Day–night pattern of energy expenditure and body temperature in cachectic tumour-bearing rats

The implication of an increase in energy expenditure in cancer cachexia, which seems to be related to the type of tumour, remains unclear. We therefore investigated the energy metabolism and body temperature in anorectic and cachectic rats bearing the Yoshida sarcoma (TB), in comparison with pair-fed (PF) and ad-libitum fed (AL) control rats. The resting energy expenditure was higher in the TB than in the two control groups when corrected for the modifications of body composition. However, the total energy expenditure did not differ between the TB and the AL, presumably because of the drop of activity in TB. There was a temporal distribution of differences in energy expenditure with higher energy expenditure in TB than in AL during the diurnal phase and a lack of difference during the nocturnal phase. The TB presented a fever, which was limited to the diurnal period. Moreover, the acrophase of the body temperature rhythm was delayed in the TB. These results highlight the circadian effects of tumour development on the energy metabolism of the host and hint to the possible implication of cytokines. © 2000 Harcourt Publishers Ltd © 2000 Cancer Research Campaig

CD36 Inhibitors Reduce Postprandial Hypertriglyceridemia and Protect against Diabetic Dyslipidemia and Atherosclerosis

CD36 is recognized as a lipid and fatty acid receptor and plays an important role in the metabolic syndrome and associated cardiac events. The pleiotropic activity and the multiple molecular associations of this scavenger receptor with membrane associated molecules in different cells and tissues have however questioned its potential as a therapeutic target. The present study shows that it is possible to identify low molecular weight chemicals that can block the CD36 binding and uptake functions. These inhibitors were able to reduce arterial lipid deposition, fatty acid intestinal transit, plasma concentration of triglycerides and glucose, to improve insulin sensitivity, glucose tolerance and to reduce the plasma concentration of HbAc1 in different and independent rodent models. Correlation between the anti-CD36 activity of these inhibitors and the known pathophysiological activity of this scavenger receptor in the development of atherosclerosis and diabetes were observed at pharmacological doses. Thus, CD36 might represent an attractive therapeutic target

8 nm nanodiamonds as markers for 2 photon excited luminescent microscopy

International audienceStructural and luminescent properties of stable suspensions of fluorescent nanodiamonds were investigated. Measurement of the effective hydrodynamic radius yields particles less than 30 nm diameter, while the TEM measurements made on the same particles shows average diameter about 8 nm. It was found that NDs have relatively low toxicity. Upon incubation, 3T3-L1 cells spontaneously take up nanodiamonds that uniformly distribute in cells cytoplasm. The possibility of fluorescent imaging using both single ore two-photon excitation was shown

Modelling adipocytes size distribution

International audienceAdipocytes are cells whose task is to store excess energy as lipid droplets in their cytoplasm. Adipocytes can adapt their size according to the lipid amount to be stored. Adipocyte size variation can reach one order of magnitude inside the same organism which is unique among cells. A striking feature in adipocytes size distribution is the lack of characteristic size since typical size distributions are bimodal. Since energy can be stored and retrieved and adipocytes are responsible for these lipid fluxes, we propose a simple model of size-dependent lipid fluxes that is able to predict typical adipocytes size distribution

Metal-Organic Frameworks for the Quantitative Detection of Endogenous H2S

SSCI-VIDE+ING+JEC:ALE:DFANational audienceAccording to the World Health Organization, the four major non-communicable diseases (NCDs) (cardiovascular disease, cancer, chronic respiratory diseases and diabetes) are responsible for 82% of NCDs deaths which corresponded to 31 million deaths in 2012. The past few years saw the increased number of scientific articles relating the intimate correlation between the clinical signs of these NCDs and Down syndrome and the blood or cerebral concentration of endogenous hydrogen sulfide.The determination of the blood level of hydrogen sulfide is thus a challenge in order to make early diagnostic and to build up a treatment protocol before the appearance of clinical signs. Hydrogen sulfide is indeed one of the three major gasotransmitters, with carbon monoxide and nitric oxide, and has a strong role in nervous and vascular systems. Its physiological concentration in the blood is only in the range of few nanomoles per liter when its pathological level can reach few micromoles per liter.Several systems based on organic chromophore molecules are already reported for the detection of H2S in simulated physiological media. Most of them are based on the reactivity of H2S with azide functions, to give the corresponding amine, and on the photoluminescent response of the amine.However, the development of applicable testing requires heterogeneous/solid H2S sensors. In this sense, Metal-Organic Frameworks (MOFs) are appealing platforms. Indeed, MOFs are crystalline and porous hybrid organic-inorganic solids. They can be built from organic chromophores and offer the advantage of site isolation. One recent example deals with the use of azido -containing MOF, made with 2-azidoterephthalate ligand, for the detection of H2S in solution but in the concentration range of 100 micromolar.We are presenting here a new MOF-based system for the detection of H2S in solution with concentration as low as 0.2 micromoles per liter. Appropriate irradiation of the azido-MOF, converted into amino-MOF upon H2S exposure, allows determining the linear correlation between photoluminescence signal intensity and H2S concentration.This opens bright new perspectives for the use of MOFs in sensing applications as well as for the applicable H2S detection for clinical diagnostic

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