Lessons learned from cloning dogs

The aim of this article is to review dog cloning research and to suggest its applications based on a discussion about the normality of cloned dogs. Somatic cell nuclear transfer was successfully used for production of viable cloned puppies despite limited understanding of in vitro dog embryo production. Cloned dogs have similar growth characteristics to those born from natural fertilization, with no evidence of serious adverse effects. The offspring of cloned dogs also have similar growth performance and health to those of naturally bred puppies. Therefore, cloning in domestic dogs can be applied as an assisted reproductive technique to conserve endangered species, to treat sterile canids or aged dogs, to improve reproductive performance of valuable individuals and to generate disease model animals.     

Composition of liquid rice hull smoke and anti-inflammatory effects in mice

A new liquid rice hull smoke extract with a smoky aroma and sugar-like odor prepared by pyrolysis of rice hulls followed by liquefaction of the resulting smoke contained 161 compounds characterized by GC/MS. Antioxidative, antiallergic, and anti-inflammatory activities of the extract were assessed in vitro and in vivo. At pH 5, the extract inhibited 1-diphenyl-2-picrylhydrazyl (DPPH) free radicals and suppressed nitric oxide (NO) and β-hexosaminidase releases from lipopolysaccharide (LPS)-induced RAW264.7 mouse macrophage leukemia cells and ionophore A23187-stimulated RBL-2H3 rat basophilic cells without significant cytotoxicity. 12-O-Tetradecanolylphorbol-13-acetate (TPA) was applied to the ears of CD-1 mice to induce inflammation (edema), which was accompanied by increases in a series of biomarkers. Topical application of 1% of the extract as well as feeding mice a standard diet with 1% extract for two weeks significantly reduced the expression of biomarkers associated with the TPA-induced inflammation. These include tumor necrosis factor-α (TNF-α), IL-1β, interleukin-1β (IL-1β), interleukin-6 (IL-6), leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), myeloperoxidase (MPO). These in vitro and in vivo findings demonstrate the potential value of rice hull smoke extract derived from a major agricultural byproduct to serve as a new biomaterial for the improvement of food quality and safety and the environment.     

Nematicidal and antifungal activities of annonaceous acetogenins from Annona squamosa against various plant pathogens

The methanol extract of Annona squamosa seeds was highly active against two phytoparasitic nematodes, Bursaphelenchus xylophilus and Meloidogyne incognita. It efficiently suppressed plant diseases, caused by Phytophthora infestans and Puccinia recondita. Ten annonaceous acetogenins (AAs) were isolated, and their chemical structures were identified by mass and nuclear magnetic resonance spectral data. Out of 10 substances, eight displayed strong in vitro nematicidal activity against B. xylophilus with LD(50) values ranging 0.006 to 0.048 μg/mL. Squamocin-G showed potent nematicidal activity against M. incognita. Squamocin, squamocin-G, and squamostatin-A also displayed potent in vitro and in vivo antifungal activities against P. infestans causing tomato late blight. In addition, squamostatin-A effectively controlled the development of wheat leaf rust caused by P. recondita. Our findings suggested that A. squamosa seeds and its bioactive AAs can be an alternative resource of a promising botanical nematicide and fungicide to control various plant diseases.     

Ahmed glaucoma valve implantation with Ologen® Collagen Matrix for the surgical treatment of feline glaucoma

An Ahmed valve implantation with an Ologen^® Collagen Matrix (Ologen^® CM, Aeon Astron, Leiden, the Netherlands) was performed for the treatment of uncontrolled glaucoma in a cat. This cat was a 5‐year‐old castrated Russian Blue male with a 12‐week history of conjunctival hyperemia and mydriasis of the left eye. During the ophthalmic examination, the intraocular pressure (IOP) oculus sinister (OS) was 52 mmHg, and a narrow iridocorneal angle (ICA) was detected by gonioscopy. Medical treatment with Cosopt^® (2% dorzolamide and 0.5% timolol) failed to decrease the IOP. The left eye still had vision, and an Ahmed valve implantation was performed. During the gonioimplantation, Ologen^® CM was used to inhibit scar formation around the valve. Following the operation, the IOP was stable at an approximate average of 15 mmHg during the 7‐month follow‐up period, and vision in the left eye was retained without medication. An adequate subconjunctival filtering bleb was formed after 140 days. This is the first case report in which an Ahmed valve gonioimplant with an Ologen^® CM has been used for the surgical treatment of glaucoma in a cat.     

Distribution of streptogramin resistance genes and genetic relatedness among quinupristin/dalfopristin-resistant Enterococcus faecium recovered from pigs and chickens in Korea

Fifty-four quinupristin/dalfopristin-resistant Enterococcus faecium (QDREF) isolated from chickens and pigs during 2002-2003 in Korea were screened by PCR for the presence of streptogramin resistance genes vatD, vatE, and vgbA, and macrolide resistance gene ermB. None of the QDREF isolates carried vgbA and vatD genes, while vatE and ermB were detected in 9.2% and 74% of the isolates, respectively. Twenty-six percent (14/54) of the QDREF isolates contained none of the resistance determinants tested. Pulsed-field gel electrophoresis (PFGE) patterns revealed high heterogeneity: 47 different patterns for 54 QDREF evaluated. Identical PFGE types were observed in two pairs of chicken isolates and a pair of pig isolates, respectively, but chicken isolates did not share PFGE pattern with pig isolates, suggesting clonal spread of QDREF strain between the same species of animals but not between different species of animals. This is the first report, to our knowledge, of vatE-positive E. faecium isolates and also the first evidence of clonal spread of QDREF strain between animals in Korea.     

Carbon dioxide partial pressure in the columbia river

Columbia River water is supersaturated with respect to atmospheric carbon dioxide by 200 to 870 parts per million. An equilibrium exists between the carbon dioxide partial pressure and pH, and Henry's law is obeyed in this natural water. The carbon dioxide pressure can be calculated by a determination of the pH, total carbon dioxide, and temperature.     

The intelligent data management system for toxicogenomics

Toxicogenomics is now emerging as one of the most important genomic application because the toxicity test based on gene expression profiles is expected to be more precise and efficient than current histopathological approaches in a pre-clinical phase. One of the challenging issues in toxicogenomics is the construction of intelligent database management system which can deal with heterogeneous and complex data from many different experimental and information sources. TEST(Toxicogenomics for Efficient Safety Test) database is especially focused on the connectivity of heterogeneous data and the intelligent query system which enable users to obtain relevant useful information from the complex data sets. The database deals with four kinds of information; compound, histopathology, gene expression, and annotation information. Currently, TEST database maintains toxicogenomics information for 16 compounds, 45 microarrays, 190 animal experiments, and customized 4.8 K rat clone set. Our presented system is expected to be a good information source for studying of toxicology mechanism in the genome-wide level and can also be applied to the designing toxicity test chip.     

Effect of dihydrotestosterone on mouse embryonic stem cells exposed to H2O2-induced oxidative stress

Oxidative stresses induced by reactive oxygen species (ROS) have been shown to be involved in several physiological and pathophysiological processes, such as cell proliferation and differentiation. Steroid hormones can protect cells against apoptosis or induce cell proliferation by several mechanisms. Among androgenic hormones, dihydrotestosterone (DHT) is generated by a 5α-reduction of testosterone. Unlike testosterone, DHT cannot be aromatized to estradiol, therefore DHT is considered a pure androgenic steroid. This study was conducted to examine the effect of DHT (10^-7 M) on H₂O₂ (10^-3 M) -induced injuries in mouse embryonic stem (ES) cells. H₂O₂ induced ROS generation and increased lipid peroxide formation and DNA fragmentation. These effects of H₂O₂ were inhibited by pretreatment with DHT. H₂O₂ also increased the phosphorylation of p38 MAPK, SAPK/JNK and nuclear factor kappa B (NF-κB), but DHT blocked these effects. Moreover, H₂O₂ decreased DNA synthesis and the levels of cell cycle regulatory proteins [cyclin D1, cyclin E, cyclin-dependent kinase (CDK) 2, and CDK 4]. These effects of H₂O₂ were inhibited by pretreatment with DHT. In conclusion, DHT may partially prevent H₂O₂-induced cell injury through inhibition of ROS and ROS-induced activation of p38 MAPK, SAPK/JNK and NF-κB in mouse ES cells.     

Antibiotic resistance and molecular characterization of ophthalmic Staphylococcus pseudintermedius isolates from dogs

The prevalence, virulence potential, and antibiotic resistance of ophthalmic Staphylococcus pseudintermedius (SP) isolated from dogs were examined. Sixty-seven Staphylococcus species were isolated from ophthalmic samples and surveyed for species-specific sequences in the Staphylococcus intermedius group (SIG) nuclease gene (SInuc), exfoliative toxin gene for SIG (siet), and antibiotic resistance genes (blaZ and mecA). PCR-restriction fragment length polymorphism analysis of the pta gene was also performed. Fifty isolates were identified as SIG strains, all of which were found to be SP. The blaZ gene was detected in 42 of the 50 SP strains and mecA gene was observed in 18 of the 50 SP strains. The 50 SP strains were most susceptible to amoxicillin/clavulanic acid (94%) and chlorampenicol (70%), and highly resistant to tetracycline (94%) and penicillin (92%). It was also found that 16 (88.9%) mecA-positive SP strains were resistant to oxacillin, tetracycline and penicillin. All mecA-positive SP were resistant to more than four of the eight tested antibiotics and therefore considered SP with multi-drug resistance (MDR). Our results indicate a high prevalence of antibiotic resistance genes in ophthalmic SP along with a close relationship between MDR SP strains and the mecA gene. Based on our findings, judicious administration of antibiotics to companion dogs is necessary.