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Biomedical subjects

M Bernard

Publications and source records attributed to M Bernard.

At least 235 records · Page 13Linked to original sources
PubMed1975

Recombination of carbon monoxide with hemoglobin after flash photolysis of the carboxyderivative in mixed solvents at subzero temperature.

The kinetics of recombination of carbon monoxide to hemoglobin produced by total flash photolysis of its carboxyderivative are studied at low temperatures (down to --55 degrees C) in mixed hydroalcoholic solvents. The rates are found to be different in two solvents used, namely ethylene glycol/buffer and methanol/buffer; for the former, the rates at subzero temperatures are simply explained by cooling and are consistent with the activation energy as measured in aqueous solution, while those in methanol/buffer show evidence of a specific solvent effect. Values are reported for the rate constants and activation energies in the two solvents.

Carbon Monoxide↗
PubMed1975

[Not Available].

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History, Ancient↗
PubMed1975

[Measurement of linear exposure nominal pose used in curietherapy].

The idea, and subsequent construction, of a dose rate meter for measuring linear exposure dose originated in those pilot centres of Curietherapie which wished to replace radium by the artificial radionucleides, Irdium-192, Caesium-137 etc. The aparatus makes it possible to measure, directly and quickly, the activity of a specified length of a linear source, a measurement which has only been possible until now by dividing the exposure dose by the length whose activity it is desired to know. If the dose-rate obtained by these two methods agrees, this apparatus shortens the time for which the sources need to be handled, thereby reducing the danger of irradiation to staff and technicians. The apparatus is thus able to reveal heterogeneity of activity along the length of a line-source. In the specific case of Iridium, our experience shows that wires which have been used in several applications may develop mechanical bends and constrictions, which can lead to fluctuation in dose rate along their length. The apparatus was first constructed in 1967, after preliminary experiments in 1965. As Curietherapy has become more widely used, the apparatus has undergone many modifications which is more precise and specific than it was initially. At the present time it can only be used with Iridium as wire, and with Caesium in the form of trains of seeds (corresponding to the AGS sources) or needles. Nevertheless, a third scale is under consideration, for use with newer radioelements, which may be used in future.

Cesium Radioisotopes↗
PubMedDate not supplied

Evaluation and treatment of urinary incontinence. Report of a physician survey.

OBJECTIVE: To determine practice patterns related to the evaluation and treatment of urinary incontinence (UI). DESIGN: Stratified random sample of physicians surveyed initially by mail with telephone follow-up. SETTING: Four counties in Central Oklahoma. PARTICIPANTS: One hundred fifty-five physicians in 4 specialties: family practice, internal medicine, obstetrics/gynecology, and urology. MEASUREMENTS: Self-reported evaluation and treatment of UI and training in treatment of UI. The overall rate of response was 80%. RESULTS: Physicians miss opportunities to identify patients with UI. Despite substantial specialty variation, behavioral treatments and medications for UI, relative to the Agency for Health Care and Policy Research clinical guidelines, are underused. More than 40% of internists and family practitioners routinely recommended absorbent pads. Only 17% of physicians were aware of the clinical guidelines. CONCLUSIONS: Physicians identified deficiencies in their level of preparation to evaluate and treat UI. Reports of practice patterns also suggest deficiencies.

Adult↗
PubMedDate not supplied

Nutritional support.

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Bibliographies as Topic↗
PubMedDate not supplied

[Study of in vivo cellular metabolism by phosphorus 31 nuclear magnetic resonance].

Phosphorus-31 nuclear magnetic resonance spectroscopy has been recently increasingly used to study cellular metabolism in a manner respecting the cell integrity. Intrinsic advantages of the phosphorus nucleus for in vivo NMR studies are discussed in this review together with some selected applications. A particular emphasis is layed on metabolite identification and quantitation (relative and absolute concentrations), the measurement of intracellular pH and the problem of cellular compartmentation. The determination of metabolite fluxes under normal and abnormal biological and physiological conditions, and the in vivo direct measurement by saturation transfer techniques of kinetic parameters for enzymatic reactions at equilibrium, are illustrated by several examples taken from the available literature and work carried out in this laboratory. Whenever possible, and appropriate, the NMR approach has been compared with other more classical techniques of investigation. The future and the potentialities of phosphorus-31 NMR study of intact biological systems, the clinical applications and the foreseeable interfacing with imaging techniques are evaluated. The concept of "functional imaging" versus "anatomic imaging" is proposed to illustrate the impact of this new technology in the understanding of cellular mechanisms, not only in the intact cell but also in whole tissues or organs after excision or in living animals and human.

Animals↗
PubMedDate not supplied

Human pro alpha 1(I) collagen gene structure reveals evolutionary conservation of a pattern of introns and exons.

The collagens represent an interesting example of a structurally related but genetically distinct family of proteins. Type I, the most abundant of the vertebrate collagens, comprises two pro alpha 1(I) chains and one pro alpha 2(I) chain, each containing terminal propeptides and a central domain of 338 (Gly, X, Y) repeats. The structure of the chicken pro alpha 2(I) gene shows an intriguing relationship between exon organization and the arrangement of (Gly, X, Y) repeats (see ref. 2 for review). This has led to the suggestion that the collagens evolved from a common ancestral unit of 54 base pairs (bp). Here we present the structure of the entire human pro alpha 1(I) gene and compare this with the chicken pro alpha 2(I). The exon arrangement of the two genes is remarkably similar, although the human pro alpha 1(I) is more compact because of the shorter length of its introns. The data strongly support the notion that the type I genes have evolved from an ancestral multi-exon unit, and that once the gene was translated, a strong evolutionary pressure caused it to maintain this elaborate structure.

Amino Acid Sequence↗
PubMedDate not supplied

Melatonin synthesis pathway: circadian regulation of the genes encoding the key enzymes in the chicken pineal gland and retina.

The mRNAs encoding three enzymes of the melatonin synthesis pathway (tryptophan hydroxylase (TPH), arylalkylamine-N-acetyltransferase (AANAT) and hydroxyindole-O-methyl-transferase (HIOMT)) are expressed with a day/night rhythm in the chicken pineal gland and retina. TPH and AANAT mRNA levels reach their peak at night. HIOMT mRNA levels peak at night in the retina, but during the day in the pineal gland. In this tissue, the rhythm of TPH, AANAT and HIOMT mRNA levels persisted in constant darkness (DD), both in vivo and in vitro, indicating that the three genes are controlled by the circadian oscillator of the chicken pineal. In the retina, the rhythms of TPH and AANAT mRNA levels also persisted in DD in vivo, suggesting that they are driven by a circadian oscillator. In contrast, the rhythm of HIOMT mRNA in the retina appeared to be controlled only by light. The clones of chicken AANAT and HIOMT genes that we have isolated should help us to understand the molecular mechanisms of: 1) their transcriptional regulation by circadian oscillators and by light; 2) their tissue-specific expression in the pineal gland and the retina.

ARNTL Transcription Factors↗