This study was conducted to examine the outbreak rate and the causative agents of otitis externa in 26 dogs(49 ears; 23 dogs = bilateral, 3 dogs = unilateral), and the normal microfloras of external ear canal in 68 dogs(133 ears; 65 dogs = bilateral, 3 dogs = unilateral) in Taegu, 1997. The breed, living environment, sex, age and season distribution of otitic dogs were as follows: Dogs with erect and hairy ears(42.3%), pendulous and hairy ears(38.5%), indoor(92.3%), female(65.4%) and below one year old(38.5%) were more prevalent. According to season, otitis externa was mainly occurred between July and October. The major causative agents of canine otitis externa were Malassezia pachydermatis(32.7%), Staphylococcus aureus(26.5%) and S intermedius(16.3%). The major causative agents of canine otitis externa were Malasszia pachydermatis(32.7%), Staphylococcus aureus(26.5%) and S intermedius(16.3%). In the microorganism isolated 39 otitic ear canals, single infection was 53.8% and mixed infection was 46.2%. The normal microfloras of canine external ear canal were fungi including M pachydermaits, Aspergillus spp, Microsporum canis, Alternaria spp, Verticillium spp and Yeast, and bacteria including Staphylococcus spp(10 species including S xylosus), Bacillus spp, Corynebacterium spp, Listeria spp, Actinomyces pyogenes and Escherichia coli. No growth was 34.6%.

This study was designed to evaluate the effect of cyclophospaide(CY) on dietynitrosamine(DEN)-induced hepatic tumors in rats. Thirty five male of femal Sprague Dawley rats were continiously given water containing O.01% DEN for 10 weeks and then were give with CY 25mg/rat/day in water for 3, 5, 7 or 9 days. The livers of rats were removed and fixed in 10% buffered neutral formalin. The appearances of positive cells by immunohistochemical methods using proliferating cell nuclear antigen (PCNA) antibody, p53 antibody and apoptotic kit were investigated. The livers of rats given with CY were grossly brilliant, red-brown color, flexible, and thin border, and stainability of the liver cells were restored microscopically, and the vaccuolated and degenerated regions were differentiated from restored regions. These restored findings also were advanced in control group becouse of no DEN treatment but tended to be less avanced. In immunohistochemistry, positive cells to PCNA antibody appeared more numerous in control groups than that of CY treated groups. Appearance of positive cells in CY-treated group for 7 days and for 9 days were more numerous than those of CY-treated groups for 3 days and for 5 days, respectively. So these findings suggested that CY suppressed cell proliferations and effects of these action were decreased with CY-treated days. The numbers of positive cells to PCNA antibody were more prominent in hepatocelular carcinoma regions and cholangiocarcinoma regions, and then were ranked as order of large liver cell regions and normal liver cell regions. Also the numbers of the positive cells by apoptotic kit tended to be higher in hepatocelular carcinoma regions and cholangiocarcinoma regions but not uniformly in order in all regions nd were much less numbers than those of OCNA positive cells. So immunohistochemical methods using PCNA antibody together than using apoptotic kit alone when anti-carcinogen experiments. Rats with positive cells by p53 antibody were 11 of 15 rats(73.4%) in control groups and 12 of 18 rats(66.7%) in CY treated group, respectively. These positive cells appeared focally in early vacuole-occurring regions and were low in numbers.

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 purpose of the present study was to investigate the effect of bovine amniotic membrane grafts on healing of full-thickness skin wound in dogs. Two 3cm*3cm area-matched full-thickness skin wounds were induced bilaterally on the dorsolateral aspect of the trunk of 15 dogs Chlorhexidine-treated amnion, dried amnion, silver sulfadiazine and 0.9% sterile saline solution were applied on the wound area and examined grossly and histopathologically. Begining 14 days after wounding, amnion applied group had appreciably less amount of inflammatory exudate and hemorrhage than sulfadiazine and saline treated groups. From 14 days after wounding, the degree of wound contraction in amnion groups, especially in the dried amnion group was greater than that of the sulfadiazine and saline treated groups. The percentages of wounds completely healed on 28 days after wounding in saline treated group, chlorhexidine-treated amnion group, dried amnion group and sulfadiazine treated group were 33%, 50%, 83% and 50%, respectively. Microscopically neovascularization and fibrosis were first noticed on 5 days after wounding in the dried amnion group and sulfadiazie treated group, on 7 days in the chlorhexidine-treated amnion group and on 14 days in the saline treated group. Epithlialization in thedried amion and sulfadizine treated groups ws first noticed on 9 days after wounding, which was faster than that in the other groups. The present study suggests that bovine amniotic membrane, especially dried bovine amnion is effective on healing of full-thickness skin wound in dogs through both wound contraction and epithelialization.

The study was designated to investigate the electron microscopic findings following diethylnitrosamine (DEN) treatment in rats. Forty four male (Srague Dawley) rats were continuously given water containing 0.01% DEN for 13 weeks and livers of five rats with more tumor lesions at 16 and 17 weeks after initial treatment were used as EM materials. In transmission electron microscopic findings, most small-sized hepatocytes were active cells containing large mount of organelles, but light (pale staining) hepatocyte among small-sized hepatocytes were injured cells containg disorganized organelles. Tumor cells among small-sized hepatocytes were irregularly arranged and have ;leomorphic nuclei containing electron dense chromatin but the organelles in cytoplasm were swelled. Large-sized hepatocytes were active cells with condensed chromatin but the cytoplasm of these cells were pale due to be injured and dilated organelles. Dark hepatocytes were apoptotic cells with homogenous pyknotic nuclei and cytoplasm, and the cytoplasm of these cells contained dilated smooth endoplasmic reticulum (sER) but these sER were non-vesiculated. Cholangiocarninoma cells were crowed and were pale by far less number of organelles in cytoplasm and nuclei. In scanning electron microscopic findings, the lumens of portal veins, bile canaliculi, bile ductules, bile ducts and sinusoids were dilated and have irregular folded inner surface by protruded parenchyma.

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.

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.

The morphometrical characteristics such as external measurements and mandible size assessment in mice and rats have to be highly heritable and sufficiently variable between strains in order to calculate a strain specific profiles. The coat color of Korean wild rats were observed and morphometric analysis of external measurements were carried out on Korean wild rats compared to laboratory strains in order to clarify the genetic characteristics of Korean wild rats and to establish background data as a domestication of Korean wild rats for new laboratory strain. Korean wild rats were captured from Chunchon and Hoengsong. 4 inbred and 1 outbred strains of rats were used in this study for the comparison of genetic characteristics of Korean wild rats. Total body length, head length, tail length, hind foot length and ear length were measured and then statistical analysis were carried out by discrimiant analysis. The coat color of Korean wild rat showed golden white in ventral portion and dark agouti in dorsal portion. Korean wild rats could be distinguished from the other laboratory strains distinctly by morphogenetical analysis. There was sighificant variations among Korean wild rat compared to those of the other laboratory strains of rat. This study may provide that Korean wild rats have a unique genetic characterization compared to those other inbred strains of rats based on morphogenetical characteristics by external measurements.

We performed this study to evaluate the potential clinical marker of urinary trypsinogen-2 together with amylase, lipase and urinary amylase creatinine clearance ratio (ACCR) for the diagnosis of acute pancreatitis in dogs. In the experiment on daily changing pattern of amylase, lipase and ACCR measurements in experimentally induced pancreatitis dogs, compared to values measured in pre-induction state, significant difference was seen in amylase until 5th day of induction, and for lipase significant difference was found during the 7th day of observation period (p0.05). No significant difference was found in ACCR for the study period (p0.05). On SDS-PAGE analysis of urine from experimentally induced pancreatitis dog, The 26kd band was markedly increased compared with that of normal state and that band was confirmed trypsinogen-2 using substrate interaction and isoelectric focusing assay after being eluted. When assessing the appearance of 26kd band on urine SDS-PAGE 87.1% (range:50~100%) of experimentally induced pancreatitis dogs showned positive results, whereas no corresponding band was seen in dog without pancreatic disorders. With this result, determination of urinary trypsinogen-2 assay was found to have a high diagnostic value with a 70% of sensitivity and 100% of specificity as a routine test for pancreatitis, although the detection of trypsinogen-2 in urine can be varied on the progressionstage of pancreatitis at the initial visit to animal clinic. We therefore suggest that the promising results in this study be used for the development of dipstick test for detecting acute pancreatitis in the future research.

The regional distributions and relative frequencies of the gastrin, secretin and pancreatic polypeptide(PP)-immunoreactive cells in the gastrointestinal tract of the fetus(180 days of gestation) of Korean native goat were sutdied with immunohistochemical(ABC) methods. Gastrin-immunoreactive cells were detected in fundus, pylorus and duodenum and these cells were most predominant in pylorus. Secretin-immunoreactive cells were observed in pylorus, duodenum and ileum. PP-immunoreactive cells were restricted to fundus. These immunoreactive cells were situated in surfact epithelium and mucosal gland regions. The regional distribution and relative frequency of PP-immunoreactive cells was somewhat different to the adult Korean native goat. Immunoreactive cells in thesurface epithelial regions were open typed cells which were spindle shaped cells but closed typed cells which were round or/to spherical shaped cells were observed in the mucosal gland regions.