Okjin Kim

Anti-obesity and anti-diabetic effects of Yerba Mate (Ilex paraguariensis) in C57BL/6J mice fed a high-fat diet

Yerba Mate, derived from the leaves of the tree, Ilex paraguariensis, is widely-used as a tea or as an ingredient in formulated foods. The aim of the present study was to evaluate the effects of Yerba Mate extract on weight loss, obesity-related biochemical parameters, and diabetes in high-fat diet-fed mice.To this end, by using in vivo animal models of dietary-induced obesity, we have made the interesting observations that Yerba Mate has the ability to decrease the differentiation of pre-adipocytes and to reduce the accumulation of lipids in adipocytes, both of which contribute to a lower growth rate of adipose tissue, lower body weight gain, and obesity. Our data from in vivo studies revealed that Yerba Mate treatment affects food intake, resulting in higher energy expenditure, likely as a result of higher basal metabolism in Yerba Mate-treated mice. Furthermore, in vivo effects of Yerba Mate on lipid metabolism included reductions in serum cholesterol, serum triglycerides, and glucose concentrations in mice that were fed a high fat diet. In conclusion, Yerba Mate can potentially be used to treat obesity and diabetes.

Molecular identification of Mycoplasma cynos from laboratory beagle dogs with respiratory disease.

In this study, we examined a colony of 20 beagle dogs in a laboratory animal facility. Mycoplasma was detected by consensus PCR assay in 1 dog with respiratory and constitutional symptoms. None of the other dogs were affected. The dog was euthanized and necropsied. In postmortem examinations, gray or plum-colored gross lesions were found on the lung, most commonly in the apical and cardiac lobes. Some lesions showed clear demarcation and consolidation. Microscopic examination showed peribronchiolar lymphoid hyperplasia and interstitial thickening, lesions pathognomonic for mycoplasma pneumonia. To identify canine Mycoplasma species, we used species-specific PCR reactions for M. arginini, M. canis, M. cynos, M. edwardii, M. felis, M. gateae, M. maculosum, M. molare, M. opalescens, M. spumans, Mycoplasma sp. HRC 689, and M. collis. As the result, we identified Mycoplasma cynos by amplification of DNA extracted from lung tissue of the laboratory beagle dog with respiratory disease.

Sensitive and Specific Detection of Mycoplasma species by Consensus Polymerase Chain Reaction and Dot Blot Hybridization

Mycoplasmas are highly fastidious bacteria, difficult to culture and slow growing. Many species of mycoplasmas are important pathogens that cause respiratory infection in laboratory animals and that are known to affect experimental results obtained with contaminated animals. The aim of the present study was to develop a sensitive and specific assay for the detection of mycoplasma species. To this end, we developed a polymerase chain reaction and dot blot hybridization assay (PCR/DBH) for detecting mycoplasma DNA and evaluated it for its sensitivity and specificity. Mycoplasma consensus primer pairs were used for the amplification of target DNA. When PCR product was visually detected, the limit of detection of the PCR test was 102 pg of mycoplasma purified DNA. For DBH, the amplified DNA was labeled by incorporation of digoxigenin (DIG). This DIG-labeled probe was capable of detecting 104 pg of purified mycoplasma DNA by DBH. PCR/DBH was more sensitive than PCR or DBH alone and was also very specific. Our PCR/DBH assay can be applied efficiently to confirm the presence of mycoplasma species on clinical samples and to differentiate between mycoplasma species infection and other bacterial infections.

Cronobacter sakazakii Infection Induced Fatal Clinical Sequels Including Meningitis in Neonatal ICR Mice

Cronobacter sakazakii (C. sakazakii), formerly Enterobacter sakazakii, is an emerging pathogen associated with the ingestion of contaminated reconstituted formula that causes serious illnesses such as bacteremia, septicemia, necrotizing enterocolitis, meningitis and death in low-birth-weight preterm neonatal infants. The objective of this study was to develop an animal model for human neonatal C. sakazakii infections. We acquired timed-pregnant ICR mice and allowed them to give birth naturally. On postnatal day 3.5, each pup was administered orally a total dose of approximately 107 CFU C. sakazakii strain 3439. Mice were observed twice daily for morbidity and mortality. At postnatal day 10.5, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of C. sakazakii. C. sakazakii was isolated from cecum and other tissues in inoculated mice. In the tissues of C. sakazakii infected mice, meningitis and gliosis were detected in brain. In this study, we confirmed the neonatal ICR mice may be used a very effective animal model for human neonatal C. sakazakii infections.

Effects of male silkworm pupa powder on the erectile dysfunction by chronic ethanol consumption in rats

Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men worldwide. ED is now considered an early manifestation of atherosclerosis, and consequently, a precursor of systemic vascular disease. This study was designed to investigate the effects of male silkworm pupa powder (SWP) on the levels of nitric oxide synthase (NOS) expression, nitrite, and glutathione (GSH); lipid peroxidation; libido; and erectile response of the corpus cavernosum of the rat penis. We induced ED in the study animals by oral administration of 20% ethanol over 8 weeks. The SWP-treated male rats were divided into 3 groups that were orally administered 200, 400, and 800 mg/kg. The libido of the SWP-administered male rats was higher than that of the ethanol control group. In addition, the erectile response of the corpus cavernosum was restored in males on SWP administration, to a level similar to that of the normal group without ED. The testosterone concentration did not increase significantly. The lipid peroxidation in the corpus cavernosum of the male rats administered SWP decreased significantly. In contrast, compared to the ethanol group, SWP-administered male rats showed increased GSH levels in the corpus cavernosum. The level of nitrite and NOS expression in the corpus cavernosum of SWP-administered male rats increased significantly. These results indicated that SWP effectively restored ethanol-induced ED in male rats.

Sensitive and specific identification by polymerase chain reaction of Eimeria tenella and Eimeria maxima, important protozoan pathogens in laboratory avian facilities.

Eimeria tenella and Eimeria maxima are important pathogens causing intracellular protozoa infections in laboratory avian animals and are known to affect experimental results obtained from contaminated animals. This study aimed to find a fast, sensitive, and efficient protocol for the molecular identification of E. tenella and E. maxima in experimental samples using chickens as laboratory avian animals. DNA was extracted from fecal samples collected from chickens and polymerase chain reaction (PCR) analysis was employed to detect E. tenella and E. maxima from the extracted DNA. The target nucleic acid fragments were specifically amplified by PCR. Feces secreting E. tenella and E. maxima were detected by a positive PCR reaction. In this study, we were able to successfully detect E. tenella and E. maxima using the molecular diagnostic method of PCR. As such, we recommended PCR for monitoring E. tenella and E. maxima in laboratory avian facilities.

Uterine adenocarcinoma with feline leukemia virus infection

Feline endometrial adenocarcinomas are uncommon malignant neoplasms that have been poorly characterized to date. In this study, we describe a uterine adenocarcinoma in a Persian cat with feline leukemia virus infection. At the time of presentation, the cat, a female Persian chinchilla, was 2 years old. The cat underwent surgical ovariohystectomy. A cross-section of the uterine wall revealed a thickened uterine horn. The cat tested positive for feline leukemia virus as detected by polymerase chain reaction. Histopathological examination revealed uterine adenocarcinoma that had metastasized to the omentum, resulting in thickening and the formation of inflammatory lesions. Based on the histopathological findings, this case was diagnosed as a uterine adenocarcinoma with abdominal metastasis. To the best of our knowledge, this is the first report of a uterine adenocarcinoma with feline leukemia virus infection.

Effects of Ficus carica paste on constipation induced by a high-protein feed and movement restriction in beagles

Constipation is one of the most common functional digestive complaints worldwide. We investigated the laxative effects of figs (Ficus carica L) in a beagle model of constipation induced by high protein diet and movement restriction. The experiments were consecutively conducted over 9 weeks divided into 3 periods of 3 weeks each. All 15 beagles were subjected to a non-treatment (control) period, a constipation induction period, and a fig paste treatment period. We administered fig paste (12 g/kg daily, by gavage) for 3 weeks following a 3-week period of constipation induction in dogs. Segmental colonic transit time (CTT) was measured by counting radiopaque markers (Kolomark) using a radiograph performed every 6 h after feeding Kolomark capsules, until capsules were no longer observed. Fig paste significantly increased fecal quantity in constipated dogs, and segmental CTT was also reduced following fig paste administration. There were no significant differences in feed intake, water intake, body weight, or blood test results, between the constipation and fig paste administration periods. Our results demonstrate that fig is an effective treatment for constipation in beagles. Specifically, stool weight increased and segmental CTT decreased. Fig pastes may be useful as a complementary medicine in humans suffering from chronic constipation.

Spontaneous osteosarcoma of the femur in a non-obese diabetic mouse.

An abnormal swelling was identified in the distal portion of the right femur in a 1-year-old non-obese diabetic (NOD) mouse. Grossly, a large mass of the distal femur was observed in the right femur. Lesions were poorly marginated, associated with destruction of the cancellous and cortical elements of the bone, and showed ossification within the soft tissue component. Histologically, the tumor was identified as a poorly differentiated sarcoma. Histopathologic examination of the bone masses revealed invasive proliferation of poorly differentiated neoplastic mesenchymal cells forming streams, bundles, and nests, which resulted in destruction of normal bone. Neoplastic cells exhibited random variation in cellular appearance and arrangement, as well as matrix composition and abundance. Haphazard and often intermingling patterns of osteogenic, chondroblastic, lipoblastic, and angiogenic tissues were present. Larger areas of neoplastic bone and hyaline cartilage contained multiple large areas of hemorrhage and necrosis bordered by neoplastic cells. The mass was diagnosed as an osteosarcoma. To our knowledge, this is the first spontaneous osteosarcoma in an NOD mouse.

Usefulness of a Helicobacter pylori stool antigen test for diagnosing H. pylori infected C57BL/6 mice

Among several diagnostic tests, a Helicobacter pylori stool antigen (HpSA) test may offer a useful noninvasive method for diagnosing infection without sacrificing animals. In this study, male C57BL/6 mice (n=6) were infected with H. pylori ATCC 49503 (1×108 CFU/mouse) by intragastric inoculation three times at 2-day intervals, and H. pylori infected stool specimens were collected 1, 3, 5, 7, 14, 21 days after infection to assess reliability of the HpSA test. Five of six specimens were positive at 5-21 days after infection, and the sensitivity of the HpSA test was 83.33%. The presence of H. pylori infection was confirmed by the rapid urease test and genomic DNA polymerase chain reaction (PCR), and showed the same results as the HpSA. However, the rapid urease test and genomic DNA PCR are invasive tests and require animal sacrifice to detect H. pylori in gastric biopsy samples. We suggest that an HpSA test kit would be useful and effective for monitoring H. pylori in various laboratory animals, as H. pylori can be easily monitored without sacrificing animals.