Although it has been reported that hormones or chemicals, which increse in intracellular cAMP, produced Mg2+ release from the heart, it is not well characterized whether a specific Mg2+ exchanger is involved in cAMP-induced Mg2+ efflux in themammalian hearts In this work, we studied the relationship between the increase in intracellular cAMP and ion transport system on Mg2+ regulation in the perfused rat heart and isolated myocytes. The Mg2+ content in the perfusate and supernatant were measured by atomic absorption spectrophotometer. The addition of membrane permeable cAMP analogue to the perfused hearts and myocytes. cAMP-induced Mg2+ efflux was ingibited by H7, benzamil or imipramine in the perfused hearts and myocytes, but not by EIPA. We confirmed that a significant Mg2+ efflux was induced by an increase in intracellular cAMP in the hearts and myocytes. The cAMP-induced increase of Mg2+ efflux in the hearts may be involved in ion transport system(Na+-Ca2+ and Na+-Mg2+ exchanger)

The present study was carried out to investigate the prevalence of mycoplasmal pneumonia of slaughter pigs in Youngnam area during the period from 1995 to 1997. The prevalence and pathomorphology of gross lung lesions were studied from 682 slaughter pigs in 8 swine herds. Gross lesions of pneumonia were recorede in the lungs of 442(64.8%), from 367 out of them(83.0%) were diagnosed as mycoplasmal pneumonia. Microbiological examination was performed with 197 lungs with gross lesions of mycoplasmal pneumonia of slaughter pigs from 8 differentswine herds. M hyopneumoniae, P multocida, A pleuropneumoniae, Streptococcus spp, Corynebacterium spp, and H parasuis were detected in 24.4%, 48.2%, 2.5%, 11.2%, 3.6%, and 1.0% of the pneumonic lungs, respectively. A total of 48 strains of M hyopneumoniae was investigated for thier in vitro susceptibility to antibiotics. Among the drugs tested, lincomycin, oxytetracycline, tiamulin and tylosin showed the high activity in minimal inhibitory concentration(MIC) of 0.04-5 micro gram/ml while erythromycin showed low activity in MIC values(1.25~40micro gram/ml).

We analyzed the conentes of 12 types of minerals such as calcium in muscle from various species. Thereafter we ovserved changes of the concetrations according to age, part and sex in major domestic animals. The concentraions of calcium, iron, sodium, potassium, magnesium and zinc were high respectively whilst the content of cobalt, chromium, copper, manganese, molybdenum and nickel were low respectively in the muscle. The concentration of calcium was high in duck and dog but low in pig and horse. Also high level of sodium content was detected in dog and the content of potassium, iron showed high level in horse compared with the content in other animals. In 6 types of microminerals as cobalt, the level of muscle wer no more than 1 ppm showing very low content in all animal, but 2.99+_0.85ppm of copper in duck was an exceptional case. According to the age some species showed small range of variation centering on macrominerals and there was no remarkable change in microminerals. Distribution of minerals was different according to the part and the variation was very diverse compared with other factors such as age and sex. Additionally, the content of mnerals in muscle was higher in female than in male chicken and duck. In conclusion, the difference of the content of minerals according to the species was mainly focused on macrominerals.

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.

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.

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.

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.

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.

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.

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.