Gelsolin rs1078305 and rs10818524 polymorphisms were associated with risk of oral squamous cell carcinoma in a Chinese Han population

Background: Gelsolin (GSN) is one of the most abundant actin-binding proteins, and is involved in cancer development and progression.

Patients and methods: A hospital-based case-control study including 201 patients with OSCC and 199 healthy controls was conducted. Seventeen single-nucleotide polymorphisms (SNPs) of GSN were investigated by Sequenom Mass ARRAY and iPLEX-MALDI-TOF technology.

Results: Through comparison of the 17 SNPs on GSN gene between the two groups, SNP rs1078305 and rs10818524 were verified to be significantly associated with an increased risk of OSCC. For GSN rs1078305, the TT genotype was associated with increased risk for OSCC (OR?=?1.92, 95% CI?=?1.11–3.32, p?=?0.028). CT/TT variants were also associated with increased risk for OSCC compared to the CC genotype (OR?=?1.83, 95% CI?=?1.25–3.84, p?=?0.032).

Conclusion: The rs1078305 and rs10818524 SNPs of GSN were associated with increased risk for OSCC development in a Chinese Han population.     

Deletion of amino acids 1641-2437 from the foot region of skeletal muscle ryanodine receptor alters the conduction properties of the Ca release channel.

The ryanodine receptor (RyR) of skeletal muscle contains two functional domains: a carboxyl-terminal hydrophobic domain that forms the putative conduction pore of the calcium release channel, and a large cytoplasmic domain that corresponds to the "foot structure." To understand the contribution of the foot structure to the function of the calcium release channel, we studied a RyR deletion mutant, delta(1641-2437)-RyR, in which a region that is rich in glutamate and aspartate residues (a.a. 1641-2437) was removed. The wild-type and delta(1641-2437)-RyR proteins were expressed in a Chinese hamster ovary (CHO) cell line, and functions of single calcium release channels were measured in the lipid bilayer membrane. The wild-type RyR forms functional calcium release channels with a linear current-voltage relationship similar to that of the native channel identified in the sarcoplasmic reticulum membrane of skeletal muscle, whereas the channels formed by delta(1641-2437)-RyR exhibit significant inward rectification, i.e., currents moving from cytoplasm into SR lumen were approximately 20% less than that in the opposite direction. As in to the wt-RyR channel, opening of the delta(1641-2437)-RyR channel has a bell-shaped dependence on the cytoplasmic calcium, but the calcium-dependent activation and inactivation processes of the delta(1641-2437)-RyR channel are shifted to higher calcium concentrations. Our data show that deletion of a.a. 1641-2437 from the foot region of the skeletal muscle RyR results in changes in both ion conduction and calcium-dependent regulation of the calcium release channel.     

通过研究改性壳聚糖与细胞的相互作用评价其生物相容性

利用细胞生物学的方法, 研究了四种不同的细胞在经过改性的壳聚糖（ＣＨＩＴＯＳＡＮ） 膜上的生长,测定了细胞相对黏附力、细胞初始黏附率, 并利用ＦＤＡ 实验测定了细胞活力,从而从多个方面评价了这几种不同材料的生物相容性。实验结果表明,与明胶交联的壳聚糖膜明显比其它两种膜有利于细胞的黏附和生长,为进一步对材料进行筛选奠定了基础。     

东亚大都市学生头型的比较研究

为了研讨居住区域的气候条件和社会经济环境对头型的影响,采用国际通用的人体测量法,调查测量了东亚三个国家四个集团３４７２名６－１７岁学生的头长和头宽,经统计学处理求得其平均值、头指数,回归方程,并作性差和地区差检验,其结果表明：中国大连学生为特圆头型,菲律宾马尼拉学生为圆头型,地理位置在大连和马尼拉之间的日本东京的学生的头型也位于二者之间,生活富裕集团的头长和头宽明显大于生活贫穷集团的学生,但头型二     

渭北旱塬保护性耕作对冬小麦-春玉米轮作田蓄水保墒效果和产量的影响

通过2007—2010年田间定位试验,研究了平衡施肥、常规施肥和无肥(或低肥)条件下,免耕、深松和翻耕处理对渭北旱塬冬小麦-春玉米轮作田土壤贮水量、作物产量、水分利用效率(WUE)和纯收益的影响.结果表明:休闲期免耕处理蓄水保墒效果最好,深松次之,翻耕最差;轮作田生育期内免耕和深松处理0~200 cm平均土壤贮水量分别较翻耕提高6.7%和1.9%;各施肥条件下作物产量、WUE和纯收益均以深松处理最高,且以平衡施肥深松处理表现最好,2007—2008年冬小麦、2009年春玉米、2009—2010年冬小麦产量分别为6909、9689、5589 kg.hm-2,WUE分别为18.5、25.2、23.0 kg.hm-2.mm-1,纯收益分别为5034、5045、7098元.hm-2.因此,平衡施肥与深松组合处理的蓄水保墒和增产增收效果最好,是渭北旱塬冬小麦-春玉米轮作田较适合的施肥耕作模式.     

醋酸棉酚诱导人粘液表皮样癌MEC-1细胞DNA双链断裂

本文研究醋酸棉酚(gossypol acetic acid,GAA)对人粘液表皮样癌细胞MEC-1体外增殖的影响,并初步探讨其抑制肿瘤细胞增殖的机制.体外培养人粘液表皮样癌细胞系MEC-1细胞,用MTT法检测GAA对MEC-1细胞增殖的影响;用中性彗星实验检测GAA对MEC-1细胞的DNA双链断裂;用免疫荧光染色法检测...     

Simulating the rice yield change in the middle and lower reaches of the Yangtze River under SRES B2 scenario

As one of the most important crops in China, rice accounts for 18% of the country’s total cultivated area. Increasing atmospheric CO₂ concentration and associated climate change may greatly affect the rice productivity. Therefore, understanding the impacts of climate change on rice production is of great significance. This paper aims to examine the potential impacts of future climate change on the rice yield in the middle and lower reaches of the Yangtze River, which is one of the most important food production regions in China. Climate data generated by the regional climate Model PRECIS for the baseline (1961–1990) and future (2021–2050) period under IPCC SRES B2 scenario were employed as the input of the rice crop model ORYZA2000. Four experimental schemes were carried out to evaluate the effects of future climate warming, CO₂ fertilization and water managements (i.e., irrigation and rain-fed) on rice production. The results indicated that the average rice growth duration would be shortened by 4 days and the average rice yield would be declined by more than 14% as mean temperature raised by 1.5 °C during the rice growing season in 2021–2050 period under B2 scenario. This negative effect of climate warming was more obvious on the middle and late rice than early rice, since both of them experience higher mean temperature and more extreme high temperature events in the growth period from July to September. The significance effect of the enhanced CO₂ fertilization to rice yield was found under elevated CO₂ concentrations in 2021–2050 period under B2 scenario, which would increase rice yield by more than 10%, but it was still not enough to offset the negative effect of increasing temperature. As an important limiting factor to rice yield, precipitation contributed less to the variation of rice yield than either increased temperature or CO₂ fertilization, while the spatial distribution of rice yield depended on the temporal and spatial patterns of precipitation and temperature. Compared to the rain-fed rice, the irrigated rice generally had higher rice yield over the study area, since the irrigated rice was less affected by climate change. Irrigation could increase the rice yield by more than 50% over the region north of the Yangtze River, with less contribution to the south, since irrigation can relieve the water stress for rice growing in the north region of the study area. The results above indicated that future climate change would significantly affect the rice production in the middle and lower reaches of the Yangtze River. Therefore, the adverse effect of future climate change on rice production will be reduced by taking adaptation measures to avoid disadvantages. However, there is uncertainty in the rice production response prediction due to the rice acclimation to climate change and bias in the simulation of rice yield with uncertainty of parameters accompanied with the uncertainty of future climate change scenario.     

The survival mechanism of dune reed (Phragmites communis) cultures under high sodium chloride concentration

Adaptations to salt stress were studied in embryogenic cultures from two ecotypes of reed (Phragmites communisT.). In the 600 mM NaCl treatment, relative cell viability of dune reed embryogenic cultures from a desert region was 56% greater than the control, 198% greater than swamp reed embryogenic cultures. After treatment with different NaCl concentrations, their relative growth rates (RGRs), pyridine nucleotides, activities of antioxidant enzymes and plasma membrane H⁺-ATPase (EC 3.6.1.35) were determined. The results showed that NADPH content, NADPH/NADP⁺ ratio and the activity of plasma membrane H⁺-ATPase in dune reed embryogenic cultures were higher than those of the control in the present of 600 mM NaCl. The activities of peroxidase (POD, EC 1.11.1.7) and catalase (CAT, EC 1.11.1.6) increased more in dune reed embryogenic cultures than in swamp reed embryogenic cultures. Dune reed embryogenic cultures tolerated higher concentration of NaCl than swamp reed embryogenic cultures. Under high concentration of NaCl, the survival of dune reed embryogenic cultures might be due to reductive status maintenance and ions absorption regulation in the plant cells. This phenomenon would be a result of cross-adaptation in nature.     

Identification of LI-F type antibiotics and di-n-butyl phthalate produced by Paenibacillus polymyxa

Paenibacillus polymyxa strain JSa-9, a soil isolate that displayed antibacterial and antifungal activities in vitro, had been found to produce two types of antimicrobial substances. The two compounds were extracted from the fermentation broth of JSa-9 using ethyl acetate and subsequently purified by high performance liquid chromatography. By means of liquid chromatography-mass spectrometry and tandem mass spectrometry analysis, one of two antagonistic compounds was determined as di-n-butyl phthalate. And another was characterized as a mixture of related peptides of molecular masses of 883, 897, 911, 947, and 961 Da, with the most likely structure of them determined to be a cyclic depsipeptide with an unusual 15-guanidino-3-hydroxypentadecanoic acid moiety bound to a free amino group. These peptides were therefore members of the LI-F group of cyclic depsipeptides.     

High-sensitive electrochemical detection of point mutation based on polymerization-induced enzymatic amplification

Here a highly sensitive electrochemical method is described for the detection of point mutation in DNA. Polymerization extension reaction is applied to specifically initiate enzymatic electrochemical amplification to improve the sensitivity and enhance the performance of point mutation detection. In this work, 5'-thiolated DNA probe sequences complementary to the wild target DNA are assembled on the gold electrode. In the presence of wild target DNA, the probe is extended by DNA polymerase over the free segment of target as the template. After washing with NaOH solution, the target DNA is removed while the elongated probe sequence remains on the sensing surface. Via hybridizing to the designed biotin-labeled detection probe, the extended sequence is capable of capturing detection probe. After introducing streptavidin-conjugated alkaline phosphatase (SA-ALP), the specific binding between streptavidin and biotin mediates a catalytic reaction of ascorbic acid 2-phosphate (AA-P) substrate to produce a reducing agent ascorbic acid (AA). Then the silver ions in solution are reduced by AA, leading to the deposition of silver metal onto the electrode surface. The amount of deposited silver which is determined by the amount of wild target can be quantified by the linear sweep voltammetry (LSV). The present approach proved to be capable of detecting the wild target DNA down to a detection limit of 1.0×10(-14) M in a wide target concentration range and identifying -28 site (A to G) of the β-thalassemia gene, demonstrating that this scheme offers a highly sensitive and specific approach for point mutation detection.