Search PubMed⌕ Search

Biomedical subjects

C Roche

Publications and source records attributed to C Roche.

At least 91 records · Page 5Linked to original sources
PubMed1985

Electrophoretic analysis of red blood cells in polycythaemia.

In contrast with previously published observations, this study has found no increase in the net negative surface charge of the red blood cells (RBC) from patients with various forms of polycythaemia when compared with normal subjects. Two sub-populations of RBCs with different electrophoretic mobilities (EPM), termed fast and slow, were present in samples from both patients and normal individuals. Frequently, the slow cell population in RBCs from patients with polycythaemia, particularly the apparent polycythaemia sub-group, was of a lower EPM and contained more cells than the corresponding population in normal subjects. The membrane-bound sialic acid content of RBCs from patients with primary proliferative polycythaemia, associated with iron deficient RBC changes, was increased if the results were expressed per unit volume of RBCs and decreased if the sialic acid concentration was presented per number of RBCs. These results imply that differences in surface charge of RBCs are of no value in discriminating between primary and secondary polycythaemia.

Electrophoresis↗
PubMed1984

[Intestinal absorption of calcium and its regulation. Tissue, membrane and molecular events].

The intestinal absorption of calcium involves an active transport against an electrochemical gradient, a saturable and a nonsaturable transfer following the gradient. The active and the saturable components are transcellular, the nonsaturable component is partly paracellular. Calcium transfer through the intestinal cell includes three steps: 1) the "down-hill" crossing of the brush-border implies binding to specific sites, carrier-mediated transport using channels or carrier proteins specific to Ca and dependent upon composition phosphorylations alkaline phosphatases; the phospholipid composition of the brush-border also plays a role; 2) the intracellular transfer is characterized by an uptake by such organelles as mitochondria, lysosomes and Golgi vesicles and by a transfer on a specific calcium-binding protein; 3) the "up-hill" transfer across the baso-lateral membrane requires energy and energy is mediated by an ATP-activated Ca2+ pump and a Na+/Ca2+ antiport. 1.25 dihydroxycholecalciferol, steroid hormone synthetized from vitamin D3 is the major direct regulator of Ca absorption: in the vitamin D-deprived animal, it increases the selective permeability for Ca of the brush-border, induces the synthesis of proteins after genomic transcription, activates the Ca-ATPases, and acts as a trophic hormone. The other hormones principally act by modulation of the renal biosynthesis of 1.25 dihydroxycholecalciferol. The efficiency of Ca absorption depends on site, with duodenum greater than jejunum greater than caecum greater than ileum. Dietary constituents such as carbohydrates and amino acids increase Ca absorption whereas phytic acid and excess of phosphorus decrease it. They act by modifying Ca bioavailability and perhaps brush-border permeability. Adaptation to increased demand occurs during growth, pregnancy and lactation in normal states but disappears during vitamin D deficiency. In man, lowered efficiency with increasing age is often aggravated by a low calcium diet.

Animals↗
PubMed1984

[Growth of the fetal kidney. Echographic study].

An echographic study of the fetal normal kidney in 274 fetuses (548 kidneys measured) from 15 to 40 weeks of pregnancy is proposed by the authors. This work includes morphologic and biometric study with the growth curves of 4 parameters. It is shown that both kidneys are morphologically similar and their growth is continuous and there is a constant ratio between the different parameters. Ratios are established: Length/BPD = 0,45 +/- 10%, Width/BPD = 0,27 +/- 10%, Thickness/BPD = 0,26 +/- 10% which are very useful for the echographist. One hopes that with morphologic and biometric criteria of normality, the early detection of urinary tract malformations will be easier.

Female↗
PubMed1983

Duodenal and ileal calcium absorption in the rat and effects of vitamin D.

An in situ ligated loop procedure was applied to dissect transmural calcium transport in the intestine into two components, a saturable and a nonsaturable process. The existence of two such processes was confirmed in the duodenum, but ileal calcium transport was devoid of the saturable component. There was a small saturable component in the upper jejunum. The level of CaBP, the vitamin D-dependent cytosolic calcium-binding protein (Mr, approximately or equal to 9,000), corresponded to the magnitude of the saturable component. No CaBP was detected in the ileum. Vitamin D dependence of the saturable component was established by inducing it in the duodenum of vitamin D-deficient animals following intraperitoneal injection of 1,25-dihydroxyvitamin D3. In these same animals, conversely, the ileum did not respond to exogenous 1,25-dihydroxyvitamin D3. This confirms the absence in the ileum of the saturable component of transmural calcium movement and the fact that the nonsaturable component is not vitamin D dependent. Everted sac experiments also showed that duodenal sacs from vitamin D-replete or -repleted animals transported calcium against a chemical gradient, whereas ileal sacs did not. Vitamin D regulation of intestinal calcium absorption thus occurs only in the proximal intestine, even though calcium is absorbed down its chemical gradient all along the small intestine.

Animals↗
PubMed1982

Effect of somatostatin on the secretin-induced gastric secretions of pepsin and mucus in cats.

The effect of somatostatin 14 on gastric stimulation produced by secretin was determined in 6 conscious cats equipped with a gastric fistula and a denervated fundic pouch. Somatostatin strongly inhibited the basal and secretin-induced pepsin secretion. It did not, however, inhibit the secretin-induced mucus secretion, even though it decreased the basal mucus secretion. During somatostatin administration, the secretagogue effect of secretin on mucus secretion might be dissociated from its stimulatory action on pepsin secretion.

Animals↗
PubMed1982

Orientational changes of the absorbing dipole or retinal upon the conversion of rhodopsin to bathorhodopsin, lumirhodopsin, and isorhodopsin.

The orientational change of the absorbing dipole of the retinal chromophore in vertebrate rhodopsin (rhodo) upon photo-excitation to bathorhodopsin (batho), lumirhodopsin (lumi) and isorhodopsin (iso), has been studied by polarized absorption and linear dichroism measurements on magnetically oriented frog rod suspensions that were blocked at liquid nitrogen temperature. Both the azimuthal component delta theta and the polar component delta theta of the total angular change were studied in separate experiments. Delta theta was estimated from polarized absorption measurements on rods oriented transversally with respect to the analyzing beam. The data show unequivocally that upon the rhodo leads to batho transition, the dipole shifts out of the membrane plane by only few degrees; delta theta congruent to -3 degree. This azimuthal shift was nearly exactly reversed upon the batho leads to lumi decay. A very small shift (delta theta less than or equal to 1 degree) toward the membrane plane was observed upon a rhodo leads to iso conversion. The polar component delta theta of the angular shift was estimated by studying the photoreversion of linear dichroism induced by photo-excitation with polarized light in rods oriented parallel to the analyzing beam. Upon the rhodo leads to batho transition, ther was a shift delta theta = 11 +/- 3 degrees. The overall angular shift upon this first photo-exciting step, which corresponded to the isomerisation of retinal, was only delta omega = 11 +/- 3 degrees. This is smaller than what may be expected for a cis-trans isomerization of a retinal molecule with one end fixed, and different from what has been previously estimated by another group. These discrepancies are discussed.

Animals↗
PubMed1982

[Focal and multifocal electroencephalogram in the neonatal period. Prognostic correlations].

In a prospective study of 35 newborns, with acute neurological manifestations of diverse etiology and focal or multifocal neonatal EEG recordings, both clinical and EEG evolution wee evaluated at three and fourteen months of age. More than half of the patients who presented this type of recording at birth were found to have neurological sequelae and almost one fourth had seizures upon posterior evaluation. Authors compare this type of EEG recording with others observed in neonatal period and discuss their results in the light of etiologic, clinical and EEG findings in the literature.

Asphyxia Neonatorum↗
PubMed1981

150 bicycle injuries in children: a comparison with accidents due to other causes.

One hundred and fifty bicycle accidents seen at the Children's Hospital Sheffield over a 6-month period from mid-August 1979 were analysed and 9.3 per cent of the cases were admitted. Twenty-two per cent had fractures, 20 per cent had soft tissue injuries of face or scalp, 8 children having damaged their teeth. Of the accidents 17.3 per cent were due to hitting an obstruction, 30.7 per cent were due to loss of control on a hill or corner and 8 per cent were of mechanical origin. Eighty-eight per cent had cycling experience of a year or more, and 32.7 per cent had had previous cycling accidents. Comparison with other types of accidents previously studied at the hospital, involving skateboards, playground equipment or road traffic accidents affecting child pedestrians, showed that by far the most serious were those involving child pedestrians. The injuries from bicycle accidents were similar in severity to those involving skateboards.

Accidents↗
PubMed1980

[Septicemia following infection of an endocardial electrode lead (author's transl)].

The authors report one case of septicemia following the infection of a remaining endocardial electrode lead. From this observation and the literature's data, they are thinking that it is essential to remove the entire pacemaker system (electrode lead and generator) to cure this complication. They remind the different technics used to remove the endocardial leads.

Adult↗
PubMed1980

[Mesenteric clamp syndrome complicating pancreatic trauma (author's transl)].

Duodenal obstruction by the mesenteric artery has mostly been reported in profoundly denutrated patients. We here report one case after left spleno-pancreatectomy following pancreatic isthmus rhexis concerning a seventeen years old injured young boy, who was kept in supination position because of a backbone fracture. Vertebral osteo-synthesis allowed a quickly efficient postural treatment.

Adolescent↗