bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of parity and advanced maternal age on obstetric outcome
Authors: Chan Ben Chong‐Pun , Lao Terence Tsz‐Hsi 
Published: July 2008

AbstractObjectivesTo examine the effect of parity on obstetric outcome in women aged 40 years or older.MethodsA retrospective cohort of 16 427 singleton pregnancies delivered between 1998 and 2001 was studied. Obstetric outcomes in women aged 40 years or older versus women younger than 40 years were compared for both nulliparous and multiparous women.ResultsOf the 15 727 pregnancies (95.7%) that satisfied the inclusion criteria, 606 (3.9%) were in women aged 40 years or older. Advanced age was independently associated with cesarean delivery, birth and spontaneous preterm labor before 37 weeks, and low birth weight neonates in nulliparous women, but only with preterm birth before 37 weeks and cesarean delivery in multiparous women.ConclusionObstetric outcome in women aged 40 years or older was influenced by parity. Cesarean delivery and preterm birth before 37 weeks were independently associated with older age irrespective of parity. Advanced age is a risk factor for preterm birth.
Longitudinal selenium status in healthy British adults: assessment using biochemical and molecular biomarkers
Authors: Sunde Roger A. , Paterson Elaine , Evenson Jacqueline K. , Barnes Kimberly M. , Lovegrove Julie A. , Gordon Michael H. 
Published: July 2008

Human selenium (Se) requirements are currently based on biochemical markers of Se status. In rats, tissue glutathione peroxidase-1 (Gpx1) mRNA levels can be used effectively to determine Se requirements; blood Gpx1 mRNA levels decrease in Se-deficient rats, so molecular biology-based markers have potential for human nutrition assessment. To study the efficacy of molecular biology markers for assessing Se status in humans, we conducted a longitudinal study on 39 subjects (age 45 ± 11) in Reading, UK. Diet diaries (5 day) and blood were obtained from each subject at 2, 8, 17 and 23 weeks, and plasma Se, glutathione peroxidase (Gpx3) enzyme activity, and selenoprotein mRNA levels were determined. There were no significant longitudinal effects on Se biomarkers. Se intake averaged 48 ± 14 μg/d. Plasma Se concentrations averaged 1·13 ± 0·16 μmol/l. Plasma Sev.energy-corrected Se intake (ng Se/kJ/d) was significantly correlated, but neither Gpx3 activityv.Se intake (ng Se/kJ/d) nor Gpx3 activityv.plasma Se was significantly correlated. Collectively, this indicates that subjects were on the plateaus of the response curves. Selenoprotein mRNAs were quantitated in total RNA isolated from whole blood, but mRNA levels for Gpx1, selenoprotein H, and selenoprotein W (all highly regulated by Se in rodents), as well selenoprotein P, Gpx3, and phospholipid hydroperoxide glutathione peroxidase were also not significantly correlated with plasma Se. Thus selenoprotein molecular biomarkers, as well as traditional biochemical markers, are unable to further distinguish differences in Se status in these Se replete subjects. The efficacy of molecular biomarkers to detect Se deficiency needs to be tested in Se-deficient populations.
Effect of a pen in group-feeding trials: modelling data from suckler cows
Authors: JAUHIAINEN L. , MANNINEN M. , ÖFVERSTEN J. 
Published: July 2008

SUMMARYThis paper provides information on the extent and containment of intraclass correlation (ICC) concerning group-feeding trials on suckler cows. The research comprised the re-analysis of six previously reported experiments and a parallel simulation study. ICC coefficients were estimated for eight variables. They were seen to be higher in experiments on bulls compared with those on cows and more notable in the measurements of live weight gain compared with final weight. Moreover, the ICC coefficients were generally high for all variables measuring behavioural patterns. The simulation study showed that using a single animal as an experimental unit could be valid in certain situations, but it could not be extended to cover all the cases. The simulation study also showed that the common mixed model approach had significant problems when the ICC was slight. In general, the research strengthened the arguments that much more effort should be placed on the planning and statistical analysis of group-feeding experiments, especially in behavioural studies.
Temporal and between-site variation in helminth communities of bank voles (Myodes glareolus) from N.E. Poland. 1. Regional fauna and component community levels
Authors: BEHNKE J. M. , BAJER A. , HARRIS P. D. , NEWINGTON L. , PIDGEON E. , ROWLANDS G. , SHERIFF C. , KULIŚ-MALKOWSKA K. , SIŃSKI E. , GILBERT F. S. , BARNARD C. J. 
Published: July 2008

SUMMARYHelminth infections were studied in bank voles (Myodes glareolus) from 3 woodland sites in N.E. Poland in the late summers of 1999 and 2002, to assess the temporal stability of derived statistics describing the regional helminth fauna and component community structure, and spatial influence on the latter. Regional helminth fauna changed dramatically between the two years, primarily due to a fall in the abundance ofSyphacia petrusewiczibut was partially compensated for by an increase inMesocestoides lineatusandCladotaenia globifera. It was dominated by nematodes overall, but more so in 1999 than in 2002 when larval cestodes were more frequent. Most derived parameters for component community structure varied considerably between sites and the two surveys, the hierarchical order for sites not being maintained between surveys. They were susceptible to the disproportionate influence of three relatively rare, unpredictable species with the greatest overall aggregated distribution among hosts. Jaccard's similarity index was less influenced by the rare species, showing greater stability between sites and across years. In conclusion, temporal variation confounded any site-specific characteristics of the summary measures quantified in this study and their usefulness is therefore restricted to the years in which the surveys were conducted.
Biology and life-cycle of the microsporidium Kneallhazia solenopsae Knell Allan Hazard 1977 gen. n., comb. n., from the fire ant Solenopsis invicta
Authors: Sokolova Y. Y. , Fuxa J. R. 
Published: July 2008

SUMMARYThelohania solenopsae is a unique microsporidium with a life-cycle finely tuned to parasitizing fire ant colonies. Unlike other microsporidia of social hymenopterans, T. solenopsae infects all castes and stages of the host. Four distinctive spore types are produced: diplokaryotic spores, which develop only in brood (Type 1 DK spores); octets of octospores within sporophorous vesicles, the most prominent spore type in adults but never occurring in brood; Nosema-like diplokaryotic spores (Type 2 DK spores) developing in adults; and megaspores, which occur occasionally in larvae 4, pupae, and adults of all castes but predominantly infect gonads of alates and germinate in inseminated ovaries of queens. Type 2 DK spores function in autoinfection of adipocytes. Proliferation of diplokaryotic meronts in some cells is followed by karyogamy of diplokarya counterparts and meiosis, thereby switching the diplokaryotic sequence to octospore or megaspore development. Megaspores transmit the pathogen transovarially. From the egg to larvae 4, infection is inapparent and can be detected only by PCR. Type 1 DK spore and megaspore sequences are abruptly triggered in larvae 4, the key stage in intra-colony food distribution via trophallaxis, and presumably the central player in horizontal transmission of spores. Molecular, morphological, ultrastructural and life-cycle data indicate that T. solenopsae must be assigned to a new genus. We propose a new combination, Kneallhazia solenopsae.
Advances in the sequencing of the genome of the adenophorean nematodeTrichinella spiralis
Authors: Mitreva M. , Jasmer D. P. 
Published: July 2008

SUMMARYThe adenophorean nematodes are evolutionarily distant from other species in the phylum Nematoda. Interspecific comparisons of predicted proteins have supported such an ancient divergence. Accordingly,Trichinella spiralisrepresents a basal nematode representative for genome sequencing focused on gaining a deeper insight into the evolutionary biology of nematodes. In addition, molecular characteristics that are conserved across the phylum could be of great value for control strategies with broad application. In this review, we describe and summarize progress that has been made on the sequencing and analysis of theT. spiralisgenome. The genome sequence was used in preliminary analyses for the investigation of specific questions relating to the biology ofT. spiralisand, more generally, to parasitic nematodes. For instance, we evaluated an unusually large DNase II-like protein family, predicted proteins of prospective interest in the parasite-host muscle cell interaction, anthelmintic targets and prospective intestinal genes, the encoded proteins (potentially) linked to immunological control against other nematodes. The results are discussed in relation to characteristics that are broadly conserved among evolutionary distant nematodes. The results lead to expectations that this genome sequence will contribute to advances in research onT. spiralisand other parasitic nematodes.
Problems with continuous-time malaria models in describing gametocytogenesis
Authors: CROOKS L. 
Published: July 2008

SUMMARYMost mathematical models of malaria infection represent parasites as replicating continuously at a constant rate whereas in reality, malaria parasites replicate at a fixed age. The behaviour of continuous-time models when gametocytogenesis is included, in comparison to a more realistic discrete-time model that incorporates a fixed replication age was evaluated. Both the infection dynamics under gametocytogenesis and implications for predicting the amount parasites should invest into gametocytes (level of investment favoured by natural selection) are considered. It is shown that the many malaria models with constant replication rates can be represented by just 3 basic types. For these 3 types, it is then shown that under gametocytogenesis (i) in 2 cases, parasite multiplication and gametocyte production is mostly much too low, (ii) in the third, parasite multiplication and gametocyte production is mostly much too high, (iii) the effect of gametocyte investment on parasite multiplication is mostly too high, (iv) the effect of gametocyte investment on gametocyte production is nearly always too low and (v) with a simple approximation of fitness, the predicted level of gametocyte investment is mostly much too low. However, a continuous model with 48 age-compartments compares well to the discrete model. These findings are a further argument for modelling malaria infections in discrete time.
Editorial
Authors: Jonsson Egon , Reiser Stanley J. 
Published: July 2008

In 1982 we began discussions about the need for a new journal devoted to exploring the impact of technology on health care, and in 1984 we signed on with Cambridge University Press to launch theInternational Journal of Technology Assessment in Health Care. The first issue appeared in 1985 in connection to the inaugural meeting that year of the International Society for Technology Assessment in Health Care (ISTAHC), which has held annual meetings for 18 years starting in Washington DC in 1986. The Society was later reformed as Health Technology Assessment International (HTAi) in 2003. The Journal has served as the official scientific publication of both ISTAHC and HTAi for 24 years, and its mission remains as it was stated in the introduction to the first issue: to serve as an international forum to explore the effects of health care technology, and to provide “a channel of communication among the diverse and world-wide audience of scholars, practitioners, policy makers, and administrators concerned with this issue. . .to nurture the discipline of technology assessment” (1).
Overuse or underuse of MRI scanners in private radiology centers in Tehran
Authors: Saadat Soheil , Ghodsi Seyed Mohammad , Firouznia Kavous , Etminan Mahyar , Goudarzi Khadijeh , Naieni Kourosh Holakouie 
Published: July 2008

Objectives:The semiprivate health system in Iran has created an opportunity for unnecessary uses of advanced medical equipments including magnetic resonance imaging (MRI). This study aimed to evaluate the evidence for MRI overuse in private diagnostic imaging centers in Tehran, Iran. The objectives of this study were to determine the frequency of use of MRI scans for different complaints and to explore frequency of normal MRI findings as a function of unnecessary MRI use.Methods:We conducted a survey among private MRI centers in Tehran, Iran, to study the proportion of MRI scans that may result in significant clinical finding. All MRI reports at a specific point in time at selected MRI centers were reviewed by a physician and the findings were recorded as normal, abnormal, or substantial changes.Results:Of all the MRI reports, 17.2 percent had resulted in normal findings; 9.8 percent ordered for examination of headache, and 4.8 percent for lower back pain.Conclusion:Unnecessary MRIs are most likely to result in normal finding; although not all the MRI with normal results could be identified as unnecessary. Negative findings from MRI scans may be reassuring to both clinicians and patients. The proportion of normal findings in MRI scans did not provide evidence of MRI overuse in Iran. The results of this study warrant formation of guidelines for the use of MRIs for headache and low back pain disorders.
Economic analysis of medical practice variation between 1991 and 2000: The impact of patient outcomes research teams (PORTs)
Authors: Parente Stephen T. , Phelps Charles E. , O'Connor Patrick J. 
Published: July 2008

Objectives:The aim of this study was to examine the impact of the multi-hundred million dollar investment by the federal government in the developing Patient Outcomes Research Teams (PORTs) in over a dozen major academic medical centers in the United States throughout the 1990s. The objective of the PORTs was to reduce unnecessary clinical variation in medical treatment.Methods:Using an economic derivation of welfare loss attributable to medical practice variation and hospital admission claims data for 2 million elderly patients generalizable to the nation, we estimate the change in welfare between 1991 and 2000, the period within which the PORTs were designed and executed and their results disseminated.Results:Our results show inpatient admission types targeted by the PORTs did have less welfare loss relative to their total expenditure by 2000, but that there was not a net decrease in the welfare loss for all hospital admissions affected by the PORT.Conclusions:We conclude that PORTs may have had favorable effects on welfare, most likely by reducing variation in clinical care, but that causality cannot be proved, and the effects were not equal across all conditions targeted by PORTs. This research provides a methodological template that may be used to evaluate the impact of patient safety research on welfare loss and on variation in medical treatment in both hospital and ambulatory settings.
Avoiding adverse drug reactions by pharmacogenetic testing: A systematic review of the economic evidence in the case of TPMT and AZA-induced side effects
Authors: Compagni Amelia , Bartoli Simona , Buehrlen Bernhard , Fattore Giovanni , Ibarreta Dolores , de Mesa Emma Gutierrez 
Published: July 2008

Objectives:The study aims at evaluating the economic evidence related to testing for genetic variants of the drug-metabolizing enzyme, TPMT. Detecting TPMT genetic variants before the administration of azathioprine (AZA) has the potential to prevent serious and costly adverse drug reactions (ADRs), such as neutropenia. In particular, our analysis concentrated on assessing the reliability of data on costs of neutropenia and performing the tests, the two main cost categories that could inform an economic evaluation of TPMT pharmacogenetic testing.Methods:A systematic literature review was performed to gather evidence on the costs of testing and neutropenia. Articles were critically appraised for their comprehensiveness and quality. To better estimate costs of TPMT tests, a small-scale survey of European diagnostic laboratories was conducted.Results:Only seven articles were retrieved specifying the costs associated with the management and treatment of AZA-induced neutropenia. Most of these studies are based on theoretical modeling reconstructed with key-informants or on very few cases of ADRs, and either the methodology for cost calculation is not specified or costs are based on national cost databases and tariffs. After critical appraisal of these studies, we considered €2,116 as the most reliable estimate for the cost of a case of neutropenia. Literature review accompanied by the survey of several diagnostic laboratories also provided an estimate (€68) for TPMT testing. Based on these values, the net cost per prevented case of neutropenia equals to €5,300.Conclusions:Solid economic considerations related to TPMT pharmacogenetic testing are still limited by underreporting of ADRs and high level of approximation related to cost data. Ad hoc observational studies and the ADR recording process embedded in pharmacovigilance systems, established across Europe, should represent more reliable sources of cost data in the future.
Economics of preventing premature mortality and impaired cognitive development in children through home-fortification: A health policy perspective
Authors: Sharieff Waseem , Zlotkin Stanley H. , Ungar Wendy J. , Feldman Brian , Krahn Murray D. , Tomlinson George 
Published: July 2008

Background:Home-fortification is a new strategy of adding micronutrients including zinc and iron to home-made foods. Zinc supplementation may prevent morbidity and mortality related to diarrheal illnesses, and iron supplementation may improve cognitive development, in children.Objectives:To project clinical and economic effects of home-fortification in children in an urban slum of Karachi, Pakistan.Methods:This is a cost benefit analysis of 5,000 simulated male and female infants (6–12 months) assigned to micronutrients or placebo for 4 months and followed for 55 years. We linked the effect of zinc on longitudinal prevalence of diarrhea to mortality, and the effect of iron on hemoglobin to IQ scores and lifetime earnings. Cost estimates were based on volumes of resource utilization from the Pakistan Sprinkles Diarrhea study. Main outcome was incremental benefit defined as the gain in lifetime earnings after accounting for the incremental costs of micronutrients over placebo (societal perspective).Results:Our model projected that the reduction in diarrhea and improvement in hemoglobin concentrations through home-fortification was associated with reduced child mortality, higher IQ scores, and higher earnings. The present value of incremental benefit was $106 (95 percent probability interval = $17 to $193) U.S. dollars, which corresponds to $464.79 ($74.54 to $846.27) international dollars using a purchasing power parity exchange rate.Conclusions:Home-fortification appears to improve clinical outcomes at a reasonable cost, and may actually be cost beneficial when lifetime earnings are considered.
Why did some Danish counties introduce breast cancer screening and others not? An exploratory study of four selected counties
Authors: Hjulmann Kasper , Vondeling Hindrik , Bech Mickael 
Published: July 2008

Objectives:Of the fourteen counties and two municipalities that until recently were responsible for healthcare provision in Denmark, five introduced mammography screening (MS) programs. The objective of this research is to explain this decision-making variation and to gain insight into priority setting processes in health-care provision at the county level in Denmark.Methods:Literature on priority setting in health care was used to derive seven explanatory factors for comparing decision making on MS between four selected counties, of which two had implemented MS. The relative importance of each explanatory factor in each county was determined by analyzing policy documents, supplemented with interviews of selected stakeholders. The results were combined and compared at the county level.Results:Evidence of effectiveness of MS was considered satisfactory and ethical issues related to MS were perceived relatively unproblematic only in those counties that introduced MS. Lack of resources, that is, radiologists, was an additional important factor for counties not implementing MS. Local opinion leaders have played a stimulating role, whereas advisory policy documents at the central government level and even legislation have had a minor impact.Conclusions:The four counties have based their decision making on the introduction of MS on different combinations of a limited number of factors that have been differentially weighted. The pattern of relevant factors in both counties not introducing MS is rather similar. The study elucidates the role of complementary factors to evidence in decision making. Of interest, recent public sector reforms have resulted in the decision to have MS implemented nationwide.
Use of expert knowledge in evaluating costs and benefits of alternative service provisions: A case study
Authors: Garthwaite Paul H. , Chilcott James B. , Jenkinson David J. , Tappenden Paul 
Published: July 2008

Objectives:A treatment pathway model was developed to examine the costs and benefits of the current bowel cancer service in England and to evaluate potential alternatives in service provision. To use the pathway model, various parameters and probability distributions had to be specified. They could not all be determined from empirical evidence and, instead, expert opinion was elicited in the form of statistical quantities that gave the required information. The purpose of this study is to describe the procedures used to quantify expert opinion and note examples of good practice contained in the case study.Methods:The required information was identified and preparatory discussion with four experts refined the questions they would be asked. In individual elicitation sessions they quantified their opinions, mainly in the form of point and interval estimates for specified variables. New methods have been developed for quantifying expert opinion and these were implemented in specialized software that uses interactive graphics. This software was used to elicit opinion about quantities related to measurable covariates.Results:Assessments for thirty-four quantities were elicited and available checks supported their validity. Eight points of good practice in eliciting and using expert judgment were evident. Parameters and probability distributions needed for the pathway model were determined from the elicited assessments. Simulation results from the pathway model were used to inform policy on bowel cancer service provision.Conclusions:The study illustrates that quantifying and using expert judgment can be acceptable in real problems of practical importance. For full benefit to be gained from expert knowledge, elicitation must be conducted carefully and should be reported in detail.
Hausdorff dimension of hairs and ends for entire maps of finite order
Authors: BARAŃSKI KRZYSZTOF 
Published: July 2008

AbstractWe study transcendental entire mapsfof finite order, such that all the singularities off−1are contained in a compact subset of the immediate basinBof an attracting fixed point off. Then the Julia set offconsists of disjoint curves tending to infinity (hairs), attached to the unique point accessible fromB(endpoint of the hair). We prove that the Hausdorff dimension of the set of endpoints of the hairs is equal to 2, while the union of the hairs without endpoints has Hausdorff dimension 1, which generalizes the result for exponential maps. Moreover, we show that for every transcendental entire map of finite order from class(i.e. with bounded set of singularities) the Hausdorff dimension of the Julia set is equal to 2.