Improved sero-monitoring assay for classical swine fever (CSF) using the recombinant E2 protein of a recent Korean isolate

Classical swine fever (CSF) is a highly contagious disease of pigs that causes fever, diarrhea and paralysis, often resulting in death. E2 is the major structural protein of the CSF virus (CSFV) and mediates the entrance of the virus, subsequently inducing a neutralizing immune response. In this study, the E2 gene of a recent Korean isolate of CSF, SW03, was cloned and the DNA sequence was compared to other strains via phylogenetic analysis. With the purified E2 protein, an enzyme-linked immunosorbent assay (ELISA) was developed for the serodiagnosis of CSFV infection. The sensitivity and specificity of the E2-ELISA were 96.1% and 94.8%, respectively. A total of 17 out of 485 field-collected pig sera tested demonstrated conflicting results between two ELISA methods, a commercial kit and the E2-ELISA. Of these sera, 60% were determined to be CSFV positive by a virus neutralization test (VNT), suggesting involvement of different immune responses in the cases of CSFV infection. As the E2-ELISA was developed using a recent Korean isolate, SW03, this assay is capable of rapidly identifying newly emerging CSFV strains.     

Coronaviruses in cattle

Bovine coronaviruses are spread all over the world. They cause two types of clinical manifestations in cattle either an enteric, calf diarrhoea and winter dysentery in adult cattle, or respiratory in all age groups of cattle. The role of coronaviruses in respiratory infections is still a hot topic of discussion since they have been isolated from sick as well as healthy animals and replication of disease is rarely successful. Bovine coronavirus infection is characterised by high morbidity but low mortality. The laboratory diagnosis is typically based on serological or molecular methods. There is no registered drug for the treatment of virus infections in cattle and we are limited to supportive therapy and preventative measures. The prevention of infection is based on vaccination, biosecurity, management and hygiene. This paper will cover epidemiology, taxonomy, pathogenesis, clinical signs, diagnosis, therapy, economic impact and prevention of coronavirus infections in cattle.

     

Lipid Inhibitory Effect of (−)-loliolide Isolated from Sargassum horneri in 3T3-L1 Adipocytes: Inhibitory Mechanism of Adipose-Specific Proteins

Sargassum horneri (S. horneri) is a well-known brown seaweed widely distributed worldwide. Several biological activities of S. horneri have been reported. However, its effects on lipid metabolism and the underlying mechanisms remain elusive. In the present study, we examined the inhibitory effect of the active compound “(−)-loliolide ((6S,7aR)-6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydro-1-benzofuran-2(4H)-one (HTT))” from S. horneri extract on lipid accumulation in differentiated adipocytes. MTT assays demonstrated that (−)-loliolide is not toxic to 3T3-L1 adipocytes in a range of concentrations. (−)-loliolide significantly reduced intracellular lipid accumulation in the differentiated phase of 3T3-L1 adipocytes as shown by Oil Red O staining. Western blot analysis revealed that (−)-loliolide increased the expression of lipolytic protein phospho-hormone-sensitive lipase (p-HSL) and thermogenic protein peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1). Additionally, (−)-loliolide decreased expression of adipogenic and lipogenic proteins, including sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), and fatty acid-binding protein 4 (FABP4) in 3T3-L1 adipocytes. These results indicate that (−)-loliolide from S. horneri could suppress lipid accumulation via regulation of antiadipogenic and prolipolytic mechanisms in 3T3-L1 cells. Considering the multifunctional effect of (−)-loliolide, it can be useful as a lipid-lowering agent in the management of patients who suffer from obesity.     

Effects of Ethanol Extracts from Grateloupia elliptica,a Red Seaweed,and Its Chlorophyll Derivative on 3T3-L1 Adipocytes: Suppression of Lipid Accumulation through Downregulation of Adipogenic Protein Expression

Grateloupia elliptica (G. elliptica) is a red seaweed with antioxidant, antidiabetic, anticancer, anti-inflammatory, and anticoagulant activities. However, the anti-obesity activity of G. elliptica has not been fully investigated. Therefore, the effect of G. elliptica ethanol extract on the suppression of intracellular lipid accumulation in 3T3-L1 cells by Oil Red O staining (ORO) was evaluated. Among the eight red seaweeds tested, G. elliptica 60% ethanol extract (GEE) exhibited the highest inhibition of lipid accumulation. GEE was the only extract to successfully suppress lipid accumulation among ethanol extracts from eight red seaweeds. In this study, we successfully isolated chlorophyll derivative (CD) from the ethyl acetate fraction (EA) of GEE by high-performance liquid chromatography and evaluated their inhibitory effect on intracellular lipid accumulation in 3T3-L1 adipocytes. CD significantly suppressed intracellular lipid accumulation. In addition, CD suppressed adipogenic protein expression such as sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), and fatty acid binding protein 4 (FABP4). Taken together, our results indicate that CD from GEE inhibits lipid accumulation by suppressing adipogenesis via the downregulation of adipogenic protein expressions in the differentiated adipocytes. Therefore, chlorophyll from G. elliptica has a beneficial effect on lipid metabolism and it could be utilized as a potential therapeutic agent for preventing obesity.     

Reduction of adult hippocampal neurogenesis is amplified by aluminum exposure in a model of type 2 diabetes

In this study, we investigated the effects of chronic aluminum (Al) exposure for 10 weeks on cell proliferation and neuroblast differentiation in the hippocampus of type 2 diabetic rats. Six-week-old Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were selected and randomly divided into Al- and non-Al-groups. Al was administered via drinking water for 10 weeks, after which the animals were sacrificed at 16 weeks of age. ZDF rats in both Al- and non-Al-groups showed increases in body weight and blood glucose levels compared to ZLC rats. Al exposure did not significantly affect body weight, blood glucose levels or pancreatic β-cells and morphology of the pancreas in either ZLC or ZDF rats. However, exposure to Al reduced cell proliferation and neuroblast differentiation in both ZLC and ZDF rats. Exposure to Al resulted in poor development of the dendritic processes of neuroblasts in both ZLC and ZDF rats. Furthermore, onset and continuation of diabetes reduced cell proliferation and neuroblast differentiation, and Al exposure amplified reduction of these parameters. These results suggest that Al exposure via drinking water aggravates the impairment in hippocampal neurogenesis that is typically observed in type 2 diabetic animals.     

Antihypertensive effect of angiotensin i converting enzyme-inhibitory peptide from hydrolysates of Bigeye tuna dark muscle, Thunnus obesus

Angiotensin I converting enzyme (ACE) inhibitory peptide was isolated from tuna dark muscle hydrolysate prepared by alcalase, neutrase, pepsin, papain, alpha-chymotrypsin, and trypsin, respectively. Among hydrolysates, the pepsin-derived hydrolysate exhibited the highest ACE I inhibitory activity versus those of other enzyme hydrolysates. The structure of the peptide was identified to be Trp-Pro-Glu-Ala-Ala-Glu-Leu-Met-Met-Glu-Val-Asp-Pro (molecular weight 1581 Da) by time of flight mass spectrometry/mass spectrometry analysis, and the IC 50 value of the peptide was 21.6 microM. The Lineweaver-Burk plots revealed that the peptide acts as a noncompetitive inhibitor, and the inhibitor constant ( K i) was calculated as 26.6 microM using the secondary plots. The peptide had an antihypertensive effect according to the time-course measurement after oral administration to spontaneously hypertensive rats. Maximal reduction was detected 3 h after oral administration at a dose of 10 mg/kg of body weight. These results suggest that the peptide derived from tuna dark muscle would be a beneficial ingredient for functional food or pharmaceuticals against hypertension and its related diseases.     

N and P losses from a paddy field plot in central Korea

Abstract

The study was carried out to investigate the water balance and runoff and infiltration losses of nutrients in a paddy field plot located in southern Korea. Field monitoring was carried out during the cropping season from May 1, 1999 to September 30, 2000. The soil of the experimental paddy field belonged to the Jisan series (SiL; fine loam, mixed, mesic Fluventic Haplaquepts) covering on area of 5,000 m² (100 m × 50 m). The measured input quantities of N and P into the paddy field were as follows: 122 and 140 kg N ha^?1 and 29 and 30 kg P₂O₅ kg ha^?1 from chemical fertilizer, 20 and 28 kg N ha^?1 and 0.35 and 0.36 kg P ha^?1 from precipitation, and 26 and 35 kg N ha^?1 and 0.57 and 0.72 kg P ha^?1 from irrigation water, respectively. The measured outputs of N and P during the study period were as follows: 48 and 52 kg N ha^?1 and 1.1 and 1.6 kg P ha^?1 from runoff water, and 9 and 12 kg N ha^?1 and 0.04 and 0.05 kg P ha^?1 from infiltration. The runoff loading was the highest in June, presumably because of the higher concentrations of chemical components associated with chemical fertilizer application. The runoff losses of nutrients were compared to the amounts of nutrients supplied by chemical fertilizers. It was found that the losses of N accounted for 34.3 and 42.6% of the chemical fertilizer applied, while those of P accounted for 3.8 and 5.3%. The ratio between nutrient losses by infiltration and the chemical fertilizer applied was 6.4 and 9.8% for N and 0.1 and 0.2% for P, respectively.     

Changes in cyclooxygenase-2 immunoreactivity in the hippocampus in a model of streptozotocin-induced type 1 diabetic rats

In this study, we investigated diabetic stage dependent cyclooxygenase-2 (COX-2) immunoreactivity in the dentate gyrus in streptozotocin (STZ)-induced type 1 diabetic rats. The animals were sacrificed at 2, 3 and 4 weeks after STZ treatment. Blood glucose levels were increased after STZ treatment. COX-2 immunoreactivity in dentate gyrus was significantly increased in these regions 3 weeks after STZ treatment and restored to its basal level to 4 weeks after STZ treatment. In contrast, COX-2 immunoreactivity was not changed in CA3 region in all groups. These results suggest that STZ-induced type 1 diabetes transiently, but not permanently, decreased synaptic transmission and plasticity 3 weeks after STZ treatment in the dentate gyrus.     

金属聚氨酯夹芯板对蚕种孵化率的影响

金属聚氨酯夹芯板是一种新型建筑材料,保温性能好,在蚕种冷藏中有高效、节能的优点,经孵化试验对蚕种孵化率没有不良影响.