Association Analysis of TEC Polymorphisms with Aspirin-Exacerbated Respiratory Disease in a Korean Population

The tyrosine-protein kinase Tec (TEC) is a member of non-receptor tyrosine kinases and has critical roles in cell signaling transmission, calcium mobilization, gene expression, and transformation. TEC is also involved in various immune responses, such as mast cell activation. Therefore, we hypothesized that TEC polymorphisms might be involved in aspirin-exacerbated respiratory disease (AERD) pathogenesis. We genotyped 38 TEC single nucleotide polymorphisms in a total of 592 subjects, which comprised 163 AERD cases and 429 aspirin-tolerant asthma controls. Logistic regression analysis was performed to examine the associations between TEC polymorphisms and the risk of AERD in a Korean population. The results revealed that TEC polymorphisms and major haplotypes were not associated with the risk of AERD. In another regression analysis for the fall rate of forced expiratory volume in 1 second (FEV1) by aspirin provocation, two variations (rs7664091 and rs12500534) and one haplotype (TEC_BL2_ht4) showed nominal associations with FEV1 decline (p = 0.03-0.04). However, the association signals were not retained after performing corrections for multiple testing. Despite TEC playing an important role in immune responses, the results from the present study suggest that TEC polymorphisms do not affect AERD susceptibility. Findings from the present study might contribute to the genetic etiology of AERD pathogenesis.

Screening of Genetic Polymorphisms of CYP3A4 and CYP3A5 Genes

Given the CYP3A4 and CYP3A5's impact on the efficacy of drugs, the genetic backgrounds of individuals and populations are regarded as an important factor to be considered in the prescription of personalized medicine. However, genetic studies with Korean population are relatively scarce compared to those with other populations. In this study, we aimed to identify CYP3A4/5 polymorphisms and compare the genotype distributions among five ethnicities. To identify CYP3A4/5 SNPs, we first performed direct sequencing with 288 DNA samples which consisted of 96 Koreans, 48 European-Americans, 48 African-Americans, 48 Han Chinese, and 48 Japanese. The direct sequencing identified 15 novel SNPs, as well as 42 known polymorphisms. We defined the genotype distributions, and compared the allele frequencies among five ethnicities. The results showed that minor allele frequencies of Korean population were similar with those of the Japanese and Han Chinese populations, whereas there were distinct differences from European-Americans or African-Americans. Among the pharmacogenetic markers, frequencies of CYP3A4*1B (rs2740574) and CYP3A5*3C (rs776742) in Asian groups were different from those in other populations. In addition, minor allele frequency of CYP3A4*18 (rs28371759) was the highest in Korean population. Additional in silico analysis predicted that two novel non-synonymous SNPs in CYP3A5 (+27256C>T, P389S and +31546T>G, I488S) could alter protein structure. The frequency distributions of the identified polymorphisms in the present study may contribute to the expansion of pharmacogenetic knowledge.

Multilocus Sequence Typing for Candida albicans Isolates from Candidemic Patients: Comparison with Southern Blot Hybridization and Pulsed-field Gel Electrophoresis Analysis / 대한진단검사의학회지

BACKGROUND: We evaluated the efficacy of multilocus sequence typing (MLST) for assessing the genetic relationship among Candida albicans isolates from patients with candidemia in a hospital setting. METHODS: A total of 45 C. albicans isolates from 21 patients with candidemia were analyzed. The MLST results were compared with results obtained by Southern blot hybridization (C1 fingerprinting) and pulsed-field gel electrophoresis (PFGE). PFGE analysis included karyotyping and restriction endonuclease analysis of genomic DNAs using BssHII (REAG-B) and SfiI (REAG-S). RESULTS: The 45 isolates yielded 20 unique diploid sequence types (DSTs) by MLST, as well as 12 karyotypes, 15 REAG-B patterns, 13 REAG-S patterns, and 14 C1 fingerprinting types. Microevolution among intra-individual isolates was detected in 6, 5, 3, 5, and 7 sets of isolates by MLST (1 or 2 allelic differences), REAG-B, REAG-S, C1 fingerprinting, and a combination of all methods, respectively. Among 20 DSTs, 17 were unique, and 3 were found in more than 1 patient. The results of 2 DSTs obtained from 9 patient isolates were in agreement with REAG and C1 fingerprinting patterns. However, the remaining DST, which was shared by 2 patient isolates, showed 2 different PFGE and C1 fingerprinting patterns. In addition, 3 sets of isolates from different patients, which differed in only 1 or 2 alleles by MLST, also exhibited different PFGE or C1 fingerprinting patterns. CONCLUSIONS: MLST is highly discriminating among C. albicans isolates, but it may have some limitations in typing isolates from different patients, which may necessitate additional analysis using other techniques.

Association Analysis of SERPINB5 Polymorphisms with HBV Clearance and HCC Occurrence in a Korean Population

Serpin peptidase inhibitor, Clade B (ovalbumin), Member 5 (SERPINB5), also known as maspin, is a potent tumor suppressor gene. It has correlations with many tumor cells, from pancreas cancer to breast cancer, so it is possible that it may also affect liver cancer. There has also been a report that SERPINB12, a gene placed right next to SERPINB5, is expressed in liver. For this study, 32 polymorphisms were identified in SERPINB5 by direct DNA sequencing, and 11 of them were selected to be tested with a larger scale subjects. The association of the 11 SERPINB5 polymorphisms with Hepatitis B virus (HBV) clearance, hepatocellular carcinoma (HCC) occurrence and the onset age of HCC were analyzed. There were no significant associations found between 11 SERPINB5 polymorphisms and HBV clearance. In the case of HCC occurrence, one of the haplotypes (ht) showed association with HCC occurrence (OR=2.26, p=0.005, P(Cor)=0.05), albeit with a low statistical power (40.8%) and haplotype frequency (0.052). Further study with a bigger sample size will be needed to clearly verify the association between ht5 and HCC occurrence.

Putative Association of ITGB1 Haplotype with the Clearance of HBV Infection

Integrins are transmembrane receptor proteins that mediate cell-cell adhesion and cell-extracellular matrix (ECM) adhesion. The deregulation of cell-ECM adhesion and the abnormal expression of beta1 (beta1) integrins (ITGB1s) are involved in tumor development and metastasis. In the liver, the expression of integrins and ECM proteins can be a cause of hepatocellular carcinoma (HCC) development. We performed direct DNA sequencing of 24 individuals, and identified 23 sequence variants of ITGB1 polymorphisms. Among these 23 variants, 7 common variants were selected based on frequencies and linkage disequilibrium, and then genotyped in a larger-scale group of subjects (n=1,103). The genetic associations of ITGB1 polymorphisms with the clearance of HBV and HCC outcome of HBV patients were analyzed using logistic regression models and Cox relative hazard models. Although there was no significant association observed between the polymorphisms and the HCC outcome of HBV patients, the second most common haplotype (ITGB1 haplotype-2 [C-C-C-C-T-C-T]) was putatively associated with HBV clearance (OR=0.75, p=0.008 and P(corr)=0.05). The minor allele frequency (MAF) of ITGB1 haplotype-2 of the spontaneously recovered (SR) group was significantly higher than that of the chronic carrier group (CC) (freq. = 0.248 vs. 0.199). The information derived from this study could be valuable for understanding the genetic factors involved in the clearance of HBV.

Identification of Polymorphisms in CYP2E1 Gene and Association Analysis among Chronic HBV Patients

Cytochrome P450 2E1 (CYP2E1) is a member of the cytochrome P450 superfamily, and it is a key enzyme responsible for the metabolic activation of many smallmolecular-weight compounds such as alcohol, which is classified as a human carcinogen. In this study, we identified 19 single nucleotide polymorphisms (SNPs) in CYP2E1 in Korean population. In these SNPs, we examined possible genetic association of CYP2E1 polymorphisms with HBV clearance and the risk of hepatocellular carcinoma (HCC). Five common polymorphic sites were selected, CYP2E1 polymorphisms at rs381-3867, rs3813870, rs2070673, rs2515641 and rs2480257 , considering their allele frequencies, haplotype-tagging status and LDs for genotyping in larger-scale subjects (n=1,092). Statistical analysis demonstrated that CYP2E1 polymorphisms and haplotypes show no significant association with HBV clearance, HCC occurrence and onset age of HCC (p>0.05). Previous studies, however, have shown contradictory findings on associations of CYP2E1 polymorphisms with CYP2E1 activities and HCC risk. Comparing the contrasting results of previous researches suggest that CYP2E1 polymorphism is associated with CYP2E1 activity induced by ethanol, but is not directly associated with HCC risk. CYP2E1 variation/haploype information identified in this study will provide valuable information for future studies on CYP2E1.

Lack of Association of BIRC5 Polymorphisms with Clearance of HBV Infection and HCC Occurrence in a Korean Population

BIRC5 (Survivin) belongs to the inhibitor of apoptosis gene family. The BIRC5 protein inhibits caspases and consequently blocks apoptosis. Thus, BIRC5 contributes to the progression of cancer allowing for continued cell proliferation and survival. In this study, we identified eight sequence variants of BIRC5 through direct DNA sequencing. Among the eight single nucleotide polymorphisms (SNPs), six common variants with frequencies higher than 0.05 were selected for larger-scale genotyping (n=1,066). Results of the study did not show any association between the promoter region polymorphisms and the clearance of hepatitis B virus (HBV) infection and hepatocellular carcinoma (HCC) occurrence. This is in line with a previous study in which polymorphisms in the promoter region does not influence the function of BIRC5. Initially, we were able to detect a signal with the +9194A>G, which disappeared after multiple corrections but led to a change in amino acid. Similarly, we were also able to detect an association signal between two haplotypes (haplotype-2 and haplotype- 5) on the onset age of HCC and/or HCC occurrence, but the signals also disappeared after multiple corrections. As a result, we concluded that there was no association between BIRC5 polymorphisms and the clearance HBV infection and/or HCC occurrence. However, our results might useful to future studies.

Comparison of Real-Time Quantitative PCR with Northern Hybridization for Quantification of CgCDR1 and CgCDR2 Gene Expression in Candida glabrata / 대한의진균학회지

BACKGROUND: One of main mechanisms responsible for acquired azole resistance of Candida glabrata is the increased drug efflux mediated ABS transporters, which are encoded by CgCDR1 and CgCDR2 genes. OBJECTIVES: We compared real-time reverse transcriptase PCR (RT-PCR) with northern hybridization for quantitative analysis of CgCDR1 and CgCDR2 expression in bloodstream isolates of C. glabrata. METHODS: Nineteen blood isolates of C. glabrata were selected, including nine fluconazole susceptible (MIC < or =8 microgram/ml), nine susceptible dose-dependent (S-DD, MIC 16~32 microgram/ml), and one resistant (MIC 128 microgram/ml), isolates. The expression of CgCDR1 and CgCDR2 was quantified using real-time RT-PCR with ROTOR Gene 3000 (Corbettet research, Austria). The results were compared with northern hybridization with sequence-specific probes. RESULTS: Correlation of quantification results between real-time RT-PCR and northern hybridization yielded correlation coefficients of 0.92 for CgCDR1 and 0.82 for CgCDR2 gene. By both methods, no significant differences were observed in the levels of expression of CgCDR1 and CgCDR2 between fluconazole-susceptible isolates and S-DD isolates. In contrast, a strain with high fluconazole resistance (MIC 128 microgram/ml) revealed a greater abundance of CgCDR1 by both methods, compared to the other isolates. Conclusion: This study show that real-time PCR method for C. glabrata RNA quantification correlates well with traditional northern hybridization and can be a valuable alternative to northern hybridization for rapid quantification of CgCDR1 and CgCDR2 genes in clinical isolates of C. glabrata.

In Vitro Susceptibilities of Clinical Isolates of Aspergillus Species against Echinocandins

BACKGROUND: Echinocandins are a new class of antifungal agents with potent in vitro and in vivo activities against Aspergillus species. We investigated the in vitro activity of caspofungin and micafungin against Korean clinical Aspergillus isolates. MATERIALS AND METHODS: A total of 100 clinical isolates of Aspergillus species (32 A. fumigatus, 26 A. flavus, 22 A. niger and 20 A. terreus) were tested. The susceptibilities of caspofungin, micafungin, amphotericin B and itraconazole were established by means of the Clinical and Laboratory Standards Institute (CLSI) M38-A microdilution methods. The results for caspofungin and micafungin were evaluated by using the end points of minimum inhibitory concentrations (MIC) and minimum effective concentration (MEC, the lowest concentration that produces short and aberrant hyphal branchings microsopically). RESULTS: The MEC ranges of caspofungin and micafungin against 100 isolates of Aspergillus species were 0.06 to 0.5 microgram/mL and 16 microgram/mL unexpectedly, in 5% (5/100) and 4% (4/100) of isolates, respectively, which resulted in the loss of a consistent correlation between the two endpoint readings. The MEC50 of all Aspergillus isolates for caspofungin and micafungin were 0.25 and < or =0.03 /mL, respectively, and the MIC50 for amphotericin B and itraconazole were 0.5 and 0.25 microgram/mL, respectively. There were no species-related differences in caspofungin and micafungin MECs for Aspergillus species. CONCLUSION: This data demonstrates excellent in vitro activity of echinocandins against clinical strains of Aspergillus species.

In Vitro Susceptibilities of Clinical Isolates of Aspergillus Species against Echinocandins

BACKGROUND: Echinocandins are a new class of antifungal agents with potent in vitro and in vivo activities against Aspergillus species. We investigated the in vitro activity of caspofungin and micafungin against Korean clinical Aspergillus isolates. MATERIALS AND METHODS: A total of 100 clinical isolates of Aspergillus species (32 A. fumigatus, 26 A. flavus, 22 A. niger and 20 A. terreus) were tested. The susceptibilities of caspofungin, micafungin, amphotericin B and itraconazole were established by means of the Clinical and Laboratory Standards Institute (CLSI) M38-A microdilution methods. The results for caspofungin and micafungin were evaluated by using the end points of minimum inhibitory concentrations (MIC) and minimum effective concentration (MEC, the lowest concentration that produces short and aberrant hyphal branchings microsopically). RESULTS: The MEC ranges of caspofungin and micafungin against 100 isolates of Aspergillus species were 0.06 to 0.5 microgram/mL and 16 microgram/mL unexpectedly, in 5% (5/100) and 4% (4/100) of isolates, respectively, which resulted in the loss of a consistent correlation between the two endpoint readings. The MEC50 of all Aspergillus isolates for caspofungin and micafungin were 0.25 and < or =0.03 /mL, respectively, and the MIC50 for amphotericin B and itraconazole were 0.5 and 0.25 microgram/mL, respectively. There were no species-related differences in caspofungin and micafungin MECs for Aspergillus species. CONCLUSION: This data demonstrates excellent in vitro activity of echinocandins against clinical strains of Aspergillus species.

Species Distribution and Susceptibility to Azole Antifungals of Candida Bloodstream Isolates from Eight University Hospitals in Korea

PURPOSE: The incidence of Candida bloodstream infections (BSI) has increased over the past two decades. The rank order of occurrence and the susceptibility to antifungals of the various Candida species causing BSI are important factors driving the establishment of empirical treatment protocols; however, very limited multi-institutional data are available on Candida bloodstream isolates in Korea. MATERIALS AND METHODS: We investigated the susceptibility to azole antifungals and species distribution of 143 Candida bloodstream isolates recovered from eight university hospitals over a six-month period. Minimal inhibitory concentrations (MICs) of fluconazole, itraconazole, and voriconazole for each isolate were determined by the broth microdilution method of the Clinical and Laboratory Standards Institute (CLSI). RESULTS: The Candida species recovered most frequently from the blood cultures was C. albicans (49%), followed by C. parapsilosis (22%), C. tropicalis (14%), and C. glabrata (11%). The MIC ranges for the Candida isolates were 0.125 to 64microgram/mL for fluconazole, 0.03 to 2microgram/mL for itraconazole, and 0.03 to 1microgram/mL for voriconazole. Overall, resistance to fluconazole was found in only 2% of the Candida isolates (3/143), while the dose-dependent susceptibility was found in 6% (8/143). The resistance and dose-dependent susceptibility of itraconazole were found in 4% (6/143) and 14% (20/143) of the isolates, respectively. All bloodstream isolates were susceptible to voriconazole (MIC, < or = 1microgram/mL). CONCLUSION: Our findings show that C. albicans is the most common cause of Candida-related BSI, followed by C. parapsilosis, and that the rates of resistance to azole antifungals are still low among bloodstream isolates in Korea.

Comparison of Amicus and CS-3000 Plus for the Collection of Peripheral Blood Stem Cells / 대한수혈학회지

BACKGROUND: The efficient collection of peripheral blood stem cells (PBSC) from donors who donate for allogeneic transplants as well as from patients undergoing autologous transplants is essential for a successful transplant. Recently, the Amicus cell separator and the associated MNC collection computer software program for PBSC collection were introduced in Korea. METHODS: Two apheresis machines (Amicus, Baxter Healthcare; and CS-3000 plus, Baxter Healthcare) were compared retrospectively. A total number of 144 procedures were performed on 14 donors and 28 patients. The pre- and post-apheresis complete blood cell (CBC) counts and the number of hematopoietic progenitor cells (HPC) were determined in the peripheral blood from the subjects. The CBC, HPC, CD34+ cell counts and the level of colony-forming unit-granulocyte-macrophages (CFU-GM) were measured in the PBSC product collected from both machines. RESULTS: Both machines collected a similar number of CD34+ cells from the donors and patients. On the other hand, the Amicus collected significantly more nucleated cells, MNCs, HPCs and CFU-GM in the patients with significantly less RBC contamination than those with CS-3000 plus. The decrease in the peripheral blood platelet counts in the donors and patients was more prominent after apheresis using the CS-3000 plus (117.00+/-42.75 x 10(3)/microliter, 61.22+/-43.62 x 10(3)/microliter) than Amicus (26.04+/-18.68 x 10(3)/microliter, 22.15+/-28.66 x 10(3)/microliter)(p<0.05). CONCLUSION: PBSC collection can be performed successfully using CS-3000 plus and Amicus. Amicus is superior to CS-3000 plus in avoiding apheresis-induced thrombocytopenia, and is expected to prevent unnecessary platelet transfusion.

Serologic Variability of the A(var) (784G>A) and Its Property of Different Expression Depending on Co-inherited ABO Allele / 대한수혈학회지

BACKGROUND: A allele, A(var), characterized by a 784G>A polymorphism (Asp262Asn) has been identified only in Korean A(weak)B donors. This study evaluated the serological and genetic characteristics of thirteen samples with newly identified A(var) allele. METHODS: This study examined 10 samples with the A(var) allele including 4 members from a family, who were randomly obtained from blood donors recruited at Gwangju-Chonnam Red Cross Blood Center, and patients at the Chonnam National University Hospital. Routine ABO serologic tests, ABO genotyping using an allele specific polymerase chain reaction (AS-PCR), and the sequencing of exon 6 and 7 of ABO gene were performed on all samples. In addition, sequencing of exon 1~5 of the ABO gene was carried out on two randomly selected samples. RESULTS: The A(var) allele was identified in nine A(weak)B and one O (II-1 of the family study) sample. Eight of these nine individuals showed 1+ agglutination with the monoclonal anti-A reagents on forward typing but one sample showed no agglutination. Weak anti-A was detected in all sera. From the family study, the A(var) allele, which was transmitted from the propositus through her descendant (II-1, II-3 and III-1), produced either the weak A phenotype when inherited with a B allele or the O phenotype when inherited with an O allele. CONCLUSION: A(var) erythrocytes showed different agglutination patterns to anti-A. Different expressions (possible allelic enhancement) were observed depending on the co-inherited ABO alleles from samples with the A(var) allele.

A Family Study of Ael02 Allele Expressing Different Phenotypes Depending on Co-inherited ABO Alleles / 대한수혈학회지

Compared with A101, Ael02 is characterized by 467C>T, 646T>A and 681G>A polymorphisms, resulting in two amino acid substitutions (Pro156Leu and Phe216Ile). The first study in Korea was reported at 2003. However, only unrelated donors were characterized. This study carried out molecular genetic analysis of a 26 year-old male propositus diagnosed with the Ael subgroup by serological tests along with his family. The propositus had the genotype Ael02/B101 expressing the AelB phenotype, and his father the genotype Ael02/O01 expressing the O phenotype. These findings suggest that the AelO2 allele is expressed as different phenotypes depending on the co-inherited ABO alleles.

Resolution of ABO Discrepancies by ABO Genotyping / 대한진단검사의학회지

BACKGROUND: Before a blood transfusion, both red cell and serum typing need to be matched for ABO tests on the donor and patient (recipient). When a mismatch exists in the tests, additional ABO genotyping and serological tests are required for the resolution of the discrepancy. We performed ABO genotyping on a series of blood donors and patients with ABO discrepancies to assist in resolving their blood groups. METHODS: We examined 46 samples with ABO discrepancies from a random pool of donors recruited at Gwangju-Chonnam Red Cross Blood Center and from patients at Chonnam National University Hospital between May 2004 and July 2005. ABO genotyping was performed on all samples with an allele specific polymerase chain reaction for differentiation of A, B,O, cis-AB, A(var) (784 G>A), and B(var) (547 G>A) alleles; routine serologic tests were also performed. Exon 6 and 7 of ABO gene from five samples were sequenced. RESULTS: The genotypes of 18 donors/patients with weakened A or B antigen expressions consisted of 4 cases of cis-AB/O (3 A(2)B(3), 1 A(2)B); 5 cases of cis-AB/A (5 A(1)B(x or el)); 2 cases of A/O (1 O, 1 A(m or x)); 1 case of B/O (1 B(m or x)); 4 cases of A/B (1 A(2)B , 1 A(1)B(x or el), 2 A(1)B(3)); and 2 cases of A(var)/B (2 A(w)B). On the other hand, the genotypes of 28 samples with unexpected serum reactions included 18 cases of A/O (16 A(1), 2 A(int)); 7 cases of A/A (5 A(1), 1 A(1)B(x or el), 1 A(1)B(w)); and 3 cases of O/O (1 O, 2 B(w)). CONCLUSIONS: ABO genotyping is useful for differentiating the ABO discrepancies that were difficult to resolve by serological tests. The most frequent unusual red cell reactions were weak A and B antigen expressions, which were resulted from the ABO subgroup alleles including cis-AB allele, whereas the most frequent unusual serum reactions were caused by decreased anti-B titers.

Usefulness of NaCl/Enzyme Gel Test for the Identification of Unexpected Antibodies / 대한진단검사의학회지

BACKGROUND: The microcolumn assay technique offers significant advances in identification of unexpected antibodies; however, some erythrocyte antibodies still remain unidentified. To see if NaCl/Enzyme test is useful for the identification of antibodies, we compared the LISS/Coombs and NaCl/Enzyme tests for identification rates, and investigated an association between the frequency of each antibody and a history of transfusion or gestation. METHODS: From June 2004 to June 2005, antibody screening tests were carried out on 5,517 patients using the LISS/Coombs gel test (DiaMed AG, Switzerland). When antibodies were detected, antibody identification tests were carried out with the LISS/Coombs and NaCl/Enzyme gel tests (DiaMed AG) simultaneously. RESULTS: Unexpected antibodies were detected in 79 patients (1.43%). These antibodies were identified in 39 (49.4%), 59 (74.7%), and 68 patients (86.1%) by the LISS/Coombs test, the NaCl/Enzyme test, and the two tests combined, respectively. With the addition of the NaCl/ Enzyme test, unexpected antibodies were further identified in 29 cases (anti-Lewis, 14; anti-Rhesus, 13; and anti-P1, 2). On the other hand, 9 cases (anti-M, 5; anti-Fy(b), 3; and anti-N, 1) were identified by the LISS/Coombs test only. Of the unexpected antibodies found in patients without a previous history of transfusion or gestation, anti-Lewis (50.0%, 10/20) was the most common, while in patients with the history anti-Rhesus (48.1%, 26/54) was the most frequent. CONCLUSIONS: The NaCl/Enzyme combined with LISS/Coombs gel test was useful for the identification of unexpected antibodies, and antibodies found in patients without a previous history of transfusion or gestation were clinically less relevant than those found in patients with the history.

In Vitro Susceptibilities to Caspofungin and Micafungin of Clinical Isolates of Candida Species / 대한진단검사의학회지

BACKGROUND: Caspofungin and micafungin are echinochandins with potent activities against Candida species. However, in vitro susceptibility to these agents of clinical Candida isolates in Korea has not been fully surveyed. We determined minimum inhibitory concentrations (MICs) of caspofungin and micafungin against clinical isolates of Candida species. METHODS: A total of 107 blood isolates of Candida species (24 C. albicans, 25 C. tropicalis, 24 C. glabrata, 20 C. parapsilosis, 8 C. krusei, and 6 other Candida species) were tested by using the National Committee for Clinical Laboratory Standards M27-A2 broth microdilution methods. The in vitro antifungal activities and spectrum of caspofungin and micafungin were compared with those of amphotericin B, fluconazole, and itraconazole. RESULTS: Caspofungin and micafungin exhibited a broad-spectrum activity against Candida species: caspofungin MIC ranged from 0.125 to 1 microgram/mL and micafungin MIC from < or =0.03 to 1 microgram/mL. C. albicans, C. tropicalis and C. glabrata showed high susceptibility to caspofungin (MIC90, 0.25 to 0.5 microgram/mL) and micafungin (MIC90 , < or =0.03 microgram/mL), whereas C. parapsilosis was less susceptible to both echinocandins (MIC90, 1 microgram/mL). The MIC50 for caspofungin, micafungin, amphotericin B, fluconazole, and itraconazole were 0.25, < or =0.03, 0.5, 1, and 0.125 microgram/mL, respectively. Caspofungin MIC50 of C. glabrata and C. krusei isolates with decreased susceptibility to azoles were 0.25 and 0.5 microgram/mL, respectively, and micafungin MIC50 were < or =0.03 and 0.125 microgram/mL, respectively. CONCLUSIONS: These data showed an excellent in vitro activity of caspofungin and micafungin against clinical strains of Candida species, including isolates with reduced susceptibility to azoles.

Clinical and Laboratory Features of Candidemia Caused by Different Candida Species / 대한진단검사의학회지

BACKGROUND: Recently, the incidence of candidemia due to Candida species other than C. albicans have increased. In this study, we analyzed the laboratory and clinical characteristics of candidemia caused by four different Candida species (C. albicans, C. parapsilosis, C. tropicalis and C. glabrata) occurring at Chonnam National University Hospital (CNUH). METHODS: The demographic, clinical and microbiological data of 157 patients with candidemia at CNUH from 1996 to 2002 was analyzed, retrospectively. The etiologic agents for 157 cases of candidemia were C. albicans (n=48), C. parapsilosis (n=48), C. tropicalis (n=32) and C. glabrata (n= 29). The characteristics of candidemia due to each single Candida species were compared with those with all other species combined. RESULTS: Although the majority (77%) of candidemic patients were adults, candidemia due to C. albicans or C. parapsilosis occurred significantly more often in premature infants (15%, retrospectively, P=0.002), in comparison with other Candida species (0%). Candidemia due to C. glabrata was more common in patients with neutropenia (41%, P<0.001), and they also occurred frequently in the absence of central venous catheter related candidemia (86%, P<0.001). Bloodstream infections with C. parapsilosis were more frequently the cause of catheter related candidemia (56%, P=0.012), and they had a better clinical outcome (90%, P=0.004) than those with other Candida species. CONCLUSIONS: This study confirms that some characteristics of candidemia such as age, underlying conditions, relatedness of catheter, and outcome can be different according to the species of Candida.

Plating Efficiency of Single CD34+ Cell from Bone Marrow, Peripheral Blood and Cord Blood / 대한혈액학회지

BACKGROUND: Although bone marrow (BM) CD34+cells and peripheral blood (PB) CD34+ cells are developmentally and functionally related, the recent data suggested that they may have different functional and clinical capabilities. Moreover, they have differential gene expression underlying the functional distinctions of primary human CD34+ hematopoietic stem and progenitor cells from BM and PB. The aim of this study was to investigate the plating efficiency of single CD34+ progenitor cell from BM, PB and umbilical cord blood (UCB). METHODS: After sorting, single CD34+ cells were cultured in individual wells of 96-well plates in serum-free medium containing selected hematopoietic growth factors, with or without G-CSF. Plating efficiency was microscopically determined by the presence of clusters of viable cells:[the number of positive (cells were present) wells/total wells]x100. CD34+ cell-derived colonies were classified according to the cell number per well. RESULTS: Although there was some variation of plating efficiency of CD34+ cells among six normal BMs, six PBs and five UCBs, overall average plating efficiency of single CD34+ cells from BM, PB and UCB was 30% (30.0+/-11.7, mean+/-SD), 79% (78.6+/-11.7) and 45% (45.3+/-9.3) respectively. As expected, the colony size was increased in the presence of G-CSF. CONCLUSION: The results of this study clearly showed that the different ex vivo expansion of single CD34+ progenitor cells from BM, PB and UCB. These might be an important data for understanding stem cell expansion in vivo and designing clinical application.