bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of twins: what can they tell us about the fetal origins of adult disease?
Authors: Morley Ruth , Dwyer Terence 
Published: January 2005

SummaryThere has been much interest in evidence that people with lower birthweight have higher risk of adult cardiovascular disease, but the causal pathways underlying such observations are uncertain. Study of twins offers an opportunity to shed light on the underlying causal pathways, in particular by investigating the role of ‘shared’ factors vs. factors affecting each individual fetus. This involves comparing results of within‐cohort vs. within‐pair analyses.Twins share many factors during gestation but birthweight discordance (difference in birthweight within a twin pair) cannot be determined by these shared factors and must relate to factors affecting growth of each individual fetus. If associations seen in a cohort of twins remain in within‐pair analyses, then factors specific to each individual must be involved in the underlying causal pathways. Conversely, if the relationships disappear or substantially diminish in within‐pair analyses, then factors common to the pair must be involved. Comparison of findings in monozygotic vs. dizygotic twins may provide insights into the role of genetic factors, although issues related to chorionicity need to be taken into account.We tabulate published data and conclude that differences in methodology and analyses preclude informative meta‐analysis, and that analysis of pooled data would provide more useful information.
A discussion of some statistical methods for separating within‐pair associations from associations among all twins in research on fetal origins of disease
Authors: Dwyer Terence , Blizzard Leigh 
Published: January 2005

SummaryTwin data can be used to gain insights into the origin of associations between factors arising in fetal life and the risk of later disease. This is because twin data afford an opportunity to conduct paired analyses that take the influence of shared factors into account. When an association that is present in an unpaired analysis is present also in a paired analysis, there is evidence that the causal pathway linking the fetal factor and the disease may have a fetal origin. If the association disappears in the paired analysis, there is evidence that it may have has arisen from a shared source such as the mother. The relevant factors include diet and socio‐economic status.There are several statistical approaches to this. The simplest involves comparing, say, a coefficient from a regression of an outcome on a fetal factor for all subjects in a twin sample, with the coefficient obtained from regressing the within‐pair difference in the outcome on the within‐pair difference in the fetal factor. Alternative approaches involve simultaneously estimating regression parameters for between‐ and within‐pair components. These approaches permit similar inferences about whether the association is due to individual (fetal) or shared (maternal) factors, and are valid in the circumstances that non‐shared factors missing from the regression model do not influence the regression estimates.
Epidemiology of blood donors in Japan, positive for hepatitis B virus and hepatitis C virus by nucleic acid amplification testing
Authors: Murokawa H. , Yoshikawa A. , Ohnuma H. , Iwata A. , Katoh N. , Miyamoto M. , Mine H. , Emura H. , Tadokoro K. ,   the Japanese Red Cross NAT Screening Research Group
Published: January 2005

Background and Objectives  The Japanese Red Cross screens seronegative blood donors by nucleic acid amplification testing (NAT) for hepatitis B, hepatitis C and human immunodeficiency virus‐1 markers. NAT‐positive donors thus identified seemed to have a different infectious background from serologically positive donors. The purpose of our study was to characterize this background in the hepatitis B virus (HBV) and hepatitis C virus (HCV) NAT‐positive donors.Materials and Methods  Some 328 HBV DNA‐positive and 44 HCV RNA‐positive donors were detected by NAT testing of seronegative blood donors. These were characterized regarding age, gender and genotype of HBV and HCV.Results Those who were HBV NAT‐positive were mainly young, in particular teenage girls. In Japan, genotypes C and B have previously been dominant, but recently genotype A has increased, and genotype H was recently detected. In HBV NAT‐positive donors, the rate of genotype A was high (12·2%) compared with patients in hospital (1·7–2%). Donors who were HCV NAT‐positive were also young, but mostly men in their twenties. The ratio of genotype 1b to 2a or 1b to 2b in HCV NAT‐positive donors differed from that of hospitalized patients in Japan. We did not find genotype 1a, which is dominant in the USA.Conclusions  The high‐risk donors detected by NAT were mainly young, with a different distribution of genotypes from that of hospitalized patients, regarding both HBV and HCV. The rare HBV genotype H has been found for the first time in Japan. The findings reflect the present spread of hepatitis viruses B and C.
Inoculated Host Range and Effect of Host on Morphology and Size of Macroconidia Produced by Claviceps africana and Claviceps sorghi
Authors: Muthusubramanian V. , Bandyopadhyay R. , Tooley P. W. , Rajaram Reddy D. 
Published: January 2005

AbstractTwenty graminaceous plant species were evaluated for their susceptibility to the two sorghum ergot pathogens Claviceps sorghi and Claviceps africana. Five species viz., Sorghum arundinaceum, Sorghum halepense, Sorghum versicolor, Sorghum virgatum and Pennisetum glaucum were found to become infected by both pathogens via inoculation with 106 conidia/ml. Species which did not become infected under these conditions included Pennisetum pedicellatum, Zea mays, and species of Panicum, Brachiaria, Cenchrus, Andropogon, Dichanthium, Chrysopogon, Iseilema, Bothriochloa and Chloris. Honeydew secretions were observed from infected flowers of susceptible plant species. There was marked variation in size of macroconidia of both C. sorghi and C. africana on different hosts on which the pathogens were able to establish symptoms. Dimorphism was observed for macroconidia produced on P. glaucum, as elliptical and spindle shaped macroconidia were observed. Based on inoculation under greenhouse conditions, we conclude that C. sorghi and C. africana may have similar host ranges.
As good as dead? Sublethal predation facilitates lethal predation on an intertidal clam
Authors: Meyer John J. , Byers James E. 
Published: January 2005

AbstractAlthough ecologists have speculated that sublethal predation can impact prey dynamics, consequences of these predator effects have seldom been experimentally tested. In soft‐sediment marine communities, fishes crop extended feeding siphons of buried clams, potentially causing clams to reduce their burial depth, thereby enhancing their susceptibility to excavating lethal predators. We simulated cropping of the confamilial clams, Protothaca staminea and Venerupis philippinarum, by removing the top 40% of siphons, which caused each species to burrow 33–50% shallower than conspecifics with intact siphons. To examine subsequent consequences of reduced burial depth, we exposed cropped and intact clams to natural levels of predation in the field. Because of a naturally longer siphon, Protothaca, even after cropping, remained at relatively safe burial depths. In contrast, siphon cropping nearly doubled the mortality rate of Venerupis. Thus, while sublethal predation facilitates lethal predation, this linkage depends on specific life history characteristics, even among ecologically similar species.
A general model of local competition for space
Authors: Crowley Philip H. , Davis Heather M. , Ensminger Amanda L. , Fuselier Linda C. , Kasi Jackson J. , Nicholas McLetchie D. 
Published: January 2005

AbstractLocal competition for space across a wide array of taxa typically involves three mechanisms that we denote here as expansion (spreading into unoccupied habitat), lottery (replacing dead competitors), and overgrowth (encroaching on competitors along zones of contact). By formulating and analysing a simple, general model incorporating these features, we identify ecological conditions and life‐history features that lead to stable coexistence or competitive exclusion (with or without initial‐condition dependence) and gain insight by linking these to case studies in the literature. We demonstrate the importance of contact inhibition, a little‐studied feature of overgrowth, and we show how life‐history tradeoffs may influence and be influenced by local competition for space. The general model we present can help indicate whether local interactions are sufficient to explain patterns of coexistence or exclusion and can serve as the foundation for more specific, realistic models of spatial competition.
Identification of high‐use habitat and threats to leatherback sea turtles in northern waters: new directions for conservation
Authors: James Michael C. , Andrea Ottensmeyer C. , Myers Ransom A. 
Published: January 2005

AbstractIncidental capture in fisheries threatens many marine vertebrates, however, conservation cannot be effective without identifying major sources of mortality. For the critically endangered leatherback turtle (Dermochelys coriacea), a reliance on fisheries observer data and an absence of behavioural data sets corresponding to a large and diverse sample of animals have focused conservation efforts on a very limited part of the species marine habitat. Using the largest satellite telemetry data set for Atlantic leatherbacks, morphometrics from foraging animals and entanglement records, we show annual return migrations to key feeding areas by males, females and juveniles, and demonstrate the importance of northern latitudes to leatherbacks. We show that leatherbacks are vulnerable to entanglement in northern coastal and shelf waters, where turtle–fishery interactions represent a greater threat to this species than previously recognized. Unless conservation efforts expand to coastal and shelf areas, present efforts alone will not be sufficient to save the species.
Belowground organism activities affect plant aboveground phenotype, inducing plant tolerance to parasites
Authors: Blouin Manuel , Zuily‐Fodil Yasmine , Pham‐Thi Anh‐Thu , Laffray Daniel , Reversat Georges , Pando Anne , Tondoh Jerome , Lavelle Patrick 
Published: January 2005

AbstractSoil fauna activities are probably more important than currently acknowledged in determining individual plant response to stresses and overall plant diversity. Here we demonstrate that the positive effect of earthworms on rice could be the result of a systemic effect on plant physiology. Moreover, this effect could improve tolerance to stressors such as parasitic nematodes. In a controlled experiment, an 82% decrease in the production of infested plants was suppressed when earthworms were present. Earthworms had no direct effect on nematode population size. In their presence, however, root biomass was not affected by nematodes and the expected inhibition of photosynthesis was suppressed. In the leaves, the expression of three stress‐responsive genes (coding for lipoxygenase, phospholipase D and cysteine protease) was modulated by the presence of belowground invertebrate activities. We document conflicting systemic effects of parasitic nematodes and beneficial earthworms, although we cannot precisely identify the mechanism involved. These results reveal the importance of non‐trophic belowground/aboveground interactions for plant health and response to stresses.
The Effects of Geography and Spatial Behavior on Health Care Utilization among the Residents of a Rural Region
Authors: Arcury Thomas A. , Gesler Wilbert M. , Preisser John S. , Sherman Jill , Spencer John , Perin Jamie 
Published: January 2005

Objective.This analysis determines the importance of geography and spatial behavior as predisposing and enabling factors in rural health care utilization, controlling for demographic, social, cultural, and health status factors.Data Sources.A survey of 1,059 adults in 12 rural Appalachian North Carolina counties.Study Design.This cross‐sectional study used a three‐stage sampling design stratified by county and ethnicity. Preliminary analysis of health services utilization compared weighted proportions of number of health care visits in the previous 12 months for regular check‐up care, chronic care, and acute care across geographic, sociodemographic, cultural, and health variables. Multivariable logistic models identified independent correlates of health services utilization.Data Collection Methods.Respondents answered standard survey questions. They located places in which they engaged health related and normal day‐to‐day activities; these data were entered into a geographic information system for analysis.Principal Findings.Several geographic and spatial behavior factors, including having a driver's license, use of provided rides, and distance for regular care, were significantly related to health care utilization for regular check‐up and chronic care in the bivariate analysis. In the multivariate model, having a driver's license and distance for regular care remained significant, as did several predisposing (age, gender, ethnicity), enabling (household income), and need (physical and mental health measures, number of conditions). Geographic measures, as predisposing and enabling factors, were related to regular check‐up and chronic care, but not to acute care visits.Conclusions.These results show the importance of geographic and spatial behavior factors in rural health care utilization. They also indicate continuing inequity in rural health care utilization that must be addressed in public policy.
Response Rates and Response Bias for 50 Surveys of Pediatricians
Authors: Cull William L. , O'Connor Karen G. , Sharp Sanford , Tang Suk‐fong S. 
Published: January 2005

Research Objective. To track response rates across time for surveys of pediatricians, to explore whether response bias is present for these surveys, and to examine whether response bias increases with lower response rates.Data Source/Study Setting. A total of 63,473 cases were gathered from 50 different surveys of pediatricians conducted by the American Academy of Pediatrics (AAP) since 1994. Thirty‐one surveys targeted active U.S. members of the AAP, six targeted pediatric residents, and the remaining 13 targeted AAP‐member and nonmember pediatric subspecialists. Information for the full target samples, including nonrespondents, was collected using administrative databases of the AAP and the American Board of Pediatrics.Study Design. To assess bias for each survey, age, gender, location, and AAP membership type were compared for respondents and the full target sample. Correlational analyses were conducted to examine whether surveys with lower response rates had increasing levels of response bias.Principal Findings. Response rates to the 50 surveys examined declined significantly across survey years (1994–2002). Response rates ranged from 52 to 81 percent with an average of 68 percent. Comparisons between respondents and the full target samples showed the respondent group to be younger, to have more females, and to have less specialty‐fellow members. Response bias was not apparent for pediatricians' geographical location. The average response bias, however, was fairly small for all factors: age (0.45 years younger), gender (1.4 percentage points more females), and membership type (1.1 percentage points fewer specialty‐fellow members). Gender response bias was found to be inversely associated with survey response rates (r=−0.38). Even for the surveys with the lowest response rates, amount of response bias never exceeded 5 percentage points for gender, 3 years for age, or 3 percent for membership type.Conclusions. While response biases favoring women, young physicians, and nonspecialty‐fellow members were found across the 52–81 percent response rates examined in this study, the amount of bias was minimal for these factors that could be tested. At least for surveys of pediatricians, more attention should be devoted by investigators to assessments of response bias rather than relying on response rates as a proxy of response bias.
Resolving Controversies Regarding Hemodiafiltration versus Hemodialysis: The Dutch Convective Transport Study
Authors: Penne E. Lars , Blankestijn Peter J. , Bots Michiel L. , Van Den Dorpel Marinus A. , Grooteman Muriel P. C. , Nubé Menso J. , Ter Wee Piet M. ,   on behalf of the CONTRAST Group
Published: January 2005

ABSTRACTHemodialysis patients suffer from a high incidence of cardiovascular disease. Among the many predisposing factors, such as high blood pressure, dyslipidemia, and fluid overload, the accumulation of high molecular weight uremic toxins, the so‐called middle molecules, may play an important role. Since convective therapies such as online hemodiafiltration have a better clearance profile for these compounds than standard hemodialysis, it has been suggested that these dialysis strategies may reduce cardiovascular morbidity and mortality. As reliable data on these issues are not available, the Dutch Convective Transport Study (CONTRAST) was recently initiated. This prospective randomized trial was designed to compare online hemodiafiltration with low‐flux hemodialysis with respect to cardiovascular morbidity and mortality.
Cultural identities and cultural congruency: a new model for evaluating mental distress in immigrants
Authors: Bhugra D. 
Published: January 2005

Objective:  Societies and cultures have been described as being individualistic or collectivist (also called ego‐centric or socio‐centric). Similarly individuals are idiocentric or allocentric.Method:  Using migration, migrants, ethnic minorities, collectivism and individualism, four databases of Embase, Medline, PsychInfo and Social Sciences abstracts were searched. Other key words included mental disorder, mental distress, psychiatric and psychological disorders. In addition, hand searches were conducted from the relevant books, monographs and secondary references.Results:  Migration, cultural identity and mental distress are linked. In addition, social support can provide a buffer against mental illness. Other vulnerability factors in migrants include the type of society they originate from and the type of society they settle in.Conclusion:  When individuals migrate from one type of culture to another it is likely that depending upon their own personality traits (along with their biopsycho‐social vulnerabilities) may develop psychiatric disorders. The cognitions and idioms of distress will be influenced by cultural factors. The clinicians must take into account cultural background when planning any interventions to enable a stronger therapeutic alliance.
Antibody-Mediated Protection againstCryptococcus neoformansPulmonary Infection Is Dependent on B Cells
Authors: Rivera Johanna , Zaragoza Oscar , Casadevall Arturo 
Published: January 2005

ABSTRACTThe pathogenesis of pulmonaryCryptococcus neoformansinfection and the efficacy of passive immunoglobulin G1 (IgG1) administration were investigated in B-cell-deficient and C57BL/6J mice. C57BL/6J mice lived longer than B-cell-deficient mice after both intratracheal and intravenous infections. Administration of IgG1 prior to infection prolonged the survival of C57BL/6J mice but had no effect on the survival or numbers of CFU in the lungs of B-cell-deficient mice.C. neoformansinfection in B-cell-deficient mice resulted in significantly higher levels of gamma interferon (IFN-γ), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1α (MIP-1α) than in C57BL/6J mice. IgG1 administration reduced IFN-γ and MCP-1 levels in C57BL/6J mice but not in B-cell-deficient mice. In addition, compared to its effect in C57BL/6J mice,C. neoformansinfection in FcRγIII-deficient, athymic, and SCID mice significantly increased IFN-γ and MCP-1 levels. IgG1 administration was associated with reduced IFN-γ levels in C57BL/6J mice but not in FcRγIII-deficient, athymic, and SCID mice. These observations suggest that IgG1-mediated protection in this system is a consequence of alterations in the inflammatory response that translate into less damage to the host without directly reducing the fungal burden. For hosts with impaired immunities, the ineffectiveness of passive antibody (Ab) may reflect an inability to down-regulate inflammation and avoid self-damage. The results indicate an important role for B cells in host defense againstC. neoformansinfection and demonstrate a surprising dependence of Ab-mediated protection on B cells in this system.
Peroxisome Proliferator-Activated Receptor γ and Retinoid X Receptor Agonists Have Minimal Effects on the Interaction of Endothelial Cells withPlasmodium falciparum-Infected Erythrocytes
Authors: Serghides Lena , Kain Kevin C. 
Published: January 2005

ABSTRACTPeroxisome proliferator-activated receptor γ-retinoid X receptor (PPARγ-RXR) agonists had minimal effects on the surface levels of CD36, intercellular cell adhesion molecule-1, or platelet-endothelial cell adhesion molecule-1 and had no effect on the cytoadherence of infected erythrocytes to either human umbilical vein endothelial cells or human microvascular endothelial cells or on malaria-induced interleukin-6 secretion from these cells. PPARγ-RXR agonists do not significantly modify malaria-infected erythrocyte-endothelial cell interactions in vitro.
Age-Dependent Changes in Susceptibility of Suckling Mice to Individual Strains of
Helicobacter pylori
Authors: Suto Hiroyuki , Zhang Maojun , Berg Douglas E. 
Published: January 2005

ABSTRACT

To model establishment of
Helicobacter pylori
infection in infants, suckling mice were inoculated with mixtures of strains that preferentially colonize different gastric regions and coexist in vivo. Characterization of
H. pylori
recovered 2 weeks later showed that susceptibility begins earlier for some strains than for others and that the onset of susceptibility varies among mouse lines.
Lactobacillus johnsoniiLa1 AntagonizesGiardia intestinalisIn Vivo
Authors: Humen Martín A. , De Antoni Graciela L. , Benyacoub Jalil , Costas María E. , Cardozo Marta I. , Kozubsky Leonora , Saudan Kim-Yen , Boenzli-Bruand Angele , Blum Stephanie , Schiffrin Eduardo J. , Pérez Pablo F. 
Published: January 2005

ABSTRACTThis study describes the in vivo activity ofLactobacillus johnsoniiLa1 (NCC533) inGiardia intestinalis-infected gerbils (Meriones unguiculatus). Daily administration of lactobacilli in the drinking water from 7 days before inoculation withGiardiatrophozoites efficiently preventedG. intestinalisstrain WB clone C6 from infecting gerbils. More specifically, shedding of fecalGiardiaantigens (GSA65 protein) was diminished in the La1-treated group, and resolution of infection was observed by 21 days postinoculation. Histology and analysis of enzymatic markers of microvillus membrane integrity revealed that probiotic administration also protected against parasite-induced mucosal damage. In addition, a cellular response toGiardiaantigens was stimulated in spleen cells from La1-treated gerbils. Results show for the first time the antigiardial effect of probiotic lactobacilli in vivo and provide further insight into the antagonistic properties of lactic acid bacteria against protozoa involved in intestinal infections.