高危型HPV-DNA检测对宫颈病变的诊断价值

目的:评价高危型人类乳头瘤病毒(high-risk human papilloma virus,HR-HPV)DNA检测对宫颈病变的诊断价值.方法:对门诊450例细胞学异常的患者,采用杂交捕获试验法(Hybrid Capture Ⅱ,HCⅡ)检测HR-HPV-DNA,并行阴道镜检查.结果:细胞学诊断中非典型鳞状细胞332例,低度鳞状上皮内病变87例,高度鳞状上皮内病变31例,HPV-DNA阳性率分别为30.7%(102/332),44.8%(39/87),90.3%(28/31);病理学诊断中无上皮内病变或恶性病变、子宫颈上皮瘤(cervical intra-qaithelial neoplasia,CIN)Ⅰ/Ⅱ、CIN Ⅲ和原位癌HPV-DNA阳性率分别为31.2%(73/219)、47.3%(96/203)、100%(28/28),随细胞学检查的级别增高,HPV-DNA高危型阳性率增加(P＜0.05).结论:高危型HPV-DNA检测是宫颈癌筛查的有效方法,建议临床推广应用.     

乙烯对网纹甜瓜花器官及花粉结构和活力的影响

以网纹甜瓜‘西域1号'为材料,于幼苗三叶一心期喷施浓度为150 mg/L的乙烯利诱导主蔓形成两性花,以清水为对照,比较乙烯处理后形成的主蔓、侧蔓和对照侧蔓两性花,以及处理与对照雄花外观形态、解剖结构及花粉表面超微结构间的异同,并对其花粉活力进行了测定,以明确乙烯对甜瓜花器官形态及花粉结构和活力的影响.结果表明:乙烯诱导形成的主蔓两性花外观形态和解剖结构与对照侧蔓两性花没有差异,花粉超微结构相似,但存在部分畸形花粉,花粉活力仅为70%左右,显著低于其他花粉的活力,但其雌蕊发育正常,授粉后可正常结实.研究证实,乙烯处理对主蔓雄花及侧蔓两性花器官形态及花粉结构和活力无显著影响.     

Harvesting and cryopreservation of lymphatic endothelial cells for lymphatic tissue engineering

In order to provide a suitable source of cells for lymphatic tissue engineering, the present study was designed to investigate techniques for harvesting and cryopreservation of human dermal lymphatic endothelial cells (LECs) in vitro. The LECs were isolated from children’s foreskins and then cultured in endothelial growth medium-2 MV (EGM-2-MV) with 5% FBS. The second passage LECs were suspended in cryopreservation solution containing 40% FBS and 10% Me₂SO in EGM-2-MV, cooled to −80 °C at about 1 °C/min and stored in liquid nitrogen. Samples were thawed quickly in a 37 °C water bath, and the cryoprotectant was removed by serial elution. The membrane integrity of thawed LECs was determined by trypan blue staining exclusion, and their proliferation was evaluated using the MTT method. The expanded cells of two groups were identified using immunofluorescence staining and RT-PCR with lymphatic-specific markers such as Podoplanin and VEGFR-3. Uptake of fluorescent DiI-Ac-LDL and microtubular formation in three-dimensional cultures were used to detect the function of LECs. Flow cytometry was applied to identify cells and to measure the apoptosis rate as well. Cryopreservation resulted in a retrieval of 67 ± 4% and an intact cell rate of 80 ± 3%. The early apoptosis rate of thawed LECs (9.15 ± 0.34%) was higher than that of fresh control LECs (5.31 ± 0.23%). The growth curves of thawed LECs were similar to those of fresh LECs. The thawed LECs were propagated for at least 6-7 passages without alterations in phenotype and function. Highly purified LECs can be isolated by immunomagnetic beads from human dermis. The cryopreserved/thawed and recultivated LECs are proven to have high vitality and growth potential in vitro and may be considered suitable seed cells for lymphatic tissue engineering.     

Bioaccumulation and Biovolatilisation of Pentavalent Arsenic by Penicillin janthinellum, Fusarium oxysporum and Trichoderma asperellum Under Laboratory Conditions

Some fungi are able to control and remediate arsenic (As)-contaminated soil, sediment, or water. Here, we investigate potential accumulation and volatilisation of As by three fungi strains. Results indicated that the highest level of As was accumulated by Penicillin janthinellum with 39.54 μg after 10 days in the culture system amended with 2,500 μg As(V), which represents 50 mg/l As. Fusarium oxysporum showed the highest amount of volatilised As with 304.06 μg after 15 days. The As content in the treated system (filter paper + As + fungi) was significantly higher than that in the control (filter paper + As; filter paper + fungi; filter paper). Trichoderma asperellum and F. oxysporum showed superior abilities for the absorption of extracellular As and accumulation of intracellular As, which accounted for 82.2 and 63.4% of the total accumulated As, respectively. However, P. janthinellum presented an equal distribution of intracellular and extracellular As. Scanning electron microscope (SEM) analysis suggested that little impact on mycelium growth of the three fungal strains was seen after exposure to 50 mg/l As(V) for 5 days, while the growth of fungi in the control was inhibited. The present results demonstrate that P. janthinellum, F. oxysporum, and T. asperellum would be expected to tackle As-contaminated environments.     

New syntax to describe local continuous structure-sequence information for recognizing new pre-miRNAs

As an important complement to experimental identification of pre-miRNA, computational prediction methods are attracting more and more attention. Features extracted from pre-miRNA are the key to computational prediction. Among the features, local continuous structure-sequence information is usually employed by existing computational methods. As more and more species-specific miRNAs have been identified, a new syntax is required to describe pre-miRNA local continuous structure-sequence features. Therefore, we proposed here the use of couplet syntax to describe pre-miRNA intrinsic features. When tested on a dataset from miRBase12.0 with the use of features extracted by couplet syntax, the SVM classifier achieves a sensitivity of 81.98% and specificity of 87.16% on a human test set and a sensitivity of 86.71% on all other species. The obtained results indicate that the proposed couplet syntax can describe the intrinsic features of pre-miRNA better than traditional methods. By means of describing pre-miRNA secondary structure more precisely and masking frequently mutated nucleotides, couplet syntax provides a powerful feature-describing method that can be applied to many computational prediction methods.     

Efficient production of lactic acid from sucrose and corncob hydrolysate by a newly isolated <Emphasis Type="Italic">Rhizopus oryzae</Emphasis> GY18

The aim of this study is to investigate production of l-lactic acid from sucrose and corncob hydrolysate by the newly isolated R. oryzae GY18. R. oryzae GY18 was capable of utilizing sucrose as a sole source, producing 97.5 g l⁻¹ l-lactic acid from 120 g l⁻¹ sucrose. In addition, the strain was also efficiently able to utilize glucose and/or xylose to produce high yields of l-lactic acid. It was capable of producing up to 115 and 54.2 g l⁻¹ lactic acid with yields of up to 0.81 g g⁻¹ glucose and 0.90 g g⁻¹ xylose, respectively. Corncob hydrolysates obtained by dilute acid hydrolysis and enzymatic hydrolysis of the cellulose-enriched residue were used for lactic acid production by R. oryzae GY18. A yield of 355 g lactic acid per kg corncobs was obtained after 72 h incubation. Therefore, sucrose and corncobs could serve as potential sources of raw materials for efficient production of lactic acid by R. oryzae GY18.     

Thirty allele-level haplotypes centered around KIR2DL5 define the diversity in an African American population

KIR2DL5 alleles were physically linked to alleles at adjacent KIR loci to define this region of KIR haplotypes in 55 gene-positive random African Americans. The majority carried KIR2DL5B. Three KIR2DL5A and six KIR2DL5B alleles that have been previously described and 11 novel KIR2DL5 alleles were identified by DNA sequencing. Novel alleles included variation that may impact promoter activity; two alleles carried nonsynonymous coding region variation. Based on linkage with KIR2DS1, KIR2DS3, KIR2DS5, KIR2DL2, KIR2DL3, and KIR3DS1 alleles, seven haplotypes of KIR2DL5A and 23 haplotypes of KIR2DL5B were observed. The phylogenetic relationships among the KIR2DL5 alleles predicted their association with either KIR2DS3 (six alleles) or KIR2DS5 (seven alleles). All of the KIR2DL5A alleles were linked either to KIR3DS1*01301 or KIR3DS1*049N. The majority of the KIR2DL5B alleles were linked to seven KIR2DL2 alleles; two were linked to a novel allele of KIR2DL3. These findings underscore the diversity of KIR haplotypes present in this population.     

Mimotopes selected with a neutralizing antibody against urease B from <Emphasis Type="Italic">Helicobacter pylori</Emphasis>induce enzyme inhibitory antibodies in mice upon vaccination

Background  

Urease B is an important virulence factor that is required for Helicobacter pylori to colonise the gastric mucosa. Mouse monoclonal antibodies (mAbs) that inhibit urease B enzymatic activity will be useful as vaccines for the prevention and treatment of H. pylori infection. Here, we produced murine mAbs against urease B that neutralize the enzyme's activity. We mapped their epitopes by phage display libraries and investigated the immunogenicity of the selected mimotopes in vivo.     

Cloning and characterization of the ddsA gene encoding decaprenyl diphosphate synthase from Rhodobacter capsulatus B10

A decaprenyl diphosphate synthase gene (ddsA, GenBank accession No. DQ191802) was cloned from Rhodobacter capsulatus B10 by constructing and screening the genome library. An open reading frame of 1002 bp was revealed from sequence analysis. The deduced polypeptide consisted of 333 amino acids residues with an molecular mass of about 37 kDa. The DdsA protein contained the conserved amino acid sequence (DDXXD) of E-type polyprenyl diphosphate synthase and showed high similarity to others. In contrast, DdsA showed only 39% identity to a solanesyl diphosphate synthase cloned from R. capsulatus SB1003. DdsA was expressed successfully in Escherichia coli. Assaying the enzyme in vivo found it made E.coli synthesize UQ-10 in addition to the endogenous production UQ-8.     

Genotypic characteristics of the rrn operon and genome of indigenous soybean Bradyrhizobia in cropping zones of China

Four genetic assays, 16S rRNA restriction fragment length polymorphism (RFLP), 16S rRNA sequencing, 16S-23S rRNA intergenetic spacer (IGS) RFLP, and amplified fragment length polymorphism (AFLP), were conducted to determine the genotypic characteristics of 44 indigenous strains of Bradyrhizobium from soybean (Glycine max L.) cropping zones of China. The results generated from different assays showed that soybean bradyrhizobial isolates comprised four genomic groups. Group I was composed of strains mainly isolated from the North and Northeast plains of China. All four assays confirmed this group as phylogenetically divergent from all the reference strains. Strains of the group may represent a new species. Strains in Group II isolated from a variety of geographic regions were ascribed to B. liaoningense. Strains in Group III, mainly isolated from Central and East China, were closely related to the reference strains of B. japonicum. Strains in Group IV belonged to B. elkanii.