Application of the electronic book to promote self-directed learning in medical technologist continuing education: a cross-sectional study.

BACKGROUND: Continuing education (CE) is essential for health professionals to improve competence in clinical practice, yet many medical technologists still experience barriers to learning in complex clinical settings. To better manage CE and address medical technologists' learning needs, we developed a learner-centred electronic book (e-book) to promote self-directed learning for medical technologists. METHODS: A cross-sectional study was conducted to explore the acceptability and learning impacts of the e-book as CE material for medical technologists in two medical centres in Taiwan. We designed the learner-centred context in the e-book based on medical technologists' practice requirements and learning needs. Moreover, we adopted The New World Kirkpatrick Model with four levels (reactions, learning, behaviours and results) to evaluate the e-book's learning impacts on medical technologists. A total of 280 medical technologists were invited to complete a questionnaire and a post-test, providing learning patterns as well as their satisfaction with the e-book and their learning outcomes after using it. RESULTS: Most readers had positive learning experiences and better learning outcomes, including knowledge acquisition and behavioural change, after reading the e-book. The e-book became a new CE activity and reached medical technologists in various types of laboratories. CONCLUSIONS: The low-cost and learner-centred e-book effectively overcame CE learning barriers for medical technologists. The interactivity and flexibility of e-learning particularly helped learners to engage in clinical scenarios in laboratory medicine. This study could pave the way for medical educators to build a high-quality e-learning model in CE.

Trend in blood lead levels in Taiwanese adults 2005-2017.

This study examined the trend of blood lead levels (BLLs) in Taiwanese adults and analyzed the variations in the BLL between Linkou (northern) and Kaohsiung (southern) hospital branches. Between 2005 and 2017, 3,804 adult participants received blood lead tests at the Linkou (n = 2,674) and Kaohsiung (n = 1,130) branches of Chang Gung Memorial Hospital. The geometric mean of BLL was 2.77 µg/dL. The adult participants from the Kaohsiung branch were not only age older (49.8±14.1 versus 39.4±14.2 years; P<0.001) and male predominant (65.8 versus 41.7%; P<0.001) but also showed a higher BLL (4.45±3.93 versus 2.82±2.42 µg/dL; P<0.001) and lower estimated glomerular filtration rate (87.62±25.94 versus 93.67±23.88; P<0.001) than those from the Linkou branch. Multivariable logistic regression analysis revealed that the Kaohsiung branch [odds ratio (OR): 7.143; 95% confident interval (CI): 5.682-8.929; P<0.001], older age (OR: 1.008; 95% CI: 1.000-1.015; P = 0.043) and reduced estimated glomerular filtration rate (OR: 1.009; 95% CI: 1.004-1.014; P = 0.001) were significant predictors for BLL > 5 µg/dL. Therefore, this study confirmed a continuous decreasing trend in the BLL in Taiwan after banning leaded petrol in 2000.

Evaluation the diagnostic accuracy of albuminuria detection in semi-quantitative urinalysis.

BACKGROUND: Taiwan has the highest end-stage renal disease prevalence in the world, and the costs on the maintenance of dialysis imposes a great financial burden on National Health Insurance. Routine urinalysis provides an opportunity for the early detection of microalbuminuria. We evaluated the accuracy of semi-quantitative chemical methods from Siemens Novus Pro12 dipstick for albumin-creatinine ratio (ACR). METHODS: We collected 1029 random urine samples and performed urinary analytic tests by Siemens Novus with Pro12 dipsticks and also calculated the urinary ACR. The reference method was performed by Hitachi LST008, a quantitative assay. The percentage of exact agreement in ACR was 81.9% between Siemens Novus and Hitachi LST008. The percentage of agreement within 1 level between the 2 methods was 98.5%. When ACR > 30 mg/g was defined as the threshold for positive results, the sensitivity, specificity, positive, and negative predictive values for microalbuminuria were 87.2%, 91.6%, 91.5%, and 87.3%, respectively. There were 778 cases with negative results of urinary protein, analyzed by conventional dipsticks. 149 of 778 (19.2%) cases were positive, measured by Pro12 dipsticks, and 111 of 149 (74.5%) cases were confirmed positive ACR by Hitachi LST008. CONCLUSIONS: Urinary ACR measured by Siemens Novus with Pro12 dipsticks was shown to be a reliable test for detection of microalbuminuria.

Increase Trichomonas vaginalis detection based on urine routine analysis through a machine learning approach.

Trichomonas vaginalis (T. vaginalis) detection remains an unsolved problem in using of automated instruments for urinalysis. The study proposes a machine learning (ML)-based strategy to increase the detection rate of T. vaginalis in urine. On the basis of urinalysis data from a teaching hospital during 2009-2013, individuals underwent at least one urinalysis test were included. Logistic regression, support vector machine, and random forest, were used to select specimens with a high risk of T. vaginalis infection for confirmation through microscopic examinations. A total of 410,952 and 428,203 specimens from men and women were tested, of which 91 (0.02%) and 517 (0.12%) T. vaginalis-positive specimens were reported, respectively. The prediction models of T. vaginalis infection attained an area under the receiver operating characteristic curve of more than 0.87 for women and 0.83 for men. The Lift values of the top 5% risky specimens were above eight. While the most risky vigintile was picked out by the models and confirmed by microscopic examination, the incremental cost-effectiveness ratios for T. vaginalis detection in men and women were USD$170.1 and USD$29.7, respectively. On the basis of urinalysis, the proposed strategy can significantly increase the detection rate of T. vaginalis in a cost-effective manner.

Measuring serum total and free indoxyl sulfate and p-cresyl sulfate in chronic kidney disease using UPLC-MS/MS.

Chronic kidney disease (CKD) is a complex disorder that affects multiple organs and increases the risk of cardiovascular complications. CKD affects approximately 12% of the population in Taiwan. Loss of kidney function leads to accumulation of potentially toxic compounds such as indoxyl sulfate (IS) and p-cresyl sulfate (pCS), two protein-bound uremic solutes that can stimulate the progression of CKD. The aim of this study was to assess whether IS and pCS levels were correlated with CKD stage. We developed and validated a method for quantitating total and free IS and pCS in serum by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Serum samples were pretreated using protein precipitation with acetonitrile containing stable isotope-labeled IS and pCS as internal standards. After centrifugation, the supernatant was diluted and injected into a UPLC-MS/MS system. Analyte concentrations were calculated from the calibration curve and ion ratios between the analyte and the internal standard. The calibration curves were linear with a correlation coefficient of >0.999; the analytical measurement range was 0.05-5 mg/L. The limit of quantitation of this assay was 0.05 mg/L for both analytes. The reference interval was ≤0.05-1.15 mg/L for total-form IS, ≤0.05-5.33 mg/L for total-form pCS, ≤0.05 mg/L for free-form IS, and ≤0.12 mg/L for free-form pCS. A positive correlation was observed between analyte concentration and CKD stage. Our sensitive UPLC-MS/MS method for quantifying total and free-form IS and pCS in serum can be used to monitor the progression of CKD in clinical settings, identify patients at risk, and facilitate development of further therapies for this devastating disease.

ClpA and HtpX Proteases Are Involved in Intrinsic Aminoglycoside Resistance of Stenotrophomonas maltophilia and Are Potential Aminoglycoside Adjuvant Targets.

The linkage of the protease-chaperon system, SmeYZ pump, and aminoglycoside resistance was assessed in Stenotrophomonas maltophilia The clpA, clpS, clpP, and htpX genes were upregulated in response to kanamycin exposure. Of these, clpA and htpX were the primary determinants responsible for intrinsic aminoglycoside (AG) resistance. Inactivation of clpA and htpX compromised protease-mediated intrinsic aminoglycoside resistance and weakened SmeYZ pump-mediated aminoglycoside resistance, signifying HtpX and ClpA as potential AG adjuvant targets for treatment of S. maltophilia infections.

Validation and evaluation of two porphobilinogen deaminase activity assays for diagnosis of acute intermittent porphyria.

BACKGROUND: Acute intermittent porphyria (AIP) is caused by diminished activity of porphobilinogen deaminase (PBGD). The purpose of this study was to validate and compare two assays for PBGD activity. The clinical sensitivity of the PBGD activity assays in AIP diagnosis was also evaluated. METHODS: This study included 74 subjects from 18 Taiwanese families including symptomatic patients with AIP, asymptomatic carriers, and healthy family members. The specific mutations in AIP patients were identified by DNA sequencing. PBGD activity was measured in erythrocytes by quantifying formation of coproporphyrin or uroporphyrin by the enzyme using porphobilinogen (PBG) as a substrate and fluorimetry for detection. RESULTS: The calibration curves obtained with pure coproporphyrin or uroporphyrin were linear with correlation coefficients >0.99 in the range of 0-200nM for coproporphyrin and 0-150nM for uroporphyrin. The coefficients of variation for within-run and between-day imprecision were <9.8% for both assays. The three groups of subjects were used to establish the best cut-off of PBGD activity for identifying symptomatic AIP patients by using area under receiver operating characteristic curve analysis. The symptomatic AIP patients and asymptomatic carriers had significantly lower PBGD activity compared with the healthy family members (all p<.001). CONCLUSION: Two different PBGD activity assays were validated. The best cut-off for coproporphyrin was derived as 46.4nmol/h/mL RBC with corresponding sensitivity of 100% and specificity of 100% and the best cut-off for uroporphyrin was derived as 43.7nkat/L RBC with corresponding sensitivity of 100% and specificity of 97.4%.

Survey of urinary nickel in peritoneal dialysis patients.

This study surveyed urinary nickel concentrations in peritoneal dialysis (PD) patients, and analyzed the association of urinary nickel concentrations with clinical outcomes and inflammatory biomarkers. In total, 50 PD patients and 50 healthy controls were recruited for this study. All participants were examined for the presence of toxic trace elements (antimony, arsenic, bismuth, cadmium, copper, manganese, mercury, nickel, lead, tellurium, thallium and zinc) in their urine by using inductively coupled plasma mass spectrometry (ICP-MS). It was found that PD patients demonstrated higher urinary nickel concentrations than healthy controls (6.1±3.5 versus 2.8±1.4 µg/L, P<0.001). There were 24 (48.0%) PD patients with normal urinary nickel concentrations, and 26 (52.0%) PD patients with high urinary nickel concentrations. The PD patients with high urinary nickel concentrations demonstrated higher log serum levels of high sensitivity C-reactive protein (0.4±0.5 versus 0.1±0.5 mg/L, P=0.046) than patients with normal urinary nickel concentrations. Furthermore, patients with high urinary nickel concentrations exhibited higher levels of cadmium (1.3±0.9 versus 0.6±0.5 µg/L, P<0.001), copper (7.7±5.7 versus 3.3±1.4 µg/L, P<0.001) and manganese (0.9±1.1 versus 0.4±0.4 µg/L, P=0.023) than patients with normal urinary nickel concentrations. Nevertheless, there were no significant differences in the clinical outcomes between PD patients with high and normal urinary nickel concentrations (P>0.05). Thus, it is concluded that approximately half of the patients undergoing PD had elevated urinary nickel levels, and these patients also had elevated serum levels of high sensitivity C-reactive protein. Nevertheless, no other real correlations were discovered including no impact on patient outcome. Further studies are warranted.

Relationship of the CreBC two-component regulatory system and inner membrane protein CreD with swimming motility in Stenotrophomonas maltophilia.

The CreBC two-component system (TCS) is a conserved regulatory system found in Escherichia coli, Aeromonas spp., Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. In this study, we determined how CreBC TCS regulates secreted protease activities and swimming motility using creB, creC, and creBC in-frame deletion mutants (KJΔCreB, KJΔCreC, and KJΔBC) of S. maltophilia KJ. Compared to wild-type KJ, KJΔCreB had a comparable secreted protease activity; however, the secreted protease activities were obviously reduced in KJΔCreC and KJΔBC, suggesting that CreC works together with another unidentified response regulator (not CreB) to regulate secreted protease activity. Single gene inactivation of creB or creC resulted in mutants with an enhanced swimming motility, and this phenotype was exacerbated in a double mutant KJΔBC. To elucidate the underlying mechanism responsible for the ΔcreBC-mediated swimming enhancement, flagella morphology observation, RNA-seq based transcriptome assay, qRT-PCR, and membrane integrity and potential assessment were performed. Flagella morphological observation ruled out the possibility that swimming enhancement was due to altered flagella morphology. CreBC inactivation upregulated the expression of creD and flagella-associated genes encoding the basal body- and motor-associated proteins. Furthermore, KJΔBC had an increased membrane susceptibility to Triton X-100 and CreD upregulation in KJΔBC partially alleviated the compromise of membrane integrity. The impact of creBC TCS on bacterial membrane potential was assessed by carbonyl cyanide m-chlorophenyl hydrazine (CCCP50) concentration at which 50% of bacterial swimming is inhibited. CCCP50 of wild-type KJ increased when creBC was deleted, indicating an association between the higher membrane potential of KJΔBC cells and enhanced motility. Upregulation of the basal body- and motor-associated genes of flagella in KJΔBC cells may explain the increased membrane potential. Collectively, inactivation of creBC increased swimming motility through membrane potential increase and creD upregulation in S. maltophilia. The increased membrane potential may supply more energy for flagella propelling and CreD upregulation supports membrane stability, providing a strong membrane for flagellum function.

A metagenomics study for the identification of respiratory viruses in mixed clinical specimens: an application of the iterative mapping approach.

Metagenomic approaches to detect viral genomes and variants in clinical samples have various challenges, including low viral titers and bacterial and human genome contamination. To address these limitations, we examined a next-generation sequencing (NGS) and iterative mapping approach for virus detection in clinical samples. We analyzed 40 clinical specimens from hospitalized children diagnosed with acute bronchiolitis, croup, or respiratory tract infections in which virus identification by viral culture or polymerase chain reaction (PCR) was unsuccessful. For our NGS data analysis pipeline, clinical samples were pooled into two NGS groups to reduce sequencing costs, and the depth and coverage of assembled contigs were effectively increased using an iterative mapping approach. PCR was individually performed for each specimen according to the NGS-predicted viral type. We successfully detected previously unidentified respiratory viruses in 26 of 40 specimens using our proposed NGS pipeline. Two dominant populations within the detected viruses were human rhinoviruses (HRVs; n = 14) and human coronavirus NL63 (n = 8), followed by human parainfluenza virus (HPIV), human parechovirus, influenza A virus, respiratory syncytial virus (RSV), and human metapneumovirus. This is the first study reporting the complete genome sequences of HRV-A101, HRV-C3, HPIV-4a, and RSV, as well as an analysis of their genetic variants, in Taiwan. These results demonstrate that this NGS pipeline allows to detect viruses which were not identified by routine diagnostic assays, directly from clinical samples.

Overexpression of SmeDEF Efflux Pump Decreases Aminoglycoside Resistance in Stenotrophomonas maltophilia.

The SmeDEF pump of Stenotrophomonas maltophilia is negatively regulated by SmeT. In this study, strains KJΔT (smeT deletion mutant) and KJT-Dm (mutant with a defective SmeT-binding site) showed increased resistance to chloramphenicol/nalidixic acid/macrolides and susceptibility to aminoglycoside. Overexpression of the SmeDEF pump, in either KJΔT or KJT-Dm, downregulated smeYZ expression, which is responsible for the reduced aminoglycoside resistance. Furthermore, the SmeRySy two-component regulatory system was downregulated in response to SmeDEF overexpression, which supports its involvement in the regulatory circuit.

Reduction in Hospital-Wide Clinical Laboratory Specimen Identification Errors following Process Interventions: A 10-Year Retrospective Observational Study.

BACKGROUND: Accurate patient identification and specimen labeling at the time of collection are crucial steps in the prevention of medical errors, thereby improving patient safety. METHODS: All patient specimen identification errors that occurred in the outpatient department (OPD), emergency department (ED), and inpatient department (IPD) of a 3,800-bed academic medical center in Taiwan were documented and analyzed retrospectively from 2005 to 2014. To reduce such errors, the following series of strategies were implemented: a restrictive specimen acceptance policy for the ED and IPD in 2006; a computer-assisted barcode positive patient identification system for the ED and IPD in 2007 and 2010, and automated sample labeling combined with electronic identification systems introduced to the OPD in 2009. RESULTS: Of the 2000345 specimens collected in 2005, 1023 (0.0511%) were identified as having patient identification errors, compared with 58 errors (0.0015%) among 3761238 specimens collected in 2014, after serial interventions; this represents a 97% relative reduction. The total number (rate) of institutional identification errors contributed from the ED, IPD, and OPD over a 10-year period were 423 (0.1058%), 556 (0.0587%), and 44 (0.0067%) errors before the interventions, and 3 (0.0007%), 52 (0.0045%) and 3 (0.0001%) after interventions, representing relative 99%, 92% and 98% reductions, respectively. CONCLUSIONS: Accurate patient identification is a challenge of patient safety in different health settings. The data collected in our study indicate that a restrictive specimen acceptance policy, computer-generated positive identification systems, and interdisciplinary cooperation can significantly reduce patient identification errors.

Inactivation of SmeSyRy Two-Component Regulatory System Inversely Regulates the Expression of SmeYZ and SmeDEF Efflux Pumps in Stenotrophomonas maltophilia.

SmeYZ efflux pump is a critical pump responsible for aminoglycosides resistance, virulence-related characteristics (oxidative stress susceptibility, motility, and secreted protease activity), and virulence in Stenotrophomonas maltophilia. However, the regulatory circuit involved in SmeYZ expression is little known. A two-component regulatory system (TCS), smeRySy, transcribed divergently from the smeYZ operon is the first candidate to be considered. To assess the role of SmeRySy in smeYZ expression, the smeRySy isogenic deletion mutant, KJΔRSy, was constructed by gene replacement strategy. Inactivation of smeSyRy correlated with a higher susceptibility to aminoglycosides concomitant with an increased resistance to chloramphenicol, ciprofloxacin, tetracycline, and macrolides. To elucidate the underlying mechanism responsible for the antimicrobials susceptibility profiles, the SmeRySy regulon was firstly revealed by transcriptome analysis and further confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and promoter transcription fusion constructs assay. The results demonstrate that inactivation of smeRySy decreased the expression of SmeYZ pump and increased the expression of SmeDEF pump, which underlies the ΔsmeSyRy-mediated antimicrobials susceptibility profile. To elucidate the cognate relationship between SmeSy and SmeRy, a single mutant, KJΔRy, was constructed and the complementation assay of KJΔRSy with smeRy were performed. The results support that SmeSy-SmeRy TCS is responsible for the regulation of smeYZ operon; whereas SmeSy may be cognate with another unidentified response regulator for the regulation of smeDEF operon. The impact of inverse expression of SmeYZ and SmeDEF pumps on physiological functions was evaluated by mutants construction, H2O2 susceptibility test, swimming, and secreted protease activity assay. The increased expression of SmeDEF pump in KJΔRSy may compensate, to some extents, the SmeYZ downexpression-mediated compromise with respect to its role in secreted protease activity.

Evaluation of the Elecsys(®) Anti-HCV II assay for routine hepatitis C virus screening of different Asian Pacific populations and detection of early infection.

BACKGROUND: Early diagnosis of hepatitis C virus (HCV) infection is essential to allow appropriate treatment and prevent transmission. OBJECTIVES: To evaluate the Elecsys(®) Anti-HCV II assay as a routine screening assay in Asia using a large number of samples from different Asian Pacific populations and compare its performance with other HCV assays routinely used in the region. STUDY DESIGN: The sensitivity and specificity of the Elecsys(®) Anti-HCV II assay were determined using routine hospital samples and compared with at least one of the following comparator assays at nine independent centers: ARCHITECT™ Anti-HCV; Serodia(®)-HCV Particle Agglutination; Vitros(®) ECi Anti-HCV; Elecsys(®) Anti-HCV; ADVIA Centaur(®) HCV; InTec(®) HCV EIA; or Livzon(®) Anti-HCV. Commercially available seroconversion panels were used to assess sensitivity for early detection of infection. RESULTS: The Elecsys(®) Anti-HCV II assay was more sensitive in recognizing early infection and detected acute HCV infection earlier on average than the comparator assays for all six panels tested. 7,726 routine samples were tested and 322 identified as HCV positive. Elecsys(®) Anti-HCV II had a sensitivity of 100% and a specificity of 99.66%, both of which were comparable or superior to the results obtained for competitor assays, which ranged from 87.5-100% and 98.98-100%, respectively. CONCLUSIONS: The Elecsys(®) Anti-HCV II assay has the sensitivity and specificity to support its use as a routine screening method in the Asia Pacific region. Furthermore, this assay shortens the diagnostic window between infection and the detection of antibodies compared with established methods.

Association of small dense lowdensity lipoprotein cholesterol in type 2 diabetics with coronary artery disease.

BACKGROUND: The risk of coronary artery disease (CAD) increases two- to fourfold in diabetes. Small dense low-density lipoprotein (sdLDL) particles have been linked to an increased risk for CAD. In this study, we sought to compare the sdLDL cholesterol (sdLDL-C) level between the healthy control group and diabetics with CAD in the Taiwanese population. METHODS: Serum specimens were collected from healthy females and males of various age groups (n = 294), type 2 diabetics (DM) without complications (n = 113), and patients having DM with CAD (DM-CAD) (n = 46). The commercial kit was used for the measurement of sdLDL-C level, which employs a simpler method. After heparin-magnesium precipitation of lipoproteins with density <1.044 g/ml, sdLDL (density = 1.044-1.063 g/ml) remained in the supernatant and this sdLDL-C was measured using an automated chemistry analyzer. RESULTS: The sdLDL-C level was significantly higher in males than in females (p < 0.001) and there was an age effect on sdLDL-C (p < 0.001). The DM-CAD group had significantly higher sdLDL-C levels than the healthy control group (p < 0.001), but there was no statistical difference in the LDL-C level between DM-CAD group and the healthy control group. In addition, only individuals having both high LDL-C and sdLDL-C levels had a higher risk for DM-CAD, compared to those with low LDL-C levels and low sdLDL-C levels [Odds Ratio (OR) 4.97; 95% Confidence Interval (CI) 1.96-12.57; p = 0.001]. CONCLUSIONS: Our data suggest that the sdLDL-C level together with the LDL-C level are better risk assessment markers for type 2 diabetics with CAD than the LDL-C level alone.

Effect of glycemic control on microalbuminuria development among type 2 diabetes with high-normal albuminuria.

This study was aimed at revealing the factors and the interrelationships between factors on microalbuminuria development among type 2 diabetes (T2D) patients. Between 2004 and 2011, 461 T2D patients with a baseline urine albumin-to-creatinine ratio (UACR) of <30 mg/g, and an estimated glomerular filtration rate (eGFR) of >60 mL/min were evaluated retrospectively. Sixty-eight (14.8%) subjects had developed microalbuminuria in a mean follow-up of 6.82 years. Statistical analysis had revealed that the higher baseline UACR (10 mg/g; sensitivity, 80.9%, specificity, 63.6%; AUC = 0.774) and glycohemoglobin level (HbA1c) (8%; sensitivity, 72.1%, specificity, 61.6%; AUC = 0.698) were the two independent microalbuminuria risk factors. When considering the risk of microalbuminuria, the data were normalized with respect to subjects with low-normal UACR (<10 mg/g) and HbA1c < 8%. The adjusted hazard ratio for subjects with low-normal UACR/HbA1c > 8%, high-normal UACR/HbA1c < 8%, and high-normal UACR/HbA1c >8% were 2.59 (p = 0.107), 6.15 (p = 0.001), and 16.96 (p < 0.001), respectively. It was determined that an increase of HbA1c levels (<8, 8-9, 9-10, >10%) showed a progressively increase of the hazard risk in baseline high-normal UACR group. But the same correlation was not shown in the low-normal UACR group. This study identified the relationships of high-normal albuminuria and glycemic control on microalbuminuria development among T2D patients. Glycemic control is especially beneficial for T2D patients with baseline high-normal UACR in preventing microalbuminuria development.

Real-time amplification of glyceraldehyde-3-phosphate dehydrogenase gene for quality control of leukopoor platelets.

BACKGROUND: Leukoreduction of blood products is crucial to prevent white blood cell (WBC)-associated complications during transfusion. Of the widely accepted methods for quantifying WBCs in blood components, Nageotte hemocytometry is time-consuming and laborious whereas a specialized instrument is required for flow cytometry. A reliable and affordable method to assess WBC count in blood products is of particular interest. STUDY DESIGN AND METHODS: Real-time polymerase chain reaction (PCR) of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was developed for quantifying WBCs in leukopoor platelets (LPPs). After normalization by the cell-free prefiltrated and postfiltrated plasma DNA, the relative copy number of GAPDH gene in the platelet (PLT) concentrate and its corresponding LPPs was calculated according to the equation of 2(-ΔΔCt) of which Ct is defined as the threshold cycle. The percentage and the number of WBCs that remained in LPPs were consequently determined. This method was compared to Nageotte hemocytometry and was validated by using serially diluted PLT concentrate and 10 pairs of PLT concentrate-LPP samples. RESULTS: Consistent with the removal of WBCs after filtration, the Ct values for the LPP samples were increased when compared to their corresponding PLT concentrate. As revealed by real-time PCR of GAPDH gene, there is a correlation between the calculated and theoretical WBC count in the serially diluted PLT concentrate (correlation coefficient, 0.9532). The WBC counts for the 10 LPP samples were comparable between Nageotte and real-time PCR method and were all below 3.3 × 10(6) WBCs/L. CONCLUSION: The real-time PCR method we report in this study is applicable for routine quality assurance during leukoreduction process.

Neurological complications of acute intermittent porphyria.

BACKGROUND: Acute intermittent porphyria (AIP) is an inherited disorder of heme biosynthesis, the clinical manifestations of which are incompletely understood. In this report, we describe 12 cases of AIP, focusing on the neurological manifestations. METHODS: Twelve patients were diagnosed with AIP on the basis of characteristic clinical findings, erythrocyte porphobilinogen deaminase (PBGD) activity, and molecular genetics. Central and peripheral nervous system manifestations were noted, and electrophysiological and radiological studies performed. Potential precipitating factors were recorded. RESULTS: Eleven PBGD gene mutations were identified in 12 patients. Nine patients experienced neurological symptoms involving the central nervous system (consciousness disturbance, n = 8; convulsion/seizure, n = 4; behavior change, n = 1), while 7 patients experienced peripheral neuropathies (motor paresis, n = 7; impairment of bulbar or respiratory function, n = 4). The electrophysiological and electroencephalographic findings were consistent with the neurological symptoms of AIP. Urinary PBG and δ-aminolevulinic acid levels were elevated in all patients. PBGD enzyme activity levels were below normal in all patients. Eight patients had documented exposure to porphyrogenic agents. CONCLUSIONS: Our detailed description of a relatively large number of cases of AIP may help clinicians to recognize this often difficult-to-diagnose disorder.

Evaluation of the value of rapid D-dimer test in conjunction with cardiac troponin I test for early risk stratification of myocardial infarction.

We sought to determine the diagnostic value of a D-dimer test for myocardial infarction (MI). The prospective cohort study was carried in the ED of a university hospital. All included patients were tested for D-dimer and cardiac troponin I (cTnI) on ED admission and additional cTnI 6 h later. AMI was retrospectively confirmed by employing the ESC-ACC-AHA-WHF 2007 universal definition. The discriminative value of D-dimer test was assessed by ROC curve analysis. Multivariate analysis was used to identify independent risk factors associated with D-dimer elevation other than MI. A total of 178 patients were included in this study. Median D-dimer levels were significantly higher in MI patients. A D-dimer value greater than 200 ng/ml was significantly associated with MI. When used alone, the test has a high sensitivity of 91.8% but a low specificity of 23.9%. Combined use of cTnI and D-dimer tests raised the sensitivity to 98.4% and helped early triage a subgroup of low risk patients. However, the test had the downside of 58% false positives. High false positives could be partly explained by the high prevalence of underlying hypercoagulable comorbidities. Diabetes mellitus with chronic renal insufficiency was identified as the strongest risk factor associated with D-dimer elevation in patients without MI. D-dimer test alone has a low diagnostic value for MI. Co-existing hypercoagulable conditions may confound the results. Combining cTnI and D-dimer tests enables early identification a low risk group of patients for MI at the cost of high false positives.