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Biomedical subjects

S Sakurai

Publications and source records attributed to S Sakurai.

At least 127 records · Page 7Linked to original sources
PubMed1997

[State of art: Epstein Barr virus-associated gastric carcinoma].

Epstein Barr virus(EBV)-associated gastric carcinoma (EBVaGC), comprising 10% of gastric carcinoma, is the most frequent EBV-associated neoplasm in Japan. EBVaGC is a distinct type of gastric carcinoma, which is marked by the monoclonal EBV, and its morphogenesis seems to be different from that of other gastric carcinomas. Future studies are necessary to disclose precise timing of EBV infection to the epithelial cells of the stomach, status and mechanism of EBV-infection in the non-neoplastic gastric mucosa, molecular mechanism of the development of EBVaGC, and role of EBV in the maintenance of EBVaGC. Development of new therapeutic approach specific to EBVaGC will also facilitate the recognition of this entity in clinical medicine.

Herpesviridae Infections↗
PubMed1997

[Endemic fluorosis in southern China: radiological findings].

Fluorosis continues to be prevalent in the southern regions of China. The endemic fluorosis caused by inhalation of fluoride-containing coal dust etiologically contrasts with the common occurrence of endemic fluorosis due to the intake of fluoride-containing water. We investigated the radiologic findings in 49 affected individuals in a district of this region. More than 80% of patients exhibited radiologic evidence of skeletal fluorosis, and most patients belonged to stage 3 of Singh and Jolly's classification. The most common skeletal abnormality was ossification of the interosseous ligaments in the extremities, which warranted radiographic examination of the limbs as a tool for screening.

Adult↗
PubMed1997

IFN-gamma-mediated protection against intracerebral challenge with Bordetella pertussis in mice.

Mice inoculated with whole cell pertussis vaccine (WCV) acquired protection against intracerebral challenge with Bordetella pertussis without any appreciable antibody production against pertussis toxin or filamentous hemagglutinin. Spleen cells from mice immunized with WCV produced a significant amount of IFN-gamma upon stimulation in vitro with WCV. Furthermore, mice inoculated with recombinant IFN-gamma along with a suboptimal dose of WCV survived longer than those that received WCV alone. These results suggest that, in WCV-immune mice, IFN-gamma plays an important role in protection against intracerebral challenge with B. pertussis.

Animals↗
PubMed1997

[Aortic arch replacement performed in emergency in a short-term after grafting for abdominal aortic aneurysm].

Two cases of successful staged replacement of multiple aortic aneurysms are reported. Case 1: A 65-year-old man was found to have abdominal aortic and aortic arch aneurysms. He underwent abdominal aneurysmectomy and Y-grafting in the first stage. A month after his discharge, he was transferred to our hospital because of abrupt chest pain. Two days later, he fell into shock and emergent aortic arch replacement was performed successfully. Case 2: A 46-year-old man was transferred to our hospital because of abrupt abdominal pain and shock. CT scan revealed the rupture of the abdominal aneurysm. He received emergent abdominal aneurysmectomy and Y-grafting successfully. Three months later, he was readmitted because of back pain. CT scan revealed DeBakey Type I dissecting aneurysm. After three days, PaO2 of blood gas analysis fell to 46 mmHg, and absent femoral pulsation and oliguria were also observed. Therefore, aortic arch replacement was performed in emergency. The intimal tear was found in the distal aortic arch. The both of cases are doing well 24 months and 10 months after surgery respectively. It is important to scrutinize the order of surgery for multiple aortic aneurysms and to control blood pressure properly after aneurysmectomy.

Aged↗
PubMed1996

Bombyxin gene expression in tissues other than brain detected by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization.

Bombyxin is a 5 kDa insulin-related peptide produced in four pairs of medial neurosecretory cells in the brain of the silkmoth Bombyx mori. We demonstrate here the presence of bombyxin mRNA in tissues other than brain: ganglia, epidermis, testis, ovary, fat body, silk gland, Malpighian tubule, midgut, and hindgut of the Bombyx fifth instar larvae. Bombyxin mRNA was detected by Oligotex reverse transcription-polymerase chain reaction (RT-PCR), a rapid and simple procedure of reverse transcription-PCR, and in situ hybridization. The Oligotex RT-PCR method effectively eliminated the contaminating DNA in RNA samples and amplified bombyxin mRNA efficiently. In situ hybridization of the Bombyx ovary clearly demonstrated the localization of the bombyxin mRNA in the ovariole. The present study is the first demonstration of expression of brain neurosecretory peptide in tissues other than the central nervous system in insects at RNA level.

Animals↗
PubMed1996

Hypertrophic neuritis due to chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): a postmortem pathological study.

A postmortem pathological study of a 65-year-old woman with hypertrophic neuritis associated with hand tremor and limb ataxia is described. There were many onion bulbs and loss of myelinated nerve fibers in the peripheral nerves, including the facial and subserosal visceral nerves. The hypertrophic neuritis was caused by chronic inflammatory demyelinating neuropathy (CIDP), in which interstitial amorphous substances in the endoneurium and onion bulb formation might contribute to nerve swelling. We speculate that visceral autonomic nerves as well as somatic peripheral nerves are involved in patients with a long clinical CIDP course and that peripheral nerve pathology in this disorder shows more heterogeneous changes than previously recognized.

Aged↗
PubMed1996

Variations in ribosomal DNA and mitochondrial DNA among chromosomal species of subterranean mole rats.

Restriction site variations in nuclear ribosomal DNA (rDNA) spacers and mitochondrial DNA (mtDNA) were examined in several populations of mole rats with variable numbers of chromosomes, which represented the two superspecies Spalax leucodon (2n = 38, 54, or 62) and Spalax ehrenbergi (2n = 52, 54, 58, or 60). Sequence divergence of rDNA spacers between the members of the superspecies was approximately 8%, while the variation within each superspecies was 4% on average. The intrasuperspecies differentiation of rDNA spacers was generally associated with changes in the diploid number of chromosomes. However, substantial divergence (approximately 1.5%) was also detected among populations with the same diploid number of chromosomes. The sequence divergence of mtDNA among haplotypes of S. ehrenbergi was 10% or higher and among haplotypes of S. leucodon it was approximately 12%. By contrast, the range of sequence divergence between superspecies was 7.4%-12%. The large divergence of mtDNAs within each superspecies of mole rats may be explained by the preservation of ancient mtDNA polymorphisms.

Animals↗
PubMed1996

Association of restriction fragment-length polymorphisms in the alcohol dehydrogenase 2 gene with alcoholic brain atrophy.

Alcohol abuse can induce brain atrophy, but it only occurs in some alcoholics. To investigate whether genetic polymorphism of alcohol-metabolizing enzymes [including alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] was related to alcoholic brain atrophy, we determined restriction fragment-length polymorphisms of the ADH2 and ALDH2 genes in 77 male alcoholics. Computed tomography was used to determine the severity of brain atrophy. Digestion with MaeIII and MboII after polymerase chain reaction amplification showed that the ADH2(1) gene frequency was significantly higher in patients with brain atrophy than in those without brain atrophy (chi 2 = 9.274, p < 0.01), whereas no significant association was observed between brain atrophy and the ALDH2 gene Multivariate analysis (including age, total alcohol intake, liver cirrhosis, and ADH2 genotype) showed that the ADH2(1)/ADH2(1) genotype was associated with alcoholic brain atrophy. These findings suggest that the ADH2(1) allele may be associated with alcoholic brain atrophy.

Adult↗
PubMed1996

Nitric oxide induction by pertussis toxin in mouse spleen cells via gamma interferon.

We examined the major pathogenic substances of Bordetella pertussis for the ability to induce nitric oxide, and important biological function of macrophages, via gamma interferon in spleen cells. B. pertussis, which produces a variety of pathogenic substances, including pertussis toxin and filamentous hemagglutinin, causes a severe respiratory disease. Nitric oxide was detected in the culture fluid of spleen cells stimulated with pertussis toxin or its B oligomer but not in the culture fluid of spleen cells stimulated with the A protomer of pertussis toxin or with filamentous hemagglutinin. Incubation of the peritoneal exudate macrophages with pertussis toxin, B oligomer, A protomer, or filamentous hemagglutinin induced little nitric oxide, whereas incubation with gamma interferon induced a significant amount of nitric oxide. The induction of nitric oxide in spleen cells stimulated with pertussis toxin was completely inhibited by anti-gamma interferon antibody. The treatment of spleen cells with anti-Thy-1.2 antibody plus complement followed by stimulation with pertussis toxin decreased the secretion of gamma interferon and nitric oxide. These results suggest that gamma interferon from T lymphocytes stimulated with pertussis toxin induces nitric oxide.

Animals↗
PubMed1996

Rat 5S rDNA spacer sequences and chromosomal assignment of the genes to the extreme terminal region of chromosome 19.

Fragments of the spacer region of genes for rat 5S ribosomal RNA (rDNA), which are tandemly repeated, were amplified by PCR with primers specific to the two ends of the coding region for 5S rRNA. Two amplified fragments of approximately 1.6 kb were subcloned and sequenced. The spacer sequences showed a high degree of sequence identity to each other (99.2%) but substantial divergence from those of analogous mouse clones. The homologous regions in the mouse clones were interrupted by the duplication or deletion of small segments of DNA. A 12-mer, 5'-GGCTCTTGGGGC-3', thought to be responsible for efficient transcription, was located from position -33 to position -22 in the rat -5S clones. The genes were mapped by fluorescence in situ hybridization with cloned fragments of rat 5S rDNA as probe. The genes were localized exclusively in a single telomeric region of chromosome 19.

Animals↗
PubMed1996

An Economic Analysis of Water and Sanitation Infrastructure Improvements in the Colonias of El Paso County, Texas.

The authors conducted a cost-benefit analysis of a project to improve water supply and sanitation infrastructure in a rural community (colonia) along the United States-Mexico border. The present value of total costs in the scenario without improvements was $42,937,507, compared with net costs with improvements of $34,600,800. It is estimated that improved access to safe drinking water and solid waste sanitation prevented 155 cases of hepatitis A and 5,165 cases of gastrointestinal illness over 26 years and saved $846,541 in associated health care costs, approximately 10% of the total estimated savings. The majority of benefits was in the form of time savings and increased land values. The authors did not consider the value of improving environmental conditions for future generations and preventing communicable disease epidemics associated with poor sanitation. Accurate value estimates for these benefits might strengthen the argument for undertaking similar infrastructure-improvement projects in the colonias and in other underdeveloped rural areas of the United States. cost-benefit analysis; water supply and sanitation; health care costs; disease-prevention effectiveness Hanley & Belfus, Inc. Int J Occup Environ Health 1077-3525 2 3 1996 July/September Decreases in Subpopulations of T Lymphocytes and Natural Killer Cells in the Blood of Retired Chromate Workers 222 225 EN Takeshi Tanigawa Shunichi Araki Department of Public Health, Faculty of Medicine, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113, Japan. Akinori Nakata Takaharu Araki Susumu Sakurai To examine the effects of past exposure to chromates on lymphocyte subpopulations in man, the authors measured subpopulations of T lymphocytes and natural killer (NK) cells by flow cytometry together with B lymphocytes in blood samples from 27 male workers and 22 healthy controls. All subjects were nonsmokers. The numbers of CD4+CD45RA+ (suppressor-inducer), CD8+ (suppressor/cytotoxic) and total T lymphocytes, CD16+CD57+ NK cells, and total lymphocytes in the blood of chromate workers were significantly smaller than those in the blood of healthy controls (analysis of covariance with age as a covariate). It is suggested that suppressor-inducer and suppressor/cytotoxic T lymphocytes and NK cells with intermediate NK cell activity are most susceptible to the effects of past exposure to chromates as compared with other lymphocyte subpopulations such as B and CD4+CD29+ T lymphocytes.

Journal Article↗
PubMed1996

Synthesis of [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives containing pyridyl or imidazolyl groups and their thromboxane A2 receptor antagonistic and thromboxane A2 synthase inhibitory activities.

As part of our search for a dual inhibitor possessing both thromboxane A2 (TXA2) receptor antagonistic and TXA2 synthase inhibitory activities, some [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives possessing a pyridyl or imidazolyl group were synthesized. Their TXA2 receptor antagonistic and TXA2 synthase inhibitory activities were evaluated in terms of the inhibitory effects on U-46619-induced guinea-pig platelet aggregation and on thromboxane B2 (TXB2) production in human platelets, respectively. It was found that 3-[4-[2-(1-imidazolyl)-1-(4-chlorobenzenesulfonamido)ethyl]phenyl] propionic acid (22a), containing an imidazolyl group, is a well-balanced dual inhibitor having both TXA2 receptor antagonistic activity (IC50 = 0.31 microM) and TXA2 synthase inhibitory activity (IC50 = 0.39 microM).

Animals↗
PubMed1996

Synthesis and thromboxane A2 antagonistic activity of [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives.

In order to find new antiasthmatic and antithrombotic agents, various [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives were synthesized. Evaluation of these compounds for thromboxane A2 (TXA2) antagonistic activities indicated that 4-[4-[(4-chlorobenzenesulfonamido)phenylmethyl]phenyl]butyric acid (6h) ,4-[4-[1-(4-chlorobenzenesulfonamido)-2-phenylethyl]phenyl]butyric acid (6y) and many other compounds have potent inhibitory effects on U-46619-induced guinea-pig platelet aggregation. No significant difference in the inhibitory effect between (+)-6h and its antipode could be detected, although (+)-6h and its antipode could be detected, although (+)-6y was about 10 times more potent than (-)6y. The pKb values of 6h and 6y were estimated to be 8.9 and 10, respectively on U-46619-induced contraction of guinea-pig trachea as a pharmacological measure of TXA2 antagonistic activity. These compounds also showed potent inhibitory effects on U-46619-induced bronchoconstriction in guinea-pig after oral administration in vivo. They were also evaluated for other related pharmacological effects involving the arachidonic acid cascade. It was found that these compounds possess TXA2 synthase inhibitory activity together with TXA2 antagonistic activity, and 6h also possesses weak leukotriene D4 (LTD4) antagonistic activity. Structure-activity relationships for TXA2 antagonistic activity of these derivatives are discussed.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1996

Increase in CD57 + CD16-lymphocytes in workers exposed to benzidine and beta-naphthylamine: assessment of natural killer cell subpopulations.

Previously, we found a decrease in CD4 + CD45RA + T lymphocytes in workers exposed to the aromatic amines (AAs) [benzidine (BZ) and beta naphthylamine (BNA)]. For further investigation of the effects of AAs on lymphocyte subpopulations, we measured natural killer (NK) cell subpopulations using two-color staining with anti-Leu7 (CD57) and anti-Leu11 (CD16) monoclonal antibodies in peripheral blood in 78 male dyestuff workers. The workers had been exposed to AAs before 1972 at a chemical plant, either in the production of AAs (40 workers, high-exposure group) or in other work that involved handling dyestuffs (38 workers, low-exposure group). The controls were 30 "healthy" male volunteers without a history of occupational exposure to AAs or hazardous chemicals. The number of CD57 + CD16- cells in the high-exposure group was significantly higher than that in the controls (P < 0.01, analysis of covariance with age as a covariate). No significant differences were found in CD57 + CD16-, CD57 + CD16+ and CD57- CD16 + NK cells between the low-exposure group and the controls. It is suggested that a decrease in the number of CD4+ T lymphocytes following exposure to AAs might be compensated by the increase in CD57 + CD16- cells, i.e. circulating peripheral lymphocytes with poor NK cell activity.

2-Naphthylamine↗
PubMed1996

[Differentiation of hypertrophic cardiomyopathy and hypertensive cardiac hypertrophy using the patterns of interventricular septum hypertrophy].

The patterns of interventricular septal hypertrophy were analyzed on two-dimensional echocardiograms to differentiate hypertrophic cardiomyopathy (HCM) from hypertensive cardiac hypertrophy. The control group comprised 110 patients without cardiovascular disease who were matched for age and gender with the hypertension group. The hypertension group comprised 110 patients with uncomplicated essential hypertension, and the HCM group comprised 32 patients in whom the wall thickness of the interventricular septum was 12 mm or more at the mid-portion and no underlying heart disease responsible for cardiac hypertrophy was detected. The interventricular septal thickness was measured both at the thickest portion within 15 mm distal to the aortoseptal junction (basal portion: B) and at the mid-portion (M) in the end-diastolic image on the left parasternal long-axis tomograms, and the B/M ratio was calculated in each patient. The B/M ratio was 1.07 +/- 0.16 in the control group, 1.19 +/- 0.18 in the hypertension group, and 0.83 +/- 0.12 in the HCM group. Compared with the control group, the B/M ratio was significantly high in the hypertension group (p < 0.05) and significantly low in the HCM group (p < 0.01). These results indicate that hypertrophy of the interventricular septum is dominant at the basal portion in hypertensive patients but at the mid-portion in patients with HCM.

Aged↗
PubMed1996

[Experimental production of tricuspid valve and papillary muscle lesions by premature ventricular contractions due to ventricular stimulation in rabbits].

Ventricular bigeminy or trigeminy can spontaneously occur in anesthetized rabbits forced into the supine position. Premature ventricular contractions (PVCs) of this type are characterized by a long coupling time and superimposition of the following P waves. Rabbits with PVCs of this type frequently develop peculiar mitral complex lesions which are detected by deposition of colloidal carbon. This study examined the effects on the tricuspid complex of artificial PVCs induced by left ventricular pacing in rabbits. Anesthetized rabbits were forced into the supine position under electrocardiographic monitoring. The animals were divided into those with spontaneous PVCs, those with artificial PVCs, and those without PVCs as controls. Colloidal carbon (1 ml) was intravenously injected into the animals the next day. All animals were sacrificed after 1 week. Tricuspid complex lesions were found in 2.0% of animals with spontaneous PVCs, in 17.6% of those with artificial PVCs, and in none of the controls. These results indicate that artificial PVCs induced by left ventricular pacing can cause peculiar tricuspid complex lesions.

Animals↗