Real-world experience of SARS-CoV-2 antibody assays in UK healthcare workers.

Background: The seroprevalence of antibodies to SARS-CoV-2 in healthcare workers is variable throughout the world. This study compares the use of two antibody assays among large cohorts of healthcare workers in southern England.

Methods: This cohort study includes data obtained from staff at Western Sussex Hospitals NHS Foundation Trust (WSHT) and Brighton and Sussex University Hospitals (BSUH) during voluntary antibody testing, using Abbott and Roche SARS-CoV-2 antibody assays at each Trust respectively.

Age and sex variation in serum albumin concentration: an observational study.

Background: In the UK, a common reference interval for serum albumin is widely used irrespective of age or sex. Implicit in this is that laboratories produce analytically similar results. This paper challenges the validity of this approach.

Impaired renal function and biomarkers of vascular disease in Alzheimer's disease.

Renal disease is a risk factor for vascular diseases and for dementia, and renal insufficiency can be a feature of Alzheimer's disease (AD). Evidence has suggested that vascular mechanisms mediate the link between renal disease and dementia. Our study sought to test this hypothesis by examining renal and vascular functioning in AD by investigating estimated glomerular filtration rates (eGFR), calculated from serum creatinine concentrations, and established biomarkers of vascular functioning, asymmetrical dimethylarginine (ADMA) and plasma homocysteine (Hcy), in individuals with mild to moderate AD (n = 34) and a group of older adult controls (n = 34).

Pro-inflammatory cytokines IL-1β and TNF-α are not associated with plasma homocysteine concentration in Alzheimer's disease.

Increased concentrations of pro-inflammatory blood cytokines and plasma homocysteine (Hcy) are frequently reported in Alzheimer's disease (AD). Hcy appears to have immunomodulating and pro-inflammatory activities. Further, emerging evidence from animal and non-AD human studies implicates Hcy in potentiating the activities of proinflammatory cytokines; Hcy toxicity may also, in part, be mediated by these cytokines.

Pro-inflammatory cytokines IL-1β and TNF-α are not associated with blood homocysteine concentration in Alzheimer's disease.

Increased concentrations of pro-inflammatory blood cytokines and plasma homocysteine (Hcy) are frequently reported in Alzheimer's disease (AD). Hcy appears to have immunomodulating and pro-inflammatory activities. Further, emerging evidence from animal and non-AD human studies implicates Hcy in potentiating the activities of pro-inflammatory cytokines; Hcy toxicity may also, in part, be mediated by these cytokines.

Instability of fibroblast growth factor-23 (FGF-23): implications for clinical studies.

Background: Fibroblast growth factor-23 (FGF-23) is a bone secreted hormone that regulates phosphate homeostasis and calcitriol levels. FGF-23 concentrations are elevated in chronic kidney disease (CKD), oncogenic osteomalcia and a number of rare hereditary disorders. Studies systematically evaluating the pre-analytical stability of intact FGF-23 are lacking.

Plasma fetuin-A is associated with the severity of cognitive impairment in mild-to-moderate Alzheimer's disease.

The significance of vascular risk factors in the development and progression of Alzheimer's disease (AD) is now widely recognized. Fetuin-A is an abundant plasma protein that predicts vascular risk in a variety of clinical settings. In the context of cerebral ischemia, fetuin-A appears to be anti-inflammatory.

Arginine and methylated arginines in human plasma and urine measured by tandem mass spectrometry without the need for chromatography or sample derivatisation.

A method for the simultaneous analysis of asymmetric dimethylarginine, symmetric dimethylarginine, monomethylarginine and arginine in human plasma and urine, with short analysis time and isotopic internal standardisation for each analyte is described. The method requires neither sample derivatisation nor the need for chromatographic separation of analytes. The method described shows good precision and accuracy and is suited for both research purposes and implementation in the busy, routine clinical laboratory.

Simultaneous quantitation of homocysteine, cysteine and methionine in plasma and urine by liquid chromatography-tandem mass spectrometry.

Background: A method utilizing liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) has been developed and evaluated for the determination of total homocysteine, cysteine and methionine in plasma and urine. The simultaneous measurement of homocysteine and methionine concentrations may help explain the underlying mechanism responsible for hyperhomo-cysteinaemia.

Methods: Samples were prepared by simple protein precipitation after reduction of disulphides by dithiothreitol.

Behavioural and psychological symptoms of Alzheimer type dementia are not correlated with plasma homocysteine concentration.

Background/aims: Vitamin B12 and folate deficiencies have been associated with cognitive impairment and various psychiatric symptoms but not specifically with behavioural and psychological symptoms of dementia (BPSD). A limitation of previous studies in dementia was lack of concurrent homocysteine measurement especially as it may provide a better indicator of tissue activities of these vitamins. This study was designed to clarify whether a relationship exists between plasma homocysteine concentration and BPSD.