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Biomedical subjects

R Girard

Publications and source records attributed to R Girard.

At least 73 records · Page 4Linked to original sources
PubMed1986

Membrane glycolipid and phospholipid composition of lipopolysaccharide-responsive and -nonresponsive murine B lymphocytes.

Neutral glycolipids, gangliosides, and phospholipids present on membranes of unstimulated or lipopolysaccharide (LPS)-stimulated B cells were analyzed in LPS-responsive C3H/HePAS and LPS-nonresponsive C3H/HeJ mice. In the set of neutral glycolipids, asialo GM1 reacted preferentially with galactose oxidase but was not detectable with monospecific antibodies during immunocytofluorescence analysis. Another, more polar, neutral glycolipid appeared exclusively after stimulation of responsive B cells. Among the membrane gangliosides 1 to 5 that were able to react with galactose oxidase on B cells, ganglioside 3 was not detected in the mutant strain, and its absence was counterbalanced by the presence of a larger amount of ganglioside 1. The biosynthesis of total membrane phospholipids and the balance between phosphatidylethanolamine and phosphatidylcholine were significantly different in the two mouse strains examined and were quantitatively and qualitatively modified during the mitogenic response to LPS.

Animals↗
PubMed1985

Preparative scale separation of functionally distinct murine B cell subpopulations.

Mouse splenic B cells were found to be rapidly and reproducibly fractionated by adherence at 4 degrees C to plastic dishes pretreated with an alkaline buffer. The cell subsets obtained exhibited marked differences in size, surface immunoglobulins (sIg), and responses to B mitogens. Adherent B lymphocytes, bearing high densities of sIg, responded particularly to LPS whereas non-adherent B lymphocytes, with low densities of sIg, responded especially to dextran sulfate. The correlations between the separated populations and subsets at distinct maturation stages are discussed.

Animals↗
PubMed1985

Enhancement of murine B cell responses to lipopolysaccharide by supernatants of irradiated peripheral blood leukocytes.

At low cell density, the proliferative response of B cells to lipopolysaccharide (LPS) is not detectable. We investigated under these experimental conditions the role of several cell populations on the LPS-induced B-cell proliferation. The addition to murine B cells of irradiated peripheral blood leukocytes (PBL) from the C3H/HeJ mouse strain, or of culture supernatants of these cells, efficiently restored a response to LPS. Similar results were also obtained with irradiated PBL from other mouse strains and from rabbits. The activities of the culture supernatants were not significantly modified when the PBL were depleted of adherent cells or of Thy-1.2 positive cells, thus suggesting that the active factors were secreted neither by T cells, nor by monocytes.

Animals↗
PubMed1985

Inhibition of lipopolysaccharide mitogenicity with characterized anti-lipid A monoclonal antibodies.

Antibodies to lipid A were raised in mice immunized with non-hydrolysed Bordetella pertussis microorganisms, coated with lipid A isolated from the same bacteria. Anti-lipid A activity of immune sera was measured by radioimmunoassay. Four hybrid cell lines that secrete antibodies directed against the hydrophobic region of B. pertussis lipopolysaccharide were produced by cell fusion between myeloma cells and spleen cells from immunized C3H/He-PAS mice. Differences were observed in the potency of the isolated monoclonal antibodies to inhibit B cell proliferation induced by lipopolysaccharide (LPS) or by lipid A, suggesting a selective recognition of effector sites present on the hydrophobic region of LPS.

Animals↗
PubMed1984

Blunt diaphragmatic rupture.

Diaphragmatic injury is often a missed diagnosis in patients with multiple trauma. For this reason, mortality can be high. From 1970 to 1981, 32 patients with diaphragmatic injuries were seen at Maisonneuve-Rosemont Hospital. Twenty-four of the patients (22 men and 2 women aged 18 to 79 years) had blunt abdominal or thoracic trauma causing diaphragmatic disruption. Rupture occurred 20 times on the left side of the diaphragm, and 3 times on the right side. There was one pericardiophrenic rupture. Motor vehicle accident was the most common cause of trauma. On arrival, 21 patients had acute diaphragmatic rupture. Clinical signs and radiography permitted early diagnosis in 15 patients, whereas diagnosis was made later in 3 other patients because of deterioration of vital signs. In two patients, diagnosis was made at laparotomy for another reason. Four patients were operated on for post-traumatic chronic diaphragmatic hernia. The abdominal approach was used in 18 patients, the thoracic approach in 4, and the thoracoabdominal approach in 2. Three patients died, two of whom had a late diagnosis. Fourteen patients had no complications. Diaphragmatic trauma can be easily managed surgically when diagnosis is made early after trauma. It must always be looked for in patients with multiple trauma.

Accidents, Traffic↗
PubMed1984

Binding of a rhodamine-labeled lipopolysaccharide to lipopolysaccharide-responder and nonresponder lymphocytes.

The binding levels of a highly soluble rhodamine-labeled lipopolysaccharide (LPS-Rh) on different LPS-responsive and nonresponsive murine spleen cells were measured with a cytofluorometer (CFM). In all the experiments, a preferential binding of LPS-Rh to LPS-responsive cells was observed. Furthermore, only a proportion of B cells from the responder mouse strain was selectively stained after addition of LPS-Rh. These findings suggested that LPS-Rh binds to specific components of the cell membrane, involved in the triggering of B-cell mitogenicity.

Animals↗
PubMed1983

Costs of nosocomial infection in a neonatal unit.

Hospital costs for 61 neonates with acquired nosocomial infection were compared with 61 matched, uninfected controls. The increase in length of hospital stay (+23 per cent) added to the number of laboratory tests increase total hospitalization costs to 32 per cent. An additional US $1250 for each case of infection is the cost to the Social Security system. The importance of this increase, contrasted with the generally benign nature of the infections studied, justifies the maintenance of high standards of quality in neonatal care.

Costs and Cost Analysis↗
PubMed1983

Life expectancy following spinal cord injury: a ten-years survey in the Rhône-Alpes Region, France, 1969-1980.

A ten years survey of 848 patients having sustained traumatic spinal cord injury between 1969 and 1979 was conducted in the Rhône-Alpes Region, France. All patients had been referred to the spinal cord injury unit, Hôpital Henry Gabrielle. 48 deaths were recorded: 36 patients admitted early to the Unit, and 12 patients injured before 1969 but followed-up in the Unit. The deceased patients were older and more frequently male and tetraplegic than the rest of the group. In 75 per cent of the deceased patients, the survival time was less than 1/5 of the theoretical life expectancy. In 59 per cent, it was less than 1/10. Twenty tetraplegics died of respiratory complications. Three patients committed suicide, the rest died of urinary complications. The results appear to determine a secondary period with high mortality rate, after the initial high mortality of these patients. About one year post-injury, the life expectancy in our series appears to tend towards the values observed in the French population.

Adolescent↗
PubMed1983

The female paraplegic: a statistical survey.

From November 1969 to December 1979, 1234 patients with spinal cord lesions were treated at the Henry Gabrielle Hospital. Of these 386 were from medical causes and 848 from trauma. The computer study of these cases brings out statistical differences between the sexes as the overall incidence in females is 30 per cent and even lower if one considers traumatic cases only 22.4 per cent out of the 848 cases. Furthermore, the average female paraplegic is two years older and it was noted that more females are married. In females the causes of spinal cord injuries are more frequently car accidents and suicidal falls from high places, whereas in males the causes are related to direct blows, that is sport injuries, motorcycle accidents and industrial falls. Clinical symptoms are similar in the two groups with the exception that there is less heterotopic ossifications and fewer bladder stones in females. The duration of hospitalisation is shorter in females. A well equipped household is more important for the handicapped females than for males.

Adolescent↗
PubMed1981

Mitogenic response of C3H/HeJ mouse lymphocytes to polyanionic polysaccharides obtained from Bordetella pertussis endotoxin and from other bacterial species.

Lipopolysaccharide extracted from Bordetella pertussis was mitogenic for spleen cells of endotoxin-resistant C3H/HeJ mice. Although endotoxic lipid A was inactive, mitogenic activity of lipopolysaccharide was exhibited by purified preparations of polysaccharides I and II, which constitute the carbohydrate moiety of the macromolecule. These low-molecular-weight (2,800 and 3,600) polysaccharides, containing carboxyl groups, were not mitogenic for thymocytes and splenic T-cells of C3H/HeJ mice, but did show mitogenic activity for splenic B-cells of C3H/HeJ mice and for spleen cells of C57BL/6 athymic nude mice. The mitogenic activities of polysaccharides I and II were also compared with those of other polyanionic polysaccharides, and the results indicate that high molecular weight is not necessary, and negative charges are not sufficient, for mitogenicity.

Animals↗