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S Araki

Publications and source records attributed to S Araki.

At least 91 records · Page 5Linked to original sources
PubMed1999

Immunohistochemical evaluation of the marbled state in childhood hypoxic encephalopathy.

We have immunohistochemically analyzed the marbled state in 8 cases of perinatal hypoxic ischemic encephalopathy and 4 cases of infantile hypoxic encephalopathy, using antibodies against calbindin-D28k (CaBD), glial fibrillary acidic protein (GFAP), methionine-enkephalin (MEnk), myelin basic protein (MBP), neurofilament (NF), parvalbumin (PV), substance-P (SuP) and synaptophysin (SP). The marbled state was found in the thalamus in 11 cases, whose age at death was over 10 years. Four cases demonstrated the marbled state in the cerebral cortex, in addition to the striatum and/or the thalamus. The abnormally myelinated fibers in the marbled state were stained with both Kluver-Barrera and Holzer stainings; however, they were partly immunopositive for MBP and completely immunonegative for GFAP, CaBD, MEnk, PV, SuP and SP, although some of the neurons and/or fibers showed immunoreactivities for those calcium-binding proteins and/or neurotransmitters. The axons were visualized in the abnormally myelinated fibers by Bodian staining and/or anti-NF immunostainings in the cerebral cortex and striatum but not in the thalamus. GFAP-positive astrocytes did not show any continuity with the abnormally myelinated fibers. These histological features were seen in the cerebral cortex, striatum and thalamus. Difference of the etiology did not affect the histological features with the exception of anti-PV staining, in which PV-immunopositive neurons were observed only in aged subjects with infantile hypoxic encephalopathy, and seemed to be more severely affected by hypoxic stress during the perinatal period than the early infantile period. These data suggest that the site of lesion or the length of survival period after brain injury might influence the formation of the marbled state rather than the etiology. And the direct relationship between the abnormally myelinated fiber and astrocytic process was not verified.

Adolescent↗
PubMed1999

The STR polymorphisms in intron 8 may provide information about the molecular evolution of RH haplotypes.

We identified simple-sequence repeat polymorphisms in intron 8 of the RHD and RHCE genes, both of which contained the 5-bp repeat unit (AAAAT)n. We analyzed the polymorphisms of this short tandem repeat (STR) in 104 Japanese RhD-positive and 124 RhD-negative (87 RHD gene negative and 37 nonfunctional RHD gene positive) donors by the polymerase chain reaction (PCR) and subsequent typing by electrophoresis and silver staining. We found five alleles (10, 11, 12, 13, and 14 repeats) in the RHD gene and four (7, 8, 9, and 10 repeats) in the RHCE gene. The Rh phenotypes were closely associated with polymorphisms of the STR. The Ce allele had 12 repeats in the RHD gene and 9 repeats in the RHCE gene at high frequency. The cE allele frequently had 10-12 repeats in the RHD gene and 10 repeats in the RHCE gene. The 10 repeats in the RHCE gene were identified exclusively in the 87 RHD gene-negative donors and 9 repeats were identified only in those with the RhC antigen. These results indicate that both haplotypes of dce and dcE arose from single RHD gene deletion and recombination events, respectively. In the 37 RhD-negative donors with a nonfunctional RHD gene, 12 repeats in the RHD gene and 9 repeats in the RHCE gene were frequently observed. Thus, the RhD-negative with a nonfunctional RHD gene combination might have arisen from the DCe haplotype via a mutation that abolished RHD gene expression. These findings suggest that the STR polymorphisms might shed light upon the molecular evolution of RH haplotypes.

Alleles↗
PubMed1999

Semiautomatic suturing device (Maniceps) for laparoscopic surgery.

The only automatic device now available to laparoscopic surgeons is Endo-Stitch, which is costly for single use and has the disadvantage of leaving a large needle hole in the tissue. A semiautomatic suturing device (Maniceps) for laparoscopic use was developed from a forceps-type of needle holder for open pelvic surgery. The first generation of the instrument was designed for use with the abdominal wall-lift method of laparoscopic surgery, whereas the second generation can be applied for gas insufflation as well. Exchange of the needle is done by an automatic grasping action of a resilient slit in one jaw and by manual pull-down of the needle via the thread onto the other jaw. The new instrument was employed in 10 cases of laparoscopic surgery for various procedures including suture of the perforated gallbladder wall and running suture of the peritoneum after mesh placement in transabdominal repair of inguinal hernia. Maniceps provides an economic advantage and has the merit of a smaller needle hole.

Equipment Design↗
PubMed1999

Preparation and properties of novel gramicidin S analogs possessing a tri-, tetra- or pentamethylene bridge between ornithine side chains.

Gramicidin S (GS) analogs in which the Ndelta atoms of the two Orn side chains are linked by an oligomethylene bridge [-(CH2)n-; n=3-5] were prepared via the bis(p-nitrobenzenesulfonyl) derivative [Orn(NBS)2,2']GS. For comparison the nonbridged secondary amino group-containing analog [Orn(Me)2,2']GS was also prepared. 1H NMR and CD spectral analysis indicated that these analogs adopt the same beta-sheet conformation as GS. The antimicrobial activities of these analogs were very similar, but were slightly dependent on the bridge chain length, the trimethylene-bridged analog being the most potent.

Anti-Bacterial Agents↗
PubMed1999

Convenient preparation of [Orn(Tfa)2]- and [Orn(Boc)2, Orn(Tfa)2]gramicidin S, versatile unsymmetrically protected derivatives of gramicidin S.

Treatment of gramicidin S (GS) with trifluoroacetic anhydride afforded a derivative in which only one of the two Orn side chains was trifluoroacetylated in 72% yield, furnishing the first efficient method for the preparation of a monoprotected derivative of GS. The mono(Tfa) derivative [Orn(Tfa)2']GS was treated with di-tert-butyl dicarbonate to yield dually protected derivative [Orn(Boc)2,Orn(Tfa)2']GS from which another monoprotected derivative [Orn(Boc)2]GS was prepared in high yield. These unsymmetrically protected GS derivatives are versatile starting materials for the preparation of various other GS derivatives. As an example of application of the unsymmetrically protected derivatives, a dimeric GS derivative was prepared via a singly p-nitrobenzenesulfonyl(NBS)-activated derivative [Orn(Boc)2,Orn(NBS)2']GS.

Amino Acid Sequence↗
PubMed1999

Involvement of gene expressions in apoptosis of vascular endothelial cells induced by rattlesnake venom.

Formation of apoptotic bodies is a typical character of apoptotic cell death, but how the processes are controlled is not known. In this study, we compared two apoptosis inducing systems in vascular endothelial cells (VEC). We found that the formation of apoptotic bodies during apoptosis induced by rattlesnake venom, which is an unique and specific apoptosis inducer to vascular endothelial cells, was much faster than that induced by deprivation of survival factors (aFGF and serum). When we blocked the synthesis of mRNAs in cells treated with rattlesnake venom by DRB (5, 6-dichloro-1-beta-D-ribofuranosylbenzimidazole), an inhibitor of transcription, the formation of apoptotic bodies was dramatically inhibited. We examined the expression of p53 gene and found that its expression was much higher in apoptosis induced by rattlesnake venom than that in apoptosis induced by deprivation of aFGF and serum. Our results suggest that gene expression is important and p53 gene may play a major role in inducing the formation of apoptotic bodies in VEC.

Apoptosis↗
PubMed1999

Chronic electrical stimulation of the auditory nerve using non-charge-balanced stimuli.

This study was designed to evaluate the pathophysiological response of the cochlea following long-term intracochlear electrical stimulation using a poorly charge-balanced stimulus regime, leading to direct current (DC) levels >0.1 microA. Four normal-hearing adult cats were bilaterally implanted with scala tympani electrode arrays and unilaterally stimulated for periods up to 2200 h. Stimuli consisted of 50 micros monophasic current pulses presented at 2000 pulses per second (pps) per channel, and resulted in DC levels of 0.4-2.8 microA. Both acoustic and electrical (EABR) evoked potentials were periodically recorded during the stimulation program. Frequency-specific stimuli indicated that an extensive and widespread hearing loss occurred over the 4-24 KHz region in all stimulated cochleae, although the 2 KHz region exhibited thresholds close to normal in some animals, despite long-term implantation and chronic stimulation. Longitudinal EABRs showed a statistically significant increase in threshold for three of the four animals. Histopathological evaluation of the cochleae revealed a highly significant reduction in ganglion cell density in stimulated cochleae compared with their controls. Spiral ganglion cell loss was significantly correlated with the degree of inflammation, duration of electrical stimulation, and the level of DC. In conclusion, the present study highlights the potential for neural damage following stimulation using poorly charge-balanced stimuli.

Action Potentials↗
PubMed1999

Successful metaphase chromosome analysis of human elongated spermatids using mouse oocytes.

Human elongated spermatids from azoospermic patients were inserted into mouse oocytes by intracytoplasmic sperm injection (ICSI). The injection resulted in survival rates of 46.5% (180 out of 387) and activation rates of 36.1% (65 out of 180). The rate of two pronuclear (2PN) formation was 35.4% (23 out of 65). Only 34.8% (eight out of 23) metaphase chromosome spreads from 2PN zygotes could be analysed; however, all were of normal karyotype. Cytogenetic analysis at the first metaphase revealed that human elongated spermatid chromosomes were able to undergo replication in a heterogeneous environment.

Animals↗
PubMed1999

Chronic active desease refext cancer riski in ulcreative collitis.

There is an increased risk of developing colorectal neoplasia in ulcerative colitis (UC) and surveillance colonoscopy is recommended for early detection. We investigated the precise features of UC retrospectively to identify a subgroup with longstanding extensive UC at increased risk of neoplasia. From 1985 to August 1997, we experienced eight UC patients with colorectal cancer and eight with definite dysplasia. All 16 had extensive disease of seven years or more in duration. During the same period, 61 of 334 UC patients without colorectal neoplasia were available for detailed study, allowing evaluation of non-surgical patients with extensive colitis of seven years or more in duration. Basic clinical factors including family history of cancer, expressions of disease activity and durations of pharmacotherapy were investigated. Univariate analysis revealed four significant factors: intractability (P=0.001), periods of inflammation persisting for 3 months or more (P<0.01) and total durations of diarrhea (P<0.01) and hematochezia (P<0.05). The number of admissions and the duration of systemic steroid administration were higher in the neoplasia group but without statistical significance. Multivariate analysis revealed two significant factors: duration of diarrhea (P<0.001) and age at onset (P<0.01). Chronic active disease is a risk factor for colorectal cancer or dysplasia in extensive and longstanding UC.

Adult↗
PubMed1999

Overtime, psychosocial working conditions, and occurrence of non-insulin dependent diabetes mellitus in Japanese men.

OBJECTIVES: To ascertain the effects of overtime and psychosocial job conditions on the occurrence of non-insulin dependent diabetes mellitus (NIDDM) in Japan. DESIGN: An eight year prospective cohort study. SETTING: An electrical company in Japan. PARTICIPANTS: In 1984, a mailed questionnaire was sent to industrial workers of an electrical company in Japan. After excluding those who had a history of diabetes mellitus or other chronic diseases, 2597 male respondents were prospectively followed up for the succeeding eight years. Data from 2194 (84%) who were completely followed up were analysed. The occurrence of NIDDM during the follow up period was assessed according to the WHO criteria on the basis of an annual screening programme. MAIN RESULTS: The age adjusted incidence of NIDDM was significantly higher in those who worked overtime more than 50 hours per month than in those who worked 25 hours or less per month (p < 0.05). It was significantly higher in those who worked with new technology at baseline than in those who did not (p < 0.05). Cox's proportional hazard model indicated that those who worked overtime more than 50 hours per month had 3.7 times higher risk of NIDDM after controlling for known risk factors (p < 0.01) and those who worked with new technology had 2.4 times higher risk of NIDDM (p < 0.05). CONCLUSIONS: It is suggested that longer overtime and use of new technology are risk factors of NIDDM in Japanese men.

Adolescent↗
PubMed1999

Reasons for drinking in relation to problem drinking behavior in a sample of Japanese high school students.

To clarify reasons for drinking in relation to problem drinking behavior, 494 male students, aged 15 to 18 years old and attending high schools in Tokyo, Japan, were examined by self-rating questionnaires including the Kuriharna Alcoholism Screening Test (KAST). Three hundred and forty-two students (69%) completed the questionnaires, of whom 143 indicated that they were current drinkers of alcohol (42% of respondents). Of the 143,16 (11%) reported, through the KAST, experience of problem drinking behavior. A factor analysis of 36 reasons for drinking identified 5 factors: Escapism, Sociability, Tension Reduction, Acting Like a Man, and Enjoyment/Home. A logistic regression analysis showed that drinking because of Escapism, Sociability, and Tension Reduction was significantly related to problem drinking behavior. Also, there was significant correlation between the 3 factors and the number of KAST items experienced by the 143 respondents. Our findings suggest that the factors of Escapism, Sociability, and Tension Reduction lead to problem drinking in Japanese high school students.

Journal Article↗
PubMed1999

Decavanadate inhibits the cell-free activation of neutrophil NADPH oxidase without affecting tyrosine phosphorylation.

NADPH oxidase was activated by arachidonate in a cell-free system consisting of membrane and cytosol fractions prepared from guinea pig neutrophils. Vanadate apparently inhibited the NADPH oxidase activity in the cell-free system (IC50=2 microM) without phosphotyrosine accumulation. The pH dependency and stability of the inhibitory effect observed for vanadate solution indicated that decavanadate, an isopolyanion of vanadate, was responsible for the inhibition. Pervanadate (vanadyl hydroperoxide) also inhibited the oxidase activity but at a higher concentration (IC50=0.2 mM). Decavanadate lowered the Vmax but did not affect the Km value of NADPH oxidase for NADPH. Decavanadate inhibited the activation process of NADPH oxidase but not the oxidase activity itself. Decavanadate-pretreatment of membrane and cytosol fractions irreversibly decreased the abilities of both fractions to activate NADPH oxidase in the cell-free system. Translocation of p47-phox, one of the cytosolic activation factors of NADPH oxidase, from cytosol to membrane, was little affected by decavanadate. These results suggest that decavanadate inhibits the activation of NADPH oxidase in the cell-free system without affecting the phosphotyrosine phosphatase, and that decavanadate can bind to both the membrane and cytosolic activation factors when they are in a dormant state, but not to the active oxidase complex.

Amino Acid Sequence↗
PubMed1999

[A study on the factors affecting friendship with HIV-infected students in high school: from the survey of AIDS related knowledge, information sources and attitudes in 1989 and 1992].

To clarify the factors affecting the friendship with human immunodeficiency virus (HIV)-infected persons, a self-reported questionnaire study was conducted in two high schools in Tokyo in 1989 and 1992. A complete set of responses was obtained from 541 (98%) and 517 (99%) students in 1989 and 1992, respectively. The following results were obtained: 1) The proportion of the students who received information on HIV/acquired immunodeficiency syndrome (AIDS) from school teachers in 1992 was higher than that in 1989 for both males and females. Similarly, for both males and females, the proportion of students with correct knowledge on HIV transmission was significantly higher in 1992. The proportion of the students who intended to have a friendship with a hypothetical HIV-infected classmate or close friend in 1992 was significantly higher. 2) The results of multiple logistic regression analysis indicated that such factors as having more correct knowledge on HIV transmission and considering the confidentiality of persons with HIV/AIDS were significantly related to having friendship with a hypothetical HIV-infected classmate for both 1989 and 1992; such factors as being a female and having an increasing risk of HIV infection were significantly related to the responses obtained for 1992.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Effects of mailed advice on stress reduction among employees in Japan: a randomized controlled trial.

We conducted a randomized controlled trial (RCT) to examine the effects of mailed advice on reducing psychological distress, blood pressure, serum lipids, and sick leave of workers employed in a manufacturing plant in Japan. Those who indicated higher psychological distress (defined as having GHQ scores of three or greater) in the baseline questionnaire survey (n = 226) were randomly assigned to an intervention group or a control group. Individualized letters were sent to the subjects of the intervention group, informing them of their stress levels and recommending an improvement in daily habits and other behaviors to reduce stress. Eighty-one and 77 subjects in the intervention and control groups, respectively, responded to the one-year follow-up survey. No significant intervention effect was observed for the GHQ scores, blood pressure, serum lipids, or sick leave (p > 0.05). The intervention effect was marginally significant for changes in regular breakfasts and daily alcohol consumption (p = 0.09). The intervention effect was marginally significant for the GHQ scores among those who initially did not eat breakfast regularly (p = 0.06). The study suggests that only sending mailed advice is not an effective measure for worksite stress reduction. Mailed advice which focuses on a particular subgroup (e.g., those who do not eat breakfast regularly) may be more effective.

Absenteeism↗
PubMed1999

Job stressor-mental health associations in a sample of Japanese working adults: artifacts of positive and negative questions?

To examine whether positive and negative components of mental health were differently related to job stressors and life events, correlational analyses were conducted using data for the GHQ-12 and some scales of the NIOSH Generic Job Stress Questionnaire collected from 765 workers in Japan. Six positive items and six negative items of the GHQ-12 were summed up for positive and negative components of mental health (GHQ-POS, GHQ-NEG). The GHQ-POS was significantly correlated with only positively-oriented job stressors. The GHQ-NEG was significantly correlated with only negatively-oriented job stressors. Most correlations were significantly different between GHQ-POS and GHQ-NEG. This correlation pattern resulted in smaller, but significant, correlations between job stressors and the GHQ-12. These results may reflect "measuring similarity" due to item-wording. Detailed inspection suggested that GHQ-POS and GHQ-NEG, as well as positively- and negatively-oriented job stressors, were not attributable only to positive affectively or negative affectivity, respectively. Work-related events showed higher correlations with all mental health variables than their job stressors' counterparts. For females, mental health variables were seldom correlated with job stressors, but significantly correlated with life events. These results might indicate the superiority of "event-type stress measure" as compared to perceived rating scale in assessing job stressors. Further direction was discussed.

Adolescent↗