• Title/Summary/Keyword: Plasma membrane

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Synthesis of (4-$[^{18}F]$Fluorophenyl)triphenylphosphonium as a Mitochondrial Voltage Sensor for PET (PET영상용 미토콘드리아 막전위 감지기 (4-$[^{18}F]$Fluorophenyl)triphenylphosphonium의 합성)

  • Kim, Dong-Yeon;Yu, Kook-Hyun;Bom, Hee-Seung;Min, Jung-Joon
    • Nuclear Medicine and Molecular Imaging
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    • v.41 no.6
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    • pp.561-565
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    • 2007
  • Purpose: Lipophilic cations including tetraphenylphosphonium (TPP) salts penetrate the hydrophobic barriers of the plasma and mitochondrial membranes, resulting in accumulation in mitochondria in response to the negative inner transmembrane potentials. The development of radiolabeled phosphonium cations as a noninvasive imaging agent may serve as a new molecular "voltage sensor" probe to investigate the role of mitochondria in the pathophysiology and diagnosis of cancer. Materials and Methods: We have synthesized a reference compound (4-fluorophenyl)triphenylphosphonium (TPP) and a labeled compound $[^{18}F]$TPP via two step nucleophilic substitution of no-carrier-added $[^{18}F]$fluoride with the precursor, 4-iodophenyltrimethylammonium iodide, in the presence of Kryptofix-2.2.2 and $K_2CO_3$. Result: The reference compound (4-fluorophenyl)triphenylphosphonium (TPP) was synthesized in 60% yield. The radiolabeled compound $[^{18}F]$TPP was synthesized in $10\sim15%$ yield. The radiochemical purity of the $[^{18}F]$TPP was $95.57{\pm}0.51%$ (n=11). Conclusion: $[^{18}F]$TPP was successfully synthesized that might have a potential to be utilized as a novel myocardial or cancer imaging agent for PET. However, it is required to improve the radiochemical yield to apply $[^{18}F]$TPP in preclinical or clinical researches.

Role of $K^+$ Channels in $H_2O_2$- and Cryo-induced Apoptosis of Mouse and Bovine Embryos (과산화수소와 동결에 의해 유도된 생쥐와 소 수정란의 사멸에 있어서 칼륨 통로의 역할)

  • Choe, Changyong;Kim, Chang-Woon;Kang, Dawon;Han, Jaehee
    • Journal of Embryo Transfer
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    • v.29 no.3
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    • pp.249-255
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    • 2014
  • Programmed cell death or apoptosis is associated with changes in $K^+$ concentration in many cell types. Recent studies have demonstrated that two-pore domain $K^+$ ($K_{2P}$) channels are involved in mouse embryonic development and apoptotic volume decrease of mammalian cells. In cerebellar granule neurons that normally undergo apoptosis during the early developmental stage, TASK-1 and TASK-3, members of $K_{2P}$ channels, were found to be critical for cell death. This study was performed to identify the role of $K^+$ channels in the $H_2O_2$-induced or cryo-induced cell death of mouse and bovine embryos. Mouse and bovine two-cell stage embryos (2-cells) exposed to $H_2O_2$ for 4 h suffered from apoptosis. The 2-cells showed positive TUNEL staining. Treatment with high concentration of KCl (25mM) inhibited $H_2O_2$-induced apoptosis of 2-cells by 19%. Cryo-induced death in bovine blastocysts showed positive TUNEL staining only in the cells near the plasma membrane. Cryoprotectant supplemented with 25 mM KCl reduced apoptosis slightly compared to cryoprotectant supplemented with 5 mM KCl. However, the combination of antioxidants (${\beta}$-mercaptoethanol) with 25 mM KCl significantly decreased the rate of $H_2O_2$-induced and cryo-induced apoptosis compared to treatments with only antioxidants or 25 mM KCl. These results show that blockage of $K^+$ channel efflux for a short-time reduces $H_2O_2$- and cryo-induced apoptosis in mouse and bovine embryos. Our findings suggest that apoptosis in mouse and bovine embryos might be controlled by modulation of $K^+$ channels which are highly expressed in a given cell type.

Cloning, Expression, and Polymerization Assay of FtsZ Protein from Staphylococcus aureus (Staphylococcus aureus FtsZ의 클로닝, 발현 및 폴리머 형성 활성 분석)

  • Son, Sang Hyeon;Lee, Dong Yun;Kim, Ye Jun;Ko, Sooho;Cho, Seong Jun;Jung, Hyo Cheol;Lee, Hyung Ho
    • Microbiology and Biotechnology Letters
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    • v.40 no.3
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    • pp.274-277
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    • 2012
  • Cytokinesis is the final stage of cell division, dividing one mother cell into two daughter cells. For the cutting of a plasma membrane during bacterial cytokinesis, a tubulin homolog FtsZ protein is recruited from the cytoplasm to the division site. FtsZ protein polymerizes in a GTP-dependent manner and its N-terminal domain has a GTPase activity. In this study, we have begun to characterize FtsZ from Staphylococcus aureus (SA). Full-length SA FtsZ was cloned into pRSFDuet-1 vector and the clone was transformed into a BL21 (DE3) star cell. The recombinant SA FtsZ protein was purified using Ni-NTA affinity chromatography and dialysis. Using a spectrofluorometer, we showed that SA FtsZ undergoes a GTP-dependant polymerization in vitro. The polymer of the SA FtsZ protein disappeared after a few minutes, suggesting that the polymer is degraded as the GTP is consumed. This assay system may well be applied for inhibitor screening targeting S. aureus FtsZ.

Effects of Subatmospheric Pressure Storage on Ultrastructural Changes in the Chloroplasts of Apple Fruit (사과과실 엽록체의 초미세구조 변화에 미치는 감압저장의 영향)

  • Ha, Young-Sun;Sohn, Tae-Hwa
    • Applied Biological Chemistry
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    • v.28 no.3
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    • pp.174-181
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    • 1985
  • Ultrastructural changes in the chloroplast of apple fruits was examined with Malus Pumila Mill var. Fugi harvested during preclimacteric stage the subatmospheric pressure storage condition at 380mmHg, $20^{\circ}C$. Electron micrographs obtained from the fruits stored at 760mmHg, $20^{\circ}C$ indicated that the initiation of ultrastructural changes is in parallel with the onset of respiratory climacteric. Chloroplast of the apple fruits stored for 25 days is vacuolated and the lamellar system are a little disorganized. Chloroplast of the apple fruits stored for 50 days is showing extensive vacuolation, the lamellar system are completely disorganized and the plasma membrane has pulled away from the cell wall. In the case of subatmospheric presssure storage caused to delay the onset of ultrastructural changes in chloroplast such as vacuolation, disorganization of lamellar system and dispersal of stroma lamella about 2 months. These results suggested that ripening of apple fruits is correlated not only to the activity of respiration but to the involvement of ultrastructural changes in fruit cells. The evidences obtained here led to the conclusion that subatmospheric pressure treatment extends storage life of apple fruits by inhibiting ultrastructural changes of cell organelles in concomitance with respiratory activity.

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Patch Graft of the Canine Esophagus (식도이식에 관한 실험적 연구)

  • Ha, Gye-Sik
    • Journal of Chest Surgery
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    • v.2 no.2
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    • pp.167-167
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    • 1969
  • Two groups of esophagus graft were done in canine esophagus in 34 adult mongrel dogs. For the first group segmental replacement graft was done with fresh autologous pericardium tube, and for the second, patch graft was done utilizing fresh autologous pericardium, fresh homologous pericardium,and dacron piece. All eight dogs in the first segmental replacement graft group died 2 to 5 days after operation with severe empyema caused by anastomosis disruption. Among 26 patch graft dogs 2 died during operation and 7 died 13 to 18 days after operation. For the 17 long-term patch grafted survivors esophagography and postoperative weight check were done. Postoperative stool was collected and examined for dacron patch excretion. One, two, three, and four months postoperative long-term survivors were sacrificed to obtain specimens in each group respectively and the following observations were made.I. Survival; Autologous pericardium patch group showed no mortality but in homologous pericardium and dacron patch group only two thirds were long-term survivors. II. Postoperative swallowing; There was no case which demonstrated postoperative dysphagia. About half of the cases showed postoperative weight increase and in only 3 cases weight decrease followed operation. III. Dacron patch was excreted in the stool 8 to 23 days after operation. Animals which excreted dacron patch up to 9 days after operation all died of empyema due to anastomosis disruption.IV. Postoperative esophagogram; All esophagograms in each group showed no leakage of barium, no passage disturbances and no remarkable stenotic signs.V. Morphological findings; [A] Macroscopical findings; In one month group specimens of each group dense adhesion with surrounding structures was noted and luminal surface was smooth with contraction of the patched area. In two month groups anastomosis sutures were still exposed but patched area showed lesser abnormality. In three to four months groups sutures were covered completely and patched area showed only very slight signs of contraction. [B] Microscopic findings; In one month group luminal surface of the replaced tissue [transplanted tissue] showed almost complete epithelial covering that is composed of several layers of squamous cells with no evidence of keratinization. Basement membrane was also well distinct throughout. Slight to minimal inflammatory cells comprising of large mononuclears, lymphocytes and plasma cells were observed in the subepithelial fibrous stroma consisted entirely of loose fibrous tissue containing many newly formed capillaries and fibroblastic proliferation. Scattered suture granulomas were found, few of which became acutely inflamed. In two months group repairing process progressed with lesser degree of inflammatory cell infiltration and young capillary proliferation. Fibrous tissue was more matured showing even focal collagenization.Suture granuloma persisted but with lesser reactive changes. Epithelial covering was that of a mature non-keratinizing stratified squamous epithelium. In three and four months groups the replaced area showed essentially similar histological findings. However, subepithelial stroma still consisted entirely of connective tissue without evidence of smooth muscle regeneration. In this group, inflammatory cell infiltration was minimal or negligible. Among these patch materials autologous pericardium group showed the most satisfactory repairing process.The above mentioned results may signify the feasibility of autogenous pericardium patch graft in clinical esophageal surgery.

Patch Graft of the Canine Esophagus (식도이식에 관한 실험적 연구)

  • 하계식
    • Journal of Chest Surgery
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    • v.2 no.2
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    • pp.168-186
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    • 1969
  • Two groups of esophagus graft were done in canine esophagus in 34 adult mongrel dogs. For the first group segmental replacement graft was done with fresh autologous pericardium tube, and for the second, patch graft was done utilizing fresh autologous pericardium, fresh homologous pericardium,and dacron piece. All eight dogs in the first segmental replacement graft group died 2 to 5 days after operation with severe empyema caused by anastomosis disruption. Among 26 patch graft dogs 2 died during operation and 7 died 13 to 18 days after operation. For the 17 long-term patch grafted survivors esophagography and postoperative weight check were done. Postoperative stool was collected and examined for dacron patch excretion. One, two, three, and four months postoperative long-term survivors were sacrificed to obtain specimens in each group respectively and the following observations were made. I. Survival; Autologous pericardium patch group showed no mortality but in homologous pericardium and dacron patch group only two thirds were long-term survivors. II. Postoperative swallowing; There was no case which demonstrated postoperative dysphagia. About half of the cases showed postoperative weight increase and in only 3 cases weight decrease followed operation. III. Dacron patch was excreted in the stool 8 to 23 days after operation. Animals which excreted dacron patch up to 9 days after operation all died of empyema due to anastomosis disruption. IV. Postoperative esophagogram; All esophagograms in each group showed no leakage of barium, no passage disturbances and no remarkable stenotic signs. V. Morphological findings; [A] Macroscopical findings; In one month group specimens of each group dense adhesion with surrounding structures was noted and luminal surface was smooth with contraction of the patched area. In two month groups anastomosis sutures were still exposed but patched area showed lesser abnormality. In three to four months groups sutures were covered completely and patched area showed only very slight signs of contraction. [B] Microscopic findings; In one month group luminal surface of the replaced tissue [transplanted tissue] showed almost complete epithelial covering that is composed of several layers of squamous cells with no evidence of keratinization. Basement membrane was also well distinct throughout. Slight to minimal inflammatory cells comprising of large mononuclears, lymphocytes and plasma cells were observed in the subepithelial fibrous stroma consisted entirely of loose fibrous tissue containing many newly formed capillaries and fibroblastic proliferation. Scattered suture granulomas were found, few of which became acutely inflamed. In two months group repairing process progressed with lesser degree of inflammatory cell infiltration and young capillary proliferation. Fibrous tissue was more matured showing even focal collagenization. Suture granuloma persisted but with lesser reactive changes. Epithelial covering was that of a mature non-keratinizing stratified squamous epithelium. In three and four months groups the replaced area showed essentially similar histological findings. However, subepithelial stroma still consisted entirely of connective tissue without evidence of smooth muscle regeneration. In this group, inflammatory cell infiltration was minimal or negligible. Among these patch materials autologous pericardium group showed the most satisfactory repairing process. The above mentioned results may signify the feasibility of autogenous pericardium patch graft in clinical esophageal surgery.

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Ultrasonographic and radiographic study on experimental cystitis in rabbit (실험적 방광염 유발 토끼에서의 초음파 및 방사선학적 연구)

  • Sung, Jai-ki;Chang, Dong-woo;Yoon, Jung-hee
    • Korean Journal of Veterinary Research
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    • v.36 no.4
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    • pp.973-990
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    • 1996
  • To investigate diagnostic imaging of cystitis and to apply it to the small animal practice, ultrasonogram of urinary bladder with moderate distension(4ml/kg) and with complete distension(9ml/kg) to evaluate the irregularity and thickness of bladder, radiography and histopathological examination were performed after experimental cystitis induction. On double contrast cystography, mucosal membrane of the urinary bladder was smooth and thickening urinary bladder wall was not found before cystitis induction. At 3rd day post induction(PI), mucosal irregularity was noted at the cranioventral region of the urinary bladder. Thickening of the urinary bladder wall and filling defect was observed as well. Cystographic findings of 7, 10, 15, 21 day PI were similar to that of 3rd day PI. On ultrasonographic findings of the mural thickness in induction group, it was ascertain that the mural thickness with moderate distention was more thickened than with complete distention at transverse scan. Ultrasonographic findings at longitudinal scan were similar to those of transverse scan. On ultrasonographic findings of mucosal irregularity in induction group, from PI to 7 day PI, mucosal irregularity with moderate distention was more irregular than mucosal irregularity with complete distention. At 10 day PI, there was similarity between moderate distention and complete distention. On histopathologic examination of a section of urinary bladder taken 3 day PI, the mucosal and submucosa were infiltrated by a mixture of thick inflammatory exudate which was composed of neutrophil, plasma protein, bacterial colony and necrotic cells. Congestion, hemorrhage and edema were also observed in the submucosa. At 7th day PI, the mucosal change was similar to that of 3rd day PI, but neovascularization and fibroplasia were observed in the submucosa. At 15th and 21th day PI, mild hyperplasia of mucosal epithelium was observed in the mucosa. Deposition of collagen, neovascularization and severe diffuse infiltration of lymphocyte were observed. These results suggest that ultrasonographic examination with moderate distention is considered to be a more simple, rapid, noninvasive, sensitive and useful diagnostic method than other diagnostic methods for the diagnosis of the cystitis and the differential diagnosis of urinary tract infection.

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Ultrastructural studies on the surface of Puragonimus westermani metacercaria (폐흡충 피낭유충 표피의 형태학적 관찰)

  • Kim, Gyeong-Min;An, Myeong-Hui;Min, Deuk-Yeong
    • Parasites, Hosts and Diseases
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    • v.25 no.2
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    • pp.129-140
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    • 1987
  • The present study was undertaken to demonstrate the surface structure of Paragonimus westermani metacercaria in Korea with special reference to the distribution of sensory papillae. Metacercariae were isolated from crayfish, one of the second intermediate tost of P. westermani in Bogil island, Chollanam-do (Province), Korea, where has been known as an endemic area of human paragonimiasis. Isolated metacercariae were encysted and examined with light. scanning and transmission electron microscopes for morphological features. On the surface of iBetacercariae, three types of sensory FaFillae were identified. Large domed papillae ($3~5{\mu\textrm{m}}$), which were covered with wrinkled plasma n!embrane of the worm, were distributed on the oral and ventral suckers only. On the oral sucker, these large domed papillae were 12~13 in number. On the other hand large domed papillae on the ventral sucker were constantly 6 in number and hexagonal in distribution. Small domed papillae ($2~3{\mu\textrm{m}}$), of which surface was more smooth than those of large ones, were distributed symmetrically on the ventral (30~32 pairs) and dorsal surfaces (40~42 Pairs). Ciliated Papillae ($0.8~1.5{\mu\textrm{m}}$) were observed about 5~6 in number around the oral sucker and 3~5 pairs each on the ventral and dorsal surface of the body. Single Fcinted spines covered the entire surface of the body except around the excretory pore. Spines on the anterior fart of the body were 0.9~2.0${\mu\textrm{m}}$ in length and $45~55/100{\mu\textrm{m}}$2 in number, and were gradually reduced in length ($0.4~1.4{\mu\textrm{m}}$) and in nuns.her ($12~27/100{\mu\textrm{m}}$2) toward the posterior part. The body wall of p. westermoni metacercariae was consisted with anucleated syncytium layer, fibrous interstitial layer and musclar layer. In the anucleated syncytium, biconcave ($0.15~0.55{\mu\textrm{m}}$) and spherical ($0.08~0.16{\mu\textrm{m}}$) secretory granules, which were transferred from epidermal cells via protoplasmic tubules, mitochondria and rihoEorses, T-ere observed. Spines originated around the basement membrane protruded externally. Epidermal cells were consisted with a nucleus and a cytoplasm, and connected to syncytium with protoplasmic tubules. In the cytoplasm many secretory granules, mitochondria, Golgi complex, endoplasmic reticula, ribosomes and lipid droplets were observed.

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Transmission electron microscopic ultastructure of the tegument of Fibricola seoulenis (Fibricola seouenis 표피의 투과전자현미경적 미세구조)

  • 손운목;이순형
    • Parasites, Hosts and Diseases
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    • v.31 no.4
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    • pp.301-314
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    • 1993
  • An electron microscopic study was performed to observe the ultrastructure of the tegument of U seoulensis. The outer surface of the tegument was covered with a tnlaminated plasma membrane. The electron-dense cytoplasmic layer was $2.5{\;}\mu\textrm{m}$ wide In the anterior portion and contained numerous vacuoles, mitochondriae and granular materials in its matrix. The basement layer was 330 nm wade or so, and Its numerous extensions protruded into the cytoplasmic layer. The sensory organ was composed of a small vesicle of $1.7{\;}{\times}{\;}1.1{\;}\mu\textrm{m}$ in dimensions, which possessed a cilium of $1.2{\;}{\times}{\;}0.19{\;}\mu\textrm{m}$ in size. The pharynx was composed of the epithelial layer of about $0.5{\;}\mu\textrm{m}$ wide, well developed muscle layer and basement layer. The tegument of the oral sucker was composed of a cytoplasmic layer of $0.4-0.5{\;}\mu\textrm{m}$ width, a narrow basement layer, a well developed muscle layer and tegumental cells. Some kinds of secretory granules that seemed to be originated from the cells of the oral sucker were observed In the parenchymal portions of the adjacent cells. The tribocytic organ consisted of numerous microvilli. The microvilli were 5 nm wide and heptalaminated. Two types of secretory granules originated from the gland cells of tribocytic organ were observed In the tegument and parenchyme. The tegumental cells were irregular in shape, and of which nuclei were multifarious.

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Insulin-like Growth Factor-I Regulates the FAT/CD36 Expression in C2C12 Skeletal Muscle Cells (C2C12 골격근 세포에서 FAT/CD36 발현 조절에 있어 Insulin-like growth factor-I이 미치는 영향)

  • Kim, Hye Jin;Yoon, Hae Min;Kim, Tae Young;Lee, Won Jun
    • Journal of Life Science
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    • v.26 no.7
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    • pp.758-763
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    • 2016
  • Fatty acid transporters are key mediators of skeletal muscle lipid metabolism. Several protein groups have been implicated in cellular long-chain fatty acid uptake or oxidation, including fatty acid transporter proteins (FATPs), the plasma membrane fatty acid-binding protein (FABPpm), and the fatty acid translocase (FAT/CD36). FAT/CD36 is highly expressed in skeletal muscle and known to be regulated by various factors such as exercise and hormones. Insulin-like growth factor-I (IGF-I) is a well-known regulator of skeletal muscle cells. However, it has not been studied whether there is any interaction between IGF-I and FAT/CD36 in skeletal muscle cells. In this study, the effects of IGF-I treatment on FAT/CD36 induction were examined. Differentiated C2C12 cells were treated with 20 ng/ml of IGF-I at different time points. Treatment of C2C12 cells with IGF-I resulted in increased FAT/CD36 mRNA and protein expression. After 24 and 48 hr of IGF-I treatment, FAT/CD36 mRNA increased 89% and 24% respectively. The increase of both proteins returned to the control level after 72 hr of IGF-I treatment, suggesting that the FAT/CD36 gene is regulated pretranslationally by IGF-I in skeletal muscle cells. These results suggest that IGF-I can regulate the expression of FAT/CD36 in skeletal muscle cells. In conclusion, IGF-I induces a rapid transcriptional modification of the FAT/CD36 gene in C2C12 skeletal muscle cells and has modulating effects on fatty acid uptake proteins as well as oxidative proteins.