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Biomedical subjects

A Cordier

Publications and source records attributed to A Cordier.

At least 73 records · Page 4Linked to original sources

[Calorimetric study of enteral low-carbohydrate diet in patients with respiratory insufficiency and decompensation].

Standard artificial feeding is not suitable for patients with acute respiratory failure due to the increase in CO2 production it entails, effect of carbohydrate metabolism. Randomized use of an enteral diet comprising 55% of fats in 10 patients with chronic pulmonary disease during an acute phase, receiving mechanical ventilatory support, achieved a rapid decrease of VCO2 value, 243 to 215 ml.min-1, while it increased to 250 ml.min-1 with the control diet. These variations are metabolic and not ventilatory in origin for they are not accompanied by changes in plasmatic total CO2 rate.

Blood Gas Analysis↗

Limb bud cell culture for in vitro teratogen screening: validation of an improved assessment method using 51 compounds.

Rat embryo limb bud cells multiply and undergo chondrogenesis in micromass culture. Teratogenic agents are identified from their inhibition of chondrogenesis, which is quantified by determination of cartilaginous foci number or proteoglycan production. In other in vitro systems, the detection is based on their ability to affect cell proliferation. So far, these methods have failed to distinguish among true inhibition of differentiation, inhibition of cell proliferation, and nonspecific cytotoxicity. The improved technique involves simultaneous measurement of cartilage synthesis and cell multiplication. Differentiation was evaluated by measurement, using an Artek Counter, of nodule areas after Alcian blue staining and proliferation by spectrophotometric quantification of Crystal-Violet bound to micromass cells. Using this method, retinoic acid was shown to inhibit chondrogenesis without affecting cell multiplication, whereas 6-aminonicotinamide preferentially inhibited cell multiplication without affecting nodule size. Doxylamine (succinate), a known nonteratogen, induced inhibition of chondrogenesis, but with a parallel inhibition of cell multiplication, reflecting a nonspecific toxic effect. This improvement increases the specificity of the micromass culture test. Validation was performed using 51 compounds. Compounds were classified according to their inhibitory activity and their active concentration. The sensitivity of the test was 61%; the specificity, 100%; and the final accuracy, 75%. The method is fully miniaturised, automated, and computerised, allowing numerous compounds to be rapidly tested at very low cost.

Animals↗

In vivo micronucleus test using mouse hepatocytes.

The bone-marrow micronucleus (BMM) test is highly specific for clastogenic effects but its sensitivity is determined to a great extent by the substances tested, particularly by their metabolism. Some compounds, such as unstable mutagens or those which generate short-lived metabolites, are not detected in this test because the metabolites produced in the liver do not reach the bone marrow. In an attempt to provide qualitative and quantitative assessments of chromosomal mutations produced in vivo by genotoxic agents not detected in the mouse BMM test, a mouse-liver micronucleus test, adapted from Tates model, was developed. The animals were treated twice, with an interval of 24 h between treatments, and then subjected to partial hepatectomy (PH) 24 h after the second treatment in order to induce mitotic stimulation. The incidence of micronucleated hepatocytes was determined 96 h after PH. The test was evaluated with 5 procarcinogens, each with a complex metabolic pattern: dimethylnitrosamine (DMN), diethylnitrosamine (DEN), 1,1-dimethylhydrazine (1,1-DMH), 4-aminophenol (4-APOL), 4-aminobiphenyl (4-ABPYL) and one direct unstable mutagen, beta-propiolactone (BPL). All these compounds are negative in the mouse BMM test but caused a major increase in the incidence of micronuclei in mouse hepatocytes. This test is simple and can be readily compared with the BMM test. Furthermore, it offers a better assessment of the impact of a compound at the chromosomal level in a metabolically competent cell and can therefore be used for the evaluation of the genotoxic activity of compounds with complex metabolic pathways.

Aminobiphenyl Compounds↗

[Separation of pygopagous Siamese twins].

The successful separation of pygopagous twins is described. The sacrum formed a common canal since S 1 to coccyx with two medullary cords side to side and diastematomyelia with, at this level, two dural sacks. In each baby there was small atrophy in one lower limb. There were two opposite vulvovaginal ducts and two recto-perineal fistules.

Anesthesia, General↗

Selective hypoplasia of pelvic bone marrow.

6 patients with thrombocytopenia and anaemia had fatty marrow replacement at the site of an iliac crest. 52Fe scans showed marked abnormalities of bone marrow distribution. Particularly, the uptake of radioiron into the pelvis was almost absent. The sternal marrow was cellular. Studies of the bone marrow which included cytology, histology and electron microscopy failed to reveal why the pelvic marrow was aplastic. Occasional vascular lesions could not seen in the iliac crest bone marrow sections. The cellular morphology showed slight maturation abnormalities. Ferrokinetics were consistent with erythroid marrow hypoplasia. The pelvic and sternal marrow cellularity in patients with pancytopenia may not be representative of the cellularity of the whole marrow, and the pelvic marrow especially may be prone to aplasia.

Adult↗

Murine yolk sac hematopoiesis studied with the diffusion chamber technique.

The proliferation and differentiation of visceral and of parietal yolk sac cells from 9-day-old mouse embryos were studied in diffusion chambers (DC). After culture, the visceral yolk sac yielded predominantly macrophages whereas the parietal yolk sac displayed mainly plasmocyte-like cells. It is shown the latter do not synthesize immunoglobulin but rather elaborate Reichert's membrane. Neither visceral nor parietal yolk sac contained detectable pluripotent stem cells (CFUs) prior to or after DC culture, a finding which is discussed in the light of the current literature.

Animals↗

[Ultrastructure of achromic malignant melanoma of the gingiva. value in differential diagnosis].

The authors report a case of a large oral tumour. On the basis of classical histological and histochemical techniques, the diagnosis was oriented towards an angiosarcoma though it was not possibile to eliminate an achromic melanoma. Ultrastructural studies demonstrated the presence of premelanosomes and established the diagnosis of an achromic malignant melanoma. The clinical interest of this approach isthus emphasised.

Aged↗

A new hematologic syndrome with a distinct karyotype: the 5 q--chromosome.

Five patients, four women and one man, age 32-8- yr, all whites, had refractory anemia with the same abnormal bone marrow karyotype, i.e., a partial deletion of the long arm of the No. 5 chromosome. The hematologic syndrome was practically the same in these five cases. Examination of the blood revealed a moderate to severe, generally macrocytic anemia with slight leukopenia but normal or elevated platelet count. The bone marrow showed a depressed erythroid series and some abnormalities of the granulocytic series with an occasional excess of myeloblasts. Most of the megakaryocytes had a nonlobulated nucleus. These features, as well as cytogenetic, electron microscopic, isotopic, platelet function, and immunologic studies, are described in detail. The relationship of this newly established syndrome to other hematologic diseases is discussed. The syndrome constitutes another example of the association between a specific abnormal chromosome and a distinct hematologic disorder.

Adult↗