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B Collin

Publications and source records attributed to B Collin.

13 recordsLinked to original sources

Morphometric study of the equine navicular bone: age-related changes and influence of exercise.

Navicular bones from the four limbs of 95 horses, classified in 9 categories, were studied. The effects of age on navicular bone morphometry and histomorphometry were estimated, after adjustment of the data to even out the effects of front and rear limbs, morphometrical type, sex, weight, and size. All the external measurements of the navicular bone decreased significantly with increasing age. From the histomorphometrical data, cortical bone volume decreased with age in most horses, whereas cancellous bone volume and, in particular, the marrow spaces increased. The increase in the cancellous bone volume could have resulted from tunnelling of the internal part of the cortex, which converted it progressively into a porous trabecular-like structure. Trabecular bone volume also decreased with age and the trabecular lattice changed dramatically to become disconnected in aged horses. These observations corresponded closely to those reported for ageing of the skeletal system in humans. However, in sporting horses, the navicular cortical bone volume increased with age and the cancellous bone volume decreased. Exercise appeared to have decreased bone resorption and increased bone formation at the endocortical junction. The cancellous bone architecture was also improved. in that the trabecular lattice and trabecular bone volume remained unchanged in aged sporting horses. Our findings confirmed that exercise may be good practice to prevent age-related bone loss.

Age Factors↗

Cross-clade recognition of p55 by cytotoxic T lymphocytes in HIV-1 infection.

OBJECTIVES: To evaluate cross-clade recognition of p55 antigen by cytotoxic T lymphocytes (CTL) in persons infected with diverse clades of HIV-1; to facilitate the development of a CTL-inducing vaccine to prevent transmission of multiple clades of HIV-1. DESIGN: Experiments were designed to evaluate whether persons in Uganda and the United Kingdom, infected with diverse clades of HIV-1, have CTL capable of recognizing and killing autologous target cells infected with recombinant vaccinia viruses (rVV) expressing the Gag protein from A, B, C and D clade HIV-1. The extent of cross-reactivity within such individuals, each infected with characterized virus, might reflect the type of cross-reactive immune response inducible by a monovalent vaccine. METHODS: Asymptomatic HIV-positive individuals were fully tissue-typed by ARMS (amplification of refractory mutation system) polymerase chain reaction. rVV expressing the Gag protein from identified A, B, C and D viruses were prepared. CTL were cultured and tested for cytolytic activity on autologous rVV-infected or peptide-pulsed B cells. RESULTS: Ugandan patients had inducible CTL responses recognizing A, B, C and D clade HIV-1 Gag. The majority of UK patients had inducible CTL responses that recognized two or more clades. No patient showed any HIV-2 cross-reactivity. Cross-reactive responses were characterized in three Ugandan patients. CONCLUSIONS: Most patients tested mounted cross-reactive CTL responses that recognized Gag proteins from clades of HIV-1 other than those with which they were infected.

Amino Acid Sequence↗

Morphometric study of the equine navicular bone: variations with breeds and types of horse and influence of exercise.

Navicular bones from the 4 limbs of 95 horses, classified in 9 categories, were studied. The anatomical bases were established for the morphometry of the navicular bone and its variations according to the category of horse, after corrections were made for front or rear limb, sex, weight, size and age. In ponies, navicular bone measurements were smallest for light ponies and regularly increased with body size, but in horses, navicular bone dimensions were smallest for the athletic halfbred, intermediate for draft horse, thoroughbreds and sedentary halfbreds and largest for heavy halfbreds. The athletic halfbred thus showed reduced bone dimensions when compared with other horse types. Navicular bones from 61 horses were studied histomorphometrically. Light horses and ponies possessed larger amounts of cancellous bone and less cortical bone. Draft horses and heavy ponies showed marked thickening of cortical bone with minimum intracortical porosity, and a decrease in marrow spaces associated with more trabecular bone. Two distinct zones were observed for the flexor surface cortex: an external zone composed mainly of poorly remodelled lamellar bone, disposed in a distoproximal oblique direction, and an internal zone composed mainly of secondary bone, with a lateromedial direction for haversian canals. Flexor cortex external zone tended to be smaller for heavy ponies than for the light ponies. It was the opposite for horses, with the largest amount of external zone registered for draft horses. In athletic horses, we observed an increase in the amount of cortical bone at the expense of cancellous bone which could be the result of reduced resorption and increased formation at the corticoendosteal junction. Cancellous bone was reduced for the athletic horses but the number of trabeculae and their specific surfaces were larger. Increased bone formation and reduced resorption could also account for these differences.

Animals↗

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Contract Services↗

Serological survey of herpesvirus infections in wild ruminants of France and Belgium.

The presence of antibodies against bovine herpesvirus 1 (BHV-1), bovid herpesvirus 6 (BHV-6), herpesvirus of Cervidae type 1 (HVC-1), reindeer herpesvirus, bovine herpesvirus 2 (BHV-2) and bovid herpesvirus 4 (BHV-4) was investigated in wild ruminants of France and Belgium between 1981 and 1986. There were no animals serologically positive for BHV-4. Antibodies against BHV-2 were demonstrated in roe deer (Cervus capreolus) (less than 1%) and chamois (Rupicapra rupicapra) (1%) in France. Animals seropositive to the four related viruses (BHV-1, BHV-6, HVC-1, reindeer herpesvirus) were detected in red deer (Cervus elaphus) in France and Belgium (1% and 11%, respectively), in roe deer (less than 1%) from France, in chamois (4%) in France and in ibex (Capra ibex) (4%) from France. The presence of antibodies against HVC-1, especially in red deer from Belgium, may suggest that wild ruminants in continental Europe are now infected with this virus, which previously has been isolated only in Scotland.

Animals↗

Intrinsic fasciotomy. When and why?

Major trauma to the upper extremity may lead to ischemic contracture of various muscle groups, sometimes including the intrinsic muscles of the hand. The clinical consequence of such necrotic fibrosis of the intrinsics is clawing of the digits with marked stiffness. After a short anatomical review of the fascias of the intrinsics, indications and operative techniques are discussed, in parallel with clinical cases. Intrinsic fasciotomy thus appears to be a major step in the prevention of digital clawing, when associated with early physiotherapy.

Amputation, Traumatic↗

[Stress ulcer by hypovolemic shock in pregnant and normal rabbits and in the fetuses (author's transl)].

The purpose of this experimental work was to study the possibility of stress ulcer in fetal Surgery. Firstly an experimental model of production of stress ulcer by hypovolemic shock was worked out: by removing a volume of blood equivalent to 2% of body weight out of the femoral artery, a stress ulcer was was regularly induced in 25 female rabbits in the fundic area within 3 hours. In 10 pregnant rabbits and in the fetuses a stress ulcer could not be produced by the same method. This observation suggests the hypothesis that the reactions of the gastric wall are modified by the specific hormonal situation of the pregnant rabbit. This assumption ought to be elucidated by further investigations.

Animals↗

[Automation of extraction in the determination of blood triglyceride].

A complete automation of the determination of triglycerides is described which replaces the manual extraction and the final determination with an autoanalyzer chain, based on the method of Royer et al. For the automation of triglyceride extraction, we have modified the sampler, by incorporating a magnetic stirrer under the sample table. The sample table has two rows of holes. The sera, which are taken from the inner row and diluted with sulphuric acid, are reacted quantitatively with the extraction reagent in the beakers of the outer row, which contain a magnetic follower. After stirring, the upper phase is quantitatively removed and the determination is started. The problem of phasing the individual steps of the analysis is thus solved.

Autoanalysis↗