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Biomedical subjects

M Fujishima

Publications and source records attributed to M Fujishima.

At least 109 records · Page 6Linked to original sources
PubMed1999

Troglitazone inhibits the capacitative Ca2+ entry in endothelial cells.

To investigate the effects of troglitazone on the capacitative Ca2+ entry, we monitored changes in cytosolic Ca2+ concentrations ([Ca2+]i) induced by thapsigargin in fura-2-loaded porcine endothelial cells in situ and in primary culture. In aortic valve endothelial cells in situ, thapsigargin induced sustained elevation of [Ca2+]i. Both troglitazone and SKF 96365 inhibited the steady state increase in [Ca2+]i in a concentration-dependent manner. At 30 microM, troglitazone and SKF 96365 inhibited the [Ca2+]i elevation to 19.4 +/- 3.6% and 43.9 +/- 4.5%, respectively. In aortic endothelial cells in primary culture, both troglitazone (10 microM) and SKF 96365 (100 microM) completely inhibited the thapsigargin-induced [Ca2+]i increase. The EC50 value of troglitazone (1.4 +/- 0.1 microM) was lower than that of SKF 96365 (10.0 +/- 3.3 microM). We suggest that troglitazone would be a useful tool to investigate the capacitative Ca2+ entry.

Adenosine Triphosphate↗
PubMed1999

Chaos and spectral analyses of heart rate variability during head-up tilting in essential hypertension.

To investigate nonlinear and linear components of heart rate variability (HRV) in essential hypertension (EHT), we analyzed HRV by chaos and spectral analyses in patients with EHT (n = 18) and normotensives (n = 10) during head-up tilting. We used the correlation dimension (CD) and Lyapunov exponents as the parameters of chaos. The CD, an index of complexity, was lower at rest in EHT group than in normotensives, and did not change in EHT group in response to head-up tilting, but decreased in normotensives. Head-up tilting did not change the Lyapunov exponents, an index of sensitive dependence on initial condition, a hallmark of chaos, in both groups. In the spectral analysis, the normalized high-frequency component (%HF) was decreased in EHT group at rest, and head-up tilting increased the low- to high-frequency ratio (L/H) and reduced the %HF in both groups. The CD and Lyapunov exponents at rest were correlated with the %HF and L/H. These results suggest that chaos analysis can assess the different aspect of HRV from spectral analysis and that nonlinear components of HRV may be associated with hypertension through an impaired dynamic regulation of HRV.

Adult↗
PubMed1999

Antisense inhibition of angiotensinogen attenuates vasopressin release in the paraventricular hypothalamic nucleus of spontaneously hypertensive rats.

It has been reported that intracerebroventricularly injected antisense oligonucleotide to angiotensinogen reduces arterial pressure in spontaneously hypertensive rats (SHR), but the mechanism and the sites of action remain unclear. In the present study, we examined whether injection of antisense oligonucleotide to angiotensinogen into the paraventricular hypothalamic nucleus (PVN) would influence arterial pressure and vasopressin release. For this purpose, 12-week-old male SHR were cannulated into the bilateral PVN. One week later, we injected antisense or sense oligonucleotide to angiotensinogen into the bilateral PVN (0.2 nmol/200 nl each side). After 24 h, we directly monitored arterial pressure, and then took blood samples to measure plasma vasopressin, catecholamines and renin activity. Mean arterial pressure did not change in either group (from 144+/-3 to 154+/-4 mmHg for the antisense oligonucleotide group, n=11; from 147+/-4 to 156+/-3 mmHg for the sense oligonucleotide group, n=11). Antisense oligonucleotide attenuated vasopressin release compared with sense oligonucleotide (1.30+/-0.28 vs. 3.29+/-0.60 pg/ml, respectively, P<0.01). Plasma catecholamines also decreased in the antisense oligonucleotide group compared with the sense oligonucleotide group. However, the plasma renin activity did not differ between the groups. In the additional experiment, we examined the neurohormonal and cardiovascular effects of intracerebroventricularly injected antisense oligonucleotide to angiotensinogen in SHR. Mean arterial pressure, plasma vasopressin and plasma norepinephrine were significantly lower in the antisense oligonucleotide group than in the sense oligonucleotide group. These results suggest that angiotensinogen in PVN plays important roles in vasopressin release and sympathetic nerve activity, but may not contribute to the maintenance of arterial pressure in SHR.

Angiotensinogen↗
PubMed1999

Normalization of glucose entry under the high glucose condition by phlorizin attenuates the high glucose-induced morphological and functional changes of cultured bovine retinal pericytes.

We previously reported that sodium-dependent glucose uptake is present in bovine retinal pericytes and that phlorizin normalizes its glucose consumption under high glucose conditions. To clarify the effect of phlorizin on morphological and functional change of retinal pericytes under high glucose conditions, retinal pericytes were incubated in media with 5 mM glucose, 30 mM glucose, and 30 mM glucose plus 0.2 mM phlorizin for 7 days. The diameter of cells in the concentrations of glucose more than 10 mM were significantly larger than those in 5 mM glucose and 30 mM glucose plus phlorizin. Glucose, sorbitol and fructose contents of the cells in 30 mM glucose were significantly increased compared with those in 5 mM glucose, and were normalized by phlorizin. Thymidine uptake in the concentrations of glucose more than 20 mM was significantly decreased compared with that in 5 mM glucose. Myoinositol uptake, and DNA in 30 mM glucose were significantly reduced, and were normalized with phlorizin. Myoinositol content in 30 mM glucose was the same as that in 5 mM glucose, but was significantly decreased by phlorizin. The ratios of glucose to sorbitol or fructose in 30 mM glucose were significantly decreased, compared with those in 5 mM glucose and 30 mM glucose plus phlorizin. Therefore, the cellular enlargement and decreased DNA synthesis in cultured bovine retinal pericytes with abnormal glucose metabolism under high glucose conditions are attenuated by phlorizin, independent of the cellular myoinositol content.

Animals↗
PubMed1999

Progressive motor deficits in lacunar infarction.

OBJECTIVE: To study the clinical characteristics of the progression of motor deficits in lacunar stroke patients. BACKGROUND: Some patients with lacunar infarction have progression of their neurologic deficits, but it is not known which patients will progress or why they progress. METHODS: The authors evaluated 92 consecutive patients (47 men, 45 women; age, 69.4 +/- 10.9 years [mean +/- SD]) with first-ever stroke due to supratentorial lacunes in the internal capsule or the corona radiata. By defining lacunar infarction in which motor deficits progressed between admission and the day after admission as progressive lacunar infarction, the authors compared progressive lacunar infarction with stable lacunar infarction. RESULTS: Of 92 patients, 25 (27%) had progression of deficits. Diabetes mellitus (p = 0.02) and severity of motor deficit on admission (p = 0.006) were related independently to progression in a logistic multiple regression analysis. Size of the infarct was slightly larger (1.2 +/- 0.4 cm2 versus 0.9 +/- 0.5 cm2; p = 0.01) and functional status at discharge was worse (median Barthel index, 45 versus 100; p < 0.001) in patients with progressive infarction than in those without progression. There were no significant differences between the two groups regarding the site of the infarct or blood pressure or hematocrit levels on or after admission. CONCLUSIONS: The progression of motor deficits is associated with a relatively poor functional outcome. Diabetes mellitus and the severity of motor deficit on admission may predict progression of motor deficits.

Activities of Daily Living↗
PubMed1999

Suppression of sodium-dependent glucose uptake by captopril improves high-glucose-induced morphological and functional changes of cultured bovine retinal pericytes.

The effects of captopril on glucose uptake, as well as morphological and functional changes of retinal pericytes, in a high-glucose medium were examined. Retinal pericytes were incubated in medium with 5 and 30 mM glucose and 30 mM glucose with 10(-6) to 10(-3) M captopril. Captopril decreased the cellular uptakes of d-glucose and alpha-methyl glucoside in the presence, but not in the absence, of sodium. The cellular size and contents of glucose, sorbitol, and fructose were increased in 30 mM glucose concomitant with the decreased thymidine, cellular DNA content, and ratios in glucose to sorbitol and to fructose, compared with those in 5 mM glucose. These changes observed in 30 mM glucose were reversed by 10(-4) M captopril. These data suggest that the suppression of d-glucose uptake through a sodium-coupled glucose transporter by captopril may attenuate the swelling and loss of pericytes observed in the early stage of diabetic retinopathy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

Can quinolones cause hemorrhagic colitis of late onset? Report of three cases.

PURPOSE: This study was undertaken to demonstrate that quinolones may cause acute colitis resembling penicillin-induced hemorrhagic colitis. METHODS: We reviewed the medical records of patients with acute colitis in our institutes. Twenty-eight patients with acute hemorrhagic colitis in which no pathogenic microorganisms were identified were the subjects of this study. Pseudomembranous colitis caused by Clostridium difficile was excluded. Ulcerative colitis, Crohn's disease, and radiation proctocolitis were also excluded. RESULTS: Among these patients, 25 had a history of recent administration of penicillin derivatives. The remaining three patients had never been given any penicillin derivatives, but had ingested quinolones approximately four weeks before the developing colitis had been identified. Klebsiella oxytoca was also isolated in these three patients. CONCLUSIONS: Quinolones may cause acute hemorrhagic colitis. The time interval from antibiotic ingestion to onset of the condition may be much longer in quinolones than in penicillin derivatives.

Acute Disease↗
PubMed1999

Increased sensitivity to thyroid hormone replacement therapy followed by hyponatremia and eosinophilia in a patient with long-standing young-onset primary hypothyroidism.

We describe a 51-year-old woman with long-standing young-onset primary hypothyroidism. Serum cortisol, adrenocorticotropin, and arginine vasopressin levels were normal, but urinary excretion of 17-hydroxycorticosteroid was decreased. Administration of a very small initial dose of thyroid hormone induced severe acute complications including fever, palpitation, and sweating associated with a rapid decrease in serum thyrotropin level, a dramatic increase in serum alkaline-phosphatase level, and a decrease in serum total cholesterol level. A week later, the late complications of nausea, severe hyponatremia, and eosinophilia occurred. Serum cortisol level decreased slightly but remained within normal limits during this hyponatremic period. This rare case suggests that increased sensitivity to thyroid hormone can occur in long-standing primary hypothyroidism with biphasic clinical course of acute thyrotoxic complications followed by severe hyponatremia resembling hypoadrenocorticism.

17-Hydroxycorticosteroids↗
PubMed1999

Serrated adenoma of the colorectum: colonoscopic and histologic features.

BACKGROUND: Serrated adenoma is a recently recognized epithelial neoplasm of the colorectum. The aim of this study is to clarify the colonoscopic features of serrated adenomas. METHODS: The endoscopic findings for 52 serrated adenomas of the colorectum were investigated; these were then divided into three groups according to surface features. The histologic type (tubular, tubulovillous or villous) and the incidence of high-grade dysplasia were compared among the three groups. RESULTS: The surface under chromoscopy showed a hyperplastic pattern in 17 lesions, a cerebriform pattern in 18 lesions and a combined pattern in 17 lesions. The tubular type of serrated adenoma was predominant in the hyperplastic pattern group (94%), whereas the tubulovillous or villous histologic types were frequent in the cerebriform pattern (89%) and combined pattern (82%) groups. High-grade dysplasia was found in 18% of the combined pattern adenomas; the incidence was lower in hyperplastic (6%) or cerebriform pattern (0%) adenomas. CONCLUSIONS: Surface features of serrated adenomas have a close correlation with their histologic type. A combined hyperplastic-cerebriform surface pattern under chromoscopy was seen only in serrated adenomas.

Adenoma↗
PubMed1999

Renal complications in patients with diabetes mellitus associated with an A to G mutation of mitochondrial DNA at the 3243 position of leucine tRNA.

The substitution of guanine for adenine at position 3243 of the leucine tRNA gene of mitochondrial DNA was originally described in association with MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes). Diabetes mellitus associated with the mutation (mitochondrial diabetes) is a different phenotype from MELAS. We identified 11 patients with the mutation among 385 Japanese diabetic patients: two had MELAS and nine had mitochondrial diabetes. We present data on a male patient with mitochondrial diabetes who developed the nephrotic syndrome at the age of 23. Light microscopy revealed mesangial expansion, PAS-positive deposits and segmental sclerosis in the glomeruli. Scattered mesangial electron-dense deposits and thickening of the basement membrane were found on electron microscopy, suggesting that diabetic glomerulosclerosis accompanied by focal glomerulosclerosis (FGS). Mitochondrial diabetes may pre-dispose patients to renal complications, including forms of glomerulonephritis, such as FGS.

Adult↗
PubMed1999

Hemodialysis causes severe orthostatic reduction in cerebral blood flow velocity in diabetic patients.

Orthostatic hypotension is a serious problem in patients with diabetes mellitus (DM) undergoing hemodialysis (HD). To evaluate cerebral circulation during orthostasis in patients with DM, we examined changes in mean blood flow velocity in the middle cerebral artery (VMCA) during 60 degrees head-up tilt for 5 minutes in patients with DM (six men, two women; age, 57 +/- 3 years [mean +/- SEM]; HD duration, 47 +/- 27 months) before and after bicarbonate HD by using transcranial Doppler sonography. The findings were compared with those in HD patients without diabetes (non-DM; 12 men, 5 women; age, 47 +/- 3 years; HD duration, 82 +/- 23 months). Mean blood pressure (MBP) in the supine position, hematocrit (Hct), plasma fibrinogen, and volume of fluid removed by HD were not significantly different between the two groups (MBP, 106 +/- 6 versus 103 +/- 4 mm Hg; Hct, 26% +/- 1% versus 28% +/- 1%; fibrinogen, 355 +/- 37 versus 357 +/- 27 mg/dL; fluid, 2.5 +/- 0.2 versus 2.3 +/- 0.2 L). Percentage of change in VMCA (% VMCA) during tilt was compared between the groups before and after HD. Before HD, MBP decreased significantly to 93 +/- 5 mm Hg during tilt only in patients with DM. The degree of MBP reduction was -13 +/- 2 mm Hg in DM and -2 +/- 2 mm Hg in non-DM patients (P < 0.01). % VMCA equally decreased during tilt; DM, -12% +/- 3%, and non-DM, -12% +/- 2%. After HD; MBP decreased by 36 +/- 7 mm Hg in patients with DM, which was significantly greater than before HD. VMCA also decreased in both groups after HD, and % VMCA in DM (-32% +/- 5%) was significantly greater than before HD (P < 0.01) and in non-DM patients (-13% +/- 2%; P < 0.01). % VMCA positively correlated with the percentage of change ratio of MBP during tilt in both groups after HD (DM, r = 0. 87, P < 0.01; non-DM, r = 0.61, P < 0.01). Our results showed a significant decrease in cerebral blood flow velocity during tilt of equal magnitude in both groups before HD despite differences in the level of hypotension, whereas reduction in cerebral blood flow velocity and decrease in MBP were more marked in DM after HD. Orthostasis could thus cause hemodynamically mediated brain damage after HD, especially in patients with DM.

Aged↗
PubMed1999

Association of a T-cell receptor constant alpha chain gene polymorphism with progression of IgA nephropathy in Japanese patients.

Immunogenetic studies have suggested the role of the T-cell receptor (TCR) in the development of immune-mediated diseases. We investigated whether a genetic polymorphism in the TCR constant alpha (Calpha) chain region might modify the susceptibility or progression of immunoglobulin A (IgA) nephropathy. The TCR Calpha chain genotype was studied in 213 Japanese patients with IgA nephropathy and 73 individuals from the general population. A polymerase chain reaction-based TaqI restriction fragment length polymorphism assay (TaqI RFLP) was applied on the 5' flanking region of the TCR Calpha first exon. The TaqI-undigested (t) and TaqI-digested (T) alleles showed similar genotype distributions between the patients with IgA nephropathy and controls (tt:Tt:TT = 16.9%:46.5%:36.6% in IgA nephropathy v 9.6%:58.9%:31.5% in controls; chi(2) = 1.9; P = not significant). To further investigate the role of TCR Calpha chain gene polymorphism in renal prognosis, we analyzed those patients with IgA nephropathy in whom renal status had been monitored for a period of more than 3 years (n = 182). According to outcome, two groups were formed. The stable (S) group included 98 patients with renal function that remained unchanged during an average follow-up of 10.7 +/- 0.4 (SE) years. The progressive (P) group (n = 84) included patients with progressively declining renal function, with an average follow-up of 11.9 +/- 0.5 years. The genotype distributions of the TCR Calpha chain gene polymorphisms between these two groups differed significantly (tt:Tt:TT = 25.5%:40.8%:33.7% in S v 10.7%:44.1%:45.2% in P; chi(2) = 7.0; P < 0.05). The frequency of the T allele was greater in the P group (67.3% in P v 54.1% in S; chi(2) = 6.6; P = 0.01). The TT or Tt genotypes were more commonly observed in patients from the P group (89.3% of T allele carriers in P v 74.5% in S; chi(2) = 6.5; P = 0.01). It appeared the T allele might foreshadow a poor renal prognosis, conferring a potential risk for developing renal failure with time (odds ratio, 2.7; confidence interval, 1.2 to 6.0; P < 0.05). In summary, TCR Calpha chain genetic variability was associated with loss of renal function over time in patients with IgA nephropathy. In conclusion, the TCR Calpha chain polymorphism might prove helpful to predict progression to chronic renal failure in Japanese patients with IgA nephropathy.

Adult↗
PubMed1999

Effects of interferon on circadian changes in blood pressure and heart rate variability in patients with chronic hepatitis.

We have determined the effects of interferon therapy on circadian changes in blood pressure and heart rate variability in normotensive hospitalized patients with chronic active hepatitis. Body temperature and pulse rate increased for the initial few days of interferon therapy without significant change in casual or ambulatory blood pressure. Interferon therapy failed to elicit any significant changes in the power spectrum of R-R intervals. In addition, urinary excretion of norepinephrine did not differ between before and during the therapy. These results suggest that interferon therapy caused transient increases in body temperature and pulse rate, but that it did not change either sympathetic or parasympathetic outflow, or the circadian rhythm of blood pressure and heart rate variability, in normotensive subjects.

Antiviral Agents↗
PubMed1999

Cerebral blood flow threshold and regional heterogeneity of heat shock protein 72 induction following transient forebrain ischemia in rats.

Heat shock proteins (HSPs) induced by brain ischemia may play an important role in neuroprotection from neuronal degeneration. In this study, we examined the cerebral blood flow (CBF) threshold to produce regional differences in HSP72 induction after transient forebrain ischemia in spontaneously hypertensive rats (SHRs). Female SHRs were subjected to 20 min of cerebral ischemia induced by bilateral carotid artery occlusion. The CBF was measured by laser Doppler flowmetry. At forty-eight hours after cerebral ischemia and reperfusion, the rats were decapitated and the brains were removed. Specific areas (hippocampal CA1, CA2-3, dentate gyrus, dorsolateral and ventromedial striatum, and parietal cortex) were thereafter dissected from the brain. The amounts of HSP72 in these samples were determined using Western blot analysis. In the hippocampus, HSP72 was induced when the CBF decreased to less than 18-25% of the resting level. The mean values of HSP72 produced in the CA1 area, CA2-3 area, and the dentate gyrus following ischemia and reperfusion treatment were 4.44 +/- 1.43 (+/-SD) ng/microg protein, 3.51 +/- 0.72 ng/microg protein and 3.77 +/- 1.05 ng/microg protein, respectively. In the parietal cortex, the amount of HSP72 induction was less pronounced (2.55 +/- 0.40 ng/microg protein), while HSP72 was hardly detected at all in the striatum, even under conditions of very severe CBF reduction and reperfusion. We demonstrated the existence of both a CBF threshold (i.e., approximately 20% of the resting level) for HSP72 induction and regional heterogeneity for the induction of HSP72 protein.

Animals↗
PubMed1999

Helicobacter pylori and mucosal atrophy in patients with gastric cancer: a special study regarding the methods for detecting Helicobacter pylori.

We assessed the sensitivities of several methods for detecting Helicobacter pylori (culture, histology, rapid urease test, and serology), and evaluated the H. pylori positivity considering the degree of atrophy in the background mucosa in 202 gastric cancer patients and 101 controls. The positivity of H. pylori determined by culture (81%) was significantly higher than that determined by serology (62%) in gastric cancer patients (P < 0.001). The positivities of H. pylori determined by biopsy and/or serology in intestinal (84%) and diffuse (95%) types of gastric cancer were higher than that observed in controls (54%) (P < 0.001). Intestinal-type gastric cancer tended to occur in the atrophic mucosa, in which H. pylori positivity was not different from that in controls after adjusting for the degree of atrophy, whereas diffuse-type gastric cancer was observed more often in the nonatrophic mucosa, in which H. pylori positivity was higher than that in controls even after adjusting for the degree of atrophy.

Aged↗