1,720,991 research outputs found
Pooled analysis on metabolic gene polymorphisms and lung cancer
No full textThis article reports an update of pooled analysis on metabolic gene polymorphisms and cancer (the Genetic Susceptibility to Environmental Carcinogens [GSEC] study). The study started in 1997, and has collected data from over 52,000 subjects (half cases, half controls). The distribution of cases shows that the most represented cancer is lung cancer (6465 cases), followed by bladder cancer (3289 cases). The analyses conducted on lung cancer and metabolic gene polymorphisms are summarized and discussed. Pooled analysis allows one to study rare subgroups of subjects, such as lung cancer at young ages, or in nonsmokers, and is a useful approach for generating new working hypothesis and for fostering collaboration
Meta-analysis of cancer incidence in children born after assisted reproductive technologies
No full textA meta-analysis was performed on 11 cohort studies of Assisted Reproductive Technologies (ART) and subsequent childhood cancer, published up to February 2005, which reported comparable, nonoverlapping data, and then restricted to eight studies which presented a similar research design. The overall Standardised Incidence Ratio was 1.33 (95% CI 0.62-2.85), and 0.77 (95% CI 0.41-1.42) when the analysis was restricted to eight studies. No evidence of publication bias was observed for the overall analysis. The data are consistent with a lack of increase in risk of childhood cancer, though the amount of data on ART and cancer is still limited; larger multicentric studies as well as a pooled analysis on the available data are warranted
APIKIDS : a cohort of children born after assisted reproductive technologies
No full textA cohort of children born after assisted reproductive technologies (ART) was set up in 2003 in Italy. It aims to follow up the children in order to study the short- and long-term effects of ART. Parents who agreed to participate were contacted for a telephone interview; questions included occupational and non-occupational exposure to carcinogens, reproductive history, history of index pregnancy (including drugs used during pregnancy), delivery and the child's health status. By August 2005, 40 out of the 50 centres contacted (80%) had agreed to participate in the study, and 17 had already sent their data. Information on a total of 2451 cycles ending with a pregnancy are currently available, from 2245 couples. We have contacted 351 of these couples (16%), 309 of whom (88% of the contacts) agreed to participate in the study and were interviewed, while 36 (11%) refused to be interviewed. The total number of children currently included in the database is 411. This study is the first attempt to create a database containing information on children born after ART in Italy. It will provide results on both short- and long-term outcomes in these children
Hyperhomocysteinemia in cerebral vein thrombosis
No full textHigh plasma levels of total homocysteine (tHcy) are a risk factor for deep vein thrombosis. Because no information on the relationship between cerebral vein thrombosis and hyperhomocysteinemia is available, a case-control study of 121 patients with a first episode of cerebral vein thrombosis and 242 healthy control subjects was carried out. Fasting plasma levels of tHcy and their postmethionine load (PML) increments, together with other laboratory markers of thrombophilia, were measured in plasma or DNA. Hyperhomocysteinemia (high fasting tHcy and/or PML increments) was diagnosed in 33 patients (27%) and 20 control subjects (8%) (odds ratio, 4.2; 95% confidence interval [CI], 2.3-7.6). Low levels of serum folate and the 677TT methylene tetrahydrofolate reductase were associated with hyperhomocysteinemia, but in a multivariate model hyperhomocysteinemia only was associated with an increased risk of cerebral vein thrombosis. Oral contraceptive intake was associated with the disease with an odds ratio of 6.1 (95% CI, 3.3-11.0). The combined presence of the latter and hyperhomocysteinemia increased the risk of the disease with an odds ratio of 19.5 (95% CI, 5.7-67.3). In conclusion, hyperhomocysteinemia is associated with a 4-fold increased risk of cerebral vein thrombosis; whether or not its correction with vitamins reduces the risk of the disease remains to be demonstrated
Review of prevalence of Simian Virus 40 (SV40) genomic infection in healthy subjects
No full textBecause of the carcinogenicity of SV40 in rodents, and its possible distribution through the polio vaccine, many studies have been conducted to determine if there is an association between SV40 genomic infection and different types of cancer; sometimes, these studies included data on the prevalence of genomic infection in healthy subjects as secondary information. We reviewed all the studies that reported the prevalence of SV40 genomic infection in healthy subjects, tested by PCR based methods. The 20 articles considered here included 1103 samples from healthy subjects, with a prevalence of infection ranging from 0 to 25.6%, with high heterogeneity, and no association with the type of sample analyzed (Mantel-Haenszel OR: 0.74; 95% CI: 0.44-1.23). The wide variation in frequency pose problems in terms of study design; in fact, the representativeness of the samples used as controls in the published studies may be very limited. Larger studies on healthy subjects, tested for SV40 genomic infection at various genomic regions, conducted in different geographic areas, are needed
Genetics of leptin and obesity : a HuGE review
No full textLeptin is an important regulator of the mass of adipose tissue and of body weight; it operates by inhibiting food intake and stimulating energy expenditure. Some polymorphic genes involved in the regulation of leptin-the leptin gene (LEP A19G), the leptin receptor gene (LEPR Q223R, K109R, and K656N), and the peroxisome proliferator-activated receptor-gamma gene (PPARG P12A and C161T)--have been investigated as possible factors associated with obesity. Allelic frequencies of these polymorphisms show ethnic variation. The authors performed a meta-analysis of the available data on the association between these polymorphisms and obesity based on case-control studies. Odds ratios and 95% confidence intervals for obesity associated with leptin polymorphisms were calculated by using both fixed- and random-effects models. Results suggest no evidence of association between the genes under study and obesity. The lack of association could be due to the complex pathogenesis of obesity, which involves a number of genetic and environmental factors. Large studies including testing of multiple genes in both obese and lean subjects, with epidemiologic data on dietary habits in different ethnic groups, are necessary to better understand the role of leptin in regulating weight in human populations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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