A practical approach to the implementation of autoverify

Autoverification is a process in which computer software will automatically evaluate laboratory test results, verify result integrity, and then release the results to the hospital interface without any technologist intervention. Autoverify release criteria are user defined and can be customized. The process of developing, implementing, and monitoring autoverify is achievable for most test results in laboratory medicine. The use of autoverification will improve result quality, increase revenue, and create faster turn-around times. All of this put together will ultimately lead to improved customer satisfaction. Computers and autoverification are survival tools in the competitive market of laboratory diagnostics services.Presented at the 8th Conference on Quality in the Spotlight, 17–18 March 2003, Antwerp, Belgium     

Uric acid quantification in fingernail of gout patients and healthy volunteers using HPLC‐UV

The presence of elevated uric acid (UA) levels is a sign of gout, that is, hyperuricemia. In this study the monitoring of the UA levels in less‐invasive biological samples, such as the human fingernail, is suggested for the diagnosis and therapy of gout. Twenty‐six healthy volunteers (HV) and 22 gout patients (GP) were studied. The UA was extracted from human fingernail samples, then separated on an Inertsil ODS‐3 column (250 × 4.6 mm i.d., 4.0 μm, GL Sciences) by isocratic elution using methanol–74 mm phosphate buffer (pH 2.2) 2:98 (v/v). A UV detector was used to monitor the samples at 284 nm. Using the developed method, different UA concentrations were found in the GP and HV. When comparing the concentrations from GP with those from HV, a statistically significant correlation was observed between the UA (p < 0.01). In this study, the UA was confirmed as a potential biomarker for the diagnosis and therapy of gout. We have developed a novel sensitive, and simple method for the determination of UA in the fingernails of GP and HV. The human fingernail may serve as a noninvasive biosample for the diagnosis of gout. Copyright © 2016 John Wiley & Sons, Ltd.     

Monitoring the brain metabolites of children with acute encephalopathy caused by the H1N1 virus responsible for the 2009 influenza pandemic: a quantitative in vivo H MR spectroscopy study

Background and Purpose

Influenza viral infection, which results in central nervous system dysfunction, is a major cause of acute encephalopathy (AE). The purpose of this study was to investigate the changes in the concentrations of brain metabolites in children with AE using single-voxel magnetic resonance spectroscopy (MRS) and to provide diagnostic information about the relationship between the symptoms of AE and metabolite concentrations.

Materials and Methods

The subjects were 10 children (mean age: 6.2 years; range: 1–13) with AE caused by the novel influenza A virus responsible for the 2009 influenza pandemic. The serial MRS data (TE/TR=30/5000 ms, 3 T) acquired from the basal ganglia (BG) and centrum semiovale (CS) of each patient were categorized into three periods: (1) initial neurological symptom presentation and the start of treatment (n= 10), (2) short-term follow-up (n= 9) and (3) long-term follow-up (n= 3). As controls, the magnetic resonance (MR) spectra of eight age-matched children were also investigated.

Results

In both regions, the concentrations of the major metabolites (N-acetylaspartate, creatine, choline, myo-inositol, glutamate/glutamine complex and glutamate) only showed minor fluctuations between the three periods. On the other hand, higher levels of taurine (Tau) were observed in the BG during the second period (P=.005), and increased levels of glucose were observed in the CS during the first (P=.005) and second (P=.036) periods.

Conclusions

Serial monitoring of brain metabolite changes was carried out with a clinical MR system. The concentrations of major metabolites only displayed very minor fluctuations in response to mild H1N1-related AE. However, a higher Tau concentration was found to be associated with neurological symptoms. Further studies are required to improve our understanding of the detailed activity of Tau in AE.     

Sensitive determination of norepinephrine, synephrine, and isoproterenol by capillary electrophoresis with indirect electrochemiluminescence detection

A new and sensitive method for the determination of norepinephrine (NE), synephrine, and isoproterenol was developed by CE separation and indirect electrochemiluminescence detection (ECL) based on their quenching effects on the tris(2,2'-bipyridyl)-ruthenium(II)/tripropylamine (TPA) system. The conditions for CE separation and ECL detection were investigated in detail. Under the optimum conditions, the three analytes were well separated within 9 min. The LODs (S/N = 3) in standard solution are 2.6 x 10(-8) mol/L for NE, 6.6 x 10(-9) mol/L for synephrine and 8.4 x 10(-8) mol/L for isoproterenol, respectively. The precisions of intraday and interday are less than 4.4 and 6.1%, respectively. The LOQs (S/N = 10) in real human urine samples are 2.6 x 10(-7) mol/L for NE, 8.8 x 10(-8 ) mol/L for synephrine, and 8.8 x 10(-7) mol/L for isoproterenol, respectively. The applicability of the proposed method was illustrated in the determination of 20 human urine samples from diabetic patients and healthy persons. The results obtained indicated that the level of NE in patients (mean value 0.41 micromol/L) was higher than that in healthy persons (mean value 0.24 micromol/L).     

精神分裂症病人血清、指甲、头发中微量元素含量变化分析

应用双光束双通道原子吸收光谱仪测定了精神分裂症病人血清、指甲、头发中的微量元素Cu、Zn、Fe、Mn及宏量元素Ca、Mg的含量，并作了初步分析，结果表明：精神分裂症病人血清、指甲、头发中的元素含量均明显低于正常人，笔者认为，这些元素的缺乏，与精神分裂症的病因有一定关联，代表了精神分裂症病人的基本营养水平，值得进一步深入探讨。     

Study on the quality assurance of diagnostic X-ray machines and assessment of the absorbed dose to patients

Radiation exposure and image quality in X-ray diagnostic radiology provide a clear understanding of the relationship between the radiation dose delivered to a patient and image quality in optimizing medical diagnostic radiology. Because a certain amount of radiation is unavoidably delivered to patients, this should be as low as reasonably achievable. Several X-ray diagnostic machines were used at different medical diagnostic centers in Egypt for studying the beam quality and the dose delivered to the patient. This article studies the factors affecting the beam quality, such as the kilo-volt peak (kVp), exposure time (mSc), tube current (mAs) and the absorbed dose in (μGy) for different examinations. The maximum absorbed dose measured per mAs was 594±239 and 12.5±3.7 μGy for the abdomen and the chest, respectively, while the absorbed dose at the elbow was 18±6 μGy, which was the minimum dose recorded. The compound and expanded uncertainties accompanying these measurements were 4±0.35% and 8±0.7%, respectively. The measurements were done through quality control tests as acceptance procedures.     

Development and evaluation of a simple and easy high-performance liquid chromatography–ultraviolet system simultaneously suitable for determination of 24 anti-epileptic drugs in plasma

We aim to establish a simple and easy high-performance liquid chromatography system coupled with an ultraviolet detector suitable for simultaneous determination of 24 antiepileptic drugs in human plasma. Optimized chromatographic separation was performed on a ZORBAX Eclipse Plus-C18 (4.6 × 150 mm², 3.5 μm) column with acetonitrile and 5 mM potassium dihydrogen phosphate water solution as mobile phase. Note that, 24 antiepileptic drugs were divided into three groups and eluted with different gradient procedures, respectively. The column temperature was maintained at 35°C and the detection wavelength was set at 210 nm. Plasma was processed with ethyl acetate or acetonitrile. The calibration curves of 24 antiepileptic drugs demonstrated good linearity within the test range (r > 0.996). The intra- and inter-batch precision and accuracy were all less than 15%, while extraction recoveries were in the range of 74.57–90.89% with the relative standard deviation values less than 15%. The validated methods have been successfully applied to determination of some antiepileptic drugs in rat or patient plasma. Those results indicated that the developed methods were simple and easy, and could be suitable for the determination of 24 antiepileptic drugs in plasma just by changing the gradient elution procedures of mobile phase.     

Threshold start-up control policy for polling systems

A threshold start-up policy is appealing for manufacturing (service) facilities that incur a cost for keeping the machine (server) on, as well as for each restart of the server from its dormant state. Analysis of single product (customer) systems operating under such a policy, also known as the N-policy, has been available for some time. This article develops mathematical analysis for multiproduct systems operating under a cyclic exhaustive or globally gated service regime and a threshold start-up rule. It pays particular attention to modeling switchover (setup) times. The analysis extends/unifies existing literature on polling models by obtaining as special cases, the continuously roving server and patient server polling models on the one hand, and the standard M/G/1 queue with N-policy, on the other hand. We provide a computationally efficient algorithm for finding aggregate performance measures, such as the mean waiting time for each customer type and the mean unfinished work in system. We show that the search for the optimal threshold level can be restricted to a finite set of possibilities. This revised version was published online in June 2006 with corrections to the Cover Date.     

Two-Queue Polling Models with a Patient Server

We consider two-queue polling models with the special feature that a timer mechanism is employed at Q ₁: whenever the server polls Q ₁ and finds it empty, it activates a timer and remains dormant, waiting for the first arrival. If such an arrival occurs before the timer expires, a busy period starts in accordance with Q ₁'s service discipline. However, if the timer is shorter than the interarrival time to Q ₁, the server does not wait any more and switches back to Q ₂. We consider three configurations: (i) Q ₁ is controlled by the 1-limited protocol while Q ₂ is served exhaustively, (ii) Q ₁ employs the exhaustive regime while Q ₂ follows the 1-limited procedure, and (iii) both queues are served exhaustively. In all cases, we assume Poisson arrivals and allow general service and switchover time distributions. Our main results include the queue length distributions at polling instants, the waiting time distributions and the distribution of the total workload in the system.     

A review of autovalidation software in laboratory medicine

Although autovalidation procedures have been around for many years, through the use of computers and the application of (medical) protocols, they are now becoming part of the production environment of medical laboratories. The introduction of high volume instruments within routine medical laboratory testing certainly speeded up their application as well. After defining autovalidation, autoverification and autoconfirmation, this paper provides a framework for the different ways and places where these tools can be applied within laboratory medicine. Technology as well as organization are essential building blocks to reach well-defined, transparent and assured quality. A laboratory automation system (LAS) brings both areas together in a logical, future-oriented way. Strengthening the information loop, reaching guaranteed quality (analytical, turnaround times and efficiency), leads towards strict management of the laboratory processes. This includes all laboratory processes and here autovalidation and autoreporting become essential. A survey of currently available software routines and their appraisal from a managerial viewpoint are given. It can be concluded that autovalidation software in laboratory medicine is maturing and is rapidly becoming a critical success factor in any medical laboratory. Quality can be automated for sure and autovalidation software will prove to be a valuable aid to do so. Received: 23 August 2002 Accepted: 26 August 2002 Presented at the European Conference on Quality in the Spotlight in Medical Laboratories, 7–9 October 2001, Antwerp, Belgium