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Biomedical subjects

T Uchida

Publications and source records attributed to T Uchida.

At least 73 records · Page 4Linked to original sources

Hypermethylation of p16INK4A gene promoter during the progression of plasma cell dyscrasia.

Recent studies have indicated a close relationship between inactivation of tumor suppressor genes (TSGs) and disease progression. The genes encoding the cyclin-dependent kinase inhibitors p16INK4A and p15INK4B are potent TSGs, and correlations between their inactivation and disease progression have also been reported in various malignancies. In this study, we analyzed the methylation status of p16INK4A and p15INK4B gene promoters in plasma cell dyscrasias (PCDs) by methylation-specific PCR (MSP). In analyses using DNAs extracted from bone marrow mononuclear cells (BM-MNCs), patients with multiple myeloma (MM) showed frequent hypermethylation of the p16INK4A gene (15/37, 41%), whereas p15INK4B gene methylation was not so frequent (5/37, 14%). Many patients whose BM-MNC showed dense methylation of the p16INK4A gene had extramedullary plasmacytoma (extra-PC), and all available extra-PC samples showed alterations of the p16INK4A gene (4; dense methylation, 1; homozygous deletion). In contrast to MM, hypermethylation of the p16INK4A gene was significantly infrequent in indolent PCDs (2/22, 9%, P= 0.0055). The infrequency in indolent PCDs was also confirmed by analyses using DNAs extracted from BM smears (1/29, 3%). It is possible that hypermethylation of the p16INK4A gene promoter contributes to progression to aggressive MM from indolent PCD, especially to extra-PC development.

Biomarkers↗

A case of autoimmune hepatitis with a high titer of antimitochondrial antibody and normal gamma-globulinemia.

We report here a patient with chronic active hepatitis who had no markers for hepatitis viruses and no hyper-gamma-globulinemia, but had high titers of antimitochondrial antibody. Serum levels of alkaline phosphatase were normal, and antinuclear antibody, antismooth muscle antibody, and antiliver kidney microsome antibody tested negative. The titers of antimitochondrial antibody exceeded 1:640, and the positivity for anti-M2 was ascertained by using both ELISA and immunoblot with beef-heart mitochondria and a recombinant pyruvate dehydrogenase E2 subunit as antigens. This patient responded to ursodeoxycholic acid (UDCA) therapy in the beginning, but her hepatitis flared up during UDCA therapy. In contrast, she responded completely to corticosteroid therapy. The clinical course and histological findings of this patient strongly suggest that this patient has autoimmune hepatitis.

Aged↗

Irregular regeneration of hepatocytes is an important factor in the hepatocarcinogenesis of liver disease.

The goal of this study was to assess the relationship between the degree of irregular regeneration of hepatocytes (IR) and the development of hepatocellular carcinoma (HCC). We examined the liver biopsy specimens from patients with chronic liver disease (CLD), and the noncancerous liver tissue in the surgically resected specimens from patients with HCC. Liver tissues were obtained from 18 patients with B-viral CLD, 38 with C-viral CLD, and 5 with nonB-nonC (NBNC)-CLD who underwent liver biopsy, and 24 patients with B-viral HCC, 67 with C-viral HCC, and 17 with NBNC-HCC who underwent surgical resection. The IR score of the noncancerous region of the liver of the HCC patients and that of the liver biopsy specimens of the CLD patients, were compared. Of the 108 samples of noncancerous liver tissue from the HCC patients, 70% showed an IR score of moderate or higher (IR = 3 or 4), and only 1.9% showed an IR score of none or minimal (IR = 0 or 1). The degree of IR of hepatocytes in the HCC patients was significantly more severe than that in the CLD patients in each etiological type of CLD. High IR may reflect the histologic expression of genetic instability, namely a carcinogenic state, although prospective studies are needed to determine its relationship to the risk for developing HCC.

Adult↗

Relative importance of calcium-activated potassium channels in nipradilol-induced aortic relaxation in rats.

Nipradilol (CAS 81486-22-8), a vasodilatory beta-blocker, has been shown to dilate smaller vessels than nitroglycerin does, and the vasodilative effects of nipradilol have been reported to be less mediated by cyclic GMP (guanosine monophosphate) than those of nitroglycerin. To test the hypothesis that cyclic GMP-independent potassium channels have a larger role in nipradilol-induced aortic relaxation than cyclic GMP-dependent mechanisms, the effects of a potassium channel blocker, tetraethylammonium (TEA, CAS 56-34-8), and of a guanylate cyclase inhibitor, methylene blue (MB, CAS 61-73-4), on nipradilol-induced aortic relaxation were investigated and compared with those on nitroglycerin-induced aortic relaxation in isolated rat aortic rings. Relaxation response was expressed as percent relaxation, which is a percentage of the tension developed by 10(-7) mol/l norepinephrine. Nitroglycerin and nipradilol similarly relaxed the aortic ring in a concentration-dependent manner (10(-9)-10(-4) mol/l). In contrast, desnitronipradilol, a nipradilol analogue which has no nitroxy group, induced almost no aortic relaxation. TEA at 10(-3) mol/l, which is selective for calcium-activated potassium channels, inhibited the aortic relaxation induced by nipradilol (10(-5) mol/l) to a significantly greater extent than that induced by nitroglycerin (10(-5) mol/l) (% relaxation: 30.0 +/- 6.8 vs. 51.1 +/- 6.1%, p < 0.05). MB (10(-5) mol/l) suppressed the relaxation by nitroglycerin slightly but not significantly more than that by nipradilol. (% relaxation: 54.7 +/- 9.9 vs. 64.6 +/- 5.7%). The combination of TEA and MB almost completely eliminated the relaxation induced by nipradilol as well as by nitroglycerin. Thus, cyclic GMP-independent calcium activated potassium channels may be more involved in the aortic relaxation by nipradilol than that by nitroglycerin in rats.

Adrenergic beta-Antagonists↗

Expression of tyrosine kinase receptors Tie-1 and Tie-2 in giant cell tumor of the tendon sheath: a possible role in synovial proliferation.

We have recently demonstrated that Tie-1 and Tie-2 are expressed in synovial cells from rheumatoid arthritis (RA). To elucidate the possible involvement of Tie receptors in synovial proliferation, we analyzed their expression by immunostaining in five cases of giant cell tumor of tendon sheath (GCTTS), which represents a proliferating lesion of synovial cells. Strong immunoreactivity for both Tie-1 and Tie-2, regardless of the individual patient's profile, was observed in all cases of GCTTS. Six sets of double immunohistochemical stainings for Tie-1/Tie-2 and fibronectin, CD68, or CD34 were carried out to determine the phenotype of Tie-1 and Tie-2-positive tumor components. In these studies, both Tie-1 and Tie-2 immunoreactivity were widely observed in the fibronectin-positive fibroblastic and the CD68-positive histiocytic mononuclear cells, as well as in the osteoclast-like giant cells. In tumor vasculature, Tie receptors were expressed in the CD34-positive endothelial cells possessing proliferating cell nuclear antigen (PCNA) immunoreactivity. We also evaluated the correlation of Tie-1/Tie-2 expression and proliferating cells in GCTTS by using double staining of Tie-1/Tie-2 together with PCNA. Overexpression of PCNA immunoreactivity was frequently found in Tie receptors-positive cells with no obvious differences in the expression pattern of Tie-1 and Tie-2. These findings suggest the possible involvement of Tie receptors in the pathogenesis of GCTTS other than solely via their involvement in angiogenesis and subsequent vascularization. It was demonstrated that Tie-2 immunoreactivity was restricted to the fibroblastic, but not histiocytic, phenotype in RA synovium, suggesting different regulatory control of Tie-2 expression in GCTTS and RA synovium. Overexpression of Tie receptors in GCTTS may imply a biological role for these receptors in synovial proliferation.

Adult↗

Significance of platelet aggregability immediately after blood sampling and effect of cigarette smoking.

A novel type platelet aggregometer, a WBA Analyzer, has enabled us to obtain the platelet aggregability data immediately after blood sampling, which is considered to closely reflect in vivo platelet function. Using this analyzer, we measured the platelet aggregatory threshold index (PATI) 5 min after blood sampling and compared it with that 60 min after blood sampling in 20 healthy male volunteers (10 smokers and 10 non-smokers). In the non-smokers, PATI was 10.3+/-2.3 microM 5 min after blood sampling, and it decreased to 4.7+/-1.5 (P<0.001) 60 min after blood sampling. In the smokers, the PATI was 7.7+/-2.9 microM 5 min after blood sampling, and it decreased to 3.8+/-1.5 (P<0.001) at 60 min after blood sampling. In the smokers, the PATI 5 min after blood sampling increased after a 4-week cessation of smoking (10.4+/-2.9, P<0.01), although the PATI 60 min after blood sampling did not change (4.2+/-1.6 microM). The measurement of platelet aggregability immediately after blood sampling using a WBA Analyser may be useful to evaluate not only platelet function in various thrombotic disorders, but also the effects of various anti-platelet drugs. Cessation of smoking should also be encouraged in the light of the adverse effects on platelet function.

Adult↗

p53 Mutation in bladder cancer patients in Japan and inhibition of growth by in vitro adenovirus-mediated wild-type p53 transduction in bladder cancer cells.

BACKGROUND: Altered expression of p53 has been described in nearly half of bladder cancers, and p53 mutations are presumed to play a role in the multistep progression of these tumors. MATERIALS AND METHODS: The incidence of mutation in the p53 gene and its correlation with histopathologic findings and patient survival were evaluated in 105 Japanese patients with bladder cancer. Laboratory experiments were also performed to confirm the infectivity and efficacy in tumor growth inhibition of an adenovirus expressing wild-type p53 in EJ bladder cancer cells. RESULTS: Mutations of p53 were observed in 38 bladder cancer specimens (36%), with a significantly higher incidence of mutation being seen in tumors of higher stage and grade. The overall survival was worse in patients with the p53 mutation. In laboratory experiments, adenoviral vectors infected bladder cancer cells in a dose- and cell density-dependent manner. The adenovirus-mediated transduction of wild-type p53 resulted in dose-dependent growth inhibition of bladder cancer cells in vitro. No significant cytotoxicity was observed after infection by a control adenovirus. CONCLUSION: Transduction of wild-type p53 might be a potential therapeutic option for bladder cancer.

Adenoviridae↗

Antitumor effect of bcl-2 antisense phosphorothioate oligodeoxynucleotides on human renal-cell carcinoma cells in vitro and in mice.

BACKGROUND AND PURPOSE: Programmed cell death is a genetically regulated pathway that is altered in many cancers. This process is, in part, regulated by the bcl-2 oncogene. Antisense oligodeoxynucleotides (ODNs) targeted to specific oncogenes have been used with some therapeutic success in animal models of leukemia and melanoma cells and human Hodgkin's lymphoma. We evaluated the effects of antisense ODNs targeted to the bcl-2 oncogene on the proliferation of human renal-cell carcinoma (RCC) cells in vitro and on the growth of human RCC xenografts in BALBc nude (nu/nu) mice. MATERIALS AND METHODS: Expression bcl-2 mRNA in five RCC cell lines (ACHN, Caki-1, RCZ, RCW, and OS-RC-2) was analyzed by reverse transcriptase-polymerase chain reaction. The effects of phosphorothioated ODNs containing human bcl-2 sense and bcl-2 antisense sequences that were transfected with Lipofectin on the proliferation and viability of cultures of established human RCC cell lines were determined by MTS assay. The expression of Bcl-2 protein in ACHN tumor cells following antisense bcl-2 (AS2) ODN treatment was evaluated by Western blot analysis, and the extent of apoptosis in these cells was determined by fluorescence-activated cell sorter (FACS) analysis. The antitumor activity in ACHN xenografts in nu/nu mice was monitored by measuring differences in tumor weight in treated and control mice. RESULTS: Expression of bcl-2 mRNA was detected in all five RCC lines. Treatment with antisense bcl-2 ODNs inhibited the growth of all tested RCC cells and decreased Bcl-2 protein expression in ACHN cells. The AS2 antisense ODN complementary to the coding region of bcl-2 mRNA showed a superior antiproliferative effect compared with AS1 ODN complementary to the translation initiation region. Inhibition by antisense bcl-2 ODNs of ACHN cells was dose dependent. The FACS analysis revealed that growth inhibition was associated with the induction of programmed cell death. In vivo, AS2 ODN antitumor activity was noted in locally injected groups. CONCLUSIONS: Treatment of human RCC with antisense ODNs targeted to bcl-2 inhibits growth and is associated with the induction of programmed cell death. These results suggest therapeutic use of antisense bcl2 in the treatment of RCC.

Animals↗

Unusual coronary artery aneurysm and acute myocardial infarction in a middle-aged man with systemic lupus erythematosus.

A 55-year-old man developed acute myocardial infarction (AMI) related to a large coronary artery aneurysm and a distal coronary stenotic lesion after steroid therapy for systemic lupus erythematosus (SLE). Only 13 SLE patients with AMI caused by coronary artery aneurysms have been reported, 11 of whom were young or middle-aged women and the 2 remaining were young men. This is the first report of a middle-aged man with multiple coronary lesions.

Arteriosclerosis↗

New technique for application of fibrin sealant: rubbing method devised to prevent cerebrospinal fluid leakage from dura mater sites repaired with expanded polytetrafluoroethylene surgical membranes.

OBJECTIVE: The effectiveness of a strong, pressure-tight method for fibrin sealant application was experimentally and clinically evaluated, using expanded polytetrafluoroethylene (ePTFE) surgical membranes. METHODS: Two application methods were examined in two groups. For Group 1, 1 ml each of Solutions A and B was simply sprayed over the surface (spray method). For Group 2, a small amount of Solution A was rubbed into the sutured site and then Solutions A and B were sprayed over the surface (rubbing method). In the experimental study, a moment pressure elevation test and a continuous stepwise pressure elevation test were performed for both groups. The clinical study was conducted using 350 patients undergoing craniotomies. The ePTFE surgical membrane was used for 180 patients but not the other 170 patients. RESULTS: In the experimental study, the bursting pressures were 51.4 +/- 13.0 cm H2O for Group 1 and 129 +/- 35.0 cm H2O for Group 2 in the moment pressure elevation test and 27.0 +/- 6.7 cm H2O and 100 +/- 31.9 cm H2O, respectively, in the continuous stepwise pressure elevation test. The sealing effect was significantly greater for Group 2 than for Group 1 in both tests (P < 0.001). In the clinical study using ePTFE surgical membranes, the rubbing method significantly reduced the incidence of postoperative cerebrospinal fluid leakage (1.4%), compared with the spray method (18.3%), when external decompression was not concomitantly used (P < 0.01). CONCLUSION: The sealing effect of fibrin sealant on cerebrospinal fluid leakage was significantly greater with the rubbing method than with the spray method. The strong sealing effect obtained with the rubbing method is thought to result from firm linkage between the ePTFE surgical membrane and the fibrin sealant and also from fibrin being formed even in needle holes and spaces in the sutured site.

Adolescent↗

Expression of multidrug resistance-related transporters in human breast carcinoma.

The expression levels of mRNA for multidrug resistance 1 (MDR1) gene, multidrug resistance protein 1 (MRP1), lung resistance-related protein (LRP) and breast cancer resistance protein (BCRP), which confer multidrug resistance in vitro, were examined in 43 untreated breast carcinoma patients, of whom 38 subsequently received doxorubicin-based chemotherapy after surgery, in order to elucidate the roles of these genes in drug resistance in vivo. The mRNA levels were determined using a semi-quantitative reverse-transcription polymerase chain reaction method in breast carcinoma tissues including at least 80% carcinoma cells. The expression level of BCRP gene was low and did not vary markedly in comparison with that of MDR1, MRP1 or LRP gene. The expressions of MDR1 and MRP1 genes were correlated with each other, but the expression of BCRP or LRP gene did not correlate with that of other genes. These four gene expressions were independent of age, TNM categories and the status of progesterone or estrogen receptor. The expression levels of these four genes were not related to the relapse or prognosis of the 38 patients treated with doxorubicin-based chemotherapy. P-glycoprotein (P-gp) / MDR1, MRP1 and LRP may play more important roles than BCRP in chemotherapy of human breast carcinoma.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Nucleotide sequence of the precore/core gene and X gene of hepatitis B virus DNA in asymptomatic hepatitis B virus carriers who are negative for serum hepatitis B core antibody.

A hepatitis B virus (HBV) carrier who is positive for hepatitis B surface (HBs) antigen but negative for hepatitis B core (HBc) antibody despite persistent HBV infection, is designated as having hepatitis B virus 2 (HBV2). HBV2 is reported to be induced by mild-grade hepatitis. Patients with HBV2 have been reported in Taiwan and Senegal. In the present study, we determined the nucleotide (nt) sequence of the precore/core gene coding region and X gene region of the HBV DNA sequence in 7 subjects who were positive for HBs antigen and negative for HBc antibody. HBV DNA was detected by nested polymerase chain reaction (PCR). Nested PCR was carried out to amplify the precore/core and X open reading frames (ORFs) of HBV DNA. The second PCR products were sequenced, followed by investigation of nt homology. There were no deletions nor insertions in the nt sequence of the precore/core and X ORFs in the HBV DNA of these 7 patients, and mutations were found only sporadically in the 7 patients. Also, there were no common amino acid substitutions in the examined regions of the amino acid sequence of HBV in the 7 patients, and we could not find a common mutation in the examined regions of HBV DNA that could potentially contribute to the development of negativity for HBc antibody. Thus, it is suggested that negativity for HBc antibody in patients with HBV2 is due to an immune response abnormality in the host.

Adolescent↗

Acute pancreatitis signals activation of apoptosis-associated and survival genes in mice.

In experimental models of acute pancreatitis (AP), acinar cell death occurs by both necrosis and programmed cell death or apoptosis. Apoptosis is an active form of cell death associated with a tightly regulated expression of gene products that are either pro- or antiapoptotic. The aim of this study was to characterize pancreatic mRNA levels by Northern blotting analysis of apoptosis-associated genes used during the course of cerulein-induced AP in mice. Histone H3 mRNA levels were also examined as an indicator of cell proliferation. Acinar cell apoptosis was confirmed histologically. The findings show that AP modifies pancreatic mRNA levels of both pro- and antiapoptotic genes simultaneously. Pancreatic bclXL, bax, and p53 mRNA levels increased significantly in a temporal fashion during induction of AP. Pancreatic bcl-2 mRNA levels were unchanged during AP. Pancreatic mRNA levels of insulin-like growth factor-1 (IGF-1), a mitogen and cell survival factor, and its receptor (IGF-1R) also increased in a temporal fashion during induction of AP. In summary, this study indicates that acinar cell death during cerulein-induced AP in mice can occur by the apoptotic pathway. Since factors promoting and antagonistic for cell survival are activated simultaneously, regulation of acinar cell survival appears complex and dynamic during AP.

Acute Disease↗