Reduction of sample matrix effects - The analysis of benzimidazole residues in serum by immunobiosensor

Regulatory authorities, the food industry and the consumer demand reliable determination of chemical contaminants present in foods. A relatively new analytical technique that addresses this need is an immunobiosensor based on surface plasmon resonance (SPR) measurements. Although a range of tests have been developed to measure residues in milk, meat, animal bile and honey, a considerable problem has been encountered with both serum and plasma samples. The high degree of non-specific binding of some sample components can lead to loss of assay robustness, increased rates of false positives and general loss of assay sensitivity. In this paper we describe a straightforward precipitation technique to remove interfering substances from serum samples to be analysed for veterinary anthelmintics by SPR. This technique enabled development of an assay to detect a wide range of benzimidazole residues in serum samples by immunobiosensor. The limit of quantification was below 5 ng/ml and coefficients of variation were about 2%.

Serum erythropoietin levels in paroxysmal nocturnal haemoglobinuria: Implications for therapy

In order to assess the rationale and possible indications for the use of recombinant erythropoietin in paroxysmal nocturnal haemoglobinuria (PNH), we have measured endogenous erythropoietin (Epo) levels in 18 patients with PNH and in 44 patients with iron deficiency anaemia (IDA), In both groups of patients we found a significant inverse correlation between Epo and haemoglobin (Hb). However, the mean Epo level was significantly higher in the PNH group (385 mU/ml) than in the IDA group (136 mU/ml), The range of Epo levels at any given Hb was greater in the PNH group than in the IDA group. There was a significant positive correlation between Epo and absolute reticulocyte count, Since Epo administration is unlikely to benefit patients with high levels of endogenous Epo, we conclude that in the majority of patients with PNH there is no indication for treatment with Epo.

Serum eosinophilic cationic protein and blood eosinophil counts for the prediction of the presence of airways inflammation in children with wheezing

Background Serum eosinophilic cationic protein (ECP) concentrations may be useful noninvasive markers of airways inflammation in atopic asthma. However, the usefulness of serum ECP measurement for the prediction of airways inflammation in children with a history of wheezing is unknown.

Growth-phase regulation of lipopolysaccharide O-antigen chain length influences serum resistance in serovars of Salmonella

The amount of lipopolysaccharide (LPS) O antigen (OAg) and its chain length distribution are important factors that protect bacteria from serum complement. Salmonella enterica serovar Typhi produces LPS with long chain length distribution (L-OAg) controlled by the wzz gene, whereas serovar Typhimurium produces LPS with two OAg chain lengths: an L-OAg controlled by Wzz(ST) and a very long (VL) OAg determined by Wzz(fepE). This study shows that serovar Enteritidis also has a bimodal OAg distribution with two preferred OAg chain lengths similar to serovar Typhimurium. It was reported previously that OAg production by S. Typhi increases at the late exponential and stationary phases of growth. The results of this study demonstrate that increased amounts of L-OAg produced by S. Typhi grown to stationary phase confer higher levels of bacterial resistance to human serum. Production of OAg by serovars Typhimurium and Enteritidis was also under growth-phase-dependent regulation; however, while the total amount of OAg increased during growth, the VL-OAg distribution remained constant. The VL-OAg distribution was primarily responsible for complement resistance, protecting the non-typhoidal serovars from the lytic action of serum irrespective of the growth phase. As a result, the non-typhoidal species were significantly more resistant than S. Typhi to human serum. When S. Typhi was transformed with a multicopy plasmid containing the S. Typhimurium wzz(fepE) gene, resistance to serum increased to levels comparable to the non-typhoidal serovars. In contrast to the relevant role for high-molecular-mass OAg molecules, the presence of Vi antigen did not contribute to serum resistance of clinical isolates of serovar Typhi.

Factors associated with serum antibodies to reticulin, endomysium, and gliadin in an adult population

Gluten sensitivity is thought to be significantly under-diagnosed in the population.

Posttranscriptional regulation of acute phase serum amyloid A2 expression by the 5'- and 3'-untranslated regions of its mRNA

Human acute-phase serum amyloid A protein (A-SAA) is a major acute phase reactant, the concentration of which increases dramatically as part of the body's early response to inflammation. A-SAA is the product of two almost identical genes, SAA1 and SAA2, which are induced by the pro-inflammatory cytokines, IL-1 and IL-6. In this study, we examine the roles played by the 5'- and 3'-untranslated regions (UTRs) of the SAA2 mRNA in regulating A-SAA2 expression. SAA2 promoter-driven luciferase reporter gene constructs carrying the SAA2 5'-UTR and/or 3'-UTR were transiently transfected into the HepG2 human hepatoma cell line. After induction of chimeric mRNA with IL-1beta and IL-6, the SAA2 5'- and 3'-UTRs were both able to posttranscriptionally modify the expression of the luciferase reporter. The SAA2 5'-UTR promotes efficient translation of the chimeric luciferase transcripts, whereas the SAA2 3'-UTR shares this property and also significantly accelerates the rate of reporter mRNA degradation. Our data strongly suggest that the SAA2 5'- and 3'-UTRs each play significant independent roles in the posttranscriptional regulation of A-SAA2 protein synthesis.

Cigarette smoking and random serum cholesterol levels in a Northern Ireland general practice population of 18- to 20-year-old students and non-students

Coronary heart disease is the commonest cause of death in Northern Ireland, but few data exist on the incidence of risk factors in young adult students and non-students.

Nurse-mediated serum cholesterol reduction and health locus of control--a device for targeting health promotion?

Varying intensities of nurse-mediated health education advice were administered to subjects over a three-month period. Mean serum total cholesterol was calculated for each group at the outset and completion of the study. A multidimensional health locus of control (MHLC) scales questionnaire was self-completed by subjects at the outset. A highly significant association between internality and reduction in serum total cholesterol in the high-intensity intervention group was observed. The completion of a MHLC scale questionnaire may assist health professionals in identifying which subjects may most benefit from high-intensity health education advice when raised serum total cholesterol is prevalent.