Causes and symptoms of varicose veins

Varicose veins are a common disease that cause edema, heaviness, pigmentation, and skin ulcers, ultimately affecting the quality of life. Various treatments have recently been developed; therefore, clinicians need to understand the anatomy, pathophysiology, risk factors, and symptoms of varicose veins to provide optimal treatment.Current Concepts: Lower extremity veins are composed of deep, superficial, perforating, and communicating vein systems, and the main axial superficial veins are composed of the great and small saphenous veins. Venous circulation primarily relies on muscle pumps in the foot and calf. Pressure on the sole and contraction of calf muscles compress the veins, sending blood upward or to the deep vein system. Varicose veins are caused by valvular abnormalities, muscle pump failure, etc., and associated risk factors include age, pregnancy, obesity, and family history. The main symptoms include heaviness, fatigue, and edema.Discussion and Conclusion: Varicose veins have complex anatomical structures and are developed by various factors. Therefore, appropriate treatments should be selected considering patients’ symptoms, anatomical structure, and economic aspects.

Analysis of splint weaning in temporomandibular disorder patients

Purpose@#There are many studies on the indications and efficacy of splint therapy commonly used in patients with temporomandibular disorders (TMD). However, there have been no studies on the splint weaning in terms of the splint use tapering period in relation to symptom improvement of TMD. This retrospective study aims to analyze a proper splint weaning method in patients with TMD based on symptom improvement. @*Materials and Methods@#The authors examined 130 TMD patients with TMJ disorders, masticatory muscle disorders, and clenching/bruxism who had received splint therapy (occlusion stabilization splint, anterior positioning splint) of patients who visited the Department of Orofacial Pain and Oral Medicine at Yonsei University Dental Hospital from 2015 to 2020. They were evaluated according to the method to wean splints. @*Results@#The mean splint therapy period was 29.0 months, during which patients wore splints 7 days a week for 8.4 months, 3 - 4 days a week for 9.5 months, and finally 1 - 2 days a week for 11.1 months (a total of 29.0 months, about 2.5 years). @*Conclusion@#It seems that TMD symptoms can be alleviated and side effects such as occlusal change can be minimized if patients wear a splint 7 days a week for the first 6 months, followed by 3 - 4 days a week for the next 6 to 18 months, and finally 1 - 2 days a week after 18 months.

Factors affecting objective and subjective masticatory ability assessment of Korean elderly people / 대한구강보건학회지

OBJECTIVES: The purpose of the study was to investigate factors affecting the assessment of objective and subjective masticatory ability in the elderly, and to evaluate masticatory ability assessment more accurately. METHODS: A total of 112 participants were recruited after oral examination in senior citizen welfare facilities. The participants' masticatory ability was evaluated objectively (Mixing ability index; MAI), and subjectively (Key food intake ability; KFIA). Participants' general characteristics and oral health-related variables were also recorded. Based on masticatory ability assessment, participants were classified as either high or low. IBM SPSS Statistics Ver.23.0 was used for all analyses, including descriptive statistics, Chi-square test, Mann-Whitney U test, Spearman rank correlation, and Logistic regression analysis. RESULTS: Higher masticatory ability was positively correlated with higher scores on MAI and KFIA. Additionally, there was a significant positive correlation between MAI and KFIA. When analyzing factors affecting objective and subjective masticatory ability assessments, Functional tooth units (FTUs) were revealed as a related factor. In subjective masticatory ability assessment, oral moisture, difficulty in chewing, and the Geriatric Oral Health Assessment Index (GOHAI) were also influential factors. CONCLUSIONS: In order to accurately assess masticatory ability, it is necessary to use both objective and subjective measures. Additionally, to improve the masticatory ability in the elderly, treatment should be provided to improve overall oral health and satisfaction.

Current Status and Corresponding Strategy of Transplant Tourism / 대한이식학회지

Transplant tourism (TT) has developed into a global concern for international organizations, transplant communities, researchers, and the press. Increasing the knowledge of organ trafficking and TT is essential to raise awareness and prepare responses that will prevent the occurrence of illicit organ transplantation through TT. This review article describes the current status and legal framework of international organ trafficking and TT. Collection and analysis of data concerning TT from national and international registries will provide the best estimates of global activities, which are necessary to develop an appropriate local and worldwide collaborative response to organ trafficking and TT. International collaboration and multifaceted strategies are needed to address the complex challenges of TT.

Intraoperative indocyanine green angiography for the objective measurement of blood flow

PURPOSE: Intraoperative assessment of tissue perfusion is important to predict wound healing or improvement of symptoms in patients with peripheral arterial disease (PAD) or vascular trauma. There is no widely accepted standard for intraoperative measurement of tissue perfusion. Here, we report the use of indocyanine green (ICG)-based angiography to determine the blood flow in patients with PAD and vascular trauma. METHODS: The SPY fluorescent imaging system was utilized. A dose of 3-5 mL of ICG (2.5 mg/mL) was injected intravenously followed by a 10 mL normal saline flush. The SPY imaging system was used to quantitatively assess perfusion. During the study period, the SPY imaging system was applied in 4 patients with PAD and one patient with vascular trauma. RESULTS: In 3 patients with PAD associated with an ischemic wound, complete wound healing was achieved with the indication of viable tissue by the SPY system. In one patient with severe claudication in both lower extremities, the ICG angiography was used to determine the increased blood flow after revascularization. In the case of vascular trauma, this imaging system enabled the delineation of viability of the injured tissue. CONCLUSION: ICG angiography can determine the surface tissue viability in PAD patients. In cases of severe vascular trauma,the SPY system can be used to determine tissue perfusion. Further study is warranted to define the definite utility of this technology to assess perfusion, response to revascularization, and potentially, to predict the likelihood of wound healing.

National trends for the treatment of peripheral arterial disease in Korea between 2004 and 2013

PURPOSE: Peripheral arterial disease (PAD) has been a major public health issue in the elderly. Advances in endovascular surgery have led to a substantial shift in the management of PAD. Although the nationwide trend of PAD treatment in the Western countries was reported, limited data have been available on this in Korea. This study examined the national trend in the treatment of PAD in Korea over the past decade. METHODS: Health Insurance Review and Assessment Service data were used. We sought to analyze trends in the open and endovascular surgery for the treatment of PAD in Medicare beneficiaries between 2004 and 2013. We also analyzed trends in each types of surgery in the lower extremity. A linear-by-linear association was performed to determine the changes of PAD treatment for this period. RESULTS: The rate of open surgery per 100,000 Medicare beneficiaries decreased significantly from 8 procedures in 2004 to 6 in 2013. At the same time, endovascular surgery increased from 23 procedures in 2004 to 59 in 2013. Endovascular surgery in the lower extremity increased more than twofold, while the open surgery decreased by 39%. The rate of balloon angioplasty among endovascular surgery was increased by almost threefold, while the bypass surgery using artificial graft decreased by half. CONCLUSION: Endovascular surgery is now performed more commonly than open surgery for PAD treatment. Balloon angioplasty increased by almost threefold, while the bypass surgery using artificial graft decreased by about 50%.

Effect of Diameter of Saphenous Vein on Stump Length after Radiofrequency Ablation for Varicose Vein

PURPOSE: Radiofrequency ablation (RFA) has gained popularity for treatment of varicose veins. The diameter of the saphenous vein should be considered before RFA because occlusion of the vein may differ depending on its diameter. Until now, however, there have been few data about the correlation between the diameter of the saphenous vein and the stump length after RFA. The purpose of our study was to investigate its correlation. MATERIALS AND METHODS: A retrospective review was performed from prospectively collected data of RFA patients between March 2009 and December 2011. Preoperatively, the saphenous vein diameter was measured. Ablation was initiated 2 cm distal from the junction. Postoperatively, stump length was measured at 1 week and 6 months. After 2 years, we measured the length from the saphenofemoral junction to the leading point of occlusion for great saphenous vein, and length from the saphenopopliteal junction to the leading point of occlusion for small saphenous vein. The paired t-test, independent t-test, and correlation analysis were used for statistical analysis. P-value <0.05 was considered statistically significant. RESULTS: During the study period, RFA was performed in 201 patients. Endovenous heat-induced thrombosis developed in 3 patients (1.5%). After 2 years, the stump length was obtained in 74 limbs. The mean diameter and stump length of the saphenous vein were 6.7+/-1.8 mm and 12.5+/-8.5 mm, respectively. Correlation analysis showed that the Pearson correlation coefficient of these factors was -0.017. CONCLUSION: There was no correlation between the diameter of saphenous vein and stump length.

Change of Distribution and Timing of Bite Force after Botulinum Toxin Type A Injection Evaluated by a Computerized Occlusion Analysis System

PURPOSE: The aim of this study was to determine the force distribution and pattern of mastication after injection of botulinum toxin type A (BTX-A) into both masseter muscles. The hypothesis to be tested was that the difference between right and left balance of occlusal force diminishes over time following BTX-A injection. MATERIALS AND METHODS: Fifteen patients were submitted to BTX-A injection therapy for subjective masseter hypertrophy. A total of 25 U of BTX-A (50 U in total) was injected into two points located 1 cm apart at the center of the lower one-third of both masseter muscles. All patients were examined using the T-Scan occlusion analysis system before and 4, 8, 12, and 24 weeks after BTX-A injection. RESULTS: A significant change in force balance was found between the right and left sides over time and the difference between the two sides decreased with the time post-injection, reaching a minimum at 12 weeks. Comparison of the force balance between the anterior and posterior occlusions revealed no significant difference at any of the time points. The occlusion and disclusion times (right and left sides) did not differ significantly with time since BTX-A injection. CONCLUSION: A decline in the difference in the clenching force between the left and right sides was found with increasing time up to 12 weeks following BTX-A injection.

Reference Diameters of the Abdominal Aorta and Iliac Arteries in the Korean Population

PURPOSE: It is important to know the normal diameter of artery throughout the body so that clinicians are able to determine when an artery becomes aneurysmal. However, there are no previous studies on the normal diameter of arteries in the general Korean population. The purpose of this article is to determine the normal reference diameters of the abdominal aorta and iliac arteries in the Korean population. MATERIALS AND METHODS: We recruited the study population from three cities in Korea for the abdominal aortic aneurysm (AAA) screening. We measured the diameter of the aorta and iliac arteries. We analyzed the reference diameter of the population without AAA. The results were analyzed by Student's t-test and ANOVA on SPSS version 19. A p value <0.05 was considered to be statistically significant. RESULTS: One thousand two hundred and twenty-nine people were enrolled. 478 men and 751 women, with a mean age of 63.9+/-10.1 years (range 50 to 91) were examined. Eleven out of 1229 (0.89%) were diagnosed with AAA. In the population of 1218 people without AAA, the mean diameters (cm) of male/female were 2.20/2.11 (p<0.001) at suprarenal, 2.04/1.90 (p<0.001) at renal, 1.90/1.79 (p<0.001) at infrarenal, 1.22/1.17 (p<0.001) at right iliac and 1.47/1.15 (p=0.097) at the left iliac, respectively. There was a significantly larger diameter in the male population. The diameter of each level increased with age. CONCLUSION: The normal reference diameter of the infrarenal abdominal aorta in the Korean population is 1.9 cm in males and 1.79 cm in females. The diameter of the abdominal aorta increases with age.

Splenectomy affects the balance between hepatic growth factor and transforming growth factor-beta and its effect on liver regeneration is dependent on the amount of liver resection in rats / 대한외과학회지

PURPOSE: Small-for-size syndrome (SFSS) is a major problem in liver surgery, and splenectomy has been used to prevent SFSS. However, it is unknown whether splenectomy has the same effect on liver regeneration in both standard and marginal hepatectomy. The aim of this study is to see a difference in effect of splenectomy on liver regeneration according to the amount of liver resection. METHODS: Thirty male Sprague-Dawley rats (220 to 260 g) were divided into the following five groups: control (n = 6), 70% hepatectomy (n = 6), 70% hepatectomy with splenectomy (n = 6), 90% hepatectomy (n = 6), and 90% hepatectomy with splenectomy (n = 6). The animals were euthanized 24 hours after surgery and liver specimens were obtained. To assess liver regeneration, we performed immunohistochemistry of liver tissue using 5-bromo-2-deoxyuridine (BrdU) labeling and Western blot analysis of hepatic growth factor (HGF) and transforming growth factor-beta (TGF-beta) in the liver tissue. RESULTS: The splenectomized subgroup had a higher BrdU-positive cell count in the 90% hepatectomy group, but not in the 70% hepatectomy group (P < 0.001). Splenectomy significantly decreased TGF-beta expression (P = 0.005) and increased the HGF to TGF-beta ratio (P = 0.002) in the 90% hepatectomy group, but not in the 70% hepatectomy group. CONCLUSION: The positive effect of splenectomy on liver regeneration was greater in the group with the larger liver resection. This phenomenon may be related to the relative balance between HGF and TGF-beta in the liver.

Duplex Criteria for Carotid Artery Stenosis / 대한혈관외과학회지

PURPOSE: Various duplex criteria have been used to predict hemodynamically significant carotid artery stenosis. Clinicians have relied on published institutional experience for carotid duplex ultrasound interpretation. Duplex parameters for interpreting carotid artery stenosis severity consist of peak systolic velocity (PSV) and end-diastolic velocity of the internal carotid artery (ICA), the ratio of ICA PSV and end-diastolic velocity (EDV) to common carotid artery (CCA) PSV (PSVICA/CCA) and EDV (EDVICA/CCA). This study was performed to elucidate which duplex parameter can predict the severity of the carotid artery stenosis more accurately. METHODS: The carotid duplex ultrasound and angiographic results of 121 carotid arteries were analyzed. Receiver operater characteristic (ROC) curves were used to compare PSV, EDV, and both ratios in detecting > or =50%, > or =60%, and > or =70% stenosis of the internal carotid artery. RESULTS: The PSVICA/CCA ratio can accurately detect > or =50%, > or =60%, and > or =70% stenosis of the internal carotid artery. To detect > or =50% angiographic stenosis, a PSVICA/CCA ratio of 1.2 has a sensitivity of 83% and specificity of 77%. A PSVICA/CCA ratio of 1.8 can detect > or =60% angiographic stenosis with a sensitivity of 80% and specificity of 79%. Finally, a PSVICA/CCA ratio of 2.2 can detect > or =70% angiographic stenosis with a sensitivity and specificity of 70 and 89%, respectively. CONCLUSION: The PSVICA/CCA ratio can be used for detecting internal carotid artery angiographic stenosis. PSVICA/CCA ratios of 1.2, 1.8, and 2.2 are proper criteria for interpreting 50%< or =, 60%< or = and 70%< or = stenosis, respectively.

Outcomes of Bypass Surgery Versus Endovascular Therapy for TASC II C and D Femoro-Popliteal Lesions in Patients with Chronic Limb Ischemia

PURPOSE: We wanted to define the appropriate treatment modalities for Trans-Atlantic Inter-Society Consensus (TASC) II C and D femoro-popliteal lesions. So we compared the primary patency rate and several clinical factors between percutaneous balloon angioplasty with or without stenting (PTA/S) and bypass surgery (BP). METHODS: We reviewed the medical records of patients who underwent BP or PTA/S for TASC II C (BP-C, PTA/S-C) and D (BP-D, PTA/S-D) femoro-popliteal lesions from March 2001 to May 2009. We analyzed the primary and secondary patency rates, and the major limb salvage rates. RESULTS: Eighty two limbs in 74 patients (mean age: 68.7+/-10.2 years, males: 82.9%) were treated (PTA/S-C: 18, PTA/S-D 19: BP-C 12, BP-D 33). The mean follow-up duration was 30.0+/-19.0 months. The twenty four month primary patency rates was 82.4% for PTA/S-C and 73.3% for BP-C (P=0.876), and 45.3% for PTA/S-D and 66.6% for BP-D (P=0.034). The twenty four month secondary patency rates were 88.2% for PTA/S-C and 73.3% for BP-C (P=0.669), and 54.7% for PTA/S-D and 73.3% for BP-D (P=0.077). The twenty four month major limb salvage rates were 100.0% for PTA/S-C and 75.0% for BP-C (P=0.030) but there were no statistical differences between the TASC II D groups (P=0.377). CONCLUSION: Bypass surgery is a preferred initial therapeutic option for TASC II D femoro-popliteal lesions. However, several clinical factors must be carefully considered when selecting the primary treatment modality for TASC II C lesions.

The Incidence of Giacomini Vein and Its Association with Lower Extremity venous Insufficiency: An Ultrasonographic Study

PURPOSE: We wanted to evaluate the incidence of Giacomini vein and its association with lower extremity venous insufficiency by performing US. MATERIALS AND METHODS: From September 2006 to July 2007, 173 patients (58 males and 115 females, mean age: 52.7 years, age range: 22-72 years) who had been diagnosed with unilateral/bilateral varicose veins or telangiectasias were evaluated with duplex Doppler ultrasonography. The presence of Giacomini vein, superficial/deep vein reflux, the anatomical sites of the venous reflux and the abnormal perforating veins was investigated in 346 legs. RESULTS: Giacomini veins were found in 33 limbs (9.5%) of 21 patients (12.1%). Bilateral Giacomini veins were found in 12 patients. Of the 33 limbs that had Giacomini veins, 20 limbs had great saphenous vein (GSV) reflux and 4 limbs had small saphenous vein (SSV) reflux. The patients with Giacomini veins were classified into two groups according to the presence of Giacomini vein. There was no significant difference of the GSV reflux (p = 0.155), the SSV reflux (p = 0.760) and the mean velocity of the GSV reflux or the SSV reflux (p = 0.685, p = 0.431, respectively) between the two groups. CONCLUSIONS: Our results indicated that Giacomini vein is not associated with either GSV or SSV reflux, and this is contrary to conventional belief.

Assessing Primary Percutaneous Aspiration Thrombectomy for the Treatment of Deep Vein Thrombosis

PURPOSE: The aim of this study is to evaluate the role of percutaneous aspiration thrombectomy (AT) for the initial endovascular management of deep vein thrombosis (DVT) and to analyze the success rate and complications according to the symptom duration. METHODS: Forty patients who were diagnosed with DVT from June 2004 to January 2009 were retrospectively examined. The patients were divided into 3 groups; group I, those with symptoms lasting 28 days. All of the patients were initially treated with percutaneous AT using the Pullback technique. The incomplete elimination of large and hard thrombus was managed with overnight catheter directed thrombolysis (CDT) and additional AT. Successful recanalization was defined as successful restoration of antegrade flow in the treated veins with elimination of any underlying obstructive lesion. RESULTS: Initial successful recanalization with only AT was achieved in 24 (60%) patients. CDT was required in 16 (40%) patients who had remaining thrombus. Final successful recanalization was achieved in 37 (92.5%) patients. There were no significant differences in the final recanalization rate, the mean number of ATs and the duration of the procedure among groups I, II and III. There was one case (group I) of procedure-related complication, which was the occurrence of a retroperitoneal hematoma after overnight CDT. CONCLUSION: Percutaneous AT may be an initial therapeutic option for DVT, and it minimizes the risk of hemorrhagic complications. It is an effective treatment method for subacute and chronic DVT, as well as acute DVT.

Risk Factors that Influence the Early Access Patency of an Arteriovenous Fistula in Hemodialysis Patients

PURPOSE: It is very important to obtain vascular access that resists repeated punctures and maintains an adequate blood flow for performing hemodialysis in patients with end stage renal disease. This study was designed to identify the risk factors that may influence the early patency rate of arteriovenous fistulas (AVFs). METHOD: We analyzed 304 cases of AVFs in 299 patients who underwent hemodialysis access surgery in our hospital from January 2000 to March 2007. The rate of early access failure and the risk factors of early access patency were evaluated retrospectively. RESULT: The rate of early access failure of an AVF was 14.5%. The early access failure group showed a higher incidence in women and in the patients with a previous history of ipsilateral central venous catheterization. Further examination by multivariate analysis demonstrated that a history of ipsilateral central venous catheterization was an independent risk factor for early access failure of AVFs. CONCLUSION: A history of ipsilateral central venous catheterization was an independent risk factor for early access failure of AVFs in this study.

A Pig to Canine Auxiliary Hepatic Xenotransplantation Model: Prevention of Hyperacute Rejection via Blocking the Kupffer Cells and Regulating the Complement Family

PURPOSE: We designed a pig to canine liver xenotransplantation model to study the diverse immunologic and hemodynamic consequences that follow xenotransplantation and hyperacute rejection. METHODS: The animals were divided into two groups: the cobra venom factor and Gadolinium chloride treatment group (CVF+Gd group) (3 cases) and the control group (3 cases). The donor pig's whole liver was harvested, and then the harvested pig's whole liver was transplanted into a dog after the dog underwent left hepatectomy. After reperfusion of the graft, blood samples were taken 20, 40 and 60 minutes after reperfusion, and the liver, lung and kidney tissues were taken 1 hour after reperfusion. RESULTS: In the control group, the grafts showed a patchy hypoperfused liver surface and it felt rubbery solid compared to the CVF+Gd group. The serum total protein, albumin, fibrinogen and platelets decreased abruptly and there were no significant differences between the two groups. The serum PT, PTT and FDP were increased in both groups and the CVF+Gd group showed a more obtuse slope than the control group. We could not find any intravascular pathologic changes on the microscopic findings of the graft. Only scant intravascular fibrin deposition was found. Hepatocellular vacuolization and sinusoidal dilatation were also found. There were patches of necrosis without any zonal distribution, intrasinusoidal neutrophil sequestration and interstitial hemorrhage. These findings were milder in the CVF+Gd group. CONCLUSION: The pig to canine partial auxiliary liver xenotransplantation model is feasible and it is a good model before starting to perform pig to primate liver xenotransplantation. In the CVF+Gd group, pathologic findings like patch hepatocyte necrosis etc. were less severe. As there were no corresponding vascular pathologic findings, these findings are not the direct effect of CVF and gadolinium treatment, and so other factors like Ischemia- reperfusion injury should be considered.

Early Detection of Hemodialysis Ateriovenous Fistula Dysfunction by Trend Analysis of Intra-access Pressure / 대한신장학회지

PURPOSE: To detect early arteriovenous fistula (AVF) dysfunction, we have developed a new method of intra-access total pressure (pT), and static pressure (pS) measurements. The purpose of this study is to assess the relationship between intra-access pressure and vascular stricture in order to establish the clinical validity of the method. METHODS: Total 46 of native AVFs were enrolled. They were measured intra-access pS and pT monthly. In initial angiography, 6 of 10 inflow stricture (As), 6 of 7 outflow stricture (Vs) and 2 having both lesions were taken PTA (percutaneous angioplasty) and compared pressure and ratio changes. If delta p (pT-pS) decreased more than 10% over 3 months or pT/MAP (mean arterial pressure) ratio dropped more than 10% over 3 months with below 0.8, then the patients were referred to angiography. Thirtyone patients were performed final angiography, and we compared the results with those of initial angiography. RESULTS: Although pT/MAP ratio and delta p were increased after PTA, there was no statistical significance in 6 As (+) patients (p>0.05). Six Vs (+) and 2 AS (+) and Vs (+) patients' delta p were increased significantly (p0.45). CONCLUSION: Intra-access stricture could be detected with pT/MAP ratio and delta p change. However, more careful MAP and pT measurement should be recommended for accurate diagnosis.

Effects of Mycophenolic Acid on Oleic Acid- induced Rat Vascular Smooth Muscle Cell Proliferation

PURPOSE: Vascular smooth muscle cell (VSMC) proliferation plays an important role in the development and progression of chronic allograft vasculopathy. Mycophenolic acid (MPA) inhibits various mesenchymal cell proliferation, and reactive oxygen species (ROS) are involved in the anti-pro-liferative effect of MPA. In this study, we investigated the effects of MPA on oleic acid (OA)-induced VSMC proliferation and also the role of ROS in these processes. METHODS: Primary cultured rat VSMCs from Sprague-Dawley were stimulated with OA 100micrometer. MPA 0.1~10micrometer and N-acetylcystein (NAC) 5 mM were administered 1 hour before adding the OA. Cell proliferation was measured by Methylthiazoletetrazolium (MTT) assay, proliferating cell nuclear antigen (PCNA) expression by Western blot analysis, and dichlorofluorescein (DCF)-sensitive cellular ROS by flow cytometry. RESULTS: OA at 100micrometer significantly increased MTT level by 1.6-fold as well as PCNA expression at 48 hours in rat VSMCs. OA also induced DCF-sensitive cellular ROS by 1.6-fold at 5 minutes and the increment of cellular ROS remained for up to 1 hour. MPA at above 1micrometer inhibited OA- induced VSMC proliferation and cellular ROS in a dose-ependent manner. NAC 5 mM also inhibited OA-induced rat VSMC activation. CONCLUSION: These results suggest that MPA inhibits OA-induced VSMC proliferation partially through the inhibition of cellular ROS.

Effects of Inosine Monophosphate Dehydrogenase Inhibition on Platelet-derived Growth Factor- Induced Fibronectin Secretion and Cellular Reactive Oxygen Species in Mouse Mesangial Cells / 대한이식학회지

PURPOSE: Mesangial cell extracellular matrix (ECM) synthesis plays an important role in various renal diseases. Mycophenolic acid (MPA), which is an inhibitor of inosine monophosphate dehydrogenase (IMPDH), inhibits mesangial cell proliferation and ECM synthesis. However, the exact mechanism of MPA has not been clearly elucidated in mesangial cells. To examine the relative importance of IMPDH on the inhibitory action of MPA, we compared the effects of MPA or IMPDH2 siRNA on platelet-derived growth factor (PDGF)-induced fibronectin secretion and cellular reactive oxygen species (ROS) in mouse mesangial cells (MMC). METHODS: MMC were stimulated with PDGF 10 ng/ml with or without MPA 0.1~10micrometer, IMPDH2 siRNA 10~50 nM, or N-acetylcystein (NAC). IMPDH2 siRNA was transiently transfected by lipofectamine for 24 hours. MPA 0.1~10micrometer, ribavirin 10~100micrometer, and NAC 5 mM were administered 1 hour before the stimulation. Cell viability was measured by methylthiazoletetrazolium (MTT) assay, fibronectin secretion by Western blot analysis, and dichlorofluorescein (DCF)-sensitive cellular ROS by flow cytometry. RESULTS: PDGF 10 ng/ml effectively increased fibronectin secretion and cellular ROS in MMC. MPA and NAC at concentration without affecting basal level of fibronectin and cellular ROS ameliorated PDGF-induced fibronectin secretion and cellular ROS. However, IMPDH2 siRNA only partially reduced PDGF- induced fibronectin secretion and cellular ROS in MMC. CONCLUSION: These results suggest that MPA may inhibit PDGF-induced fibronectin secretion partly through IMPDH2 or cellular ROS in MMC, and there may be other mechanisms on the inhibitory action of MPA in mesenchymal cells.

Early Detection of Hemodialysis Arteriovenous Fistula Dysfunction with Intra-access Static and Total Pressure Measurement / 대한신장학회잡지

PURPOSE: To detect the dysfunction of arteriovenous fistula (AVF) early, we have developed a new method to calculate the intra-vascular conduit flow rate based on the Bernoulli's theory. However, this method has limitation on detection of inflow stenosis. For detection of both in- and out-flow stenosis, we tried to measure intra-access static (pS) and total pressure (pT), and compared with angiographic findings. METHODS: From a total of 46 cases of native AVFs, of at least 3 months of construction, intra-access pS and pT were measured, before starting hemodialysis. deltap (pT-pS) and pT/mean arterial pressure (MAP) ratio were calculated, and compared with angiographic findings. RESULTS: Among 37 patients without outflow stenosis (Vs) in fistulogram, 10 patients with inflow stenosis (As) had significantly lower pT/MAP ratio and deltap than those without As patients (p<0.005). Among 34 patients without As, deltap was significantly lower in 7 patients with Vs than those 27 patients without Vs (p=0.001). CONCLUSION: pT/MAP ratio was correlated with As, and deltap reflects Vs in angiography. The measurement of pS and pT might be useful to predict inflow and outflow stenosis of AVFs.