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S Tsuruta

Publications and source records attributed to S Tsuruta.

At least 37 records · Page 2Linked to original sources
PubMed2001

Use of the preconditioned conjugate gradient algorithm as a generic solver for mixed-model equations in animal breeding applications.

Utility of the preconditioned conjugate gradient algorithm with a diagonal preconditioner for solving mixed-model equations in animal breeding applications was evaluated with 16 test problems. The problems included single- and multiple-trait analyses, with data on beef, dairy, and swine ranging from small examples to national data sets. Multiple-trait models considered low and high genetic correlations. Convergence was based on relative differences between left- and right-hand sides. The ordering of equations was fixed effects followed by random effects, with no special ordering within random effects. The preconditioned conjugate gradient program implemented with double precision converged for all models. However, when implemented in single precision, the preconditioned conjugate gradient algorithm did not converge for seven large models. The preconditioned conjugate gradient and successive overrelaxation algorithms were subsequently compared for 13 of the test problems. The preconditioned conjugate gradient algorithm was easy to implement with the iteration on data for general models. However, successive overrelaxation requires specific programming for each set of models. On average, the preconditioned conjugate gradient algorithm converged in three times fewer rounds of iteration than successive overrelaxation. With straightforward implementations, programs using the preconditioned conjugate gradient algorithm may be two or more times faster than those using successive overrelaxation. However, programs using the preconditioned conjugate gradient algorithm would use more memory than would comparable implementations using successive overrelaxation. Extensive optimization of either algorithm can influence rankings. The preconditioned conjugate gradient implemented with iteration on data, a diagonal preconditioner, and in double precision may be the algorithm of choice for solving mixed-model equations when sufficient memory is available and ease of implementation is essential.

Algorithms↗
PubMed2001

Dimethyl sulfoxide inhibits dimethylnitrosamine-induced hepatic fibrosis in rats.

We studied the preventive effects of dimethyl sulfoxide (DMSO) on experimental hepatic fibrosis induced by dimethylnitrosamine (DMN) in rats. Treatment with DMN caused a significant decrease in body and liver weight. Oral DMSO (2 ml/kg daily for 4 weeks) essentially prevented this DMN-induced body and liver weight loss with no major side effects. DMSO suppressed the induction of hepatic fibrosis, as determined by histological evaluation, and reduced hepatic hydroxyproline. It also suppressed the expression of mRNA for type I collagen in the liver. Because hepatic stellate cells (HSC) are the major cellular source of the collagen in hepatic fibrosis, we examined the effects of DMSO on collagen production in vitro using rat primary HSC culture. However, it was found that DMSO did not inhibit the collagen production in vitro. We next evaluated the effects of DMSO on tumor necrosis factor alpha (TNFalpha) and nitric oxide (NO) production by Kupffer cells, because these factors represent major activator of HSC, and because monocyte-macrophage infiltration has been implicated as being pathogenetically important for hepatic fibrosis induced by DMN. DMSO inhibited lipopolysaccharide (LPS)-induced TNFalpha and NO production, and reduced TNFalpha mRNA levels. DMSO also suppressed the LPS-induced nuclear factor kappa B activation in a murine macrophage-like cell line. These results suggest that the inhibitory effects of DMSO on hepatic fibrosis may be primarily exerted via blocking of DMN-induced inflammation. These results also implied that DMSO may be potentially useful for preventing the development of hepatic fibrosis.

Animals↗
PubMed2000

Impacts of the Detection of Cassiopeia A Point Source.

Very recently the Chandra first light observation discovered a point-like source in the Cassiopeia A supernova remnant. This detection was subsequently confirmed by the analyses of the archival data from both ROSAT and Einstein observations. Here we compare the results from these observations with the scenarios involving both black holes (BHs) and neutron stars (NSs). If this point source is a BH, we offer as a promising model a disk-corona type model with a low accretion rate in which a soft photon source at approximately 0.1 keV is Comptonized by higher energy electrons in the corona. If it is an NS, the dominant radiation observed by Chandra most likely originates from smaller, hotter regions of the stellar surface, but we argue that it is still worthwhile to compare the cooler component from the rest of the surface with cooling theories. We emphasize that the detection of this point source itself should potentially provide enormous impacts on the theories of supernova explosion, progenitor scenario, compact remnant formation, accretion to compact objects, and NS thermal evolution.

Journal Article↗
PubMed2000

IL-4 production by PBMCs on stimulation with mite allergen is correlated with the level of serum IgE antibody against mite in children with bronchial asthma.

BACKGROUND: Although IL-4, IL-13, and IFN-gamma are known to affect IgE synthesis, it remains unclear which one plays the most important role in in vivo IgE synthesis in atopic patients. OBJECTIVE: The aim of this study is to clarify the difference in importance among these cytokines in up-regulation of IgE synthesis in atopic patients. METHODS: We measured IL-4, IL-13, and IFN-gamma production by PBMCs on stimulation with house dust mite (HDM) in 23 children, 3 to 15 years old, with bronchial asthma (BA) and analyzed the correlation with HDM-specific IgE antibody levels expressed as HDM IgE radioallergosorbent test (RAST) results. RESULTS: The production of IL-4 and IL-13 by PBMCs on stimulation with HDM was significantly higher in children with BA than in nonatopic control subjects (IL-4, 752.9 +/- 365.9 vs 312.3 +/- 230.0 fg/mL, P <.001; IL-13, 21.9 pg/ml [<12.0-77.6] vs <12.0, P <.01). IL-4 production showed a close positive correlation with HDM IgE RAST (r = 0.71, P <.001), which was distinctly stronger than that between IL-13 production and HDM IgE RAST (r = 0.46, P <.05). IFN-gamma production was neither different between children with BA and nonatopic control subjects (7. 24 [1.54-33.90] pg/mL vs 11.2 [1.66-75.9] pg/mL) nor correlated with HDM IgE RAST levels. Essentially the same result was obtained by stimulation of PBMCs with a purified HDM major allergen Der f 1. CONCLUSION: IL-4 is likely to be the most important cytokine in up-regulation of in vivo IgE synthesis against HDM in children with BA.

Adolescent↗
PubMed2000

Effect of acid-suppressive therapy on Helicobacter pylori production of interleukin-8 in the gastric mucosa.

BACKGROUND: Recent studies have shown that acid-suppressive therapy increases the severity of Helicobacter pylori- associated gastritis in the corpus. PURPOSE: To evaluate interleukin (IL)-8 production in the gastric corpus mucosa before and during acid-suppressive therapy in H pylori-infected patients. PATIENTS AND METHODS: Ten patients with reflux esophagitis (five H pylori-positive and five H pylori-negative) were treated with omeprazole 20 mg. Serum gastrin concentrations, H pylori colonization density and mucosal IL-8 levels in the corpus were investigated at entry and two weeks after starting therapy. IL-8 levels were measured by ELISA. The organism density was determined, and scored according to area occupied by the bacterial colonies. The presence of H pylori was assessed by rapid urease testing and histological finding of gastric biopsy specimens. RESULTS: In H pylori-positive patients, concentrations of IL-8 during therapy significantly exceeded those before therapy (36.2+/-6. 8 versus 18.3+/-3.8 pg/mg protein; P<0.05) without altering H pylori density. In H pylori-negative patients, IL-8 levels were similar before and during therapy (6.1+/-2.7 versus 6.3+/-3.0 pg/mg protein). Concentrations of gastrin during therapy were significantly higher than those before therapy in all patients. CONCLUSIONS: The results suggest that acid suppression increases mucosal IL-8 levels in H pylori-infected patients with reflux esophagitis.

Adult↗
PubMed2000

IFN-gamma plays a dominant role in upregulation of Candida-specific IgE synthesis in patients with atopic dermatitis.

BACKGROUND: Although Candida albicans (CA) is known to induce Th1 clones that suppress IgE synthesis, serum IgE antibody against CA is often increased in atopic patients. This study aims to elucidate the mechanism of IgE synthesis against CA in atopic patients. METHODS: We measured the production of IL-4 and IFN-gamma by peripheral blood mononuclear cells (PBMCs) from atopic patients upon stimulation with CA and examined the correlation with the level of serum IgE antibody against CA. RESULTS: The level of serum CA-specific IgE antibody (CA-IgE) was significantly higher in patients with atopic dermatitis (AD) than in patients with bronchial asthma (BA) (geometric mean = 3.6 vs. 0.27 U(A)/ml, p < 0.02) (U(A) = unit allergen), while there was no difference in the level of house dust mite-specific IgE antibody between them (67.6 vs. 87.1 U(A)/ml). Although IL-4 production by PBMCs upon stimulation with CA in patients with AD was not significantly different from that in patients with BA (mean = 359.1 vs. 515.3 fg/ml), IFN-gamma production was significantly lower in the former than in the latter group (8.1 vs. 56.2 pg/ml, p < 0.001). Consequently, the ratio of IL-4/IFN-gamma production was apparently higher in patients with AD than in those with BA, which corresponds to the difference between them in the level of serum CA-IgE. A significant negative correlation was seen in patients with AD between IFN-gamma production by CA-stimulated PBMCs and the level of serum CA-IgE (p < 0.05). CONCLUSIONS: IgE synthesis against CA in atopic patients may be precipitated not by enhancing IL-4 production, but by reducing IFN-gamma secretion.

Adolescent↗
PubMed2000

Bias in genetic evaluations by records of cows treated with bovine somatotropin.

Records from Dairy Records Management Systems in Raleigh were used to estimate effects of bovine somatotropin (bST) treatment and to predict breeding values for milk production traits. The data comprised 5245 test-day records of bST-treated cows and 126,223 test-day records of untreated cows in first lactation for milk, fat, and protein yields. Fixed effects of bST treatment were estimated from test-day animal models with herd-test-date as another fixed factor. Percentage increases due to bST treatment ranged from 7 to 8% for test-day milk, fat, and protein yields. Random regression coefficients for additive genetic and permanent environmental effects were included in the model. To assess the potential for bias in genetic evaluations when some and not all cows are treated with bST, breeding values predicted by the test-day model with and without effects of bST treatment were compared for cows and sires. Correlations between breeding values predicted from models with and without effects of bST treatment were 0.99. However, relatively large bias was found for individual animals. This result suggests that bias in genetic evaluation caused by ignoring bST treatment may be significant.

Animals↗
PubMed1999

Effect of simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on alpha-fetoprotein gene expression through interaction with the ras-mediated pathway.

BACKGROUND/AIMS: The ras proto-oncogene encodes a small GTP-binding protein (Ras) which regulates cell growth and differentiation by relaying signals from the cell surface to the nucleus. In the present study, the role of Ras signal transduction pathway in alpha-fetoprotein (AFP) gene expression was evaluated in HuH-7 human hepatoma cells using simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, which blocks Ras function through inhibition of farnesylation, and the ras(val-12) expression vector. METHODS: The HuH-7 cells were treated with simvastatin (10 micromol/l), or both simvastatin and mevalonate (300 micromol/l), and numbers of viable cells were counted after treatment. To elucidate the effects of simvastatin on AFP gene expression and the interactive effect of simvastatin on Ras signal transduction pathway, Northern blotting and transient chloramphenicol acetyltransferase plasmid transfection assays were performed. RESULTS: Cell growth was inhibited by simvastatin, and this growth inhibition was restored by addition of mevalonate. Levels of AFP mRNA but not albumin mRNA were elevated by simvastatin in a dose-dependent manner (1-10 micromol/l). AFP promoter and enhancer activities were stimulated by simvastatin. In contrast, both activities were repressed by transfection with the ras(val-12) expression vector. The ras(val-12)-mediated repression was restored by simvastatin and returned to the repressed level by simvastatin plus mevalonate. CONCLUSIONS: These results indicate that the Ras signal transduction pathway functions to down-regulate the AFP gene transcription in human hepatoma cells.

Carcinoma, Hepatocellular↗
PubMed1999

Utilization of variant-type of human alpha-fetoprotein promoter in gene therapy targeting for hepatocellular carcinoma.

We previously reported that the retroviral vector (LNAFW0.3TK) expressing the herpes simplex thymidine kinase (HSVtk) gene under the control of the 0.3 kb human alpha-fetoprotein (AFP) promoter provided the ganciclovir (GCV)-mediated cytotoxicity in the high AFP-producing (HuH-7) but not in the low AFP-producing (huH-1/cl.2) human hepatoma cells. In the present study, we constructed the retroviral vector (LNAFM0.3TK) in which the HSVtk gene expression is regulated by the variant-type of the 0.3 kb human AFP promoter with a G-to-A substitution at nucleotide -119, a point mutation responsible for hereditary persistence of human AFP and the vector was applied to three human hepatoma cell lines HuH-7, huH-1/cl.2 and intermediate AFP-producing cells (PLC/PRF/5). By the reporter gene transfection assay, the activity of the variant-type of the promoter was much higher than that of the wild-type of the promoter in both HuH-7 and huH-1/cl.2 cells. Consistent with this, LNAFM0.3TK infection could sensitize huH-1/cl.2 cells, as well as HuH-7 and PLC/PRF/5 cells to GCV, but did not affect cell growth of nonhepatoma cells (HeLa). In addition, the bystander effect was achieved more efficiently by LNAFM0.3TK infection than LNAFW0.3TK infection in HuH-7 cells. These results suggest that the variant-type of the human AFP promoter ensures the therapeutic gene expression in gene therapy particularly for the low AFP-producing hepatoma cells.

Carcinoma, Hepatocellular↗
PubMed1999

Differences in cytokine production by peripheral blood mononuclear cells (PBMC) between patients with atopic dermatitis and bronchial asthma.

It is widely accepted that type 2 helper T (Th2) lymphocytes play a crucial role in the pathogenesis of atopic dermatitis (AD) as well as bronchial asthma (BA). We measured the amounts of IL-5 and interferon-gamma (IFN-gamma) produced by PBMC upon stimulation with house dust mite (HDM) or Candida albicans (CA) in 17 children (3-15 years) with AD, and compared these values with those of 16 children with BA. Although IL-5 production by PBMC upon stimulation with HDM in patients with AD was significantly higher than that in 13 non-atopic controls (geometric mean = 23.4 pg/ml versus 5.9 pg/ml, P < 0.05), it was significantly lower than that in patients with BA (177.8 pg/ml, P < 0.001). The amount of IL-5 produced by PBMC upon stimulation with CA was also significantly lower in patients with AD than in those with BA (7.2 pg/ml versus 100.0 pg/ml, P < 0.001). The production of IFN-gamma by PBMC stimulated with HDM or CA was also significantly lower in patients with AD than in those with BA (HDM 4. 3 pg/ml versus 12.6 pg/ml, P < 0.05; CA 6.5 pg/ml versus 60.3 pg/ml, P < 0.001). Consequently the ratio of IL-5 to IFN-gamma production was high not only in patients with BA but also in those with AD. These findings suggest that there are some differences in the regulation of in vivo cytokine production between patients with AD and those with BA, although a Th2-dominant profile is common to both.

Adolescent↗
PubMed1999

Nondestructive prediction method for yolk:albumen ratio in chicken eggs by computer image analysis.

The purpose of this study was to develop a nondestructive prediction method for the yolk: albumen ratio by computer image analysis for candling inspection. Twenty-two to 49 eggs per line were randomly sampled from four chicken lines. After weighing the eggs, the eggs were illuminated by an overhead projector beam through a small hole in dark room. Video images were taken of the eggs from four directions, the eggs rotated each time by 90 degrees. The eggs were broken for measuring egg traits, including the yolk:albumen ratio. The average value obtained from four directions was used for statistical analysis. The ratio of the number of pixels of light and dark parts (light: dark ratio), and the CV of red (R), green (G), and blue (B) components for the whole egg and for light and dark parts of the egg were calculated and defined as image analysis traits. Correlation coefficients between the yolk: albumen ratio and CV of R and G components of the whole egg were significant (0.42 to 0.79) in all the lines. The determination coefficient of multiple regression of the yolk:albumen ratio on the CV of R and G components of the whole egg and the light:dark ratio was 0.83. Observed and predicted yolk:albumen ratios were classified into five levels. The ratio of zero difference between observed and predicted values was 76.1%, and the percentage of 0 to +/- 1 difference between observed and predicted values was 100.0%. The image analysis method accurately predicted the yolk:albumen ratio without breaking the egg.

Albumins↗
PubMed1999

Prevalence and characterization of hepatitis C virus in hemodialysis patients.

OBJECT: Chronic hepatitis C virus (HCV) infection is common in hemodialysis (HD) patients. In the present study, the prevalence and properties of HCV in HD patients were analyzed. METHODS AND RESULTS: Of 125 HD patients, 34 (27%) were positive for antibody to HCV, and HCV-RNA was detected in 23 (68%) of the 34 patients using reverse transcription polymerase chain reaction. The HCV-RNA sequence analysis did not identify the alterations specific to HD patients with HCV, although one patient had a variant virus containing the deletion of the core gene sequence. When serial changes in the levels of HCV-RNA were evaluated in 15 patients by a branched DNA assay, the values decreased immediately after HD procedure, but returned to the baseline values 2 days after the procedure. CONCLUSION: These results indicate that HCV in HD patients is replication-competent, although a transient reduction in the levels of HCV-RNA occurs during HD.

Adult↗
PubMed1999

Detection of hepatitis B virus X-region DNA in liver tissue from patients with hepatitis C virus-associated cirrhosis who subsequently developed hepatocellular carcinoma.

The risk of hepatocellular carcinoma (HCC) in patients chronically infected by hepatitis C virus (HCV) is relatively higher in Japan than in Western countries. The presence of hepatitis B virus X (HBX)-DNA in the liver tissue samples obtained on enrollment from 69 patients with HCV-associated cirrhosis who were subsequently followed in our hospital was analyzed by polymerase chain reaction (PCR). During the follow-up period of 5.7+/-3.2 years (mean +/- SD), 52 (75%) of 69 patients developed HCC. The PCR analysis indicated that the HBX-DNA sequence was detected in 25 (48%) of 52 patients who developed HCC during follow-up, but in only 3 (18%) of 17 patients who did not (P<0.05). These results suggest that HBX, a hepatitis B viral product relevant to hepatocarcinogenesis, is involved in development of HCC in some patients chronically infected by HCV in Japan.

Adult↗
PubMed1998

Denitrification by yeasts and occurrence of cytochrome P450nor in Trichosporon cutaneum.

Yeasts of various genera were screened for denitrifying activity, and several yeast strains such as Trichosporon cutaneum, Fellomyces fuzhouensis, and Candida sp. were found to exhibit distinct activities to convert nitrite to nitrous oxide. Dissimilatory nitrite reductase (Nir) or nitric oxide reductase (Nor) activities were detected in the cell-free extracts of these yeasts. Spectrophotometric as well as Western blot analyses showed that T. cutaneum contains Nor of the cytochrome P450 type. This is the first report that shows that denitrification is also distributed among yeasts although their systems are incomplete, only capable of reducing nitrite to nitrous oxide.

Anaerobiosis↗
PubMed1998

Jejunal lipomatosis with diverticulosis: report of a case.

We herein report the very rare case of a 68-year-old Japanese man with multiple jejunal lipomatosis and diverticulosis. He was admitted to our hospital with the chief complaint of melena and anemia. A barium study of the small bowel showed multiple lipomatosis and diverticulosis. An approximately 200-cm length of the jejunum was therefore resected. Thereafter, two diverticula and 215 lipomas were recognized in the resected specimen. A pathological examination showed mature adipose tissue with fibrous septa in the submucosal and muscularis propria. These findings were thus suggested to be due to the attenuation of the muscularis propria. The complications of lipomatosis are also discussed.

Aged↗
PubMed1998

Unique profile of IL-4 and IFN-gamma production by peripheral blood mononuclear cells in infants with atopic dermatitis.

Although the level of house dust mite (HDM)-specific lymphocyte proliferation is high in infants with atopic dermatitis (AD), the level of HDM-specific IgE antibody (HDM-IgE-RAST) is usually very low or negative. To elucidate the cause of the deficient HDM-specific IgE antibody formation in infants with AD, we examined the profile of IL-4 and IFN-gamma production by HDM-stimulated PBMCs. The amount of IL-4 production was higher in infants with AD and in children with AD (3 to 15 years) than in the nonatopic control subjects. Although the amount of IFN-gamma production in children with AD was lower than that found in nonatopic children, it was higher in infants with AD than in nonatopic infants. This result suggests that HDM-specific helper T lymphocytes in infants with AD have not yet differentiated into TH2 but rather stayed at the stage of TH0. The level of IgE-RAST for egg white (EW) is already elevated in infants with AD. The amount of IL-4 produced by EW-stimulated PBMCs was comparable to that produced by HDM-stimulated PBMCs in infants with AD. However, the amount of IFN-gamma produced by EW-stimulated PBMCs was distinctly lower than that produced by HDM-stimulated PBMCs in infants with AD. Although there was no correlation between the amount of IL-4 production by HDM-stimulated PBMCs and the level of HDM-IgE-RAST in infants with AD, the amount of IL-4 production by EW-stimulated PBMCs was closely correlated with the level of EW-IgE-RAST. These results suggest that it is not the lack of IL-4 but rather a relative increase in IFN-gamma production by HDM-specific helper T lymphocytes that causes the deficiency of HDM-specific IgE-antibody synthesis in infants with AD.

Adolescent↗
PubMed1998

Correlation of house dust mite-specific lymphocyte proliferation with IL-5 production, eosinophilia, and the severity of symptoms in infants with atopic dermatitis.

Because house dust mite (HDM)-specific IgE antibody (IgE-RAST) is usually not detectable in infants with atopic dermatitis (AD), HDM has not been regarded as the cause of infantile AD. The level of HDM-specific lymphocyte proliferation (expressed as stimulation index measured by flow cytometry [SIF]), however, was found to be markedly elevated in AD infants. This suggests that the sensitization of T cells to HDM extract occurs even in infancy. Moreover, the level of HDM-SIF is correlated closely with the severity of infantile AD, suggesting that HDM is a major cause of this disease not only in adults and children but also in infants. Although the level of HDM-SIF did not correlate with the level of HDM-specific IgE-RAST in infants with AD, it did intimately correlate with the absolute number of peripheral blood eosinophils. Because T lymphocytes are known to secrete some cytokines, such as IL-5, that enhance the proliferation of eosinophils, we measured the IL-5 production by peripheral blood mononuclear cells in infants with AD on stimulation with HDM extract. The amount of IL-5 production is significantly higher in infants with AD, as well as in children with AD, than that found in nonatopic control subjects. Moreover, the level of IL-5 production is correlated closely with the level of HDM-SIF in infants with AD. Taken together, these results suggest that HDMs play an important role in the development of infantile AD by inducing IL-5 production from HDM-specific T lymphocytes.

Adolescent↗