966 resultados para Recombinant hepatitis B vaccines


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Background: Premature infants, who have to spend the first week of their lives in neonatal intensive care units (NICUs), experience pain and stress in numerous cases, and they are exposed to many invasive interventions. The studies have shown that uncontrolled pain experienced during early life has negative and long-term side effects, such as distress, and such experiences negatively affect the development of the central nervous system Objectives: The purpose of the study was to examine the effects of touching on infant pain perception and the effects of eutectic mixture of local anesthetic (EMLA) on the reduction of pain. Patients and Methods: Data for the study were collected between March and August 2012 from the neonatal clinic of a university hospital located in eastern Turkey. The population of the study consisted of premature infants who were undergoing treatment, completed the first month and who were approved for Hepatitis B vaccine. The study consisted of two experimental groups and one control group. Information forms, intervention follow-up forms, and Premature Infant Pain Profile (PIPP) were used to collect the data. EMLA cream was applied on the vastus lateralis muscles of the first experimental group before the vaccination. The second experimental group was vaccinated by imitation (placebo), without a needle tip or medicine. Vaccination was carried out using instrumental touch in this group. A routine vaccination was applied in the control group. Results: Mean pain scores of the group to which EMLA was applied were lower in a statistically significant way (P < 0.05) compared to the pain scores of the other groups. Moreover, it was determined that even though invasive intervention was not applied to the newborns, the touching caused them to feel pain just as in the placebo group (P < 0.005). Conclusions: The results demonstrated that EMLA was an effective method for reducing pain in premature newborns, and the use of instrumental touch for invasive intervention stimulated the pain perception in the newborns.

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Toxoplasmosis is one zoonosis caused by Toxoplasma gondii protozoan. Goats, amongst the production animals, are one of the species most susceptible to this parasite, being one them main involved agents in ovine and goat abortions, determining great economic losses and implications for public health, since the presence it parasite in the products of goat origin, consist in one of the main sources of infection for the man. In this study 244 blood samples in 8 farms situated in 4 cities from the Sertão do Cabugi region, Rio Grande do Norte State, northeast of Brazil and, tested by ELISA assay. The results had shown a prevalence of 47.13% for anti- T. gondii antibodies and a significant association between positivity and variable evaluated as age, locality and property. The IgG avidity assay evaluated in 115 positive samples was carried to discriminate acute and chronic infection. Twelve samples (10.4%) had presented antibodies of low avidity while 103 (89.6%) presented high avidity antibodies; indicating that most of the animals was precocious exposure to the parasite. Significant difference was verified only for the variable sex. We also evaluate the capacity of recombinant adenoviruses codifying SAG1, SAG2, SAG3 and CMV in inducing activation of specific immune response in goat. These 109 animals received 109 pfu of the AdSAG1, AdSAG2, AdSAG3, AdCMV or PBS in vaccine protocol with 3 immunizations. Serum samples of the each animal, before and after mmunization, had been submitted to the ELISA. The results demonstrate that the immunizations had induced the production of IgG antibodies specific against T. gondii proteins

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Objetivo: Determinar un modelo predictivo para uso del condón y consumo de alcohol como conductas de riesgo relacionadas el contagio de VIH/Sida en mujeres trabajadoras sexuales de la ciudad de Bogotá en el año 2015. Métodos Estudio de tipo transversal con diseño observacional, se tomaron 255 mujeres trabajadoras sexuales de la ciudad de Bogotá; La información analizada fue tomada del estudio realizado en cinco ciudades de Colombia en el año 2015, las hipótesis planteadas se soportaron en la asociación entre las condiciones sociodemográficas, de conocimiento, practicas, hábitos, apoyo social y de ocupación propia de las mujeres trabajadoras sexuales que podían explicar y predecir la adopción de conductas riesgosas para VIH/sida como son el uso del condón y el consumo de alcohol en ejercicio de su ocupación. Resultados El promedio de edad de inicio en el trabajo sexual fue 22,1±7,1 años, tres cuartas partes son solteras y residen en estrato dos y tres; el 96,5% dijo usar el condón con el último cliente y el 27,8% de ellas consumió alcohol durante su último servicio. En la conducta de riesgo uso del condón, se encontraron asociados entre otras, la edad [OR=1,10(1,03-1,17)], vivir en estrato dos [OR=7,7(1,5-39,5)], el ingreso por trabajo sexual [OR=1,0(1,0-1,0)], la disponibilidad del condón para el servicio [OR=0,03(0,008-0,16)] y contar con otro método de planificación (ligadura de trompas) [OR=4,47(1,0-18,3)]. En la conducta de riesgo consumo de alcohol, se encontró asociado ente otros: estrato socioeconómico dos [OR=5,8(1,54-22,3)], nivel de escolaridad secundaria [OR=0,12(0,16-0,96)], vivir con otros familiares [OR=3,45(1,7-7,02)], ingreso por trabajo sexual [OR=1,0(1,0-1,0)] y el sitio donde se ofrece el servicio [OR=0,07(0,04-0,15)]. Después de ajustar, se encontró que las variables que mejor explican el uso del condón fueron edad [OR=1,1(1,02-1,17)] y disponibilidad del condón [OR=0,04(0,008-0,024)], el modelo tuvo poca sensibilidad 33,3% y buena capacidad predictiva (84,6%). Las variables que mejor explicaron el consumo de alcohol durante el servicio fueron edad [OR= 0,95(0,91-0,98)], Número de clientes por semana [OR=0,9(0,90-0,98)], sitio donde ofrece el servicio [OR=7,1(3,45-14,8)], y estrato socioeconómico [OR=1,8 (0,90-3,83)], resultando un modelo con buena sensibilidad (71,8%) y buena capacidad predictiva (86,4%). Conclusiones Aspectos como la edad, el estrato socioeconómico, escolaridad, estado civil, ingreso económico por trabajo sexual, edad de inicio en el trabajo sexual, número de clientes antiguos en la última semana, disponibilidad del condón para prestar el servicio y ligadura de trompas como método diferente de planificación, se asociaron estadísticamente con el uso del condón. Sin embargo al ajustar las variables solo la edad y la disponibilidad del condón se mantuvieron como variables explicativas. Cabe anotar, que aunque el modelo mostró buena capacidad predictiva (84,6%), la precisión en sus estimaciones fue baja debido a la poca frecuencia del no uso del condón con el ultimo cliente (3,5%), y la sensibilidad del modelo apenas fue del 33,3%. Por otro lado, factores como la edad, el estrato socioeconómico, nivel educativo, ingreso económico, sitio de oferta del servicio, composición familiar, número de hijos, número de clientes atendidos en la última semana y número de clientes antiguos mostraron asociación estadística con el consumo de alcohol. Sin embargo, al ajustar las variables solo edad, estrato socioeconómico, sitio donde se ofrece el servicio y número de clientes por semana mantuvieron asociación estadística; observándose además que el estrato socioeconómico (uno y dos) y sitio donde se ofrece el servicio (establecimiento), son factores de riesgo para el consumo de alcohol en ejercicio de la ocupación y la poca edad y un número reducido de clientes por semana se comportan como factores de protección para el consumo de alcohol. El modelo predictivo que se desarrolló para la conducta de riesgo de consumo de alcohol, con una sensibilidad del 71,8% y un poder predictivo del 86,4%. .

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Marek's disease (MD) is a contagious, lymphoproliferative and neuropathic disease of poultry caused by a ubiquitous lymphotropic and oncogenic virus, Gallid alphaherpesvirus 2 (GaHV-2). MD has been reported in all poultry-rearing countries and is among the viral diseases with the highest economic impact in the poultry industry worldwide, including Italy. MD has been also recognized as one of the leading causes of mortality in backyard poultry. The present doctoral thesis aimed at exploring Marek's disease virus molecular epidemiology in Italian commercial and backyard chicken flocks and, for the first time, in commercial turkeys affected by clinical MD. Molecular biology techniques targeting the full-length meq gene, the major GaHV-2 oncogene, were used to detect and characterize the circulating GaHV-2 strains searching for genetic markers of virulence. A final study focused on the development of rapid, sensitive, and species-specific loop-mediated isothermal amplification assays coupled with a lateral flow device readout for the detection of conventional and recombinant HVT-based vaccines is included in the thesis. HVT vaccines, currently used to protect chickens from MD, are referred to as "leaky", as they do not impede the infection, replication, and shedding of field GaHV-2: vaccinal and field viruses can coexist in the vaccinated host and molecular tests able to discriminate between GaHV-2 and HVT are required. These new simple, fast, and accurate tests for the monitoring of MD vaccination success in the field could be greatly beneficial for field veterinarians, small laboratories, and more broadly for resource-limited settings.

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Screening blood donations for anti-HCV antibodies and alanine aminotransferase (ALT) serum levels generally prevents the transmission of hepatitis C virus (HCV) by transfusion. The aim of the present study was to evaluate the efficiency of the enzyme immunoassay (EIA) screening policy in identifying potentially infectious blood donors capable to transmit hepatitis C through blood transfusion. We have used a reverse transcriptase (RT)-nested polymerase chain reaction (PCR) to investigate the presence of HCV-RNA in blood donors. The prevalence of HCV-RNA positive individuals was compared with the recombinant immunoblot assay (RIBA-2) results in order to assess the usefulness of both tests as confirmatory assays. Both tests results were also compared with the EIA-2 OD/C ratio (optical densities of the samples divided by the cut off value). ALT results were expressed as the ALT quotient (qALT), calculated dividing the ALT value of the samples by the maximum normal value (53UI/l) for the method. Donors (n=178) were divided into five groups according to their EIA anti-HCV status and qALT: group A (EIA > or = 3, ALT<1), group B (EIA > or = 3, ALT>1), group C (1<=EIA<3, ALT<1), group D (1<=EIA<3, ALT>1) and group E (EIA<=0.7). HCV sequences were detected by RT-nested PCR, using primers for the most conserved region of viral genome. RIBA-2 was applied to the same samples. In group A (n=6), all samples were positive by RT-nested PCR and RIBA-2. Among 124 samples in group B, 120 (96.8%) were RIBA-2 positive and 4 (3.2%) were RIBA-2 indeterminate but were seropositive for antigen c22.3. In group B, 109 (87.9%) of the RIBA-2 positive samples were also RT-nested PCR positive, as well as were all RIBA-2 indeterminate samples. In group C, all samples (n=9) were RT-nested PCR negative: 4 (44.4%) were also RIBA-2 negative, 4 (44.4%) were RIBA-2 positive and 1 (11.1%) was RIBA-2 indeterminate. HCV-RNA was detected by RT-nested PCR in 3 (37.5%) out of 8 samples in group D. Only one of them was also RIBA-2 positive, all the others were RIBA-2 indeterminate. All of the group E samples (controls) were RT- nested PCR and RIBA-2 negative. Our study suggests a strong relation between anti-HCV EIA-2 ratio > or = 3 and detectable HCV-RNA by RT-nested PCR. We have also noted that blood donors with RIBA-2 indeterminate presented a high degree of detectable HCV-RNA using RT-nested PCR (75%), especially when the c22.3 band was detected.

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Genes encoding lipoproteins LipL32, LipL41 and the outer-membrane protein OmpL1 of leptospira were recombined and cloned into a pVAX1 plasmid. BALB/c mice were immunized with LipL32 and recombined LipL32-41-OmpL1 using DNA-DNA, DNA-protein and protein-protein strategies, respectively. Prime immunization was on day 1, boost immunizations were on day 11 and day 21. Sera were collected from each mouse on day 35 for antibody, cytokine detection and microscopic agglutination test while spleen cells were collected for splenocyte proliferation assay. All experimental groups (N = 10 mice per group) showed statistically significant increases in antigen-specific antibodies, in cytokines IL-4 and IL-10, as well as in the microscopic agglutination test and splenocyte proliferation compared with the pVAX1 control group. The groups receiving the recombined LipL32-41-OmpL1 vaccine induced anti-LipL41 and anti-OmpL1 antibodies and yielded better splenocyte proliferation values than the groups receiving LipL32. DNA prime and protein boost immune strategies stimulated more antibodies than a DNA-DNA immune strategy and yielded greater cytokine and splenocyte proliferation than a protein-protein immune strategy. It is clear from these results that recombination of protective antigen genes lipL32, lipL41, and ompL1 and a DNA-protein immune strategy resulted in better immune responses against leptospira than single-component, LipL32, or single DNA or protein immunization.

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Hepatitis E virus (HEV) is classified within the family Hepeviridae, genus Hepevirus. HEV genotype 3 (Gt3) infections are endemic in pigs in Western Europe and in North and South America and cause zoonotic infections in humans. Several serological assays to detect HEV antibodies in pigs have been developed, at first mainly based on HEV genotype 1 (Gt1) antigens. To develop a sensitive HEV Gt3 ELISA, a recombinant baculovirus expression product of HEV Gt3 open reading frame-2 was produced and coated onto polystyrene ELISA plates. After incubation of porcine sera, bound HEV antibodies were detected with anti-porcine anti-IgG and anti-IgM conjugates. For primary estimation of sensitivity and specificity of the assay, sets of sera were used from pigs experimentally infected with HEV Gt3. For further validation of the assay and to set the cutoff value, a batch of 1100 pig sera was used. All pig sera were tested using the developed HEV Gt3 assay and two other serologic assays based on HEV Gt1 antigens. Since there is no gold standard available for HEV antibody testing, further validation and a definite setting of the cutoff of the developed HEV Gt3 assay were performed using a statistical approach based on Bayes' theorem. The developed and validated HEV antibody assay showed effective detection of HEV-specific antibodies. This assay can contribute to an improved detection of HEV antibodies and enable more reliable estimates of the prevalence of HEV Gt3 in swine in different regions.

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Recombinant Bacillus subtilis strains, either spores or vegetative cells, may be employed as safe and low cost orally delivered live vaccine vehicles. In this study, we report the use of an orally delivered B. subtilis vaccine strain to boost systemic and secreted antibody responses in mice i.m. primed with a DNA vaccine encoding the structural subunit (CfaB) of the CFA/I fimbriae encoded by enterotoxigenic Escherichia coli (ETEC), an important etiological agent of diarrhea among travelers and children living in endemic regions. DBA/2 female mice submitted to the prime-boost immunization regimen developed synergic serum (IgG) and mucosal (IgA) antibody responses to the target CfaB antigen. Moreover, in contrast to mice immunized only with one vaccine formulation, sera harvested from prime-boosted vaccinated individuals inhibited adhesion of ETEC cells to human red blood cells. Additionally, vaccinated dams conferred full passive protection to suckling newborn mice challenged with a virulent ETEC strain. Taken together the present results further demonstrate the potential use of recombinant B. subtilis strains as an alternative live vaccine vehicle. (C) 2008 Elsevier Ltd. All rights reserved.

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Background & Aims: HLA-B⁄27 is associated with spontaneous HCV genotype 1 clearance. HLA-B⁄27-restricted CD8+ T cells target three NS5B epitopes. Two of these epitopes are dominantly targeted in the majority of HLA-B⁄27+ patients. In chronic infection, viral escape occurs consistently in these two epitopes. The third epitope (NS5B2820) was dominantly targeted in an acutely infected patient. This was in contrast, however, to the lack of recognition and viral escape in the large majority of HLA-B⁄27+ patients. Here, we set out to determine the host factors contributing to selective targeting of this epitope. Methods: Four-digit HLA class I typing and viral sequence analyses were performed in 78 HLA-B⁄27+ patients with chronic HCV genotype 1 infection. CD8+ T cell analyses were performed in a subset of patients. In addition, HLA/peptide affinity was compared for HLA-B⁄27:02 and 05. Results: The NS5B2820 epitope is only restricted by the HLA-B⁄27 subtype HLA-B⁄27:02 (that is frequent in Mediterranean populations), but not by the prototype HLA-B⁄27 subtype B⁄27:05. Indeed, the epitope is very dominant in HLA-B⁄27:02+ patients and is associated with viral escape mutations at the anchor position for HLA-binding in 12 out of 13 HLA-B⁄27:02+ chronically infected patients. Conclusions: The NS5B2820 epitope is immunodominant in the context of HLA-B⁄27:02, but is not restricted by other HLA-B⁄27 subtypes. This finding suggests an important role of HLA subtypes in the restriction of HCV-specific CD8+ responses. With minor HLA subtypes covering up to 39% of specific populations, these findings may have important implications for the selection of epitopes for global vaccines.

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DNA vaccines express antigens intracellularly and effectively induce cellular immune responses. Because only chimpanzees can be used to model human hepatitis C virus (HCV) infections, we developed a small-animal model using HLA-A2.1-transgenic mice to test induction of HLA-A2.1-restricted cytotoxic T lymphocytes (CTLs) and protection against recombinant vaccinia expressing HCV-core. A plasmid encoding the HCV-core antigen induced CD8+ CTLs specific for three conserved endogenously expressed core peptides presented by human HLA-A2.1. When challenged, DNA-immunized mice showed a substantial (5–12 log10) reduction in vaccinia virus titer compared with mock-immunized controls. This protection, lasting at least 14 mo, was shown to be mediated by CD8+ cells. Thus, a DNA vaccine expressing HCV-core is a potential candidate for a prophylactic vaccine for HLA-A2.1+ humans.

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We have determined the post-translational modifications of the major capsid protein, L1 of human papillomavirus (HPV) type 6b. Since this virus cannot be cultured in the laboratory to obtain sufficient material for a study, a recombinant L1 protein produced in a vaccinia virus expression system was used in this investigation. Our results show that this protein is phosphorylated at serine residues and is also glycosylated. No myristoylation or palmitoylation was detected. The fraction of L1 protein incorporated into virus-like particles was not glycosylated. Since recombinant L1 protein is a potential human vaccine candidate, knowledge of the post-translation modifications of this protein may prove useful for the design of anti-HPV vaccines. (C) 1999 Elsevier Science B.V. All rights reserved.

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The NS5 protein of the flavivirus Kunjin (KUN) contains conserved sequence motifs characteristic of RNA-dependent RNA polymerase (RdRp) activity. To investigate this activity in vitro, recombinant NS5 proteins with C-terminal (NS5CHis) and N-terminal (NS5NHis) hexahistidine tags were produced in baculovirus-infected insect cells and purified to near homogeneity by nickel affinity chromatography. Purified NS5CHis exhibited RdRp activity with both specific (9 kb KUN replicon) and non-specific (8.3 kb Semliki Forest virus replicon) RNA templates; this activity did not require the presence of additional viral and/or cellular cofactors. RdRp activity of purified NS5NHis protein was reduced in comparison to NS5CHis, while purified NS5NHis incorporating a GDD -> GVD mutation within the polymerase active site (NS5GVD) lacked RdRp activity. RNase A digestion of the RdRp reaction products indicated that they were double-stranded and of a similar size to the KUN replicative form produced in Vero cells, thus demonstrating that the KUN NS5 protein has an intrinsic, albeit low and non-specific RdRp activity in vitro, similar to that reported for recombinant RdRp of other flaviviruses. However, in contrast to RNA polymerases of other Flavivirus species, purified KUN NS5 polymerase produced a single, full-length replicon RNA product, thus demonstrating efficient processivity. (C) 2001 Elsevier Science B.V. All rights reserved.