Concurrent gastrointestinal signs in hypothyroid dogs

Few observations about prevalence and features of gastrointestinal (GI) signs in hypothyroid dogs (hypoT-dogs) are available.The study aimed (1) to evaluate concurrent GI signs in hypoT-dogs; (2) to analyze clinico-pathological and ultrasound features ofhypoT-dogs with and w/out GI signs, and (3) to analyzed GI signs follow-up after thyroid hormone replacement therapy (THRT).Medical records of hypoT-dogs from two Veterinary Teaching Hospitals were retrospectively reviewed. Dogs were classified ashypothyroid if TT4 or fT4 were low/normal with normal/high TSH or inadequate TSH-stimulation test response. Clinical history, GIsigns (vomiting, diarrhea, constipation), hematobiochemical parameters and abdominal ultrasound were collected. HypoT-dogs were divided based on the presence of at least one GI signs (GI group and not-GI group). Twenty-seven GI dogs had 3-4 weeks recheck from the beginning of THRT and information on GI signs were recorded. A total of 166 dogs were included (GI group, n=45, 27%; not-GI group, n=121, 73%). GI dogs showed nausea (42%), vomiting(40%), constipation (22%), large bowel diarrhea (40%), small bowel diarrhea (4%) and aspecific diarrhea (40%). No significant difference between GI and not-GI groups on hematobiochemical parameters was found. GI group had significantly higherfrequency (20%) of large intestine involvement than not-GI group at the ultrasound (P = 0.03; Chi-square test). Twenty-one out of27 GI dogs had a resolution of GI signs at recheck (P = 0.0001; McNemar test). Most of hypoT-dogs had concurrent GI signs mainly due to large bowel involvement. After THRT beginning the concurrent GI signs in hypoT-dogs seem to be reduce

Validation of microscopic observation drug susceptibility testing for rapid, direct rifampicin and isoniazid drug susceptibility testing in patients receiving tuberculosis treatment.

Drug susceptibility testing (DST) is often needed in patients clinically failing tuberculosis (TB) therapy. Most studies of phenotypic direct drug susceptibility tests, such as microscopic observation drug susceptibility (MODS) tests, have been performed in patients not receiving TB treatment. The effect of ongoing TB treatment on the performance of MODS direct DST has not been previously explored, but patients failing such therapy constitute an important target group. The aim of this study was to determine the performance of MODS direct rifampicin and isoniazid DST in patients clinically failing first-line TB treatment, and to compare MODS direct DST with indirect proportion method DST. Sputa from 264 TB patients were cultured in parallel in Lowenstein-Jensen (LJ) and MODS assays; strains were tested for rifampicin and isoniazid susceptibility by the proportion method at the national reference laboratory. Ninety-three samples were culture-positive by LJ and MODS (concordance of 96%; kappa 0.92). With conventional MODS plate DST reading (performed on the same day as the sample is classified as culture-positive), the isoniazid DST concordance was 96.8% (kappa 0.89), and the concordance for rifampicin susceptibility testing was 92.6% (kappa 0.80). Reading of MODS DST plates 1 week after cultures had been determined to be culture-positive improved overall performance marginally-the isoniazid DST concordance was 95.7% (kappa 0.85); and the rifampicin DST concordance was 96.8% (kappa 0.91). Sensitivity for detection of multidrug-resistant TB was 95.8%. MODS testing provided reliable rifampicin and isoniazid DST results for samples obtained from patients receiving TB therapy. A modified DST reading schedule for such samples, with a final reading 1 week after a MODS culture turns positive, marginally improves the concordance with reference DST

The spatial distribution of HO2in an atmospheric pressure plasma jet investigated by cavity ring-down spectroscopy

Cold atmospheric pressure plasma jets make important contributions to a range of fields, such as materials processing and plasma medicine. In order to optimise the effect of those plasma sources, a detailed understanding of the chemical reaction networks is pivotal. However, the small diameter of plasma jets makes diagnostics challenging. A promising approach to obtain absolute number densities is the utilisation of cavity-enhanced absorption spectroscopy methods, by which line-of-sight averaged densities are determined. Here, we present first measurements on how the spatial distribution of HO2 in the effluent of a cold atmospheric pressure plasma jet can be obtained by cavity ring-down spectroscopy in an efficient way. Instead of recording fully wavelength resolved spectra, we will demonstrate that it is sufficient to measure the absorption coefficient at two wavelengths, corresponding to the laser being on and off the molecular resonance. By sampling the effluent from the 1.6 mm diameter nozzle in the radial direction at various axial positions, we determined that the distances over which the HO2 density was distributed were (3.9 ± 0.5) mm and (6.7 ± 0.1) mm at a distance of 2 mm and 10 mm below the nozzle of the plasma jet, respectively. We performed an Abel inversion in order to obtain the spatial distribution of HO2 that is presented along the symmetry axis of the effluent. Based on that localised density, which was (4.8 ± 0.6) ⋅ 1014 cm-3 at the maximum, we will discuss the importance of the plasma zone for the production of HO2

Differences in HIV Burden and Immune Activation within the Gut of HIV-Positive Patients Receiving Suppressive Antiretroviral Therapy

Background. The gut is a major reservoir for human immunodeficiency virus (HIV) in patients receiving antiretroviral therapy (ART). We hypothesized that distinct immune environments within the gut may support varying levels of HIV. Methods. In 8 HIV-1-positive adults who were receiving ART and had CD4+ T cell counts of >200 cells/µL and plasma viral loads of <40 copies/mL, levels of HIV and T cell activation were measured in blood samples and endoscopic biopsy specimens from the duodenum, ileum, ascending colon, and rectum. Results. HIV DNA and RNA levels per CD4+ T cell were higher in all 4 gut sites compared with those in the blood. HIV DNA levels increased from the duodenum to the rectum, whereas the median HIV RNA level peaked in the ileum. HIV DNA levels correlated positively with T cell activation markers in peripheral blood mononuclear cells (PBMCs) but negatively with T cell activation markers in the gut. Multiply spliced RNA was infrequently detected in gut, and ratios of unspliced RNA to DNA were lower in the colon and rectum than in PBMCs, which reflects paradoxically low HIV transcription, given the higher level of T cell activation in the gut. Conclusions. HIV DNA and RNA are both concentrated in the gut, but the inverse relationship between HIV DNA levels and T cell activation in the gut and the paradoxically low levels of HIV expression in the large bowel suggest that different processes drive HIV persistence in the blood and gut. Trial registration. ClinicalTrials.gov identifier: NCT00884793 (PLUS1

Performance of Ultra-Deep Pyrosequencing in Analysis of HIV-1 pol Gene Variation

INTRODUCTION: Ultra-deep pyrosequencing (UDPS) has been used to detect minority variants within HIV-1 populations. Some aspects of the quality and reproducibility of UDPS have been previously evaluated, but comprehensive studies are still needed. PRINCIPAL FINDING: In this study the UDPS technology (FLX platform) was evaluated by analyzing a 120 base pair fragment of the HIV-1 pol gene from plasma samples from two patients and artificial mixtures of molecular clones. UDPS was performed using an optimized experimental protocol and an in-house data cleaning strategy. Nine samples and mixtures were analyzed and the average number of reads per sample was 19,404 (range 8,858-26,846). The two patient plasma samples were analyzed twice and quantification of viral variants was found to be highly repeatable for variants representing >0.27% of the virus population, whereas some variants representing 0.11-0.27% were detected in only one of the two UDPS runs. Bland-Altman analysis showed that a repeated measurement would have a 95% likelihood to lie approximately within ±0.5 log(10) of the initial estimate. A similar level of agreement was observed for variant frequency estimates in forward vs. reverse sequencing direction, but here the agreement was higher for common variants than for rare variants. UDPS following PCR amplification with alternative primers indicated that some variants may be incorrectly quantified due to primer-related selective amplification. Finally, the in vitro recombination rate during PCR was evaluated using artificial mixtures of clones and was found to be low. The most abundant in vitro recombinant represented 0.25% of all UDPS reads. CONCLUSION: This study demonstrates that this UDPS protocol results in low experimental noise and high repeatability, which is relevant for future research and clinical use of the UDPS technology. The low rate of in vitro recombination suggests that this UDPS system can be used to study genetic variants and mutational linkage

Factors limiting the transmission of HIV mutations conferring drug resistance: fitness costs and genetic bottlenecks

Transmission of HIV strains with drug-resistance mutations (DRMs) causes public health problems in resource-rich countries. We use a stochastic model, with data from viral competition experiments, to analyze the effect of fitness costs (FCs) and genetic bottlenecks on limiting transmission of 10 clinically significant DRMs. Transmission of DRMs with low FCs (∼0.2%) is similar to wild-type; transmission chains last ∼8 generations causing clusters of ∼60 infected individuals. Genetic bottlenecks substantially limit transmission of DRMs with moderately high FCs (∼0.6%); chains last ∼1–3 generations with transmission clusters of 2–7. Transmission of DRMs with extremely high FCs (>6%) only occurs from ∼5% of index cases. DRMs can revert to wild-type and remain as minority strains, within treatment-naïve individuals, undetectable by current resistance assays. We calculate, based on assay sensitivity, the length of time each DRM is detectable within individuals. Taken together, our results imply a hidden epidemic of transmitted resistance may exist

Protective Human Leucocyte Antigen Haplotype, HLA-DRB1*01-B*14, against Chronic Chagas Disease in Bolivia

Chronic Chagas disease consists of four different forms categorized on the basis of their clinical manifestations, namely; cardiac, digestive, cardiodigestive and indeterminate. In Latin America, there are 8–10 million seropositive persons who are at risk of, or have already developed serious clinical complications and who have limited access to effective treatment. The cardiac and digestive forms are characterized by tissue damage caused by persistent infection of Trypanosoma cruzi and are thought to be modulated by host immunity. In our large scale screening for chronic Chagas disease in Santa Cruz, Bolivia, hearts and colons of 229 seropositive patients were examined. We found 31.4% of patients had abnormal electrocardiograms (ECGs), 15.7% presented with megacolon, 5.2% had a combination of abnormal ECG and megacolon, and 58.1% were of indeterminate status. Previously, we attempted to ascertain whether parasite genetic polymorphism might account for the differences in clinical manefestations, by analyzing parasite DNA taken from the same study group (with the addition of a further 62 megacolon post-operational patients). We found no relationships between parasite lineages and clinical disease form. The present study reveals that host HLA polymorphisms associate with clinical manifestations of Chagas

Standing genetic variation and the evolution of drug resistance in HIV

Drug resistance remains a major problem for the treatment of HIV. Resistance can occur due to mutations that were present before treatment starts or due to mutations that occur during treatment. The relative importance of these two sources is unknown. We study three different situations in which HIV drug resistance may evolve: starting triple-drug therapy, treatment with a single dose of nevirapine and interruption of treatment. For each of these three cases good data are available from literature, which allows us to estimate the probability that resistance evolves from standing genetic variation. Depending on the treatment we find probabilities of the evolution of drug resistance due to standing genetic variation between 0 and 39%. For patients who start triple-drug combination therapy, we find that drug resistance evolves from standing genetic variation in approximately 6% of the patients. We use a population-dynamic and population-genetic model to understand the observations and to estimate important evolutionary parameters. We find that both, the effective population size of the virus before treatment, and the fitness of the resistant mutant during treatment, are key-parameters that determine the probability that resistance evolves from standing genetic variation. Importantly, clinical data indicate that both of these parameters can be manipulated by the kind of treatment that is used.Comment: 33 pages 6 figure