The Effect of Long-Term Continuous Cropping of Black Pepper on Soil Bacterial Communities as Determined by 454 Pyrosequencing

In the present study, 3 replanted black pepper orchards with continuously cropping histories for 10, 21, and 55 years in tropical China, were selected for investigating the effect of monoculture on soil physiochemical properties, enzyme activities, bacterial abundance, and bacterial community structures. Results showed long-term continuous cropping led to a significant decline in soil pH, organic matter contents, enzymatic activities, and resulted in a decrease in soil bacterial abundance. 454 pyrosequencing analysis of 16S rRNA genes revealed that the Acidobacteria and Proteobacteria were the main phyla in the replanted black pepper orchard soils, comprising up to 73.82% of the total sequences; the relative abundances of Bacteroidetes and Firmicutes phyla decreased with long-term continuous cropping; and at genus level, the Pseudomonas abundance significantly depleted after 21 years continuous cropping. In addition, bacterial diversity significantly decreased after 55 years black pepper continuous cropping; obvious variations for community structures across the 3 time-scale replanted black pepper orchards were observed, suggesting monoculture duration was the major determinant for bacterial community structure. Overall, continuous cropping during black pepper cultivation led to a significant decline in soil pH, organic matter contents, enzymatic activities, resulted a decrease in soil bacterial abundance, and altered soil microbial community membership and structure, which in turn resulted in black pepper poor growth in the continuous cropping system.     

同工酶研究在嗜热脂肪芽孢杆菌分类中的应用

嗜热脂肪芽孢杆菌是一个尚未被严格定义的种,它几乎包括芽孢杆菌属内所有能在65℃以上生长的细菌。用聚丙烯酰胺凝胶电泳的方法对151株嗜热脂肪芽孢杆菌的9种酶(G6PDH、LDH、MDH、IDH、AlaDH、LeuDH、过氧化氢酶、过氧化物酶、酯酶)的酶谱进行测定分析。根据其酶谱的差异,可将151株菌株分成两个类型。两型之间8个酶的13或14个基因产物的相异度约为91.8％,两型间的标准遗传距离是2.55。因此这两种类型的细菌也许可以被看作为两个不同的种。     

类风湿关节炎的关节滑膜病理生理机制

类风湿关节灸(rheumatoid arthritis,RA)的主要病理特点是滑膜细胞增生,衬里层增厚,多种炎性细胞浸润,血管留形成等,这种病理改变是多种因素共同作用的结果。本文从基因突变、原癌基因活化、滑膜细胞演变、炎性细胞浸润,以及信号转导等方面,阐述其关节滑膜病理生理机制。     

山羊关节炎─脑炎前病毒的PCR检测

山羊关节炎─脑炎前病毒的ＰＣＲ检测相文华,丁恩雨,秦运安,吕晓玲,沈荣显（中国农业科学院哈尔滨兽医研究所哈尔滨１５０００１）关键词聚合酶链反应,山羊关节炎—脑炎病毒,整合山羊关节炎—脑炎（ＣａｐｒｉｎｅＡｒｔｈｒｉｔｉｓ－Ｅｎｃｅｐｈａｌｉｔｉｓ,Ｃ...     

Clonal immune responses of Mycobacterium-specific γδ T cells in tuberculous and non-tuberculous tissues during M. tuberculosis infection

Background

We previously demonstrated that unvaccinated macaques infected with large-dose M.tuberculosis(Mtb) exhibited delays for pulmonary trafficking of Ag-specific αβ and γδ T effector cells, and developed severe lung tuberculosis(TB) and “secondary” Mtb infection in remote organs such as liver and kidney. Despite delays in lungs, local immunity in remote organs may accumulate since progressive immune activation after pulmonary Mtb infection may allow IFNγ-producing γδ T cells to adequately develop and traffic to lately-infected remote organs. As initial efforts to test this hypothesis, we comparatively examined TCR repertoire/clonality, tissue trafficking and effector function of Vγ2Vδ2 T cells in lung with severe TB and in liver/kidney without apparent TB.

Methodology/Principal Findings

We utilized conventional infection-immunity approaches in macaque TB model, and employed our decades-long expertise for TCR repertoire analyses. TCR repertoires in Vγ2Vδ2 T-cell subpopulation were broad during primary Mtb infection as most TCR clones found in lymphoid system, lung, kidney and liver were distinct. Polyclonally-expanded Vγ2Vδ2 T-cell clones from lymphoid tissues appeared to distribute and localize in lung TB granuloms at the endpoint after Mtb infection by aerosol. Interestingly, some TCR clones appeared to be more predominant than others in lymphocytes from liver or kidney without apparent TB lesions. TCR CDR3 spetratyping revealed such clonal dominance, and the clonal dominance of expanded Vγ2Vδ2 T cells in kidney/liver tissues was associated with undetectable or low-level TB burdens. Furthermore, Vγ2Vδ2 T cells from tissue compartments could mount effector function for producing anti-mycobacterium cytokine.

Conclusion

We were the first to demonstrate clonal immune responses of mycobacterium-specific Vγ2Vδ2 T cells in the lymphoid system, heavily-infected lungs and lately subtly-infected kidneys or livers during primary Mtb infection. While clonally-expanded Vγ2Vδ2 T cells accumulated in lately-infected kidneys/livers without apparent TB lesions, TB burdens or lesions appeared to impact TCR repertoires and tissue trafficking patterns of activated Vγ2Vδ2 T cells.     

Silencing of FABP3 promotes apoptosis and induces mitochondrion impairment in embryonic carcinoma cells

Fatty acid binding protein 3 (FABP3) (also known as H-FABP) is a member of the intracellular lipid-binding protein family, and is mainly expressed in cardiac muscle tissue. The in vivo function of FABP3 is proposed to be in fatty acid metabolism, trafficking, and cell signaling. Our previous study found that FABP3 is highly regulated in patients with ventricular septal defect (VSD), and may play a significant role in the development of human VSD. In the present study, we aimed to investigate the impact of FABP3 knockdown by RNA interference (RNAi) on apoptosis and mitochondrial function of embryonic carcinoma (P19) cells. The results revealed that downregulated FABP3 expression promoted apoptosis, and resulted in mitochondrial deformation, increased mitochondrial membrane potential (MMP), and decreased intracellular ATP synthesis. In addition, the knockdown of FABP3 also led to excess intracellular ROS production. However, there was no obvious influence on the amount of mitochondrial DNA. Collectively, our results indicated that FABP3 knockdown promoted apoptosis and caused mitochondrial dysfunction in P19 cells, which might be responsible for the development of human VSD.     

Subgroup economic analysis for glioblastoma in a health resource-limited setting

Background

The aim of this research was to evaluate the economic outcomes of radiotherapy (RT), temozolomide (TMZ) and nitrosourea (NT) strategies for glioblastoma patients with different prognostic factors.

Methodology/Principal Findings

A Markov model was developed to track monthly patient transitions. Transition probabilities and utilities were derived primarily from published reports. Costs were estimated from the perspective of the Chinese healthcare system. The survival data with different prognostic factors were simulated using Weibull survival models. Costs over a 5-year period and quality-adjusted life years (QALYs) were estimated. Probabilistic sensitivity and one-way analyses were performed. The baseline analysis in the overall cohort showed that the TMZ strategy increased the cost and QALY relative to the RT strategy by $25,328.4 and 0.29, respectively; and the TMZ strategy increased the cost and QALY relative to the NT strategy by $23,906.5 and 0.25, respectively. Therefore, the incremental cost effectiveness ratio (ICER) per additional QALY of the TMZ strategy, relative to the RT strategy and the NT strategy, amounts to $87,940.6 and $94,968.3, respectively. Subgroups with more favorable prognostic factors achieved more health benefits with improved ICERs. Probabilistic sensitivity analyses confirmed that the TMZ strategy was not cost-effective. In general, the results were most sensitive to the cost of TMZ, which indicates that better outcomes could be achieved by decreasing the cost of TMZ.

Conclusions/Significance

In health resource-limited settings, TMZ is not a cost-effective option for glioblastoma patients. Selecting patients with more favorable prognostic factors increases the likelihood of cost-effectiveness.     

Habitat loss other than fragmentation per se decreased nuclear and chloroplast genetic diversity in a monoecious tree

Generally, effect of fragmentation per se on biodiversity has not been separated from the effect of habitat loss. In this paper, using nDNA and cpDNA SSRs, we studied genetic diversity of Castanopsis sclerophylla (Lindl. & Paxton) Schotty populations and decoupled the effects of habitat loss and fragmentation per se. We selected seven nuclear and six cpDNA microsatellite loci and genotyped 460 individuals from mainland and island populations, which were located in the impoundment created in 1959. Number of alleles per locus of populations in larger habitats was significantly higher than that in smaller habitats. There was a significant relationship between the number of alleles per locus and habitat size. Based on this relationship, the predicted genetic diversity of an imaginary population of size equaling the total area of the islands was lower than that of the global population on the islands. Re-sampling demonstrated that low genetic diversity of populations in small habitats was caused by unevenness in sample size. Fisher's α index was similar among habitat types. These results indicate that the decreased nuclear and chloroplast genetic diversity of populations in smaller habitats was mainly caused by habitat loss. For nuclear and chloroplast microsatellite loci, values of F(ST) were 0.066 and 0.893, respectively, and the calculated pollen/seed dispersal ratio was 162.2. When separated into pre-and post-fragmentation cohorts, pollen/seed ratios were 121.2 and 189.5, respectively. Our results suggest that habitat loss explains the early decrease in genetic diversity, while fragmentation per se may play a major role in inbreeding and differentiation among fragmented populations and later loss of genetic diversity.     

中国特有珍稀濒危植物猪血木的研究进展

对我国特有珍稀濒危植物猪血木的分类地位、资源现状及分布、生物学和生态学特性、发育生物学、保护遗传学、繁殖生物学、和濒危机制进行了综述,为该物种的种群恢复研究提供了参考.     

Identification of the gene imds-60 in mouse epididymis

Sperm maturation, including the acquisition of motility and the full ability to fertilize oocyte, occurs during its transit through the dynamic environment of the epididymis. However, the roles of many genes involved in the process of sperm maturation still remain to be found. Based on an expressed sequence tag named imds-60, which was first found in uterus but is highly expressed in epididymis, the full-length cDNA sequence of imds-60 with a complete open reading frame was obtained in mouse epididymis by GenBank searching, polymerase chain reaction-based procedures, and 5＇- and 3＇-rapid amplification of cDNA ends. This protein was predicted to have an N-terminal signal peptide and a C-terminal DNase I-like domain with nine transmembrane motifs in the middle part of the protein. Northern blot analysis showed that the mRNA of imds-60 was highly expressed in epididymis but at a rather lower level in uterus, seminal vesicle gland, and stomach. Further study revealed that the mRNA of imds-60 is only expressed in corpus and cauda regions of epididymis, not in caput. It is regulated partially by androgen and peaked in male mice aged from 3 weeks to adult. The imds-60 protein might play an important role in cell communication during sperm maturation.