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Biomedical subjects

C Tschopp

Publications and source records attributed to C Tschopp.

6 recordsLinked to original sources
PubMed1995

[Automated static perimetry in the child: methodologic and practical problems].

PURPOSE: In a pediatric population, the use of computerized static perimetry is known as particularly difficult. The specific difficulties which may occur when testing young subjects are stability of fixation, ability to maintain concentration, resistance throughout the procedure, and reliability of the answers. It seems important to investigate and to develop appropriate strategies for the examination of children aged 8 years and younger according to their ability to undergo visual field evaluation using automated static perimetry. PATIENTS AND METHODS: Eighty normal children aged 5 to 8 years old were evaluated using an Octopus 2000R perimeter, with a one-level strategy. Adaptation of the procedure were included. RESULTS: The analysis of answers and false-positive catch-trials showed that children as young as five years old did remarkably well regarding both the duration of the examination and the reliability of answers. CONCLUSIONS: Automated static perimetry examination can provide reliable results in children as young as five years old once a familiarization procedure has been conducted and if the duration of examination does not exceed the child's capacity to remain task focused.

Child↗
PubMed1994

In vitro characterization of major ligands for Src homology 2 domains derived from protein tyrosine kinases, from the adaptor protein SHC and from GTPase-activating protein in Ramos B cells.

Antigen receptors of B lymphocytes transmit their activation signal to the cell interior by associating with and activation of specific non-receptor tyrosine kinases. Most of these kinases as well as other cytoplasmic effectors contain at least one Src homology 2 (SH2) domain, known to bind tyrosine-phosphorylated proteins. We examined the binding specificity of SH2 domains from different signaling molecules in B cells and found that each of the SH2 domains tested bound distinct subsets of stimulation-dependent phosphoproteins in vitro. SH2 domains from Src-like tyrosine kinases bound predominantly to the HS1 phosphoprotein. The tandem SH2 domains of the ZAP-70 tyrosine kinase bound to phosphorylated Ig-beta but only weakly to Ig-alpha. Also the SHC-derived SH2 domain formed complexes with the tyrosine-phosphorylated Ig-alpha/beta heterodimer, while the C- and N-terminal SH2 domains of GTPase-activating protein displayed completely different binding preferences. These results suggest that cytoplasmic effector molecules can be recruited to the activated B cell receptor in an SH2-phosphotyrosine-mediated manner. The data also provide a possible explanation for the notion that Ig-alpha and Ig-beta might couple to different biochemical pathways.

Adaptor Proteins, Signal Transducing↗
PubMed1994

IL-2 promoter-driven lacZ expression as a monitoring tool for IL-2 expression in primary T cells of transgenic mice.

A transgenic mouse system has been established to follow the pattern of IL-2 expression at the level of single T cells. This was achieved by introducing a human IL-2 promoter-driven reporter gene (Escherichia coli lacZ) into the germline of mice and monitoring its product, beta-galactosidase (beta-gal), by FACS analysis. Ex vivo experiments confirmed that the regulated expression of the transgene is comparable with that of the endogenous IL-2 gene. Transgene expression is inducible by mitogens, restricted to T cells, and diminished by immunosuppressive agents, such as cyclosporin A, at concentrations known to suppress IL-2 transcription. Depending on the mitogens used, 30-50% of peripheral T cells produced IL-2 with an asynchronous induction pattern, as measured by transgenic beta-gal activity. Both helper (CD4+CD8-) and cytotoxic T cells (CD4-CD8+) respond with comparable heterogenous expression levels but they show different frequencies of beta-gal production. Transgenic beta-gal-producing T cells were detectable as early as 2 h after mitogen stimulation. These cells represent a transitional IL-2 secreting, IL-2 receptor alpha-chain negative T cell population, which occurs in the autocrine process of T cell activation. Administration of staphylococcal enterotoxin A (SEA), a bacterial superantigen, resulted in a T cell specific (Thy-1.2) increase (2.5-fold) of reporter gene expression in vivo. In summary, we could demonstrate that IL-2 promoter-driven reporter gene expression in transgenic mice is a sensitive tool to characterize IL-2 expressing cells phenotypically.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Mood and body image of women after surgery for breast cancer].

The purpose of the following study is an intensive, longitudinal assessment of psychophysical well-being, stress and stress development after breast cancer diagnosis and surgery. 15 patients were investigated by means of a semistructured diary guiding to systematic daily self-observation during the first ninety days after primary treatment. Although the general trend over time is positive, the results show a considerable variability in the development of mood and body states which cannot exhaustively be explained by medical parameters. The experience of stress is often related to somatic disorders and adjuvant treatment. The results afford an insight in the psychological characteristics of this difficult period and may help to support the patient's rehabilitation more efficiently.

Adaptation, Psychological↗
PubMed1980

Nasopharyngeal carcinoma in Alaskan Eskimos Indians, and Aleuts: a review of cases and study of Epstein-Barr virus, HLA, and environmental risk factors.

The records of thirty-one patients with nasopharyngeal carcinoma (NPC) diagnosed from 1966 through 1976 among the Alaskan native population (Eskimo, Aleut, Indian) were reviewed. There were 25 males and six females, which results in relatively high incidence rates per 100,000 of 13.5 for males and 3.7 for females. Clinical and pathologic features were similar to those found among southern Chinese NPC patients. Five-year survival rate was 48%. Antibodies to Epstein-Barr virus were higher in NPC patients than in patients with other tumors or matched controls. On histocompatibility testing Sin-2 was not detected, nor was there significantly increased frequency of A2. Instead, BW40 and a second locus blank occurred more often among NPC patients than among other groups. In response to a questionnaire, NPC patients more often reported use of salt fish in the childhood diet, smoking of cigarettes, and exposure to noxious inhalants than did controls, but the differences were not statistically significant.

Adult↗