Non-nosocomial healthcare-associated infective endocarditis in Taiwan: an underrecognized disease with poor outcome.

BACKGROUND: Non-nosocomial healthcare-associated infective endocarditis (NNHCA-IE) is a new category of IE of increasing importance. This study described the clinical and microbiological characteristics and outcome of NNHCA-IE in Taiwan. METHODS: A retrospective study was conducted of all patients with IE admitted to the Kaohsiung Veterans General Hospital in Kaohsiung, Taiwan over a five-year period from July 2004 to July 2009. The clinical and microbiological features of NNHCA-IE were compared to those of community-acquired and nosocomial IE. Predictors for in-hospital death were determined. RESULTS: Two-hundred episodes of confirmed IE occurred during the study period. These included 148 (74%) community-acquired, 30 (15%) non-nosocomial healthcare-associated, and 22 (11%) nosocomial healthcare-associated IE. Staphylococcus aureus was the most frequent pathogen. Patients with NNHCA-IE compared to community-acquired IE, were older (median age, 67 vs. 44, years, p < 0.001), had more MRSA (43.3% vs. 9.5%, p < 0.001), more comorbidity conditions (median Charlson comorbidity index [interquartile range], 4[2-6] vs. 0[0-1], p < 0.001), a higher in-hospital mortality (50.0% vs. 17.6%, p < 0.001) and were less frequently recognized by clinicians on admission (16.7% vs. 47.7%, p = 0.002). The overall in-hospital mortality rate for all patients with IE was 25%. Shock was the strongest risk factor for in-hospital death (odds ratio 7.8, 95% confidence interval 2.4-25.2, p < 0.001). CONCLUSIONS: NNHCA-IE is underrecognized and carries a high mortality rate. Early recognition is crucial to provide optimal management and improve outcome.

Molecular detection of circulating cancer cells in the peripheral blood of patients with colorectal cancer by using membrane array with a multiple mRNA marker panel.

The objective of this study was mainly to evaluate the simultaneous detection of expression levels of a multiple mRNA marker panel in the peripheral blood of colorectal cancer (CRC) patients for use in complementary CRC diagnosis. Twenty-seven tumor tissue specimens and 80 peripheral blood specimens were collected from CRC patients. Firstly, the levels of multiple molecular markers in the tumor tissue and blood specimens were evaluated by using real-time quantitative PCR (RT-QPCR) and membrane array. The result of linear regression showed a high degree of correlation (r=0.954, P<0.0001) between the data of these two methods. CK-19 was the marker with the highest detection rate (87.5%) in the peripheral blood, followed by CEA (82.6%), REG4 (80.8%), and then uPA (80.0%) and TLAM1 (80.0%). The levels of the six markers in the peripheral blood were extensively explored. In the 80 patients, the frequency of CK-19, CK-20, CEA, REG4, uPA, and TIAM1 mRNA overexpression was 82.5% (66/80), 78.8% (63/80), 82.5% (66/80), 80.0% (64/80), 78.8% (63/80), and 80.0% (64/80), respectively. Then, a panel combining these 6 mRNA markers was evaluated for its utility in the clinical diagnosis of CRC. The sensitivity, specificity, and accuracy of membrane array-based diagnostic method were 88.8%, 87.8%, and 88.2%, respectively; much higher than those of examinations with single markers. Finally, lymph node metastasis (P=0.024) and TNM stage (P=0.009) were found to be significantly correlated with overexpression of the multiple mRNA marker panel. The detection rates of stage-I and -II CRC by using the multi-marker membrane array were 54.5% (6/11) and 92.0% (23/25), respectively. In conclusion, the results of the present study have shown that this innovative membrane array technique with a multiple mRNA marker panel can significantly improve the diagnosis rate of early colorectal cancer.

Molecular mechanisms underlying the tumorigenesis of colorectal adenomas: correlation to activated K-ras oncogene.

Mutations of K-ras gene have been demonstrated in 40-50% of colorectal cancer and large adenoma (>1 cm). This study was intended to clarify the correlation between the existence of K-ras oncogene and the pathological features of colorectal adenomas using our recently developed membrane arrays. Moreover, the downstream genes regulated by K-ras oncogene were explored to serve as potential biomarkers in the early diagnosis and risk assessment of patients with colorectal adenoma. Specimens were collected from 70 patients with colorectal adenoma. The alterations of K-ras oncogene were analyzed by direct sequencing and our constructed membrane arrays, respectively. The results of direct sequencing showed that 21 of 70 samples (30%) had K-ras gene mutations. The most frequently mutated sites included codons 12, 13, 15 and 18. Furthermore, activated K-ras oncogene was identified in 18 of 70 (25.7%) adenoma by membrane arrays. Statistical analyses showed that the membrane array had the accuracy of 90.0%, sensitivity of 88.9%, and specificity of 90.4%. The frequency of the mutational sites of K-ras gene was located as follows: codon 12, 100% (4/4); codon 13, 100% (4/4); codon 15, 75% (6/8); and codon 18, 100% (2/2). The analysis of the correlation between the experimental data and pathological characteristics of adenoma showed that activated K-ras oncogenes were significantly associated with the size, number and histology of adenomas (all P<0.001). Finally, we found the downstream genes activated by K-ras oncogene, including B-cell CLL/lymphoma 2 (BCL2), Homo sapiens H2A histone family, member Z (H2AFZ), Homo sapiens RAP1B, member of RAS oncogene family (RAP1B), Homo sapiens T-box 19 (TBX19), Homo sapiens E2F transcription factor 4, p107/p130-binding (E2F4) and matrix metallopeptidase 1 (MMP1), of which were overexpressed in most of all examined adenomas. These genes were then suggested to have functions involved in cell growth. The preliminary results indicated that the accuracy of membrane arrays was comparable to conventional DNA sequencing in the detection of activated K-ras oncogenes. Therefore, we propose that activated K-ras oncogene in colorectal adenomas may play an important role in the subsequent colorectal carcinogenesis through a group of K-ras-related molecular targets.

Rapid onset of rhabdomyolysis after switching to a raltegravir-based antiretroviral regimen.

Raltegravir is the first integrase inhibitor antiretroviral agent that has been demonstrated to have antiviral efficacy and safety. However, the US Food and Drug Administration has recommended use with caution in patients with risk factors for rhabdomyolysis, based on four case reports of rhabdomyolysis in patients with identifiable risk factors. We present a 32-year-old Asian man with human immunodeficiency virus (HIV), but without other underlying diseases, who developed rapid-onset, raltegravir-associated rhabdomyolysis and hyperlactatemia. Our patient lacked predisposing factors for rhabdomyolysis, and the rapid onset time of 4 days was the shortest reported. Therefore, clinicians should exercise caution when using raltegravir and closely monitor all patients for the symptoms of muscle pain and weakness. This case has been reported to the National Adverse Drug Reactions Reporting System of the Department of Health in Taiwan.

Simultaneous detection of multiple single-nucleotide polymorphisms by a simple membrane chip.

Technologies that screen multiple single-nucleotide polymorphisms (SNPs) could be very valuable in predicting patients' susceptibilities to diseases or responses to therapeutic interventions. In this study, we developed a chip that can accurately detect four SNPs at same time. This chip is cost-effective and user-friendly because it uses a detection protocol analogous to dot blotting and does not require sophisticated instruments. To establish this chip, we designed and blotted onto a nylon membrane SNP-specific oligonucleotide probes for human angiotensinogen, cholesteryl ester transfer protein, and apolipoprotein E. This chip detected the corresponding SNPs harbored within the angiotensinogen, cholesteryl ester transfer protein, and apolipoprotein E sequences from 20 donors. Importantly, the SNPs detected by our chip matched exactly with the direct sequencing results, thereby highlighting the accuracy of this chip. In conclusion, our chip is a robust tool for multiple SNP screening and holds the potential to future refinement in detecting diseases-associating genes in patients.

High prevalence of latent tuberculosis infection in dialysis patients using the interferon-gamma release assay and tuberculin skin test.

BACKGROUND AND OBJECTIVES: Patients in ESRD on hemodialysis with latent tuberculosis (TB) infection have 10 to 25 times the risk of reactivation into active disease compared with healthy adults. This study investigates the prevalence of latent TB infection in dialysis patients from a country with an intermediate burden of TB and its associated risk factors using the QuantiFERON-TB Gold in-tube test (QGIT) and the tuberculin skin test (TST). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a prospective, cross-sectional study performed at a medical center in Taiwan on dialysis patients. Each patient underwent QGIT, two-step TST using 2 tuberculin units (TU) of PPD RT-23, a chest x-ray to exclude active TB, and an interview to determine TB risk factors. RESULTS: Ninety-three of 190 eligible patients were enrolled: 35 men and 58 women. 64.8% were vaccinated with the Bacille-Calmette-Guérin (BCG) vaccination. Overall, 34.4% were positive by QGIT and 10.8% were indeterminate. Using a 10-mm TST cutoff, 53.9% were positive. There was poor correlation between TST and QGIT at any TST cutoff criteria. There was a significant increasing trend of QGIT positivity with age in those younger than 70 years, and, conversely, a decreasing trend of TST reactivity with age. Significant risk factors for QGIT positivity included age and past TB disease. CONCLUSIONS: This study shows a high prevalence of latent TB infection in dialysis patients in a country with an intermediate burden of TB. QGIT in dialysis patients correlated better than TST with the risk of TB infection and past TB disease.