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Find video protocols related to scientific articles indexed in Pubmed.
Drug resistance in the HIV-1-infected paediatric population worldwide: a systematic review.
J. Antimicrob. Chemother.
PUBLISHED: 04-30-2014
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Drug resistance monitoring of the paediatric HIV-1-infected population is required to optimize treatment success and preserve future treatment options.
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New findings in cleavage sites variability across groups, subtypes and recombinants of human immunodeficiency virus type 1.
PLoS ONE
PUBLISHED: 01-01-2014
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Polymorphisms at cleavage sites (CS) can influence Gag and Pol proteins processing by the viral protease (PR), restore viral fitness and influence the virological outcome of specific antiretroviral drugs. However, data of HIV-1 variant-associated CS variability is scarce.
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Different trends of transmitted HIV-1 drug resistance in Madrid, Spain, among risk groups in the last decade.
Arch. Virol.
PUBLISHED: 06-05-2013
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The presence of transmitted HIV drug resistance (TDR) threatens the efficacy of antiretroviral treatment. We aimed to assess the changes in TDR prevalence over the last decade in Madrid, Spain, to verify the role of the patients risk groups in these changes. We analysed the trends of TDR between 2000 and 2011 in a cohort of 1,022 naïve HIV-infected patients in Madrid, Spain, whose pol sequences were available. They included, among others, 369 heterosexuals, 340 men who have sex with men (MSM), and 90 injection drug users (IDUs). TDR was reported following the WHO mutation list. The TDR rate in the whole cohort was 8.3 %, being the highest in MSM (9.1 %) and the lowest in IDUs (4.4 %). Over time, this rate decreased significantly (to 5.4 % in 2009-2011) since the period 2004-2006, when it peaked (10.7 %). Heterosexuals and IDUs showed similar trends, but in the 2009-2011 period, the TDR rate among MSM rebounded to 9.0 % (being absent among IDUs). TDR stabilized in the last years (2007-2011) for nucleoside reverse transcriptase inhibitors. The risk group also determined differences in the mutational profile, sex distribution, proportion of immigrants, and viral variants. In conclusion, the risk group caused different HIV sub-epidemics, determined by the patients profiles. Despite the general decreasing trend in TDR, we observed a non-significant increase in TDR rate among MSM, a tendency that needs confirmation. Periodic TDR surveillance is important to prevent the widespread distribution of resistance, especially in MSM, given the growing HIV/AIDS epidemic in this high-risk population.
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Dried blood as an alternative to plasma or serum for Trypanosoma cruzi IgG detection in screening programs.
Clin. Vaccine Immunol.
PUBLISHED: 06-05-2013
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Trypanosoma cruzi serological screening is recommended for people potentially exposed to this parasite in countries where Trypanosoma cruzi is endemic and those where it is not endemic. Blood samples on filter paper may be a practical alternative to plasma/serum for antibody detection. Using the Architect Chagas assay, we detected the presence of IgG against T. cruzi in matched serum and dried blood spots (DBS) collected from 147 patients residing in Madrid, Spain, who had potential previous exposure to T. cruzi. The ? statistic for the DBS/serum proportion of agreement for the detection of antibodies against T. cruzi was 0.803, considering an S/CO (assay result unit; chemiluminescent signal from the sample [S] divided by the mean chemiluminescent signal for the three calibrators used in the test [CO]) cutoff value of ?1.00. The relative sensitivity of the Architect test using DBS increased from 95.2% to 98.8% when the cutoff was lowered from ?1.00 to ?0.88, while the relative specificity decreased from 84.1% to 71.6%. Overall, the median S/CO values for DBS were significantly lower than those for serum (2.6 versus 6.5; P < 0.001). Discrepancies that occurred with the use of DBS included 10 false positives (with low S/CO values in 9 cases [median, 2.13]) and 4 false negatives, with mean S/CO values of 0.905 (gray zone). Using DBS plus a highly sensitive and specific enzyme-linked immunosorbent assay (ELISA) may be a simple and reliable method for detecting IgG against T. cruzi when blood sampling by venipuncture is not feasible. This method may also reduce the false-negative rates observed with some rapid diagnostic tests. The lower relative sensitivity compared to the reference method may be increased by lowering the optical density threshold.
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Prevalence of primary resistance mutations to integrase inhibitors in treatment-naïve and -experienced patients infected with B and non-B HIV-1 variants.
HIV Clin Trials
PUBLISHED: 02-02-2013
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Raltegravir (RAL) constitutes the first available integrase strand transfer inhibitor (INSTI) available in clinical practice. Three independent pathways have been described to confer resistance to RAL. Secondary mutations with little effect on INSTI susceptibility and additional substitutions with an uncertain role have also been described especially in HIV-1 non-B variants.
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Phylogenetic and demographic characterization of HIV-1 transmission in Madrid, Spain.
Infect. Genet. Evol.
PUBLISHED: 01-02-2013
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The combination of phylogenetic analyses of HIV sequences with patients demographic data allows us to understand local HIV transmission, a necessary knowledge for designing prevention strategies. The Community of Madrid represents a challenge for the control of HIV epidemic in Spain given its high HIV prevalence and increasing proportion of immigrant people among HIV-infected population.
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Reconstructing the timing and dispersion routes of HIV-1 subtype B epidemics in the Caribbean and Central America: a phylogenetic story.
PLoS ONE
PUBLISHED: 01-01-2013
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The Caribbean and Central America are among the regions with highest HIV-1B prevalence worldwide. Despite of this high virus burden, little is known about the timing and the migration patterns of HIV-1B in these regions. Migration is one of the major processes shaping the genetic structure of virus populations. Thus, reconstruction of epidemiological network may contribute to understand HIV-1B evolution and reduce virus prevalence. We have investigated the spatio-temporal dynamics of the HIV-1B epidemic in The Caribbean and Central America using 1,610 HIV-1B partial pol sequences from 13 Caribbean and 5 Central American countries. Timing of HIV-1B introduction and virus evolutionary rates, as well as the spatial genetic structure of the HIV-1B populations and the virus migration patterns were inferred. Results revealed that in The Caribbean and Central America most of the HIV-1B variability was generated since the 80 s. At odds with previous data suggesting that Haiti was the origin of the epidemic in The Caribbean, our reconstruction indicated that the virus could have been disseminated from Puerto Rico and Antigua. These two countries connected two distinguishable migration areas corresponding to the (mainly Spanish-colonized) Easter and (mainly British-colonized) Western islands, which indicates that virus migration patterns are determined by geographical barriers and by the movement of human populations among culturally related countries. Similar factors shaped the migration of HIV-1B in Central America. The HIV-1B population was significantly structured according to the country of origin, and the genetic diversity in each country was associated with the virus prevalence in both regions, which suggests that virus populations evolve mainly through genetic drift. Thus, our work contributes to the understanding of HIV-1B evolution and dispersion pattern in the Americas, and its relationship with the geography of the area and the movements of human populations.
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Description of HIV-1 group M molecular epidemiology and drug resistance prevalence in Equatorial Guinea from migrants in Spain.
PLoS ONE
PUBLISHED: 01-01-2013
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The HIV epidemic is increasing in Equatorial Guinea (GQ), West Central Africa, but few studies have reported its HIV molecular epidemiology. We aimed to describe the HIV-1 group M (HIV-1M) variants and drug-resistance mutations in GQ using sequences sampled in this country and in Spain, a frequent destination of Equatoguinean migrants.
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Most HIV type 1 non-B infections in the Spanish cohort of antiretroviral treatment-naïve HIV-infected patients (CoRIS) are due to recombinant viruses.
J. Clin. Microbiol.
PUBLISHED: 12-07-2011
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HIV-1 group M is classified into 9 subtypes, as well as recombinants favored by coinfection and superinfection events with different variants. Although HIV-1 subtype B is predominant in Europe, intersubtype recombinants are increasing in prevalence and complexity. In this study, phylogenetic analyses of pol sequences were performed to detect the HIV-1 circulating and unique recombinant forms (CRFs and URFs, respectively) in a Spanish cohort of antiretroviral treatment-naïve HIV-infected patients included in the Research Network on HIV/AIDS (CoRIS). Bootscanning and other methods were used to define complex recombinants not assigned to any subtype or CRF. A total of 670 available HIV-1 pol sequences from different patients were collected, of which 588 (87.8%) were assigned to HIV-1 subtype B and 82 (12.2%) to HIV-1 non-B variants. Recombinants caused the majority (71.9%) of HIV-1 non-B infections and were found in 8.8% of CoRIS patients. Eleven URFs (accounting for 13.4% of HIV-1 non-B infections), presenting complex mosaic patterns, were detected. Among them, 10 harbored subtype B fragments. Four of the 11 URFs were found in Spanish natives. A cluster of three B/CRF02_AG recombinants was detected. We conclude that complex variants, including unique recombinant forms, are being introduced into Spain through both immigrants and natives. An increase in the frequency of mosaic viruses, reflecting the increasing heterogeneity of the HIV epidemic in our country, is expected.
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Drug resistance prevalence and HIV-1 variant characterization in the naive and pretreated HIV-1-infected paediatric population in Madrid, Spain.
J. Antimicrob. Chemother.
PUBLISHED: 08-02-2011
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Drug resistance mutations affect antiretroviral therapy (ART) effectiveness in HIV-1-infected children, compromising long-term therapy. HIV-1 variants and drug resistance mutations were identified in HIV-infected children from Madrid, Spain.
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Molecular surveillance of HIV-1 in Madrid, Spain: a phylogeographic analysis.
J. Virol.
PUBLISHED: 07-27-2011
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The molecular epidemiology of HIV-1 is constantly changing, mainly as a result of human migratory flows and the high adaptive ability of the virus. In recent years, Spain has become one of Europes main destinations for immigrants and one of the western European countries with the highest rates of HIV-positive patients. Using a phylogeographic approach, we have analyzed the relationship between HIV-1 variants detected in immigrant and native populations of the urban area of Madrid. Our project was based on two coincidental facts. First, resistance tests were extended to naïve and newly diagnosed patients, and second, the Spanish government legislated the provision of legal status to many immigrants. This allowed us to obtain a large data set (n = 2,792) from 11 Madrid hospitals of viral pol sequences from the two populations, and with this unique material, we explored the impact of immigration in the epidemiological trends of HIV-1 variants circulating in the largest Spanish city. The prevalence of infections by non-B HIV-1 variants in the studied cohort was 9%, rising to 25% among native Spanish patients. Multiple transmission events involving different lineages and subsubtypes were observed in all the subtypes and recombinant forms studied. Our results also revealed strong social clustering among the most recent immigrant groups, such as Russians and Romanians, but not in those groups who have lived in Madrid for many years. Additionally, we document for the first time the presence of CRF47_BF and CRF38_BF in Europe, and a new BG recombinant form found in Spaniards and Africans is tentatively proposed. These results suggest that the HIV-1 epidemic will evolve toward a more complex epidemiological landscape.
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Increase of transmitted drug resistance among HIV-infected sub-Saharan Africans residing in Spain in contrast to the native population.
PLoS ONE
PUBLISHED: 06-17-2011
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The prevalence of transmitted HIV drug resistance (TDR) is stabilizing or decreasing in developed countries. However, this trend is not specifically evaluated among immigrants from regions without well-implemented antiretroviral strategies.
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Drug resistance prevalence in human immunodeficiency virus type 1 infected pediatric populations in Honduras and El Salvador during 1989-2009.
Pediatr. Infect. Dis. J.
PUBLISHED: 02-18-2011
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Emergence of viral resistance is a major obstacle for antiretroviral treatment (ART) effectiveness. Human immunodeficiency virus type-1 (HIV-1) variants and drug-resistance mutations were identified in naive and antiretroviral drug-experienced children with virologic failure, in Honduras and El Salvador.
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Drastic decrease of transcription activity due to hypermutated long terminal repeat (LTR) region in different HIV-1 subtypes and recombinants.
Antiviral Res.
PUBLISHED: 03-30-2010
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Transcriptional activation of HIV-1 gene expression is partially controlled by the interaction between viral and cellular transcription factors acting at HIV-1 long terminal repeat (LTR) sequences. HIV-1 subtyping at LTR region and nucleotide LTR variability from clinical samples in 48 subjects carrying different HIV-1 subtypes (9A, 5C, 3D, 3F, 21G, 2H, 3J and 2 undefined) at the protease (PR) gene, were performed. LTR sequences from each HIV-1 clade were cloned in luciferase-expression vectors to determine basal and Tat-induced transcriptional activities in the presence and absence of PMA stimulation. A high number (37.8%) of recombinants at LTR/PR regions were identified. All HIV-1 promoters presented low basal transcriptional activity that was nevertheless induced by Tat and PMA. LTR activity was similar across the majority of HIV-1 variants in response to Tat and cell activation. Only subtype C and CRF01_AE LTRs presented higher basal and induced-PMA transcription activities than HXB2 clade B promoter. No basal or Tat/PMA induced activity was found in those promoters presenting G to A hypermutation compared to the wild type promoter activities. G to A hypermutation at some important transcription binding-factor sites within LTR compromised the activity of the viral promoter, decreasing the in vitro viral transcription of the luciferase gene.
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[Epidemiology of drug-resistant HIV-1 transmission in naïve patients in Spain].
Med Clin (Barc)
PUBLISHED: 08-04-2009
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HIV-1 drug-resistance transmission compromises the effectiveness of antiretroviral therapy. Thus, epidemiological studies of resistance in naïve patients acquire a major relevance for the first treatment design. However, their methodological heterogeneity complicates the comparison of results. The global transmitted primary resistance prevalence in Spain from 1997 through 2008 was 10.6%, similar to the rest of Europe. Regarding drug families, prevalence was 5.8% for NRTI, 5% for NNRTI and 3.8% for PI. In further studies, it should be considered: i) to homogenize resistance testing favouring genetic sequencing instead of other methods and to improve minority resistances detection; ii) to create a unique mutations list to be applied to all HIV-1 variants; iii) to be aware of the circulating subtypes and established therapy in the areas of infection that could determine the resistance pattern; and iv) to promote multicenter studies including representative and numerous populations.
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Performance of OraQuick Advance Rapid HIV-1/2 Antibody Test for detection of antibodies in oral fluid and serum/plasma in HIV-1+ subjects carrying different HIV-1 subtypes and recombinant variants.
J. Clin. Virol.
PUBLISHED: 04-15-2009
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Rapid, simple, low-cost, sensitive, and specific tests are needed to detect antibodies to all HIV-1 subtypes, especially in developing countries.
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Clinical differences and viral diversity between newly HIV type 1-diagnosed African and non-African patients in Spain (2005-2007).
AIDS Res. Hum. Retroviruses
PUBLISHED: 02-03-2009
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Abstract The diagnosis of HIV-1 is increasing in African-born persons residing in Europe. They present a high prevalence of HIV-1 non-B variant infections and of parasitic infections, both of which are infrequent in Western countries. Immigration favors their presence in nonendemic countries. In this study, all newly HIV-diagnosed individuals at an HIV/AIDS and Tropical Medicine reference center in Madrid from 2005 through 2007 were retrospectively studied. HIV-1 subtyping was performed in gag, pol, and gp41 coding regions by phylogenetic analyses. The presence of other pathogens was also evaluated. Furthermore, all HIV-1-infected Africans were screened for parasitic infections. Newly diagnosed HIV-1 subjects included 90 sub-Saharan Africans and 188 non-Africans (116 Spaniards, 13 other Europeans, and 59 Latin Americans). Significantly higher numbers of HIV-1-infected Africans than non-Africans were females, acquired HIV-1 by heterosexual contact, and presented a more advanced clinical CDC stage and criteria for starting antiretroviral therapy in the first clinical visit. They predominantly carried non-B subtype infections, mainly intersubtype recombinants. Half of HIV-1-infected Africans had parasitic infections. CD4(+) T cell counts were lower among Africans than Europeans at the time of HIV-1 diagnosis. At 12 months of follow-up after starting antiretroviral treatment, a significantly lower proportion of Africans than non-Africans achieved undetectable viremia due to their higher loss to follow-up. However, CD4(+) T cell recovery and virological failure rates were similar. Therefore, the profile of African HIV-1-infected immigrants varies widely with respect to Spanish HIV-infected individuals. More advanced immunodeficiency and the coexistence of parasitic diseases and infections with a large diversity of HIV-1 non-B and recombinant variants are expected.
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High drug resistance prevalence among vertically HIV-infected patients transferred from pediatric care to adult units in Spain.
PLoS ONE
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Antiretroviral treatment (ART) has contributed to increased life expectancy of HIV-1 infected children. In developed countries, an increasing number of children reaching adulthood are transferred to adult units. The objectives were to describe the demographic and clinical features, ART history, antiviral drug resistance and drug susceptibility in HIV-1 perinatally infected adolescents transferred to adult care units in Spain from the Madrid Cohort of HIV-1 infected children.
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Trends in drug resistance prevalence in HIV-1-infected children in Madrid: 1993 to 2010 analysis.
Pediatr. Infect. Dis. J.
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Drug resistance mutations compromise antiretroviral treatment (ART) effectiveness in HIV-1-infected children. Trends in drug resistance prevalence have not been previously evaluated in HIV-infected children in Spain.
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[Dried blood spots for monitoring HIV infection in Public Health Programs in developing countries].
Enferm. Infecc. Microbiol. Clin.
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As access to antiretroviral treatment increases in the developing countries, efforts towards making it easier and less costly to collect, store, and deliver the biological samples to reference laboratories, where the serological and genetic diagnosis techniques are performed, have become a high priority. Blood sampling on filter papers is an inexpensive and practical alternative to plasma for antiretroviral treatment monitoring in countries with limited resources and no access to cold chains or refrigeration. The main clinical applications and uses of blood-sampling onto filter papers (dried blood spots [DBS]) are reviewed, focusing on how these can be applied in monitoring HIV infection, particularly for use in National Health Programs in developing countries, or in resource-limited settings. A review is presented of studies that have used the DBS technique for quantifying viral load, analysis of antiretroviral drug-resistance mutations, early infant diagnosis, adult serological diagnosis, detection of viral p24 antigen, and molecular epidemiology of HIV-1, in different geographical locations. Those variables that could affect the use of DBS, particularly in the HIV field, as well as explaining how these procedures can be optimised to increase their sensitivity are also reviewed. The aim of this study was to review the advantages of implementing the DBS technique in the HIV field, especially in resource-constrained regions.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.