Biomedical subjects

Sueli M Oba-Shinjo

Publications and source records attributed to Sueli M Oba-Shinjo.

10 recordsLinked to original sources

PubMed2007

Lower HDL-cholesterol among healthy middle-aged Japanese-Brazilians in São Paulo compared to Natives and Japanese-Brazilians in Japan.

Blood lipid levels are determined by a combination of genetic and environmental factors. Higher than average values of high-density lipoprotein cholesterol (HDL-cholesterol) have been observed in people of Japanese ethnicity. The aim of this study was to investigate whether Japanese immigrants to Brazil and subsequent generations maintain the protective benefits associated with higher levels of HDL-cholesterol, and to examine the potential associations between HDL-cholesterol and a variety of other blood lipids, anthropometric and lifestyle factors. Healthy men and women aged 35 years and older who were Native Japanese (n = 198) or Japanese-Brazilians (JB) living in São Paulo, Brazil (n = 198) and in some Japanese cities (n = 246) were investigated. Anthropometric variables, blood lipids including HDL-cholesterol, and lifestyle factors were assessed. Serum HDL-cholesterol was observed to be lower for JB in São Paulo (both women and men) compared with Natives and JB in Japan. Among the groups, triglycerides, waist circumference, LDL-cholesterol, meat intake, stress, and smoking were observed to be independently negatively associated with HDL-cholesterol, whereas total cholesterol, fish intake, and physical activity were positively associated. Lower levels of HDL-cholesterol among both men and women of JB in São Paulo compared with both other groups were confirmed even after lifestyle adjustments. Our findings highlight the significantly lower levels of HDL-cholesterol among Japanese-Brazilians living in São Paulo city compared to Japanese-Brazilians and Native Japanese residing in Japan. Although several lifestyle factors were found to be significantly associated with HDL-cholesterol, they cannot adequately explain the role of the Brazilian cultural environment on HDL-cholesterol levels.

Acculturation↗

PubMed2006

Community-based familial study of Helicobacter pylori infection among healthy Japanese Brazilians.

BACKGROUND: The present study of Helicobacter pylori infection was conducted in family units of Japanese Brazilians living in São Paulo city. The authors attempted to determine the seroprevalence of H. pylori infection within family units of Japanese Brazilians and to identify risk factors associated with intrafamilial transmission. METHODS: The seroprevalence was determined in 1037 healthy and asymptomatic volunteer subjects aged 0-69 years (530 adults and 507 children) of 265 families. Demographic data and details of living conditions were obtained from each family. RESULTS: H. pylori seropositive infection was found in 39.2% of the parents and 9.3% of the children. A reduced risk of H. pylori infection was found for girls (odds ratio [OR] 0.45; 95% confidence interval [CI], 0.23-0.86). The prevalence of infection was 3.5% for children with uninfected parents; 9.9% (OR, 2.51; 95% CI, 0.95-6.61) for those with a seronegative mother and a seropositive father; 14.9% (OR, 4.93; 95% CI, 1.86-13.06) for those with a seropositive mother and a seronegative father; and 16.0% (OR, 5.29; 95% CI, 1.98-14.14) for those with seropositive parents. On multivariate analysis, the use of a pacifier, and mother's symptoms of nausea and vomiting were significantly associated with the risk of H. pylori infection for children, and the child having her/his own room was significantly associated with a reduced risk. Income was not associated with H. pylori infection in children and was inversely associated in parents. CONCLUSION: The prevalence of H. pylori infection in family units of Japanese Brazilians supports the hypothesis of a predominant role for mother-child transmission of H. pylori infection, mainly through contact with regurgitated gastric juice in the mother's mouth.

Adolescent↗

PubMed2006

Associations of TNF-A-1031TT and -857TT genotypes with Helicobacter pylori seropositivity and gastric atrophy among Japanese Brazilians.

BACKGROUND: Our previous study in a Japanese population showed elevated Helicobacter pylori seropositivity in those with tumor necrosis factor (TNF) A -1031TT and -857TT genotypes. This study examined the associations of this seropositivity and serum pepsinogen (PG) levels with these genotypes in Japanese Brazilians. METHODS: The subjects were 963 individuals (399 males and 564 females), aged 33 to 69 years, from four regions (Sao Paulo, Curitiba, Mogi das Cruzes, and Mirandopolis) in Brazil. Gastric atrophy was evaluated with serum pepsinogens (PGI < 70 ng/dl and PGI/II < 3), and TNF T-1031C and C-857T were genotyped by polymerase chain reaction with confronting two-pair primers (PCR-CTPP). RESULTS: The frequency of TNF-A T-1031C was 68.4% TT, 28.4% TC, and 3.3% CC, and that of C-857T was 64.5% CC, 31.7% CT, and 3.8% TT, whose distributions were in Hardy-Weinberg equilibrium. No significant associations of the genotypes with H. pylori seropositivity or gastric atrophy were found. However, male participants with TNF-A -1031CC and -857CC showed the lowest seropositivity (43.8% out of 16), and males with TNF-A -1031TT and -857TT showed the highest (61.5% out of 13). CONCLUSION: This study demonstrated that the associations between H. pylori seropositivity and TNF-A genotypes were not marked for Japanese Brazilians. The genotypes were not associated with gastric atrophy among the seropositive individuals.

Adult↗

PubMed2006

PIK3CA gene mutations in pediatric and adult glioblastoma multiforme.

The phosphatidylinositol 3-kinases (PI3K) are a family of enzymes that relay important cellular growth control signals. Recently, a large-scale mutational analysis of eight PI3K and eight PI3K-like genes revealed somatic mutations in PIK3CA, which encodes the p110alpha catalytic subunit of class IA PI3K, in several types of cancer, including glioblastoma multiforme. In that report, 4 of 15 (27%) glioblastomas contained potentially oncogenic PIK3CA mutations. Subsequent studies, however, showed a significantly lower mutation rate ranging from 0% to 7%. Given this disparity and to address the relation of patient age to mutation frequency, we examined 10 exons of PIK3CA in 73 glioblastoma samples by PCR amplification followed by direct DNA sequencing. Overall, PIK3CA mutations were found in 11 (15%) samples, including several novel mutations. PIK3CA mutations were distributed in all sample types, with 18%, 9%, and 13% of primary tumors, xenografts, and cell lines containing mutations, respectively. Of the primary tumors, PIK3CA mutations were identified in 21% and 17% of pediatric and adult samples, respectively. No evidence of PIK3CA gene amplification was detected by quantitative real-time PCR in any of the samples. This study confirms that PIK3CA mutations occur in a significant number of human glioblastomas, further indicating that therapeutic targeting of this pathway in glioblastomas is of value. Moreover, this is the first study showing PIK3CA mutations in pediatric glioblastomas, thus providing a molecular target in this important pediatric malignancy.

Adolescent↗

PubMed2006

Melanocyte transformation associated with substrate adhesion impediment.

Exclude experimental models of malignant transformation employ chemical and physical carcinogens or genetic manipulations to study tumor progression. In this work, different melanoma cell lines were established after submitting a nontumorigenic melanocyte lineage (melan-a) to sequential cycles of forced anchorage impediment. The great majority of these cells underwent anoikis when maintained in suspension. After one deadhesion cycle, phenotypic alterations were noticeable in the few surviving cells, which became more numerous and showed progressive alterations after each adhesion impediment step. No significant differences in cell surface expression of integrins were detected, but a clear electrophoretic migration shift, compatible with an altered glycosylation pattern, was observed for beta1 chain in transformed cell lines. In parallel, a progressive enrichment of tri- and tetra-antennary N-glycans was apparent, suggesting increased N-acetylglucosaminyltransferase V activity. Alterations both in proteoglycan glycosylation pattern and core protein expression were detected during the transformation process. In conclusion, this model corroborates the role of adhesion state as a promoting agent in transformation process and demonstrates that cell adhesion disturbances may act as carcinogenic stimuli, at least for a nontumorigenic immortalized melanocyte lineage. These findings have intriguing implications for in vivo carcinogenesis, suggesting that anchorage independence may precede, and contribute to, neoplastic conversion.

Animals↗

PubMed2005

Identification of novel differentially expressed genes in human astrocytomas by cDNA representational difference analysis.

Diffuse infiltrating gliomas are the most common tumors of the central nervous system (CNS), naturally progressing from a lower-grade to a higher-grade malignancy. Several genetic alterations have been correlated with astrocytic tumors; however, a number of as yet unknown genes may also be involved. Therefore, we set out to search for genes that are differentially expressed in anaplastic astrocytoma and normal CNS tissue by applying a PCR-based subtractive hybridization approach, namely, representational difference analysis (RDA). The results of DNA sequencing of a sample (96 cDNA clones) from the subtracted library allowed the identification of 18 different genes, some of which were represented by several cDNA clones, coding for the Np95, LMO1, FCGBP, DSCAM, and taxilin proteins. Quantitative real-time PCR analysis for five of these genes was performed using samples of astrocytic tumors of different grades, confirming their higher expression when compared to non-tumoral CNS tissue. Identification of differentially expressed genes present in gliomas but not in normal CNS tissue is important not only to better understand the molecular basis of these cancers, but also to generate diagnostic DNA chips, which may be useful in future therapeutic intervention.

Base Sequence↗

PubMed2004

Identification and complete sequencing of novel human transcripts through the use of mouse orthologs and testis cDNA sequences.

The correct identification of all human genes, and their derived transcripts, has not yet been achieved, and it remains one of the major aims of the worldwide genomics community. Computational programs suggest the existence of 30,000 to 40,000 human genes. However, definitive gene identification can only be achieved by experimental approaches. We used two distinct methodologies, one based on the alignment of mouse orthologous sequences to the human genome, and another based on the construction of a high-quality human testis cDNA library, in an attempt to identify new human transcripts within the human genome sequence. We generated 47 complete human transcript sequences, comprising 27 unannotated and 20 annotated sequences. Eight of these transcripts are variants of previously known genes. These transcripts were characterized according to size, number of exons, and chromosomal localization, and a search for protein domains was undertaken based on their putative open reading frames. In silico expression analysis suggests that some of these transcripts are expressed at low levels and in a restricted set of tissues.

Amino Acid Sequence↗

PubMed2004

A transcript finishing initiative for closing gaps in the human transcriptome.

We report the results of a transcript finishing initiative, undertaken for the purpose of identifying and characterizing novel human transcripts, in which RT-PCR was used to bridge gaps between paired EST clusters, mapped against the genomic sequence. Each pair of EST clusters selected for experimental validation was designated a transcript finishing unit (TFU). A total of 489 TFUs were selected for validation, and an overall efficiency of 43.1% was achieved. We generated a total of 59,975 bp of transcribed sequences organized into 432 exons, contributing to the definition of the structure of 211 human transcripts. The structure of several transcripts reported here was confirmed during the course of this project, through the generation of their corresponding full-length cDNA sequences. Nevertheless, for 21% of the validated TFUs, a full-length cDNA sequence is not yet available in public databases, and the structure of 69.2% of these TFUs was not correctly predicted by computer programs. The TF strategy provides a significant contribution to the definition of the complete catalog of human genes and transcripts, because it appears to be particularly useful for identification of low abundance transcripts expressed in a restricted set of tissues as well as for the delineation of gene boundaries and alternatively spliced isoforms.

Alternative Splicing↗

PubMed2004

Possible association of interleukin 1B C-31T polymorphism among Helicobacter pylori seropositive Japanese Brazilians with susceptibility to atrophic gastritis.

Associations between anti-Helicobacter pylori seropositivity (HP+) and interleukin 1B (IL-1B) C-31T polymorphism have been reported and little is known about the host factors involved in the development of atrophic gastritis (AG) among infected individuals. This study aimed to examine the IL-1B C-31T polymorphism among anti-HP antibody seropositive Japanese descendants with AG in Brazil and to investigate the interactions with lifestyle factors. Subjects were 455 seropositive from four cities in Brazil, aged 33-69 years. Sex-age-adjusted odds ratio (OR) of AG for 61 current smokers was 1.29, 95% confidence interval (CI): 0.18-9.26 for T/T, while that for 325 never smokers was 0.52, 95% CI: 0.27-0.98. A negative association for AG and never alcohol drinking, every day fruit consumption and milk drinking, and less frequently coffee drinking in individuals with C/T or T/T genotype was observed. This study suggested that host genetic constitution and lifestyle factors may influence the protective effect for AG development.

Adult↗

PubMed2003

Lifestyle factors associated with atrophic gastritis among Helicobacter pylori-seropositive Japanese-Brazilians in São Paulo.

BACKGROUND: Studies of lifestyle factors related to gastric atrophy development in Helicobacter pylori-infected individuals are limited. The present cross-sectional study aimed to examine the associations between lifestyle factors and serum pepsinogens (PGs) among anti- H. pylori antibody-seropositive Japanese in Brazil, where gastric cancer mortality was reported to be as high as in Japanese in Japan, and seropositive individuals were still frequently detected. METHODS: The subjects were 291 seropositive individuals (129 males and 162 females; age, 30 to 69 years) out of 656 Japanese-Brazilian volunteers in São Paulo city. Information on lifestyle factors was obtained using a self-administered questionnaire. Atrophic gastritis was defined as a PG1 serum level less than 70 ng/ml and PG1/PG2 ratio less than 3. RESULTS: The prevalence of atrophic gastritis was 31.9% (95% confidence intervals, 26.6%-37.6%). The proportion of subjects with atrophic gastritis increased with age, but there were no significantly marked differences in the proportions of subjects with atrophic gastritis among the three generations studied (first generation [Issei], second generation [Nisei], and third generation [Sansei]) for any 10-year age group. The associations with smoking and alcohol drinking were not significant. Length of education was inversely associated with gastric atrophy, while infrequent rice intake was preventive; the odds ratio relative to everyday rice intake was 0.13 (95% confidence intervals, 0.39-0.46) on multivariate analysis. CONCLUSIONS: The present study demonstrated that frequent rice intake was a risk factor for atrophic gastritis among the H. pylori-infected Japanese-Brazilians, suggesting that diet including rice plays a role in the step from H. pylori infection to gastric atrophy.

Adult↗