PubMed Health⌕ Search

Biomedical subjects

J Lecomte

Publications and source records attributed to J Lecomte.

At least 37 records · Page 2Linked to original sources
PubMed1989

Production and characterization of neutralizing monoclonal antibodies against poliovirus type 1, 2, and 3.

Neutralizing monoclonal antibodies were produced against a reference vaccine or a reference wild strain of poliovirus type 1, 2, and 3. After 26 fusions, 55 monoclonal antibodies were obtained with serotype 1 as the immunizing antigen, 180 with serotype 2, and 115 with serotype 3. The neutralizing activity of these monoclonal antibodies was tested first with the two reference strains and then if reactive, against a panel of 10 well-characterized strains of each serotype, 5 vaccinelike (VL) and 5 nonvaccinelike (NVL). All monoclonal antibodies were type specific without reactivity with any of the heterologous strains. There was a wide range of reactivity within the strains of each serotype. Several monoclonal antibodies to serotype 1 reacted with all type 1 strains, while several neutralized strongly all VL strains and weakly one or more of the NVL strains. Most of the 180 monoclonal antibodies to serotype 2 neutralized to various degrees all strains of this serotype and about half reacted very strongly with all homologous strains whether VL or NVL. None could differentiate all VL and NVL homologous strains. Of the 115 monoclonal antibodies to serotype 3, several monoclonal antibodies neutralize to various levels all homologous strains and some can differentiate VL and NVL strains.

Animals↗
PubMed1989

Cisplatin versus cisplatin plus etoposide in the treatment of advanced non-small-cell lung cancer. Lung Cancer Working Party, Belgium.

We conducted a randomized study comparing the survival after treatment with cisplatin (120 mg/m2) or cisplatin plus etoposide (100 mg/m2 on days 1, 2, and 3) in 162 evaluable patients with advanced non-small-cell lung cancer (NSCLC). No statistically significant difference in survival was detected; the median survival was 26 and 22 weeks, respectively, for patients receiving cisplatin and for those receiving cisplatin plus etoposide. The objective response rate was 19% for cisplatin and 26% for the combination; the corresponding response rates were 17% and 43% in patients with limited disease. No significant differences were detected between the two study arms as far as toxicity was concerned, except for alopecia and granulocytopenia, which occurred more frequently in patients treated with cisplatin plus etoposide.

Adenocarcinoma↗
PubMed1989

[Hypobaric hypoxia and catecholaminuria in normal humans].

Consequences of hypoxic hypobaric chemostimulation have been analyzed in six normal subjects arriving in excellent ambient conditions in a mountain scientific station (Jungfraujoch, 3,580 m). During the first two days of the sojourn, neither systemic blood pressure, nor catecholamines urinary excretion were modified in comparison with their values at the sea level. It is concluded that the chemostimulation due to hypobaric hypoxia does not affect orthosympathetic activities as far as other stressing solicitations are avoided (muscular exercise, temperature modifications, psychic alertness...etc.).

Adult↗
PubMed1988

Rapid titration of bovine, caprine and human RS virus by a micro-immunoperoxidase assay using a monoclonal antibody and a permissive ovine kidney cell line.

An indirect immunoperoxidase micro-assay, using a continuous cell line derived from ovine kidney cells (OK) and a previously characterized monoclonal antibody (7C2), specific for an exposed and highly conserved epitope of the fusion protein of different strains of RS virus, was used advantageously to rapidly titrate bovine, caprine and human strains of RSV by either quantal (TCID50) or plaque forming assays. Virus titers, obtained in less than 36 h, were in agreement with those obtained by the conventional plaque assays which required an incubation period of 4 days or more. This assay is also applicable to micro-neutralization of fusion inhibition assays for testing serum or screening monoclonal antibodies.

Animals↗
PubMed1988

Bovine viral diarrhea virus proteins: heterogeneity of cytopathogenic and non-cytopathogenic strains and evidence of a 53K glycoprotein neutralization epitope.

Intracellular virus-induced polypeptides from 3 cytopathogenic and 2 non-cytopathogenic bovine viral diarrhea (BVD) virus reference strains were analyzed by radioimmunoprecipitation and polyacrylamide gel electrophoresis, using a specific bovine multivalent antiserum and a neutralizing BVD-virus monoclonal antibody. Electrophoretic patterns of major proteins demonstrate extensive variation between strains. Most notably, a major 80,000 (80K) polypeptide was present in all cytopathogenic strains but absent in both non-cytopathogenic strains. Furthermore, a neutralizing monoclonal antibody produced against the NADL strain immunoprecipitated a 53K glycoprotein indicating that this protein carries an important neutralization epitope that is not present in all strains tested.

Animals↗
PubMed1988

Further biological, serological and biochemical characterization of North American, European and Southeast Asian strains of bovine herpesvirus 1 compared with other alphaherpesvirinae members.

Hemagglutination activity, structural protein profiles and neutralization assays were used in a comparative study of bovine herpesvirus 1 strains from the U.S.A., Canada, Great Britain, Denmark and Malaysia with equine, feline and human herpesviruses in order to further characterize the bovine herpesvirus 1 hemagglutinin. Bovine herpesvirus 1 strains of different geographical origins all showed hemagglutinating activity for mouse erythrocytes; furthermore, feline herpesvirus 1 was also shown to hemagglutinate mouse erythrocytes. Analyses of partly purified viruses showed that a distinctive and specific polypeptides profile is associated with each species of herpesviruses used in our study; strains of bovine herpesvirus 1 from North America, Europe and Southeast Asia however, presented a remarkable similarity as to their electrophoretic protein patterns. A protein similar to the 97-kDa bovine viral hemagglutinin was not identified with the hemagglutinating feline herpesvirus. An important neutralization epitope on the bovine viral hemagglutinin was also not found on feline, equine and human herpesviruses but was identified on all bovine strains tested from North America, Europe and Southeast Asia stressing the importance of the bovine hemagglutinin for eventual prophylactic purposes.

Animals↗
PubMed1988

Evaluation of three methods for curing hybridomas from mycoplasma contamination.

Hybridomas are as susceptible to mycoplasma contamination as animal cell cultures. Two in vitro methods and one in vivo passage into mice were compared for efficiency of curing hybridomas from mycoplasma contaminations. Four contaminated clones were treated with the combined action of 5-bromouracil (5-BrUra) and the Hoechst 33258 followed by photosensitization. The other in vitro method involved the use of BM-cycline. The success of overcoming the mycoplasma contamination was dependent on the level of the initial contamination of the individual hybridoma. BM-cycline was more efficient than the photosensitization method. For the most contaminated hybridomas, 10 successive treatments with 5-BrUra were necessary as compared to six treatments with BM-cycline. Moreover, the use of BM-cycline reduced the contamination by as much as 50% after the first treatment. After twenty passages following the curing of hybridomas with BM-cycline, cells were stable and retained their specificity and secretion of their respective immunoglobulins. Whereas, treatment with 5-bromouracil, recurrence of contamination was observed in one of the four hybridomas after 10 passages following treatment. Decontamination after one passage in peritoneal cavity in mice was not always sufficient since one of four hybridomas remained contaminated. BM-cycline appears to be the method of choice since it is more efficient, less time consuming, simpler and less expensive. Mycoplasma strains that could be identified were of bovine origin: Mycoplasma arginini and Acholeplasma laidlawii.

Animals↗
PubMed1988

Typing of cytopathic and noncytopathic bovine viral diarrhea virus reference and Canadian field strains using a neutralizing monoclonal antibody.

Cytopathic and noncytopathic reference strains as well as Canadian field isolates of bovine viral diarrhea virus were analyzed by neutralization and immunofluorescence tests using a bovine viral diarrhea virus-specific neutralizing monoclonal antibody. Results on reference strains indicated three major antigenic groups: I) NADL-like, II) New York 1-like and III) Oregon C24V-like. Field isolates could be segregated into groups I and II and none could be typed into the group III. It appears that most bovine viral diarrhea virus strains share a common antigen which carries a major neutralization epitope. These characteristics would make this monoclonal antibody a useful reagent for taxonomic and epizootiological studies.

Animals↗