Stimulating action of methyl 12, 12, 12-trifluorofarnesoate on in vitro juvenile hormone III biosynthesis in blattella germanica

Methyl 12, 12, 12-trifluorofarnesoate (MTFF) at a dose of 10 μM, stimulated in vitro juvenile hormone (JH) release in corpora allata (CA) from 6-day-old, freshly ecdysed, and 8-day-old (period of ootheca transport) adult virgin females of Blattella germanica. In addition, MTFF also induced intraglandular accumulation of JH and MF in treated CA. Trifluorofarnesoic acid (TFFA) and trifluorofarnesol (TFF) exhibited the same properties, although to a lesser extent than MTFF. The detection of MTFF in TFFA-treated CA suggested that TFFA and TFF were biotransformed into MTFF by the CA enzymatic system and that this ester might be responsible for the activity observed. Equivalent experiments carried out with farnesoic acid (FA) resulted in a more significant stimulation of JH production. This is not surprising, because exogenous FA is readily epoxidized at C10-C11 double bond and methylated to afford JH. Conversely, analytical data have shown that the C6-C7 double bond of MTFF is epoxidized by the CA enzymatic system, whereas that at C10-C11 remains practically unaltered.     

Micronutrient deficiency and the prevalence of mothers' overweight/obesity in Egypt.

I examine the relationship between micronutrient deficiency and the prevalence of mothers' overweight/obesity in Egypt using the 1997 Egyptian Integrated Household Survey. The ordered logit results show an overlap between micronutrient deficiency and the prevalence of mothers' overweight/obesity in Egypt. The odds of being overweight/obese are 80.8% higher for micronutrient deficient mothers than for non-deficient mothers, keeping all other variables constant. These results have at least two interesting policy implications. First, as the potential impact of the interaction between micronutrient deficiency and chronic diseases is not well known, the coexistence of micronutrient deficient and overweight/obese women can raise new and serious public health problems in the country. Second, the Egyptian food subsidy program, which lowers the relative prices of energy-dense, nutrient-poor food items, can be one of the major factors for the emergence of overweight/obese and micronutrient deficient mothers in the country. Changing the orientation of the food subsidy program may help to simultaneously address this double burden of mothers' malnutrition.     

On the mechanism of the oxygenation of arachidonic acid by human platelet lipoxygenase

Formation of 12L-hydroxy-5,8,10,14-eicosatetraenoic acid from [10L-³H; 3-¹⁴C]arachidonic acid in suspensions of human platelets occurred with extensive loss of tritium and was accompanied by an isotope effect. These experiments showed that there is an antarafacial relation between the elimination of hydrogen from C-10 and insertion of oxygen at C-12 by human platelet lipoxygenase, and that the hydrogen elimination probably occurs as the initial step of the conversion. (Endo) peroxide intermediates formed by the fatty acid cyclo-oxygenase pathway activated platelet lipoxygenase.     

Twin differences in birth weight: the effects of genotype and prenatal environment on neonatal and post-neonatal mortality.

There is much evidence to suggest that both genes and prenatal environment influence life chances. However, recent within-twin estimates also raise questions about how the influence of genes and prenatal environment may vary across different subgroups of a population and over time. This paper explores such potential variation within the 1st year of life. Using data on twin births from the 1995-1997 Matched Multiple Birth Database and an analytic strategy based on the Weinberg assumption, this paper considers how associations between birth weight and infant mortality vary across identical and fraternal twins, gestational age, and time. Results suggest that the influence of genes and prenatal environment vary most significantly by gestational age. In pregnancies that lasted less than 37 weeks, within-twin variation in prenatal environment is able to account for negative associations between birth weight and infant mortality. However, in pregnancies that lasted 37 weeks or longer, underlying genetic variation across fraternal twins appears to be largely responsible for birth weight-mortality associations. Such distinct findings by gestation suggest that genes and prenatal environment may play varying roles in birth weight-mortality associations across different situations.     

p38L12 TAT融合肽对山梨糖醇引起的 ECV304细胞ATF2磷酸化的抑制作用

构建p38 Loop-12(L12)的TAT融合表达载体,纯化原核表达的p38L12融合蛋白并鉴定其在真核细胞内的功能.利用PCR方法分别扩增出p38L12及其“T-X-Y”双磷酸化位点的AF突变体p38L12（AF）片段,克隆入His标记的TAT-EGFP融合蛋白原核表达载体pHTE（pET14b-His-TAT-EGFP）,经酶切、测序鉴定正确后,将重组质粒转化原核表达菌,诱导表达纯化融合蛋白;将融合蛋白加入ECV304细胞后于荧光显微镜下观察并行Western印迹分析,检测融合蛋白的细胞内转导活性;通过检测内源性ATF2磷酸化水平,鉴定高渗刺激下p38L12对内源性p38活性的影响.成功构建了p38L12和p38L12(AF)片段与TAT的融合表达载体,并获得相应的融合蛋白.在ECV304细胞中可见导入的HTE-p38L12和THE-p38L12(AF)融合蛋白具有较高的细胞内转导活性和转导效率,并可竞争性抑制高渗刺激对内源性p38的活化.基于HIV-1 TAT细胞转导系统证实p38L12可竞争性抑制高渗刺激诱导的内源性p38对ATF2的活化,从而发挥对p38激活特异性抑制的功能.     

腺苷钴胺素合成酶基因cobs的克隆及其在产1,3-丙二醇菌中的应用

甘油脱水酶是催化由甘油到1,3-丙二醇过程中的关键酶,它需要在辅酶B_(12)存在的情况下才能有效的进行催化;而在此催化过程中甘油脱水酶会出现失活现象,研究表明辅酶B_(12)可以有效的促使甘油脱水酶复活。因此,辅酶B_(12)在由甘油生物催化生产1,3-丙二醇过程中起到非常重要的作用。本研究利用PCR扩增技术,从Escherichia K-12菌株中扩增出产VB_(12)关键酶—腺苷钴胺素合成酶基因cobs,其序列与NCBI上已经公布的序列比对,同源性为99.6%,将基因cobs与产1,3-丙二醇关键酶基因dhaB、yqhD在Klebsiella pneumoniae中共表达,发酵结果显示重组菌所需额外添加的VB_(12)由原始菌株的0.01 g/L下降到0.004 g/L。     

重组人受体蛋白FKBP12与新型神经生长促进剂非共价键复合物的电喷雾质谱

系统地用电喷雾质谱(ESI-MS)研究了重组人受体蛋白FKBP12(rhFKBP12)和其小分子神经生长促进剂配体的非共价键相互作用, 从52个化合物中筛选出3个有非共价键结合的化合物000107, 000308和A2B12, 并通过竞争实验测定了它们与rhFKBP12的结合位点和相对结合强度. 清华大学对其中的两个000107, 000308做出了复合物X射线晶体衍射的三维结构, 与ESI-MS的结果相同, 其中000308有较好的促神经生长的活性.     

Alcohol abuse and suicide attempts among youth.

This study uses the Youth Risk Behavior Survey (YRBS) and the National Comorbidity Survey (NCS) to explore the causal relationship between alcohol abuse (binge drinking and clinically defined alcohol use disorders) and suicide attempts among youth. We use an empirical approach that allows one to assess the possible existence and strength of a causal relationship without relying on identifying assumptions. Our results suggest that a causal relationship between binge drinking and suicide attempts is very unlikely. The findings, however, support a causal relationship between clinically defined alcohol use disorders and suicide attempts among girls.     

蝰科(Viperidae)蝮亚科(Crotalinae)线粒体12S rRNA基因序列分析及其系统发育

对蝮亚科(蛇岛蝮Gloydius shedaoensis Zhao、黑眉蝮Gloydius saxatilis Emelianov、乌苏里蝮Gloydius ussurriensis Emelianov、竹叶青Trimeresurus stejnegeri Schmidt 和分别来自不同地区的尖吻蝮Deinagkistrodon acutus Guenther、短尾蝮Gloydius brevicaudus Stejneger各两条)6种蛇共8个个体测定、分析了约370bp线粒体12S rRNA基因序列,以游蛇科链蛇属半棱鳞链蛇Dinodon semicarinatus 序列为外群构建分子系统树.分子数据结果支持尖吻蝮形态学的属级分类地位;提示蛇岛蝮位于黑眉蝮的蛇岛亚种分类地位,同时探讨了蛇岛蝮的起源问题;并提示短尾蝮和乌苏里蝮同位于种级分类地位.     

由12S rDNA序列探讨中国狼蛛科主要类群的分子系统发育关系

将自测的我国蜘蛛目狼蛛科4属6个种和从互联网GenBank中检索到相关物种的线粒体基因组12SrDNA的序列进行同源性比较,计算核苷酸使用频率。然后据此进行分子分析,利用2个外群(漏斗蛛科的机敏漏斗蛛Agelena difficilis和缘漏斗蛛Agelena limbat)和2种建树方法(邻近法Neighbour Joining,NJ和最大简约法Maximum Parsimony,MP)分析我国狼蛛科内的亲缘关系。获得平均为291.6 bp的序列中,A T平均含量为78.13%,而G C含量只要21.87%,颠换取代(tranversion)的速度多数大于或接近转换取代(transition)的速度,其中161个核苷酸位点存在变异。研究结果表明:在蜘蛛目狼蛛科有差异的161 bp中,属内种间仅为1.08%,狼蛛科属间为6.85%~14.80%。所构建的分子系统树表明:科内的属和属内的种均优先聚在一起;狼蛛科现行分类系统中各亚科的演化关系顺序为:马蛛亚科→狼蛛亚科→豹蛛亚科;狼蛛科各属的演化关系顺序为:水狼蛛属→马蛛属(或水狼蛛属和马蛛属)→獾蛛属→狼蛛属→豹蛛属;水狼蛛属为最早分出的一支或者水狼蛛属和马蛛属...     

基于线粒体12S rRNA基因鉴别混合牛肉及制品的牛种来源

线粒体基因组具有种内高度保守性。它的12S rRNA基因同时具有抗腐蚀、耐高温的特点, 而被用于饲料、鲜肉及肉制品的来源追踪和物种成分鉴别等研究。利用牦牛、普通牛、水牛作为研究材料, 在牛线粒体12S rRNA基因通用引物扩增片段区域发现3种特异的酶切位点, 可用于混合鲜牛肉及制品的牛种来源的鉴别。结果显示: 牦牛12S rRNA扩增片段被酶切为203 bp和250 bp, 普通牛为134 bp和318 bp, 水牛为86 bp和367 bp, 通过测序验证了特异性位点和酶切的正确性; 对样品经过不同温度(100℃、120℃、140℃、160℃和180℃)处理均能扩增到目的条带, 但条带从120℃开始变淡。该方法在鲜牛肉及制品的牛种来源鉴别上具有简单、快速、廉价等优点。     

DNA 12S rRNA基因序列测定在野生动物毛发样本鉴定中的应用

目的利用mtDNA 12S rRNA基因序列测定法对西藏自治区森林公安局送检的三件毛发物证进行种属鉴定,并探讨该方法在无毛囊毛发样本鉴定中的应用价值。方法用酚/氯仿法从毛发样本中提取出基因组总DNA,再用一通用引物通过PCR技术扩增mtDNA上12S rRNA基因的部分片段并进行序列测定。测序结果在GenBank上进行BLAST搜索,再利用DNAMAN软件进行同源性分析。结果1号样和3号样扩增产物序列与藏原羚的线粒体DNA的12S rRNA基因序列的部分片段的同源性均高达99%;2号样的序列与盘羊的线粒体DNA的12S rRNA基因序列的部分片段的同源性高达98%。结论1号和3号样为藏原羚,2号样为盘羊。本研究所用方法在野生动物案件的样本鉴定中有极高的应用价值。     

根据12S rRNA和Cyt b基因部分序列鉴定药用猴骨样品

利用线粒体12S rRNA基因和cyt b基因部分序列,通过DNA序列比对的方法,对毫州市药品监督管理局送检的三件猴骨样品（BZ01、BZ02和BZ03）进行了分子鉴定。结果表明,BZ01号样品为藏酋猴（Macaca thibetana）,BZ02和BZ03号样品为猕猴（Macaca mulatta）,通过本文的研究,作者还提出,在利用DNA序列比对法进行近缘物种的鉴定时,不同种群间的DNA序列变异,可能对结果造成一定的影响。     

Isolation of the postulated precursor of nor-patchoulenol in Patchouli leaves

Patchoulan-1,12-diol, postulatedtobe the biogenetic precursor of nor-patchoulenol, has been isolated in the leaves of patchouli.     

Photosensitised oxidation of 12,13-epoxy-, 12-hydroxy-, 12-oxo- and 12-bromo-oleate

The photosensitised oxidation of four substituted methyl oleates (12,13-epoxy, 12-hydroxy, 12-oxo, and 12-bromo) has been studied. The expected hydroperoxides were isolated by chromatography and indentified by spectroscopic procedure.     

huBC1-IL12, an immunocytokine which targets EDB-containing oncofetal fibronectin in tumors and tumor vasculature,shows potent anti-tumor activity in human tumor models

IL-12 is a cytokine which showed anti-tumor effects in clinical trials, but also produced serious toxicity. We describe a fusion protein, huBC1-IL12, designed to achieve an improved therapeutic index by specifically targeting IL-12 to tumor and tumor vasculature. huBC-1 is a humanized antibody that targets a cryptic sequence of the human ED-B-containing fibronectin isoform, B-FN, present in the subendothelial extracellular matrix of most aggressive tumors. B-FN is oncofetal and angiogenesis-associated, and is undetectable in most normal adult tissues. The original murine BC-1 antibody has been used successfully for immunoscintigraphy to image brain tumor mass in glioblastoma patients. In huBC1-IL12, each of the IgG heavy chains is genetically fused to the N-terminus of the IL-12 p35 subunit, which in turn is disulfide-bonded to the p40 subunit, resulting in a hexameric molecule of MW of ∼300 kDa. Since human IL-12 has no biological activity in mice, we produced huBC1-muIL12 as a surrogate molecule for animal tumor models. Despite the relatively poor PK profile of this molecule in mice and the apparent drawbacks of xenogeneic models in SCID mice, which lack T and B cells, one cycle of treatment with huBC1-muIL12 was efficacious in the PC3mm2, A431, and HT29 subcutaneous tumor models and PC3mm2 lung metastasis model. This molecule also was found to have surprisingly low toxicity in immunocompetent mice. A fusion protein that contains human IL-12 (huBC1-huIL12), which is a suitable molecule for investigation as a therapeutic, has also been produced. This protein has been shown to have a longer serum half-life than huBC1-muIL12 in mice, and retains both antigen binding and IL-12 activity in in vitro assays.