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Biomedical subjects

S Tsuji

Publications and source records attributed to S Tsuji.

At least 325 records · Page 18Linked to original sources
PubMed1998

A distamycin A-inducible fragile site, FRA8E, located in the region of the hereditary multiple exostoses gene, is not involved in HPV16 DNA integration and amplification.

The rare fragile site is a specific point on a chromosome that is expressed as an isochromatid gap or break under certain conditions of cell culture and is inherited in a Mendelian codominant fashion. Five folate-sensitive fragile sites were cloned, and the molecular basis of fragile site mutation was shown to be a new class of mutation, called dynamic mutation, resulting from an allelic expansion of (CCG)n repeats. The mechanism responsible for other types of rare fragile sites, i.e., distamycin A-inducible and BrdU-requiring, is unknown, although cytogenetic studies suggested that these fragile sites play a mechanistic role in breakage and recombination and may also be integration and modification sites of foreign viral DNA genomes. A distamycin A-inducible fragile site, FRA8E, is mapped to 8q24.1 in which various loci implicated in genomic instability are located. Here we identified a YAC clone spanning both FRA8E and the hereditary multiple exostosis (EXT1) gene, using fluorescence in situ hybridization (FISH) analysis of a yeast artificial chromosome (YAC) contig. By using P1 clones as probes, the FRA8E locus was further localized to a 400-kb region including the EXT1 gene. Furthermore, the integration and amplification site of human papillomavirus 16 DNA in the ASCC (argyrophil small cell carcinoma) cells were shown not to coincide with FRA8E, but to be involved in an extensively broad genomic region of 8q24.1, including the c-myc gene.

Chromosome Fragile Sites↗
PubMed1998

Sympathetic skin responses recorded from non-palmar and non-plantar skin sites: their role in the evaluation of thermal sweating.

OBJECTIVE: To characterize the sympathetic skin responses (SSRs) recorded from non-palmar and non-plantar (non-Pa/P1) skin sites and to evaluate their clinical usefulness. METHODS: SSRs were recorded from 6 non-Pa/P1 sites as well as palmar and plantar (Pa/P1) sites using magnetic neck stimulation in 33 normal subjects, 17 neurological patients with dysautonomia and one patient with lumbar sympathectomy. A conventional thermoregulatory sweat test (TST) was also carried out in 3 patients. RESULTS: Clear and reproducible SSRs were obtained from all recording sites in all of the normal subjects when the skin temperatures of the subjects were maintained above 34 degrees C and the subjects drank 100-200 ml of hot water. The distribution of absent SSRs was closely correlated with that of anhidrosis or a sweating delay shown by the TST in the patients. Nine of the 17 neurological patients (53%) showed normal responses at Pa/P1 sites, and abnormal responses at non-Pa/P1 sites. CONCLUSIONS: Recording SSRs from multiple skin sites including non-Pa/P1 sites after magnetic stimulation is more sensitive in detecting sudomotor dysfunction than is the conventional method of recording SSRs from only Pa/P1 sites. In addition, this new method is very useful for the objective clinical evaluation of thermal sweating.

Adrenoleukodystrophy↗
PubMed1998

HLA-A*24-B*07-DRB1*01 haplotype implicated with genetic disposition of peak bone mass in healthy young Japanese women.

HLA exhibits the most extensive polymorphism of any of the known human genes and is known as a genetic marker which allows genetic background of many diseases and physical phenomena. In this study, we, therefore, tried to investigate the regulation of HLA polymorphism and peak bone mass (PBM) in order to elucidate the genetic backgrounds of bone metabolism in young women. Subjects were 67 healthy young Japanese women (average age: 23.6 +/- 2.6 years, Body Mass Index (BMI): 19.9 +/- 2.0 who were randomly chosen. Allelic polymorphisms in HLA class I (HLA-A and -B) and HLA-class II (DRB1) were investigated by PCR-SSOP and PCR-SSP. Vitamin D Receptor (VDR) and Estrogen Receptor (ER) gene polymorphisms were also analyzed. Lifestyle factors, such as exercise and nutrition, were examined by questionnaire. Bone mineral density was examined using with Lunar DPX-L. Subjects who possessed HLA-B*07 had a significantly lower PBM than those without B*07 (p < 0.05). All subjects were divided into 3 groups according to HLA haplotypes linked with HLA-B*07, as follows: A*24(+/-)B*07(-)DRB1*01(+/-), A*24(+)B*07(+)DRB1*01(-), and A*24(+)B*07(+)DRB*01(+). There were no significant differences between these three groups in factors that affect bone metabolism, such as age, age at menarche, BMI, calcium intake, exercise habits, VDR or ER allele frequency. The HLA-A*24-B*07-DRB1*01 haplotype had a significantly lower Z score in the lumbar spine compared with subjects without this haplotype (p < 0.05). When the Z score was divided by values higher or lower than +1 or -1, all 3 subjects whose Z score was lower than -1.0 were found to have the HLA-A*24-B*07-DRB1*01 haptotype. A significant association between HLA-A*24-B*07-DRB1*01 and Z score < -1 was found (Yate's correction chi(2) = 10.82, p = 0.001, RR = 204). In conclusion, the HLA-A*24-B*07-DRB*01 haplotype can be considered a new genetic marker implicated with low PBM in healthy young Japanese women.

Adult↗
PubMed1998

Helicobacter pylori infection induces cyclooxygenase-2 expression in human gastric mucosa.

Recent studies indicate that expression of mitogen-inducible cyclooxygenase-2 (COX-2) occurs in gastrointestinal tumors. We investigated the effects of Helicobacter pylori (H. pylori) infection, a class I carcinogen for the human stomach, on gastric COX-2 expression using immunohistochemistry. Human subjects without macroscopic lesions, as determined by endoscopic screening, were biopsied for H. pylori infection. The biopsy samples were immunohistochemically examined for COX-2 expression. COX-2 was expressed in gastric epithelia and subepithelial inflammatory cells in all H. pylori-infected subjects. There was no expression of COX-2 in the gastric mucosa of H. pylori-negative subjects. COX-2 expression has been reported in gastrointestinal carcinomas, gastrointestinal cancer cell-lines, and in the gut after carcinogenic treatment. The present study demonstrates that H. pylori infection leads to gastric mucosal expression of COX-2, indicating that the enzyme is involved in H. pylori-related gastric pathology in humans.

Adult↗
PubMed1998

Expression of two angiogenic factors, vascular endothelial growth factor and platelet-derived endothelial cell growth factor in human pancreatic cancer, and its relationship to angiogenesis.

Tumour angiogenesis, as assayed by microvessel density (MVD), and the expression of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) have become established as important prognostic indicators for many tumour types. In this study, MVD and the expression of VEGF and PD-ECGF were examined by immunohistochemical staining of 50 pancreatic cancer tissues, and the relationships between either MVD or the expression of these two angiogenic factors and the clinicopathological features, including survival, were analysed. The expression of VEGF and PD-ECGF proteins were confirmed by Western blot analysis and VEGF mRNA isoforms were determined by reverse transcriptase-polymerase chain reaction (RT-PCR) in five pancreatic cancer cell lines. Twenty-eight (56%) of 50 pancreatic cancers were positive for VEGF protein in cancer cells, and 16 (32%) showed strong PD-ECGF staining in cancer and infiltrating cells. VEGF121 and VEGF165 were identified as the predominant species produced in pancreatic cancer cells. The overexpression of VEGF and PD-ECGF protein significantly correlated with high MVD (P = 0.002, 0.044, respectively). Advanced stage of disease was significantly more frequent in patients with high MVD (P = 0.025). No significant association was found between the expression of VEGF or PD-ECGF and clinicopathological features, except for tumour histology. The expression of PD-ECGF correlated with poor survival (P = 0.011), but MVD and VEGF expression were not found to be useful for the prediction of overall survival. This study suggests that VEGF and PD-ECGF may play an important role in tumour angiogenesis, and that PD-ECGF expression seems to be useful for establishing prognoses for pancreatic cancer.

Blotting, Western↗
PubMed1998

Age-dependent changes in physiological threshold asymmetries for the motor evoked potential and silent period following transcranial magnetic stimulation.

OBJECTIVE: To study the effect of age on the physiological threshold asymmetries for the motor evoked potential (MEP) and silent period (SP) following transcranial magnetic stimulation. METHODS: We studied 63 right-handed subjects and 13 young left-handed subjects (19-39 years). The right-handers were classified into three age groups; 22 young (20-38 years), 20 middle-aged (40-58 years) and 21 old (61-82 years) subjects. We measured the MEP thresholds at rest and during voluntary contraction (VC), and the SP thresholds from the right and left abductor pollicis brevis (APB) muscles. We also measured the side to side differences of the F wave persistency and the F wave/M wave amplitude ratio from the same muscles. RESULTS: Among young subjects, all of the MEP and SP thresholds for the right APB were significantly lower than those for the left APB in the right-handers, and the reverse was true in the left-handers. The results in the middle-aged right-handers were similar to those in the young right-handers, but in the old right-handers, none of the thresholds were different between the two sides. We did not find any asymmetries of the F wave in the subjects of any age group. CONCLUSION: We speculate that the age-dependent threshold asymmetries are preferentially related to functional asymmetries at the cortical level.

Adult↗
PubMed1998

Brain injury and growth inhibitory factor (GIF)--a minireview.

Growth inhibitory factor (GIF) is a small (7 kDa), heat-stable, acidic, hydrophilic metallothionein (MT)-like protein. GIF inhibits the neurotrophic activity in Alzheimer's disease (AD) brain extracts on neonatal rat cortical neurons in culture. GIF has been shown to be drastically reduced and down-regulated in AD brains. In neurodegenerative diseases in humans, GIF expression levels are reduced whereas GFAP expression levels are markedly induced in reactive astrocytes. Both GIF and GIF mRNA are present at high levels in reactive astrocytes following acute experimental brain injury. In chronological observations the level of GIF was found to increase more slowly and remain elevated for longer periods than that of glial fibrillary acidic protein (GFAP). These differential patterns and distribution of GIF and GFAP seem to be important in understanding the mechanism of brain tissue repair. The most important point concerning GIF in AD is not simply the decrease in the level of expression throughout the brain, but the drastic decrease in the level of expression in reactive astrocytes around senile plaques in AD. Although what makes the level of GIF decrease drastically in reactive astrocytes in AD is still unknown, supplements of GIF may be effective for AD, based on a review of current evidence. The processes of tissue repair following acute brain injury are considered to be different from those in AD from the viewpoint of reactive astrocytes.

Amino Acid Sequence↗
PubMed1998

Suppression of aggregate formation and apoptosis by transglutaminase inhibitors in cells expressing truncated DRPLA protein with an expanded polyglutamine stretch.

To elucidate the molecular mechanisms whereby expanded polyglutamine stretches elicit a gain of toxic function, we expressed full-length and truncated DRPLA (dentatorubral-pallidoluysian atrophy) cDNAs with or without expanded CAG repeats in COS-7 cells. We found that truncated DRPLA proteins containing an expanded polyglutamine stretch form filamentous peri- and intranuclear aggregates and undergo apoptosis. The apoptotic cell death was partially suppressed by the transglutaminase inhibitors cystamine and monodansyl cadaverine (but not putrescine), suggesting involvement of a transglutaminase reaction and providing a potential basis for the development of therapeutic measures for CAG-repeat expansion diseases.

Animals↗
PubMed1998

Peripheral primitive neuroectodermal tumour of the lung: report of two cases.

AIMS: We report two unusual cases of intrapulmonary small round cell tumour with evidence that they are primitive neuroectodermal tumours. METHODS AND RESULTS: The patients were a 25-year-old woman and a 15-year-old man, in whom mass shadows were found by routine chest radiography. Both tumours were located in the pulmonary parenchyma, and there was no evidence of an extrapulmonary involvement by the tumour. The lesions showed morphological and immunophenotypic features consistent with peripheral primitive neuroectodermal tumour (pPNET). These features included a hypercellular diffuse growth pattern of closely packed small round cells occasionally forming abortive Homer-Wright-type rosettes and intense immuroreactivities to neurone-specific enolase and MIC2 gene product (O13). Unusual chondroid foci were present in one of the cases. This diagnosis was further supported by the cytogenetic and reverse transcriptase-polymerase chain reaction (RT-PCR) findings of the characteristic t(11;22) chromosomal translocation and EWS/FLI-1 fusion transcripts, respectively, in one of the cases. CONCLUSIONS: These morphological and cytogenetic findings substantiate pPNET as a subtype of intrapulmonary small round cell tumours.

Adolescent↗
PubMed1998

Dorsal root ganglia-specific expression of the beta-galactoside alpha1,2-fucosyltransferase genes in rabbits.

The neurons of dorsal root ganglia (DRG) mediate several sensation modalities. The carbohydrate antigens on DRG neurons differ with the sensation modalities that subsets of neurons convey. Despite the important roles of gangliosides and glycoproteins in neuronal differentiation and neuritogenesis of the mammalian nervous system, little is known about the mechanisms underlying the regulation of glycosylation. We previously demonstrated the expression of H-blood type antigens (Fuc alpha1, 2Gal beta) on rabbit DRG neurons of small diameter and dramatic changes in H antigens during the perinatal period. To investigate the possible biological roles and regulatory mechanisms of H antigens, we recently cloned three types of rabbit alpha1,2-fucosyltransferase gene that catalyze the biosynthesis of H antigens. Here, we analyze the expression of these genes, RFT-I, II, and III, in rabbit DRG. The H-type alpha1,2-fucosyltransferase gene, RFT-I, was expressed in DRG in late embryos to adult rabbits, as detected on northern blotting. The other two secretor-type alpha1,2-fucosyltransferase genes, RFT-II and III, were observed to be expressed in late embryonic DRG on RT-PCR analysis but were not detectable on northern blotting. The expression of the H-type alpha1,2-fucosyltransferase gene was analyzed by in situ hybridization and was found to be abundant in small-diameter DRG neurons. These results indicate that the H-type alpha1,2-fucosyltransferase gene plays a major role in the regulation of the H antigen expression in DRG during the perinatal period.

Animals↗
PubMed1998

Close associations between prevalences of dominantly inherited spinocerebellar ataxias with CAG-repeat expansions and frequencies of large normal CAG alleles in Japanese and Caucasian populations.

To test the hypothesis that the frequencies of normal alleles (ANs) with a relatively large number of CAG repeats (large ANs) are related to the prevalences of the dominant spinocerebellar ataxias (SCAs)-SCA types 1, 2, 3 (Machado-Joseph disease), 6, and dentatorubral-pallidoluysian atrophy (DRPLA)-we investigated the relative prevalences of these diseases in 202 Japanese and 177 Caucasian families and distributions of the number of CAG repeats of ANs at these disease loci in normal individuals in each population. The relative prevalences of SCA1 and SCA2 were significantly higher in Caucasian pedigrees (15% and 14%, respectively) than in Japanese pedigrees (3% and 5%, respectively), corresponding to the observation that the frequencies of large ANs of SCA1 (alleles >30 repeats) and of SCA2 (alleles >22 repeats) were significantly higher in Caucasians than in Japanese. The relative prevalences of MJD/SCA3, SCA6, and DRPLA were significantly higher in Japanese pedigrees (43%, 11%, and 20%, respectively) than in Caucasian pedigrees (30%, 5%, and 0%, respectively), corresponding to the observation that the frequencies of large ANs of MJD/SCA3 (>27 repeats), SCA6 (>13 repeats), and DRPLA (>17 repeats) were significantly higher in Japanese than in Caucasians. The close correlations of the relative prevalences of the dominant SCAs with the distributions of large ANs strongly support the assumption that large ANs contribute to generation of expanded alleles (AEs) and the relative prevalences of the dominant SCAs.

Asian People↗
PubMed1998

Mitochondrial DNA variation and evolution of Japanese black cattle (Bos taurus).

This article describes complete mitochondrial DNA displacement loop sequences from 32 Japanese Black cattle and the analysis of these data in conjunction with previously published sequences from African, European, and Indian subjects. The origins of North East Asian domesticated cattle are unclear. The earliest domestic cattle in the region were Bos taurus and may have been domesticated from local wild cattle (aurochsen; B. primigenius), or perhaps had an origin in migrants from the early domestic center of the Near East. In phylogenetic analyses, taurine sequences form a dense tree with a center consisting of intermingled European and Japanese sequences with one group of Japanese and another of all African sequences, each forming distinct clusters at extremes of the phylogeny. This topology and calibrated levels of sequence divergence suggest that the clusters may represent three different strains of ancestral aurochs, adopted at geographically and temporally separate stages of the domestication process. Unlike Africa, half of Japanese cattle sequences are topologically intermingled with the European variants. This suggests an interchange of variants that may be ancient, perhaps a legacy of the first introduction of domesticates to East Asia.

Animals↗
PubMed1998

Alpha 1,6-linked fucose affects the expression and stability of polysialic acid-carrying glycoproteins in Chinese hamster ovary cells.

To determine the effect of alpha1,6-linked fucose modification of N-glycans on the expression of polysialic acids (PSAs), the expression of PSAs in a fucose-lacking mutant of Chinese hamster ovary (CHO) cells, Lec13, was compared with that in CHO K1 cells. PSA synthase activity in these cells and the antennary structures of N-glycans associated with the neural adhesion molecule (NCAM), which is a major PSA-carrying glycoprotein, did not differ between the two types of cells. Metabolic labeling of cells with [3H]glucosamine for 48 h followed by immunoprecipitation with anti-PSA monoclonal antibodies revealed that the amount of labeled PSA-carrying glycoproteins obtained from Lec13 cells was 10-times less than that from K1 cells, although the incorporation of [3H]glucosamine into total extracts and NCAM was almost the same. In contrast, when cells were pulse labeled with [35S]methionine followed by a 1 h chase, there was not such a great difference in PSA-carrying protein synthesis between K1 and Lec13 cells. However, during a prolonged chase period, PSA-carrying proteins rapidly decreased in Lec13 cells, whereas those in K1 cells did not change. The degradation of PSA-carrying glycoproteins in Lec13 cells was partly prevented when the cells were grown in fucose-containing medium. Therefore, fucose modification of core N-glycans may affect the efficient expression of PSAs through the intracellular stability of PSA-carrying glycoproteins.

Animals↗
PubMed1998

Chicken ornithine transcarbamylase gene, structure, regulation, and chromosomal assignment: repetitive sequence motif in intron 3 regulates this enzyme activity.

Ornithine transcarbamylase (OTC) is one of the urea cycle enzymes. While the chicken is a uricotelic animal, it has measurable OTC activity in its kidney. OTC activity is highly variable within and between chicken breeds. Chicken OTC may have some physiological significance because of its significant activity in the kidney. We cloned the OTC cDNA from chicken kidney and found 77% homology between the deduced amino acid sequence of the mature protein and that of mammals. The chicken OTC gene spans 26 kb, consists of 10 exons and 9 introns, and utilizes the same exon-intron boundaries as the human gene. The 5'-flanking region contains a putative TATA box and two potential regulatory sites, but neither the 5'-flanking region nor the splice sites correlated with variation in OTC activity. In intron 3, two polymorphic sites were found: one comprising a deletion of 401 nucleotides; and the other was a length and sequence polymorphic region located 8 bases upstream from the deletion. The latter polymorphism provides an explanation for phenotypic variation in OTC. Linkage analysis has suggested reassignment of the chicken OTC gene from the suggested Z chromosome to chromosome 1q.

Amino Acid Sequence↗
PubMed1998

Effects of NSAIDs on proliferation of gastric cancer cells in vitro: possible implication of cyclooxygenase-2 in cancer development.

The roles of cyclooxygenase-2 (COX-2) in the development of gastric cancer are unknown. We investigated the effects of nonsteroidal antiinflammatory drugs (NSAIDs), which are specific and nonspecific inhibitors of COX-2, on proliferation of the gastric cancer cell lines KATOIII, MKN28, and MKN45. The protein level of COX-2 was examined in these cell lines by Western analysis, and mRNA levels of COX-1/2 by Northern analysis. These cell lines expressed comparable levels of COX-1 mRNA. However, mRNA and protein expression of COX-2 in these cell lines was different. MKN45 expressed higher levels of COX-2 mRNA and protein than KATOIII and MKN28. We also examined the effects of NS-398 and indomethacin, specific and nonspecific inhibitors of COX-2, on the increase in cell number and [3H]thymidine uptake of these cell lines. NS-398 and indomethacin suppressed proliferation of MKN45 cells that overexpressed COX-2, although they exerted minimal effects on proliferation of KATOIII and MKN28, which expressed lower levels of COX-2. These results are consistent with the hypothesis that COX-2 is expressed in certain groups of gastric cancers and is related to their cell proliferation. It was proposed that COX-2 plays an important role in development of gastric cancer cells. Furthermore, NSAIDs may exert antiproliferative activity against gastric adenocarcinomas that overexpress COX-2.

Adenocarcinoma↗
PubMed1998

Detection of TLS/FUS-CHOP fusion transcripts in myxoid and round cell liposarcomas by nested reverse transcription-polymerase chain reaction using archival paraffin-embedded tissues.

The reciprocal translocation t(12;16)(q13;p11) has been shown to be highly characteristic of myxoid and round cell subtypes of liposarcoma, and the TLS/FUS-CHOP fusion gene that resulted from the translocation is expected to be a diagnostic molecular marker of these sarcomas. In this study, we conducted a nested reverse transcription-polymerase chain reaction (RT-PCR)-based assay to detect the TLS/FUS-CHOP fusion gene transcripts using archival formalin-fixed, paraffin-embedded tumor specimens. Of 18 paraffin-embedded specimens from 16 myxoid and round cell liposarcoma cases, the fusion transcripts could be identified in 16 (89%) specimens from 15 (94%) cases. A sequence analysis using the PCR products confirmed that the detected messages were derived from either type I or type II TLS/FUS-CHOP fusion gene, the latter of which was predominant (80%). The results were consistent in primary and recurrent lesions of the same patients and in paraffin-embedded and snap-frozen samples from the same tumors. In two negative specimens, transcripts of the beta-actin gene could not be detected by RT-PCR, and intact mRNA including the fusion messages might have been degraded. No fusion transcripts were detected in snap-frozen or paraffin-embedded material of other types of tumors with myxoid morphology (seven myxoid malignant fibrous histiocytomas and four lipomas with myxoid change). These results indicate that this molecular assay can be applied to formalin-fixed, paraffin-embedded tumor tissues as a diagnostic aid for these subtypes of liposarcoma.

Adolescent↗
PubMed1998

Flow cytometric analysis of cell proliferation kinetics during duodenal ulcer healing.

Cell proliferation in the gastroduodenal mucosa of patients with duodenal ulcers was evaluated using flow cytometry. Forty patients with duodenal ulcers and 12 normal subjects were investigated. Biopsy samples were obtained during endoscopic examination and subjected to DNA analysis by flow cytometry. Thirty patients with duodenal ulcers were healed within 3 months with H2 blockers (tractable or responsive ulcers), whereas 10 patients did not respond to treatment (intractable ulcers). The percentage of cells at the DNA-synthetic phase, an index of cell proliferation, was constant in the adjacent duodenal mucosa 2 cm from ulcer margin and antral mucosa during duodenal ulcer healing. The index at the margin of tractable ulcers was elevated during the active stage (12.9 +/- 1.3), peaked during the healing stage (15.4 +/- 2.8) and returned to the same level at the scarring stage (10.9 +/- 2.0) as normal controls (10.3 +/- 1.7). However, the index was not elevated in intractable ulcers (10.3 +/- 1.7 in the healing stage) and was smaller than in tractable ulcers. These data indicate that augmented mucosal cell proliferation at the ulcer margin plays an important role in duodenal ulcer healing and intractable ulcers are characterized by an abnormal failure to accelerate DNA synthesis to achieve ulcer repair.

Adult↗