小麦—中间偃麦草抗条锈衍生系的分子细胞遗传学研究

应用缺体回交法,以部分阿勃缺体为母本,中4为父本,培育出1个对目前条锈病优势小种和新小种高抗至免疫的小麦－－中间偃麦草衍生系N9025－3－3－2－1－1。研究表明,该选系在形态学和细胞学上已经基本稳定,染色体构型为2n=42=21“,抗病性来自中间偃麦草（Thinopyron intermedium）。以中间偃麦草DNA为探针,对N9025－3－3－2－1－1进行基因组原位杂交分析结果证明,它为小麦－中间偃麦草异代换－易位系。     

Identification of Hox Gene Sequences in the Sea Cucumber Holothuria glaberrima Selenka (Holothuroidea: Echinodermata)

The Echinodermata is a unique animal group forming an early branch in the deuterostomes phylogenetic tree. In echinoids and asteroids a single Hox cluster with nine cognates of the vertebrate Hox paralogous groups has been reported, but no data are available from other echinoderm classes. We report here nine Hox-type sequences from the sea cucumber Holothuria glaberrima, a member of the class Holothuroidea. Partial homeodomain sequences were amplified by polymerase chain reaction from genomic DNA and from a regenerating gastrointestinal tract complementary DNA library. Sequence analyses suggest that the holothuroid cluster has at least three genes of the anterior, one of the medial, and five of the posterior groups. This is the first evidence of five posterior sequences in echinoderms. Received July 19, 1999; accepted October 18, 1999.     

Liver stem cells: a two compartment system

Hepatocytes and biliary epithelia are phenotypically very dissimilar, but share a common ancestry. Hepatocytes regenerate very efficiently, and their division potential indicates that many of them are functional stem cells. When hepatocyte-damaging agents also impair the regenerative ability of surviving hepatocytes, a potential stem cell system of biliary origin is activated to generate new hepatocytes — a reversal of ontogeny. Now both bile duct derived cells and hepatocytes can be isolated from the liver, genetically modified in vitro and returned to their in vivo origins where, after considerable population expansion, they can function as hepatocytes — paving the way for ex vivo gene therapy.     

A biomimetic strategy in the synthesis and fragmentation of cyclic protein.

This paper describes a simple biomimetic strategy to prepare small cyclic proteins containing multiple disulfide bonds. Our strategy involves intramolecular acyl transfer reactions to assist both the synthesis and fragmentation of these highly constrained cyclic structures in aqueous solution. To illustrate our strategy, we synthesized the naturally occurring circulin B and cyclopsychotride (CPT), both consisting of 31 amino acid residues tightly packed in a cystine-knot motif with three disulfide bonds and an end-to-end cyclic form. The synthesis of these small cyclic proteins can be achieved by orthogonal ligation of free peptide thioester via the thia zip reaction, which involves a series of reversible thiol-thiolactone exchanges to arrive at an alpha-amino thiolactone, which then undergoes an irreversible, spontaneous ring contraction through an S,N-acyl migration to form the cyclic protein. A two-step disulfide formation strategy is employed for obtaining the desired disulfide-paired products. Partial acid hydrolysis through intramolecular acyl transfer of X-Ser, X-Thr, Asp-X, and Glu-X sequences is used to obtain the assignment of the circulins disulfide bond connectives. Both synthetic circulin B and CPT are identical to the natural products and, thus, the total synthesis confirms the disulfide connectivity of circulin B and CPT contain a cystine-knot motif of 1-4, 2-5, and 3-6. In general, our strategy, based on the convergence of chemical proteolysis and aminolysis of peptide bonds through acyl transfer, is biomimetic and provides a useful approach for the synthesis and characterization of large end-to-end cyclic peptides and small proteins.     

Variation in sclerophylly among Iberian populations of Quercus coccifera L. is associated with genetic differentiation across contrasting environments

Evergreen oaks are an emblematic element of the Mediterranean vegetation and have a leaf phenotype that seems to have remained unchanged since the Miocene. We hypothesise that variation of the sclerophyll phenotype among Iberian populations of Quercus coccifera is partly due to an ulterior process of ecotypic differentiation. We analysed the genetic structure of nine Iberian populations using ISSR fingerprints, and their leaf phenotypes using mean and intracanopy plasticity values of eight morphological (leaf angle, area, spinescence, lobation and specific area) and biochemical traits (VAZ pool, chlorophyll and β-carotene content). Climate and soil were also characterised at the population sites. Significant genetic and phenotypic differences were found among populations and between NE Iberia and the rest of the populations of the peninsula. Mean phenotypes showed a strong and independent correlation with both genetic and geographic distances. Northeastern plants were smaller, less plastic, with smaller, spinier and thicker leaves, a phenotype consistent with the stressful conditions that prevailed in the steppe environments of the refugia within this geographic area during glaciations. These genetic, phenotypic, geographic and environmental patterns are consistent with previously reported palaeoecological and common evidence. Such consistency leads us to conclude that there has been a Quaternary divergence within the sclerophyllous syndrome that was at least partially driven by ecological factors.     

脑室镜和腹腔镜辅助脑室腹腔分流术治疗老年脑积水的疗效

目的:探讨脑室镜和腹腔镜辅助脑室腹腔分流术治疗老年脑积水的疗效。方法:选择我院90例老年脑积水患者,按随机数字表法平均分为A、B、C 3组各30例,A组患者给予传统脑室腹腔分流术治疗,B组患者给予腹腔镜辅助下脑室腹腔分流术治疗,C组患者给予脑室镜和腹腔镜综合辅助下脑室腹腔分流术治疗,比较3组患者治疗有效率及术后并发症发生率。结果:C组患者治疗有效率为90.0%,明显高于A组63.3%及B组76.7%,比较差异具有统计学意义(均P0.05);C组患者术后感染及分流管堵塞并发症发生率明显低于A组和B组,比较差异均有统计学意义(均P0.05);B组和C组脑实质内出血发生率均低于A组,与A组比较差异具有统计学意义(P0.05)。结论:脑室镜和腹腔镜综合辅助下脑室腹腔分流术治疗老年脑积水的疗效显著,术后并发症少,值得推广。     

早期胃癌的治疗现状与进展

胃癌是常见的消化道肿瘤之一,是我国死亡率最高的恶性肿瘤之一。与日本韩国等发达国家相比,我国胃癌患者多数在就诊时已处于进展期,早期胃癌所占比例不足10%。传统的开腹胃癌手术仍是治疗早期胃癌的主要手段。相较于传统开腹手术,腹腔镜手术对于早期胃癌的治疗优势是显而易见的。早期胃癌患者行腹腔镜手术,具有术后恢复快,生活质量好,近期疗效佳等优势。内镜黏膜下剥离术(ESD,endoscopic submucosal dissection)是近年来出现的一项新的治疗早期胃癌的手段。本文就传统开腹手术、腹腔镜手术及ESD分别在早期胃癌治疗中的应用进行了综述。微创手术治疗早期胃癌将逐渐代替开腹手术,成为早期胃癌治疗的主要手段。     

腹腔镜辅助下阴式子宫切除术与阴式子宫全切除术治疗子宫良性病变的临床比较

目的:探究阴式子宫全切除术与腹腔镜辅助下阴式子宫切除术治疗子宫良性病变的临床效果。方法:选择2011年10月~2013年9月我院收治的子宫良性病变的患者120例,其中行腹腔镜辅助下阴式子宫切除术80例(研究组)和行阴式子全宫切除术40例(对照组),观察并分析两组的临床指标及手术并发症。结果:研究组住院费用明显高于对照组(P0.05),手术时间、术中出血量及住院时间均低于对照组(P0.05);研究组无邻近脏器损伤,对照组输尿管损伤2例(5.00%),研究组患者出现手术损伤率明显低于对照组,差异存在统计学差异(x2=3.968,P=0.046);对两组患者术后随访1年,两组患者均无出现再手术情况;两组患者术后阴道残端均愈合较好,未出现阴道残端漏,患者无大小便困难及其他不适。结论:腹腔镜辅助下阴式子宫切除术治疗子宫良性病变疗效优于阴式子宫全切术,其手术时间、术中出血量及住院时间均较低,创伤小,更有利于患者恢复健康,在临床上值得应用推广。     

Absolute quantification of DcR3 and GDF15 from human serum by LC‐ESI MS

Biomarkers are widely used in clinical diagnosis, prognosis and therapy monitoring. Here, we developed a protocol for the efficient and selective enrichment of small and low concentrated biomarkers from human serum, involving a 95% effective depletion of high‐abundant serum proteins by partial denaturation and enrichment of low‐abundant biomarkers by size exclusion chromatography. The recovery of low‐abundance biomarkers was above 97%. Using this protocol, we quantified the tumour markers DcR3 and growth/differentiation factor (GDF)15 from 100 μl human serum by isotope dilution mass spectrometry, using ¹⁵N metabolically labelled and concatamerized fingerprint peptides for the both proteins. Analysis of three different fingerprint peptides for each protein by liquid chromatography electrospray ionization mass spectrometry resulted in comparable concentrations in three healthy human serum samples (DcR3: 27.23 ± 2.49 fmol/ml; GDF15: 98.11 ± 0.49 fmol/ml). In contrast, serum levels were significantly elevated in tumour patients for DcR3 (116.94 ± 57.37 fmol/ml) and GDF15 (164.44 ± 79.31 fmol/ml). Obtained data were in good agreement with ELISA and qPCR measurements, as well as with literature data. In summary, our protocol allows the reliable quantification of biomarkers, shows a higher resolution at low biomarker concentrations than antibody‐based strategies, and offers the possibility of multiplexing. Our proof‐of‐principle studies in patient sera encourage the future analysis of the prognostic value of DcR3 and GDF15 for colon cancer patients in larger patient cohorts.