Establishment of a chronic obstructive pulmonary disease mouse model based on the elapsed time after LPS intranasal instillation / 한국실험동물학회지

Chronic obstructive pulmonary disease (COPD) was the 3rd leading cause of death in 2012 worldwide. It is particularly severe in the elderly, who are at risk of death by coughing, mucous hypersecretion, and finally breathlessness. Recently, anti-COPD drug development has increased, and many animal screening systems have been studied. Tobacco smoke animal models are the best known animal screening system, but have several preparation requirements, such as a tobacco smoke generator and a separate facility to prevent smoke release. Accordingly, we evaluated the properties of a lipopolysaccharide (LPS) murine model for COPD screening and the effect of the time elapsed from 0 to 72 hr after LPS intranasal instillation on various biomarkers of COPD severity, such as WBC and neutrophils in bronchoalveolar fluid (BALF), IgE in serum, histopathology in the lung, and cytokines (IL-8, TNF-α, IFN-γ, and TGF-β) and chemokines (CCL-2, CXCL1, CXCL9, CXCL10, and CXCL11) in the respiratory system. Although from 48 hr after LPS treatment several factors which could be evaluated as biomarkers for COPD establishment such as WBC and neutrophil in BALF, IgE in serum, cytokines (IL-8, TNF-α, and IFN-γ), and chemokines (CCL-2, CXCL1, CXCL9, CXCL10, and CXCL11) increased at 72 hr the increment of important factors for COPD establishment such as IgE, fibrosis in the lung, and cytokines (IL-8, TNF-α, and IFN-γ) was more clear. Based on our results, we concluded that the optimal time after LPS intranasal instillation is 72 hr.

Safety of 8-weeks oral administration of Arctium lappa L / 한국실험동물학회지

Recently, worldwide dietary reference intakes have been considered an important guideline for public health. Some governments and the World Health Organization (WHO) provide guidelines concerning dietary intake. Although an ingredient may have a history of use as a culinary material, changes in the environment over time suggest that the acceptable maximum intake each of food/culinary material should be regularly evaluated. Arctium lappa L. has been used as a culinary material for many centuries in Korea and Japan and some recent studies have reported related therapeutic effects. However, there are no reports on the safety of repeated oral administration. In this study, we evaluated the safety of a 8-weeks repeated oral intake of A. lappa. We concluded that treatment with <250 mg/kg A. lappa, which was within the safety range, resulted in body weight decrease and blood glucose suppression.

Age-associated changes in pancreatic exocrine secretion of the isolated perfused rat pancreas / 한국실험동물학회지

Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and beta-cell's sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCK-stimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.

Aerobic bacteria from oral cavities and cloaca of snakes in a petting zoo / 대한수의학회지

It is important to identify the bacteria in snakes because they can cause disease; importantly, bacteria such as Stenotrophomonas maltophilia, Escherichia coli, Proteus vulgaris etc. could be pathogens especially in hospitalized, debilitated hosts, and immunocompromised patients. To analyze the distribution of snakes' bacteria in petting zoo, samples from 20 snakes were collected from 2002 to 2008. Nine bacteria species were isolated from both oral and cloaca while four and six species were identified only from oral and cloaca, respectively. Except for Actinobacter sp., all of the identified strains are opportunistic pathogens, and most of them can cause nosocomial infections in humans. Present results indicate that prevalence of various zoonotic bacterial strains in snakes could be involved in potential transfer of these bacteria into caretakers and other animals. Therefore, it needs to examine the antibiotic resistance of these pathogens to prevent outbreaks.

Identification of bacteria from the oral cavity and cloaca of snakes imported from Vietnam / 한국실험동물학회지

Reptiles are used for various purposes these days, including public exhibits, medicinal applications, and as laboratory animals. As the international exchange of reptiles has gradually increased, more people have had the opportunity to come in contact with these animals. Snakes typically live in the rhizosphere where various bacterial strains exist and as such they can lead to opportunistic human diseases. When snakes are encountered in veterinary medicine, it is necessary to monitor their microflora. Native microflora of reptiles imported from other countries has not yet been reported in Korea. In this study, oral and cloacae samples were collected from 18 Burmese pythons transported from Vietnam. The specimens were incubated at 37degrees C for 18 h to produce colony growth under aerobic condition and isolated colonies were then identified using a VITEK automated identification system. There were fourteen types of aerobic bacteria isolated from both oral and cloacae samples, nine from only oral specimens, and fifteen from only cloacae specimens. Most bacteria isolated were opportunistic pathogens of humans which therefore have the potential to induce disease in people. Based on the microflora and the prevalence of bacterial strains in snakes, quarantine procedures for reptiles transported internationally should be strengthened. Characterization of the microflora of reptiles with the potential to induce zoonosis should be performed in those used as laboratory animals and to prevent zoonotic outbreaks in the general population as well as among veterinarians.

Anti-hepatofibrogenic Effect of Turnip Water Extract on Thioacetamide-induced Liver Fibrosis / 한국실험동물학회지

Liver fibrosis is a chronic liver disease and lots of people in Korea are suffered. There are many efforts to find candidates to suppress liver fibrogenesis and several chemical-induced model or bile duct ligation model have been used to research and develop hepatic fibrogenic suppressor. From the previous study about functional effects of turnip which cultivated in Kangha Island, we got the feasibility which turnip might be able to inhibit heptatic fibrogenesis. TAA is a representative hepatic fibrosis inducer, repeated 7-weeks i.p. injection of it results in hepatic fibrosis. We compared the level of hepatic fibrosis in TAA-turnip group, TAA group, and vehicle control group. Nodules-formed by TAA were observed; they were rarely shown in vehicle control group, observed in most area in TAA group, but only shown in periportal regions in TAA-turnip group. These results were confirmed through Masson's trichrom stain; fibrous structures increased in TAA group (fibrosis score: 4) but significantly decreased in TAA-turnip group (fibrosis score: 2-3). In conclusion, we got the result that turnip water extract has a potency to protect TAA-induced hepatic fibrogenesis but it is necessary further study to find its mechanism.

Melatonin enhances hepatic glutathione-peroxidase activity in Sprague-Dawley rats

Effects of melatonin on hepatic glutathione-peroxidase (GSH-Px) and glutathione-reductase (GSH-reductase) activities were studied in Sprague-Dawley (SD) rats administered i.p. (10 mg/kg body weight) with melatonin during 15 days. The activity of cytosolic GSH-reductase in the liver was not changed by melatonin. However, melatonin injection increased significantly the activity of liver cytosolic GSH-Px activity compared with those in saline-treated rats. At the same time, plasma GSH-Px was also increased significantly in melatonin-treated rats. Since GSH-Px, a major antioxidative enzyme, removes H-2O-2 and lipid peroxides which are formed during lipid peroxidation from cellular membrane, such elevation of heptatic GSH-Px activity may contribute to the improvement of antioxidative effects under oxidative damage in the liver.