Relationship between growth arrest and autophagy in midgut programmed cell death in Drosophila

Autophagy has been implicated in both cell survival and programmed cell death (PCD), and this may explain the apparently complex role of this catabolic process in tumourigenesis. Our previous studies have shown that caspases have little influence on Drosophila larval midgut PCD, whereas inhibition of autophagy severely delays midgut removal. To assess upstream signals that regulate autophagy and larval midgut degradation, we have examined the requirement of growth signalling pathways. Inhibition of the class I phosphoinositide-3-kinase (PI3K) pathway prevents midgut growth, whereas ectopic PI3K and Ras signalling results in larger cells with decreased autophagy and delayed midgut degradation. Furthermore, premature induction of autophagy is sufficient to induce early midgut degradation. These data indicate that autophagy and the growth regulatory pathways have an important relationship during midgut PCD. Despite the roles of autophagy in both survival and death, our findings suggest that autophagy induction occurs in response to similar signals in both scenarios.     

Ultrasound complex enzymes assisted extraction and biochemical activities of polysaccharides from Epimedium leaves

Ultrasound complex enzymes (UCE) were used to extract crude polysaccharides (CEP) from Epimedium leaves. The response surface methodology (RSM) based on Box–Behnken Design (BBD) was employed to further optimize the extraction conditions. The optimum conditions were: complex enzyme dose of 50, 250, 200, 100 U/g (papain, pectase, cellulase and α-amylase), extraction temperature 46.8 °C, ultrasound time 42.3 min, pH 4.28, and ultrasound power 311 W. Under these conditions, the experimental yield of CEP was 5.98%, which was well matched with the value predicted by the model. Three major polysaccharide fractions (EP-1, EP-2 and EP-3) were obtained by ultrafiltration, chromatography on DEAE-Sepharose Fast Flow and Sephadex G-100 column. Their chemical–physical characteristics were investigated using chemical methods, gas chromatography (GC) and high-performance size-exclusion chromatography (HPSEC). Biochemical characterization of the polysaccharide fractions was evaluated on the basis of free radical scavenging, ferric-reducing antioxidant power (FRAP), lymphocyte proliferation, macrophage phagocytosis and NK cell activity assay in vitro. The results showed that all fractions contained higher galacturonic acid (GalA) and galactose (Gal), possessed considerable antioxidant activity, and could promote proliferation of splenic lymphocytes, activate macrophages and enhance NK cells’ activity. UCE as a more effective and environment-friendly technique could be employed for extracting active ingredients from plant materials, extensively applied in pharmaceutical and food industries.     

Dietary Intake of Whole and Refined Grain Breakfast Cereals and Weight Gain in Men

Objective: Prospective studies have suggested that substituting whole grain for refined grain products may lower the risk of overweight and obesity. Breakfast cereal intake is a major source of whole and refined grains and has also been associated with having a lower BMI. The aim of this study was to prospectively assess the association between whole and refined grain breakfast cereal intakes and risk of overweight (BMI ≥ 25 kg/m²) and weight gain. Research Methods and Procedures: We examined 17, 881 U.S. male physicians 40 to 84 years of age in 1982 who were free of cardiovascular disease, diabetes mellitus, and cancer at baseline and reported measures of breakfast cereal intake, weight, and height. Results: Over 8 and 13 years of follow‐up, respectively, men who consumed breakfast cereal, regardless of type, consistently weighed less than those who consumed breakfast cereals less often (p value for trend = 0.01). Whole and refined grain breakfast cereal intake was inversely associated with body weight gain over 8 years, after adjustment for age, smoking, baseline BMI, alcohol intake, physical activity, hypertension, high cholesterol, and use of multivitamins. Compared with men who rarely or never consumed breakfast cereals, those who consumed ≥1 serving/d of breakfast cereals were 22% and 12% less likely to become overweight during follow‐up periods of 8 and 13 years (relative risk, 0.78 and 0.88; 95% confidence interval, 0.67 to 0.91 and 0.76 to 1.00, respectively). Discussion: BMI and weight gain were inversely associated with intake of breakfast cereals, independently of other risk factors.     

Multiparametric evaluation of hindlimb ischemia using time‐series indocyanine green fluorescence imaging

Peripheral arterial disease (PAD) can further cause lower limb ischemia. Quantitative evaluation of the vascular perfusion in the ischemic limb contributes to diagnosis of PAD and preclinical development of new drug. In vivo time‐series indocyanine green (ICG) fluorescence imaging can noninvasively monitor blood flow and has a deep tissue penetration. The perfusion rate estimated from the time‐series ICG images is not enough for the evaluation of hindlimb ischemia. The information relevant to the vascular density is also important, because angiogenesis is an essential mechanism for post‐ischemic recovery. In this paper, a multiparametric evaluation method is proposed for simultaneous estimation of multiple vascular perfusion parameters, including not only the perfusion rate but also the vascular perfusion density and the time‐varying ICG concentration in veins. The target method is based on a mathematical model of ICG pharmacokinetics in the mouse hindlimb. The regression analysis performed on the time‐series ICG images obtained from a dynamic reflectance fluorescence imaging system. The results demonstrate that the estimated multiple parameters are effective to quantitatively evaluate the vascular perfusion and distinguish hypo‐perfused tissues from well‐perfused tissues in the mouse hindlimb. The proposed multiparametric evaluation method could be useful for PAD diagnosis.

The estimated perfusion rate and vascular perfusion density maps (left) and the time‐varying ICG concentration in veins of the ankle region (right) of the normal and ischemic hindlimbs.     

远缘杂交在转移有益基因创造小麦新种质中的潜力

本文概述了小麦远缘杂交技术的发展以及这些技术的应用对以染色体易位方式转移有益基因到普通小麦中的影响。通过对小麦远缘杂交技术的总结得出,普通小麦由于本身的多倍性,对导入的外源基因具有较强的调节能力,是适宜外源有益基因导入的良好受体。而以染色体易位方式转移有益基因是创造小麦新种质的有效方法之一,许多研究也表明以染色体易位导入的外源有益基因更利于表达。近几年,随着细胞遗传学以及其它生物技术的发展,对小麦族进化途径和染色体间的亲缘关系进一步明确,从而更便于进行易位导入的技术选择,也使得染色体易位鉴定方法更趋完善。现在已有更良好的外源导入的工具和方法,使多基因控制的外源优良性状导入成为可能。在小麦远缘杂交中染色体易位所具有的上述优势,在育种实践中逐步显示出来,为开拓小麦种质资源开创了一条新的途径。     

Insulin Resistance,Hyperleptinemia, and Obstructive Sleep Apnea in Launois‐Bensaude Syndrome

Objective: Launois‐Bensaude Syndrome (LBS) is a very rare cause of obesity, characterized by a symmetrical accumulation of a very large number of lipomata in different regions of the body, excluding the face, the forearms, and the shanks. Obesity is known to be closely associated with insulin resistance, hyperleptinemia, and obstructive sleep apnea (OSA). We were interested in studying whether these conditions are also present in patients with obesity due to LBS with a similar frequency as in patients with “simple” truncal obesity. Research Methods and Procedures: We performed polysomnography and hyperinsulinemic euglycemic clamp studies and measured serum leptin in three patients with LBS and in six patients with “simple” truncal obesity, matched for sex and body mass index (LBS group, 36.39 kg/m²; controls, 35.82 kg/m²). Results: Polysomnography revealed severe OSA in one LBS patient with marked “horsecollar lipomata.” In the other LBS patients, no OSA could be demonstrated. The leptin levels of the two groups were comparable (LBS group, 36.39 μg/liter; controls, 37.18 μg/liter) and the insulin responsiveness index was also comparable in the two groups (LBS group, 3.47 μmol/kg · minute; controls, 3.79 μmol/kg · minute). Discussion: Patients with LBS demonstrated similar metabolic features in terms of insulin sensitivity and hyperleptinemia as patients with “simple” truncal obesity. LBS is not strictly associated with OSA.     

Predicting drug-target interactions using Lasso with random forest based on evolutionary information and chemical structure

The identification of drug-target interactions has great significance for pharmaceutical scientific research. Since traditional experimental methods identifying drug-target interactions is costly and time-consuming, the use of machine learning methods to predict potential drug-target interactions has attracted widespread attention. This paper presents a novel drug-target interactions prediction method called LRF-DTIs. Firstly, the pseudo-position specific scoring matrix (PsePSSM) and FP2 molecular fingerprinting were used to extract the features of drug-target. Secondly, using Lasso to reduce the dimension of the extracted feature information and then the Synthetic Minority Oversampling Technique (SMOTE) method was used to deal with unbalanced data. Finally, the processed feature vectors were input into a random forest (RF) classifier to predict drug-target interactions. Through 10 trials of 5-fold cross-validation, the overall prediction accuracies on the enzyme, ion channel (IC), G-protein-coupled receptor (GPCR) and nuclear receptor (NR) datasets reached 98.09%, 97.32%, 95.69%, and 94.88%, respectively, and compared with other prediction methods. In addition, we have tested and verified that our method not only could be applied to predict the new interactions but also could obtain a satisfactory result on the new dataset. All the experimental results indicate that our method can significantly improve the prediction accuracy of drug-target interactions and play a vital role in the new drug research and target protein development. The source code and all datasets are available at https://github.com/QUST-AIBBDRC/LRF-DTIs/ for academic use.