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Biomedical subjects

R Fontanges

Publications and source records attributed to R Fontanges.

At least 55 records · Page 3Linked to original sources
PubMed1976

[Karyometry of thymic reticular cells in the rat. Effect of hydrocortisone and adrenalectomy].

A new process in taxinomic analysis clearly confirmed the presence of three different types of cells (epithelial, hypertrophic and mesenchymal) in the reticular zone of the thymus. The injection of hydrocortisol as well as adrenalectomy induced specific changes in nuclear surfaces of three cell types, while hydrocortisol tented to increase the surface of epithelial and mesenchymal cells, adrenalectomy reduced it, while a modification was seen in the percentages relative of the cell types. In adrenalectomized animals, the effect result was counteracted by injections of hydrocortisol.

Adrenalectomy↗
PubMed1976

[Measurement of potential environmental carcinogens. II. Final determination methods].

As part of a general study of the biological activity of atmospheric micro constituants, we have perfected the methods for the rapid determination of polycyclic aromatic hydrocarbons. The method involves the use of two selective collectors, a high output rotatory freeze-drier, two-dimensional thin-layer chromatography and gas chromatography. A pollution map has been prepared of the Lyons areas showing the atmospheric concentrations of 13 polycyclic aromatic hydrocarbons and their variation with weather and sampling point.

Air Pollution↗
PubMed1976

[Bronchioloalveolar metaplasia during experimental influenza in mice--histological and ultrastructural study].

Squamous and "adenomatous" metaplastic changes which developed in the lungs of mice during the healing phase of experimental influenza were studied by histology and electron microscopy. The squamous nests contained epithelial cells possessing bundles of tonfibrils and being similar to bronchial basal cells. The "adenomatous" cavities were lined, either by cells related to Clara cells or by basal type-cells, which underlined cells related to Clara cells. A local and transitory hyperplasia of type II pneumocytes occurred by the third week. Both kinds of metaplasia seemed to proceed from the bronchial or bronchiolar epithelium. The adenomatous cavities might partly result from progressive differentiation of squamous epithelial cells into cells of glandular type. A ten-month long histologic survey failed to exhibit carcinomatous transformation of metaplasia. Pleiomorphism of influenza regenerative metaplasia might arise from extensive and severe epithelial changes involving all levels of the lower respiratory tract. Such a long persistence of metaplastic changes remains unexplained.

Animals↗
PubMed1976

Compared efficiency of a killed vaccine of Salmonella typhimurium, a live vaccine and an antigenic fraction in oral immunization of mice.

In an attempt to determine the best method of immunizing mice by oral route against Salmonella typhimurium, the animals were vaccinated by means of a killed-pathogenic strain, an avirulent mutant of the same bacteria, and a protective antigen removed from the supernatant culture of this mutant. After changing doses of vaccines and the interval between vaccination and challenge, the results obtained show the superiority of the live vaccine and protective antigen with regard to the killed one. Under our experimental conditions enteral vaccination appears to be more effective than the parenteral one.

Administration, Oral↗
PubMed1976

Dry aerosol vaccination against Newcastle disease. I. Safety and activity controls on chickens.

A new technic or immunization against Newcastle disease in chicken was developed: this method consists of dispersing lyophilized products by aerosols. One to fourteen day old chickens, with and without parental antibodies, were vaccinated with increasing amounts (10(-1) to 10(5)EID50) of HB1 and LaSota attenuated viruses. 10(4)EID50, inhaled theoretical dose, gave better results when the animals were challenged with the virulent strain. Under laboratory conditions, no respiratory problems occurred in vaccinated animals; but there is 10 to 20% mortality among animals treated by aerosols in poultry houses, because of respiratory diseases developed after vaccination.

Aerosols↗
PubMed1976

Dry aerosol vaccination against Newcastle disease: II. Serological response in chicks.

Day-old chickens with Newcastle disease maternal antibodies are separated in two batches. One batch (S) is vaccinated by liquid spray method with HB1 strain: the other one (NS) is not vaccinated. At 2, 3 or 4 weeks subgroups from S and NS batches are vaccinated with HB1 strain by dry aerosol method. Serological controls reveal an important increase of Newcastle antibodies within two weeks after dry aerosol vaccination. Then a drop of the antibody quantities is observed during weeks 2 to 4 post dry aerosol vaccination. In the following weeks, the antibody level increases very slowly.

Aerosols↗
PubMed1975

[Effect of intratumoral injection of bacterial and viral neuraminidase in rats].

We studied the effect of neuraminidase injection in rat's tumor at different doses: 5,10,50,100, 500 U and we concluded that: There was no difference between the rats treated with 5,10,50 U and the controls. The y died 3 weeks after the injection. But the rats treated by 100 at 500 U of NA died quickley, in the week, of long metastases.

Animals↗
PubMed1975

[Isolation of surface antigens of influenza virus A/Hong Kong 1/68 (H3N2) by density gradient fractionation with a new carboxypolypeptidase (author's transl)].

Isolation of pure neuraminidase and hemagglutinin from influenza virus A/Hong Kong 1/68 (H3N2) can be achieved using the coupled action of a new carboxypolypeptidase from Streptomyces fradiae and sodium dodecyl sulfate (SDS). Biochemical, physical and physico-chemical studies showed that the two molecules are in pure form and of glycoproteic nature.

Carboxypeptidases↗
PubMed1975

[Hypothalamo-hypophysial-thymic axis in the rat].

Thymic extracts, with proved immunologic properties, decrease, in vitro, RNA and DNA synthesis of hypothalamic fragments of adult rat and have no effect on hypophysis culture; we found a similar action in vivo. Growth hormone inhibits the nucleic acids synthesis of thymic fragments; no action is found with hypothalamic extracts. Hypothesis, that thymic activity is dependent on hypophysis with retroaction on hypothalamus, is discussed.

Animals↗
PubMed1975

[Influence of environmental conditions on human hematologic constants].

A blood investigation was carried out on 3,030 volunteer blood donors and the results treated on a computer by multivariant analysis. The authors noted a depressor effect of the urban environment on the red and white cells, a rise in small lymphocytes and a reduction in monocytes in patients living in industrial areas. This stimulation of the lymphocyte system may be compared with the experimental results obtained by the same authors in animals.

Adult↗
PubMed1975

[Effect of neonatal thymectomy on the content of magnesium in the plasma and in various tissues of the rat].

White rats were thymectomized neonatally. After 60 days, no alteration was noted in the plasma or testis magnesium level. On the other hand, a marked decrease was observed in the magnesium content of muscle (-23%) and of bone (-19%). The injection of thymosin reversed these changes. These findings suggest that a correlation between the thymus and the muscle is exerted by a protein factor (thymosin), and that the thymus may act on sex glands through an indirect pathway.

Animals↗