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1.
J Environ Manage ; 351: 119614, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38043309

RESUMEN

This comprehensive review delves into the forefront of wastewater treatment technology, with a specific focus on the revolutionary concept of Zero Liquid Discharge (ZLD). (ZLD), underpinned by a sustainable ethos, aspires to accomplish total water reclamation, constituting a pivotal response to pressing environmental issues. The paper furnishes a historical panorama of (ZLD), elucidating its motivating factors and inherent merits. It navigates a spectrum of (ZLD) technologies encompassing thermal methodologies, (ZLD) synergized with Reverse Osmosis (RO), High-Efficiency Reverse Osmosis (HERO), Membrane Distillation (MD), Forward Osmosis (FO), and Electrodialysis Reversal (EDR). Moreover, the study casts a global purview over the deployment status of (ZLD) systems in pursuit of resource recovery, accentuating nations such as the United States, China, India, assorted European Union members, Canada, and Egypt. Meticulous case studies take center stage, underscoring intricate scenarios involving heavily contaminated effluents from challenging sectors including tanneries, textile mills, petroleum refineries, and paper mills. The report culminates by distilling sagacious observations and recommendations, emanating from a collaborative brainstorming endeavor. This compendium embarks on an enlightening journey through the evolution of wastewater treatment, (ZLD)'s ascendancy, and its transformative potential in recalibrating water management paradigms while harmonizing industrial progress with environmental stewardship.


Asunto(s)
Resiliencia Psicológica , Purificación del Agua , Aguas Residuales , Agua , Membranas Artificiales , Ósmosis , Tecnología , Abastecimiento de Agua
2.
Sci Rep ; 13(1): 7034, 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-37120645

RESUMEN

Powder metallurgy (PM) is a technique that involves the manufacturing of metal powders and their consolidation into finished products or components. This process involves the mixing of metal powders with other materials such as ceramics or polymers, followed by the application of heat and pressure to produce a solid, dense material. The use of PM has several advantages over traditional manufacturing techniques, including the ability to create complex shapes and the production of materials with improved properties. Cu-TiO2 composite materials are of great interest due to their unique properties, such as high electrical conductivity, improved mechanical strength, and enhanced catalytic activity. The synthesis of Cu-TiO2 composites using the PM technique has been gaining popularity in recent years due to its simplicity, cost-effectiveness, and ability to produce materials with excellent homogeneity. The novelty of using the PM technique for the preparation of Cu-TiO2 composite lies in the fact that it enables the production of materials with controlled microstructures and optical properties. The microstructure of the composite can be fine-tuned by controlling the particle size and distribution of the starting powders, as well as the processing parameters such as temperature, pressure, and sintering time. The optical properties of the composite can also be tailored by adjusting the size and distribution of the TiO2 particles, which can be used to control the absorption and scattering of light. This makes Cu-TiO2 composites particularly useful for applications such as photocatalysis and solar energy conversion. In summary, the use of Powder Metallurgy for the preparation of Cu-TiO2 composite is a novel and effective technique for producing materials with controlled microstructures and optical properties. The unique properties of Cu-TiO2 composites make them attractive for a wide range of applications in various fields, including energy, catalysis, and electronics.

5.
Sci Rep ; 12(1): 20974, 2022 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-36470902

RESUMEN

The major objective of this study was to examine the viability of using 5, 10, or 15 mass% of Activated Alum Sludge waste (AAS) instead of Ordinary Portland Cement (OPC) as a pozzolanic ingredient in concrete. This fundamental inquiry framed the investigation and OPC-AAS-hardened composites were studied to see whether they may benefit from inexpensive nanocomposites in terms of improved physical properties, mechanical strength, and resistance to heat and flame. The investigation set out to see how inexpensive nanocomposite might be put to use and the nanoparticles of CuFe2O4 spinel with an average size of less than 50 nm were successfully manufactured. Many different OPC-AAS-hardened composites benefit from the addition of CuFe2O4 spinel, which increases the composites' resistance to fire and enhances their physicomechanical properties at roughly average curing ages. Synthesized CuFe2O4 spinel was shown to have desirable characteristics by TGA/DTG and XRD. By using these methods, we were able to identify a broad variety of hydration yields, including C-S-Hs, C-A-S-Hs, C-F-S-Hs, and Cu-S-Hs, that enhance the physicomechanical properties and thermal resistivity of OPC-AAS-hardened composites as a whole. The composite material comprising 90% OPC, 10% AAS waste, and 2% CuFe2O4 has several positive economic and environmental outcomes.


Asunto(s)
Materiales de Construcción , Aguas del Alcantarillado , Análisis Costo-Beneficio
6.
Sci Rep ; 12(1): 20611, 2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36446843

RESUMEN

The goal of this research is to determine what chemicals are present in two different extracts (hexane and acetone) of Vicia faba (family Fabaceae, VF) peels and evaluate their effectiveness as a corrosion inhibitor on mild steel in a saline media containing 3.5% sodium chloride. Gas chromatography-mass spectrometry (GC/MS) was used to determine the composition of various extracts. It was determined that fourteen different chemicals were present in the hexane extract, the most prominent of which were octacosane, tetrasodium tetracontane, palmitic acid, and ethyl palmitate. Heptacosane, lauric acid, myristic acid, ethyl palmitate, and methyl stearate were some of the 13 chemicals found in the acetone extract. Using open circuit potential, potentiodynamic polarisation, and electrochemical impedance spectroscopic techniques, we can approximate the inhibitory effects of (VF) extracts on mild steel. The most effective inhibitory concentrations were found to be 200 ppm for both the hexane and acetone extracts (97.84% for the hexane extract and 88.67% for the acetone extract). Evaluation experiments were conducted at 298 K, with a 3.5% (wt/v) NaCl content and a flow velocity of about 250 rpm. Langmuir adsorption isotherm shows that the two extracts function as a mixed-type inhibitor in nature. Docking models were used to investigate the putative mechanism of corrosion inhibition, and GC/MS was used to identify the major and secondary components of the two extracts. Surface roughness values were calculated after analyzing the morphology of the metal's surface with and without (VF) using a scanning electron microscope (SEM). The results showed that throughout the surface of the mild steel, a thick adsorbate layer was formed. Quantum chemical calculations conducted on the two extracts as part of the theoretical research of quantum chemical calculation demonstrated a connection between the experimental analysis results and the theoretical study of the major chemical components.


Asunto(s)
Acero , Vicia faba , Corrosión , Hexanos , Ácidos Grasos , Agua , Análisis Costo-Beneficio , Acetona
8.
Sci Rep ; 12(1): 12536, 2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35869239

RESUMEN

The purpose of this work lies in the use of ionic liquids as corrosion inhibitors due to the difficulty in some oil fields with the solubility of corrosion inhibitors and these materials can be miscible with water and thus provide a solution to such problems in the industry. The second purpose is concerned with the lower toxicity of these compounds compared with the most common corrosion inhibitors. The study covered the corrosion inhibition performance of the ionic liquid 1-butyl-3-methylimidazolium trifluoromethyl sulfonate ([BMIm]TfO) for carbon steel in 3.5% NaCl solutions. The study comprised electrochemical, adsorption, and quantum chemical investigations. The results manifested that [BMIm]TfO can be considered a promising corrosion inhibitor and the inhibition efficacy intensifies as the concentration rises. The observed inhibitive effect can be correlated to the adsorption of the ionic liquid species and the creation of protecting films on the surface. The mode of adsorption follows the Langmuir adsorption isotherm. The polarization results showed that the ionic liquid [BMIm]TfO functions as a mixed inhibitor. Reliance of the corrosion influence on the temperature in the existence and absence of [BMIm]TfO was demonstrated in the temperature range of 303-333 K using polarization data. Activation parameters were determined and discussed. The observed inhibition performance of [BMIm]TfO was correlated with the electronic properties of the ionic liquid using a quantum chemical study.

9.
Appl Biochem Biotechnol ; 194(9): 4105-4134, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35633433

RESUMEN

Eichhornia crassipes root powder (ECRP) has been used to remove ammonia from aqueous solutions. The biosorption factors such as biosorbent dosage, pH, initial ammonia concentration, and contact time have been considered in batch conditions. The optimal conditions, at pH (6), sorbent dose 5 g/l, time (30 min) ammonia concentration (10 mg/l). Langmuir is better suited than Freundlich isotherm. The kinetic models Thomas, Yoon-Nelson, and Bohart-Adams were applied. These models showed that the adsorption capacity decreased with flow rate increases as follows: 32.57, 31.82, 31.25, and 30.17 mg/g, respectively, at a flow rate 10, 15, 20, and 25 ml/min. The root powder of Eichhornia crassipes was used to treat specific drainage wastewater obtained from the Sabal drain at Menoufia, Egypt. The average efficiency of ammonia removal was 87% per batch adsorption method at pH value = 7.5, sorbent dose 5 g/l, uptake period (30 min), and primary load 7.1 mg/l; however, ammonia removal by column continuous adsorption method exceeded 94%. In addition, ECRP is efficient in removing arsenic, sulfate, nitrates, nitrite, silica, iron, manganese, copper, zinc, aluminum, and lead from actual sewage wastewater, in addition to removing more than 75% COD.


Asunto(s)
Amoníaco , Aguas Residuales , Contaminantes Químicos del Agua , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Polvos , Contaminantes Químicos del Agua/análisis
10.
Leukemia ; 34(5): 1394-1406, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31811236

RESUMEN

The frailty index (FI) is based on the principle that the more deficits an individual has, the greater their risk of adverse outcomes. It is expressed as a ratio of the number of deficits present to the total number of deficits considered. We developed an MDS-specific FI using a prospective MDS registry and assessed its ability to add prognostic power to conventional prognostic scores in MDS. The 42 deficits included in this FI included measurements of physical performance, comorbidities, laboratory values, instrumental activities of daily living, quality of life and performance status. Of 644 patients, 440 were eligible for FI calculation. The median FI score was 0.25 (range 0.05-0.67), correlated with age and IPSS/IPSS-R risk scores and discriminated overall survival. With a follow-up of 20 months, survival was 27 months (95% CI 24-30.4). By multivariate analysis, age >70, FI, transfusion dependence, and IPSS were significant covariates associated with OS. The incremental discrimination improvement of the frailty index was 37%. We derived a prognostic score with five risk groups and distinct survivals ranging from 7.4 months to not yet reached. If externally validated, the MDS-FI could be used as a tool to refine the risk stratification of current clinical prognostication models.


Asunto(s)
Fragilidad/mortalidad , Fragilidad/patología , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/patología , Calidad de Vida , Sistema de Registros/estadística & datos numéricos , Medición de Riesgo/métodos , Actividades Cotidianas , Anciano , Anciano de 80 o más Años , Comorbilidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Tasa de Supervivencia
11.
Arch Pediatr ; 25(6): 378-382, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30145014

RESUMEN

OBJECTIVE: Genetic factors contribute significantly to type 1 diabetes (T1D) etiology. A single nucleotide polymorphism in the CD226 gene (rs763361 C>T) has been associated with T1D susceptibility in European patients, but data from other populations is limited. Our aim was to study the contribution of this polymorphism to T1D susceptibility among Egyptian children. METHODS: A case-control study including 74 children with T1D and 82 healthy children as a control group. Genotyping of CD226 gene polymorphism was performed for all participants by DNA extraction followed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS: The frequency of T allele was 78.4% in patients and 68.3% in controls (OR, 1.68; 95% CI, 1.01-2.8; P=0.046). TT, TC, and CC genotypes were found in 62.2%, 32.4%, and 5.4% of the patients, respectively, and in 41.5%, 53.7%, and 4.9% of controls, respectively. Under the recessive model, TT genotype was significantly associated with T1D risk (OR, 2.32; 95% CI, 1.21-4.41; P=0.010). The mean age at diabetes onset was significantly lower in patients carrying T allele compared with C allele (8.03±3.8 year vs. 10.5±2.54 year; P<0.001) and among those with TT genotype compared with the pooled TC+CC genotypes (7.5±2.6 year vs. 10.6±2.6 year; P<0.001). No significant difference was found between genotypes or alleles regarding the HbA1c level. CONCLUSION: T allele and TT genotype of the CD226 rs763361 polymorphism is associated with susceptibility to T1D and with a lower age of disease onset among Egyptian children.


Asunto(s)
Antígenos de Diferenciación de Linfocitos T/genética , Diabetes Mellitus Tipo 1/genética , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Egipto , Femenino , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Masculino , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple
12.
J Environ Manage ; 219: 325-331, 2018 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-29753240

RESUMEN

A potential and cost-effective treatment method utilizing thermally activated bentonite was evaluated for the treatment of highly loaded real petroleum processing wastewater (COD = 4500 mg/L) in order to reduce its COD and improve the corrosion properties. A save discharging COD limit of the treated effluent (800 mg/L) is achieved by using 6 g/L of calcinated bentonite after reaching the steady state (1 h of shaking) at pH 5. The durability of bentonite is proved. The corrosion behavior of the treated wastewater was investigated for mild steel by using electrochemical and weight loss measurements. The results proved that the corrosion rate of the wastewater was slightly reduced after the treatment process. More improvement of the corrosion resistance was achieved by adding sodium hexa-meta-phosphate (SHMP) corrosion inhibitor to the treated water. Tri-methyl ammonium bromide (CTAB) biocide was also added before discharging into municipal networks.


Asunto(s)
Petróleo , Aguas Residuales , Corrosión , Acero , Eliminación de Residuos Líquidos
13.
Drug Dev Ind Pharm ; 35(3): 311-20, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18798033

RESUMEN

The aim of this study was to develop fluconazole in an ultrapure polyvinyl alcohol (PVA) hydrogel able to deliver the drug in a sustained release pattern for local treatment of skin fungal infections. The topical fluconazole hydrogels were prepared using PVA hydrogels physically cross-linked by freeze-thaw technique. Polyethylene glycol (PEG) was added as a hydrophilic excipient as a release enhancer of fluconazole. The effects of PVA molecular weight, PEG molecular weight, and PEG concentration were studied using a 2 x 4 x 2 factorially designed experiment. The selected fluconazole hydrogel proved to be physically stable over a period of 6 months and to be effective in the topical treatment of cutaneous candidiasis. Therefore, it could be concluded that the formula composed of 10% PVA 205000 and 1.5% PEG 4000 and 2% fluconazole and prepared by three cycles of freezing, and thawing is very promising in the local treatment of skin fungal infection as an alternative to the systemic use of fluconazole.


Asunto(s)
Antifúngicos/administración & dosificación , Candidiasis Cutánea/tratamiento farmacológico , Fluconazol/administración & dosificación , Alcohol Polivinílico/química , Administración Cutánea , Animales , Antifúngicos/química , Reactivos de Enlaces Cruzados/química , Preparaciones de Acción Retardada , Portadores de Fármacos/química , Estabilidad de Medicamentos , Almacenaje de Medicamentos , Excipientes/química , Fluconazol/química , Congelación , Cobayas , Hidrogeles/química , Masculino , Peso Molecular , Polietilenglicoles/química
14.
AAPS PharmSciTech ; 9(1): 154-62, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18446476

RESUMEN

The purpose of this study was to prepare lipospheres containing aceclofenac intended for topical skin delivery with the aim of exploiting the favorable properties of this carrier system and developing a sustained release formula to overcome the side effects resulting from aceclofenac oral administration. Lipospheres were prepared using different lipid cores and phospholipid coats adopting melt and solvent techniques. Characterization was carried out through photomicroscopy, scanning electron microscopy, particle size analysis, DSC, In vitro drug release and storage study. The anti-inflammatory effect of liposphere systems was assessed by the rat paw edema technique and compared to the marketed product. Results revealed that liposphere systems were able to entrap aceclofenac at very high levels (93.1%). The particle size of liposphere systems was well suited for topical drug delivery. DSC revealed the molecular dispersion of aceclofenac when incorporated in lipospheres. Both entrapment efficiency and release were affected by the technique of preparation, core and coat types, core to coat ratio and drug loading. Lipospheres were very stable after 3 months storage at 2-8 degrees C manifested by low leakage rate (less than 7%) and no major changes in particle size. Finally, liposphere systems were found to possess superior anti-inflammatory activity compared to the marketed product in both lotion and paste consistencies. Liposphere systems proved to be a promising topical system for the delivery of aceclofenac as they possessed the ability to entrap the drug at very high levels and high stability, and to sustain the anti-inflammatory effect of the drug.


Asunto(s)
Preparaciones de Acción Retardada/química , Diclofenaco/análogos & derivados , Composición de Medicamentos/métodos , Inflamación/prevención & control , Liposomas/química , Administración Tópica , Animales , Antiinflamatorios no Esteroideos/administración & dosificación , Preparaciones de Acción Retardada/administración & dosificación , Diclofenaco/administración & dosificación , Diclofenaco/química , Difusión , Evaluación Preclínica de Medicamentos , Inflamación/patología , Masculino , Ensayo de Materiales , Ratas
15.
Int J Pharm ; 326(1-2): 107-18, 2006 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-16935442

RESUMEN

Mebeverine hydrochloride, a spasmolytic agent on GIT smooth muscles, was reported to have a local anesthetic effect. Thus, it was desired in this study to formulate mebeverine HCl into a gel that could be used locally in the treatment of different oral painful conditions. Poloxamer 407 (P-407) was used as the base for this gel. Different additives were used to enhance drug release from the preparation while others were used to enhance the residence time for the preparation. Different formulae were characterized in terms of drug release and mucoadhesion. The formula which has shown the best compromise between the aforementioned parameters was selected for clinical evaluation in comparison to Lidocaine HCl gel and rheologically examined. The best drug release enhancer was cetrimide (0.005%, w/w), while hydroxypropylcellulose (0.5%, w/w) as a mucoadhesive additive has shown the best compromise between fast drug release and mucoadhesion. The gel formula (G) has shown a better pain reduction efficiency (p=0.0078) and longer duration (p=0.0313) than Lidocaine HCl gel. Histopathological examination has shown no change in the inflammatory cells count of rat oral mucosa. Therefore, it could be concluded that (G) is very promising as a local anesthetic preparation for the treatment of different oral painful conditions.


Asunto(s)
Anestésicos Locales/administración & dosificación , Química Farmacéutica/métodos , Parasimpatolíticos/administración & dosificación , Tecnología Farmacéutica/métodos , Administración Tópica , Adolescente , Adulto , Anciano , Animales , Celulosa/análogos & derivados , Celulosa/química , Cetrimonio , Compuestos de Cetrimonio/administración & dosificación , Femenino , Humanos , Lidocaína/farmacología , Masculino , Persona de Mediana Edad , Mucosa Bucal/efectos de los fármacos , Fenetilaminas/farmacología , Ratas , Ratas Sprague-Dawley
16.
Respir Med ; 99(4): 415-20, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15763447

RESUMEN

Although factors influencing sputum smear conversion in tuberculosis have been studied well, the effect of smoking is largely unknown. Excluding those with incomplete history or drug resistant isolates, 339 patients out of the 526 sputum positive patients registered between 1998 and 2000 were studied. At the end of 2 months, smokers and non-smokers converted with almost the same frequency to a negative sputum status {P=0.065, OR (95%CI) 0.47 (0.21-1.06)}. Although gender or age had no effect on sputum conversion with respect to smoking status, expatriate smokers as a whole showed a significant difference. (P=0.039). On applying logistic regression model, smokers with far advanced radiographic abnormalities (P<0.038) or with 3+ smear status (P=0.011), were found to have a less chance of an early smear conversion. In conclusion smoking did not influence sputum smear conversion in tuberculosis. However, as expatriate smokers and smokers with advanced disease showed a delay in smear conversion, smoking should be discouraged in patients with pulmonary tuberculosis.


Asunto(s)
Antituberculosos/uso terapéutico , Fumar/efectos adversos , Esputo/microbiología , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto , Anciano , Combinación de Medicamentos , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Factores Sexuales , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Pulmonar/microbiología
18.
Clin Exp Immunol ; 138(1): 139-44, 2004 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-15373916

RESUMEN

The immunological diagnosis and development of new antituberculosis vaccines require the characterization of Mycobacterium tuberculosis antigens inducing cell-mediated immune responses. In this study, we have tested peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients (n = 43) and Bacille Calmette-Guérin (BCG)-vaccinated healthy subjects (n = 24) for in vitro cellular immune responses, as indicated by antigen-induced proliferation and interferon (IFN)-gamma secretion, in response to a panel of complex (culture filtrate and cell wall preparations) and single recombinant antigens (Mtb8.4, Mtb9.8, Mtb9.9, Mtb32A, Mtb39A, Mtb40, Mtb41 and Ag85B) of M. tuberculosis. The results of cellular responses showed that the majority (ranging from 70 to 98%) of TB patients and healthy donors responded to the complex antigens in antigen-induced proliferation and IFN-gamma secretion assays. However, when PBMC from the same groups of patients and healthy donors were tested with the recombinant antigens, TB patients showed strong recognition (>50% responders) of Mtb9.8 and Mtb39A in proliferation assays (median SI = 6.2 and 6.4, respectively) and of Mtb9.8, Mtb39A, Mtb40 and Ag85B in IFN-gamma assays (median delta IFN-gamma= 15.5, 10.8, 7.8 and 8.1 U/ml, respectively). BCG-vaccinated healthy donors showed weak (<30% responders) to moderate (31-50% responders) responses to all of the recombinant antigens in both assays. When PBMC of a subset of TB patients (n = 11) were tested for secretion of protective Th1 cytokines [IFN-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-12] and the immunosuppressive cytokine IL-10, the complex CF and CW antigens as well as the recombinant Mtb9.8, Mtb9.9, Mtb40 and Ag85B induced the secretion of both types of cytokines. On the other hand, Mtb41 induced only IL-10, while Mtb8.4, Mtb32Aand Mtb39A induced the secretion of one or more of Th1 cytokines, but not IL-10. In conclusion, the recombinant antigens inducing the secretion of Th1 cytokines could be useful as subunit vaccine candidates against TB.


Asunto(s)
Antígenos Bacterianos/inmunología , Inmunidad Celular/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis Pulmonar/inmunología , Vacuna BCG/inmunología , División Celular/inmunología , Células Cultivadas , Humanos , Interferón gamma/inmunología , Interleucina-10/inmunología , Interleucina-12/inmunología , Leucocitos Mononucleares/inmunología , Proteínas Recombinantes/inmunología , Células TH1/inmunología , Factor de Necrosis Tumoral alfa/inmunología
19.
Scand J Immunol ; 57(2): 125-34, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12588658

RESUMEN

We have used a synthetic-peptide approach to map epitope regions of the Mycobacterium tuberculosis ESAT-6 antigen recognized by human T cells in relation to major histocompatibility complex (MHC) restriction. ESAT-6-specific CD4+ T-cell lines were established by stimulating peripheral blood mononuclear cells from 25 HLA-DR-typed tuberculosis patients with complete antigen in vitro. The established T-cell lines were then screened for proliferation and interferon-gamma (IFN-gamma) secretion in response to eight overlapping 20-mer peptides covering the ESAT-6 sequence. The response of the T-cell lines to ESAT-6 and peptides from a human leucocyte antigen (HLA)-heterogeneous group of donors suggested the presence of multiple epitopes and promiscuous recognition of the antigen. Analysis of antigen and peptide recognition in the presence of anti-HLA class I and class II antibodies suggested that the T-cell lines recognized ESAT-6 in association with HLA-DR and -DQ molecules. Furthermore, testing of selected T-cell lines with ESAT-6 and the peptides in the presence of autologous and allogeneic HLA-DR- and -DQ-typed antigen-presenting cells identified HLA-DR2, -DR52 and -DQ2 amongst the HLA molecules involved in the presentation of ESAT-6 and its peptides to human Th1 cells. In addition, the T-cell lines were cytotoxic for monocytes and macrophages pulsed with ESAT-6 and peptides. In conclusion, the recognition of ESAT-6 by IFN-gamma-secreting and cytotoxic CD4+ T cells in association with frequently expressed HLA class II molecules supports the application of this antigen to either specific diagnosis or subunit vaccine design.


Asunto(s)
Antígenos Bacterianos/inmunología , Linfocitos T CD4-Positivos/inmunología , Antígenos HLA-DQ/inmunología , Antígenos HLA-DR/inmunología , Mycobacterium tuberculosis/inmunología , Células TH1/inmunología , Secuencia de Aminoácidos , Proteínas Bacterianas , Mapeo Epitopo , Humanos , Interferón gamma/biosíntesis , Datos de Secuencia Molecular , Péptidos/inmunología , Linfocitos T Citotóxicos/inmunología
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