Kyung Eun Song

Individual Variation in Growth Factor Concentrations in Platelet-rich Plasma and Its Influence on Human Mesenchymal Stem Cells

Background The objective of this study was to explore whether individual variations in the concentration of growth factors (GFs) influence the biologic effects of platelet-rich plasma (PRP) on human mesenchymal stem cells (HMSCs). Methods The concentrations of 7 representative GFs in activated PRP (aPRP) were measured using ELISA. The effects of PRP on the proliferation and alkaline phosphatase (ALP) activity of HMSCs were examined using several concentrations of aPRP from 3 donors; the relationships between the GF levels and these biologic effects were then evaluated using 10% aPRP from 5 subgroups derived from 39 total donors. HMSCs were cultured in DMEM with the addition of aPRP for 4 or 12 days; then, DNA content and ALP activity were measured. Results The quantity of DNA increased significantly at a 10% concentration of aPRP, but the ALP activity was suppressed at this concentration of aPRP. The GF concentrations varied among donors, and 5 subgroups of characteristic GF release patterns were identified via cluster analysis. DNA levels differed significantly between groups and tended to be higher in groups with higher concentrations of transforming growth factor-beta1 (TGF-β1) and platelet-derived growth factors (PDGFs). DNA quantity was positively correlated with TGF-β1 concentration, and was negatively correlated with donor age. ALP activity was negatively correlated with PDGF-BB concentration. Conclusions The varying GF concentrations may result in different biologic effects; thus, individual differences in GF levels should be considered for reliable interpretation of the biologic functions and standardized application of PRP.

Reducing Patient Waiting Time for the Outpatient Phlebotomy Service Using Six Sigma

BACKGROUND One of the challenging issues of the outpatient phlebotomy services at most hospitals is that patients have a long wait. The outpatient phlebotomy team of Kyungpook National University Hospital applied six sigma breakthrough methodologies to reduce the patient waiting time. METHODS The DMAIC (Define, Measure, Analyze, Improve, and Control) model was employed to approach the project. Two hundred patients visiting the outpatient phlebotomy section were asked to answer the questionnaires at inception of the study to ascertain root causes. After correction, we surveyed 285 patients for same questionnaires again to follow-up the effects. RESULTS A defect was defined as extending patient waiting time so long and at the beginning of the project, the performance level was 2.61 sigma. Using fishbone diagram, all the possible reasons for extending patient waiting time were captured, and among them, 16 causes were proven to be statistically significant. Improvement plans including a new receptionist, automatic specimen transport system, and adding one phlebotomist were put into practice. As a result, the number of patients waited more than 5 min significantly decreased, and the performance level reached 3.0 sigma in December 2007 and finally 3.35 sigma in July 2008. CONCLUSIONS Applying the six sigma, the performance level of waiting times for blood drawing exceeding five minutes were improved from 2.61 sigma to 3.35 sigma.

Measurement of Amylase in Saliva Collected by Salivette

BACKGROUND Saliva is increasingly being used as a specimen for systemic disease as well as for oral health status. Especially, salivary amylase has been studied as an excellent index for psychological stress. Authors evaluated the measurement of salivary amylase activities collected by Salivettes (Sarstedt, Germany). METHODS Saliva specimens were collected from 13 healthy adults between 10:00 and 11:00 a.m. Participants were asked to gently chew tampons of Salivettes for 1 min. Immediately after collection, all specimens were stored frozen. On the day of testing, they were centrifuged after thawing and diluted with distilled water. Amylase was measured by Dimension RxL Max (Dade Behring Inc., USA). We evaluated precision, linearity, and recovery rate of Salivette. Amylase activities between collection of saliva by Salivette and passive drool were compared, and also the changes of amylase by the storage temperature were evaluated. RESULTS Intra-run CVs for three levels of amylase were excellent. Between-day CVs and total CVs were good only for mid and high levels. A good linear relationship was found at all diluted levels. Dosing Salivettes with 2 mL, 1.5 mL, and 1 mL yielded sample recovery 85.5+/-2.4%, 82.4+/-1.5%, and 72.2+/-3.1%, respectively and amylase recovery 78.9+/-10.9%, 74.1+/-13.7%, and 37.3+/-26.9%, respectively. Amylase by Salivette and passive drool were correlated well (r=0.757), although they showed a significant difference. Amylase activity was not affected by the storage temperature. CONCLUSIONS Measurement of salivary amylase using Salivette could be a useful test having good intra-run CVs and linearity. More than 1.5 mL of saliva would be needed to have more than 70% recovery of Salivette.

Impact of dialysis modality on the incidence of 2009 pandemic H1N1 influenza in end-stage renal disease patients.

Patients with end-stage renal disease are among the groups at high risk for influenza-related complications (1), but few data are available about the incidence and clinical characteristics of pandemic H1N1 influenza in these patients (2). Here, we compare the incidence of pandemic H1N1 influenza in peritoneal dialysis (PD) and hemodialysis (HD) groups, describe the clinical characteristics of dialysis patients with pandemic H1N1 influenza, and identify risk factors for hospitalization attributable to pandemic H1N1 influenza.

Novel influenza A (H1N1) infection in immunocompromised patients

BACKGROUND Since April 2009, novel influenza A (H1N1) infection is spreading throughout the world. This infection might be fatal for immunocompromised patients who are at a potentially high risk of developing infectious complications. We investigated the detection rate and features of H1N1 infection in immunocompromised patients. METHODS Between August 2009 and February 2010, we examined 8,112 subjects, including 390 immunocompromised patients, for H1N1. Swab samples were taken from the nose and throat of the participants. Real-time PCR was performed to identify H1N1 viral genes. RESULTS Positive results were obtained in 2,953/8,112 (36.4%) subjects and 46/390 (11.8%) immunocompromised patients. H1N1 was identified in 8.7% patients with solid cancer, 12.9% patients with hematologic malignancy, 16.7% patients with chronic renal disease, and 14.5% patients with kidney transplantation. The mean cycle threshold (Ct) value of PCR was significantly lower (P<0.05) in patients with hematologic malignancy as compared to that in patients with chronic renal disease and control subjects. Four patients died due to respiratory complications. CONCLUSIONS The detection rate of H1N1 was significantly lower in immunocompromised patients than in other patients. The Ct value of patients with hematologic malignancy was significantly lower than that of other immunocompromised patients and control subjects.

Usefulness of mycophenolic acid monitoring with PETINIA for prediction of adverse events in kidney transplant recipients

Abstract Background Therapeutic drug monitoring of mycophenolic acid (MPA) is required to optimize the immunosuppressive effect and minimize toxicity. We validated a new particle-enhanced turbidimetric inhibition immunoassay (PETINIA) for the determination of MPA levels and evaluated the relationship of MPA trough level with drug-related adverse events. Methods PETENIA and liquid chromatography-mass spectrometry (LC-MS) were used to determine MPA concentrations from 54 kidney transplant recipients (KTRs). Agreement between PETINIA and LC-MS results was assessed by Passing-Bablok regression and the Bland-Altman plot method. The association of adverse events with MPA trough level obtained by PETINIA was analyzed. Results PETINIA revealed a good agreement with the LC-MS; Regression analysis gave an equation of y = 1.27x − 0.12 (r2 = 0.975, p < 0.001). PETINIA showed a systemic positive bias with a mean difference of 0.66 mg/L compared to LC-MS. However, the magnitude of the positive bias decreased to 0.44 mg/L within the therapeutic range of MPA. Multiple logistic regression showed that MPA trough level determined by PETINIA was an independent risk factor for adverse events (odds ratio 2.28, 95% CI 1.25–4.16, p = 0.007). MPA trough level predicted adverse events with a sensitivity of 77.8% and a specificity of 86.7% using a cut-off level of 5.25 mg/L. Conclusions Good correlation between the two methods indicates that PETINIA is an acceptable method for the monitoring of MPA therapeutic levels. Furthermore, MPA trough level obtained by PETINIA is a useful monitoring tool to minimize toxicity in KTRs.

Two Cases of Bacteremia Due to Roseomonas mucosa

Roseomonas is a genus of pink-pigmented nonfermentative bacilli. These slow-growing, gram-negative cocobacilli form pink-colored colonies on sheep blood agar. They differ from other pink-pigmented nonfermenters, including Methylobacterium, in morphology, biochemical characteristics, and DNA sequence. Roseomonas strains are rarely isolated in clinical laboratories; therefore, we report two cases in order to improve our ability to identify these pathogens. We isolated two strains of Roseomonas mucosa from the venous blood cultures of two patients, an 84-yr-old woman with common bile duct obstruction and a 17-yr-old male with acute myeloid leukemia who had an indwelling central-venous catheter for chemotherapy. The isolated strains were confirmed as R. mucosa by 16S rRNA sequencing.

Molecular epidemiology and antimicrobial susceptibility of Clostridium difficile isolates from two Korean hospitals

Clostridium difficile is one of the main etiological agents causing antibiotic-associated diarrhea. This study investigated the genetic diversity of 70 toxigenic C. difficile isolates from two Korean hospitals by employing toxinotyping, ribotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Toxin gene amplification resulted in 68 A⁺B⁺ and two A-B+ isolates. Most isolates (95.7–100%) were susceptible to daptomycin, metronidazole, and vancomycin. Seventy C. difficile isolates were classified into five toxinotypes, 19 ribotypes, 16 sequence types (STs), and 33 arbitrary pulsotypes. All C. difficile isolates of ribotype 018 (n = 38) were classified into ST17, which was the most prevalent ST in both hospitals. However, C. difficile isolates of ST17 (ribotype 018) exhibited pulsotypes that differed by hospital. ST2 (ribotype 014/020), 8 (ribotypes 002), 17 (ribotype 018), and 35 (ribotypes 015) were detected in both hospitals, whereas other STs were unique to each hospital. Statistical comparison of the different typing methods revealed that ribotyping and PFGE were highly predictive of STs. In conclusion, our epidemiological study indicates that C. difficile infections in both hospitals are associated with the persistence of endemic clones coupled with the emergence of many unique clones. A combination of MLST with PFGE or ribotyping could be useful for monitoring epidemic C. difficile strains and the emergence of new clones in hospitals.

Spontaneous tumour lysis syndrome in cervical cancer

Tumor lysis syndrome (TLS) is caused by massive lysis of tumour cells with rapid release of cellular material rich in potassium, phosphorus, nucleic acid, and cytokines into the bloodstream. Thus, it results in metabolic derangements including hyperkalaemia, hyperphosphatemia, hyperuricaemia, and hypocalcaemia, requiring urgent recognition and management. TLS is primarily observed in haematologic malignancies with high proliferative rates including Burkitt lymphoma and acute lymphoblastic leukaemia, however, recent reports have been described a few cases of TLS in various solid tumours (Baeksgaard and Sorensen 2003; Vodopivec et al. 2012). To-date, only one case with TLS in cervical cancer has been reported (Weed et al. 2003). Here, we present a case of spontaneous TLS in patient with cervical cancer.