bluuebunny/crossref_metadata_2025_split huggingface dataset:
Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan
Authors: Inaba T. , Mizuno M. , Take S. , Suwaki K. , Honda T. , Kawai K. , Fujita M. , Tamura T. , Yokota K. , Oguma K. , Okada H. , Shiratori Y. 
Published: February 2005

AbstractBackground  The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients.Materials and methods  Thirty‐five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1‐week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 × 109 L−1 were defined as idiopathic thrombocytopenic purpura responders.Results  Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 × 109 L−1 in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori‐negative patients experienced the same improvement (P = 0·015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0·015).Conclusions  Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.
Quantification of dose perturbation by plaque in vascular brachytherapy
Authors: Wexberg P. , Kirisits C. , Berger D. , Sulzbacher I. , Maurer G. , Potter R. , Georg D. , Glogar D. 
Published: February 2005

AbstractBackground  Dose prescription and reporting in vascular brachytherapy (VBT) is based on the assumption that the vessel wall is water equivalent, which does not consider a possible dose perturbation by plaque. As the extent of this perturbation is unknown, we aimed to quantify dose attenuation by atherosclerotic plaque for beta‐ and gamma‐radiation.Material and methods  The dose delivered from Strontium‐90/Yttrium‐90 (90Sr/Y) and Iridium‐192 (192Ir) sources with and without human peripheral arteries (90Sr/Y: n = 38, 192Ir: n = 7) surrounding the respective delivery catheter was determined with radiochromic films. Plaque and vessel wall thickness were measured using light microscopy. From the ratio‐attenuated doseunattenuated dose (dose perturbation factor: DPF) we determined averaged attenuation coefficients for atherosclerotic plaque (µP) and the residual part of the vessel wall (µW) by regression analysis based on the function DPF = exp(–µP * plaque thickness –µW * residual wall thickness).Results  Attenuation in case of 192Ir was less than the measurement uncertainties. For beta‐radiation correlation was found by discrimination between calcified and noncalcified plaque. Classifying noncalcified plaque as normal arterial tissue, the regression coefficient was r = 0·845 at µP= 0·5356 mm−1 and µW = 0·0663 mm−1.Conclusions  Vascular brachytherapy with beta radiation in calcified arteries results in significant dose attenuation within the vessel wall, which can be calculated on knowing the vascular morphometry. Thus, plaque thickness should be taken into account in treatment planning and retrospective analyses.
Clinical practice guidelines: barriers to durability after effective early implementation
Authors: Brand C. , Landgren F. , Hutchinson A. , Jones C. , MacGregor L. , Campbell D. 
Published: February 2005

AbstractBackground:  Clinical practice guidelines in general (General‐CPG) may reduce variation in clinician performance and improve patient outcomes. Short‐term evaluation is now routine, but demonstration of early successful implementation does not necessarily ensure longer‐term effectiveness.Aim:  To assess adherence to chronic obstructive pulmonary disease (COPD)‐CPG recommendations at the Royal Melbourne Hospital (RMH), 2 years after successful implementation. To identify barriers to sustained success of General‐CPG.Methods:  A multi‐faceted evaluation was performed to document: (i) current adherence to COPD management recommendations (medical record audit); (ii) awareness of attitudes towards and barriers for the use of COPD‐CPG and General‐CPG (staff survey, focus groups and key informant interviews) and (iii) access to and quality of available General‐CPG (internet review and random sample General‐CPG evaluation.Results:  Adherence to COPD‐CPG recommendations was highly variable. Adherence was higher in the Emergency Department than the general wards and for specific therapeutic recommendations. It was lower for non‐pharmacological therapy and for recommendations relating to processes of care. Most health professionals were in favour of General‐CPG. Barriers to use of General‐CPG were in keeping with previous literature reports. Organizational issues including high levels of staff turnover and lack of integration of General‐CPG into hospital quality frameworks were highlighted as major barriers. Hospital intranet access and presentation of General‐CPG identified lack of consistency in terminology and presentation.Conclusion:  Short‐term effectiveness of COPD‐CPG implementation did not ensure sustained success. Departmental organizational behaviours and organizational system barriers are major factors influencing durability. (Intern Med J 2005; 35: 162–169)
Medical history from the viewpoint of the patient
Authors: Wiltshire J. 
Published: February 2005

Abstract The patient narrative is now an established literary form, but has been largely disregarded within medicine. Medical history in general also pays only passing attention to the testimonies of individual patients. The patient narrative is not a merely contemporary development, however, but has many precursors in the past. This article outlines a project to bring medical history and the patient narrative into relationship and thereby to give the patient an intellectual history. (Intern Med J 2005; 35: 193–194)
Prolonged neglect following unilateral disruption of a prefrontal cortical–dorsal striatal system
Authors: Christakou Anastasia , Robbins Trevor W. , Everitt Barry J. 
Published: February 2005

AbstractWe investigated the potential function of the system formed by connections between the medial prefrontal cortex and the dorsomedial striatum in aspects of attentional function in the rat. It has been reported previously that disconnection of the same corticostriatal circuit produced marked deficits in performance of a serial, choice reaction‐time task while sparing the acquisition of an appetitive Pavlovian approach behaviour in an autoshaping task (Christakou et al., 2001). Here, we hypothesized that unilateral disruption of the same circuit would lead to hemispatial inattention, contrasting with the global attention deficit following complete disconnection of the system. Combined unilateral lesions of the medial prefrontal cortex (mPFC) and the medial caudate–putamen (mCPu) within the same hemisphere produced a severe and long‐lasting contralesional neglect syndrome while sparing the acquisition of autoshaping. These results provide further evidence for the involvement of the medial prefrontal‐dorsomedial striatal circuit in aspects of attentional function, as well as insight into the nature of neglect deficits following lesions at different levels within corticostriatal circuitry.
A role for synGAP in regulating neuronal apoptosis
Authors: Knuesel Irene , Elliott Abigail , Chen Hong‐Jung , Mansuy Isabelle M. , Kennedy Mary B. 
Published: February 2005

AbstractThe brain‐specific Ras/Rap GTPase‐activating protein synGAP is a major component of the postsynaptic density at glutamatergic synapses. It is a target for phosphorylation by Ca2+/calmodulin‐dependent protein kinase II, which up‐regulates its GTPase‐activating activity. Thus, SynGAP may play an important role in coupling N‐methyl‐d‐aspartate‐type glutamate receptor activation to signaling pathways downstream of Ras or Rap. Homozygous deletion of synGAP is lethal within the first few days after birth. Therefore, to study the functions of synGAP, we used the cre/loxP recombination system to produce conditional mice mutants in which gradual loss of synGAP begins at ∼ 1 week, and usually becomes maximal by 3 weeks, after birth. The resulting phenotypes fall into two groups. In a small group, the level of synGAP protein is reduced to 20–25% of wild type, and they die at 2–3 weeks of age. In a larger group, the levels remain higher than ∼ 40% of wild type, and they survive and remain healthy. In all mutants, however, an abnormally high number of neurons in the hippocampus and cortex undergo apoptosis, as detected by caspase‐3 activation. The effect is cell autonomous, occurring only in neuronal types in which the synGAP gene is eliminated. The level of caspase‐3 activation in neurons correlates inversely with the level of synGAP protein measured at 2 and 8 weeks after birth, indicating that neuronal apoptosis is enhanced by reduction of synGAP. These data show that synGAP plays a role in regulation of the onset of apoptotic neuronal death.
Descending respiratory polysynaptic inputs to cervical and thoracic motoneurons diminish during early postnatal maturation in rat spinal cord
Authors: Juvin Laurent , Morin Didier 
Published: February 2005

AbstractIsolated brainstem‐spinal cord preparations were used to explore the coexistence of a direct and an indirect descending drive from the brainstem respiratory centre to cervical and thoracic respiratory motoneurons in the neonatal Sprague–Dawley rat. Polysynaptic spinal relay pathways from the respiratory centre were suppressed by selectively perfusing the cord with mephenesin (1 mm) or a solution enriched with Ca2+ and Mg2+. At birth, both direct and spinally relayed pathways are functional and contribute equally to the global descending respiratory drive. However, during the first postnatal week, significant maturational changes appear in the way the respiratory centre controls its target respiratory motoneurons in the cervical and thoracic spinal cord, with the direct respiratory drive becoming progressively predominant with maturation (from 50% to around 75% of the global descending command). The relative contributions of the monosynaptic and the polysynaptic spinal pathways may therefore have important implications for effective respiratory control during early postnatal development.
The broad‐scale ecology of energy expenditure of endotherms
Authors: Anderson Kristina J. , Jetz Walter 
Published: February 2005

AbstractEnergy expenditure in animals scales allometrically with body mass, but residual variation is not well understood. We examine the existing data on field metabolic rates (FMR) in endotherms for the potential role of environmental conditions. Across latitude, mass‐corrected FMR of 248 bird and mammal populations fall between two constraint lines: a lower bound that increases towards the poles and is driven by environmental factors and an upper bound that is invariant with latitude and may represent physiological limitations. This triangular pattern can be explained statistically with a multipredictor model that combines environmental conditions and species biology (including phylogeny). Lower environmental temperature and longer day length increase FMR, while taxonomy and diet explain much of the remaining variation. Combined, these effects appear to form a diversity of ‘metabolic niches’ that overall decreases from the tropics to the poles. The potential of factors related to latitude acting as constraints on the ecology and evolution of metabolic strategies in endotherms is discussed.
A framework for fostering a community of practice: scaffolding learners through an evolving continuum
Authors: Hung David , Chee Tan Seng , Hedberg John G , Thiam Seng Koh 
Published: February 2005

AbstractThis paper proposes a framework of an evolving community of practitioners along a simulation, participation, and codetermined interactions continuum. Simulation, participation, and codetermined interactions are three models of learning, which describe how learners can be brought through a scaffolded process within a community experience. The framework also focuses on the processes rather than on the outcomes or products of a community. In this paper, we describe a case study of a group of heads of Information and Communications Technology (ICT) in schools being scaffolded through an experiential workshop to achieve learning outcomes such as ICT‐based project work (as product) and other constructivist dispositions of learning (as processes). The proposed framework is intended to be sufficiently broad so that learners are supported from simulation to codetermined interactions where autonomy of learners’ co‐construction efforts are encouraged and experienced.
Direct in situ detection of cells in deep‐sea sediment cores from the Peru Margin (ODP Leg 201, Site 1229)
Authors: MAUCLAIRE L. , ZEPP K. , MEISTER P. , MCKENZIE J. 
Published: February 2005

ABSTRACTMicrobiological investigations of deep‐sea sediments recovered from the Peru Margin during the ODP Leg 201 (Hole 1229A, 1–110 mbsf) demonstrated that microoganisms were a consistent component throughout the profile. Optimization of the dilution factor and DAPI‐staining procedures for direct cell counts allowed the determination of the abundance of the entire microbial community, which was about 108 cells per g dry sediment. Microbial diversity in discrete samples taken from the 110‐m profile was analysed using horseradish‐peroxydase‐rRNA‐probes. In general, the majority of the detected cells belonged to the Eubacteria kingdom with a dominance of sulphate‐reducing bacteria. The composition of the suflate‐reducing community varied with depth. Desulfobacteriaceae were dominant in the uppermost sulphate‐reducing zone and Desulfovibrionaceae at deeper depths in the upward diffusing sulphate‐rich brines. Both sulphate‐reducing groups were also detected in the methanogenic zone. Similarly, Archaea were detected throughout the profile, not only in the methanogenic zone but also in the upper and lower sulphate‐reducing zones.
Biosynthetic pathways, gene replacement and the antiquity of life
Authors: RAYMOND JASON , BLANKENSHIP ROBERT E. 
Published: February 2005

ABSTRACTThe appearance of oxygen in the Earth's atmosphere, a by‐product of oxygenic photosynthesis invented by primitive cyanobacteria, stands as one of the major events in the history of life on Earth. While independent lines of geological data suggest that oxygen first began to accumulate in the atmosphere c. 2.2 billion years ago, a growing body of biomarker data purports to push this date back fully 500 million years, based on the presumption that an oxygen‐dependent biochemistry was functional at this time. Here, we present a cautionary tale in the extension of modern biochemistry into Archean biota, identifying a suite of examples of evolutionary convergence where an enzyme catalysing a highly specific, O2‐requiring reaction has an oxygen‐independent counterpart, able to carry out the same reaction under anoxic conditions. The anaerobic enzyme has almost certainly been replaced in many reactions by the more efficient and irreversible aerobic version that uses O2. We suggest that the unambiguous interpretation of Archean biomarkers demands a rigorous understanding of modern biochemistry and its extensibility into ancient organisms.
Iron reduction in the metal‐rich guts of wood‐feeding termites
Authors: VU AMY THI , NGUYEN NHA CAO , LEADBETTER JARED R. 
Published: February 2005

ABSTRACTTermites play important roles in lignocellulose and humus turnover in diverse terrestrial ecosystems, and are significant sources of global atmospheric methane and carbon dioxide. All known termite species engage in obligate, complex nutritional symbioses with their gut microbes to carry out such processes. Several hundred microbial species, representing a broad phylogenetic and physiological diversity, are found within the well‐bounded, microliter‐in‐scale gut ecosystem of a given termite. However, most of these species have never been obtained in laboratory culture, and little can be said about their functional roles in the gut community or symbiosis. Herein, an unappreciated facet of the gut chemistry and microbiology of wood‐feeding termites is revealed: the redox metabolism of iron. Gut fluids from field‐collected termites contained millimolar amounts of ferrous iron and other heavy metals. When iron(III) hydroxides were amended to a filter paper diet of Zootermopsis nevadensis, a dampwood termite collected in the San Gabriel Mountains of Southern California, the specimens accumulated high levels of iron(II) in their guts. Additionally, iron was reduced at rapid initial rates in anoxic gut homogenates prepared from field‐collected Z. nevadensis specimens. A Clostridium sp. and a Desulfovibrio sp. were isolated from dilution‐to‐extinction enrichments of Z. nevadensis gut contents and were found to reduce iron(III), as did the termite gut spirochete Treponema primitia. The iron in the guts of wood‐feeding termites may influence the pathways of carbon‐ and electron‐flow, as well as microbial community composition in these tiny ecosystems of global importance.
Daytime Sleepiness Is Associated with 3‐Year Incident Dementia and Cognitive Decline in Older Japanese‐American Men
Authors: Foley Daniel , Monjan Andrew , Masaki Kamal , Ross Web , Havlik Richard , White Lon , Launer Lenore 
Published: February 2005

OBJECTIVES: To assess the longitudinal association between sleep disturbances (insomnia and daytime sleepiness) and incidence of dementia and cognitive decline in older men.DESIGN: Community‐based longitudinal cohort study.SETTING: The Honolulu‐Asia Aging Study of dementia that is linked to the Honolulu Heart Program's fourth examination, conducted 1991–1993, and the 3‐year follow‐up fifth examination, conducted 1994–1996.PARTICIPANTS: Two thousand three hundred forty‐six Japanese‐American men age 71 to 93 years who screened negative for prevalent dementia at baseline and were screened again for dementia incidence in a 3‐year follow‐up examination.MEASUREMENTS: Baseline self‐reports of trouble falling asleep or early morning awakening (insomnia) and being sleepy during the day (daytime sleepiness); Cognitive Abilities Screening Instrument (CASI) scores from baseline and followup; clinical diagnosis of incident dementia; and other baseline measures including age, years of education, body mass index, depressive symptoms, and history of hypertension, heart disease, diabetes mellitus, asthma, and use of benzodiazepines.RESULTS: After adjusting for age and other factors, persons reporting excessive daytime sleepiness at baseline (8%) were twice as likely to be diagnosed with incident dementia than were those not reporting daytime sleepiness (odds ratio (OR) = 2.19, 95% confidence interval (CI) = 1.37–3.50) and about 40% more likely to have ≥9 point drop in their CASI score between examinations (OR = 1.44, 95% CI = 1.01–2.08). In contrast, insomnia was not associated with cognitive decline or incidence of dementia.CONCLUSIONS: Daytime sleepiness in older adults may be an early indicator of decline in cognitive functioning and onset of dementia.
Self‐Reported Utilization of Preventive Health Services by Retired Employees Age 65 and Older
Authors: Musich Shirley , Ignaczak Aartee , McDonald Timothy , Hirschland David , Edington Dee W. 
Published: February 2005

OBJECTIVES: Increased utilization of preventive services among the aging has been associated with improved health status and decreased medical costs. We sought to examine the use of the Health Risk Appraisal (HRA) in benchmarking compliance and characterizing those retired employees who met preventive service guidelines.DESIGN: A retrospective cohort study of retired employees age 65 and older.SETTING: Nation‐wide health promotion program offered by General Motors Corporation.PARTICIPANTS: 59,670 retired General Motors employees age 65 and older who participated in a nationwide mailed HRA health promotion program.MEASUREMENTS: Preventive health services compliance was measured using selected HRA questions. Gender, HRA participation patterns, overall health risk status, medical plan selection and disease status were examined as predictors of increased compliance. Multivariate logistic regression models were developed to test the relative contributions of participant characteristics to increased utilization.RESULTS: The self‐reported HRA data indicated that compliance levels were higher than national averages. The Healthy People 2000 goals for the preventive services studied were met and exceeded (with the exception of tetanus immunization). Higher compliance was associated with being male, younger than 70 years, multiple‐year HRA participation, overall low risk status and HMO insurance plan selection.CONCLUSION: The results from the HRA indicated that this population participated at a higher level than a comparable national sample exceeding goals set by Healthy People 2000.
Is Serum Uric Acid Level Associated with All‐Cause Mortality in High‐Functioning Older Persons: MacArthur Studies of Successful Aging?
Authors: Hu Peifeng , Seeman Teresa E. , Harris Tamara B. , Reuben David B. 
Published: February 2005

OBJECTIVES: To explore the effect of serum uric acid level on subsequent all‐cause mortality in high‐functioning community‐dwelling older persons. It is controversial whether high serum uric acid level is a true independent risk factor for cardiovascular and total mortality or the association is due to other confounding variables. Furthermore, it remains unclear whether the predictive value of uric acid level on mortality observed in younger cohorts can be extended to older people.DESIGN: Prospective cohort study.SETTING: A sample of community‐dwelling older people.PARTICIPANTS: A cohort of 870 participants from the MacArthur Studies of Successful Aging.MEASUREMENTS: Baseline information was obtained for serum uric acid level, C‐reactive protein (CRP), interleukin‐6 (IL‐6), prevalent medical conditions, and health behaviors. Crude and multivariate logistic regression analyses were used to examine the association between serum uric acid levels and 7‐year all‐cause mortality, while adjusting for potential confounders.RESULTS: In men, the multiply adjusted risk ratios for 7‐year total mortality were 1.07 (95% CI = 0.61–1.88) for the mid tertile of uric acid level and 1.24 (95% CI = 0.70–2.20) for the top tertile. In women, the multiply adjusted risk ratios were 0.58 (95% CI = 0.29–1.18) and 0.47 (95% CI = 0.22–0.99), for the mid and top tertiles respectively. CRP and IL‐6 were important confounders in the relationship between serum uric acid and overall mortality.CONCLUSIONS: High serum uric acid level is not independently associated with increased total mortality in high‐functioning older men and women. When evaluating the association between serum uric acid and mortality, the potential confounding effect of underlying inflammation and other risk factors must be considered.