皮肤细胞复合改性聚乳酸构建组织工程皮肤

目的:探讨以改性聚乳酸为细胞外基质网架构建组织工程皮肤的可行性。方法:采用盐溶法制备机械性能得到部分改进的聚乳酸多孔泡沫网架,向改进的聚乳酸网架接种真皮成纤维细胞和表皮角质形成细胞,以普通聚乳酸支架作为对照,构建组织工程皮肤。体外培养一周,对网架进行形态学观察。主要观察指标:①一般形态观察②组织学观察。结果:复层组织工程皮肤在结构上与正常皮肤相似,具有真皮、表皮双层结构。改性聚乳酸网架上有双层细胞生长,生长的细胞与网架接触,并且在其表面形成较为明显而连续的细胞层。随着培养时间的延长,发生了一系列变化:表皮部分细胞层数逐渐增多,真皮部分细胞也逐渐增多,并向表皮层深入,位于表皮与网架之间。结论:双醛淀粉作为良好的增柔剂在改善聚乳酸网架的机械性能的同时,也具有良好的细胞相容性,不影响细胞的生长增殖和代谢,可以进一步用作组织工程皮肤的支架材料。     

Cloning and characterization of PhPI9 involved in floral development from Phalaenopsis Orchid

In the attempt to discover new genes involved in the floral development in monoeotyledonousin species,we have cloned and characterized the homologous PISTALLATA-like (PI-like) gone from Phalaenopsis hybrid cultivar named PhPI9 (Phalaenopsis PI STILLATA # 9).The eDNA of PhPI9 has a fragment of 834 bp and has 60% identity with the PISTILATA from Arabidopsis.The deduced amino acid sequence of PhPI9 had the typical PI-motif.It also formed a subelade with other monoeot PI-type genes in phylogenetie analysis.Southern analysis showed that PhPI9 was present in the Phalaenopsis orchid genome as a single copy.Furthermore,it was expressed only in the lip of the Phalaenopsis flower and no expression was detected in vegetative organs.Thus,as a B-function MADS-box gone,PhP19 specifies floral organ identity in orchids.     

Correlation between haplotype of apolipoprotein B gene and natural longevity persons in Uygur Nationality

This paper investigated the correlation between polymorphisms and haplotypes in the apolipoprotein B (apoB) gene (SP-I/D, XbaI-RFLP, VNTR) and natural longevity persons among the Uygur people in Xin-jiang. For this purpose, 191 healthy Uygur individuals aged above 90 from Hetian area of Xinjiang were recruited, and another 53 persons aged 65—70 from the same nationality, the same region and with the same gender ratio, served as the control group. Genotyping was performed by PCR-SSP, PCR-RFLP and PCR-sequencing methods. Logistic regression analyses revealed that the frequencies of X X genotype, M and L alleles and the genetypes composed of M and L were significantly higher in the longevity group than in the control group. In haplotype analyses, we found that, in the long-lived people, the frequency of haplotypes composed of the X and M alleles was significantly higher whereas the frequency of haplotypes composed of the X- and S alleles was significantly lower (both P<0.05) I than those of their controls. These results indicated that the S allele, SS genotype and X -S, D-S, D-X -S haplotypes were the possible adverse factors, whereas the M, L alleles, X X , MM, ML, LL genotypes and I-X -M, X -M haplotypes were the possibe protective factors for the naturally long-lived Uygur people in China.     

Structure comparisons of Aedes albopictus densovirus with other parvoviruses

Parvoviridae is a family of the smallest viruses known with a wide variety of hosts. The capsid structure of the Aedes albopictus C6/36 cell densovirus (C6/36 DNV) at 1.2-nm resolution was obtained by elec-tron cryomicroscopy (cryoEM) and three-dimensional (3D) image reconstruction. Structure compari-sons between the C6/36 DNV and other parvoviruses reveal that the degree of structural similarity be-tween C6/36 DNV and the human parvovirus B19 is higher than that between C6/36 DNV and other in-sect parvoviruses. The amino acid sequence comparisons of structural and non-structural proteins also reveal higher levels of similarity between C6/36 DNV and parvovirus B19 than those between C6/36 DNV and other parvoviruses. These findings indicate that C6/36 DNV is closely related to the human virus B19, and the former might evolve from the human species other than from other insect viruses.     

Con A affinity glycoproteomics of normal human liver tissue

In order to establish the novel high throughput, high efficiency and Iow cost technological platform for the research of N-glycoproteomics, to resolve the significance of characteristic expression profile of glycoprotein and to find the proteins with biological functional importance, the glycoproteins with high-mannose core and the two antennary types were purified and enriched by the Con A affinity chromatography. Con A affinity protein expression profiles of normal human liver tissue were generated by using SDS-PAGE, two-dimensional electrophoresis (2-DE) followed by fast fluorescence staining based on multiplexed proteomics (MP) technology. 301 visible protein spots on the gel were detected and 85 of glycoproteins were further successfully identified via peptide mass fingerprinting (PMF) by a matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS/MS) and annotated to IPI databases. Identified glycoproteins definitely take part in the regulation of cell cycle and metabolic processes. The glycosylation sites were predicted with NetNGlyc 1.0 and NetOGlyc 3.1 software, meanwhile they were classified according to the geneontology methods. The construction of Con A affinity glycoprotein database of normal human liver tissue would contribute to the subsequent research.     

Mesozoic birds of China-a synoptic review

A synoptic review of the discoveries and studies of Chinese Mesozoic birds is provided in this paper.40Ar/39Ar dating of several bird-bearing deposits in the Jehol Group has established a geochronological framework for the study of the early avian radiation.Chinese Mesozoic birds had lasted for at least 11 Ma during about 131 Ma and 120 Ma (Barremian to Aptian)of the middle and late Early Cretaceous,respectively.In order to further evaluate the change of the avian diversity in the Jehol Biota,six new orders and families are erected based on known genera and species,which brings the total number of orders of Chinese Mesozoic birds to 15 and highlights a remarkable radiation ever since the first appearante of birds in the Late Jurassic.Chinese Early Cretaceous birds had experienced a significant differentiation in morphology,flight,diet and habitat.Further examination of the foot of Jeholornis suggests this bird might not have possessed a fully reversed hallux.However,the attachment of metatarsal Ⅰ to the medial side of metatarsal Ⅱ does not preclude trunk climbing,a pre-adaptation for well developed perching life of early birds.Arboreality had proved to be a key adaptation in the origin and early evolution of bird flight,and the adaptation to lakeshore environment had played an equally important role in the origin of omithurine birds and their near-modern flight skill.Many Chinese Early Cretaceous birds had preserved the direct evidence of their diet,showing that the most primitive birds were probably mainly insectivorous and that specialized herbivorous or carnivorous (e.g.,piscivorous)dietary adaptation had appeared only in later advanced forms.The only known Early Cretaceous bird embryo fossil has shown that precocial birds had occurred prior to altricial birds in avian history,and the size of the embryo and other analysis indicate it probably had a short incubation period.Leg feathers probably have a wide range of distribution in early birds,further suggesting that leg feathers had played a key role in the beginning stage of the flight of birds.Finally,the Early Cretaceous avian radiation can be better understood against the background of their unique ecosystem.The advantage of birds in the competitions with other vertebrate groups such as pterosaurs had probably not only resulted in the rapid differentiation and radiation of birds but also the worldwide spreading of pterosaurs and other vertebrates from East Asia in the Early Cretaceous.     

Novel N-(3-carboxyl-9-benzyl-carboline-1-yl)ethylamino acids: synthesis, anti-proliferation activity and two-step-course of intercalation with calf thymus DNA

To explore the intercalating mechanism of -carbolines, four novel N-(3-carboxyl-9-benzyl-carboline-1-yl)ethylamino acids [-phenylalanine (6a), -alanine (6b), -isoleucine (6c) and -glycine (6d)] were prepared here. Their in vitro anticancer activities were examined by their anti-proliferation for 5 human carcinoma cell lines. The average IC50s against 5 human carcinoma cell lines are 53.54 microM, 118.77 microM, 147.34 microM and greater than 291.63 microM for 6a, 6b, 6c and 6d, respectively. The DNA intercalating mechanism of 6a-d was approved by the comparison of the parameters and signals of UV, CD and fluorescence spectra of calf thymus DNA (CT DNA) alone and the CT DNA/6a-d system. Using fluorescence titration based kinetic analysis a two-step-course consisting of stacking and intercalating was described and the stacking was considered as the key step to the CT DNA intercalating mechanism of 6a-d. Using fluorescence titration based thermomechanical analysis, the stacking complexes of 6a-d with CT DNA were described to be formed spontaneously and to be stabilized predominantly by their hydrophobic interactions. The intercalation itself goes very fast and only has limited contribution to their anticancer activities.     

Organotypic culture of adult rabbit retina

Organotypic culture systems of functional neural tissues are important tools in neurobiological research. Ideally, such a system should be compatible with imaging techniques, genetic manipulation, and electrophysiological recording. Here we present a simple interphase tissue culture system for adult rabbit retina that requires no specialized equipment and very little maintenance. We demonstrate the dissection and incubation of rabbit retina and particle-mediated gene transfer of plasmids encoding GFP or a variety of subcellular markers into retinal ganglion cells. Rabbit retinas cultured this way can be kept alive for up to 6 days with very little changes of the overall anatomical structure or the morphology of individual ganglion- and amacrine cells.     

Two new antibacterial sesquiterpenoids from Centipeda minima

Two new guaiane-type sesquiterpene lactones, compounds 1 and 2, along with three known guaianolide- or pseudoguaianolides, were isolated from Centipeda minima (whole plant). Their structures were identified by spectroscopic and mass-spectrometric analyses. The configuration at C5 of the guaiane framework of 1 was rationalized by quantum-mechanical calculations (Table 2). All compounds were found to be active against eight different microbial pathogens (Table 3), with MIC values in the range of 6.25-100 microg/ml.     

A fundamental regulatory role of formate on thuringiensin production by resting cell of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> YBT-032

In this work, a fundamental regulatory role of formate on thuringiensin production by resting cell of Bacillus thuringiensis YBT-032 was investigated. Nicotinamide adenine dinucleotide (NADH) production and formate dehydrogenase activity increased with formate addition from 0.5 to 2.0 g/L, respectively. However, with the formate addition of 1.5 g/L, the activities of pyruvate kinase and glucose 6-phosphate dehydrogenase reached a peak and increased by 316 and 150% relative to those of the control, respectively. In addition, intracellular production of pyruvate, aspartate, citrate and adenine were significantly enhanced by 75, 66, 32 and 78% as well. An improvement (90%) of thuringiensin production was also successfully obtained. Interestingly to point out, thuringiensin yield was closely correlative with adenine production, and the linear relationship was also observed. The results suggest that appropriate formate addition did act as a modulator and facilitate carbon flux in glycolysis and pentose phosphate pathway to synthesize adenine and thuringiensin via intracellular NADH availability.