An Ethanol Extract Derived from Bonnemaisonia hamifera Scavenges Ultraviolet B (UVB) Radiation-Induced Reactive Oxygen Species and Attenuates UVB-Induced Cell Damage in Human Keratinocytes

The present study investigated the photoprotective properties of an ethanol extract derived from the red alga Bonnemaisonia hamifera against ultraviolet B (UVB)-induced cell damage in human HaCaT keratinocytes. The Bonnemaisonia hamifera ethanol extract (BHE) scavenged the superoxide anion generated by the xanthine/xanthine oxidase system and the hydroxyl radical generated by the Fenton reaction (FeSO₄ + H₂O₂), both of which were detected by using electron spin resonance spectrometry. In addition, BHE exhibited scavenging activity against the 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species (ROS) that were induced by either hydrogen peroxide or UVB radiation. BHE reduced UVB-induced apoptosis, as shown by decreased apoptotic body formation and DNA fragmentation. BHE also attenuated DNA damage and the elevated levels of 8-isoprostane and protein carbonyls resulting from UVB-mediated oxidative stress. Furthermore, BHE absorbed electromagnetic radiation in the UVB range (280–320 nm). These results suggest that BHE protects human HaCaT keratinocytes against UVB-induced oxidative damage by scavenging ROS and absorbing UVB photons, thereby reducing injury to cellular components.     

Estimation of design water requirement using FAO Penman–Monteith and optimal probability distribution function in South Korea

Estimation of the design water requirement (DWR) is a key part of design and operation of agricultural water resource systems. DWR is determined from frequency analysis of crop water requirement, and the reference return period has been 10 years in South Korea. This study aimed to propose a guideline for determining DWR using Food and Agriculture Organization (FAO) Penman–Monteith method and optimal probability distribution function (PDF). To find an optimal PDF, nine types of PDF were tested using the Kolmogorov–Smirnov (K–S) and Probability Plot Correlation Coefficient (PPCC) goodness-of-fit methods. From the test, the Generalized Logistic (GLO) was selected and DWRs were estimated using the chosen optimal PDF. To demonstrate the DWR differences among the PDFs, DWR and drought reference design year were compared for the three selected PDFs, GLO, Generalized Extreme Values (GEV) and Weibull (WBU). The results would effect on the design and operation of the agricultural water resources structures in terms of capacity and capability in South Korea.     

DDGS和酵母培养物对奶牛生产性能和乳成分的影响

选择16头泌乳天数为127±52d经产荷斯坦泌乳牛用于评价酵母培养物(达农威益康XP)和玉米酒糟及其可溶物(DDGS)在试验日粮中含有限草料纤维数量(草料中的中性洗涤纤维含量为19.3%,干物质基础)之情况下对产奶量和乳成分的影响及其它们之间的互作效应。本次试验采用4重复4×4拉丁方设计,试验时间为4个星期。处理组均按照2×2因子排列而设定,其中:1)日粮中不含酵母培养物和DDGS(对照组);2)日粮中含有20%DDGS,无酵母培养物(DDGS组);3)日粮中含有60g/d的酵母培养物益康XP(XP组);4)日粮中含有20%DDGS和60g/d的益康XP(XP+DDGS组)。本次试验结果表明:各处理组之间对奶牛体重和体况评分无显著的影响。日粮的处理并不影响干物质采食量(DMI),在使用草料纤维含量较低且添加20%DDGS的日粮情况下乳脂率会降低。添加益康XP的确能够提高产奶量及乳蛋白产量,但却不能够完全阻止因DDGS所造成的乳脂率下降的趋势。无论日粮中是否含有DDGS,益康XP都能够提高奶牛的生产性能。     

Prevalence of genes for enterotoxins,toxic shock syndrome toxin 1 and exfoliative toxin among clinical isolates of Staphylococcus pseudintermedius from canine origin

A total of 74 Staphylococcus pseudintermedius strains were isolated from the 99 clinical cases of canine pyoderma or chronic otitis in our veterinary teaching hospital during May 2006–February 2008. In this study, we examined the genetic distribution of staphylococcal pyogenic toxins such as staphylococcal enterotoxins A (sea), B (seb), C (sec), D (sed), E (see), and toxic shock syndrome toxin 1 (tst) as well as the previously characterized S. intermedius exfoliative toxin (siet) among those isolates. The polymerase chain reaction analyses with the toxin gene‐specific primers revealed that 18 (24.3%) of 74 S. pseudintermedius isolates carried the sec genes, but none of the sea, seb, sed, see and tst genes. Further DNA sequencing analysis of the amplified sec genes revealed that they all belonged to the canine type C staphylococcal enterotoxin (SEC_canine) whose superantigenic activity has been demonstrated. In addition to the sec_canine genes, our polymerase chain reaction results showed that all the 74 isolates carried the siet gene. Since both SEC_canine and SIET toxins are known to be biologically active, it would be interesting to investigate how those toxins are involved in the pathogenesis of the canine diseases by S. pseudintermedius such as pyoderma or chronic otitis.     

Construction and evaluation of genetically engineered replication-defective porcine reproductive and respiratory syndrome virus vaccine candidates

Porcine reproductive and respiratory syndrome virus (PRRSV) is an emerging pathogen causing significant economic losses in the swine industry worldwide. Two novel gene-deleted viruses were constructed and evaluated as vaccine candidates. Using the full-length infectious cDNA clone of North American PRRS isolate P129, the ORF2 and ORF4 genes (which encoded minor structural glycoproteins GP2a/2b and GP4, respectively) were individually deleted from the viral genome. Both deletion mutants were non-viable in MARC-145 cells and porcine alveolar macrophages, indicating that both genes are essential for virus replication. To rescue the replication-defective PRRSV, two complementing cell lines, MARC-2000 and MARC-400, were established to stably express the PRRSV GP2 and GP4 proteins, respectively. These cells were able to complement the deleted gene function of PRRSV in trans and supported production of the replication-defective DeltaORF2-PRRSV and DeltaORF4-PRRSV viruses. Both DeltaORF2-PRRSV and DeltaORF4-PRRSV viruses were propagated for 40-50 generations in the corresponding complementing cells and remained replication-defective in MARC-145 cells. To examine the immunogenic potential of the replication-defective PRRSV as vaccine candidates, four groups of pigs, 20 pigs per group, were immunized twice with DeltaORF2-PRRSV or DeltaORF4-PRRSV and challenged with the homologous virulent virus at 3 weeks post-immunization. In spite of the fact one group showed significant reduction in virus load, we could not demonstrate improvement from clinical diseases in this vaccination/challenge study. However, we did show that the cDNA clone of PRRSV can be a useful tool to genetically engineer PRRSV vaccine candidates and to study pathogenesis and viral gene functions.     

Infectious cDNA clones of porcine reproductive and respiratory syndrome virus and their potential as vaccine vectors

Full-length infectious cDNA clones have recently become available for both European and North American genotypes of porcine reproductive and respiratory syndrome virus (PRRSV), and it is now possible to alter the PRRSV genome and create genetically defined mutant viruses. Among many possible applications of the PRRSV infectious cDNA clones, development of genetically modified vaccines is of particular interest. Using infectious clones, the PRRSV genome has been manipulated by changing individual amino acids, deleting coding regions, inserting foreign sequences, and generating arterivirus chimeras. The limited available data suggest that all structural proteins of PRRSV are essential for replication of the virus, and that PRRSV infectivity is relatively intolerant of subtle changes within the structural proteins. The major tasks in PRRSV research are to identify virulence factors and pathogenic mechanisms, and to understand the structure-function relationships of individual viral proteins. Utilizing these infectious clones as tools, a new generation of safe and efficacious PRRS vaccines may be constructed.     

Detection of bovine lactoferrin binding protein on Jurkat human lymphoblastic T cell line

Lactoferrin (Lf), a member of the transferrin family protein, is an iron-binding protein that is known to interact with mammalian cells through a specific receptor. We examined binding of Lf to Jurkat human lymphoblastic T cell line (Jurkat cells) by far Western blotting, and found that bovine Lf and human Lf bound to the same protein components of Jurkat cells, and that pepsin digestion of Lf disrupts the sites responsible for binding to cellular proteins. We also found that the sugar chains of bovine Lf are not involved in binding between bovine Lf and Jurkat cells. Bovine Lf, bovine transferrin and ovotransferrin bound to the same proteins of Jurkat cells, which had molecular weights of about 35 kDa.     

Reverse effects of tetraarsenic oxide on the angiogenesis induced by nerve growth factor in the rat cornea

To compare the antiangiogenic effects of tetraarsenic oxide (As4O6) with those of diarsenic oxide (As2O3) in the rat cornea, rat cornea micropocket assay was conducted to induce angiogenesis by implantation of the pellet contained 1.0 ng of nerve growth factor (NGF). Ten of thirty eyes of Sprague-Dawley rats were randomly assigned to one of three groups, namely, control group (no medication), As2O3 group (50 mg/kg As2O3, PO, s.i.d.), and As4O6 group (50 mg/kg As4O6, PO, s.i.d.). After implantation, the number of new vessels, vessel length and clock hour of neovascularization were examined under the microscope from day 3 to day 7. The area of neovascularization was calculated using a mathematical formula. Although new vessels in control and As2O3 groups were first noticed at day 3, whereas those of As4O6 group were first observed on day 5. The number, length, clock hour of neovascularization and areas of the vessels in As4O6 group showed more significant inhibition than those of control and As2O3 groups from day 5 (P<0.05). However, there were no differences in all parameters between control group and As2O3 group during the entire study period. These results showed that As4O6 had antiangiogenic effects on the new vessels induced by NGF in the rat cornea.