不同橡胶品种幼苗对遮荫的生理响应及耐荫能力评价

以不同遮荫条件(100%、50%、25%和5%自然光)下适应生长1年后的6个橡胶品种幼苗为研究对象,测定分析了干季和雨季时幼苗叶片多项生理生化指标的变化特征,并对幼苗的耐荫性进行综合评价。结果表明:(1)不同光处理对所有6个橡胶品种幼苗叶片的超氧化物歧化酶(SOD)活性、可溶性蛋白质(SP)含量、可溶性糖(SS)含量、蔗糖(Suc)含量、叶绿素(Chl)含量、叶绿素a/b(Chl a/b)、脯氨酸(Pro)含量、丙二醛(MDA)含量和质膜相对透性(RMP)都有显著影响,且幼苗叶片的SOD、SP、SS、Suc、Chl、Chla/b和RMP在6个品种之间也有显著差异。(2)与雨季相比,干季时各品种的SS和Chl显著下降,而SOD、SP、Suc、Pro、Chla/b、MDA和RMP显著升高。(3)各品种的SP、SS、Suc、SOD和MDA均随着光强的减弱而下降。(4)主成分分析法筛选结果显示,与橡胶幼苗对光强反应密切相关7个生理生化指标是SP、SS、Suc、SOD、Pro、Chl a/b和MDA;9个生理生化指标的平均隶属度比较发现,干季和雨季对光强变化适应能力较强的3个品种是‘RRIM600’、‘云研77-4’和‘云研77-2’,‘GT1’和‘PR107’品种次之,‘热研523’品种最弱。     

国产生化试剂福司可林研制成功

福司可林(forskolin)是医学和生物化学中研究环核苷酸系统的良好试剂,用途广泛。目前从sigma公司进口此生化试剂,价格昂贵,且不易买到。中国科学院动物研究所立足于国内资源,已研究开发出了这种生化试剂。经研究单位实验证明,此试剂与sigma     

螺旋霉素3-O-酰基转移酶基因的删除和主要产生螺旋霉素组分Ⅰ菌株的获得

螺旋霉素(SP)为16元环大环内酯类抗生素,含有螺旋霉素Ⅰ、Ⅱ和Ⅲ个组分,其结构的差异为16元内酯环的C3上分别连接羟基(SPⅠ)、乙酰基(SPⅡ)和丙酰基(SPⅢ);SPⅡ和SPⅢ是在相同的3-O-酰基转移酶催化下SPⅠ进一步酰化的产物。SPⅠ、SPⅡ和SPⅢ在生物学活性方面无大差异。为简化螺旋霉素组分,便于今后对其结构进行进一步改造,根据碳霉素和麦迪霉素生物合成中的3-O-酰基转移酶序列,设计了简并性PCR引物,并采用SON-PCR(single oligonucleotide nested PCR)方法,从螺旋霉素产生菌S.spiramyceticus F21中进行特异性扩增,获得了螺旋霉素3-O-酰基转移酶基因(sspA)及其侧翼序列,共约4.3kb(其中的3457nt DNA序列已被Genbank收录,DQ642742)。采用DNA同源双交换技术对S.spiramyceticus F21中的sspA进行了删除。对螺旋霉素原株和sspA缺失变株进行发酵产物提取和HPLC分析表明:原株中SPⅠ、SPⅡ和SPⅢ的相对含量分别为7.8%、67%和25%,变株中则分别为72%、18%和9.6%;变株主要组分为SPⅠ。螺旋霉素sspA缺失变株的获得为螺旋霉素组分简化及其衍生物的结构改造奠定了基础。     

稻壳作为缓释碳源及载体的改性研究

稻壳可作为废水处理的外加碳源, 通过适当改性处理可提高其应用性能。为探索稻壳的改性条件, 以不同浓度的NaOH、Ca(OH)2、NaClO为改性试剂对稻壳进行改性处理, 并研究了改性后稻壳的表面结构、芽孢杆菌吸附量、静态释碳量、可生化性以及成分含量变化。结果表明: 6% NaOH、0.9% Ca(OH)2和3% NaClO处理对稻壳表面糙化、芽孢杆菌吸附性和静态释碳能力有良好的提升效果。在此三组中, 6% NaOH处理后稻壳可生化效果最佳, CD600增长率为其他处理组的4倍; 纤维素含量增加了16.03%, 灰分含量显著降低, 仅剩4.9%; 且结构改性效果最为明显, 适用于稻壳改性优化。     

氟芬那酸丁酯软膏联合丁酸氢化可的松治疗儿童慢性湿疹及特应性皮炎的疗效

目的:探讨氟芬那酸丁酯软膏联合丁酸氢化可的松治疗儿童慢性湿疹及特应性皮炎的临床疗效。方法:选取我院诊治的110例慢性湿疹及特应性皮炎患儿作为研究对象,使用随机数字表法分为研究组和对照组(各55例),对照组单用丁酸氢可的松软膏治疗,研究组联合应用氟芬那酸丁酯软膏和丁酸氢化可的松软膏,比较两组患儿的治疗效果。结果:研究组治疗后的疾病积分显著低于对照组,P0.05;研究组的治疗总有效率为85.45%,对照组为63.64%,组间比较,差异具有统计学意义(P0.05)。结论:临床治疗儿童慢性湿疹和特应性皮炎,联合应用氟芬那酸丁酯软膏和丁酸氢化可的松,具有显著疗效,且安全性好,值得推广。     

肠激酶在毕赤酵母中的分泌表达优化

肠激酶 (Enterokinase,EK) 是一类特异性识别切割DDDDK序列的丝氨酸蛋白酶,作为一种工具酶广泛应用于生物医药领域。目前,EK在毕赤酵母Pichia pastoris中的表达水平较低,难以应用。本研究比较了6种不同的信号肽SP1、SP2、SP3、SP4、SP7和SP8对毕赤酵母分泌表达EK的影响。在摇瓶水平上,与α-factor信号肽相比,SP1信号肽显著提高了EK的分泌表达 (从6.8 mg/L提高至14.3 mg/L),酶活从 (2 390±212) U/mL提高至 (4 995±378) U/mL。在此基础上,通过共表达毕赤酵母内源蛋白Kex2,EK酶活提高至 (7 219±489) U/mL。另外,N端融合WLR三个氨基酸进一步提高酶活至 (15 145±920) U/mL,比酶活为 (1 174 600±53 100) U/mg。EK在毕赤酵母中的高效分泌表达为未来应用奠定了基础。     

甲硝唑栓与雌激素软膏联合治疗老年性阴道炎的临床疗效观察

探究老年性阴道炎应用甲硝唑栓与雌激素软膏联合治疗的临床疗效。方法:择取我院2012年9月~2013年9月收治的老年性阴道炎患者74例,研究组应用甲硝唑栓与雌激素软膏联合治疗,参照组单独应用甲硝唑栓治疗,对比其临床效果。结果:研究组的总有效率(97.30%)和复发率(5.41%)均明显优于参照组(81.08%,21.62%),对比差异具有统计学意义(P0.05)。结论:老年性阴道炎应用甲硝唑栓与雌激素软膏联合治疗,具有良好的疗效,且安全可靠,值得推广。     

Dot-ELISA法检测血液及唾液HIV抗体的应用评价

评价人类免疫缺陷病毒1+2型抗体检测试剂盒(Dot-ELISA法)检测血清和唾液样本的临床性能。采用对照试验研究,选取背景清晰的研究对象200例,采集同一研究对象的血清和唾液样本,应用万泰生物药业公司生产的人类免疫缺陷病毒1+2型抗体检测试剂盒作为考核试剂,法国生物梅里埃公司生产的人类免疫缺陷病毒抗体诊断试剂盒(ELISA法)作为参考试剂,考核试剂检测结果与参考试剂及研究对象背景进行比较分析。考核试剂检测血清HIV抗体与参考试剂相比较,阳性符合率100%,阴性符合率100%,总符合率100%,Kappa值1.00,一致性为最强;考核试剂检测唾液HIV抗体与参考试剂检测结果相比较,阳性符合率98.78%,阴性符合率100%,总符合率99.50%,Kappa值0.99,一致性为最强。Dot-ELISA法人类免疫缺陷病毒1+2型抗体检测试剂盒对血清及唾液样本检测性能优越,适合HIV抗体快速筛查。     

开放试剂在罗氏生化分析仪使用评价

目的评价开放试剂在罗氏全自动生化分析仪(cobas8000-c702)上使用情况方法使用开放性试剂[三酞甘油(TG),丙氨酸氨基转移酶(ALT),碱性磷酸酶(ALP),天门冬氨酸氨基转移酶(AST),总胆固醇(TC),γ-谷氨酞基转移酶(GGT)]由利徳曼厂家提供,以上开放试剂的分析类型,方法原理,试剂组分以及试剂的组成均使用效果合理,且使用开放试剂混合的血清来作为量值传递的载体,用其开放性试剂校准后在对cafs校准品进行赋值,并且对cafs校准品及开放性试剂组成测定的系统进行赋值。结果开放性试剂在检测高值还是低值的血清结果是,批内以及批间的变异系数(CV)均小于5%,这样就开放试剂同时在检测60份临床样本时,所测的结果基本就保持一致(P0.05),相关系数(r)均0.968。开放试剂之间的自比对实验结果,在医学上决定水平处的偏倚都是低于允许误差的范围。试剂的抗干扰能力就没有明显的差异,r值均大于0.968(P0.05)[1]。结论开放试剂在罗氏全自动生化分析上相关性较好、精密度高、偏差小,抗干扰能力强等优点;其检验的结果也具有一定溯源性以及可比性。     

新疆436例不孕症患者阴道分泌物检测

目的探讨生化检测法在阴道感染诊断中的应用价值。方法采用常规检测法和生化检测法对新疆自治区人口和计划生育科研所妇科门诊436例不孕症患者进行阴道分泌物检测。结果在436例患者中,使用常规检测法共筛查出细菌性阴道病患者71例,阳性率为16.28%;使用生化检测法共筛查出细菌性阴道病患者82例,阳性率为18.80%。在诊断细菌性阴道病方面,这两种方法的符合率达到了86.5%,经Kappa一致性检测,二者具有中度一致性(Kappa=0.72,P>0.05)。结论生化检测法与Amsel法的符合率较高,且具有准确、快速,不需使用大型昂贵仪器等特点,适宜在基层医院推广使用。     

Cloning, expression and enzymatic properties analysis of dihydrofolate reductase gene from the silkworm, Bombyx mori

Tetrahydrobiopterin (BH4) is an essential cofactor for aromatic acid hydroxylases, which control the levels of monoamine neurotransmitters. BH4 deficiency has been associated with many neuropsychological disorders. Dihydrofolate reductase (DHFR) can catalyze 7,8-dihydrobiopterin to 5,6,7,8-tetrahydrobiopterin (BH4) in the salvage pathway of BH4 synthesis from sepiapterin (SP), a major pigment component contained in the integument of silkworm Bombyx mori mutant lemon (lem) in high concentration. In this study, we report the cloning of DHFR gene from the silkworm B. mori (BmDhfr) and identification of enzymatic properties of BmDHFR. BmDhfr is located on scaffold Bm_199 with a predicted gene model BGIBMGA013340, which encodes a 185-aa polypeptide with a predicted molecular mass of about 21?kDa. Biochemical analyses showed that the recombinant BmDHFR protein exhibited high enzymatic activity and suitable parameters to substrate. Together with our previous studies on SP reductase of B. mori (BmSPR) and the lem mutant, it may be an effective way to industrially extract SP from the lem silkworms in large scale to produce BH4 in vitro by co-expressing BmSPR and BmDHFR and using the extracted SP as a substrate in the future.     

Electrophoretic pattern of sorbitol dehydrogenase (E.C.1.1.1.14) in human seminal plasma and spermatozoa

An electrophoretic study of sorbitol dehydrogenase (SORD) in sperm and seminal plasma (SP) was realized. In SP, three phenotypes (one slow band, one fast, and both bands) were observed, corroborating the electrophoretic variability of SP-SORD formerly reported by us, while, in sperm, SORD showed a phenotype of one band faster than the one of SP. Biochemical studies showed that thiol groups participate in the mobility of the SP fast band; furthermore, an interchange of the bands of SP-SORD was observed which suggests that the isozymes are due to conformational isomerism or to molecular aggregates.     

Recent Progress on Spray Pyrolysis for High Performance Electrode Materials in Lithium and Sodium Rechargeable Batteries

Advanced electrode materials have been intensively explored for next‐generation lithium‐ion batteries (LIBs), and great progresses have been achieved for many potential candidates at the lab‐scale. To realize the commercialization of these materials, industrially‐viable synthetic approaches are urgently needed. Spray pyrolysis (SP), which is highly scalable and compatible with on‐line continuous production processes, offers great fidelity in synthesis of electrode materials with complex architectures and chemistries. In this review, motivated by the rapid advancement of the given technology in the battery area, we have summarized the recent progress on SP for preparing a great variety of anode and cathode materials of LIBs with emphasis on their unique structures generated by SP and how the structures enhanced the electrochemical performance of various electrode materials. Considering the emerging popularity of sodium‐ion batteries (SIBs), recent electrode materials for SIBs produced by SP will also be discussed. Finally, the powerfulness and limitation along with future research efforts of SP on preparing electrode materials are concisely provided. Given current worldwide interests on LIBs and SIBs, we hope this review will greatly stimulate the collaborative efforts among different communities to optimize existing approaches and to develop innovative processes for preparing electrode materials.     

Inhibitors of c-Jun N-terminal kinases: JuNK no more?

The c-Jun N-terminal kinases (JNKs) have been the subject of intense interest since their discovery in the early 1990s. Major research programs have been directed to the screening and/or design of JNK-selective inhibitors and testing their potential as drugs. We begin this review by considering the first commercially-available JNK ATP-competitive inhibitor, SP600125. We focus on recent studies that have evaluated the actions of SP600125 in lung, brain, kidney and liver following exposure to a range of stress insults including ischemia/reperfusion. In many but not all cases, SP600125 administration has proved beneficial. JNK activation can also follow infection, and we next consider recent examples that demonstrate the benefits of SP600125 administration in viral infection. Additional ATP-competitive JNK inhibitors have now been described following high throughput screening of small molecule libraries, but information on their use in biological systems remains limited and thus these inhibitors will require further evaluation. Peptide substrate-competitive ATP-non-competitive inhibitors of JNK have also now been described, and we discuss the recent advances in the use of JNK inhibitory peptides in the treatment of neuronal death, diabetes and viral infection. We conclude by raising a number of questions that should be considered in the quest for JNK-specific inhibitors.     

Lower bounds on multiple sequence alignment using exact 3-way alignment

Background  

Multiple sequence alignment is fundamental. Exponential growth in computation time appears to be inevitable when an optimal alignment is required for many sequences. Exact costs of optimum alignments are therefore rarely computed. Consequently much effort has been invested in algorithms for alignment that are heuristic, or explore a restricted class of solutions. These give an upper bound on the alignment cost, but it is equally important to determine the quality of the solution obtained. In the absence of an optimal alignment with which to compare, lower bounds may be calculated to assess the quality of the alignment. As more effort is invested in improving upper bounds (alignment algorithms), it is therefore important to improve lower bounds as well. Although numerous cost metrics can be used to determine the quality of an alignment, many are based on sum-of-pairs (SP) measures and their generalizations.     

Steady state peripheral blood provides cells with functional and metabolic characteristics of real hematopoietic stem cells

Hematopoietic stem cells (HSCs), which are located in the bone marrow, also circulate in cord and peripheral blood. Despite high availability, HSCs from steady state peripheral blood (SSPB) are little known and not used for research or cell therapy. We thus aimed to characterize and select HSCs from SSPB by a direct approach with a view to delineating their main functional and metabolic properties and the mechanisms responsible for their maintenance. We chose to work on Side Population (SP) cells which are highly enriched in HSCs in mouse, human bone marrow, and cord blood. However, no SP cells from SSBP have as yet been characterized. Here we showed that SP cells from SSPB exhibited a higher proliferative capacity and generated more clonogenic progenitors than non‐SP cells in vitro. Furthermore, xenotransplantation studies on immunodeficient mice demonstrated that SP cells are up to 45 times more enriched in cells with engraftment capacity than non‐SP cells. From a cell regulation point of view, we showed that SP activity depended on O₂ concentrations close to those found in HSC niches, an effect which is dependent on both hypoxia‐induced factors HIF‐1α and HIF‐2α. Moreover SP cells displayed a reduced mitochondrial mass and, in particular, a lower mitochondrial activity compared to non‐SP cells, while they exhibited a similar level of glucose incorporation. These results provided evidence that SP cells from SSPB displayed properties of very primitive cells and HSC, thus rendering them an interesting model for research and cell therapy.     

3D geometric reconstruction of thoracic aortic aneurysms

Background

Ruptured abdominal aortic aneurysms (AAAs) are the 13^th leading cause of death in the United States. While AAA rupture may occur without significant warning, its risk assessment is generally based on critical values of the maximum AAA diameter (>5 cm) and AAA-growth rate (>0.5 cm/year). These criteria may be insufficient for reliable AAA-rupture risk assessment especially when predicting possible rupture of smaller AAAs.

Methods

Based on clinical evidence, eight biomechanical factors with associated weighting coefficients were determined and summed up in terms of a dimensionless, time-dependent severity parameter, SP(t). The most important factor is the maximum wall stress for which a semi-empirical correlation has been developed.

Results

The patient-specific SP(t) indicates the risk level of AAA rupture and provides a threshold value when surgical intervention becomes necessary. The severity parameter was validated with four clinical cases and its application is demonstrated for two AAA cases.

Conclusion

As part of computational AAA-risk assessment and medical management, a patient-specific severity parameter 0 < SP(t) < 1.0 has been developed. The time-dependent, normalized SP(t) depends on eight biomechanical factors, to be obtained via a patient's pressure and AAA-geometry measurements. The resulting program is an easy-to-use tool which allows medical practitioners to make scientific diagnoses, which may save lives and should lead to an improved quality of life.     

Identification of Cancer Stem-Like Side Population Cells in Purified Primary Cultured Human Laryngeal Squamous Cell Carcinoma Epithelia

Cancer stem-like side population (SP) cells have been identified in many solid tumors; however, most of these investigations are performed using established cancer cell lines. Cancer cells in tumor tissue containing fibroblasts and many other types of cells are much more complex than any cancer cell line. Although SP cells were identified in the laryngeal squamous cell carcinoma (LSCC) cell line Hep-2 in our pilot study, it is unknown whether the LSCC tissue contains SP cells. In this study, LSCC cells (LSCCs) were primary cultured and purified from a surgically resected LSCC specimen derived from a well-differentiated epiglottic neoplasm of a Chinese male. This was followed by the verification of epithelium-specific characteristics, such as ultrastructure and biomarkers. A distinct SP subpopulation (4.45±1.07%) was isolated by Hoechst 33342 efflux analysis from cultured LSCCs by using a flow cytometer. Cancer stem cell (CSC)-associated assays, including expression of self-renewal and CSC marker genes, proliferation, differentiation, spheroid formation, chemotherapy resistance, and tumorigenicity were then conducted between SP and non-SP (NSP) LSCCs. In vitro and in vivo assays revealed that SP cells manifested preferential expression of self-renewal and CSC marker genes, higher capacity for proliferation, differentiation, and spheroid formation; enhanced resistance to chemotherapy; and greater xenograft tumorigenicity in immunodeficient mice compared with NSP cells. These findings suggest that the primary cultured and purified LSCCs contain cancer stem-like SP cells, which may serve as a valuable model for CSC research in LSCC.     

Involvement of substance P and the NK-1 receptor in human pathology

The peptide substance P (SP) shows a widespread distribution in both the central and peripheral nervous systems, but it is also present in cells not belonging to the nervous system (immune cells, liver, lung, placenta, etc.). SP is located in all body fluids, such as blood, cerebrospinal fluid, breast milk, etc. i.e. it is ubiquitous in human body. After binding to the neurokinin-1 (NK-1) receptor, SP regulates many pathophysiological functions in the central nervous system, such as emotional behavior, stress, depression, anxiety, emesis, vomiting, migraine, alcohol addiction, seizures and neurodegeneration. SP has been also implicated in pain, inflammation, hepatitis, hepatotoxicity, cholestasis, pruritus, myocarditis, bronchiolitis, abortus, bacteria and viral infection (e.g., HIV infection) and it plays an important role in cancer (e.g., tumor cell proliferation, antiapoptotic effects in tumor cells, angiogenesis, migration of tumor cells for invasion, infiltration and metastasis). This means that the SP/NK-1 receptor system is involved in the molecular bases of many human pathologies. Thus, knowledge of this system is the key for a better understanding and hence a better management of many human diseases. In this review, we update the involvement of the SP/NK-1 receptor system in the physiopathology of the above-mentioned pathologies and we suggest valuable future therapeutic interventions involving the use of NK-1 receptor antagonists, particularly in the treatment of emesis, depression, cancer, neural degeneration, inflammatory bowel disease, viral infection and pruritus, in which that system is upregulated.     

Galvanic microparticles increase migration of human dermal fibroblasts in a wound-healing model via reactive oxygen species pathway

Electrical signals have been implied in many biological mechanisms, including wound healing, which has been associated with transient electrical currents not present in intact skin. One method to generate electrical signals similar to those naturally occurring in wounds is by supplementation of galvanic particles dispersed in a cream or gel. We constructed a three-layered model of skin consisting of human dermal fibroblasts in hydrogel (mimic of dermis), a hydrogel barrier layer (mimic of epidermis) and galvanic microparticles in hydrogel (mimic of a cream containing galvanic particles applied to skin). Using this model, we investigated the effects of the properties and amounts of Cu/Zn galvanic particles on adult human dermal fibroblasts in terms of the speed of wound closing and gene expression. The collected data suggest that the effects on wound closing are due to the ROS-mediated enhancement of fibroblast migration, which is in turn mediated by the BMP/SMAD signaling pathway. These results imply that topical low-grade electric currents via microparticles could enhance wound healing.