158 resultados para Recombinant Antigen


Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND The long-term safety of growth hormone treatment is uncertain. Raised risks of death and certain cancers have been reported inconsistently, based on limited data or short-term follow-up by pharmaceutical companies. PATIENTS AND METHODS The SAGhE (Safety and Appropriateness of Growth Hormone Treatments in Europe) study assembled cohorts of patients treated in childhood with recombinant human growth hormone (r-hGH) in 8 European countries since the first use of this treatment in 1984 and followed them for cause-specific mortality and cancer incidence. Expected rates were obtained from national and local general population data. The cohort consisted of 24,232 patients, most commonly treated for isolated growth failure (53%), Turner syndrome (13%) and growth hormone deficiency linked to neoplasia (12%). This paper describes in detail the study design, methods and data collection and discusses the strengths, biases and weaknesses consequent on this. CONCLUSION The SAGhE cohort is the largest and longest follow-up cohort study of growth hormone-treated patients with follow-up and analysis independent of industry. It forms a major resource for investigating cancer and mortality risks in r-hGH patients. The interpretation of SAGhE results, however, will need to take account of the methods of cohort assembly and follow-up in each country.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Contagious bovine pleuropneumonia (CBPP) is a serious respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides. Current vaccines against CBPP induce short-lived immunity and can cause severe postvaccine reactions. Previous studies have identified the N terminus of the transmembrane lipoprotein Q (LppQ-N') of M. mycoides subsp. mycoides as the major antigen and a possible virulence factor. We therefore immunized cattle with purified recombinant LppQ-N' formulated in Freund's adjuvant and challenged them with M. mycoides subsp. mycoides. Vaccinated animals showed a strong seroconversion to LppQ, but they exhibited significantly enhanced postchallenge glomerulonephritis compared to the placebo group (P = 0.021). Glomerulonephritis was characterized by features that suggested the development of antigen-antibody immune complexes. Clinical signs and gross pathological scores did not significantly differ between vaccinated and placebo groups. These findings reveal for the first time the pathogenesis of enhanced disease as a result of antibodies against LppQ during challenge and also argue against inclusion of LppQ-N' in a future subunit vaccine for CBPP.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND Recombinant bone morphogenetic protein two (rhBMP2) has been utilised for a variety of clinical applications in orthopaedic surgery and dental procedures. Despite its widespread use, concerns have been raised regarding its short half-life and transient bioactivity in vivo. Recent investigation aimed at developing rhBMP2 synthesized from a shorter polypeptide chain (108 amino acids) has been undertaken. METHODS The osteopromotive properties of BMP2 were investigated on cell behaviour. Five concentrations of rhBMP2_108 including 10, 50, 100, 200 and 500 ng/ml were compared to a commercially available rhBMP2 (100 ng/ml). Each of the working concentrations of rhBMP2_108 were investigated on MC3T3-E1 osteoblasts for their ability to induce osteoblast recruitment, proliferation and differentiation as assessed by alkaline phosphatase (ALP) staining, alizarin red staining, and real-time PCR for genes encoding ALP, osteocalcin (OCN), collagen-1 (COL-1) and Runx2. RESULTS The results demonstrate that all concentrations of rhBMP2_108 significantly improved cell recruitment and proliferation of osteoblasts at 5 days post seeding. Furthermore, rhBMP2_108 had the most pronounced effects on osteoblast differentiation. It was found that rhBMP2_108 had over a four fold significant increase in ALP activity at seven and 14 days post-seeding and the concentrations ranging from 50 to 200 ng/ml demonstrated the most pronounced effects. Analysis of real-time PCR for genes encoding ALP, OCN, COL-1 and Runx2 further confirmed dose-dependant increases at 14 days post-seeding. Furthermore, alizarin red staining demonstrated a concentration dependant increase in staining at 14 days. CONCLUSION The results from the present study demonstrate that this shorter polypeptide chain of rhBMP2_108 is equally as bioactive as commercially available rhBMP2 for the recruitment of progenitor cells by facilitating their differentiation towards the osteoblast lineage. Future in vivo study are necessary to investigate its bioactivity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fetal antigen 1/delta-like 1 homologue (FA1/dlk1) belongs to the epidermal growth factor superfamily and is considered to be a non-canonical ligand for the Notch receptor. Interactions between Notch and its ligands are crucial for the development of various tissues. Moreover, FA1/dlk1 has been suggested as a potential supplementary marker of dopaminergic neurons. The present study aimed at investigating the distribution of FA1/dlk1-immunoreactive (-ir) cells in the early postnatal and adult midbrain as well as in the nigrostriatal system of 6-hydroxydopamine (6-OHDA)-lesioned hemiparkinsonian adult rats. FA1/dlk1-ir cells were predominantly distributed in the substantia nigra (SN) pars compacta (SNc) and in the ventral tegmental area. Interestingly, the expression of FA1/dlk1 significantly increased in tyrosine hydroxylase (TH)-ir cells during early postnatal development. Co-localization and tracing studies demonstrated that FA1/dlk1-ir cells in the SNc were nigrostriatal dopaminergic neurons, and unilateral 6-OHDA lesions resulted in loss of both FA1/dlk1-ir and TH-ir cells in the SNc. Surprisingly, increased numbers of FA1/dlk1-ir cells (by 70%) were detected in dopamine-depleted striata as compared to unlesioned controls. The higher number of FA1/dlk1-ir cells was likely not due to neurogenesis as colocalization studies for proliferation markers were negative. This suggests that FA1/dlk1 was up-regulated in intrinsic cells in response to the 6-OHDA-mediated loss of FA1/dlk1-expressing SNc dopaminergic neurons and/or due to the stab wound. Our findings hint to a significant role of FA1/dlk1 in the SNc during early postnatal development. The differential expression of FA1/dlk1 in the SNc and the striatum of dopamine-depleted rats could indicate a potential involvement of FA1/dlk1 in the cellular response to the degenerative processes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tick-borne encephalitis (TBE) is one of the most dangerous human neurological infections occurring in Europe and Northern parts of Asia with thousands of cases and millions vaccinated against it. The risk of TBE might be assessed through analyses of the samples taken from wildlife or from animals which are in close contact with humans. Dogs have been shown to be a good sentinel species for these studies. Serological assays for diagnosis of TBE in dogs are mainly based on purified and inactivated TBEV antigens. Here we describe novel dog anti-TBEV IgG monoclonal antibody (MAb)-capture assay which is based on TBEV prME subviral particles expressed in mammalian cells from Semliki Forest virus (SFV) replicon as well as IgG immunofluorescence assay (IFA) which is based on Vero E6 cells transfected with the same SFV replicon. We further demonstrate their use in a small-scale TBEV seroprevalence study of dogs representing different regions of Finland. Altogether, 148 dog serum samples were tested by novel assays and results were compared to those obtained with a commercial IgG enzyme immunoassay (EIA), hemagglutination inhibition test and IgG IFA with TBEV infected cells. Compared to reference tests, the sensitivities of the developed assays were 90-100% and the specificities of the two assays were 100%. Analysis of the dog serum samples showed a seroprevalence of 40% on Åland Islands and 6% on Southwestern archipelago of Finland. In conclusion, a specific and sensitive EIA and IFA for the detection of IgG antibodies in canine sera were developed. Based on these assays the seroprevalence of IgG antibodies in dogs from different regions of Finland was assessed and was shown to parallel the known human disease burden as the Southwestern archipelago and Åland Islands in particular had considerable dog TBEV antibody prevalence and represent areas with high risk of TBE for humans.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Currently there are no effective vaccines for the control of bovine neosporosis. During the last years several subunit vaccines based on immunodominant antigens and other proteins involved in adhesion, invasion and intracellular proliferation of Neospora caninum have been evaluated as targets for vaccine development in experimental mouse infection models. Among them, the rhoptry antigen NcROP2 and the immunodominant NcGRA7 protein have been assessed with varying results. Recent studies have shown that another rhoptry component, NcROP40, and NcNTPase, a putative dense granule antigen, exhibit higher expression levels in tachyzoites of virulent N. caninum isolates, suggesting that these could be potential vaccine candidates to limit the effects of infection. In the present work, the safety and efficacy of these recombinant antigens formulated in Quil-A adjuvant as monovalent vaccines or pair-wise combinations (rNcROP40+rNcROP2 and rNcGRA7+rNcNTPase) were evaluated in a pregnant mouse model of neosporosis. All the vaccine formulations elicited a specific immune response against their respective native proteins after immunization. Mice vaccinated with rNcROP40 and rNcROP2 alone or in combination produced the highest levels of IFN-γ and exhibited low parasite burdens and low IgG antibody levels after the challenge. In addition, most of the vaccine formulations were able to increase the median survival time in the offspring. However, pup survival only ensued in the groups vaccinated with rNcROP40+rNcROP2 (16.2%) and rNcROP2 (6.3%). Interestingly, vertical transmission was not observed in those survivor pups immunized with rNcROP40+rNcROP2, as shown by PCR analyses. These results show a partial protection against N. caninum infection after vaccination with rNcROP40+rNcROP2, suggesting a synergistic effect of the two recombinant rhoptry antigens.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Cattle immunised with a recombinant form of p67, the major surface antigen of Theileria parva sporozoites, have been shown to be protected against parasite challenge. In an attempt to simplify the immunisation procedure live attenuated Salmonella strains expressing p67 have been constructed and used to induce anti-p67 immune responses in cattle. All animals immunised with these strains developed strong antibody responses to p67. Specific T cell responses could be detected in the majority of immunised cattle. Challenge with T. parva sporozoites revealed a significant level of protection in immunised calves compared to naive control animals or animals inoculated with non-recombinant attenuated Salmonella.