花苜蓿小尺度空间遗传结构研究

以花苜蓿（Medicago ruthenica Trautv.）为材料,在内蒙古克什克腾旗建立两个25 m×50 m的样方（山谷YF1和山坡YF2）,采集该范围内的所有个体,利用8对SSR分子标记对其遗传变异特性进行分析。结果显示,克什克腾旗花苜蓿居群遗传多样性较高。两个居群个体的空间自相关分析结果表明,9 m内的个体间为非随机邻近交配,且在同距离范围内,山谷居群的个体间遗传相似性更低,推测此区域可能是历史和地理因素塑造了花苜蓿丰富的遗传多样性,两个小尺度空间格局的个体间基因流模式主要受地形影响。     

Polymorphism of Fecundity Genes (FecB,FecX, and FecG) in the Indian Bonpala Sheep

The 37-kDa laminin receptor precursor/67-kDa laminin receptor (LRP/LR, also known as ribosomal protein SA, RPSA) has been reported to be involved in cancer development and prion internalization. Previous studies have shown that the LRP/LR is expressed in a wide variety of tissues. In particular, expression of LRP/LR mRNA may be closely related to the degree of PrP^Sc propagation. This study presents a detailed investigation of the LRP/LR mRNA expression levels in eleven normal ovine tissues. Using real-time quantitative PCR, the highest LRP/LR expression was found in neocortex (p < 0.05). Slightly lower levels were found in the heart and obex. Intermediate levels were seen in hippocampus, cerebellum, spleen, thalamus, mesenteric lymph node, and the lowest levels were present in liver, kidney, and lung. In general, the LRP/LR mRNA levels were much higher in neuronal tissues than in peripheral tissues. The observation that differences in LRP/LR mRNA expression levels are consistent with the corresponding variation in PrP^Sc accumulation suggests that the 37-kDa/67-kDa laminin receptor may be involved in the regulation of PrP^Sc propagation.     

MicroRNA-409-3p inhibits migration and invasion of bladder cancer cells via targeting c-Met

There is increasing evidence suggesting that dysregulation of certain microRNAs (miRNAs) may contribute to tumor progression and metastasis. Previous studies have shown that miR-409-3p is dysregulated in some malignancies, but its role in bladder cancer is still unknown. Here, we find that miR-409-3p is down-regulated in human bladder cancer tissues and cell lines. Enforced expression of miR-409-3p in bladder cancer cells significantly reduced their migration and invasion without affecting cell viability. Bioinformatics analysis identified the pro-metastatic gene c-Met as a potential miR-409-3p target. Further studies indicated that miR-409-3p suppressed the expression of c-Met by binding to its 3′-untranslated region. Silencing of c-Met by small interfering RNAs phenocopied the effects of miR-409-3p overexpression, whereas restoration of c-Met in bladder cancer cells bladder cancer cells overexpressing miR-409-3p, partially reversed the suppressive effects of miR-409-3p. We further showed that MMP2 and MMP9 may be downstream effector proteins of miR-409-3p. These findings indicate that miR-409-3p could be a potential tumor suppressor in bladder cancer.     

Prevention of Hemodynamic Instability in Extra-Cranial Carotid Angioplasty and Stenting Using Temporary Transvenous Cardiac Pacemaker

Hemodynamic instability is a common condition during extra-cranial carotid angioplasty and stenting (CAS). We evaluated the safety and efficacy of prophylactic placement of temporary cardiac pacemaker during extra-cranial CAS for the prevention of hemodynamic instability. For this, forty-seven carotid artery stents were deployed in 41 high-risk patients. Temporary transvenous cardiac pacemakers were inserted before CAS procedure. The pacers were set to capture a heart rate <60 bpm. Clinical symptoms, blood pressure, heart rate, and pacing activation were monitored and data were collected. We found that pacing occurred in 25 carotid lesions during balloon predilatation; pacemakers were activated transiently in 25 patients. The longest pacing continued for 1 day. Among cases with pacemaker activation, 1 patient developed post-procedural symptomatic hypotension that lasted for 4 days. No related complications were observed. It was, therefore, concluded that pacing was technically effective in producing electrical ventricular responses and was hemodynamically effective in 25 carotid lesions which underwent balloon predilatation. The prophylactic use of a temporary transvenous cardiac pacemaker during CAS was rapid and effective in controlling peri-operative hemodynamic instability and preventing stroke and other complications. The prophylactic use of temporary pacemaker is particularly recommended for patients at high risk for developing hemodynamic instability.     

WormFarm: a quantitative control and measurement device toward automated Caenorhabditis elegans aging analysis

Caenorhabditis elegans is a leading model organism for studying the basic mechanisms of aging. Progress has been limited, however, by the lack of an automated system for quantitative analysis of longevity and mean lifespan. To address this barrier, we developed ‘WormFarm’, an integrated microfluidic device for culturing nematodes. Cohorts of 30–50 animals are maintained throughout their lifespan in each of eight separate chambers on a single WormFarm polydimethylsiloxane chip. Design features allow for automated removal of progeny and efficient control of environmental conditions. In addition, we have developed computational algorithms for automated analysis of video footage to quantitate survival and other phenotypes, such as body size and motility. As proof‐of‐principle, we show here that WormFarm successfully recapitulates survival data obtained from a standard plate‐based assay for both RNAi‐mediated and dietary‐induced changes in lifespan. Further, using a fluorescent reporter in conjunction with WormFarm, we report an age‐associated decrease in fluorescent intensity of GFP in transgenic worms expressing GFP tagged with a mitochondrial import signal under the control of the myo‐3 promoter. This marker may therefore serve as a useful biomarker of biological age and aging rate.     

MMP13 is a critical target gene during the progression of osteoarthritis

Introduction

Osteoarthritis (OA) is a degenerative joint disease affecting a large population of people. The mechanism of this highly prevalent disease is not fully understood. Currently there is no effective disease-modifying treatment for OA. The purpose of this study was two-fold: 1) to investigate the role of MMP13 in the development of OA; and 2) to evaluate the efficacy of the MMP13 inhibitor CL82198 as a pharmacologic treatment for preventing OA progression.

Methods

To investigate the role of the endogenous Mmp13 gene in OA development, tamoxifen was administered to two-week-old Col2CreER;Mmp13^fx/fx (Mmp13^Col2ER) and Cre-negative control mice for five days. OA was induced by meniscal-ligamentous injury (MLI) when the mice were 10 weeks old and MLI or sham-operated joints were harvested 4, 8, 12, or 16 weeks after surgery. To evaluate the efficacy of CL82198, MLI surgery was performed on 10-week-old wild type mice. CL82198 or saline was administered to the mice daily beginning immediately after the surgery for up to 16 weeks. The joint tissues collected from both experiments were evaluated by cartilage grading, histology/histomorphometry, immunohistochemistry (IHC), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The ability of CL82198 to inhibit MMP13 activity in vitro was confirmed by ELISA.

Results

The OA progression was decelerated in Mmp13^Col2ER mice 8, 12, and 16 weeks post-surgery. Cartilage grading by blinded observers confirmed decreased articular cartilage degeneration in Mmp13^Col2ER mice at 8, 12 and 16 weeks compared to Cre-negative mice. Histomorphometric analysis demonstrated that Mmp13^Col2ER mice had a higher articular cartilage area and thickness at 12 and 16 weeks post-surgery compared to the control mice. Results of IHC revealed greater type II collagen and proteoglycan expression in Mmp13^Col2ER mice. Chondrocyte apoptosis, as determined by TUNEL staining, was higher in control mice compared to Mmp13^Col2ER mice. CL82198 inhibited MMP13 activity in conditioned media from vehicle (> 85%) or bone morphogenetic protein 2 (BMP2)-treated (> 90%) primary murine sternal chondrocytes. Intraperitoneal injection of CL82198 decelerated MLI-induced OA progression, increased type II collagen and proteoglycan levels, and inhibited chondrocyte apoptosis compared to saline treatment as determined by OA grading, histology, histomorphometry, IHC, and TUNEL staining, respectively.

Conclusions

Mmp13 is critical for OA progression and pharmacologic inhibition of MMP13 is an effective strategy to decelerate articular cartilage loss in a murine model of injury-induced knee OA.     

Variation Characteristics of Chlorpyrifos in Nonsterile Wetland Plant Hydroponic System

Six wetland plants were investigated for their effect on the degradation characteristics of chlorpyrifos in nonsterile hydroponic system at constant temperature of 28°C. The results showed that the removal rates of chlorpyrifos in the water of plant systems were 1.26–5.56% higher than that in the control without plants. Scirpus validus and Typha angustifolia were better than other hygrophytes in elimination of chlorpyrifos. The removal rates of the two systems were up to 88%. Plants of acaulescent group had an advantage over caulescent group in removing chlorpyrifos. Phytoaccumulation of chlorpyrifos was observed, and the order of chlorpyrifos concentration in different plant tissues was root > stem > leaf. It was also found that chlorpyrifos and its metabolite TCP decreased rapidly at the initial step of the experiment.     

Unique Characteristics of Pb in Soil Contaminated by Red Lead Anti-Corrosion Paint

Red lead (Pb₃O₄) has been extensively used in the past in anti-corrosion paints for the protection of steel constructions such as electricity pylons or bridges. Until recently, little has been known about the behavior of these Pb compounds in soils. Therefore, three pylon soils and six red lead anti-corrosion paints were characterized in terms of solubility, Pb mineral composition, extractability, sorption and desorption, and the chemical speciation of Pb in soil extracts. The pylon soils were characterized by moderate total Pb concentrations (≈700 mg kg^?1), while NH₄NO₃ extractable Pb was exceptionally high (up to 15% of total Pb). In soil extracts, the free Pb²⁺ fraction ranged from 33 to 81% of total soluble Pb. The equilibrium concentration of Pb derived from Pb₃O₄ in ultra-pure water reached 68.5 mg L^?1. This high solubility explains the observed high extractability in soils and contradicts earlier reports of much lower water solubilities of the compound.     

Fossils from the Middle Jurassic of China shed light on morphology of Choristopsychidae (Insecta,Mecoptera)

Choristopsychidae, established by Martynov in 1937 with a single isolated forewing, is a little known extinct family in Mecoptera. Since then, no new members of this enigmatic family have been described. Based on 23 well-preserved specimens with complete body and wings from the Middle Jurassic of northeastern China, we report one new genus and three new species of Choristopsychidae, two new species of the genus Choristopsyche Martynov, 1937: Choristopsyche perfecta sp. n. and Choristopsyche asticta sp. n.; one new species of Paristopsyche gen. n.: Paristopsyche angelineae sp. n.; and re-describe Choristopsyche tenuinervis Martynov, 1937. In addition, we emend the diagnoses of Choristopsychidae and Choristopsyche. Analyzing the forewing length/width ratios of representative species in Mecoptera, we confirm that choristopsychids have the lowest ratio of forewing length/width, meaning broadest forewings. These findings, the first fossil choristopsychids with well-preserved body structure and the first record of Choristopsychidae in China, shed light on the morphology of these taxa and broaden their distribution from Tajikistan to China, while increasing the diversity of Mesozoic Mecoptera in China.