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J Berthet

Publications and source records attributed to J Berthet.

50 records · Page 3Linked to original sources
PubMed1967

Electron microscopic examination of subcellular fractions. I. The preparation of representative samples from suspensions of particles.

A method is described for preparing, by filtration on Millipore filters, very thin (about 10 micro) pellicles of packed particles. These pellicles can be embedded in Epon for electron microscopic examination. They are also suitable for cytochemical assays. The method was used with various particulate fractions from rat liver. Its main advantages over the usual centrifugal packing techniques are that it produces heterogeneity solely in the direction perpendicular to the surface of the pellicle and that sections covering the whole depth of the pellicle can be photographed in a single field. It thus answers the essential criterion of random sampling and can be used for accurate quantitative evaluations.

Acid Phosphatase↗
PubMed1967

Electron microscopic examination of subcellular fractions. II. Quantitative analysis of the mitochondrial population isolated from rat liver.

Large granule fractions, containing about 80% of the cytochrome oxidase of the tissue, were isolated from rat liver and used to prepare thin pellicles of packed particles which were submitted to quantitative electron microscopic examination. Various parameters describing the mitochondrial population were determined by measuring the size and number of mitochondrial profiles in sections, and the ratio of the inner to the outer membrane area. The mean particle radius and volume were found to be respectively 0.38 micro and 0.29 micro(3); the average areas per mitochondrion were 2 and 5 micro(2) for the outer and inner membranes respectively. On the basis of the cytochrome oxidase activity recovered in the particulate fractions, the results were extrapolated to the whole liver, and it was concluded that rat liver contains about 5.10(11) mitochondria per gram; this corresponds to a volume of 0.14 ml/g and to an area of 2.5 and 1 m(2)/g for the inner and outer membranes respectively. The validity and the accuracy of these determinations is discussed and the results are compared to the information which has been obtained by independent methods or by other investigators.

Animals↗
PubMedDate not supplied

Comparative clinical performances of 4 copper-releasing IUDs.

Clinical performances of the Copper 7, Gyne T 200, MLcu 250 and Tcu 200 were compared on 203 patients in this random study conducted over a period of 18 months. Insertion-linked events, tolerance (markers were bleeding or spotting, IUD-linked pain and partner discomfort) and causes for removal (spontaneous expulsion, pregnancies and pelvic infection) were considered. Randomization was performed at the beginning, using prescriptions that came from a randomized pool. Validity of the randomization method was checked against four criteria: number of models inserted per IUD type, prevalence of IUD type per age group, per previous gravidities and per previous means of contraception. No major difference in clinical performance among the four IUD types appeared upon analysis of the resulting data.

Adult↗