CREG gene silencing induces spontaneous apoptosis of ESCs-derived Ebs

AIM: To investigate the effect of cellular repressor of E1A-stimulated genes (CREG) on the spontaneous apoptosis of murine embryonic stem cells(ESCs)-derived embryoid bodies (EBs).METHODS: The murine ESCs R1 were infected with pDS-shRNA-CREG and pDS-shRNA-GFP retrovirus, respectively. R1, R1-GFP and R1-shCREG were cultured on STO feeder cells in DMEM supplied with leukemia inhibitory factor(LIF). Alkaline phosphatase(AKP) staining and teratoma formation assay inoculated into mouse myocardium were used to detect stemness of transfected ESCs. R1/EB, R1-GFP/EB and R1-shCREG/EB were produced by liquid suspension method. The expression of CREG and cleaved caspase-3 were analyzed by Western blotting and quantitative RT-PCR on day 7. The apoptotic rates of the 3 kinds of EBs were analyzed by flow cytometry(FCM) analysis with Annexin V/PI dual staining. RESULTS: The stably-transfected ES cells (R1-shCREG and R1-GFP) were obtained by screening the G418-resistant clones. R1-GFP and R1-shCREG had the stem cell properties similar to those of R1 detected by AKP staining. However, it was found that R1-shCREG didn't show the same almighty differentiation function as of R1 and R1-GFP by tumor experiments in mouse myocardium that it couldn't form teratomas analogue and had the lower ability of cell differentiation. Observation under phase-contrast microscope showed that the cell differentiation was inhibited while the number of cell death was increased in R1-shCREG/EB group. Compared with R1/EB and R1-GFP/EB, Western blotting analysis demonstrated that the protein expression of CREG was decreased to (78.0±1.3)% and (84.0±2.4)% on day 7, respectively. The mRNA expression of CREG was also decreased, but the expression of cleaved caspase-3 at the mRNA and protein levels was increased obviously. Annexin V/PI FCM assay indicated that the apoptotic rate of R1-shCREG/EB was significantly higher those that in other 2 groups on day 7. CONCLUSION: The down-regulation of CREG inhibits ESCs differentiation and promotes cell apoptosis.     

三株坦桑尼亚野生灵芝菌株人工栽培子实体活性成分含量分析

以国内灵芝(Ganoderma)栽培菌株粤GL-YW( G.lucidum)和粤GL-YWZ(G.sinense)为对照,对3株采自坦桑尼亚的野生灵芝(Ganoderma)菌株的人工栽培子实体进行多糖和三萜含量测定.结果表明,3个野生菌株子实体中多糖和三萜含量均显著高于对照菌株,值得进一步开发和推广.     

文心兰原球茎诱导条件的优化

以蜜糖文心兰不同生长期的新芽为试材,研究影响文心兰原球茎诱导的主要因素,结果表明:以半开展新芽的顶芽或侧芽为外植体,用0.1%升汞溶液灭菌9 min,待外植体成活长成第一代植株时,再进行剥茎尖处理诱导原球茎形成,采用这种方法,外植体成活率明显提高,并在最短时间内诱导形成原球茎(PLB)。适宜的PLB诱导培养基为改良1号 6-BA 2.0 mg.L-1 NAA 0.2 mg.L-1。     

Small mountain reservoirs in the Alps: New habitats for alpine freshwater biodiversity?

1. Today, aquatic biodiversity suffers from many pressures linked to human activities, including climate change, which particularly affects alpine areas. Many alpine freshwater species have shifted their geographical distribution to colder areas, but a reduced availability of suitable habitats is also forecasted. New artificial water bodies could provide habitat enhancement opportunities, including small mountain reservoirs built to overcome a lack of snow during winter.
2. To investigate the role of reservoirs as a habitat for freshwater invertebrates, a case study was conducted on eight reservoirs in the Swiss Alps. The study aimed to compare the water quality and freshwater biodiversity of the reservoirs with those of 39 natural and newly excavated ponds. Data were collected on physico‐chemistry, freshwater habitat structure, and aquatic insects (dragonflies and aquatic beetles).
3. The study showed that the mountain reservoirs investigated did not differ from natural ponds in terms of surface area, conductivity, and trophic level. Similarly to natural ponds, reservoirs showed signs of impairment owing to surface run‐off carrying pollutants linked to ski tourism. They presented a low diversity of mesohabitats, and in particular lacked vegetation. Compared with natural ponds, the species richness in reservoirs was lower for dragonflies but not for beetles. At the regional scale, the community from the reservoirs was a subset of the natural ponds community, supporting 38% of the regional species richness for these two insect groups.
4. The results suggest that mountain reservoirs are likely to be important for biodiversity in alpine areas, both as habitats and as stepping stones for species shifting their geographical range. These water bodies can be enhanced further by some nature‐friendly measures to maximize benefits for biodiversity, including margin revegetation or the creation of adjacent ponds. Ecological engineering needs to be innovative and promote freshwater biodiversity in artificial reservoirs.

     

Accuracy of capillary blood 3-β-hydroxybutyrate determination for the detection and treatment of canine diabetic ketoacidosis

In human medicine, diagnosis of diabetic ketoacidosis (DKA) is usually based on measurement of capillary 3-β-hydroxybutyrate (3-HB) with a hand held ketone sensor. This study was conducted to determine if measurement of capillary 3-HB could be useful for the diagnosis and monitoring of canine DKA. Fifteen dogs with diabetic ketosis and 10 with DKA were evaluated. Paired measurements of 3-HB of capillary and venous blood samples were analysed by the electrochemical sensor and reference method. Use of capillary 3-HB measurement during DKA management was then evaluated through simultaneous measurements of capillary 3-HB, urinary AcAc and venous blood gas analysis. Good agreement between capillary and venous 3-HB measurement was detected by the electrochemical sensor and reference method. Monitoring treatment of DKA revealed a significant correlation between capillary 3-HB and acidosis markers, while no significant correlation was observed between AcAc and acidosis markers. A cut-off value of capillary blood 3-HB >3.8 mmol/L for diagnosis of DKA resulted in 70% and 92% sensitivity and specificity. The electrochemical sensor accurately measures 3-HB concentration in both capillary and venous blood samples, is accurate in diagnosing canine DKA, and appears to reflect the patient''s metabolic status during DKA treatment.     

光质对狗蔷薇类原球茎发生和植株再生的影响

为探讨光照对狗蔷薇类原球茎的发生和植株再生的影响,采用发光二极管(LED)调制获取不同光谱能量分布的光质配比(纯红光、偏红光(3∶1)、等比光(1∶1)、偏蓝光(1∶3)、纯蓝光),以荧光灯和黑暗作对照,结果表明:偏蓝光条件下狗蔷薇类原球茎的发生率最高,达64%;蓝光、偏红光以及荧光灯下PLBs发生率30%左右,黑暗情况下仅14%。在偏蓝光条件下平均每外植体产生的类原球茎量是其他光质下的2倍。PLBs萌发率在纯红光条件下达到30%,在红蓝混合光下达20%左右,纯蓝光下仅为17%。但在PLBs分化和萌发过程中,含红光条件下的PLBs萌发后更易形成假珠芽,最高达12%,蓝光下仅形成畸形苗。说明不同光质组合对PLBs发育的不同阶段产生不同的影响,偏蓝光有利于狗蔷薇PLBs的发生,红光有利于PLBs的分化和萌发,在含红光的光照下容易诱导出假珠芽。     

Serological examination and egg production of progeny of fowl experimentally infected with Egg Drop Syndrome 1976 virus

Summary

Following EDS'76 virus (BC14 virus) infection of breeder chickens by the conjunctival route, vertical transmission occurred in the first week after infection. In the progeny which had been infected with EDS'76 virus by the vertical route, increasing haemagglutination inhibiting (HI) litres to BC14 virus and increasing numbers of birds with HI litres were observed from 3 weeks to 15 weeks of age. Sixty‐one per cent of the hens and 77 per cent of the cocks had ²log HI BC14 virus litres exceeding 4 at an age of 15 weeks.

Some birds which had been serologically negative throughout the rearing period, seroconverted between 25 and 28 weeks of age. This phenomenon occurred in hens as well as in cocks. Simulation of stress twice during the laying period by injection of corticosteroid hormone did not increase the number of birds serologically positive to EDS'76 virus.

EDS'76 was observed in the group of hens that was vertically infected, since egg production was significantly depressed between 28 and 34 weeks of age. Probably this was mainly the result of a production drop in the hens showing seroconversion at 27 or 28 weeks of age.

In the group of fowl vertically infected with EDS'76 virus, serologically positive birds appeared to be protected for the greater part to BC14 virus challenge at 50 weeks of age, while negative birds seemed to be fully susceptible. Chicks hatched from eggs collected in the third and fourth week after infection of the dams had maternal antibodies. Fertility and hatchability of apparently normally shelled eggs seemed not to be affected after BC14 virus infection of the dams. Intensive contact with contaminated faeces is probably an indispensable condition for lateral transmission of the virus.     

Do perceived walking distance to and use of urban blue spaces affect self-reported physical and mental health?

A cross-sectional analysis among 1041 urban residents was done to examine associations between self-reported walking distance to and use of freshwater urban blue space and health-related quality of life in two German cities: a city with “poor” urban blue space supply (Bielefeld; 0.8% blue space) and one with “better” urban blue space supply (Gelsenkirchen; 3.0% blue space). Health-related quality of life was assessed with the SF-12v2, which measures residents’ self-reported mental and physical health. Results showed a significant association between use frequency and perceived walking distance to blue space. Blue space use was a better indicator of health outcomes than perceived walking distance. After controlling for green space, socio-economic and demographic variables, use frequency was associated with higher mental health in Gelsenkirchen. These cross-sectional findings suggest that blue space use increases the probability of being healthier in highly urbanised areas in cities with an appropriate amount of blue space.     

谈灵谷东溪水系景观改造

充分分析灵谷东溪水系景观改造项目背景,提出设计理念,深入研究设计手法,进而做出具体的规划及设计内容。     

不同方法从小鼠胚胎干细胞分化拟胚体

建立简便有效的胚胎干细胞体外分化研究中制备拟胚体的方法。本实验以3种方法形成拟胚体：滋养层过生长法、悬浮法和胶原酶处理法，并与传统的悬滴法进行了比较。在不同的分化培养体系中以最终分化出搏动的心肌细胞评价形成有分化发育能力的拟胚体的效率。以RT—PCR检测了拟胚体和心肌细胞形成中基因的表达。结果表明，4种方法分化出搏动心肌细胞的比例不同。滋养层过生长法形成拟胚体的比例接近悬滴法．而悬浮法和胶原酶处理形成拟胚体的比例显著低于滋养层过生长法和悬滴法。形态学研究显示，拟胚体发育经历了简单拟胚体阶段到囊状拟胚体或成熟拟胚体。在拟胚体成熟过程中特异性胚层分化发育分子标记HNF-4、Bmp-4与Otx-2表达上调，与心肌细胞分化相关的基因α—MHC、β-MHC、GATA-4及Nkx2．5同样表达上调。表明不同途径可获得不同比例的有发育能力的拟胚体，在体外分化研究中滋养层过生长法则是简便有效的获得正常发育拟胚体的方法。