Level of dietary energy during prepubertal growth and reproductive development of gilts.

Development of gilts that conceive early and continue to produce offspring is a primary objective of swine production. The objective of this study was to determine the degree of feed restriction during development required to optimize reproductive performance and efficiency in gilts. The effects that various patterns of growth had on reproductive development and performance of gilts through d 30 of gestation were investigated. At 13 wk of age and 41 kg BW, 192 white crossbred gilts were penned individually and assigned to receive 87.5%, 75%, 62.5%, and 50% of predicted ad libitum energy intake. The study was replicated in two seasons. At 25 wk of age, gilts were moved to group pens and allowed ad libitum access to feed, and estrous detection was initiated. Gilts were inseminated at first observed estrus and those recycling were remated. Post-mating gilts were fed 1.5x maintenance in stalls. Gilts that did not return to estrus 17 to 30 d after mating were slaughtered at 30 d of gestation. Reproductive tracts were collected and numbers of corpora lutea and live embryos were recorded. Feed restriction during development resulted in differences in BW and backfat thickness at the start of the breeding period and differences in feed intake during breeding. Gilts subjected to the greatest feed restriction during development consumed the greatest quantity of feed during breeding. Feed intake during breeding was associated with BW and backfat gain during breeding. The treatment group that entered breeding lightest and leanest (50% of predicted ad libitum intake) had the least number of days to first estrus, followed by the fattest, heaviest group (87.5% of predicted ad libitum intake). Treatment groups did not differ (P > 0.38) in ovulation rate or live embryo numbers. Significant relationships between quantity of GE consumed during development and variables considered important in reproductive development and performance were evident, such as BW and fatness at start of breeding and first detected estrus, and ovulation rate. Variation in dietary energy during the development period impacted many aspects of reproductive development and performance. However, coupling restricted energy intake during development with ad libitum intake during breeding negated many of the effects of feed restriction during the development period.     

Production and characterization of human extracellular superoxide dismutase in the methylotrophic yeast Pichia pastoris

Reactive oxygen species are associated with various diseases including cardiovascular diseases, neurological disorders, and pulmonary diseases. Extracellular superoxide dismutase (ECSOD) is an antioxidant enzyme secreted by cells to prevent overproduction of reactive oxygen species. We expressed an ECSOD gene isolated from a human aortic smooth muscle cDNA library in the methylotrophic yeast Pichia pastoris. A synthetic secretion cassette was constructed with the inducible promoter of the alcohol oxidase 1 gene (AOX1) and the yeast alpha-mating factor signal peptide. As much as 25% of the total protein was ECSOD in some transformants grown under inducing conditions. After 36 h of methanol induction, ECSOD was exported into the culture medium at a concentration of approximately 440 mg/L with an antioxidative activity of 760 +/- 20 U/mg ECSOD. Transformed yeast cells were more resistant to heat shock and H(2)O(2) oxidative stress, indicating that the human ECSOD expressed by P. pastoris had multiple biological functions. Our data suggest that the methylotrophic yeast inducible system is suitable for large-scale production of enzymatically active human ECSOD.     

鹦鹉热嗜衣原体PCR检测体系的建立

鹦鹉热是由鹦鹉热嗜衣原体(Chlamydophila psittaci,C. psittaci)引起,并可由带病鸟类传染给人类的一种人畜共患传染病.虽然有巢式PCR和多重PCR被开发用于C.psittaci的检测,但是这些方法较为繁琐.本研究应用了32株衣原体和嗜衣原体菌株,24株来自鸟类及人的肠道与呼吸道的细菌菌株,此外还使用606个禽鸟粪便、泄殖腔棉拭子及人体气管分泌物的临床样本.笔者以C.psittaci的MOMP基因(major outer membrane protein gene)为靶基因而开发了PCR检测方法.该最低能检测到100fgDNA(相当于10个衣原体)相当的鹦鹉热嗜衣原体.该靶基因区域涵盖了除C.pneumoniae、C.pecorum、C. trachomatis、C.suis和C.muridarum以外的鹦鹉热嗜衣原体所有的菌株及其他部分嗜衣原体菌株.606例临床样本中有29例鸟类粪便样本、25例泄殖腔棉拭子样本和2例人源样长检测为阳性.结果表明,该PCR检测法是检测鸟源鹦鹉热嗜衣原体的快速、敏感、有效的方法.     

Determination of caffeine, theobromine, and theophylline in standard reference material 2384, baking chocolate, using reversed-phase liquid chromatography

A rapid and selective isocratic reversed-phase liquid chromatographic method has been developed at the National Institute of Standards and Technology to simultaneously measure caffeine, theobromine, and theophylline in a food-matrix standard reference material (SRM) 2384, Baking Chocolate. The method uses isocratic elution with a mobile phase composition (volume fractions) of 10% acetronitrile/90% water (pH adjusted to 2.5 using acetic acid) at a flow rate of 1.5 mL/min with ultraviolet absorbance detection (274 nm). Total elution time for these analytes is less than 15 min. Concentration levels of caffeine, theobromine, and theophylline were measured in single 1-g samples taken from each of eight bars of chocolate over an eight-day period. Samples were defatted with hexane, and beta-hydroxyethyltheophylline was added as the internal standard. The repeatability for the caffeine, theobromine, and theophylline measurements was 5.1, 2.3, and 1.9%, respectively. The limit of quantitation for all analytes was <100 ng/mL. The measurements from this method were used in the value-assignment of caffeine, theobromine, and theophylline in SRM 2384.     

Crossability percentages of bread wheat landraces from Shaanxi and Henan provinces,China with rye

Summary The crossability percentages of 118 landraces of wheat (Triticum aestivum L.) from Shaanxi and Henan provinces, China with rye (Secale cereale L.) have been tested. 14 landraces possess a higher crossability percentage than Chinese Spring, 30 landraces have a similar to and 74 landraces have a lower crossability percentage than Chinese Spring or are non-crossable with rye. Most landraces with high crossability percentage occur in south part of Shaanxi, and the west and southwest of Henan, their geographical distribution in these regions fits up with that in the Sichuan province.     

Crossability percentages of bread wheat collections from Tibet,China with rye

Summary The crossability percentages of 282 accessions of wheat (Triticum aestivum L.) collected in Tibet, China with rye (Secale cereale L.) have been tested. Five collections have a similar to and 277 accessions have a lower crossability percentage than Chinese Spring or are non-crossable with rye. The accessions with high crossability percentage occur along the highway near Lhasa. No landraces with higher crossability than Chinese Spring and rare landraces with similar crossability to Chinese Spring indicated that the landraces in Tibet region are different from those in Sichuan, Shaanxi and Henan provinces in the distribution frequency of high crossability, and there is no distribution of recessive kr4 alleles.     

Flavonoids with DNA strand-scission activity from Rhus javanica var. roxburghiana

The flavonoids isolated from the stems of Rhus javanica var. roxburghiana, taxifolin (1), fisetin (2), fustin (3), 3,7,4'-trihydroxyflavanone (4) and 3,7,4'-trihydroxyflavone (5) caused breakage of supercoiled plasmid pBR322 DNA in the presence of Cu(II). Cu(I) was shown to be an essential intermediate by using the Cu(I)-specific sequestering reagent neocuproine. The Cu(II)-mediated DNA scissions induced by 1, 2, 3 and 5 were inhibited by the addition of catalase and exhibited DNA strand break by the addition of KI and superoxide dimutase (SOD), while in the Cu(II)-mediated DNA scissions induced by 4 was inhibited by the addition of KI, SOD, and catalase. It is concluded that 1, 2, 3, and 5 can induce H(2)O(2) and superoxide anion, while 4 can induce OH() and H(2)O(2) and subsequent oxidative damage of DNA in the presence of Cu(II).     

A QTL on chromosome 2DS of ‘Sumai 3’ increases susceptibility to <Emphasis Type="Italic">Fusarium</Emphasis> head blight in wheat

Much effort has been invested in identifying molecular markers in wheat (Triticum aestivum L.) linked to quantitative trait loci (QTL) that confer resistance to Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein) Petch]. Even after several generations of crossing and selection by many wheat breeding programs, resistance of the Chinese spring wheat cultivar ‘Sumai 3’ (PI 481542) remains among the most effective. It therefore seems that undocumented resistance QTL present in Sumai 3 were not detected in various mapping studies. Using an extremely susceptible Tibetan landrace (‘Y1193-6’; unknown pedigree) in the creation of a mapping population with Sumai 3, the objective of this research was to identify undocumented resistance QTL in Sumai 3. This was accomplished through collecting disease index (DI) and Fusarium damaged kernel (FDK) phenotypic values along with 305 Diversity Array Technology (DArT) and 52 Simple Sequence Repeat (SSR) marker genotypes on 160 F_2:6 recombinant inbred lines (RILs). Disease response evaluations were based on four (two greenhouse and two field) experiments where spray inoculation methods were used. Three QTL were identified on chromosome arms 3BS, 6BL and 2DS explaining 26.1, 10.7 and 18.9% of the phenotypic variation for DI, respectively. The same QTL were also significantly associated with reduced FDK scores and explained 28.0, 11.0 and 23.0% of phenotypic variation. Lines within the mapping population were placed in eight categories with respect to their various QTL combinations. Lines with no QTL were the most susceptible, whereas those with the Sumai 3-derived 3BS and 6BL QTL combined with the 2DS QTL from Y1193-6 were the most resistant. Though the 3BS and 6BL QTL are well-documented, the 2DS resistance QTL, which was contributed by the susceptible parent, confers increased susceptibility when derived from Sumai 3. In this study no new FHB QTL from Sumai 3 was discovered, but results suggest that Sumai 3 contains a QTL for susceptibility on chromosome arm 2DS. Selection against this QTL may potentially increase resistance levels among Sumai 3-derived populations.     

神经网路模式在流量之预测

本文以倒传递神经网路模式,进行长期流量预测之应用研究,并以台湾中部德基水库上游松茂流量站历年观测资料进行探讨。初步得到预测结果与实测值比较尚有一倍以上的误差。但以神经网路之潜在应用潜力,寻找系统化网路参数值建立方法以得到更精确预测结果之经验,为寻人相当值得继续研究之课题。     

Induction of apoptosis by the Anthocyanidins through regulation of Bcl-2 gene and activation of c-Jun N-terminal kinase cascade in hepatoma cells

Anthocyanidins that are reddish pigments widely distributed in fruit and vegetables have been reported to possess antioxidant and anticancer activities. To understand the molecular basis of the putative anticancer activity of anthocyanidins, we investigated the antiproliferation effects of anthocyanidins in human hepatoma cell lines. Delphinidin, cyanidin, and malvidin exhibited strong growth inhibitory effects against human hepatoma HepG(2), but were less effective against Hep3B. According to the appearance of the caspase-3 fragments and stimulated proteolytic cleavage of poly (ADP-ribose) polymerase (PARP) in time-dependent studies, delphinidin induced apoptotic cell death characterized by internucleosomal DNA fragmentation and caused a rapid induction of caspase-3 activity. RT-PCR and Western blot data revealed that delphinidin stimulated an increase in the c-Jun and JNK phosphorylation expression at mRNA and protein levels, respectively. Moreover, delphinidin-induced apoptotic cell death was accompanied by up-regulation of Bax and down-regulation of Bcl-2 protein. Dephinidin-induced DNA fragmentation was blocked by N-acetyl-l-cysteine and catalase, suggesting that the death signaling was triggered by oxidative stress. Our experiments provide evidence that delphinidin is an effective apoptosis inducer in HepG(2) cells through regulation of Bcl-2 family moleculars and activation of c-Jun N-terminal kinase cascade. The results suggest that induction of apoptosis by anthocyanidins is a pivotal mechanism of their cancer chemopreventive functions.