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Biomedical subjects

C Vela

Publications and source records attributed to C Vela.

48 records · Page 3Linked to original sources
PubMed1992

Recombinant vaccine for canine parvovirus in dogs.

VP2 is the major component of canine parvovirus (CPV) capsids. The VP2-coding gene was engineered to be expressed by a recombinant baculovirus under the control of the polyhedrin promoter. A transfer vector that contains the lacZ gene under the control of the p10 promoter was used in order to facilitate the selection of recombinants. The expressed VP2 was found to be structurally and immunologically indistinguishable from authentic VP2. The recombinant VP2 shows also the capability to self-assemble, forming viruslike particles similar in size and appearance to CPV virions. These viruslike particles have been used to immunize dogs in different doses and combinations of adjuvants, and the anti-CPV responses have been measured by enzyme-linked immunosorbent assay, monolayer protection assays, and an assay for the inhibition of hemagglutination. A dose of ca. 10 micrograms of VP2 was able to elicit a good protective response, higher than that obtained with a commercially available, inactivated vaccine. The results indicate that these viruslike particles can be used to protect dogs from CPV infection.

Animals↗
PubMed1991

Fine mapping of canine parvovirus B cell epitopes.

In this report we describe the topological mapping of neutralizing domains of canine parvovirus (CPV). We obtained 11 CPV-specific monoclonal antibodies (MAbs), six of which are neutralizing. The reactivities were as determined by ELISA and Western blot (immunoblot) analysis. VP2, the most abundant protein of the CPV capsid, seemed to contain all the neutralization sites. Also, an almost full-length genomic clone of CPV was constructed in the bacterial plasmid pUC18 to enable expression of CPV proteins. All the neutralizing MAbs recognized recombinant VP2 when it was expressed as a free protein in Escherichia coli but not when expressed as a fusion protein with glutathione-S-transferase. When two large fragments containing about 85% and 67% of the C terminus of VP2 were expressed, no neutralization sites were detected. When fusion proteins containing the N terminus were expressed, two linear determinants were mapped, one between residues 1 to 10 of VP2, and the other between amino acids 11 and 23. The peptide 11 GQPAVRNERATGS 23, recognized by MAb 3C9, was synthesized chemically and checked for immunogenicity, not being able to induce neutralizing activity. Although the antibody response in rabbits to all the fusion proteins was uniformly high, the anti-CPV response was very variable. Protein from pCPVEx11, which contains a T cell epitope (peptide PKIFINLAKKKKAG) present in the VP1-specific region as well as the B cell epitopes, seemed to be the most effective in inducing virus neutralization.

Amino Acid Sequence↗
PubMed1982

IgG antibodies: in vitro blocking activity of IgE mediated reactions.

Sera from 177 atopic patients treated by immunotherapy were screened in order to detect IgD antibodies against a purified fraction of Lollium perenne (fractions C). IgD antibodies were found in 23% of the subjects. Eight of these sera were selected and their IgD isolated by means of immunoabsorption. The in vitro biological activity of the IgD antibodies against fraction C was tested by three methods: basophil degranulation, histamine release and RAST inhibition test. In all these assays, the data obtained indicated a possible blocking effect of the IgD antibodies upon the IgE in vitro mediated reactions.

Antibodies, Anti-Idiotypic↗
PubMed1982

Fractionation and biological characterization of Olea europea pollen extract.

Preliminary fractionation of Olea european pollen extract has been performed. At least 10 antigenic fractions have been found by crossed electrophoresis. After Sephadex gel filtration, two fractions with a molecular weight of 160,000 and 65,000 have been obtained. The fractions were evaluated for allergenic activity by two in vitro techniques: polystyrene tube radioimmunoassay (PTRIA) and basophil degranulation test (BDT), and by skin tests. All tests indicated that the most reactive fractions were those in the 65,000 molecular weight peak. BDT has been shown to be a very reliable method as compared with histamine release and other parameters. Although common antigenic fractions have been found for Lollium perenne and O. europea, no cross-allergenicity has been shown by PTRIA inhibition.

Basophils↗
PubMed1981

Role of T gamma cells in the in vitro IgE response after antigenic stimulation.

Fifteen patients with seasonal allergic pollenosis and five controls were investigated to elucidate the role of the T gamma-cell population in the in vitro IgE response by peripheral blood lymphocytes (PBL). In vitro IgE production by PBL of atopic patients after antigenic stimulation was measured in culture supernatants. The optimal dose for antigenic stimulation was found to be 0.16 micrograms/20 X 10(6) cells of purified antigen. No difference was found when comparing the percentages of T cells (E rosettes) between the two groups: mean per cent for controls was 69.2 +/- 5.76 versus 69.54 +/- 4.42 for the allergic group. With regard to the T gamma-cell population, the values obtained by rosetting with ox erythrocytes sensitized with IgG antibody were 12 +/- 0.71% in normals and 9.8 +/- 1.32% in those with allergic pollenosis. This difference, although significant, may not be enough to explain the different pattern when the in vitro IgE production of both groups investigated was compared. In order to detect the role of T gamma cells in this system, lymphocyte cultures, depleted of T gamma cells, were performed and compared with unfractionated cultures from the same donors. Our results show no differences in the in vitro IgE production when T gamma cells were depleted as compared with the unfractionated cultures.

Humans↗
PubMed1979

In vitro production of IgE and IgG by sensitized human peripheral lymphocytes.

Antigenic stimulation of peripheral lymphocytes was made in two different groups of atopic patients, testing their capabilities to produce IgE and IgG in vitro. For this purpose, Marbrook's technique was used in the cultures. The immunoglobulins produced were measured in the supernatants by a sensitive double-antibody method. Results demonstrate that it is possible to produce enough IgE and IgG to be detected. Some important parameters had to be considered: appropriate selection of the patients and the antigens used in the antigenic stimulation, as well as the number of cells and the duration of the culture.

Allergens↗
PubMedDate not supplied

ThinPrep Pap Test. Accuracy for glandular disease.

OBJECTIVE: Although the ThinPrep Pap Test is replacing conventional Pap smears in many clinical practices, experience with the identification of glandular lesions is limited. In this study, ThinPrep cytology of glandular lesions was evaluated in a large, inner city teaching hospital with high rates of glandular abnormality. STUDY DESIGN: Six months of ThinPrep diagnoses in 1998, following nearly 100% conversion of the laboratory to the ThinPrep Pap Test, were compared to January-December 1997 conventional smear diagnoses for glandular disease. Biopsy confirmation was evaluated for these cases. Findings on all biopsy-confirmed glandular cases were also compared to findings on cytology. RESULTS: Similar overall rates of glandular cytology were found. For conventional smears (12 months), 46 cases were diagnosed out of 43,289 smears (0.11%). For ThinPrep cytology (six months), 36 cases were diagnosed out of 25,783 slides (0.14%, P = NS). In the year 1997, 9 biopsy-confirmed conventional smear diagnoses of adenocarcinoma in situ (AIS) or adenocarcinoma were noted versus 10 for six months of 1998 for the ThinPrep method. A statistically significant reduction in the number of miscellaneous nonglandular (squamous) biopsy diagnoses were found with ThinPrep glandular cytology (14 vs. 4 cases, P < .05). For known biopsy-confirmed glandular cases of AIS or adenocarcinoma, a statistically significant reduction in the cytology false negative rate was noted with the ThinPrep method (17 vs. 4 cases, P < .02). CONCLUSION: The ThinPrep method provides more accurate diagnoses of glandular disease, with an increase in both sensitivity and specificity for glandular lesions.

Adenocarcinoma↗
PubMedDate not supplied

Cytologic diagnosis of Chlamydia in cervicovaginal secretions. Use of a Papanicolaou stain modification with buffered wright solution.

OBJECTIVE: To carry out a prospective study on 1,569 females to evaluate the diagnostic utility of adding buffered Wright solution to Papanicolaou stain for observing cytoplasmic inclusions in cervicovaginal cytology. STUDY DESIGN: Group A had multivacuolated cells and group B, granules (not in a vacuole) in the cytoplasm of low-intermediate epithelial or parabasal cells. There were 7 patients in group A and 16 in group B. Two duplicate plates of cervicovaginal secretions were obtained from each patient before and after treatment; one was stained with Papanicolaou stain and the other with our variant. The trial of therapy consisted of doxycycline (effectiveness for statistical analysis = 0.9) in oral doses of 100 mg every 12 hours for 7 days; 7 days after the beginning of treatment, check samples were obtained. RESULTS: In group A, six patients had cytoplasmic inclusions with the variant stain, and two had cytoplasmic inclusions with Papanicolaou stain. The binomial test revealed that probably six of the seven patients had infections with Chlamydia (P = .372) and that in 100% of cases, the variant stain showed cytoplasmic inclusions, while Papanicolaou stain was observed in 33% of cases. These findings were morphologically and statistically proven (P = .124) on control slides with posttreatment absence of multivacuolated cells. CONCLUSION: In relation to the selection criteria for B group, the intracytoplasmic granules found in parabasal and low intermediate cells had no relation to Chlamydia. The study demonstrated the superiority of our variant of Papanicolaou stain for cervicovaginal Chlamydia diagnosis.

Buffers↗