1,721,057 research outputs found
Etiology of Balkan endemic nephropathy and associated urothelial cancer
No full textBalkan endemic nephropathy (BEN) is a familial chronic tubulointerstitial disease with insidious onset and slow progression to terminal renal failure. Evidence has accumulated that BEN is an environmentally induced disease. There are three actual theories attempting to explain the environmental cause of this disease: (1) the aristolochic acid hypothesis, which considers that the disease is produced by chronic intoxication with Aristolochia, (2) the mycotoxin hypothesis, which considers that BEN is produced by ochratoxin A, and (3) the Pliocene lignite hypothesis, which proposes that the disease is caused by long-term exposure to polycyclic aromatic hydrocarbons and other toxic organic compounds leaching into the well drinking water from low-rank coals in the vicinity to the endemic settlements. Moreover, it was suggested that BEN risk is influenced by inherited susceptibility. Therefore, it has been expected that molecular biological investigations will discover genetic markers of BEN and associated urothelial cancer, permitting early identification of susceptible individuals who may be at risk of exposure to the environmental agents. Since kidney pathophysiology is complex, gene expression analysis and highly throughput proteomic technology can identify candidate genes, proteins and molecule networks that eventually could play a role in BEN development. Investigation of gene-gene and gene-environment interactions could be the content of further studies determining the precise risk for BEN. Copyright (C) 2006 S. Karger AG, Basel
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
Y-chromosomal haplogroups in Bulgarians
No full textIn order to reconstruct Bulgarian paternal genetic history, we have analyzed the Y chromosome diversity across the country. This initial effort was performed through genotyping of 13 biallelic markers in a sample of 127 Bulgarian males. These markers define the main Y chromosome haplogroups and some of their subclades. We have determined five predominant haplogroups, which probably reflect three different steps in the colonization of the Balkan Peninsula. The obtained pattern of the Bulgarian Y chromosome diversity was compared to that of populations previously analyzed at the same phylogenetic resolution. Based on this comparison and on historical data, we have estimated definitely greater Indo-European (IE) than Central Asian (Altaic, AL) contribution to the modern Bulgarian gene pool
MDR1 haplotypes modify BEN disease risk: A study in Bulgarian patients with balkan endemic nephropathy compared to healthy controls
No full textBackground: Balkan endemic nephropathy ( BEN) is a slow progressive nephropathy with frequent occurrence of uroepithelial tumors in the upper urinary tract. Genetic factors involved in xenobiotic detoxification mechanisms may cause genetic predisposition to BEN and influence the risk for this disease. Polymorphic MDR1 variants with decreased P-glycoprotein (P-gp) activity modulate the risk for renal neoplasm. We have therefore investigated the impact of MDR1 polymorphisms on BEN manifestation. Methods: The constitutional genotype frequencies of two SNPs (C3435T and G2677T) in the MDR1 gene in 112 healthy control subjects were investigated and compared with those of 96 patients with BEN. Identification of the SNPs was done with rapid cycle real-time PCR and melting curve analysis with allele-specific probes. Results: The frequency of mutant alleles was comparable in both groups. Significant differences were revealed when the MDR1 haplotypes were analyzed. Individuals with a predicted haplotype 12 (2677G/3435T) were less frequent in BEN cases ( frequency 7.3%) than in controls (16.1%, p = 0.006). We found that carriers of the haplotype 12 had a decreased risk for BEN ( OR = 0.411; 0.21 - 0.78). Conclusions: The data suggest that haplotype 12 is protective against BEN. There is no clear molecular explanation of the MDR1 haplotype effects on the protein activity, which can explain the modified effect of the haplotype 12 on BEN risk. Copyright (C) 2004 S. Karger AG, Basel
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