Expression of {beta}-galactoside {alpha}2,6-sialyltransferase does not alter the susceptibility of human colon cancer cells to NK-mediated cell lysis

The extent of processing of N-linked oligosaccharides and thesialylation of the target cell membranes has been positivelycorrelated with resistance to lysis mediated by NK cells, buta conclusive evidence has never been reached. Colon cancer tissuesexpress an increased activity of ß-ga-lactoside     

Hibernation and daily torpor in an armadillo, the pichi (Zaedyus pichiy).

Hibernation and daily torpor are physiological strategies to cope with energetic challenges that occur in many mammalian and avian taxa, but no reliable information exists about daily torpor or hibernation for any xenarthran. Our objective was to determine whether the pichi (Zaedyus pichiy), a small armadillo (Xenarthra, Dasypodidae) that inhabits arid and semi-arid habitats in central and southern Argentina and Chile, enters shallow daily torpor or prolonged deep hibernation during winter when environmental temperature and food availability are low. We studied body temperature changes during winter in semi-captive pichis by means of temperature dataloggers implanted subcutaneously. All individuals entered hibernation, characterized by torpor events of 75+/-20 h during which the subcutaneous temperature (T(sc)) decreased to 14.6+/-2.1 degrees C. These events were interrupted by periods of euthermia of 44+/-38 h with a T(sc) of 29.1+/-0.7 degrees C. After the hibernation season, daily torpor bouts of 4 to 6 h occurred irregularly, with T(sc) dropping to as low as 24.5 degrees C. We conclude that the pichi is a true hibernator and can enter daily torpor outside of the hibernation season.     

Intact memory for irrelevant information impairs perception in amnesia

Memory and perception have long been considered separate cognitive processes, and amnesia resulting from medial temporal lobe (MTL) damage is thought to reflect damage to a dedicated memory system. Recent work has questioned these views, suggesting that amnesia can result from impoverished perceptual representations in the MTL, causing an increased susceptibility to interference. Using a perceptual matching task for which fMRI implicated a specific MTL structure, the perirhinal cortex, we show that amnesics with MTL damage including the perirhinal cortex, but not those with damage limited to the hippocampus, were vulnerable to object-based perceptual interference. Importantly, when we controlled such interference, their performance recovered to normal levels. These findings challenge prevailing conceptions of amnesia, suggesting that effects of damage to specific MTL regions are better understood not in terms of damage to a dedicated declarative memory system, but in terms of impoverished representations of the stimuli those regions maintain.     

An integrated assessment of histopathological changes of the enteric neuromuscular compartment in experimental colitis

Bowel inflammatory fibrosis has been largely investigated, but an integrated assessment of remodelling in inflamed colon is lacking. This study evaluated tissue and cellular changes occurring in colonic wall upon induction of colitis, with a focus on neuromuscular compartment. Colitis was elicited in rats by 2,4‐dinitrobenzenesulfonic acid (DNBS). After 6 and 21 days, the following parameters were assessed on paraffin sections from colonic samples: tissue injury and inflammatory infiltration by histology; collagen and elastic fibres by histochemistry; HuC/D, glial fibrillar acidic protein (GFAP), proliferating cell nuclear antigen (PCNA), nestin, substance P (SP), von Willebrand factor, c‐Kit and transmembrane 16A/Anoctamin1 (TMEM16A/ANO1) by immunohistochemistry. TMEM16A/ANO1 was also examined in isolated colonic smooth muscle cells (ICSMCs). On day 6, inflammatory alterations and fibrosis were present in DNBS‐treated rats; colonic wall thickening and fibrotic remodelling were evident on day 21. Colitis was associated with both an increase in collagen fibres and a decrease in elastic fibres. Moreover, the neuromuscular compartment of inflamed colon displayed a significant decrease in neuron density and increase in GFAP/PCNA‐positive glia of myenteric ganglia, enhanced expression of neural SP, blood vessel remodelling, reduced c‐Kit‐ and TMEM16A/ANO1‐positive interstitial cells of Cajal (ICCs), as well as an increase in TMEM16A/ANO1 expression in muscle tissues and ICSMCs. The present findings provide an integrated view of the inflammatory and fibrotic processes occurring in the colonic neuromuscular compartment of rats with DNBS‐induced colitis. These morphological alterations may represent a suitable basis for understanding early pathophysiological events related to bowel inflammatory fibrosis.     

In Central Obesity,Weight Loss Restores Platelet Sensitivity to Nitric Oxide and Prostacyclin

Central obesity shows impaired platelet responses to the antiaggregating effects of nitric oxide (NO), prostacyclin, and their effectors—guanosine 3′,5′‐cyclic monophosphate (cGMP) and adenosine 3′,5′‐cyclic monophosphate (cAMP). The influence of weight loss on these alterations is not known. To evaluate whether a diet‐induced body‐weight reduction restores platelet sensitivity to the physiological antiaggregating agents and reduces platelet activation in subjects affected by central obesity, we studied 20 centrally obese subjects before and after a 6‐month diet intervention aiming at reducing body weight by 10%, by measuring (i) insulin sensitivity (homeostasis model assessment of insulin resistance (HOMA_IR)); (ii) plasma lipids; (iii) circulating markers of inflammation of adipose tissue and endothelial dysfunction, and of platelet activation (i.e., soluble CD‐40 ligand (sCD‐40L) and soluble P‐selectin (sP‐selectin)); (iv) ability of the NO donor sodium nitroprusside (SNP), the prostacyclin analog Iloprost and the cyclic nucleotide analogs 8‐bromoguanosine 3′,5′‐cyclic monophosphate (8‐Br‐cGMP) and 8‐bromoadenosine 3′,5′‐cyclic monophosphate (8‐Br‐cAMP) to reduce platelet aggregation in response to adenosine‐5‐diphosphate (ADP); and (v) ability of SNP and Iloprost to increase cGMP and cAMP. The 10 subjects who reached the body‐weight target showed significant reductions of insulin resistance, adipose tissue, endothelial dysfunction, and platelet activation, and a significant increase of the ability of SNP, Iloprost, 8‐Br‐cGMP, and 8‐Br‐cAMP to reduce ADP‐induced platelet aggregation and of the ability of SNP and Iloprost to increase cyclic nucleotide concentrations. No change was observed in the 10 subjects who did not reach the body‐weight target. Changes of platelet function correlated with changes of HOMA_IR. Thus, in central obesity, diet‐induced weight loss reduces platelet activation and restores the sensitivity to the physiological antiaggregating agents, with a correlation with improvements in insulin sensitivity.     

Stepping beyond Sí Se Puede: Dichos as a Cultural Resource in Mother—Daughter Interaction in a Latino Family

This mother—daughter case study focuses on a key feature of discourse within a Mexican immigrant family that links oral traditions to resilience and motivation. I combine observations from a previous ethnographic study with recent follow-up interviews of a Mexican immigrant student building on a funds of knowledge framework and an ecological perspective. Expanding on current mother—daughter pedagogic theory, I map "dichos" as they are emblematic of cultural funds of knowledge and how they assume a relationship to resistance and academic attainment for a young Mexican immigrant. The findings challenge the notion that working-class Latino families do not care about the educational fortunes of their youth and lack knowledge and resources to guide their children academically.     

New exopolysaccharides produced by Aureobasidium pullulans grown on glucosamine

The polysaccharides produced by Aureobasidium pullulans, grown using glucosamine as the carbon source, were investigated by means of methylation analysis, affinity chromatography and NMR spectroscopy. The results indicated that, besides a small amount of pullulan, this micro-organism was capable of producing-in low yields-mixtures of at least two different complex polysaccharides containing mainly mannose and galactose. (1)H NMR spectra of two fractions obtained by lectin affinity chromatography indicated that one polymer was constituted exclusively of mannose residues while the other contained both galactofuranosyl and mannopyranosyl residues.     

Evaluation of the Cell Population of the Seminiferous Epithelium and Spermatic Indexes of the Bat Sturnira lilium (Chiroptera: Phyllostomidae)

Due to the scarcity of information about patterns of spermatogenesis in bats, this study aimed to provide information on the testicular activity of the bat Sturnira lilium along the annual seasons. Thus, a series of morphometrical and stereological analyses were made using the testes of adult S. lilium in order to achieve a better understanding of the sperm production dynamics. Light and transmission electron microscopy analyses were performed in testicular fragments of animals captured during dry and rainy seasons. The testes followed the pattern of organization described for other mammals, and there were no morphological differences between organs collected either in dry or in rainy seasons. Each tubular cross-section in stage 1 was made of 0.5 type-A spermatogonia, 4.4 primary spermatocytes in preleptotene/leptotene, 3.7 in zygotene, 11.9 in pachytene, 35.6 round spermatids and 8.5 Sertoli cells. The mitotic and meiotic indexes were 15.4 and 2.9 cells, respectively, while the spermatogenesis yield was 68.7 cells. The testicular sperm reserves was 37.61×10⁶ cells, and daily sperm production per gram of testis averaged 209.68×10⁶ cells, both highest averages occurring in the rainy season. S. lilium male bats have a continuous reproductive pattern, high spermatogenesis yield and low support capacity by the Sertoli cells.     

Crystal structure of the receptor-binding protein head domain from Lactococcus lactis phage bIL170

Lactococcus lactis, a gram-positive bacterium widely used by the dairy industry, is subject to lytic phage infections. In the first step of infection, phages recognize the host saccharidic receptor using their receptor binding protein (RBP). Here, we report the 2.30-A-resolution crystal structure of the RBP head domain from phage bIL170. The structure of the head monomer is remarkably close to those of other lactococcal phages, p2 and TP901-1, despite any sequence identity with them. The knowledge of the three-dimensional structures of three RBPs gives a better insight into the module exchanges which have occurred among phages.