High-density lipoprotein cholesterol subfraction HDL2 is associated with improved endothelial function in systemic lupus erythematosus.

OBJECTIVE: Patients with systemic lupus erythematosus (SLE) have increased risk of premature atherosclerosis but the exact mechanisms remains unclear. Flow-mediated dilatation (FMD) is an established non-invasive assessment of vascular endothelial function. Lipoprotein subfractions may be better predictors of FMD than conventional cholesterol measurements. We tested the hypothesis that lipoprotein subfractions are independently associated with FMD. METHODS: Forty-one consecutive adult patients with SLE without known cardiovascular risk factors or disease were recruited in this cross-sectional study. Endothelial function and early atherosclerosis were assessed by brachial FMD and common carotid artery (CCA) intima-media thickness (IMT). High-density lipoprotein (HDL)/low-density lipoprotein (LDL) subfractions were measured. Machine learning models were also constructed to predict FMD and CCA IMT. RESULTS: Median FMD was 4.48% (IQR 5.00%) while median IMT was 0.54 mm (IQR 0.12 mm). Univariate analysis showed lower LDL1 (r=-0.313, p<0.05) and higher HDL2 subfractions (r=0.313, p<0.05) were significantly associated with higher log-transformed FMD. In a multiple linear regression model, HDL2 (ß=0.024, SE=0.012, p<0.05) remained an independent predictor of higher FMD after adjusting for age, body mass index, LDL1 and systolic blood pressure. The machine learning model included parameters such as HDL2 (positive association), prednisolone dose, LDL cholesterol and LDL1 for prediction of FMD (r=0.433, p<0.01). Age, LDL cholesterol and systolic blood pressure were independently associated with higher CCA IMT after adjusting for body mass index and HDL2. CONCLUSIONS: HDL 2, a large HDL particle, was independently associated with greater FMD and may be a biomarker of vascular health in SLE.

Calibration Practices in Clinical Mass Spectrometry: Review and Recommendations.

Background: Calibration is a critical component for the reliability, accuracy, and precision of mass spectrometry measurements. Optimal practice in the construction, evaluation, and implementation of a new calibration curve is often underappreciated. This systematic review examined how calibration practices are applied to liquid chromatography-tandem mass spectrometry measurement procedures. Methods: The electronic database PubMed was searched from the date of database inception to April 1, 2022. The search terms used were "calibration," "mass spectrometry," and "regression." Twenty-one articles were identified and included in this review, following evaluation of the titles, abstracts, full text, and reference lists of the search results. Results: The use of matrix-matched calibrators and stable isotope-labeled internal standards helps to mitigate the impact of matrix effects. A higher number of calibration standards or replicate measurements improves the mapping of the detector response and hence the accuracy and precision of the regression model. Constructing a calibration curve with each analytical batch recharacterizes the instrument detector but does not reduce the actual variability. The analytical response and measurand concentrations should be considered when constructing a calibration curve, along with subsequent use of quality controls to confirm assay performance. It is important to assess the linearity of the calibration curve by using actual experimental data and appropriate statistics. The heteroscedasticity of the calibration data should be investigated, and appropriate weighting should be applied during regression modeling. Conclusions: This review provides an outline and guidance for optimal calibration practices in clinical mass spectrometry laboratories.

Transient Atrioventricular Block as a Complication of Influenza A Virus: A Case Report.

Influenza is one of the most common respiratory viral infections, causing annual epidemics of respiratory illnesses characterized by sudden onset of fever, malaise, myalgias, cough, and other respiratory complaints. A spectrum of cardiovascular complications has also been reported in association with influenza infection. Cardiovascular involvement can occur through the direct effects of the virus on the myocardium or through the exacerbation of the existing cardiovascular disease. We report the case of an 86-year-old woman without a history of cardiac disease before admission who developed a transient complete atrioventricular block without myocarditis after acute infection with the influenza A virus.

Using a Web-Based Platform as an Alternative for Conducting International, Multidisciplinary Medical Conferences During the Novel COVID-19 Pandemic: Analysis of a Conference.

BACKGROUND: The COVID-19 pandemic has stunted medical education activities, resulting in most conferences being cancelled or postponed. To continue professional education during this crisis, web-based conferences can be conducted via livestream and an audience interaction platform as an alternative. OBJECTIVE: The unprecedented COVID-19 pandemic has affected human connections worldwide. Conventional conferences have been replaced by web-based conferences. However, web-based conferencing has its challenges and limitations. This paper reports the logistics and preparations required for converting an international, on-site, multidisciplinary conference into a completely web-based conference within 3 weeks during the pandemic. METHODS: The program was revised, and a teleconference system, live recording system, director system setup, and broadcasting platform were arranged to conduct the web-based conference. RESULTS: We used YouTube (Alphabet Inc) and WeChat (Tencent Holdings Limited) for the web-based conference. Of the 24 hours of the conventional conference, 21.5 hours (90%) were retained in the web-based conference via live broadcasting. The conference was attended by 71% (37/52) of the original international faculties and 71% (27/38) of the overall faculties. In total, 61 out of 66 presentations (92%) were delivered. A special session-"Dialysis access management under the impact of viral epidemics"-was added to replace precongress workshops and competitions. The conference received 1810, 1452, and 1008 visits on YouTube and 6777, 4623, and 3100 visits on WeChat on conference days 1, 2, and 3, respectively. CONCLUSIONS: Switching from a conventional on-site conference to a completely web-based format within a short period is a feasible method for maintaining professional education in a socially responsible manner during a pandemic.

Increased risk of dementia following herpes zoster ophthalmicus.

This retrospective cohort study aimed to examine the relationship between herpes zoster ophthalmicus (HZO) and the subsequent risk of dementia using a population-based database. We retrieved the study sample from the Taiwan Longitudinal Health Insurance Database 2005. The study group included 846 patients with HZO, and the comparison group included 2538 patients without HZO. Each patient was individually followed for a 5-year period to identify those patients who subsequently received a diagnosis of dementia. We performed a Cox proportional hazards regression to calculate the hazard ratios (HRs) along with 95% confidence intervals (CIs) for dementia during the follow-up period between patients with HZO and comparison patients. The respective incidence rates of dementia per 1000 person-years were 10.15 (95% CI: 7.22~13.87) and 3.61 (95% CI: 2.61~4.89) for patients with HZO and comparison patients. The Cox proportional analysis showed that the crude HR of dementia during the 5-year follow-up period was 2.83 (95% CI: 1.83-4.37) for patients with HZO than comparison patients. After adjusting for patients' characteristics and comorbidities, HZO patients were still at a 2.97-fold greater risk than comparison patients for developing dementia. Furthermore, we found that of sampled male patients, the crude HR of dementia for patients with HZO was as high as 3.35 (95% CI = 1.79-6.28) compared to comparison patients. This study demonstrated an association between HZO and dementia. Clinicians must be alert to suspect dementia in patients with cognitive impairment who had prior HZO.

Recovery of spiked troponin I in four routine assays.

INTRODUCTION: This study aimed to examine the recovery of spiked human cardiac troponin I (cTnI) results measured by four routine assays, and investigate possible interference from microclots. MATERIALS AND METHODS: 457 consecutive samples with cTnI concentration below limit of quantitation (12 ng/L), declared by the Vitros TnI ES assay (reference assay), were measured on Beckman Coulter Accu TnI+3, Siemens TnI-Ultra and Roche TnI STAT assays. These samples were enriched with native full-length cTnI to a concentration of 100 ng/L and retested. A post-spiking result that exceeded the critical difference at a predefined probability of 0.0005 of the target concentration (the median post-spiking result for each individual assay) was considered as outlier. To determine whether microclots were a significant cause of critically discrepant outlier results, a separate 50 samples were centrifuged twice between two post-spiking measurements using the Vitros TnI ES assay. RESULTS: The median recovery of the enriched cTnI was highest with the Roche assay (271 ng/L) and lowest with the Vitros assay (29 ng/L). The Vitros assay had the highest percentage of results that exceeded the critical difference (49%), followed by the Siemens (38%), Roche (18%) and Beckman Coulter (7%) assays. None of the 50 additional samples produced a critically lower cTnI result after re-centrifugation. CONCLUSIONS: Our findings underscored the variability of cTnI assays in measuring native cTnI. The lack of cTnI results that became significantly lower after re-centrifugation suggested that microclots are unlikely to be a major cause of the outlier results.

Bacteremic pneumonia caused by extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae: Appropriateness of empirical treatment matters.

BACKGROUND: Clinical information about bacteremic pneumonia caused by extended-spectrum beta-lactamase (ESBL)-producing organism is limited. METHODS: A retrospective study was conducted at two medical centers in Taiwan. From May 2002 to August 2010, clinical information and outcome of adults with bacteremic pneumonia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae were analyzed. The primary outcome is the 30-day mortality. RESULTS: A total of 111 patients with bacteremic pneumonia caused by E. coli (37 patients, 33.3%) and K. pneumoniae (74, 66.7%) were identified. Their mean age was 69.2 years and 51.4% were male patients. Fifty-seven (51.3%) episodes were classified as hospital-acquired infections, 19 (17.1%) as health-care-associated infections, and four (3.6%) as community-acquired infections. Fifty-one (45.9%) patients received appropriate empiric antimicrobial therapy. The 30-day mortality rate was 40.5% (45 patients). In the multivariate analysis, several independent risk factors, including rapidly fatal underlying disease [odds ratio (OR), 5.75; 95% confidence interval (CI), 1.54-21.48; p = 0.009], severe sepsis (OR, 4.84; 95% CI, 1.55-15.14; p = 0.007), critical illness (OR, 4.28; 95% CI, 1.35-13.57; p = 0.013), and receipt of appropriate empirical therapy (OR, 0.19; 95% CI, 0.07-0.55; p = 0.002), were associated with 30-day mortality. The survival analysis consistently found that individuals with appropriate empiric therapy had a higher survival rate (log-rank test, p < 0.001). CONCLUSION: ESBL-producing bacteremic pneumonia, especially health-care-associated infections, often occurred in adults with comorbidities. Appropriate empirical therapy was associated with a favorable outcome.

Salmonella infective endocarditis.

OBJECTIVE: Salmonella endocarditis is so rarely reported that its clinical features, prognosis, and optimal treatment remain unclear. In this paper, we report a female with nontyphoid Salmonella endocarditis complicated with perivalvular abscess. We also review and summarize other cases reported in the English literature. METHODS: Using the key words "Salmonella", "infective endocarditis", and "mural endocarditis" to search the PubMed database, we reviewed case reports on Salmonella endocarditis published between 1976 and 2014 and case series of infective endocarditis that included at least 500 cases. RESULTS: Salmonella species were rare infective endocarditis pathogens. Among 16 large case series, they accounted for less than 0.01% and up to 2.9% of bacterial endocarditis cases. From 1976 to 2014, a total of 87 cases of typhoid and nontyphoid Salmonella endocarditis were reported, which included 42 cases in 1976-1984, 30 cases in 1986-2002, and 15 cases in 2003-2014. Men predominated among the cases (58.6%), and the mean age was approximately 50-60 years. The major affected valves were the mitral valves (33.3%). Mural endocarditis was common (26.4%). Perivalvular abscess was only reported in 10.5% (6 cases) of 57 cases. The overall mortality rate was 42.5% and decreased over time from 69.0% to 13.3% during the three study periods. CONCLUSION: Salmonella endocarditis, although rare, may cause purulent infections in the perivalvular area or myocardium and lead to substantial mortality.

Pneumomediastinum in patients with AIDS: a case report and literature review.

OBJECTIVE: Pneumomediastinum is a rare complication of opportunistic infections in HIV-infected patients. However, the relationship between the causative pathogens and the prognosis is unclear. We report the case of a patient with AIDS presenting with community-acquired pneumonia complicated by pneumomediastinum. The cases of a further 10 HIV-infected patients with pneumomediastinum reported in the English language literature are reviewed. METHODS: PubMed was searched for cases of HIV-infected patients with pneumomediastinum published in the English language literature. RESULTS: Pneumocystis jirovecii is the most common pathogen causing pneumonia and concurrent pneumomediastinum in HIV-infected patients. Only one of the identified cases was caused by cytomegalovirus. Excluding the two cases with incomplete information, the overall mortality rate in the remaining nine cases was 55.5%. CONCLUSION: In HIV-infected patients, Pneumocystis jirovecii pneumonia can occasionally present as pneumomediastinum. In such cases, adequate appropriate antimicrobial therapy is needed due to the high mortality rate.

Activated nickel platform for electrochemical sensing of phosphate.

We report here a highly selective enzymeless approach for the determination of phosphate (PO(4)(3-)) by flow injection analysis (FIA). In this system, the activation of barrel plated nickel electrode (Ni-BPE) in alkaline media to form a Ni(OH)(2)/NiO(OH) film was found to trigger the adsorption of phosphate at the electrode surface. Based on the suppressed current of the electrocatalytic oxidation of glucose at the activated Ni-BPE in 0.1 M NaOH solution caused by adsorption of phosphate, we develop an FIA detection scheme for the determination of phosphate. Under the optimized conditions of flow rate = 300 microL/min and detection potential = 0.55 V vs Ag/AgCl with 25 microM glucose in 0.1 M NaOH as carrier solution, the calibration curve showed a linear range up to 1 mM. Possible interferences from the coexisting ions were also investigated. The results demonstrated that sensor could be used for the determination of phosphate in the presence of nitrate, chloride, sulfate, acetate, oxalate, carbonate, and some anionic species of toxicological and environmental interest, such as chlorate, chromate, and arsenate ions. The electrode can be effectively regenerated without extra treatment under the hydrodynamic condition. For eight continuous injections of 40 microM PO(4)(3-), a relative standard deviation of 0.28% was obtained, indicating good reproducibility of the proposed method. The detection limit (S/N = 3) was calculated as 0.3 microM.

A disposable screen-printed silver strip sensor for single drop analysis of halide in biological samples.

A screen-printed silver strip with three-electrode configuration of Ag-working, Ag-counter and Ag/Ag(x)O reference electrodes was developed for simultaneous determination of chloride, bromide and iodide in aqueous solutions. It was fabricated simply by screen-printing silver ink onto a polypropylene (PP) base. The in-situ prepared Ag/Ag(x)O reference electrode can avoid the leaching interference in chloride detection while using a conventional Ag/AgCl reference electrode. A single drop of analyte (50 microl) is enough to determine iodide, bromide and chloride by measuring the well-separated oxidation peak currents of respective silver halides. The calibration graph was linear from 10 microM to 20 mM for iodide and bromide and 100 microM to 20 mM for chloride and the detection limit (S/N=3) was 3.05 microM, 2.95 microM and 18.83 microM for iodide, bromide and chloride, respectively. The strip is designed to be disposable and as such manual polishing is not necessary. The proposed sensor is not only simple to manufacture and easy to operate but also fast and precise with little detection volume. It is successfully applied to the determination of halide ions in real samples.