[en] The aims of this study were to generate chimeric human papillomavirus (HPV)-16 L1 virus-like particles (VLPs) in order to identify immunogenic domains and conformational neutralizing epitopes, and to characterize the regions where a foreign epitope could be introduced. We hypothesized that these regions could be on L1 protein loops since they are exposed on the surface of VLPs. The aims of this study were achieved by mutating HPV-16 L1 proteins. Six amino acids encoding for the epitope 78-83 (DPASRE) of the hepatitis B core (HBc) antigen were introduced within the different loops of the L1 protein at positions 56/57, 140/141, 179/180, 266/267, 283/284 or 352/353. All these chimeric L1 proteins were capable of self-assembly into VLPs. The antigenicity and immunogenicity of some of these VLPs were reduced compared to the levels observed with wild-type VLPs. All were nevertheless able to induce neutralizing antibodies. VLPs with insertion at position 266/267 induced lower levels of neutralizing antibodies, suggesting the involvement of residues situated on FG loop in L1 neutralizing epitopes. All the chimeric L1 proteins except the one with insertion at position 56/57 were also able to induce anti-HBc antibodies, thus suggesting exposure of the HBc epitope on the VLP surface. Taken together, our findings indicate the possibility of designing HPV-derived vectors that are less immunogenic and suggest positions for insertion of defined immune epitopes or cell ligands into L1 protein to be exposed on the surface of VLPs

[en] A unitized, solid phase kit for radioimmunoassay is described. All of the necessary assay reagents are incorporated in a single tube. Requiring only the addition of the patient's sample, all phases of the assay procedure are performed in this tube. Antibodies are bound to the tube surface, while labelled antigens are also present but unbound. Storage in the absence of air and water results in the stabilization of the reagents such that the system can be stored for long periods

No abstract available

No abstract available

[en] The world experience shows that the technetium obtained by extraction not always shows satisfactory results for that reason we recommend to use a generator of absorption. For it we have optimized the production of anti-CEA that understands three stages: reduction, purification and formulation. The reduction of the antibody was reduced by 2-ME, we tested two relations AcMo:2ME of 1:1000 and 1:2000; the purification was done in column PD 10 and column of sephadex G25, and two formulations were tested done using a ligand MDP, as antibody ior-CEA1 and stannous fluoride anhydrous, the modifications done to the ligand and to MoAb (1 to 1,2 mg for vial) and the process of lyophilization was optimized. The labeling of MoAb was done with Tc-99m obtained by extraction by MEC, of high radiochemical purity (> 99 %) and high radionuclide purity (> 99,98%). The radiochemical evaluation is done by chromatography in thin layer, as the literature reports, to 30 minutes of labelling until 4 hours, there have been done tests of support of activity and volume, challenger cysteine, essays of immunoreactivity and it was complemented with studies of stability on real time to 4 experimental lots. We have concluded that the process of production is ideal, in 9 experimental lots, obtaining radiochemical purity major of 95 % with stability on real time 12 months with a major PRQ of 90 %. (author)

[en] New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8⁺ T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

[en] A review is presented of radioimmunoassay applications in oncology and the most frequent tumor markers are discussed with respect to their characteristics and diagnostic significance. (L.O.). 68 refs

[en] This study was conducted during the period from February 2004 to July 2004; with the objective of measuring the levels of estrogen (E2), carcinoembryonic Antigen (CEA) and cancer antigen of breast (CA-15.3) so as to facilitate the early diagnosis of breast cancer and to determine the involvement of these parameters as risk factors for breast cancer. Ninety blood samples were collected from Sudanese females, divided into two groups; control group and patients groups. The patients group was sixty Sudanese females visiting the Radio Isotope Center, Khartoum (RICK) and they were confirmed as breast cancer patients by histopathology. The levels of the above mentioned parameters were determined by using radioimmunoassay technique. The results showed that, no significant (p=0.05) difference between the levels of the estrogen in patients compared to the control, on the other hand, there was non-significant (p>0.05) elevation in CEA levels in the patients with breast cancer compared to the control. The level of CA15.3 was significantly (p<0.0001) higher in the breast cancer patients compared to the control.

[en] SV40 has been linked to some human malignancies, and the evidence that this virus plays a causative role in mesothelioma and brain tumors is mounting. The major SV40 oncoprotein is the Large tumor antigen (Tag). A key Tag transforming activity is connected to its capability to bind and inactivate cellular p53. In this study we developed an effective, high throughput, ELISA-based method to study Tag-p53 interaction in vitro. This assay allowed us to screen a chemical library and to identify a chemical inhibitor of the Tag binding to p53. We propose that our in vitro assay is a useful method to identify molecules that may be used as therapeutic agents for the treatment of SV40-related human cancers

[en] The need for improved diagnostic tests for malaria over conventional methods based on indirect immunofluorescence for the measure of antimalarial antibodies, and for identification of malaria parasites on stained blood films for antigen detection (diagnostic of ongoing infection) has led to the development of several solid phase assays. These assays have been used in limited trials for both antibody and antigen detection. Solid phase assays for antimalarial antibodies are relatively easy to perform but the currently available assays for antigen detection which are based on solid phase antibody binding inhibition are still complicated, poorly standardised and time consuming. They can not be used on a large scale in endemic areas. Several new developments including the availability of monoclonal antimalarial antibodies of known specifications, the cloning of several malarial antigens and the synthesis of malaria specific nucleotides and polypeptides may allow in the near future the development of simple and reliable assays for malarial antigens detection or the identification of genomic malaria DNA by hybridisation on infected blood samples. Moreover the measure of antimalarial antibodies of known specificities would be easily achievable. (author)