KIM Ock-Joo and PARK Jiyoung. Sim Bo-Sung / 의사학

No abstract available.

A Structural Model of Stress, Motivation, and Academic Performance in Medical Students

OBJECTIVE: The purpose of the present study was 1) to identify factors that may influence academic stress in medical students and 2) to investigate the causal relationships among these variables with path analysis. METHODS: One hundred sixty medical students participated in the present study. Psychological parameters were assessed with the Medical Stress Scale, Minnesota Multiphasic Personality Inventory, Hamilton Depression Scale, Beck Depression Inventory, and Academic Motivation Scale. Linear regression and path analysis were used to examine the relationships among variables. RESULTS: Significant correlations were noted between several factors and Medical Stress scores. Specifically, Hamilton Depression Scale scores (beta=0.26, p=0.03) and amotivation (beta=0.20, p=0.01) and extrinsically identified regulation (beta=0.27, p<0.01) response categories on the Academic Motivation Scale had independent and significant influences on Medical Stress Scale scores. A path analysis model indicated that stress, motivation, and academic performance formed a triangular feedback loop. Moreover, depression was associated with both stress and motivation, and personality was associated with motivation. CONCLUSION: The triangular feedback-loop structure in the present study indicated that actions that promote motivation benefit from interventions against stress and depression. Moreover, stress management increases motivation in students. Therefore, strategies designed to reduce academic pressures in medical students should consider these factors. Additional studies should focus on the relationship between motivation and depression.

Effects of Intraarticular Prolotherapy on Sacroiliac Joint Pain

BACKGROUND: Sacroiliac (SI) joint pain is a challenging condition that causes lower back or buttock pain; however, there is no universally accepted long-term treatment. There have been several reports of ligament prolotherapy for SI joint pain, but these have had inconsistent results, probably due to the lack of a specific diagnosis for patient selection and variability in the volume, number and sites of injection. Therefore, this study was conducted to assess the efficacy of intraarticular prolotherapy for relieving SI joint pain diagnosed by local anesthetic intraarticular injection. METHODS: Twenty-two patients with SI joint pain confirmed by 50% or more improvement in response to local anesthetic block underwent intraarticular prolotherapy with 25% dextrose water every other week three times. The numeric rating scale (NRS) for pain and Oswestry disability index (ODI) were assessed at the initial visit and after completion of a series of prolotherapy and the NRS was checked during monthly follow-up sessions to evaluate the long-term effectiveness of this technique. RESULTS: Twenty patients completed prolotherapy and followed up as scheduled. The NRS and ODI were significantly improved from 6 (4-8) and 34.1 +/- 15.5 to 1 (0-3) and 12.6 +/- 9.8 (P < 0.01), respectively, at 1 month after prolotherapy. The mean duration of pain relief of 50% or more was 12.2 months (95% CI, 10.0-14.3) as determined by Kaplan-Meier survival analysis. CONCLUSIONS: Intraarticular prolotherapy provided long-term relief of sacroiliac joint pain and may have more benefits than ligament prolotherapy or neurolysis.

The effect of remifentanil and lidocaine on time interval acquired for successful tracheal intubation in inhalational induction using sevoflurane / 대한마취과학회지

BACKGROUND: This study was conducted to investigate the optimal time interval for tracheal intubation and the effect of adjuvant drugs such as remifentanil and lidocaine during induction and tracheal intubation using sevoflurane inhalation without muscle relaxant. METHODS: This study enrolled patients with the age of 20-60 years old and ASA 1 or 2. Patients were randomly assigned into one of 4 groups (S, SR, SRL, SL), in which they were given remifentanil (R) i.v. at a rate of 0.25microgram/kg/min, or lidocaine (L) i.v. bolus of 1.5 mg/kg during sevoflurane inhalation (S). Anesthesia was performed as inhalation induction 2 minutes after pre-filling with sevoflurane 8 vol%. The time interval between induction and tracheal intubation was determined using up-and-down method. When satisfied all of the categories of response to tracheal intubation, the case was assigned to 'success', otherwise 'fail'. In each groups, effective time for successful intubation in 50% (ET50) and 95% (ET95) were calculated by probit analysis. RESULTS: ET50 was 3.90 minutes (95% confidence interval 3.32-4.38) in group S, 3.18 minutes (2.92-3.48) in group SL, 2.83 minutes (2.47-3.07) in group SR, and 2.68 minutes (2.37-2.95) in group SRL. In group S, SL, SR, and SRL, ET95 was 4.52 minutes (4.17-7.95), 3.63 minutes (3.37-4.97), 3.30 minutes (3.06-4.64), and 3.12 minutes (2.89-4.42), respectively. CONCLUSIONS: The optimal time to intubate successfully using sevoflurane without muscle relaxant in 95% patients was 4.5 minutes. The optimal time is reduced to 3.1 minutes by coadministration of remifentanil and lidocaine.

The effect of remifentanil and lidocaine on time interval acquired for successful tracheal intubation in inhalational induction using sevoflurane / 대한마취과학회지

BACKGROUND: This study was conducted to investigate the optimal time interval for tracheal intubation and the effect of adjuvant drugs such as remifentanil and lidocaine during induction and tracheal intubation using sevoflurane inhalation without muscle relaxant. METHODS: This study enrolled patients with the age of 20-60 years old and ASA 1 or 2. Patients were randomly assigned into one of 4 groups (S, SR, SRL, SL), in which they were given remifentanil (R) i.v. at a rate of 0.25microgram/kg/min, or lidocaine (L) i.v. bolus of 1.5 mg/kg during sevoflurane inhalation (S). Anesthesia was performed as inhalation induction 2 minutes after pre-filling with sevoflurane 8 vol%. The time interval between induction and tracheal intubation was determined using up-and-down method. When satisfied all of the categories of response to tracheal intubation, the case was assigned to 'success', otherwise 'fail'. In each groups, effective time for successful intubation in 50% (ET50) and 95% (ET95) were calculated by probit analysis. RESULTS: ET50 was 3.90 minutes (95% confidence interval 3.32-4.38) in group S, 3.18 minutes (2.92-3.48) in group SL, 2.83 minutes (2.47-3.07) in group SR, and 2.68 minutes (2.37-2.95) in group SRL. In group S, SL, SR, and SRL, ET95 was 4.52 minutes (4.17-7.95), 3.63 minutes (3.37-4.97), 3.30 minutes (3.06-4.64), and 3.12 minutes (2.89-4.42), respectively. CONCLUSIONS: The optimal time to intubate successfully using sevoflurane without muscle relaxant in 95% patients was 4.5 minutes. The optimal time is reduced to 3.1 minutes by coadministration of remifentanil and lidocaine.

The Role of Adrenergic and Cholinergic Receptors on the Antinociception of Korean Red Ginseng in the Spinal Cord of Rats / 대한통증학회지

BACKGROUND: Experimental evidence indicates that ginseng modulate the nociceptive transmission. Authors examined the role of adrenergic and cholinergic receptors on the antinociceptive action of Korean red ginseng against the formalin-induced pain at the spinal level. METHODS: Catheters were inserted into the intrathecal space of male Sprague-Dawley rats. Fifty microl of 5% formalin solution was injected to the hindpaw for induction of pain and formalin-induced pain (flinching response) was observed. The role of spinal adrenergic and cholinergic receptors on the effect of Korean red ginseng was assessed by antagonists (prazosin, yohimbine, atropine and mecamylamine). RESULTS: Intrathecal Korean red ginseng produced a dose-dependent suppression of the flinching response in the rat formalin test. All of prazosin, yohimbine, atropine and mecamylamine antagonized the antinociception of Korean red ginseng. CONCLUSIONS: Spinal Korean red ginseng is effective against acute pain and facilitated pain state evoked by formalin injection. All of alpha 1, alpha 2, muscarinic and nicotinic receptors may play an important role in the antinociceptive action of Korean red ginseng at the spinal level.

Changes of Serum Alkaline Phosphatase and Osteocalcin during Fracture Healing / 대한정형외과학회잡지

PURPOSE: To investigate changes of serum osteoblastic marker during fracture healing. MATERIALS AND METHODS: The study included 22 patients with fresh fractures. Serum alkaline phosphatase (ALP), bone specific alkaline phosphatase and osteocalcin were analyzed on the first day and 1, 2, 4 and 8 weeks after injury. The bone specific-ALP was quantified by electrophoresis. Osteocalcin was quantified by enzyme linked immunosorbent assay (ELISA). RESULTS: One, 2, 4 and 8 weeks after injury, mean values of serum ALP increased 1.26, 1.45, 1.63, and 1.2 times that on the first day after injury, respectively. Similarly, during the same period, bone specific ALP increased 1.38, 1.33, 1.73 and 1.25 times, and serum osteocalcins increased 1.32, 1.2, 1.64 and 2.09 times. CONCLUSION: Serum ALP increased during the early soft callus phase. However, serum osteocalcins increased during the late hard callus phase. Serum alkaline phosphatase and osteocalcin warrant further study as useful prognostic indicators of fracture healing.

The Influence of Admission Characteristics on Premedical School Achievement at a Medical School / 한국의학교육

PURPOSE: This study examined the relationship between the achievement of premedical students and admission characteristics at University of Ulsan College of Medicine: high school types and majors, gender, admission assessment method and interval from the high school graduation to the entrance of premedical school. METHODS:: Admission characteristics and demographic informations was obtained for students who entered from 1999 to 2001. Academic achievement was measured according to the results of grade point average(GPA) of total subjects and science subjects and each subject's grades. Admission characteristics and the GPA's and grades were analysed. Multiple linear regression was used to examine the relationship between admission variables and academic achievement. RESULTS: 1. For the first year of premedical school students who studied natural science at ordinary high school, or who graduated science high school showed better achievement than others. 2. Students entered by general selection method also got significantly higher GPA's than other students in the first year. 3. Female students got significantly higher GPA's than male students in two consecutive semesters(1-2 and 2-1). 4. Students qualified by the national highschool graduation examination showed significantly lower achievement than other students in the first semester of the second year. 5. There were no relationships between achievement and other characteristics. CONCLUSION: Students who have academic difficulties in the first year of the premedical course is those who were not exposed to the natural science subjects. It seemed that the premedical course worked as a buffer absorbing differences from the students of various academic backgrounds in their high school period. For the second year, high school majors did not influence the academic achievement.

Cytokine Induced Differential Expression of Adhesion Molecules and HLA-DR in Cultured Human Glomerular Endothelial Cells / 대한신장학회잡지

BACKGROUND: Glomerular endothelial cells should participate in the process of glomerular disease by expressions of HLA antigens and adhesion molecules. However, few have been known about the regulation of the expression of these molecules in human glomerular endothelial cells(HGEC). The aim of this study was to evaluate the expressions of VCAM-1, ICAM-1 and HLA-DR to see if there are any cytokine-dependent or time-dependent differences. METHODS: HGEC were isolated and cultured from the normal portion of the kidneys removed due to renal cell carcinoma, which was confirmed by factor VIII and fluorescent-labeled acetylated LDL. The effects of cytokine on the cell surface expression of VCAM-1, ICAM-1 and HLA-DR were measured by ELISA. RESULTS: ICAM-1 was increased by IL-1 beta, TNF-alpha and IFN-gamma. VCAM-1 was increased by IL-1 beta and TNF-alpha, not by IFN-gamma. IFN-gamma only increased expression of HLA-DR. Basal expression of ICAM-1 was higher than VCAM-1 and HLA-DR. The time course of expression was different according to adhesion molecule. CONCLUSIONS: These data showed that the expression of adhesion molecules and HLA-DR in HGEC were regulated differentially by inflammatory and immune-regulatory cytokines.

The Role of Growth Factors to Rabbit Chondrocytes and Subtypes of Collagen in Three Dimensional High Density Culture

Cartilage is commonly used autogenous material for aesthetic and reconstructive surgery and major donor sites of cartilage are ear, nasal septum, and rib. As the cartilage correlates with ossification and can be used for joint reconstruction. Many growth factors influencing growth and differentiation of chondrocytes have been reported, and matrix composition produced by chondrocytes may vary in types and quantity according to culture duration. Initially the chondrocytes in culture aggregate, then secrete type I collagen. Type II collagen is produced during differentiation process, and synthesis of type X collagen is the last step. In this study, chondrocytes were isolated from ear cartilage of the New Zealand white rabbit weighing 400 gm. We performed high density culture using penicylinder and pellet method. The cells were polygonal in morphology and viable under the inverted microscope. This experiment was designed to evaluate the effect of IGF-I, TGF- p, and b- FGF on the synthesis of collagen in chondrocyte culture. Optimal concentration of growth factors was determined using H-thymidine incorporation into DNA. After the addition of optimal concentration of each growth factors in experimental groups, the uptake of H-proline was measured. Only IGF-I showed a statistically significant increase of collagen synthesis. We observed how subtypes of collagen were influenced by growth factors in two culture methods and by differing the addition timing of growth factors. SDS-PAGE was adopted for subtyping of collagen. All subtypes of collagen were found in both culture methods and all growth factors facilitated the production of type II and type X collagen and may be devoted to the differentiation of chondrocytes. Immunohistochemical staining for type I, and type II collagen was examined to confirm the above result. In pellet culture, type II collagen was stained densely in response to the addition of three kinds of growth factors. The results of penicylinder culture showed similar outcome to those from pellet cultured group. From the above results, we concluded as follows; First, IGF-I generally influence the synthesis of type I and II collagen. Second, TGF beta increased the synthesis of collagen. Third, b-FGF increased the synthesis of type II and type X collagen. We concluded that IFG-I is the only growth factor which is effective regardless of culture duration and method. TGF- beta and b-FGF, which are potent mitogen, facilitate the secretion of collagen.

Fibroblast growth factor-induced Thymidylate Synthase activity and expression in the serum-starved UMR 106-01 osteoblast cells / 대한정형외과연구학회지

PURPOSE: In the present study, the effects of bFGF on the early responses of proliferation of UMR 106-01 osteoblast cells during cell cycle reentry from the latent(G0/G1) to the proliferative periods(S/M) were investigated. MATERIALS AND METHODS: The synchronized cell culture method using the serum starvation was utilized. After the addition of bFGF, the time courses of protein synthesis, DNA synthesis, thymidylate synthase(TS) activity, TS mRNA level and expression of c-fos were determined. RESULTS: 87% UMR 106-01 cells were synchronized to G0/G1 by serum starvation for seven days in the medium containing 0.1% serum. The protein level began to increase 3 hours after bFGF treatment and reached the maximum at 18 hours. TS activity began to increase 3 hours after the bFGF treatment and reached its peak at 6 hours while its mRNA level, determined by quantitative PCR, reached the maximum at 12 hours. The expression of c-fos protein, determined by western blot analysis and immunocytochemistry, increased 3 hours after bFGF treatment. On the contrary, these prominent changes and responses to bFGF were not observed in the case of using non-synchronized cells cultured in the medium containing 10% serum. CONCLUSION: Based on these data it can be concluded that bFGF-induced DNA synthesis in the early proliferative phase is due to increases in both TS activity and mRNA amount and that the increase in c-fos expression and TS activity occur before the increase in TS mRNA level.

Fibroblast growth factor-induced Thymidylate Synthase activity and expression in the serum-starved UMR 106-01 osteoblast cells / 대한정형외과연구학회지

PURPOSE: In the present study, the effects of bFGF on the early responses of proliferation of UMR 106-01 osteoblast cells during cell cycle reentry from the latent(G0/G1) to the proliferative periods(S/M) were investigated. MATERIALS AND METHODS: The synchronized cell culture method using the serum starvation was utilized. After the addition of bFGF, the time courses of protein synthesis, DNA synthesis, thymidylate synthase(TS) activity, TS mRNA level and expression of c-fos were determined. RESULTS: 87% UMR 106-01 cells were synchronized to G0/G1 by serum starvation for seven days in the medium containing 0.1% serum. The protein level began to increase 3 hours after bFGF treatment and reached the maximum at 18 hours. TS activity began to increase 3 hours after the bFGF treatment and reached its peak at 6 hours while its mRNA level, determined by quantitative PCR, reached the maximum at 12 hours. The expression of c-fos protein, determined by western blot analysis and immunocytochemistry, increased 3 hours after bFGF treatment. On the contrary, these prominent changes and responses to bFGF were not observed in the case of using non-synchronized cells cultured in the medium containing 10% serum. CONCLUSION: Based on these data it can be concluded that bFGF-induced DNA synthesis in the early proliferative phase is due to increases in both TS activity and mRNA amount and that the increase in c-fos expression and TS activity occur before the increase in TS mRNA level.

The Effect of IGF-I on Collagen Synthesis in Cultured Chondrocytes

Cartilage is one of the most commonly manipulated tissue in esthetic and reconstructive surgery. Cartilage has an important role in longitudinal bone growth. Anabolic hormones and locally produced peptide growth factors are known to influence this process Matrix composition changes through proliferation, maturation, and differentiation of chondrocytes, and endochondral ossification thereafter. Defined cartilage matrix is synthesized during the maturation of chondrocytes where the major change is the increment of type II collagen. Variable sulfated mucololysaccharides and hyaluronic acid are also synthesized during this maturation. IGF-I(insulin like growth factor-I), so called somatomedin C, is a prominent growth factor in serum. IGF-I is known to be involved in long growth. IGF-I is affected by pituitary growth hormone. There are few studies done on IGF-I effect in cartilage matrix formation and possible changes of collagen subtypes. This experiment was designed to see the IGF-I effect on the colagen synthesis of cultured chondrocytes. Optimal concentration of IGF-I for the experiment was determined using H3-thymidine incorporation into DNA. The IGF-I effect on collagen synthesis was studied using H3-proline. The IGF-I effect on the synthesis of subtypes of collagen was studied using SDS-PAGE and immunocytochemical staining. Chondrocytes were isolated from the ears of New Zealand white rabbit and cultured in 2 X 10(5) cells/300 microgram density. IGF-I increased DNA synthesis, and optimal concentration of IGF-I was determined by dose-relationship curve as 10ng/ml. Collagen synthesis was increased by IGF-I. Type II collagen was increased on SDS-PAGE with IGF-I and this gel electrophoresis showed type X collagen, also. The increase in type II collagen was confirmed with immunocytochemical staining, the reaction becoming stronger with the addition of IGF-I. Type I collagen was not changed with IGF-I on immunocytochemistry. We conclude that IGE-I is an important modulator influencing not only proliferation and maturation but also terminal different-iation of chondrocytes.

Effect of Aprotinin on Changes in Plasma Thromboxane B2 and Endothelin-1 Concentratin after Extracorporeal Circulation / 대한흉부외과학회지

BACKGROUND: Thromboxane A2 and endothelin-1 are the potent vasoconstrictors affecting pulmonary pathophysiology in response to whole body inflammatin following CPB. Aprotinin, as an antiiflammatory agent, may decrease the release of such vasoactive substance from pulmonary tissues, preventing pulmonary hypertension after cardiopulmonary bypass. MATERIAL AND METHOD: Ten mongrel dogs(Bwt. ac. 20kg) were subjected to cardioupulmonary bypass for 2 hours and postbypass pulmonary vascular resistance(0, 1, 2, 3 hours) were compared with prebypass level. The dogs were divided into 2 groups; control group(n-5) and aprotinin group(n=5). In the aprotinin group, aprotinin was administered as follows; 50,000 KIU/kg mixed in pump priming solution, 50,000 KIU/kg prebypass intravenous infusion over 30 minutes, 10,000 KIU/kg/hour postbypass continuous infusion. Prebypass and postbypass 0, 1, 2, 3 hour pulmonary vascular resistance were measured. At prebypass and postbypass 0, 90, 180 minutes, blood samples were obtained from pulmonary arterial and left atrial catherers for the assay of plasma thromboxane B2 a stable metabolite of thromboxane A2, and endothelin-1 concentrations. RESULT: The ratios of pustbypass over prebypass pulmonary vascular at postbypass 0, 1, 2, 3 hours were 1.28+/-0.20, 1.82+/-0.23, 1.90+/-0.19, 2.14+/-0.18 in control group, 1.58+/-0.18, 1.73+/-0.01, 1.66+/-0.10, 1.50+/-0.08 in aprotinin group ; the ratios gradually increased in control group while decreased or fluctuated after postbypass 1 hour in aprotinin group. There was statistically significant difference between control group and aprotinin group at postbypass 3 hours(P=0.014). Pulmonary arterial plasma concentration of thromboxane B2(pg/ml) at prebypass, postbypass 0, 90, 180 minutes were 346.4+/-61.9, 529.3+/-197.6, 578.3+/-255.8, 493.3+/-171.3 in control group, 323.8+/-118.0, 422.6+/-75.6, 412.3+/-59.9, 394.5+/-154.0 in aprotinin group. Left atrial concentrations were 339.3+/-89.2, 667.0+/-65.7, 731.2+/-192.7, 607.5+/-165.9 in control group, 330.0+/-111.2, 468.4+/-190.3, 425.4+/-193.6, 4.7.3+/-142.8 in aprotinin group. These results showed decrement of pulmonary thromboxane A2 generation in aprotinin group. Pulmonary arterial concentrations of endothelin-1(fmol/ml) at the same time sequence were 7.84+/-0.31, 13.2+/-0.51, 15.0+/-1.22, 16.3+/-1.73 in control group, 7.76+/-0.12, 15.3+/-0.71, 22.6+/-6.62, 14.9+/-1.11 in aprotinin group. Left atrial concentrations were 7.61+/-17.2, 57.1+/-28.4, 18.9+/-18.2, 31.5+/-20.5 in control group, 5.61+/-7.61, 37.0+/-26.2, 28.6+/-21.7, 37.8+/-30.6 in aprotinin group. These results showed that aprotinin had no effect on plasma endothelin-1 concentration after cardiopulmonary bypass. CONCLUSIONS: Administration of aprotinin during cardiopulmonary bypass could attenuate the increase in pulmonary vascular resistance after bypass. Inhibition of pulmonary thromboxane A2 generation was thought to be one of the mechanism of this effect. Aprotinin had no effect on postbypass endothelin-1 concentration.

Effects of Interleukin-1 on Cell Proliferation in UMR-106-01 Osteoblast-like cells / 대한정형외과학회잡지

Interleukin 1(IL-1), a 17.5 KD glycoprotein, is known to be associated with local bone resorption. In the present study, we examined the effects of IL-1, compared with insulin and parathyroid hormone (PTH), on DNA, protein and collagen synthesis in UMR-106-01 rat osteoblastic osteosarcoma cells. When 200 units/mL IL-1 was administered to UMR-106-01 cells, [3H]-thymidine uptake increased to 119% of the untreated control. But when 10 nM insulin was added to the cells, [3H]- thymidine uptake increased to 130% and when 1 nM PTH was added, the uptake decreased to 89% of the control. On the other hand, protein and collagen synthesis, measured by [3H]-leucine and [3H]-proline incorporation respectively, were not affected by IL-1 administration compared to the other hormones. These results indicate that IL-1 effects osteoblast-like cells, stimulating DNA synthesis via a different mechanism to the well-known cell growth factor, insulin.

Effect of VCAM-1 expression in human endothelial cells by proinflammatory cytokines / 천식및알레르기

BACKGROUND: The expression of adhesion molecules contribute to development of systemic diseases. Vascular cell adhesion molecule-l(VCAM-1) is an endothelial cell membrane glycoprotein that has been implicated in leukocyte/endothelial cell interactions in inflammation. OBJECTIVE: The aim of this study was to characterize the surface expression and regulation of VCAM-1 on two different endothelial cells. METHOD: We examined the effects of the expression of VCAM-1 in two different endothelial cells, isolated from human umbilical cords and human glomerulus. Expression of VCAM-1 was measured by enzyme-linked immunosorbent assay(ELISA) and flow cytometry. RESULTS: In human umbilical cord endothelial cells(HUVECs), both interleukin-l B(IL-lB) and tumor necrosis factor-a (TNF-a) increased VCAM-1 expression. VCAM-1 expression increased by TNF-a was higher than that increased by IL-lB. In human glomerular endothelial cells(HGECs), IL-lB and TNF-a markedly increased VCAM-1 expression. Conclusion. The regulation of VCAM-1 appears to be somewhat different in HGECs compared with HUVECs. These differences between the responsiveness of the two cells may possibly indicate inherent differences in endothelial cell derived from different vascular beds.

The Effect of Cycolsporine A on the Expression of Von Willebrand Factor in Human Glomerular Endothelial Cells / 대한신장학회잡지

Cyclosporine(CsA) is a modulator of the immune system used therapeutically to prevent organ transplant rejection. However, it is nephrotoxic and causes thrombotic phenomena after renal and bone marrow transplantation. CsA nephrotoxicity in vivo is associated with elevated levels of von Willebrand factor(vWf), which is a multimeric plasm glycoprotein secreted by endothelial cells and platelets. CsA is not soluble in water and the intravenous form given to patients is dissolved in a vehicle called cremophor EL. The vehicle has been implicated in anaphylatic reactions and associated with the release of histamine in vivo. We hypothesized that CsA or cremophor might affect the release of vWf from human glomerular endothelial cells. vWf was measured in culture supernant using ELISA kit after speed vaccum for 3 hour. The expression of vWf in cultured human glomerular endothelial cells was relatively low compared to human plasm in vivo. CsA alone did not increase vWf release(100%, 99.9+/-0.7%, 99.1+/-2.9%, 106+/-21.5%, CsA 0, 0.1, 1, 10microM mean S.E., n=2), but cremophor EL increased vWf release (100%, 104.0+/-8.6%, 117.6+/-9.5%, 121.3+/-12.2%, mean+/-S.E., n=3). These results were same as the results of experiments under thrombin(1IU/ml) and histamine(10(-4)M). The increased expression of vWf in human glomerular endothelial cells in response to CsA seems to be related to cremophor, the solvent, rather than CsA itself in vitro culture experiments.

The Effect of Erythropoietin on the Production of Endothelin in Human Glomerular and Umbilical Endothelial Cells / 대한신장학회잡지

The administration of erythropoietin for renal failure patients is frequently associated with a mild-to-marked rise in arterial blood pressure. The erythropoietin-induced hypertension has been variably attributed to the rise in erythrocyte concentration and/or a direct or indirect pressor action of erythropoietin on vascular smooth muscle. Especially erythropoietin-induced hypertension may be mediated by increased production of the potent vasoactive peptide endothelin. This study was designed to determine the effect of erythropoietin to the production of endothelin in human glomerular endothelial cells and human umbilical vein endothelial cells. ELISA method was used to measure the endothelin- 1, after 4 X 10(4) endothelial cells were grown to confluency on 24-well plates, in which erythropoietin 25u/ml was incubated for 24 hours. The results showed that the endothelin production in human glomerular endothelial cells was insignificant (116.0+/-14.0%, P>0.05, mean+/-S.E., n=5, each n means the mean of duplicate experiments), but the endothelin production in human umbilical endothelial cells was increased after 25u/ml erythropoietin treatment(126.5+/-15.2%, P<0.05, mean+/-S.E., n=4). In glomerular endothelial cells, TGF-beta(0.5ng/ml) increased the production of endothelin(218.8+/-57.2%, P<0.01, mean+/-S.E., n=5), also it looks like that TNF-alpha and thrombin might increase the production of endothelin according to the concentration. In conclusion, the responsiveness of endothelial cells to erythropoietin may be different according to the cell type, and glomerular endothelial cells could increase the production of endothelin, if appropriate stimuli were given.

The Effect of Dexamethasone and Transforming Growth Factor-beta1 on the Cytokine Induced Expression of VCAM-1 in Glomerular Endothelial Cells / 대한신장학회잡지

Endothelial cell have been shown to play an active role in many phases of immunologic process, including binding of T lymphocytes, neutrophils, platelets, and monocytes to the endothelium, as well as phagocytosis. Endothelial cells can also serve as targets that undergo cell injury. The most prominent mediators of endothelial cell activation are IL-1beta and TNF-alpha. VLA-4 was first identified as an endothelial cell surface receptor. We performed the culture of endothelial cells derived from human glomerular capillaries and studied the cytokine-regulated expression of VCAM-1, and the effect of dexamethasone and TGF-beta on the cytokine induced VCAM-1 expression using ELISA method. Expression of VCAM-1 was not detectable above background level in the basal unstimulated state. However, VCAM-1 was rapidly induced after exposure to IL-1beta (5ng/ml) or TNF-alpha (1, 10ng/ml) (O.D.=1.76+/-0.15, 1.95+/-0.35, 1.88+/-0.17, mean+/-S.E., control=0.36+/-0.028, n=8-24, P<0.05). But IFN-gamma did not increase the expression of VCAM-1. Addition of dexamethasone (10 micrometer) and TGF-beta1 (1ng, 10ng/ml) blunted IL-1beta and TNF-alpha induced expression of VCAM-1. Therefore, VCAM-1 could be inducible in human glomerular endothelial cells, and it was regulated by dexamethasone and TGF-beta1. The negative findings in histopathology may reflect the transience of VCAM-1 expression and does not necessarily exclude an important role of this molecule in the early stages of renal disease.

Effects of Parathyroid Hormone and Insulin on Proliferation in Osteogenic Sarcoma UMR-106-01 Cells / 대한정형외과학회잡지

Parathyroid hormone(PTH), a major bone hormone, inhihits DNA and collagen syntheses in osteohlast-like cells in vitro, but increase the proliferation of osteoblast in vivo as secn in hyperparathyroidism. On the other hand, insulin is known to increase DNA and collagen syntheses and modify the effects of PTH in osteoblast-like cells. We have examined the effects of PTH and insulin in rat osteosarcoma UMR-l06-01 cells and whether PTH plays a role in the insulin-mediated bone formation. When 1 nM PTH and 10 nM insulin were administered to VMR-l06-01 ceils, the rates of DNA synthesis were 124% and 136% of the untreated control, respectively. When the two hormones were administered serially by exposing to 1 nM PTH for 7 days followed by 10 nM insulin lor 24h, the largest increase was observed. The protein synthesis was also increased remarkahly when the two hormones were aclministered serially: the[3H]-leucine incorporation rates, compared to the control group, were 75% and l62% with PTH ancl insulin administration, respectively, but the rate was 297% with the serial administration of the two. The collaeen synthesis, as measured by the (3H)-proline incorporation rates were 60% and l64% with PTH and insulin administration, respectively, but 351% with serial administration, again showing a dramatic effect. These results showed that 1 nM PTH decreased DNA and collagen syntheses in UMR-l06-01 cells after both a 24h and a more prolonged exposure. Similar exposures to insulin tended to increase the syntheses. The comhination of PTH and insulin tended to increase the syntheses. hut not beyond the effect of insulin alone. However, the sequential administration of PTH and insulin markedly increases ihose rales relative to the simultaneous adminstration of these two hormones. Thus, it is possihle that sequential stimulation of PTH and insulin in hone matrix exerts an synergistic effect on hone formation in vivo.