Genome-wide studies of von Willebrand factor propeptide identify loci contributing to variation in propeptide levels and von Willebrand factor clearance.

UNLABELLED: Essentials Variants at ABO, von Willebrand Factor (VWF) and 2q12 contribute to the variation in plasma in VWF. We performed a genome-wide association study of plasma VWF propeptide in 3,238 individuals. ABO, VWF and 2q12 loci had weak or no association or linkage with plasma VWFpp levels. VWF associated variants at ABO, VWF and 2q12 loci primarily affect VWF clearance rates. SUMMARY: Background Previous studies identified common variants at the ABO and VWF loci and unknown variants in a chromosome 2q12 linkage interval that contributed to the variation in plasma von Willebrand factor (VWF) levels. Whereas the association with ABO haplotypes can be explained by differential VWF clearance, little is known about the mechanisms underlying the association with VWF single-nucleotide polymorphisms (SNPs) or with variants in the chromosome 2 linkage interval. VWF propeptide (VWFpp) and mature VWF are encoded by the VWF gene and secreted at the same rate, but have different plasma half-lives. Therefore, comparison of VWFpp and VWF association signals can be used to assess whether the variants are primarily affecting synthesis/secretion or clearance. Methods We measured plasma VWFpp levels and performed genome-wide linkage and association studies in 3238 young and healthy individuals for whom VWF levels had been analyzed previously. Results and conclusions Common variants in an intergenic region on chromosome 7q11 were associated with VWFpp levels. We found that ABO serotype-specific SNPs were associated with VWFpp levels in the same direction as for VWF, but with a much lower effect size. Neither the association at VWF nor the linkage on chromosome 2 previously reported for VWF was observed for VWFpp. Taken together, these results suggest that the major genetic factors affecting plasma VWF levels, i.e. variants at ABO, VWF and a locus on chromosome 2, operate primarily through their effects on VWF clearance.

The effects of sieving and spatial variability of estuarine sediment toxicity samples on sediment chemistry.

In 1998, we conducted a field-validation study of the chronic 28-day whole-sediment toxicity test with Leptocheirus plumulosus in Baltimore Harbor, MD, an area where this amphipod is indigenous. This study included an evaluation of the effect of sieving on sediment chemical concentrations and the use of field replicates, or separate grabs from the same site, which provided an estimation of within-site chemical and toxicologic variability. Six stations in Baltimore Harbor, MD, were included in this evaluation. Chemical analysis of two separate unsieved field replicates from the six sites indicated that, overall, the chemical concentrations of replicates within each site were similar, especially for metals. Organic contaminants particularly total PCBs, had the highest variability between replicates. Chemical variability did not appear to be related to differences in organic carbon content or grain size or to variability in toxicologic end points. Results supported the use of composite samples in sediment toxicity tests. In addition, in most cases, sieving had little effect on sediment chemistry. For the metals and trace elements, only selenium showed a substantial change after sieving, with some samples increasing after sieving and others decreasing. Concentrations of acid-volatile sulfide (AVS) increased 194.6% at one station after sieving, although in most other cases, AVS and simultaneously extracted metals remained relatively unchanged. As expected, concentrations of organics generally decreased after sieving, but in the majority of cases this decrease was small (i.e., coefficient of variation < or = 25%). Total benzene hexachloride and total chlordanes had the greatest changes, whereas polychlorinated biphenyl concentrations decreased at only two stations after sieving. Concentrations of polyaromatic hydrocarbons showed little change after sieving. These changes in sediment chemistry due to sieving must be viewed in the larger context of the potentially confounding effects that indigenous organisms may have on the interpretation of test results from whole-sediment toxicity tests.

Perfectionism is multidimensional: a reply to Shafran, Cooper and Fairburn.

provided a cognitive-behavioural analysis of perfectionism that focused primarily on self-oriented perfectionism. They argued against studying perfectionism from a multidimensional perspective that they regard as inconsistent with prior work on perfectionism as a self-oriented phenomenon. We respond to by offering historical, empirical, and theoretical support for the usefulness and the importance of a multidimensional model of perfectionism involving both intrapersonal processes and interpersonal dynamics. It is concluded that a multidimensional approach to the study of perfectionism is still warranted.

Mutations in a member of the ADAMTS gene family cause thrombotic thrombocytopenic purpura.

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening systemic illness of abrupt onset and unknown cause. Proteolysis of the blood-clotting protein von Willebrand factor (VWF) observed in normal plasma is decreased in TTP patients. However, the identity of the responsible protease and its role in the pathophysiology of TTP remain unknown. We performed genome-wide linkage analysis in four pedigrees of humans with congenital TTP and mapped the responsible genetic locus to chromosome 9q34. A predicted gene in the identified interval corresponds to a segment of a much larger transcript, identifying a new member of the ADAMTS family of zinc metalloproteinase genes (ADAMTS13). Analysis of patients' genomic DNA identified 12 mutations in the ADAMTS13 gene, accounting for 14 of the 15 disease alleles studied. We show that deficiency of ADAMTS13 is the molecular mechanism responsible for TTP, and suggest that physiologic proteolysis of VWF and/or other ADAMTS13 substrates is required for normal vascular homeostasis.

A field-based population model for the sediment toxicity test organism Leptocheirus plumulosus: I. Model development.

We describe the development of a stage-structured population matrix model for the estuarine amphipod Leptocheirus plumulosus, a sediment toxicity test organism, based on regular sampling of a natural population for approximately 2 years. Annual population dynamics were characterized by abundance peaks in the spring and fall, and low densities in the summer and winter. We use a sequence of seasonal projection matrices to capture these qualitative patterns in population dynamics. We compare two methods for estimating transition probabilities: multiple regression and truncated singular value decomposition (SVD). Overall, SVD gave more realistic parameter estimates than regression, although fecundity estimation was problematic. There were predictable trends in growth, survival and fecundity within years. The SVD-derived model provides a framework for assessing the population-level effects of contaminants on Leptocheirus.

A field-based population model for the sediment toxicity test organism Leptocheirus plumulosus: II. Model application.

A stage-structured population model has been developed for the estuarine amphipod Leptocheirus plumulosus to provide interpretive guidance for sediment toxicity tests with this species. This time-varying, field-based model includes several matrices to reflect seasonal changes in demographics. In this paper, we conduct sensitivity analysis of the model to identify which life history parameters have the greatest potential impact on population growth rate (lambda). Results indicate seasonal variability in the relative demographic importance of vital rates. Over winter, annual population growth is most sensitive to the persistence of juveniles and adults and growth from the juvenile to the adult stage. In spring and fall, changes in fecundity are likely to have large effects on population dynamics. In addition, we demonstrate the applicability of the model by using it to interpret toxicological data from an assessment of sediment contamination in Baltimore Harbor, MD. The model was parameterized with survival data from acute toxicity tests with L. plumulosus to project effects on population growth rate (lambda). Results of these model simulations indicate that relatively small changes in survival can result in large changes in lambda, indicating high risk to benthic populations. Furthermore, population projections mirror observed abundances of L. plumulosus at the test sites. These analyses provide a first indication of the usefulness of the Leptocheirus population model as a tool for exploring ecological effects of sediment contamination.

Validity of a telephone-administered 24-hour dietary recall in telephone and non-telephone households in the rural Lower Mississippi Delta region.

OBJECTIVE: To determine if 24-hour dietary recall data are influenced by whether data are collected by telephone or face-to-face interviews in telephone and non-telephone households. DESIGN: Dual sampling frame of telephone and non-telephone households. In telephone households, participants completed a 24-hour dietary recall either by face-to-face interview or telephone interview. In non-telephone households, participants completed a 24-hour dietary recall either by face-to-face interview or by using a cellular telephone provided by a field interviewer. SUBJECTS/SETTING: Four hundred nine participants from the rural Delta region of Arkansas, Louisiana, and Mississippi. MAIN OUTCOME MEASURES: Mean energy and protein intakes. STATISTICAL ANALYSES PERFORMED: Comparison of telephone and non-telephone households, controlling for type of interview, and comparison of telephone and face-to-face interviews in each household type using unpaired t tests and linear regression, adjusting for gender, age, and body mass index. RESULTS: Mean differences between telephone and face-to-face interviews for telephone households were -171 kcal (P = 0.1) and -6.9 g protein (P = 0.2), and for non-telephone households -143 kcal (P = 0.6) and 0.4 g protein (P = 1.0). Mean differences between telephone and non-telephone households for telephone interviews were 0 kcal (P = 1.0) and -0.9 g protein (P = 0.9), and for face-to-face interviews 28 kcal (P = 0.9) and 6.4 g protein (P = 0.5). Findings persisted when adjusted for gender, age, and body mass index. No statistically significant differences were detected for mean energy or protein intake between telephone and face-to-face interviews or between telephone and non-telephone households. APPLICATIONS/CONCLUSIONS: These data provide support that telephone surveys adequately describe energy and protein intakes for a rural, low-income population.

Perceptions of community nutrition and health needs in the Lower Mississippi Delta: a key informant approach.

OBJECTIVE: Key informants' perceptions of nutrition and health needs in their southern rural communities were assessed prior to nutrition intervention planning. DESIGN: This cross-sectional survey used in-person interviews. SUBJECTS/SETTINGS: A sample of 490 individuals from 12 professional and lay roles in 8 community sectors in 36 counties in Arkansas, Louisiana, and Mississippi was chosen. STATISTICAL ANALYSES PERFORMED: Factor analysis was carried out on reported food, nutrition, and health problems and contributing factors. The General Linear Models procedure identified within- and between-subject effects for factors. Tukey's post hoc tests identified differences between sectors and states. Frequencies and weighted rankings were computed for health problems. RESULTS: Key informants rated individual-level factors (food choices, education, willingness to change, health behavior) as more important than community-level factors (food and health care access, resources) with regard to nutrition and health problems and contributors to problems. The number one health problem was hypertension. IMPLICATIONS: Key informants are knowledgeable about nutrition and health problems, contributing factors, and available resources. Individual factors were perceived as more important contributors to nutrition and health problems providing valuable information for planning nutrition interventions.

Cardiac sarcoplasmic reticulum and sarcolemmal proteins separated by two-dimensional electrophoresis: surfactant effects on membrane solubilization.

We evaluated the use of the alkyaryl amidosulfobetaine zwitterionic detergent, designated as C8psi, to facilitate the solubilization of cardiac subcellular, membrane-associated proteins. Hearts from 7-week-old male Sprague-Dawley rats were isolated, and the left ventricles dissected and subsequently homogenized. The sarcolemma (SL) and the sarcoplasmic reticulum (SR) were isolated from different homogenate preparations originating from rat hearts by ultracentrifugation methods. The isolated membrane preparations were solubilized and the proteins precipitated. After resuspension, protein separation was achieved in first-dimensional IEF using an immobilized (pH 4-7) gradient and in the second dimension using 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Gels were then stained, images analyzed, and protein spots excised for subsequent identification. Protein identification from both SR and SL samples did not identify any of the known major membrane-associated proteins. Solubilization of whole tissue lysates with C8psi resulted in no increase in the total number of proteins detected relative to samples solubilized in the presence of 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulforate (CHAPS). The data suggest the utility of newer surfactants such as C8psi to improve both the resolution of (2-D) protein profiles and increase the number of proteins extracted from subcellular organelle fractions.

Prevalence of self-reported nutrition-related health problems in the Lower Mississippi Delta.

OBJECTIVES: The purpose of this study was to assess demographic and geographic differences in prevalence of self-reported nutrition-related health problems in Arkansas, Louisiana, and Mississippi. METHODS: The authors analyzed 1991 and 1993 Behavioral Risk Factor Surveillance System data for adults 18 years or older. RESULTS: Less educated African American women and women of other minority groups who were aged 35 to 64 years reported the highest prevalence of health problems. Geographic differences involved prevalence of hypertension, health status, and insurance status. CONCLUSIONS: Specific demographic subgroups and geographic areas with a high risk of health problems are in particular need of targeted interventions.

Menu design and selection for multicenter controlled feeding studies: process used in the Dietary Approaches to Stop Hypertension trial. DASH Collaborative Research Group.

Outpatient feeding studies are being used increasingly more often than inpatient studies because they are less expensive to conduct and less disruptive to participants' daily lives. Frequently, however, they are more difficult to implement. Studies involving multiple feeding centers add an additional layer of cooperation, coordination, and standardization to the already complex task of developing and delivering research diets. This was true for the 4-year Dietary Approaches to Stop Hypertension (DASH) trial, one of the first multicenter outpatient controlled feeding studies. This 4-center, randomized clinical trial was designed to compare the effects of 3 dietary patterns on blood pressure. After a year of development, 3 sets of 7-day cycle menus that met the study nutrient criteria and that were appropriate for varying food production routines and staffing patterns at the 4 clinical centers were adopted. The major development tasks were: defining methodologies to guide menu design and food production; selecting a nutrient database and calculating nutrient content of menus; evaluating and selecting the menus; and adjusting the menus for final use. The purpose of this article is to describe the steps and considerations in the design and selection of menus for the DASH trial, a process applicable to all well-controlled feeding studies.

The role of the clinical forensic nurse in critical care.

Forensic nursing deals with the population of people whose lives have been affected by societal violence. The clinical forensic nurse (CFN) is seen as a means of coping with the resultant increased complexity of nursing practice, society, and the law. Critical care areas are clinical forensic domains where the CFN addresses the needs of living forensic patients through activities involving physical and non-physical evidence collection, crisis intervention, and documentation. Within a health care team, the CFN enhances patient care management, resulting in clinical service, legal order, and forensic protocol.

Incidence of passive exposure to crack/cocaine and clinical findings in infants seen in an outpatient service.

OBJECTIVES: Passive exposure to crack/cocaine and the associated clinical symptoms may present a significant health risk to very young infants and children. This study was designed to determine the incidence of cocaine exposure, presumed to be passive, in ill infants younger than 1 year of age, using a threshold of detection for cocaine and/or its major metabolite, benzoylecognine (BE), that is lower than the current National Institute on Drug Abuse standard. The study also investigates the morbidity associated with passive cocaine exposure in this population. METHODS: We prospectively obtained 124 samples of urine from 122 children younger than 1 year of age for routine clinical indications from the emergency department at Yale-New Haven Hospital. Samples were analyzed by radioimmunoassay (RIA) for cocaine, with cross-reactivity for BE. The presence of BE in a portion of the RIA-positive samples also was detected in additional analyses by enzyme-multiplied immunoassay technique or by gas chromatography-mass spectrometry. A chart review was conducted on all 122 patients by reviewers blind to the urine toxicology results. Presenting complaints, symptoms, vital signs, and diagnosis were obtained for all visits before the first birthday. Birth history, including maternal drug history and birth weight, demographics, and number of medical visits in the first year, were recorded as well. RESULTS: Of the 124 samples, 45 (36.3%) were positive (>/=50 ng/mL of BE equivalents) for cocaine and/or cocaine metabolite by RIA testing. The positive results, determined by RIA, were highly correlated with patients who had lower and upper respiratory symptoms and sought medical care more often. CONCLUSIONS: The incidence of unsuspected, passive cocaine exposure in ill infants seeking medical care primarily through an emergency service may be as high as 1 in 3 to 6 infants from our predominantly inner city population. Current immunoassay methods, specific for BE, and their routine threshold of detection (200 to 300 ng/mL) may not be sensitive enough to detect cocaine and BE in the urine samples of children younger than 1 year of age who are exposed passively. The development of upper and lower respiratory symptoms is correlated significantly with positive urine results in this study. The increased use of health care resources correlated with passive cocaine exposure in this sample may serve as an indirect marker for the increased medical needs of these infants.

Biotic factors modifying acute toxicity of aqueous cadmium to estuarine amphipod Leptocheirus plumulosus.

A 96-h exposure to aqueous cadmium (Cd) is the recommended reference toxicity test for 10-day sediment bioassays with the estuarine amphipod, Leptocheirus plumulosus (US EPA 1994). This water-only test was used to assess the influence of organism size, sex, and nutritional status on the sensitivity of laboratory-cultured L. plumulosus to Cd. In addition, the response of field-collected amphipods was compared to similarly sized laboratory animals to assess potential seasonal changes in Cd sensitivity. Lipid content of test organisms was measured in these seasonal experiments and those evaluating effects of nutritional status because of its potential as an indicator of physiological condition. LC50 values of laboratory animals size-sorted on nested 500-, 710-, and 1000-micron mesh sieves, increased with size class: 0.36, 0.65, and 0.88 mg Cd/L, respectively. Gravid females were less sensitive than males or mature females to aqueous Cd. Studies on the influence of the molt cycle on Cd toxicity indicated enhanced sensitivity of immediate postmolt animals that may explain some of the observed differences in Cd tolerance. Nutritional effects were investigated by comparing the sensitivity of fed and starved laboratory-reared amphipods. Starved juveniles and adults were significantly smaller than their fed counterparts and exhibited a 28-43% reduction in lipid content, respectively. However, comparison of LC50 values indicated no significant differences in sensitivity to Cd between starved and fed juveniles (0.23 vs 0.30 mg Cd/L) or adults (0.37 vs 0.52 mg Cd/L). Field-collected amphipods were typically more sensitive to Cd than laboratory animals, regardless of the season, although their lipid content varied, ranging from 6.6% in August to 13.7% in November. Results are discussed with respect to the use and interpretation of toxicity tests with this species.

B lymphocytic clonal expansion in rheumatoid arthritis.

OBJECTIVE: To learn whether rheumatoid factor (RF), HLA-DR4, or current therapy influences clonal expansion of B lymphocytes (B cells) in persons with rheumatoid arthritis (RA). METHODS: We measured clonal expansion by analysis of cell surface staining for immunoglobulin light chains. Double staining methods detected a B cell marker (CD19) plus either kappa or lambda on peripheral blood lymphocytes from subjects with RA (n = 26) and controls (n = 26). The difference between frequency histograms of surface kappa and lambda staining was determined by the Kolmogorov-Smirnov statistic D that represents the fraction of clonally expanded B cells. RESULTS: The mean D value in RA was over 50% higher than in the controls [0.225 +/- SD 0.155 versus 0.144 +/- 0.025 (p < 0.0001)]. Ten subjects with RA had values exceeding +2 SD for controls (p = 0.0007). Mean D correlated with RF titer (Spearman's rank correlation coefficient rSp + 0.53, p = 0.006). All 10 high D values were found in the RA subgroups with positive serum tests for RF and with the HLA-DR4 positive genotype. The channel of maximal difference between kappa and lambda staining was higher in the RA group than in controls, showing that clonal expansion was most marked among brightly staining cells. Patients with RA currently receiving low dose methotrexate (MTX) tended to have higher D values than those not receiving MTX (mean 0.29 versus 0.18, respectively, p < 0.025). The RA group currently receiving MTX had a higher frequency of abnormal D values (7 of 11 versus 3 of 15 not currently receiving MTX, p = 0.03). This probably reflects preferential use of MTX for severely affected individuals. Confirmatory studies to detect clonal immunoglobulin gene rearrangements were attempted in selected individuals with high D values, but none was demonstrated in total leukocytic or B cell enriched fractions. CONCLUSION: Findings consistent with B cell clonal expansion occur in about 40% of persons with RA, particularly in the subgroups with positive serum tests for RF and with the HLA-DR4 genotype. However, the clonal expansion level must be below the sensitivity of confirmatory methods.

Sediment contamination and biological effects in a Chesapeake Bay marina.

Complementary measures of sediment toxicity, sediment chemistry and benthic community structure were evaluated at stations within and on the outside perimeter of an enclosed marina on the Bohemia River, a northeastern tributary to Chesapeake Bay. Sediment concentrations of polynuclear aromatic hydrocarbons, copper and tributyltin (TBT) were elevated at stations inside the marina basin. A 28 day partial life-cycle test with the amphipod Hyalella azteca indicated no significant lethal effects associated with test sediments. However, amphipods exposed to sediments collected from three stations inside the marina basin were significantly larger than amphipods from control sediments, possibly as the result of hormesis. Sediment pore water from two out of the three stations eliciting enhanced amphipod growth caused a reduction in light emission by luminescent bacteria in the Microtox(®) assay. Furthermore, sediments from these two stations contained the greatest measured concentrations of copper and TBT. Benthic infaunal communities that typically reflect environmental degradation were found exclusively at stations within the marina basin. The area of environmental impact appears to be localized to the enclosed basin, as the marina design limits flushing and, hence, contaminant export.

The use of the DSM-III-R Checklist for initial diagnostic assessments.

The DSM-III-R Checklist is an efficient method for screening psychiatric patients for major psychiatric disorders while amassing a data base that can be used for later clinical and research activities. It yields valid diagnoses and key adjunctive symptoms. Patients enjoyed the interview, demonstrating an interest in the computer as well as a feeling of confidence in the complete review of symptoms. The psychiatry resident users in this project found the Checklist to be a valuable teaching instrument, a way to develop their thinking about symptoms and diagnostic rules, an efficient means of collecting an automated clinical data base, and a stimulus to pursue further research activities. Finally, the Checklist is an ideal diagnostic tool to amass a research data base and is currently being used in numerous studies by clinicians and nonclinicians.

Acupuncture heroin detoxification: a single-blind clinical trial.

The increasing prevalence of HIV infection among injection drug users mandates the development of innovative treatments. While extensive clinical experience suggests that acupuncture detoxification is both safe and acceptable to those in withdrawal, little research has been conducted to assess its efficacy as a treatment modality. In this first controlled study of acupuncture heroin detoxification, 100 addicted persons were randomly assigned, in a single-blind design, to the standard auricular acupuncture treatment used for addiction or to a "sham" treatment that used points that were geographically close to the standard points. Attrition was high for both groups, but subjects assigned to the standard treatment attended the acupuncture clinic more days and stayed in treatment longer than those assigned to the sham condition. Additionally, attendance varied inversely with self-reports of frequency of drug use, suggesting that those with lighter habits found the treatment modality more helpful. Limitations of the study are discussed.