9 research outputs found
Protective effect of leptin against ischemia-reperfusion injury in the rat small intestine
BACKGROUND: The small intestine is extremely sensitive to ischemia-reperfusion (I/R) injury and a range of microcirculatory disturbances which contribute to tissue damage. Previous studies have shown that leptin plays an important physiological role in the microvasculature. The aim of this study was to evaluate the protective effects of leptin in I/R – induced mucosal injury in the small intestine. METHODS: Forty rats were divided into 5 groups (n = 8). Group I was subjected to a sham operation. Following mesenteric ischemia in group II (control); physiologic saline 1 cm(3), in group III; leptin 100 μg/kg, and physiologic saline 1 cm(3), in group IV; N(G)-L-arginine methyl ester (L-NAME) 20 mg/kg, and physiologic saline 1 cm(3), in group V; leptin 100 μg/kg, L-NAME 20 mg/kg, and physiologic saline 1 cm(3 )were given intra-peritoneally. In these groups, an I/R procedure was performed by occlusion of the superior mesenteric artery for 45 min followed by 120 min reperfusion. After reperfusion, the small intestines were resected for malondialdehyde (MDA) and nitric oxide (NO) concentration and histopathologic properties. Mucosal lesions were scored between 0 and 5. Tissue MDA and NO concentration and histopathologic grades were compared statistically. RESULTS: Tissue MDA level significantly increased (P < 0.05), tissue NO level significantly decreased in group V animals, compared to group III animals respectively (P < 0.001). Histopathologically, intestinal injury significantly decreased in the leptin treated ischemic group. CONCLUSION: Leptin can be used safely in mesenteric occlusive diseases, since it induces NO formation and release in mesenteric vessels
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
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Copy number variation and regions of homozygosity analysis in patients with MÜLLERIAN aplasia
Background: Little is known about the genetic contribution to Müllerian aplasia, better known to patients as Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. Mutations in two genes (WNT4 and HNF1B) account for a small number of patients, but heterozygous copy number variants (CNVs) have been described. However, the significance of these CNVs in the pathogenesis of MRKH is unknown, but suggests possible autosomal dominant inheritance. We are not aware of CNV studies in consanguineous patients, which could pinpoint genes important in autosomal recessive MRKH. We therefore utilized SNP/CGH microarrays to identify CNVs and define regions of homozygosity (ROH) in Anatolian Turkish MRKH patients. Result(s) Five different CNVs were detected in 4/19 patients (21%), one of which is a previously reported 16p11.2 deletion containing 32 genes, while four involved smaller regions each containing only one gene. Fourteen of 19 (74%) of patients had parents that were third degree relatives or closer. There were 42 regions of homozygosity shared by at least two MRKH patients which was spread throughout most chromosomes. Of interest, eight candidate genes suggested by human or animal studies (RBM8A, CMTM7, CCR4, TRIM71, CNOT10, TP63, EMX2, and CFTR) reside within these ROH. Conclusion(s) CNVs were found in about 20% of Turkish MRKH patients, and as in other studies, proof of causation is lacking. The 16p11.2 deletion seen in mixed populations is also identified in Turkish MRKH patients. Turkish MRKH patients have a higher likelihood of being consanguineous than the general Anatolian Turkish population. Although identified single gene mutations and heterozygous CNVs suggest autosomal dominant inheritance for MRKH in much of the western world, regions of homozygosity, which could contain shared mutant alleles, make it more likely that autosomal recessively inherited causes will be manifested in Turkish women with MRKH
Perinatal Diagnostic Approach to Fetal Skeletal Dysplasias: Six Years Experience of a Tertiary Center
<div><p>Skeletal dysplasias (SDs) constitute a group of heterogeneous disorders affecting growth morphology of the chondro-osseous tissues. Prenatal diagnosis of SD is a considerable clinical challenge due to phenotypic variability. We performed a retrospective analysis of the fetal autopsies series conducted between January 2006 and December 2012 at our center. SD was detected in 54 (10%) out of 542 fetal autopsy cases which included; 11.1% thanatophoric dysplasia (<i>n</i> = 6), 7.4% achondroplasia (<i>n</i> = 4), 3.7% osteogenesis imperfect (<i>n</i> = 2), 1.9% Jarcho-Levin Syndrome (<i>n</i> = 1), 1.9% arthrogryposis (<i>n</i> = 1), 1.9% Dyggve-Melchior-Clausen syndrome (<i>n</i> = 1), 72.1% of dysostosis cases (<i>n</i> = 39). All SD cases were diagnosed by ultrasonography. In 20 of the cases, amniocentesis was performed, 4 cases underwent molecular genetic analyses. Antenatal identification of dysplasia is important in the management of pregnancy and in genetic counseling. Our data analysis showed that SD is usually detected clinically after the 20th gestational week. Genetic analyses for SD may provide early diagnosis and management.</p></div