Serological survey and comparison of two polymerase chain reaction (PCR) assays with enzyme-linked immunosorbent assay (ELISA) for the diagnosis of canine visceral leishmaniasis in dogs

Visceral leishmaniasis (VL) is systemic zoonotic parasitic infection that is a health problem in some tropical and subtropical countries. The purpose of our study is to determine the seroprevalence of canine visceral leishmaniasis (CVL) in owned dogs of the Sarab area and to identify the species of Leishmania isolated from these dogs. We also compared the sensitivities and specificities of two polymerase chain reaction (PCR) assays (kDNA and ITS1) used for Leishmania infantum identification with culture, microscopic detection and enzyme-linked immunosorbent assay (ELISA) methods as well as validate the PCR techniques for the molecular diagnosis of CVL. Sera from 384 dogs of 30 villages around Sarab, were tested by ELISA and buffy coat blood fractions after sampling tested with PCR by specific primers (kDNA, ITS-18sRNA). Thirty-five dogs were seropositive by ELISA. The seroprevalence rate (SPR) of CVL was 9.1% (CI, 95% 6.6 -12.4). The most important serological result was a high proportion of seropositivity for leishmaniasis. Out of 361 (94%) asymptomatic dogs, 31 (8.6%) were seropositive, and out of 23 (6%) symptomatic dogs, 4 (17.4%) were seropositive. Agreement betweenthe ELISA test and clinical signs was 86.7%. Each assay was performed on 60 blood samples. PCR of kDNA (7/60 positives, 11.8%) was the most sensitive of the assays examined, followed by ELISA (3/60, 5%) and ITS1-PCR (2/60, 3.4 %). All diagnostic assays were highly specific (100 %) and had positive predictive values (PPV) >90% and negative predictive values (NPV) >88% for CVL. As expected, kDNAPCR proved to be the most sensitive (87.5 %) assay for leishmanial DNA in peripheral blood. This study shows that kDNA-PCR is significantly more sensitive than the other parasitological and serological methods, allowing the identification of infected dogs even before the appearance of serum L. infantum antibodies. Because kDNA-PCR is the most reliable, sensitive, and also a rapid diagnostic assay for CVL, it should be employed as the new standard for routine diagnosis.Key words: Leishmania infantum, polymerase chain reaction, kinetoplast DNA, enzyme-linked immunosorbent assay, Visceral leishmaniasis, dogs, prevalence

Combinatorial CRISPR-Cas9 screens for de novo mapping of genetic interactions.

We developed a systematic approach to map human genetic networks by combinatorial CRISPR-Cas9 perturbations coupled to robust analysis of growth kinetics. We targeted all pairs of 73 cancer genes with dual guide RNAs in three cell lines, comprising 141,912 tests of interaction. Numerous therapeutically relevant interactions were identified, and these patterns replicated with combinatorial drugs at 75% precision. From these results, we anticipate that cellular context will be critical to synthetic-lethal therapies

Species identification by experts and non-experts: comparing images from field guides

Accurate species identification is fundamental when recording ecological data. However, the ability to correctly identify organisms visually is rarely questioned. We investigated how experts and non-experts compared in the identification of bumblebees, a group of insects of considerable conservation concern. Experts and non-experts were asked whether two concurrent bumblebee images depicted the same or two different species. Overall accuracy was below 60% and comparable for experts and non-experts. However, experts were more consistent in their answers when the same images were repeated, and more cautious in committing to a definitive answer. Our findings demonstrate the difficulty of correctly identifying bumblebees using images from field guides. Such error rates need to be accounted for when interpreting species data, whether or not they have been collected by experts. We suggest that investigation of how experts and non-experts make observations should be incorporated into study design, and could be used to improve training in species identification

Properties and expression of Na+/K+-ATPase α-subunit isoforms in the brain of the swamp eel, Monopterus albus, which has unusually high brain ammonia tolerance

10.1371/journal.pone.0084298PLoS ONE812-POLN

Threatened reef corals of the world

10.1371/journal.pone.0034459PLoS ONE73

Prevention of non-communicable disease in a population in nutrition transition: Tehran Lipid and Glucose Study phase II

<p>Abstract</p> <p>Background</p> <p>The Tehran Lipid and Glucose Study (TLGS) is a long term integrated community-based program for prevention of non-communicable disorders (NCD) by development of a healthy lifestyle and reduction of NCD risk factors. The study begun in 1999, is ongoing, to be continued for at least 20 years. A primary survey was done to collect baseline data in 15005 individuals, over 3 years of age, selected from cohorts of three medical heath centers. A questionnaire for past medical history and data was completed during interviews; blood pressure, pulse rate, and anthropometrical measurements and a limited physical examination were performed and lipid profiles, fasting blood sugar and 2-hours-postload-glucose challenge were measured. A DNA bank was also collected. For those subjects aged over 30 years, Rose questionnaire was completed and an electrocardiogram was taken. Data collected were directly stored in computers as database software- computer assisted system. The aim of this study is to evaluate the feasibility and effectiveness of lifestyle modification in preventing or postponing the development of NCD risk factors and outcomes in the TLGS population.</p> <p>Design and methods</p> <p>In phase II of the TLGS, lifestyle interventions were implemented in 5630 people and 9375 individuals served as controls. Primary, secondary and tertiary interventions were designed based on specific target groups including schoolchildren, housewives, and high-risk persons. Officials of various sectors such as health, education, municipality, police, media, traders and community leaders were actively engaged as decision makers and collaborators. Interventional strategies were based on lifestyle modifications in diet, smoking and physical activity through face-to-face education, leaflets & brochures, school program alterations, training volunteers as health team and treating patients with NCD risk factors. Collection of demographic, clinical and laboratory data will be repeated every 3 years to assess the effects of different interventions in the intervention group as compared to control group.</p> <p>Conclusion</p> <p>This controlled community intervention will test the possibility of preventing or delaying the onset of non-communicable risk factors and disorders in a population in nutrition transition.</p> <p>Trial registration</p> <p>ISRCTN52588395</p