Characterization and Differentiation of Circulating Blood Mesenchymal Stem Cells and the Role of Phosphatidylinositol 3-Kinase in Modulating the Adhesion

Bone marrow mesenchymal stem cells (BM MSCs) can differentiate into multi-lineage tissues. However, obtaining BM MSCs by aspiration is difficult and can be painful; therefore peripheral blood (PB) MSCs might provide an easier alternative for clinical applications. Here, we show that circulating PB MSCs proliferate as efficiently as BM MSCs in the presence of extracellular matrix (ECM) and that differentiation potential into osteoblast in vitro and in vivo. Both BM MSCs and PB MSCs developed into new bone when subcutaneously transplanted into immune-compromised mice using hydroxyapatite/tricalcium phosphate as a carrier. Furthermore, LY294002 and Wortmannin blocked mesenchymal stem cell attachment in a dose-dependent manner, suggesting a role of phosphatidylinositol 3-kinase in MSC attachment. Our data showed that the growth of PB MSCs could be regulated by interaction with the ECM and that these cells could differentiate into osteoblasts, suggesting their potential for clinical applications.

Osseointegration of the titanium implant coated with rhTGF-beta2/PLGA particles by electrospray: a preliminary microCT analyzing rabbit study / 대한치과보철학회지

PURPOSE: This preliminary rabbit study was conducted to evaluate the effect of recombinant human transforming growth factor-beta2 (rhTGF-beta2)/poly lactic-co-glycolic acid (PLGA) coating on osseointegration of the titanium (Ti) implant. MATERIALS AND METHODS: Eight Ti implants were anodized with 300 voltages for three minutes. Four of those were coated with rhTGF-beta2/PLGA by an electrospray method as the experimental group. The implants were placed into tibiae of four New Zealand rabbits, two implants per a tibia, one implant per each group. After 3 and 6 weeks, every two rabbits were sacrificed and micro-computed tomography (microCT) was taken for histomorphometric analysis. RESULTS: In scanning electron microscope (SEM) image, the surface of rhTGF-beta2/PLGA coated Ti implant showed well distributed particles. Although statistically insignificant, microCT analysis showed that experimental group has higher bone volume / total volume (BV/TV) and trabecular thickness (Tb.Th) values relatively. Cross sectional view also showed more newly formed bone in the experimental group. CONCLUSION: In the limitation of this study, rhTGF-beta2/PLGA particles coating on the Ti implant show the possibility of more favorable quantity of newly formed bone after implant installation.

A study of mesenchymal stem cell proliferation and surface characteristics of the titanium discs coated with MS275/PLGA by an electrospray / 대한치과보철학회지

PURPOSE: This study was conducted to identify the surface characteristics of titanium discs coated with MS275/PLGA by electrospray and which is effective to mesenchymal stem cell proliferation. MATERIALS AND METHODS: We used anodized surface coated with PLGA as a control group and anodized surface coated with MS275 0.5 microM, 1 microM, 1.5 microM as test groups. To examine that the coating particles are nanometer sized, FE-SEM was used and AFM was utilized to determine the difference of coating surface roughness. We checked the mesenchymal stem cell proliferation by using MTT assay on 1st, 4th, 7th days. RESULTS: There was no significant difference between control groups and test groups in AFM results (P>.05). In MTT assay results, mesenchymal stem cell proliferation was increased with time, at 7th day, cell viability on discs coated with 1.5 microM MS275 was significantly higher than control group (P<.05). As SEM showed, the number of cells on all discs was increased and the morphology of cell attachment was also wider and closer with time. CONCLUSION: Titanium surface coated with MS275/PLGA showed significantly higher cell proliferation and the more density of MS275 was dispersed on titanium discs, the faster cells grew.

Could HBx Protein Expression Affect Signal Pathway Inhibition by Gefitinib or Selumetinib, a MEK Inhibitor, in Hepatocellular Carcinoma Cell Lines?

Hepatitis B virus X (HBx) protein has been known to play an important role in development of hepatocellular carcinoma (HCC). The aim of this study is to find out whether HBx protein expression affects antiproliferative effect of an epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitor and a MEK inhibitor in HepG2 and Huh-7 cell lines. We established HepG2 and Huh-7 cells transfected stably with HBx gene. HBx protein expression increased pERK and pAkt expression as well as beta-catenin activity in both cells. Gefitinib (EGFR-TK inhibitor) inhibited pERK and pAkt expression and beta-catenin activity in both cells. Selumetinib (MEK inhibitor) reduced pERK level and beta-catenin activity but pAkt expression was rather elevated by selumetinib in these cells. Reduction of pERK levels was much stronger with selumetinib than gefitinib in both cells. The antiproliferative efficacy of selumetinib was more potent than that of gefitinib. However, the antiproliferative effect of gefitinib, as well as selumetinib, was not different between cell lines with or without HBx expression. Signal pathway activation by HBx might not be strong enough to attenuate the antiproliferative effect of EGFR-TK inhibitor. Future experiments are needed to understand the role of HBx protein expression in HCC treatment using molecular targeting agent.

Effect of Posture on Muscle Activity and Oxygen Uptake in Cycle Ergometer / 대한스포츠의학회지

This study evaluated the effects of saddle height on the muscle activity and oxygen uptake during bicycling. The subjects were 20 young adult volunteers. Muscle activity and oxygen uptake were measured with the two saddle heights (maximum knee extension of 180degrees and 120degrees) and at two power outputs (70 and 100 watts, respectively.) The pedaling rate was 40 rpm. The exercise time was 1 minute and the resting time between each condition was 3 minutes. The raw electromyogram activity was measured for 1 minute and was converted to a root mean square value. Oxygen uptake was measured during exercise using the mixing chamber mode. The activities of two flexors (the medial hamstring and medial head of gastrocnemius) increased at the high saddle height and the activities of four extensors (rectus femoris, vastus medialis, vastus lateralis, and tibialis anterior) increased at the low saddle height. The oxygen uptake at the low saddle height was significantly higher than that at the high saddle height. The oxygen uptake positively correlated with the muscle activities of the knee extensors. The muscle activity and oxygen uptake were significantly affected by the postures (saddle heights) in cycle ergometer. The postures should be considered in the exercise test and prescription.

Erratum: Effect of Posture on Muscle Activity and Oxygen Uptake in Cycle Ergometer / 대한스포츠의학회지

No abstract available.

Mutations within the interferon sensitivity determining region in Korean patients infected with hepatitis C virus genotype 1b / 대한간학회지

BACKGROUND/AIMS: The treatment response to interferon could differ with mutations in the interferon-sensitivity-determining region (ISDR) in patients infected with hepatitis C virus (HCV) genotype-1b (HCV-Ib). We examined the pattern of ISDR mutations and analyzed whether the number of amino acid substitutions influences the treatment response to peginterferon plus ribavirin in chronic hepatitis or cirrhotic patients infected with HCV-Ib. METHODS: The study population comprised 52 patients who visited Seoul Asan Medical Center and Seoul National University Bundang Hospital from January 2006 to December 2008 and who received peginterferon alpha-2a (n=37) or -2b (n=15) plus ribavirin, and whose serum was stored. We analyzed the early virologic response, end-of-treatment response, and sustained virologic response (SVR), and examined the ISDR using direct sequencing. RESULTS: The proportions of patients with ISDR mutation types of wild (0 mutations), intermediate (1-3 mutations), and mutant (> or =4 mutations) were 50.0%, 42.3%, and 7.7%, respectively, and the corresponding SVR rates were 63%, 50%, and 67% (p>0.05). The SVR rates were 59.4% and 50.0% in patients with or =2 mutations, respectively (p>0.05). On univariate analysis, age was the only predictive factor for SVR (p=0.016). The pretreatment HCV RNA titer tended to be lower in those with SVR, but without statistical significance (p=0.069). CONCLUSIONS: The frequency of ISDR mutations was low in our cohort of Korean patients infected with HCV-Ib. Therefore, ISDR mutations might not contribute to the response to treatment with peginterferon plus ribavirin.

The requirement of natural killer T-cells in tolerogenic APCs-mediated suppression of collagen-induced arthritis

TGF-beta-induced tolerogenic-antigen presenting cells (Tol-APCs) could induce suppression of autoimmune diseases such as collagen-induced arthritis (CIA) and allergic asthma. In contrast, many studies have shown that NKT cells are involved in the pathogenesis of Th1-mediated autoimmune joint inflammation and Th2-mediated allergic pulmonary inflammation. In this study, we investigated the effect of CD1d-restricted NKT cells in the Tol-APCs-mediated suppression of autoimmune disease using a murine CIA model. When CIA-induced mice were treated with Tol-APCs obtained from CD1d+/- or CD1d-/- mice, unlike CD1d+/- APCs, CD1d-/- Tol-APCs failed to suppress CIA. More specifically, CD1d-/- Tol-APCs failed to suppress the production of inflammatory cytokines and the induction of Th2 responses by antigen-specific CD4 T cells both in vitro and in vivo. Our results demonstrate that the presence of CD1d-restricted NKT cells is critical for the induction of Tol-APCs-mediated suppression of CIA.

TGF-beta-treated antigen presenting cells suppress collagen-induced arthritis through the promotion of Th2 responses

Collagen-induced arthritis (CIA) is mediated by self-reactive CD4+ T cells that produce inflammatory cytokines. TGF-beta2-treated tolerogenic antigen-presenting cells (Tol-APCs) are known to induce tolerance in various autoimmune diseases. In this study, we investigated whether collagen-specific Tol-APCs could induce suppression of CIA. We observed that Tol-APCs could suppress the development and severity of CIA and delay the onset of CIA. Treatment of Tol-APCs reduced the number of IFN-gamma- and IL-17-producing CD4+ T cells and increased IL-4- and IL-5-producing CD4+ T cells upon collagen antigen stimulation in vitro. The suppression of CIA conferred by Tol-APCs correlated with their ability to selectively induce IL-10 production. We also observed that treatment of Tol-APCs inhibited not only cellular immune responses but also humoral immune responses in the process of CIA. Our results suggest that in vitro-generated Tol-APCs have potential therapeutic value for the treatment of rheumatoid arthritis as well as other autoimmune diseases.

A New Reporter Vector System Based on Flow-Cytometry to Detect Promoter Activity

In this study, we report the development of a new dual reporter vector system for the analysis of promoter activity. This system employs green fluorescence emitting protein, EGFP, as a reporter, and uses red fluorescence emitting protein, DsRed, as a transfection control in a single vector. The expression of those two proteins can be readily detected via flow cytometry in a single analysis, with no need for any further manipulation after transfection. As this system allows for the simultaneous detection of both the control and reporter proteins in the same cells, only transfected cells which express the control protein, DsRed, can be subjected to promoter activity analysis, via the gating out of all un-transfected cells. This results in a dramatic increase in the promoter activity detection sensitivity. This novel reporter vector system should prove to be a simple and efficient method for the analysis of promoter activity.

The presence of CD8+ invariant NKT cells in mice

Invariant natural killer T (iNKT) cells develop in the thymus upon recognition of CD1d expressed on developing thymocytes. Although CD4 and CD8 coreceptors are not directly involved in the interaction between CD1d and the T cell receptors (TCRs) of iNKT cells, a conspicuous lack of CD8+ iNKT cells in mice raised the question of whether CD8+ iNKT cells are excluded due to negative selection during their thymic development, or if there is no lineage commitment for the development of murine CD8+ iNKT cells. To address this question, we analyzed iNKT cell-specific TCR Valpha14+ transgenic mice, where the Valpha14 transgene forces the generation of iNKT cells. This allows detailed study of the iNKT cell repertoire. We were able to identify CD8+ iNKT cells which respond to the NKT cell-specific glycolipid ligand alpha-galactosylceramide. Unlike conventional iNKT cells, CD8+ iNKT cells produce predominantly IFN-gamma but not IL-4 upon antigen stimulation. We also confirmed the presence of CD8+ iNKT cells in wild type mice. Our results suggest that CD8+ NKT cells do exist in mice, although their population size is quite small. Their Th1-skewed phenotype might explain why the population size of this subtype needs to be controlled tightly.

The Effects of Cardiac Rehabilitation in Patients with ST Elevation Myocardial Infarction and Non-ST Elevation Myocardial Infarction

OBJECTIVE: To compare the effects of cardiac rehabilitation between patients with ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI). METHOD: Thirty three patients with STEMI or NSTEMI who underwent percutaneous transluminal coronary angioplasty were recruited. All patients participated in cardiac rehabilitation program including ECG monitoring exercise for 6 weeks. Several parameters such as exercise duration, oxygen consumption, heart rate, blood pressure and rate pressure product were evaluated through graded exercise test before and 6 months after initiation of cardiac rehabilitation program. RESULTS: After cardiac rehabilitation program, the STEMI group showed significant changes in exercise time, maximum oxygen consumption, resting heart rate and submaximal rate pressure product. The NSTEMI group also showed significant improvement of exercise time, maximum oxygen consumption and submaximal rate pressure product. There was no significant difference in the changing rate between two groups. CONCLUSION: Both the STEMI and the NSTEMI groups showed similar improvement of cardiopulmonary exercise capacity 6 months after cardiac rehabilitation program.

Cardiopulmonary Exercise Capacity in Coronary Artery Disease Patients Receiving Percutaneous Coronary Intervention Compared with Coronary Artery Bypass Grafting

OBJECTIVE: To compare the exercise capacity after cardiac rehabilitation (CR) in patients with percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery. METHOD: 27 patients who underwent PCI and 18 patients who underwent CABG surgery were included. All the subjects performed supervised exercise training for 6~8 weeks at hospital and self-exercise at community for additional 16~18 weeks. Exercise capacity was measured by symptom limited graded exercise tests at study entry and 6 months later. RESULTS: After 6 months of CR, maximal oxygen consumption (VO2max) was significantly increased, resting heart rate (HR) and submaximal rate pressure product (RPP) were significantly decreased in both groups (p<0.05). There were no significant change of maximal HR in both groups (p<0.05). Maximal RPP in CABG increased significantly (p<0.05) but did not change significantly in PCI group. Resting HR was significantly higher, VO2max was significantly lower in CABG group than PCI group at study entry (p<0.05). Resting HR was not significantly different in both groups but, VO2max was still lower in CABG group than PCI group even after 6 months of CR (p<0.05). CONCLUSION: The cardiac rehabilitation program was effective in both PCI and CABG group. Although VO2max in PCI group was higher than CABG group after 6 month CR, the range of improvement was greater in CABG group than PCI group.

The Causes for the Premature Termination of Graded Exercise Test in a Cardiac Rehabilitation Setting

OBJECTIVE: To observe the termination point of graded exercise test (GXT) in cardiac patients and the reasons for the premature termination. METHOD: Cardiac patients taking GXT within 4 weeks after medical intervention or surgery were reviewed. If the GXT was stopped below the respiratory exchange ratio of 1.0, the subjects were chosen as the final study subjects and reviewed for the reason of premature termination. RESULTS: 115 out of a total of 715 subjects terminated GXT prematurely. There were 36 cardiovascular, and 79 non- cardiovascular reasons. The cardiovascular reasons were abnormal blood pressure response (19.1%), dysrhythmia (6.1%), ST abnormality (3.5%), vascular claudication (2.6%). The non-cardio-vascular reasons were subjective dyspnea (45.2%), lower limb fatigue (7.8%), hemiplegic gait (5.2%), arthralgia (3.5%), anxiety (3.5%), neurogenic claudication (2.6%), and abdominal pain (0.9%). The causes of dyspnea were low physical fitness (71.1%), concurrent chronic obstructive pulmonary disease (15.4%), poor motivation (5.8%), and secondary gain (7.7%). CONCLUSION: 16.1% of GXT were terminated prematurely and 68.7% of those for non-cardiovascular reasons. The main causes of the non-cardiovascular premature GXT were subjective dyspnea due to low physical fitness.

A Case of Successful Endoscopic Injection Sclerotherapy with N-butyl-2-cyanoacrylate for Ruptured Duodenal Varices / 대한소화기학회지

Duodenal varix is a rare cause of hemorrhage in patients with portal hypertension, however their rupture is serious and often life threatening. Treatments for duodenal variceal bleeding include endoscopic procedures, surgery, or interventional radiologic procedures. We report a case of duodenal varices rupture in a 45-year-old man with alcoholic liver cirrhosis who presented with melena and dizziness. Emergent upper endoscopy revealed large nodular varices with a ruptured erosion on the top in the distal second portion of duodenum. Two consecutive injections with 1.0 mL of n-butyl-2-cyanoacrylate (Histoacryl; Braun-Melsungen, Germany) mixed with 1.0 mL of lipiodol (Laboratoire-Guerbet, France) were performed intravariceally and achieved successful hemostasis. This suggests that endoscopic injection sclerotherapy with histoacryl may be an effective therapeutic option for the control of ruptured duodenal variceal bleeding.

Pulmonary Toxicity by Pegylated Interferon alpha-2a in a Patient with Chronic Hepatitis C / 대한간학회지

The combination therapy with pegylated interferon alpha and ribavirin has increasingly prescribed for chronic hepatitis C. Although many side effects of interferon such as flu-like symptoms, gastrointestinal and neuropsychiatric symptoms are well known, only several cases of interferon-induced pulmonary toxicity have been reported. Interferon-induced pulmonary toxicity usually develops from 2 weeks to 12 weeks after treatment for HCV infection. Diagnosis is commonly based on clinical findings such as a dry cough, dyspnea, hypoxemia, and a restrictive pattern in pulmonary function testing, bilateral diffuse parenchymal infiltrations, histopathological findings of interstitial pneumonitis, and exclusion of any other causative agents. Prompt withdrawal of the drug is the cornerstone of treatment. We report a case of PEG-IFN alpha-2a induced pulmonary toxicity in a 50-year-old male patient with hepatitis C. To our knowledge, this is the first case of pegylated interferon alpha-2a induced pulmonary toxicity in Korea.

A Case of Primary Omental Torsion Presenting as an Acute Abdominal Pain / 대한소화기학회지

Torsion of greater omentum is a rare cause of acute abdomen. However, it should be included in the differential diagnoses in addition to acute cholecystitis, acute appendicitis, cecal diverticulitis, and other variable causes of acute abdomen. Diagnosis is usually made at laparotomy for suspected appendicitis. In some cases, computed tomography demonstrates a successful preoperative detection of omental torsion. We report a case of surgically and pathologically proven torsion with subsequent infarction of greater omentum presented as an acute abdominal pain.

Sonographically Guided Musculocutaneous Nerve Phenol Block for Elbow Flexor Spasticity: Case report

Seven hemiplegic stroke patients suffering elbow flexor spasticity were selected for musculocutaneous nerve (MN) blocks. The MN was identified at the proximal 1/3 area on anteromedial surface of upper arm at supine position. An injectable monopolar EMG needle electrode was inserted into MN under real time ultrasonography. The 7% phenol solution was injected 0.2 ml at a time into MN until biceps brachii and brachialis muscle contractions were completely blocked at a maximum of 5 mA electrical stimulation. The total dose of injected phenol solution was 1.2~2.2 ml. We examined modified Ashworth scale (MAS) of elbow flexor and elbow angle at the standing position. In all the subjects, MAS was decreased and elbow angle was increased after nerve block. Ultrasonography guidance makes it exact to identify MN and to inject neurolytic solution to target. It can lead minimal complications by using the least dosage of neurolytic drug.

Incidence of Gallbladder Stones in Renal Transplant Recipients / 대한소화기학회지

BACKGROUND/AIMS: Gallbladder stone is one of the major cause of morbidity in adults. Renal transplantation has been found to increase the risk of gallbladder stone formation. The real incidence of gallbladder stones in renal transplant recipients is not exactly known. We performed this study to identify the risk factors for cholecystolithiasis. METHODS: We compared the prevalence of gallbladder stone in 222 renal transplantation patients with that in 222 age and sex matched controls. Patients who had chronic liver disease, renal disease, and diabetes were excluded from the control group. RESULTS: In our study, the incidence of gallbladder stones is 8.6% (19/222 patients) in renal transplantation patients, which was significantly higher than 3.60% (8/222 control) in the control group (p=0.029). In the most of our renal transplantation patients, cholecystolithiasis was asymptomatic. We did not find a difference in age, sex, duration after transplantation, causes of renal failure, resistance index between patients with and without gallbladder stones in renal transplantation patients. CONCLUSIONS: Our results suggest that the incidence of gallbladder stones is higher in renal transplant recipients than non-transplant population in Korea. Further studies will be needed to focus the factors contributing to the gallbladder stone formation after renal transplantation, especially in regard to immunosuppressive drugs.

A case of lung metastasis of malignant eccrine poroma / 대한내과학회지

Malignant eccrine poroma is a rare skin appendage tumor, originating from the intraepidermal and upper dermal eccrine ducts. It is a locally aggressive neoplasm with a high propensity to metastasize. A 47-year-old woman was admitted to the hospital because of dyspnea. One and half years before admission, she had been diagnosed porocarcinoma of left sole and treated with wide local excision. One months after excision, examination had revealed an inguinal lymph node metastasis and she had been treated with lymph node resection and radiotherapy. During the two weeks before admission, the patient had increasing exertional dyspnea, which was accompanied by Rt-sided chest wall pain. On admission right pleural effusion and multiple nodular densities were noted at initial chest radiograph. A computed tomographic (CT) scan of the chest showed lymphatic and hematogenous lung metastasis with pleural seeding of unknown primary tumor. Fine-needle aspiration biopsy of the pleura revealed typical cytologic findings of porocarcinoma. She was treated with therapeutic thoracentesis and pleurodesis with bleomycin. Because porocarcinoma is resistant to chemotherapy and radiotherapy, she has been treated with conservative treatment.