Biomedical subjects

K Kishi

Publications and source records attributed to K Kishi.

At least 199 records · Page 11Linked to original sources

PubMed1998

Severe muscle damage induced by high carbohydrate intake from elemental diet in a patient with Crohn's disease.

Crohn's disease is associated with complications in multiple organs. However, there are very few reported cases of patients with Crohn's disease with muscle symptoms and/or high serum creatine phospho-kinase (CPK) levels. We report here a patient with Crohn's disease who experienced skeletal muscle damage with extremely high serum CPK level during treatment with an elemental diet. The non-parenteral administration of large amounts of carbohydrate and limited glycogen degradation capability may be a possible causative mechanism for this elemental diet-induced muscle damage.

Adult↗

PubMed1998

Glutathione depletion inhibits oxidant-induced activation of nuclear factor-kappa B, AP-1, and c-Jun/ATF-2 in cultured guinea-pig gastric epithelial cells.

The aim of this study was to reveal the role of intracellular glutathione in the oxidative stress responses of gastric epithelial cells. Metabolic radiolabeling with L-[35S]methionine and analysis of synthesized proteins by gel electrophoresis and fluorography showed that upon exposure to hydrogen peroxide (H2O2) or diamide, primary cultures of guinea-pig gastric epithelial cells rapidly induced several undefined proteins, as well as heat shock proteins. When intracellular glutathione was depleted to less than 10% of the control value by treatment with buthionine-[S,R]-sulfoximine, these inductions were completely inhibited. Gel mobility shift assay demonstrated that H2O2 and diamide rapidly activated nuclear factor-kappa B (NF-kappaB), and diamide activated activator protein (AP)-1, and c-Jun/activating transcription factor (ATF)-2, suggesting that the response may be coupled to these reduction-oxidation (redox)-sensitive transcription factors, as well as heat shock transcription factor 1. The activations of NF-kappaB, AP-1, and c-Jun/ATF-2 by the oxidants did not occur in glutathione-depleted cells. Northern blot analysis showed that glutathione depletion markedly or completely suppressed the diamide-induced expression of c-fos and c-jun mRNAs. These results suggest that intracellular glutathione redox may participate in the initiation of oxidative stress responses; thereby, it plays an important role in gastric mucosal defense.

Activating Transcription Factor 2↗

PubMed1998

Guinea pig gastric mucosal cells produce abundant superoxide anion through an NADPH oxidase-like system.

BACKGROUND & AIMS: Superoxide anion (O2-) plays an important role in gastric pathophysiology. The aims of this study were to identify O2--producing activity in gastric mucosal cells and to elucidate its possible roles in inflammatory responses of the cells. METHODS: The amount of O2- was measured by the reduction of cytochrome c, and O2--producing cells were visualized by nitroblue tetrazolium reaction. Cytosolic components of the phagocyte reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase were detected by immunoblotting and immunocytochemical analyses with antibodies against p47-phox and p67-phox. RESULTS: Gastric pit cells, but not parietal cells, spontaneously released O2- at 50 nmol . mg protein-1 . h-1. NADPH or guanosine 5'-O-(3-thiotriphosphate) increased the release more than threefold, whereas diphenylene iodonium inhibited it. A reconstituted cell-free system showed that both membrane fraction and neutrophil-related cytosolic components were required for the activity. p47-phox and p67-phox were expressed in the cells. Live Helicobacter pylori organisms and their culture supernatants significantly increased the O2- release. Furthermore, H. pylori lipopolysaccharide could enhance the release more effectively than Escherichia coli lipopolysaccharide. The O2--dependent activation of nuclear factor kappaB occurred in these primed cells. CONCLUSIONS: Gastric pit cells may actively regulate inflammatory responses of gastric mucosa through a phagocyte NADPH oxidase-like activity.

Animals↗

PubMed1998

Comparison of the signal transduction pathways activated by gastrin in enterochromaffin-like and parietal cells.

BACKGROUND & AIMS: Gastrin stimulates acid secretion from parietal cells and histamine release from enterochromaffin-like (ECL) cells through identical gastrin receptors. However, gastrin has been shown to have a trophic effect only on ECL cells. The aim of this study was to compare gastrin-induced signal transduction pathways in the ECL and parietal cells of Mastomys natalensis, an African rodent. METHODS: Both ECL and parietal cells were isolated from the gastric mucosa of M. natalensis, and intracellular signal transduction events in response to gastrin were investigated. RESULTS: Gastrin elicited histamine release from ECL cells and acid secretion from parietal cells in association with enhanced inositol phospholipid turnover. Although gastrin increased [3H]thymidine incorporation into ECL cells, it had no effect on parietal cells. Moreover, tyrosine phosphorylation and activation of mitogen-activated protein (MAP) kinase as well as c-fos and c-jun gene expression were augmented only in ECL cells. In addition, gastrin increased the formation of guanosine triphosphate-Ras with a simultaneous decrease in guanosine diphosphate-Ras levels in ECL but not in parietal cells. CONCLUSIONS: Although gastrin receptors are present in both ECL and parietal cells, they activate the Ras-MAP kinase pathway only in ECL cells.

Animals↗

PubMed1998

Rat gastric mucosal cells express ICAM-1 and proinflammatory cytokines during indomethacin-induced mucosal injury.

Adhesion molecules and cytokines are known to be involved in the formation of acute gastric mucosal injury. However, it is not clear whether the gastric mucosal cells express these molecules and modulate the inflammation. To clarify whether gastric mucosal cells express intercellular adhesion molecule-1 (ICAM-1) and proinflammatory cytokines (tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha (IL-1-alpha), and cytokine-induced neutrophil chemoattractant-2-beta (CINC-2-beta)) in the formation of gastric mucosal injury, we have used rat indomethacin-induced gastric mucosal lesions as an in vivo model. The gene expression of all cytokines and ICAM-1 increases at the early stages of indomethacin-induced gastritis (TNF-alpha and IL-1-alpha gene expression began to increase earlier than that of ICAM-1 and CINC-2-beta) and can mainly be detected in the gastric epithelial layer. To further identify the source of those molecules, the epithelial cells were separated into seven fractions according to their sizes by a counterflow elution. ICAM-1 and CINC-2-beta gene expressions are particularly enhanced in the middle-sized cell fractions that are rich in gastric mucous-producing cells. The effect of TNF-alpha or IL-1-alpha on the gene expression of ICAM-1 and cytokines was examined by using RGM-1 cells as a model for gastric mucosal cells. RGM-1 cells show an augmented ICAM-1 and proinflammatory cytokine expression in response to TNF-alpha or IL-1-alpha stimulation. Moreover, immunohistochemical staining also reveals an increase in ICAM-1 and CINC protein production in RGM-1 cells in response to TNF-alpha stimulation. We conclude that gastric mucosal cells express various cytokines and an adhesion molecule during the formation of acute gastric mucosal injury and that they may modulate the inflammation.

Animals↗

PubMed1998

Multiple brain metastases from adenoid cystic carcinoma of the parotid gland. Case report and review of the literature.

BACKGROUND: Adenoid cystic carcinoma is a slow-growing malignant tumor occurring in the head and neck. Intracranial involvement usually results from direct skull invasion from adjacent primary sites. To our knowledge, this is the first reported case of multiple brain parenchymal metastases manifesting with hemorrhage. CASE DESCRIPTION: A 60-year-old male experienced sudden onset of hemiparesis caused by an intracerebral hematoma in a brain metastasis from adenoid cystic carcinoma. The primary parotid tumor was treated 15 months before the appearance of the brain metastases. The hemorrhagic metastasis was resected, and cranial irradiation was performed. The brain metastasis had increased cellular atypism compared with the primary tumor. The patient remained well and free of neurologic dysfunctions until 5 months after the radiotherapy was completed; he died of systemically advanced disease 8 months after the craniotomy. CONCLUSION: Hematogeneous brain metastases of adenoid cystic carcinoma are quite rare and cannot be distinguished from those of other cancers radiologically. We assume that the intratumoral hemorrhage is related to the tendency of the tumor to spread around the vessels. Although radiation therapy is not curative, it is beneficial in controlling tumor regrowth.

Bacteremia↗

PubMed1998

Effect of aging on gastrin receptor gene expression in rat stomach.

Gastrin is a pivotal humoral factor which regulates gastric acid secretion through its receptors. There is no report, however, concerning the age-related changes of gastrin receptor gene expression in the stomach. Northern blot analysis and in situ hybridization were performed to clarify the changes of gastrin receptor expression during the aging. In situ hybridization clarified that gastrin receptor mRNA was expressed mainly in enterochromaffin-like (ECL) cells in adult rat gastric mucosa. With aging, gastrin receptor gene expression in the stomach increased with the concomitant increase in histidine decarboxylase mRNA. Since histidine decarboxylase is a marker of gastric ECL cells, the augmented gastrin receptor mRNA in aged rats may be caused by the increased ECL cells in gastric mucosa during the aging.

Aging↗

PubMed1998

Radiographic and morphologic studies of multiple miliary osteomas of cadaver skin.

OBJECTIVES: The purpose of this study was to examine the frequency, chemical composition, and radiographic and morphologic features of multiple miliary osteomas of the facial skin. STUDY DESIGN: Facial skin was obtained from 33 cadavers. After contact radiographs were taken, osteomas were examined by photo and scanning electron microscopy. Radiographic microanalysis of inorganic elements of the osteomas was also performed. In addition, clinical dental radiographic examinations were performed on 158 living subjects. RESULTS: Radiographic examination revealed milia-like osteomas in the facial skin of all of the cadavers. Nodules of 0.5 to 2.0 mm in diameter were scattered symmetrically in the skin of the cheek, mandibular angle, and forehead. Each nodule consisted of a concentric, multilamellated, osteoid cortex and an adipose medulla. Microanalysis suggested the presence of hydroxyapatite similar in composition to that of normal cortical bone. The condition was detected in 28% (44/158) of the living subjects by clinical dental radiographic examination. CONCLUSION: Multiple miliary osteoma is a very common condition and may not be related to specific diseases.

Adipose Tissue↗

PubMed1998

Expression of protooncogene c-kit and its ligand stem cell factor (SCF) in gastric carcinoma cell lines.

We examined 13 human gastric carcinoma cell lines for the expression of both c-kit and stem cell factor (SCF). Expression of mRNAs was detected by both Northern blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR), and expression of translated proteins was detected by western blotting. Using RT-PCR we confirmed the expression of c-kit in five (ECC12, TMK1, MKN7, GCIY, and HGC27) cell lines. Northern blot analysis showed coexpression of both c-kit and SCF in ECC12 and expression of SCF in five other (MKN74, MKN1 OKAJIMA, KATOIII, and TMK1) cell lines. SCF stimulated both tyrosine phosphorylation of c-kit and growth of ECC12, whereas it did not stimulate those of GCIY. The sizes of c-kit transcript and protein in GCIY were slightly smaller than those of the reported ones, suggesting the presence of a biologically inactive truncated form of c-kit in GCIY. The present study suggests that c-kit/SCF system might play an important role in the carcinogenesis and tumor growth of ECC12 and that the truncated form of c-kit in GCIY might not be associated with malignant transformation.

Blotting, Northern↗

PubMed1998

Structure and organization of the human deoxyribonuclease II (DNase II) gene.

The structure of the human gene for deoxyribonuclease II (DNase II; EC 3.1.22.1) was determined using several specific primers based on the human DNase II cDNA sequence [Yasuda et al. (1998). J. Biol. Chem. 273, 2610-2616] in a polymerase chain reaction-based strategy. The gene spanned about 6 kb and consisted of 6 exons. No canonical TATA or CAAT boxes could be identified within the 1341 nucleotides upstream of the putative transcription start site, although the 5'-flanking region contained a CpG island and several putative binding motifs for transcription factors Sp1 and ETF. These properties indicate that the DNase II gene is a housekeeping gene and this is compatible with its ubiquitous expression in human tissues. Three different cleavage/polyadenylation sites were identified in the 3'-flanking region, leading to the production of multiple DNase II mRNA species. However, a comparison of the entire translated sequences of the gene from a pair of subjects with homozygous DNase II phenotypes H and L revealed no differences in the nucleotide sequences.

Base Sequence↗

PubMed1998

Vitamin A up-regulates expression of bone-type alkaline phosphatase in rat small intestinal crypt cell line and fetal rat small intestine.

Vitamin A is a potent inducer for liver/bone/kidney alkaline phosphatase (L/B/K ALP) in a variety of tissues. However, the evidence for induction of L/B/K ALP by vitamin A in small intestine is limited. In this study, we investigated the influence of vitamin A on L/B/K ALP expression in rat small intestinal crypt IEC-6 cells and fetal rat small intestine. Treatment of IEC-6 cells with all-trans retinoic acid (RA) increased the levels of activity, protein and mRNA of L/B/K ALP, whereas enterocyte-specific proteins, including intestinal ALP, sucrase-isomaltase and glucose transporter-2, were not induced. The reverse transcription-polymerase chain reaction technique revealed that this L/B/K ALP transcript had the bone-type but not the liver-type leader exon. IEC-6 cells constitutively expressed mRNAs of all subtypes of retinoic acid receptor (RAR) and retinoid X receptor (RXR) at varied concentrations. Among these receptor mRNAs, RARbeta mRNA quickly responded to RA treatment, and the level was doubled within 4 h. Gel mobility shift assay showed that RA induced an RXRE-binding activity in IEC-6 cells. The L/B/K ALP transcript, expressed in fetal rat small intestine, also contained the bone-type leader exon. Intragastric administration of 10 mg retinyl acetate to pregnant rats from gestational d 7 to 15 increased the levels of this transcript and enzyme in 15-d fetal rat small intestine. Our results suggest that vitamin A may be an important regulator for L/B/K ALP expression in fetal rat small intestine as well as in IEC-6 cells.

Alkaline Phosphatase↗

PubMed1998

The maltitol-induced increase in intestinal calcium transport increases the calcium content and breaking force of femoral bone in weanling rats.

Maltitol is a disaccharide alcohol that is produced by hydrogenation of maltose and exhibits resistance to intestinal disaccharidases. We demonstrated previously that maltitol stimulated transepithelial diffusional calcium transfer in the ileum, accompanied by an elevation of intestinal calcium absorption as well as calcium retention in the body. In this study we examined whether the maltitol-induced increase in the diffusional transfer of intestinal calcium absorption leads to an alteration of the physical properties of bones in the weanling rats which exhibit the maximal level of intestinal active calcium absorption. Rat pups were removed from dams at 24 d of age and were fed the diets containing either maltose (control) or maltitol and a requisite amount of calcium (0.52%) for 21 d. Balance studies performed during the final 5-d period showed that maltitol-fed rats had greater calcium retention and calcium absorption. The breaking force of femoral bones was 13% greater in the rats fed the maltitol diet than in controls. The calcium content and dry weight of both femurs and tibias, as well as the bone mineral density of tibias, were elevated in the rats fed the maltitol diet. In a separate experiment, gastric intubation of maltitol-containing diet increased the serum calcium concentration in the portal vein at 2 and 4 h compared to controls. These results indicate that the maltitol-induced increase in the intestinal calcium absorption through paracellular pathway leads to enhancement of the calcium content and the breaking strength in the bone of weanling rats.

Absorptiometry, Photon↗

PubMed1998

Random nuclear p53 overexpression pattern in tamoxifen-mediated endometrial carcinoma.

In a previous paper, we suggested that tamoxifen (TAM)-mediated endometrial carcinogenesis may not involve estrogenic pathways because of random estrogen receptor positivity among endometrial carcinomas with and without TAM treatment for breast cancer. DNA adduct formation (reported in rat liver and human endometrium) was considered to be a more plausible mechanism for TAM-mediated carcinogenesis. To examine the reported correlation between DNA adduct formation and p53, the present study examined p53 expression in the endometrial carcinomas reported in the previous study. Seven endometrial adenocarcinomas associated with long-term TAM treatment for breast carcinoma and 4 carcinomas without TAM treatment but with history of breast carcinoma were immunohistochemically investigated for nuclear p53 expression. The bcl-2 product was also examined. Diffuse and intense nuclear reactivity for p53 protein was present in only one TAM-related case. Essentially, no differences were observed in the bcl-2 staining patterns of TAM-treated and -untreated patients with cancer. Thus, p53 overexpression in endometrial carcinomas occurring in patients with breast cancer seems to be not specific for TAM-treated patients, and, if DNA adduct formation has any role in this type of endometrial carcinogenesis, it may not be related preferentially to p53 gene alteration. Further studies are needed to understand the precise mechanism(s) of the endometrial carcinogenesis.

Adult↗

PubMed1998

Relationship between severity and symptoms of reflux oesophagitis in elderly patients in Japan.

Since information concerning reflux oesophagitis in the elderly is limited, particularly in Japan, the severity and symptomatic profiles of reflux oesophagitis in elderly patients were investigated. One hundred and nineteen patients with reflux oesophagitis found among 2278 endoscopy cases between 1993 and 1996 were investigated in this study. The patients were divided into two groups, elderly and non-elderly. The severity of reflux oesophagitis was estimated by the Los Angeles classification. The presence or absence of typical symptoms (heartburn and regurgitation) was determined by interview. Reflux oesophagitis was not only more frequently found in the elderly group, but was more severe than in the non-elderly. Although the degree of manifestation of typical symptoms was similar between the elderly and the non-elderly with high-grade oesophagitis, the elderly patients with mild reflux oesophagitis were less symptomatic than the non-elderly. Mild reflux oesophagitis in the elderly may be missed due to its rarity of typical reflux symptoms and a substantial number of elderly persons might have subclinical reflux oesophagitis.

Adult↗

PubMed1998

Diversity in protein synthesis and viability of Helicobacter pylori coccoid forms in response to various stimuli.

The viability of the coccoid forms of Helicobacter pylori was evaluated by assessing protein synthesis. Metabolic labeling studies showed the synthesis of proteins and the specific protein profiles of H. pylori coccoids produced under various conditions. Harsh conditions such as aerobiosis and starvation (lack of horse serum) in the culture did not affect the synthesis of proteins in the coccoids. Lowering of the pH to that of gastric secretions induced expression of several proteins in the coccoids. However, the coccoids produced under prolonged microaerobic conditions exhibited a profile of acid stress-induced protein expression different from that induced by aerobiosis or starvation. Our data suggest that coccoid H. pylori exhibits diversity in viability following exposure to different stresses and that the response to acid stress of coccoid H. pylori could be involved in infection of the host stomach.

Acids↗

PubMed1998

Parvalbumin immunoreactive neurons in the main olfactory bulb of the house musk shrew, Suncus murinus.

The distribution, morphological features, and postnatal development of parvalbumin (PV) immunoreactive neurons in the main olfactory bulb (MOB) of the house musk shrew, Suncus murinus, were studied to report for the first time on PV positive bulbar interneurons in the order Insectivora. In adult animals, PV neurons are distributed in the glomerular layer (GL), the external plexiform layer (EPL), the internal plexiform layer (IPL) and the granule cell layer (GCL) of the MOB. These neurons were identified as a subpopulation of periglomerular cells and perinidal cells [Alonso et al., 1995] in the GL and at the GL-EPL border, respectively, and as bipolar and multipolar neurons in the EPL and four types of the interneurons (horizontal cells, Cajal cells, Golgi cells, and bitufted cells) in the layers deeper than the mitral cell layer. During development of PV neurons, neurons exhibiting extremely faint PV immunoreactivity first appeared in the GCL at postnatal day 14 and increased markedly in number and intensity of their PV immunoreactivity from postnatal days 14 to 28. At postnatal day 21, PV neurons were identified as periglomerular cells in the GL, perinidal cells at the GL-EPL border, and morphologically unidentifiable neurons in the EPL, IPL and GCL. At postnatal day 28, PV neurons exhibited a nearly adult pattern with respect to distribution and structural features. The present results strongly suggest that a wide variety of PV positive neurons in the MOB of the house musk shrew may develop postnatally.

Animals↗

PubMed1998

Increased hepatocyte growth factor content in rat stomach during omeprazole treatment.

BACKGROUND AND AIMS: Hepatocyte growth factor (HGF) is a potent mitogen of gastric epithelial cells, and its production is stimulated during the healing of gastric mucosal lesions. In this study, the effect of a proton pump inhibitor, omeprazole, on the production and degradation of HGF in the stomach was examined to elucidate the mechanism of the omeprazole-induced acceleration of gastric mucosal healing. METHODS: Indomethacin-induced gastric mucosal lesions were induced in rats with or without omeprazole pretreatment. HGF gene expression and the content of HGF was investigated in the rat stomach. HGF degradation by gastric juice was also tested. RESULTS: In omeprazole-treated rats, the healing of gastric mucosal lesions was accelerated in comparison with those of untreated rats. Although omeprazole treatment did not enhance the indomethacin-induced increase in HGF gene expression, it significantly augmented the gastric HGF content. Furthermore, omeprazole increased the gastric content not only of the inactive but also of the active heterodimeric form of HGF, and this appeared to be due to the inhibition of the HGF degradation by gastric juice. CONCLUSION: Omeprazole-induced acceleration of gastric mucosal healing may be mediated at least in part by the reduced degradation of HGF in the stomach.

Animals↗

PubMed1998

Detection of deoxyribonuclease I along the secretory pathway in Paneth cells of human small intestine.

The expression and distribution of deoxyribonuclease I (DNase I) in human duodenum, jejunum and ileum were examined by DNase I activity assay and the reverse transcriptase-polymerase chain reaction (RT-PCR), immunofluorescence, in situ hybridization, and immunocytochemical ultrastructural analyses. High levels of DNase I were detected in the cytoplasm of Paneth cells in human small intestine. A tissue homogenate fraction rich in Paneth cells showed strong DNase I-specific enzymatic activity. Immunofluorescence analysis using several specific anti-human DNase I antibodies showed very strong immunoreactivity in the cytoplasm of every Paneth cell. In situ hybridization demonstrated high levels of DNase I mRNA in Paneth cells. Immunogold electron microscopy revealed gold particles localized along the secretory pathway, with the exocrine secretory granules mostly labeled. Our findings strongly suggest that Paneth cells synthesize and secrete DNase I into the intestinal lumen.

Adult↗