RESUMEN
BACKGROUND: Evidence synthesis in the field of occupational safety and health (OSH) has been continuously growing over the last two decades. With over 100 systematic reviews now published, the Cochrane Work Review group has played an important role in this development and the Cochrane Thematic Group 'Work & Health & Social Security' was established recently to combine evidence from both the OSH and insurance medicine fields. Worldwide, many organizations produce and synthesize evidence in OSH that can complement and support each other. We believe that a global network including Cochrane and others can collaborate on methods development and in the production, synthesis, use and dissemination of different types of evidence even more effectively. AIMS: To determine if establishing a global network for evidence synthesis in OSH is feasible. METHODS: We conducted a survey of international and national institutions between November 2022 and January 2023 using LimeSurvey. Participants included representatives of affiliated and sustaining members of the International Commission on Occupational Health, national institutes for OSH, academia and other international organizations. RESULTS: From 151 invitations, we received responses from 57 representatives of 54 organizations. Representatives reported that their organization will contribute financially on an annual basis (nâ =â 1) or provide in-kind support (nâ =â 10), and will probably be able to provide financial or in-kind support (nâ =â 25). CONCLUSIONS: The feasibility criterion was met and an international network is being established.
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Salud Laboral , Humanos , Estudios de Factibilidad , Encuestas y CuestionariosRESUMEN
A study leaded in 2005 by the ILO on diet habits in different countries pointed out that poor diet at the workplace (leading to malnutrition or overweight and obesity) costs up to 20% & in lost productivity. Obesity is a major cause for absenteeism and can modify physiologic and immune responses to neurotoxins and chemical agents. Obese subjects show a higher risk to develop cardiovascular diseases, musculoskeletal disorders, due to exposure to vibrations, etc; quite often these workers are discriminated, are more sensitive to work-related stress and might experience a reduced self-esteem. Obesity can cause relevant working handicaps linked to reduction of agility, to early fatigue and to difficulties in identifying and use of suitable PPE. As a consequence, obese workers show a higher rate of work accidents and may receive some restrictions in the fitness assessment carried out by the occupational health physician during periodical examinations.
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Dieta , Promoción de la Salud , Obesidad/prevención & control , Salud Laboral , HumanosRESUMEN
Chagas' disease (CD) is highly prevalent in South America. Brazilian surgeons and gastroenterologists gained valuable experience in the treatment of CD esophagopathy (chagasic achalasia) due to the high number of cases treated. The authors reviewed the lessons learned with the treatment of achalasia by different centers experienced in the treatment of Chagas' disease. Preoperative evaluation, endoscopic treatment (forceful dilatation and botulinum toxin injection), Heller's myotomy, esophagectomy, conservative techniques other than myotomy, and reoperations are discussed in the light of personal experiences and review of International and Brazilian literature. Aspects not frequently adopted by North American and European surgeons are emphasized. The review shows that nonadvanced achalasia is frequently treated by Heller's myotomy. Endoscopic treatment is reserved to limited cases. Treatment for end-stage achalasia is not unanimous. Esophagectomy was a popular treatment in advanced disease; however, the morbidity/mortality associated to the procedure made some authors seek different alternatives, such as Heller's myotomy and cardioplasties. Minimally invasive approach to esophageal resection may change this concept, although few centers perform the procedure routinely.
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Enfermedad de Chagas/cirugía , Acalasia del Esófago/cirugía , Esófago/patología , Brasil , Cateterismo/métodos , Enfermedad de Chagas/mortalidad , Enfermedad de Chagas/terapia , Acalasia del Esófago/mortalidad , Acalasia del Esófago/terapia , Esofagectomía/métodos , Esofagoplastia/métodos , Esofagoscopía/métodos , Esófago/cirugía , Femenino , Humanos , Inyecciones Intralesiones , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Fármacos Neuromusculares/uso terapéutico , Pronóstico , Medición de Riesgo , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Resultado del TratamientoRESUMEN
CONCLUSIONS: The absence of recurrences after final nasal reconstruction demonstrates the reliability of our three-stage strategy and the necessity to delay nasal reconstruction, focusing attention on oncological safety for nasal non-melanoma skin cancer (NMSC) with mucosal invasion. OBJECTIVES: To validate a therapeutic strategy aimed at oncological safety and minimization of possible recurrences after full-thickness excision of nasal NMSC with mucosal invasion. The strategy was divided into three stages: surgical excision with clinically safe perilesional skin margins and extemporary frozen section histological control; 8-15 months follow-up leaving the nasal defect unreconstructed with a 'wait and see' strategy; new extemporary histological control of defect margins and, if negative, definitive reconstruction. PATIENTS AND METHODS: Twenty patients affected by nasal NMSC with mucosal invasion were treated and followed up. RESULTS: Basal cell carcinoma was the most common lesion (75%), followed by squamous cell carcinoma (25%). Ultrasonography excluded lymphatic involvement for SCC. Before final reconstruction, extemporary histological examination revealed the presence of tumour cells in three patients. After tumour extirpation, these patients were resubmitted to a new follow-up period before reconstruction. No recurrences were observed after definitive nasal reconstruction in all patients during the 5-year follow-up.
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Carcinoma Basocelular/cirugía , Carcinoma de Células Escamosas/cirugía , Neoplasias Nasales/cirugía , Rinoplastia/métodos , Neoplasias Cutáneas/cirugía , Anciano , Carcinoma Basocelular/patología , Carcinoma de Células Escamosas/patología , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mucosa Nasal , Invasividad Neoplásica , Neoplasias Nasales/patología , Estudios Retrospectivos , Neoplasias Cutáneas/patología , Resultado del TratamientoRESUMEN
BACKGROUND: General dental care can effectively control disease and restore damaged tissue, yet little is known about its impact on patients' subjective oral health, namely treatment goals and oral health-related quality of life (OHRQoL). This study aimed to evaluate change in both aspects of subjective oral health among elderly adults receiving publicly-funded, general dental care. METHODS: We conducted a prospective, single-group intervention study of adults aged 75+ years receiving care through the South Australian Dental Service (SADS). Before receiving dental care, subjects completed the Oral Health Impact Profile (OHIP-14) questionnaire which evaluates OHRQoL. In this questionnaire, subjects rated the extent to which they had attained a self-nominated oral health goal. Dentists provided standard-of-care treatment and six months later the OHIP-14 and goal attainment questions were re-administered. RESULTS: Among the 253 adults studied, overall improvements in OHRQoL were observed (p < 0.05), although the effect was dependent on pre-treatment goal: mean OHIP-14 scores did not change significantly for subjects whose goal was less pain/discomfort while significant improvements were observed for subjects with other treatment goals. In contrast, mean goal attainment ratings improved significantly (P < 0.05), regardless of treatment goal categories. CONCLUSIONS: Dental care was associated with improvements in subjective oral health, although different patterns of improvement were observed for OHRQoL compared with goal attainment ratings.
Asunto(s)
Cuidado Dental para Ancianos , Objetivos , Salud Bucal , Calidad de Vida , Anciano , Anciano de 80 o más Años , Actitud Frente a la Salud , Atención Odontológica Integral/clasificación , Cuidado Dental para Ancianos/clasificación , Dentaduras , Dolor Facial/prevención & control , Femenino , Estudios de Seguimiento , Estado de Salud , Humanos , Arcada Parcialmente Edéntula/clasificación , Masculino , Masticación/fisiología , Estudios ProspectivosRESUMEN
The authors present the section, part of the ISPESL's website, dedicated to tobacco smoke at work. In this subdivision many topics regarding problems caused by tobacco smoke in the workplaces are gathered and discussed so that different personnel responsible for health and prevention at work can find a technical answer to take part to the improvement of the psychophysical welfare of both smokers and non smokers. The general information section has collected the relative Italian and international laws regarding smoking in the workplace along with representative court cases, and some publications and essays which have been presented on this topic. Inside the section dedicated to the employers and companies, the authors have posted useful importation on smoking in the workplace which includes some tools that can turn to be interesting to those who are supposed to be involved with prevention, the updated addresses of the national public antismoking centers, experiences and activities against tobacco smoke of national and international companies, events regarding smoke at work, informative sheets and leaflets for smokers, link to other site that argue about this topic. Moreover, there is a section dedicated to a forum where Internet user can share their experiences and thoughts on workplaces free from tobacco smoke.
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Internet , Salud Laboral , Prevención del Hábito de Fumar , Contaminación por Humo de Tabaco/prevención & control , Lugar de Trabajo , HumanosRESUMEN
Discovered in 1830, paraffin oil, a purified hydrocarbon from petroleum, has been used in the past as an augmentation material in various parts of the human body, for restoration body defects or aesthetic body contouring. We illustrated the case of an 18-year-old guy who self-injected some paraffin oil (Baby Johnson's Oil) in his lips, cheek and chin, with aesthetical purpose. We showed the classical course and proper management of paraffinoma's lesions. The need for complete excision of all involved tissue to treat the condition successfully is illustrated, and a clinical, pathological and histological discussion is presented. To our knowledge paraffinoma of the face caused by a self-injection of mineral oil has been never reported in literature.
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Técnicas Cosméticas/efectos adversos , Aceites/administración & dosificación , Parafina/administración & dosificación , Adolescente , Humanos , Inyecciones Subcutáneas , MasculinoRESUMEN
We have studied the plasma membrane fluidity of rat C6 glioblastoma cells and simian virus 40-transformed mouse liver cells in culture that had been rendered resistant to doxorubicin. This was done by the evaluation of fluorescence anisotropy of two probes; diphenylhexatriene was used on membrane microsomal fractions, and trimethylammonium-diphenylhexatriene was used on whole cell suspensions as a plasma membrane-specific probe since it does not enter the cells. A higher degree of membrane fluidity was exhibited with both techniques by doxorubicin-resistant glioblastoma cells as compared to the doxorubicin-sensitive strain, but in the transformed liver cells no such alteration was seen in the physical properties of their plasma membranes. A higher degree of acyl group unsaturation was noticed in the glioblastoma cells but not in the transformed liver cells upon acquisition of doxorubicin resistance. A similar simultaneous increase in acyl group unsaturation and membrane fluidity can be obtained easily by growing the sensitive cells with a medium supplemented with exogenous polyunsaturated fatty acids. This alteration does not modify the sensitivity of the cells to doxorubicin. We conclude from our work that the increase in membrane fluidity, which is frequently associated with drug resistance, is neither necessary nor sufficient for the expression of the resistance. The reason for a link between cell resistance to doxorubicin and plasma membrane fluidity remains to be found.
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Doxorrubicina/farmacología , Glioma/fisiopatología , Animales , Ciclo Celular/efectos de los fármacos , Línea Celular , Membrana Celular/fisiología , Resistencia a Medicamentos , Ácidos Grasos Insaturados/fisiología , Polarización de Fluorescencia , Glioma/patología , Glioma/ultraestructura , Fluidez de la Membrana , Lípidos de la Membrana/fisiología , Microsomas/fisiología , RatasRESUMEN
We have studied the lipid composition and the acyl group composition, transport, and metabolism of doxorubicin-sensitive and -resistant rat glioblastoma cells in monolayer cultures (C6 clone). No difference in lipid composition was evidenced; the acyl group composition was, in contrast, highly modified in resistant cells, and these modifications appeared progressively during the acquisition of the resistance. Resistant cells were characterized by a decrease of n-9 eicosatrienoic acid and by a 2-3-fold increase of the proportions of the polyunsaturated fatty acids of the n-6 and n-3 families, especially arachidonic acid and n-3 docosahexaenoic acid. These differences were probably due to a 2-fold increase of the uptake of fatty acids by resistant cells as compared to sensitive cells, this increase allowing the suppression of an essential fatty acid deficiency. Only small changes in the transformations of 16 and 18-carbon atoms' fatty acids to higher analogues were evidenced. A small reduction of the desaturation of stearic acid to oleic acid and of linoleic acid to arachidonic acid was the main characteristic of resistant cells; these differences can be explained as a consequence of the suppression of the essential fatty acid deficiency.
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Doxorrubicina/uso terapéutico , Resistencia a Medicamentos , Ácidos Grasos/metabolismo , Glioma/metabolismo , Metabolismo de los Lípidos , Animales , Transporte Biológico , Ácidos Grasos Esenciales/metabolismo , Ácidos Grasos Insaturados/metabolismo , Glioma/tratamiento farmacológico , RatasRESUMEN
A large-scale purification procedure was developed to isolate the five subunits of F1-ATPase from pig heart mitochondria. The previously described procedure (Williams, N. and Pedersen, P.L. (1986) Methods Enzymol. 126, 484-489) to dissociate the rat liver F1-ATPase by cold treatment followed by warming at 37 degrees C has been adapted for the pig heart enzyme. Removal of endogenous nucleotides from that enzyme before dissociation led to the efficient separation of the alpha and gamma subunits from beta, delta and epsilon subunits. The beta subunit was purified in the hundred-milligram range by anion-exchange chromatography in the absence of any denaturing agent. This subunit was free from any bound nucleotide and almost no ATPase and adenylate kinase-like activities were detected. The delta and epsilon subunits were purified by reversed-phase chromatography (RP-HPLC) in the milligram range. As recently reported (Penin, F., Deléage, G., Gagliardi, D., Roux, B. and Gautheron, D.C. (1990) Biochemistry 29, 9358-9364), these purified subunits kept biophysical features of folded proteins and their ability to reconstitute the tight delta epsilon complex. The alpha and gamma subunits remained poorly soluble and required dissociation by 8 M guanidinium chloride prior to their purification by RP-HPLC. In addition, characterizations of the five subunits by IEF and SDS-polyacrylamide gel electrophoresis are reported, as well as ultraviolet spectra and solubility properties of the beta, delta and epsilon subunits.
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Cromatografía Líquida de Alta Presión/métodos , Mitocondrias Cardíacas/enzimología , ATPasas de Translocación de Protón/aislamiento & purificación , Animales , Electroforesis en Gel de Poliacrilamida , ATPasas de Translocación de Protón/metabolismo , ATPasas de Translocación de Protón/ultraestructura , Espectrofotometría Ultravioleta , PorcinosRESUMEN
The region comprised between the amino acids 175 and 199 of the HTLV-I envelope surface glycoprotein is one of the immunodominant domains of this molecule. In this region, which is well recognized by sera from HTLV-I infected patients, a substitution of the proline at position 192 by a serine has been described in some isolates. Because this mutation could modify the secondary structure of the glycoprotein molecule, we studied the inference of the presence of proline or serine on the recognition of the region 175-199 by human sera. For this, three peptides have been synthetized (a 25-mer 175-199 corresponding to the sequence of the ATK prototype, and two internal 10-mer 190-Pro-199 and 190-Ser-199 having a proline or a serine at position 192) and tested by immunosorbent assay. While most sera reacted with 190-Pro-199 and with 190-Ser-199 synthetic peptides, a differential recognition was observed according to the pathology associated to HTLV-I infection. Moreover sera corresponding to patients infected with a virus harboring a serine at position 192 were found to recognize only the 10-mer with a serine. These data indicates that HTLV-I is subject to antigenic variability.
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Productos del Gen env/inmunología , Antígenos HTLV-I/inmunología , Infecciones por HTLV-I/inmunología , Proteínas Oncogénicas de Retroviridae/inmunología , Infecciones por HTLV-I/sangre , Humanos , Leucemia de Células T/inmunología , Modelos Moleculares , Fragmentos de Péptidos/inmunologíaRESUMEN
Essential HTLV-I biological functions depend on the structural motives of the surface glycoprotein (gp46). Monoclonal antibodies (mAbs) have been generated in order to identify functional regions of gp46. We obtained three monoclonal antibodies (3F3F10, 4F5F6 and 7G5D8) by immunizing Balb/c mice with beta-propiolactone inactivated HTLV-I producing cells and partially purified gp46. The mAbs are of the IgG 1 subclass. They have been characterized by western blot analysis, reactivity with HTLV-I and HTLV-II producing cells and ELISA binding assays using synthetic peptides. The immunoblot analysis performed with sheets prepared with the virus released by HUT 102 and 2060 cells (an HTLV-I virus producing cell line established in our laboratory) indicate that the three mAbs recognize a 46 kDa product as did the anti -gp46 mAb 0.5 alpha (18). Reactivity of the three mAbs with various cell lines was examined by indirect immunofluorescence assay. The mAb 7G5D8 stained strongly the membrane of all HTLV-I producing cells (MT2, C91/PL, HUT102 and cells of seven lines established in our laboratory and by A. Gessain); uninfected lymphoid cells (HSB-2, MOLT 4, CEM and PHA activated lymphocytes from normal donors) were negative. Interestingly cells of a HTLV-II producing line (344 MO) were positive. The mAbs 3F3F10 and 4F5F6 reacted with the same cells as did 7G5D8 but the fluorescence intensity was much lower than that observed with this later. A long synthetic peptide corresponding to the immunodominant region of the gp46 defined by the amino acids 175-199 and 10-mer peptides overlapping this region were used in an approach to identify the recognized epitope(s). The long 175-199 peptide was recognized by the three mAbs. 3F3F10 and 4F5F6 recognized none of the 10-mer peptides whereas 7G5D8 bound to 186-195 and 182-191 peptides. In addition 7G5D8 did not inhibit either syncytia formation or virus infection. In view of the data concerning the previously described mAbs 0.5 alpha, LAT 27 (5) and KE36-11 (6), our results suggest that the epitope recognized by 7G5D8 is different from those recognized by the former ones. As the 183-191 sequence corresponds to a region in which HTLV-I and HTLV-II harbour six common amino acids and two similar ones, this is consistent with the observation that 7G5D8 stained the HTLV-II producing cells 344 MO as well as all HTLV-I producing ones. Altogether our data support the hypothesis whereby this epitope recognized by 7G5D8 is contained within a sequence defined by amino acids 183-191.
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Anticuerpos Monoclonales/inmunología , Productos del Gen env/inmunología , Antígenos HTLV-I/inmunología , Proteínas Oncogénicas de Retroviridae/inmunología , Animales , Epítopos/análisis , Humanos , Immunoblotting , Ratones , Ratones Endogámicos BALB C , Fragmentos de Péptidos/inmunologíaRESUMEN
The majority of neutralizing antibodies of HTLV-I are directed against linear epitopes of the envelope surface glycoprotein (gp46) in the immunodominant region 175-199. Although gp46 presents a remarkable degree of conservation, the substitution of the proline at position 192 by a serine is described for 10 isolates among the 54 sequenced ones. This amino acid substitution is known to induce an important change in the orientation of the exposed residues of this region and has drastic consequences on the immunogenicity of the neutralizable epitopes located in this region. We developed monoclonal antibodies directed against epitopes located in this region containing a proline or a serine at position 192. The six monoclonal antibodies obtained recognize the gp46 at the surface of living HTLV-I producing cells, two of them are specific of a 190-197 epitope with a serine at position 192. This demonstrates that the antigenicity of this epitope differs depending on the presence of a proline or a serine at position 192. Altogether, these results demonstrate that the immunodominant neutralizable region 175-199 is antigenically variable.
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Anticuerpos Monoclonales , Variación Antigénica , Productos del Gen env/inmunología , Virus Linfotrópico T Tipo 1 Humano/inmunología , Proteínas Oncogénicas de Retroviridae/inmunología , Secuencia de Aminoácidos , Línea Celular , Epítopos/química , Epítopos/inmunología , Productos del Gen env/química , Humanos , Activación de Linfocitos , Linfocitos/inmunología , Linfocitos/virología , Datos de Secuencia Molecular , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Prolina , Proteínas Oncogénicas de Retroviridae/química , Serina , Células Tumorales CultivadasRESUMEN
The proteins involved in mitochondrial mRNA processing and degradation in higher plants have yet to be identified. As a first step towards this aim, we report here the characterisation of a nuclear-encoded DExH box RNA helicase (AtSUV3) localised in Arabidopsis thaliana mitochondria. The AtSUV3 mRNA is assembled from the 16 exons of a weakly expressed unique gene and the predicted protein has a calculated molecular weight of 63.6 kDa. Subcellular fractionation of transgenic plants expressing AtSUV3/GUS fusion proteins localises this protein in mitochondria. The N-terminal domain of AtSUV3 containing the motifs characteristic of DExH box RNA helicases exhibits a low endogenous ATPase activity in vitro which can be stimulated by the presence of mitochondrial RNA, confirming that AtSUV3 is an RNA helicase.
Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/enzimología , Proteínas de Plantas/genética , ARN Helicasas/genética , ARN/metabolismo , Adenosina Trifosfatasas/metabolismo , Secuencia de Aminoácidos , ARN Helicasas DEAD-box , Regulación de la Expresión Génica de las Plantas , Mitocondrias/enzimología , Datos de Secuencia Molecular , Proteínas de Plantas/química , Plantas Modificadas Genéticamente , Seudogenes , ARN Helicasas/química , ARN Mensajero/metabolismo , ARN Mitocondrial , Proteínas Recombinantes de Fusión , Homología de Secuencia de Aminoácido , Solanum tuberosum/genéticaRESUMEN
Daunorubicin and doxorubicin, two antibiotics belonging to the anthracycline group, are widely used in human cancer chemotherapy. Their activity has been attributed mainly to their intercalation between the base pairs of native DNA. Complex formation between daunorubicin or doxorubicin with polydeoxyribonucleotides and DNAs of various base composition or chromatins has been investigated by numerous techniques. Many authors have tried to correlate biological and therapeutic activities with the affinity of the drugs for DNA or some specific sequences of DNA. In vivo these anthracycline drugs cause DNA damage such as fragmentation and single-strand breaks. The mechanism of action of anthracyclines involves the inhibition of RNA and DNA syntheses. There exists two limiting factors in the use of anthracyclines as antitumoral agents: a chronic or acute cardiotoxicity and a spontaneous or acquired resistance. In both cases, there is probably an action at the membrane level. It has to be noted that daunorubicin and doxorubicin have a particular affinity for phospholipids and that the development of resistance is linked to some membrane alterations.
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ADN/metabolismo , Daunorrubicina , Doxorrubicina , Animales , Fenómenos Químicos , Química , Replicación del ADN/efectos de los fármacos , Daunorrubicina/análogos & derivados , Daunorrubicina/farmacología , Daunorrubicina/toxicidad , Doxorrubicina/análogos & derivados , Doxorrubicina/farmacología , Doxorrubicina/toxicidad , Corazón/efectos de los fármacos , Humanos , Conformación Molecular , Desnaturalización de Ácido Nucleico , Relación Estructura-Actividad , Transcripción Genética/efectos de los fármacosRESUMEN
Fractionation of native DNA on hydroxyapatite columns depends, when flat and continuous gradients are used, on the base composition, GC-rich fractions being eluted in the first fractions. Crab satellite DNA behaves abnormally : the first eluted fractions are enriched in poly d(A-T).d(A-T) instead of GC as usual. It amy be suggested that these differences in the behaviour could be attributed to the fact that the secondary structure of crab DNA satellite is different from the secondary structure of the main DNA component.
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ADN Satélite/aislamiento & purificación , ADN/aislamiento & purificación , Testículo/análisis , Conducto Deferente/análisis , Animales , Braquiuros , Centrifugación por Gradiente de Densidad , Cromatografía en Gel , Desoxirribonucleasas , Hidroxiapatitas , Masculino , SonicaciónRESUMEN
Human T-cell leukemia virus (HTLV-I) induces adult T cell leukemia/lymphoma (ATL) and a chronic neurological disease named either tropical spastic paraparesis (TSP) or HTLV-I associated myelopathy (HAM). We report here the establishment and characterization of eight HTLV-I-infected lymphoid cell lines derived either from patients with TSP (5) or from asymptomatic carriers (1). Southern blot analysis of T cell beta chain gene rearrangements indicates that all cell lines are composed of clonal populations. The same type of analysis performed with HTLV-I-specific probes showed that they harbor 1 to 5 copies of full length proviruses often associated with deleted proviruses with a restriction map for BamHI, HindIII, PstI and SacI restriction enzymes resembling those of HTLV-I previously isolated from Japan and Caribbean area. One of the cell lines, 2060, derived from a TSP patient was shown to express a relative large amount of virus easily transmissible to fresh peripheral and cord blood lymphocytes. The full length proviral genome contained in this cell line was cloned and used in transient expression experiments. We showed that the cloned provirus was able to direct the synthesis of the major structural viral proteins, the protease and the tax and rex regulatory proteins. The structural viral proteins could be assembled into free particles detected in the culture medium of transfected cells. Although the infectivity of these viral particles remains to be determined, this new clone can be employed to examine the cell types in which this TSP-derived provirus directs viral protein synthesis and eventually replicates. It should also prove of value in studies on the early cellular events induced by viral products.
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Infecciones por HTLV-I/microbiología , Virus Linfotrópico T Tipo 1 Humano , Animales , Secuencia de Bases , Línea Celular , Chlorocebus aethiops , Clonación Molecular , ADN Viral/genética , Guyana Francesa , Expresión Génica , Genes env , Virus Linfotrópico T Tipo 1 Humano/genética , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Virus Linfotrópico T Tipo 1 Humano/fisiología , Humanos , Martinica , Microscopía Electrónica , Datos de Secuencia Molecular , Provirus/genética , Provirus/aislamiento & purificación , Provirus/fisiología , Integración Viral , Replicación ViralRESUMEN
The surface envelope glycoprotein gp46 of the human T cell leukemia virus type 1 elicits a strong immune response. Its protective role against HTLV-1 infection in animal models is well established, suggesting that recombinant envelope glycoproteins or synthetic peptides could be used as an effective vaccine. However, reports have indicated that some variations in envelope sequences may induce incomplete cross-neutralization between HTLV-1 strains. To identify amino acid changes that might be involved in induction of specific neutralizing antibodies, we studied sera from three patients (2085, 2555, and 2709) infected by HTLV-1 with surface glycoprotein gp46 harboring variations in amino acid sequence at positions 39, 72, 265, and 290. Inhibition of syncytia induced by parental, chimeric, or point-mutated envelope proteins indicated that sera 2555 and 2709 primarily recognized neutralizable epitopes located in N- and C-terminal parts of the gp46 glycoprotein. Amino acids changes at positions 39, 265, and 290 greatly impaired recognition of neutralizing epitopes recognized by these two sera. These results demonstrate that amino acid changes in envelope glycoprotein gp46 can induce strain-specific neutralizing antibodies in some patients. On the other hand, the neutralizing activity of serum 2085 was not affected by amino acid changes at positions 39, 265, and 290, suggesting that the neutralizing antibodies present in this serum were directed against epitopes located in other parts of the molecule, possibly those located in the central domain of the molecule, which has the same amino acid sequence in the three viruses.
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Productos del Gen env/química , Productos del Gen env/inmunología , Variación Genética/genética , Anticuerpos Anti-HTLV-I/sangre , Virus Linfotrópico T Tipo 1 Humano/inmunología , Proteínas Oncogénicas de Retroviridae/química , Proteínas Oncogénicas de Retroviridae/inmunología , Secuencia de Aminoácidos , Animales , Línea Celular , Productos del Gen env/genética , Células Gigantes/fisiología , Anticuerpos Anti-HTLV-I/inmunología , Antígenos HTLV-I/inmunología , Infecciones por HTLV-I/inmunología , Infecciones por HTLV-I/virología , Humanos , Datos de Secuencia Molecular , Mutación , Pruebas de Neutralización , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Oncogénicas de Retroviridae/genética , TransfecciónRESUMEN
By the use of sera of human T cell leukemia virus type I (HTVL-I)-infected individuals it was shown that amino acid substitutions at positions 192 (proline to serine) and 250 (serine to proline) in major immunodominant regions (175-199 and 239-261) of the surface envelope glycoprotein (gp46) of the virus may influence the humoral response. Since human sera are polyclonal in nature, one cannot readily discriminate between an immunoglobulin-specific recognition and multiple bindings of diverse antibodies. To overcome this difficulty we generated murine monoclonal antibodies to synthetic peptides mimicking all or portions of these gp46 regions. The reactivity of some of these antibodies to synthetic peptides harboring (or not harboring) the preceding amino acid substitutions at position 192 or 250, to denatured gp46 by Western blotting, and to live (variously substituted) HTLV-I-infected cells, combined with blocking experiments with various peptides, allow us to conclude that the major epitopes (positions 183-191, 190-197, 190-199, and 246-252) in the two immunodominant regions may elicit different antibody responses according to their sequences. It is worth noting that in a reporter gene inhibition assay, it was found that a neutralizing monoclonal antibody (MF1), the epitope for which is located between residues 190 and 197, had a high level of activity when cells (2060) harboring a gp46 with proline at position 192 were used and had no activity toward cells (1010) with a serine at this position. Therefore our results establish that certain amino acid substitutions of gp46 may drastically affect the antigenicity of the molecule and the biological activity of the antibodies elicited.
Asunto(s)
Anticuerpos Antideltaretrovirus/inmunología , Antígenos de Deltaretrovirus/inmunología , Epítopos de Linfocito B/inmunología , Productos del Gen env/inmunología , Virus Linfotrópico T Tipo 1 Humano/inmunología , Epítopos Inmunodominantes/inmunología , Péptidos/inmunología , Proteínas Oncogénicas de Retroviridae/inmunología , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Anticuerpos Monoclonales/biosíntesis , Anticuerpos Monoclonales/inmunología , Línea Celular , Chlorocebus aethiops , Cricetinae , Anticuerpos Antideltaretrovirus/biosíntesis , Antígenos de Deltaretrovirus/química , Mapeo Epitopo , Técnica del Anticuerpo Fluorescente Indirecta , Productos del Gen env/síntesis química , Humanos , Immunoblotting , Epítopos Inmunodominantes/química , Isotipos de Inmunoglobulinas/inmunología , Hígado/citología , Hígado/inmunología , Ratones , Datos de Secuencia Molecular , Péptidos/síntesis química , Proteínas Oncogénicas de Retroviridae/síntesis química , Células VeroRESUMEN
The reactivity of sera of 96 individuals infected with human T-cell leukemia virus type I (HTLV-I) was tested against various synthetic peptides corresponding to the gp46 immunodominant antigenic domains: residues 86-107, 175-199, and 239-261. The frequency of reactive sera was higher for 175-199 (93%) than for 239-261 (78%) or 86-107 (24%) with some variations in geographical regions and in diseases. The region 239-261 was extensively analyzed and five (linear or conformational) epitopes were found. The reactivity of sera toward functional or immunodominant domains may depend on the sequence of the infecting virus, and the role of three frequent substitutions (asparagine by tyrosine, proline by serine, and serine by proline or leucine at positions 93, 192, and 250 respectively) was established. Finally, the role of the genetic background of the host may condition the humoral immune response as individuals infected by HTLV-Is harboring the same predicted gp46 peptide sequence may recognize one, several, or all regions examined.