Acaricidal activity of plant essential oils against Dermanyssus gallinae (Acari: Dermanyssidae)

The acaricial activity of 56 plant essential oils against poultry house-collected adult Dermanyssus gallinae De Geer was examined using direct contact and fumigation methods. In a filter paper contact bioassay, 100% mortality at 0.07 mg cm⁻² was observed in bay, cade, cinnamon, clove bud, coriander, horseradish, lime dis 5F, mustard, pennyroyal, pimento berry, spearmint, thyme red and thyme white oils, whereas the mortality of these oils was significantly decreased at 0.02 mg cm⁻². In fumigation tests with adult D. gallinae at 0.28 mg cm⁻², cade, clove bud, coriander, horseradish and mustard oils were more effective in closed containers than in open ones, indicating that the effect of these essential oils was largely due to action in the vapour phase. Plant essential oils described herein merit further study as potential D. gallinae control agents.     

Increased expression of both constitutive and inducible forms of nitric oxide synthase in the delayed phase of acute experimental testicular torsion

To elucidate the roles of both constitutive endothelial nitric oxide synthase (eNOS) and neuronal NOS (nNOS), and inducible NOS (iNOS) in acute experimental testicular torsion, the expression of iNOS and constitutive eNOS and nNOS were studied in the rat testis with ischemia/reperfusion (I/R) injury. Western blot analysis showed that all three isoforms of NOS increased significantly at 24-48 hr after I/R and declined slightly thereafter. After I/R, immunoreactivity for both iNOS and nNOS was detected, mainly in the interstitial space around damaged tubules, while germ cells in the damaged tubules were immunostained intensely for eNOS. We postulate that increased expression of the three NOS isoforms in the testis after I/R, which might generate nitric oxide, affects delayed germ cell death following I/R via paracrine or autocrine fashion.     

Role of gap junctional intercellular communication (GJIC) through p38 and ERK1/2 pathway in the differentiation of rat neuronal stem cells

Gap junctional intercellular communications (GJIC) contributes to neural function in development and differentiation of CNS. In this study, we have investigated the expression of GJIC during the differentiation of neuronal stem cells and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neuronal stem cell-derived cells from rat brain. During neuronal stem cell differentiation, expressions of Cx43 and 32 were increased for the duration of 72 hr, however the effect were decreased on the 7d. In the neuronal stem cell-derived cells, pretreatments with p38 MAP kinase inhibitor, SB203580, and MEK inhibitor, PD98059, could protect GJIC against TPA-induced inhibition of GJIC. Our data suggest that GJIC plays an important role during neuronal stem cell differentiation, and ERK1/2 and p38 MAP kinase signaling pathway may be closely related functionally to regulate gap junction in rat neuronal stem cell-derived cells.     

Identification of syn- and anti-anethole-2,3-epoxides in the metabolism of trans-anethole by the newly isolated bacterium Pseudomonas putida JYR-1

Bacterial strain JYR-1, which utilizes high concentrations (up to 100 mM) of trans-anethole as the sole source of carbon and energy, was isolated from soil. It grew to OD(600)(nm) = 2.6 with a doubling time of 8 h when grown on 20 mM trans-anethole. Strain JYR-1 was identified as Pseudomonas putida based on the partial gene sequence of its 16S rDNA. Elution profiles of culture extracts were examined by high-performance liquid chromatography and showed that four metabolites were produced from the bacterial culture containing trans-anethole that were not detected in control experiments. LC-MS analysis showed molecular weights of 138.2, 164.5, 164.3, and 152.3. The metabolites with molecular weights at 152.3 and 138.2 were confirmed to be p-anisic acid and p-hydroxybenzoic acid, respectively, when compared with HPLC retention times and molecular weights of authentic compounds. The metabolites with molecular weights at 164.5 and 164.3 were further analyzed by NMR and were proved to be stereoisomer syn- and anti-anethole epoxides. Therefore, strain JYR-1 most likely initiates the metabolism of trans-anethole through the formation of epoxides on the propene group of the compound.     

Genetic analysis of VP2 gene of canine parvovirus isolates in Korea

The purpose of this study was to genetically characterize CPV isolates from Korea. The VP2 gene of 31 isolates was characterized by DNA sequencing and their phylogeny. Among the 31 field CPV isolates, 28 isolates were classified as type 2a and other 3 isolates as type 2b. The isolates in 2a-I, II and III subclusters have unique mutations. The isolates in 2a-IV and V subclusters had similar amino acid sequences to type 2a isolates from other parts of the world. The isolates in type 2b had similar amino acid sequences to type 2b isolates from Asia, Italy, and U.S.A. The molecular analysis of VP2 gene of CPV provided the useful information for the identification of CPV types and the understanding of their genetic relationship.     

Effects of ginsenosides on organogenesis and expression of glutathione peroxidase genes in cultured rat embryos

Ginseng has been extensively used around the world for several thousand years as a food or drug. However, recently, several reports have indicated that the organogenesis of cultured embryos is inhibited by treatment with ginsenoside, the principal component of ginseng. In this study, we evaluated the morphological changes of embryos and the gene expression patterns of antioxidant enzymes, 3 types of glutathione peroxidases [GPx; cytosolic (cGPx), plasma (pGPx) and phospholipid hydroperoxide (phGPx) forms], in cultured rat embryos (embryonic days 9.5-11.5) exposed to ginsenosides Rb1, Rg1, Re and Rc at levels of 5, 50 and 100 microg/ml. With regard to total morphological scores, no significant differences were noted in the embryos exposed to all doses of ginsenosides, with the exception of 50 microg/ml of Rc. In the cultured embryos exposed to Rg1, a majority of the developmental parameters were normal, but growth of the hind- and mid- brains and the caudal neural tube was significantly increased compared with that observed in the control group (P<0.05). Furthermore, Rc significantly enhanced the growth of a variety of developmental parameters in the cultured embryos, with the exception of the hindlimbs. According to the results of our semiquantitative RT-PCR analysis, the levels of cGPx and phGPx mRNA in the cultured embryos were unaffected by treatment with the ginsenosides. However, the levels of pGPx mRNA increased significantly in the embryos treated with ginsenosides Re, Rc and Rb1 compared with the control group (P<0.05). These findings indicate that ginsenosides may exert a stimulatory effect on the growth of embryos via differential expression of GPx genes.     

Evaluation of growth differentiation factor 11 (GDF11) levels in dogs with chronic mitral valve insufficiency

Growth differentiation factor 11 (GDF11) regulates cell growth and differentiation in both embryonic and adult tissues. Circulating GDF11 levels have recently been reported to be significantly lower in aging mice and restoration of GDF11 reversed age-related cardiac hypertrophy in old mice. Here, we evaluated the potential of serum levels of GDF11 as a circulating biomarker in dogs at different stages of heart failure, due to chronic mitral valve insufficiency (CMVI). We found no significant differences in serum GDF11 levels between dogs at different stages of CMVI-associated heart failure. Furthermore, the circulating levels of GDF11 did not correlate with age, body weight, echocardiographic variables, and the severity of CMVI-induced heart failure in dogs.     

Statistical Modeling of Phosphorus Dry Deposition Rates Measured in South Florida

Dry deposition may be a substantial source ofphosphorus (P) to the Florida Everglades. Drydeposition has been measured on a weekly basis in theregion since 1987, but a significant amount of thisdata is missing (about 34%) due to instrumentalfailures and sample contamination. This study developsa statistical model of the P dry depositiontime-series to estimate missing data. The model isbased on a multivariate stochastic time-series theory.Model parameters are calibrated using theexpectation-maximization algorithm which is efficientfor data sets with many gaps. The pooled mean andstandard deviation of the data before estimating themissing values was 88.4±85.7 μg P m^-2d^-1 and after estimating the missing values was87.8±82.4 μg P m^-2 d^-1. Modelverification demonstrates that the calibrated modelsprovide unbiased data estimates while preserving thestatistics of the raw data. For each sampling site themean and standard deviation before and after werequite similar. No trend with time was detected. The Pdeposition fluctuates seasonally (highest in Octoberand lowest in June), but this fluctuation does notfollow the seasonal pattern of Florida's rainfall. Random noise in the data, however, is significant andcauses long-term fluctuations of the data. The datawith gaps filled in are useful for computing theweekly P load distribution.     

Effects of irradiated phytic acid on antioxidation and color stability in meat models

Lipid oxidation and color stability of meats treated with irradiated phytic acid were investigated during storage for 2 weeks at 4 degrees C. The phytic acid in deionized distilled water (DDW) was degraded by irradiation at 10 and 20 kGy, and the irradiated phytic acid showed a strong antiradical activity. For measuring the antioxidant effects of irradiated phytic acid in food models, beef and pork were prepared with DDW (control), irradiated (10 and 20 kGy) or non-irradiated phytic acid, and ascorbic acid as a model system. Irradiated phytic acid significantly inhibited the lipid oxidation in meats compared to the control and ascorbic acid treated samples during storage (P < 0.05). The redness of the meats treated with phytic acid had a higher value than did the control and ascorbic acid treated samples, but a significant difference was not observed in the samples treated with phytic acid regardless of irradiation treatment. Irradiated phytic acid was also effective in inhibiting the loss of heme iron and metmyoglobin formation during storage. Results indicated that irradiation might be helpful for improving the antioxidant activity of phytic acid in meats.     

Preparation and characterization of polyurethane foam using a PLA/PEG polyol mixture

Polyurethanes are polymers with urethane linkages in their backbone. It is prepared by polyaddition polymerization between isocyanates and polyols, which produce different chemical, physical, and mechanical properties depending on their types and characteristics. Previous reports of polyurethane foams prepared by using PEG polyol indicated prominent features in the elasticity and recovery of the foams. However, it is necessary to improve the mechanical strength of these materials. In this study, polyurethane foams were prepared using a PLA/PEG polyol mixture and 1,6-hexamethylene diisocyanate. PLA polyol was synthesized by the direct condensation polymerization of lactic acid. The polyurethane foams were characterized using FE-SEM analysis, FT-IR spectroscopy, water absorbency measurement, and mechanical property measurement. In FE-SEM analysis, it was shown that the PLA content of polyol mixture significantly affected the porous structure. FT-IR spectra confirmed that urethane linkages formed between the PLA/PEG polyols and the isocyanates. The water absorbency decreased due to the hydrophobicity of PLA. With respect to the mechanical properties, the breaking stress and the Young’s modulus increased with increasing PLA content. When the PLA content of polyols was 60 and 70 percent, the breaking strain was significantly higher than those of other polyurethane foams.