辽宁三角洲区域生态经济分区及其功能分析

应用主成分分析和系统聚类分析方法,将辽河三角洲划分为３个生态经济区和８个生态经济小区．通过对反映系统功能的３个表现属性的分析,评价了辽河三角洲农业生态经济系统的功能状况．     

Homologous recombination of monkey alpha-satellite repeats in an in vitro simian virus 40 replication system: possible association of recombination with DNA replication.

To study homologous recombination between repeated sequences in an in vitro simian virus 40 (SV40) replication system, we constructed a series of substrate DNAs that contain two identical fragments of monkey alpha-satellite repeats. Together with the SV40-pBR322 composite vector encoding Apr and Kmr, the DNAs also contain the Escherichia coli galactokinase gene (galK) positioned between two alpha-satellite fragments. The alpha-satellite sequence used consists of multiple units of tandem 172-bp sequences which differ by microheterogeneity. The substrate DNAs were incubated in an in vitro SV40 DNA replication system and used to transform the E. coli galK strain DH10B after digestion with DpnI. The number of E. coli galK Apr Kmr colonies which contain recombinant DNAs were determined, and their structures were analyzed. Products of equal and unequal crossovers between identical 172-bp sequences and between similar but not identical (homeologous) 172-bp sequences, respectively, were detected, although those of the equal crossover were predominant among all of the galK mutant recombinants. Similar products were also observed in the in vivo experiments with COS1 cells. The in vitro experiments showed that these recombinations were dependent on the presence of both the SV40 origin of DNA replication and SV40 large T antigen. Most of the recombinant DNAs were generated from newly synthesized DpnI-resistant DNAs. These results suggest that the homologous recombination observed in this SV40 system is associated with DNA replication and is suppressed by mismatches in heteroduplexes formed between similar but not identical sequences.     

Microbial transformation of sucrose and glucose to erythritol

Summary Two strains of osmophilic yeast which were isolated from honey-comb, produced good yields of erythritol as a main product. These strains were identified as Trichosporonoides sp., 150-5 and 331-1.From the fermentation studies with these strains using glucose and sucrose as substrate, strain 331-1 produced more erythritol as the sole polyhydric product,with trace quantities of glycerol, than strain 150-5.     

人──板系统最佳蹬伸动作的控制模型及数值分析

本文基于Hanavan模型和人体测量学参数,以人体各环节间的相对运动作为控制量,建立了人-板系统中起跳蹬伸动作的数学模型,给出了模型的数值计算方法,在此基础上给出了实现最佳蹬伸用力过程的计算实验途径与运动技术诊断方法。     

Polymorphic microsatellites and Wilson disease (WD)

Wilson disease (WD), an autosomal recessive disorder of copper metabolism, has been previously mapped to chromosome 13q. Highly informative PCR-based polymorphic microsatellites closely linked to the WD locus (WND) at 13q14.3, as well as sequence-tagged sites for closely linked loci, are described. Two polymorphic microsatellite markers at D13S118 and D13S119 lie within 3 cM of WND. Two others (D13S227 and D13S228) were derived from a yeast artificial chromosome containing D13S31. These were placed on a genetic linkage map of chromosome 13 and were typed in 74 multiplex WD families from a variety of geographic origins (166 affected members). Multipoint analysis provides very high odds that the location of WND is between D13S31/D13S227/D13S228 and D13S59. Previous odds with RFLP-based markers were only 7:1 more likely than any other location. Current odds are 5,000:1. Preclinical testing of three cases of WD by using the highly informative polymorphic microsatellite markers is described. The markers described here ensure that 95% of predictive tests using DNA from both parents and from at least one affected sib will have an accuracy >99%.     

Dieckol,a natural polyphenolic drug,inhibits the proliferation and migration of colon cancer cells by inhibiting PI3K,AKT, and mTOR phosphorylation

This study investigated that dieckol (DKL), a natural drug, inhibits colon cancer cell proliferation and migration by inhibiting phosphoinositide-3-kinase (PI3K), protein kinase B (AKT), and mammalian target of rapamycin (mTOR) phosphorylation in HCT-116 cells. The cells were treated with DKL in various concentrations (32 and 50 μM) for 24 h and then analyzed for various experiments. MTT (tetrazolium bromide) and crystal violet assay investigated DKL-mediated cytotoxicity. Dichlorodihydrofluorescein diacetate staining was used to assess the reactive oxygen species (ROS) measurement, and apoptotic changes were studied by dual acridine orange and ethidium bromide staining. Protein expression of cell survival, cell cycle, proliferation, and apoptosis protein was evaluated by western blot analysis. Results indicated that DKL produces significant cytotoxicity in HCT-116, and the half-maximal inhibitory concentration was found to be 32 μM for 24-h incubation. Moreover, effective production of ROS and enhanced apoptotic signs were observed upon DKL treatment in HCT-116. DKL induces the expression of phosphorylated PI3K, AKT, and mToR-associated enhanced expression of cyclin-D1, proliferating cell nuclear antigen, cyclin-dependent kinase (CDK)-4, CDK-6, and Bcl-2 in HCT-116. In addition, proapoptotic proteins such as Bax, caspase-9, and caspase-3 were significantly enhanced by DKL treatment in HCT-116. Hence, DKL has been considered a chemotherapeutic drug by impeding the expression of PI3K-, AKT-, and mTOR-mediated inhibition of proliferation and cell cycle-regulating proteins.     

Recognition of the Qa-2k tumor antigen by T cell receptor γ/δ of an immunopotentiator-induced tumoricidal T cell of mice

Tumor-specific expression of Qa-2^k antigen coded by the Q5^k gene on various mouse tumor cells and immunological response of the host mice to the antigen have been demonstrated [Seo et al. (1992) J Exp Med 175: 547; Tanino et al. (1992) Cancer Immunol Immunother 35: 230]. The possibility was examined that Qa-2 antigen is one of the recognition target molecules of immunopotentiator-induced, H-2-nonrestricted tumoricidal lymphocytes of Qa-2^– mice. Lymphocytes stimulated in vivo withP. acnes or culture-induced anomalous killers of B6.K1 mice did not exhibit significant in vitro cytotoxicity against B6.K1 lymphoblasts but lysed their Qa-2,3-congenic counterpart B6 lymphoblasts. To demonstrate the Qa-2 specificity of such cytotoxic cells more precisely, an L cell transformant clone (L^Q7b/Kb), which expressed the 1 and 2 domains of the Qa-2 antigen (Q7^b gene product), was generated by transfecting a cloned plasmid DNA containing a hybrid gene constructed from the 5 half of the Q7^b gene and the 3 half of the H-2K^b gene (pQ7^b/K^b). Using L^Q7b/Kb cells as the target cells and the nylon-wool-nonadherent fraction of lymphocytes fromP. acnes-stimulated (C3H/He × B6.K1)F1 mice (H-2^k, Qa-2^–) as the effector cells of the in vitro cytotoxicity reaction, the presence of cytotoxic cells that recognize the 1/2 region of the Q7^b gene product was demonstrated. The cytotoxic activity was dependent on T cells bearing T cell receptors of the / type (TCR/). The (C3H/He × B6.K1)F1 effector cells, as well as the B6.K1 effector cells also lysed BW5147 lymphoma cells (Qa-2^k+) derived from AKR mice (Qa-2^–, H-2^k). By target-competition experiments it was shown that some of the effector cells lytic to BW5147 were identical to those that lysed L^Q7b/Kb. Therefore some of the tumoricidal cells induced by the immunopotentiator interact with the target tumor cells through recognition of the 1/2 region of the Qa-2^k tumor antigen by TCR/.     

嗜黏蛋白阿克曼氏菌治疗疾病的潜力与作用机制研究进展

嗜黏蛋白阿克曼氏菌(Akkermansia muciniphila, AKK)可促进肠道黏液分泌,维持肠道黏液动态平衡,调节肠黏膜屏障功能,在机体代谢调节、免疫应答中发挥重要作用。AKK对肠道炎症、神经炎症、机体代谢紊乱和癌症等疾病具有显著改善作用,被视为极具潜力的下一代益生菌。本文分别从消化系统、神经系统、代谢性紊乱和癌症等角度入手,系统概述AKK在疾病治疗中的潜力及作用分子机制。