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Prior Study (prior + study)
Selected AbstractsCorporate Boards and Company Performance: review of research in light of recent reformsCORPORATE GOVERNANCE, Issue 5 2007David Finegold Recent US corporate governance reforms introduced extensive regulations and guidelines for public corporations, particularly corporate boards. This article evaluates the extent to which empirical research on corporate boards and firm performance supports these reforms. Building on the meta-analysis conducted by Zahra and Pearce (1989), we review 105 studies published between 1989 and 2005. We find most of the practices mandated by the Sarbanes-Oxley Act of 2002, and the regulations issued by the New York Stock Exchange (NYSE) and the NASDAQ, had not been subject to prior study. Where board characteristics have been studied, we find limited guidance for policymakers on identifying governance practices that result in more effective firm performance. In an effort to increase the relevance of future research on boards and firm performance, we provide a framework on corporate boards. [source] Fine-needle aspiration of primary osseous lesions: A cost effectiveness studyDIAGNOSTIC CYTOPATHOLOGY, Issue 4 2010Lester J. Layfield M.D. Abstract Fine-needle aspiration (FNA) is not widely used in the work-up of osseous lesions because of concerns regarding its high incidence of nondiagnostic specimens. Although several studies have shown that FNA is less expensive than surgical biopsy, the authors are aware of only one prior study evaluating the cost effectiveness of FNA, which includes the cost of incisional or core needle biopsies necessary to establish a diagnosis when the initial FNA was noncontributory. A computerized search of the pathology records of three medical centers was performed to obtain all FNAs of primary osseous lesions. For each FNA case, all subsequent core needle, incisional or excisional biopsies were recorded as was the result of the definitive operative procedure. The cost of obtaining the definitive diagnosis was calculated for each case including the cost of FNA, imaging guidance utilized, and cost of subsequent surgical biopsy when necessary. The cost of an alternate approach using only surgical biopsy was calculated. The average per patient costs of these two protocols were compared. A total of 165 primary bone tumors underwent FNA. One hundred six of these yielded a definitive cytologic diagnosis. In 59 cases, FNA yielded a result insufficient for definitive therapy necessitating surgical biopsy. FNA investigation of the 165 bone lesions cost 575,932 (average of 3,490 per patient). Surgical biopsy alone would have cost 5,760 per patient. FNA resulted in a cost savings of 2,215 per patient. Diagn. Cytopathol. 2010 © 2009 Wiley-Liss, Inc. [source] A unique binding epitope for salvinorin A, a non-nitrogenous kappa opioid receptor agonistFEBS JOURNAL, Issue 9 2006Brian E. Kane Salvinorin A is a potent kappa opioid receptor (KOP) agonist with unique structural and pharmacological properties. This non-nitrogenous ligand lacks nearly all the structural features commonly associated with opioid ligand binding and selectivity. This study explores the structural basis to salvinorin A binding and selectivity using a combination of chimeric and single-point mutant opioid receptors. The experiments were designed based on previous models of salvinorin A that locate the ligand within a pocket formed by transmembrane (TM) II, VI, and VII. More traditional sites of opioid recognition were also explored, including the highly conserved aspartate in TM III (D138) and the KOP selectivity site E297, to determine the role, if any, that these residues play in binding and selectivity. The results indicate that salvinorin A recognizes a cluster of residues in TM II and VII, including Q115, Y119, Y312, Y313, and Y320. Based on the position of these residues within the receptor, and prior study on salvinorin A, a model is proposed that aligns the ligand vertically, between TM II and VII. In this orientation, the ligand spans residues that are spaced one to two turns down the face of the helices within the receptor cavity. The ligand is also in close proximity to EL-2 which, based on chimeric data, is proposed to play an indirect role in salvinorin A binding and selectivity. [source] Excessive, optimal, and insufficient fundraising among the Nonprofit Times 100INTERNATIONAL JOURNAL OF NONPROFIT & VOLUNTARY SECTOR MARKETING, Issue 2 2006Fred A. Jacobs Using a six-factor model of donations, we estimate the effect on net donations; i.e., donations less fundraising expenditures, of a one percent marginal increase in fundraising expenditures, for each sample nonprofit organization (NPO) from the Nonprofit Times 100 from 2000 to 2002. No prior study of U.S. NPOs estimates the effect of fundraising expense on net donations. We then use these estimates and what we argue is the correct benchmark, the ratio of fundraising expense to donations, to provide evidence, for each NPO, on whether the NPO's level of fundraising is ,excessive,' ,optimal,' or ,insufficient,' relative to the level that maximizes net donations. All prior studies using log-log models use what we suggest is an incorrect benchmark for evaluating NPO fundraising behavior. The estimated effect of a 1% increase in fundraising on net donations varies widely across NPOs in our sample,from an increase in net donations of 0.18% of gross donations to a decrease of 0.66% of gross donations. Of the 76 Nonprofit Times 100 NPOs with usable data in 2002, we estimate that 24 engaged in ,excessive' fundraising, 18 engaged in ,insufficient' fundraising, and 34 did not engage in ,excessive' or ,insufficient' fundraising; i.e., we could not reject the null hypothesis of ,optimal' levels of fundraising. Copyright © 2006 John Wiley & Sons, Ltd. [source] Akt expression may predict favorable prognosis in cholangiocarcinomaJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 11 2006Milind M Javle Abstract Background:, Overexpression of signaling proteins including epidermal growth factor receptor (EGFR), Akt, mitogen activated protein kinase (MAPK) and cyclooxygenase-2 (COX-2) occurs in cholangiocarcinoma cell lines. However, the prognostic value of these markers is unknown. No prior study correlated the expression of these signaling proteins with clinical outcome. Further, co-expression of these proteins has not been reported. Co-expression may reflect cross-talk between signaling pathways. The aim of this clinicopathological study was to investigate the overexpression and co-expression of EGFR and related signaling proteins in cholangiocarcinoma and explore their relationship to clinical outcome. Methods:, Twenty-four consecutive cases of cholangiocarcinoma treated from 1996 to 2002 at Roswell Park Cancer Institute were included. Immunohistochemical staining of paraffin-embedded tissue sections was performed using antibodies against Akt, p-Akt, MAPK, p-MAPK, COX-2, EGFR and p-EGFR. Two pathologists independently scored the protein expression. Results:, Cyclooxygenase-2, Akt, and p-MAPK were commonly expressed in biliary cancers (100%, 96% and 87% of malignant cells, respectively). EGFR (60%) and p-EGFR (22%) overexpression was also detected. There was a significant association between EGFR and p-EGFR (P = 0.027) and between Akt and p-Akt (P = 0.017) expression in tumor tissue. A noteworthy association was shown between MAPK and p-Akt (P = 0.054). Multivariate analysis using the Cox proportional hazard model identified the use of chemotherapy (hazard ratio [HR] = 0.039, P = 0.0002), radiation (HR = 0.176, P = 0.0441) and Akt expression (HR = 0.139, P = 0.006) as the best predictors of overall prognosis. Conclusion:, Epidermal growth factor receptor signaling intermediates are commonly expressed in cholangiocarcinoma. Expression of Akt and use of systemic chemotherapy or radiation may correlate with improved survival. [source] Smaller pituitary volume in adult patients with obsessive,compulsive disorderPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 4 2009Murad Atmaca md Aims:, Another structure in the obsessive,compulsive disorder (OCD) circuit may be the pituitary gland because of the fact that limbic,hypothalamic,pituitary,adrenal (LHPA) axis abnormality has been reported in patients with OCD. There has been only one prior study, however, concerning pituitary volumetry, in which the sample was a pediatric group. The purpose of the present study was therefore to investigate this in an adult OCD patient group using magnetic resonance imaging (MRI). Methods:, Pituitary volume was measured in 23 OCD patients and the same number of healthy control subjects. Volumetric measurements were made on T1-weighted coronal MRI, with 2.40-mm-thick slices, at 1.5 T, and were done blindly. Results:, A statistically significantly smaller pituitary volume was found in OCD patients compared to healthy controls (age and intracranial volume as covariates). With regard to gender and diagnosis, there was a significant difference in pituitary gland volume (F = 4.18, P < 0.05). In addition, post-hoc analysis indicated near-significant difference in men with OCD as compared with women with OCD (P = 0.07) and significant difference between control men and control women (F = 10.96, P < 0.001). Conclusions:, Taking into consideration that the prior study found decreases in pituitary volume in pediatric patients with OCD as compared with healthy control subjects, future large MRI studies should investigate pituitary size longitudinally, with a careful characterization of hypothalamo-pituitary-adrenal (HPA) function in conjunction with anatomic MRI evaluation. [source] Hind-limb paraparesis in a rat model for neurolathyrism associated with apoptosis and an impaired vascular endothelial growth factor system in the spinal cordTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 6 2010Kuniko Kusama-Eguchi Abstract Neurolathyrism is a motor neuron disease characterized by lower limb paraparesis. It is associated with ingestion of a plant excitotoxin, ,-N-oxalyl-L-,,-diaminopropionic acid (L -,-ODAP), an agonist of ,-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate-type glutamatergic receptors. Previously, a limited model of neurolathyrism was reported for the rat. To improve upon the model, we stressed rat pups by separation from their mothers, followed by the subcutaneous L -,-ODAP treatment, resulting in a 4.6-fold higher incidence (14.0,15.6%) of the paraparesis compared with the prior study. The number and size of motor neurons in these rats were decreased only in the lumbar and sacral cord segments, at approximately 13,36 weeks after treatment. Only lumbar and sacral spinal cord tissue revealed pathological insults typical of physical and ischemic spinal cord injury in the surviving motor neurons. In addition, extensive but transient hemorrhage occurred in the ventral spinal cord parenchyma of the rat, and numerous TdT-mediated dUTP-biotin nick end-labeling (TUNEL)-positive cells were also observed. In parallel, vascular endothelial growth factor receptor (VEGFR)-2 (Flk-1) levels were significantly lowered in the lumbosacral spinal cord of the paraparetic rats compared with their controls, suggesting a failure of the VEGF system to protect neurons against L -,-ODAP toxicity. We propose, based on these data, a novel pathological process of motor neuron death induced by peripheral L -,-ODAP. For the first time, we present a model of the early molecular events that occur during chemically induced spinal cord injury, which can potentially be applied to other neurodegenerative disorders. J. Comp. Neurol. 518:928,942, 2010. © 2009 Wiley-Liss, Inc. [source] Which clinical factors predict response to prophylactic lithium?BIPOLAR DISORDERS, Issue 5 2005A systematic review for bipolar disorders Objectives:, The aim of this study was to systematically integrate the available evidence on response prediction to prophylactic lithium based on clinical factors. Methods:, Each clinical variable that was related to lithium response in at least one prior study was examined with respect to response prediction. If several studies were located for the same variable, results were integrated using the meta-analytic approach as suggested by DerSimonian and Laird which was developed for substantial heterogeneity in primary studies. Results:, Of 42 potential clinical predictors investigated, five variables were identified as possible response predictors of prophylactic lithium: [1] An episodic pattern of mania-depression-interval, and [2] a high age of illness onset were identified as potentially protective against a recurrence under lithium. [3] A high number of previous hospitalizations, [4] an episodic pattern of depression-mania-interval, and [5] continuous cycling were identified as potential risk factors. Six further variables were found to be significantly related to lithium response, though calculation of fail-safe numbers indicates that current evidence is not sufficient to hold these variables as reliable predictors of lithium response. All effect-sizes relating clinical predictors to response were small to moderate. Conclusions:, Although a few variables are quite robustly supported as response-predictors in this review, a more in-depth analysis of each potential predictor is needed. As none of the potential predictors had a very strong impact on response, prediction of lithium response should be based on a multitude of variables. [source] Diclofenac and acute myocardial infarction in patients with no major risk factorsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 5 2007Susan S. Jick What is already known about this subject ,,We recently published the results of a study on the risk of acute myocardial infarction (AMI) in users of five nonsteroidal anti-inflammatory drugs during the years 2001 to 2005. ,,The results demonstrated, as has been reported in randomized trials, that rofecoxib and celecoxib increase the risk of AMI when taken for at least 10 months. ,,As expected, ibuprofen and naproxen did not materially increase the risk. ,,However, long-term users of diclofenac were at an increased risk of AMI similar to that of users of rofecoxib and celecoxib. What this study adds ,,Extensive use of diclofenac, similarly to rofecoxib and celecoxib, substantially increases the risk of AMI. ,,There is little suggestion of such an effect in users of ibuprofen and naproxen. Aims To explore further a recent finding that long-term users of diclofenac are at increased risk of acute myocardial infarction (AMI) similar to users of rofecoxib and celecoxib. Methods Using the General Practice Research Database, we conducted three separate nested case,control studies of three nonsteroidal anti-inflammatory drugs (NSAIDs) where use started after 1 January 1993 , diclofenac, ibuprofen and naproxen. Cases of AMI were identified between 1 January 1993 and 31 December 2000. Relative risk (RR) estimates for AMI in patients with no major clinical risk factors were determined for each NSAID according to number of prescriptions received compared with one prescription. Results were adjusted for variables possibly related to risk of AMI. Results There was no material elevation of AMI risk according to the number of prescriptions for ibuprofen [RRs and 95% confidence intervals (CIs) 1.0 (0.6, 1.6) and 1.7 (0.9, 3.1) for use of 10,19 and 20+ prescriptions, respectively, compared with one prescription] or naproxen [RRs 1.0 (0.5, 2.2) and 2.0 (0.9, 4.5) for use of 10,19 and 20+ prescriptions, respectively]. However, a substantial increased risk similar to that obtained in our prior study was found in patients who received ,10 prescriptions for diclofenac [RRs 1.9 (1.3, 2.7) and 2.0 (1.3, 3.0) for use of 10,19 and 20+ prescriptions, respectively]. Conclusions Extensive use of diclofenac substantially increases the risk of AMI. There is little suggestion of such an effect in users of ibuprofen and naproxen. [source] Modifying the metaphor in order to improve understanding of control languages,the little-person becomes a cast of actorsBRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 4 2007Peter Whalley The instructional metaphor is an important bridge to understanding, particularly when students are undertaking tasks that are conceptually difficult and outside their previous experience. It is suggested that the limitations of the implicit metaphor of the procedural control languages are the main cause of the problems experienced with delivering the control topic within the Information and Communication Technology (ICT) curriculum. These continue to dominate classroom practice despite Papert warning more than 25 years ago of the conceptual restrictions that they place on children's thinking. It is also claimed that the procedural control languages do not provide an adequate representation of the underlying input,process,output model of control, and that this contributes to a systematic pattern of misunderstanding. Classroom trials of a graphic object-orientated language are related to a prior study made with the procedural control language Control Logo. The relatively more sophisticated mental models developed by students working with actor-lab are discussed in terms of the different underlying metaphors and the problem representation provided. [source] Substance Use in Emergency Medicine Training ProgramsACADEMIC EMERGENCY MEDICINE, Issue 1 2008Brian D. McBeth MD Abstract Objectives:, To explore the prevalence of substance use among emergency medicine (EM) residents and compare to a prior study conducted in 1992. Methods:, A voluntary, anonymous survey was distributed in February 2006 to EM residents nationally in the context of the national in-service examination. Data regarding 13 substances, demographics, and perceptions of personal patterns of substance use were collected. Results:, A total of 133 of 134 residencies distributed the surveys (99%). The response rate was 56% of the total EM residents who took the in-service examination (2,397/4,281). The reported prevalence of most illicit drug use, including cocaine, heroin, amphetamines, and other opioids, among EM residents are low. Although residents reporting past marijuana use has declined (52.3% in 1992 to 45.0% in 2006; p < 0.001), past-year use (8.8%,11.8%; p < 0.001) and past-month use (2.5%,4.0%; p < 0.001) have increased. Alcohol use appears to be increasing, including an increase in reported daily drinkers from 3.3% to 4.9% (p < 0.001) and an increase in number of residents who indicate that their consumption of alcohol has increased during residency (from 4% to 12.6%; p < 0.001). Conclusions:, Self-reported use of most street drugs remains uncommon among EM residents. Marijuana and alcohol use, however, do appear to be increasing. Educators should be aware of these trends, and this may allow them to target resources for impaired and at-risk residents. [source] | |||||||||||||