Discordance

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


The effect of discordance among violence and general recidivism risk estimates on predictive accuracy

CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 3 2006
Jeremy F. Mills
Introduction,Previous research has shown that the prediction of short-term inpatient violence is negatively affected when clinicians' inter-rater agreement is low and when confidence in the estimate of risk is low. This study examined the effect of discordance between risk assessment instruments used to predict long-term general and violence risk in offenders. Methods,The Psychopathy Checklist , Revised (PCL,R), Level of Service Inventory , Revised (LSI,R), Violence Risk Appraisal Guide (VRAG), and the General Statistical Information on Recidivism (GSIR) were the four risk-prediction instruments used to predict post-release general and violent recidivism within a sample of 209 offenders. Results,The findings lend empirical support to the assumption that predictive accuracy is threatened where there is discordance between risk estimates. Discordance between instruments had the impact of reducing predictive accuracy for all instruments except the GSIR. Further, the influence of discordance was shown to be greater on certain instruments over others. Discordance had a moderating effect on both the PCL,R and LSI,R but not on the VRAG and GSIR. Conclusions,There is a distinct advantage when attempting to predict recidivism to employing measures such as the LSI-R, which includes dynamic variables and intervention-related criminogenic domains, over a measure purely of fixed characteristics, such as the GSIR; however, if there is discordance between the risk estimates, caution should be exercised and more reliance on the more static historically based instrument may be indicated. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Discordance between intramuscular triglyceride and insulin sensitivity in skeletal muscle of Zucker diabetic rats after treatment with fenofibrate and rosiglitazone

DIABETES OBESITY & METABOLISM, Issue 5 2007
K. J. Nadeau
Aim:, Intramyocellular triglyceride (IMTG) correlates with insulin resistance, but there is no clear causal relationship. Insulin resistance and associated hyperinsulinaemia may increase IMTG, via the insulin-regulated transcription factor, sterol regulatory element,binding protein 1 (SREBP-1). PPAR agonists may also affect IMTG via changes in insulin sensitivity, SREBP-1 or other factors. Methods:, We examined skeletal muscle IMTG and SREBP-1 expression, and metabolic parameters in Zucker diabetic fatty rats (ZDF) after 25 weeks of PPAR-, or PPAR-, administration. Results:, Compared with Zucker lean rats (ZL), untreated ZDF had significantly higher weights, serum glucose, insulin, free fatty acids, total cholesterol and triglycerides. IMTG and SREBP-1c messenger RNA (mRNA) were also higher in untreated ZDF; both were decreased by fenofibrate (FF). Rosiglitazone (Rosi), despite marked improvement in glycaemia, hyperinsulinaemia and hyperlipidaemia, failed to affect SREBP-1 expression, and increased body weight and IMTG. Rosi/FF combination caused less weight gain and no IMTG increase, despite metabolic effects similar to Rosi alone. Conclusions:, IMTG and SREBP-1c mRNA are high in the ZDF. FF and Rosi both improved insulin sensitivity but had opposite effects on IMTG. Thus, there was a clear discordance between insulin sensitivity and IMTG with PPAR agonists, indicating that IMTG and insulin sensitivity do not share a simple relationship. [source]


Monozygotic twins are discordant for chronic periodontitis: clinical and bacteriological findings

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2010
Gaudy L. Torres de Heens
Torres de Heens GL, Loos BG, van der Velden U. Monozygotic twins are discordant for chronic periodontitis: clinical and bacteriological findings. J Clin Periodontol 2010; 37: 120,128. doi: 10.1111/j.1600-051X.2009.01511.x. Abstract Objectives: The aim of this study was to assess, in monozygotic (MZ) and dizygotic (DZ) twin pairs in whom the proband of the twin pair was suffering from moderate to severe chronic periodontitis, the contribution of genetics, periodontal pathogens and lifestyle factors towards the clinical phenotype. Material and Methods: For this study, 18 adult twin pairs were selected on the basis of interproximal attachment loss (AL) 5 mm in 2 non-adjacent teeth in one twin member. The study included 10 MZ and eight DZ twin pairs, in whom the periodontal condition, presence of periodontal pathogens, educational level, smoking behaviour and body mass index (BMI) were evaluated. Results: Both MZ and DZ twins were discordant regarding AL and alveolar bone loss. Discordance was greater in DZ compared with MZ twins. In MZ twins, the discordance could not be explained by education, smoking, BMI and periodontal pathogens. In DZ twins, 45.6% of the discordance could be explained by more pack-years of the probands. Conclusion: The results confirm a possible role of genetic factors in periodontitis. However, the magnitude of the genetic effects on disease severity may have been overestimated previously. [source]


Discordance in the histopathologic diagnosis of difficult melanocytic neoplasms in the clinical setting

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2008
Saurabh Lodha
Background:, The gold standard for diagnosing melanocytic neoplasms is by histopathologic examination. However, lack of agreement among expert dermatopathologists in evaluating these tumors has been well established in experimental settings. Objective:, This study examines the discordance among dermatopathologists in evaluating difficult melanocytic neoplasms in a clinical setting where the diagnosis impacts patient management. Methods:, Retrospective review of consultation reports over a 6-year period. Results:, There was complete agreement among the consultants in 54.5% of the cases. However, a high level of disagreement was found in 25% of the cases. Limitations:, The analysis was limited to two consultant dermatopathologists. Conclusions:, There are limitations to the practical applications of histologic criteria for diagnosing difficult melanocytic tumors. It is not malpractice for a pathologist to have rendered a diagnosis that did not predict clinical outcome as long as ,standard of care' has been followed in his/her evaluation of the specimen. [source]


Spatial patterns of recruitment in Mediterranean plant species: linking the fate of seeds, seedlings and saplings in heterogeneous landscapes at different scales

JOURNAL OF ECOLOGY, Issue 6 2008
Lorena Gómez-Aparicio
Summary 1Plant recruitment is a multiphase process that takes place in environments that are heterogeneous in space and time. In this work, I analyse how environmental heterogeneity in Mediterranean forests affects dynamics of early recruitment at different scales, using the wind-dispersed tree Acer opalus subsp. granatense as a case study. 2Seed dispersal and viability, post-dispersal predation, seedling emergence and seedling and sapling survival were evaluated in different habitats (regional scale) and microhabitats (local scale). Simultaneously, a review of the literature on spatial dynamics of plant recruitment in Mediterranean systems was conducted to look for general patterns and investigate their fit to the Acer system. Nineteen woody and herbaceous species were included in the review. 3At the regional scale, Acer recruitment dynamics strongly converged among sites of the same habitat. This was mainly due to large seedling emergence and survival differences among habitats. Although most of the studies reviewed analyzed only one site per habitat type, they also support strong regional variation (either site- or habitat-specific) in recruitment patterns. 4At the local scale, Acer recruitment was microhabitat-specific, a result shared by almost all the reviewed species independently of their life form and dispersal syndrome. This was mostly due to spatial differences in seed arrival (higher under conspecifics) and seedling survival (higher under nurse shrubs). 5Spatial discordance among seed rain and recruitment was found in 60% of the reviewed species at the regional scale, and in 67% at the local scale. Acer results supported this predominant lack of concordance. Discordance among seed rain and recruitment suggests that regeneration is largely limited by safe sites than by seed availability. Because seedling survival was the limiting process with a larger impact on the magnitude and spatial pattern of recruitment, safe sites might be defined as those where seedlings have a higher survival probability. 6Synthesis: This study indicates that the influence of seed dispersal on the spatial patterns and demography of plant species could be limited in heterogeneous and stressful environments (as are found in the Mediterranean), where recruitment is restricted to a small fraction of the landscape. If we are to preserve the distribution and abundance of Mediterranean species in the face of environmental changes, we need to explicitly consider the strong patch-specificity that characterizes their recruitment process at all scales. [source]


Prevalence, risk factors and causes of discordance in fibrosis staging by transient elastography and liver biopsy

LIVER INTERNATIONAL, Issue 10 2010
Robert P. Myers
Abstract Background and aims: Liver stiffness measurement (LSM) by transient elastography (TE) is widely used for the noninvasive assessment of fibrosis. Our objectives were to examine the prevalence, risk factors and causes of discordance between fibrosis estimated by TE and liver biopsy. Methods: Two hundred and fifty-one patients with hepatitis B, C and nonalcoholic fatty liver disease underwent LSM by TE and liver biopsy. Predictors of discordance (,2 fibrosis stages) between measures, which occurred in 14% of patients (n=35), were identified by comparing patient, TE and biopsy characteristics of discordant and nondiscordant cases. Results: According to predefined criteria, 40% of discordances were attributed to TE error and 23% to biopsy error; 37% were indeterminate. In multivariate analysis, mild fibrosis (F0,2 vs. F3,4), and higher body mass index (BMI), ALT and LSM variability [assessed by the ratio of the interquartile range to median LSM (IQR/M)] were independently associated with discordance. Discordance was three-fold more common in patients with obesity (28 vs. 9%), ALT,60 U/L (20 vs. 7%) and IQR/M ,0.17 (22 vs. 7%; all P<0.005). Based on these variables, a discordance risk score assigning 1 point to each factor was developed. The prevalence of discordance in patients with 0, 1, 2 and 3 factors were 2, 7, 20, and 55% respectively (P<0.0005). Conclusions: Discordance between liver fibrosis estimated by TE and biopsy occurs in one in seven patients. In assessing the validity of TE results, clinicians must recognize risk factors for discordance and in at-risk patients, consider alternative measures including biomarkers and possibly biopsy. [source]


Discordance between serum cardiac biomarker and immunoglobulin-free light-chain response in patients with immunoglobulin light-chain amyloidosis treated with immune modulatory drugs,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2010
Angela Dispenzieri
We evaluated the capability of soluble cardiac biomarkers to predict tolerability and outcomes of IMiD-containing treatments among 106 patients treated on clinical trials. Baseline elevations in troponin T (TnT) and N-terminal brain naturietic protein (NT-proBNP) predicted for an inability to tolerate IMiD-based regimens. The best predictors for early attrition during cycle 1 were TnT , 0.07 ,g/L and NT-proBNP , 11,939 ng/L. NT-proBNP-response underperformed TnT-response as a predictor for overall survival (OS), but both predicted for early protocol attrition. Despite hematologic response, IMiD-treated patients were at higher risk for NT-proBNP rises and early drug discontinuation than a control population but not for early death. These observations prompt two questions: (1) does IMiD-based therapy lead to increased fluid retention and/or cardiac toxicity and (2) is an NT-proBNP-driven cardiac response system valid in IMiD-treated amyloidosis patients? Recognition of potential drug-induced cardiac toxicity is important so that increased cardiac surveillance and drug dose-adjustment or discontinuation may be implemented. Am. J. Hematol. 85:757-759, 2010. © 2010 Wiley-Liss, Inc. [source]


Phosphodiesterase Type 5 Inhibitors and Female Sexual Response: Faulty Protocols or Paradigms?

THE JOURNAL OF SEXUAL MEDICINE, Issue 2pt2 2010
Meredith L. Chivers PhD
ABSTRACT Introduction., Phosphodiesterase type 5 inhibitors (PDE5), such as sildenafil, tadalafil, and vardenafil, have revolutionized the treatment of erectile dysfunction. Few successes, in contrast, have been reported for the use of these agents in treatment of sexual arousal problems in women. Aim., To review research examining efficacy of PDE5 in women, critique the methods and models employed, and integrate the findings within a broader, gender-specific understanding of female sexual response. Methods., A conceptual and methodological review of all published studies examining PDE5 efficacy in female samples. Main Outcome Measures., Study methods, populations, outcome measures, study results. Results., A total of 16 studies were reviewed. Studies using self-reported measures of sexual functioning showed mixed results whereas studies examining physiological effects of PDE5 on genital vasocongestion consistently report significant effects on genital sexual response. Conclusions., The lack of efficacy of PDE5 treatment in women is likely attributable to gender differences in the concordance between physiological and psychological components of sexual response. Discordance between genital and subjective measures of sexual response in women may be augmented by PDE5 effects on genital vasocongestion in some populations, rendering successful treatment unlikely via pharmacological treatment alone. Chivers M, and Rosen RC. PDE5 inhibitors and female sexual response: Faulty protocols or paradigms? J Sex Med 2010;7:858,872. [source]


Different Gene Expressions on the Left and the Right: A Genotype/Phenotype Mismatch in Need of Attention

ANNALS OF HUMAN GENETICS, Issue 1 2008
Ursula Mittwoch
Summary Discordance in monozygotic twins has traditionally been explained in terms of environmental influences. A recent investigation has found a difference in epigenetic markers in older but not in younger twins. However, phenotypic differences that depend on an individual's postnatal life style do not address the problem of discordance in congenital malformations, or the reason why malformations are frequently unilateral, often with a preference for one or the other side. One such condition, cleft lip with or without cleft palate, which is preferentially expressed on the left, is a multifactorial condition, that is caused by a failure of the critical timing necessary for different groups of cells to meet and develop into a normal face. This process is dependent on cell proliferation and migration, which are energy-dependent, while the additional requirement for apoptosis to allow cell fusion suggests the involvement of mitochondria. Recent progress in two separate areas of research could lead to a better understanding of the problem of facial clefts: (1) the recognition of an interaction between gene products and mitochondria in the aetiology of neurodegenerative diseases and (2) the discovery of an increasing number of genes, including transcription factors, growth factors and members of the TGF-, signalling family, that are differentially expressed on the left and right side, thus pointing to a difference in their micro-environment. These findings emphasize the importance of investigating the activity of candidate genes for complex developmental processes separately on the left and right sides. Data presented in this review suggest that differential growth rates may lead to an inversion of laterality. A method is described to test for a possible mitochondrial difference between left and right sides, using a mouse model with cleft lip. [source]


Discordance in body size, colour pattern, and advertisement call across genetically distinct populations in a Neotropical anuran (Dendropsophus ebraccatus)

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009
MICHEL E. OHMER
Patterns of intraspecific geographic variation in morphology and behaviour, when examined in a phylogenetic context, can provide insight into the microevolutionary processes driving population divergence and ultimately speciation. In the present study, we quantified behavioural and phenotypic variation among populations from genetically divergent regions in the Central American treefrog, Dendropsophus ebraccatus. Our fine-scale population comparisons demonstrated regional divergence in body size, colour pattern frequencies, and male advertisement call. None of the characters covaried with phylogenetic history or geographic proximity among sampled populations, indicating the importance of highly localized selection pressures and genetic drift in shaping character divergence among isolated regions. The study underscores how multiple phenotypic characters can evolve independently across relatively small spatial scales. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 298,313. [source]


Combining molecular, morphological and ecological data to infer species boundaries in a cryptic tropical pitviper

BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2006
KATE L. SANDERS
Few operational methods exist for delimiting species boundaries, and these usually require sampling strategies that are unrealistic for widespread organisms that occur at low densities. Here we apply molecular, morphological and ecological species delimitation criteria to a wide-ranging, fragmented group of Asian green pitvipers, the Popeia popeiorum complex. A mitochondrial DNA phylogeny for the group indicates two well-differentiated clades, corresponding mainly to northern and southern parts of its range. Strong phylogeographical structure within each clade suggests isolation in forest refugia during the Pliocene and a southward colonization of the Sunda islands during the Pleistocene. Multivariate analysis of morphological characters reveals a generally conserved pattern of geographical variation, incongruent with the recovered phylogenetic history. We compare groups delineated by mtDNA variation to morphological and ecological divisions in the complex, and discuss the implications of these for the taxonomy of the group. Discordance between species boundaries inferred from different criteria suggests that combining independent sources of data provides the most reliable estimation of species boundaries in organisms that are difficult to sample in large numbers. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87, 343,364. [source]


Assessment of occupational health and safety risks of farmworkers in Colorado ,

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue S2 2002
Martha Soledad Vela-Acosta MD
Abstract Background Migrant farmworkers face a variety of hazards including exposure to pesticides and agricultural chemicals. However, few studies have quantatively evaluated these risks. Methods Hazards were assessed during 32 field surveys conducted in the agricultural fields and 15 surveys at five camps. Observations of 1,461 farmworkers for potential hazards were recorded. Estimated risk was evaluated on a four-point scale (no hazard, minor, serious, and critical). A total of 229 farmworkers were interviewed about field conditions. Results Two out of the five camps did not have safe drinking water. Risks for farmworkers were lower when a manager was living on site. Field surveys estimated higher risk when provision of sanitation was deficient (P,<,0.05). Farmworkers' responses concerning field conditions differed from the survey findings. Conclusions Risks for farmworkers depended largely on the environment provided. Discordances between survey results and farmworkers' interview responses suggested that self-reported data might have limited validity for this population. Working and living conditions require improvement to decrease occupational risks for farmworkers. Am. J. Ind. Med. Suppl. 2:19,27, 2002. © 2002 Wiley-Liss, Inc. [source]


The effect of discordance among violence and general recidivism risk estimates on predictive accuracy

CRIMINAL BEHAVIOUR AND MENTAL HEALTH, Issue 3 2006
Jeremy F. Mills
Introduction,Previous research has shown that the prediction of short-term inpatient violence is negatively affected when clinicians' inter-rater agreement is low and when confidence in the estimate of risk is low. This study examined the effect of discordance between risk assessment instruments used to predict long-term general and violence risk in offenders. Methods,The Psychopathy Checklist , Revised (PCL,R), Level of Service Inventory , Revised (LSI,R), Violence Risk Appraisal Guide (VRAG), and the General Statistical Information on Recidivism (GSIR) were the four risk-prediction instruments used to predict post-release general and violent recidivism within a sample of 209 offenders. Results,The findings lend empirical support to the assumption that predictive accuracy is threatened where there is discordance between risk estimates. Discordance between instruments had the impact of reducing predictive accuracy for all instruments except the GSIR. Further, the influence of discordance was shown to be greater on certain instruments over others. Discordance had a moderating effect on both the PCL,R and LSI,R but not on the VRAG and GSIR. Conclusions,There is a distinct advantage when attempting to predict recidivism to employing measures such as the LSI-R, which includes dynamic variables and intervention-related criminogenic domains, over a measure purely of fixed characteristics, such as the GSIR; however, if there is discordance between the risk estimates, caution should be exercised and more reliance on the more static historically based instrument may be indicated. Copyright © 2006 John Wiley & Sons, Ltd. [source]


A randomized, placebo-controlled trial of paroxetine in nursing home residents with non-major depression

DEPRESSION AND ANXIETY, Issue 3 2002
Adam B. Burrows M.D.
Abstract Depression is common across a broad spectrum of severity among nursing home residents. Previous research has demonstrated the effectiveness of antidepressants in nursing home residents with major depression, but it is not known whether antidepressants are helpful in residents with less severe forms of depression. We conducted a randomized double-blind placebo-controlled 8-week trial comparing paroxetine and placebo in very old nursing home residents with non-major depression. The main outcome measure was the primary nurse's Clinical Impression of Change (CGI-C). Additional outcome measures were improvement on the interview-derived Hamilton Depression Rating Scale (HDRS) and Cornell Scale for Depression (CS) scores. Twenty-four subjects with a mean age of 87.9 were enrolled and twenty subjects completed the trial. Placebo response was high, and when all subjects were considered, there were no differences in improvement between the paroxetine and placebo groups. Two subjects that received paroxetine developed delirium, and subjects that received paroxetine were more likely to experience a decrease in Mini Mental State Exam scores (P = .03). There were no differences in serum anticholinergic activity between groups. In a subgroup analysis of 15 subjects with higher baseline HDRS and CS scores, there was a trend toward greater improvement in the paroxetine group in an outcome measure that combined the CGI-C and interview-based measures (P = .06). Paroxetine is not clearly superior to placebo in this small study of very old nursing home residents with non-major depression, and there is a risk of adverse cognitive effects. Because of the high placebo response and the trend towards improvement in the more severely ill patients, it is possible that a larger study would have demonstrated a significant therapeutic effect for paroxetine as compared with placebo. The study also illustrates the discordance between patient and caregiver ratings, and the difficulties in studying very elderly patients with mood disorders. Depression and Anxiety 15:102,110, 2002. © 2002 Wiley-Liss, Inc. [source]


Birthweight-discordance and differences in early parenting relate to monozygotic twin differences in behaviour problems and academic achievement at age 7

DEVELOPMENTAL SCIENCE, Issue 2 2006
Kathryn Asbury
This longitudinal monozygotic (MZ) twin differences study explored associations between birthweight and early family environment and teacher-rated behaviour problems and academic achievement at age 7. MZ differences in anxiety, hyperactivity, conduct problems, peer problems and academic achievement correlated significantly with MZ differences in birthweight and early family environment, showing effect sizes of up to 2%. As predicted by earlier research, associations increased at the extremes of discordance, even in a longitudinal, cross-rater design, with effect sizes reaching as high as 12%. As with previous research some of these nonshared environmental (NSE) relationships appeared to operate partly as a function of SES, family chaos and maternal depression. Higher-risk families generally showed stronger negative associations. [source]


Discordance between intramuscular triglyceride and insulin sensitivity in skeletal muscle of Zucker diabetic rats after treatment with fenofibrate and rosiglitazone

DIABETES OBESITY & METABOLISM, Issue 5 2007
K. J. Nadeau
Aim:, Intramyocellular triglyceride (IMTG) correlates with insulin resistance, but there is no clear causal relationship. Insulin resistance and associated hyperinsulinaemia may increase IMTG, via the insulin-regulated transcription factor, sterol regulatory element,binding protein 1 (SREBP-1). PPAR agonists may also affect IMTG via changes in insulin sensitivity, SREBP-1 or other factors. Methods:, We examined skeletal muscle IMTG and SREBP-1 expression, and metabolic parameters in Zucker diabetic fatty rats (ZDF) after 25 weeks of PPAR-, or PPAR-, administration. Results:, Compared with Zucker lean rats (ZL), untreated ZDF had significantly higher weights, serum glucose, insulin, free fatty acids, total cholesterol and triglycerides. IMTG and SREBP-1c messenger RNA (mRNA) were also higher in untreated ZDF; both were decreased by fenofibrate (FF). Rosiglitazone (Rosi), despite marked improvement in glycaemia, hyperinsulinaemia and hyperlipidaemia, failed to affect SREBP-1 expression, and increased body weight and IMTG. Rosi/FF combination caused less weight gain and no IMTG increase, despite metabolic effects similar to Rosi alone. Conclusions:, IMTG and SREBP-1c mRNA are high in the ZDF. FF and Rosi both improved insulin sensitivity but had opposite effects on IMTG. Thus, there was a clear discordance between insulin sensitivity and IMTG with PPAR agonists, indicating that IMTG and insulin sensitivity do not share a simple relationship. [source]


Fine-needle aspiration cytology of salivary glands: Diagnostic pitfalls,revisited

DIAGNOSTIC CYTOPATHOLOGY, Issue 8 2006
Arvind Rajwanshi M.D., F.R.C.Path.
Abstract Fine needle aspiration cytology (FNAC) of salivary gland lesions is a safe, effective diagnostic technique. Several amply illustrated reviews are available in the English literature. The reported diagnostic accuracy varies between 86% to 98%. The sensitivity ranges from 62% to 97.6% and specificity is higher from 94.3% to 100%. In this present study, we have analyzed 172 cases of salivary gland aspirates and the histopathological diagnosis was available in 45 cases. There was discordance in cytological and histopathological diagnosis in nine cases. Five cases had discrepancies in benign versus malignant diagnosis with four cases being false negative. The errors in these FNA diagnoses were due to sampling error, observational error and interpretational error. Therefore, this study illustrates high diagnostic accuracy of FNAC in salivary gland lesions and shows that FNAC offers valuable information that allows the planning of subsequent patient management. Diagn. Cytopathol. 2006;34:580,584. © 2006 Wiley-Liss, Inc. [source]


Tricuspid Valve Malfunction and Ventricular Pacemaker Lead: Case Report and Review of the Literature

ECHOCARDIOGRAPHY, Issue 8 2006
Said B. Iskandar M.D.
Pacemaker implantation can be associated with several complications, including myocardial perforation with or without pericardial effusion, venous thrombosis, vegetations of the tricuspid valve (TV) or pacing lead, and tricuspid regurgitation (TR). The TR is thought to be derived from deformity or perforation of the TV by the pacing lead or secondary to atrioventricular discordance with asynchronous ventricular pacing. Severe TR can be deleterious to the patient because it raises the central venous pressure by increasing the right sided preload. Chronically, the increase in right sided blood volume can result in an increase in the right atrial pressure leading to a decrease in venous return and low cardiac output. Severe TR from leaflet adhesion to the pacemaker lead has not been reported before. With the aging of the population and the expanding use of pacemakers and implantable cardioverter defibrillators (ICD) in clinical practice, this complication may be seen more frequently. We present a patient diagnosed with severe TR, years after his pacemaker implantation. His TR was thought to be caused by adhesion of the tricuspid valve to his pacemaker lead. [source]


THE COMBINED EFFECTS OF RIVERS AND REFUGIA GENERATE EXTREME CRYPTIC FRAGMENTATION WITHIN THE COMMON GROUND SKINK (SCINCELLA LATERALIS)

EVOLUTION, Issue 2 2010
Nathan D. Jackson
Rivers can act as both islands of mesic refugia for terrestrial organisms during times of aridification and barriers to gene flow, though evidence for long-term isolation by rivers is mixed. Understanding the extent to which riverine barrier effects can be heightened for populations trapped in mesic refugia can help explain maintenance and generation of diversity in the face of Pleistocene climate change. Herein, we implement phylogenetic and population genetic approaches to investigate the phylogeographic structure and history of the ground skink, Scincella lateralis, using mtDNA and eight nuclear loci. We then test several predictions of a river,refugia model of diversification. We recover 14 well-resolved mtDNA lineages distributed east,west along the Gulf Coast with a subset of lineages extending northward. In contrast, ncDNA exhibits limited phylogenetic structure or congruence among loci. However, multilocus population structure is broadly congruent with mtDNA patterns and suggests that deep coalescence rather than differential gene flow is responsible for mtDNA,ncDNA discordance. The observed patterns suggest that most lineages originated from population vicariance due to riverine barriers strengthened during the Plio,Pleistocene by a climate-induced coastal distribution. Diversification due to rivers is likely a special case, contingent upon other environmental or biological factors that reinforce riverine barrier effects. [source]


GENETIC ANALYSIS OF A CHROMOSOMAL HYBRID ZONE IN THE AUSTRALIAN MORABINE GRASSHOPPERS (VANDIEMENELLA, VIATICA SPECIES GROUP)

EVOLUTION, Issue 1 2009
Takeshi Kawakami
Whether chromosomal rearrangements promote speciation by providing barriers to gene exchange between populations is one of the long-standing debates in evolutionary biology. This question can be addressed by studying patterns of gene flow and selection in hybrid zones between chromosomally diverse taxa. Here we present results of the first study of the genetic structure of a hybrid zone between chromosomal races of morabine grasshoppers Vandiemenella viatica, P24(XY) and viatica17, on Kangaroo Island, Australia. Chromosomal and 11 nuclear markers revealed a narrow hybrid zone with strong linkage disequilibrium and heterozygote deficits, most likely maintained by a balance between dispersal and selection. Widths and positions of clines for these markers are concordant and coincident, suggesting that selection is unlikely to be concentrated on a few chromosomes. In contrast, a mitochondrial marker showed a significantly wider cline with centre offset toward the P24(XY) side. We argue that the discordance between the mitochondrial and nuclear/chromosomal clines and overall asymmetry of the clines suggest a secondary origin of the contact zone and potential movement of the zone after contact. Genome-wide scans using many genetic markers and chromosomal mapping of these markers are needed to investigate whether chromosomal differences directly reduce gene flow after secondary contact. [source]


EVIDENCE FOR HISTORICAL INTROGRESSION ALONG A CONTACT ZONE BETWEEN TWO SPECIES OF CHAR (PISCES: SALMONIDAE) IN NORTHWESTERN NORTH AMERICA

EVOLUTION, Issue 5 2002
Z. Redenbach
Abstract Phylogeographic analyses can yield valuable insights into the geographic and historical contexts of contact and hybridization between taxa. Two species of char (Salmonidae), Dolly Varden (Salvelinus malma) and bull trout (S. confluentus) have largely parapatric distributions in watersheds of northwestern North America. They are, however, sympatric in several localities and hybridization and some introgression occurs across a broad area of contact. We conducted a comparative phylogenetic analysis of Dolly Varden and bull trout to gain a historical perspective of hybridization between these species and to test for footprints of historical introgression. We resolved two major Dolly Varden mitochondrial DNA (mtDNA) clades (with 1.4,2.2% sequence divergence between haplotypes) that had different geographical distributions. Clade N is distributed across most of the range of Dolly Varden, from southern British Columbia through to the Kuril Islands in Asia. Clade S had a much more limited distribution, from Washington state, at the southern limit of the Dolly Varden range, to the middle of Vancouver Island. The distribution and inferred ages of the mtDNA clades suggested that Dolly Varden survived the Wisconsinan glaciation in a previously unsuspected refuge south of the ice sheet, and that Dolly Varden and bull trout were probably in continuous contact over most of the last 100,000 years. When bull trout were included in the phylogenetic analysis, however, the mtDNA of neither species was monophyletic: Clade S Dolly Varden clustered within the bull trout mtDNA clade. This pattern was discordant with two nuclear phylogenies produced (growth hormone 2 and rRNA internal transcribed sequence 1), in which Dolly Varden and bull trout were reciprocally monophyletic. This discordance between mtDNA- and nDNA-based phylogenies indicates that historical introgression of bull trout mtDNA into Dolly Varden occurred. Percent sequence divergence within these introgressed Dolly Varden (clade S) was 0.2,0.6%, implying that the introgression occurred prior to the most recent glaciation. Our analysis and other evidence of contact between divergent lineages in northwestern North America strongly suggests that the area may be the site of previously unsuspected suture zones of aquatic biotas. [source]


Timing primate evolution: Lessons from the discordance between molecular and paleontological estimates

EVOLUTIONARY ANTHROPOLOGY, Issue 4 2008
M. E. Steiper
Abstract The molecular clock has become an increasingly important tool in evolutionary biology and biological anthropology. Nevertheless, a source of contention with respect to this method is the frequent discordance with fossil-based estimates of divergence times. The primate radiation is a case in point: Numerous studies have dated the major primate nodes (reviewed in Steiper and Young,1, 2) and there are many instances where molecular and fossil-based estimates of divergence times differ (Fig. 1). Some investigators have recently focused on phenomena such as stratigraphic dating, the stochastic nature of molecular time estimates, and other sources as potential biases in molecular clock estimates.3, 4 In this paper we do not focus on accuracy or statistical error; rather, we argue that discordance is a predictable phenomenon that provides valuable information about the tempo and mode of primate molecular and morphological evolution. Using this perspective, we reexamine the principal theoretical and methodological factors that lead to discordance between molecular and fossil estimates of the origins of taxa and discuss how a better understanding of these factors can help to improve our understanding of primate evolution. [source]


Heterogeneous tumor clones as an explanation of discordance between plasma DNA and tumor DNA alterations

GENES, CHROMOSOMES AND CANCER, Issue 3 2001
Jose M. Garcia
No abstract is available for this article. [source]


The Combined Effects of Participatory Styles of Elderly Patients and Their Physicians on Satisfaction

HEALTH SERVICES RESEARCH, Issue 2 2004
K. Tom Xu
Objectives. To test whether concordance or discordance of patient participation between patients and physicians is associated with higher satisfaction, and to examine the effects of patients' and physicians' participatory styles on patients' satisfaction with their physicians. Data. Data collected in the Texas Tech 5000 Survey of elderly patients in West Texas were used. Patient satisfaction with their physicians was measured by a single item from the Consumer Assessment of Health Plans (CAHPS), representing patients' ratings of their physicians. Patient participation was measured by an index derived from a three-item instrument and physicians' participatory decision-making (PDM) style was measured by a three-item instrument developed by the Medical Outcomes Study. Methods. An ordered logit multivariate regression was used to investigate the effects of patients' and physicians' participatory styles on satisfaction with physicians. The interaction between patients' participation and physicians' participatory styles was also included to examine the dependency of the two variables. Results. Controlling for confounding factors, a higher PDM score was associated with a higher rating of patient satisfaction with physicians. A higher patient participation score was related to a lower physician satisfaction rating. The combined effect of patients' and physicians' participation styles indicated that for a low patient participation score, a high PDM score was not needed to produce high satisfaction. The greater the discordance in this direction, the higher the satisfaction. However, with a high patient participation score, only an extremely high PDM score would produce relatively high satisfaction. Conclusions. The current study supports the discordance hypothesis. Participatory physicians and patient,physician communications concerning patient participation can promote higher satisfaction. [source]


Six-week postpartum maternal depressive symptoms and 4-month mother,infant self- and interactive contingency,

INFANT MENTAL HEALTH JOURNAL, Issue 5 2008
Beatrice Beebe
Associations of 6-week maternal depressive symptoms [Center for Epidemiological Studies Depression Scale (CES-D)] with 4-month mother,infant self- and interactive contingency patterns during face-to-face play were investigated in 132 dyads. Self- and interactive contingency (auto- and lagged cross-correlation, respectively) were assessed by multilevel time-series analysis. Infant and mother gaze, facial and vocal affect, touch, and spatial orientation behaviors were coded second-by-second from split-screen videotape, and a multimodal measure of facial,visual "engagement" was constructed, generating nine modality pairings. With higher CES-D, the self-contingency of both partners was lowered in most modalities. With higher CES-D, interactive contingency values were both heightened (in some modalities) and lowered (in others), varying by partner. These results are consistent with an optimal midrange model. With higher CES-D, interactive contingency showed the following patterns: (a) Mothers and their infants had a reciprocal orientational sensitivity; (b) mothers and infants manifested a reciprocal intermodal discordance in attention versus affect coordination, lowering gaze coordination, but heightening affective coordination; (c) infants heightened, but mothers lowered, touch coordination with partner touch,an "infant approach,mother withdraw" touch pattern. Nonlinear analyses indicated that altered self- and interactive contingency were similar at both the low ("denial") as well as the high ("endorsement") poles of depressive symptoms, in half the findings. These complex, multimodal findings define different aspects of communication disturbance, with relevance for therapeutic intervention. [source]


Comparing senior executive and project manager perceptions of IT project risk: a Chinese Delphi study

INFORMATION SYSTEMS JOURNAL, Issue 4 2010
Shan Liu
Abstract The success rate for information technology (IT) projects continues to be low. With an increasing number of IT projects in developing countries such as China, it is important to understand the risks they are experiencing on IT projects. To date, there has been little research documenting Asian perceptions of IT project risk. In this research, we examine the risks identified by Chinese senior executives (SEs) and project managers (PMs), and compare these two groups. The importance of top management support in IT projects is well documented. Prior research has shown that from the perspective of IT PMs, lack of support from SEs is the number one risk in IT projects. Surprisingly, senior executives' perceptions towards IT project risk have never been systematically examined. One reason why lack of support from senior executives continues to represent a major risk may be that senior executives themselves do not realize the critical role that they can play in helping to deliver successful projects. In this study, we use the Delphi method to compare the risk perceptions of senior executives and project managers. By comparing risk factors selected by each group, zones of concordance and discordance are identified. In terms of perceived importance ascribed to risk factors, PMs tend to focus on lower-level risks with particular emphasis on risks associated with requirements and user involvement, whereas SEs tend to focus on higher-level risks such as those risks involving politics, organization structure, process, and culture. Finally, approaches for dealing with risk factors that are seen as important by both SEs and PMs are provided. [source]


Reconciling user and project manager perceptions of IT project risk: a Delphi study,

INFORMATION SYSTEMS JOURNAL, Issue 2 2002
Mark Keil
Abstract. In an increasingly dynamic business environment characterized by fast cycle times, shifting markets and unstable technology, a business organization's survival hinges on its ability to align IT capabilities with business goals. To facilitate the successful introduction of new IT applications, issues of project risk must be addressed, and the expectations of multiple stakeholders must be managed appropriately. To the extent that users and developers may harbour different perceptions regarding project risk, areas of conflict may arise. By understanding the differences in how users and project managers perceive the risks, insights can be gained that may help to ensure the successful delivery of systems. Prior research has focused on the project manager's perspective of IT project risk. This paper explores the issue of IT project risk from the user perspective and compares it with risk perceptions of project managers. A Delphi study reveals that these two stakeholder groups have different perceptions of risk factors. Through comparison with a previous study on project manager risk perceptions, zones of concordance and discordance that must be reconciled are identified. [source]


Frequently discordant results from therapeutic drug monitoring for digoxin: clinical confusion for the prescriber

INTERNAL MEDICINE JOURNAL, Issue 1 2010
N. M. Rogers
Abstract Background: Digoxin remains a commonly prescribed medication for the treatment of congestive cardiac failure or atrial tachyarrhythmias. Its utility is offset by its narrow therapeutic index requiring regular blood concentration monitoring. Recent evidence suggests that a lower therapeutic range (0.5,0.8 µg/L, or 0.6,1.0 nmol/L) is associated with reduced mortality in patients with congestive cardiac failure. Therapeutic drug monitoring for digoxin is carried out by immunoassays that are well established in routine clinical practice. Laboratories using different immunoassays may be involved in monitoring individual patients throughout the protracted course of therapy. These results should be concordant to ensure consistent dose individualization and optimum clinical management. We have investigated the discordance in digoxin measurements involving five different laboratories across the Adelaide metropolitan area. Methods: Aliquots from routine digoxin samples (n= 261) were analysed by accredited laboratories using commercially available immunoassays. Results: The results showed that 119 (46%) of 261 samples were so varied that a different clinical outcome was indicated when reviewed by the treating physician. The differences between the highest and lowest readings from any one sample were also substantial, with 45% of the measurements exceeding 0.3 µg/L. Conclusions: Our study shows the considerable variation in the routine monitoring of digoxin. This makes therapeutic drug monitoring difficult to interpret and complicates clinical management when treating physicians are endeavouring to avoid toxicity and optimize dosing. These results raise a significant concern for the quality of therapeutic drug monitoring of digoxin and have direct repercussions on patient care. [source]


Dieting history in obese youngsters with and without disordered eating

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 8 2006
Line Claus MA
Abstract Objective: This article examines the relationship between the emergence of disordered eating and the history of weight and dieting in obese youngsters. Method: Both child and parent reports were obtained from 40 obese disordered eaters (objective bulimic episodes, n = 20; objective overeating episodes, n = 20) and 40 obese matched controls aged 10,16 years. Results: No significant differences between subsamples with regard to weight and dieting history were found. In dieters, it was shown that overweight onset preceded dieting onset, which in turn preceded dietary restraint onset. Despite some discordance regarding precise onset ages of different behaviors, parent and child re ports revealed the same temporal sequences. Conclusion: A developmental pathway from weight problems through dieting to binge eating is plausible for a subgroup of obese children. Convergence between parent and child reports supports the assumption that children's reports are a viable means of monitoring dieting and weight behaviors. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006; 39:721,728 [source]


Molecular clocks keep dispersal hypotheses afloat: evidence for trans-Atlantic rafting by rodents

JOURNAL OF BIOGEOGRAPHY, Issue 2 2010
Diane L. Rowe
Abstract Aim, In order to resolve disputed biogeographical histories of biota with Gondwanan continental distributions, and to assess the null hypothesis of vicariance, it is imperative that a robust geological time-frame be established. As an example, the sudden and coincident appearance of hystricognath rodents (Rodentia: Hystricognathi) on both the African and South American continents has been an irreconcilable controversy for evolutionary biologists, presenting enigmas for both Gondwanan vicariance and Late Eocene dispersal hypotheses. In an attempt to resolve this discordance, we aim to provide a more robust phylogenetic hypothesis and improve divergence-date estimates, which are essential to assessing the null hypothesis of vicariance biogeography. Location, The primary centres of distribution are in Africa and South America. Methods, We implemented parsimony, maximum-likelihood and Bayesian methods to generate a phylogeny of 37 hystricognath taxa, the most comprehensive taxonomic sampling of this group to date, on the basis of two nuclear gene regions. To increase phylogenetic resolution at the basal nodes, these data were combined with previously published data for six additional nuclear gene regions. Divergence dates were estimated using two relaxed-molecular-clock methods, Bayesian multidivtime and nonparametric rate smoothing. Results, Our data do not support reciprocal monophyly of African and South American lineages. Indeed, Old World porcupines (i.e. Hystricomorpha) appear to be more closely related to New World lineages (i.e. Caviomorpha) than to other Old World families (i.e. Bathyergidae, Petromuridae and Thryonomyidae). The divergence between the monophyletic assemblage of South American lineages and its Old World ancestor was estimated to have occurred c. 50 Ma. Main conclusions, Our phylogenetic hypothesis and divergence-date estimates are strongly at odds with Gondwanan-vicariance isolating mechanisms. In contrast, our data suggest that transoceanic dispersal has played a significant role in governing the contemporary distribution of hystricognath rodents. Molecular-clock analyses imply a trans-Tethys dispersal event, broadly confined to the Late Cretaceous, and trans-Atlantic dispersal within the Early Eocene. Our analyses also imply that the use of the oldest known South American rodent fossil as a calibration point has biased molecular-clock inferences. [source]