A5062211051- Hepatitis C virus research
- Hepatitis B Virus Studies
- SARS-CoV-2 and COVID-19 Research
- SARS-CoV-2 detection and testing
- Liver Disease Diagnosis and Treatment
- Hepatitis Viruses Studies and Epidemiology
- Bacillus and Francisella bacterial research
- COVID-19 Clinical Research Studies
- Lymphoma Diagnosis and Treatment
- HIV/AIDS drug development and treatment
- Viral gastroenteritis research and epidemiology
- Poxvirus research and outbreaks
- Viral-associated cancers and disorders
- CNS Lymphoma Diagnosis and Treatment
- HIV Research and Treatment
- HIV/AIDS oral health manifestations
- Hemoglobinopathies and Related Disorders
- Bacteriophages and microbial interactions
- Animal Virus Infections Studies
- Chronic Lymphocytic Leukemia Research
- Viral Infections and Vectors
- vaccines and immunoinformatics approaches
- Blood groups and transfusion
- Influenza Virus Research Studies
- Viral Infections and Outbreaks Research
Instituto Venezolano de Investigaciones Científicas
2014-2024
Harvard University
2024
Universidad de las Fuerzas Armadas ESPE
2024
Universidad Nacional Experimental Simón Rodríguez
2024
University Hospital Complex Of Vigo
2008
Simón Bolívar University
2004
University of Southern California
1988-1991
Central University of Venezuela
1991
LAC+USC Medical Center
1990
USC Norris Comprehensive Cancer Center
1990
Twenty-two consecutive patients with high-grade, B-cell lymphomas related to the acquired immunodeficiency syndrome (AIDS) were accrued onto two sequential phase II studies, consisting of a standard regimen (M-BACOD, group no. 1, N = 13), or novel, intensive (group 2, 9), which included high-dose cytosine arabinoside (HD-Ara-C), and methotrexate (HD-MTX), in an attempt prevent CNS relapse improve response rates. Stage IV disease was present 82%. Complete remission (CR) achieved seven 13...
Autopsies in 20 patients with the acquired immune deficiency syndrome (AIDS)-related lymphoma were studied retrospectively to ascertain precise cause of death and extent lymphomatous disease. Eight had primary central nervous system (CNS) lymphoma: two them diagnosed antemortem; CNS was suspected three others by computerized tomographic (CT) scan confirmed at autopsy. The remaining incidentally All concurrent infections autopsy, including opportunistic infection six pyogenic two....
Abstract The objective of this study was the evaluation genetic diversity found in HBV circulating among Venezuelan Amerindians and general population Colombia. Phylogenetic analysis S region 194 isolates showed that genotype F is highly predominant Colombia Venezuela. This might be related to background population. F3 main subgenotype which circulates both countries. 61 complete genome sequences American genotypes confirms presence two H, 4 subgenotypes. In Venezuela, subgenotypes F1, F2,...
Hepatitis delta virus (HDV) is a defective human that lacks the ability to produce its own envelope proteins and thus dependent on presence of helper virus, which causes surface infectious particles. B (HBV) was so far thought be only described associated HDV. However, recent studies showed divergent HDV‐like viruses can detected in fishes, birds, amphibians, invertebrates without evidence any HBV‐like agent supporting infection (reviewed Maya Ploss(1)). Another study demonstrated HDV...
Pilot studies were conducted to evaluate the toxicity and efficacy of two relatively marrow-sparing chemotherapy regimens in treatment advanced or progressive epidemic Kaposi's sarcoma. Chemotherapy consisted bleomycin (10 mg/m2), vincristine (1.4 mg/m2, 2 mg maximum) Adriamycin (doxorubicin) at either 10 mg/m2 (Group I) 20 II). The therapy was given intravenously, every weeks, until intolerable maximum antitumor response. Thirty-three patients treated. Although patient populations similar...
In less than two years since SARS-CoV-2 emerged, the new coronavirus responsible for COVID-19, has accumulated a great number of mutations. Many these mutations are located in Spike protein and some them confer to virus higher transmissibility or partial resistance antibody mediated neutralization. Viral variants with such confirmed abilities designated by WHO as Variants Concern (VOCs). The aim this study was monitor introduction VOCs Venezuela. A small fragment viral genome sequenced...
Some of the lineages SARS-CoV-2, new coronavirus responsible for COVID-19, exhibit higher transmissibility or partial resistance to antibody-mediated neutralization and were designated by WHO as Variants Interests (VOIs) Concern (VOCs). The aim this study was monitor dissemination VOIs VOCs in Venezuela from March 2021 February 2022. A 614 nt genomic fragment sequenced detection some relevant mutations these variants. Their presence confirmed complete genome sequencing, with a correlation...
Abstract The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among Venezuelan Amerindian populations, where these are endemic, were determined by sequencing PCR amplified products from HBsAg positive sera. HDV genotype I (n = 7, 6 West Amerindians), III 5, 4 South found. Only one isolate was associated with HBV D, 2 infected individuals co‐infected F. failure to detect the American in Amerindians might be related outbreak fulminant high mortality rate occurred between 1979...
We previously reported HIV-1 infection in Warao Amerindians from Venezuela. The aim of this study was to evaluate the extent and dynamic dissemination eight communities.HIV-1 evaluated 576 Orinoco Delta. Partial pol sequences were analyzed reconstruct spatiotemporal demographic dynamics epidemic.HIV-1 antibodies present 9.55% Amerindians, ranging 0 22%. A significantly higher prevalence found men (15.6%) compared with women (2.6%), reaching up 35% one community. All but isolates classified...
Recent reports show that R70Q and L/C91M amino acid substitutions in the core from different hepatitis C virus (HCV) genotypes have been associated with variable responses to interferon (IFN) ribavirin (RBV) therapy, as well an increase of hepatocellular carcinoma (HCC) risk, liver steatosis insulin resistance (IR). Mutations NS5B also IFN, RBV, nucleoside non-nucleoside inhibitors drug resistance. The prevalence these mutations was studied HCV RNA samples chronically HCV-infected drug-naïve...
Abstract Surface antigen negative hepatitis B virus (HBV) infection was evaluated in Venezuela, by molecular characterization of blood samples positive for antibodies to core (anti‐HBc) and surface (HBsAg) donors (residual infections). HBV DNA found 11/258 (4.3%), significantly associated with high levels anti‐HBc (>25 UI/ml, P < 0.05), while no correlation between the presence anti‐HBs. Synonymous non‐synonymous mutations were region (but not vaccine escape mutants) precore/core...
The subtype diversity of the hepatitis C virus (HCV) genotypes is unknown in Venezuela.Partial sequencing NS5B region was performed 310 isolates circulating patients from 1995 to 2007. In samples collected between 2005 and 2007, HCV genotype 1 (G1) most common (63%), composed as expected mainly G1a G1b. G2 second (33%), being G2a almost absent G2j frequent subtype. Sequence analysis core confirmed assignment within NS5b 63 isolates. complete genome sequence obtained. has been described...
SARS-CoV-2 is the new coronavirus responsible for COVID-19 disease. The first two cases of were detected in Venezuela on March 13, 2020. aim this study was genetic characterization Venezuelan isolates. A total 7 full genome sequences obtained by Sanger sequencing, from patients different regions Venezuela, mainly beginning epidemic. Ten out 11 isolates (6 complete genomes and 4 partial spike genomic regions) belonged to lineage B, bearing D614G mutation Spike protein. Isolates outbreak that...
Background Changes in hepatitis C virus (HCV) genotype distribution with time have been reported several countries. Goals To explore eventual changes HCV Venezuela over a 10 years period. Study was determined by direct sequencing of the 5′ noncoding region, 236 isolates circulating patients treated during 2005 to 2006. Genotype compared one observed 43 followed 1994 1996. Results The prevalence 1 and 2 70% 26%, respectively, frequency significantly increased 41% (P=0.04) A significant...
Hepatitis B virus (HBV) and hepatitis C (HCV) infections are the principal risk factor associated to end-stage liver diseases in world. A study was carried out on disease cases admitted an important hepatology unit Medellin, second largest city Colombia. From 131 patients recruited this prospective study, 71% of were diagnosed as cirrhosis, 12.2% HCC, 16.8% cirrhosis HCC. Regarding factors these patients, alcohol consumption most frequent (37.4%), followed by viral etiology (17.6%). Blood...
Prevalence and molecular epidemiology studies for hepatitis B (HBV) C (HCV) virus are scarce in Warao Amerindians from Venezuela, where an epidemic of human immunodeficiency type 1 (HIV-1) has recently been documented. To carry out a analysis individuals the Delta Amacuro State Venezuela. A total 548 sera were tested serological markers HBV HCV. The prevalence active infection (presence surface antigen, HBsAg), exposure to Antibody core anti-HBc) anti-HCV, was 1.8%, 13% 0% respectively....
The genetic diversity of HBV in human population is often a reflection its admixture. aim this study was to explore the genotypic Cuba. S genomic region Cuban isolates sequenced and for selected complete genome or precore-core sequence analyzed. most frequent genotype A (167/250, 67%), mainly A2 (149, 60%) but also A1 one A4. total 77 were classified as D (31%), with co-circulation several subgenotypes (56 D4, 2 D1, 5 D2, 7 D3/6 D7). Three belonged E, two H B3. Complete analysis confirmed...
The aim of this study was to evaluate the prevalence and genetic diversity hepatitis B virus (HBV) C (HCV) in human immunodeficiency type 1 (HIV-1)-co-infected Venezuelan patients. HBV HCV markers infection HIV-1 patients 14 % for anti-hepatitis core antigen, 3 surface antigen 0.7 anti-HCV, respectively. higher than HCV, as expected a country where sexual intercourse, not intravenous drug use, is main mode transmission. genotype distribution HIV-1-co-infected similar that obtained...