Small intestinal morphology and sugar transporters expression when consuming diets of different energy levels: comparison between Tibetan and small-tailed Han sheep

Some non-structural carbohydrates, especially starch, escape ruminal fermentation, are converted into glucose, and are absorbed from the small intestine. This glucose provides an important source of energy, and its usage is more efficient than glucose from carbohydrates which are fermented as short chain fatty acids in the rumen and, subsequently, undergo hepatic gluconeogenesis. Tibetan sheep graze on the harsh Qinghai-Tibetan Plateau (QTP) all year round and their carbohydrate and energy intakes fluctuate greatly with seasonal forage availability. Consequently, a high capacity to absorb glucose from the small intestine would be particularly beneficial for Tibetan sheep to allow them to cope with the inconsistent dietary intakes. This study examined how the small intestinal morphology and sugar transporters' expression of Tibetan and Small-tailed Han (Han) sheep respond to fluctuating energy intakes under the harsh conditions of the QTP. Han sheep graze on the QTP only in summer and are generally raised in feedlots. Twenty-four Tibetan sheep and 24 Han sheep, all wethers, were assigned randomly to four groups (n = 6 per breed/group), with each group offered a diet differing in digestible energy content: 8.21, 9.33, 10.45 and 11.57 MJ/kg DM. After 49 d, all sheep were slaughtered, tissues of the small intestine were collected, and measurements were made of the morphology and glucose transporters and the related regulation gene expressions. At intakes of low energy levels, Tibetan sheep had a greater villus surface area in the duodenum, jejunum and ileum and higher mRNA expression of sodium-dependent glucose transporter 1 in the duodenum and ileum (P < 0.05) than Han sheep. In the glucose transporter 2 (GLUT2) mediated glucose absorption pathway, Tibetan sheep had higher GLUT2 and taste receptor family 1 member 2 and 3 mRNA expressions than Han sheep in the duodenum, jejunum and ileum (P < 0.05). We concluded that the differences between breeds indicated a greater glucose absorption capacity in the small intestine of Tibetan than Han sheep, which would confer an advantage to Tibetan over Han sheep to an inconsistent energy intake on the harsh QTP. These findings suggested that ruminants raised under harsh environmental conditions with highly fluctuating dietary intakes, as is often the case in grazing ruminants worldwide, are able to absorb glucose from the small intestine to a greater extent than ruminants raised under more moderate conditions.

Progress in the study of markers related to glioma prognosis

OBJECTIVE

In the era of precision medicine, molecular and genetic biomarkers act as the key indicators for glioma patients' recurrence and prognosis.

MATERIALS AND METHODS

We summarize the biomarkers of glioma prognosis from molecular level, gene level and microRNA level.

RESULTS

In molecular biomarkers, cyclinD1 high expression/P16 low expression, MIF high expression and VEGF high expression were all related to glioma patients' poor prognosis; in genetic biomarkers, MGMT promoter methylation absence, IDH1 wild type, HIF-α high expression, Chromosome 1p/19q non-deletion and TERT promoter mutation were associated with poor prognosis for glioma; in microRNA biomarkers, miR-524-5p, miR-586, miR-433, miR-619, miR-548d-5p, miR-525-5p, miR-301a, miR-210, miR-10b-5p, miR-15b-5p and miRNA-182 high expression, miR-124, miR-128, miR-146b and miR-218 low expression were commonly seen in glioma poor prognosis patients.

CONCLUSIONS

With the continuous development of science and technology, the diagnosis of glioma will tend to the gene and molecular level. Finding specific markers is helpful for the early diagnosis and accurate prognosis of glioma, which provides the possibility for individualized treatment.

Energy substrate metabolism in skeletal muscle and liver when consuming diets of different energy levels: comparison between Tibetan and Small-tailed Han sheep

The energy intake of Tibetan sheep on the harsh Qinghai-Tibetan Plateau (QTP) varies greatly with seasonal forage fluctuations and is often below maintenance requirements, especially during the long, cold winter. The liver plays a crucial role in gluconeogenesis and skeletal muscle is the primary tissue of energy expenditure in mammals. Both play important roles in energy substrate metabolism and regulating energy metabolism homeostasis of the body. This study aimed to gain insight into how skeletal muscle and liver of Tibetan sheep regulate energy substrate metabolism to cope with low energy intake under the harsh environment of the QTP. Tibetan sheep (n = 24; 48.5 ± 1.89 kg BW) were compared with Small-tailed Han sheep (n = 24; 49.2 ± 2.21 kg BW), which were allocated randomly into one of four groups that differed in dietary digestible energy densities: 8.21, 9.33, 10.45 and 11.57 MJ /kg DM. The sheep were slaughtered after a 49-d feeding period, skeletal muscle and liver tissues were collected and measurements were made of the activities of the key enzymes of energy substrate metabolism and the expressions of genes related to energy homeostasis regulation. Compared with Small-tailed Han sheep, Tibetan sheep exhibited higher capacities of propionate to glucose conversion and fatty acid oxidation and ketogenesis in the liver, higher glucose utilization efficiency in both skeletal muscle and liver, but lower activities of fatty acid oxidation and protein mobilization in skeletal muscle, especially when in negative energy balance. However, the Small-tailed Han sheep exhibited higher capacities to convert amino acids and lactate to glucose and higher levels of glycolysis and lipogenesis in the liver than Tibetan sheep. These differences in gluconeogenesis and energy substrate metabolism conferred the Tibetan sheep an advantage over Small-tailed Han sheep to cope with low energy intake and regulate whole-body energy homeostasis under the harsh environment of the QTP.

[The impact of red blood cell distribution width on outcome of elective percutaneous coronary intervention in non-anemia patients]

Objective: Previous studies have revealed that the red blood cell distribution width (RDW) was associated with long-term prognosis in patients undergoing percutaneous coronary intervention (PCI). However, they did not exclude patients with anemia. This study, thus, investigated the association between RDW and prognosis in non-anemia patients. Methods: A total of 2 732 patients underwent elective PCI from July 2009 to September 2011 were enrolled in the study. These patients were divided into two groups based on their baseline median RDW levels: low RDW group (RDW<12.1%) and high RDW group (RDW≥12.1%). All the subjects were followed up for an average period of 18 months and the associations between baseline RDW levels and postoperative mortality were analyzed. Results: Patients in the high RDW group were elder and had more women than those in low RDW group. Most of them had prior history of hypertension, stroke, myocardial infarction, but few of them were current smokers. Subjects in the high RDW group had higher systolic blood pressure and total cholesterol levels, and lower erythrocyte mean corpuscular volume, hemoglobin level, estimated glomerular filtration rate level, and left ventricular ejection fraction. Moreover, more subjects in the high RDW group were combined with left main, ostial and chronic total occlusion lesion, and had a lower complete revascularization rate. The postoperative mortality was significantly higher in the high RDW group than that in the low RDW group (2.4% vs 0.6%, P<0.001). Multivariate Cox regression analysis revealed that preoperative high RDW level was an independent risk factor for postoperative mortality after adjustment of other factors (HR 3.930, 95%CI 1.600-9.656, P=0.003). Conclusion: High RDW might be a marker for the postoperative mortality in non-anemic patients undergoing elective PCI.