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Biomedical subjects

H Masuyama

Publications and source records attributed to H Masuyama.

At least 19 recordsLinked to original sources
PubMed2006

Expression and potential role of peroxisome proliferator-activated receptor gamma in the placenta of diabetic pregnancy.

Peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed predominantly in adipose tissue and is known to be involved in adipocyte differentiation and insulin sensitivity. Recent reports indicated that PPARgamma-deficient mice were embryonic lethal due to abnormal placental development, suggesting that PPARgamma plays an important role in normal development of placenta. On the other hand, expression of vascular endothelial growth factor (VEGF), the other important factor in placental development, has been demonstrated to be regulated by PPARgamma in vascular smooth muscle cells. Also, diabetic pregnancy is often associated with defective placental functions. In order to investigate physiological roles of PPARgamma and VEGF in placental development during diabetic pregnancy, we examined the expressions of PPARgamma and VEGF in placentas, which were obtained from normal and streptozotocin-induced diabetic pregnant mouse, and studied in vitro effects of hyperglycemic condition and PPARgamma ligands (rosiglitazone and 15-deoxy-delta(12,14)prostaglandin J(2)) on trophoblasts using human choriocarcinoma cell lines. In diabetic mouse placentas (n=5), expressions of PPARgamma and VEGF proteins significantly increased as compared with these in normal placenta (n=3 or 4). In vitro studies indicated that hyperglycemic condition (42 mM) significantly enhanced the PPARgamma expression and hCG production, and significantly suppressed cell proliferation, however these effects were attenuated by PPARgamma ligands that accompanied with increased VEGF production. These data suggest that the PPARgamma pathway might be involved in the impairment of placental development induced by high glucose conditions, and that VEGF might play some roles in this pathway.

Animals↗
PubMed2005

Minimal change oesophagitis: a disease with characteristic differences to erosive oesophagitis.

BACKGROUND: The majority of gastro-oesophageal reflux disease (GERD) seems to be non-erosive reflux disease. Nonerosive reflux disease includes minimal change oesophagitis (whitish or reddish, oedematous change and erosion that is not regarded as mucosal break) and no endoscopic abnormalities. AIM: To investigate the accurate proportion of those with minimal change oesophagitis and to clarify its characteristics. In addition, we evaluated the effect of famotidine (40 mg/day) in those with minimal change. METHODS: Prospective endoscopic assessment was performed for consecutive 606 out-patients. Of the 582 patients suitable for analysis, 347 were non-treated. The latter were divided into those with erosive GERD or minimal change, and their endoscopic findings and characteristics were compared. RESULTS: Among 347 non-treated patients, 88 (25%) had erosive GERD and 249 (72%) had minimal change. Compared with patients who have erosive GERD and those with minimal change, the latter were less likely to have hiatal hernia or bile reflux, but more likely to have gastric atrophy. Symptomatic patients (n = 55) with minimal change oesophagitis were more likely to have hiatal hernia than those who were asymptomatic (n= 194). Most patients preferred taking famotidine on-demand, during a 4-week follow-up period. CONCLUSIONS: Most non-erosive reflux disease can be classified as minimal change oesophagitis, and that have different characteristics from erosive GERD. On-demand famotidine may be a suitable alternative treatment for patients with minimal change disease.

Adult↗
PubMed2003

The different effects of endocrine-disrupting chemicals on estrogen receptor-mediated transcription through interaction with coactivator TRAP220 in uterine tissue.

An endocrine-disrupting chemical (EDC) can alter endocrine functions through a variety of mechanisms, including nuclear receptor-mediated changes in protein synthesis, interference with membrane receptor binding, steroidogenesis or synthesis of other hormones. Although major chemicals have been shown to disrupt estrogenic actions mainly through their binding to estrogen receptor (ER) or androgen receptor, it is not clear how EDCs affect endocrine functions in vivo. We present evidence that the EDCs bisphenol A and phthalate activate ER-mediated transcription through interaction with TRAP220. Moreover, bisphenol A had positive effects on the interaction between ER-beta and TRAP220 and on the expression of ER-beta and TRAP220 compared with phthalate and estradiol in uterine tIssue. These data suggested that some EDCs might alter endocrine function through the change of the receptor and coactivator levels in uterine tIssue and through the different effect on the interaction between ERs and coactivator TRAP220.

Animals↗
PubMed2001

The expression of pregnane X receptor and its target gene, cytochrome P450 3A1, in perinatal mouse.

Recently, pregnane X receptor (PXR) has been described to mediate the genomic effects of several steroid hormones, such as progesterone (P), glucocorticoid (Dex), pregnenolone (Preg), and xenobiotics through the cytochrome P-450 3A gene family (CYP3A), which are monooxygenases, responsible for the oxidative metabolism of some endogenous substrates and xenobiotics. In the present study, we used a transient transfection reporter gene expression assay of COS-7 cells to demonstrate that P, Dex and Preg significantly stimulate PXR-mediated transcription at relatively high concentration comparable with that of progesterone near term pregnancy. In yeast two-hybrid protein interaction assay, PXR interacted with nuclear receptor coactivator proteins, SRC1, RIP140, and SUG1 in a ligand-dependent manner. The expression of PXR mRNA was observed in the liver, intestine, uterus, ovary and placenta. The expressions of PXR mRNA in the liver and ovary increased towards term about fifty-fold compared with that of non-pregnancy and decreased postpartum. Its expression in the placenta was not drastically changed towards term. CYP3A, a target gene of PXR, was also expressed in the liver, ovary, and placenta. The expressions of CYP3A mRNA as well as PXR in the liver and ovary increased about 20-fold during prenatal period. These data suggest that PXR may play certain roles in perinatal period, possibly in the protection of the feto-maternal system from the toxic effect of endogenous steroids and foreign substrates.

Animals↗
PubMed2001

Coexistence of Graves' disease and struma ovarii: case report and literature review.

We report a rare case of Graves' disease associated with struma ovarii. A 26-year-old Japanese woman had preexisting Graves' disease and was positive for TSH receptor antibody. She had been on antithyroid medication at presentation. She noted a mass in the lower left abdomen, which was diagnosed as a left struma ovarii by radiological work-up including computed tomography, magnetic resonance imaging and scintigraphy. The surgically excised teratomatous tumor, containing cystic spaces with thyroid tissue, was histologically proved to be struma ovarii. Since thyroid function tests and TSH receptor antibody did not change after surgery, her hyperthyroidism was considered to be due to Graves' disease. Our case was diagnosed as struma ovarii before surgery using various imaging studies.

Adult↗
PubMed2000

Streptozotocin-induced diabetic pregnant rats exhibit signs and symptoms mimicking preeclampsia.

The number of patients with hypertension, obesity, diabetes, and hyperlipidemia is increasing. This tendency is observed in pregnant women, in whom many obstetrical and perinatal complications occur. The prevention of these abnormalities is important in reducing perinatal mortality and the risk of coronary disease. We established a pregnant rat model with diabetes and signs and symptoms mimicking preeclampsia. On day 6 of pregnancy, streptozotocin (STZ) or citrate buffer was injected into the tail vein. After STZ administration, plasma glucose was increased within 48 hours and sustained at a high level until day 20 of pregnancy, and plasma insulin was decreased. Fetuses from STZ-treated mothers were growth-restricted, and plasma glucose was 6-fold higher in fetuses of STZ-treated versus control rats. The systolic blood pressure, urinary protein, and hematocrit were increased significantly in STZ-treated rats. Total cholesterol and triglycerides were also elevated in STZ-treated rats, but plasma leptin levels were decreased. The STZ-induced diabetic pregnant rat model exhibited preeclampsia, hemoconcentration, hyperlipidemia, hypoleptinemia, and intrauterine growth restriction. This model closely mimics the features of human pregnancy complicated by diabetes and is useful for the basic study of the pathophysiology of pregnancy with diabetes.

Animals↗
PubMed2000

Heavy-for-date infants: their backgrounds and relationship with gestational diabetes.

OBJECTIVE: Gestational diabetes (GDM) is closely related to birth weight. Heavy-for-date (HFD) infants, especially those with macrosomia, cause many perinatal complications. This study was performed to examine the backgrounds of HFD infants and to determine such infants' relationship with GDM. METHOD: Eighty cases of HFD infants who were delivered from 1996 through 1998 were analyzed. The random blood-glucose level was used for screening for GDM. RESULTS: Maternal body weight and the body-mass index before pregnancy and at delivery and the blood glucose level at the second trimester were positively correlated with birth weight. However, only 8.8% of HFD cases were detected by this screening method in the first trimester, and 11.3% of HFD cases were detected in the second trimester and only 1 case of borderline-type was detected by subsequent 75-g OGTT. CONCLUSIONS: Maternal obesity is an independent and more important risk factor for HFD infants than glucose intolerance.

Adult↗
PubMed2000

Endocrine disrupting chemicals, phthalic acid and nonylphenol, activate Pregnane X receptor-mediated transcription.

Recently, Pregnane X receptor (PXR), a new member of the nuclear receptor superfamily, was shown to mediate the effects of several steroid hormones, such as progesterone, glucocorticoid, pregnenolone, and xenobiotics on cytochrome P450 3A genes (CYP3A) through the specific DNA sequence for CYP3A, suggesting that PXR may play a role in steroid hormone metabolism. In this paper, we demonstrated that phthalic acid and nonylphenol, endocrine-disrupting chemicals (EDCs), stimulated PXR-mediated transcription at concentrations comparable to those at which they activate estrogen receptor-mediated transcription using a transient reporter gene expression assay in COS-7 cells. However, bisphenol A, another EDC, had no effect on PXR-mediated transcription, although this chemical significantly enhanced ER-mediated transcription. In the yeast two-hybrid protein interaction assay, PXR interacted with two nuclear receptor coactivator proteins, steroid hormone receptor coactivator-1 and receptor interacting protein 140, in the presence of phthalic acid or nonylphenol. Thus, EDC-occupied PXR may regulate its specific gene expression through the receptor-coactivator interaction. In contrast, these EDCs had no effect on the interaction between PXR and suppressor for gal 1, a component of proteasome. Finally, the expression of CYP3A1 mRNA in the liver of rats exposed to phthalic acid or nonylphenol markedly increased compared with that in rats treated with estradiol, bisphenol A, or ethanol as assessed by competitive RT-PCR. These data suggest that EDCs may affect endocrine functions by altering steroid hormone metabolism through PXR.

Animals↗
PubMed2000

[On the differences in attitude and awareness of clinical doctors, health administrators and other health workers to tuberculosis treatment in Japan and the US].

Peculiarity of TB treatment in Japan is a higher rate and duration of hospitalization than in other developed countries. Improvement of the TB control policy in Japan necessitates reexamination of the issue of treatment policy, which requires consideration of recognition and understanding of the concept of TB infection, human rights and the protection of patients as well as the society. Therefore, this study aims at clarifying and analyzing the differences in TB treatment policies in Japan and the US. For the US, a questionnaire was sent to TB Directors of states and large cities in order to analyze TB control policies. Moreover, the author attended the NTCA meeting held in Chicago to interview 16 TB Directors. In Japan, the author sent the same questionnaire translated into Japanese to medical doctors in 54 National TB sanatoria. The hospitalization rates of new smear-positive TB patients were 100% (median) in Japan and 59% in the US. The periods of hospitalization of these patients were 150 days (median) in Japan and 10 days in the US. The total expenses of TB diagnosis and treatment per capita were approximately US $25,000 and 20,000, respectively in Japan and the US. If the DOT strategy were applied to the new smear-positive TB cases in Japan, those total expenses would be reduced to half. On the measures against the TB patients who pose a threat to the public, the US has the series of TB control strategies which contain the reporting system, home isolation, incarceration and penalties for violation, while Japan has only the strategy of hospitalization. The TB policies of Japan in future would need to focus more selectively and carry out thoroughly as seen in the US. The recommended TB policies for Japan obtained from this study are to set TB policies adapted to regional characteristics and to review the strategy against patients posing a threat to the public.

Attitude of Health Personnel↗
PubMed1999

Treatment of gastric tumors by endoscopic mucosal resection with a ligating device.

BACKGROUND: This study attempted to determine the indication for endoscopic mucosal resection with a ligating device (EMRL) and to assess the efficacy of radical (complete) resection of early gastric carcinoma and adenoma. METHODS: Sixteen patients with early gastric carcinoma (17 lesions) and 21 patients with gastric adenoma (23 lesions) underwent EMRL with an endoscope with a ligating device. After epinephrine solution was injected into the submucosa, the lesions were aspirated, ligated, and resected. RESULTS: Twelve of 17 early carcinomas (70.6%) and 18 of 23 adenomas (78.3%) were radically resected by EMRL. The average size of the resected specimens was 12.8 x 11.0 mm. The rate of successful radical resection by EMRL, including piecemeal resection, was 100% (15/15) for lesions located in the antrum, 80% (4/5) in the angle, 61.1% (11/18) in the body, and 0% (0/2) for lesions at the cardia. Repeat EMRL was performed successfully in cases of partial resection (n = 3). No serious complication was encountered. No recurrence of the tumors was identified in cases of radical resection during a median follow-up period of 22.8 months. CONCLUSION: EMRL is suitable for the treatment of gastric tumorous lesions. For the treatment of early carcinoma, well-differentiated mucosal carcinomas smaller than 10 mm located in the distal stomach represent the best indication for EMRL.

Adenocarcinoma↗
PubMed1999

Effects of invaginating anastomosis in Kasai hepatic portoenterostomy on resolution of jaundice, and long-term outcome for patients with biliary atresia.

BACKGROUND/PURPOSE: This report describes a technique of hepatic portoenterostomy (HPE) to keep sustained bile drainage in biliary atresia patients. In conventional HPE, the medial posterior row of the anastomosis is placed behind the main portal vein. But around both lateral corners where the portal branches enter the liver parenchyma, the anastomosis is placed across and outside of the portal veins. Resultantly, the proximal part of the portal veins become included in anastomosis attaching directly to the dissected area where bile ducts are copious. In a devised procedure designated as invaginating anastomosis (IA), an anastomotic line was placed to invaginate the medial branch of the right portal vein and also placed behind the veins even at their roots. This technique puts all portal branches outside of the anastomosis, preventing cicatricial adhesion at the dissected area with the posterior wall of the veins. METHODS: The effect of IA was evaluated in terms of resolution of jaundice and long-term outcome compared with conventional anastomosis (CA). Group IA consisted of 20 patients and group CA of 18 patients. RESULTS: Patients in whom jaundice resolved included 19 (95%) in group IA and 11 (61%) in group CA (P < .05). Reoperation was needed in only one infant in group IA, and in six in CA (P < .05). In patients with reoperation in group CA, the portahepatis was found to be contracted with dense cicatricial tissues. The survival rates for patients with a native liver, calculated excluding those in whom the cause of death was not liver deterioration, was 87% for IA compared with 41% for CA (P < .05). Averaged biliary atresia prognostic index at the last follow-up evaluation was 20.2+/-24.5 for group IA and 62.6+/-29.8 for group CA (P < .001). CONCLUSION: The invaginating anastomosis in portoenterostomy promised a sustained bile drainage and improved long-term outcome by preventing cicatricial contraction of the portahepatis.

Anastomosis, Surgical↗
PubMed1998

Proteasome-mediated degradation of the vitamin D receptor (VDR) and a putative role for SUG1 interaction with the AF-2 domain of VDR.

The AF-2 helix of nuclear receptors is essential for ligand-activated transcription, and it may function to couple the receptor to transcriptional coactivator proteins. This domain also contacts components of the proteasome machinery, suggesting that nuclear receptors may be targets for proteasome-mediated proteolysis. In the present study, we demonstrate that mSUG1 (P45), a component of the 26S proteasome, interacts in a 1,25-(OH)2D3-dependent manner with the AF-2 domain of the vitamin D receptor (VDR). Furthermore, treatment of ROS 17/2.8 osteosarcoma cells with the proteasome inhibitors MG132 or beta-lactone increased steady-state levels of the VDR protein. In the presence cycloheximide (10 microg/ml), the liganded VDR protein was degraded with a half-life of approximately 8 h, and this rate of degradation was completely blocked by 0.05 mM MG132. The role of SUG1 -VDR interaction in this process was investigated in transient expression studies. Overexpression of wild-type mSUG1 in ROS17/2.8 cells generated a novel proteolytic VDR fragment of approximately 50 kDa, and its production was blocked by proteasome inhibitors or by a nonhydrolyzable ATP analog. Parallel studies with SUG1 (K196H), a mutant that does not interact with the VDR, did not produce the 50 kDa VDR fragment. Functionally, expression of SUG1 in a VDR-responsive reporter gene assay resulted in a profound inhibition of 1,25-(OH)2D3-activated transcription, while expression of SUG1 (K196H) had no significant effect in this system. These data show that the AF-2 domain of VDR interacts with SUG1 in a 1,25-(OH)2D3-dependent fashion and that this interaction may target VDR to proteasome-mediated degradation as a means to downregulate the 1,25-(OH)2D3-activated transcriptional response.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1998

Treatment of chronic post-radiation proctitis with oral administration of sucralfate.

Several nonsurgical approaches to the treatment of postradiation proctitis have been described, but no effective conservative treatment has yet been established. As an alternative to the usual treatment, three cases of chronic postradiation proctitis with hemorrhage were successfully treated with oral administration of sucralfate, with resultant decreased bleeding in long term follow-up period. Oral sucralfate may provide a novel approach to the treatment of intractable postradiation proctitis.

Administration, Oral↗
PubMed1998

[The first-three year report of the Tuberculosis Control Project, Lumbini, Rupandehi].

The Tuberculosis Control Project, Lumbini, Rupandehi (TCPLR) is a bilateral cooperative venture between two NGO's, the Nepal Anti-Tuberculosis Association (NATA) and the Japan Anti-Tuberculosis Association (JATA), which consists of planning and implementing pilot tuberculosis control activities in Lumbini, Rupandehi district in Nepal, aiming at achieving high cure rate of newly detected smear-positive pulmonary tuberculosis patients before introducing DOTS strategies. Between December 1993 and July 1996, 349 tuberculosis (TB) cases were enrolled in the TCPLR. The categories of cases were as follows: 138 cases (40%) of new smear-positive pulmonary TB [new Sm(+) PTB], and 54 cases (15%) of smear positive pulmonary TB other than new Sm(+) PTB [other Sm(+) PTB] including such cases as continued treatment and relapse, 106 cases (30%) of new smear-negative TB [new Sm(-) TB], and 51 cases (15%) of other smear-negative TB other than New Sm(-) PTB [other Sm(-) TB]. The number and proportion of new Sm(+) PTB cases enrolled in the project have been increasing [6 cases (23%) for the first year, 102 cases (54%) for the third year] although the proportion is still low (40% overall). The regimens of chemotherapy in the initial intensive and the continuation phases of treatment according to the categories of TB were as follows: New Sm(+) PTB; 2HRZE(S)/6HE, other Sm(+) PTB; 2HRZES/1HRZE/5HRE, and Sm(-) TB; 2HRZ/6HE. The proportion of cases treated by the appropriate regimen of chemotherapy has increased. The cohort analysis of the treatment outcome of the cases enrolled in the project showed the following. The proportion of cured cases plus smear-unconfirmed cases completing treatment among new Sm(+) PTB was 74% overall, however, the proportion of defaulters increased in the third year. The proportion of cured cases plus smear-unconfirmed cases completing treatment among other Sm(+) PTB cases was 66% overall, which is slightly lower than that of new Sm(+) PTB cases, however, the difference was not so marked. The proportion of treatment completed cases among smear-negative pulmonary TB cases was 77% overall, however, proportion of defaulters increased in the third year. The treatment outcome in this report was obtained before the adoption of DOTS strategies: However, it showed that cure and treatment completion rates were comparable to those obtained in the SEARO countries which adopt DOTS strategies. The treatment outcome could be improved after the introduction of DOTS strategies in 1997.

Adolescent↗
PubMed1997

More than 10 years' follow-up to total colonic aganglionosis--severe iron deficiency anemia and growth retardation.

Seven cases of total colonic aganglionosis were reviewed with a follow-up period of 10 to 26 years, focusing on the relationship between the length of aganglionic ileum and postoperative metabolic disorders. Pulled-through ileum ranged from 0 to 65 cm from the ileocecal valve, and suprapelvic side-to-side anastomosis was performed between the pulled-through ileum and 17 to 40 cm of aganglionic colon (left side and transverse colon, four; right side colon, one; no colonic patch, two). Hemoglobin level in three out of four patients with ileal involvement of more than 25 cm was below 11 g/dL (10.9, 7.7, 6.6 g/dL, respectively). Serum iron level was less than 30 micrograms/dL (27, 21, 20, 18 micrograms/dL, respectively) in four out of five patients with ileal involvement of more than 10 cm. Serum vitamin B12 level was below 100 (100, 46 pg/dL, respectively) in two patients whose pulled-through ileum was 45 cm and 65 cm, respectively from the ileocecal valve. One patient needs periodical parenteral iron therapy and one was treated as megaloblastic anemia. In the patients with ileal involvement of more than 25 cm, both weight and height for age are very low at less than the fifth percentile, except for one patient whose side patch was at the right colon. One patient still needs parenteral nutritional support. Severe iron deficiency anemia, low level of B12, and growth retardation are apparent in the patients with total colonic aganglionosis with ileal involvement. Colonic side-to-side anastomosis does not substitute for the loss of terminal ileum.

Anastomosis, Surgical↗
PubMed1997

Impaired expression of neural cell adhesion molecule L1 in the extrinsic nerve fibers in Hirschsprung's disease.

Immunohistochemical studies on the ganglionic and aganglionic segment in Hirschsprung's disease (HD) were carried out using antibodies against three neural membrane proteins, Thy-1, integrin alpha5, and L1. Enteric neural elements were immunostained with antibodies against neurofilament, which is the neuronal cytoskeletal protein. In ganglionic segments, neurofilament-immunoreactivity was detected in neuronal cell bodies and fine nerve fibers of the myenteric and submucosal plexuses. All of these neural elements were immunopositive for Thy-1, integrin alpha5, and L1. In aganglionic segments, no intrinsic neurons were detected, and instead, hypertrophied nerve bundles were observed in intermuscular space, in submucosa, and in circular muscle layer by immunochemistry for neurofilament. These hypertrophied nerve bundles were immunopositive with anti-Thy-1 and anti-integrin alpha5 antibodies. However, they were not immunostained with anti-L1 in all five cases. These findings indicate that the expression of L1 molecule, which plays an important role in cell adhesion, neural cell migration, and neurite outgrowth, is impaired in the extrinsic nerve fibers in aganglionic colon. And this may perturb neural crest migration and adequate neurite outgrowth, with resulting aganglionic segment and abnormal nerve bundles of extrinsic fibers in HD.

Antigens, CD↗