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Biomedical subjects

J Robert

Publications and source records attributed to J Robert.

At least 469 records · Page 26Linked to original sources
PubMed1980

Radionuclide imaging in hip abnormalities.

The uptake of Tc-99m-diphosphonate was studied topographically and quantitatively on 258 diseased hips. For many diseased hips, bone scintigraphy provides items of information that complement the clinical, radiological, and biological data, with which it should always be compared. The localization, extent, and intensity of the uptake differ greatly according to the hip disorder studied, and depend not only on the cause of the lesion but also on its stage of evolution. Bone scintigraphy can shed light on the etiologic diagnosis of a painful hip at the beginning of its evolution, before definite roentgenographic signs appear, thanks to some very precise characteristics of the uptake, this is the case for transient osteoporosis of the hip, aseptic osteonecrosis, Legg-Perthes disease, early arthritis of the hip joint, and stress fractures of the femoral neck or of the pubic rami.

Adult↗
PubMed1980

Biochemical characterization of endogenous type C virus information in differentiated and undifferentiated murine teratocarcinoma-derived cell lines.

Undifferentiated teratocarcinoma cells express sixfold-higher levels of endogenous xenotropic type C virus-related RNA than differentiated cells. Three species of polyadenylated viral RNA (35S, 24S, and 14S) have been identified in the undifferentiated teratocarcinoma cells. Paradoxically, neither viral particles nor viral proteins have been detected in these cells.

Animals↗
PubMed1980

[Membrane polyunsaturated fatty acids of mammalian nerve cells in culture].

We have observed some important changes in the distribution of fatty acid classes in cultured nerve cells according to the normal or tumoral origin of the cells: normal cells exhibit higher levels of polyunsaturated fatty acids and lower levels of monounsaturated fatty acids than tumoral cells do. When the culture medium of neuroblastoma cells is supplemented with polyunsaturated fatty acids, these fatty acids are incorporated into membrane phospholipids and some specific alterations of membrane functions occur: modification of the kinetic parameters of ecto-enzyme activities, modification of amino-acid transport characteristics. A brief review of the literature shows that polyunsaturated fatty acids are not essential for cell life in vitro, provided that monounsaturated fatty acids can be present in the cells. Polyunsaturated fatty acids seem therefore play only a regulatory role of some membrane functions.

Amino Acids↗
PubMed1980

[Radioisotopic study of the nasal muco-ciliary clearance (author's transl)].

The authors propose a method for the investigation of the muco-ciliary function of the nasal mucosa: they record the motion of radioactive particles, which are put by sonic nebulisation on nasal mucosa. The average speed is calculated by means of the analysis of sequential images and by the study of the variation of activity in relation to time in several main zones. A half-clearing time of the initial activity is also measured. The average speed is 8.33 mm/minute for normal persons and 2.36 mm/minute for a group of patients. This simple, accurate, non aggressive method is used for pharmacodynamic tests.

Adenosine Triphosphate↗
PubMed1980

[Investigation of obliterative arterial disease of the lower limbs, by muscular scintigraphy using thallium (author's transl)].

The behaviour of thallium is similar to that of potassium. It participates in transmembrane exchanges and accumulates within the cells, in particular muscle cells. The subjects being at rest or at the maximum phase of an effort test, an injection of 2 mCi of thallium 201 as given. Quantitative scintigraphies were performed during the minutes following injection. Ten control subjects were studied in this way. Uptake of thallium in the muscle masses of the lower limbs was symmetrical and homogeneous and was more marked after effort. Acute ischemia for a few minutes was obtained using a tourniquet in a volunteer. The ischemic area was clearly seen on the early scintigraphy. There was redistribution of thallium in the later scintigraphic studies. Fifteen patients with obliterative arterial disease underwent scintigraphy at rest and after effort. Good agreement was found between arteriography, measurement of pressures, plethysmography and deficiencies demonstrated by scintigraphy. The effort test, by inducing transient ischemia, was useful in detecting moderate circulatory disturbances.

Adult↗
PubMed1979

Membrane lipids in bromodeoxyuridine-differentiated astroglial cells in culture.

Embryonic hamster astroblasts (NN strain) grown in continuous line were cultivated in the presence of bromodeoxyuridine (BrdU). A decrease in the growth rate of the cells and striking changes in their morphology were observed, the morphology of the cells resembling that of mature astrocytes. Membrane lipids of BrdU-differentiated and standard cells were compared. No modification of the lipid/protein ratio was observed. Phospholipids and cholesterol were increased in the same proportions in the cells, and no modification of the phospholipid distribution was observed. Ganglioside sialic acid remained at the same level, but the ganglioside distribution was highly modified. Complex gangliosides appeared (GM1 and GD1a), while the proportion of simple gangliosides (GM3 and GD3) decreased. However, neither GT1 nor GQ1 were detected in differentiated cells. The distribution of phosphoglyceride acyl groups was highly modified, the proportion of arachidonic and docosapentaenoic acids being 2 to 3 times higher in BrdU-treated cells than in proliferating ones. These results were compared to those obtained with another clonal line of glial cells (C6) which exhibited no morphological differentiation in the presence of BrdU; the lipids of these cells were not modified by such a treatment.

Animals↗