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J Nishikawa

Publications and source records attributed to J Nishikawa.

At least 37 records · Page 2Linked to original sources
PubMed2000

Molecular evidence of complex tissue- and sex-specific mRNA expression of the rat alpha(2u)-globulin multigene family.

alpha(2u)-Globulin is well known to be a rat protein encoded by a highly homologous multigene family with more than twenty members. We report here the cloning and identification of major alpha(2u)-globulin mRNA species expressed in various tissues. Initially, eight individual clones (PGCL1-8) were obtained from a male preputial gland cDNA library. Data base analysis with BLAST demonstrated six mRNAs to be novel, all clones being characterized by highly conserved sequence motifs as lipocalins. All cDNAs contained an open reading frame of 543 nucleotides and encode 181 amino acid proteins showing 92.5-98.7% and 87.3-98.3% nucleic and amino acid identity, respectively. Denaturing gradient gel electrophoresis (DGGE) with sequence analysis showed that PGCL4 is a major member in the female mammary gland, and in the submaxillary and lachrymal glands of both sexes, while the counterpart in male liver and the coagulate glands was found to be PGCL1. Numbers of cDNA species including PGCL1 and PGCL4 were found in preputial glands, no sex-related difference being observed. These results directly demonstrate complex tissue- and sex-specific expression of alpha(2u)-globulins in terms of mRNA species, providing useful information for understanding regulation of the alpha(2u)-globulin multigene family.

Alpha-Globulins↗
PubMed2000

Estrogenic activity of chemicals for dental and similar use in vitro.

The estrogenic activities of chemicals for dental and similar use were tested by a reporter gene assay (yeast two-hybrid system) and an estrogen/estrogen receptor (ER-alpha) competition binding assay (fluorescence polarization system). Among the 10 chemicals [bisphenol-A (BPA), bis-2-hydroxypropyl methacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA), dibutyl phthalate (DBP), n-butyl benzyl phthalate (BBP), n-butyl phthalyl n-butyl glycolate (BPBG), di-2-ethylhexyl phthalate (DEHP), and di-2-ethylhexyl adipate (DOA)], which were diluted with DMSO to concentrations ranging from 5 x 10(-7) to 5 x 10(-3) M, and 17beta-estradiol (E2) as a positive control, BPA and BBP showed estrogenic activity in these two assays, while the remaining eight chemicals did not at the concentrations tested. Additional data, together with in vivo and epidemiological examinations, are required. Such investigations should also provide information on the validity of these methods for testing the estrogenic activity of chemicals.

Journal Article↗
PubMed2000

Evaluation of the heart with magnetic resonance imaging.

After compensating for two kinds of motion artifacts caused by cardiac beating and respiration, cardiac magnetic resonance (MR) imaging is now feasible for the diagnosis of various cardiac diseases. Taking cost-effectiveness into consideration, this paper reviews the experiences of preferable indications of cardiac MR imaging by demonstrating the characteristic preciseness and uniqueness that play an important role in obtaining time-volume curves consisting of the theoretically most accurate measurements of left and right ventricular volumes, in overall evaluation of the left ventricular apex and the right ventricle, in delineating the wide range of the coronary arterial tree, in measuring the most precise blood flow volume through the cross-sectional images of the vessels, and in assessing the spatial derivative of the blood flow velocity at the vessel wall, i.e., wall shear rate.

Blood Flow Velocity↗
PubMed2000

[Quantitative evaluation for scatter and attenuation correction in 99mTc SPECT--multicenter cooperation phantom study].

A multicenter cooperation phantom study was conducted to evaluate the accuracy of a triple energy window scatter correction technique in combination with various attenuation correction methods for 99mTc single photon emission computed tomography (SPECT) imaging. Six centers participated in this research and the data obtained with seven SPECT instruments were analyzed. The phantom used in the experiment was a 20 x 10 cm cylinder filled with homogeneous 99mTc solution, containing two kinds of cold spots (cold rod phantoms). One had a water-filled cylinder 5.5 cm in diameter positioned 2.5 cm from the center. The other contained 6 water-filled cylinders of various sizes. Contrasts of cold regions were in the range from 74% to 120% (true 100%). Another phantom had the shape of a pie-chart divided into six chambers symmetrically positioned in a cylinder 20 cm in diameter and 10 cm in height. Each chamber had volume of 480 ml and contained homogeneous 99mTc solution of different concentrations. This phantom was used to test for linearity between the radio activity concentration and reconstructed count density (linearity phantom). The intercept of the regression line obtained from the linearity phantom was 8.4 kBq ml-1 without scatter correction and -6.8 kBq ml-1 with scatter correction. Contrast was in the range from 78% to 132% (true 100%). The mean relative error for the measured activity concentration was 4.9% +/- 3.5% (mean +/- sd).

Phantoms, Imaging↗
PubMed1999

New screening methods for chemicals with hormonal activities using interaction of nuclear hormone receptor with coactivator.

The endocrine system exerts important functions in a multitude of physiological processes including embryogenesis, differentiation, and homeostasis. Xenobiotics may modify natural endocrine function and so affect human health and wildlife. It is necessary, therefore, to understand the degree to which xenobiotics can disrupt endocrine systems. The key targets of endocrine disruptors are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We have developed relevant assay systems based on the ligand-dependent interaction between nuclear hormone receptor and coactivator. The coactivators used in this study contained CBP, p300, RIP140, SRC1, TIF1, and TIF2. By two hybrid assay in yeast, the interactions of estrogen receptor with RIP140, SRC1, TIF1, and TIF2 were detected and they were completely dependent on the presence of estrogen. Specificity of this assay was assessed by determining the effect of steroids, known estrogen receptor agonists, and phytoestrogens. The pattern of response to chemicals were consistent with estrogenic activity measured by other assay systems, indicating that this assay system is reliable for measuring estrogenic activity. In addition, we carried out in vitro binding studies: GST pull-down assay and surface plasmon resonance analysis. The estrogen receptor also bound to coactivator in response to chemicals depending on their estrogenic activity in vitro. These data demonstrate that the measurement of interaction between steroid hormone receptor and coactivator serves as a useful tool for identifying chemicals that interact with steroid receptors.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Identification of a novel ice-nucleating bacterium of Antarctic origin and its ice nucleation properties.

A novel ice-nucleating bacterium (INB) was isolated from Ross Island, Antarctica. INBs could be isolated more frequently than was generally thought. INB strain IN-74 was found in the white colony group. Strain IN-74 was identified from its taxonomic characteristics as a novel INB, Pseudomonas antarctica IN-74. When strain IN-74 was cultured aerobically in a medium consisting of the ice-nucleating broth (pH 7.0) for 6 days at 4 degrees C, the ice-nucleating activity of strain IN-74 cells was obtained. Strain IN-74 cells produced ice nuclei only at extremely low growth temperatures. The nuclei appeared to be less thermolabile than those of INB Pseudomonas fluorescens KUIN-1. The freezing difference spectra in D2O and H2O at ice-nucleating temperature for strain IN-74 cells and conventional INBs (Pseudomonas fluorescens KUIN-1, Pseudomonas viridiflava KUIN-2, and Pseudomonas syringae C-9) exhibited different curves.

Antarctic Regions↗
PubMed1999

Involvement of peritoneal macrophage in the induction of cytotoxicity due to apoptosis in ascitic fluid associated with severe acute pancreatitis.

The aim of this study was to assess the significance of peritoneal macrophage in inducing cytotoxicity in ascitic fluid associated with severe acute pancreatitis. The involvement of peritoneal macrophage was examined experimentally in rats by macrophage depletion with peritoneal lavage prior to the development of pancreatitis. More than 94% of the cellular components collected from peritoneal cavities by the lavage are macrophages. Although the ascitic fluid collected from the rats with necrotizing pancreatitis showed cytocidal effects via apoptosis on Madin-Darby canine kidney cells in a dose- and time-dependent manner, cytotoxicity or apoptosis-inducing activity almost disappeared from the ascitic fluid by the preceding peritoneal lavage. The ascitic fluid did not show significant differences by the lavage in osmolarity and in concentrations of albumin, bilirubin, amylase, and lipase. Although a slight reduction of tumor necrosis factor-alpha was noted with the lavage, tumor necrosis factor-alpha failed to induce apoptotic cell death in the cells, and the neutralization by antibody ameliorated neither cell death nor apoptosis. We conclude that peritoneal macrophages secrete apoptosis-inducing factor(s) into pancreatitis-associated ascitic fluid, other than tumor necrosis factor-alpha.

Acute Disease↗
PubMed1999

Morphological onset and early diagnosis in apical hypertrophic cardiomyopathy: a long term analysis with nuclear magnetic resonance imaging.

OBJECTIVES: A long-term follow-up study with nuclear magnetic resonance (NMR) imaging was undertaken to detect the morphological onset and to establish the early diagnosis in apical hypertrophic cardiomyopathy (HCM). BACKGROUND: A spadelike configuration on left ventriculogram (LVG) is regarded as a diagnostic criterion for the classical apical HCM. There also exists a segmented hypertrophy at the apical level without indicating the spadelike features (a nonspade configuration). To detect the hypertrophied myocardium of the nonspade configuration, circumferential scrutiny of the apex is required. Although both configurations can be underlying causes of giant negative T waves, etiological relationship between the two is not clarified. METHODS: The criteria for the spadelike configuration defined on left ventricular short-axis NMR images were as follows: (apical maximal thickness > or = 15 mm), (apical anterior thickness over basal anterior thickness > or = 1.3) and (apical posterior thickness over basal posterior thickness > or =1.3). Thirteen patients who had predominant hypertrophy (> or = 15 mm) at the apical level without the spadelike configuration underwent NMR imaging twice before and after 54+/-10 months' follow-up. RESULTS: Apical hypertrophy that had been confined to the lateral wall in four, the anterior-lateral wall in two, and the septal-anterior wall in one developed to become circumferential hypertrophy that fulfilled the criteria for the spadelike configuration after the follow-up period. CONCLUSIONS: The spadelike configuration can begin with the nonspade configuration and therefore, both can constitute a single disease entity of apical HCM. The early diagnosis of apical HCM can be achieved by identifying the hypertrophy frequently confined to the lateral wall at the apical level.

Adult↗
PubMed1999

Epstein-Barr virus-associated gastric carcinoma and atrophic gastritis.

Although Epstein-Barr virus (EBV) has been reported to be present in some 7% of gastric carcinomas, the nature of the background gastric mucosa of carcinoma has not been elucidated. The authors evaluated the degree of gastritis in the background gastric mucosa of EBV-associated gastric carcinoma. EBV was detected using in situ hybridization for EBV-encoded small ribonucleic acid 1 (EBER-1) in carcinoma cells. The authors compared gastritis in surgically resected stomachs with 8 EBER-1-positive and 16 EBER-1-negative gastric carcinomas of a similar histologic type using histologic variables of the Updated Sydney System. All eight lesions of EBER-1-positive gastric carcinomas had intestinal metaplasia in the background. Mild to moderate glandular atrophy was common in both groups. Many of the tested lesions, 87.5% of EBER-1-positive and 62.5% of EBER-1-negative lesions, were located near the mucosal atrophic border. The background gastric mucosa for EBV-associated gastric carcinomas is rich in atrophic changes. EBV-associated gastric carcinomas are located near the mucosal atrophic border.

Gastric Mucosa↗
PubMed1999

Epstein-Barr virus promotes epithelial cell growth in the absence of EBNA2 and LMP1 expression.

We attempted to infect primary gastric epithelia (PGE) with recombinant Epstein-Barr virus (EBV) carrying a selectable marker that made it possible to select EBV-infected cells. Cells dually positive for EBV-determined nuclear antigen (EBNA) and cytokeratin were detected in 3 of 21 primary cultures after 3 days of EBV inoculation. From one culture, EBV-infected cell clones were repeatedly obtained at a frequency of 3 to 5 cell clones per 10(6) cells. EBV-infected clones had enhanced population doubling and grew to attain a highly increased saturation density, together with acquisition of marked anchorage independence. The infected clones retained the ultrastructural morphology characteristic of gastric mucosal epithelium and have been growing stably for more than 18 months (corresponding to at least 300 generations) so far, in clear contrast to the parental PGE cells, which ceased growth after 60 generations. The p53 gene of the parental PGE cells was found to be overexpressed, perhaps thereby conferring the basal potential for long-term survival in vitro. Moreover, EBV infection accelerated, to a significant extent, the growth rate and agar clonability of NU-GC-3 cells, an established EBV-negative but EBV-susceptible human gastric carcinoma cell line. Both EBV-converted PGE and NU-GC-3 clones, like EBV-positive gastric carcinoma biopsy specimens, expressed a restricted set of EBV latent infection genes characterized by the absence of EBNA2 and latent membrane protein 1 (LMP1) expression. These results indicate that EBV infection causes a transformed phenotype on PGE in the setting of possible unregulated cell cycling and renders even established gastric carcinoma cells more malignant via a limited spectrum of viral latent-gene expression. This study may reflect an in vivo scenario illustrating multiphasic involvement of EBV in carcinogenesis of gastric or other epithelial cancers.

Cell Division↗
PubMed1999

Evaluating the performance of academic medical education administrators.

Educators have devoted little attention to formal evaluation of educational administrative personnel. The authors surveyed the educational administrators working in McMaster University's Department of Medicine residency program and found they felt they were receiving little useful feedback. The authors also surveyed the colleagues, residents, and administrative staff with whom the administrators worked and found they felt they had inadequate input into the administrators' evaluation. In response to these results, a measurement instrument was developed based on existing job descriptions and feedback was obtained on administrators' performance from relevant individuals. After three yearly evaluations, administrators and evaluators acknowledged much broader input into evaluation but saw little evaluation-related improvement in performance. Of the administrators, 85% felt the process should continue as did 91% of the evaluators. An evaluation process may not alter perceived performance when it is already good but there may be other benefits to rigorous evaluation.

Attitude of Health Personnel↗
PubMed1999

Clinical implication of left precordial T wave inversions in the presence of complete right bundle branch block.

This study was designed to elucidate whether left precordial negative T waves are electrocardiographic indicators for the diagnosis of hypertrophic cardiomyopathy (HCM) even in the presence of complete right bundle branch block (CRBBB). In 7 consecutive patients with CRBBB accompanied by negative T waves in at least one of the left precordial leads (V4, V5, V6, maximal negativity; 1.06 +/- 0.40 mVol) (left precordial negative T wave group) and in 15 randomly selected CRBBB patients without left precordial T wave inversions (control group), echocardiography was performed to rule out underlying diseases causing left ventricular overload and to identify candidates for magnetic resonance (MR) imaging. None had anginal pain indicating ischemic heart disease. When 2-dimensional echocardiography indicated left ventricular hypertrophy with wall thickness > or = 15 mm, the magnitude and distribution of hypertrophy were scrutinized on contiguous left ventricular MR short-axis images. The diagnostic criterion of HCM was the demonstration of hypertrophy with a wall thickness of 20 mm or more on the left ventricular MR short-axis images. All patients in the left precordial negative T wave group had negative T waves in both I (negativity; 0.27 +/- 0.17 mVol) and aVL (negativity; 0.23 +/- 0.14 mVol), whereas none in the control group did. The diagnostic criterion for HCM was fulfilled in six patients in the left precordial negative T wave group. However there were no patients who fulfilled the criterion in the control group. Negative T waves were recorded in the I (negativity; 0.30 +/- 0.17 mVol), aVL (negativity; 0.25 +/- 0.14 mVol), V4 (negativity; 1.03 +/- 0.46 mVol), V5 (negativity; 0.83 +/- 0.37 mVol) and V6 leads (negativity; 0.31 +/- 0.31 mVol) in all patients with HCM, while they were recorded in only 6% of the patients without HCM. In conclusion, the existence of left precordial negative T waves in the presence of CRBBB strongly indicates HCM.

Bundle-Branch Block↗
PubMed1999

Increased renal retention of 99mTc-methylene diphosphonate after nephron-sparing surgery.

UNLABELLED: Nephron-sparing surgery has become established as an effective treatment for localized renal cell carcinoma when preservation of renal function is necessary. The surgery usually requires temporary renal artery occlusion and may induce ischemic renal damage. In this study, we retrospectively evaluated renal activity on bone scintigraphy after nephron-sparing surgery. METHODS: Eleven patients who underwent nephron-sparing surgery for renal cell carcinoma and had a normal contralateral kidney were studied. A total of 12 bone scintigraphy images with 99mTc-labeled methylene diphosphonate were obtained within 1 y after surgery in these patients to assess skeletal metastasis. Activity in the spared renal parenchyma was compared visually with that in the contralateral normal kidney. RESULTS: The tumor was successfully resected in every patient, and no clinically significant complications occurred. Activity in the spared renal parenchyma was elevated in six of seven examinations performed within 21 d after surgery. In three examinations, the increase in renal activity was heterogeneous, being relatively prominent near the surgical margin. Increased renal activity was not observed on five examinations performed 3 mo or more after surgery. CONCLUSION: Renal retention of bone-seeking agents is elevated in the early period after nephron-sparing surgery, probably as a result of ischemic insult during the surgical procedure. Bone scintigraphy may aid in evaluating the presence and degree of ischemic damage of the spared renal parenchyma.

Adult↗
PubMed1999

Apoptotic cell death of renal tubules in experimental severe acute pancreatitis.

BACKGROUND: Recently renal cell apoptosis has been reported in various disorders that result in renal failure. Thus we hypothesized that renal cell injury resulting from apoptosis is involved in renal failure with severe acute pancreatitis. METHODS: Renal cell apoptosis in kidneys harvested from rats with necrotizing pancreatitis was evaluated by in situ nick-end labeling. Ascitic fluid that had been collected 6 hours after development of pancreatitis was injected into the peritoneal cavities of healthy rats, and renal apoptosis was also evaluated. The apoptosis-inducing activity of the ascitic fluid was estimated in vitro with use of isolated rat renal tubules and the normal rat kidney cell line NRK52E by nuclear staining, cell cycle analysis, and DNA electrophoresis. RESULTS: Apoptosis was detected by in situ nick-end labeling on the renal tubules 6 hours after induction of pancreatitis in vivo. Similar tubular apoptosis was detected in the rats that had intraperitoneal injection of the ascitic fluid. In in vitro analyses the ascitic fluid induced nuclear and DNA fragmentation on the isolated renal tubules and promoted apoptosis on NRK52E cells in a time-dependent manner. CONCLUSIONS: Apoptotic cell death of renal tubules occurs in severe acute pancreatitis within several hours and is possibly involved in the mechanism of renal failure through undefined substance(s) in the ascitic fluid associated with pancreatitis.

Animals↗
PubMed1998

Thymic atrophy caused by thymocyte apoptosis in experimental severe acute pancreatitis.

Although a reduction in peripheral lymphocytes has been reported in clinical cases of acute pancreatitis, the thymic change remains still unknown. To investigate impairment of cellular immunity in acute pancreatitis, alterations of the thymus in rats with acute pancreatitis were examined experimentally. Male Wistar rats were used. Two groups with pancreatitis of different severity and a control group for each were established. The thymus was weighed and the number of thymocytes counted. Apoptosis in the thymus was examined by in situ nick-end labeling, DNA agarose gel electrophoresis, and cell cycle analysis using propidium iodide. Both thymus weight and number of thymocytes decreased significantly in the rats with necrotizing pancreatitis 20 h after induction of pancreatitis (P <0.02 vs sham operation). Neither thymus atrophy nor thymocyte reduction was observed in rats with edematous pancreatitis. In thymuses from rats with necrotizing pancreatitis, in situ nick-end labeling showed a significant increase in apoptotic changes of thymocytes, which was also confirmed by the stepladder pattern on agarose gel electrophoresis of the extracted DNA and by cell cycle analysis. It is concluded that thymus atrophy associated with apoptosis occurs in rats with necrotizing pancreatitis.

Alanine Transaminase↗
PubMed1998

Role of positron emission tomography using fluorine-18 fluoro-2-deoxyglucose in predicting improvement in left ventricular function in patients with idiopathic dilated cardiomyopathy.

Improvement in left ventricular (LV) function in patients with idiopathic dilated cardiomyopathy (DCM) by medical treatment has been suggested. Thus, it is important to evaluate which patients will respond to medical therapy. Positron emission tomography (PET) with fluorine-18 fluoro-2-deoxyglucose (FDG) and cardiac catheterization were performed in 20 patients with DCM before the initiation of medical therapy. The regional myocardial glucose utilization rate (rMGU) was measured with FDG PET. Subjects were divided into two groups, group 1 (event-free patients, n=10) and group 2 (clinical cardiac events, n=10). Haemodynamic and PET parameters before the initiation of medication were compared between the two groups and between patients with and patients without improvement in LV function. Ejection fraction (EF) was significantly higher in group 1 (35.8%+/-9.0%) than in group 2 (24.8%+/-7.0%) and LV end-diastolic pressure (LVEDP) was significantly lower in group 1 (8.4+/-1.7 mmHg) than in group 2 (11.6+/-3.5 mmHg). Average rMGU (mg min-1 100 g-1) was similar in group 1 (11.2+/-2.5 mg min-1 100 g-1) and group 2 (11.2+/-2.9 mg min-1 100 g-1), while %CV of rMGU was significantly lower in group 1 (11.1%+/-6.3%) than in group 2 (29. 9%+/-13.9%, P<0.01). Furthermore, LV function normalized in seven patients in group 1. In these seven patients, EF (35.1%+/-10.9%), LVEDP (8.2+/-2.0 mmHg) and average rMGU (11.8+/-2.7 mg min-1 100 g-1) were comparable with those in patients without LV functional improvement (EF: 31.6%+/-9.1%; LVEDP: 10.7+/-3.3 mmHg; average rMGU: 10.8+/- 2.7 mg min-1 100 g-1). However,% CV of rMGU in patients with LV functional improvement (9.6%+/-5.6%) was significantly lower than in those without such improvement (26.3%+/-14.1%, P<0.01). %CV of rMGU <13.6% predicted prognosis with a sensitivity of 80%, a specificity of 100% and an accuracy of 90%. %CV of rMGU <13.6% also predicted improvement in LV function, with a sensitivity of 75%, a specificity of 92% and an accuracy of 85%. However, EF failed to predict improvement of LV function. In is concluded that homogeneous myocardial glucose utilization rate can predict both prognosis and improvement in LV function achieved by medical therapy in patients with DCM.

Adult↗