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Biomedical subjects

F Lévy

Publications and source records attributed to F Lévy.

98 records · Page 6Linked to original sources
PubMedDate not supplied

Learning of olfactory cues is not necessary for early lamb recognition by the mother.

Ewes identify their young through the use of different sensory modalities. Olfactory recognition, which mediates selective acceptance at the udder, is established at 4 h postpartum (pp). Visual and auditory cues are involved in recognition at a distance, which is evident at 12 h pp. This study investigates whether anosmic ewes are able (a) to develop visual and auditory recognition and (b) to restore selective acceptance of their lamb at the udder. Visual and auditory recognition was assessed in anosmic and intact ewes at 12 h and 24 h pp by a test of two choices: their own and an alien lamb. Selectivity at allowing suckling was tested by presenting successively an alien and the familiar lamb at 4 h, 3 days, and 1 month pp. In the two-choice recognition test, at both 12 h and 24 h pp, anosmic as well as intact ewes showed a preference for their familiar lamb. Although anosmic ewes showed no difference in their acceptance of alien and familiar lambs for suckling at 4 h and 3 days pp, they nursed the alien lamb less at 1 month pp and showed more rejection behaviors toward it. Thus, visual, auditory, or both those types of recognition can be rapidly established, independent of olfactory recognition. Moreover, differential behavior of anosmic ewes toward their own versus an alien lamb at the udder at 1 month suggests that vision and audition may compensate to some extent for the loss of olfaction.

Acoustic Stimulation↗
PubMedDate not supplied

Psychobiological consequences of two different weaning methods in sheep.

Weaning is associated with a break in the mother-infant contact. In sheep, under natural conditions, the rupture of the social bond is progressive. In contrast, weaning imposed by breeders may result in psychobiological disturbances. The aim of this experiment was to measure the behavioural, hormonal and immune consequences of two types of sudden weaning: total separation (TS) and partial separation (PS), in 42 Ile-de-France ewes and their 60 lambs. TS animals (lambs and ewes) vocalized less frequently and for a shorter period of time than did the PS animals. Neither the plasmatic cortisol level in lambs nor the humoral response of dams and young were modified by the two weaning methods. In contrast, the excretion of coccidial oocysts increased significantly after weaning in TS lambs only and the growth rate of TS females was lower than that of the other lambs. These results suggest that these methods of rupture of mother-young social contact have only limited negative consequences on both partners in sheep, contrary to primates and rodents.

Animals↗
PubMedDate not supplied

Behavioural, growth and immune consequences of early weaning in one-week-old large-white piglets.

Genetic improvement in sows' prolificity is limited by their milk capacities, which do not allow all piglets to survive or grow normally. This experiment compared the behaviour, growth and immune responses of piglets that were weaned early at 6 days of age (EW) vs. control Large White piglets' (C) suckled by their mothers. Behaviour of 9 litters of 5 to 8 piglets in each group were observed from d5 to d20. All piglets were weighed from birth to d74. Three piglets from each group were slaughtered on d36 for immunological analysis. Until they began to eat dry food, EW piglets walked and vocalised more than C piglets. After that time, when resting, they were less often lying down and more frequently in contact with littermates under the heater. Aggressive behaviour and belly-nosing were more frequent. They displayed a more marked growth check after weaning than did C piglets until 28 days of age. In EW piglets, at 36 days of age, there was a higher density of T- and B-lymphocytes in the gut epithelium and lamina propria, fespectively, in relation to the size of lymphoid follicles of Peyer's patches. The results indicate great behavioural adaptation capacities of very early-weaned piglets, together with earlier maturation of their gut immune system.

Adaptation, Physiological↗
PubMedDate not supplied

[Compartment syndrome].

Partition syndrome constitutes a nosological entity which amalgamates various disorders whose common feature is hyperpressure in a muscular cavity of the limbs; one such case is Volkmann's Syndrome, another is Anterior Tibial Syndrome. This hyperpressure is caused by extrinsic compression or an increase in volume of the contents of the cavity (block of the venous return, or hyperhaemia). It brings on muscular and nervous ischemia. Sometimes a retrocession of the symptoms can be hoped for, by a halt in the causal factor (effort, plaster too tight) mostly a fasciotomy has to be performed to open the cavity and avoid the vicious circles which this process triggers off and maintains.

Blood Pressure↗
PubMedDate not supplied

[Evaluation of coronary risk in patients with subrenal abdominal aortic aneurysm].

Atheroma lesions are often found in multiple localizations. In addition, operative mortality for aneurysms of the non-ruptured sub-renal aorta is mainly related to coronary risk. In an attempt to reduce coronary risk, coronarography was performed in all patients (n = 297) from January 1989. Operation for the aneurysm was performed in 192 patients (reasons for not operating were small size of the aneurysm, other contraindication). There were 5 deaths, all related to coronary artery disease. Coronary bypass was performed in 42 patients either before (n = 38) or at the same time (n = 4) as the operation for the aneurysm of the aorta. There were no operative deaths. These results clearly demonstrate the importance of search and treatment of associated coronary lesions in all patients with an aneurysm of the subrenal abdominal aorta. Coronary lesions should be treated whenever morphology allows.

Adult↗