Search results for "Chain reaction"
showing 10 items of 1862 documents
Kinetics and Topology of DNA Associated with Circulating Extracellular Vesicles Released during Exercise.
2021
AbstractAlthough it is widely accepted that cancer derived extracellular vesicles (EVs) carry DNA cargo, the association of cell-free circulating DNA (cfDNA) and EVs in plasma of healthy humans remains elusive. Using a physiological exercise model, where EVs and cfDNA are synchronously released, we aimed to characterize the kinetics and localization of DNA associated with EVs. EVs were separated from human plasma using size exclusion chromatography or immuno-affinity capture for CD9+, CD63+, and CD81+ EVs. DNA was quantified with an ultra-sensitive qPCR assay targeting repetitive LINE elements, with or without DNase digestion. This model shows that a minute part of circulating cell-free DNA…
Epigenetic differences arise during the lifetime of monozygotic twins.
2005
Monozygous twins share a common genotype. However, most monozygotic twin pairs are not identical; several types of phenotypic discordance may be observed, such as differences in susceptibilities to disease and a wide range of anthropomorphic features. There are several possible explanations for these observations, but one is the existence of epigenetic differences. To address this issue, we examined the global and locus-specific differences in DNA methylation and histone acetylation of a large cohort of monozygotic twins. We found that, although twins are epigenetically indistinguishable during the early years of life, older monozygous twins exhibited remarkable differences in their overall…
Clinical features and epidemiology of cutaneous leishmaniasis and Leishmania major/HIV co-infection in Cameroon: results of a large cross-sectional s…
2011
Cutaneous leishmaniasis (CL) is endemic in Central Africa, including Cameroon. However, data on its prevalence and co-infection with HIV are scarce. Here we present the results of a large cross-sectional study reporting the prevalence, clinical features and species identification of CL and HIV co-infection in northern Cameroon. A total of 32 466 subjects were clinically screened for CL during a door-to-door survey, followed by parasitological diagnosis in the field laboratory. Amongst the subjects surveyed, 146 (0.4%) were diagnosed with active CL. Seven (4.8%) of these 146 CL patients tested positive for HIV-1 and/or HIV-2. The number of lesions per CL patient ranged from 1 to 20. Three of…
Early onset of polyglandular failure is associated with HLA-DRB1*03.
2008
ObjectivesPolyglandular failure or autoimmunity (PGA) involves at least two endocrine diseases. Several genes may play a role in its etiology. This study analyzed 1) whether HLA-DRB1, HLA-DQB1, and MHC class I chain-related gene A (MICA) polymorphisms are associated in PGA and 2) whether PGA patients display stronger associations with these immune genes than patients with monoglandular autoimmunity (MGA).DesignAssociation study.MethodsHLA-DRB1, HLA-DQB1, and MICA alleles were analyzed in 73 patients with PGA, 283 with MGA, and 206 healthy controls. The HLA-DRB1 and HLA-DQB1 polymorphisms were determined with PCR-amplified DNA being hybridized with PCR-sequence-specific oligonucleotide probe…
Effectiveness of the 2010–2011 seasonal influenza vaccine in preventing confirmed influenza hospitalizations in adults: A case–case comparison, case-…
2012
Highlights ► We perform a case–case comparison as an improvement of the test-negative design. ► We report IVE estimates with a low probability of bias. ► Influenza vaccination halved the risk of confirmed influenza hospitalization. ► This effect was consistent regardless of age over 60. ► The measured effect was specific for confirmed influenza hospitalizations.
Amplification of human β-glucoronidase gene for appraising the accuracy of negative SARS-CoV-2 RT-PCR results in upper respiratory tract specimens
2020
Real-time reverse transcription polymerase-chain reaction (RT-PCR) is the mainstay of Covid-19 diagnosis. False-negative RT-PCR results may hamper clinical management of patients and hinder the adoption of epidemiological measures to control the pandemic. The current study was aimed at assessing whether amplification of β-glucoronidase (GUSB) gene would help estimate the accuracy of SARS-CoV-2 RT-PCR negative results in upper respiratory tract (URT) specimens. URT specimens that tested negative by SARS-CoV-2 RT-PCR displayed higher GUSB RT-PCR cycle thresholds (CT) (P=0.070) than those testing positive (median, 30.7; range, 27.0-40.0, and median 29.7; range 25.5-36.8, respectively), this re…
Aetiology and epidemiology of viral gastroenteritis outbreaks in Catalonia (Spain) in 2004-2005.
2007
Abstract Background Acute infectious gastroenteritis causes substantial morbidity and economic loss. Objective The aetiology, epidemiology, and clinical features of acute viral gastroenteritis outbreaks reported during 1 year in Catalonia were investigated. Study Design This was a population-based study in which enzyme immunoassay and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques were used to determine the presence of virus in stool specimens from outbreaks clinically and epidemiologically compatible with a viral aetiology and negative for bacteria, parasites and toxins. Results Sixty outbreaks affecting 1791 people were evaluated. Fifty-five outbreaks were positive fo…
HPV DNA in clinically different variants of oral leukoplakia and lichen planus
2004
Abstract Objectives Our objectives were to determine the prevalence of human papillomavirus (HPV) infection in oral leukoplakia (OL) and oral lichen planus (OLP) in comparison with that in healthy oral mucosa, also conditionally to age, gender, smoking, and drinking habits of patients, so as to investigate any possible association of HPV infection with a specific clinical variant of OL or OLP. Study design We did research on HPV DNA in 68 cases of OL (homogeneous form [H] in 45 cases and nonhomogeneous form [non-H] in 23 cases), and in 71 cases of OLP (nonatrophic/erosive form [non-AE] in 27 cases, atrophic/erosive form [AE] in 44 cases). HPV DNA was investigated in exfoliated oral mucosa c…
Evidence for association between structural variants in lissencephaly-related genes and executive deficits in schizophrenia or bipolar patients from …
2008
There is evidence for an association between structural variants in genes for lissencephaly, which are involved in neuronal migration, and prefrontal cognitive deficits in schizophrenia and bipolar patients. On the basis of these intriguing findings, we analyzed 16 markers located in the lissencephaly critical region (LCR in chromosome 17p13.3) in 124 schizophrenic, 56 bipolar, and 141 healthy individuals. All recruits were from a Spanish population isolate of Basque origin that is characterized by low genetic heterogeneity. In addition, we examined whether structural genomic variations in the LCR were associated with executive cognition. Twenty-three patients (12.8%), but none of the contr…
Enhanced reduction in oxidative stress and altered glutathione and thioredoxin system response to unsaturated fatty acid load in familial hypercholes…
2014
Abstract Objectives Familial hypercholesterolemia (FH) is characterized by increased oxidative stress (OS) levels. In the postprandial state, lipids and lipoproteins modulate OS status through their impact on pro-oxidant and antioxidant mechanisms. The objective of this study was to evaluate in patients with FH the response to an unsaturated oral fat load test (OFLT) by analyzing the mRNA levels of genes involved in the glutathione and thioredoxin antioxidant systems. Design and Methods We analyzed 14 FH patients and 20 normolipidemic and normoglycemic controls. In both groups, mRNA values of antioxidant enzyme genes (glutathione and thioredoxin systems) were determined at baseline and at 2…