bluuebunny/crossref_metadata_2025 huggingface dataset:
3D numerical modeling of hydrothermal processes during the lifetime of a deep geothermal reservoir
Authors: Blöcher M. G. , Zimmermann G. , Moeck I. , Brandt W. , Hassanzadegan A. , Magri F.
Published: April 2010

Understanding hydrothermal processes during production is critical to optimal geothermal reservoir management and sustainable utilization. This study addresses the hydrothermal (HT) processes in a geothermal research doublet consisting of the injection well E GrSk3/90 and production well Gt GrSk4/05 at the deep geothermal reservoir of Groß Schönebeck (north of Berlin, Germany) during geothermal power production. The reservoir is located between −4050 to −4250 m depth in the Lower Permian of the Northeast German Basin. Operational activities such as hydraulic stimulation, production (T = 150°C; Q = −75 m3 h−1; C = 265 g l−1) and injection (T = 70°C; Q = 75 m3 h−1; C = 265 g l−1) change the HT conditions of the geothermal reservoir. The most significant changes affect temperature, mass concentration and pore pressure. These changes influence fluid density and viscosity as well as rock properties such as porosity, permeability, thermal conductivity and heat capacity. In addition, the geometry and hydraulic properties of hydraulically induced fractures vary during the lifetime of the reservoir. A three‐dimensional reservoir model was developed based on a structural geological model to simulate and understand the complex interaction of such processes. This model includes a full HT coupling of various petrophysical parameters. Specifically, temperature‐dependent thermal conductivity and heat capacity as well as the pressure‐, temperature‐ and mass concentration‐dependent fluid density and viscosity are considered. These parameters were determined by laboratory and field experiments. The effective pressure dependence of matrix permeability is less than 2.3% at our reservoir conditions and therefore can be neglected. The results of a three‐dimensional thermohaline finite‐element simulation of the life cycle performance of this geothermal well doublet indicate the beginning of thermal breakthrough after 3.6 years of utilization. This result is crucial for optimizing reservoir management.

Geofluids (2010) 10, 406–421
When cortical development goes wrong: schizophrenia as a neurodevelopmental disease of microcircuits
Authors: Garey Laurence
Published: April 2010

Schizophrenia probably has a developmental origin. This review refers to three of our published series of studies related to this hypothesis: loss of dendritic spines on cerebral neocortical pyramidal neurons, decreased numerical density of glutamatergic neurons, and microgliosis. First, brains of schizophrenic patients and non‐schizophrenic controls were obtained post mortem and blocks of multiple cortical areas impregnated with a Rapid Golgi method. Spines were counted on the dendrites of pyramidal neurons of which the soma was in layer III (which takes part in corticocortical connectivity) and which met strict criteria for impregnation quality. Data were obtained blind: diagnoses were only revealed by a third party after measurements were completed. The mean spine count in all cortical areas studied in the control series was 243 mm−1 of dendrite and in the schizophrenics 108. Measurements in frontal and temporal association cortex showed the greatest reduction in spine number in schizophrenia (299 in control frontal cortex and 101 in schizophrenics, and 276 mm−1 in control temporal cortex and 125 in schizophrenics). There was no correlation of spine loss with age at death. Our results support the concept of a neurodevelopmental defect in the neuropil affecting glutamatergic neurons in schizophrenia and may help to explain loss of cortical volume without loss of neurons. In a second part of our study we used an antibody to the kainate receptor subunit GluR 5/6/7 and showed a decrease in numerical density of presumed glutamatergic neurons in schizophrenic orbitofrontal cortex. Finally, as glia play a major role in the developing nervous system, we investigated whether schizophrenia was associated with glial changes in frontal and temporal cortex. Astroglia and microglia were identified in schizophrenic and control brains, using antibodies to glial fibrillary acidic protein (GFAP) and class II human leucocyte antigen (HLA‐DR), respectively. Significant increases were found in microglial numerical density in schizophrenics compared with controls: 28% in frontal area 9 (115 cells mm−2 compared with 89), and a 57% increase in temporal area 22 (139 cells mm−2 compared with 88). For both areas, astroglia showed no significant differences between schizophrenics and controls. No significant differences were found in cortical thickness or total neuronal numerical density between the two groups. This specific increase in numerical density of microglia in temporal and frontal cortex of chronic schizophrenics, not related to aging, could be related to possible changes in cortical neuropil architecture as revealed by loss of dendritic spines.
The comparability of mother‐report structured interviews and checklists for the quantification of youth externalizing symptoms
Authors: Dirks Melanie A. , Boyle Michael H.
Published: April 2010

Background: Although structured interviews are assumed to be scientifically superior to checklists for measuring youth psychopathology, few studies have tested this hypothesis. Interviews place a much greater burden on respondents, making it critical to determine their added value when quantifying psychiatric symptoms.

Methods: Confirmatory factor analysis was used to compare interviews and checklists in community (N = 251) and clinically referred (N = 406) samples of youth aged 5 to 17 years. We examined the associations between mother‐reported externalizing symptoms assessed by interview versus checklist against (a) teacher‐reported externalizing symptoms, and (b) child’s gender, academic performance, single‐ versus two‐parent family, and family income. Models in which associations were estimated freely were contrasted to models in which the interview and the checklist were constrained to have equal associations with the variables. Finding these models fit comparably would suggest no difference between interviews and checklists.

Results: In the community sample, both the constrained and unconstrained models provided comparable fit to the data, suggesting no marked differences between interviews and checklists. In the clinical sample, associations with the interview were generally stronger. Reducing the number of items on the interview to match those on the 6‐item checklist eliminated these differences, suggesting that the increased reliability of the interview scales, afforded by additional items, enhanced their quantification of psychopathology.

Conclusions: Consistent with previous studies, interviews were not notably superior to checklists for the measurement of externalizing symptoms. When only a few items are used, small performance differences between checklists and interviews may be due to scale length.
Restricted ketogenic diet enhances the therapeutic action of N‐butyldeoxynojirimycin towards brain GM2 accumulation in adult Sandhoff disease mice
Authors: Denny Christine A. , Heinecke Karie A. , Kim Youngho P. , Baek Rena C. , Loh Katrina S. , Butters Terry D. , Bronson Roderick T. , Platt Frances M. , Seyfried Thomas N.
Published: April 2010

J. Neurochem. (2010) 113, 1525–1535.

Sandhoff disease is an autosomal recessive, neurodegenerative disease involving the storage of brain ganglioside GM2 and asialo‐GM2. Previous studies showed that caloric restriction, which augments longevity, and N‐butyldeoxynojirimycin (NB‐DNJ, Miglustat), an imino sugar that hinders the glucosyltransferase catalyzing the first step in glycosphingolipid biosynthesis, both increase longevity and improve motor behavior in the β‐hexosaminidase (Hexb) knockout (−/−) murine model of Sandhoff disease. In this study, we used a restricted ketogenic diet (KD‐R) and NB‐DNJ to combat ganglioside accumulation. Adult Hexb−/− mice were placed into one of the following groups: (i) a standard diet (SD), (ii) a SD with NB‐DNJ (SD + NB‐DNJ), (iii) a KD‐R, and (iv) a KD‐R with NB‐DNJ (KD‐R + NB‐DNJ). Forebrain GM2 content (μg sialic acid/100 mg dry wt) in the four groups was 375 ± 15, 312 ± 8, 340 ± 28, and 279 ± 26, respectively, indicating an additive interaction between NB‐DNJ and the KD‐R. Most interestingly, brain NB‐DNJ content was 3.5‐fold greater in the KD‐R + NB‐DNJ mice than in the SD + NB‐DNJ mice. These data suggest that the KD‐R and NB‐DNJ may be a potential combinatorial therapy for Sandhoff disease by enhancing NB‐DNJ delivery to the brain and may allow lower dosing to achieve the same degree of efficacy as high dose monotherapy.
Posterior corneal curvature change and recovery after 6 months of overnight orthokeratology treatment
Authors: Chen Davie , Lam Andrew K. C. , Cho Pauline
Published: April 2010

Purpose:  To investigate the changes in, and recovery of, posterior corneal curvature after 6 months of overnight orthokeratology (ortho‐k).

Methods:  Twenty‐eight healthy young adults were recruited for a 6‐month period of ortho‐k treatment and data from their right eyes were analyzed. The mean ± standard deviation spherical equivalent refraction (SER) at baseline was −2.95 ± 0.88 D. Posterior simulated keratometry (Sim K) readings were measured with a corneal topographer based on rotating Scheimpflug imaging. The three phases in the study were the 6‐month treatment period (Phase I); diurnal changes over a period of 8 h immediately after lens removal at the completion of the treatment period (Phase II); and a 2‐month recovery period after cessation of treatment (Phase III). Measurements were taken after lens wear overnight, and after 1 week, and 1, 2, 3 and 6 months of lens wear in Phase I. In Phase II, measurements were taken immediately, and then 2, 4 and 8 h after lens removal. In Phase III, corneal parameters were monitored 1 week, 2 weeks, 1 month and 2 months after cessation of ortho‐k treatment.

Results:  In Phase I, the posterior Sim K readings were significantly steepened after the first overnight lens wear. These significant changes were not found at other visits. In Phase II, the posterior Sim K readings were the steepest immediately after lens removal and significantly flattened 2 h after lens removal. In Phase III, all the posterior Sim K readings were similar to the baseline results.

Conclusions:  Steepening of the posterior cornea was only observed immediately after lens removal. It returns to its original shape within 2 h after cessation of lens wear. These changes appear to be in line with recent reports of the diurnal variation in the posterior corneal shape in non‐contact lens wearers. The reduction in myopia from ortho‐k treatment is therefore mainly due to a flattening of the anterior cornea.
Sunglasses, the European directive and the European standard
Authors: Dain Stephen John , Ngo Thi Phuong Thao , Cheng Brian Barry , Hu Angel , Teh Adrian Ghim Boon , Tseng Jane , Vu Nam
Published: April 2010

Purpose:  The Optics and Radiometry Laboratory (ORLAB) provides a testing service for the Australian sunglass industry to assist its compliance with the mandatory Consumer Product Safety Standard. In doing so, a number of sunglasses carrying the CE mark (in effect a claim of compliance with the European Union Personal Protective Equipment Directive) have been tested. Since there is no mandatory testing in Europe (the sunglass industry is deemed self regulating), evaluating their performance will give an insight into compliance with the Directive.

Methods:  Consecutive submissions to ORLAB over a period of 18 months were examined for CE marked sunglasses. The results for 646 CE marked pairs of sunglasses tested during 2003 and first half 2004 were examined and evaluated for compliance with EN 1836 (the European sunglass standard) on the basis of refractive power, prismatic power, transmittance (visible, UV and coloration) and polarization.

Results:  A total of 17.3% failed EN 1836 and 3.3% were borderline (i.e. within our uncertainties of measurement of the requirement). The failures comprised: 0.9% lens defect; 12.5% polarization alignment error; 2.7% excessive vertical prism; 22.3% excessive horizontal prism; 27.7% excessive spherical power; 14.3% excessive cylindrical power; 1.8% excessive UV transmittance; and 23.2% transmittance difference between lenses (always gradient tints).

Conclusion:  With up to 20% non‐compliance, self regulation is not working particularly well in providing the public with complying sunglasses.
A 4 year retrospective survey of strabismus surgery in Tongren Eye Centre Beijing
Authors: Jie Ying , Xu Zhaoyang , He Yongning , Wang Ningli , Wang Jinghui , Lu Wei , Wu Xiao , Jiao Yonghong
Published: April 2010

Purpose:  To investigate the distribution pattern of the strabismus surgery undertaken at an eye centre in Beijing, China.

Methods:  A retrospective analysis was conducted including the data of all strabismus surgeries performed in Beijing Tongren hospital for the 4 year period from 2003 to 2006. The proportions of different surgery types and their association with patients’ age and gender were analyzed.

Result:  During the study period, 8997 strabismus surgeries were performed. The number of the surgeries increased progressively each year from 1507 in 2003 to 2769 in 2006 (p < 0.05). Intermittent exotropia was the most common of all strabismus surgeries (27.9%). Superior oblique palsy was the most common type among the paralytic strabismus surgeries. The proportions of different types of strabismus showed no significant change between successive years. Among the patients, the number of surgeries performed in the population aged 0–12 years was significantly higher than other age groups and increased from 35.37% in 2003 to 42.80% in 2006 (p < 0.05).

Conclusion:  There has been a continuous increase in the number of strabismus operations in our eye centre in Beijing, and this pattern is especially obvious in children. The distribution of surgery type remained relatively constant each year. Surgery for intermittent exotropia is the most common type of procedure.
Extended wearing trial of Trifield lens device for ‘tunnel vision’
Authors: Woods Russell L. , Giorgi Robert G. , Berson Eliot L. , Peli Eli
Published: April 2010

Severe visual field constriction (tunnel vision) impairs the ability to navigate and walk safely. We evaluated Trifield glasses as a mobility rehabilitation device for tunnel vision in an extended wearing trial. Twelve patients with tunnel vision (5–22° wide) due to retinitis pigmentosa or choroideremia participated in the 5‐visit wearing trial. To expand the horizontal visual field, one spectacle lens was fitted with two apex‐to‐apex prisms that vertically bisected the pupil on primary gaze. This provides visual field expansion at the expense of visual confusion (two objects with the same visual direction). Patients were asked to wear these spectacles as much as possible for the duration of the wearing trial (median 8, range 6–60 weeks). Clinical success (continued wear, indicating perceived overall benefit), visual field expansion, perceived direction and perceived visual ability were measured. Of 12 patients, nine chose to continue wearing the Trifield glasses at the end of the wearing trial. Of those nine patients, at long‐term follow‐up (35–78 weeks), three reported still wearing the Trifield glasses. Visual field expansion (median 18, range 9–38°) was demonstrated for all patients. No patient demonstrated adaptation to the change in visual direction produced by the Trifield glasses (prisms). For reported difficulty with obstacles, some differences between successful and non‐successful wearers were found. Trifield glasses provided reported benefits in obstacle avoidance to 7 of the 12 patients completing the wearing trial. Crowded environments were particularly difficult for most wearers. Possible reasons for long‐term discontinuation and lack of adaptation to perceived direction are discussed.
Adaptive gait changes in long‐term wearers of contact lens monovision correction
Authors: Chapman Graham J. , Vale Anna , Buckley John , Scally Andy J. , Elliott David B.
Published: April 2010

Introduction:  The aim of the present study was to determine adaptive gait changes in long‐term wearers of monovision correction contact lenses by comparing gait parameters when wearing monovision correction to those observed when wearing binocular distance correction contact lenses.

Methods:  Gait and toe clearance parameters were measured in eleven participants (53.5 ± 4.6 years, median monovision wearing time 5 years) as they repeatedly walked up to and onto a raised surface with either monovision or distance correction.

Results:  Compared to distance correction, monovision resulted in a large reduction in stereoacuity from 17″ to 87″, a slower walking velocity (p = 0.001), a reduced horizontal toe clearance of the step edge (p = 0.035) and, for trials when monovision correction occurred first, a 33% greater variability in vertical toe clearance (p = 0.021). Variability in some gait data was large due to certain study design features and learning effects.

Conclusion:  A slower walking velocity with monovision correction suggests participants became more cautious, likely as a result of the significantly reduced stereoacuity. The decreased horizontal toe clearance and increased vertical toe clearance variability suggests that monovision correction may cause a greater likelihood of hitting step edges and tripping during everyday gait. Recommended study design features are suggested for future adaptive gait studies to increase the precision of the data and to attempt to minimize the effects of learning from somatosensory feedback.
Targeting Residents for Transitions from Nursing Home to Community
Authors: Arling Greg , Kane Robert L. , Cooke Valerie , Lewis Teresa
Published: April 2010

Objective. To analyze nursing home utilization patterns in order to identify potential targeting criteria for transitioning residents back to the community.

Data Sources. Secondary data from minimum data set (MDS) assessments for an annual cohort of first‐time admissions (N=24,648) to all Minnesota nursing homes (N=394) from July 2005 to June 2006.

Study Design. We conducted a longitudinal analysis from admission to 365 days. Major MDS variables were discharge status; resident's preference and support for community discharge; gender, age, and marital status; pay source; major diagnoses; cognitive impairment or dementia; activities of daily living; and continence.

Principal Findings. At 90 days the majority of residents showed a preference or support for community discharge (64 percent). Many had health and functional conditions predictive of community discharge (40 percent) or low‐care requirements (20 percent). A supportive facility context, for example, emphasis on postacute care and consumer choice, increased transition rates.

Conclusions. A community discharge intervention could be targeted to residents at 90 days after nursing home admission when short‐stay residents are at risk of becoming long‐stay residents.
Do Medicaid Wage Pass‐through Payments Increase Nursing Home Staffing?
Authors: Feng Zhanlian , Lee Yong Suk , Kuo Sylvia , Intrator Orna , Foster Andrew , Mor Vincent
Published: April 2010

Objective. To assess the impact of state Medicaid wage pass‐through policy on direct‐care staffing levels in U.S. nursing homes.

Data Sources. Online Survey Certification and Reporting (OSCAR) data, and state Medicaid nursing home reimbursement policies over the period 1996–2004.

Study Design. A fixed‐effects panel model with two‐step feasible‐generalized least squares estimates is used to examine the effect of pass‐through adoption on direct‐care staff hours per resident day (HPRD) in nursing homes.

Data Collection/Extraction Methods. A panel data file tracking annual OSCAR surveys per facility over the study period is linked with annual information on state Medicaid wage pass‐through and related policies.

Principal Findings. Among the states introducing wage pass‐through over the study period, the policy is associated with between 3.0 and 4.0 percent net increases in certified nurse aide (CNA) HPRD in the years following adoption. No discernable pass‐through effect is observed on either registered nurse or licensed practical nurse HPRD.

Conclusions. State Medicaid wage pass‐through programs offer a potentially effective policy tool to boost direct‐care CNA staffing in nursing homes, at least in the short term.
Inhibition of glutamate/glutamine cycle in vivo results in decreased benzodiazepine binding and differentially regulated GABAergic subunit expression in the rat brain
Authors: Cremer Christian M. , Bidmon Hans‐Jürgen , Görg Boris , Palomero‐Gallagher Nicola , Escobar Jennifer Lopez , Speckmann Erwin‐Josef , Zilles Karl
Published: April 2010

Purpose:  The astrocytic enzyme glutamine synthetase (GS) is a key regulator of glutamate and γ‐aminobutyric acid (GABA) metabolism in the glutamate/glutamine cycle (GGC). Inhibition of GS results in changes of neurotransmitter release and recycling. However, little is known about the influence of GGC on neurotransmitter receptor expression. In the pentylenetetrazole model of epilepsy, GS becomes nitrated and partially inhibited, and we demonstrated alterations of neurotransmitter receptor expression in the same model. Therefore, we hypothesized similar changes of neurotransmitter receptor expression when GS is inhibited in vivo.

Methods:  Rats were treated with a single dose (100 mg/kg bodyweight) of l‐methionine sulfoximine (MSO), an irreversible inhibitor of GS. We used 3H‐receptor autoradiography to measure glutamatergic [α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazol‐propionic acid (AMPA), kainate, N‐methyl‐d‐aspartate (NMDA)], GABAergic (GABAA, GABAB and GABAA‐associated benzodiazepine (BZ) binding sites], dopamine D1, and adenosine A1 receptor subtypes. In addition, we performed saturation analysis of BZ binding sites on cerebral membrane homogenates and investigated the expression of GABAAα1 and γ2 subunits (which primarily mediate BZ binding) by western blot analysis.

Results:  We demonstrated a significant reduction of BZ binding in the somatosensory, piriform, and entorhinal cortices and in the amygdala, 24 and 72 h after MSO treatment. Saturation analysis revealed decreased BZ binding (Bmax) on cerebral membrane homogenates 72 h after MSO treatment, without changes in binding site affinity (KD). Furthermore, we found differential changes of α1, γ2, and phosphorylated γ2 subunits following MSO treatment.

Conclusion:  On the basis of our findings, we conclude that the glutamate/glutamine cycle directly influences GABAergic neurotransmission by regulating GABAA subunit composition, thereby affecting its modulation by endogenous benzodiazepines.
Role of Wake‐Promoting Basal Forebrain and Adenosinergic Mechanisms in Sleep‐Promoting Effects of Ethanol
Authors: Thakkar Mahesh M. , Engemann Samuel C. , Sharma Rishi , Sahota Pradeep
Published: April 2010

Background: Ethanol intake has significant impact on sleep. However, the cellular substrates responsible for sleep promotion following ethanol intake are unknown. The purine nucleoside, adenosine, is responsible for mediating many neuronal and behavioral responses to ethanol. Studies performed in cell cultures suggest that ethanol inhibits equilibrative nucleoside transporter 1 to block the reuptake of adenosine resulting in increased extracellular adenosine. Adenosine also has a pivotal role in sleep regulation. Adenosine acts via A1 receptor to inhibit the wake‐promoting neurons of the basal forebrain (BF) resulting in the promotion of sleep. Is ethanol‐induced sleep associated with the inhibition of the BF wake‐promoting neurons? Do adenosinergic mechanisms in the BF have a role in sleep‐promoting effects of ethanol?

Methods: To address these questions, we performed 3 experiments in Sprague–Dawley rats. First, we verified the effect of ethanol on sleep promotion. Second, we evaluated the effect of ethanol on c‐Fos expression (a marker of neuronal activation) in the BF wake‐promoting neurons and third we monitored the effects of A1 receptor blockade in the BF on ethanol‐induced sleep.

Results: Significant increase in non‐rapid eye movement (NREM) sleep with a concomitant decrease in wakefulness was observed during the first 12 hours postethanol. REM sleep remained unaffected. Ethanol administration caused a significant decrease in the number of BF wake‐promoting neurons with c‐Fos immunoreactivity. Bilateral microinjections of a selective A1R receptor antagonist 8‐cyclopentyl‐1, 3‐dipropylxanthine into the BF significantly attenuated sleep‐promoting effects of ethanol.

Conclusion: These results suggest that the inhibition of BF wake‐promoting neurons by adenosinergic mechanism may be responsible for the sleep promoting effects of ethanol. We believe our study is the first to investigate the cellular mechanisms responsible for the somnogenic effects of ethanol.
Effects of Naltrexone Treatment for Alcohol‐Related Disorders on Healthcare Costs in an Insured Population
Authors: Kranzler Henry R. , Montejano Leslie B. , Stephenson Judith J. , Wang Shaohung , Gastfriend David R.
Published: April 2010

Objective:  To determine the impact of treatment with oral naltrexone on healthcare costs in patients with alcohol‐related disorders.

Methods:  Using data from the MarketScan Commercial Claims and Encounters Database for 2000–2004, we identified a naltrexone group (with an alcohol‐related diagnosis and at least one pharmacy claim for oral naltrexone) and two control groups. Alcohol controls had an alcohol‐related diagnosis and were not prescribed an alcoholism treatment medication. Nonalcohol controls had no alcohol‐related diagnosis and no prescription for an alcoholism treatment medication. The control groups were matched three to one to the naltrexone group on demographic and other relevant measures. Healthcare expenditures were calculated for the 6‐month periods before and after the index naltrexone drug claim (or matched date for controls). Univariate and multivariate analyses were used to compare the groups on key characteristics and on healthcare costs.

Results:  Naltrexone patients (n = 1,138; 62% men; mean age 45 ± 11 years) had significantly higher total healthcare expenditures in the pre‐index period than either of the control groups. In the postindex period, naltrexone patients had a significantly smaller increase than alcohol controls in total alcohol‐related expenditures. Total nonalcohol‐related expenditures also increased significantly less for the naltrexone group than for the alcohol control group. Multivariate analyses showed that naltrexone treatment significantly reduced alcohol‐related, nonalcohol‐related, and total healthcare costs relative to alcohol controls.

Conclusions:  Although prior to treatment patients with alcohol‐related disorders had higher healthcare costs, treatment with oral naltrexone was associated with reductions both in alcohol‐related and nonalcohol‐related healthcare costs.
Medicare Beneficiaries' Knowledge of and Choices Regarding Part D, 2005 to the Present
Authors: Polinski Jennifer M. , Bhandari Aman , Saya Uzaib Y. , Schneeweiss Sebastian , Shrank William H.
Published: April 2010

In the months before and years since Medicare Part D's implementation in January 2006, many have been concerned with beneficiaries' ability to benefit from the complex program. A systematic review of published Medline and gray literature from January 1, 2005, to August 20, 2009, was undertaken to evaluate Medicare beneficiaries' knowledge about Part D and how this knowledge informed decisions regarding enrollment and plan choice. Thirty articles that reported original results describing seniors' knowledge of the Part D benefit, decision to enroll, or selection of plans; results from patient surveys addressing these issues; or results that analyzed enrollment data or plan selection patterns were included. Of these 30 articles, 10 described beneficiaries' knowledge, 12 described enrollment and plan choices, and eight described knowledge and choice. Across studies and years, beneficiaries' knowledge of the Part D program and benefit structure and design was poor, particularly with regard to the coverage gap and the low‐income subsidy. Beneficiaries had great difficulty choosing the lowest‐cost Part D plans and were disinclined to switch plans to improve their benefits. Knowledge deficits, enrollment problems, and plan choice difficulties were most pronounced during Part D implementation in early 2006 but persisted in subsequent years of the benefit. Beneficiaries' knowledge and choices should be monitored on an ongoing basis to inform potential changes to the Part D program.
Trajectories of Quality of Life in Older Persons with Advanced Illness
Authors: Solomon Rachel , Kirwin Paul , Van Ness Peter H. , O'Leary John , Fried Terri R.
Published: April 2010

OBJECTIVES: To examine subjective ratings of quality of life (QoL) in older adults with advanced illness.

DESIGN: Observational cohort study with interviews at least every 4 months for up to 2 years conducted between December 1999 and December 2002.

SETTING: Participants' homes.

PARTICIPANTS: One hundred eighty‐five community‐dwelling individuals aged 60 and older with advanced cancer, heart failure, or chronic obstructive pulmonary disease.

MEASUREMENTS: Participants were asked how they would rate their overall QoL.

RESULTS: Of participants who died, 46% reported good or best possible QoL at their final interview, 21% reported improvement in QoL from their penultimate to final interview, and 39% reported no change. Forty‐nine percent of participants reported two or more changes in the direction of their QoL trajectories (e.g., QoL improved then declined). As measured over time in a multivariable longitudinal regression analysis, greater activity of daily living disability (adjusted odds ratio (AOR)=0.85, 95% confidence interval (CI)=0.75–0.95) and depressed mood (AOR=0.42, 95%CI=0.27–0.66) were associated with poorer QoL, whereas better self‐rated health (AOR=4.79, 95% CI=2.99–7.69) and having grown closer to one's church (AOR=1.99, 95% CI=1.17–3.39) were associated with better QoL.

CONCLUSION: Although declining QoL is not an inevitable consequence of advancing illness, individuals' ratings of QoL are highly variable over time, suggesting that temporary factors may influence subjective QoL. Functional status, depression, and connection to one's religious community are shared determinants of QoL.
Left Ventricular Extracellular Matrix Remodeling in Dogs with Right Ventricular Apical Pacing
Authors: LIN JIH‐MIN , LAI LING‐PING , LIN CHIH‐SHENG , CHOU NAI‐KUAN , CHIU CHIH‐YUAN , LIN JIUNN‐LEE
Published: April 2010

Left Ventricular Remodeling in Pacing Dogs. Introduction: Right ventricle (RV) apical pacing is associated with increased incidence of heart failure due to left ventricle (LV) desynchronization. We aim to investigate extracellular matrix (ECM) remodeling of the LV in dogs with atria‐sensed RV apical pacing.

Methods and Results:
Dogs with pacemakers underwent AV nodal ablation. After 12 weeks of atria‐sensed obligatory RV pacing, LVs were separated into septum and lateral wall for analysis. Zymographic activity, including matrix metalloproteinase‐2 (MMP‐2), MMP‐9, tissue inhibitors of metalloproteinase‐1 (TIMP‐1), TIMP‐3, collagen transcript expression, and histology were examined in opposite portions of the LV to identify possible ECM remodeling changes by RV apical pacing. Compared with sham‐operated dogs, increased interstitial fibrosis and fragmentation of myofibrils was found in the LV lateral wall in the pacing group. Collagen type II mRNA showed a significant 2‐fold increase in the LV lateral wall in the pacing group. Although collagen type I mRNA was increased, the difference was not significant. Zymography demonstrated MMP‐9 activity was enhanced in both the LV lateral wall and septum in the pacing group, but MMP‐2 activity was enhanced in the LV lateral wall. Immunfluorescence stain confirmed the activation of MMP‐2 and MMP‐9 in the LV lateral wall in the pacing group. Protein expression of TIMP‐1 and TIMP‐3 showed regional differences in the pacing group and both proteins were increased in the LV lateral wall.

Conclusion:
LV dyssynchrony by RV apical pacing elicits heterogeneous ECM remodeling in the LV. These findings assist in the elucidation of the pathophysiology of LV desynchronization. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1142‐1149)
Increased Right Ventricular Repolarization Gradients Promote Arrhythmogenesis in a Murine Model of Brugada Syndrome
Authors: MARTIN CLAIRE A. , ZHANG YANMIN , GRACE ANDREW A. , HUANG CHRISTOPHER L.‐H.
Published: April 2010

Repolarization Gradients in Brugada Syndrome.  Introduction: Brugada syndrome (BrS) is associated with loss of Na+ channel function and increased risks of a ventricular tachycardia exacerbated by flecainide but reduced by quinidine. Previous studies in nongenetic models have implicated both altered conduction times and repolarization gradients in this arrhythmogenicity. We compared activation latencies and spatial differences in action potential recovery between different ventricular regions in a murine Scn5a+/− BrS model, and investigated the effect of flecainide and quinidine upon these.

Methods and Results: Langendorff‐perfused wild‐type and Scn5a+/− hearts were subjected to regular pacing and a combination of programmed electrical stimulation techniques. Monophasic action potentials were recorded from the right (RV) and left ventricular (LV) epicardium and endocardium before and following flecainide (10 μM) or quinidine (5 μM) treatment, and activation latencies measured. Transmural repolarization gradients were then calculated from the difference between neighboring endocardial and epicardial action potential durations (APDs). Scn5a+/− hearts showed decreased RV epicardial APDs, accentuating RV, but not LV, transmural gradients. This correlated with increased arrhythmic tendencies compared with wild‐type. Flecainide increased RV transmural gradients, while quinidine decreased them, in line with their respective pro‐ and antiarrhythmic effects. In contrast, Scna5+/− hearts showed slowed conduction times in both RV and LV, exacerbated not only by flecainide but also by quinidine, in contrast to their differing effects on arrhythmogenesis.

Conclusion: We use a murine genetic model of BrS to systematically analyze LV and RV action potential kinetics for the first time. This establishes a key role for accentuated transmural gradients, specifically in the RV, in its arrhythmogenicity. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1153‐1159)
The role of caveolae in endothelial cell dysfunction with a focus on nutrition and environmental toxicants
Authors: Majkova Zuzana , Toborek Michal , Hennig Bernhard
Published: April 2010

Introduction

Caveolae‐associated signalling and regulation of endothelial cell function

Caveolae as modulators of cardiovascular toxicity induced by persistent environmental pollutants

Nutrition and caveolae function: implication in inflammatory disease

Regulation of caveolae function by nutrients and implications in endothelial dysfunction by environmental toxicants

Conclusion

Complications of vascular diseases, including atherosclerosis, are the number one cause of death in Western societies. Dysfunction of endothelial cells is a critical underlying cause of the pathology of atherosclerosis. Lipid rafts, and especially caveolae, are enriched in endothelial cells, and down‐regulation of the caveolin‐1 gene may provide protection against the development of atherosclerosis. There is substantial evidence that exposure to environmental pollution is linked to cardiovascular mortality, and that persistent organic pollutants can markedly contribute to endothelial cell dysfunction and an increase in vascular inflammation. Nutrition can modulate the toxicity of environmental pollutants, and evidence suggests that these affect health and disease outcome associated with chemical insults. Because caveolae can provide a regulatory platform for pro‐inflammatory signalling associated with vascular diseases such as atherosclerosis, we suggest a link between atherogenic risk and functional changes of caveolae by environmental factors such as dietary lipids and organic pollutants. For example, we have evidence that endothelial caveolae play a role in uptake of persistent organic pollutants, an event associated with subsequent production of inflammatory mediators. Functional properties of caveolae can be modulated by nutrition, such as dietary lipids (e.g.fatty acids) and plant‐derived polyphenols (e.g.flavonoids), which change activation of caveolae‐associated signalling proteins. The following review will focus on caveolae providing a platform for pro‐inflammatory signalling, and the role of caveolae in endothelial cell functional changes associated with environmental mediators such as nutrients and toxicants, which are known to modulate the pathology of vascular diseases.
Willingness to pay for implant therapy: a study of patient preference
Authors: Leung Katherine C. M. , McGrath Colman P. J.
Published: April 2010

Aims: This study determined the amount of willingness to pay (WTP) for implant treatment and identified the factors affecting WTP.

Methods: Subjects attending a university dental hospital were recruited (n=59). They were presented with two hypothetical clinical scenarios: missing one anterior/posterior tooth. The clinical procedures, outcome and plausible complications of various replacement options (fixed and removable partial dentures, implants) and sequelae of no treatment were presented. They were then asked how much they were willing to pay for tooth replacement under the two situations using a bidding method, with a starting bid of Hong Kong (HK)$20,000 in HK$1000 increment/decrement if they were willing/unwilling to pay that amount (1 USD=7.8 HKD). The amount was recorded at which the subject chose the opposite option or it reached HK$0. Demographic data were also collected. WTP values were compared between anterior and posterior replacements, and among various demographic subgroups. Spearman's correlations and linear regression analysis were also conducted.

Results: Ninety‐four percent and 84% of the subjects chose implant treatment to replace missing anterior and posterior teeth, respectively. The mean WTP amounts for anterior/posterior tooth replacement were HK$11,000/HK$10,000 (P>0.05). Higher WTP amounts were obtained from females, subjects without missing teeth or restorative need, and had attained higher level of education (P<0.05). Gender (P<0.05), level of education (P=0.042), and the presence of missing teeth (P=0.001) were independent predictors of WTP.

Conclusions: The estimated WTP value for a single tooth replacement using dental implants was HK$10,000. Gender, level of education and presence of missing teeth were independent predictors that influenced WTP.

To cite this article:
 Leung KCM, McGrath CPJ. Willingness to pay for implant therapy: a study of patient preference. Clin Oral Impl Res. 21, 2010; 789–793. doi: 10.1111/j.1600‐0501.2009.01897.x
Effects of fluoride tablets on caries and fluorosis occurrence among 6‐ to 9‐year olds using fluoridated salt
Authors: Meyer‐Lueckel H. , Grundmann E. , Stang A.
Published: April 2010

Meyer‐Lueckel H, Grundmann E, Stang A. Effects of fluoride tablets on caries and fluorosis occurrence among 6‐ to 9‐year olds using fluoridated salt. Community Dent Oral Epidemiol 2010; 38: 315–323. © 2010 John Wiley & Sons A/S

Abstract –  Objective:  The aim of this retrospective cohort study was to investigate the association between the use of fluoride tablets among users of fluoridated salt and the occurrence of caries and fluorosis.

Materials and methods:  We examined 583 school children aged 6–9 years in Berlin, Germany for caries‐status (modified defs ≥ 1; d3‐level) and fluorosis occurrence on central incisors (TSIF ≥ 1). Parents completed questionnaires about several sociodemographic and oral health related factors of the previous years. To adjust for confounding, we used log‐risk regression and estimated relative risks (RR) and 95% confidence intervals.

Results:  The mean modified defs was 3.2 (SD = 5.9) and 58% children were caries‐free. Twenty‐two per cent of the children revealed mild fluorosis (TSIF 1 and 2). Length of fluoride tablet use was inversely associated (adjusted for age and SES) with caries‐status: 2–4 years: RR = 0.8, 95%CI: 0.7–1.0, ≥5 years: RR = 0.5, 95%CI 0.3–0.7 (reference: 0–1 year use). This inverse association could mainly be observed in children who consumed fluoridated salt as well. Relative risks for mild fluorosis were 1.8 (95%CI: 1.1–2.9) and 2.7 (95%CI: 1.6–4.5) for fluoride tablet use of 2–4 years and ≥5 years, respectively compared with 0–1 year use.

Conclusions:  Fluoride tablets seem to be effective in reducing the occurrence of caries in children with low caries levels in particular among those using fluoridated salt as well. However, fluoride tablets increase the occurrence of mild fluorosis in permanent incisors.
ORIGINAL ARTICLES: Definitions/Epidemiology/Risk Factors for Sexual Dysfunction
Authors: Lewis Ronald W. , Fugl-Meyer Kerstin S. , Corona Giovanni , Hayes Richard D. , Laumann Edward O. , Moreira Edson D. , Rellini Alessandra H. , Segraves Taylor
Published: April 2010

Introduction

Accurate estimates of prevalence/incidence are important in understanding the true burden of male and female sexual dysfunction and in identifying risk factors for prevention efforts. This is the summary of the report by the International Consultation Committee for Sexual Medicine on Definitions/Epidemiology/Risk Factors for Sexual Dysfunction.

Aim

The main aim of this article is to provide a general overview of the definitions of sexual dysfunction for men and women, the incidence and prevalence rates, and a description of the risk factors identified in large population-based studies.

Methods

Literature regarding definitions, descriptive and analytical epidemiology of sexual dysfunction in men and women were selected using evidence-based criteria. For descriptive epidemiological studies, a Prins score of 10 or higher was utilized to identify population-based studies with adequately stringent criteria. This report represents the opinions of eight experts from five countries developed in a consensus process and encompassing a detailed literature review over a 2-year period.

Main Outcome Measures

The study aims to provide state-of-the-art prevalence and incidence rates reported for each dysfunction and stratified by age and gender. Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate.

Results

A wealth of information is presented on erectile dysfunction, its development through time, and its correlates. The field is still in need of more epidemiological studies on the other men’s sexual dysfunction and on all women’s sexual dysfunctions.

Conclusions

A review of the currently available evidence from epidemiological studies is provided.
Single nucleotide polymorphisms and haplotypes of TLR6 gene in Chinese Cantonese population
Authors: Xiao W.J. , Gong Y.X. , Liu Z.H. , Wang J.M.
Published: April 2010

Sequence polymorphisms in the coding region of Toll‐like receptor 6 gene were investigated in Chinese Cantonese population. By amplifying and sequencing a 2787 bp segment containing the entire coding region of TLR6 gene of 191 individuals in Chinese Cantonese population, a total of seven single nucleotide polymorphisms (SNP) along with their frequencies were detected. Comparing these data with SNP published in dbSNP database of National Center for Biotechnology Information (NCBI), two SNP (+176T/C and +1408G/T) were firstly reported, and five SNP caused amino‐acid substitution. Sixteen haplotypes and their distributions were reconstructed. Linkage disequilibrium analysis and neutrality test were also performed. Comparing with other ethnic populations, Chinese Cantonese displayed obvious differences in TLR6 polymorphism. It may in part reflect the ethnic diversity of pathogen susceptibility and facilitate to develop the disease‐association studies as well as population genetics and evolutionary research.
Enzyme activity of the phenylpropanoid pathway as a response to apple scab infection
Authors: Slatnar A. , Mikulic Petkovsek M. , Halbwirth H. , Stampar F. , Stich K. , Veberic R.
Published: April 2010

The study was performed on apple trees, ‘Golden Delicious' cv., which is a scab‐susceptible cultivar. The phenolic content of apple fruit was determined in different parts of the peel. The phenolic compounds were analysed in the scab spot, in the tissue around the spot and in the healthy tissue. We determined the concentration of various phenolic compounds and related enzyme activities. Infection with the Venturia inaequalis fungus enhanced the metabolism of phenolic compounds at the scab spot, around the spot and in healthy peel. Compared with the healthy tissue and the tissue around the spot, the scab spot showed higher enzyme activity for all tested enzymes, except for dihydrochalcone 2′‐O‐glucosyltransferase, which had lower activity in the scab spot. In comparison to the healthy peel, the scab spot showed up to 3.4 times more hydroxycinnamic acids, up to 1.1 times more dihydrochalcones and up to 1.4 times more flavan‐3‐ols. In contrast, the healthy peel showed up to 1.6 times more flavonols than the scab spot.
Understanding Adoption of Livestock Health Management Practices: The Case of Bovine Leukosis Virus
Authors: Gramig Benjamin M. , Wolf Christopher A. , Lupi Frank
Published: April 2010

Herd‐level livestock health management decisions have implications for farm profitability and the potential public impact of a livestock disease outbreak. Thus, adoption of health management practices is of interest to government officials concerned with managing the risk of disease outbreak and controlling the spread of infection. This paper uses a fractional logit model to estimate the disease risk reduction for livestock health management practices on farms, and then uses the economic benefits of these risk reductions as explanatory variables in an econometric model of adoption of these practices. We find that the economic damages from disease associated with a particular practice are statistically significant but ultimately of little practical economic importance in adoption decisions. Implications for policy and relation to prior research findings are discussed.

Les décisions entourant la gestion sanitaire du troupeau ont des répercussions sur la rentabilité des fermes et sur l'impact qu'une éclosion de maladies animales pourrait avoir sur la population. Par conséquent, l'adoption de pratiques de gestion sanitaire intéresse les représentants du gouvernement soucieux de gérer le risque d'éclosion de maladies et de maîtriser la propagation d'une infection. Dans le présent article, nous avons utilisé un modèle logit fractionnaire pour estimer la diminution du risque de maladies lorsque des pratiques de gestion sanitaire du troupeau sont adoptées à la ferme et nous avons ensuite utilisé les avantages économiques de cette diminution du risque comme variables explicatives dans un modèle économétrique d'adoption de ces pratiques. Les résultats ont montré que les dommages économiques liés aux maladies associées à une pratique en particulier sont statistiquement significatifs, mais qu'ils sont finalement sans importance économique dans les décisions d'adoption. Nous avons examiné les répercussions sur la politique agricole et avons fait le lien avec des résultats de recherche antérieurs.