随机力对激光育种频率影响的研究

本文对ＤＮＡ分子势场用辏力场近似,建立了该近似了Ｆｏｋｋｅｒ－Ｐｌａｎｃｋ方程并用数值法求解了本征值,发现处于生物体内的ＤＮＡ分子,由于受随机力噪声作用,影响了能级分立状态,使其振吸收频率拓宽,从而使激光育种中使用有效激光范围较广。     

利用GFP示踪细胞内源性P53活性检测DNA损伤

ＤＮＡ损伤的检测对预防癌症和遗传病等非常重要。采用分子克隆技术,将报告基因—绿色荧光蛋白（ＧＦＰ）置于ＳＶ４０基本启动子调控下,构建成对照载体ｐＳＶ－ＧＦＰ。在ＳＶ４０基本启动子上游插入寡核苷酸Ｐ５３ＲＥ,构建成示踪载体ｐ５３ＲＥ－ＧＦＰ。转染ＮＩＨ３Ｔ３细胞,以ＧＦＰ示踪细胞内源性Ｐ５３的转录激活活性。紫外线照射或Ｈ２Ｏ２处理转化细胞使ＤＮＡ损伤,诱导细胞内源性Ｐ５３的表达。用激光扫描共聚焦成像系统（ＬＳＣＩＳ）对细胞进行红、绿、蓝三色光融合成像,并测定ＧＦＰ经４８８ｎｍ激发后发出的绿色荧光光密度,验证ＧＦＰ示踪Ｐ５３的特异性。ｐ５３ＲＥ－ＧＦＰ转化细胞３Ｔ３－ＲＥＧ经紫外线照射或Ｈ２Ｏ２处理后,ＧＦＰ的表达增高,处理后１ｈｒ光密度即达到最高水平,随后逐渐降低。血清“饥饿”—非ＤＮＡ损伤处理的３Ｔ３－ＲＥＧ细胞,以及经紫外和Ｈ２Ｏ２处理的对照载体ｐＳＶ－ＧＦＰ转化细胞３Ｔ３－ＳＶＧ,ＧＦＰ的表达无明显增强。实验表明：ＧＦＰ示踪内源性Ｐ５３转录激活活性用于检测ＤＮＡ损伤有很高的灵敏度和特异性,适宜推广应用。     

花生种子高纯度DNA的提取（简报）

花生种子高纯度ＤＮＡ的提取（简报）王艳,何军贤,傅家瑞（中山大学生命科学学院,广州５０２７５）关键词花生;种子;ＤＮＡ;十六烷基三甲基溴化铵ＲＡＰＩＤＡＮＤＥＦＦＩＣＩＥＮＴＰＵＲＩＦＩＣＡＴＩＯＮＯＦＤＮＡＦＲＯＭＰＥＡＮＵＴ（ＡＲＡＣＨＩＳＨＹＰ...     

低氧对肺动脉内皮细胞PDGF—B链释放及平滑肌细胞生长的影响

应用蛋白ｄｏｔｂｌｏｔ技术检测了低氧内皮细胞条件培养液（ＨＥＣＣＭ）和常氧内皮细胞条件培养液（ＮＥＣＣＭ）内ＰＤＧＦ相对含量,并利用［３Ｈ］－ＴｄＲ掺入法和流式细胞术观察了ＨＥＣＣＭ和ＮＥＣＣＭ及加入特异ＰＤＧＦ抗体对肺动脉平滑肌细胞（ＰＡＳＭＣ）生长的影响。结果表明,ＨＥＣＣＭ中的ＰＤＧＦ含量明显高于ＮＥＣＣＭ;ＨＥＣＣＭ能明显增强ＰＡＳＭＣ内ＤＮＡ合成,促进ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期;当预先加入ＰＤＧＦ－Ｂ链抗体时,则会明显地抑制ＨＥＣＣＭ对ＰＡＳＭＣ的ＤＮＡ合成,阻止ＰＡＳＭＣ从Ｇｏ／Ｇ１期进入Ｓ期。结果提示,低氧时ＰＡＳＭＣ增殖与肺动脉内皮细胞分泌释放ＰＤＧＦ增加有关     

P63和p73参与p53依赖的细胞凋亡过程

Ｐ5 3是一个重要的抑癌基因 ,其转录翻译出的蛋白分子 ｐ5 3通过与凋亡相关靶基因 ｐ2 1、ｍｄｍ2、ｂａｘ、ＰＥＲＰ作用而使有潜在癌变倾向的细胞凋亡 ,一些ＤＮＡ损伤诱发的细胞凋亡过程也依赖于 ｐ5 3分子的启动。Ｐ6 3和 ｐ73属于 ｐ5 3基因家族成员 ,其蛋白分子 ｐ6 3和 ｐ73与ｐ5 3有结构上的相似性 ,且功能亦与细胞凋亡相关 ,但ｐ6 3和 ｐ73在凋亡中所起作用的详细机制尚且不清。麻省理工学院和哈佛大学学者ＥｌｓａＲ .Ｆｌｏｒｅｓ和ＫｅｎｎｅｔｈＹ .Ｔｓａｉ等用基因敲除法 ,先后通过 4种ＤＮＡ损伤诱导凋亡的实验 ,同时在体外…     

一种改进的λDNA分子大小的标记物：百万碱基ⅡDNA标准品

一种改进的λＤＮＡ分子大小的标记物：百万碱基ⅡＤＮＡ标准品ＬｉＷｕｂｏＨｕＡｌｉ著／李络红译／申宗侯校线性双链λ噬菌体ＤＮＡ多连体作为脉冲电场凝胶电泳（ＰＦＧＥ）分子量大小的标记物是有用的。由于野生型λ噬菌体ＤＮＡ（Ｃ／８５Ｊｓａｎ７）的大小已被确定...     

孤生受体的相互作用对视黄酸应答元件的影响

孤生受体ＣＯＵＰ－ＴＦ和ｎｕｒ７７的功能及其作用机理仍未阐明．以ＤＮＡ瞬时转染和测定氯霉素乙酰转移酶（ＣＡＴ）活性,以及凝胶阻抑测定,分析ＣＯＵＰ－ＴＦ和ｎｕｒ７７的相互作用对视黄酸应答元件（ＲＡＲＥｓ）的影响．实验表明,ＣＯＵＰ－ＴＦ通过降低ＲＡＲＥｓ的基础活性,来增强ＲＡＲＥ对视黄酸（ＲＡ）的敏感性,而ｎｕｒ７７则拮抗ＣＯＵＰ－ＴＦ的作用．ｎｕｒ７７能够加强不同ＲＡＲＥｓ的转录活性,并且与ＲＡ的诱导无关．结果证实,ｎｕｒ７７通过与ＣＯＵＰ－ＴＦ的直接作用而对ＲＡＲＥｓ产生影响,从而抑制ＣＯＵＰ－ＴＦ与ＲＡＲＥｓ结合和ＣＯＵＰ－ＴＦ的转录活性     

两个反义基因在番茄工程植株中的生理抑制效应分析

用番茄乙烯形成酶（ＥＦＥ）和多聚半乳糖醛酸酶（ＰＧ）反义ｃＤＮＡ转化番茄子叶,获得两个转基因系统。分别比较了两个基因系统果实和叶片的乙烯生成速率、果实中ＥＦＥ酶活性和果胶酶活性,表明反义ＥＦＥ基因在番茄工程植株中能显著抑制ＥＦＥ酶活性和乙烯生成;反义ＰＧ基因则主要是抑制其ＰＧ酶活性。     

两个反义基因在番茄工程植株中的生理抑制效应分析

用番茄乙烯形成酶（ＥＦＥ）和多聚半乳糖醛酸酶（ＰＧ）反义ｃＤＮＡ转化番茄子叶,获得两个转基因系统,分别比较了两个基因系统果实和叶片的乙烯生成速率,果实中ＥＦＥ酶活性和果胶酶活性,表明反义ＥＦＥ基因在番茄工程植株中能显著抑制ＥＦＥ酶活性和乙烯生成,反义ＰＧ基因则主要抑制是ＰＧ酶活性。     

植物分子分类与鉴定综述

以高等植物为对象,首先从ｎＤＮＡ、ｃｐＤＮＡ、ｍｔＤＮＡ三方面对植物分子分类与鉴定的分子基础进行综述,然后阐述ＲＦＬＰ、ＲＡＰＤ、ＡＦＬＰ及ＳＳＲ等分子分类方法的特点及应用。     

The use of fluorescein-dipalmitoylphosphatidylethanolamine for measuring pH-changes in the internal compartment of phospholipid vesicles

The synthesis and characterisation of fluorescein-phosphatidylethanolamine (FPE) is described. The effects of dielectric constant, ionic strength and ambient pH upon the optical absorbance properties of FPE are presented. It is shown that under appropriate conditions, FPE rapidly and quantitatively reports the pH of the aqueous bulk phases when incorporated into phospholipid vesicles. It is also shown that, when the external medium is highly buffered, FPE is capable of specificity reporting only the pH of the intravesicular compartment. The application of FPE for studies of intravesicular pH changes of reconstituted membranous protein systems is discussed.     

DNA 分子简谐特性的研究

考虑周期驱动力下的ＤＮＡ分子系统的福克普朗克方程。通过数值计算，研究期望值〈ｘ（ｔ）〉的简谐性。根据随机力强度对简谐特性的研究，我们得到温度有益于癌症治疗的结论。     

The interacting effect of urea and fenoxaprop-P-ethyl on photosynthesis and chlorophyll fluorescence in Perilla frutescens

We studied the effect of herbicide and nitrogen supply on photosynthesis in Perilla frutescens L. Britt. Plants were exposed to combined treatment of urea and herbicide, fenoxaprop-P-ethyl (FPE), in various concentrations. FPE reduced significantly chlorophyll (Chl) content, photosynthetic rate, and stomatal conductance, but increased significantly intercellular CO₂ concentration; thus, FPE inhibited significantly the photosynthetic capacity. In addition, FPE also decreased significantly the PSII photochemical efficiency, effective quantum yield of photochemical energy conversion in PSII, PSII potential activity, and photochemical quenching of variable Chl fluorescence. It also decreased nonphotochemical quenching. It indicated that FPE impaired PSII and blocked the electron transport in light reaction. The urea treatment at moderate concentration (1–4 g L^?1) could antagonize the negative effect of FPE, while the high urea concentration (8 g L^?1) aggravated this effect. The treatment with urea (4 g L^?1) and then with FPE (1.33 mL L^?1) enhanced Chl content index, photosynthetic rate, and stomatal conductance by 12.5, 36.1, and 28.5% compared to FPE treatment alone. Thus, we suggested to treat plants first with urea (4 g L^?1) and then by FPE (1.33 mL L^?1) as the best and the safest method to balance the fertilization and weeding.     

用荧光素磷脂酰乙醇胺直接测定线粒体内膜外表面pH

由磷脂极性头部基团和结合水分子组成的氢键网络有利于质子沿膜表面侧向快速扩散。因而在线粒体氧化磷酸化过程中,与呼吸链电子传递相偶联的跨膜转运质子是否滞留于线粒体内膜外表面即成为一个值得探讨的课题。本文采用荧光素磷脂酰乙醇胺标记于线粒体内膜外表面,首次建立了直接测定线粒体内膜外表面ｐＨ的方法。标记后,线粒体内膜体呼吸控制率,呼吸链电子传递驱动的质子跨膜转移活性及ＡＴＰ合成活性下降了近２８．０％,１１．     

Focal palatine erosion in captive and free-living cheetahs (Acinonyx jubatus) and other felid species

We examined 1,092 skulls of captive and free-living individuals, representing 33 felid species, to determine the prevalence of focal palatine erosion (FPE). FPE was detected in 3.2% of cats evaluated, including cheetah (Acinonyx jubatus) and 14 other felid species. The prevalence of FPE between cheetah (9.4%; n = 64) and non-cheetah species (2.8%; n = 1,028) (χ(2) test; P = 0.004) and between captive (5.7%; n = 246) and free-living (2.4%; n = 824) individuals (χ(2) test; P = 0.010) were significantly different, with prevalence between captive (19%; n = 21) and free-living (2.9%; n = 34) cheetahs approaching significance (Fisher's exact test; P = 0.064). FPE was diagnosed with equal prevalence in skulls from individuals in which the lower molars did not meet the palatine bone (60.6%) and individuals in which it did (39.4%; n = 33) (χ(2) test; P = 0.139). In cheetahs with FPE, one was a captive animal in Germany, one a free-living cheetah from Mali, one captive cheetah from Kenya, and three captive cheetahs of unknown origin. Additionally, we evaluated the medical records of 49 captive cheetahs in Namibia. Of these cheetahs, 48 (98.0%) had clinical signs consistent with FPE, although only 16 of these 48 (39.6%) had perforation of the palatine bone. Based on physical examinations, FPE was diagnosed in two caracals (Caracal caracal) and one fishing cat (Prionailurus viverrinus) from a North American Zoo. Results from this study confirm FPE in cheetahs outside of Namibia, in a minimum of 15 felid species, and a higher FPE prevalence in captive individuals than free-living ones. Clinical implications of these findings and recommendations for future studies are provided.     

Mannitol-enhanced, fluid-phase endocytosis in storage parenchyma cells of celery (Apium graveolens; Apiaceae) petioles

We recently demonstrated the occurrence of a sucrose-enhanced, fluid-phase endocytic (FPE) mechanism of nutrient uptake in heterotrophic cells. In the present work, the possible enhancement/induction of FPE by photoassimilates other than sucrose was investigated by measuring the incorporation of the fluorescent endocytosis marker d-TR (dextran-Texas red, 3000 mw) into celery (Apium graveolens) petiole storage parenchyma (CSP), a tissue that transports and accumulates mannitol. Mannitol uptake in these cells is biphasic, with a hyperbolic phase at concentrations below 20 mM and a linear phase above 20 mM external solute concentration. In the absence of mannitol, or in its presence at concentrations within the hyperbolic phase, CSP cells accumulated low levels of d-TR. Conversely, d-TR accumulation by CSP cells was greatly enhanced in the presence of mannitol at concentrations within the linear phase. At high external mannitol concentration, d-TR accumulation was prevented by the endocytic inhibitors LY294002 and latrunculin B. In addition, d-TR uptake was temperature dependent under high mannitol concentration. Microscopic observations revealed that d-TR accumulated in the vacuole. These data support the occurrence of an FPE mechanism in CSP cells that participates in trapping and transport of photoassimilates to the vacuole. The FPE mechanism is enhanced by high mannitol concentrations.     

The effects of the level of physical activity on calcaneal ultrasound measurements: bone properties of medical and physical education students

The aim of the study was to compare bone properties of two groups of students which strongly differ in the level of their everyday physical activity; the School of Medicine (SM) students and the Faculty of Physical Education (FPE) students, University of Zagreb. Quantitative ultrasound parameters--broadband ultrasound attenuation (BUA) and speed of sound (SOS) were measured. Quantitative ultrasound index (QUI) and estimated bone mineral density (BMD) were calculated by the device software. The final study sample consisted of 165 students from SM (94 males and 71 females) and 215 students from the FPE (164 males, 51 females). Sixty eight percent of FPE students and 21% of SM students reported a high level of everyday physical activity (P < 0.001). All ultrasound parameters were significantly higher in FPE students than in SM students (at the P < 0.001 level). The multiple regression model of the QUI confirmed that the school students attended was the single significant predictor variable for both genders. Our data indirectly showed the beneficial role of physical activity on bone properties.     

The proenkephalin A-processing product peptide E, which encompasses two enkephalin sequences, has a much lower opioid activity than beta-endorphin.

Peptide E is a 25-amino acid peptide derived from proenkephalin A that was originally isolated from the bovine adrenal medulla. Bovine peptide E (BPE), which possesses a Met- and a Leu-enkephalin sequence at its N- and C-terminus, respectively, has been described as a highly potent and selective mu-opioid receptor agonist. Paradoxically, the frog counterpart of peptide E (FPE), which exhibits only two amino acid substitutions (Met15-->Gln and Leu25-->Met) compared with BPE, was found to be totally devoid of antinociceptive activity. To decipher this apparent discrepancy, we have decided to compare the structural and pharmacological characteristics of FPE, BPE, and the chimeric peptide [Gln15]BPE (Q15BPE). In methanol, all three peptides exhibited virtually the same conformation, the central region of each peptide (residues 10-20) being involved in a regular helix. Intracerebroventricular administration of FPE, BPE, or Q15BPE, at doses up to 1000 ng per mouse, did not induce any analgesic effects, as evaluated by the hot plate and writhing tests, whereas, in the same tests, beta-endorphin at a dose of 100 ng provoked profound analgesia. Concomitant administration of FPE, BPE, or Q15BPE (100 ng) with the aminopeptidase-N inhibitor bestatin (50 microg) or the endopeptidase 24-11 inhibitor thiorphan (10 microg) did not produce analgesic responses. Antinociceptive effects were only observed when very high doses of FPE, BPE, and Q15BPE (10000 ng per mouse) were administered. These data clearly demonstrate that, contrary to what has been previously reported, peptide E is virtually devoid of opioid activity.     

Polyhydroxyalkanoate production from animal by-products: Development of a pneumatic feeding system for solid fat/protein-emulsions

Fat-containing animal by-product streams are locally available in large quantities. Depending on their quality, they can be inexpensive substrates for biotechnological processes. To accelerate industrial polyhydroxyalkanoate (PHA) bioplastic production, the development of efficient bioprocesses that are based on animal by-product streams is a promising approach to reduce overall production costs. However, the solid nature of animal by-product streams requires a tailor-made process development. In this study, a fat/protein-emulsion (FPE), which is a by-product stream from industrial-scale pharmaceutical heparin production and of which several hundred tons are available annually, was evaluated for PHA production with Ralstonia eutropha. The FPE was used as the sole source of carbon and nitrogen in shake flask and bioreactor cultivations. A tailored pneumatic feeding system was built for laboratory bioreactors to facilitate fed-batch cultivations with the solid FPE. The process yielded up to 51 g L⁻¹ cell dry weight containing 71 wt% PHA with a space–time yield of 0.6 g_PHA L⁻¹ h⁻¹ without using any carbon or nitrogen sources other than FPE. The presented approach highlights the potential of animal by-product stream valorization into PHA and contributes to a transition towards a circular bioeconomy.