• Development and Reproduction
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• v.12 no.3
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• pp.251-259
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• 2008

The plasticizer di(2-ethylhexyl)phthalate(DEHP) is one of the most well known endocrine disrupting chemicals (EDCs) because of its strong anti-androgenic effects on the reproductive and developmental process in male rodents and human. The present study was performed to examine whether prepubertal exposure to DEHP can make any alteration during the maturation of accessory sex organs in male rats. As a result, there was no significant change in body weights, serum T levels and tissue weights except of seminal vesicle and ventral prostate in DEHP-treated animals compared to vehicle-treated ones. The seminal vesicle weights in high-dose group (200 mg/kg) were significantly lower than those from the control group (p<0.05), and ventral prostate weights were significantly lower than those from the control group (p<0.05) in both low-dose (20 mg/kg) and high-dose group. Histological studies revealed that the seminal vesicles from DEHP-treated groups showed reduced areas of mucosal folds. Pseudostratified columnar epithelia were observed in the ventral prostates of DEHP-treated samples while cuboidal epithelia were found in the control group. The transcriptional activities of ER-$\alpha$ in seminal vesicle from high-dose group (p<0.05) were significantly higher than those from the control group, and ER-$\beta$ expression was significantly decreased in low-dose group (p<0.05) compared to the control. In ventral prostate, ER-$\beta$ mRNA levels from low-dose group (p<0.05) were significantly lower than those from the control group, and significantly increased in high-dose group (p<0.01). AR expressions, however, were not significantly different in all experimental groups of both seminal vesicle and ventral prostate. In conclusion, the present study demonstrated that (i) adverse effect (s) of DEHP on sexual maturation during prepubertal period could be limited, (ii) seminal vesicle and prostate gland were sensitive targets to DEHP in prepubertal rats and (iii) the deleterious effects of DEHP might be mediated through ER-associated mechanism.

• Korean Journal of Veterinary Service
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• v.22 no.4
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• pp.325-347
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• 1999

This study was conducted to investigate the epidemiological, clinicopathological, microbiological, pathological observations and other tests from sudden death in feedlot cattle at the region of Sarari in Korea during the period from 1994 to 1999. Massive or sporadic occurrence of sudden death has been observed in 101 heads of 47 farmhouse. There were 20.8% in spring, 29.7% in summer, 16.8% in autumn, 32.7% in winter, and 62.3% in reproductive, 27.7% in growing, 5.0% in beef cattle, 5.0% in calf in prevalence of sudden death in cattle. Enterotoxemia(88.0%), pneumonia(3.5%), intestinal diarrhea(3.5%), liver abscess(1.5%) and indigestion(1.5%) were detected from 67 heads of sudden death cattle. In clinical observations, cattle were generally died of sudden recumbency with convulsions followed anorexia, depression, ataxia, muscular tremor, tachycardia and dyspnea without any premonitory symptoms. Epidemiological surveys showed no evidence that other factors such as pesticide, insecticide, fertilizer, chemical drug3 and those of others caused sudden death. Macroscopically, there were coagulation disorders of blood, congestion, edema and haemorrhage of lung, congestion and haemorrhages, watery and blood-tinged contents of small intestine. Histopathologically, we observed pulmonary congestion and haemorrhage, necrotic intestinal mucosa accompanied with haemorrhage and congestion, and also increased globule leukocytes between bronchial epithelia with mild pneumonia. Clinicopathologically, only elevation of blood glucose and aspartate aminotransferase(AST) was detected. Magnesium and calcium deficiency were not detected, but parasites were detected highly in normal and dead cattles. Microbiologically, Clostridium(Cl) pefringens were detected from small intestinal contents of 94% (63/67) of sudden death cattle and 51%(51/101) of slaughter cattle, and the population were $10^{6-8}$/cfu/$m\ell$ after 16~32 hours. Consequently, it was proved that the cause of death in cattle was enterotoxemia. Pathogenic test of mouse and goat inoculated with Cl perfringens type A toxin has been demonstrated as similar observation to natural cases. In antimicrobial susceptibility test, ampicillin, bacitracin, polymycin, cephalothin, penicillin, choramphenicol, erythromycin, tetracycline were highly susceptible, and amikacin, gentamicin, kanamycin, neomycin, streptomycin, sulfamethoxine, sulfamethazine were resistant. Cl perfringens were resisted for 4 hours in 3% formalin, 20 minutes in 4% phenol, 20 minutes in 0.5% mercuric chloride and 40 minutes in 0.1% sodium hydroxide, respectively. The useful method to prevent from occurrance of enterotoxemia in feedlot cattle was a dietary administration of antibiotics and miyari acid.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.425-438
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• 1997

To assess the testicular toxicity induced by DA-125, a new anthracycline anticancer agent, the test substance was intraveneously administered to male beagle dogs at dose levels of 0, 0.0023, 0.0375, 0.15, and 0.6 mg/kg/day, 6 days a week for 26 weeks. At 0.6 mg/kg/day, 1 out of 3 dogs had died on day 42 of treatment and the other dogs were sacrificed on days 46 and 122 of treatment due to the increasingly severe clinical condition. Clinical signs considered to be related to treatment were included anorexia, vomiting, salivation, decreased activity, mucous and/or dark faeces, diarrhea, and swelling, abscess and/or ulceration of injection sites. Suppression in body weight gain, reduction in food intake, decreases in testicular weight and size, and hemorrhage of epididymis were also observed in male dogs. Microscopically, severe degenerative changes such as atrophy of seminiferous tubules, loss of germ cells, degeneration of germ cells, vacuolization of Sertoli cells, and hyperplasia of Leydig cells were observed in all dogs. Azoospermia in epididymal tubules, atrophy of epithelia in the cauda epididymis, and prostate atrophy were also found. At 0.15 mg/kg/day, anorexia, vomiting, salivation, diarrhea, and swelling of injection sites were observed. In addition, suppression in body weight gain and decreases in testicular weight and size were found in male dogs. Atrophy of seminiferous tubules, decrease of germ cells, degeneration, exfoliation and retention of germ cells, vacuolization of Sertoli cells, and hyperplasia of Leydig cells were observed by histopathological examination. Azoospermia in epididymal tubules and prostate atrophy were also found. At 0.0375 mg/kg/day, there were no clinical signs considered to be indicative of a reaction to treatment, but testicular size was significantly reduced. Microscopically, decreases in the number of spermatogonia and epidydimal speramtozoa were found. There were no evidences of general or testicular toxicity at 0.0023 mg/kg/day. These results indicate that DA-125 produces significant and persistent damage to the spermatogenic compartments of the testes in male beagle dogs.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.106-106
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• 2003

Human papillomavirus type 16(HPV16) has been known to the major factor for the development of uterine cervical carcinomas. We have extended these studies to investigate the in vivo activities of HPV-16 E6/E7 when expressed in squamous epithelia of transgenic mice. Grossly, hK14HPV16E6/E7 transgenic mice had multiple phenotypes, including wrinkled skin that was apparent prior to the appearance of hair on neonates, thickened ears, and loss of hair in adults. In the transgenic mice, the wrinkled skin phenotype on the body and legs died at the age of 3-4 weeks. Histological analysis of demonstrated that E6/E7 causes epidermal hyperplasia in multiple transgenic lineages with high penetrance. This epithelial hyperplasia was characterized by an expansion of the proliferating compartment and an expansion of the keratinocyte and was associated with hyperkeratosis. These transgenic mice expressed E6/E7 transgene mainly in skin, heart, pancreas and kidney. Hyperplasia was found at the skin. The enzyme activities of GR, GPx and CuZnSOD were measured from the transgene cause keratinocyte at the skin. The specific enzyme activities were significantly higher in transgenic mice skin compared to the normal mice skin. Thus these transgenic mice may be useful for the develpment of antioxidant enzymes or other therapies for HPV-associated hyperkeratosis.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.775-782
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• 1998

The purpose of this study is to investigate the change of the EGFR mRNA expression in the rat gingival epithelium by the experimental tooth movement. We applied reciprocal force between the upper anterior teeth using NiTi open coil spring and stainless steel wire for 1, 2 3, 7 days. For the detection of EGFR mRNA, in situ hybridization was done in the tissue samples which were taken from the pressure and tension sides of teeth. The results were as follows ; 1. The expression of EGFR mRNA was increased application-time dependently. a. Day 1 mild expression on the basal and spinous cell layers b. Day 2 . moderate expression on the whole layers c. Day 3 : severe expression on the basal and spinous cell layers 4. Day 7 severe expression on the whole layers 2. The expression level of EGFR mRNA in the pressure and tension sides were similar during the whole Period of experiment except seven day application at which the cornified layer of the tension side showed moderate expression. 3. Removal of the appliance after 7-day force application lowered the level of EGRF mRNA expression. It was returned to the mild and control (rare) level at three and seven days after the removal, respectively. In conclusion, EFGR mRNA was increased by the experimental tooth movement on the rat ginigval epithelium. Up-regulation of EGFR mRNA in the gingival epithelium can be regarded as responses to the possible changes caused by the physical stersses to the oral environment to maintain the homeostatic conditions of the periodontium.

• Applied Microscopy
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• v.28 no.3
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• pp.363-377
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• 1998

After the investigation on the eye of Incilaria fruhstorieri with light and electron microscopes, the following results were obtained. The eye of Incilaria fruhstorferi comprises cornea, lens, vitreous body, retina, and optic nerve inward from the outside. Cornea is composed of squamous, cuboid, columnar and irregular cells, which appear to be light due to their low electron density. In their cytoplasms, glycogen granules, multivesicular body, and nucleus were observed. Vitreous body, located behind non-cellular transparent lens, is filled with long and short microvilli protruding from the retinal epithelia. Retinal epithelium, the organ to perceive objects, is divided into four parts; microvillar layer pigment layer, nuclear layer, and neutrophils layer, from the apical portion. Microvillar layer consists of the type-I photoreceptor cells and pigmented granule cells. In the apical portion of their cytoplasms, long microvilli (length, $19{\mu}m$) , short microvilli (length, $8{\mu}m$), and rolled microvilli grow thick in the irregular and mixed forms. Photoreceptor cells are classified into type-I and type-II, according to their structures. The type-I cell has the apical portion rising roundly like a fan and the lower part which looks like the helve of a fan. In the cytoplasm of the apical portion, there are clear vesicles, cored vesicles, ovoid mitochondria, and microfilaments, and in the cytoplasm of the lower part, photic vesicles with their diameters about 60nm aggregate densely. The type-II photoreceptor cell, located at the lower end of the type-I cells, has a very large ovoid nucleus 3nd no microvilli. In the cytoplasm of the type-II cell, the photic vesicles with sizes 60nm aggregate more densely than in the cytoplasm of the type-I cell. Pigmented cells are classified into type-A and type-B, according to their structures. The type-A is identified to be a large cell containing round granules (diameter, $0.5{\mu}m$) of very high electron density, while the type-B is identified as a small cell where the irregular granules (diameter, $0.6{\mu}m$) of a little lower electron density amalgamate. Nuclear layer ranges from the bottom of pigment layer to the top of the capsule, and contains three kinds of nuclei (nuclei of the type-II photoreceptor cell, pigmented granule cell, and accessory neuron). The capsules covering the outmost part of the eyeball are composed of collagenous fiber and three longitudinal muscle layers (the thickness of each longitudinal muscle layer, $0.4{\mu}m$) and thick circular muscle layer (thickness, $0.3{\mu}m$). Around the capsules, there is a neurophile layer consisting of neurons and nerve fibers. Each neuron has a relatively large ovoid nucleus for its cytoplasm, and in the karyosome, large lumps of keterochromatin form a wheel nucleus.

• Parasites, Hosts and Diseases
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• v.30 no.4
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• pp.309-322
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• 1992

In order to observe the antigenic localization in the tissues of Metngonimus yokogawai in growth stages, immunogoldlabeling method was applied to using serum of the cat which Infected with isolated metacercariae from Plecoglossus aztivelis. The sectioned worm tissues from each growth stages were embedded in Lowicryl HM 20 medium, stained with infected serum IgG and protein A gold complect (particle size: 12 nm) and observed by electron microscopy. In the worm tissues of all experimental groups, the geld particles were specifically concentrated on the tegumental synch- tium and cytoplasm of the tegumental cell as well as the secretory granules in the parenchymal tissue. In the 16th and 20th week grown worm tissues, the gold particles were specifically concentrated on the vesicles in the tegumental syncytium and cl·toplasm of the tegumental cell. The gold particles were specifically concentrated on the caecal epithelia of the 4th, 8th and 12th week growth groups but slightly concentrated on those of the 16th and 20th week.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.537-547
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• 1994

Ninety seven cases of histopathologically diagnosed spontaneous canine parvovirus enteritis(CPE) were studied gross pathologically, histopathologically, immunohistochemically, to investigate histopathological types of small intestinal lesions, and antigen distributions in each pattern related to the infected age. And also, reliability of histopathological method in diagnosis of CPE was inspected with immunohistochemistry. The results were as follows : 1. Age-related occurring ratio in histopathologically diagnosed CPE was 53.6% in 4-8 weeks, 26.8% in 9-15 weeks, 8.25 in 16-19 weeks and 11.3% in 20-45 weeks of the clog age. 2. In histopathologic classification based on patterns of villi/crypts lesions of small intestine(jejunum), the ratio of A type (initial phase of necrosis of crypt epithelia, desquamated epithelial cells in the dilated lumen of the crypt) was 20.6%; the ratio of B type(middle phase of atrophy and fission of the villi, collapse of the mucosa, loss of normal crypt structure) was 62.9%, and C type(regenerative phase of the crypt architecture) was 16.5%. 3. The ratio of A, B, C type in 4-8 weeks old, respectively, was 23.5%, 61.5%, 15.4%; in 9-15 weeks old was 19.2%, 65.4%, 15.3% in 16-19 weeks old was 25.0%, 75.0%, 0.0%; and in 20-45 weeks old was 9.0%, 54.5%, 36.4%. 4. The antigen distribution in the nuclei of the crypt epithelial cells was higher than of the cytoplasm and numerous desquamated epithelial cells in dialated crypts in A type; The antigen cytoplasm and numerous desquamated epithelial cells in dialated crypts in A type; The antigen distribution in the nuclei of the collapsed crypt epithelial cells was not higher than that of the cytoplasm, crypts were lined by and filled with released viral antigens from the destructed epithelial cells in B type; and its distribution was also higher than in the epithelial cells adjacent to the tips of the villi, but it was not reacted in the regenerative crypt epithelial cells in C type. 5. Immunohistochemically detected antigen ratio in the small intestine of histopathologically diagnosed CPE was 94.6%, and this result indicates that histopathological diagnosis is very reliable method in diagnosis of CPE.

• Development and Reproduction
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• v.13 no.2
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• pp.89-95
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• 2009

p63 has been demonstrated to localize in stem cells and precursor cells of various epithelial tissues previously, but the localization of p63 throughout tooth formation, particularly during the enamel and root formation stages, remains to be adequately characterized. Therefore, in this study, we have demonstrated, via immunohistochemical methods, that p63 is ubiquitously expressed in the dental epithelium during tooth development. p63 was detected in the basal and suprabasal layers of the epithelia, including the skin, hair follicles, oral mucosa, and submandibular ducts. However, in the tooth region, all cells of the dental lamina, enamel organ, Hertwig's epithelial root sheath (HERS), and epithelial cell rests of Malassez (ERM) evidenced immunoreactivity for p63. These results indicate that p63 may perform different roles, other than stem cell maintenance, in tooth development.

• Applied Microscopy
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• v.30 no.1
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• pp.89-100
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• 2000

We observed the salivary ducts of two species of snails, Achatina fulica and Incilaria fruhstoferi with an electron microscope, and obtained the following results. The intralobular and interlobular ducts of Achatina fulica assume the forms of round or ellipsoidal doughnuts. The boundaries between the endothelial cells are not clear. It is also found that the cytoplasm of the endothelial cells consists of the membrane infolded in interdigital form, and there are well -developed microvilli at the apical portion of the cytoplasm. On the other hand, the intralobular and interlobular ducts of Incilaria fruhtoferi consist of the irregular simple columnar epithelia. The high electron dense cytoplasm is filled with the irregular round granules. The microvilli at the apical portion of the cytoplasm are not so well-developed as those in Achatina fulica. In the salivary duct of Achatina fulica, the lumen has narrow and long tubular structure. The boundaries between the endothelial cells are not clear. The cytoplasm is full of many vacuoles and electron lucent granules. At the apical portion of the cytoplasm, lots of short and thin microvilli are found. The salivary duct of Incilaria fruhstorferi is wider ($65\times250{\mu}m$ in diameter) than that of Achatina fulica, and consists of endothelial cells of the same structures. At the apical portion of those endothelial cells, a lot of junction apparatus such as desmosomes are observed. The vessels in the salivary ducts of Achatina fulica and Incilaria fruhstoferi are observed mainly in the connective tissues between the salivary glands. The endothelial cell of the vessel has the irregular structure and looks dark due to the high electron density. These cells protrude their filopodia and phagocytosize foreign bodies.