Development and validation of the Standard method EN ISO 19020 - microbiology of the food chain - Horizontal method for the immunoenzymatic detection of staphylococcal enterotoxins in foodstuffs.

In the frame of the CEN Mandate M/381 from the European Commission to CEN (European Committee for Standardization), a method for the detection of staphylococcal enterotoxins in foodstuffs has been developed, validated and standardized. An extraction procedure based on dialysis concentration followed by an immuno-enzymatic detection has been defined. In addition, performance criteria (minimum values of sensitivity, specificity and level of detection) to be achieved by the commercially available immuno-enzymatic kits that could be used to detect staphylococcal enterotoxins in food matrices, were developed.

Peripheral deiodinase activity: A potential explanation for the association between maternal weight and gestational hyperglycemia.

Background: High maternal weight is known to associate with both low free thyroxine and gestational diabetes mellitus. We explore a deiodinase-related mechanism that may help explain these associations.

Methods: Among 108 women receiving routine oral glucose tolerance testing for gestational diabetes mellitus, we collected biophysical data and measured free thyroxine and total triiodothyronine, using residual plasma samples.

Measuring maternal serum screening markers for Down's syndrome in plasma collected for cell-free DNA testing.

Objectives To determine whether maternal plasma collected in cell-free DNA stabilizing tubes is suitable for measuring prenatal screening 'serum' markers. Methods Matched plasma and serum samples were collected from 41 second trimester and 42 first trimester non-Down's syndrome pregnancies. Second trimester samples were tested for alpha-fetoprotein, unconjugated estriol, human chorionic gonadotropin, and inhibin-A (Beckman Coulter DxI immunoassay).

Free Thyroxine During Early Pregnancy and Risk for Gestational Diabetes.

Several studies have now reported associations between gestational diabetes mellitus (GDM) and low free thyroxine (fT4) during the second and third trimesters, but not in the first trimester. The present study further examines relationships between low fT4, maternal weight, and GDM among women in the FaSTER (First and Second Trimester Evaluation of Risk) trial, in an effort to determine the extent to which thyroid hormones might contribute to causality. The FaSTER cohort includes 9351 singleton, euthyroid women; 272 of these women were subsequently classified as having GDM.

Use of first or second trimester serum markers, or both, to predict preeclampsia.

Objectives: Preeclampsia is a serious complication of pregnancy, threatening fetal and maternal health. The aim of our study is to examine the association between preeclampsia and biochemical markers, in matched first and second trimester maternal serum samples.

Study Design: This is a nested case/control study derived from the cohort of pregnancies delivering at Women & Infants Hospital.

An Inverse Relationship Between Weight and Free Thyroxine During Early Gestation Among Women Treated for Hypothyroidism.

Background: Following treatment sufficient to normalize thyrotropin (TSH), nonpregnant hypothyroid adults display higher free thyroxine (FT(4)) concentrations than a reference population. Our aim is to determine whether FT(4) concentrations are higher during pregnancy among women treated for hypothyroidism and whether their weight is associated with FT(4) levels. Weight/FT(4) relationships have not previously been reported in treated hypothyroid adults (either pregnant or nonpregnant).

Evaluating first trimester maternal serum screening combinations for Down syndrome suitable for use with reflexive secondary screening via sequencing of cell free DNA: high detection with low rates of invasive procedures.

Objectives: Examine primary Down syndrome screening using combinations of first trimester serum markers, with and without sequencing of cell free DNA as a secondary reflexive test.

Methods: Samples from 40 Down syndrome cases were matched with five control samples and tested for PAPP-A, free β, AFP, inhibin-A and PlGF. Results were converted to weight-adjusted multiples of the median (MoM) and population parameters computed.

Implications of High Free Thyroxine (FT4) concentrations in euthyroid pregnancies: the FaSTER trial.

Context: Lower birth weight has been reported in conjunction with high maternal free T4 (FT4) in euthyroid pregnancies, raising concerns for suboptimal outcomes.

Objective: The objective of the study was to explore the relationships between high maternal FT4 and pregnancy complications in euthyroid women and to further examine the relationships among maternal size, FT4, and birth weight.

Design: This was an observational multicenter cohort study.

Maternal Body Mass Index during Pregnancy and Offspring Neurocognitive Development.

Background: This hypothesis generating study explores second trimester maternal body mass index (BMI) during pregnancy and offspring neurocognitive development.

Methods: Mothers and offspring served as controls in two earlier studies: 101 children at age two years and 118 children at age eight years.

Results: Frequency of maternal BMI ≥30 kg/m increased from 10% in 1987-1990 to 30% in 2004-2006 ( < 0.

Feasibility of using plasma rather than serum in first and second trimester multiple marker Down's syndrome screening.

Objective: To compare maternal plasma with serum for measuring markers currently used in first and second trimester screening for Down's syndrome.

Setting: A laboratory-based investigation of two sample types in assays used in prenatal screening for Down's syndrome.

Methods: A paired data-set included both plasma and serum from 101 pregnant women.

Impact of adjusting for the reciprocal relationship between maternal weight and free thyroxine during early pregnancy.

Background: Among euthyroid pregnant women in a large clinical trial, free thyroxine (FT4) measurements below the 2.5th centile were associated with a 17 lb higher weight (2.9 kg/m(2)) than in the overall study population.

DNA sequencing of maternal plasma reliably identifies trisomy 18 and trisomy 13 as well as Down syndrome: an international collaborative study.

Purpose: To determine whether maternal plasma cell-free DNA sequencing can effectively identify trisomy 18 and 13.

Methods: Sixty-two pregnancies with trisomy 18 and 12 with trisomy 13 were selected from a cohort of 4,664 pregnancies along with matched euploid controls (including 212 additional Down syndrome and matched controls already reported), and their samples tested using a laboratory-developed, next-generation sequencing test. Interpretation of the results for chromosome 18 and 13 included adjustment for CG content bias.

Mid-gestational maternal free thyroxine concentration and offspring neurocognitive development at age two years.

Context: Lower neurocognitive development scores at age 2 yr have been reported in association with euthyroid hypothyroxinemia during early pregnancy.

Objective: The objective of this study was to further explore this association with euthyroid hypothyroxinemia during early pregnancy.

Design: This was an observational, nested case-control study.

DNA sequencing of maternal plasma to detect Down syndrome: an international clinical validation study.

Purpose: Prenatal screening for Down syndrome has improved, but the number of resulting invasive diagnostic procedures remains problematic. Measurement of circulating cell-free DNA in maternal plasma might offer improvement.

Methods: A blinded, nested case-control study was designed within a cohort of 4664 pregnancies at high risk for Down syndrome.

The relationship between PTH and 25-hydroxy vitamin D early in pregnancy.

Objective: Measure serum PTH and 25(OH)D in a cross-sectional sample of pregnant women at 11th through 13th weeks' gestation to examine vitamin D status and consider implications.

Design: Observational: we retrieved residual sera stored at -20 °C after routine first trimester Down's syndrome screening, distributed over 12 months.

Patients: 430 African American women and 586 Caucasian women.

Thyroperoxidase and thyroglobulin antibodies in early pregnancy and placental abruption.

Objective: To estimate the relationship between thyroid antibodies and placental abruption.

Methods: This cohort study assesses thyroperoxidase and thyroglobulin antibodies in relation to placental abruption among 10,062 women with singleton viable pregnancies (from the First and Second Trimester Risk of Aneuploidy [FaSTER] trial). A thyroperoxidase antibody cutoff of 50 international units/mL is used for comparison with published data from another cohort.

Use of genomic profiling to assess risk for cardiovascular disease and identify individualized prevention strategies--a targeted evidence-based review.

Purpose: To address the key question of whether using available "cardiogenomic profiles" leads to improved health outcomes (e.g., reduction in rates of myocardial infarction and stroke) and whether these profiles help in making medical or personal decisions.

Thyroperoxidase and thyroglobulin antibodies in early pregnancy and preterm delivery.

Objective: To further evaluate the relationship between thyroid antibodies and preterm births.

Methods: This is a prospective study of pregnancy outcome and demographic data combined with retrospective measurement of thyroperoxidase and thyroglobulin antibodies. Sera were obtained at 11-13 and 15-18 weeks of gestation from 10,062 women with singleton viable pregnancies (a subset from the First- and Second-Trimester Risk of Aneuploidy [FaSTER] trial).

Early onset preeclampsia and second trimester serum markers.

Objective: To examine serum markers measured in the second trimester to identify women who subsequently develop preeclampsia.

Methods: Clinically defined preeclampsia was confirmed in 45 women who had provided a serum sample as part of Down syndrome screening. Preeclampsia was categorized as mild or severe, as well as early (<32 weeks) or late onset.

Quality assessment of routine nuchal translucency measurements: a North American laboratory perspective.

Purpose: To assess nuchal translucency measurements that were performed as part of routine prenatal screening for Down syndrome.

Methods: Collect ultrasound measurements of nuchal translucency and crown rump length provided by individual sonographers over a 6-month period to six North American prenatal screening laboratories, along with the laboratory's nuchal translucency interpretation in multiples of the median. For sonographers with 50 or more observations, compute three nuchal translucency quality measures (medians, standard deviations, and slopes), based on epidemiological monitoring.

Estimating first-trimester combined screening performance for Down syndrome in dried blood spots versus fresh sera.

Purpose: The study purpose was to examine the consequences of using dried blood spots rather than fresh sera in first-trimester Down syndrome screening.

Methods: We collected and compared human chorionic gonadotropin and pregnancy-associated plasma protein-A results from clients providing dried blood spots (Cohort 1) and from other clients providing fresh sera (Cohort 2). Inclusion and exclusion criteria aimed at ensuring the two cohorts were similar.

Hyperglycosylated-hCG (h-hCG) and Down syndrome screening in the first and second trimesters of pregnancy.

Objective: To validate Down syndrome screening protocols that include hyperglycosylated-hCG (h-hCG) measurements.

Methods: Measuring h-hCG in 21 641 fresh first- and second-trimester maternal serum samples, but not for clinical interpretation. Nuchal translucency (NT) and pregnancy associated plasma protein-A (PAPP-A) measurements were available in the first trimester; alpha-fetoprotein (AFP), unconjugated estriol (uE3), and human chorionic gonadotropin (hCG) measurements in the second trimester.

Comparison of serum markers in first-trimester down syndrome screening.

Objective: To estimate patterns of total hCG and inhibin A levels in the late first trimester of Down syndrome pregnancies, compare them with that of free beta-hCG, and assess screening performance of these markers individually and in combination with pregnancy-associated plasma protein-A (PAPP-A) and nuchal translucency.

Methods: Seventy-nine matched case-control sets of maternal serum samples (each Down syndrome case matched to 5 controls) from 11 through 13 completed weeks of gestation were taken from the sample bank of the First and Second Trimester Evaluation of Risk Consortium, a population-based study, and assayed for levels of free beta-hCG, total hCG, and inhibin A. Distribution characteristics and correlations of the multiples of the median values were estimated in cases and controls.

Reference distributions for apolipoproteins AI and B and B/AI ratios: comparison of a large cohort to the world's literature.

Limiting the clinical utility of apolipoproteins AI (apo AI) and B (apo B) and the apo B/AI ratios until the last decade has been the lack of satisfactory methods for quantifying serum levels and credible reference materials. Great technological strides have been made in the last few years. The remaining barrier to more relevant and cost-effective use of serum protein data for diagnosis and prognosis has been the availability of widely recognized reliable reference intervals from birth to old age for both males and females.