Hi Jeong Kwon

Methylation of p16INK4A and p57KIP2 are involved in the development and progression of gastric MALT lymphomas

p16INK4A and p57KIP2 are inhibitors of cyclin-dependent kinases and their inactivation by methylation has been reported as a major tumorigenic mechanism in tumors. To examine whether methylation of p16INK4A and p57KIP2 is involved in the development and progression of gastric MALT lymphomas, 24 gastric low-grade lymphomas of MALT, 11 diffuse large B-cell lymphomas, and 10 each case of gastric lymphoid follicles with and without Helicobacter pylori infection were studied. H. pylori infection was positive in 85.7% of the gastric lymphomas. In the gastric lymphoid follicles positive for H. pylori, methylation of p16INK4A was detected in 10% of cases, while methylation of p57KIP2 was not detected. In low-grade MALT lymphomas, p16INK4A and p57KIP2 were methylated in 41.7 and 29.2% of the cases, respectively. In diffuse large B-cell lymphomas, methylation of p16INK4A and p57KIP2 was found in 72.7 and 36.4% of the cases, respectively. All but one case with p16INK4A and p57KIP2 methylation was H. pylori positive and most of them were stage I. Our results indicate that methylation of p16INK4A followed by p57KIP2 methylation involves during the tumorigenesis of gastric MALT lymphomas associated with H. pylori infection. As methylation of these two genes was more frequent in the higher grade (P<0.05), it may contribute to the malignant progression of gastric MALT lymphomas.

Automated Heart-Type Fatty Acid–Binding Protein Assay for the Early Diagnosis of Acute Myocardial Infarction

We compared an automated quantitative heart-type fatty acid-binding protein (H-FABP) assay with other cardiac-marker assays to examine its usefulness as an early diagnostic marker of acute myocardial infarction (AMI). Serum samples for cardiac troponin T (cTnT), creatine kinase-MB isozyme (CK-MB), myoglobin, and H-FABP were obtained from 64 patients with AMI and 53 patients with other conditions (control group). H-FABP was measured by using 2 immunoassays, the H-FABP enzyme-linked immunosorbent assay (ELISA; Biocheck, Foster City, CA) and the H-FABP latex turbidimetric immunoassay (LTIA; HBI, Anyang, Korea). Sensitivities of assays for cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and electrocardiogram (ECG) for the diagnosis of AMI at hospital admission were 39.1%, 59.4%, 64.1%, 68.7%, 70.3%, and 54.7%, respectively. Specificities of cTnT, CK-MB, myoglobin, H-FABP (by ELISA), H-FABP (by LTIA), and ECG were 98.1%, 71.7%, 81.1%, 77.4%, 90.6%, and 92.5%, respectively. The automated H-FABP (by LTIA) is superior to cTnT, CK-MB, myoglobin, and H-FABP (by ELISA) tests for the diagnosis of AMI in patients admitted within 4 hours from the onset of chest pain.

Comparison of quantitative results among two automated Rapid Plasma Reagin (RPR) assays and a manual RPR test

BACKGROUND We compared two automated Rapid Plasma Reagin (RPR) assay kits with a manual RPR assay kit to evaluate the possibility of using the two automated RPR assays as an alternative to the manual RPR assay for a quantitative monitoring. METHODS One hundred eighty-five samples were analyzed, including 16 sera from patients with primary, secondary, and latent syphilis. Measured RPR unit (R.U.) values of two automated RPR assay kits, Mediace RPR (Sekisui Chemical Co., Ltd, Japan) and HBi Auto RPR (HBI Co., Ltd, Korea), were compared with the RPR titers of Macro-Vue RPR card test (Becton Dickinson BD Microbiology systems, USA). As a confirmatory test, Anti-Treponema pallidum EUROLINE WB (IgG) and Anti-Treponema pallidum EUROLINE WB (IgM) (Euroimmun, Germany) were used. RESULTS There was a prozone effect with Mediace RPR at RPR titer (card test) of 1:16, but not with HBi Auto RPR. The R.U. values of the two automated RPR assays did not show proportional increase to the RPR titer. Agreement between manual RPR and two automated RPR assay kits, Mediace RPR assay and HBi Auto RPR assay, were 83.8% and 83.2%, respectively. CONCLUSIONS The two automated RPR assay kits could not be used as an alternative to manual RPR test for quantitative analysis of RPR titer. As Mediace RPR shows a prozone effect at relatively low RPR titer, caution is needed in the interpretation of the measured values.

Nasal Angiocentric Lymphoma With Hemophagocytic Syndrome

Objectives Hemophagocytic syndrome(HS) is a fatal complication of nasal angiocentric lymphoma (AL) and difficult to distinguish from malignant histiocyosis. Epstein-Barr virus(EBV)-associated HS is frequently observed in lymphoma of T-cell lineage and EBV is highly associated with nasal AL. Clinicopathologic features of 10 nasal ALs with HS were reviewed to determine the clinical significance and the pathogenetic association with EBV. Methods Ten patients of HS were identified from a retrospective analysis of 42 nasal ALs diagnosed from 1987 to 1996. Immunohistochemical study and in situ hybridization were performed on the paraffin-embedded tumor specimens obtained from 10 patients. Serologic study of EBV-Ab was performed in 3 available patients. Results Five patients had HS as initial manifestation, 3 at the time of relapse and 2 during the clinical remission of AL. Four patients were treated by combination chemotherapy (CHOP) and others had only supportive care. The median survival of all patients with HS was 4.1 months (range 2 days–36.5 months) and all had fatal outcome regardless of the treatment-modality. AH cases were positive for UCHL1 (CD45RO) and EBV by EBER in situ hybridization. The data of serologic tests indicated the active EBV infection. Conclusions HS is a fatal complication of nasal AL and has a high association with EBV. Reactivation of EBV may contribute to HS and further investigation of predictive factors and effective treatment of HS should be pursued in the future.

The Comparison of Parathyroid Hormone Degradation Effect by Various Protease Inhibitors in Blood Specimen

BACKGROUND The objective of this study was to evaluate the role of proteases on the degradation of parathyroid hormone (PTH) in blood samples. METHODS Protease inhibitors with specificity against serine proteases (aprotinin), cysteine proteases (E-64), serine and cysteine proteases (leupeptin), metalloproteases (EDTA), or a protease inhibitor cocktail with a broad spectrum of inhibitory activity were added to blood samples. After storage at room temperature (0-48 hr), PTH levels were measured. RESULTS PTH levels in samples with the protease inhibitor cocktail did not change significantly after 48 hr of storage at room temperature, but the average PTH levels decreased by 40.7% and 20.1%, in samples stored at room temperature and stored at 4 degrees C without protease inhibitors, respectively. PTH levels in samples with leupeptin were stable for up to 24 hr. After 48 hr, the mean PTH levels decreased by 17.1%, 16.0%, 26.2%, and 32.1%, with 500 KIU/mL aprotinin, 100 micromol/L leupeptin, 10 micromol/L E-64, and 10 micromol/L EDTA, respectively, in the samples stored at room temperature. CONCLUSIONS The decrease in PTH levels in blood samples seemed to be due to the degradation of PTH by proteases. Various proteases, including especially serine proteases, would act together to degrade PTH in blood specimen. The PTH degradation may be inhibited in blood specimen with protease inhibitor cocktail.

Usefulness of biological variation in the establishment of delta check limits.

BACKGROUND Biological variation is used in the calculation of reference change values (RCVs) for a delta check. In this study, we examined the correlation between intra-individual biological coefficients of variation (CVI) and delta check limits according to population distribution. METHODS A total of 1,533,359 paired test results of nine routine chemistry tests were used to make the population distributions of delta percent changes. Their 0.5th, 2.5th, 97.5th, and 99.5th percentiles were then used for delta check limits. RESULTS A large difference was observed between the chemistry tests in the percentage exceeding the delta check limits according to the RCVs. The mean percentage of test results of each test item exceeding the delta check limits of RCV95% ranged from 12.3% to 40.6%. Delta percent changes of protein, albumin, sodium (Na), potassium (K) and chloride (Cl) showed a symmetric distribution. However, an asymmetric distribution was observed in the delta percent changes of glucose, aspartate transaminase (AST), alanine aminotransferase (ALT) and creatinine. A good correlation was observed between CVI and the delta check limits according to population distribution and a closer correlation was observed when using the test items with CVI of <5.0%. CONCLUSIONS Intra-individual biological coefficients of variation (CVI) would be useful for the establishment of delta check limits.

Automated screening for tuberculosis by multiparametric analysis of data obtained during routine complete blood count

The main goal of this study was to develop a multiparametric cell population data (CPD) model that combines information from several morphologic parameters generated by DxH800, in addition to the traditional parameters regularly reported in the CBC‐diff, and to test the performance of this model in screening the general population for primary tuberculosis (TB).

Evaluation of a novel point-of-care test kit, ABSOGEN PCT, in semi-quantitative measurement of procalcitonin in whole blood.

In response to inflammation, procalcitonin plasma concentrations increase more rapidly than other acute‐phase reactants and higher values are associated with severe disease. Procalcitonin measurements assist in determining whether antibiotic therapy should be used. point‐of‐care testing (POCT) is performed for early decision making about additional testing or therapy. The ABSOGEN™ PCT (Bumyoungbio, Inc., Suwon, Korea) is a rapid novel semi‐quantitative immunochromatographic PCT assay that analyses whole blood samples. We compared the patient quantitative test results to ABSOGEN™ PCT test results.

Intactness of Medical Nonsterile Gloves on Use of Alcohol Disinfectants

Dear Editor, Phlebotomists wear gloves for their own protection and for patient safety; they wash hands (or apply alcohol disinfectants when pressed for time) and change gloves between patients [13]. Blood collection is delayed when gloves are changed after washing and drying hands. Moreover, latex glove disposal might increase environmental pollution. Cleansing gloved hands to prolong the use of gloves results in considerable savings of disposable examination gloves. However, the current regulation prohibits alcohol disinfection when gloves are worn, because of the concern that sanitary intactness of gloves may be compromised by alcohol; it also prohibits examination gloves to be reprocessed because of their composition, thinness, and inelasticity [1]. We evaluated the intactness of 50 medical nonsterile gloves after using alcohol disinfectants, by testing five pairs of gloves from different brands: four brands of powder-free non-sterile latex medical examination gloves and one brand of nitrile gloves. Latex glove of brands Top glove (Top Glove, Klang, Malaysia) and HandyCare (Latexx Manufacturing, Kamunting, Malaysia) were sanitized with 62% ethanol Clesis hand sanitizer gel (Liebecos, Cheonan, Korea), and Dowoo (Siam Sempermed Corp., Bangkok, Thailand) brand, with 62% ethanol 3M Hand Instant Sanitizer (3M Korea, Seoul, Korea). Gloves were sanitized by rubbing and drying the gloves 30 times. DERMAGRIP Nitrile extended cuff examination gloves (WRP Asian Pacific, Sepang, Malaysia) were sanitized in the same way, using 62% ethanol 3M Hand Instant Sanitizer. After sanitation, the gloves were filled with water and checked for leakage. All the gloves were intact after the sanitization procedure. Latex gloves of the brand Maxter (Maxter Glove Manufacturing, Klang, Malaysia) were still intact after performing the rub-and-dry action 100 times with 83% ethanol skin cleaner, New Clean Swab A (Meditop, Yongin, Korea). The distribution of major contaminated regions on the hands of phlebotomists was studied to check for decontamination after venipuncture. Fig. 1 shows the contact points of the five phlebotomists’ hands with the forearm of the patient. Bacterial suspensions of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii were prepared to match 0.5 McFarland turbidity standards. Glass slides were smeared with each inoculum and dried for 30 minutes at room temperature. Gloved fingertips were placed on the smeared surface for 1 minute; then, they were pressed onto blood agar plate, and the plate was incubated at 35°C for 18 hours to allow for bacterial growth. Subsequently, we rubbed the gloved fingertips with alcohol disinfectant and dried them; the