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Biomedical subjects

A Garnier

Publications and source records attributed to A Garnier.

At least 19 recordsLinked to original sources

Effects of sleep disturbances on subsequent physical performance.

The purpose of the study was to compare the cardiovascular, respiratory and metabolic responses to exercise of highly endurance trained subjects after 3 different nights i.e. a baseline night, a partial sleep deprivation of 3 h in the middle of the night and a 0.25-mg triazolam-induced sleep. Sleep-waking chronobiology and endurance performance capacity were taken into account in the choice of the subjects. Seven subjects exercised on a cycle ergometer for a 10-min warm-up, then for 20 min at a steady exercise intensity (equal to the intensity corresponding to 75% of the predetermined maximal oxygen consumption) followed by an increased intensity until exhaustion. The night with 3 h sleep loss was accompanied by a greater number of periods of wakefulness (P less than 0.01) and fewer periods of stage 2 sleep (P less than 0.05) compared with the results recorded during the baseline night. Triazolam-induced sleep led to an increase in stage 2 sleep (P less than 0.05), a decrease in wakefulness (P less than 0.05) and in stage 3 sleep (P less than 0.05). After partial sleep deprivation, there were statistically significant increases in heart rate (P less than 0.05) and ventilation (P less than 0.05) at submaximal exercise compared with results obtained after the baseline night. Both variables were also significantly enhanced at maximal exercise, while the peak oxygen consumption (VO2) dropped (P less than 0.05) even though the maximal sustained exercise intensity was not different.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Information storage by the French blood banking community in 1988].

This report presents the results of a survey about computerization of the French Blood Bank Community. Questionnaires issued on the behalf of the French Automation Working Party (G.A.I.T.S.) were sent, then analysed during the second term of 1988. The answers allowed us to obtain a picture of the advance of computerization in the French Blood Transfusion Services.

Blood Banks

[Disturbance of sports performance after partial sleep deprivation].

The changes in cardiac and ventilatory responses were measured in 7 endurance athletes during physical exercise on a bicycle ergometer, taking place after a control night and after a night with partial sleep deprivation in the middle of the night. The results show that, despite the maximal work load was not modified with control, heart rate, ventilation and VE/VO2 ratio (ERO2) were greater at the submaximal (75% of the VO2 max) and maximal work load and oxygen consumption decreased at maximal work, after the night of partial sleep deprivation as compared to the control. These findings suggest that acute sleep loss may contribute to alter the endurance performance by impairment of aerobic pathways.

Adult

[Results of surgical treatment of alphabetical syndromes in esotropia. Apropos of 98 cases].

The authors report the results of 98 cases of esotropia treated by global surgery. They treated 72 "V" syndromes, 22 "A" syndromes and 4 cases without vertical incommitance but presenting visible hyperactivities of the oblique muscles. The alphabetical variations have been treated by weakening of the oblique muscles and sometimes have been treated by weakening of the oblique muscles and sometimes of the vertical recti which are part of the same torsional couple (inferior oblique - inferior rectus in the "V" syndrome, superior oblique - superior rectus in the "A" syndrome). Post-operative improvement has been obtained in 76% of the cases for the "V" syndrome and in 63% of the cases for the "A" syndrome. The surgery of the oblique muscle must be done according to the importance of the incommitance. The arc-technique permits these adjustments. Some pronounced "X" syndromes appear in the post-operative period. All anomalies found during motility examination should be surgically corrected.

Child

1H-NMR study of the interaction of daunomycin with B-DNA helices of methylated oligodeoxynucleotides.

The interaction of daunomycin with B-DNA double helices of several methylated deoxynucleotides, d(C-G-m5C-G), d(m5C-G-C-G), d(C-G-m5C-G-C-G) and d(m5C-G-C-G-m5C-G) in solution was investigated by 1H-NMR spectroscopy at 500 MHz. At low temperature (t less than 20 degrees C for the tetramer and t less than 40 degrees C for the hexamers), several daunomycin-DNA complexes were observed in slow exchange with the drug-free DNA duplexes. The presence of daunomycin in a self-complementary double helix cancels the conformational symmetry of the two strands; the proton signals can split into several others owing to the difference between free and intercalated duplexes and to the many possible intercalation sites in a duplex (three for a tetramer, five for an hexamer). A model relating the chemical shifts of splitted proton signals to the various intercalated duplex conformations was given. The results show that one daunomycin molecule is associated with one duplex and that it can enter any intercalation site with equal probability; no side-effects were observed even for very short helices (of a tetramer). In the case of d(C-G-m5C-G) the association constant and the dissociation and association rates of the intercalated complex were evaluated.

5-Methylcytosine

Spectroscopic and photoreduction studies of copper chromophores in ceruloplasmin.

Photoreduction of native ceruloplasmin, using the 454.5-nm line of an Ar+ laser, enables the identification of type-Ia, type-Ib and type-II copper. The circular dichroic spectra of N--3-bound type-II copper and SCN-- -bound type-II copper are obtained by the same procedure after anionic treatment of ceruloplasmin. From circular dichroic and resonance Raman evidence it appears that some of type-Ia and type-Ib copper ligands differ. Type-Ib copper ligands seem to the same as type-I copper in plastocyanin and azurin. Even though type-Ib copper is coordinated to one sulfur of cysteine and one sulfur of methionine (or disulfide of cystine), the methionine sulfur is not a ligand for type-Ia copper.

Azides

Circular dichroism investigation of the (L lysine)n-Cu(II) (1:1) systems with n = 4 and n = 25.

The study of the (L Lys)n-Cu(II) (1:1) system with n = 4 and n = 25 using circular dichroism (CD) data has provided evidence indicating the formation of two complexes in a two-step process. In the first of these complexes, obtained at pH 6.6, the alpha-amino terminal group and the adjacent deprotonated amide nitrogen are bound to the metal. In the second, additional amino nitrogens of side chains lie at the other two corners of the coordination square. A comprehensive investigation of changes occuring in spectral patterns when coordination takes place enables the assignment of three bands that are characteristic to each type of nitrogen coordination.

Chemical Phenomena

Formation and spectral characterization of Cu(II)-poly(L-ornithine) complexes.

Cu(II)-Poly-(1-ornithine) complexes in aqueous solution have been studied using potentiometric titration and absorption and circular dichroism spectra. As in the case of Cu(II)-poly(L-arginine) complexes studied previously, two types of compounds have been detected, labeled complexes I and II. Complex I contains two amine nitrogens and two water molecules coordinated to the copper. Complex II, two amine and two amide nitrogens. Amide nitrogen coordination confers optical activity to the copper d-d transitions. Furthermore, amine and amide nitrogen coordination to the copper are characterized by charge transfer transitions at 250 and 320 nm respectively which were already identified in Cu(II)-poly(L-arginine) systems.

Cations, Divalent

Ceruloplasmin-anion interaction. A circular dichroism spectroscopic study.

The effect of anion binding to ceruloplasmin has been studied using absorption and cirbular dichroism spectral data. At anion to ceruloplasmin molar ratios approaching infinite, OCN-, N3- and SCN- bind to ceruloplasmin giving rise to similar alterations in circular dichroism and absorption spectra. The positive bands at 610 and 520 nm in circular dichroism spectra disappear, a negative one apperars at 600 nm and the peak at 450 nm is only slightly modified. There is a new negative band at 410 nm well-defined in OCN- ceruloplasmin spectra. The decrease in absorption at 610 nm is ascribed to the disruption of one type I Cu-S(cysteine) bond owing presumably to the changes induced by anions in the protein secondary structure. The new band at 410 nm is assigned to a charge transfer transition from the ligand replacing cysteine at its binding site. Both absorption and circular dichroism spectra show isobestic points indicating that anion binding to the enzyme, disruption of one of the two type I Cu-S bonds and coordination of this Cu to another protein residue take place simultaneously.

Anions