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Biomedical subjects

D Picard

Publications and source records attributed to D Picard.

142 records · Page 8Linked to original sources
PubMedDate not supplied

A lymphocyte-specific enhancer in the mouse immunoglobulin kappa gene.

During differentiation of lymphocytes into antibody-producing cells, an immunoglobulin kappa variable-region gene is transcriptionally activated by rearrangement linking it to a kappa constant (C kappa) region gene which is already transcribed prior to somatic rearrangement. The presence of a transcriptional enhancer element within the large intron of the kappa light-chain gene has been postulated to explain this mode of activation, supported by evidence of a chromatin region which is preferentially accessible to DNase I and restriction enzymes. This DNA region contains a segment of about 130 base pairs (bp) which is strongly conserved between mouse, rabbit and man. Moreover, no transcripts are detectable from a kappa gene, which is truncated within the large intron. Recently, a lymphocyte-specific enhancer has been identified downstream of the joining region in immunoglobulin heavy-chain genes. We now show direct evidence for a functionally similar enhancer within the large kappa gene intron of the mouse. It is, however, less active than the heavy-chain gene enhancer. In contrast, no enhancer was found to be associated with a cloned lambda I light-chain gene.

Animals↗
PubMedDate not supplied

Phonocardiogram spectral analysis simulator of mitral valve prostheses.

Spectral analysis of sounds produced in vitro by mitral valve prostheses placed in a specially designed flow simulator has been carried out using a short-time Fourier representation of the recorded signal. Time variations of power spectra are displayed as a three-dimensional plot. Sounds produced by three types of valves, namely ball and cage, tilting disk and porcine valves, were analysed. Each valve type produced a characteristic spectrogram, and, for a given valve, spectrograms were reproducible to within a margin of 5 dB. The simulator may be used to detect structural deficiencies and functional abnormalities of prosthetic heart valves. In addition to quantifying the noise level of mechanical valves, the system may be used for quality control purposes to identify faulty valves.

Equipment Design↗
PubMedDate not supplied

Familial resemblance of bone mineral density between females 18 years and older and their mothers.

Potential determinants of bone mass were investigated in a group of 70 young females (mean age 26.6 years), daughters of women studied in premenopause. Nutritional data, leisure physical activity level, lifestyle habits as well as familial similarities were assessed. The daughters' bone mineral density (BMD), measured by dual-energy absorptiometry, was significantly correlated with their body mass index (BMI) (r = 0.22), dietary vitamin D intake (r = 0.19) and their mothers' BMD (r = 0.44). Multiple regression analysis indicated that only the mothers' BMD remained an independent predictor of bone mass. Mother-daughter correlations were also observed for body weight (r = 0.24), height (r = 0.39), BMI (r = 0.29), dietary calcium intake (r = 0.20), and calcium (r = 0.20) or vitamin D (r = 0.25) intakes from dairy products. Hence, these observations support the evidence that mothers' BMD is the strongest predictor of bone mass of young women in their third decade.

Adult↗
PubMedDate not supplied

A recombinant yeast strain as a short term bioassay to assess estrogen-like activity of xenobiotics.

The study investigated the responsiveness of a recombinant Saccharomyces cerevisiae yeast strain to screen estrogen-like chemicals in order to use it as a first level short-term bioassay for environmental preventive medicine purposes. We used the yeast strain RMY326 ER-ERE, containing the human estrogen receptor alpha and a reporter gene lacZ encoding the enzyme b-galactosidase. We tested the natural steroid hormone 17beta-estradiol, diethylstilbestrol, colchicine, some phytoestrogens and pesticides, and organochlorine insecticides. The relative inductive efficiency (RIE) and EC50 values confirmed the sensitivity and specificity of the yeast strain. A statistically significant reproducibility of results in repeated experiments was assessed.

Biological Assay↗
PubMedDate not supplied

[Acute abdominal syndromes and anisakiasis. A new case (author's transl)].

To the list of the well known parasitic diseases which are expressed by acute abdominal syndromes and which need laparotomy, we may now add the anisakiasis. At the end of a complex cycle, the ingestion of herring can infected man : frequently the parasite is fixed at the level of the stomach, or of the ileum and seldom at the level of the bowel. Its presence gives rise to pain, hemorragy, tumor or occlusion in relation with the parietal granuloma. From one personal case the authors analyse the originality of this parasitic disease, the difficulty of its diagnosis before surgical time and its good prognosis.

Abdomen, Acute↗
PubMedDate not supplied

[Three new cases of presacral tumor (author's transl)].

Presacral tumors have miscellaneous histologic structures: some of them, among the most uncommon, are malignant tumors and lay it down that the extirpation must be the most complete as possible. Often they are uncovered when they compress adjoining organs (rectum, bladder, ureters, sacral plexus) and they appear voluminous, encrusted in the pelvic excavation, taking a rich vascularisation from surroundings. This adhesion involves a laborious extirpation, often hemorraegic, but needful even in benignant tumors. On this understanding and with the help of a good approach, pelvic organs can be decompressed with restricted risks of recurrence.

Adult↗