Effects of selenium on growth and ultrastructure of the marine unicellular alga <Emphasis Type="Italic">Dunaliella salina</Emphasis> (Chlorophyta)

This study examines the effects of selenium in concentrations of 0.01, 0.5, 1, 5, and 10 mg/liter on the growth and ultrastructure of the microalga Dunaliella salina. Selenium in concentrations of 0.01 and 0.5 mg/liter stimulated cell population growth, while the number of ultrastructural alterations was the same as in the control cells. At a selenium concentrations of 1 mg/liter, cell population growth slightly decreased by the end of the experiment, and there was some increase in the number of cells with damaged organoids and in the number of completely destroyed cells. As well, the excretory function of cell vacuoles was suppressed, and the autophagic activity of these vacuoles was activated to destroy the cytoplasm and nucleus. Concentrations of 5 and 10 mg/liter were toxic to D. salina, suppressing cell population growth and promoting extensive destructive changes. The threshold concentration of selenium for D. salina was 1 mg/liter, which is 1000 times greater than the maximum permissible concentration (MPC). The fact that the microalga was able to survive for several days in this concentration is indicative of its high resistance to selenium.     

The influence of ultra-low temperatures on marine microalgal cells

The development of cryopreservation methods for microalgae opens great prospects for marine biotechnology and aims to establish a bank of cryopreserved cultures. Eight of ten marine microalgae species used in this study (the diatoms, green, red, and golden algae), including five previously untested species, were successfully recovered after freezing to ultra-low temperatures (?196 °C) using penetrating (dimethyl sulfoxide, glycerol, and ethylene glycol) and non-penetrating (trehalose and polyvinylpyrrolidone) cryoprotectants. We found that ethylene glycol in combination with trehalose possessed the most effective cryoprotective activity among the algae cryoprotectants tested. However, the chief factor for the successful preservation of microalgal cells during freeze–thawing was shown to be the cooling rate. Cooling was performed in two ways: step or fast droplet freezing. The droplet freezing described here was effective only for cryopreserving green algae, whereas step freezing was optimal for all other algal species. Three diatoms of the genus Attheya were successfully cryopreserved for the first time, but none of the tested protocols had a positive result for the diatoms belonging to Pseudo-nitzschia. The failure may be explained rather by peculiarities in the cell wall composition (higher content of silica and fewer organic components) than by the specific (long and thin) shape of these cells. The pigment content in all of the studied species tended to decrease after thawing as compared with unfrozen cells and increase significantly during cell recovery. Cryosensitivity of marine algae depended on the differences in natural intrinsic characteristics rather than their taxonomic position.     

The development of Porphyridium purpureum (Bory de Saint-Vincent) Drew et Ross, 1965 (Rhodophyta) from Amursky Bay,Sea of Japan,in a laboratory culture

The growth of the microscopic red alga Porphyridium purpureum was experimentally studied in different culture media and at various levels of water salinity. The ability of this species to recover after cryopreservation was analyzed. It was revealed that the growth rate and generation time of P. purpureum during the exponential growth phase did not significantly differ between cultures on f medium and those on Goldberg’s medium. The species has been found to withstand salinity variations ranging from 8 to 32 vol %. Cryopreservation of P. purpureum cells using three-step freezing with trehalose as a cryoprotectant showed that the dynamics of cell density after thawing insignificantly differed from the control ones.     

The JAK–STAT Pathway Is Critical in Ventilator-Induced Diaphragm Dysfunction

Mechanical ventilation (MV) is one of the lynchpins of modern intensive-care medicine and is life saving in many critically ill patients. Continuous ventilator support, however, results in ventilation-induced diaphragm dysfunction (VIDD) that likely prolongs patients’ need for MV and thereby leads to major associated complications and avoidable intensive care unit (ICU) deaths. Oxidative stress is a key pathogenic event in the development of VIDD, but its regulation remains largely undefined. We report here that the JAK–STAT pathway is activated in MV in the human diaphragm, as evidenced by significantly increased phosphorylation of JAK and STAT. Blockage of the JAK–STAT pathway by a JAK inhibitor in a rat MV model prevents diaphragm muscle contractile dysfunction (by ~85%, p < 0.01). We further demonstrate that activated STAT3 compromises mitochondrial function and induces oxidative stress in vivo, and, interestingly, that oxidative stress also activates JAK–STAT. Inhibition of JAK–STAT prevents oxidative stress-induced protein oxidation and polyubiquitination and recovers mitochondrial function in cultured muscle cells. Therefore, in ventilated diaphragm muscle, activation of JAK–STAT is critical in regulating oxidative stress and is thereby central to the downstream pathogenesis of clinical VIDD. These findings establish the molecular basis for the therapeutic promise of JAK–STAT inhibitors in ventilated ICU patients.     

高血压患者用药的依从性

高血压是人类健康面临的一个重要挑战,对患者及其家庭和社会造成了巨大的疾病负担。药物治疗是控制高血压的重要手段,合理应用抗高血压药能使90%的患者血压处于正常范围,但实际高血压的控制率仍很低,且发病率逐年上升,究其根本原因,是由于患者用药依从性不良。本文综述了高血压患者用药依从性的概念、现状及评估方法,并对其影响因素进行了详细的阐述,指出应积极干预及加强健康教育,以最大限度提高患者的用药依从性,降低高血压带来的靶器官损害,并进一步对寻求更准确、客观的用药依从性评估方法做出展望。     

白簕叶挥发油的化学成分

用GCMS联用技术首次研究了云南西双版纳白簕叶挥发油的化学成分,并应用色谱峰面积归一化法计算各成分的相对含量。一共分离出108个峰,确认了其中的81种成分,所鉴定的组分占挥发油总量的96.50%,主要是萜烯类及其含氧衍生物等。     

垂体瘤转化基因1(PTTG1)的表达变化对人前列腺癌细胞LNCaP生长增殖的影响

垂体肿瘤转化基因1(PTTG1)具有促进肿瘤生长和转移的作用.通过上调或下调基因表达的策略,观察PTTG1基因对人前列腺癌细胞株LNCaP细胞生长增殖的影响.利用PCR技术分离出PTTG1全长cDNA,分别正向和反向插入真核表达载体pIRES2-EGFP,重组载体分别命名为正义PTTG1-S/pIRES2-EGFP(即pI-P-S)和反义PTTG1-AS/pIRES2-EGFP(即pI-P-AS),将这两种重组载体稳定转染LNCaP细胞,通过流式细胞仪和MTT法分别检测了细胞周期和细胞增殖的情况.转染正义PTTG1后处于S期和G2期的细胞明显增加,细胞生长增殖能力增强;相反,转染反义PTTG1后处于S期和G2期细胞明显减少,细胞生长增殖能力减弱(P<0.05).结果表明,PTTG1能明显改变人前列腺癌细胞株LNCaP的细胞周期和细胞生长增殖能力,它的异常表达可能参与前列腺癌细胞生长增殖过程.     

4种桦树幼苗耐盐性分析与评价

耐盐植物引种和培育是开发利用盐碱地的主要方式,具有重要的研究价值。本试验以哈萨克斯坦引进的吉尔吉斯白桦（Betula kirghisorum）、欧洲白桦（B.pendula）、毛枝桦（B.pubescens）和本地的白桦（B.platyphylla Suk.）1年生幼苗为试验材料,于2014年7月在东北林业大学进行中性盐（NaCl）和碱性盐（NaHCO₃）的胁迫试验,测定生长量、光合参数和叶绿素含量,并通过因子分析法,对比评价4种桦树幼苗的耐盐碱能力,筛选出综合性状优良的桦树树种,为耐盐植物引种和培育提供有价值的数据。结果表明：随着盐浓度的升高,桦树幼苗的高生长和光合效率受到显著抑制,而当浓度≥0.5%时,大部分幼苗枯死。株高增长量、基径增长量、净光合速率（P_n）、光能利用效率（SUE）、羧化效率（CUE）、表观量子效率（AQY）及叶绿素含量之间的相关性多数达到了显著水平;最后利用因子分析法分别构建了0.1% NaCl、0.3% NaCl、0.1% NaHCO3和0.3% NaHCO₃胁迫处理的综合评价公式,并分别筛选出了综合性状相对优良的单株,其中NaCl胁迫下较优单株为32、33、34、35;NaHCO₃胁迫下较优单株为262、263、264、35。综合比较认为,吉尔吉斯白桦对低中浓度的中性盐的抗性最强,本地对照白桦对低中浓度碱性盐的抗性最强,而吉尔吉斯白桦和毛枝桦对高浓度碱性盐抗性较强。     

Identification of over-expressed genes in human renal cell carcinoma by combining suppression subtractive hybridization and cDNA library array

Renal cell carcinoma (RCC) is a common uro- genital malignancy and often shows odd biological features. RCC accounts for approximately 2% of ma- lignancies worldwide. The incidence of and mortality from RCC have continuously increased during the last 50 years. One third of the patients already have me- tastases when first consulting the doctors. Another 30%—40% of patients develop metastasis after surgi- Identification of over-expressed genes in human RCC 149 cal excision of the pri…     

腺花香茶菜中的对映-贝壳杉烯类二萜化合物

从昆明产腺花香茶菜(Isodon adenanthus (Diels) Kudo)的地上部分分离到8个化合物,通过波谱分析鉴定,化合物1-3为新的对映-贝壳杉烯类二萜化合物,命名为腺花香茶菜素N、0和P;4个已知二萜为白叶香茶菜戊素(4)、无毛狭叶香茶菜素C(5)、腺花香茶菜甲素(6)和白叶香茶菜乙素(7),同时得到一个高度不饱和脂肪酸9,16-二羰基-10,12,14-三烯-十八碳酸(8)。根据ROESY波谱,对化合物4的结构进行了修正。化合物1对K562细胞显示出明显的细胞毒活性(IC50=0．45μg／mL)。