Expression of natural killer cell stimulatory receptor NKG2D and its ligand MICA in Tibetan patients with gastric cancer at Qinghai plateau

AIM: To investigate the expression of natural killer cell stimulation receptor D(NKG2D) in peripheral blood and the expression of major histocompatibility complex class I chain-related protein A(MICA) on the gastric carcinoma tissue and the neighboring non-cancerous tissue in Tibetan patients with gastric cancer at Qinghai plateau. METHODS: Samples of 33 patients and 20 healthy persons were collected to detect NKG2D in peripheral blood by Flow cytometry analysis. The expressions of MICA in part of the correspondent tissues were examined by RT-PCR and immunohistochemistry.RESULTS: The expression of NKG2D in the plateau of Tibetan patients with gastric cancer group (13.47 ±5.26)% was significantly lower than that in healthy groups (32.62±10.08)%. The mRNA level of MICA in gastric cancer was significantly higher than that in neighboring non-cancerous tissue (P<0.05). The expressions of MICA proteins showed a significant difference between the neighboring non-cancerous tissue (21.21%, 7/33) and the gastric carcinoma tissue (78.79%, 26/33), between the high differentiation (60.00%, 3/5) and the moderate (72.73%, 8/11), low differentiation (88.24%, 15/17). The expressions of MICA were not correlated with tumor size, sex, age, lymph node metastasis of the patients (P>0.05). Spearman rank correlation displayed that the expressions of MICA mRNA were positively correlated with the MICA protein level (r=0.903, P<0.01).CONCLUSION: The immune escape in Tibetan patients with gastric cancer at Qinghai plateau probably relates to the down-regulation of NKG2D and the up-regulation of its ligand MICA. The activity of NK cells and the anti-cancer cellular immunity level are descending in the plateau of Tibetan patients with gastric cancer. The decrease in the receptor NKG2D is a reason for the activity of NK cell descending.     

Unrecognized diversity in New Guinean crayfish species (Decapoda,Parastacidae): The evidence from molecular data

The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes (COI, 16S and 12S) and by comparison with available GenBank sequences of 14 Cherax species. Furthermore, the concordance of previously described species obtained from a wholesaler (Cherax boesemani, C. holthuisi and C. peknyi) with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species. Recently described species C. gherardiae, C. pulcher and C. subterigneus belong to the northern group of Cherax species. Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species, suggesting 5 putative new species. Surprisingly, species assigned to the subgenus Astaconephrops do not form a monophyletic clade; this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae. Increasing importation of crayfish underscores the importance of accurate species identification. Use of basic molecular methods is a necessary requisite for documenting occurrence, abundance and population trends of target species. Consequently, it helps to support eventual conservation decision‐making by stakeholders.     

The influence of diel period on fish assemblage in the unstructured littoral of reservoirs

Abstract Diel changes in littoral fish assemblage were studied in four reservoirs in the Czech Republic (Central Europe). The sampling was performed by beach seining in an unstructured littoral zone. Perch, Perca fluviatilis L., roach, Rutilus rutilus (L.), bream, Abramis brama (L.), carp, Cyprinus carpio L., ruffe, Gymnocephalus cernua (L.), pikeperch, Sander lucioperca (L.), eel, Anguilla anguilla (L.) and A. brama × R. rutilus hybrids exhibited higher densities at night. Only bleak, Alburnus alburnus (L.) exhibited higher densities during the day. The number of species was higher in night hauls, and mean body size of roach and bleak was also higher at night. Diel changes in fish densities resulted in the change in species composition between day and night. The study has implication for the sampling design to assess littoral fish assemblages using beach seine netting and recommends night sampling for a representative assessment or sampling during both diel periods for a robust assessment.     

高pH胁迫对“黄海1号”中国对虾免疫相关酶的影响

对高pH养殖水体中"黄海1号"中国对虾(Fenneropenaeus chinensis)群体和野生群体的存活率,血清中的溶菌酶(LSZ)、酚氧化酶(PO)、超氧化物歧化酶(SOD)、碱性磷酸酶(AKP)及酸性磷酸酶(ACP)活力变化进行了测定.经高pH胁迫72 h后检测发现,在pH8.2～8.6,"黄海1号"和野生群体存活率均高于90%,两群体机体表现出一定的应激能力;在pH8.8～9.0时,"黄海1号"及野生群体死亡率都急剧增加,几种免疫相关酶类较在pH 8.6时都有较高幅度的变化,"黄海1号"的死亡率及酶突变程度均小于野生群体;在pH 9.2时,2群体的死亡率及体内的几种免疫相关酶活性变化幅度继续增大,但2群体间差异减弱;在pH 9.4时,两群体中国对虾全部死亡.比较发现,当海水pH在一定的范围内升高时,"黄海1号"免疫能力要高于野生群体.     

石菖蒲挥发性组分提取方法的对比研究

采用超临界CO2流体萃取（SCFE）与分级分离技术联用提取石菖蒲挥发性组分．并与水蒸气提取（HD）法所得挥发油进行了对比,发现挥发油成分相对含量有所差异。在SCFE挥发油中烯烃单萜、倍半萜类的相对含量高;而含氧单萜、含氧倍半萜类则正好相反．HD法所提挥发油中含氧萜类明显高于SCFE。其主要有效成分口一细辛醚在SCFE和HD所提挥发油中的相对含量分别为52．84％和38．67％,这说明SCFE对口一细辛醚的提取有较好的选择性。     

New techniques for breeding maize (Zea mays) varieties with fall armyworm resistance and market-preferred traits for sub-Saharan Africa

Deploying maize varieties with fall armyworm (Spodoptera frugiperda [J.E. Smith]; FAW) resistance, desirable product profiles (PPs) and climate resilience is fundamental for food and economic security in sub-Saharan Africa (SSA). This study reviewed and identified challenges and opportunities for effective and accelerated breeding of demand-led maize hybrids with FAW resistance and adaptation to the diverse agro-ecologies of SSA. Lessons were drawn on improving breeding efficiency through adequate genetic variation delivered via prebreeding programmes, speed breeding and a reduced breeding stage plan. Appropriate PPs aligned with demand-led breeding approaches were highlighted as foundations for variety design and commercialization. Challenges to accelerated FAW resistance breeding in maize included inadequate funds and modern tools; poor adaptation of some exotic donor parental lines; lack of information on FAW resistance among local varieties; lack of integration of molecular markers associated with FAW resistance and agronomic traits into selection plans; and limited infrastructure for FAW rearing and germplasm screening. Integration of modern breeding tools and scientific innovations were recommended for accelerated development and release of FAW resistant and market-preferred maize varieties.     

Characterisation of sweet stem sorghum genotypes for bio-ethanol production

In an effort to characterise and select promising sweet stem sorghum genotypes with enhanced biofuel productivity, the present study investigated phenotypic variability present among diverse sweet stem sorghum genotypes based on ethanol production and related agronomic traits. One hundred and ninety genotypes were evaluated. Data were subjected to variance, cluster, correlation, path coefficient and principal component analyses. Significant differences (P?<?0.01) were detected among tested genotypes for all measured traits. Days to flowering varied from 62 to 152 with a mean of 93. Plant height varied from 90 to 420?cm with a mean of 236?cm. Stem diameter ranged from 7 to 31?mm with a mean of 16?mm. Biomass yield varied from 6.668 to 111.2?t?ha^?1 with a mean of 30?t?ha^?1. Stalk dry matter content ranged from 17.2% to 44.2% with a mean of 29.8%, while fibre content varied from 8.92% to 34.8% with a mean of 17.2%. The stalk brix yield varied from 3.3% to 18.9% with a mean of 12.1%. Ethanol productivity ranged from 240.9 to 5500?l?ha^?1 with a mean of 1886?l?ha^?1. The best ethanol producing genotypes were AS203, AS391, AS205, AS251 and AS448. Days to flowering, plant height, stalk brix and stem diameter exerted the greatest indirect effects on ethanol production through higher biomass production. Biomass yield had the greatest direct effect on ethanol production. Therefore, the above traits should be considered during breeding sorghum for bio-ethanol production. Also, the traits had high heritability values, hence selection should provide for good genetic gains. Overall, the above sweet stem sorghum genotypes are useful genetic resources for breeding of sorghum with enhanced bio-ethanol production.     

Leaf gas exchange and water-use efficiency of dry-land wheat genotypes under water stressed and non-stressed conditions

The objective of this study was to determine drought tolerance characteristics of dryland wheat genotypes based on leaf gas exchange and water-use efficiency in order to identify promising genotypes for drought tolerance breeding. Physiological responses of ten genetically diverse wheat genotypes were studied under non-stressed (NS) and water stressed (WS) conditions using a 2?×?10 factorial experiment replicated 3 times. A highly significant water condition?×?genotype interaction (P?<?0.001) was observed for photosynthetic rate (A), ratio of photosynthetic rate and internal CO₂ concentration (A/C_i), ratio of internal and atmospheric CO₂ (C_i/C_a), intrinsic (WUE_i) and instantaneous (WUE_inst) water-use efficiencies suggesting genotypic variability among wheat genotypes under both test conditions. Principal component analysis (PCA) identified three principal components (PC’s) under both test conditions accounting for 84% and 89% of total variation, respectively. Bi-plot analysis identified G339 and G344 as drought tolerant genotypes with higher values of A, T, gs, A/C_i, WUE_i and WUE_inst under WS condition. The current study detected significant genetic variation for drought tolerance among the tested wheat genotypes using physiological parameters. Genotypes G339 and G344 were identified to be drought tolerant with efficient A, T, gs, A/Ci and water-use under water stressed condition.     

Polymorphism of microsatellite loci in sugar beet’s selection lines

The genetic polymorphism of 12 microsatellite loci was revealed and unique DNA-profiles were obtained for initial lines of sugar beet. Two loci were monomorphic, other loci exhibited polymorphism. The genetic distances between the breeding materials were determined; the dendrogram of cluster analysis reflecting the probable divergence of samples was constructed. The data about the distance of the selection material will be used in the selection of pairs in heterotic breeding.     

气相色谱法检测辐照牛肉中的碳氢化合物

利用气相色谱法分析牛肉辐照前后碳氢化合物的类型与浓度差异,建立了一种能判别辐照牛肉的鉴定方法。本试验通过正己烷溶剂萃取,Florisil柱分离和气相色谱分析,对辐照牛肉产生的6种碳氢化合物进行了定性和定量分析。研究结果表明,牛肉经辐照处理后,显著产生1,7-C16:2(1,7-十六二烯),而在未辐照的牛肉中没有检测到,因而1,7-C16:2是鉴定牛肉是否经过辐照处理的最适合标志物。