Biomedical subjects

A Tanabe

Publications and source records attributed to A Tanabe.

At least 37 records · Page 2Linked to original sources

PubMed2001

Dynamic computer tomography is useful in the differential diagnosis of juxtaglomerular cell tumor and renal cell carcinoma.

We compared dynamic computer tomographic CT images of 3 cases of juxtaglomerular (JG) cell tumor with those of 8 cases of renal cell carcinoma (RCC). The JG cell tumor was visualized as a low- to high-density area in case 1, a low-density area in case 2, and a low- to iso-density area in case 3 before contrast enhancement. None of the JG cell tumors were stained during the early phase (1 min), but all were stained moderately during the late phase (5 min) after contrast enhancement. Although all cases of RCC were visualized as a low- to iso-density area before contrast enhancement, they were intensely stained during the early phase with significant washout during the late phase. The present results suggest that the dynamic CT scan is useful in the differential diagnosis of the JG cell tumor and RCC.

Adenocarcinoma↗

PubMed2001

Widespread distribution of adenovirus-transduced monkey amniotic epithelial cells after local intracerebral injection: implication for cell-mediated therapy for lysosome storage disorders.

Cell-mediated therapy for mucopolysaccharidosis type VII (MPSVII) was studied using monkey amniotic epithelial cells (mAEC). The cells were transduced with a recombinant adenovirus expressing human beta-glucuronidase (GUSB), and cells overexpressing GUSB were generated. The cells expressed 2000-fold higher activities than the endogenous GUSB activities of nontransduced mAEC, demonstrating that mAEC were successfully transduced with adenoviral vectors. These cells also secreted high levels of GUSB. To clarify the cross-correction of GUSB secreted from mAEC, the conditioned medium containing high levels of GUSB was added into the medium for culturing human or murine fibroblasts established from an MPSVII patient or a mouse model of the disease. Dramatic increases in GUSB activities were observed in both fibroblasts. We then transplanted the cells transduced with an adenovirus expressing LacZ into the caudate-putamen of monkey brain. Survival and distribution of the transplanted cells 1 month after the treatment were evaluated. Histochemical analysis showed that LacZ-positive cells were widely distributed in the brain, suggesting that the transplanted cells had migrated and were distributed even at regions far from the implantation site. These findings suggest that local intracerebral engraftment of genetically engineered amniotic epithelial cells is favorable for the treatment of lysosome storage disorders, whose pathological abnormalities are not restricted to specific regions of the brain.

Adenoviridae↗

PubMed2000

Two nuclear localization signals are required for nuclear translocation of nuclear factor 1-A.

Nuclear factor 1 (NF1) proteins are encoded by at least four genes (NF1-A, B, C, X). Although DNA-binding and the transcription regulation domains of these proteins are well characterized, the nuclear localization signals (NLSs) are still unknown in all NF1s. We have identified two NLSs in NF1-A, and both are required for full translocation to the nucleus, although one of them itself has a partial translocation ability. These two NLSs are conserved in all four NF1s. Interestingly, three isoforms of NF1-A (NF1-A1, A2, A4) have two NLSs and translocate completely to the nucleus. In contrast, NF1-A3 lacks the second NLS and partially stays in the cytoplasm. Since NF1s construct homodimer and heterodimer, these findings indicate the differential regulations of the NF1 translocation.

Amino Acid Sequence↗

PubMed2000

Adrenocortical carcinoma manifesting pure primary aldosteronism: a case report and analysis of steroidogenic enzymes.

Adrenocortical carcinoma manifesting pure hyperaldosteronism is extremely rare. We report here a 61-year-old woman with biochemically proven primary aldosteronism due to right adrenocortical carcinoma. Computed tomographic scan showed 4.5x5.3 cm lobulated mass with tiny calcification, while there was no significant uptake of 131I-iodomethyl norcholesterol in the tumor. Immunohistochemical analysis demonstrated expression of steroidogenic enzymes in the tumor tissue: P-450scc, P-45c21, 3beta-hydroxysteroid dehydrogenase, P450(17alpha), and P-450(11beta). In addition, we could demonstrate mRNA expression of aldosterone synthase (P-450aldo:CYP11B2) in the tumor by specific ribonuclease protection assay. This is the first report of a case of primary aldosteronism due to adrenocortical carcinoma, in which expression of all sets of steroidogenic enzymes required for aldosterone synthesis was proven.

Adrenal Cortex Neoplasms↗

PubMed2000

Identification of hydrocarbons and oxygen compounds in sediments from Niigata, Japan.

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Alkanes↗

PubMed2000

Intermittent antegrade warm blood cardioplegia for CABG: extended interval of cardioplegia.

BACKGROUND: Intermittent delivery of warm cardioplegia provides a bloodless surgical field, but it is clinically important to evaluate the periods of normothermic ischemia. The aims of this study are to compare intermittent antegrade warm blood cardioplegia (IAWBC) with intermittent antegrade cold blood cardioplegia (IACBC) groups in terms of myocardial protection, and also to evaluate whether the length of ischemic time in the IAWBC group has an effect on myocardial dysfunction. METHODS: This study is based on a retrospective review of patients who underwent elective coronary artery bypass surgery: 162 consecutive patients with IAWBC and 107 consecutive patients with IACBC. RESULTS: The creatinine kinase peak was smaller in the IAWBC group compared with the IACBC group (p<0.0001). The cardiac index after cardiopulmonary bypass was higher in the IAWBC group (p<0.02), and the amount of inotropic support required to wean from cardiopulmonary bypass was less in the IAWBC group compared with the IACBC group (p<0.0001). CONCLUSIONS: IAWBC with 30 minutes of ischemia provides to be clinically acceptable myocardial protection for coronary bypass surgery.

Aged↗

PubMed2000

Hydralazine decreases blood pressure and endothelin-1 mRNA expression in tissues but not cardiac weight in SHR-SP/Izm rats.

Although evidence has been accumulated to support a role of endothelin-1 (ET-1) in cardiac hypertrophy, details of the pathophysiological significance of ET-1 in cardiac hypertrophy remain to be elucidated. In the present study, we investigated the effects of the vasodilator hydralazine on the blood pressure, cardiac hypertrophy and ET-1 gene expression in various tissues of spontaneously hypertensive rats (SHR-SP/Izm). Hydralazine (20 mg/kg/day) was administered orally from the age of 4 weeks for 8 weeks. Tissues of the kidney, heart, aorta and brain were obtained at the age of 12 weeks. Tissue expression of ET-1 mRNA was determined by reverse transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot analysis. Administration of hydralazine resulted in a significant decrease in the blood pressure (156 +/- 1 mmHg vs 212 +/- 4 mmHg in controls) and an increase in the heart rate (470 +/- 20 bpm vs 402 +/- 23 bpm in controls). ET-1 mRNA expression was significantly decreased in the heart (x 1/2), kidney (x 1/4) and brain (x 1/2). There was no significant change of the cardiac weight (309 +/- 4 mg/100 g body weight vs 307 +/- 5 mg/100 g body weight in controls). The dissociation between ET-1 mRNA expression and cardiac hypertrophy in hydralazine-treated rats may suggest that the increased tissue ET-1 is not an indispensable factor of cardiac hypertrophy in hypertension. Sympathetic activation, as shown by the reactive tachycardia, may overcome the effects on the blood pressure and ET-1 expression.

Animals↗

PubMed2000

Augmented expression of tissue endothelin-1 messenger RNA is a common feature in hypertensive rats.

Recent studies revealed important roles for endothelin-1 (ET-1) in the pathogenesis of hypertension. Whether ET-1 could be a primary cause of hypertension or a secondary factor associated with hypertension, however, remains unknown. In this study, we determined plasma ET-1 levels and the expression of ET-1 mRNA in tissues of rats rendered hypertensive using distinct mechanisms: deoxycorticosterone acetate (DOCA)-salt hypertension: N(G)-nitro-L-arginine-methyl ester- (L-NAME) induced hypertension; and spontaneously hypertensive rats (SHR-SP). ET-1 mRNA expression level was determined by reverse transcriptase polymerase chain reaction (RT-PCR) followed by Southern blotting. There was no significant difference in plasma ET-1 levels between the hypertensive rats and normotensive rats. By contrast, ET-1 mRNA level was significantly increased in various tissues including the adrenal, lung, kidney and brain of these hypertensive rats compared with control rats. Thus, ET-1 gene expression was ubiquitously augmented in tissues of hypertensive rats irrespective of the cause of the hypertension. The results suggest that the increase in ET-1 expression is not the primary cause of hypertension but a secondary outcome which may further exacerbate the hypertension.

Animals↗

PubMed2000

Effects of acute and chronic cigarette smoking on the expression of endothelin-1 mRNA of the cardiovascular tissues in rats.

Although smoking has been suggested to be involved in the development of cardiovascular diseases, details of the mechanism still need to be revealed. We investigated the effects of cigarette smoking on the tissue mRNA expression of endothelin-1 (ET-1). Male Wistar rats of 4 weeks of age were exposed to smoke from six cigarettes for 30 min (acute exposure) and six cigarettes for 30 min/day, 5 days a week for 6 months (chronic exposure). Half of the rats exposed to 6 months smoking were kept in clean-air conditions for a further 3 months to clear the effects. Tissue expression of ET-1 mRNA in the kidney, aorta, heart and lung was determined by reverse transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot analysis. There was no significant difference in body and organ weight of the heart and kidney between the control and smoking group in either the acute or chronic experiment. In the acute-exposure experiment, expression of ET-1 mRNA was increased in the heart and lung, while that in the kidney and aorta was unchanged. In the chronic-exposure experiment, however, there was no significant difference in the expression of ET-1 mRNA in all the tissues between the smoking and control groups. These results suggest that cigarette smoking could cause cardiovascular and pulmonary diseases by modulating ET-1 mRNA expression in the tissues.

Animals↗

PubMed2000

Hemodynamic and biochemical effects of endothelin-A- and -B-receptor antagonist TAK-044 in stroke-prone spontaneously hypertensive rats.

We have demonstrated previously that endothelin-1 (ET-1) mRNA expression is increased in hypertensive rats. The aim of the study reported here was to elucidate the effects of the endothelin (ET) receptor antagonist on the hemodynamic and biochemical parameters in stroke-prone spontaneously hypertensive rats (SHRSPs/Izm). The endothelin-A- and -B- (ETA/ETB) receptor antagonist (TAK-044, Takeda Chemical Industries, Osaka, Japan) was administered subcutaneously at a dose of 10 mg/kg/day from the age of 8 weeks for 4 weeks. Blood samples and tissues of the kidney, heart and brain were obtained at the age of 12 weeks. Tissue expression of ET-1 mRNA was determined by reverse transcriptase-polymerase chain reaction (RT-PCR) followed by Southern blot analysis. Treatment with TAK-044 resulted in a significant decrease in systolic blood pressure (SBP), blood urea nitrogen (BUN), serum creatinine concentration, plasma aldosterone level, heart weight, and kidney weight. In addition, ET-1 contents and mRNA expression level in the kidney, heart and brain were significantly decreased by the treatment with TAK-044. These results suggest that the ET receptor antagonist TAK-044 is able to attenuate ET-1 gene expression in addition to its specific antagonism of the biological actions of ET via the receptors.

Animals↗

PubMed2000

Gene expression of CCAAT/enhancer-binding protein delta mediated by autoregulation is repressed by related gene family proteins.

CCAAT/enhancer-binding protein delta (C/EBPdelta) transcription factor is rapidly induced at an early stage of acute phase response. We previously reported that this induction was mainly mediated by acute phase response factor/signal transducers and activators of transcription 3 (APRF/STAT3). Furthermore, the high expression level of C/EBPdelta is maintained by autoregulation mechanisms through the C/EBPdelta binding sites located downstream of C/EBPdelta gene. Thereafter, the expression of C/EBPdelta gene decreases rapidly to the basal level. However, these mechanisms are still unknown. According to both transfection and DNA binding analyses, liver-enriched inhibitory protein (LIP), the shorter form of C/EBPbeta and C/EBP-homologous protein 10 (CHOP10), were found to inhibit C/EBPdelta gene expression. DNA binding analysis has further indicated that both LIP and CHOP10 form heterodimers with C/EBPdelta, and inhibit the binding of C/EBPdelta homodimer to the C/EBPdelta binding sites located downstream of C/EBPdelta gene. Taken together, these findings indicated that the maintained expression of C/EBPdelta gene by autoregulation was inhibited and decreased to the basal level as a result of the competition of other C/EBP family proteins. Thus, C/EBPdelta gene expression is mediated by the gene regulation circuit through the downstream C/EBPdelta binding sites.

Animals↗

PubMed2000

A defect of lipopolysaccharide-induced nitric oxide synthase gene expression in the paraventricular nucleus of Lewis rats.

The hypothalamo-pituitary-adrenal (HPA) axis activity of Lewis rats has been reported to be hyporesponsive to immune challenge, and nitric oxide (NO) has been demonstrated to be involved in the regulation of the HPA axis during the response to immune challenge. The present study investigates the effect of systemic injection of lipopolysaccharide (LPS) on NO production within the paraventricular nucleus (PVN) of immature female Fisher-344 (F344) and Lew/N rats (Lew/N), to clarify the pathophysiological role of NO in the dysregulation of the HPA axis in Lewis/N. Intraperitoneal injection of 25 mg/kg LPS significantly increased neuronal NO synthase (nNOS) mRNA expression in the PVN of F344 rats, but did not change nNOS mRNA levels in the PVN of Lew/N rats. CRF mRNA levels in the PVN significantly increased in response to LPS injection only in F344 rats. In contrast, inducible NOS (iNOS) mRNA increased similarly in both strains. These results demonstrated a defect of up-regulation of nNOS gene expression in the PVN of Lew/N rats following immune challenge. The defect appears to be associated with the dysfunction of the HPA axis in this strain. An increase in iNOS mRNA may partially restore NO production in the PVN.

Animals↗

PubMed2000

[Insulin resistance and vascular function].

There is a very close interrelationship between the metabolic disorders such as obesity and diabetes mellitus and cardiovascular diseases such as hypertension and atherosclerosis, with insulin resistance and endothelial dysfunction as common features. Insulin has vasculoprotective effects through production of nitric oxide in the endothelial cells, while it produces atherogenic effects by stimulating proliferation and migration of vascular smooth muscle cells(VSMC). The insulin-activated pathway is the phosphatidylinositol 3-kinase pathway in the endothelial cells and MAP kinase pathway in the VSMC. Insulin resistance and hyperinsulinemia may result in the attenuation of the endothelium-mediated action and stimulation of the VSMC-mediated action. Insulin resistance and endothelial dysfunction are related to each other and may cause vicious cycle, leading to the metabolic and cardiovascular diseases.

Arteriosclerosis↗

PubMed2000

Analysis of the candidate genes responsible for non-syndromic cleft lip and palate in Japanese people.

In order to assess the association of alleles for candidate genes with non-syndromic cleft lip and palate, DNA samples from 43 Japanese patients were compared with those from 73 control subjects with respect to the genes encoding transforming growth factor alpha (TGFalpha), TGFbeta and gamma-aminobutyric acid type A receptor beta3 (GABRB3). The restriction fragment length polymorphisms of the 3'-non-coding region of the TGFalpha gene K-primer region were observed after digestion with NcoI and HinfI. Allele 4 was the most common among cases of cleft lip with or without cleft palate, whereas allele 2 was the most common among controls. A significant difference was found in this region between groups with cleft lip (with or without cleft palate) and controls (chi2=10.190; P=0.017). Three alleles of the TGFbeta2 gene were tested, and allele 2 was the most common in both cases and controls. The proportion of allele 2 in the case group was greater than that in the control group, showing a significant difference between cases of cleft lip (with or without cleft palate) and controls (chi(2)=19.208; P<0.0001). No significant differences in variants of TGFbeta3 or GABRB3 between case and control populations were observed. Thus it is concluded that TGF genes play a role in craniofacial development, and that alleles of TGFalpha or/and TGFbeta2 are associated with cleft lip and cleft palate in Japanese populations.

Adolescent↗

PubMed2000