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1.
AIDS Behav ; 23(12): 3277-3285, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30778809

RESUMEN

We evaluated characteristics associated with recent HIV infection among persons who inject drugs (PWID) from 19 U.S. cities who participated in 2012 National HIV Behavioral Surveillance. Recent infection was defined as having a reactive HIV test, a Bio-Rad Avidity index cutoff ≤ 30%, no reported HIV diagnosis ≥ 12 months before interview, and no evidence of viral suppression. Of 8667 PWID, 50 (0.6%) were recently HIV infected. Having a greater number of sex partners (≥ 2 partners vs. 0) [prevalence ratio (PR) 4.7, 95% confidence interval (CI) 1.3-17.8], injecting heroin and other drugs (PR 3.0, 95% CI 1.3-6.6) or exclusively non-heroin drugs (PR 5.9, 95% CI 1.7-20.7) compared to injecting only heroin, and having male-male sex in the past year (PR 7.1, 95% CI 3.0-16.6) were associated with recent infection. Promoting not only safe injection practices but also safe sex practices will be key to preventing new HIV infections.


Asunto(s)
Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Tamizaje Masivo/psicología , Asunción de Riesgos , Abuso de Sustancias por Vía Intravenosa/complicaciones , Adolescente , Adulto , Sistema de Vigilancia de Factor de Riesgo Conductual , Ciudades/epidemiología , Estudios Transversales , Femenino , Infecciones por VIH/psicología , Humanos , Incidencia , Masculino , Prevalencia , Parejas Sexuales , Abuso de Sustancias por Vía Intravenosa/epidemiología , Estados Unidos/epidemiología , Adulto Joven
2.
AIDS Behav ; 19(12): 2304-10, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25680518

RESUMEN

We tested blood samples from men who have sex with men (MSM) to detect early HIV infection. Early HIV included both acute (infected past 30 days) and recent (estimated recency past 240 days). Acute infections were defined as screen immunoassay (IA) negative/NAAT-positive or IA-positive/Multispot-negative/NAAT-positive. Recent infections were defined as avidity index cutoff <30 % on an avidity-based IA and, (1) not reporting antiretroviral therapy use or, (2) HIV RNA >150 copies/mL. Of 937 samples, 26 % (244) were HIV-infected and of these 5 % (12) were early. Of early infections, 2 were acute and 10 recent; most (8/12) were among black MSM. Early infection was associated with last partner of black race [adjusted relative risk (ARR) = 4.6, confidence intervals (CI) 1.2-17.3], receptive anal sex at last sex (ARR = 4.3, CI 1.2-15.0), and daily Internet use to meet partners/friends (ARR = 3.3, CI 1.1-9.7). Expanding prevention and treatment for black MSM will be necessary for reducing incidence in the United States.


Asunto(s)
Infecciones por VIH/epidemiología , Homosexualidad Masculina , Ciudades , Humanos , Masculino , Asunción de Riesgos , Minorías Sexuales y de Género , Estados Unidos/epidemiología
3.
J Chem Ecol ; 36(11): 1255-70, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20872171

RESUMEN

The capacity to produce carbon-based secondary compounds (CBSC), such as phenolics (including tannins) and terpenes as defensive compounds against herbivores or against neighboring competing plants can be involved in the competition between alien and native plant species. Since the Hawaiian Islands are especially vulnerable to invasions by alien species, we compared total phenolic (TP), total tannin (Tta), and total terpene (TT) leaf contents of alien and native plants on Oahu Island (Hawaii). We analyzed 35 native and 38 alien woody plant species randomly chosen among representative current Hawaiian flora. None of these CBSC exhibited phylogenetic fingerprinting. Alien species had similar leaf TP and leaf Tta contents, and 135% higher leaf TT contents compared with native species. Alien plants had 80% higher leaf TT:N leaf content ratio than native plants. The results suggest that apart from greater growth rate and greater nutrient use, alien success in Oahu also may be linked to greater contents of low cost chemical defenses, such as terpenes, as expected in faster-growing species in resource rich regions. The higher TT contents in aliens may counterbalance their lower investment in leaf structural defenses and their higher leaf nutritional quality. The higher TT provides higher effectiveness in deterring the generalist herbivores of the introduced range, where specialist herbivores are absent. In addition, higher TT contents may favor aliens conferring higher protection against abiotic and biotic stressors. The higher terpene accumulation was independent of the alien species origin, which indicates that being alien either selects for higher terpene contents post-invasion, or that species with high terpene contents are pre-adapted to invasiveness. Although less likely, an originally lower terpene accumulation in Hawaiian than in continental plants that avoids the increased attraction of specialist enemies associated to terpenes may not be discarded.


Asunto(s)
Especies Introducidas , Plantas/química , Hawaii , Fenoles/química , Hojas de la Planta/química , Plantas/clasificación , Taninos/química , Terpenos/química
4.
Proc Natl Acad Sci U S A ; 106(44): 18447-51, 2009 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-19841269

RESUMEN

More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly" fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O(3)), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O(3) concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O(3) concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.


Asunto(s)
Agricultura , Contaminación del Aire/análisis , Arecaceae/fisiología , Nitrógeno/análisis , Ozono/análisis , Aceites de Plantas/análisis , Clima Tropical , Aeronaves , Butadienos/análisis , Geografía , Hemiterpenos/análisis , Monoterpenos/análisis , Óxido Nítrico/análisis , Dióxido de Nitrógeno/análisis , Aceite de Palma , Pentanos/análisis , Ácido Peracético/análogos & derivados , Ácido Peracético/análisis , Factores de Tiempo
5.
J Clin Microbiol ; 46(5): 1588-95, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18322061

RESUMEN

Serodiagnosis of human immunodeficiency virus (HIV) infection in the United States has traditionally relied on a sequential two-test algorithm: an initial screen with an enzyme immunoassay (EIA) and reflex testing of EIA-reactive specimens with a more specific supplemental test such as Western blotting or immunofluorescence. The supplemental tests are tedious, subjective, and expensive. In addition, there have been major improvements in the performance and accuracy of the EIA tests as well as the introduction of rapid serologic tests (RT) and HIV nucleic acid amplification tests (NAAT). Related to these improvements is the possibility that alternative algorithms using combinations of currently approved HIV tests may function as well as if not better than the current algorithm, with more flexibility, improved accuracy, and lower cost. To this end, we evaluated the performance of 12 currently licensed tests and 1 in-house HIV test (6 EIA, 4 RT, and 3 NAAT) on panels of plasma samples from HIV-infected (n = 621 HIV type 1 [HIV-1] and 34 HIV-2) and uninfected (n = 513) people and of sequential specimens from people early in seroconversion (183 specimens from 15 patients). Test combinations were analyzed in two dual-test (sensitivity-optimized and specificity-optimized) algorithms and in a three-test (tie-breaking) algorithm, and performance was compared to the conventional algorithm. The results indicate that alternative algorithm strategies with currently licensed tests compare favorably with the conventional algorithm in detecting and confirming established HIV infection. Furthermore, there was a lower frequency of discordant or indeterminate results that require follow-up testing, and there was improved detection of early infection.


Asunto(s)
Algoritmos , Infecciones por VIH/diagnóstico , VIH/genética , VIH/inmunología , Inmunoensayo/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Anticuerpos Antivirales/sangre , Humanos , Plasma/inmunología , Plasma/virología , ARN Viral/sangre , Sensibilidad y Especificidad , Estados Unidos
6.
J Pept Res ; 63(6): 469-76, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15175019

RESUMEN

The ability of certain theta-defensins, including retrocyclin-1, to protect human cells from infection by HIV-1 marks them as potentially useful molecules. Theta-defensins composed of L-amino acids are likely to be unstable in environments that contain host and microbial proteases. This study compared the properties of two enantiomeric theta-defensins, retrocyclin-1, and RC-112. Although these peptides have identical sequences, RC-112 is composed exclusively of D-amino acids, whereas retrocyclin-1 contains only L-amino acids. We compared the ability of these peptides to protect JC53-BL human cells from infection by 30 primary HIV-1 isolates. JC53-BL cells are modified HeLa cells that express surface CD4, CXCR4, and CCR5. They also contain reporter cassettes that are driven by the HIV-1 LTR, and express beta-galactosidase and luciferase. The HIV-1 isolates varied in co-receptor specificity and included subtypes A, B, C, D, CRF01-AE, and G. RC-112 was several fold more potent than retrocyclin-1 across the entire HIV-1 panel. Although RC-112 bound immobilized gp120 and CD4 with lower affinity than did retrocyclin-1, surface plasmon resonance experiments performed with 1 microg/mL of RC-112 and retrocyclin-1 revealed that both glycoproteins were bound to a similar extent. The superior antiviral performance of RC-112 most likely reflected its resistance to degradation by surface-associated or secreted proteases of the JC53-BL target cells. Theta-defensins composed exclusively of D-amino acids merit consideration as starting points for designing microbicides for topical application to the vagina or rectum.


Asunto(s)
Defensinas/química , Defensinas/farmacología , VIH-1/efectos de los fármacos , Aminoácidos/química , Animales , Fármacos Anti-VIH/farmacología , Defensinas/metabolismo , Infecciones por VIH/tratamiento farmacológico , Humanos , Estereoisomerismo
7.
Environ Sci Technol ; 36(7): 1554-60, 2002 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-11999066

RESUMEN

Data illustrating the performance characteristics of a proton transfer reaction-mass spectrometer (PTR-MS) under both laboratory and field conditions are presented. Under laboratory conditions, we demonstrate that PTR-MS measures (within 10%) a 2.6 ppbv concentration of gaseous dimethyl sulfide. Using a stepwise dilution of a gaseous isoprene standard, we demonstrate the linearity of the response of PTR-MS across 3 orders of magnitude of mixing ratios, from 100 ppbv to less than 100 pptv. By combining this data set with that of its monosubstituted 13C isotopic analogue, we demonstrate the ability of the instrumentto reliably measure concentrations as low as approximately 50 pptv and to detect concentrations at significantly lower levels. We conclude our laboratory characterization by investigating the components of the instrument noise signal (drift, mean, and range) and develop an expression (noise statistic) that reliably predicts the instrumental noise associated with any signal across a wide range of masses. In the field, we deployed a PTR-MS at a clean-air coastal site and an urban kerbside monitoring station to demonstrate the measurement of atmospheric dimethyl sulfide and benzene concentrations, respectively. At both sites, we were able to monitor diurnal variations in concentrations at unprecedented temporal resolutions (<5 min between successive measurements). We then demonstrate how the noise statistic can be applied to enable real fluctuations in atmospheric VOC concentrations to be reliably distinguished from instrument noise. We conclude by demonstrating how PTR-MS can be used to measure real-time VOC emission rate changes from vegetation in response to external forcing by examining the effect varying photon-flux density has upon emissions of isoprene from a Sitka spruce tree.


Asunto(s)
Contaminantes Atmosféricos/análisis , Espectrometría de Masas/métodos , Compuestos Orgánicos/análisis , Protones , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sulfuros/análisis , Volatilización
8.
J Virol ; 74(12): 5702-8, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10823878

RESUMEN

Primary simian immunodeficiency virus (SIV) isolated from sooty mangabey (SIVsm [n = 6]), stumptail (SIVstm [n = 1]), mandrill (SIVmnd [n = 1]), and African green (SIVagm [n = 1]) primates were examined for their ability to infect human cells and for their coreceptor requirements. All isolates infected human peripheral blood mononuclear cells (PBMCs) from a CCR5(+/+) donor, and seven of eight isolates tested also infected CCR5(-/-) PBMCs. Analysis of coreceptor utilization using GHOST and U87 cell lines revealed that all of the isolates tested used CCR5 and the orphan receptors STRL33 and GPR15. Coreceptors such as CCR2b, CCR3, CCR8, and CX3CR1 were also utilized by some primary SIV isolates. More importantly, we found that CXCR4 was used as a coreceptor by the SIVstm, the SIVagm, and four of the SIVsm isolates in GHOST and U87 cells. These data suggest that primary SIV isolates from diverse primate species can utilize CXCR4 for viral entry, similar to what has been described for human immunodeficiency viruses.


Asunto(s)
Leucocitos Mononucleares/virología , Receptores CXCR4/metabolismo , Receptores Acoplados a Proteínas G , Receptores Virales , Virus de la Inmunodeficiencia de los Simios/fisiología , Animales , Anticuerpos Monoclonales/inmunología , Línea Celular , Células Cultivadas , Cercocebus atys/virología , Quimiocina CXCL12 , Quimiocinas CXC/metabolismo , Quimiocinas CXC/farmacología , Chlorocebus aethiops/virología , VIH-1/metabolismo , VIH-1/fisiología , Humanos , Macaca nemestrina/virología , Papio/virología , Filogenia , Receptores CCR5/genética , Receptores CCR5/metabolismo , Receptores CXCR4/antagonistas & inhibidores , Receptores CXCR4/genética , Receptores CXCR4/inmunología , Receptores CXCR6 , Receptores de Quimiocina , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Receptores de Péptidos/genética , Receptores de Péptidos/metabolismo , Eliminación de Secuencia/genética , Virus de la Inmunodeficiencia de los Simios/clasificación , Virus de la Inmunodeficiencia de los Simios/efectos de los fármacos , Virus de la Inmunodeficiencia de los Simios/metabolismo , Factores de Tiempo , Replicación Viral
9.
J Am Vet Med Assoc ; 217(10): 1475-9, 2000 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11128537

RESUMEN

OBJECTIVE: To examine exposure risks, possibility of zoonosis, and potential disease associations for feline retroviruses among a group of occupationally exposed individuals. DESIGN: Unlinked voluntary cross-sectional epidemiologic survey. SAMPLE POPULATION: 204 veterinarians, laboratory scientists, and other occupationally exposed individuals who attended a veterinary conference on feline geriatric medicine. PROCEDURE: Blood was collected from participants who also completed a 13-question survey requesting demographic, occupational, exposure, and health information. Blood specimens were fractionated into plasma and mononuclear cell components. Plasma was tested for antibodies against feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), as well as p27 antigen of FeLV. Mononuclear cell lysates were tested for FeLV provirus. RESULTS: Subjects reported extensive duration of work with cats (mean, 17.3 years) and multiple high-risk exposures (eg, cat bites, scratches, and injuries with sharp instruments) per year. However, neither serologic nor molecular evidence of zoonosis with any of the 3 feline retroviruses was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians encounter occupational exposures to animal material that place them at high risk for zoonoses. For feline retroviruses, the risk of zoonosis among healthy adult humans appears to be extremely small. However, potential for retroviral zoonosis, especially for viruses such as FeLV and FeFV that can replicate in human cells, cannot be eliminated, and universal precautions to reduce potential exposures should be used when handling sick cats.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida del Felino/transmisión , Virus de la Inmunodeficiencia Felina/patogenicidad , Zoonosis/transmisión , Adulto , Técnicos de Animales , Animales , Anticuerpos Antivirales/sangre , Antígenos Virales/sangre , California/epidemiología , Gatos , Estudios Transversales , ADN Viral/química , ADN Viral/aislamiento & purificación , Síndrome de Inmunodeficiencia Adquirida del Felino/sangre , Femenino , Georgia/epidemiología , Humanos , Immunoblotting/veterinaria , Virus de la Inmunodeficiencia Felina/genética , Masculino , Persona de Mediana Edad , Ohio/epidemiología , Reacción en Cadena de la Polimerasa/veterinaria , Veterinarios
10.
Percept Mot Skills ; 88(2): 648-50, 1999 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10483657

RESUMEN

This study compared scores on future time perspective of 50 female prison inmates who were participating in a vocational training program within the Julia Tutwiler Prison. There was no control group. Zimbardo's measure of future time perspective, administered a year earlier, was associated with success or failure in the program. Associations of future time perspectives with education, age, and ethnicity were investigated. An analysis of covariance between the 21 graduates and 16 dropouts while controlling for education was significant. Despite the incomplete design, some implications are of interest.


Asunto(s)
Inventario de Personalidad/estadística & datos numéricos , Prisioneros/educación , Rehabilitación Vocacional , Percepción del Tiempo , Adulto , Educación/estadística & datos numéricos , Escolaridad , Femenino , Humanos , Prisioneros/psicología
11.
J Clin Microbiol ; 37(8): 2581-6, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10405405

RESUMEN

The high degree of genetic diversity within human immunodeficiency virus type 1 (HIV-1), which includes two major groups, M (major) and O (outlier), and various env subtypes within group M (subtypes A to J), has made designing assays that will detect all known HIV-1 strains difficult. We have developed a generic primer set based on the conserved immunodominant region of transmembrane protein gp41 that can reliably amplify as few as 10 copies/PCR of viral DNA from near-full-length clones representing group M subtypes A to H (subtypes I and J were not available). The assay is highly sensitive in detecting plasma viral RNA from HIV-1 strains of diverse geographic origins representing different subtypes of HIV-1 group M as well as HIV-1 group O. Of the 253 group M plasma specimens (subtypes A, 68 specimens; B, 71; C, 19; D, 27; E, 23; F, 33; and G, 12), 250 (98.8%) were amplified by using the gp41 M/O primer set. More importantly, all 32 (100%) group O plasma samples were also amplified with these primers. In vitro spiking experiments further revealed that the assay could reliably detect as few as 25 copies/ml of viral RNA and gave positive signals in HIV-1-seropositive specimens with plasma copy numbers below the limits of detection by all commercially available viral load assays. In addition, analysis of five seroconversion panels indicated that the assay is highly sensitive for early detection of plasma viremia during the "window period." Thus, the highly sensitive assay will be useful for early detection of HIV-1 in clinical specimens from all known HIV-1 infections, regardless of their genotypes and geographic origins.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/virología , Genoma Humano , VIH-1/genética , VIH-1/aislamiento & purificación , Sondas de Oligonucleótidos , Síndrome de Inmunodeficiencia Adquirida/sangre , Variación Genética , Humanos , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/análisis , ARN Viral/genética , Sensibilidad y Especificidad
12.
AIDS ; 12(13): F137-43, 1998 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-9764773

RESUMEN

OBJECTIVE: To study coreceptor usage of sequential primary HIV-1 isolates in a longitudinal follow-up cohort of HIV-1-infected men to understand its contribution to pathogenesis of HIV disease. DESIGN: Viral coreceptor usage of sequential primary isolates from HIV-1-infected individuals was examined at various timepoints and data was compared with CD4 cell counts, rates of disease progression and beta-chemokine production. METHODS: Fifty-eight sequential primary isolates were obtained from four rapid progressors, six late progressors, and three long-term nonprogressors (LTNP) and their coreceptor usage was examined by infection of peripheral blood mononuclear cells (PBMC) from donors with wild-type or non-functional CC-chemokine receptor (CCR)-5, and by infection of GHOST4 cells expressing CD4 and various chemokine receptors [CCR-1-CCR-5, CXC-chemokine receptor (CXCR)-4, BOB/GPR15, BONZO/STRL33]. Production of RANTES and macrophage inflammatory protein (MIP)-1beta was examined using unstimulated or phytohemagglutinin (PHA)-stimulated PBMC isolated from these individuals at multiple timepoints during infection. RESULTS: A switch from single CCR-5 coreceptor usage to multiple coreceptor usage occurred in all four rapid progressors and three out of six late progressors. In addition to the commonly used coreceptors CXCR-4, CCR-5, and CCR-3, some of the viruses isolated from patients in the terminal stage of infection also used CCR-1, CCR-2b, CCR-4, and BOB as coreceptors. The emergence of viral variants capable of utilizing multiple coreceptors generally preceded CD4 cell decline to < 200 x 10(6)/l and correlated with the onset of AIDS. In contrast, three LTNP maintained exclusive usage of CCR-5 over a period of 7-12 years post-infection. Endogenous production of RANTES and MIP-1beta by PBMC from LTNP was not significantly different from rapid and late progressors. However, PHA-driven production of both chemokines was significantly higher in LTNP, suggesting that in vivo activating stimuli might curtail HIV replication by inducing these chemokines. CONCLUSIONS: Viral variants capable of utilizing a broad range of coreceptors correlated with HIV-1 disease progression. In contrast, LTNP maintain exclusive usage of CCR-5 and produce higher levels of beta-chemokines. Thus, both viral and host determinants leading to the emergence of viral variants capable of using an expanded range of coreceptors may be likely determinants of disease progression.


Asunto(s)
Seropositividad para VIH/virología , VIH-1/patogenicidad , Homosexualidad Masculina , Receptores Acoplados a Proteínas G , Receptores del VIH/metabolismo , Adaptación Fisiológica , Línea Celular , Quimiocina CCL4 , Quimiocina CCL5/metabolismo , Quimiocinas CC/metabolismo , Estudios de Cohortes , Progresión de la Enfermedad , Proteínas de Unión al GTP/metabolismo , VIH-1/metabolismo , Humanos , Proteínas Inflamatorias de Macrófagos/metabolismo , Masculino , Receptores CCR1 , Receptores CCR2 , Receptores CCR3 , Receptores CCR5/metabolismo , Receptores CXCR4/metabolismo , Receptores de Quimiocina/metabolismo , Receptores de Citocinas/metabolismo , Receptores de Péptidos/metabolismo
13.
Aliment Pharmacol Ther ; 12(1): 41-7, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9692699

RESUMEN

BACKGROUND: There is documentation of the long-term use of omeprazole 10 mg o.d. in patients with reflux oesophagitis but not in the large number of gastrooesophageal reflux disease (GERD) patients without oesophagitis. There is also a paucity of data on the long-term use of cimetidine in GERD patients. METHODS: One hundred and fifty-six patients (100 male) who previously had symptomatic non-ulcerative oesophagitis (81%) or symptoms without oesophagitis (19%), were recruited. All patients were in symptomatic remission following 4 weeks of omeprazole 20 mg o.d. or cimetidine 400 mg q.d.s. and, if required, a further 4 weeks of omeprazole 20 mg o.d. Patients were randomized to receive, double-blind, either omeprazole 10 mg o.m. (n = 77) or cimetidine 800 mg nocte (n = 79) for 24 weeks. RESULTS: A greater proportion of patients receiving omeprazole, compared with cimetidine, were in symptomatic remission after 12 (69 vs. 27%) and 24 weeks (60 vs. 24%) (each P < 0.0001). The median time to symptomatic relapse was longer for patients receiving omeprazole (169 vs. 15 days) (P = 0.0001). Of patients leaving the study in symptomatic remission, a greater proportion receiving omeprazole, compared with cimetidine, was free of oesophagitis (84 vs. 53%) (P < 0.05). CONCLUSION: Omeprazole 10 mg o.m. is more effective than cimetidine 800 mg nocte in the prevention of recurrence of GERD-associated heartburn and the occurrence of underlying oesophagitis.


Asunto(s)
Antiulcerosos/uso terapéutico , Cimetidina/uso terapéutico , Esofagitis/prevención & control , Reflujo Gastroesofágico/tratamiento farmacológico , Pirosis/prevención & control , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Omeprazol/uso terapéutico , Administración Oral , Antiulcerosos/administración & dosificación , Distribución de Chi-Cuadrado , Cimetidina/administración & dosificación , Método Doble Ciego , Esofagitis/etiología , Femenino , Reflujo Gastroesofágico/complicaciones , Pirosis/etiología , Antagonistas de los Receptores H2 de la Histamina/administración & dosificación , Humanos , Masculino , Omeprazol/administración & dosificación , Prevención Secundaria , Resultado del Tratamiento
14.
J Virol ; 72(7): 5425-32, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9620997

RESUMEN

Several members of the seven-transmembrane chemokine receptor family have been shown to serve, with CD4, as coreceptors for entry by human immunodeficiency virus type 1 (HIV-1). While coreceptor usage by HIV-1 primary isolates has been studied by several groups, there is only limited information available concerning coreceptor usage by primary HIV-2 isolates. In this study, we have analyzed coreceptor usage of 15 primary HIV-2 isolates, using lymphocytes from a donor with nonfunctional CCR5 (CCR5 -/-; homozygous 32-bp deletion). Based on the infections of PBMCs, seven of these primary isolates had an absolute requirement for CCR5 expression, whereas the remaining eight exhibited a broader coreceptor usage. All CCR5-requiring isolates were non-syncytium inducing, whereas isolates utilizing multiple coreceptors were syncytium inducing. Blocking experiments using known ligands for chemokine receptors provided indirect evidence for additional coreceptor utilization by primary HIV-2 isolates. Analysis of GHOST4 cell lines expressing various chemokine receptors (CCR1, CCR2b, CCR3, CCR4, CCR5, CXCR4, BONZO, and BOB) further defined specific coreceptor usage of primary HIV-2 isolates. The receptors used included CXCR4, CCR1-5, and the recently described receptors BONZO and BOB. However, the efficiency at which the coreceptors were utilized varied greatly among the various isolates. Analysis of V3 envelope sequences revealed no specific motif that correlated with coreceptor usage. Our data demonstrate that primary HIV-2 isolates are capable of using a broad range of coreceptors for productive infection in vitro. Additionally, our data suggest that expanded coreceptor usage by HIV-2 may correlate with disease progression.


Asunto(s)
VIH-2/fisiología , Receptores CCR5/fisiología , Receptores Virales/fisiología , Secuencia de Aminoácidos , Variación Genética , VIH-2/genética , Humanos , Datos de Secuencia Molecular , Fenotipo
15.
J Virol ; 72(6): 5279-84, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9573305

RESUMEN

Unlike most other characterized retroviruses, there is little published information on the biochemical properties of human T-lymphotropic virus type 1 (HTLV-1) reverse transcriptase (RT). Specifically, no reports of a cloned functional RT enzyme have been published. Since the RT enzyme is an essential component of the virus, our objective was to clone, express, and purify a functional RT enzyme from HTLV-1. Our approach was to clone and express a protein of approximately 60 to 65 kDa that we hypothesized would correspond to the RT region encoded by the pol reading frame. The predicted region encoding the RT enzyme comprised nucleotides 2617 to 4312 of the HTLV-1 MT-2 isolate. A putative RT gene was obtained by PCR and was ligated into various prokaryotic expression vectors. A novel cloning approach allowed us to generate a stable clone in the prokaryotic expression vector pGEX-4T-1 and produce a recombinant protein of approximately 60 to 65 kDa. The partially purified protein displays RT activity in both amplification RT (AMP-RT) assays and traditional RT assays. This is the first report of a cloned protein from HTLV-1 which displays RT activity and is the first step in the characterization of HTLV-1 RT.


Asunto(s)
Genes Virales , Virus Linfotrópico T Tipo 1 Humano/genética , ADN Polimerasa Dirigida por ARN/genética , Proteínas Virales/genética , Secuencia de Aminoácidos , Clonación Molecular , Humanos , Datos de Secuencia Molecular , Plásmidos
16.
J Virol ; 72(4): 3383-6, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9525666

RESUMEN

Human T-cell leukemia virus type 1 (HTLV-1) is an oncovirus that is clinically associated with adult T-cell leukemia. We report here the construction of a pET19-based expression clone containing HTLV-1 protease fused to a decahistidine-containing leader peptide. The recombinant protein is efficiently expressed in Escherichia coli, and the fusion protein can be easily purified by affinity chromatography. Active mature protease in yields in excess of 3 mg/liter of culture can then be obtained by a novel two-step refolding and autoprocessing procedure. The purified enzyme exhibited Km and Kcat, values of 0.3 mM and 0.143 sec(-1) at pH 5.3 and was inhibited by pepstatin A.


Asunto(s)
Ácido Aspártico Endopeptidasas/biosíntesis , Ácido Aspártico Endopeptidasas/aislamiento & purificación , Virus Linfotrópico T Tipo 1 Humano/enzimología , Secuencia de Aminoácidos , Ácido Aspártico Endopeptidasas/química , Ácido Aspártico Endopeptidasas/genética , Clonación Molecular , Virus Linfotrópico T Tipo 1 Humano/genética , Humanos , Datos de Secuencia Molecular , Plásmidos , Procesamiento Proteico-Postraduccional , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación
17.
Virology ; 240(1): 83-92, 1998 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-9448692

RESUMEN

The cellular tropism of human immunodeficiency virus type 1 (HIV-1) is dependent on utilization of specific chemokine co-receptor: macrophage-tropic/non-syncytium-inducing (NSI) viruses use CCR5, whereas T-cell tropic/syncytium-inducing (SI) viruses preferentially use CXCR4. We have analyzed co-receptor usage of 24 phylogenetically distinct primary HIV-1 isolates representing group M (clades A-F) and group O with known SI and NSI phenotype, using lymphocytes from donor with nonfunctional CCR5 (CCR5-/-; homozygous 32-bp deletion). While all SI isolates infected CCR5-/- lymphocytes (and hence do not require CCR5 for viral entry), all NSI isolates, regardless of clade, did not infect CCR5-/- lymphocytes. Thus, CCR5 expression is required for infection with NSI isolates and the CCR5 usage is independent of viral genotype. To localize the viral determinant involved in CCR5 binding, the V3 sequences across the clades were aligned based on the CCR5 usage. There were conserved uncharged residues at position 11 of V3 (mostly serine/glycine) and negatively charged residues at residue 25 (mostly glutamic/aspartic acid) among all isolates that used CCR5, whereas substitution with arginine or glutamine at these two positions led to usage of a co-receptor other than CCR5. This analysis led us to identify a consensus motif S/GXXXGPGXXXXXXXE/D within the V3 loop that predicts CCR5 co-receptor usage. Most isolates, with exception of one isolate, containing the conserved motif and predicted to utilize CCR5 indeed had an absolute requirement of CCR5 expression for infectibility. Site-directed mutagenesis in the infectious molecular clone further confirmed these results. Taken together, these data provide evidence that sequences within the V3 loop provide important residues that might be directly or indirectly involved in binding to a CCR5 co-receptor.


Asunto(s)
Linfocitos T CD4-Positivos/virología , Productos del Gen env/genética , VIH-1/fisiología , Filogenia , Receptores CCR5/fisiología , Replicación Viral , Secuencia de Aminoácidos , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Línea Celular , Células Cultivadas , Quimiocinas/farmacología , Secuencia de Consenso , Productos del Gen env/química , Productos del Gen env/metabolismo , Genotipo , Células Gigantes , VIH-1/clasificación , VIH-1/genética , Homocigoto , Humanos , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Fenotipo , Receptores CCR5/deficiencia , Receptores CCR5/genética , Receptores CXCR4/fisiología , Proteínas Recombinantes/metabolismo , Eliminación de Secuencia , Transfección
18.
J Infect Dis ; 177(2): 437-45, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9466533

RESUMEN

Because malaria-stimulated cytokine production may have deleterious effects on human immunodeficiency virus type 1 (HIV-1) replication, the effects of Plasmodium falciparum antigens on HIV-1 replication were studied. Stimulation with malarial antigens significantly enhanced HIV-1 replication of HIV-1LAV and primary HIV-1 isolates (subtype A) in CD8-depleted peripheral blood mononuclear cells from naive donors. The malarial antigen-induced activation of HIV-1 was due to cellular activation as judged by the expression of cell activation markers and proliferative responses. While malarial antigen stimulation increased expression of tumor necrosis factor (TNF-alpha) and interleukin-6 (IL-6), only monoclonal antibodies (MAbs) to TNF-alpha inhibited malarial antigen-induced HIV-1 replication, whereas MAb to IL-6 had no effect. Malarial antigen increased HIV-1 replication by increasing viral mRNA expression and by activating long terminal repeat-directed viral transcription. These data suggest that P. falciparum infection can modulate HIV-1 pathogenesis by activating lymphocytes and stimulating viral replication through the production of cytokines.


Asunto(s)
Antígenos de Protozoos/inmunología , Infecciones por VIH/inmunología , VIH-1 , Plasmodium falciparum/inmunología , Factor de Necrosis Tumoral alfa/metabolismo , Replicación Viral/inmunología , Animales , Anticuerpos Bloqueadores/inmunología , Linfocitos T CD8-positivos/inmunología , División Celular/inmunología , Proteína p24 del Núcleo del VIH/análisis , Infecciones por VIH/complicaciones , Infecciones por VIH/metabolismo , Duplicado del Terminal Largo de VIH/inmunología , Antígenos HLA-DR/inmunología , Humanos , Interleucina-10/metabolismo , Interleucina-6/inmunología , Interleucina-6/metabolismo , Leucocitos Mononucleares/citología , Leucocitos Mononucleares/virología , Receptores de Lipopolisacáridos/inmunología , Activación de Linfocitos , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , ARN Viral/metabolismo , Receptores CCR5/metabolismo , Receptores CXCR4/metabolismo , Transcripción Genética/inmunología , Factor de Necrosis Tumoral alfa/inmunología
19.
AIDS Res Hum Retroviruses ; 13(16): 1429-37, 1997 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-9359663

RESUMEN

In vitro infection of T cells with human T lymphotropic virus types I and II (HTLV-I and HTLV-II) resulted in constitutive expression of ICAM-1. Higher levels of ICAM-1 mRNA were expressed in HTLV-transformed cell lines (MT-2, MoT, C8166) when compared with uninfected T cell lines (A301). We demonstrate that this activation is conferred through a site on the ICAM-1 promoter that is activated in trans by the Tax protein of HTLV-I and HTLV-II. Enhanced promoter activity was detected when the ICAM-1 construct (-1162/+1) was transfected into HTLV-I-infected (MT-2), HTLV-II-infected (MoT, AI 1050), or an HTLV-I Tax-only-expressing (C8166) cell line as compared to the uninfected T cell line (A3.01). Cotransfection of the uninfected T cell line A3.01 with the ICAM construct along with Tax-I and Tax-II expression plasmid also resulted in increased promoter activity. Furthermore, experiments with deletion constructs of the ICAM-1 promoter region indicated that a region between -88 and -53 bp relative to the transcription start site is sufficient for Tax-inducible CAT expression. This segment includes an 11-bp palindromic segment (TTTCCGGGAAA) that has homology with the IFN-gamma and IL-6 response element. An 11-bp segment containing this regulatory region proved to be sufficient to confer Tax-I and Tax-II inducibility on a heterologous promoter (TK-CAT). Taken together these findings indicate that constitutive expression of ICAM-1 by HTLV-infected cells is influenced by the viral trans-activator protein Tax. This increased expression of ICAM-1 in response to the Tax protein may play an important role in the lymphoproliferation associated with HTLV infection.


Asunto(s)
Productos del Gen tax/fisiología , Genes Reguladores/fisiología , Genes , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 2 Humano/genética , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/fisiología , Linfocitos T/citología , Linfocitos T/virología , Activación Transcripcional , Línea Celular , Regulación de la Expresión Génica , Productos del Gen tax/genética , Genes Reguladores/genética , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/fisiología , Regiones Promotoras Genéticas/genética , Regiones Promotoras Genéticas/fisiología , ARN Mensajero/genética , ARN Mensajero/fisiología , Secuencias Reguladoras de Ácidos Nucleicos/genética , Secuencias Reguladoras de Ácidos Nucleicos/fisiología
20.
J Clin Child Psychol ; 26(3): 266-75, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9292384

RESUMEN

Uses a dimensional approach to evaluate the internal validity of the attention deficit hyperactivity disorder (ADHD) inattention (I) and hyperactivity/impulsivity (H/I), oppositional defiant disorder (ODD), and overt conduct disorder (CD) symptoms (i.e., whether a symptom has a stronger correlation with its own dimension than the other three dimensions). In Study 1, teachers rated 1,445 children on the DSM-III-R I, H/I, ODD, and overt CD symptoms. In Study 2, teachers rated 1,711 children on the DSM-IV I, H/I, ODD, and overt CD symptoms. All the I symptoms showed internal validity in both studies. In contrast, the H/I symptoms and the ODD symptoms, especially the H/I symptoms, showed weaker internal validity. All the overt CD symptoms showed internal validity except the DSM-IV bullies others symptom, with this symptom being more strongly related to the ODD dimension. Confirmatory factor analysis provided support for a 4-factor model consisting of I, H/I, ODD, and overt CD factors. Finally, the importance of internal validity for the construct validation of the disruptive behavior symptoms is discussed.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/diagnóstico , Trastornos de la Conducta Infantil/diagnóstico , Conducta Cooperativa , Determinación de la Personalidad/estadística & datos numéricos , Adolescente , Trastorno por Déficit de Atención con Hiperactividad/clasificación , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Trastornos de la Conducta Infantil/clasificación , Trastornos de la Conducta Infantil/psicología , Preescolar , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Psicometría , Reproducibilidad de los Resultados
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