Hatching Asynchrony in Oviraptorid Dinosaurs Sheds Light on Their Unique Nesting Biology.

Dinosaur nesting biology has been an intriguing research topic, though dinosaur behaviors were relatively less illuminated because of the constraints of the fossil record. For instance, hatching asynchrony, where eggs in a single clutch hatch at different times, is unique to modern neoavian birds but was also suggested to be present in oviraptorid dinosaurs based on a possible partial clutch of four embryo-containing eggs from Mongolia. Unfortunately, unequivocal evidence for the origination of these eggs from a single clutch is lacking. Here we report a new, better preserved partial oviraptorid clutch with three embryo-containing eggs-a single egg (Egg I) and a pair (Egg II/III)-from the Late Cretaceous Nanxiong Group of Jiangxi Province, China. Geopetal features indicate that the pair of eggs was laid prior to the single egg. Neutron tomographic images in combination with osteological features indicate that the embryo of the single egg is less developed than those of the paired eggs. Eggshell histology suggests that the embryo-induced erosion in the paired eggs is markedly more pronounced than in the single egg, providing a new line of evidence for hatching asynchrony. The inferred hatching asynchrony in combination with previously surmised thermoregulatory incubation and communal nesting behaviors very likely suggests that oviraptorid dinosaurs presented a unique reproductive biology lacking modern analogs, which is contrary to the predominant view that their reproductive biology was intermediate between that of modern crocodiles and birds.

A biologia de nidificação de dinossauros tem sido um tópico de pesquisa intrigante, embora o comportamentos do dinossauros tenham sido relativamente menos compreendidos devido às restrições do registro fóssil. Por exemplo, eclosão assincrônica, onde os ovos em uma única ninhada eclodem em momentos diferentes, é exclusiva em aves neoavianas modernas, tem-se sugerido estar presente em dinossauros oviraptorídeos com base em uma possível ninhada parcial de quatro ovos da Mongólia contendo embriões. Infelizmente, faltam evidências inequívocas para a origem desses ovos a partir de uma única embreagem. Relatamos aqui uma nova parcial ninhada oviraptoroide melhor preservada, com três ovos contendo embriões­um único ovo (ovo I) e um par (ovo II/III)­do Grupo de Nanxiong Cretáceo Final da Província de Jiangxi, China. A erosão induzida pelo embrião nos ovos emparelhados é significativamente maior que a do ovo único, fornecendo uma evidência inequívoca de eclosão assincrônica. A inferida de eclosão assincrônica, em combinação com as linhas de evidência anteriores, sugere que os dinossauros oviraptorídeos apresentavam uma biologia reprodutiva muito singular, sem análogos modernos, contrariando a visão predominante de que sua biologia reprodutiva era intermediária entre a dos crocodilos e pássaros modernos. Translated to Portuguese by Diego Vaz (dbistonvaz@vims.edu).

ICOS/ICOSL upregulation mediates inflammatory response and endothelial dysfunction in type 2 diabetes mellitus.

OBJECTIVE: ICOS/ICOSL plays a crucial part in various disease-mediated immune responses. However, the exact role of ICOS/ICOSL in type 2 diabetes mellitus (T2DM) development remains unexplored. This study aims to investigate the role of ICOS/ICOSL in the pathogenesis of T2DM. MATERIALS AND METHODS: Human peripheral blood T-lymphocytes (CD3) and umbilical vein endothelial cells (HUVECs) were treated with high-glucose (HG) or advanced glycation end products (AGEs). A portion of CD3 cells was co-cultured with HUVECs and treated with different mediums or anti-ICOS mAbs. The ICOS/ICOSL and caspase-3 protein expression was measured by Western blotting. ELISA (enzyme-linked immunosorbent assay), MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), and NOx production assays were respectively used to detect cytokines level, cell viability and the production of NOx. RESULTS: HG and AGEs significantly upregulated ICOS/ICOSL expressions in T cells and HUVECs. T cell contact with HUVECs secreted more IFN-γ, IL-4, and IL-10 compared to non-contact cells, while cytokines from IL-6-, IL-1ß-, and CM- (the conditioned medium) treated cells did not differ from the control. A significant increase of IL-8 and IL-6 was found in HUVECs under both contact and non-contact conditions vs. control cells. Similar results were also observed in the comparison between CM1- (T cell condition medium) or CM2- (co-culture condition medium) treated cells and control cells. However, CM1 and CM2 treatment significantly inhibited cell viability and increased caspase-3 and NOx production; blocking ICOS/ICOSL remarkably decreased cytokines secretion, enhanced cell viability and reduced caspase-3 and NOx production. CONCLUSIONS: HG and AGEs cause T cell inflammatory response and vascular endothelial dysfunction by upregulating ICOS/ICOSL, which may be one of the possible mechanisms of cardiovascular complications development in T2DM patients.

Effect of siglidine on glucose lipid metabolism and the expression of iNOS and GLP-1 receptors in diabetic rats.

OBJECTIVE: Diabetic nephropathy (DN) has become the major complication of diabetes. The progression of the disease impedes the efficacy of DN treatment. Therefore, the strategies to inhibit or reverse kidney damage in DN patients are of critical importance. We aim to investigate the effect of sitagliptin on DN within rat model and analyze the associated metabolism and expression of iNOS/GLP-1 receptor. MATERIALS AND METHODS: Diabetic model was generated by using Sprague-Dawley (SD) rats, which received an intra-peritoneal injection of 30 mg/kg streptozotocin. Rats were then treated with saline or 15 mg/(kg.d) sitagliptin by gavage. After 12 weeks, fasting blood glucose and insulin resistance were measured. Rat glucose and lipid metabolism were evaluated by high triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Western blot was used to measure expression of glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) related with glucose-lipid metabolism, and expression of iNOS and GLP-1 expression in kidney tissues. RESULTS: After 12 weeks of feeding, the levels of blood glucose and lipid in sitagliptin group were significantly decreased compared to those in control group (p<0.05), whilst insulin sensitivity was enhanced (p<0.05). Western blot showed that sitagliptin downregulated the expressions of glucose-lipid metabolism proteins such as G6Pase, PEPCK, ACC and FAS in rat livers, inhibited iNOS expression in kidneys and elevated GLP-1 receptor activity (p<0.05). CONCLUSIONS: Sitagliptin effectively stabilizes blood glucose and lipid levels in DN rats, significantly improves glucose-lipid metabolism and protects kidney and vascular endothelial cells during DN pathogenesis through inhibiting iNOS expression and elevating GLP-1 receptor activity.

Infrared properties of single crystal MgO, a substrate for high temperature superconducting films.

We report and analyze the infrared properties of single crystal MgO, an important substrate for high T(c), superconducting films, from 10 to 280 cm(-1) and 20-300 K.