Up-regulated P21CIP1 expression is part of the regulation quantitatively controlling serum deprivation-induced apoptosis

Among the many genes which have been suggested to be required by the molecular mechanism dictating apoptotic death, some have been shown to function as pacemakers to pave the way for cells either to live or to die. Previously we have shown that immediate early gene expressions associated with the G₁ phase of cell cycle traverse are candidates for this function. Here we report that the well-known key regulator for halting cell cycling at the G₁/S border, the p21 protein known as WAF1, Cip1, Pic1, or Sdi1, is also involved in the execution of cells' suicidal death. p21 up-regulation is seen in quiescent mouse 3T3 fibroblasts stimulated to die by serum deprivation, at both message and protein levels, evidenced by increased protein presence in its targeted functional site, the nucleus. In addition, we show that this up-regulation of p21 is functionally related to the operational efficiency of the apoptotic process, in that when cells are stably transfected with an antisense construct to repress the endogenous p21-protein level, death is delayed. Quantitative protection from apoptosis with antisense p21 transfection is relatively proportional to the repressed level of this protein in the cells. Taken together, our results suggest that the apoptosis-dependent additional increase of p21 beyond the base level, seen in serum-deprived quiescent cells, may be involved in the molecular events precipitating a rapid program of cell demise, and that repression of this increase may obstruct the operation of this program and postpone the eventual death. J. Cell. Biochem. 64:434–446. © 1997 Wiley-Liss, Inc.     

Characterization of expressed sequence tag (EST)-derived microsatellite loci in the fire ant Solenopsis invicta (Hymenoptera: Formicidae)

The fire ant Solenopsis invicta has received considerable attention as a damaging invasive pest. In the present study, 12 polymorphic microsatellite loci were developed from publicly available expressed sequence tags (ESTs) of S. invicta. The number of alleles varied between 3 and 12, with an average of 6.42 per locus. The observed and expected heterozygosities ranged from 0.4167 to 1.0000 and from 0.3446 to 0.8543, respectively. These informative EST-derived microsatellite loci provide a powerful complementary tool for genetic studies of S. invicta.     

CRP、PCT、WBC联合检测对中老年社区获得性肺炎的诊断效果

目的:研究C反应蛋白(C-reactive protein,CRP)、降钙素原(Procalcitonin,PCT)以及白细胞(White blood cell,WBC)联合检测对中老年社区获得性肺炎患者的诊断效果。方法:选择2018年1月～2019年1月我院收治的76例中老年社区获得性肺炎患者为观察组,同期在我院体检中心选取30例健康体检者为对照组。检测两组研究对象的CRP、PCT及WBC水平。采取肺炎严重程度CURB-65评分将观察组的76例患者分为低危组(n=63例),CURB-65评分3分,以及高危组(n=13例),CURB-65评分≥3分;依照观察组的转归情况分为存活组(n=70例)以及死亡组(n=6例),比较观察组和对照组患者,低危组和高危组患者,存活组和死亡组患者的CRP、PCT及WBC水平的差异。结果:观察组患者的CRP、PCT及WBC水平明显高于对照组(P0.05);高危组患者的CRP、PCT水平明显高于低危组患者(P0.05),而WBC水平两组无明显差异(P0.05);死亡组患者的CRP、PCT水平明显高于存活组患者(P0.05),而WBC水平两组无明显差异(P0.05)。经Pearson相关分析发现,CURB-65评分与PCT、CRP均呈明显的正相关(t=0.532,0.497,P均0.05)。结论:CRP、PCT以及联合检测可以为中老年社区获得性肺炎的诊断提供有利的信息,且CRP、PCT与患者的病情严重程度有一定的相关性。     

囊瓣亮花木化学成分的研究（Ⅰ）

从番荔枝科亮花木属植物囊瓣亮花木(Phaeanthus saccopetaloides)中分得8个化合物,经光谱解析和理化常数测定,鉴定了其中3个化合物,分别为穆坪马兜铃酰胺,(-)-北美鹅掌楸脂素-C和胡萝卜甙,它们均为从该属植物中首次分得。     

能源作物续随子的综合利用和栽培

介绍续随子的药用价值,在工农业方面应用的价值,特别阐述续随子作为能源植物的应用前景,并对其繁殖栽培方法作了详细介绍。     

DNA自动测序技术进展

Ｄ Ｎ Ａ 测序是遗传工程的重要技术之一, Ｄ Ｎ Ａ 测序技术的自动化对遗传工程的研究具有重要意义。七十年代末期, Ｓａｎｇｅｒ 和 Ｍａｘａｍ 、 Ｇｉｌｂｅｒｔ分别提出了切实可行的 Ｄ Ｎ Ａ序列测定方法。近二十年来, Ｄ Ｎ Ａ 测序技术发展很快。人们从不同方面对该技术进行了改进,并将许多先进的光学探测方法应用于 Ｄ Ｎ Ａ 测序技术中。目前已出现了许多商品化的 Ｄ Ｎ Ａ 测序仪。     

Mutant plant viruses with cell binding motifs provide differential adhesion strengths and morphologies

The ability of Tobacco mosaic virus (TMV) to tolerate various amino acid insertions near its carboxy terminus is well-known. Typically these inserts are based on antigenic sequences for vaccine development with plant viruses as carriers. However, we determined that the structural symmetries and the size range of the viruses could also be modeled to mimic the extracellular matrix proteins by inserting cell-binding sequences to the virus coat protein. The extracellular matrix proteins play important roles in guiding cell adhesion, migration, proliferation, and stem cell differentiation. Previous studies with TMV demonstrated that the native and phosphate-modified virus particles enhanced stem cell differentiation toward bone-like tissues. Based on these studies, we sought to design and screen multiple genetically modified TMV mutants with reported cell adhesion sequences to expand the virus-based tools for cell studies. Here, we report the design of these mutants with cell binding amino acid motifs derived from several proteins, the stabilities of the mutants against proteases during purification and storage, and a simple and rapid functional assay to quantitatively determine adhesion strengths by centrifugal adhesion assay. Among the mutants, we found that cells on TMV expressing RGD motifs formed filopodial extensions with weaker attachment profiles, whereas the cells on TMV expressing collagen I mimetic sequence displayed little spreading but higher attachment strengths.     

An approach to bioassess pelagic ciliate biodiversity at different taxonomic resolutions in response to various habitats in the Amundsen Sea (Antarctica)

The rapid melting of glaciers and loss of sea ice will result in changes in habitat conditions that may drive substantial changes in biodiversity. In order to bioassess the changing polar ecosystem and evaluate biological conservation, pelagic ciliate communities at different taxonomic resolutions were studied at five habitats in the Amundsen Sea during the austral summer from December 2010 to January 2011. Distinctive spatial patterns were observed in the communities among the five habitats (oceanic areas, transitional areas, polynyas, edges of glaciers, and edges of sea ice) in response to environmental variability (e.g., temperature, salinity, chlorophyll a, and nutrients). The distributions in the numbers of different taxonomic levels and of three biodiversity indices (Shannon-Wiener H′, Pielou’s J′, and Margalef D) also revealed clear spatial variability with the maximum mean species number and indices in the polynya and maximum genus and family numbers in the transitional area. The presence/absence of data at taxonomic resolutions up to the family level provided sufficient information to evaluate the ecological patterns of pelagic ciliate communities and could accurately reflect habitat variations. The k-dominance curves illustrated clearly that maximum diversity was presented in the polynya at the species level and in the transitional area at the genus and family level. We suggest that the diversity at higher taxonomic resolutions should be considered more in future monitoring. Our findings provide basic data and an approach toward answering important questions about biological conservation, especially the biodiversity at various taxonomic resolutions in response to the increasing climate changes in polar ecosystems.