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Biomedical subjects

A Sato

Publications and source records attributed to A Sato.

At least 235 records · Page 13Linked to original sources
PubMed1999

Effect of prolonged treatment with amlodipine on enhanced vascular contractility in cardiomyopathic hamsters.

This study examined the effects of prolonged treatment with amlodipine on the enhanced vascular contractions in dilated cardiomyopathic (CM) hamsters. From the ages of 5 to 20 weeks, CM hamsters (BIO 53.58) orally received amlodipine. Then we compared the contractile responses to vasoconstrictors in aortas and mesenteric arteries from CM hamsters with or without treatment with those in the arteries from controls (F1b). We also investigated the effect of amlodipine treatment on the Ca2+ sensitivity of tension in beta-escin-skinned smooth muscle of mesenteric artery. The contractile responses to phenylephrine, angiotensin II, and high K+ in both aorta and mesenteric artery were greatly enhanced in CM hamsters compared with controls. Amlodipine treatment slightly but significantly inhibited the enhanced responses in aorta but did not alter the responses in mesenteric arteries. The Ca2+ sensitivity of tension was significantly increased in CM hamster preparations, which was unaffected by amlodipine treatment. These data indicate that amlodipine treatment differentially affects the enhanced responses to vasoconstrictors between large and small blood vessels from CM hamsters. The lack of effect of amlodipine treatment on the responsiveness of CM mesenteric artery leads to the suggestion that the preventive effect of amlodipine on focal myocytolytic necrosis of cardiomyocytes, which was previously reported to be the main cause of cardiomyopathy, results from an action on cardiomyocytes.

Actin Cytoskeleton↗
PubMed1999

Effects of posture on left ventricular diastolic filling during exercise.

BACKGROUND: Measuring the transmitral flow velocity with Doppler echocardiography is a useful method for evaluating left ventricular diastolic function. However, there are few data regarding the effect of posture during exercise on transmitral flow velocity. METHODS: The transmitral flow velocity with pulsed-wave Doppler echocardiography was measured during supine and upright bicycle ergometer exercise in 10 normal young men without cardiac disease (26.7 +/- 5.5 yr). RESULTS: The ratio of the early rapid filling wave to the atrial filling wave (E/A) was gradually decreased with increasing exercise intensity. At rest and during recovery, the E/A ratio was significantly higher (P < 0.01) in the supine position than in the upright position. This difference was caused mainly by the higher E wave in the supine position. However, E wave and E/A ratio did not differ between the upright and supine position during exercise. CONCLUSION: Although measurement of left ventricular filling is completely noninvasive and clinically useful for evaluating diastolic function, it was found that the E/A ratio was profoundly influenced by posture and exercise intensity. These results suggest that the potential influences of posture and exercise intensity on the filling velocities should be taken into account when interpreting diastolic function by Doppler echocardiography.

Adolescent↗
PubMed1999

Specific induction of adhesion molecules in human vascular endothelial cells by rat experimental pancreatitis-associated ascitic fluids.

The molecular mechanisms that link acute pancreatitis (AP) and multiple organ failure remain unknown. To clarify the role of endothelial activation, we examined the effects of ascitic fluids from rats with experimental pancreatitis on the expression of adhesion molecules in human umbilical vein endothelial cells (HUVECs). Necrotizing hemorrhagic pancreatitis was induced with sodium taurocholate. Six and 24 h later, peritoneal exudates were collected, centrifuged and HUVECs were treated with the supernatants. The expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was quantified by enzyme-linked immunosorbent assay. Induction of mRNA was assessed by reverse-transcriptase polymerase chain reaction. The activation of transcription factors was examined by electrophoretic mobility shift assay. The expression of ICAM-1 in the tissues was examined immunohistochemically. ICAM-1 and VCAM-1, but not E-selectin expression was upregulated with comparable mRNA induction. Nuclear factor kappaB was activated, while activator protein-1 binding activity was not altered. Immunohistochemically, enhanced ICAM-1 expression was observed in the pancreas and lung, but not in the liver. Ascitic fluids may contain soluble factors responsible for the transcriptional activation of endothelial adhesion molecules, and ICAM-1 may play roles in the pathogenesis of complicated AP.

Animals↗
PubMed1999

Crystallization and preliminary analysis of bovine adenosine deaminase.

Adenosine deaminase (ADA) from bovine intestine was crystallized with purine riboside by vapour diffusion using ammonium sulfate as precipitant. The crystals are tetragonal and have unit-cell parameters a = b = 80.03, c = 141.68 A. They belong to space group P4(1)2(1)2 or P4(3)2(1)2 and diffract to at least 2.0 A resolution. The structure is being solved by molecular replacement.

Adenosine Deaminase↗
PubMed1999

Prenatal diagnosis of intrapericardial teratoma: a case report.

A hydropic fetus that exhibited intrapericardial teratoma with marked pericardial effusion was prenatally diagnosed. Intrauterine pericardiocentesis was performed to diagnose and to treat hydrops. Pericardiocentesis for tamponade secondary to a fetal intrapericardial teratoma might prevent fetal death and premature delivery.

Adult↗
PubMed1999

[A case of lymphocyst infection caused by vanB type VRE].

A case of post-operative abdominal lymphocyst infection caused by vanB type vancomycin resistant enterococcus (VRE) in reported. A 27-year-old female was diagnosed as pregnancy with uterine cervical carcinoma and underwent Cesarean section and radical hysterectomy. After discharge, she developed a high fever which was diagnosed as a lymphocyst infection. Microbiological examination demonstrated the presence of vanB type VRE in the cyst fluid. Cyst cleaning and minocyclin injection were effective. This is the first case of VRE infection in Japan.

Adult↗
PubMed1999

Effects of organic anions and vinblastine on biliary excretion of erythromycin in rats.

Since little is known about the mechanism of biliary excretion of cationic drugs, biliary excretion of erythromycin was studied in rats. Infusion of sulfobromophthalein and taurocholate significantly decreased biliary erythromycin excretion, whereas infusion of dibromosulfophthalein, cefpiramide, ursodeoxycholate-3-O-glucuronide and taurolithocholate-3-sulfate had no effect on biliary excretion of erythromycin. Vinblastine significantly inhibited biliary erythromycin excretion. Phenothiazine treatment significantly increased biliary erythromycin excretion. However, erythromycin infusion did not affect biliary vinblastine excretion. These findings indicate a multiplicity of biliary excretory pathways for organic cations; at least one additonal pathway may exist for organic cations apart from P-glycoprotein.

Animals↗
PubMed1999

A possible role of immunoglobulin E in patients with hyperthyroid Graves' disease.

To investigate the possible participation of immunoglobulin E (IgE) in the autoimmune process of Graves' disease, incidence of elevation of serum IgE level, TSH receptor antibody (TRAb), and thyroid status were studied in 66 patients with hyperthyroid Graves' disease, 54 patients with Hashimoto's thyroiditis, 19 patients with bronchial asthma, and 15 patients with pollen allergy. In hyperthyroid Graves' patients, elevation of serum IgE levels (> or = 170 U/mL) was found in 19 of 66 patients (29%), 11 of whom had hereditary and/or allergic conditions. Elevations of serum IgE levels were found in 63% of patients with bronchial asthma and in 40% of patients with pollen allergy. Mean values of serum IgE were the same in patients with hyperthyroid Graves' disease and with bronchial asthma. During methimazole treatment TRAb decreased without fluctuation of IgE levels in both groups. The decrease in TRAb was significantly greater in patients with normal IgE than in patients with IgE elevation. After prednisone administration, reduction in TRAb was greater in patients with normal IgE than that in patients with IgE elevation. High incidence of IgE elevation in hyperthyroid Graves' disease and slower reduction in TRAb in association with IgE elevation suggest a difference in the autoimmune processes in Graves' disease with and without elevation of IgE.

Adolescent↗
PubMed1999

Genetic fusion of an alpha-subunit gene to the follicle-stimulating hormone and chorionic gonadotropin-beta subunit genes: production of a bifunctional protein.

The human glycoprotein hormones, hCG, TSH, LH, and FSH, are composed of a common alpha-subunit assembled to a hormone-specific beta-subunit. The subunits combine noncovalently early in the secretory pathway and exist as heterodimers but not as multimers. LH/FSH are synthesized in the pituitary gonadotrophs, and several of the alpha-subunit sequences required for association with either the LHbeta or FSHbeta subunits are different. Thus, it is intriguing that no ternary complexes are observed for LH and FSH in vivo (e.g. two different beta-assembled to a single alpha-subunit). To examine whether the alpha-subunit can interact with more than one beta-subunit, and to study the conformational relationships between the ligand and the receptor, we constructed a vector encoding two tandemly arranged beta-subunits fused to a single alpha-subunit gene (FSHbeta-CGbeta-alpha). This approach permitted structure-function analyses of alpha/beta domain complexes without the possibility of subunit dissociation. We reported previously that the CGbeta or FSHbeta subunit gene can be genetically fused to the alpha-gene and the resulting single chains (CGbetaalpha and FSHbetaalpha, respectively) were biologically active. Here we demonstrate that a triple-domain single chain bearing the configuration FSHbeta-CGbeta-alpha is efficiently secreted from transfected Chinese hamster ovary (CHO) cells and exhibits high-affinity receptor binding to both FSH and LH/hCG receptors, comparable to the native heterodimers. These results indicate that the alpha-subunit can interact with each beta-subunit in the same complex and that an alpha-domain fused to a beta-domain can still interact with an additional beta-subunit. The data also demonstrate the remarkable flexibility of the receptor to accommodate the increased bulkiness of the triple-domain ligand. In addition, the formation of intrachain FSH- and CG-like complexes observed in a triple-domain single chain suggests that the alpha-subunit can resonate, i.e. shuttle between alpha-beta heterodimeric intermediates during the early stages of synthesis and accumulation in the endoplasmic reticulum. Such model compounds could be useful as substrates to generate a new class of analogs in which the ratio of the LH/FSH activity is varied. This could aid in the design of analogs that could be used to mimic the in vivo hormonal profiles.

Animals↗
PubMed1999

Dfrizzled-3, a new Drosophila Wnt receptor, acting as an attenuator of Wingless signaling in wingless hypomorphic mutants.

In Drosophila, two Frizzled proteins, Frizzled and Dfrizzled-2, have been reported to serve as receptors of Wingless. Here, we identified the third member of the Drosophila Frizzled family (Dfrizzled-3). In contrast to Dfrizzled-2, Dfrizzled-3 was transcriptionally upregulated by Wingless signaling. Although Dfrizzled-3 was capable of binding to Wingless in vitro, Wingless-dependent Armadillo/beta -catenin stabilization occurred much less effectively in Drosophila cells transfected with Dfrizzled-3 than in those with Dfrizzled-2. Flies lacking Dfrizzled-3 activity were viable and fertile, with few morphological defects. Genetic and immunochemical analysis indicated that the absence of Dfrizzled-3 activity suppresses the effects of hypomorphic wingless mutations such as failure of wing and antenna formation and restores target gene expression to the normal levels without change in wingless expression. Wingless signaling may thus be attenuated by Dfrizzled-3 at least in wingless hypomorphic mutants.

Amino Acid Sequence↗
PubMed1999

Long-term n-3 fatty acid deficiency induces no substantial change in the rate of protein synthesis in rat brain and liver.

The influence of long-term n-3 fatty acid deficiency on the rate of protein synthesis in rat brain and liver was investigated in relation to learning behavior or a presumed survival time-shortening factor (SSF) in rapeseed oil, using a large-dose [3H]phenylalanine (Phe) injection method. When Wistar rats were made n-3 fatty acid-deficient by feeding a safflower oil (alpha-linolenate-deficient) diet for 2 generations, conditions under which the safflower oil group had been shown to exhibit altered learning behaviors, compared with the perilla oil group, no significant changes in the rate of protein synthesis were observed compared with the perilla oil (alpha-linolenate-sufficient) or rapeseed oil (alpha-linolenate-sufficient but SSF-containing) groups. However, the rapeseed oil group had a reduced specific radioactivity of free Phe in the cerebral cortex, compared with the safflower oil group. In contrast to the reported observation of very long-term n-3 fatty acid deficiency inducing an almost 2-fold increase in the rate of protein synthesis in the brain, our results indicate that altered learning behavior resulting from n-3 fatty acid deficiency in rats is not associated with any substantial changes in the rate of protein synthesis in the brain.

Animals↗
PubMed1999

Characteristic change of urinary elastin peptides and desmosine in the aortic aneurysm.

To estimate elastin metabolism in aneurysm, urinary levels of desmosine and elastin peptide in patients (n=23, range 54 to 85 years old) with aneurysm were measured by ELISA and compared between two control groups divided by age (<10 years old and >20 years old). The amounts of urinary desmosine and elastin peptide in the aneurysm group were significantly increased compared with those in the older control group (>20 years old). There was a correlation between urinary desmosine and elastin peptide in the young group. On the other hand, no such correlation was observed in the aneurysm group and the older control group. The distribution of the ratio (desmosine/elastin peptide) in the aneurysm group was different from that of the young control group. We conclude that assay of elastin peptide and desmosine in urine are useful in characterizing elastin degradation in a patient with aneurysm.

Adult↗
PubMed1999

[Quantitative analysis of factors to influence the environment of the clean room and clean bench during preparation of intravenous hyperalimentation (IVH) admixtures].

We quantitatively studied factors influencing the environment cleanliness for intravenous hyperalimentation (IVH) admixing. The environment cleanliness was evaluated by measuring the counts of particles (> 0.5 micron) and bacteria floating in 1 ft3 of the air inside the clean room (23.6 m3) and in the clean bench built in the department of pharmacy, The University of Tokyo Hospital in 1998. The number of particles at the center of the clean room during IVH admixing by 4 pharmacists was higher than that at the medicine passing area (150 +/- 50/ft3 vs. 260 +/- 60/ft3; mean +/- S.D., n = 12). The cleanliness inside the clean room was improved as the measurement point became higher from the floor (600 +/- 180/ft3, 150 +/- 50/ft3, and 35 +/- 15/ft3 at 50, 100, and 150 cm height, respectively) and the number of persons working inside the room decreased. The changes in the counts of floating bacteria were similar to that of floating particles under the same conditions. In addition the effect of disinfection on the counts of bacteria was clearly observed. When the cleanliness of the room became lower by turning off the air conditioning, the particle counts inside the clean bench became lower along with the distance from the front glass becoming deeper (i.e., 1400 +/- 550/ft3, 140 +/- 70/ft3, and 40 +/- 30/ft3 at 0, 5, and 15 cm, respectively). From these lines of evidence, the following items were suggested in order to maintain the environment cleanliness for IVH admixing. First, the number of persons residing in the clean room should be kept to be minimum. Second, the clean bench should be set up in the center of the clean room. Finally IVH admixing operation should be performed at more than 15 cm depth inside the front glass surface of the clean bench. Moreover, the effect of mopping-up of the clean room with 0.1% benzethonium chloride clearly demonstrated the importance of disinfection on a routine basis.

Air Conditioning↗
PubMed1999

Effects of spironolactone and angiotensin-converting enzyme inhibitor on left ventricular hypertrophy in patients with essential hypertension.

There is increasing evidence for important cardiovascular effects of aldosterone via classical mineralocorticoid receptors in the heart. Administration of aldosterone with excess salt produces both cardiac hypertrophy and interstitial cardiac fibrosis in rats, and concomitant administration of potassium canrenoate at a dose that only modestly lowers blood pressure completely blocks the cardiac effects of aldosterone. In the present study, we examined the effect on left ventricular hypertrophy of adding a low dose of the mineralocorticoid receptor antagonist spironolactone (25 mg/d) to an angiotensin-converting enzyme inhibitor (enalapril maleate) in patients with essential hypertension. Eighteen untreated patients with moderate to severe essential hypertension based on the WHO/ISH guidelines participated in this study. Subjects were treated with either an angiotensin-converting enzyme inhibitor alone (group I: 10 patients, 4 men and 6 women, mean age 56 +/- 18 yr) or an angiotensin-converting enzyme inhibitor plus spironolactone (group II: 8 patients, 3 men and 5 women, mean age 59 +/- 14 yr) for 9 mo. Left ventricular mass index, various echocardiographic variables, mean blood pressure, plasma renin activity, and plasma aldosterone concentration before treatment were similar in the two groups. Blood pressure of both groups decreased significantly and similarly after antihypertensive treatment (group I, 136 +/- 9/82 +/- 9 mmHg; group II, 133 +/- 9/85 +/- 10 mmHg). Left ventricular mass index also decreased significantly in both groups (group I, -10.2 +/- 7.1%; group II, -18.1 +/- 6.9%). The extent of reduction was significantly greater in the spironolactone group (group II) (p < 0.05 vs. group I). In group II patients, spironolactone did not cause any side effects during the observation period. We conclude that spironolactone may have beneficial effects on left ventricular hypertrophy in patients with essential hypertension who are receiving an angiotensin-converting enzyme inhibitor.

Aldosterone↗
PubMed1999

Development of bronchus-associated lymphoid tissue in chronic hypersensitivity pneumonitis.

STUDY OBJECTIVES: Bronchus-associated lymphoid tissue (BALT) is well defined in animals. In humans, however, BALT has been reported to be inducible under pathologic conditions, such as chronic respiratory infection, although it is not present in healthy adults. Thus, induced BALT is considered to be involved in the mucosal immunity of the human lung under these conditions. However, there have been few studies to investigate BALT development in hypersensitivity pneumonitis. The aim of this study was to examine the presence of BALT in hypersensitivity pneumonitis, especially in its chronic form. METHODS: The subjects included five patients with chronic hypersensitivity pneumonitis (CHP) diagnosed from clinical and histologic findings. We investigated histologically the development of BALT in these patients. Further, the cellular distribution of BALT was also examined by immunohistochemistry. RESULTS: BALT was present in three of five patients with CHP. Immunohistochemical examination revealed the follicular area of BALT to be composed mainly of B cells, while the parafollicular area comprised predominantly T cells. Centroblasts located in the germinal center of BALT expressed Ki-67 antigen, a marker of cell proliferation, suggesting that these cells were actively proliferating after antigenic stimulation. Cells expressing bcl-2, which is present primarily on memory B cells, were confined to the follicular area, devoid of any germinal centers. S-100-positive, CD1a-negative interdigitating dendritic cells were observed in the dome area of BALT. CONCLUSIONS: These observations suggest that chronic antigenic stimulation and/or inflammation in CHP may cause BALT development, which, in turn, is likely to play an important role in the mucosal immune response of this disease.

Adult↗
PubMed1999

Detection and evaluation of asymptomatic myocarditis in schoolchildren: report of four cases.

STUDY OBJECTIVE: Data on the prevalence of myocarditis in children are limited. Autopsy studies have shown that myocarditis is often undiagnosed. We attempted to investigate the clinical features of asymptomatic myocarditis in four schoolchildren detected during a mass ECG screening in schoolchildren. DESIGN AND SETTING: To evaluate asymptomatic myocarditis, we clinically examined 12 schoolchildren who were referred to Shiga University of Medical Science Hospital, Otsu, Japan, because of abnormal ST or T waves detected during ECG screening. None of the 12 children had experienced any episodes suggesting cardiac disease or Kawasaki disease. Cardiac function and myocardial viability were assessed by two-dimensional echocardiography (2-DE), thallium-201 (201Tl) myocardial scintigraphy, and cardiac catheterization. Endomyocardial biopsy specimens were examined histologically. PATIENTS: Endomyocardial biopsy specimens revealed histologic evidence of myocarditis in 4 of the 12 children with abnormal ST or T waves. RESULTS: Abnormal tracer perfusion was observed on 201Tl myocardial scintigrams in these four children, but the results of coronary arteriography were normal. 2-DE showed left ventricular hypokinesis in one child and left ventricular enlargement in one of the four children with histologic evidence of myocarditis. A second endomyocardial biopsy specimen was obtained in two of four children, showing persistent myocarditis in one child. CONCLUSIONS: This type of screening program and indepth evaluation using 2-DE and 201Tl myocardial scintigraphy appear to be helpful in identifying children with myocarditis. The present histologic investigations suggested that even asymptomatic myocarditis might result in persistent heart damage.

Biopsy↗
PubMed1999

Disseminated Fusarium infection identified by the immunohistochemical staining in a patient with a refractory leukemia.

The difficulty and uncertainty encountered in diagnosing a systemic mycosis often lead to a delay in starting antifungal therapy. We reported a disseminated infection of multiple fungal isolates including Fusarium species during donor leukocyte transfusion (DLT) after allogeneic bone marrow transplantation in a 20-year-old woman with a refractory leukemia. Skin lesions are the feature of Fusarium and occur in the early period of the infection. In this case, during immunosuppression state after DLT, she presented with the whole body ache and erythematous lesions which appeared rapidly on her trunk and extremities. While administration of amphotericin B was started, her condition was further deteriorated and she died. Autopsy materials revealed that she had multiple fungal infection with different isolates, including Aspergillus and Candida in the brain, lung and liver, but not in the skin. With the immunohistochemical staining with specific antibody, Fusarium or Aspergillus infection was identified from the biopsy skin or autopsy brain, respectively. This rapid and specific immunohistochemical method may be useful for the diagnosis and treatment of invasive fungal infection without delay.

Adult↗