Laboratory assessment of iron status in pregnancy.

Background: Efforts to improve maternal nutrition during pregnancy prompted an observational study of the occurrence of maternal iron deficiency and its laboratory diagnosis in almost 500 pregnancies.

Methods: In this longitudinal study, the biochemical and haematological iron indices of women (n=492) attending a prenatal clinic in a Dublin maternity hospital were assessed at first booking (mean 15.9 weeks), and after 24 weeks, and 36 weeks of gestation.

One-year medical outcomes and emergency department recidivism after emergency department observation for cocaine-associated chest pain.

Study Objective: Chest pain is the most common complaint among cocaine users who present to the emergency department (ED) seeking care, and many hospital resources are applied to stratify cocaine users in regard to future cardiac morbidity and mortality. Little is known about the longitudinal cardiac and noncardiac medical outcomes of cocaine users who have been stratified to an ED observation period after their ED visit. We examine 1-year cardiac outcomes in a low- to intermediate-risk sample of patients with cocaine-associated chest pain in an urban ED, as well as examine ED recidivism at 1 year for cardiac and noncardiac complaints.

A dried serum spot assay for vitamin B(12).

Background: A newly developed dried serum spot (DSS) vitamin B(12) assay compares well with a conventional reference serum vitamin B(12) microbiological assay (r=0.97, n=161) and demonstrates adequate within (CV% <6) and between assay (CV% <10) reproducibility.

Methods: The consistency of long-term vitamin B(12) assay performance was supported and validated using a reconstituted International Reference Serum (IRR 81/563) stored at -70 degrees C as both whole serum aliquots and as DSS.

Maternal folate status and neural tube defects in Ireland: the need for a national food fortification program.

To determine the present risk of a Neural Tube Defect [NTD] pregnancy in the caucasian primigravid population in Dublin by comparing the serum folate and red cell folate status of primigravid patients attending the first prenatal booking clinic with data from the late 80's. This Cross-sectional population study looking at blood folate status of over 400 sequential primigravid caucasian women with a singleton pregnancy, booking at less than or equal to 20 weeks gestation. All patients were attending a prenatal booking clinic at the Rotunda Hospital in Dublin during 2003-2004.

Blood folate levels and risk of liver damage and hepatocellular carcinoma in a prospective high-risk cohort.

Background: Studies in experimental animals suggest that low folate levels may play a role in liver damage and hepatocarcinogenesis. To examine this association in humans, folate levels in blood and risk for subsequent liver damage and hepatocellular carcinoma (HCC) were assessed in a population at high risk of liver cancer in China.

Methods: Four hundred fifteen hepatitis B surface antigen-positive participants of the Haimen City Cohort were prospectively followed between 1998 and 2002.

International Standard for serum vitamin B(12) and serum folate: international collaborative study to evaluate a batch of lyophilised serum for B(12) and folate content.

Background: Vitamin B(12) and folate measurements in serum show wide inter-methodology variability. This variability appears to be due in part to the lack of standardisation against internationally accepted reference materials. Pooled human serum, lyophilised in ampoules and designated 03/178, was therefore evaluated by 24 laboratories in seven countries for its suitability to serve as an International Standard (IS) for B(12) and folate.

Evaluation of serum transferrin receptor assay in a centralized iron screening service.

This study assesses the impact of permitting unrestricted access to requests for soluble transferrin receptor (sTfR) analysis in screening for iron deficiency (ID). Biochemical data including sTfR, serum ferritin (sFn), transferrin saturation, zinc protoporphyrins (ZPP) and also erythrocyte indices are used to highlight the differences between hospital (H) and general practitioner (GP) patient groups. A significantly higher number of abnormal sFn values (40%) over abnormal sTfR values (25%) occurred in GP patients.

High serum folates and the simplification of red cell folate analysis.

Recent substantial increases in clinical blood folate concentrations are noted. Since red cell folates (RCF) are calculated from whole blood folates (WBF) by subtraction of the endogenous serum folate (SF) component, the reporting of clinical RCF results may be delayed because an ever increasing proportion (15%) of diagnostic SF levels are high (> 20 ng/ml) and need a repeat analysis. We evaluated 'plasma replacement' as a simple preanalytical procedure in which endogenous blood plasma is removed from red cells by washing and substituted with 'low-folate' plasma (serum) as an alternative conjugase (gamma-glutamyl carboxypeptidase) source for folate polyglutamate hydrolysis.

Optimization of routine plasma homocysteine monitoring.

An elevated plasma homocysteine (Hcy) level is now considered to be an important risk factor in arterial and venous thromboembolic events. As a result of this relatively recent finding, there has been a dramatic increase in the number of requests for Hcy measurement. In our laboratory, this demand has been met by employing an automated immunoassay and improving the pre-analytical handling of blood samples.

Screening of folate status with use of dried blood spots on filter paper.

Background: Dried blood spots (DBS) on filter paper have been a successful and economical matrix for neonatal screening.

Objective: Our objective was to develop and evaluate an optimized method for DBS folate analysis and to assess DBS folate stability.

Design: DBS were eluted from paper by sonication in 5 g ascorbic acid/L containing 0.

Use of folic acid-fortified milk in the elderly population.

Folic acid deficiency is common in the elderly population, resulting in anaemia, dementia, many neurological sequelae and an indirect role in atheromatous disease. An increase in natural food folate is relatively ineffective at increasing folate status and the use of folate fortification of foodstuffs is recommended. The aim of our study was to assess the benefits of folic acid-fortified milk to the folate status of an elderly institutionalised population.

Field-study screening of blood folate concentrations: specimen stability and finger-stick sampling.

We describe optimized procedures for field studies of blood folate concentrations by using finger-stick blood sampling and include relevant studies on blood folate stability. We introduce whole-blood folate adjustment using sample hemoglobin (folate/hemoglobin, nmol/g) as a novel and practical tool yielding accurate and precise results when blood volume or dilution is unknown. Red cell folate concentrations (nmol/L) of 11,887 Americans correlated well with hemoglobin-corrected whole-blood folate concentrations (r2 = 0.

Evaluation of factors influencing precision in the analysis of samples taken from blood spots on filter paper.

Dried blood spots (DBS) on filter paper have potential as a collection method in screening for haematinic deficiencies. Factors influencing the volumetric precision of uniform 'centre' punches (6.35 mm diameter) removed from dried blood spots have been evaluated.

Microbiological assay on microtitre plates of folate in serum and red cells.

Aims: To develop a simple microbiological assay for serum and red cell folates on 96-well microtitre plates, suitable for use in routine clinical diagnosis.

Methods: Use of a chloramphenicol resistant organism (NCIB 10463) saved time by avoiding aseptic precautions. Use of plate sealers facilitated mixing.

The management of heart transplant recipients treated with cyclosporine in Ireland: monitoring of cyclosporine concentrations in blood.

Thirty seven cardiac transplants have taken place at the National Cardiac Centre in Ireland since 1985. Data is presented on three still-surviving male patients aged 19 to 42 who received cardiac transplants in 1985 and 1986. Circulating levels of blood cyclosporine were measured by high pressure liquid chromatography and radioimmunoassay; plasma creatinine and bilirubin were also measured.

Cryo-preservation of Lactobacillus leichmannii for vitamin B12 microbiological assay.

An optimised method for preparing cryo-preserved cultures of Lactobacillus leichmannii for vitamin B12 microbiological assay is described. Cultures are mixed with an equal volume of 800 ml/l sterile glycerol before freezing. The percentage recovery of viable cells after thawing is highest when cultures are enclosed in polystyrene insulation and cooled to -70 degrees C.