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Postnatal development of Harderian gland in Mongolian gerbil
1999
Oh, S.H. | Park, J.Y. | Seong, J.K. (Yonsei University, Seoul (Korea Republic). Department of Laboratory Animal Medicine, Medical Research Center, College of Medicine) | Yoon, Y.S. | Lee, J.S. (Seoul National University, Suwon (Korea Republic). Department of Veterinary Histology and Embryology, College of Veterinary Medicine) | Kim, D.J. (Korea Food & Drug Administration, Seoul(Korea Republic). Toxicological Research Institute) | Nam, S.Y. (Tokyo University, Tokyo (Korea Republic). Department of Veterinary Anatomy)
This investigation was carried out to study morphological and chronological aspects of the development of the Harderian gland in the Mongolian gerbil(Meriones unguiculatus). Male and female Mongolian gerbils were sacrificed on days 1, 3, 5, 10, 30 and 60 after birth and their Harderian glands were processed for light microscopic observation. The result obtained were summarized as follows; 1. In 1-day-old Mongolian gerbil, Harderian gland was well distinguished from other tissue structures. It was composed of several immature tubules, and these tubules were separated each other by undifferentiated mesenchymal connective tissues. 2. In 3-day and 5-day-old Mongolian gerbils, the arrangement of tubules in the gland was more condensed than that of 1-day-old Mongolian gerbil. The excretory ducts started to appear in the connective tissues located between lobes. 3. In-10-day-old Mongolian gerbil, small lipid vacuoles began to be found in the cytoplasm of the secretory cells of the Harderian gland. There were some mucus-secreting cells within the epithelium of the excretory duct found in the interlobar connective tissues. 4. In 30-day-old Mongolian gerbil, there was markdely increased number of the tubules in the glands. The epithelial cells of the tubules were typically columnar in shape. Most of the columnar epithelial cells contained many small lipid vacuoles, although a few cells contained large lipid vacuoles. 5. In 60-day-old Mongolian gerbil, the Harderian gland exhibited the typical structural characteristicsl of the adult gland. The mature glandular structrues were more distinct than those of 30-day-old animals.
Show more [+] Less [-]Detection of porcine encephalomyocarditis virus by in situ hybridization
1999
Oh, S.H. | Park, N.Y. | Chung, C.Y. | Cho, K.O. | Lee, B.J. | Park, Y.S. | Park, H.S. (Chonnam National University, Kwangju (Korea Republic). College of Veterinary Medicine)
The purpose of this study was to establish a rapid, reliable diagnostic method detecting Encephalomyocarditis virus(EMCV) RNA in formalin-fixed, paraffin-embedded tissues of EMCV naturally infected pigs by cDNA probe of EMC K3, the EMCV strain isolated from Korea. Using a biotin-labelled nick translated probe for the cDNA marker. We made up for some defects of radiolabeled method. In situ hybridization(ISH) technique, differently from theother nucleic acid hybridization methods, is able to detect the virus genome specifically in the state of the intact shapes of cells and/or tissues. We succeeded in performing the experiment to detect the EMCV within 1~2 hours usign the MicroProbeTM capaillary action system. In this study, we ovserved highly specific positive sighals of red color by staining the paraffinembedded tissue sections of naturally EMCV-infected pig organs or tissues, including brain, heart, kidney and lacrimal gland with the Fast Red TR salt/Naphtol phosphate chromogen. The results suggested that this ISH method is considered as a highly sensitive and reliable tool for molecular biologic diagnosis of the EMC viral disease.
Show more [+] Less [-]Peritoneopericardial diaphragmatic hernia in a immature dog
1999
Yeon, S.C. (Seoul National University, Suwon (Korea Republic). College of Veterinary Medicine)
A 5-month-old, 5kg, intact male mixed dog was admitted to the Veterinary Medical Teaching Hospital of the College of Veterinary Medicine Cornell University because of severe systolic murmur. On physical examination, the dog appeared to be thin and slightly small for his age. Radiographic studies with barium sulfate clearly showed the presence of loops of intestines in the pericardium. Based on these findings peritoneopericardial diaphragmatic hernia was diagnosed. Many abnormalities were found in dog's heart: ventricular septal defect, pulmonic stenosis with moderate pulmonic value insufficiency, and mild mitral and tricuspid valve insufficiency. Puppy's longterm prognosis was fair. His interstines were removed from his pericardium and the defect in his deaphragm was closed. The surgery went smoothly and puppy recovered very nicely from anesthesia.
Show more [+] Less [-]Effects of GR89696 on parvalbumin positive neurons agter cerebral ischemia in the Mongolian gerbil
1999
Kwon, Y.B. | Yang, I.S. | Lee, J.H. (Seoul National University, Seoul (Korea Republic). Department of Beterinary Physiology, College of Veterinary Medicine)
Ischemic damage in the selectively vulnerable populations of neurons is thought to be caused by an abnormal accumulation of intracellular calcium. It has been reported that the neurons, expressing specific calcium binding proteins, might effectively control intracellular calcium concentrations because of a high capacity to buffer intracellular calcium in the brain ischemic condition. It is uncertain that parvalbumin, one of the calcium binding proteins, can protect the neurons from the cerebral ischemic damage. Recently, treatment of kappa opioid agonists increased survival rate, improved neurological function, and decreased tissue damage under the cerebral ischemic condition. Many evidences indicate that these therapeutic effects might result from regulation of calcium concentration. This study was desighed to analyze the changes of number in parvalbumin-positive neurons after cerebral ischemic damage according to timepoints agter cerebral ischemic inductionl In addition, we evaluated the effect of GR89696 (kappa opioid agonist) or naltrexone(non selective opioid antagonist) on the changes of number in parvalbumin expressing neurons under ischemic condition. Cerebral ischemia was induced by occluding the common carotid artery of experimental animals. The hippocampal areas were morphometrically analyzed at different time point after ischemic induction(1, 3, 5 days) by using immuno-histochemical technique and imaging analysis system. The number of parvalbumin-positive neurons in hippocampus was sighificantly reduced at 1 day after ischemia(p0.05). Furthermore, the number of parvalbumin-immunoreactive neurons was dramatically reduced at 3 and 5 days after cerebral ischemic induction(p0.05) as compared to 1 day group after ischemia, as well as sham control group. Sighificant reduction of parvalbumin positive neurons in CA1 region of hippocampus was observed at 1 day after cerebral ischemic induction. However, sighificant loss of MAP2 immunoreactivity was observed at 3 day after cerebral ischemia. The loss of parvalbumin-positive neurons and MAP2 immunoreactivity in CA1 region was prevented by pre-administration of GR89696 compared to that of saline-treated ischemic group. Furthermore, protective effect of GR89696 partially reversed by pre[treatment of naltrexone. These data indicate that parvalbumin-positive neurons more sensitively responded to cerebral ischemic damage than MAP2 protein. Moreover, this loss of parvalbumin-positive neurons was effectively prevented by the pretreatment of kappa opioid agonist. It was also suggested that the changes of number in parvalbumin-positive neurons could be used as the specific marker to analyze the degree of ischemic neuronal damage.
Show more [+] Less [-]Immunogold studies on the gonadotropes in adenohypophysis of the Korean native goat
1999
Lee, I.S. | Lee, H.S. | Song, S.H. | Yoon, S.T. | Hwang, I.K. (Seoul National University, Suwon (Korea Republic). College of Veterinary Medicine) | Seo, J.H. (Seoul National University, Seoul (Korea Republic). College of Medicine | Kang, T.C. | Won, M.H. (Hallym University, Chuncheon (Korea Republic). College of Medicine)
There have been a number of studies of gonadotropes secretin LH and FSH in the adenohypophysis, but the pattern of hormone storage and secretion of these cells still remains a controversial matter. In this study, we examined whether gonadotropes contained both of LH and FSH, and if so, how these hormones were distributed within the secretory granules. Hypophyseal sections of Korean native goat were simultaneously immunostained for LH and FSH antisera by protein A-gold technique. It was found that most gonadotropes contained both FSH and LH, but hormone storages in the secretory granules were some different among cells. Three types of gonadotropes were identified by the shape and size of the secretory granules and their hormone storage patterns. One type(I) of gonadotropes contained oval secretory granules, which immunoreactivity for FSH and LH were very weak. The size of secretory granules ranged from 160 to 310nm in diameter. Most granules contained both FSH and LH, but some contained only one of them. In another type(II)of gonadotropes, the immunreactivity and hormone storage patterns of the secretory granules were similar to those of type I cells. However, the secretory granules were round in shape and larger in size than those of type I. The other gonadotropes(type III) were distinctly distinguished by plenty of hormones in their secretory granules which were densely packed with numerous immunolabelled gold particles. These data are some inconsistent with other results that have been obtained in other ruminants like as cattle and sheep.
Show more [+] Less [-]Detection of Mycoplasma gallisepticum using Polymerase Chain Reaction(PCR)
1999
Lee, Y.J. | Kim, K.S. | Kim, J.W. (Ministry of Agriculture and Forest, Anyang (Korea Republic). National Veterinary Research and Quarantine Service) | Tak, R.B. (Kyungpook National University, Taegu (Korea Republic). College of Veterinary Medicine)
A species-specific 760 base pair(bp) BamHI to EcoRI DNA fragment(fMG-2) of lipoprotein gene was isolated from a Mycoplasma gallisepticum (M gallisepticum) genomic library. Based on the DNA sequence data of fMG-2, a pair of 25bp primers was synthesized. When used in the polymerase chain reaction(PCR), 732bp DNA products were amplified from 6 standard strains and 10 field isolates of M gallisepticum, but not from 2 Mycoplasma synoviae and 7 other Mycoplasma species. The lower detection limit was 100fg of the genomic DNA. Identity of the PCR products was confirmed by comparison of patterns of restriction endonuclease analysis with AseI, DraI, EcoRV and SspI.
Show more [+] Less [-]Therapeutic effects of 1alpha,25 dihydroxycholecalciferol on osteoporotic fracture in a rat model
1999
Bae, C.S. (Konkuk University, Seoul (Korea republic). Department of Surgery, Faculty of Veterinary Medicine)
Osteoporosis is defined as a decrease in bone mass that leads to an increased risk of fracture. The therapeutic effect of 1alpha,25 dihydroxycholecalciferol, the hormonal form of vitamin D3 that mediates calcium translation in intestine and bone, on the healing process of fracture has still been controversial. These studies were designed to understand the healing process of normal fibular fracture, the osteoporotic changes after ovariectomy, and the theraqeutic effects of 1alpha,25 dihydroxycholecalciferol on the osteoporotic fracture in rats. The simple transverse fractures of rat fibulae were produced with a rotating diamond saw. The changes of the biochemical and mechanical indices of rats were investigated. The mechanical study based on bending test revealed the healing of the fibular fracture in the 5th week after simple transverse fracture. The osteoporosis impaired more the healing of osteoporotic fibular fracture than normal non-osteoporotic fibular fracture. The healing process of osteoporotic fracture was facilitated by the treatment with 1alpha,25 dihydroxycholecalciferol, however was delayed more than the healing process of normal fracture. The bone strength based on the bending test also confirmed this tendency. The bone strengths in the 5th week after fracture of normal bone, osteoporotic bone, and 1alpha,25 dihydroxycholecalciferol-treated osteoporotic bone were 75%, 41% and 67%, respectively, in comparison with those of intact bone. In conclusion, 1alpha,25 dihydroxycholecalciferol was effective in promoting the osteroporotic fracture healing.
Show more [+] Less [-]Effects of dopaminergic receptor stimulation on Mg2+ regulation in the rat heart and isolated ventricular myocytes
1999
Kang, H.S. | Kim, J.S. | Kim, J.S. (Chonbuk National University, Chonju (Korea Republic). College of Veterinary Medicine)
Magnesium(Mg2+) is one of the most abundant intracellular divalent cation. Although recent studies demonstrate that adrenergic receptor stimulation evokes marked changes in Mg2+ homeostasis, the regulation of Mg2+ by dopaminergic receptor stimulation is not yet known. In this work, we uwed dopaminergic agents to identify which type(s) of receptors were involved inthe mobilization of Mg2+ by dopaminergic receptor stimulation in the perfused rat gearts, isolated myocytes and circulating blood. The mg2+ content was measured by atomic absorbance spedtrophotometry. Dopamine(DA), apomorphine(APO) and pergolide stimulated Mg2+ efflux in the perfused rat hearts and these effects were inhibited by haloperidol or fluphenazine, nonselective dopaminergic antagonists. SKF38393, a selective doparminergic agonist, increased Mg2+ efflux from the perfused hearts in dose dependant manners and SKF38393-induced Mg2+ efflux was potentiated in the presence of sulpiride or eticlopride, D2-selective antagonist, from the perfused hearts. This increase of Mg2+ efflux was blocked by haloperidol or imipramine. DA or pergolide increased in circulating Mg2+ from blood. By contrast, PPHT stimulated Mg2+ influx(a decrease in efflux) from the perfused hearts and circulating blood. PPHT-induced Mg2+ influx was blocked by fluphenazine in the perfused hearts. DA-stimulated Mg2+ efflux was inhibited by dopaminergic antagoinst in the isolated myocytes. In conclusion, the flux of Mg2+ is modulated by DA receptor activation in the rat hearts. The efflux of Mg2+ can be increased by D1-receptor stimulation and decreased by D2-receptor stimulation, respectively.
Show more [+] Less [-]A study on recovery of deep hypothermia in rabbits
1999
Lee, B.H. | Chun, W.C. | Kim, J.Y. | Chung, B.H. (Kon-Kuk University, Seoul (Korea Republic). School of Veterinary Medicine) | Kim, J.S. | Park, J.H. | Park, J.S. | Han, J.S. (Samsung Biomedical Research Institute, Seoul (Korea Republic). Department of Laboratory Animal Research)
The studies were carried out to investigate the effect of recovery in rewarming using the esophageal thermal tube in the deep hypothermia(25+_1 degrees centigrade ; rectal temp) in rabbits. Fifteen rabbits were divided into control group(n=6), peritoneal dialysis group(n=5) irrigated with dialysate at 42+_1 degrees centigrade, and esophageal rewarming group(n=6), peritioneal dialysis group(n=5) irrigated with dialysate at 42+_1 degrees centigrade, and esophageal rewarming group(n=4) perfused with circulating water at 38+_1 degrees centigrade. Rewarming of the rabbits was performed for 5 hours. MAP, HR, RR, esophageal temp, rectal temp, pH, pCO2, pO2, Na+, and K+ were observed. The results obtained in these experiments were summarized as follows:Esophageal rewarming group(38+_1 degrees centigrade) had more effect on esophageal temperature than other groups. Peritoneal dialysis group(42+_1 degrees centigrade) had more effect on rectal temperature and pO2 than other groups. The both groups also had more effects on MAP, HR, RR, and pCO2 than control group. Three groups had no significant effect on pH, Na+, and K+. In conclusion, we found that the simple, safe, and non-invasive esophageal rewarming method had an effect on the treatment of profound hypothermia as well as the peritoneal dialysis method in spite of the temperature difference between the dialysate and the circulating water, and the circulating water at 38+_1 degrees centigrade for esophageal rewarming also had an effect on the recovery of deep hypothermia.
Show more [+] Less [-]Effects of vitamin E on prevention and treatment of canine babesiosis
1999
Lee, K.K. | Kim, G.H. | Lee, Y.J. (Cheju National University, Cheju (Korea republic). Department of Veterinary Medicine, College of Agriculture)
This study was carried out to investigate the effects of vitamin E on the prevention and treatment of Babesia gibsoni. fifteen mongrel dogs, uninfected with Babesia spp, were assigned to three groups according to vitamin E(alpha-tocopherol) concentrations in the RBC. The concentrations in each of the three groups were, respectively : alpha-tocopherol in RBC less than 30 micro gram/micro liter(Group I), 30 micro gram/micro liter-60 micro gram/micro liter(Group II), more than 60 micro gram/micro liter(Group III). Artificial infection was accomplished by injecting 2*10 7-2*10 8 erythrocyte of Babesia gibsoni-infected dog into the cephalic vein. We investigated the clinical sighs, vitamin E concentrations in RBC and serum, Vitamin A concentrations in serum, hematological values, white blood cell(WBC) viability and RBC membrane osmotic fragility after infection of Bavesia gibsoni for a period of 20 days at 5 day intervals. The results obtained are summarized as follows: 1. After infection by Babesia gibsoni, clinical examination revealed depression, anorexia, pale mucous membranes, dark brown urine and diarrhea in proportion as time went on. After 10 days of infection, one dog each of Groups I, II and III revealed depression and anorexia. Two dogs in Group I and one dog each of Groups II and III showed dark brown urine after 15 days. Diarrhea was observed in one dog in each of the 3 groups after 20 days of infection. 2. After 5 days of infection, two dogs in each of Groups I, II and III showed Babesia gibsoni in RBC of blood smear stained with Giemsa. At the 15th day after infection with Babesia gibsoni, they were observed in all experimental animals. After both 5 days and 10 days of infection, the rate of Babesia gibsoni parasitized RBC(permillage, %) was 1%, and increased as time went on. 3. After 5 days of infection by Babesia gibsoni, Group I, which had the lowest vitamin E concentration, showed significantly decreased RBC and PCV levels(p0.01). Group II and group III also showed significantly decreased RBC and PCV levels after 15 days of infection(p0.05). particularly after 10 days of infection, Group I showed lower values in RBC and PCV levels compared to Groups II and III. WBC, RBC, fibrinogen and total protein levels between the groups did not differ during experimental periods. 4. According to the WBC differential counts, the ratios of neutrophil to lymphocyte showed a tendency to be slightly higher in Group III(more than 60 micro gram/micro liter) than in Groups I and II. 5. WBC viability did not differ between the groups. 6. RBC membrane osmotic fragility did not differ between the groups.
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