RESUMEN
BACKGROUND: The exact incidence of infantile haemangiomas (IH) in the Chinese population is still unknown. A positive family history of IH was considered as a risk factor for the development of IH. OBJECTIVES: This study aims to investigate the incidence of IH in the Chinese population and the mechanism of family history increases the risk for IH development. METHODS: A total of 2489 women and their newborns were enrolled in the prospective study. All newborns were followed up for 12 months to determine whether they developed IH. In addition, 213 IH probands and their 174 siblings were enrolled in the study. The incidence of IH in siblings of the IH probands was investigated. Information regarding risk factors for IH and demographic data were collected on all children. RESULTS: Of the 2572 newborns, 58 IH were identified in 56 (2.2%) newborns. The majority of IH were located on the trunk (46.6%). Siblings of the IH probands were at increased risk for the development of IH (P = 0.024, relative risk 2.451), and the occurrence of prenatal risk factors for IH(P = 0.003) compared with the general population. CONCLUSIONS: Our study showed that the incidence of IH is 2.2% in the Chinese population. Siblings of the individuals with IH were at increased risk for the development of IH may be related to the family clustering of prenatal risk factors for IH. Further exploration of the mechanisms and common features of these prenatal risk factors may help to disclose the origin and pathogenesis of IH.
Asunto(s)
Hemangioma Capilar , Hemangioma , Niño , Análisis por Conglomerados , Femenino , Hemangioma/epidemiología , Hemangioma/genética , Humanos , Incidencia , Recién Nacido , Embarazo , Estudios Prospectivos , Factores de RiesgoRESUMEN
In regard to the affiliation mistake that was made during our correspondence in our manuscript, we write this letter in order to correct it as per my PhD requirements and this is the Final decision as I have no other option. The correction is only in the affiliation and should be: T.N. Mahmoud(1,2), P.F. Lin(1), F.L. Chen(1), J.H. Zhou(1), X.G. Wang(1), N. Wang(1), X. Li(1) and Y.P. Jin(1). (1)Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China. (2)Department of Animal Physiology and Biochemistry, Faculty of Veterinary Medicine, Nyala University, Nyala, South Darfur, Sudan.
RESUMEN
Luman/CREB3 is a transcription factor that is a member of the cAMP-response-element-binding protein family of basic region-leucine zipper transcription factors. This protein interacts with host cell factor 1, which also associates with the herpes simplex virus protein VP16 to induce the transcription of herpes simplex virus. Currently, the physiological function of Luman/CREB3 in reproductive processes remains unclear. In this study, quantitative real-time PCR and immunofluorescence assays were used to investigate the expression and localization of Luman in mouse oocytes as well as in early embryonic development. Luman protein was detected in the germinal vesicle and metaphase II stage oocytes, and was distributed in the cytoplasm, nucleus, and polar body of the oocyte stage. However, Luman protein and mRNA expression levels were significantly (P < 0.05) increased before activation of the zygotic genome, and expression levels peaked in 4-cell embryos. Expression levels were significantly (P < 0.05) decreased following the 8-cell stage throughout the blastocyst stage. The Luman protein was also distributed in the nucleus and cytoplasm in the early preimplantation embryo and showed enhanced nuclear staining starting from the 2-cell stage embryo up to the 8-cell stage embryo. The differences in the expression and localization of Luman in mouse oocytes and early embryo suggested that Luman plays an important role in oocyte maturation and early embryonic development processes.
Asunto(s)
Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Embrión de Mamíferos/metabolismo , Animales , Implantación del Embrión/fisiología , Femenino , Técnica del Anticuerpo Fluorescente , Ratones , Oocitos/metabolismo , Embarazo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Herp, a mammalian protein with a ubiquitin-like domain, can be strongly upregulated by endoplasmic reticulum (ER) stress during ER-associated protein degradation. However, the other cellular functions of Herp remain unclear. We explored the effect of Herp on ER stress and inflammatory responses in RAW 264.7 macrophages that had been exposed to tunicamycin or thapsigargin. We successfully constructed recombinant lentiviral vectors for Herp short-hairpin RNA (shRNA) expression to better understand the contribution made by Herp to other signaling pathways. Western blotting revealed that the recombinant Herp lentiviral shRNA vector significantly inhibited the expression of the Herp protein in the thapsigargin-treated RAW 264.7 macrophages. The reverse transcription quantitative polymerase chain reaction results showed that knockdown Herp inhibited the expression of ER stress-related genes during exposure to tunicamycin or thapsigargin. In RAW 264.7 macrophages, knockdown Herp markedly attenuated the expression of inflammatory cytokines when exposed to tunicamycin; however, it strongly enhanced the expression of inflammatory cytokines when exposed to thapsigargin. We concluded that Herp lentiviral shRNA vectors had been successfully constructed; knockdown Herp inhibited ER stress and had a different effect on inflammatory responses in RAW 264.7 macrophages depending on whether they were exposed to tunicamycin or thapsigargin.
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Estrés del Retículo Endoplásmico/genética , Inflamación/genética , Proteínas de la Membrana/genética , Animales , Estrés del Retículo Endoplásmico/efectos de los fármacos , Vectores Genéticos , Inflamación/patología , Lentivirus/genética , Macrófagos/metabolismo , Macrófagos/patología , Proteínas de la Membrana/antagonistas & inhibidores , Ratones , ARN Interferente Pequeño/genética , Transducción de Señal/efectos de los fármacos , Tunicamicina/farmacologíaRESUMEN
PURPOSE: To determine the accuracy of distance autorefractions obtained by two 'open field' devices, the Tracey Visual Function Analyzer and the Shin-Nippon NVision-K 5001, by comparison with subjective refraction. METHODS: Both eyes of 50 healthy phakic participants underwent subjective refraction. Autorefractions were then performed on undilated pupils using the Tracey and a modified Shin-Nippon autorefractor and these were repeated within 50 days. Agreement with subjective refraction was calculated for sphere, mean spherical equivalent (MSE) and cylindrical vectors J(0) and J(45). Intratest and intertest variability were also evaluated. RESULTS: The mean age of the participants was 37.4 years. Subjective refraction MSE ranged from -6.25 D to +3.62 D, mean -0.49 D +/- 1.79 D. Bias between subjective refraction and Tracey was -0.001 D, +0.045 D, +0.017 D, and -0.015 D for sphere, MSE, J(0) and J(45) respectively; these were not significant. Bias between subjective refraction and Shin-Nippon was +0.004 D, +0.033 D, +0.106 D, and -0.021 D; only the J(0) vector was significantly different (p < 0.0001) although this difference was small. Intratest variability for Tracey was low, measured at 0.189 D for sphere and 0.178 for MSE, and for the Shin-Nippon 0.099 D and 0.086 D respectively. Tracey intertest variability revealed small, statistically significant bias for sphere and MSE (+0.071 D and +0.070 D, p = 0.011, 0.013). Shin-Nippon reproducibility showed no significant bias. CONCLUSIONS: Autorefraction measurements captured by both the Tracey and Shin-Nippon devices agree well with subjective refraction. The Shin-Nippon shows lower intratest variability.
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Movimientos Oculares/fisiología , Refracción Ocular/fisiología , Errores de Refracción/diagnóstico , Selección Visual/instrumentación , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
OBJECTIVES: The purpose of this study was to quantify the effect of training on outcomes following colorectal cancer resections in a District General Hospital. PATIENTS AND METHODS: Data on 102 consecutive elective colorectal cancer resections performed at a District General Hospital over a three-year period were prospectively collated. The proportion of cases performed by trainees was recorded and the seniority of the operating surgeon was related to pre-operative morbidity, operative time and postoperative outcome. RESULTS: Consultants, staff grades and registrars performed 46, 35 and 21 procedures respectively. Of the cases performed by registrars, consultant supervision was provided in seven cases, with staff grades providing supervision in 14 cases. As compared with consultants, registrars were less likely to undertake anterior resection (p = 0.001). However, the mean operating times of trainees (145 +/- 8 mins) and consultants (135 +/- 6 mins) were similar. There were no significant differences between the groups with respect to postoperative mortality or morbidity. There was a trend towards more advanced disease in consultant cases, and consultants had a significantly poorer freedom from death or recurrence at two years as compared with trainees (p = 0.03). CONCLUSIONS: In our unit, trainees performed 21% of all elective colorectal resections with no detrimental effect on length of hospital stay, overall hospital costs and early and late patient outcomes. Major colorectal procedures can be successfully accomplished in a District General setting by trainees, with the training burden shared between consultants and staff grade surgeons.
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Neoplasias Colorrectales/cirugía , Procedimientos Quirúrgicos del Sistema Digestivo/estadística & datos numéricos , Cirugía General/educación , Anciano , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Hospitales de Distrito , Hospitales Generales , Humanos , Recurrencia Local de Neoplasia , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias , Estudios ProspectivosRESUMEN
BMS-378806 is a prototype of a new class of small molecule HIV-1 inhibitors that blocks viral attachment to cells. This compound exhibits potent inhibitory activity against a panel of HIV-1 laboratory and clinical isolates (M- and T-tropic), selective for HIV-1 and inactive against HIV-2, SIV and a panel of other viruses. BMS-378806 exhibits no significant cytotoxicity and displays many attractive pharmacological properties such as low protein binding, minimal serum effect on anti-HIV-1 potency, good oral bioavailability in animal species and a clean safety profile in initial animal toxicology studies. The compound binds to gp120 and blocks the attachment of the HIV-1 envelope protein to cellular CD4 receptors via a specific and competitive mechanism. BMS-378806 binds directly to gp120 at an approximately 1:1 stoichiometry, with a binding affinity similar to that of soluble CD4. Further confirmation that this class of compounds targets the envelope in infected cells was obtained through the isolation of resistant variants and the mapping of resistance substitutions to the HIV-1 envelope. In particular, two substitutions, M426L and M475I, are situated at or near the CD4 binding pocket of gp120. Recombinant HIV-1 carrying these two substitutions demonstrated significantly reduced susceptibility to inhibition. Using these HIV-1 gp120 resistant variants and gp120/CD4 contact site mutants, the potential BMS-378806 target site was localized to a specific region within the CD4 binding pocket of gp120. Together, the data show that BMS-378806 is the first of a new class of HIV inhibitors with the potential to become a valued addition to our current repertoire of antiretroviral drugs.
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Fármacos Anti-VIH/farmacología , Antígenos CD4/metabolismo , Sistemas de Liberación de Medicamentos/métodos , Proteína gp120 de Envoltorio del VIH/metabolismo , VIH-1/efectos de los fármacos , Animales , Fármacos Anti-VIH/metabolismo , VIH-1/metabolismo , Humanos , Piperazinas/metabolismo , Piperazinas/farmacología , Unión Proteica/efectos de los fármacosRESUMEN
Six boronated tetrapeptides with the carboxy moiety of phenylalanine replaced by dihydroxyboron were synthesized, and their activities against human immunodeficiency virus 1 (HIV-1) protease subsequently investigated. The sequences of these peptides were derived from HIV-1 protease substrates, which included the C-terminal part of the scissile bond (Phe-Pro) within the gag-pol polyprotein. Enzymatic studies showed that these compounds were competitive inhibitors of HIV-1 protease with K(i) values ranging from 5 to 18 microM when experiments were performed at high enzyme concentrations (above 5 x 10(-8) M); however, at low protease concentrations inhibition was due in part to an increase of the association constants of the protease subunits. Ac-Thr-Leu-Asn-PheB inhibited HIV-1 protease with a K(i) of 5 microM, whereas the non-boronated parental compound was inactive at concentrations up to 400 microM, which indicates the significance of boronation in enzyme inhibition. The boronated tetrapeptides were inhibitory to an HIV-1 protease variant that is resistant to several HIV-1 protease inhibitors. Finally, fluorescence analysis showed that the interactions between the boronated peptide Ac-Thr-Leu-Asn-PheB and HIV-1 protease resulted in a rapid decrease of fluorescence emission at 360 nm, which suggests the formation of a compound/enzyme complex. Boronated peptides may provide useful reagents for studying protease biochemistry and yield valuable information toward the development of protease dimerization inhibitors.
Asunto(s)
Compuestos de Boro/farmacología , Inhibidores de la Proteasa del VIH/farmacología , Proteasa del VIH/metabolismo , VIH/efectos de los fármacos , Compuestos de Boro/síntesis química , Compuestos de Boro/química , Supervivencia Celular/efectos de los fármacos , Resistencia a Medicamentos , Inhibidores de la Proteasa del VIH/síntesis química , Inhibidores de la Proteasa del VIH/química , Humanos , Péptidos/síntesis química , Péptidos/química , Péptidos/farmacología , Espectrometría de Fluorescencia , Células Tumorales CultivadasRESUMEN
BMS-232632 is an azapeptide human immunodeficiency virus (HIV) type 1 (HIV-1) protease inhibitor that displays potent anti-HIV-1 activity (50% effective concentration [EC(50)], 2.6 to 5.3 nM; EC(90), 9 to 15 nM). In vitro passage of HIV-1 RF in the presence of inhibitors showed that BMS-232632 selected for resistant variants more slowly than nelfinavir or ritonavir did. Genotypic and phenotypic analysis of three different HIV strains resistant to BMS-232632 indicated that an N88S substitution in the viral protease appeared first during the selection process in two of the three strains. An I84V change appeared to be an important substitution in the third strain used. Mutations were also observed at the protease cleavage sites following drug selection. The evolution to resistance seemed distinct for each of the three strains used, suggesting multiple pathways to resistance and the importance of the viral genetic background. A cross-resistance study involving five other protease inhibitors indicated that BMS-232632-resistant virus remained sensitive to saquinavir, while it showed various levels (0. 1- to 71-fold decrease in sensitivity)-of cross-resistance to nelfinavir, indinavir, ritonavir, and amprenavir. In reciprocal experiments, the BMS-232632 susceptibility of HIV-1 variants selected in the presence of each of the other HIV-1 protease inhibitors showed that the nelfinavir-, saquinavir-, and amprenavir-resistant strains of HIV-1 remained sensitive to BMS-232632, while indinavir- and ritonavir-resistant viruses displayed six- to ninefold changes in BMS-232632 sensitivity. Taken together, our data suggest that BMS-232632 may be a valuable protease inhibitor for use in combination therapy.
Asunto(s)
Inhibidores de la Proteasa del VIH/farmacología , Proteasa del VIH/metabolismo , VIH-1/efectos de los fármacos , Oligopéptidos/farmacología , Piridinas/farmacología , Secuencia de Aminoácidos , Sulfato de Atazanavir , Farmacorresistencia Microbiana/fisiología , Resistencia a Múltiples Medicamentos/fisiología , Proteasa del VIH/genética , VIH-1/enzimología , VIH-1/genética , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Mutación , Homología de Secuencia de Aminoácido , Especificidad por SustratoRESUMEN
BMS-232632 is an azapeptide human immunodeficiency virus type 1 (HIV-1) protease (Prt) inhibitor that exhibits potent anti-HIV activity with a 50% effective concentration (EC(50)) of 2.6 to 5.3 nM and an EC(90) of 9 to 15 nM in cell culture. Proof-of-principle studies indicate that BMS-232632 blocks the cleavage of viral precursor proteins in HIV-infected cells, proving that it functions as an HIV Prt inhibitor. Comparative studies showed that BMS-232632 is generally more potent than the five currently approved HIV-1 Prt inhibitors. Furthermore, BMS-232632 is highly selective for HIV-1 Prt and exhibits cytotoxicity only at concentrations 6,500- to 23, 000-fold higher than that required for anti-HIV activity. To assess the potential of this inhibitor when used in combination with other antiretrovirals, BMS-232632 was evaluated for anti-HIV activity in two-drug combination studies. Combinations of BMS-232632 with either stavudine, didanosine, lamivudine, zidovudine, nelfinavir, indinavir, ritonavir, saquinavir, or amprenavir in HIV-infected peripheral blood mononuclear cells yielded additive to moderately synergistic antiviral effects. Importantly, combinations of drug pairs did not result in antagonistic anti-HIV activity or enhanced cytotoxic effects at the highest concentrations used for antiviral evaluation. Our results suggest that BMS-232632 may be an effective HIV-1 inhibitor that may be utilized in a variety of different drug combinations.
Asunto(s)
Inhibidores de la Proteasa del VIH/farmacología , VIH-1/efectos de los fármacos , Oligopéptidos/farmacología , Piridinas/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Sulfato de Atazanavir , Proteínas Sanguíneas , Células Cultivadas , Combinación de Medicamentos , Interacciones Farmacológicas , Productos del Gen gag/metabolismo , Humanos , Técnicas In Vitro , Pruebas de Sensibilidad Microbiana , Precursores de Proteínas/metabolismoRESUMEN
The current report summarizes the available published and unpublished data from several investigators on resistance in clinical isolates following prolonged stavudine therapy. Results suggest that stavudine resistance is both modest in degree and infrequent in appearance. Phenotypic evaluation of 61 patients on stavudine therapy showed only modest changes in drug sensitivity following up to 29 months of treatment. The post-treatment isolates from 15 patients exhibited an increase in EC50 value > fourfold (level above variability of assay) when compared with the corresponding pretreatment isolates. However, the vast majority (11) of these pretreatment isolates either had unexpectedly low EC50 levels and/or had post-treatment isolates that lacked any amino acid changes within their reverse transcriptase (RT) gene to account for the observed change in sensitivity. Of the four remaining isolates, two appeared to have a multi-resistant phenotype to several nucleoside analogues and two had no detectable RT amino acid changes to account for the observed change in stavudine sensitivity. To date, clinical HIV-1 isolates displaying stavudine-specific resistance have yet to be reported. Furthermore, full or partial RT sequence analysis of 194 post-treatment isolates failed to identify any consistent amino acid changes. The strain-specific V75T mutation reported to confer stavudine resistance to the HXB2 HIV-1 strain in vitro, was found in only six isolates and did not correlate with stavudine resistance. This low incidence of stavudine resistance is in striking contrast to that observed with other nucleoside analogues and further supports the use of stavudine in first-line combination therapy for HIV patients.
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Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Fármacos Anti-VIH/uso terapéutico , Estavudina/uso terapéutico , Resistencia a Medicamentos , VIH-1/efectos de los fármacos , Humanos , Fenotipo , ADN Polimerasa Dirigida por ARN/genéticaAsunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Estavudina/uso terapéutico , Fármacos Anti-VIH/farmacología , Recuento de Linfocito CD4 , Células Cultivadas , ADN Viral/genética , Farmacorresistencia Microbiana/genética , Proteína p24 del Núcleo del VIH/inmunología , Infecciones por VIH/genética , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Leucocitos Mononucleares/virología , Pruebas de Sensibilidad Microbiana , Reacción en Cadena de la Polimerasa , Recombinación Genética , Estavudina/farmacologíaRESUMEN
Current treatments for human immunodeficiency virus (HIV) include both reverse transcriptase and protease inhibitors. Results from in vitro and clinical studies suggest that combination therapy can be more effective than single drugs in reducing viral burden. To evaluate compounds for combination therapy, stavudine (d4T), didanosine (ddI), or BMS-186,318, an HIV protease inhibitor, were combined with other clinically relevant compounds and tested in a T-cell line (CEM-SS) that was infected with HIV-RF or in peripheral blood mononuclear cells infected with a clinical HIV isolate. The combined drug effects were analyzed by the methods described by Chou and Talalay (Adv. Enzyme Regul. 22:27-55, 1984) as well as by Prichard et al. (Antimicrob. Agents Chemother. 37:540-545, 1993). The results showed that combining two nucleoside analogs (d4T-ddI, d4T-zidovudine [AZT], and d4T-zalcitabine [ddC]), two HIV protease inhibitors (BMS-186,318-saquinavir, BMS-186,318-SC-52151, and BMS-186,318-MK-639) or a reverse transcriptase and a protease inhibitor (BMS-186,318-d4T, BMS-186,318-ddI, BMS-186,318-AZT, d4T-saquinavir, d4T-MK-639, and ddI-MK-639) yielded additive to synergistic antiviral effects. In general, analysis of data by either method gave consistent results. In addition, combined antiviral treatments involving nucleoside analogs gave slightly different outcomes in the two cell types, presumably because of a difference in phosphorylation patterns. Importantly, no strong antagonism was observed with the drug combinations studied. These data should provide useful information for the design of clinical trials of combined chemotherapy.
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VIH/efectos de los fármacos , Inhibidores de Proteasas/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Replicación Viral/efectos de los fármacos , Línea Celular , Combinación de Medicamentos , Interacciones Farmacológicas , Estudios de Evaluación como Asunto , Humanos , Replicación Viral/fisiologíaRESUMEN
A series of novel aminodiol inhibitors of HIV protease based on the lead compound 1 with structural modifications at P1' were synthesized in order to reduce the cytotoxicity of 1. We have observed a high degree of correlation between the lipophilicity and cytotoxicity of this series of inhibitors. It was found that appropriate substitution at the para position of the P1' phenyl group of 1 resulted in the identification of equipotent (both against the enzyme and in cell culture) compounds (10l, 10m, 10n, and 15c) which possess significantly decreased cytotoxicity.
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Aminas/síntesis química , Inhibidores de la Proteasa del VIH/síntesis química , Aminas/química , Aminas/farmacología , División Celular/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Inhibidores de la Proteasa del VIH/química , Inhibidores de la Proteasa del VIH/farmacología , Humanos , Relación Estructura-ActividadRESUMEN
A fungal metabolite, BMS-182123, which inhibited bacterial endotoxin-induced production of tumor necrosis factor (TNF-alpha) in murine macrophages and human peripheral blood monocytes (in vitro), was isolated from the culture broth of Penicillium chrysogenum strain V39673. The effective BMS-182123 concentration (IC50) resulting in 50% inhibition of lipopolysaccharide-induced TNF-alpha production in murine macrophages and human monocytes was 600 ng/ml and 4.0 microgram/ml, respectively. BMS-182123 suppressed the lipopolysaccharide-induced TNF-alpha promoter activity and did not affect the stability of posttranscriptional mRNA. Addition of hydrophobic resin, Amberlite XAD-8 (1%), to the fermentation enhanced the production of BMS-182123 by 5.5 fold. A total of 577 mg pure BMS-182123 was recovered from a 250-liter fermentation supplemented with 1% Amberlite XAD-8.
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Hidrocarburos Aromáticos con Puentes/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Penicillium/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Secuencia de Bases , Hidrocarburos Aromáticos con Puentes/química , Hidrocarburos Aromáticos con Puentes/metabolismo , Sondas de ADN/genética , Fermentación , Humanos , Técnicas In Vitro , Lipopolisacáridos/farmacología , Ratones , Datos de Secuencia Molecular , Estructura Molecular , Penicillium/clasificación , Regiones Promotoras Genéticas/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
During the screening of natural products for their ability to inhibit the binding of HIV-REV protein to [33P]-labeled RRE RNA, one novel compound, niruriside (1), was isolated from the MeOH extract of the dried leaf of Phyllanthus niruri L. by bioassay-guided fractionation. The structure of niruriside was determined by spectroscopic methods. Niruriside showed specific inhibitory activity against the binding of REV protein to RRE RNA with an IC50 value of 3.3 microM; however, niruriside did not protect CEM-SS cells from acute HIV infection at concentrations up to 260 microM using an XTT dye reduction assay.
Asunto(s)
Antivirales/aislamiento & purificación , Antivirales/farmacología , Cinamatos/aislamiento & purificación , Cinamatos/farmacología , Disacáridos/aislamiento & purificación , Disacáridos/farmacología , Regulación Viral de la Expresión Génica/efectos de los fármacos , Productos del Gen rev/efectos de los fármacos , VIH-1/efectos de los fármacos , Hojas de la Planta/química , Plantas Medicinales/química , Antivirales/química , Unión Competitiva , Cinamatos/química , Disacáridos/química , Productos del Gen rev/genética , VIH-1/genética , Humanos , India , Leucemia de Células T , Extractos Vegetales/química , Unión Proteica/efectos de los fármacos , Unión Proteica/genética , ARN Viral/efectos de los fármacos , Células Tumorales Cultivadas , Productos del Gen rev del Virus de la Inmunodeficiencia HumanaRESUMEN
The observed in vitro and in vivo benefit of combination treatment with anti-human immunodeficiency virus (HIV) agents prompted us to examine the potential of resistance development when two protease inhibitors are used concurrently. Recombinant HIV-1 (NL4-3) proteases containing combined resistance mutations associated with BMS-186318 and A-77003 (or saquinavir) were either inactive or had impaired enzyme activity. Subsequent construction of HIV-1 (NL4-3) proviral clones containing the same mutations yielded viruses that were severely impaired in growth or nonviable, confirming that combination therapy may be advantageous. However, passage of BMS-186318-resistant HIV-1 (RF) in the presence of either saquinavir or SC52151, which represented sequential drug treatment, produced viable viruses resistant to both BMS-186318 and the second compound. The predominant breakthrough virus contained the G48V/A71T/V82A protease mutations. The clone-purified RF (G48V/A71T/V82A) virus, unlike the corresponding defective NL4-3 triple mutant, grew well and displayed cross-resistance to four distinct protease inhibitors. Chimeric virus and in vitro mutagenesis studies indicated that the RF-specific protease sequence, specifically the Ile at residue 10, enabled the NL4-3 strain with the triple mutant to grow. Our results clearly indicate that viral genetic background will play a key role in determining whether cross-resistance variants will arise.
Asunto(s)
Inhibidores de la Proteasa del VIH/farmacología , Proteasa del VIH/genética , VIH-1/efectos de los fármacos , Secuencia de Aminoácidos , Carbamatos/farmacología , Células Clonales , Análisis Mutacional de ADN , ADN Recombinante/genética , ADN Viral/genética , Esquema de Medicación , Farmacorresistencia Microbiana/genética , Quimioterapia Combinada , Etanolaminas/farmacología , Inhibidores de la Proteasa del VIH/administración & dosificación , VIH-1/enzimología , VIH-1/genética , Células HeLa , Humanos , Indinavir , Isoquinolinas/farmacología , Compuestos de Metilurea/farmacología , Datos de Secuencia Molecular , Mutación Puntual , Provirus/enzimología , Provirus/genética , Piridinas/farmacología , Quinolinas/farmacología , Virus Reordenados/efectos de los fármacos , Virus Reordenados/genética , Proteínas Recombinantes de Fusión/antagonistas & inhibidores , Proteínas Recombinantes de Fusión/metabolismo , Saquinavir , Linfocitos T , Urea/análogos & derivados , Urea/farmacología , Valina/análogos & derivadosRESUMEN
The human immunodeficiency virus (HIV) fusion inhibitor siamycin I, a 21-residue tricyclic peptide, was identified from a Streptomyces culture by using a cell fusion assay involving cocultivation of HeLa-CD4+ cells and monkey kidney (BSC-1) cells expressing the HIV envelope gp160. Siamycin I is effective against acute HIV type 1 (HIV-1) and HIV-2 infections, with 50% effective doses ranging from 0.05 to 5.7 microM, and the concentration resulting in a 50% decrease in cell viability in the absence of viral infection is 150 microM in CEM-SS cells. Siamycin I inhibits fusion between C8166 cells and CEM-SS cells chronically infected with HIV (50% effective dose of 0.08 microM) but has no effect on Sendai virus-induced fusion or murine myoblast fusion. Siamycin I does not inhibit gp120 binding to CD4 in either gp120- or CD4-based capture enzyme-linked immunosorbent assays. Inhibition of HIV-induced fusion by this compound is reversible, suggesting that siamycin I binds noncovalently. An HIV-1 resistant variant was selected by in vitro passage of virus in the presence of increasing concentrations of siamycin I. Drug susceptibility studies on a chimeric virus containing the envelope gene from the siamycin I-resistant variant indicate that resistance maps to the gp160 gene. Envelope-deficient HIV complemented with gp160 from siamycin I-resistant HIV also displayed a resistant phenotype upon infection of HeLa-CD4-LTR-beta-gal cells. A comparison of the DNA sequences of the envelope genes from the resistant and parent viruses revealed a total of six amino acid changes. Together these results indicate that siamycin I interacts with the HIV envelope protein.