
Boris RenjifoMerck · Department of Infectious Disease
Boris Renjifo
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96
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Introduction
Skills and Expertise
Publications
Publications (96)
To determine the durability over 96 weeks of safety and efficacy of lopinavir/ritonavir (LPV/r) and raltegravir (RAL) which was demonstrated to have non-inferior efficacy relative to a regimen of LPV/r with nucleoside/nucleotide reverse transcriptase inhibitors (N(t)RTIs) (Control) in primary analysis at 48 weeks.
Open label, centrally randomised t...
Background:
WHO-recommended second-line antiretroviral therapy (ART) of a pharmacologically enhanced (boosted) protease inhibitor plus nucleoside or nucleotide reverse transcriptase inhibitors (NtRTIs) might be compromised by resistance. Results of the 96 week SECOND-LINE randomised trial showed that NtRTI-sparing ART with ritonavir-boosted lopina...
Thirty-four HIV specialists from 16 countries contributed to this project, whose primary aim was to provide guidance on the screening, diagnosis, and monitoring of bone disease in HIV-infected patients. Four clinically important questions in bone disease management were identified, and recommendations, based on literature review and expert opinion,...
Inhibition of the cytochrome p450 3A4 enzyme system leads to increases in plasma concentrations of coadministered antiretroviral agents - a concept known as pharmacokinetic boosting. Ritonavir and cobicistat are potent inhibitors of cytochrome p450 3A4. Ritonavir was initially developed as an HIV protease inhibitor, but is currently used primarily...
Aim: To assess renal function changes among 172 treatment-naive subjects treated with lopinavir/ritonavir (LPV/r) plus raltegravir (RAL) or LPV/r plus tenofovir/emtricitabine in the PROGRESS study, a prospective, randomized controlled trial. Patients & methods: Serum creatinine, creatinine clearance and chronic kidney disease category were compared...
HIV-1 undergoes rapid genetic diversification due to high mutation rates as well as frequent genomic recombination. Some regions of the genome such as the envelope gene show particularly high rates of evolution due to selection pressure exerted by the host. While only one or a few point mutations are enough to show major phenotypic changes for prop...
Although in specific instances PCR may offer some advantages over serologic techniques, efforts to capacitate more laboratories to perform PCR techniques should not replace efforts to maintain laboratories that are able to perform reliable serologic diagnosis of HIV. Even though numerous laboratories in major African cities are currently executing...
Viral genotype and intersubtype recombination may influence the rate and/or timing of mother-to-child HIV-1 transmission.
We determined the HIV-1 subtype of the C2-C5 env and 5'LTR regions from milk and blood samples of 61 Tanzanian mothers who transmitted the virus through breastfeeding and their HIV-1 positive non-transmitting controls. Cases and...
Many different subtypes of human immunodeficiency virus (HIV) type 1 have been identified, particularly in sub-Saharan Africa. However, much remains unknown regarding the relative pathogenicity of these subtypes and their influence on the clinical progression of HIV infection. We examined prospectively the associations between HIV-1 subtypes A, C,...
Transmission through breast-feeding is an important cause of infant HIV-1 infections in developing countries; however, its mechanism remains largely unknown. We have explored the association between cell-free virus (CFV) and cell-associated virus (CAV) levels in breast milk (BM), as reflected by viral RNA and proviral DNA, respectively, and the ris...
Background: Two recent analyses of HIV-1-infected mothers' mortality according to their children's feeding modality have produced conflicting results. Methods: An individual patient data meta-analysis was conducted using data regarding HIV-1-infected women from eligible clinical trials. Analyses included Cox proportional hazards regression modeling...
To determine whether different HIV-1 genotypes present in a single cohort, in Dar es Salaam, Tanzania, showed differences in timing for transmission from mothers to their infants.
We determined the maternal viral load, transmission time, and the HIV-1 envelope (env) subtype of 253 HIV-1-infected infants enrolled in a randomized double-blind placebo...
Hypermutation involving excessive G-to-A substitutions in the dinucleotide context GA or GG is common among the lentiviruses and results in multiple stop codons across the genome. Hypermutated viruses have been associated with slower disease progression and might reflect an antiviral cell-defense mechanism. However, it is unclear how soon G-to-A su...
Samples from infants infected in-utero by the human immunodeficiency virus type 1 (HIV-1) subtypes A, C, D, and recombinants from Dar es Salaam, Tanzania, were examined for the presence of viral genetic quasispecies. HIV-1 envelope diversity was measured on peripheral blood mononuclear cells collected within the first 48 h of life from 53 infants....
Type-specific serological tests have allowed for a better understanding of the epidemiology of herpes simplex virus type 2 (HSV-2) infection in Africa.
The goal was to determine risk factors for HSV-2 among bar and hotel workers in Moshi, Tanzania.
A cross-sectional study was conducted involving 515 workers in randomly selected bars and hotels in M...
The HIV-1 prevalence among bar and hotel workers in Tanzania suggests they are a high-risk group for HIV-1 infection. We determined the HIV-1 subtype of 3'-p24/5'-p7 gag and C2-C5 env sequences from 40 individuals representing this population in Moshi. Genetic patterns composed of A(gag)-A(env), C(gag)-C(env), and D(gag)-D(env) were found in 19 (48...
Transmission of HIV-1 through breastfeeding is a major problem, although its timing is not well characterized.
The authors examined the timing and correlates of HIV-1 transmission through breastfeeding among 1078 HIV-infected pregnant women from Dar es Salaam, Tanzania enrolled in a trial to examine the effect of vitamin A and other vitamin supplem...
HIV-1 transmission through breastfeeding is a global problem and has been associated with poor maternal micronutrient status.
A total of 1078 HIV-infected pregnant women from Tanzania were randomly assigned to vitamin A or multivitamins excluding A from approximately 20 weeks' gestation and throughout lactation.
Multivitamins excluding A had no eff...
Human immunodeficiency virus type 1 (HIV-1) subtypes A, C, and D are cocirculating in Tanzania, and large numbers of recombinant genomes have been reported from this region. Here we describe full-length sequences of six unlinked HIV-1 subtype A and D recombinants. The samples came from newborns, indicating that the recombination patterns were verti...
We conducted this study to determine the prevalence and risk factors for HIV-1 infection among women (N = 312) who were working in the bars and hotels in Moshi, a town in northern Tanzania. Study subjects were interviewed to obtain information about HIV-1 risk factors and examined to collect samples for the diagnosis of sexually transmitted disease...
Human immunodeficiency virus type 1 (HIV-1) subtype C is responsible for more than 56% of all infections in the HIV and AIDS
pandemic. It is the predominant subtype in the rapidly expanding epidemic in southern Africa. To develop a relevant model
that would facilitate studies of transmission, pathogenesis, and vaccine development for this subtype,...
Multiple subtypes of HIV-1 have been identified; however, there is little data on the relative transmissibility of viruses belonging to different subtypes. A matched case-control study addressed whether viruses with different long terminal repeat (LTR) subtypes were transmitted equally from mother to infant. The LTR subtype was determined for 45 ma...
Human immunodeficiency virus type 1 (HIV-1) subtype C is now the predominant subtype in the global epidemic. This subtype
is encountered in southern Africa and parts of Asia, where the epidemic is rapidly spreading. One possible explanation for
these epidemiological observations is that this subtype has genetic characteristics that may contribute t...
To examine predictors of vertical transmission of HIV-1 in Dar-es-Salaam, Tanzania.
Observational design.
Consenting HIV-1-infected pregnant women (n = 1078) were enrolled in a trial to examine the role of vitamin supplements. Intrauterine HIV-1 infection (HIV-positive at birth); intrapartum and early breastfeeding transmission (HIV-positive at 6 w...
It is becoming increasingly important to identify and to study human immunodeficiency virus type 1 (HIV-1) circulating recombinant forms (CRFs) with evidence of epidemic spread, since mosaic strains arise frequently, especially in populations where multiple subtypes cocirculate. We describe the almost complete nucleotide sequence of 3 subtype C and...
To determine whether genotypes from human immunodeficiency virus type 1 (HIV-1) subtypes A, C, or D or intersubtype recombinants have the same probability of being transmitted from mother to child.
We determined the HIV-1 genetic subtype and maternal risk factors of 51 matched transmitting and nontransmitting mothers from Tanzania. The HIV-1 gag (p...
Human immunodeficiency virus type 1 (HIV-1) subtype C is now responsible for more than half of all HIV-1 infections in the global epidemic and for the high levels of HIV-1 prevalence in southern Africa. To facilitate studies of the biological nature and the underlying molecular determinants of this virus, we constructed eight full-length proviral c...
Preliminary preclinical and clinical data suggest that granulocyte-macrophage colony-stimulating factor (GM-CSF) may decrease
viral replication. Therefore, 105 individuals with AIDS who were receiving nucleoside analogue therapy were enrolled in a
placebo-controlled, doubleblind study and were randomized to receive either 125 µg/m2 of yeast-derived...
A study of the human immunodeficiency virus Type 1 (HIV-1) 5' long terminal repeat (LTR) was performed to determine the extent of variation found within the LTR from 19 mother-infant pairs in Tanzania and to assess whether the LTR is useful in distinguishing maternal sequences that were transmitted to infants. HIV-1 subtypes A, C, and D as well as...
Background:
Observational studies suggest that poor nutritional status among HIV-infected pregnant women is associated with a higher risk of vertical transmission of HIV.
Methods:
We randomized 1083 pregnant women infected with HIV-1 in a double-blind, placebo-controlled trial to examine the effects of supplements of vitamin A and/or multivitami...
To determine whether the envelope V3 region from HIV-1 subtypes A, C or D had the same probability of being present in intersubtype recombinant genomes.
The envelope C2-C5 and the gag p24-p7 regions from one hundred infants infected perinatally in Tanzania were compared using phylogenetic and recombination analysis. Exact binomial and Fisher's exac...
To better understand the virological aspect of the expanding AIDS epidemic in southern Africa, a set of 23 near-full-length clones of human immunodeficiency virus type 1 (HIV-1) representing eight AIDS patients from Botswana were sequenced and analyzed phylogenetically. All study viruses from Botswana belonged to HIV-1 subtype C. The interpatient d...
Retroviruses such as human immunodeficiency virus type 1 (HIV-1) contain two RNA strands per virion, and recombination can occur frequently during reverse transcription. Recombination may occur between HIV-1 genomes of the same subtype or among genomes of two or more distinct subtypes present in an individual. In the current study, we found that re...
HIV-1 isolates are classified phylogenetically in several subtypes or clades according to env and gag coding sequences. Viral subtypes tend to cluster geographically. DNA sequences encoding the p51 subunit of reverse transcriptase were obtained by nested polymerase chain reaction from peripheral blood mononuclear cells of two HIV-1-seropositive ind...
Several case reports have suggested an association between human T-cell lymphotropic virus type II (HTLV-II) infection and chronic neurologic disease. We performed serial neurologic examinations in injection-drug users (IDU), a group known to be at increased risk for HTLV-II infection. At baseline, those infected with HTLV-II alone, human immunodef...
Heterosexual transmission by vaginal intercourse accounts for most transmission of human immunodeficiency virus-type 1 (HIV-1)
in Africa and Asia but is less important in the HIV-1 epidemics of the United States and Western Europe. Epithelial Langerhans'
cells (LCs) represent a possible source of initial cell contact for vaginal infection. Fifteen...
The approach taken in our laboratory to determine viral markers associated with human T cell leukemia virus type I (HTLV-I) disease induction was to compare viral genomes and host immune responses from HTLV-I-infected patients from two geographical areas with significant differences in the incidence rate of tropical spastic paraparesis/HTLV-I-assoc...
We describe nucleotide sequences of human T-lymphotropic virus type I (HTLV-I) proviruses from three symptomatic family members with tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) from Tumaco, Colombia. Polymerase chain reaction was used to clone the U3 region, envelope and tax/rex genes of these HTLV-I proviruses from fresh pe...
Studies of HIV-2 infection have shown lower rates of sexual and perinatal transmission and a prolonged incubation period to AIDS as compared to HIV-1. To evaluate the role of genetic variation in HIV pathogenesis, we studied intrapatient variability in the V3 loop of the HIV-2 envelope gene over time in five seropositive individuals. Proviral seque...
Tumaco, Colombia, is an area with elevated rates of tropical spastic paraparesis/human T-cell leukemia virus type I (HTLV-I)-associated myelopathy (TSP/HAM). We have identified a mutation in nucleotide 7959 of the tax gene of 14 Tumaco HTLV-I isolates (14 positive of 14 tested) that was present in 5 of 14 (35%) TSP/HAM patients from Japan and in 8...
Despite the likely role of mucosae in human T cell leukemia virus type I (HTLV-I) transmission, little is known about the mucosal immune response to HTLV-I. The present study evaluated the antibody response to HTLV-I in oral mucosa and the value of crevicular fluid rich saliva (CFRS) for diagnosing HTLV-I infection. CFRS and sera from patients with...
Previous studies identified two regions in the U3 region of a molecular clone of simian immunodeficiency virus, SIVmac142, that are important to transcriptional activity under conditions of induction as well as basal-level expression (B. Renjifo, N. A. Speck, S. Winandy, N. Hopkins, and Y. Li, J. Virol. 64:3130-3134, 1990). One region includes the...
A series of 5' deletions and a point mutation in the binding site for nuclear factor kappa B were introduced into the U3 region of a molecular clone of simian immunodeficiency virus from macaques (SIVmac142). The transcriptional activity of the mutated U3 regions was analyzed by transient chloramphenicol acetyltransferase assays. Two distinct regio...
Transcriptional enhancers of replication-competent mouse C-type retroviruses are potent determinants of the distinct disease-inducing phenotypes of different viral isolates and can also strongly influence the incidence and latent period of disease induction. To study the contribution of individual protein-binding sites to viral pathogenicity, we in...
The transcriptional enhancer of the Moloney murine leukemia virus (MoMLV) is organized as a 75-base-pair repeat, and in each copy of the repeat there are multiple binding sites for nuclear factors. We have introduced point mutations into each of the known nuclear factor-binding sites in the MoMLV enhancer, in both copies of the direct repeat, and h...
The approach taken in our laboratory to determine viral markers associated with human T cell leukemia virus type I (HTLV-I) disease induction was to compare viral genomes and host immune responses from HTLV-I-infected patients from two geographical areas with significant differences in the incidence rate of tropical spastic paraparesis/HTLV-I-assoc...
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