Investigation of Biomarkers Associated with Low Platelet Counts in Normal Karyotype Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) patients are at risk of bleeding due to disease-related lack of platelets and systemic coagulopathy. Platelets play a role in hemostasis. Leukemic blasts have been shown to alter platelet activation in vitro. Here we investigated biomarkers associated with thrombocytopenia in normal karyotype AML (NK-AML). From The Cancer Genome Atlas database, case-control study was performed between normal karyotype (NK) platelet-decreased AML (PD-AML, platelet count < 100 × 109/L, n = 24) and NK platelet-not-decreased AML (PND-AML, with platelet count ≥ 100 × 109/L, n = 13). Differentially expressed gene analysis, pathway analysis and modelling for predicting platelet decrease in AML were performed. DEG analysis and pathway analysis revealed 157 genes and eight pathways specific for PD-AML, respectively. Most of the eight pathways were significantly involved in G-protein-coupled receptor-related pathway, cytokine-related pathway, and bone remodeling pathway. Among the key genes involved in at least one pathway, three genes including CSF1R, TNFSF15 and CLEC10A were selected as promising biomarkers for predicting PD-AML (0.847 of AUC in support vector machine model). This is the first study that identified biomarkers using RNA expression data analysis and could help understand the pathophysiology in AML with low platelet count.

Cyclic Neutropenia From a Novel Mutation Ala57Asp of ELANE: Phenotypic Variability in Neutropenia From Mutated Ala57 Residue.

ELANE-related neutropenia includes severe congenital neutropenia and cyclic neutropenia. Both are clinically characterized by recurrent fever, skin and oropharyngeal inflammation. We report a novel mutation in ELANE in a 20-year-old man with a history of self-limiting febrile episodes and neutropenia with a cyclic pattern since 7 years of age. Direct sequencing analysis of ELANE revealed he was heterozygous for a novel missense mutation (p.Ala57Asp). The Ala57 residue is a mutation hotspot, and all previously reported missense mutations (Ala57Ser/Thr/Val) were observed in severe congenital neutropenia cases. Thus, the present case demonstrates a phenotypic variability in ELANE-related neutropenia from mutated Ala57.

Population pharmacokinetics of intravenous sufentanil in critically ill patients supported with extracorporeal membrane oxygenation therapy.

BACKGROUND: Sufentanil is commonly used for analgesia and sedation during extracorporeal membrane oxygenation (ECMO). Both ECMO and the pathophysiological changes derived from critical illness have significant effects on the pharmacokinetics (PK) of drugs, yet reports of ECMO and sufentanil PK are scarce. Here, we aimed to develop a population PK model of sufentanil in ECMO patients and to suggest dosing recommendations. METHODS: This prospective cohort PK study included 20 patients who received sufentanil during venoarterial ECMO (VA-ECMO). Blood samples were collected for 96 h during infusion and 72 h after cessation of sufentanil. A population PK model was developed using nonlinear mixed effects modelling. Monte Carlo simulations were performed using the final PK parameters with two typical doses. RESULTS: A two-compartment model best described the PK of sufentanil. In our final model, increased volume of distribution and decreased values for clearance were reported compared with previous PK data from non-ECMO patients. Covariate analysis showed that body temperature and total plasma protein level correlated positively with systemic clearance (CL) and peripheral volume of distribution (V2), respectively, and improved the model. The parameter estimates of the final model were as follows: CL = 37.8 × EXP (0.207 × (temperature - 36.9)) L h-1, central volume of distribution (V1) = 229 L, V2 = 1640 × (total plasma protein/4.5)2.46 L, and intercompartmental clearance (Q) = 41 L h-1. Based on Monte Carlo simulation results, an infusion of 17.5 µg h-1 seems to reach target sufentanil concentration (0.3-0.6 µg L-1) in most ECMO patients except hypothermic patients (33 °C). In hypothermic patients, over-sedation, which could induce respiratory depression, needs to be monitored especially when their total plasma protein level is low. CONCLUSIONS: This is the first report on a population PK model of sufentanil in ECMO patients. Our results suggest that close monitoring of the body temperature and total plasma protein level is crucial in ECMO patients who receive sufentanil to provide effective analgesia and sedation and promote recovery. TRIAL REGISTRATION: Clinicaltrials.gov NCT02581280 , December 1st, 2014.

Pharmacokinetics of a nanocrystal-containing megestrol acetate formulation: a single-dose, randomized, open-label, 2-part, 2-period crossover study in healthy Korean subjects.

UNLABELLED: OBJECTIVE: The conventional suspension of megestrol acetate contains micronized megestrol acetate, which was recently discovered to have a disadvantage of decreasing bioavailability when taken in a fasting state. Since megestrol acetate is taken to increase appetite, this property becomes a discouraging factor. To improve upon this, an advanced formulation was developed using a nanocrystal drug-delivery system. This study was conducted to compare the safety and pharmacokinetic characteristics between the conventional formulation of megestrol acetate and a generic version of the advanced formulation containing nanocrystals. METHODS: This was a randomized, open-label, 2-period, 2-treatment, crossover, single-dose, 2-part study (part 1 fasting and part 2 fed), conducted in healthy males aged between 20 and 50 years with weight within ± 20% of ideal body weight having no congenital abnormalities or chronic diseases. Different subjects were used in part 1 and part 2, but subjects received a single dose of the reference and test drugs separated by a 14-day washout period. Blood sampling was performed up to 120 hours after dosing using a pre-specified sampling time scheme. Primary pharmacokinetic parameters were C_max and AUC_last of the test and reference formulations of megestrol acetate. Bioequivalence evaluation was based on the standard criterion of 80 - 125% for the 90% confidence interval of geometric mean ratios of test to reference drugs calculated for the pharmacokinetic parameters. To monitor adverse events, both subject interviews and physical examinations were done on a regular time basis. RESULTS: 80 subjects (n = 40 each part) were enrolled, and 79 completed the study. The 90% CIs of the geometric mean ratios of C_max and AUC_last were 4.4625 - 5.6018 and 1.3602 - 1.6418, respectively, for part 1, and 0.9793 - 1.1327 and 0.7721 - 0.8431, respectively, for part 2. No significant difference was discovered in the incidence of adverse events (AEs) when test and reference treated groups were compared. CONCLUSIONS: Our findings suggest that the test formulation of megestrol-acetate-containing nanocrystals is better absorbed and has higher bioavailability compared to the reference formulation in a fasting state. This should allow for a lower dose and better patient compliance.

ClinicalTrials.gov identifier: NCT02446353.

The regulation of 2,3-butanediol synthesis in Klebsiella pneumoniae as revealed by gene over-expressions and metabolic flux analysis.

A variety of microorganism species are able naturally to produce 2,3-butanediol (2,3-BDO), although only a few of them are suitable for consideration as having potential for mass production purposes. Klebsiella pneumoniae (K. pneumoniae) is one such strain which has been widely studied and used industrially to produce 2,3-BDO. In the central carbon metabolism of K. pneumoniae, the 2,3-BDO synthesis pathway is dominated by three essential enzymes, namely acetolactate decarboxylase, acetolactate synthase, and butanediol dehydrogenase, which are encoded by the budA, budB, and budC genes, respectively. The mechanisms of the three enzymes have been characterized with regard to their function and roles in 2,3-BDO synthesis and cell growth (Blomqvist et al. in J Bacteriol 175(5):1392-1404, 1993), while a few studies have focused on the cooperative mechanisms of the three enzymes and their mutual interactions. Therefore, the K. pneumoniae KCTC2242::ΔwabG wild-type strain was utilized to reconstruct seven new mutants by single, double, and triple overexpression of the three enzymes key to this study. Subsequently, continuous cultures were performed to obtain steady-state metabolism in the organisms and experimental data were analyzed by metabolic flux analysis (MFA) to determine the regulation mechanisms. The MFA results showed that the seven overexpressed mutants all exhibited enhanced 2,3-BDO production, and the strain overexpressing the budBA gene produced the highest yield. While the enzyme encoded by the budA gene produced branched-chain amino acids which were favorable for cell growth, the budB gene enzyme rapidly enhanced the conversion of acetolactate to acetoin in an oxygen-dependent manner, and the budC gene enzyme catalyzed the reversible conversion of acetoin to 2,3-BDO and regulated the intracellular NAD(+)/NADH balance.

Evaluation of YD MolecuTech Real HPV Assay in Comparison with Roche Cobas HPV Assay and BD Onclarity HPV Assay for Detection of HPV Infection.

OBJECTIVE: Human papillomavirus (HPV) is a double-stranded DNA virus that belongs to the papillomavirus family. High-risk (HR) genotypes of HPV are associated with cervical cancer. The combination of molecular HPV testing and cytology results in an increased detection of high-grade cervical lesions. This study compares the performance of a newly developed MolecuTech Real HPV 16/18/HR assay to that of the cobas HPV assay and Onclarity HPV Assay in Korea. METHODS: A SurePath liquid-based cytology device (BD diagnostics, NC, USA) was used to prospectively collect cervical swab specimens. Onclarity HPV Assay (Onclarity; BD diagnostics), Cobas 4800 HPV Test (Cobas; Roche, Rotkreuz, Switzerland), and MolecuTech Real HPV 16/18/HR (MolecuTech; YD, Yongin, Korea) were performed to detect HPV genotypes. RESULTS: Of the 438 cervical specimens, 13.7% showed the HR-HPV genotype. The concordance rates between Onclarity and MolecuTech, cobas and MolecuTech, and Onclarity and Cobas were 94.9% (kappa=0.754), 95.7% (kappa=0.768), and 95.5% (kappa=0.791), respectively. Moreover, no statistically significant differences in HPV genotyping results were observed in the cytology-positive specimens. CONCLUSIONS: The MolecuTech Real HPV 16/18/HR assay showed good agreement in the detection of HR HPV genotypes, and similar analytical performance for the detection of HR HPV genotypes in samples with abnormal cytological findings.

KIT D816 mutation associates with adverse outcomes in core binding factor acute myeloid leukemia, especially in the subgroup with RUNX1/RUNX1T1 rearrangement.

Core binding factor (CBF)-positive acute myeloid leukemia (AML) presents a favorable prognosis, except for patients with KIT mutation, especially D816 mutation. The current retrospective study attempted to validate a prognostic role of KIT mutation in 121 Korean patients with CBF AML. The study patients consisted of 121 patients with CBF AML (82 patients with RUNX1/RUNX1T1 [67.8 %] and 39 patients with CBFB/MYH11 [32.2 %]) recruited from eight institutions in Korea. All patients received idarubicin plus cytarabine or behenoyl cytosine arabinoside 3 + 7 induction chemotherapy. The KIT gene mutation status was determined by direct sequencing analyses. A KIT mutation was detected in 32 cases (26.4 %) in our series of patients. The KIT mutation was most frequent in exon 17 (n = 18, 14.9 %; n = 16 with D816 mutation), followed by exon 8 (n = 10, 8.3 %). The presence of KIT D816 mutation was associated with adverse outcomes for the event-free survival (p = 0.03) and for the overall survival (p = 0.02). The unfavorable impact of D816 mutation was more prominent when the analysis was confined to the RUNX1/RUNX1T1 subtype. The KIT mutation was detected in 26.4 % of Korean patients with CBF AML. The KIT D816 mutation demonstrated an unfavorable prognostic implication, particularly in the RUNX1/RUNX1T1 subtype.

Effect of pH on the metabolic flux of Klebsiella oxytoca producing 2,3-butanediol in continuous cultures at different dilution rates.

The efficiency of the bioconversion process and the achievable end-product concentration decides the economic feasibility of microbial 2,3-butanediol (2,3-BDO) production. In 2,3-BDO production, optimization of culture condition is required for cell growth and metabolism. Also, the pH is an important factor that influences microbial performance. For different microorganisms and substrates, it has been shown that the distribution of the metabolites in 2,3-BDO fermentation is greatly affected by pH, and the optimum pH for 2,3-BDO production seems dependently linked to the particular strain and the substrate employed. Quantification analysis of intracellular metabolites and metabolic flux analysis (MFA) were used to investigate the effect of pH on the Klebsiella oxytoca producing 2,3-BDO and other organic acids. The main objectives of MFA are the estimation of intracellular metabolic fluxes and the identification of rate-limiting step and the key enzymes. This study was conducted under continuous aerobic conditions at different dilution rates (0.1, 0.2, and 0.3 h(-1)) and different pH values (pH 5.5 and 7.0) for the steady-state experimental data. In order to obtain the flux distribution, the extracellular specific rates were calculated from the experimental data using the metabolic network model of K. oxytoca. Intracellular metabolite concentration profiles were generated using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

Change in prostaglandin expression levels and synthesizing activities in dry eye disease.

OBJECTIVE: To investigate the expression level of prostaglandins (PGs) and their de novo synthesis in dry eye (DE) disease. DESIGN: Cross-sectional case-control study and in vivo mouse experimental study. PARTICIPANTS: Forty-six eyes from 23 DE patients and 33 eyes from 17 age- and sex-matched controls were studied. Also, DE-induced murine eyes were compared with control eyes. METHODS: Patients completed a symptom questionnaire using a 100-mm visual analog scale (VAS). Nano-liquid chromatography tandem mass spectrometry was used for the quantification of PGE2 and PGD2. A DE disease environmental chamber was used to induce DE in mice. One week after induction, enzyme expressions of cyclooxygenase-1, cyclooxygenase-2 (COX-2), PG E synthase (PGES), and PG D synthase (PGDS) in the lacrimal glands, meibomian glands, and corneas were examined using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). MAIN OUTCOME MEASURES: The mean PGE2 and PGD2 levels in the tears of DE patients were measured and compared with symptom severity scores. Immunohistochemistry staining patterns and qRT-PCR data of DE mice were quantified. RESULTS: The mean PGE2 level in the tears of DE patients (2.72 ±3 .42 ng/ml) was significantly higher than that in the control group (0.88 ± 0.83 ng/ml; P = 0.003). However, the mean PGD2 level in the tears of DE patients (0.11 ± 0.22 ng/ml) was significantly lower (0.91 ± 3.28 ng/ml; P = 0.028). The mean PGE2-to-PGD2 ratio correlated strongly with VAS scoring (P = 0.008). In DE mice, COX-2 mRNA was significantly higher in ocular surface tissue and lacrimal glands. Furthermore, PGES mRNA was significantly higher in ocular surface tissue, whereas PGDS mRNA was decreased. Immunohistochemistry staining showed elevated COX-2 expression in the lacrimal glands, meibomian glands, corneas, and conjunctivas. Furthermore, PGES expression was found in periductal infiltrated cells of the lacrimal glands and conjunctival epithelium. Also, PGDS expression was decreased in meibomian glands and increased focally in the conjunctival epithelium. CONCLUSIONS: A reciprocal change in PGE2 and PGD2 levels was found in the tears of DE patients, which correlated with patients' symptom scores. These clinical results were supported by increased COX-2 and PGES expression levels found in tear-producing tissues of DE mice.

Prevalence and clinical significance of occult hepatitis B virus infection among renal transplant recipients in Korea.

BACKGROUND: Occult hepatitis B infection (OBI) is the presence of hepatitis B virus (HBV) DNA in serum or hepatic tissue without detectable hepatitis B surface antigen (HBsAg) in serum. Kidney disease patients in the post-renal transplantation period are in a specific situation as a result of the high pre-transplantational risk of HBV infection and post-transplantational immunosuppression. We studied the pre-transplantational prevalence and post-transplantational influence of OBI on kidney transplantation patients. METHODS: We investigated pre-transplantational serum samples of 217 HBsAg-negative patients of post-renal transplant status for the presence of HBV DNA by real-time quantitative polymerase chain reaction. Serologic markers for HBV and hepatitis C virus (HCV) infection as well as liver enzymes were analyzed. RESULTS: We detected HBV DNA in 2.3% (5/217) of HBsAg-negative patients, and the median HBV DNA titer was 33.15 copies/ml (range 30.6-144.6 copies/ml). Among the 5 OBI patients, 2 had hepatitis B surface antibodies (anti-HBs) and 1 had hepatitis B core antibodies (anti-HBc IgG). None of the patients with OBI were co-infected with HCV. There was no evidence of reactivation of OBI during the 36-month (range 27-63 months) follow-up monitoring period after transplantation, in spite of immune suppression to prevent rejection. CONCLUSIONS: The prevalence of occult HBV in the setting of renal transplantation was higher than that in the general population of Korea, and no reactivation of hepatitis B was observed in patients with OBI in the post-renal transplantation period.

Genetic polymorphisms associated with 5-Fluorouracil-induced neurotoxicity.

BACKGROUND: Encephalopathy is a rare drug toxicity of fluorouracil therapy. Toxicity from fluorouracil therapy is known to be associated with the individual genetic background of the enzymes, thymidylate synthase and dihydropyrimidine dehydrogenase. METHODS: Two patients with advanced gastric cancer and metastatic pancreatic cancer who received 5-fluorouracil-based chemotherapy presented with acute mental change and hyperammonemia. To evaluate the genetic background of the fluorouracil-associated hyperammonemic encephalopathy, analysis of the polymorphisms of the TYMS, DPYD and MTHFR genes was performed. RESULTS: The patients revealed to be TYMS suppressors showing homogenous deletion of 6 bp in the 3'-UTR and 3RC/3RC genotype in the promoter enhancer region (TSER), respectively. CONCLUSION: Genetic polymorphisms of the TYMS gene would contribute to the 5-fluorouracil-associated hyperammonemic encephalopathy. The prospective validation of the clinical implication of TYMS gene polymorphisms is warranted.

Congenital zinc deficiency from mutations of the SLC39A4 gene as the genetic background of acrodermatitis enteropathica.

Acrodermatitis enteropathica (AE) is an autosomal recessive disorder with the clinical triad of acral dermatitis, diarrhea and alopecia. AE is known to be caused by mutations of the SLC39A4 gene on the chromosome band 8q24.3, encoding the zinc transporter in human. An 8-month-old Korean boy presented with eczematous changes on the inguinal area and knees and was diagnosed with AE. Blood tests revealed a markedly decreased level of plasma zinc, and his symptoms improved on oral zinc replacement. To confirm the diagnosis of AE from congenital zinc deficiency, direct sequencing analysis of SLC39A4 was performed and revealed that he was compound heterozygous for a known missense mutation (Arg95Cys) and a novel splicing mutation in the donor site of intron 7 (c.1287+2T>C). Family study showed that his parents were heterozygous carriers of the mutations. To the best of our knowledge, this is the first report of genetically confirmed AE in Korea.

Myelodysplastic Syndrome/Myeloproliferative Neoplasm with Ring Sideroblasts and Thrombocytosis with Cooccurrent SF3B1 and MPL Gene Mutations: A Case Report and Brief Review of the Literature.

BACKGROUND: Myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a new disease entity in the current WHO classification. Genetically, 60%-90% of cases have mutations in SF3B1, strongly associated with RS, and more than half of them cooccur with JAK2 V617F. This report describes the rare case of MDS/MPN-RS-T with SF3B1 mutation cooccurring with an MPL mutation. METHODS: We report a 79-year-old man who was referred because of generalized edema. Peripheral blood testing showed macrocytic anemia and thrombocytosis, and bone marrow analysis demonstrated dyserythropoiesis with RS and increased megakaryocytes. A molecular study was performed to detect SF3B1 mutations and recurrent mutations in MPN disease (JAK2 V617F/exon 12, CALR gene exon 9, and MPL gene exon 10 mutations). RESULTS: The molecular study revealed SF3B1 K666T and MPL W515R mutations, while BCR-ABL1 or JAK2 V617F/exon 12 and CALR mutations were all negative. CONCLUSION: This is a rare case of concomitant SF3B1 and MPL mutations in MDS/MPN-RS-T.

Congenital factor V deficiency from compound heterozygous mutations with a novel variant c.2426del (p.Pro809Hisfs*2) in the F5 gene: A case report.

INTRODUCTION: Congenital factor V deficiency (FVD) is a rare bleeding disorder characterized by low or undetectable plasma factor V (FV) levels leading to mild to severe bleeding symptoms. Currently, more than 100 mutations have been reported in F5. We herein report a patient with FVD from mutations in the F5 gene. PATIENT CONCERNS: A 52-year-old man with prolonged prothrombin time and activated partial thromboplastin time corrected by mixing test on preoperative screening. His past medical or family history was not remarkable. DIAGNOSIS: Factor assays revealed a markedly reduced FV activity at 7%. Other factors were not decreased. DNA sequencing analysis to detect F5 gene mutations showed the patient was compound heterozygous for c.286G>C (p.Asp96His) and c.2426del (p.Pro809Hisfs*2). Asp96His was previously described missense mutation and Pro809Hisfs*2 was a novel deleterious mutation. INTERVENTIONS: Fresh-frozen plasma was administered to supplement FV before surgery. OUTCOMES: Subsequent factor assays revealed temporarily increased FV activity at 33%. CONCLUSION: As was the case in our patient, genotype-phenotype correlations are poor in FVD, and molecular genetic test is necessary to confirm the diagnosis.

Bone density measurement in interdental areas with simulated placement of orthodontic miniscrew implants.

INTRODUCTION: The purposes of this study were to determine bone density at various orthodontic implant sites and compare them according to depth and area (anterior and posterior, buccal and lingual, and maxilla and mandible). METHODS: Maxillofacial computed tomography scan data were obtained from 30 adults with normal occlusion. Bone density was recorded in Hounsfield units with simulated placement of miniscrews with the V-Implant program (CyberMed, Seoul, Korea). Bone density was measured to a depth of 6 mm at 1-mm intervals in 60 interdental areas (30 in the maxilla, 30 in the mandible), and mean bone density was calculated at each site. RESULTS: Bone density tended to decrease with increasing depth, particularly in the posterior area. Mean bone density showed a progressive increase from posterior to anterior except for the mandibular buccal side, which had no significant differences. A comparison of the mean bone densities between the buccal and lingual sides in the mandible showed that the lingual side had higher values in the anterior area and vice versa in the posterior area. On the other hand, there were no distinct differences between the buccal and lingual sides in the maxilla. A comparison of the mean bone densities between the maxilla and the mandible showed higher values in the mandible, and these differences were more significant on the buccal side of the posterior. CONCLUSIONS: The differences in bone densities according to depth and area should be considered when selecting and placing miniscrew implants for orthodontic anchorage.

Electrolyte Additive Enabling Conditioning-Free Electrolytes for Magnesium Batteries.

Most electrolytes for rechargeable Mg batteries require time-consuming conditioning or precycling process to achieve a fully reversible Mg deposition/dissolution, which hinders the normal operation of Mg batteries. This study details a simple and effective method for eliminating this conditioning behavior using heptamethyldisilazane (HpMS) as an electrolyte additive. It was found that the HpMS additive greatly increases the current density and Coulombic efficiency of Mg deposition/dissolution from the initial cycles in various sulfone and glyme solutions containing MgCl2 or Mg(TFSI)2. The beneficial effect of HpMS was ascribed to its ability to scavenge trace water in the electrolytes and remove Mg(OH)2 and Mg(TFSI)2-decomposition products from the Mg surface. Considering its applicability for a wide range of Mg electrolytes, the use of HpMS is expected to accelerate the development of practical Mg batteries.

Effects of Pioglitazone on Nonalcoholic Fatty Liver Disease in the Absence of Constitutive Androstane Receptor Expression.

Nonalcoholic fatty liver disease or steatohepatitis (NAFLD/NASH) is a fatty liver disease that is closely related to obesity, diabetes, and dyslipidemia. Pioglitazone, which was developed as an antidiabetic drug, is known to improve NALFD. Pioglitazone is metabolized by multiple cytochrome P450 (CYP) enzymes, which are regulated by the xenobiotic receptor constitutive androstane receptor (CAR). In this study, we investigated the effects of pioglitazone on NAFLD by absence of CAR activity under high-fat (HF)-fed conditions. CAR-/- mice showed significant improvement in NALFD after 12 weeks of pioglitazone treatment compared to wild-type mice. This improvement in NAFLD persisted in CAR-/- mice regardless of blood pioglitazone concentration. The expression of lipogenesis genes in the liver, sterol-regulatory element binding protein-1c (SREBP-1c), and stearoyl-CoA desaturase (SCD)-1 was decreased after pioglitazone treatment in HF-fed CAR-/- mice. In addition, the expression of peroxisome proliferator-activated receptor gamma 2 (PPARγ2) was decreased by pioglitazone in HF-fed CAR-/- mice. Changes in SREBP-1c and PPAR γ2 remained constant over short-term (6 h) pioglitazone and lipid injection. Our results showed that NAFLD was improved significantly by pioglitazone in a CAR deletion state. These results might be valuable because they suggest that interaction with CAR and pioglitazone/PPARγ2 may be important in regulating gene expression associated with NAFLD.

High frequency of JAK2 exon 12 mutations in Korean patients with polycythaemia vera: novel mutations and clinical significance.

Gain-of-function mutations in JAK2 are the molecular hallmarks of polycythaemia vera (PV), one of the myeloproliferative neoplasms. Most (∼95%) patients harbour V617F mutation in exon 15, while the rest have small insertion/deletion mutations in exon 12. We investigated JAK2 mutations in 42 Korean patients with PV. V617F was detected by sequencing and allele-specific PCR. When V617F was negative, sequencing and fragment length analyses were performed to detect exon 12 mutations. As a result, all patients had JAK2 mutations: 37 (88%) harboured V617F, and 5 (12%) had exon 12 mutations. Two patients had novel exon 12 mutations (H538_R541delinsLII and F537_K539delinsVL). Genotype-phenotype correlations demonstrated lower white blood cell and platelet counts in exon 12 mutations than V617F. The frequency of JAK2 exon 12 mutations was higher than expected in Korean patients with PV. Molecular genetic testing for JAK2 exon 12 mutations is mandatory for diagnosis and genotype-phenotype correlations in patients with erythrocytosis and suspected PV.

Detection of MYD88 L265P in patients with lymphoplasmacytic lymphoma/Waldenstrom macroglobulinemia and other B-cell non-Hodgkin lymphomas.

BACKGROUND: Recent studies have identified a high prevalence of the MYD88 L265P mutation in lymphoplasmacytic lymphoma (LPL)/Waldenstrom macroglobulinemia (WM) cases, whereas low frequencies have been observed in other B cell non-Hodgkin lymphomas (NHLs). METHODS: We evaluated the sensitivity of the mutant enrichment 3'-modified oligonucleotide (MEMO)-PCR technique, a new detection method. We examined the MYD88 L265P mutation in a series of Korean patients with LPL/WM and other B cell NHLs in bone marrow aspirates, using the MEMO-PCR technique. RESULTS: The sensitivity of MEMO-PCR was estimated to be approximately 10-16.7%. MYD88 L265P was detected in 21 of 28 LPL cases (75%) and only three of 69 B cell NHL cases (4.3%). CONCLUSION: Although MEMO-PCR had relatively low sensitivity, we confirmed the high prevalence of the MYD88 L265P mutation in Korean LPL patients. Our study suggests the diagnostic value of MYD88 L265P for differentiating B-cell NHLs.

How long should patients remain in the supine treatment position after intratympanic dexamethasone injection?

OBJECTIVES/HYPOTHESIS: Intratympanic dexamethasone injection (ITDI) is a widely accepted treatment for patients with sudden hearing loss. We investigated the appropriate patient wait time in the supine treatment position after ITDI. STUDY DESIGN: Prospective study. METHODS: In an in vivo animal study, 24 mice were injected intratympanically with dexamethasone. Perilymphatic fluid was sampled at 5, 10, 15, 20, 25, and 30 minutes postinjection. The dexamethasone concentration was analyzed using high-performance liquid chromatography. In a separate prospective clinical study, 79 patients with refractory sudden hearing loss underwent intratympanic injection. After the injection, patients remained in the supine position with the head rotated 45° to the unaffected side. Patients were divided into two groups according to the wait time in this treatment position postinjection: 30 minutes (n = 47) and 10 minutes (n = 32). Final hearing assessments were conducted 2 months after salvage treatment. RESULTS: In the in vivo animal study, the perilymphatic concentration of dexamethasone showed no significant increase after 10 minutes. In the clinical setting, hearing improvement according to Siegel's criteria was similar in the 30-minute (14/47) and 10-minute (10/32) groups (P = 0.999). No significant differences in relative hearing gain was observed between the two groups (13.80 ± 19.9 dB and 12.57 ± 14.9 dB, respectively; P = 0.766). CONCLUSION: We suggest that 10 minutes is a sufficient time to remain in the supine treatment position after ITDI in patients with sudden hearing loss. LEVEL OF EVIDENCE: N/A.