Control of tuberculosis is threatened by widespread emergence of drug resistance in Mycobacterium tuberculosis. Understanding the molecular basis of resistance might lead to development of novel rapid methods for diagnosing drug resistance. Rifampin is a key component among therapeutic regimens for the tuberculosis; therefore, patients who have drug resistance do not convalesce satisfactorily. The molecular mechanism of resistance to rifampin in M. tuberulosis has been elucidated. Substitutions of a limited number of highly conserved amino acids encoded by the rpoB gene are responsible for the ""single-step"" high-level resistance of M. tuberculosis to rifampin. Currently, two genotype-based protocols allow drug test from minimally grown cultured materials: (i)mutation identification by direct sequencing of PCR-amplified material. and (ii)mutation screening by PCR-SSCP. The purpose of this study is to evaluate the usefulness of the both methods. A sample of 75 isolates of M. tuberculosis was studied, and it inculded 36 rifampin-resistant strains and 39 rifampin-sensitive strains by conventional methods. Mutaions were identified in 36 rifampin-resistant isolates but in none of 39 sensitive isolates. All mutations were clustered within a region of 23 amino acids. Both methods allow detection of rifampin resistance in 2 to 3 days and will thus help in the early management of infection by M. tuberculosis.
Amino Acids ; Drug Resistance ; Humans ; Mass Screening ; Mycobacterium tuberculosis* ; Mycobacterium* ; Rifampin ; Tuberculosis

Control of tuberculosis is threatened by widesread emergence of drug resistant Mycobacterium tuberculosis. Rifampin is a key component among therapeutic regimens for the tuberculosis; therefore patients in whom resistance to this drug develop have a poor outlook, particularly if rifampin resistance is associated with resistance to other tuberculosis drugs. The purpose of this study was to detect the mutation in rpoB gene of rifampin resistant M. tuberculosis in Korea and to evaluate the usefulness of the method in clinical aspects. A sample of 80 M. tuberculosis was studied, and it included 40 rifampin resistance isolates and 40 rifampin sensitive isolates by conventional methods. The detection method involved the amplification by polymerase chain reaction (PCR) of the Rif' region and the identification of mutations by single-strand DNA conformation polymorphism analysis (SSCP) of the amplification products (157 bp). Mutation were identified in 39 of 40 rifampin resistant isolates, and in 1 of 40 rifampin sensitive isolates.
Humans ; Korea ; Mycobacterium tuberculosis* ; Mycobacterium* ; Nucleic Acid Conformation ; Polymerase Chain Reaction* ; Rifampin ; Tuberculosis

No abstract available.
Blood Platelets* ; Leukocytes* ; Plateletpheresis*

No abstract available.
Hepacivirus* ; Hepatitis C* ; Hepatitis* ; Liver Diseases* ; Liver* ; Prevalence*

No abstract available.
Antigens, Surface* ; Leukemia*

BACKGROUND: Telomerase has a leading role as a potential enzyme responsible for tumorigenesis and longevity. Telomerase is a ribonucleoprotein that synthesizes a specific repeating nucleotide sequence onto the ends of telomeres. This enzyme is normally present in immortalized cell lines, germ-line tissues, and tumor tissues. We intended to compare the telomerase activity among various types of leukemia to determine the association of telomerase activity and patients status and responsiveness of chemotherapy. METHODS: Specimens were collected from Jan. 1999 to Oct. 1999 and included the leukemic bone marrow (ALL, AML and CML) and the peripheral blood or bone marrow of normal persons or patients with iron deficiency anemia and immune thrombocytopenic purpura. Telomerase activity was measured by TRAP assay using Telomerase PCR ELISA kit. RESULTS: Telomerase activities were increased in acute leukemias and relapsed acute leukemia cases, whereas in the cases of complete remission state of acute leukemia, the activity was decreased. Telomerase activity was increased in leukemias which had high percentage of immature cells, especially more than 70% of blast. Also the activity was decreased in post-chemotherapeutic group, whereas increased in untreated group. There was no significant difference between prognosis of chromosomal abnormalities and telomerase activity. CONCLUSION: These results showed that telomerase activity was increased in acute phase of leukemia, high percentage of immature cells, and chemoresistant group of leukemia.
Anemia, Iron-Deficiency ; Base Sequence ; Bone Marrow ; Carcinogenesis ; Cell Line ; Chromosome Aberrations ; Drug Therapy ; Enzyme-Linked Immunosorbent Assay ; Humans ; Leukemia* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive* ; Longevity ; Polymerase Chain Reaction ; Prognosis ; Purpura, Thrombocytopenic, Idiopathic ; Ribonucleoproteins ; Telomerase* ; Telomere

OBJECTIVES: The purpose of this study was to suggest a proper method for the detection of heaptitis B surface antibody(anti-HBs) in a screening program for hepatitis B vaccination. METHODS: Sensivitity, specificity and predictive values were compared between Immunochromatographic assay (ICA) and passive hemagglutination(PHA) in 978 subjects(565 males, 413 females, 19-78 years ranging in age, mean 46.5 years old). EIA was used as a standard method for the detection of HBsAb. RESULTS: Sensitivity in the detection of anti-HBs of PHA and ICA was 88.7% and 94.9%, specificity was 94.3% and 96.6%, negative predictive value was 96.5% and 98.0%, and positive predictive value was 82.3% and 91.3%, respectively. False negative rate(11.3%) of PHA was higher than that(5.1%) of ICA. The higher the titer of anti-HBs in EIA was, the lower the false negative rate was. There was no false negative result in the cases with 101mIU/ml or more in EIA. CONCLUSION: We suggest that ICA should be the choice of screening method in the detection of anti-HBs in Hepatitis B vaccination program.
Female ; Hepatitis B* ; Hepatitis* ; Humans ; Immunochromatography ; Korea* ; Male ; Mass Screening ; Sensitivity and Specificity ; Vaccination*

BACKGROUND: P-glycoprotein (PGP) is capable of expelling cytotoxic drugs from cytosol and the overexpression mediates drug resistance. However not all resistant leukemic cells express PGP. High expression of glutathione S-transferasepie (GSTpie) is related to clinical outcome following chemotherapy. Topoisomerase IIalpha (topo IIalpha) is a major target of anthracyclines for the treatment of leukemia. METHODS: To evaluate the relation of PGP, GSTpie and topo IIalpha expression to treatment outcome, PGP, GSTpie and topo IIalpha expression were analysed by flow cytometry using mono clonal antibodies (anti-JSB1, anti-GSTpie and anti-topo IIalpha) in 33 cases of de novo acute myelogenous leukemia. RESULTS: In patients with AML, the frequency of patients with high expression of PGP was 57.6% (19/33). The complete remission (CR) rate and mean survival duration were significantly different between patients with high expression and those with low expression of PGP (31.6 vs 92.9%, P=0.001; 83 vs 341 days, P=0.011). The frequency of patients with high expression of GST pie was 60.6% (20/33). The CR rate and mean survival duration were significantly different between patients with high expression and those with low expression of GSTpie (40.0 vs 84.6%, P=0.011; 115 vs 343 days, P=0.021). The frequency of patients with high expression of topo IIalpha is 78.8% (26/33) and treatment outcome was not related to topo IIalpha expression. In multivariate analysis with age, WBC count, PGP and GSTpie, PGP expression was an independent prognostic factor for treatment outcome. CONCLUSION: The flow cytometric measurement of PGP and GSTpie expression can be useful for the prediction of treament outcome following chemotherapy and PGP can be used as aprognostic factor in AML.
Adult* ; Anthracyclines ; Antibodies ; Cytosol ; DNA Topoisomerases, Type II* ; Drug Resistance ; Drug Resistance, Multiple ; Drug Therapy ; Flow Cytometry ; Glutathione S-Transferase pi* ; Glutathione Transferase* ; Glutathione* ; Humans ; Leukemia ; Leukemia, Myeloid, Acute* ; Multivariate Analysis ; P-Glycoprotein* ; Treatment Outcome

BACKGROUND: Staphylococcus epidermidis is a leading cause of nosocomial infections, and resistance to methicillin is common in clinical isolates. The distribution of oxacillin MIC for S. epidermidis is not clearly bimodal and it is suspected that the sensitivities for detection of oxacillin resistance by standard susceptibility assays with National Committee for Clinical Laboratory Standards (NCCLS) MIC interpretive criteria (< OR =2 g/mL, > OR =4 g/mL) in S. epidermidis strains are lower than that in Staphylococcus aureus strains. To evaluate the relationship between MIC results and true methicillin resistance, we examined the oxacillin MICs and methicillin MICs by agar dilution and detection of mecA gene by PCR for 41 S. epidermidis strains. METHODS: A total of 41 S. epidermidis strains were examined antimicrobial susceptibility test by VITEK system with GPS-AA card, oxacillin MICs and methicillin MICs by agar dilution and detection of mecA gene by PCR. RESULTS: In antimicrobial susceptibility test by VITEK system with GPS-AA card, 24 strains (58.5%) showed oxacillin resistance. 13 strains (31.7%) required MICs of > OR =4 g/mL in oxacillin MIC test and 19 strains (46.3%) required MICs of > OR =16 g/mL in methicillin MIC test. But 27 strains (65.9%) were mecA positive. One of 15 strains that required oxacillin MICs of < OR =0.5 g/mL, all 3 strains that required oxacillin MICs of 1 g/mL and all 10 strains that required oxacillin MICs of 2 g/mL were mecA positive. CONCLUSIONS: It is suspected that NCCLS MIC interpretive criteria underestimate methicillin resistance among S. epidermidis strains and the PCR method is a reliable reference method.
Agar ; Cross Infection ; Methicillin Resistance* ; Methicillin* ; Oxacillin ; Polymerase Chain Reaction ; Staphylococcus aureus ; Staphylococcus epidermidis* ; Staphylococcus*

BACKGROUND: Mycobacterial culture is a confirmatory test to detect the Mycobacterium tuberculosis, but it requires considerable time and the diagnosis and treatment may be delayed. The recently developed LCR (ligase chain reaction) is a more rapid and more specific test for the detection of M. tuberculosis. In this study, we compared the LCR results with those of the culture and AFB smear. METHODS: Mycobacterial culture was performed on 3% Ogawa media for 8 weeks. For LCR, we used LCx Mycobacterium tuberculosis assay kit (Abbott Laboratories, North Chicago, Ill.). The specimens for LCR were resuspended to LCx respiratory specimen resuspension buffer, and then separated mycobacterial DNA by ultrasonicator (Abbott LCx Lysor). Then the samples were mixed in amplification vial containing DNA polymerase and DNA ligase and amplified. For the detection, we used LCx analyzer from Abbott laboratories. RESULTS: The sensitivity, specificity, and positive and negative predictive values of the LCx M. tuberculosis assay were 95, 100, 100, 60%, respectively; 90, 100, 100, 42.9%, for culture; and 62.5, 100, 100, 16.7%, for acid-fast staining, respectively. The agreements between culture and LCx, smear and LCx, and culture and AFB smear were 86%, 65% and 60%, respectively. CONCLUSIONS: LCx was confirmed as a more rapid and sensitive test than the culture test and AFB smear.
Diagnosis ; DNA ; Mycobacterium tuberculosis ; Sensitivity and Specificity ; Tuberculosis*