Biomedical subjects

M Nishida

Publications and source records attributed to M Nishida.

At least 55 records · Page 3Linked to original sources

PubMed2001

Thiazolidinedione derivative improves fat distribution and multiple risk factors in subjects with visceral fat accumulation--double-blind placebo-controlled trial.

BACKGROUND: It has been clarified that visceral fat accumulation leads to atherosclerosis through multiple risk factors such as insulin resistance, glucose intolerance, hyperlipidemia and hypertension. So far, it has been reported that a thaizolidinedione derivative, troglitazone, improves the insulin resistance in subjects with diabetes, glucose intolerance and obesity. However, it has not been reported yet that troglitazone affects fat distribution in subjects concomitant with visceral fat accumulation and multiple risk factors. METHODS: Twenty-nine subjects with visceral fat accumulation who had at least two risk factors including glucose intolerance, hyperlipidemia and hypertension were investigated. They were randomly assigned to receive either 200 or 400 mg per day of troglitazone or placebo for 12 weeks. A 75 g oral glucose tolerance test (OGTT) was performed before and after the treatment for 12 weeks. Fasting plasma glucose, insulin, HbA(1c), total serum cholesterol (T-chol), triglyceride (TG), HDL-cholesterol (HDL-C), and blood pressure, as well as the number of risk factors were measured periodically during the treatment. The change of the abdominal fat distribution was evaluated using computed tomographic scanning (CT scan) at the umbilicus level. RESULTS: After the treatment for 12 weeks, the area under the curve (AUC) of plasma glucose from a 75 g OGTT decreased dose-dependently. HbA(1c) and TG decreased significantly in the high-dose troglitazone group (400 mg per day) compared with the placebo group (P<0.05). Systolic blood pressure was significantly lower in subjects with hypertension in the pooled troglitazone group than in the placebo group (P<0.05). Therefore, the number of risk factors decreased with the troglitazone treatment. The ratio of visceral fat area (VFA) to subcutaneous fat area (SFA) (V/S ratio) decreased in the troglitazone groups due to decreased VFA and increased SFA. CONCLUSION: These results suggest that thiazolidinedione derivative may be a useful drug to improve multiple risk factors by changing the fat distribution in subjects with visceral fat accumulation.

Adipose Tissue↗

PubMed2001

Expression of glutathione S-transferase pi (GST-pi) in human malignant ovarian tumors.

OBJECTIVES: In recent years, glutathione S-transferase pi (GST-pi) has attracted much attention and has been studied as a mechanism of multidrug resistance of tumors to anticancer drugs. In the present study, we immunohistologically measured the expression of GST-pi in tumor tissues using surgical specimens obtained from patients with malignant ovarian tumors. METHODS: Of 137 patients with malignant ovarian tumors treated and managed during a period of 20 years since the establishment of Tsukuba University Hospital, 117 patients were selected as subjects because of the presence of complete data on their clinical courses as well as paraffin blocks preserved in a good condition. GST-pi in these specimens was immunohistochemically stained to determine the correlation between GST-pi stainability and clinical outcomes. Stainability was graded as 0 when GST-pi was completely absent, 1 when less than 20% of tumor cells were stained, 2 when 20--60% were stained, and 3 when more than 60% were stained. RESULTS: When the correlation between stainability and clinical outcomes was analyzed with Kaplan--Meier method, excluding stage Ia cases that did not receive adjuvant chemotherapy at our hospital, significantly better clinical outcomes were observed in the low stainable group, compared with the high stainable group (P<0.01--0.05, Cox--Mantel test, Wilcoxon's test). CONCLUSION: Since the stainability for GST-pi was high in tumors of histological types with strong resistance to anticancer drugs, and better clinical outcomes were observed in cases having a lower stainability score, the expression of GST-pi was thought to play some role in the resistance of malignant ovarian tumors to anticancer drugs.

Adenocarcinoma, Clear Cell↗

PubMed2001

Glistening formation in an AcrySof lens initiated by spinodal decomposition of the polymer network by temperature change.

PURPOSE: To examine the effect of temperature change on the structural alteration and glistening formation in an AcrySof intraocular lens (IOL). SETTING: Department of Chemical Science and Engineering, Faculty of Engineering, Kobe University, Kobe, Japan. METHODS: The equilibrium water content of a Wagon-Wheel-packaged AcrySof IOL was determined at various temperatures by the gravimetrical method. Alterations in the microscopic structure of the lens were analyzed in situ with a reflecting microscope without staining, while the temperature of the lens was changed at different rates. RESULTS: Microvacuoles of 1.0 to 20.0 microm formed in the bulk of a swollen AcrySof IOL as the temperature decreased. The morphology of the vacuoles was similar to that of glistening particles observed in vivo. The size and density of the glistening-like vacuoles varied depending on the magnitude and rate of the temperature decrease. The glistening-like vacuoles were imprinted in the bulk of the IOL during the preceding cooling process in aqueous humor. CONCLUSIONS: Glistenings formed in the bulk of an AcrySof IOL as the medium temperature decreased. The mechanism may involve spinodal decomposition of the swollen polymer network, which initiates the formation of microvacuoles consisting of water and loosely packed network chains.

Acrylic Resins↗

PubMed2001

Genetic relationship among Japanese sentinel crabs (Decapoda: Ocypodidae: genus Macrophthalmus).

Seven species (eight populations) of sentinel crabs (genus Macrophthalmus) from the Japan coast and Uca vocans and Ocypode ceratophthalma, were examined electrophoretically for genetic variations in 13 enzymatic and one non-enzymatic protein comprising 17 loci. Most species were highly differentiated from each other (Nei's genetic distance, 0.29-1.63). The least genetic distance was found between M. japonicus and M. banzai, the genetic distinctiveness of the two taxa being supported by three divergent loci with no common allele. The genetic relationships among Macrophthalmus species differed greatly from those inferred from morphological features, with a UPGMA tree suggesting that the sub-genus Macrophthalmus is polyphyletic.

Alleles↗

PubMed2001

Development of lentiviral vectors for antiangiogenic gene delivery.

Growth and metastasis of malignant tumors requires angiogenesis. Inhibition of tumor-induced angiogenesis may represent an effective cytostatic strategy. We have constructed recombinant self-inactivating lentiviral vectors expressing angiostatin and endostatin, and have tested their antiangiogenic activities. As VSV-G-pseudotyped lentiviral vectors showed low relative transduction titers on bovine aortic and human umbilical vein endothelial cells, it was difficult to achieve significant inhibition of endothelial cell growth by lentivirus-mediated antiangiogenic gene transfer directly to endothelial cells without concomitant vector-associated cytotoxicity. However, lentivirus vectors could efficiently and stably transduce T24 human bladder cancer cells that are relatively resistant to adenovirus infection due to loss of coxsackievirus-adenovirus receptor expression. Long-term expression and secretion of angiostatin and endostatin from lentivirus-transduced T24 cells resulted in significant inhibition of cellular proliferation on coculture with endothelial cells. This report represents the first use of lentivirus-based vectors to deliver the antiangiogenic factors, angiostatin and endostatin, and suggests the potential utility of antiangiogenic gene therapy with lentiviral vectors for the treatment of cancer.

Adenoviridae↗

PubMed2001

The distribution of cyclooxygenase-1 in human temporomandibular joint samples: an immunohistochemical study.

Cyclooxygenase-1,2 (COX-1,2) or prostaglandin (PG) H synthase, is the first enzyme of the pathway in which arachidonic acid is oxidized to PGs. Thus, we examined the expression of COX-1 in 16 human temporomandibular joint (TMJ) samples with internal derangement and in 10 control specimens by an immunohistological technique using paraffin-embedded tissue and specific antihuman COX-1 polyclonal antibody. There was obvious distinction of COX-1 immunoreactivity between the control specimens and internal derangement cases, at the endothelial cells and fibroblasts, in the region of posterior and/or anterior loose connective tissues and synovial membrane. The findings of the present study suggest that COX-1 might be an important mechanism for maintaining normal homeostasis at the endothelial cells and fibroblasts with internal derangement of TMJ.

Adult↗

PubMed2001

Quantitation of human herpesvirus 6 DNA in infant with exanthem subitum by microplate PCR-hybridization assay.

BACKGROUND: Quantitative analysis of human herpesvirus 6 (HHV-6) genome is important for monitoring active virus infection. The purpose of our study is to evaluate the reliability of a hybridization-based microtiter plate assay (polymerase chain reaction enzyme-linked immunosorbent assay (PCR ELISA)) for quantifying the virus genome. METHODS: Semiquantitative analysis of the virus genome was carried out in 31 (18 male and 13 female) infants with primary HHV-6 infection. If the HHV-6 virus could be isolated from the peripheral blood mononuclear cells (PBMC), the infants were defined as being infected with HHV-6. The PCR ELISA method was used to determine the virus load. A titration of the virus was also carried out in the samples obtained during the acute phase of exanthem subitum. RESULTS: Specificity of the method was demonstrated by a lack of amplification of human herpesvirus 7 and cytomegalovirus DNA. The upper and lower detection limits of the method were 58 and 5800 copies of the virus genome, respectively. The quantity of HHV-6 DNA in the PBMC during the acute phase (879 +/- 975 copies/10(4) PBMC) was significantly higher than during the convalescent phase (54 +/- 76 copies/10(4) PBMC). Furthermore, the virus load in acute phase plasma (53 +/- 75 copies/microL) was also significantly higher than in the convalescent phase samples (2 +/- 9 copies/microL). Virus load in both PBMC and plasma gradually increased after the onset of exanthem subitum until about day 3 to 4 of the illness, but then decreased quickly. However, there was no significant association between virus load and the numbers of infected cells. CONCLUSION: Virus load in both PBMC and plasma gradually increased after the onset of exanthem subitum until about day 3 and day 4 of the illness, respectively, then it decreased quickly. These results indicate that our PCR ELISA system is reliable for monitoring active HHV-6 infection in vivo.

DNA, Viral↗

PubMed2001

Uterine inversion caused by uterine sarcoma: a case report.

Uterine inversion caused by uterine sarcoma is a rare condition with 12 reported cases to date according to a MEDLINE search. We report two cases of this rare condition. A 71- and a 72-year-old woman presented with uterine sarcomas rapidly extruded into the vagina. In both cases, magnetic resonance imaging (MRI) scans showed U-shaped uterine cavities and the pedicles of these tumors were attached to the uterine fundi. Pathological examination confirmed a leiomyosarcoma and a heterologous carcinosarcoma. Uterine inversion can occur when uterine sarcoma rapidly increases in size and extrudes into the vagina. MRI should be performed in the diagnosis of this rare combination.

Aged↗

PubMed2001

Expression of epithelial neutrophil-activating peptide 78 in cultured human endometrial stromal cells.

It has been demonstrated that human endometrial stromal cells (ESC) produce a variety of chemokines in vivo and in vitro. To evaluate the expression of epithelial neutrophil-activating peptide 78 (ENA-78) in the endometrium, concentrations of ENA-78 in cyclic endometrial tissues were measured using enzyme-linked immunosorbent assay. The expression of ENA-78 was also detected in cyclic endometrium by immunohistochemistry. Endometrial tissues in the secretory phase contained higher amounts of ENA-78 protein than did those in the proliferative phase. Immunofluorescence staining revealed that ENA-78 protein was localized mainly in the stroma of endometrium. In addition, to evaluate the involvement of inflammatory mediators and ovarian steroid hormones in the production of ENA-78 by ESC was evaluated by in-vitro studies. Unstimulated ESC constitutively secreted ENA-78. Progesterone, lipopolysaccharide, tumour necrosis factor-alpha, and interleukin-1beta significantly stimulated the expression of ENA-78 by ESC. It is suggested that the production of ENA-78 by ESC is regulated by progesterone as well as by the inflammatory mediators. The modulation of ENA-78 concentration in the local environment by these mediators may contribute to the normal and pathological processes of human reproduction through regulation of leukocyte trafficking into the endometrium.

Cells, Cultured↗

PubMed2001

Mitogenomic exploration of higher teleostean phylogenies: a case study for moderate-scale evolutionary genomics with 38 newly determined complete mitochondrial DNA sequences.

Although adequate resolution of higher-level relationships of organisms apparently requires longer DNA sequences than those currently being analyzed, limitations of time and resources present difficulties in obtaining such sequences from many taxa. For fishes, these difficulties have been overcome by the development of a PCR-based approach for sequencing the complete mitochondrial genome (mitogenome), which employs a long PCR technique and many fish-versatile PCR primers. In addition, recent studies have demonstrated that such mitogenomic data are useful and decisive in resolving persistent controversies over higher-level relationships of teleosts. As a first step toward resolution of higher teleostean relationships, which have been described as the "(unresolved) bush at the top of the tree," we investigated relationships using mitogenomic data from 48 purposefully chosen teleosts, of which those from 38 were newly determined during the present study (a total of 632,315 bp), using the above method. Maximum-parsimony and maximum-likelihood analyses were conducted with the data set that comprised concatenated nucleotide sequences from 12 protein-coding genes (excluding the ND6 gene and third codon positions) and 22 transfer RNA (tRNA) genes (stem regions only) from the 48 species. The resultant two trees from the two methods were well resolved and largely congruent, with many internal branches supported by high statistical values. The tree topologies themselves, however, exhibited considerable variation from the previous morphology-based cladistic hypotheses, with most of the latter being confidently rejected by the mitogenomic data. Such incongruence resulted largely from the phylogenetic positions or limits of long-standing problematic taxa, which were quite unexpected from previous morphological and molecular analyses. We concluded that the present study provided a basis of and guidelines for future investigations of teleostean evolutionary mitogenomics and that purposeful higher-density taxonomic sampling, subsequent sequencing efforts, and phylogenetic analyses of their mitogenomes may be decisive in resolving persistent controversies over higher-level relationships of teleosts, the most diversified group of all vertebrates, comprising over 23,500 extant species.

Animals↗

PubMed2001

Phylogenetic relationships and ancient incomplete lineage sorting among cichlid fishes in Lake Tanganyika as revealed by analysis of the insertion of retroposons.

Lake Tanganyika harbors numerous endemic species of extremely diverse cichlid fish that have been classified into 12 major taxonomic groups known as tribes. Analysis of short interspersed element (SINE) insertion data has been acknowledged to be a powerful tool for the elucidation of phylogenetic relationships, and we applied this method in an attempt to clarify such relationships among these cichlids. We studied insertion patterns of 38 SINEs in total, 24 of which supported the monophyly of three clades. The other 14 loci revealed extensive incongruence in terms of the patterns of SINE insertions. These incongruencies most likely stem from a period of adaptive radiation. One possible explanation for this phenomenon is the extensive incomplete lineage sorting of alleles for the presence or absence of a SINE during successive speciation events which took place about 5-10 MYA. The present study is the first to report the successful application of the SINE method in demonstrating the existence of such possible "ancient" incomplete lineage sorting. We discuss the possibility that it might potentially be very difficult to resolve the species phylogeny of a group that radiated explosively, even by resolving the genealogies of more than 10 nuclear loci, as a consequence of incomplete lineage sorting during speciation.

Alleles↗

PubMed2001

Antimicrobial susceptibilities of Helicobacter pylori isolates under microaerophilic atmospheres established by two different methods.

The MICs of clarithromycin, amoxicillin, and metronidazole for 150 Helicobacter pylori isolates were determined using the AnaeroPack system and were compared with those determined using a microaerophilic incubator. The MICs of clarithromycin, amoxicillin, and metronidazole determined under both microaerophilic atmospheres were mostly within one twofold dilution for 146 (97.3%), 150 (100%), and 149 (99.3%) of the isolates, respectively.

Anaerobiosis↗

PubMed2001

The protease-activated receptor-2 agonist induces gastric mucus secretion and mucosal cytoprotection.

Protease-activated receptor-2 (PAR-2), a receptor activated by trypsin/tryptase, modulates smooth muscle tone and exocrine secretion in the salivary glands and pancreas. Given that PAR-2 is expressed throughout the gastrointestinal tract, we investigated effects of PAR-2 agonists on mucus secretion and gastric mucosal injury in the rat. PAR-2-activating peptides triggered secretion of mucus in the stomach, but not in the duodenum. This mucus secretion was abolished by pretreatment with capsaicin, which stimulates and ablates specific sensory neurons, but it was resistant to cyclo-oxygenase inhibition. In contrast, capsaicin treatment failed to block PAR-2-mediated secretion from the salivary glands. Intravenous calcitonin gene-related peptide (CGRP) and neurokinin A markedly elicited gastric mucus secretion, as did substance P to a lesser extent. Specific antagonists of the CGRP1 and NK2, but not the NK1, receptors inhibited PAR-2-mediated mucus secretion. Pretreatment with the PAR-2 agonist strongly prevented gastric injury caused by HCl-ethanol or indomethacin. Thus, PAR-2 activation triggers the cytoprotective secretion of gastric mucus by stimulating the release of CGRP and tachykinins from sensory neurons. In contrast, the PAR-2-mediated salivary exocrine secretion appears to be independent of capsaicin-sensitive sensory neurons.

Animals↗

PubMed2001

Photochemically induced equilibrium dysfunction in the hamster model with evaluation by means of a new globe rotatory test system.

Thrombosis in the inner ear is regarded as one of the causes of equilibrium dysfunction. We have established an experimental thrombosis model by producing a photochemical reaction between rose bengal and green light, and have evaluated the dysfunction with a new rotatory test system. Hamsters were treated with tissue-type plasminogen activator (tPA) in doses of 0, 0.13, 0.26, and 0.52 mg/kg. The equilibrium dysfunction of the hamsters was evaluated by scoring their behavior according to visual observation and by measuring their time on the rotatory test system. Treatment of animals with sufficient tPA (> or = 0.26 mg/kg) caused a significant amelioration of the behavior and a concomitant significant prolongation of time on the rotating globe. These findings suggest that the equilibrium dysfunction induced by the photochemical reaction was due to the thrombi formed, and that our test system may provide a useful tool for evaluating equilibrium dysfunction in hamsters.

Animals↗

PubMed2001

Development and characterization of 1C6-203, a new monoclonal antibody specific to human thymidine phosphorylase.

Thymidine phosphorylase (dThdPase) is an essential enzyme for activation of the oral cytostatic drug capecitabine and its intermediate metabolite, doxifluridine, to 5-fluorouracil in tumors. Methods to estimate dThdPase expression in tumor tissue might be useful to predict the efficacy of capecitabine and doxifluridine in cancer patients. We established a new monoclonal antibody (MAb), 1C6-203, applicable for dThdPase immunohistochemistry and compared its staining characteristics with those of a previously established MAb, 654-1. In 4% paraformaldehyde-fixed colorectal carcinoma, 1C6-203 and 654-1 stained cancer cells in 19/30 and 9/30 patients, respectively. In 10% formalin-fixed colorectal carcinoma, 1C6-203 and 654-1 stained cancer cells in 18/30 and 6/30 patients, respectively. In negative 10% formalin-fixed tissues, microwave treatment improved the positivity of 654-1-stained cancer cells. These results suggest that an epitope recognized by 1C6-203 is resistant to epitope masking by formaldehyde fixation, whereas that for MAb 654-1 is sensitive. Therefore, MAb 1C6-203 might be more suitable than MAb 654-1 for evaluating dThdPase expression in colorectal carcinoma.

Animals↗

PubMed2001

Hydrogen peroxide-induced deacetylation of acetyl resorufin as a novel indicator reaction for fluorometric detection of glucose using only glucose oxidase.

Hydrogen peroxide (H2O2)-induced deacetylation of non-fluorescent acetyl resorufin (1) to fluorescent resorufin (2) as a novel indicator reaction for fluorometric detection of glucose using only glucose oxidase (GOD) is described. When a 1:1:1 mixture of 1 (in CH3CN), glucose, and GOD (each in pH 7.4 phosphate buffer) was incubated at 25 degrees C under aerobic conditions, the resulting solution turned yellow to fluorescent pink due to 2. The formation of 2 was markedly retarded on incubation under anaerobic conditions. When a mixture of 1 and H2O2 was incubated under aerobic conditions, the formation of 2 was noted as in the case of the enzymatic reaction of 1. These results demonstrated that the observed color change is brought about through deacetylation of 1 to 2 induced by H2O2 generated in GOD-catalyzed oxidation of glucose. With regard to the fluorometric traces of the enzymatic reaction with 1 (0.2 mM), GOD (0.5 mg/ml), and glucose at 25 degrees C, fluorescence intensity exhibited a linear relationship against glucose concentration between 0.2 and 2.0 mm, with a correlation coefficient of 0.997. Neither ascorbic acid, uric acid, nor bilirubin significantly interfered with the transformation of 1 to 2 through GOD-catalyzed oxidation of glucose.

Ascorbic Acid↗

PubMed2001

[Cytokine balance in the pathogenesis of rheumatoid arthritis].

Rheumatoid arthritis (RA) is a common, frequently severe, chronic inflammatory disease. Although the cause of RA remains unknown, recent advances in understanding its pathogenesis have been substantial. Despite the use of a variety of medications, the treatment of RA is not fully effective in most patients. A T-helper type 1 (Th1)/T-helper type 2 (Th2) cytokine imbalance has been suggested to be of pathogenic importance in several diseases. In this review, the information of cytokine balance in both the experimental model of arthritis and patients with arthritis were summarized. Furthermore, to characterize the cytokine balance at a single cell level, we analyzed the subtypes of cytokine-secreting cells in an experimental model of arthritis using a dual color enzyme-linked immunospot assay (Stardust assay) which we newly developed. These information including our findings might provide us the clue for diagnosis and therapy of arthritis.

Animals↗

PubMed2001

Visceral fat accumulation contributes to insulin resistance, small-sized low-density lipoprotein, and progression of coronary artery disease in middle-aged non-obese Japanese men.

Visceral fat accumulation plays an important role in the occurrence of coronary artery disease (CAD) associated with a cluster of multiple risk factors, such as glucose intolerance, insulin resistance and hyperlipoproteinemia. To clarify the detailed features of these factors, based on visceral fat accumulation, the present study examined the relationship between fat distribution and the characteristics of glucose metabolism and serum lipoproteins in middle-aged non-obese Japanese men. First, the influence of visceral fat accumulation on glucose metabolism, insulin sensitivity, and the extent and severity of coronary artery lesions was investigated in 50 subjects with CAD and compared with 15 control subjects without CAD (Study 1) and with the lipoprotein characteristics in 44 subjects without CAD who were not treated with lipid-lowering drugs (Study 2). Body fat distribution was determined by abdominal computed tomography. In Study 1, the visceral fat area (VFA), blood pressure, fasting immunoreactive insulin (FIRI), and the plasma insulin area (PIA) obtained by oral glucose tolerance test in the subjects with CAD were all significantly higher than in the control subjects. The VFA was significantly correlated with FIRI, the homeostasis model of insulin resistance, PIA and steady state plasma glucose (SSPG) concentration as an index for insulin resistance (r=0.57, p<0.001, r=0.49, p<0.01, r=0.36, p<0.01, and r=0.50, p<0.05, respectively). Although the SSPG concentration did not correlate with the coronary atherosclerosis index as a score of the extent and severity of coronary lesions, the VFA was significantly correlated with this index (r=0.43, p<0.01). In Study 2, the VFA had significant positive correlations with serum total cholesterol, triglyceride, and apolipoprotein B and E levels and the cholesterol and triglyceride concentrations of very-low-density lipoprotein, intermediate-density lipoprotein, and low-density lipoprotein (LDL) fractions. There was a negative correlation between the VFA and LDL particle size (r=-0.34, p<0.05). In conclusion, visceral fat accumulation may contribute to the development of CAD through the progression of insulin resistance and the increase of apo B-containing lipoproteins and small-sized LDLs in middle-aged non-obese Japanese men.

Adipose Tissue↗