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Biomedical subjects

Y Yamane

Publications and source records attributed to Y Yamane.

At least 73 records · Page 4Linked to original sources
PubMed1999

Significant differences in the frequency of transcriptional units, types and numbers of repetitive elements, GC content, and the number of CpG islands between a 1010-kb G-band genomic segment on chromosome 9q31.3 and a 1200-kb R-band genomic segment on chromosome 3p21.3.

We determined the nucleotide sequence of the entire 1,010,525-bp insert contained in CEPH YAC clone 867e8. This human genomic segment was derived from chromosome 9q31.3 and corresponds to a G-band region. We compared this segment, in terms of structure, with a previously characterized 1,201,033-bp sequence in CEPH YAC936c1 that had come from a portion of human chromosome 3p21.3 corresponding to an R-band region. The two segments were significantly different with respect to the frequency of transcriptional units, the types and numbers of repetitive elements present, their GC content, and the number of CpG islands. Alu elements, GC content, and CpG islands all showed positive correlations with the abundance of exons, but the distribution of LINE1s did not. These observations might reflect an influence of the first three of these features on the functions or expression of genes in the respective regions. In addition to a novel gene (F36) lying at the centromeric end of the 9q segment, we found a cluster of placenta-specific genes within a small section (about 400 kb) on the telomeric side of YAC867e8. This cluster consisted of four apparently unrelated ESTs and two genes, pregnancy-associated plasma protein-A (PAPP-A) and a novel gene (tentatively named EST-YD1). Our characterization of the two chromosomal regions provided evidence that genes are not evenly distributed throughout the human genome, and that gene richness is correlated with the GC content and with the frequency of either Alu elements or CpG islands.

Alu Elements↗
PubMed1999

Low levels of serum cholesterol and systolic blood pressure in Japanese with the apolipoprotein E3/2 genotype.

Apolipoprotein E (apoE) plays an important role in lipoprotein and cholesterol metabolism. An association between serum cholesterol and blood pressure has been suggested by epidemiological and experimental studies. But it is still not clear whether the apoE polymorphism plays a role in regulating blood pressure. The present study was undertaken to determine the association among apoE genotype, serum cholesterol and blood pressure in 303 healthy Japanese workers. Amplified fragments of DNA by the polymerase chain reaction were digested with HhaI and analyzed by 3% agarose-gel electrophoresis. Individuals with the apoE3/2 genotype had significantly lower levels of total cholesterol and systolic blood pressure than either the apoE3/3 individuals or the apoE3/4 + 4/4 individuals (P <0.05). The hypothesis that apoE indirectly influences systolic blood pressure through total serum cholesterol was supported by a covariance analysis of linear structural equations.

Adult↗
PubMed1999

Characterization of a 1200-kb genomic segment of chromosome 3p22-p21.3.

We previously determined the nucleotide sequence and characterized the 685-kb proximal half of CEPH YAC936c1, which corresponds to a portion of human chromosome 3p21.3. In the study reported here, we characterized the remaining 515-kb of this YAC clone corresponding to the telomeric half of its human insert. The newly sequenced region contained a total of ten genes including six reported previously: phospholipase C delta 1 (PLCD1), human activin receptor type IIB (hActR-IIB), organic cation transporter-like 1 (OCTL1), organic cation transporter-like 2 (OCTL2), oxidative stress response 1 (OSR1), and human xylulokinase-like protein (XYLB). The remaining four genes present in the telomeric region included two known genes, MyD88 and ACAA, and two novel genes. One (designated ENGL) of the novel sequences was found to encode an amino-acid sequence homologous to the family of DNA/RNA endonucleases, especially endonuclease G. The other gene F56 revealed no significant homology to any known genes. These results disclosed complete physical and transcriptional maps of the 1200-kb region of 3p present in YAC 936c1.

Amino Acid Sequence↗
PubMed1999

Disappearance of serum HCV-RNA after short-term prednisolone therapy in a patient with chronic hepatitis C associated with autoimmune hepatitis-like serological manifestations.

We report a 70-year-old woman with chronic hepatitis C associated with autoimmune hepatitis (AIH)-like serological manifestations, in whom elimination of hepatitis C virus (HCV) was observed after corticosteroid treatment. The patient was infected with HCV, genotype Ib, but had several laboratory findings, such as markedly elevated serum gamma-globulin and IgG, characteristic of AIH, as well as a high titer of an anti-nuclear antibody. An ultrasound (US)-guided liver biopsy disclosed chronic active hepatitis F3. Corticosteroid worsened her liver function test results and raised amounts of HCV-RNA in the serum. Withdrawal of the corticosteroid led to prompt normalization of transaminase levels and the disappearance of serum HCV-RNA, determined by reverse transcription-polymerase chain reaction (RT-PCR). For 4 years, up to the time of this study, her transaminase values have been normal and HCV viremia was not detected by repeated RT-PCR. We believe this to be the first reported case in which eradication of HCV was achieved by corticosteroid therapy alone, without the introduction of interferon.

Aged↗
PubMed1999

Pancreatoscopy for the next generation: development of the peroral electronic pancreatoscope system.

BACKGROUND: To improve visualization of the pancreatic duct with a pancreatoscope, we have developed the smallest known electronic endoscope, that is, the peroral electronic pancreatoscope. METHODS: This instrument (2.1 mm, external diameter) was developed with a 50k-pixel interline charge coupled device. A peroral fiberoptic pancreatoscope was used as control, connected to a video converter. The visibility of both systems was studied with a test chart. The model pancreatic duct, the oral mucosa, and the pancreatic ducts of a healthy control subject and patients with chronic pancreatitis were examined with both systems. RESULTS: The smallest visible interval (with a 5 mm distance between the object and the distal end of the endoscope) was 0.07 mm with the peroral electronic pancreatoscope and 0.2 mm with the peroral fiberoptic pancreatoscope. The electronic instrument produced better images of the model pancreatic duct than the fiberoptic endoscope. A clear image of the small vessels of the oral mucosa was obtained with the electronic but not with the fiberoptic instrument. The fine vessel network of the pancreatic duct was visualized only with the electronic instrument; pancreatic duct stones and rough-surfaced pancreatic duct were shown more precisely with the electronic endoscope. CONCLUSIONS: The peroral electronic pancreatoscope provides images of the fine detail of the pancreatic duct and will contribute to the diagnosis of pancreatic diseases.

Calculi↗
PubMed1999

Food intake, serum lipids and amino acids of school children in agricultural communities in Japan.

OBJECTIVE: To investigate the correlation among serum lipids, amino acids and diet of children in Japan where the mortality of ischemic heart disease is still very low. DESIGN: Cross-sectional study. SETTING: Two towns in Shimane prefecture, typical mountainous agricultural communities in the western part of the mainland of Japan. SUBJECTS: 514 children (10-15 y) in the communities were recruited. RESULTS: The mean cholesterol levels ranged from 3.9 to 4.4 mmol/l for boys and from 4.3 to 4.5 mmol/l for girls, and serum cholesterol level fell with age in boys. Serum cholesterol level of girls rose once between 11 and 13 y and fell gradually. Fish intake was positively correlated with serum omega-3 series fatty acids. Milk intake was negatively and soybean intake was positively correlated with omega-3/omega-6 series fatty acids ratio. Serum branched-chain amino acids were correlated negatively with serum polyunsaturated/saturated fatty acids ratio. CONCLUSIONS: Serum cholesterol level of children in agricultural communities in Japan has risen, and is probably affected by the change of food intake. Promoting the intake of soybean and fish, which are traditional Japanese foods, will be important in preventing atherosclerosis and ischemic heart disease. Attention should be paid to the relationship between branched-chain amino acids level in blood and fatty acids metabolism to verify the mechanism of the progress of atherosclerosis.

Adolescent↗
PubMed1999

Medical education in China for the 21st century.

Drastic changes are occurring in medical education around the world. Medicine and medical technologies are developing rapidly and expanding beyond the multidisciplinary area. The needs of medical care and medical education are different even from those of several years ago. In order to cope with these increasing social needs, the innovation of medical education in China has become an urgent and important problem. This study is an attempt to answer the question of how to develop medical education in China for the 21st century, based on a historical review of the development of medical education. This development might be divided into three periods: (1) before the Cultural Revolution; (2) the Cultural Revolution (1966-76); and (3) post-Cultural Revolution (1977-present) in modern China, and based on problem analysis of the curriculum, teaching methods, education evaluation, systems and policies and the balance between educational needs and supplies. We concentrate on the discussion of how to solve these problems, and have designed a new strategy for the further development of medical education in China. This discussion and newly developing strategy focuses on the main targets and priorities and adoption of suitable measures according to the conditions of the country. The purposes are to elevate the quality of medical education, to train qualified doctors to meet continuously increasing needs and to maintain the development of medical education for the 21st century in China.

China↗
PubMed1999

Balloon dilation of right ventricular outflow tract in a dog with tetralogy of Fallot.

Balloon dilation was performed on a dog with tetralogy of Fallot. Immediately following balloon dilation, the peak systolic pressure gradient across the pulmonic valve declined from 97 to 63 mmHg. Doppler echocardiography following balloon dilation revealed increased pulmonary blood flow. Clinical symptoms obviously improved and the dog's improved condition was maintained for 4 months. There were no serious complications in performing the procedure. It was concluded that balloon dilation was a safe and effective treatment for a dog case with tetralogy of Fallot. Long-term follow-up studies will be required to identify the exact indications of balloon dilation for tetralogy of Fallot.

Animals↗
PubMed1999

A comparative study between hypothermic and normothermic cardiopulmonary bypass in open heart surgery in dogs--effects on systemic hemodynamics.

Open heart surgery was performed on two groups of dogs under extracorporeal circulation with or without hypothermia to investigate hemodynamic changes during extracorporeal circulation. During hypothermic cardiopulmonary bypass (CPB), arterial O2 tension and postoperative blood pressure were favorably maintained, indicating that hypothermic extracorporeal circulation can be performed for a long period of time. On the other hand, during normothermic CPB, the average surgical duration was significantly shorter, and marked shifts in the concentrations of various enzymes were suppressed. However, due to reductions in arterial O2 tension, the length of cardiac arrest time was restricted, demonstrating that this method is suitable for performing extracorporeal circulation for CPB of relatively short duration. If circulation circuitry can be improved, such as through the development of a surpassing oxygenator, normothermic CPB would incur less stress on the body, thus making it preferential to hypothermic CPB in most cases.

Animals↗
PubMed1999

Dynamics of astrocyte adhesion as analyzed by a combination of atomic force microscopy and immuno-cytochemistry: the involvement of actin filaments and connexin 43 in the early stage of adhesion.

We observed the time-dependent morphological alteration of astrocytes during their adhesion by atomic force microscopy (AFM) and investigated the relationships between this morphological alteration and the localization of actin filaments and connexin 43 by immunocytochemistry. The fine processes observed as fine ridge-like structures by AFM were closely concerned with actin filaments by immunocytochemistry. During the adhesion of astrocytes, actin filaments appeared to be aligned regularly beyond the borders among different cells. Detectable connexin immunoreactivity was changed in the following regions: 1) the tips of fine cell processes and the cell margin when astrocytes started to adhere; 2) the border of cells when astrocytes tightly adhered; and 3) non-specific sites when astrocytes became a cluster. In the former two cases, the immunopositive spots for connexin were observed to colocalize with the tips of cell processes with actin filaments. These results strongly suggest that connexin associated with actin filaments at the tip of cell processes plays an important role in the early stage of the adhesion of astrocytes. These observations afford valuable clues for understanding the glial communication.

Actin Cytoskeleton↗
PubMed1999

[Primary health care in China: problems and challenges].

The World Health Organization (WHO) put forward a global strategy goal of "Health for All by year 2000" and pointed out the task of achieving this based on the primary health care (PHC) during the Alma-Ate Conference in 1978. The government of China have endorsed the WHO agreement and performed much work toward it. However, the gap between urban areas and rural areas is widening. The accomplishment of the goal of "Health for All by the year 2000" is still a critical task in China. In this study, main health problems, government policies and measures on the framework of quality of life, health status, lifestyle and health-supporting environment, medical, health and welfare system and health policies in PHC of China were diagnosed and evaluated according to the "diagnosis and evaluation for health promotion" by Green and Kreuter (1991). Japanese experiences in a combined medical, health and welfare system, elderly care, environmental protection and health education are very helpful to strengthen PHC in China. A new partnership for "Health for All" between Japan and China to achieve the goal of "Health for All by the year 2000" is imperative.

China↗
PubMed1998

Structural determination of sulfated tetrasaccharides and hexasaccharides containing a rare disaccharide sequence, -3GalNAc(4,6-disulfate)beta1-4IdoAalpha1-, isolated from porcine intestinal dermatan sulfate.

In the course of structural studies on sulfated oligosaccharides isolated from porcine intestinal heparin after extensive digestion with Flavobacterium heparinase, we isolated several heparitinase-resistant unsaturated oligosaccharides. Amino sugar analysis of these oligosaccharides indicated that they contained galactosamine residues but no glucosamine residues. They were sensitive to chondroitinase ABC but resistant to chondroitinase AC-II, and therefore derived from dermatan sulfate, which was presumably contained as a minor component in the starting heparin preparation. The structures of these oligosaccharides were characterized by enzymatic digestions in conjunction with HPLC analysis of the digests and by one-dimensional and two-dimensional 500-MHz 1H-NMR spectroscopy. Structures of two tetrasaccharides and two hexasaccharides were determined as deltaHexAalpha1-3GalNAc(4S)beta1-4IdoAalpha1-3GalNAc(4S), deltaHexAalpha1-3GalNAc(4S,6S)]beta1-4IdoAalpha1-3GalNAc(4S) , deltaHexAalpha1-3GalNAc(4S)beta1-4IdoAalpha1-3GalNAc(4S)beta 1-4IdoAalpha1-3GalNAc(4S), and deltaHexAalpha1-3GalNAc(4S)beta1-4IdoAalpha1-3GalNAc(4S,6S)b eta1-4IdoAalpha1-3GalNAc(4S), where deltaHexA, IdoA, GalNAc, 4S and 6S represent 4-deoxy-alpha-L-threo-hex-4-enepyranosyluronic acid, L-iduronic acid, N-acetyl-D-galactosamine, 4-O-sulfate and 6-O-sulfate, respectively. The latter three compounds have never been reported as discrete structures. Since the four isolated oligosaccharides contained an unsaturated uronic acid residue at the nonreducing terminus, they appear to have been generated by eliminative cleavage by the action of Flavobacterium chondroitinase that was probably present as a minor contaminant in the Flavobacterium heparinase preparation used. Two out of the four oligosaccharides shared the rare disulfated disaccharide sequence, -3GalNAc(4S,6S)beta1-4IdoAalpha1-. These oligosaccharides will be useful as authentic reference compounds for microanalyzing biologically active domains of dermatan sulfate.

Amino Sugars↗
PubMed1998

Expression of multidrug resistance protein/GS-X pump and gamma-glutamylcysteine synthetase genes is regulated by oxidative stress.

Expression of the MRP1 gene encoding the GS-X pump and of the gamma-GCSh gene encoding the heavy (catalytic) subunit of the gamma-glutamylcysteine synthetase is frequently elevated in many drug-resistant cell lines and can be co-induced by many cytotoxic agents. However, mechanisms that regulate the expression of these genes remain to be elucidated. We report here that like gamma-GCSh, the expression of MRP1 can be induced in cultured cells treated with pro-oxidants such as tert-butylhydroquinone, 2,3-dimethoxy-1, 4-naphthoquinone, and menadione. Intracellular reactive oxygen intermediate (ROI) levels were increased in hepatoma cells treated with tert-butylhydroquinone for 2 h as measured by flow cytometry using an ROI-specific probe, dihydrorhodamine 123. Elevated GSH levels in stably gamma-GCSh-transfected cell lines down-regulated endogenous MRP1 and gamma-GCSh expression. ROI levels in these transfected cells were lower than those in the untransfected control. In the cell lines in which depleting cellular GSH pools did not affect the expression of the MRP1 and gamma-GCSh genes, only minor increased intracellular levels of ROIs were observed. These results suggest that intracellular ROI levels play an important role in the regulation of MRP1 and gamma-GCSh expression. Our data also suggest that elevated intracellular GSH levels not only facilitate substrate transport by the MRP1/GS-X pump as previously demonstrated, but also suppress MRP1 and gamma-GCSh expression.

Biological Transport↗
PubMed1998

Effect of serum fatty acid composition on coronary atherosclerosis in Japan.

The serum lipid profiles of patient's with or without significant coronary stenosis diagnosed by coronary angiography and of control subjects were compared. The level of high-density-lipoprotein cholesterol and eicosapentaenoic acid were significantly lower in the patients with significant coronary stenosis than in the control subjects. It suggests that high-density-lipoprotein cholesterol and omega3 fatty acids may have a protective effect on the progress of coronary atherosclerosis. The frequency of eating dark-meat fish was positively associated with serum eicosapentaenoic acid and docosahexaenoic acid, omega3 fatty acids, and inversely associated with serum stearic acid and linoleic acid. The frequency of eating soybean products was positively associated with serum docosahexaenoic acid and inversely associated with serum linoleic acid. It is necessary to discuss a way to popularise a diet of dark-meat fish and soybean products as a means of preventing coronary heart disease.

Aged↗
PubMed1998

Doxorubicin- and daunorubicin-glutathione conjugates, but not unconjugated drugs, competitively inhibit leukotriene C4 transport mediated by MRP/GS-X pump.

Overexpression of the multidrug resistance-associated protein (MRP1) gene encoding a human GS-X pump in cultured cells resulted in increased cellular resistance to antitumor agents, including doxorubicin (Dox) and daunomycin (Dau), as well as certain heavy metals. However, studies with membrane vesicles prepared from the resistant cells revealed that Dox and Dau are poor substrates for the transport mediated by MRP/GS-X pump, suggesting that metabolic modifications of these drugs might be required for the transport. To test this hypothesis, we prepared four glutathione conjugates by linking the cysteine residue of GSH to Dox and Dau at eitehr the C-7 or C-14 position. The affinity of the synthesized conjugates toward MRP/GS-X pump was examined in the LTC4 transport assay using membrane vesicles prepared from an MRP1 gene-overexpressing cell line, SR3A. Unconjugated Dox and Dau failed to inhibit the transport of LTC4, whereas 30 microM GS-Dox or GS-Dau conjugates completely inhibited the transport. Kinetic analyses revealed that the inhibition by these GS-conjugates is competitive with Ki values ranging from 60 to 200 nM, suggesting that these compounds have high affinities toward MRP/GS-X pump and share the common binding site(s) with LTC4. Our present results support the hypothesis that glutathionation can facilitate the transport of anthracyclines by the MRP/GS-X pump.

ATP-Binding Cassette Transporters↗