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Biomedical subjects

Y Araki

Publications and source records attributed to Y Araki.

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

Survey on occupational health management of VDT workers among 84 Japanese companies.

This survey of 84 companies described the present status of occupational health management of VDT workers in Japan, in relation to the official Guideline (Guidelines on Occupational Health for VDT Work, 1985). The majority admitted 80% or more of their workers engage in VDT works. Four hours of VDT work per day was widely used as a criteria for the eligibility to the VDT health examination. Some specific measurement was performed at health examination among 54.8% of the companies. The most popular item was "near vision." A larger number of follow-up measures was performed with ophthalmic cases than with muscloskeletal cases. From these findings, with consideration to the results of the preceding literatures, we made 8 suggestions for the on-going revision of the Guideline: 1) including recommendation for flat panel display and portable computers, 2) widening target of VDT health education also to general workers, 3) clarification of the categorization of VDT workers, 4) offering practical measures to secure off VDT period, 5) use of subjective symptoms to screen high-risk workers, 6) supply of the latest scientific information on each measuring item, 7) periodical revision to provide state-of-the-art management, and 8) clear statement of the purpose and limitation of the Guideline.

Computer Terminals↗
PubMed2001

Ski7p G protein interacts with the exosome and the Ski complex for 3'-to-5' mRNA decay in yeast.

Two cytoplasmic mRNA-decay pathways have been characterized in yeast, and both are initiated by shortening of the 3'-poly(A) tail. In the major 5'-to-3' decay pathway, the deadenylation triggers removal of the 5'-cap, exposing the transcript body for 5'-to-3' degradation. An alternative 3'-to-5' decay pathway also follows the deadenylation and requires two multi-complexes: the exosome containing various 3'-exonucleases and the Ski complex consisting of the RNA helicase Ski2p, Ski3p and Ski8p. In addition, Ski7p, which has an N-terminal domain and a C-terminal elongation factor 1alpha-like GTP-binding domain, is involved in the 3'-to-5' decay. However, physical interaction between the exosome and the Ski complex, together with the function of Ski7p, has remained unknown. Here we report that the N domain of Ski7p is required and sufficient for the 3'-to-5' decay. Furthermore, the exosome and the Ski complex interact with the different regions of Ski7p N domain, and both interactions are required for the 3'-to-5' decay. Thus, Ski7p G protein appears to function as a signal-coupling factor between the two multi-complexes operating in the 3'-to-5' mRNA-decay pathway.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Application of 2-aminopyridine fluorescence labeling in the analysis of in vivo and in vitro metabolism of dextran sulfate sodium by size-exclusion high-performance liquid chromatography.

The present study describes a size-exclusion high-performance liquid chromatographic method for the separation and quantification of sulfated polysaccharides, such as dextran sulfate sodium (DSS). Pyridylamination of DSS was achieved without difficulty using 2-aminopyridine as a fluorometric label. In addition, 0.1-0.2 M phosphate buffer (pH 3.0) was found to be the mobile phase which produced the best separation. In vitro enzymatic degradation of the pyridylamino-DSS (PA-DSS5000, Mr 5000) using alpha-amylase and the in vivo metabolism in the rat feces after oral administration of PA-DSS5000 were then evaluated. Two small peaks of approximately Mr 380 and 600 appeared after co-incubation with alpha-amylase, indicating PA-DSS5000 may be considerably depolymerized. In vivo, however, PA-DSS5000 excreted in the feces was mainly of PA-DSS5000 polymer. No peaks of less than Mr 5000 were not clearly detectable in the feces because of background fluorescence attributable to gut lumen contents. This method of fluorometric analysis allows fairly selective detection of sulfated polysaccharides in biological materials.

Aminopyridines↗
PubMed2001

Coprecipitation with lanthanum phosphate as a technique for separation and preconcentration of iron(III) and lead.

The usefulness of coprecipitation with lanthanum phosphate for separation and preconcentration of some heavy metals has been investigated. Although lanthanum phosphate coprecipitates iron(III) and lead quantitatively at pH 2.3, iron(II) can barely be collected at this pH. This coprecipitation technique was applicable to the separation and preconcentration of iron(III) before inductively coupled plasma atomic-emission spectrometric (ICP-AES) determination; the recoveries of iron(III) and iron(II) from spiked water samples were 103-105% and 0.2-0.7%, respectively. The coprecipitation was also useful for separation of 20 microg lead from 100 mL of an aqueous solution that also contained 1-100 mg iron. Coprecipitation of iron was substantially suppressed by addition of ascorbic acid, which enabled recovery of 97-103% of lead added to the solution, bringing the recovery to within 1.6-5.0% of the relative standard deviations. Lanthanum phosphate can also coprecipitate cadmium and indium quantitatively, although chromium(III), cobalt, and nickel and large amounts of sodium, potassium, magnesium, and calcium are barely coprecipitated at pH approximately/= 3.

Journal Article↗
PubMed2001

Birth of a healthy baby following vitrification of human blastocysts.

OBJECTIVE: To assess vitrification of human blastocysts. DESIGN: Retrospective study of blastocyst vitrification. SETTING: A private clinic. PATIENT(S): Twenty couples with different types of infertility. INTERVENTION(S): Blastocysts were frozen with rapid vitrification and then transferred after thawing. We vitrified blastocysts using a modification of Ishimori's vitrification solution of ethylene glycol and dimethyl sulfoxide (VSED). MAIN OUTCOME MEASURE(S): After thawing, survival was defined by the embryo's development morphology after 6 hours or overnight culture. RESULT(S): Eighteen of 20 patients underwent treatment. Of 45 vitrified blastocysts, 36 survived, for a survival rate of 80% (36 of 45). The implantation rate was 21.9% (7 of 32), and the pregnancy rate (per embryo transfer cycle) was 33.3% (6 of 18). One of the pregnancies resulted in the delivery of a healthy baby. CONCLUSION(S): Supernumerary embryos were grown in culture to blastocysts, and the survival rate of vitrified-thawed blastocysts was the same as that for slow freezing of early stage embryos. Blastocyst vitrification should prove effective for clinical treatment. The present results strongly suggest that this rapid and successful vitrification procedure will replace conventional cryopreservation in the future.

Blastocyst↗
PubMed2001

Birth of healthy twins from in vitro development of human refrozen embryos.

OBJECTIVE: To avoid the risk of ovarian hyperstimulation syndrome and promote pregnancy rate by freezing pronuclear embryos at the oocyte retrieval and using developed refrozen supernumerary embryos in the event of failed pregnancies. DESIGN: A case study. SETTING: Private IVF center. PATIENT(S): Healthy infertile woman undergoing IVF treatment. INTERVENTION(S): Slowly frozen and rapidly refrozen embryos at varying stages of embryonic development were transferred. MAIN OUTCOME MEASURE(S): Survival rate of refrozen and thawed embryos; safety of refrozen embryo transference. RESULT(S): Fertilized pronuclear embryos that were frozen, thawed, and developed to morula embryos were subsequently vitrified, rethawed, and cultured until blastocyst formation before transfer. Healthy fraternal twins were born by caesarian section. The result of transfer was the novel finding of a successful delivery after the use of refrozen embryos. CONCLUSION(S): The transfer of refrozen supernumerary embryos resulted in successful pregnancy and delivery. We will continue to investigate the safety and efficacy of the elective freezing of all embryos as well as their refreezing so that supernumerary embryos can be reused to avoid ovarian hyperstimulation syndrome or in cases of repeated failed pregnancies.

Cryopreservation↗
PubMed2001

Efficiency of using frozen-thawed testicular sperm for multiple intracytoplasmic sperm injections.

PURPOSE: To compare fertilization and pregnancy rates of fresh and frozen-thawed testicular sperm injections (TESE-ICSI). METHODS: Sperm collected from the testes of 28 azoospermic patients by an open testicular biopsy technique was used for initial ICSI or cryopreserved. RESULTS: Fresh-sperm ICSI treatment (28 cycles) resulted in a 58.1% fertilization rate and a 32.1% clinical pregnancy rate per embryo transfer, while frozen-thawed sperm (24 subsequent cycles) had rates of 54.5 and 29.2%, respectively. The PR was lower using frozen-thawed sperm from nonobstructive azoospermia patients (9.1%) than from obstructive azoospermia patients (46.2%). PR declined to 0% upon the fourth ICSI attempt. CONCLUSIONS: Fertilization, embryo cleavage, and pregnancy rates were unaffected by fresh or frozen-thawed sperm use. A 57.1% cumulative clinical PR was achieved using the latter. The PR was significantly lower using frozen-thawed sperm from nonobstructive azoospermia patients than from obstructive azoospermia patients.

Biopsy↗
PubMed2001

Cooperation of interleukin-17 and interferon-gamma on chemokine secretion in human fetal intestinal epithelial cells.

Interleukin (IL)-17 is a newly identified T cell-derived cytokine that can regulate the functions of a variety of cell types. In this study, we investigated the effects of IL-17 and interferon (IFN)-gamma on chemokine secretion in human fetal intestinal epithelial cells. IL-8 and monocyte chemoattractant protein (MCP)-1 secretion by the human fetal intestinal epithelial cell line, intestine-407, was evaluated by ELISA and Northern blot. The expression of IL-17 receptor (R) was analysed by a binding assay using [(125)I]-labelled IL-17. The activation of nuclear factor-kappa B (NF-kappa B), NF-IL6 and AP-1 was assessed by an electrophoretic gel mobility shift assay (EMSA). IL-17 induced a dose-dependent increase in IL-8 and MCP-1 secretion. The inducing effects of IL-17 on IL-8 and MCP-1 mRNA abundance reached a maximum as early as 3 h, and then gradually decreased. IL-17 and IFN-gamma synergistically increased IL-8 and MCP-1 secretion and mRNA abundance. IFN-gamma induced a weak increase in IL-17 R mRNA abundance, and incubation with IFN-gamma for 24 h enhanced [(125)I]-labelled IL-17-binding by 2.4-fold. IL-17 rapidly induced the phosphorylation and degradation of I kappa B alpha molecules, and the combination of IL-17 and IFN-gamma induced a marked increase in NF-kappa B DNA-binding activity as early as 1.5 h after the stimulation. Furthermore, this combination induced an increase in NF-IL-6 and AP-1 DNA-binding activity. In conclusion, it becomes clear that IL-17 is an inducer of IL-8 and MCP-1 secretion by human fetal intestinal epithelial cells. The combination of IL-17 with IFN-gamma synergistically enhanced chemokine secretion. These effects of IL-17 and IFN-gamma might play an important role in the inflammatory responses in the intestinal mucosa.

Cell Line↗
PubMed2001

Dietary fiber fraction of germinated barley foodstuff attenuated mucosal damage and diarrhea, and accelerated the repair of the colonic mucosa in an experimental colitis.

BACKGROUND AND AIMS: Germinated barley foodstuff (GBF) contains protein and insoluble dietary fiber. We have previously shown in ulcerative colitis patients and a colitis model that GBF feeding attenuates mucosal damage by increasing luminal butyrate levels. However, the detailed mechanism remains unclear because of its heterogeneous nature. The present study was carried out to: (i) evaluate the active ingredient in GBF; and (ii) examine its effect on the repair process in colonic inflammation by using a dextran sulfate sodium (DSS) colitis model. METHODS: Colitis was induced by feeding a diet containing 0.5-3.5% DSS to male Sprague-Dawley rats. (i) Active ingredient: GBF was fractionated enzymatically into fiber- and protein-rich fractions. Each fraction was administered to DSS-colitis rats. Clinical signs, cecal short chain fatty acid concentrations and serum alpha1-acid glycoprotein (AAG) levels were determined. (ii) Effect on mucosal repair: GBF with or without salazosulfapyridine (SASP), or SASP alone was administered to rats after the onset of colitis. Seven days after initial treatment, the number of epithelial cells in HE sections was evaluated morphologically in a blind fashion and serum AAG was determined. RESULTS: (i) Germinate barley foodstuff and GBF-fiber significantly attenuated the clinical signs of colitis and decreased serum AAG levels, with a significant increase in cecal butyrate production, while GBF-protein did not. (ii) Treatment with GBF alone and GBF plus SASP significantly accelerated colonic epithelial repair and improved clinical signs. CONCLUSIONS: These findings suggest that the fiber fraction of GBF may effectively enhance luminal butyrate production, and thereby accelerate colonic epithelial repair in colitis.

Animals↗
PubMed2001

Ligation of the Fas antigen stimulates chemokine secretion in pancreatic cancer cell line PANC-1.

BACKGROUND AND AIM: The role of chemokines in the process of immune cell infiltration into pancreatic cancer tissue has been reported. In this study, we investigated the induction of chemokines (interleukin (IL)-8 and monocyte chemoattractant protein (MCP)-1) by Fas antigen (Ag)-stimulation in a human pancreatic cancer cell line, PANC-1. METHODS: The chemokine secretion was evaluated by using an ELISA and a northern blot, and the activation of nuclear factor-kappa B (NF-kappa B) was assessed by using an electrophoretic gel mobility shift assay (EMSA). RESULTS: The Fas antigen (Ag) stimulation clearly induced an increase in IL-8 and MCP-1 secretion in PANC-1 cells. This effect was also observed at the mRNA level. The induction of chemokine secretion by Fas Ag stimulation required de novo gene expression and protein synthesis. The pretreatment with interferon (IFN)-gamma markedly enhanced the effects of Fas Ag stimulation; IFN-gamma pretreatment and Fas Ag stimulation synergistically induced not only apoptosis but also IL-8 and MCP-1 secretion. Flow cytometric analysis demonstrated that IFN-gamma significantly enhanced Fas Ag expression. In addition, Fas Ag stimulation actually evoked NF-kappa B activation in this cell line. CONCLUSION: Our results indicate that Fas Ag stimulation can induce chemokine secretion in PANC-1 cells, suggesting the contribution of Fas stimulation to the accumulation of immune cells in pancreatic cancer tissue.

Adenocarcinoma↗
PubMed2001

Two cases of colonic adenomatous polyps accompanied by a migrated surgical suture.

A 56-year-old man and a 70-year-old woman, with histories of left colectomy and appendectomy respectively, were admitted to our hospital. In both cases, colonoscopy showed a pedunculated colonic polyp in the ascending colon, and a silk suture became visible in the stalk during polypectomy. The histological diagnosis was adenoma. These two cases constitute the first report of colonic adenomatous polyps accompanied by suture migration.

Adenomatous Polyps↗
PubMed2001

Sequential changes in luminal microflora and mucosal cytokine expression during developing of colitis in HLA-B27/beta2-microglobulin transgenic rats.

BACKGROUND: Transgenic rats expressing HLA-B27 and human beta2-microglobulin (HLA-B27 rats) spontaneously develop chronic colitis resembling human inflammatory bowel disease. We investigated the sequential changes in the luminal bacterial flora and mucosal cytokine mRNA expression in this model. METHODS: HLA-B27 rats were maintained in a specific pathogen-free environment, and luminal microflora was evaluated by standard bacterial culture technique. The expression of mucosal cytokine mRNA was analysed by RT-PCR methods. RESULTS: Clinical symptoms of colitis appeared at 8 weeks of age. The total number of obligate anaerobes was higher than those of facultative anaerobes during the experimental period. At 6 weeks of age, the colonization of Bacteroides spp., Bifidobacterium spp. and Lactobacillus spp. was already detectable at high concentrations, whereas Clostridium spp. and Eubacterium spp. were not detected. The expression of proinflammatory cytokines (IL-Ibeta, IL-8 and TNF-alpha) appeared at 8 weeks of age, and these were detectable until 17 weeks. A similar pattern was observed in the expression of Th1 cytokines (IL-2, IL-12 and IFN-gamma). On the other hand, the expression of Th2 cytokines (IL-4, IL-10 and TGF-beta) was weak. IL-4 mRNA expression was weakly detectable only at 6 and 8 weeks of age. The expression of IL-10 and TGF-beta mRNA was scarcely detectable throughout the experimental period. CONCLUSION: The development of colitis may be mediated by both the predominant expression of Th1 cytokines and the weakness of Th2 cytokine expression in the mucosa. The colonization of anaerobic bacteria, especially Bacteroides spp., may be initiating and promoting these cytokine responses.

Animals↗
PubMed2001

Hydrophilic and hydrophobic bile acids exhibit different cytotoxicities through cytolysis, interleukin-8 synthesis and apoptosis in the intestinal epithelial cell lines. IEC-6 and Caco-2 cells.

BACKGROUND: Bile acids have been shown to exhibit varying degrees of cytotoxicity, depending on their hydrophobic-hydrophilic balance. We have recently reported the strong cytotoxicity of hyodeoxycholic acid (HDCA), and the aim of the present study is to investigate the mechanisms underlying the cytotoxicity of HDCA. METHODS: The intestinal cell lines IEC-6 and Caco-2 cells were used. The cytotoxicities of various bile acids were evaluated using the MTS assay; their cytolytic effects were measured using the LDH release assay. The induction of apoptosis was determined by the specific figure changes in the cellular cytoplasm and nucleus, including DNA ladder formations. IL-8 synthesis induced by the bile acids was measured using an ELISA assay. RESULTS: The bile acids induced cytotoxic effects, LDH release, IL-8 synthesis and apoptosis, depending on their hydrophobic properties. On the other hand, HDCA induced strong cytotoxicity, apoptosis and IL-8 synthesis but not cytolysis, although HDCA has a hydrophilic nature. In addition, HDCA exerted the strongest effects on dispersing monolayer cells. CONCLUSIONS: These results strongly suggest that HDCA induces cytotoxicity through its ability to induce apoptosis rather than its detergent effect.

Apoptosis↗
PubMed2001

Pregnancy achieved following ICSI from a man with Klinefelter's syndrome and spinal cord injury.

Klinefelter's syndrome and spinal cord injury are major causes of male infertility. Intracytoplasmic sperm injection (ICSI) is a relatively new method of assisted reproduction. A testicular biopsy was obtained from a patient with the double complications of non-mosaic 47,XXY Klinefelter's syndrome and spinal cord damage, and motile spermatozoa were collected. ICSI was then performed. Of the four sperm-injected oocytes, three became fertilized and cleaved. Two embryos were implanted, resulting in a single pregnancy with visible evidence of a heartbeat appearing at 6 weeks gestation. The pregnancy is now entering its 20th week. To the best of our knowledge, this is the first case of a pregnancy resulting from the sperm of a patient with double complications.

Adult↗
PubMed2001

Identification, cloning, and initial characterization of a novel mouse testicular germ cell-specific antigen.

A monoclonal antibody, designated TES101, was raised by immunizing BALB/c mice with an allogenic mouse testicular homogenate followed by immunohistochemical selection as the initial screening method. By searching the expressed sequence tag (EST) database with the N-terminal amino acid sequence of TES101 reactive protein, we found that the predicted amino acid sequence encoded by a mouse testicular EST clone matched the TES101 protein sequence. Sequence analysis of the clone revealed no homologous molecule in the DNA/protein database. Based on data obtained from N-terminal amino acid analysis of the TES101 protein, the derived amino acid sequence contained a signal peptide region of 25 amino acids and a mature protein region of 225 amino acids, which translated into a protein with a molecular weight of 24 093. Northern blot analysis showed that mRNA of the TES101 protein was found in testis but not in any other mouse tissues examined. Western blot analysis revealed that TES101 reacted with a 38-kDa band on SDS-PAGE under nonreducing conditions, and this reactivity was abrogated under reducing conditions. Immunoelectron microscopic studies demonstrated that the molecule was predominantly located on the plasma membrane of spermatocytes and spermatids but not in Sertoli cells or interstitial cells, including Leydig cells. Thus, the TES101 protein is a novel molecule present primarily on the surface of developing male germ cells. TES101 protein may play a role in the processes underlying male germ cell formation.

Amino Acid Sequence↗
PubMed2001

Alterations in intestinal microflora, faecal bile acids and short chain fatty acids in dextran sulphate sodium-induced experimental acute colitis in rats.

BACKGROUND: The physiological effects on faecal bile acids and short chain fatty acids (SCFAs) or intestinal microflora in dextran sulphate sodium (DSS)-induced colitis remain unknown and are an area of interest DESIGN ALTERATIONS: of these parameters in DSS-induced colitis in rats were evaluated. METHODS: Male Sprague-Dawley rats (n = 10) were given a 3% DSS aqueous solution orally for 7 days. The concentrations of bile acids and SCFAs in the faeces were measured using gas chromatography and high-performance liquid chromatography. Intestinal microflora, especially anaerobes, were investigated by microbiological methods. RESULTS: On day 7, the concentrations of lithocholic acid and alpha-muricholic acid were significantly decreased and that of cholic acid was significantly increased. There was a strong correlation between the concentration of cholic acid and the macroscopic area of damaged tissue in the colon (R = 0.74, P < 0.05). With respect to SCFAs, DSS administration significantly decreased the concentrations of acetic acid and n-butyric acid. There was also some correlation between the concentration of acetic acid and macroscopic damaged area in the colon (R = -0.60, P = 0.07). Bacteriological studies revealed significantly decreased eubacteria, bifidobacteria and total anaerobes after the administration of DSS. In contrast, lactobacilli were significantly increased. CONCLUSIONS: With the progression of DSS-induced colitis, faecal bile acids, SCFAs and intestinal microflora were altered. It is possible that these alterations contribute in part to the progression of DSS-induced colitis.

Acute Disease↗