The role of nitric oxide in the protective action of remote ischemic per-conditioning against ischemia/reperfusion-induced acute renal failure in rat

Objective(s): We investigated the role of nitric oxide (NO) in the protective effects of remote ischemic per-conditioning (rIPerC) on renal ischemia/reperfusion (I/R) injury in male rats. Materials and Methods: I/R treatment consisted of 45 min bilateral renal artery ischemia and 24 hr reperfusion interval. rIPerC was performed using four cycles of 2 min occlusions of the left femoral artery and 3 min reperfusion at the beginning of renal ischemia. The animals were given normal saline (vehicle), NG-nitro-L-arginine methyl ester (L-NAME) or L-arginine. Following the reperfusion period, renal functional- and oxidative stress- parameters, as well as histopathological changes were assessed. Results: In comparison with the sham group, I/R resulted in renal dysfunction, as indicated by significantly lower creatinine clearance and higher fractional excretion of sodium. This went along with decreased glutathione peroxidase (GPX) and catalase (CAT) activity in the I/R group, increased malondialdehyde (MDA) contents and histological damages. In comparison with the I/R group, the rIPerC group displayed improved renal function, increased activity of GPX and CAT enzymes, and decreased MDA level. However, these effects were abrogated by L-NAME injection and augmented by L-arginine treatment. Conclusion: According to the results, the functional and structural consequences of rIPerC against I/R-induced kidney dysfunction, which is associated with reduction of lipid peroxidation and intensification of anti-oxidant systems, is partially dependent on NO production

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