Quantifying the infectiousness of post-kala-azar dermal leishmaniasis towards sandflies

Background In the Indian subcontinent, visceral leishmaniasis (VL) incidence is on track to reach elimination goals by 2020 in nearly all endemic districts. Although not included in official targets, previous data suggest post-kala-azar dermal leishmaniasis (PKDL) patients can act as an infection reservoir. Methods We conducted xenodiagnosis on 47 PKDL patients and 15 VL patients using laboratory-reared Phlebotomus argentipes. In direct xenodiagnosis, flies were allowed to feed on the patient’s skin for 15 minutes. For indirect xenodiagnosis, flies were fed through a membrane on the patient’s blood. Five days later, blood-fed flies were dissected and examined by microscopy and/or PCR. A 3-mm skin snip biopsy (PKDL) or venous blood VL) was processed by quantitative PCR. Results Twenty-seven PKDL patients (57.4%) had positive results by direct and/or indirect xenodiagnosis. Direct was significantly more sensitive than indirect xenodiagnosis (55.3% vs 6.4%, p 1 log10 unit higher than those with negative results (2.88 vs 1.66, p<0.0001). In a multivariable model, parasite load, nodular lesions and positive skin microscopy were significantly associated with positive xenodiagnosis. Blood parasite load was the strongest predictor for VL. Compared to VL, nodular PKDL was more likely and macular PKDL less likely to result in positive xenodiagnosis, but neither difference reached statistical significance. Conclusions Nodular and macular PKDL, and VL, can be infectious to sand flies. Active PKDL case detection and prompt treatment should be instituted and maintained as an integral part of VL control and elimination programs

Implications of asymptomatic infection for the natural history of selected parasitic tropical diseases

Progress has been made in the control or elimination of tropical diseases, with a significant reduction of incidence. However, there is a risk of re-emergence if the factors fueling transmission are not dealt with. Although it is essential to understand these underlying factors for each disease, asymptomatic carriers are a common element that may promote resurgence; their impact in terms of proportion in the population and role in transmission needs to be determined. In this paper, we review the current evidence on whether or not to treat asymptomatic carriers given the relevance of their role in the transmission of a specific disease, the efficacy and toxicity of existing drugs, the Public Health interest, and the benefit at an individual level, for example, in Chagas disease, to prevent irreversible organ damage. In the absence of other control tools such as vaccines, there is a need for safer drugs with good risk/benefit profiles in order to change the paradigm so that it addresses the complete infectious process beyond manifest disease to include treatment of non-symptomatic infected persons

New regimens of benznidazole monotherapy and in combination with fosravuconazole for treatment of Chagas disease (BENDITA): a phase 2, double-blind, randomised trial

Background: Current treatment for Chagas disease with the only available drugs, benznidazole or nifurtimox, has substantial limitations, including long treatment duration and safety and tolerability concerns. We aimed to evaluate the efficacy and safety of new benznidazole monotherapy regimens and combinations with fosravuconazole, in the treatment of Chagas disease. Methods: We did a double-blind, double-dummy, phase 2, multicentre, randomised trial in three outpatient units in Bolivia. Adults aged 18–50 years with chronic indeterminate Chagas disease, confirmed by serological testing and positive qualitative PCR results, were randomly assigned (1:1:1:1:1:1:1) to one of seven treatment groups using a balanced block randomisation scheme with an interactive response system. Participants were assigned to benznidazole 300 mg daily for 8 weeks, 4 weeks, or 2 weeks, benznidazole 150 mg daily for 4 weeks, benznidazole 150 mg daily for 4 weeks plus fosravuconazole, benznidazole 300 mg once per week for 8 weeks plus fosravuconazole, or placebo, with a 12-month follow-up period. The primary endpoints were sustained parasitological clearance at 6 months, defined as persistent negative qualitative PCR results from end of treatment, and incidence and severity of treatment-emergent adverse events, serious adverse events, and adverse events leading to treatment discontinuation. Primary efficacy analysis was based on the intention-to-treat and per-protocol populations and secondary efficacy analyses on the per-protocol population. Safety analyses were based on the as-treated population. Recruitment is now closed. This trial is registered with ClinicalTrials.gov, NCT03378661. Findings: Between Nov 30, 2016, and July 27, 2017, we screened 518 patients, and 210 were enrolled and randomised. 30 patients (14%) were assigned to each treatment group. All 210 randomised patients were included in the intention-to-treat population, and 190 (90%) were included in the per-protocol population. In the intention-to-treat analysis, only one (3%) of 30 patients in the placebo group had sustained parasitological clearance at 6 months of follow-up. Sustained parasitological clearance at 6 months was observed in 25 (89%) of 28 patients receiving benznidazole 300 mg daily for 8 weeks (rate difference vs placebo 86% [95% CI 73–99]), 25 (89%) of 28 receiving benznidazole 300 mg daily for 4 weeks (86% [73–99]), 24 (83%) of 29 receiving benznidazole 300 mg daily for 2 weeks (79% [64–95]), 25 (83%) of 30 receiving benznidazole 150 mg daily for 4 weeks (80% [65–95]), 23 (85%) of 28 receiving benznidazole 150 mg daily for 4 weeks plus fosravuconazole (82% [67–97]), and 24 (83%) of 29 receiving benznidazole 300 mg weekly for 8 weeks plus fosravuconazole (79% [64–95]; p<0·0001 for all group comparisons with placebo). Six patients (3%) had ten serious adverse events (leukopenia [n=3], neutropenia [n=2], pyrexia, maculopapular rash, acute cholecystitis, biliary polyp, and breast cancer), eight had 12 severe adverse events (defined as interfering substantially with the patient's usual functions; elevated alanine aminotransferase [n=4], elevated gamma-glutamyltransferase [n=2], elevated aspartate aminotransferase [n=1], neutropenia [n=3], leukopenia [n=1], and breast cancer [n=1]), and 15 (7%) had adverse events that led to treatment discontinuation (most of these were in the groups who received benznidazole 300 mg daily for 8 weeks, benznidazole 300 mg once per week for 8 weeks plus fosravuconazole, and benznidazole 150 mg daily for 4 weeks plus fosravuconazole). No adverse events leading to treatment discontinuation were observed in patients treated with benznidazole 300 mg daily for 2 weeks or placebo. There were no treatment-related deaths. Interpretation: Benznidazole induced effective antiparasitic response, regardless of treatment duration, dose, or combination with fosravuconazole, and was well tolerated in adult patients with chronic Chagas disease. Shorter or reduced regimens of benznidazole could substantially improve treatment tolerability and accessibility, but further studies are needed to confirm these results. Funding: Drugs for Neglected Diseases initiative (DNDi). Translation: For the Spanish translation of the abstract see Supplementary Materials section.Fil: Torrico, Faustino. Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente; Bolivia. Universidad Mayor de San Simón; BoliviaFil: Gascón, Joaquim. Instituto de Salud Global de Barcelona; España. Universidad de Barcelona; EspañaFil: Barreira, Fabiana. DNDi Latin America; BrasilFil: Blum, Bethania. DNDi Latin America; BrasilFil: Almeida, Igor C. University of Texas at El Paso; Estados UnidosFil: Alonso Vega, Cristina. DNDi Latin America; Brasil. Instituto de Salud Global de Barcelona; EspañaFil: Barboza, Tayná. DNDi Latin America; BrasilFil: Bilbe, Graeme. Drugs For Neglected Diseases Initiative; SuizaFil: Correia, Erika. DNDi Latin America; BrasilFil: Garcia, Wilson. Universidad Mayor de San Simón; Bolivia. Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente ; BoliviaFil: Ortiz, Lourdes. Universidad Autónoma Juan Misael Saracho; Bolivia. Fundación Ciencia y Estudios Aplicados para el Desarrollo en Salud y Medio Ambiente; BoliviaFil: Parrado, Rudy. Universidad Mayor de San Simón; BoliviaFil: Ramirez Gomez, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán". Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben"; ArgentinaFil: Ribeiro, Isabela. Drugs For Neglected Diseases Initiative; SuizaFil: Strub Wourgaft, Nathalie. Drugs For Neglected Diseases Initiative; SuizaFil: Vaillant, Michel. Luxembourg Institute Of Health; LuxemburgoFil: Sosa-Estani, Sergio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentina. DNDi Latin America; Brasi

Molecular studies on the gaba-benzodiazepine receptor

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Mammalian splicing factor SF3a120 represents a new member of the SURP family of proteins and is homologous to the essential splicing factor PRP21p of <i>Saccharomyces cerevisiae</i>

Mammalian splicing factor SF3a consists of three subunits of 60, 66, and 120 kDa and functions early during pre-mRNA splicing by converting the U2 snRNP into its active form. A cDNA encoding the 120-kDa subunit of SF3a has been cloned. The SF3a120 gene was localized to human chromosome 22, and three mRNAs of 3.2, 3.8, and 5.7 kb are ubiquitously expressed. The N-terminal half of the deduced SF3a120 amino acid sequence contains a tandemly repeated motif (the SURP module) that has recently been identified in the essential splicing factor PRP21p of Saccharomyces cerevisiae, the Drosophila alternative splicing regulator suppressor-of-white-apricot, and four proteins from nematodes and mammals; the C-terminal half is organized into a proline-rich region and a ubiquitin-like domain. The spacing between the SURP modules and the protein's essential function in constitutive splicing identify SF3a120 as the mammalian homologue of yeast PRP21p. Binding studies with truncated derivatives of SF3a120 revealed that the SURP domains function in binding to SF3a60, whereas a region of 130 amino acids C-terminal to these domains is essential for contacts with SF3a66

Applications of a Rat Multiple Tissue Gene Expression Data Set

With the sequencing and assembly of the rat genome comes the difficult task of assigning functions to genes. Tissue localization of gene expression gives some information about the potential role of a gene in physiology. Various examples of the utility of multiple tissue gene expression data sets are illustrated here. First, we highlight their use in finding genes that might play an important role in a particular tissue on the basis of exclusive expression in that tissue or coexpression with a gene or genes with known function. Second, we show how this data might be used to explain known phenotypic differences between strains. Third, we show how expression patterns of genes in a genomic interval might identify candidate genes in quantitative trait loci (QTL) mapping studies. Lastly, we show how multiple tissue and species data can help researchers prioritize follow up studies to microarray experiments. All of these applications of multiple tissue gene expression data sets will play a role in functionally annotating the rat genome

AFQ056/Mavoglurant a novel clinically effective mGluR5 antagonist: Identification, SAR and pharmacological characterization.

Here we describe the identification, structure-activity relationship and the initial pharmacological characterization of AFQ056/mavoglurant, a structurally novel, non-competitive mGlu5 receptor antagonist. AFQ056/mavoglurant was identified by chemical derivatization of a lead compound discovered in a HTS campaign. In vitro, AFQ056/mavoglurant had an IC50 of 30 nM in a functional assay with human mGluR5 and was selective over the other mGluR subtypes, iGluRs and a panel of 238 CNS relevant receptors, transporter or enzymes. In vivo, AFQ056/mavoglurant showed an improved pharmacokinetic profile in rat and efficacy in the stress-induced hyperthermia test in mice as compared to the prototypic mGluR5 antagonist MPEP. The efficacy of AFQ056/mavoglurant in humans has been assessed in L-dopa induced dyskinesia in Parkinson’s disease and Fragile X syndrome in proof of principle clinical studies

Global down-regulation of gene expression in the brain using RNA interference, with emphasis on monoamine transporters and GPCRs: implications for target characterization in psychiatric and neurological disorders.

RNA interference (RNAi) is a natural mechanism for regulating gene expression, which exists in plants, invertebrates, and mammals. We investigated whether non-viral infusion of short interfering RNA (siRNA) by the intracerebroventricular route would enable a sequence-specific gene knockdown in the mouse brain and whether the knockdown translates into disease-relevant behavioral changes. Initially, we targeted enhanced green fluorescent protein (EGFP) in mice overexpressing EGFP. A selective knockdown of both EGFP protein and mRNA was observed throughout the brain, with lesser down-regulation in regions distal to the infusion site. We then targeted endogenous genes, encoding the dopamine (DAT) and serotonin transporters (SERT). DAT-siRNA infusion in adult mice produced a significant down-regulation of DAT mRNA and protein and elicited hyperlocomotion similar, but delayed, to that produced on infusion of GBR-12909, a potent and selective DAT inhibitor. Similarly, SERT-siRNA infusion resulted in significant knockdown of SERT mRNA and protein and elicited reduced immobility in the forced swim test similar to that obtained on infusion of citalopram, a very selective and potent SSRI. Application of this non-viral RNAi approach may accelerate target validation for neuropsychiatric disorders that involve a complex interplay of gene(s) from various brain regions

Optimization of an HTRF Assay for the Detection of Soluble Mutant Huntingtin in Human Buffy Coats: A Potential Biomarker in Blood for Huntington Disease

A means for measuring levels of soluble huntingtin proteins in clinical samples is essential for assessing the biological effects of potential mutant huntingtin (mtHtt) modifying treatments being developed for Huntington’s disease (HD). We have optimized a previously described cell-based Homogeneous Time Resolved Fluorescence method that can measure soluble mtHtt and its ratio to the total Htt (tHtt) in blood buffy coats [1]. The results of the optimization and assay qualification indicate the assay to be specific for mtHtt in HD compared to Control subjects, highly sensitive, and technically and biologically reproducible. We therefore generated a Good Laboratory Practice Standard Operating Procedure which we validated, using 30 HD and 8 control buffy coat samples in which significant differences in mtHtt levels were found. We intend to deploy the assay to evaluate sample sets from observational and therapeutic studies enrolling HD subjects to further validate soluble mtHtt measurement by HTRF as a biomarker for HD and to explore its potential uses

CpG ODN D35 improves the response to abbreviated low-dose pentavalent antimonial treatment in non-human primate model of cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) affects the lives of 0.7-1 million people every year causing lesions that take months to heal. These lesions can result in disfiguring scars with psychological, social and economic consequences. Antimonials are the first line of therapy for CL, however the treatment is lengthy and linked to significant toxicities; further, its efficacy is variable and resistant parasites are emerging. Shorter or lower dose antimonial treatment regimens, which would decrease the risk of adverse events and improve patient compliance, have shown reduced efficacy and further increase the risk emergence of antimonial-resistant strains. The progression of lesions in CL is partly determined by the immune response it elicits, and previous studies showed that administration of immunomodulatory type D CpG ODNs, magnifies the immune response to Leishmania and reduces lesion severity in nonhuman primates (NHP) challenged with Leishmania major or Leishmania amazonensis. Here we explored whether the addition of a single dose of immunomodulating CpG ODN D35 augments the efficacy of a short-course, low-dose pentavalent antimonial treatment regimen. Results show that macaques treated with D35 plus 5mg/kg sodium stibogluconate (SbV) for 10 days had smaller lesions and reduced time to re-epithelization after infection with Leishmania major. No toxicities were evident during the studies, even at doses of D35 10 times higher than those used in treatment. Critically, pentavalent antimonial treatment did not modify the ability of D35 to induce type I IFNs. The findings support the efficacy of D35 as adjuvant therapy for shorter, low dose pentavalent antimonial treatment