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Biomedical subjects

F Humbert

Publications and source records attributed to F Humbert.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Serologic diagnosis of avian salmonelloses: adjustment of an ELISA test using antigens adsorbed with the aid of anti-colibacillary sera].

A serological ELISA test for diagnosis of avian salmonellosis infections with Salmonella typhimurium or enteritidis has been established. Plates were coated half with a negative antigen and half with a positive antigen. Both negative and positive antigens were adsorbed with a monovalent agglutinant anti Escherichia coli serum prior to being distributed into wells of the plates. Sera from SPF birds and from SPF birds vaccinated and/or inoculated with numerous viruses or bacteria, or sera from conventional birds bacteriologically free of any salmonellosis were tested and the percentage of false positive reactions was inferior than 1%. In groups of birds naturally infected or experimentally inoculated with Salmonella enteritidis or typhimurium the percentages of positive individuals were ranged from 15 to more than 90% according to the doses and routes of inoculation and the delay between contamination and sampling.

Animals↗
PubMed1989

Rapid identification of Salmonella from poultry meat products by using 'Mucap Test'.

A study was made in order to improve a new Salmonella identification test (Mucap Test) in which umbelliferone is released, giving a blue fluorescent light under a Wood lamp, after contact with Salmonella colonies. The study concerned 354 colonies, previously isolated from 55 poultry meat samples. Two enrichment media [Tetrathionate Bile Broth (TBB) and Rappaport Vassiliadis (RV)] and two isolation media [Brilliant Green Agar (BGA) and Desoxycholate Agar (DA)] were used, and the results of the test obtained respectively with each association were compared. The sensitivity was consistently good, but the specificity of the test was generally poor. The best association seemed to be RV/DA which gave 85% specificity, against 39% for TBB/BGA, 58% for TBB/DA, and 77% for RV/BGA. The predominant genera responsible for false-positive results were Pseudomonas and Proteus Providencia.

Animals↗
PubMed1976

Morphological changes in tight junctions of Necturus maculosus proximal tubules undergoing saline diuresis.

Tight junctions between epithelial cells are believed to control the paracellular diffusion of substances across epithelia. Epithelia in which tight junctions are poorly developed display a higher paracellular electrical conductance, while those with extensive tight junctions show lower conductance values. We described here a particular epithelium, that of the proximal tubules of the Necturus kidney, in which the development of the tight junctions varies in parallel with a change of paracellular electrical conductance. In control conditions, tight junctions between epithelial cells of the proximal tubules are more developed than in tubules undergoing saline diuresis, a situation which increases the conductance across the paracellular shunt pathway.

Animals↗
PubMed1976

[Pharmacokinetic data on phenobarbital. Study on the influence of gestational age and dysmaturity].

Blood levels of barbiturate after a single intramuscular injection of 10 mg of phenobarbiitone have been plotted against time in 15 neonates at term of whom five were normal and 10 were dysmature, and 15 pre-term infants between 32 and 34 wesks gestation, of whom 12 had a satisfactory weight and 3 were dysmature. The analysis of the experiments according to a mathematical model gave the following results. Half life of absorption +/- 1 S.D. 9.55 HR +/- 6.97 for the term neonates and 11.12 hr +/- 7.61 for the pre-term infants. The difference is not significant. Half life of elimination +/- 1 S.D. 118.06 hours +/- 64.79 for the neonates of term and 110.49 hr +/- 37.19 for the pre-term infants. The half life of elimination is much shorter in the pre-term dysmature infants 74.10 hrs +/- 40.12. The individual variations are important but the differences between the groups of neonates studied are not great. This permits re-grouping and calculation of a half life of elimination for the whole group of 114.28 hr +/- 28.05. The risk of over dosage and the large individual variation in the metabolism of phenobarbitone in the new born lead us to recommend checking the blood levels when giving repeated doses.

Birth Weight↗
PubMed1975

Patterns of membrane organization in toad bladder epithelium: a freeze-fracture study.

Two cell-types of toad bladder epithelium show uncommon plasma membrane organization in freeze-fractured specimens. One type, the granular cell, contains a plasma membrane in which the A-face is poorly particulate luminally while the B-face discloses multiple large particles at this site. In contrast, the lateral and basal portions of the granular-cell membrane are typical in that more particles occupy the A-face than the B-face. In the other cell-type, which is mitochondria-rich, the plasma membrane, luminally, laterally, and basally, contains rod-shaped and a few globular particles in the A-face. We suggest that these two peculiar membrane organizations be considered in the localization of both vasopressin and aldosterone action in toad bladder.

Animals↗
PubMed1975

Intercellular junctions in podocytes of the nephrotic glomerulus as seen with freeze-fracture.

The glomeruli of rats rendered nephrotic by administration of aminonucleoside of puromycin were studied with the freeze-fracture technique. The alterations of the podocytes consisted of a progressive blunting of the foot processes and of the disappearance of the extracellular space normally present between the foot processes at the level of the slit pore. In parallel with the closure of the extracellular space, fracture faces of the plasma membrane of the latered podocytes revealed the presence of peculiar membrane differentiations represented mainly by irregular chains of membrane-associated particles in the fracture face A and by variegated grooves in the fracture face B. The presence of grooves in fracture face B indicates that the chains of particles in fracture face A are likely to be tight junctions rather than linear gap junctions. However, since the presence of continuous ridges is exceptional, it is suggested that the tight junctions are the "leaky" -type and that the podocytes many have only limited capacities for assembling junctions of the "tight" -type.

Animals↗
PubMed1975

Freeze-fracture differences between plasma membranes of descending and ascending branches of the rat Henle's thin loop.

Freeze-fracture of Henle's thin loop of the rat shows that the plasma membrane of epithelial cells in the descending branch has far more particles (approximately 4000 per sq. mum.) than the plasma membrane in the ascending branch (approximately 1000 per sq. mum). On the contrary, the tight junctions between epithelial cells in the two branches are equally developed. The large number of particles in the descending branch may be an important factor in the water permeability of this tubular segment.

Animals↗