Contribution of colostral fat to thermogenesis and glucose homeostasis in the newborn pig.

This study was designed to determine the effects of colostral fat on energy metabolism, fat oxidation and glucose homeostasis in newborn pigs maintained during the first 29h of life at thermal neutrality (34 degrees C) or in the cold (21 degrees C). Piglets were intragastric fed normal colostrum (NFC, 6% fat) or colostrum deprived of fat (LFC, less than 1% fat). A total of 21 meals of 15 to 18g colostrum/kg birthweight was given at 65- to 70-min intervals. Feeding NFC resulted in a higher amount of retained fat with the highest value being obtained in the 34 degrees C group (P less than 0.01). Fat oxidation represented 47% of the absorbed fat in NFC-fed piglets at 34 degrees C; it was 4.5 fold higher in piglets fed NFC than in those fed LFC (P less than 0.01), and 1.8 fold higher at 21 degrees C than at 34 degrees C (P less than 0.01). At both temperatures, feeding LFC resulted in a lower energy balance (P less than 0.01), whereas nitrogen balance was not affected by temperature and colostrum treatments. At 29 hours of age, rectal temperature was the lowest in piglets fed LFC at 21 degrees C (P less than 0.05). Postnatal enhancement of fat metabolism in relation to environmental and nutritional conditions was evidenced at the tissue level through an adaptation of lipoprotein lipase and cytochrome oxidase activities, especially in the red rhomboideus muscle and the liver.(ABSTRACT TRUNCATED AT 250 WORDS)     

MCHM Acts as a Hydrotrope,Altering the Balance of Metals in Yeast

Biological Trace Element Research - While drugs and other industrial chemicals are routinely studied to assess risks, many widely used chemicals have not been thoroughly evaluated. One such...     

No mate preference associated with the supergene controlling social organization in Alpine silver ants

Disassortative mating is a powerful mechanism stabilizing polymorphisms at sex chromosomes and other supergenes. The Alpine silver ant, Formica selysi, has two forms of social organization—single‐queen and multiple‐queen colonies—determined by alternate haplotypes at a large supergene. Here, we explore whether mate preference contributes to the maintenance of the genetic polymorphism at the social supergene. With mate choice experiments, we found that females and males mated randomly with respect to social form. Moreover, queens were able to produce offspring irrespective of whether they had mated with a male from the same or the alternative social form. Yet, females originating from single‐queen colonies were more fertile, suggesting that they may be more successful at independent colony founding. We conclude that the pattern of asymmetric assortative mating documented from mature F. selysi colonies in the field is not caused by mate preferences or major genetic incompatibilities between social forms. More generally, we found no evidence that disassortative mate preference contributes to the maintenance of polymorphism at this supergene controlling ant social organization.     

A tolloid homologue from the Pacific oyster Crassostrea gigas

The genes governing mesoderm specification have been extensively studied in vertebrates, arthropods and nematodes. The latter two phyla belong to the Ecdysozoan clade but little is understood of the role that these genes might play in the development of the other major protostomal clade, the Lophotrochozoa. As part of a wider project to analyze the functions associated with transforming growth factor beta superfamily members in Lophotrochozoa, we have cloned a gene encoding a tolloid homologue from the bivalve mollusc Crassostrea gigas. Tolloid is a key developmental protein that regulates the activity of bone morphogenetic proteins (BMPs). We have determined the intron-exon structure of the gene encoding C. gigas tolloid and have compared it with those of homologous genes from both protostomes and deuterostomes. In order to analyze the functionality of oyster tolloid the zebrafish embryo has been employed as a reporter organism and we show that over-expression of this protein results in the ventralization of zebrafish embryos at 24h post fertilization. The expression of the C. gigas tolloid gene during embryonic and larval development as well as in adult tissues is also explored.     

Novel phage display-derived mycolic acid-specific antibodies with potential for tuberculosis diagnosis

Tuberculosis is a major cause of mortality and morbidity due to infectious disease. However, current clinical diagnostic methodologies such as PCR, sputum culture, or smear microscopy are not ideal. Antibody-based assays are a suitable alternative but require specific antibodies against a suitable biomarker. Mycolic acid, which has been found in patient sputum samples and comprises a large portion of the mycobacterial cell wall, is an ideal target. However, generating anti-lipid antibodies using traditional hybridoma methodologies is challenging and has limited the exploitation of this lipid as a diagnostic marker. We describe here the isolation and characterization of four anti-mycolic acid antibodies from a nonimmune antibody phage display library that can detect mycolic acids down to a limit of 4.5ng. All antibodies were specific for the methoxy subclass of mycolic acid with weak binding for α mycolic acid and did not show any binding to closely related lipids or other Mycobacterium tuberculosis (Mtb) derived lipids. We also determined the clinical utility of these antibodies based on their limit of detection for mycobacteria colony forming units (CFU). In combination with an optimized alkaline hydrolysis method for rapid lipid extraction, these antibodies can detect 10⁵ CFU of Mycobacterium bovis BCG, a close relative of Mtb and therefore represent a novel approach for the development of diagnostic assays for lipid biomarkers.     

Docking study of ligands into the colchicine binding site of tubulin

Cancer is a major cause of mortality in developed countries, following only cardiovascular diseases. Death of cancerous cells can be achieved by stopping mitosis and the antimitotic class of drugs formed by the spindle poisons can be used for this purpose. Their role is to disorganize the mitotic spindle by targeting its main constituent, the microtubules, themselves made of heterodimers of alpha and beta-tubulin. They disrupt the dynamics of the microtubules either by stabilizing them, as do paclitaxel or epothilones, or destabilizing them, as do colchicine. The binding site of colchicine seems to lie between the two units of the tubulin dimer. Here, we report on the characterization of this site by the docking of a series of reference compounds, and the subsequent docking of ligands prepared in our laboratory.     

CD40 ligand trimer and IL-12 enhance peripheral blood mononuclear cells and CD4+ T cell proliferation and production of IFN-gamma in response to p24 antigen in HIV-infected individuals: potential contribution of anergy to HIV-specific unresponsiveness

It has been suggested that CD4+ T cell proliferative responses to HIV p24 Ag may be important in the control of HIV infection. However, these responses are minimal or absent in many HIV-infected individuals. Furthermore, while in vitro and in vivo responses to non-HIV recall Ags improve upon administration of highly active antiretroviral therapy, there does not appear to be a commensurate enhancement of HIV-specific immune responses. It is possible that CD4+ p24-specific T cells are deleted early in the course of infection. However, it is also possible that a discrete unresponsiveness, or anergy, contributes to the lack of proliferation to p24. To evaluate the possible contribution of unresponsiveness to the lack of CD4+ T cell proliferation to p24 in HIV-infected individuals, we attempted to overcome unresponsiveness. CD40 ligand trimer (CD40LT) and IL-12 significantly increased PBMC and CD4+ T cell proliferative responses to p24 Ag in HIV-infected, but not uninfected, individuals. No increase in proliferative response to CMV Ag was observed. CD40LT exerted its effect through B7-CD28-dependent and IL-12- and IL-15-independent mechanisms. Finally, the increase in proliferation with CD40LT and IL-12 was associated with an augmented production of IFN-gamma in most, but not all, individuals. These data suggest the possible contribution of HIV-specific unresponsiveness to the lack of CD4+ T cell proliferation to p24 Ag in HIV-infected individuals and that clonal deletion alone does not explain this phenomenon. They also indicate the potential for CD40LT and IL-12 as immune-based therapies for HIV infection.     

First evidence of uncoupling protein-2 (UCP-2) and -3 (UCP-3) gene expression in piglet skeletal muscle and adipose tissue

Uncoupling proteins (UCPs) facilitate proton transport inside the mitochondria and decrease the proton gradient, leading to heat production. Until now, the presence of UCP1 or other UCP homologs had not been detected in tissues of pig, a species where evidence for the presence of brown adipose tissue has only been provided in 2-3 month old animals. In the light of the improving knowledge on the UCPs family, we decided to examine both UCP2 and UCP3 mRNA expression in piglet skeletal muscle and adipose tissue. Using RT-PCR we have successfully cloned a partial UCP2 sequence and a complete UCP3 cDNA. UCP3's open reading frame (936bp) shares 90, 89 and 85% similarity with bovine, human and rat UCP3 nucleotide sequences, respectively. In 3-5 day old piglets, these genes are expressed in adipose tissue and in both longissimus thoracis (LT) and rhombo?deus (RH) muscles, without any effect of muscle metabolic type. This is in good agreement with the measurement of the same membrane potential in mitochondria isolated from both types of muscles. In triiodothyronine-treated piglets, UCP3 mRNA is more expressed in LT than in RH muscle. These genes may be involved in the control of the energy metabolism of the piglet.