Changes of Apoptosis After X-irradiation During the Hindlimb Development in the Rat Fetus / 체질인류학회지

Ionizing radiation exerts harmful effect during the limb development, but the exact mechanism is still largely unknown. In this study, 2 Gy of X-ray irradiated to the rat fetuses on gestation day of 13.7 when the hindlimb buds appear, and sacrificed at GD 14.7, GD 15.7 and GD 16.7, respectively. To reveal the changes of apoptotic figures between control and experimental groups, TUNEL immunohistochemistry and confocal laser scanning microscopy were carried. Mean body weight of fetuses of irradiated groups were decreased significantly compared to the control group. Numerical digit anomalies and asymmetries between right and left sides were increased significantly in the irradiated group compared to control group. Some digit anomalies were increased significantly in the right side. Radiation-induced decrement of the density of apoptotic figures on GD 14.7 was presumed to be related with foot and digit anomalies.

TNFalpha and TNFR2 Immunohistochemistry During Ovarian Follicular Development and Atresia in the Rat / 대한해부학회지

Tumor necrosis factor alpha (TNFalpha) is an intraovarian cytokine that may play a role in ovarian development and function. Identification of ovarian TNFalpha receptors provides support for establishing a role of TNFalpha in ovarian development and function. TNFalpha exerts its effects by binding to either TNF receptor 1 or 2 (TNFR1 or TNFR2). When TNFalpha binds with TNFR2, expression of survival genes is up-regulated, resulting in proliferation of granulosa cells. In the present study, the authors identified the changes in localization of TNFalpha and the expression of TNFR2 in granulosa cells during follicular atresia in rat ovaries. In healthy follicles, intense signals for TNFalpha and TNFR2 were found in the outer surface of the granulosa layer, where many proliferating cells and no apoptotic cells were observed. In atretic follicles, decreased expression of TNFalpha and TNFR2 was observed in the granulosa layer, where many apoptotic cells were seen. These findings suggested that TNFalpha acts as a survival factor in granulosa cells during follicular atresia in rat ovaries.

Macrophages in the Corpus Luteum of the Rat : Immunohistochemical and Transmission Electron Microscopic Study / 대한해부학회지

Macrophages in the corpus luteum have many important roles during the periods of functional development and luteal regression. Not only phagocyte the apoptotic luteal cells, but also they secrete many cytokines and exert their effects via autocrine/paracrine actions.In this study, we investigated the changes of number and immunoreactivity of macrophages at various developmental periods of the corpus luteum in the rat ovary. The rats (Sprague-Dawley strain, female)at age of 8 weeks (ovulatory period), GD 6 (pregnant period), and postpartum 5 days (postpartum period)were sacrificed under ether anesthesia and obtained both ovaries, one used for macrophages immunohistochemistry and the other used for TEM. The results were as follows; 1.In the corpora lutea of the rat, macrophages were observed all the developmental periods including ovulatory, pregnant and postpartum periods. 2.In the corpora lutea of the rat, number of macrophages was highest in the ovulatory period, and decreased at postpartum period and pregnant period in order. The immunoreactivity of macrophages was high at ovulatory period, moderate at postpartum period, and low at pregnant period. 3.In TEM observations, two types of macrophages were observed: One type was non-phagocytic macrophage and the other type was phagocytic macrophage. Phagocytic macrophages were observed in the corpora lutea at ovulatory and postpartum periods and contained apoptotic bodies, phagocytic vacuoles and many lipid droplets. Non-phagocytic macrophages were observed in the corpora lutea at pregnancy period and showed slender cell body with long cytoplasmic processes and contained no apoptotic bodies. In the rat, the number and the degree of immunoreactivity of macrophages in the corpus luteum varied with the changes of functional state of the corpus luteum. It was suggested that the main function of the macrophages at the ovulatory and postpartum periods was elimination of apoptotic luteal cells and that at pregnancy period was autocrine/paracrine action.Ultrastructurally, two types, phagocytic and nonphagocytic types, of macrophages confirmed. These results will provide valuable informations on the study of the role macrophages during development and regression of corpus luteum.

Morphological Study on the Arterial Intimal Hyperplasia and the Inhibitory Action of Dexamethasone / 체질인류학회지

This study is performed to reveal the changes of the arterial wall, especially, tunica intima and tunica media, after endothelial denudation and the effects of dexamethasone sodium on intimal hyperplasia morphologically in the rat. After arterial denudation by modified air drying technique, dexamethasone 1, 200 mg/kg/day was administered intramuscularly daily from the day of operation for 14 days. At 5 DAT (days after treatment) and 14 DAT, tunica intima was greatly thickened in control groups compared with normal group, but not in the dexamethasone-treated groups. Light microscopically, greatly increased cells and intercellular matrix in the tunica intima are observed in control group, but not in the dexamethasone-treated group. In the TEM observation, the cells considered as myofibroblasts and extracellular matrix were greatly increased in both tunica intima and tunica media just below the internal elastic lamina in the control group. Myofibroblasts and extracellular matrix migrated through the apertures of internal elastic lamina into the endothelial layer. Characteristic false internal elastic lamina also found. In dexamethasone-treated group, myofibroblasts and extracellular matrix decreased significantly, and apoptotic electron-dense cells, fragmented nucleus and autophagic vacuoles are observed. Through the apertures of internal elastic lamina, comma-shaped fragmented nuclei migrated into the tunica intima. These results suggest that dexamethasone inhibits the myofibroblast-transformation and proliferation of smooth muscle cells, migration of myofibroblasts and matrix synthetic activity, and induces the apoptosis of smooth muscle cells under the internal elastic lamina.

The Effect of X-irradiation on the Developing Incisor Tooth of the Rat / 체질인류학회지

In the development of tooth, the first sign is the localized thickening of oral ectoderm to form the tooth bud, and then through the dialogue between the bud and underlying mesenchyme, proliferation and differentiation of bud cells and surrounding mesenchymal cells continue, and cap and bell stages follow. In each step of development, various teratogens may act directly and indirectly, and may result a certain congenital anomalies. To reveal the action mechanism of ionizing radiation on odontogenesis morphologically, 4 Gy X-ray irradiated on the rat (Sprague-Dawley strain) fetus on GD 12.7, and observed the histological changes of the upper incisor tooth from GD 13.5 to GD 20.5, daily. In the normal development of upper incisor tooth of rat, the bud stage was from GD 12.5 ~GD 15.5, the cap stage was from GD 16.5 to GD 17.5, and the bell stage was GD 18.5 to GD 20.5. After X-irradiation on GD 12.7, the development of incisor tooth was delayed markedly, the bud stage was prolonged from GD 13.5 to GD 17.5, and the cap stage was GD 18.5 and the bell stage was from GD 19.5 to GD 20.5. After X-irradiation, from GD 13.5 to GD 16.5, apoptosis is observed in the dental organ and surrounding mesenchyme, hemorrhagic necrosis began from GD 16.5 at the center of dental pulp, followed ischemic necrosis of dental organ and surrounding mesenchyme. After GD 19.5, the development of tooth was ceased. These suggest that at least 2 mechanisms involved during X-ray teratogenesis on developing tooth. After X-irradiation on GD 12.7, initially, X-ray induced apoptosis of the cells of dental lamina and dental bud, which resulted the delayed proliferation and differentiation of dental bud and shortage of the number of cells having signal molecules which induce aggregation of the underlying mesenchymal cells. Lately, disorganization of the endothelial cells differentiated from the damaged mesenchymal cells, which resulted in rupture of capillaries and the hemorrhagic necrosis.

Follicular Atresia and Macrophages in the Porcine Ovary; Immunohistochemical and Transmission Electron Microscopic Study / 대한해부학회지

Apoptosis of granulosa cells leads follicular atresia and macrophages have an important role during the apoptotic process. However, the propagation of apoptosis within the follicle, the ways of elimination of apoptotic bodies and degenerated oocyte, and the completion of follicular atresia are still controversial and unidentified clearly. Using adult porcine (Yorkshire-breed) ovary, in this morphological study, transmission electron microscopic observation and immunohistochemical study with pig macrophage monoclonal antibody 4E9 were performed. In light microscopy, the follicular atresia initiated with apoptosis of granulosa cells, followed by degeneration of oocyte and apoptosis of theca interna cells. Apoptosis occured in random fashion among the granulosa cells and propagated multidirectionally, and finally to the granulosa cells surrounding zona pellucida of degenerating oocyte. Pyknosis of granulosa cells was the first sign of apoptosis. In immunohistochemistry, macrophages were found only in the granulosa layer at the stage of beginning of apoptosis. With progression of apoptosis, they were proliferated greatly in number enough to eliminate all the apoptotic bodies, and found within the follicular antrum. In advanced stage of atresia, macrophages surrounded the zona pellucida of degenerating oocyte, and found also in the theca interna. In transmission electron microscopy, phagocytic granulosa cells maintained characteristic gap junctions with neighboring granulosa cells and contained several apoptotic bodies and lipid droplets within their cytoplasm. Macrophages kept many apoptotic bodies, vacuoles and autophagosomes in their cytoplasm. Apoptotic granulosa cells were ingested by intact granulosa cells and macrophages initially, but lately, all the apoptotic granulosa cells and degenerated oocyte were eliminated by macrophages. Ovarian follicular atresia completed with phagocytosis of apoptotic theca interna cells by macrophages, and the remnants of the atretic follicle became ovarian stroma. It is well known that macrophages may play an important role during follicular atresia, such as elimination of apoptotic granulosa cells, theca interna cells and degenerated oocytes, but, the valid action mechanisms of macrophages on the initiation of granulosa cell apoptosis and on the completion of atresia through the secretion of paracrine factors and autocrine factors still unclear.

The Effect of X -irradiation on Lens Development / 체질인류학회지

For the study the effects of X -ray irradiation on the development of lens and interactions between optic vesicle and lens, 200 rads X -ray irradiated to the preganat rats (Sprague -Dawley strain) on gestation day 9.5. The rats were sacrificed daily from the gestation day 10.5 to 17.5, and investigated the development of lens with light microscope. The results were as follows; 1. The survival rate of X -irradiated rat fetuses was decreased significantly compared with that of the control group. 2. The mean body weight of the X -irradiated rat fetuses was decreased significantly compared with that of the control group. 3. The congenital anomalies of the eye in the rat fetuses after X -irradiation were anophthalmia, congenital aphakia, lens aplasia, lens luxation, and coloboma of the retina. 4. The critical period of lens development of the Sprague -Dawley rats was considered from GD 9. 5 to GD 10.0. 5. In the X -irradiated rat fetuses on gestation day 9.5, optic vesicle did not developed, but lens developed independently , and moved deeply toward the forebrain vesicle. According to above results, it could be concluded that the development of lens from surface ectoderm might be independent from the inductive influence of optic vesicle, and the movement of lens toward the forebrain vesicle could be mediated by chemotactic factors secreted from the brain vesicle. Further studies are needed to reveal the mechanisms of lens development and interaction between lens and brain vesicle.

A Case of Horseshoe Kidney / 체질인류학회지

During cadaver dissection at Chungnam National University in year 2001, we found a case of horseshoe kidney. The characteristic findings of this kidney were as follows; 1. Horseshoe kidney was located at the level of 12th thoracic vertebra and 4th lumbar vertebra, and its isthmus was located at the level of 3rd lumbar vertebra, just below inferior mesenteric artery. The upper pole of the right kidney was 11 mm higherthan that of left kidney. 2. Both renal arteries originated normally from the abdominal aorta below superior mesenteric artery and divided into 2 branches at the front of the renal hilum. The lower branches entered normally into the renal hilum respectively, but, 2 upper branches of right renal artery and 3 upper branches of left renal artery entered into the upper segment of both kidneys respectively. 3. The 2 accessory renal arteries were found. One was the branch of the median sacral artery, which asended anterior to the bifurcation of abdominal aorta and divided 2 branches, of which larger right branch entered inferior pole of right kidney and smaller left branch entered into the isthmus. The other was originated from abdominal aorta 1/3 distance from the origin of inferior mesenteric artery to the bifurcation of abdominal aorta, and entered into the posteroinferior part of left kidney. 4. There were additional 2~3 minor calyces in the lower part of the both kidneys in frontal section, which formed a major calyx draining into the renal pelvis. Parenchymal tissues of both kidneys were continuous through isthmus. In frontal section, renal pyramids were twice in number, and arranged into 2 groups at the upper and lower parts of the both kidneys. Especially, one renal pyramid laid transversely in the isthmus and the renal papilla of it opened into the minor calys of left kidney. It is thought that this horseshoe kidney might be resulted from the elongation of a ureteric bud, which induced new broad -field nephron within the metanephric blastema, and formed a group of additional renal pyramids. The additional renal pyramids formed slight later than normal period, and the separation of both kidneys should be failed and resulted horseshoe kidney. During ascent of kidney, the inferior mesenteric artery interrupted upward migration. It can be concluded that the error of reciprocal induction between ureteric bud and metanephric mesenchyme may be an important mechanism of horseshoe kidney formation.

Germinal Center Formation and Integrins Expression in the Rat Thymus After 5-Fluorouracil Treatment / 대한해부학회지

Thymus is a lymphoid organ forming T-cells from hematogenous stem cells. There is no report on the germinal centers in the thymus except the Myasthenia gravis in human. In this study, new germinal centers were experimentally induced from 6 days after 5-FU treatment in the Sprague-Dawley rats. With germinal center formation, proteins of molecular weight 123 kDa on 6 days after 5-FU treatment, and 162 kDa and 205 kDa on 9 days after 5-FU treatment were increased in 5-FU treated group. These proteins revealed alpha 1 -and beta 1 -integrins on integrin Western Blot. In this experiment, it was cosidered that alpha 1-integrins and beta 1 -integrins were the key proteins for proliferation of B cells within the newly formed thymic germinal centers and the massive apoptotic disposal of B-cells from the germinal centers, and the new formation of T cells within the cortex.

Radiation -induced Congenital Anomalies in the Rat Fetuses / 체질인류학회지

X -ray irradiation induces various congenital anomalies in the human fetuses and experimental animals. The action mechanism of teratogenesis, however, still not known completely. Furthermore, the dynamics of teratogenesis according to the developmental stages are so great that complete unveiling the teratogenic action mechanism of radiation is nearly impossible. And, it is necessary to make the experimental model for the study on the damages caused by electromagnetic field, recently. In this study, the Sprague -Dawley rats were irradiated 2 Gy once on the GD 10.7, and observed the congenital anomalies of the fetuses on GD 17.5, grossly and light microscopically. The results were as follows ; 1. There was no significant difference in the survival rate between control and irradiated groups. However, mean body weight of the experimental group decreased significantly compared to control group. 2. X -irradiation -induced congenital anomalies were eye anomalies such as unilateral and/or bilateral anophthalmia, microphthalmia, and aphakia, hemorrhagic plaques on the head, tail anomalies such as short tail and curved tail, and posterior limb anomalies. 3. Posterior limb anomalies were all ecrodactyly, such as 4 -digit anomaly, 3 -digit anomaly, and cleft foot. In the sidedness of anomalies, right side showed greater dominance than left.

Azygos Lobe of Korean / 체질인류학회지

3 cases of azygos lobe were found during dissection at Chungnam National University of Korea in 2000 ~2001. All the azygos lobes located at the right upper lobe, and azygos fissures began from the upper anterior part of hilum, curved laterally and postieriorly around the apical portion of right lung toward the upper posterior part of hilum. Each azygos vein of 3 cases ran along the azygos fissure in its base, forming azygos arch, and ended into the superior vena cava at the level of 2nd costal cartilage. Bronchopulmonary dissection revealed the B 1 a and B 1 b supplying the azygos lobe in all cases.

Mastoid Foramen and Superficial Mastoid Canals of Korean Men / 체질인류학회지

The mastoid foramina and the superficial mastoid canals at the mastoid area are well known to have much clinical and anthropological significances. However, few sutdies on these structures were reported. Authors performed this study to analyze those structures of the Korean men, and compared with other populations. The existence, number, location of matoid foramen, distance from the posterior border of the opening of external acoustic meatus were measured. In addition, the existence, shape and the direction of the superficial mastoid canals were investigated. The results were as follows; 1. Among the 67 skulls of Korean men, there was no mastoid foramen on both sides in 1 case. In 10 cases, there was mastoid foramen on right side only, and in 4 cases left side only. In 52 cases (77.6%), there was mastoid foramen on both sides. 2. In the incidence of mastoid foramen, 1 in 27 cases, 2 in 23 cases and 3 in 11 cases on the right side, and 1 in 25 cases, 2 in 22 cases and 3 in 17 cases on the left side were found. 3. 64.0% of mastoid foramina located on the temporal bone, 28.5% were on the occipitomastoid suture, 5.2% were on the occipital bone, 1.9% were on parietomastoid suture, and 1 case on the parietal bone. 4. In the sidedness of mastoid foramen, 1-1 foramen on each side was 15 cases, 2-2 foramina on each side was 10 cases, 1-2 foramina on right-left side was 8 cases, and 0-0 on each side, 2-4 on right-left side, and 4-3 on right-left side were 1 case respectively. 5. The average diameter of mastoid foramen was 2.0+/-0.69 mm, and the distance from the posterior margin of the external acoustic meatus was 33.6+/-3.69 mm. There was no significant differences between right and left sides. 6. The superficial mastoid canals appeared in 23 cases (34.3%), among which 12 cases were on right side and 11 cases were on left side. 14 canals were straight in shape, 2 were grooved, and others were arched, sigmoid or bridged. 21 canals directed toward parietal bone and others directed occipital bone. According to the above results, the existence, number, size and the distance from external acoustic meatus of mastoid foramina, and the incidence, shapes and directions of superficial mastoid canals were much variable. Of course, these variations would have great clinical significances during the neurosurgical and otolaryngeal surgery. These data would contribute to study epigenetic study of minor variations of skull and anthropological study.

A Study on the Congenital Anomalies induced by Cadmium Chloride / 체질인류학회지

The purpose of this study is to observe the optimium effects of cadmium chloride on the rat fetus. Cadmium chloride 5 mg/kg was administered intraperitoneally once to the pregnant rats on GD10.5, and the rats were sacrificed on GD 17.5 followed by formalin fixation for bone-cartilage counterstaining, Bowin fixation for palate observation and fixation with 5% glutaraldehyde solution for SEM. The results were as follows; 1. In the cadmium chloride treated group, the survival rate of rat embryos was 65.7% and the average body weight was 589+/-77.5 mg. Both were significantly lower statistically than those of the control group. 2. In the cadmium chloride treated group, craniofacial anomalies such as hydrocephalus, hemorrhagic bullae and cleft palates, and anomalies of the limbs such as polydactyly and oligodactyly were observed. 3. In the cadmium chloride treated group, no primary ossification centers were found in all fetuses. In the vertebral column and the ribs, congenital anomalies such as fusion of vertebral laminae, short tail, fused ribs, division of ribs, accessary rib and loss of rib were observed. 4. In the cadmium chloride treated group, congenital anormalies of the ribs were predominently on the right side and that of the feet were predominently on the left side. 5. In the cadmium chloride treated group, a protein with molecular weight of 14.1 kDa was disappeared in the forelimbs and hindlimbs of GD12.5, and proteins with molecular weight of 14.1 kDa and 30.2 kDa were decreased in the forelimbs of GD13.5, and a protein with molecular weight of 14.1 kDa was disappeared in the hindlimbs of GD13.5, and a protein with molecular weight of 14.1 kDa was decreased in the hindlimbs of GD13.5. With the above results, it is considered that cadmium chloride causes death in utero due to direct acute poisoning of the rat fetuses, inhibits development of skeletal system, and induces various congenital anomalies. And the action mechanisms of cadmium chloride may be the cause of the destruction of capillaries in CNS as well as the inhibition of carbonic anhydrase. But this is still not confirmed.