Vincristine, a kind of anticancerous drugs, interferes with development of microtubles and synthesis of nucleic acid and proteins in cells, and destructs cytoplasmic membrane so that mitosis of cancer cells is inhibited. Unfortunately these anticancerous effects by vioneristime are not limited to specific cancer cells, so several side effects are produced. This study was performed to explore the effects of vincristine on the fine structure of cytoplasmic organelles and cartilagenous matrix in proximal epiphyseal plate of the tibia in rat. The results were as follows: 1. Cisternae of rough endoplasmic reticulum (RER) were fragmented and sacculated, and membrane-bound ribocomes of RER were detached at 3 and 6 hours after vincristine treatment. Severely dilated, fagmented and sacculated cisternae of RER were found at 12 hours after vincristine treatment, and at 24 hours after vincristine treatment a few cisternae were framented and sacculated. At 72 hours after vincristine treatment cisternae of RER were parallely well arraged. 2. Golgi complex was atrophied at 3, 6, and 12 hours after vincristine treatment, while at 72 hours after vincristine treatment the cisternae of Golgi complex were made of 5-6 layers. 3. Mitochondria with disorganized mitochondrial cristae and outer membrane-losed mitochondria were found at 3 hours after vincristine treatment. At 6 and 12 hours after vincristine treatment mitochondria had possessed disorganized cristae, and a few mitochondria with disorganized cristae were. observed at 24 hours after vincristine treatment. While at 72 hours after vincristine treatment mitochondria were shown distinct cristae and double membranes. 4. Phagosome were begun to observe at 3 hourse after vincristine treatment, and at 24 hourse after vincristine treatment many phagosomes were found, while at 72 hours after vincristine treatment a few phagosomes were observed. 5. In the cartilagenous matrix large-sized matrix granules were decreased and collagen fibrils were dispersed at 3, 6, and 12 hours after vincristine treatment, while at 72 hours after vincristine treatment many large-sized matrix granules and numerous matrix it is suggested that although vincristine may induce the degenerative changes of the chondrocyte, resulting in changes of components of the cartilagenous matirx, these toxic effects may be regressed with time.

(001) GaAs 기판 위에 성장된 (ZnSe/FeSe) 초격자의 구성층 사이에 상호확산으로 형성된 $Zn_{1-x}Fe_xSe$ 의 미세구조가 고분해능 투과전자현미경과 컴퓨터 이미지 시뮬레이션에 의해 연구되었다. 컴퓨터 이미지 시뮬레이션은 multislice 방법으로 여러 시편 두께와 초점 거리에서 실시되었다. 컴퓨터 시뮬레이션에 의해 얻은 이미지는 실험에 의해 얻은 이미지와 비교되었다. 또한, CuAu-I 형태 규칙화가 $Zn_{1-x}Fe_xSe$ 상호화산층에서 일어났다. 이 CuAu-I 형태 규칙격자는 <100>과 <110> 방향에 따라서 ZnSe와 FeSe 층이 교대로 구성되어 있다.

To investigate detoxification effects of aqua-acupuncture; Bovis Calculus and Susi Fei extract against the toxicity of aconitine were studied. We examined the GOT activities, GPT activities, $\gamma-GPT$ activites, ALP activities and ultrastructural changes of hepatocytes in rats. The GOT activities were decreased in the aqua-acupuncture group compared with control at the 48-hours and 96-hours. The $\gamma-GTP$ and ALP activities were decreased in the aqua-acpuncture group compared with control at 96-hours. We observed the ultrastructural changes of hepatocytes compared the detoxification effects of acua-acupuncture with toxicity of aconitine by transmission electron microscope. In the 24-hours group, the cisternae of rough and smooth endoplasmic reticulum hepatocytes are dilated more or less. In the 48-hours group, the nuclear envelope are irregured, and chromatins of nucleus are condensed. The cisternae of rough endoplasmic reticulum are dilated/branched. In the 96-hours group, the rough and smooth endoplasmic reticulum are well developed in aqua-acpuncture group compared with control. These results suggest that acua-acpuncture groups of the Bovis calculus and Susi fei extract showed detoxification effects against cytotoxicity of aconitine in the hepatocyte of rats.

Microstructural characterizations of II-VI blue laser diodes which consist of quaternary $Zn_{1-x}Mg_xS_ySe_{l-y}$ cladding layer, ternary $ZnS_ySe_{l-y}$ guiding layer and $Zn_{0.8}Cd_{0.2}Se$ quantum well as active layer were carried out using the transmission electron microscope working at 300 kV. Even though the entire structure is pseudomorphic to GaAs substrate, the structure had contained numerous extended stacking faults and dislocations which had created at ZnSe/GaAs interfaces and then further grown to the top of the epilayers. These faults might be expected to cause the degradation and shortening the lifetime of laser devices.

This study aims to demonstrate the effect of chitosan, one of the natural chelator, on the ultrastructural changes in the mouse liver caused by cadmium. A total of 60 healthy ICR that weighted 30 gm $({\pm}2gm)$ was used for experiment. The experimental group was divided into three groups; group A, B, and C. The group A and B administrated cadmium (4.0 mg/kg) to the intraperitoneal after pretreated with chitosan (0.5% solution) for 30 and 7 days, respectively. Each group was observed at 12, 24, 48, 72 hours and one week after injected cadmium. The results were as follows: 1. Group A The nuclear membrane and the chromatin were normal shapes at overall the time. The inner and outer membranes of the mitochondria damaged a little but almost normal in shapes. And electron-density showed slightly compacted. some enlarged rER (rough endoplasmic reticulum) showed at 12 hours. At 48 hours, typical lamellae of the rER were reformed, and a lot of transvesicles observed around them. To 48 hours, sER (smooth endoplasmic reticulum) was slightly dilated. From 72 hours, sER rehalizated in normal shape. 2. Group B Nuclear membranes were rounded-shape and chromatin showed evenly. To 72 hours, a lot of mitochondria observed around rER and development of cristae showed weakly. But at one week, cristae were clear and electron-density of matrix showed high. At 72 hours lamellae of rER showed some broken, but were reformed at one week. Also at one week, glycogen granules evenly showed over cytoplasm. 3. Group C At 12 hours, Nucleus showed the condensation of nuclear membrane and clear condensation at 24 hours. However, nuclear membrane had a slightly rounded-shape from 72 hours. From 12 hours to the one week, mitochondria showed the dilation of inner cavity and weak development of cristae. Also electron-density of matrix was a little low. Occasionally, destruction of inner and outer membrane observed at one week. The dilation of cisternae and destruction of lamellae of rER showed from 12 to 48 hours. From 72 hours, rER showed slightly dilated only. And lamella observed at one week. In sER, dilation of inner cavity was observed during whole period. These results suggest that chitosan attenuates the toxic effect of the cadmium in the mouse liver.

The effects of antimetabolite, 6-aminonicotinamide (6-AN), on ultrastrudural changes in the spinal cord of golden hamster were investigated. Intraperitoneal administration of 6-AN (10 mg/kg body weight) every two days gave rise to a marked reduction of about $30\sim40%$ in body weight after $26\sim28$ days ($13\sim14th$ injection). In the lesions of the spinal cord, neuroglial cells such as astrocytes and oligodendrocytes were severely damaged, but neurons and blood vessels were not affected by 6-AN. The myelin sheath was also affected by 6-AN. Vacuoles observed in the lesions were produced by the swelling and degenerating changes of neuropils and neuroglial cells. Numerous swollen mitochondria and cisterns of rough endoplasmic reticulum were observed in the watery cytoplasm of damaged neuroglial cells, but intermediate filaments were well preserved. Especially in the damaged astrocytes, the outer nuclear membrane were partially swollen and formed a halfmoonlike structure. It is suggested that as well as the multivesicular bodies protruding from the swollen dendrites, the conjugation of adjacent vacuoles also participated in the formation of large vacuoles.

본 연구에서는 dehydrocholic acid와 biligrafin 투여 20분 후, 기아 8일 후 및 담관결찰 48시간 후의 흰쥐 간을 동결할단하여 담세관 주위 폐쇠띠의 미세구조를 관찰하였다. 정상대조군에서 폐쇠띠는 여러부위에서 $1\sim4$개의 줄로 이루어진 망상구조를 보였다. dehydrocholic acid 투여군에서는 폐쇠띠의 폭이 넓어져서 망상구조의 줄은 $6\sim9$개로 증가된 부위가 많이 나타났다. 그러나 biligrafin 투여군에서는 줄이 감축되어 있었으며 망상구조는 흩으러져 있었다. 기아군에서는 많은 부위에서 폐쇠띠가 $2\sim3$개의 줄로 이루어져 있었으며 이들 줄은 느슨하게 연결되어 있었다. 결찰군에서도 많은 부위에서 폐쇠띠의 망상구조는 흩으러져 있었으며 줄들이 감축되어 있거나 아직 감축되지 않은 상태로 있는 부위도 관찰되었다. 그러나 모든군에서 줄들은 틈을 보이면서 단절되어 나타나거나 선상으로 배열된 입자로 이루어져 있었는데 특히 biligrafin군과 결찰군에서 이러한 소견이 현저하였다. 줄의 끝이 유리되어 있는 것들은 기아군에서 많이 관찰되었는데 dehydrocholic acid군에서는 줄의 끝이 교통반에 접해 있거나 그 주위를 둘러싸고 있는 것들을 많이 볼 수 있었다. 줄들이 불연속적으로 나타나거나 끝이 유리된 것은 정상군에서도 드물지 않게 관찰되었다. 결찰군을 제외한 모든 군에서 담세관 주위 폐쇠띠가 그망안에 입자의 집괴를 함유하고 있었다. 이상의 증거로 미루어 담세관 주위의 폐쇠띠는 담세판의 상태에 따라 쉽게 변하는 것 같이 보이며 같은 담세관에서 일지라도 부위에 따라 구조적 변화에 차이가 있는데 이러한 소견은 정상상태하에서도 비슷하게 나타나고 있어 폐쇠띠가 완전한 장벽으로서의 역할을 하고 있지 않는 경우도 있는 것 같이 보인다. 또한 폐쇠띠는 기계적 자극이나 다른 어떠한 인자에 의해서 쉽게 영향을 받는 것 같이 보이며 폐쇠띠의 변화에 연관하여 줄과 입자의 집괴 사이에도 어떠한 관계가 있을 것으로 추정된다.

The spermatogenesis of korean leech, Whitmania edentula was observed, using both light and electron microscopes. The spermatogonium and maturing spermatozoon are connected with long cytoplasmic process to the cytophore, which supplys nutrition to the germ cells and supports synchronous maturity. The truck of korean leech is divided into three regions; a long ladder-shaped acrosome and head, long middle piece and long tail. Long head region twists to the dextral helix, and nuclei are surrounded with microtubules (manchette).The nebenkern formed with long mitochondrion exists in the middle pieces, and a long tail of Whitmania edentula ($9\times2+1$ axoneme) differs from the $9\times2+2$ axoneme of Rhynchobdellae. The late cytophore is mostly formed with crystalloid matter and a number of lysosomes, and matured spermatozooms are engulfed into the late cytophore.

The dermal papilla is known to playa major role in influencing the form and dynamics of the hair follicle, which probably involves regulatory substances crossing the basal lamina. But little is known about the junctions between the dermal papilla and the surrounding epithelial cells of the hair bulb, or between the connective tissue and the epithelial cells on the outside of the hair follicle. This study was performed to identify the ultrastructural differences between dermoepidermal junction of the skin and connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla of normal anagen hair follicles in the human fetal scalp skin. Electron microscopic findings of dermoepidermal junction in scalp skin showed that basal lamina was very irregular and undulated, and it contained many attachment plaques of hemidesmosomes with sub-basal dense plates, tonofilaments, and anchoring filaments. Also invaginations of plasma membrane of basal keratinocytes were seen. There were clear differences both on the outside of the follicle and around the dermal papilla as compared with similar junction in the skin. In particular, neither hemidesmosomes nor tonofilaments, as seen in dermoepidermal junction, were observed in the dermal papilla. Also attachment plaque, sub-basal dense plate and anchoring filaments were not observed at the junction on the outside of the follicle and the dermal papilla. There were some differences between connective tissue-epithelial junctions on the outside of the hair follicle and around the dermal papilla, ie, smoothness of basal lamina and orthogonal arrangement of collagen fibers were seen in the outside of hair follicle, but not in the dermal papilla. These results indicate that the mechanical connection between the hair follicle and the connective tissue component is much weaker than that between the corresponding components in skin, and it reflects the dynamic processes during the anagen phase of the hair follicle compared to the relatively permanent state of the epidermis.

The ischemia and reperfusion injury of the skeletal muscles is caused by generation of reactive oxygen during ischemia and reperfusion. It is well known that over 4 hours of ischemia injures the skeletal muscles irreversibly. The author has demonstrated the effects of SOD (superoxide dismutase), DMTU (dimethyl thiourea) and ischemic preconditioning on ultrastructural changes of the muscle fibers in the rectus femoris muscles after 4 hours of ischemia and 1 day and 3 days of reperfusion. A total of 72 healthy Sprague-Dawley rats weighing from 200 gm to 250 gm were used as experimental animals. Under urethane(1.15 g/kg, IP, 2 times) anesthesia, lower abdominal incision was done and the left common iliac artery was occluded by using vascular clamp for 4 hours. The left rectus femoris muscles were obtained at 1 and 3 days after the removal of vascular clamp. The SOD (15,000 unit/kg) or DMTU (500 mg/kg) were administered intraperitoneally at 1 hour before induction of ischemia. The ischemic preconditioned group underwent three episodes of 5 minutes occlusion and 5 minutes reperfusion followed by 4 hours of ischemia and 1 day and 3 days of reperfusion. The specimens were sliced into $1mm^3$ and prepared by routine methods for electron microscopic observation. All specimens were stained with uranyl acetate and lead citrate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. SOD or DMTU alone did not affect the ultrastructure of muscle fibers in the rectus femoris muscles. The electron density of mitochondrial matrix was decreased by ischemic preconditioning. 2. Dilated cisternae of sarcoplasmic reticulum, triad, mitochondria and the loss of myofilament in the sarcomere were observed in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. Markedly changed sarcoplasmic reticulum, triad, disordered or loss of myofilament, indistinct A-band and I-band, and irregular electron lucent M -line and Z-line are seen in the 4 hours ischemia and 3 days reperfused rectus femoris muscles. 3. SOD reduced the changes of organelles in the muscle fibers of the 4 hours ischemia and 1 day reperfused rectus femoris muscles of the rats, but SOD did not affect the changes of muscle fibers in the 4 hours ischemia and 3 days reperfused muscles. On the other hand, DMTU markedly attenuated considerably the ultrastructural change of the 4 hours ischemia and 1 day or 3 days reperfused rectus femoris muscles. 4. By the ischemic preconditioning, the change was attenuated remarkably in the 4 hours ischemia and 1 day reperfused rectus femoris muscles. As the ischemic reperfused changes of muscle fibers were regenerated or recovered by ischemic preconditioning, the ultrastructures of them were similar to those of normal control in the 4 hours ischemia and 3 days reperfused rectus formoris muscles. Consequently, it is suggested that DMTU is stronger inhibitor to ischemic reperfused change than SOD. The ischemia and reperfusion-induced muscular damage is remarkably inhibited by ischemic preconditioning.