The association of parity with mortality outcomes among triplets

OBJECTIVE: The purpose of this study was to evaluate the association of parity with stillbirth and neonatal and infant death among triplets. STUDY DESIGN: This was a retrospective cohort study of 15,930 triplets who were delivered in the United States between 1995 and 1997. Infants of nulliparous mothers were compared with infants of multiparous mothers. Adjusted relative risks for death by parity were computed with the use of the generalized estimating equations framework. RESULTS: The likelihood for stillbirth (odds ratio, 3.40; 95% CI, 2.20-5.26) was significantly greater among nulliparous mothers. Neonatal (odds ratio, 1.17; 95% CI, 0.95-1.43) and infant mortality rates (odds ratio, 1.10; 95% CI, 0.92-1.32) were comparable, however. With an increase in parity, there was a consistent declining trend in the risk for stillbirth (P<.0001). CONCLUSION: Nulliparity more than triples the risk for intrauterine fetal death among triplets. This parity-related disparity underscores the need for care providers to be particularly concerned about triplet gestations among nulliparous mothers.     

Species differences in contaminants in fish on and adjacent to the Oak Ridge Reservation, Tennessee

Risks to humans and other organisms from consuming fish have become a national concern in the USA. In this paper, we examine the concentrations of 137Cs, arsenic, beryllium, cadmium, lead, mercury, and selenium in three species of fish from two river reaches adjacent to the US Department of Energy's Oak Ridge Reservation in Tennessee. We were interested in whether there were species and locational differences in radiocesium and metal concentrations and whether concentrations were sufficiently high to pose a potential health risk to humans or other receptors. Striped bass (Morone saxatilis) were significantly larger than white bass (M. chrysops), and crappie (Pomoxis spp.) were the smallest fish. Lead was significantly lower in striped bass, mercury was significantly higher in striped bass, and selenium was significantly higher in white bass compared to the other species. There were no other species differences in contaminants. White bass, the only species that was sufficiently abundant for a comparison, had significantly higher concentrations of cadmium, lead, and selenium in fillets from the Clinch River and significantly higher concentrations of mercury in fillets from Poplar Creek. The low concentrations of most contaminants in fish from the Clinch River do not appear to present a risk to humans or other consumers, although mercury concentrations in striped bass ranged as high as 0.79 ppm, well above the 0.5-ppm action level for human consumption of some US states.     

Towards a cognitive model and measure of dissociation

Dissociation comprises a range of psychological processes, which have largely been the subject of psychodynamic discussion. Dissociative phenomena are for the most part unaddressed by cognitive theorists. Current measures are atheoretical and our understanding of dissociation has been hampered by the absence of clear psychological models. This paper describes a new cognitive model of dissociation and the development and validation of a theoretically based measure-the Wessex Dissociation Scale (WDS). The WDS has adequate internal consistency, shows convergent validity with the Dissociative Experiences Scale (DES-II), and is equivalent to the DES-II in its associations with severe psychopathology. However, the WDS has some advantages over the DES-II, in that it is sensitive to milder manifestations of dissociation, demonstrating links to less severe pathologies. The findings described here provide preliminary support for the usefulness of the cognitive model, and the varied consequences of dissociative processes. The clinical and research utility of the model and the scale are discussed.     

What we have learned about conducting randomized controlled trials in the NICHD MFMU network

The National Institute of Child Health and Human Development (NICHD) created the NICHD Maternal Fetal Medicine Units Network in 1986 to conduct randomized trials and observational studies in perinatal medicine to improve adverse pregnancy and infant outcomes. From 1986 to 2002, the Network has started 16 randomized trials. Five of the trials are described, with particular attention given to difficult issues that arose, such as feasibility, sample size estimation, randomization in very high risk pregnancies, changing clinical practice, importance of the study question to the investigators, and lack of recruitment. Changes that the Network group made to their organization and methodology as a result of these issues are described, together with their application to some of the other trials proposed and conducted by the group.     

Data monitoring and safety committees and their operations

The scientific burden of proof for new therapies and technologies in obstetrics and gynecology has risen steadily over the past 15 to 20 years, and the randomized clinical trial has become integral to this higher standard. Data monitoring and safety committees are now critical components of clinical trials, yet their history, rationale, methods of operation, and overall role have not been well-characterized in the obstetrics and gynecology literature. In this review, an overview of the important and evolving role of data monitoring and safety committees is provided. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to describe what a data monitoring and safety committee is, plan who should comprise the DMSC, and outline the functions of a DMSC.     

Identification of human serum interferants in the recombinant P-selectin glycoprotein ligand-1 clinical ELISA using MALDI MS and RP-HPLC

A colorimetric enzyme-linked immunosorbent assay (ELISA) was developed to detect circulating levels of rPSGL to permit pharmacokinetic analysis of clinical samples. The ELISA is an asymmetric sandwich utilizing a monoclonal antibody pair. Initial validation studies indicated that 57% of normal individuals scored above the limit of detection of the assay. Specificity experiments indicated that the signal was not due to circulating endogenous P-selectin glycoprotein ligand-1 (PSGL-1). Using matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) and sampling within the individual microplate wells, the interferant was detected in the vicinity of 6.6 kDa in lipemic and normal human sera, but not delipidized sera. These results were consistent with the ELISA data where 97.5% of known lipemic, 57% of normal, and 0% of delipidized sera scored above detectable limits in the ELISA. Preparative isolations of the 6.6 kDa species were performed using reversed-phase high performance liquid chromatography (RP-HPLC) with UV and MS detection. Edman N-terminal sequencing identified the 6.6 kDa unknown as Apolipoprotein C-I. Additional apolipoproteins were found by MALDI and RP-HPLC. Digestion of sera with liposome lipase and extraction of sera with anti-apolipoprotein C-I, C-II, and C-III antibody beads significantly reduced the ELISA interference. These experiments combined with the MALDI detection of phosphatidylcholine-type lipids from NHS eluate suggested that lipoprotein particles or remnants were causing the interference. A method combining Triton-X 100 with sonication was developed to overcome this interference without altering rPSGL recovery in the ELISA.