Seasonal acclimatization to temperature in cardueline finches

1. Seasonal variation in body constituents and utilization of lipid, protein, and carbohydrate during cold stress in American goldfinches were studied to determine relations of these functions to the pronounced seasonal shift in thermogenic capacity documented in a previous study (Dawson and Carey, 1976).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47119/1/360_2004_Article_BF00686746.pd

Intérêt de la fibroscopie dans les mycoses oesogastriques (à propos de 24 observations)

A l'occasion de 24 observations de mycoses oesogastriques découvertes au cours d'examens endoscopiques, les auteurs insistent sur l'augmentation de fréquence de telles formes du fait de l'extension de la pathologie provoquée par les thérapeutiques antibiotiques et corticoïdes. L'aspect de muguet oesophagien est caractéristique en endoscopie mais on peut trouver également des aspects non spécifiques où seuls les prélèvements pour culture sur milieux spéciaux mettent en évidence les levures responsables. Pour admettre la pathogénicité de l'infection mycotique, il faut que soient rassemblés un certain nombre de critères qui sont au complet dans us tiers des observations

Altération de la perméabilité dans les maladies inflammatoires intestinales

International audienc

MORPHOMETRIC-STEREOLOGIC ANALYSIS OF BROWN ADIPOCYTE DIFFERENTIATION IN ADULT MICE

Brown adipocyte differentiation from interstitial stem cells was analyzed by morphometric-stereologic methods in adult mice. Confirming previous studies, four different stages of development were identified: 1) interstitial cells → 2) protoadipocytes (interstitial cells with tiny lipid droplets) → 3) preadipocytes → 4) mature brown adipocytes. Brown adipocyte precursor cells (interstitial cells and protoadipocytes) occupied only a small fraction of total brown adipose tissue (BAT) volume (1.7 and 1.8%, respectively). Most of the BAT volume was occupied by fully differentiated multilocular cells (65% vol/vol), preadipocytes (12%), and blood capillaries (10%). The differentiation of protoadipocytes into preadipocytes was characterized by a doubling in the cellular volume (from 800 to 1,500 μm3) that was associated with a fivefold increase in the number of mitochondria (221 to 1,464), an eightfold augmentation in mitochondrial size (from 0.042 to 0.37 μm3), a fourfold increase in the surface density of the inner mitochondrial membrane (from 8 to 35 μm2/μm3), resulting in a 14-fold enlargement in the relative volume of the mitochondrial compartment (from 2 to 29%). This remarkable mitochondrial proliferation was accompanied by an increase in the number and volume of cytosolic lipid droplets. In contrast, the differentiation of preadipocytes into brown adipocytes was mainly characterized by a doubling in the size of the lipid compartment; the mean volume of single droplets increased 35 times but their number decreased 6-7 times. The mitochondrial modifications were minor; there was only a slight increase in the surface density of the inner membrane. In conclusion, the major step of brown adipocyte differentiation consists in the transformation of protoadipocytes into preadipocytes. It is characterized by a large proliferation of mitochondria with tightly packed cristae that is associated with a marked lipogenesis resulting in a significant expansion of the cellular volume