In vitro antiprotozoal effects of artemisinin on Neospora caninum.

Neospora caninum is an intracellular apicomplexan parasite that infects a wide range of mammals and has been associated with abortion in cattle worldwide. Artemisinin is an effective antimalarial compound derived from a traditional Chinese herbal remedy, qinghao or Artemisia annua L. In the study reported, the cultured host cells (vero cells or mouse peritoneal macrophages) infected with N. caninum tachyzoites were incubated with alpha-MEM (minimal essential medium) 10%HS supplemented with various concentration or artemisinin (20, 10, 1, 0.1 and 0.01 microg/ml) to examine the efficacy of artemisinin against N. caninum tachyzoites intracellular multiplication. In long-term studies, at 20 or 10 microg/ml for 11 days, artemisinin reduced N. caninum and completely eliminated all microscopic foci of N. caninum. At 1 microg/ml for 14 days, artemisinin reduced N. caninum and completely achieved elimination of all microscopic foci of N. caninum. There was no apparent toxicity to host cells in long-term studies. In short-term studies, at > or = 0.1microg/ml, artemisinin reduced N. caninum tachyzoites intracellular multiplication, significantly (P < 0.05) and appeared to depend on the artemisinin concentrations. Pretreatment of host cells or N. caninum tachyzoites with artemisinin had no effect on N. caninum tachyzoites intracellular multiplication. These results demonstrate that artemisinin inhibited N. caninum tachyzoites intracellular multiplication.     

3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid, an active principle of kimchi, inhibits development of atherosclerosis in rabbits

The effects of 3-(4'-hydroxyl-3',5'-dimethoxyphenyl)propionic acid (HDMPPA) originating from Korean cabbage kimchi were investigated, showing an antioxidant effect on the prevention of atherosclerosis in hypercholesterolemic rabbits. Twenty-one 3-month-old rabbits were fed an atherogenic diet containing 0.5% (w/w) cholesterol and 10% (w/w) coconut oil, whereas another two groups were given an atherogenic diet with intravenous injection of either HDMPPA or simvastatin (0.33 mg/kg/day) for 4 weeks. HDMPPA inhibited the oxidative modification of low-density lipoprotein (IC 50 = 1.4 microg/mL) and increased 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity (IC 50 = 0.78 microg/mL) in a dose-dependent manner. In hypercholesterolemic rabbits, the thickness of intima of aorta of the HDMPPA group was significantly reduced (control versus HDMPPA, 42%; simvastatin, 38%) without a plasma cholesterol-lowering effect. Thiobarbituric acid reactive substance formation in the plasma of the HDMPPA group was significantly decreased compared to that of the control group. Furthermore, the generation of vascular reactive oxygen species in HDMPPA group was suppressed as the cyclooxygenase-2 protein level decreased. These findings suggest that HDMPPA prevents the development of aortic atherosclerosis in high-cholesterol-fed rabbits. The antiatherosclerotic effect of HDMPPA may be due to an antioxidative effect at a low dose without cholesterol-lowering effects.     

Evaluation of interthalamic adhesion size as an indicator of brain atrophy in dogs with and without cognitive dysfunction

Interthalamic adhesion thickness has been previously described as a parameter for quantifying canine brain atrophy and hypothesized to correlate with brain height or ventricular size. However, studies testing this hypothesis are lacking. This retrospective cross‐sectional study aimed to compare interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio values in dogs with and without cognitive dysfunction. Medical records for dogs meeting the following inclusion criteria were retrieved from two hospitals: available brain magnetic resonance imaging (MRI) or computed tomography (CT) studies, no cerebral parenchymal lesions, and no prior neurological treatment. For each included dog, values of interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio were measured by one observer from transverse CT or MRI images and a consensus was reached. A total of 113 dogs met inclusion criteria. Dogs were divided into three groups based on the following criteria: Young group (no cognitive dysfunction, <9‐year‐old, n = 43), Aging group (no cognitive dysfunction, ≥9‐year‐old, n = 61), and Dementia group (n = 9). All three parameters were significantly lower in the dementia group than in the Young and Aging groups. In the Young and Aging groups, there was significant negative correlation of all three parameters with age and positive correlation of interthalamic adhesion thickness and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio with body weight, while there was no correlation of interthalamic adhesion thickness/brain height ratio with body weight (P < 0.05). There were no differences in all three parameters according to skull type or gender. Findings from the current study supported the use of interthalamic adhesion thickness, interthalamic adhesion thickness/brain height ratio, and interthalamic adhesion thickness/brain height ratio/lateral ventricle to brain height ratio for quantifying brain atrophy in dogs with cognitive dysfunction.     

Phylogenetic analysis of benign Theileria species based on major piroplasm surface protein (MPSP) genes from ticks of grazing cattle in Korea

Complete major piroplasm surface protein (MPSP) gene sequences of benign Theileria parasites were isolated from ticks of grazing cattle in Korea. A total of 556 tick samples were collected in five provinces: Chungbuk, Jeonbuk, Jeonnam, Gyeongbuk, and Jeju during 2010-2011. Fifteen samples from Chungbuk and Jeonnam were positive for the Theileria MPSP gene by PCR amplification using a specific primer set. A phylogenetic tree was constructed with the amplified gene sequences and 26 additional sequences published in GenBank. The benign Theileria parasites were classified into eight types, those isolated from Korean cattle ticks belonged to Types 1 (Ikeda), 2 (Chitose), 4, and 8. Types 2 and 4 were the most common types, with the rate of 40%, followed by Types 1 and 8 (with the rate of 13% and 7%, respectively). Nucleotide sequence identities of 23 theilerial MPSP sequences (15 MPSP gene sequences amplified and 8 sequences published) ranged from 67.3 to 99.8%. Multiple alignments of the deduced amino acid sequences also showed that each type was characterized by specific amino acids: 7 for Type 1, 9 for Type 2, 4 for Type 4, and 3 for Type 8.     

Efficacy of silver ions against Sacbrood virus infection in the Eastern honey bee Apis cerana

Although silver is known to be a broad-spectrum biocidal agent, the effects of this metal against Sacbrood virus have not yet been investigated. In this study, we evaluated the efficacy of silver ions against natural Korean sacbrood virus (KSBV) infection of Apis (A.) cerana. Ten KSBV-infected colonies containing A. cerana with similar strength and activity were selected from an apiary located in Bosung-gun (Korea). Among these, five colonies were randomly assigned to the treatment group that was fed sugar syrup containing 0.2 mg/L silver ions. The other colonies were assigned to the untreated control group in which bees were given syrup without the silver ions. To assess the efficacy of the silver ions, colony strength, colony activity, and the number of dead larvae per hive were measured. During the experimental period, the test group maintained its strength and activity until day 32 while those of bees in the control group decreased sharply after day 8 to 16. Survival duration of the test group was significantly longer (40 days) than that of the control group (21 days). These results strongly indicated that silver ions are effective against KSBV infection in A. cerana.     

Temporal expression analyses of pancreatic and gastric digestive enzymes during early development of the olive flounder (Paralichthys olivaceus)

The olive flounder (Paralichthys olivaceus) is one of the most important aquaculture species in Korea. Previous studies focused on the morphological changes and only analysed digestive enzyme expression patterns of certain digestive systems. A comprehensive analysis of the pancreatic and gastric digestive enzymes of the olive flounder in its early developmental stages has not been performed. In this study, we determined the mRNA expression levels of pancreas and stomach digestive enzymes by extracting total RNA from the whole body of olive flounders from hatching to post‐metamorphosis and conducting real‐time PCR analysis with gene‐specific primers for each isoform. The pancreatic digestive enzymes were initially and strongly expressed from the first feeding period to pre‐metamorphosis. The expression of trypsinogen 3 was detected from the early stage of development to metamorphosis, whereas trypsinogen 2 was significantly increased only in the post‐metamorphosis period. The mRNA expression of pepsinogen was only detected at metamorphosis and corresponded to stomach differentiation. The lipid digestive‐related enzymes had already reached a certain level at the beginning of hatching, then increased during the early developmental stage and gradually decreased before metamorphosis. These results suggest that food ingestion is exclusively digested by pancreatic digestive enzymes and trypsinogen 3 during the early developmental stage until pre‐metamorphosis, and it then fully switches to digestion by pepsinogen and trypsinogen 2 in mid‐metamorphosis. In conclusion, understanding the expression profiles of digestive enzymes in the pancreas and stomach during the early developmental stages is an important consideration when developing formulated larval diets for aquacultured olive flounder.     

A comparison of one‐slope straight broken‐line,two‐slope straight broken‐line,quadratic broken‐line and quadratic models to estimate an accurate optimum feeding rate for juvenile olive flounder (Paralichthys olivaceus)

Two feeding trials using different commercial feeds and different fish sizes were conducted to compare model performance of various regression models on the estimation of optimum feeding rates (OFR; % BW/day) for juvenile olive flounder. Six feeding rates ranging from 1% to 11% in trial I and another six feeding rates ranging from 1% to 6% in trial II were tested. Final body weight, weight gain, feed conversion ratio, condition factor, nutrient gains, and whole‐body lipid and energy contents were significantly influenced by the feeding rates in both trials. The overall responses shown in trial I were generally comparable to those observed in trial II. In trial I, the OFR was estimated to be 7.3%, 5.7%, 9.8% and 10.2% by the one‐slope straight broken‐line, two‐slope straight broken‐line, quadratic broken‐line and quadratic models, respectively. In trial II, the OFR was estimated to be 4.8%, 4.6%, 8% and 8% by the one‐slope broken‐line, two‐slope broken‐line, quadratic broken‐line and quadratic models, respectively. Based on the model selection criteria (R²_adj and AICc), the quadratic broken‐line model was selected as the best‐fit model in both trials. This model that describes the dose–response relationship best among the tested models can be recommended when determining an OFR.     

Production of specific antibodies against SARS-coronavirus nucleocapsid protein without cross reactivity with human coronaviruses 229E and OC43

Severe acute respiratory syndrome (SARS) is a life-threatening disease for which accurate diagnosis is essential. Although many tools have been developed for the diagnosis of SARS, false-positive reactions in negative sera may occur because of cross-reactivity with other coronaviruses. We have raised polyclonal and monoclonal antibodies (Abs) using a recombinant form of the SARS virus nucleocapsid protein. Cross-reactivity of these anti-SARS Abs against human coronavirus (HCoV) 229E and HCoV OC43 were determined by Western blotting. The Abs produced reacted with recombinant SARS virus nucleocapsid protein, but not with HCoV 229E or HCoV OC43.