extracellular solution, PGH2 also evoked the inward current, suggesting that a divalent cation, such as Ba2+ or Ca2+, could permeate the PGH2-activated channels. In contrast, the L-type Ca2+ channel currents were not enhanced by the application of PGH2. The present results suggest that production of PGH2 contributes to the enhanced electrical activity by activating cation-permeable channels and depolarizing the membrane potential. PGH2 also directly stimulates the Ca2+ influx by activating Ca2+ permeable channels.

Animals↗

[Thyroid function in patients with Yusho: 28 year follow-up study].

To evaluate chronic effect of polychlorinated biphenyl (PCB) on thyroid functions, thyroid hormone levels and thyroidal autoantibodies were studied in 81 patients with Yusho in 1996. Serum level of thyroid stimulating hormone (TSH) was elevated in 7 cases (8.6%). All of them showed normal triiodothyronine (T3), thyroxine (T4) and free T4 levels, and regarded as latent hypothyroidism. There were no significant correlations between blood PCB concentrations and TSH levels, T2 levels, T4 levels or free T4 levels. Thyroglobulin antibodies were detected in 8 cases (19.5%) of 41 Yusho patients with high PBC concentration (higher than 3.0 ppb), and in only one case (2.5%) of 40 patients with low PBC concentration (lower than 2.9 ppb). We conclude that thyroglobulin antibody in patients with Yusho is not frequent and it may be associated with blood PCB concentration.

Aged↗

Risk factors for left ventricular hypertrophy in chronic hemodialysis patients.

Left ventricular hypertrophy is reported to be common in chronic hemodialysis patients, and also to increase the risk for mortality in chronic hemodialysis patients. An echocardiographical and clinical study was carried out to investigate the risk factors for left ventricular hypertrophy in 151 non-diabetic chronic hemodialysis patients without valvular diseases or myocardial infarction in two hemodialysis units in Fukuoka, Japan. The left ventricular mass index (LVMI) correlated positively to age, systolic blood pressure and interdialysis weight gain while it correlated negatively to the duration of hemodialysis therapy and hematocrit. Resorting to a multivariate analysis, the LVMI was found to positively correlate to age and the systolic blood pressure while it correlated negatively with the duration of hemodialysis therapy and the hematocrit level. These findings suggest that hypertension and anemia may thus be independent risk factors for left ventricular hypertrophy.

Cross-Sectional Studies↗

[Partial splenic embolization for the treatment of liver cirrhosis with hypersplenism: assessment of clinical response and liver function].

We have evaluated the efficacy of partial splenic embolization (SE) in the treatment in 10 cirrhotic patients with marked hypersplenism. The mean infarction rate of the spleen was 84%. The change of spleen size, peripheral blood cell counts and liver function tests after SE were investigated during 3 years, and also 10 cirrhotic patients without SE were followed as control. The residual spleens after SE did not enlarged except 1 case with 65% infarction rate of the spleen. In these cases, the SE led not only to a sustained increase in both platelet and white blood cell counts but also to a significant improvement of hepatic function tests (hepaplastin test, total cholesterol and albumin) during observation period. On the other hand, these parameters tended to decrease in control patients without SE. This study suggests that SE performed with a high infarction rate of spleen is an useful therapy for hypersplenism in cirrhosis.

Adult↗