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H Ishikawa

Publications and source records attributed to H Ishikawa.

At least 163 records · Page 9Linked to original sources
PubMed2000

Effect of nifedipine administration (10 mg) on esophageal acid exposure time.

The effect of nifedipine administration (10 mg) on esophageal acid exposure time was investigated in 11 non-reflux esophagitis (non-RE) patients and 11 grade C (Los Angeles classification) reflux esophagitis (RE) patients. In each subject, esophageal pH monitoring was performed, with the subject in the supine position, preprandially (1 h) and 3-h postprandially after oral administration of a placebo in the morning and oral administration of nifedipine (10 mg) in the afternoon on the same day. In the non-RE patients, there was no difference in the esophageal acid exposure time between administration of the placebo and that of nifedipine. In patients with RE, the esophageal acid exposure time after the administration of nifedipine was significantly (P<0.05) longer than that after the placebo. In patients with severe RE, the severity of RE may worsen with nifedipine administration.

Aged↗
PubMed2000

The tight junction of pancreatic exocrine cells is a morphometrically dynamic structure altered by intraductal hypertension.

The tight junction of pancreatic exocrine cells is thought to regulate paracellular permeability, and is a possible reflux route of pancreatic juice into the blood flow. Morphological changes in the tight junction of canine pancreatic acinar cells following intraductal hypertension and secretin stimulation were morphometrically analyzed to obtain evidence of the control of the paracellular reflux. Pancreatic tissues obtained from 25 dogs after intraductal hypertension, 3 dogs after secretin stimulation, and 5 control dogs were studied. Intraductal pressure was either 20 cmH2O, 30 cmH2O, or 40 cmH2O. Freeze fracture replicas of these pancreatic tissues were observed by electron microscopy. Tight junctions were classified into six morphometric types. Reticular type, parallel type, and mixed type comprised the common types predominantly found in all groups, and three special types were found, infrequently, only after intraductal hypertension. The percentages of the common types were significantly different between the groups. The areas of the tight junctions, and other morphometric parameters, were significantly less after 20 cmH2O intraductal hypertension and secretin stimulation than in the controls. However, these findings after 30 cmH2O or 40 cmH2O intraductal hypertension did not differ from those in the controls. The areas of the three special types of tight junctions were larger than those of the common types. These results suggest that the tight junction of pancreatic exocrine cells is a morphologically dynamic structure that is altered by the extent of intraductal hypertension, and support the hypothesis that paracellular permeability is the mechanism of the reflux of pancreatic juice.

Animals↗
PubMed2000

Carcinoma of the splenic flexure: multivariate analysis of predictive factors for clinicopathological characteristics and outcome after surgery.

The clinicopathological characteristics and outcome of splenic flexure cancer after surgery have yet to be fully elucidated. The aim of the current study was, therefore, to establish predictive factors related to splenic flexure cancer and outcome after surgery. We compared the clinicopathological characteristics and outcome of 34 patients with splenic flexure cancers (which represents 3.7% of the total number of colon cancers in our series) with those of 418 patients with right colon and 475 patients with left colon cancers by univariate and multivariate analyses, using logistic regression analysis and Cox's proportional hazards model. Splenic flexure cancers had a high risk of obstruction (26.5% of patients), and had a more advanced stage and lower cure rate than left colon cancers. Logistic regression analysis revealed that two independent factors, colonic obstruction and the presence of distant metastases, were related to the splenic flexure tumor site. Splenic flexure cancer patients had a poorer outcome than those with left colon cancer (P = 0.0361). However, there was no difference in survival between patients with splenic flexure, those with right colon cancer and those with left colon cancer who underwent curative surgery. Cox's regression analysis revealed that neither the site of splenic flexure nor colonic obstruction was an independent prognostic factor. In conclusion, splenic flexure cancer is characterized by a high risk of obstruction and the presence of distant metastases. However, after curative resection, splenic flexure cancer has a similar outcome to colon cancer at other sites. In addition, neither the splenic flexure site nor colonic obstruction had an independent influence on patient survival after surgery.

Colonic Neoplasms↗
PubMed2000

Optical coherence tomography and scanning laser polarimetry in normal, ocular hypertensive, and glaucomatous eyes.

PURPOSE: To evaluate the relationship between visual function and retinal nerve fiber layer measurements obtained with scanning laser polarimetry and optical coherence tomography in a masked, prospective trial. METHODS: Consecutive normal, ocular hypertensive, and glaucomatous subjects who met inclusion and exclusion criteria were evaluated. Complete ophthalmologic examination, disk photography, scanning laser polarimetry, optical coherence tomography, and automated achromatic perimetry were performed. RESULTS: Seventy-eight eyes of 78 patients (17 normal, 23 ocular hypertensive, and 38 glaucomatous) were enrolled (mean age, 56.8+/-11.5 years; range, 26 to 75 years). Eyes with glaucoma had significantly greater neural network scores on scanning laser polarimetry and lower maximum modulation, ellipse modulation, and mean retinal nerve fiber layer thickness measured with optical coherence tomography compared with normal and ocular hypertensive eyes, respectively (all P<.005). Significant associations were observed between neural network number (r = -.51, r = .03), maximum modulation (r = .39, r = -.32), ellipse modulation (r = .36, r = -.28), and optical coherence tomography-generated retinal nerve fiber layer thickness (r = .68, r = -.59) and visual field mean deviation and corrected pattern standard deviation, respectively. All scanning laser polarimetry parameters were significantly associated with optical coherence tomography-generated retinal nerve fiber layer thickness. CONCLUSION: Optical coherence tomography and scanning laser polarimetry were capable of differentiating glaucomatous from nonglaucomatous populations in this cohort; however considerable measurement overlap was observed among normal, ocular hypertensive, and glaucomatous eyes. Retinal nerve fiber layer structural measurements demonstrated good correlation with visual function, and retinal nerve fiber layer thickness by optical coherence tomography correlated with retardation measurements by scanning laser polarimetry.

Adult↗
PubMed2000

Scanning laser polarimetry measurements after laser-assisted in situ keratomileusis.

PURPOSE: To evaluate the effect of laser-assisted in situ keratomileusis on retinal nerve fiber layer thickness measurements obtained with scanning laser polarimetry. METHODS: Thirteen consecutive eyes (13 patients) undergoing laser-assisted in situ keratomileusis were enrolled in this prospective study. Scanning laser polarimetry (NFA-GDx; Laser Diagnostic Technologies, Inc, San Diego, California) examination was performed 1 week before and 1 to 8 weeks after laser-assisted in situ keratomileusis surgery. Intraocular pressure was normal at all preoperative and postoperative examinations. Total mean, and superior, temporal, inferior, and nasal mean retinal nerve fiber layer thickness values before and after laser-assisted in situ keratomileusis were compared by Student paired t test. RESULTS: Mean +/- SD patient age was 34.6 +/- 10.9 years (range, 20 to 56 years). Mean +/- SD preoperative spherical equivalent refractive error was -6.6 +/- 3.1 diopters (range, -3.25 to -13.25 diopters) and mean +/- SD spherical equivalent refractive surgical correction was -6.2 +/- 3.0 diopters (range, -2.9 to -12.25 diopters). Total mean retinal nerve fiber layer and superior, inferior, temporal, and nasal mean retinal nerve fiber layer thicknesses were thinner after laser-assisted in situ keratomileusis (P =.01, for all comparisons, paired t test). CONCLUSIONS: Measurements of the retinal nerve fiber layer with scanning laser polarimetry depend on a corneal compensator inherent in the device. Keratorefractive surgery may affect scanning laser polarimetry measurements.

Adult↗
PubMed2000

Epstein-Barr virus (EBV) genes expression in cervical intraepithelial neoplasia and invasive cervical cancer: a comparative study with human papillomavirus (HPV) infection.

To elucidate a causative role of Epstein-Barr virus (EBV) for cervical cancer, presence and expression of EBV genes were examined in 31 cervical carcinomas (ICC), 23 cervical intraepithelial neoplasias (CIN), and 35 normal cervices (NCX). In reverse transcription polymerase chain reaction (RT-PCR) analysis, EBER-1 mRNAwas expressed in 74% (23/31) of ICC, 83% (19/23) of CIN, 37% (13/35) of NCX. LMP-1 was expressed in 52% (16/31) of ICC, 70% (16/23) of CIN, and 23% (8/35) of NCX, and EBNA-2 was expressed in 32% (10/31) of ICC, in 48% (11/23) of CIN, and in 11% (4/35) of NCX. Expression rates of these genes were significantly higher in ICC and CIN than in NCX (P < .05). RNA in situ hybridization analysis showed that EBER-1 was expressed in half (7/14) of ICC and 35% (6/17) of CIN, and BamH-W, which is a leader sequence of EBNA genes, was expressed in 86% (12/14) of ICC and 71% (12/17) of CIN. LMP-1 and EBNA-2 proteins also were detected in ICC and CIN cells by inmunofluorescence staining. PCR analysis showed that EBV genome was detected in 55% (17 of 31) of ICC and in 26% (9/35) of NCX. In contrast, human papillomavirus (HPV) DNA was detected in 84% (26/31) of ICC, whereas none of NCX had HPV DNA. Either EBV or HPV was detected in 61% (19/31) of ICC, whereas both EBV and HPV was detected in 39% (12/31) of ICC. EBV infection may be involved in the development of cervical cancer, although further study should be performed to elucidate a causative role of EBV for the cancer.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Cloning, sequence analysis and expression in Escherichia coli of the gene encoding a uricase from the yeast-like symbiont of the brown planthopper, Nilaparvata lugens.

A urate oxidase (uricase; EC 1.7.3.3) gene of the yeast-like fungal endosymbiont of the brown planthopper, Nilaparvata lugens, was cloned, and sequenced together with its flanking regions. The gene comprised a open reading frame of 987 bp, that was split into two parts by a single 96 bp intron. The encoded uricase was 296 amino acids with 62% sequence identity with that of Aspergillus flavus. The molecular weight deduced was 32,882, and the predicted isoelectric point was 6.06. The symbiont's uricase conserved all the known consensus motifs, except the C-terminal PTS-1, Ser-basic-Leu. The leucine at the third position of PTS-1 was replaced by serine in the C-terminus of the symbiont's uricase. The symbiont's uricase gene was successfully expressed in Escherichia coli, and the product, tagged with histidine residues, was purified. The symbiont's uricase, thus produced, was as active as those from plants and animals, but less active than those from other fungi.

Amino Acid Sequence↗
PubMed2000

Genomic copy number of intracellular bacterial symbionts of aphids varies in response to developmental stage and morph of their host.

Buchnera, endosymbiotic bacteria of aphids possess many genomic copies per cell. In this study, we estimated genomic copy number per Buchnera cell from host insects at various developmental stages and of two different morphs, apterae and alatae, by fluorimetry and real-time quantitative PCR. The results indicated that the genomic copy number of Buchnera increased during postembryonic development of insects to adulthood, and that it decreased during the host's ageing. In Buchnera from alatae, the genomic copy number per cell was about twice as many as in those from apterae. DAPI-staining showed that the distribution of the genomic DNA in the Buchnera cells from old insects tended to aggregate, suggesting that intracellular structure of the genomic DNA of Buchnera varies in response to the physiological conditions of their host.

Animals↗
PubMed2000

Gut cryptopatches: direct evidence of extrathymic anatomical sites for intestinal T lymphopoiesis.

Athymic cytokine receptor gamma chain mutant mice that lack the thymus, Peyer's patches, cryptopatches (CP), and intestinal T cells were reconstituted with wild-type bone marrow cells. Bone marrow-derived TCR(-) intraepithelial lymphocytes (IEL) first appeared within villous epithelia of small intestine overlying the regenerated CP, and these TCR(-) IEL subsequently emerged throughout the epithelia. Thereafter, TCR(+) IEL increased to a comparable number to that in athymic mice and consisted of TCRgammadelta and TCRalphabeta IEL. In gut-associated lymphoid tissues of wild-type mice, only CP harbored a large population of c-kit(high)IL-7R(+)CD44(+)Thy-1(+/-)CD4(+/-)CD25(low/-)alpha(E) beta(7)(-)Lin(-) (Lin, lineage markers) lymphocytes that included cells expressing germline but not rearranged TCRgamma and TCRbeta gene transcripts. These findings provide direct evidence that gut CP develop progenitor T cells for extrathymic IEL descendants.

Animals↗
PubMed2000

Erratum.

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Journal Article↗
PubMed2000

Different cytokines are required for induction and maintenance of the Th2 type response in DBA/2 mice resistant to infection with Leishmania major.

Experimental cutaneous leishmaniasis is a useful model in studying the mechanism regulating immune responses between T helper type 1 (Th1) and Th2. Mice susceptible to Leishmania major infection such as BALB/c (H-2(d)) are associated with the induction of the disease-promoting Th2 response, while the resistant mice such as DBA/2 (H-2(d)) develop the protective Th1 response. To understand the induction mechanism of Th1 and Th2 responses, it is necessary to establish an immunization scheme by which the induction of each Th response can be easily and experimentally controlled. Adjuvants are known to enhance the immune responses through the combined effect of several factors: prolonged release of antigen, migration of cells, mitogenic effect and so forth. When the genetically resistant DBA/2 mice were immunized twice with soluble leishmanial antigen (SLA), emulsified in incomplete Freund's adjuvant (IFA) before L. major inoculation, these mice mounted a Th2 cell response and suffered from progressive infection. While IL-4 and IL-13 were upregulated early after the infection in both healer and non-healer groups of mice, IL-5 and IL-10 were upregulated only in non-healer mice. From these results, IL-5 and IL-10 appear to have an important role, at least in the early phases of the infection, rather than IL-4 and IL-13 in establishing the disease-promoting Th2 response in leishmaniasis. Further, IL-9 was found to be expressed in both BALB/c and DBA/2 mice immunized with IFA/SLA. This cytokine may support the establishment of a Th2 response in these mice. Therefore it is suggested that Th2 cytokines play different roles between priming and maintaining the Th2 immune response after the infection.

Animals↗
PubMed2000

Purification and characterization of organic solvent-stable lipase from organic solvent-tolerant Pseudomonas aeruginosa LST-03.

An organic solvent-stable lipase (LST-03 lipase) secreted into the culture broth of the organic solvent-tolerant Pseudomonas aeruginosa LST-03 was purified by ion-exchange and hydrophobic interaction chromatography in the presence of 2-propanol. The purified enzyme was homogeneous as determined by SDS-PAGE. The molecular mass of the lipase was estimated to be 27.1 kDa by SDS-PAGE and 36 kDa by gel filtration. The optimum pH and temperature were 6.0 and 37 degrees C. LST-03 lipase was stable at pH 5-8 and below 40 degrees C. Its hydrolytic activity was highest against tricaproin (C6), methyl octanoate (C8), and coconut oil respectively among the triacylglycerols, fatty acid methyl esters, and natural oils investigated. The enzyme cleaved not only the 1,3-positioned ester bonds, but also the 2-positioned ester bond of triolein. It exhibited high levels of activity in the presence of n-decane, n-octane, DMSO, and DMF as well as in the absence of an organic solvent. In addition, LST-03 lipase was stabler in the presence of n-decane, ethyleneglycol, DMSO, n-octane, n-heptane, isooctane, and cyclohexane than in the absence of an organic solvent.

Journal Article↗
PubMed2000

Irreversible unfolding of myoglobin in an aqueous solution by supercritical carbon dioxide.

The conformational changes in myoglobin, treated by microbubbling of supercritical carbon dioxide (SC-CO(2)), were investigated by measuring the circular dichroism spectra in the ultraviolet range and compared with those in other proteins (ovoalbumin, bovine serum albumin, and beta-lactoglobulin). Irreversible unfoldings were observed after the microbubbling of SC-CO(2) at 35 degrees C and 30 MPa for 30 min. The degree of unfolding depended on the number of intramolecular S-S bonds. alpha-Helix contents of myoglobin decreased with increasing density of SC-CO(2). Unfoldings of myoglobin induced by heating, pH-lowering, and the addition of a denaturant were reversible. The irreversible unfolding of myoglobin was also observed by the bubbling of gaseous CO(2) under atmospheric pressure, but heating was required.

Animals↗
PubMed2000

Diurnal motor activities of the esophagus in conscious dogs.

Diurnal motor activities of the upper, middle, and lower thirds of the thoracic esophagus, the lower esophageal sphincter, and the gastric body were recorded in six conscious dogs, using extraluminal force transducers. The motor activities of the thoracic esophagus and the lower esophageal sphincter were divided into three major motility patterns: feeding, digestive, and interdigestive. Each motility pattern was basically composed of repetitive bursts of contractions that were clearly classified into type I and II according to their contractile properties. Type I bursts were peristaltic contractions initiated at the upper thoracic esophagus and sequentially propagated distally to include the sphincter. Propagation velocity and duration of type I contractions were similar in all three motility patterns, and these contractions never were propagated into the stomach. Type II bursts were nonperistaltic simultaneous contractions of the thoracic esophagus and lower sphincter appearing synchronously with phase III of gastric interdigestive migrating contractions. Amplitude and duration of type II contractions were maximal at the sphincter, suggesting initiation at that site. In nonfeeding patterns, type I contractions would clear the esophagus of refluxed gastric contents, while type II contractions would prevent reflux.

Animals↗
PubMed2000

Actin bundles in perineurial cells of rat spinal nerves.

The overall distribution of the actin cytoskeleton in perineurial cells of rat spinal nerves was examined by confocal laser and thin-section electron microscopy. Confocal laser microscopy of whole-mount nerves stained with fluorescent-labelled phalloidin revealed two types of actin bundles in perineurial cells; stress fiber-type actin bundles and circumferential actin bundles. The degree of development of the actin cytoskeleton varied in different segments of different nerves. Stress fiber-type actin bundles were also immunostained for myosin and vinculin and were well-developed in the perineurial cells of large-sized nerves and dorsal root ganglia, whereas they were poor in spinal nerve root sheaths within the subarachnoid space. In peripheral nerves, stress fiber-type actin bundles tended to be arranged transverse to the nerve axis. Circumferential actin bundles were localized along intercellular junctions, which were immunostained with several junctional proteins such as alpha-catenin, occludin and ZO-1. Thin-section electron microscopy confirmed the distribution pattern of actin bundles observed by confocal laser microscopy. These findings suggest that actin bundles may play some roles in structurally stabilizing the perineurium by providing mechanical support for the cell layers as well as cell junctions to maintain perineurial integrity and form diffusion barriers in peripheral nerves.

Actin Cytoskeleton↗
PubMed2000

Cloning of the mouse desmoglein 3 gene (Dsg3): interspecies conservation within the cadherin superfamily.

Desmoglein 3 is a cadherin-like calcium-dependent cell adhesion molecule expressed primarily in suprabasal keratinocytes of the epidermis. In this study, we have cloned the full-length cDNA and characterized the entire gene structure for the mouse desmoglein 3 gene (Dsg3). Isolation of overlapping cDNA clones, together with 5' and 3' rapid amplification of cDNA ends (RACE), allowed delineation of the entire coding sequence. The transcriptional initiation site was confirmed by primer extension and reverse transcription polymerase chain reaction analysis. The entire cDNA consisted of 6407 bp with an open reading frame of 2979 bp, and the deduced polypeptide contained 993 amino acids. Comparison of mouse and human desmoglein 3 amino acid sequences demonstrated 85.6% homology. Computer analysis suggested the presence of a transmembrane segment, 5 potential calcium binding sites, and a RAL motif which corresponds to the HAV motif, the potential site for homophilic interaction of typical cadherins. The mouse desmoglein 3 gene consisted of 15 exons in chromosome 18. Comparison of the intron-exon organization of Dsg3 with various cadherins from different species revealed remarkable conservation. This relatively high level of conservation both at the protein and genomic level suggests that desmoglein 3 plays an important role in keratinocyte cell-cell adhesion.

Amino Acid Sequence↗
PubMed2000

Serum thioredoxin levels as an indicator of oxidative stress in patients with hepatitis C virus infection.

BACKGROUND/AIM: It has recently been suggested that oxidative stress may be associated with hepatitis C virus (HCV) infection. Thioredoxin (TRX) is a stress-inducible thiol-containing protein. The aim of this study was to evaluate the clinical significance of serum TRX levels in patients with HCV-related chronic liver diseases. METHODS: Serum TRX levels were determined with a sandwich enzyme-linked immunosorbent assay kit in 174 serum HCV-RNA positive patients, including 6 asymptomatic carriers, 124 chronic hepatitis, 20 liver cirrhosis, and 24 hepatocellular carcinoma, and in 15 healthy volunteers. RESULTS: The serum TRX levels (medians and [ranges], ng/ml) were significantly elevated in the HCV-infected patients; 30.9 [20.7-37.7] in asymptomatic carriers, 34.5 [8.6-135.6]* in chronic hepatitis, 42.5 [21.4-97.2]* in liver cirrhosis, and 43.9 [11.7-180.3]** in hepatocellular carcinoma (*p<0.05, **p<0.001, vs. 24.9 [1.3-50.7] in healthy controls). Serum TRX levels were significantly correlated with the serum levels of ferritin and fibrogenesis markers, and with the histological stage of hepatic fibrosis. The serum TRX levels before interferon treatment of patients whose serum HCV-RNA was still positive on day 14 following interferon treatment (42.6 [20.1-90.0]) were significantly higher than those of patients whose serum HCV-RNA was negative on day 14 following interferon treatment (25.8 [7.4-59.8], p<0.05). CONCLUSIONS: The serum TRX levels of patients with HCV infection increased with their serum ferritin levels and the progression of liver fibrosis. Patients with higher serum TRX levels exhibited resistance to interferon therapy. Oxidative stress may therefore be responsible for the pathological mechanism of HCV-related liver diseases and be one of the impediments to eradication of HCV during interferon treatment.

Adult↗