Validation of the Randox colorimetric assays for serum copper and zinc.

BACKGROUND: Serum copper and zinc are measured to assess deficiency and toxicity. Atomic absorption spectrophotometry and mass spectrometry methods are expensive and require highly trained staff. Colorimetric assays are available from Randox which are inexpensive and can be automated. We validated serum copper and zinc colorimetric assays on the Binding Site Optilite analyser including comparison with flame atomic absorption spectrophotometry (FAAS) and inductively coupled plasma-mass spectrometry (ICP-MS). METHODS: Accuracy, imprecision, lower limit of quantitation, and linearity were ascertained. The impact of triglycerides, bilirubin, nickel, and iron on assay performance was also investigated. Comparison of results from colorimetric analysis of patient and external quality assurance samples with those obtained by FAAS and ICP-MS was undertaken. RESULTS: Intra-, and inter-assay imprecision was <9%. Serum copper and zinc assays were linear between 1.8-35.6 and 2.3-45.7 µmol/L, respectively. Agreement was good between colorimetry and FAAS (intercept = -0.7, slope = 1.04) and ICP-MS (intercept = 0.6, slope = 0.99) for serum copper in patients' samples. For serum zinc, agreement was poor between colorimetry and FAAS (intercept = 2.2, slope = 0.87) and ICP-MS (intercept = 1.9, slope = 0.98) in patients' samples. There was a poor concordance in assessment of hypozincaemia between colorimetry and FAAS/ICP-MS. CONCLUSION: The Randox colorimetric assay for serum copper on the Optilite is simple to perform, has a short analysis time, and measured concentrations compare well with FAAS and ICP-MS. Due to poor agreement with FAAS and ICP-MS, colorimetry is not suitable for the measurement of serum zinc.

Verification of the Bühlmann fPELA turbo faecal elastase assay on the Binding Site Optilite benchtop analyser.

BACKGROUND: Pancreatic elastase-1 (PE1) can be measured to assess exocrine activity of the pancreas. A semi-automated particle-enhanced, open-channel turbidimetric immunoassay has been introduced by Bühlmann (fPELA turbo, Bühlmann Laboratories AG, Schoenenbuch, Switzerland). Published evaluation data is lacking. We therefore verified performance of the assay on the Binding Site Optilite benchtop analyser and undertook a sample comparison with the DiaSorin PE1 assay on the Liaison. METHODS: Accuracy, imprecision, lower limit of quantitation (LLoQ) and linearity of the Bühlmann fPELA turbo assay on the Binding Site Optilite analyser was ascertained. Comparison with the DiaSorin Liaison PE1 assay was also undertaken. Difference between assays was evaluated using the Wilcoxon signed-rank test and method comparison was undertaken using Spearman's rank correlation (rs), Bland-Altman and Passing-Bablok regression analyses. RESULTS: The fPELA turbo assay was linear between 5 and 2500 µg/g. The LLoQ was 5 µg/g. Intra- and inter-assay imprecision was <6%. There was a good agreement (rs = 0.92) and no significant bias (5.8 µg/g, P = 0.29) present between the Bühlmann fPELA turbo and DiaSorin PE1 assays. CONCLUSION: The Bühlmann fPELA turbo assay performs well on the Binding Site Optilite analyser. Faecal elastase results are commutable between with Bühlmann fPELA turbo and DiaSorin Liaison PE1 assays.

Atypical Facial Emotion Recognition in Children with Autism Spectrum Disorders: Exploratory Analysis on the Role of Task Demands.

People with autism spectrum disorders (ASDs) have difficulty with socio-emotional functioning; however, research on facial emotion recognition (FER) remains inconclusive. Individuals with ASD might be using atypical compensatory mechanisms that are exhausted in more complex tasks. This study compared response accuracy and speed on a forced-choice FER task using neutral, happy, sad, disgust, anger, fear and surprise expressions under both timed and non-timed conditions in children with and without ASD (n = 18). The results showed that emotion recognition accuracy was comparable in the two groups in the non-timed condition. However, in the timed condition, children with ASD were less accurate in identifying anger and surprise compared to children without ASD. This suggests that people with ASD have atypical processing of anger and surprise that might become challenged under time pressure. Understanding these atypical processes, and the environmental factors that challenge them, could be beneficial in supporting socio-emotional functioning in people ASD.

Multiple endocrine neoplasia type 1: clinical correlates of MEN1 gene methylation.

Multiple endocrine neoplasia type 1 (MEN 1) has marked severity variation between individuals with the same mutation. To investigate any relationship between promoter methylation and clinical features, blood and tissue samples were collected from 16 members of the Tasman 1 MEN 1 kindred carrying a common splice site mutation and 7 patients with sporadic MEN 1. Methylation at 39 CpGs in the MEN1 promoter were assessed in formalin fixed, paraffin embedded parathyroid tissue. Clinical disease severity markers included age at first parathyroid operation, parathyroid hormone level and corrected serum calcium levels. Six patients with sporadic hyperparathyroidism were used for comparison. Minimal methylation was observed in all patients across CpG sites 1-23. In contrast, hypermethylation was observed at CpG sites 24-31 in MEN 1 patients, a pattern not observed in patients with non-MEN 1 parathyroid disease. Mean methylation at sites 24-31 was significantly correlated with age at first parathyroid operation (r = 0.652, p = 0.041). A permutation test, utilising the mean correlation coefficient (r = -0.401) revealed a possible association between relative PHPT severity and methylation score for each significant CpG site (p < 0.103). This novel study reveals evidence supporting a possible association between altered MEN1 promoter methylation and clinical severity of disease.

Stroke in rural areas and small communities.

The management of stroke in rural and regional areas is variable in both the developed and developing world. Informed by best-practice guidelines and recommendations for systems of stroke care, adaptable models of care that are appropriate for local needs should be devised for rural and regional settings. This review addresses the issue of the provision of appropriate services in rural and regional settings, with particular attention to the barriers involved, according to the classification of Low Human Development Country (LHDC), Medium Human Development Country (MHDC) and High Human Development Country (HHDC). We discuss the need and feasibility of developing implementing stroke care in rural settings according to best-practice recommendations, within models of care adapted to local conditions.

The effect of nutritional supplements on osteoarthritis.

Osteoarthritis (OA) is the most common form of joint disease and cause of musculoskeletal disability in the elderly. Conventional management of OA primarily focuses on the relief of symptoms, using agents such as analgesics and non-steroidal anti-inflammatory drugs (NSAIDs). These drugs, however, are associated with significant side effects and fail to slow the progression of OA. Several nutritional supplements have been shown to be at least as effective as NSAIDs at relieving the symptoms of OA, and preliminary evidence suggests several of these supplements may have a role in influencing the course of OA. The purpose of this article is to review the available literature on the effectiveness and safety of nutritional supplements for the treatment of OA.