Search results for "INFECTIOUS"
showing 10 items of 2953 documents
Evaluation of Immunofluorescence Antibody Test Used for the Diagnosis of Canine Leishmaniasis in the Mediterranean Basin: A Systematic Review and Met…
2015
With an expected sensitivity (Se) of 96% and specificity (Sp) of 98%, the immunofluorescence antibody test (IFAT) is frequently used as a reference test to validate new diagnostic methods and estimate the canine leihmaniasis (CanL) true prevalence in the Mediterranean basin. To review the diagnostic accuracy of IFAT to diagnose CanL in this area with reference to its Se and Sp and elucidate the potential causes of their variations, a systematic review was conducted (31 studies for the 26-year period). Three IFAT validation methods stood out: the classical contingency table method, methods based on statistical models and those based on experimental studies. A variation in the IFAT Se and Sp …
Reduced prevalence of soil-transmitted helminths and high frequency of protozoan infections in the surrounding urban area of Curitiba, Paraná, Brazil
2019
Human populations living in the surrounding urban areas of large Brazilian cities have increased vulnerability to intestinal parasites. However, the epidemiological scenario of soil-transmitted helminths (STH) in Curitiba, Paraná's main city, remains largely unknown. To bridge this gap of knowledge, this study aims to determine the prevalence of intestinal parasites and to investigate potential transmission pathways of the most prevalent species detected. We conducted a cross-sectional epidemiological study between July and September 2014 among schoolchildren in urban and peri-urban (deprived) areas of the municipality of Campo do Tenente, Curitiba. A total of 549 stool samples were used fo…
Effect of Buthionine Sulfoximine on the Sensitivity to Doxorubicin of Parent and MDR Tumor Cell Lines
1994
We have studied the interaction of glutathione-depleting concentrations of buthionine sulfoximine (BSO) with the anti-proliferative activity of doxorubicin (DXR) in three tumor lines, the mouse B16 melanoma. Friend erythroleukemia and the human K562 leukemia, both as DXR-sensitive and-resistant (with typical multidrug resistance) variants. BSO significantly enhanced the DXR effects in the wild-type Friend and K562 leukemias, and especially in the drug-resistant subline of Friend leukemia. BSO did not modify DXR accumulation and retention in the latter clone. Moreover, neither BSO nor verapamil used alone completely reversed the resistance to DXR of this cell line; their combination was more…
Repurposing old drugs to fight multidrug resistant cancers.
2020
Overcoming multidrug resistance represents a major challenge for cancer treatment. In the search for new chemotherapeutics to treat malignant diseases, drug repurposing gained a tremendous interest during the past years. Repositioning candidates have often emerged through several stages of clinical drug development, and may even be marketed, thus attracting the attention and interest of pharmaceutical companies as well as regulatory agencies. Typically, drug repositioning has been serendipitous, using undesired side effects of small molecule drugs to exploit new disease indications. As bioinformatics gain increasing popularity as an integral component of drug discovery, more rational approa…
Chromatin organization regulates viral egress dynamics.
2017
Various types of DNA viruses are known to elicit the formation of a large nuclear viral replication compartment and marginalization of the cell chromatin. We used three-dimensional soft x-ray tomography, confocal and electron microscopy, combined with numerical modelling of capsid diffusion to analyse the molecular organization of chromatin in herpes simplex virus 1 infection and its effect on the transport of progeny viral capsids to the nuclear envelope. Our data showed that the formation of the viral replication compartment at late infection resulted in the enrichment of heterochromatin in the nuclear periphery accompanied by the compaction of chromatin. Random walk modelling of herpes s…
Impaired Kupffer Cell Self-Renewal Alters the Liver Response to Lipid Overload during Non-alcoholic Steatohepatitis
2020
International audience; Kupffer cells (KCs) are liver-resident macrophages that self-renew by proliferation in the adult independently from monocytes. However, how they are maintained during non-alcoholic steatohepatitis (NASH) remains ill defined. We found that a fraction of KCs derived from Ly-6C+ monocytes during NASH, underlying impaired KC self-renewal. Monocyte-derived KCs (MoKCs) gradually seeded the KC pool as disease progressed in a response to embryo-derived KC (EmKC) death. Those MoKCs were partly immature and exhibited a pro-inflammatory status compared to EmKCs. Yet, they engrafted the KC pool for the long term as they remained following disease regression while acquiring matur…
Enzymatic Activity of HPGD in Treg Cells Suppresses Tconv Cells to Maintain Adipose Tissue Homeostasis and Prevent Metabolic Dysfunction.
2019
Summary Regulatory T cells (Treg cells) are important for preventing autoimmunity and maintaining tissue homeostasis, but whether Treg cells can adopt tissue- or immune-context-specific suppressive mechanisms is unclear. Here, we found that the enzyme hydroxyprostaglandin dehydrogenase (HPGD), which catabolizes prostaglandin E2 (PGE2) into the metabolite 15-keto PGE2, was highly expressed in Treg cells, particularly those in visceral adipose tissue (VAT). Nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ)-induced HPGD expression in VAT Treg cells, and consequential Treg-cell-mediated generation of 15-keto PGE2 suppressed conventional T cell activation and proliferation. C…
Herpes simplex virus 1 induces egress channels through marginalized host chromatin
2016
AbstractLytic infection with herpes simplex virus type 1 (HSV-1) induces profound modification of the cell nucleus including formation of a viral replication compartment and chromatin marginalization into the nuclear periphery. We used three-dimensional soft X-ray tomography, combined with cryogenic fluorescence, confocal and electron microscopy, to analyse the transformation of peripheral chromatin during HSV-1 infection. Our data showed an increased presence of low-density gaps in the marginalized chromatin at late infection. Advanced data analysis indicated the formation of virus-nucleocapsid-sized (or wider) channels extending through the compacted chromatin of the host. Importantly, co…
Comprehensive Screening for Naturally Occurring Hepatitis C Virus Resistance to Direct-Acting Antivirals in the NS3, NS5A, and NS5B Genes in Worldwid…
2015
ABSTRACTThere is no comprehensive study available on the natural hepatitis C virus (HCV) polymorphism in sites associated with resistance including all viral genotypes which may present variable susceptibilities to particular direct-acting antivirals (DAAs). This study aimed to analyze the frequencies, genetic barriers, and evolutionary histories of naturally occurring resistance-associated variants (RAVs) in the six main HCV genotypes. A comprehensive analysis of up to 103 RAVs was performed in 2,901, 2,216, and 1,344 HCV isolates for the NS3, NS5A, and NS5B genes, respectively. We report significant intergenotypic differences in the frequencies of natural RAVs for these three HCV genes. I…
A retrospective study of the characterization of Rickettsia species in ticks collected from humans
2017
Rickettsiae (family Rickettsiaceae, order Rickettsiales) are obligate intracellular bacteria transmitted by arthropod vectors. Several Rickettsia species causing vector-borne rickettsioses belong to the spotted fever group (SFG). Traditionally, Rickettsia conorii has been considered as the main etiologic agent of Mediterranean spotted fever. However, the molecular characterization of rickettsiae allowed identifying other species involved in spotted fever in the Mediterranean region. In this study, 42 ticks collected from humans were subjected to morphological identification and molecular characterization of Rickettsia species potentially involved in human rickettsiosis in Sicily. Fourteen t…