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Showing papers by "Tufts University published in 2004"


Journal ArticleDOI
TL;DR: The main goals of the updated document are to improve the quality of care provided to patients with COPD and to develop the project using a disease-oriented approach.
Abstract: The Standards for the Diagnosis and Treatment of Patients with COPD document 2004 updates the position papers on chronic obstructive pulmonary disease (COPD) published by the American Thoracic Society (ATS) and the European Respiratory Society (ERS) in 1995 1, 2. Both societies felt the need to update the previous documents due to the following. 1) The prevalence and overall importance of COPD as a health problem is increasing. 2) There have been enough advances in the field to require an update, especially adapted to the particular needs of the ATS/ERS constituency. 3) It allows for the creation of a “live” modular document based on the web; it should provide healthcare professionals and patients with a user friendly and reliable authoritative source of information. 4) The care of COPD should be comprehensive, is often multidisciplinary and rapidly changing. 5) Both the ATS and the ERS acknowledge the recent dissemination of the Global Initiative of Obstructive Lung Disease (GOLD) 3 as a major worldwide contribution to the battle against COPD. However, some specific requirements of the members of both societies require adaptation of the broad GOLD initiative. Those requirements include specific recommendations on oxygen therapy, pulmonary rehabilitation, noninvasive ventilation, surgery in and for COPD, sleep, air travel, and end-of-life. In addition, special emphasis has been placed on issues related to the habit of smoking and its control. ### Goals and objectives The main goals of the updated document are to improve the quality of care provided to patients with COPD and to develop the project using a disease-oriented approach. To achieve these goals, both organisations have developed a modular electronic web-based document with two components. 1) A component for health professionals that intends to: raise awareness of COPD; inform on the latest advances in the overall pathogenesis, diagnosis, monitoring and management of COPD; and …

4,312 citations


Journal ArticleDOI
TL;DR: The BODE index, a simple multidimensional grading system, is better than the FEV1 at predicting the risk of death from any cause and from respiratory causes among patients with COPD.
Abstract: background Chronic obstructive pulmonary disease (COPD) is characterized by an incompletely reversible limitation in airflow. A physiological variable — the forced expiratory volume in one second (FEV 1 ) — is often used to grade the severity of COPD. However, patients with COPD have systemic manifestations that are not reflected by the FEV 1 . We hypothesized that a multidimensional grading system that assessed the respiratory and systemic expressions of COPD would better categorize and predict outcome in these patients. methods We first evaluated 207 patients and found that four factors predicted the risk of death in this cohort: the body-mass index (B), the degree of airflow obstruction (O) and dyspnea (D), and exercise capacity (E), measured by the six-minute–walk test. We used these variables to construct the BODE index, a multidimensional 10-point scale in which higher scores indicate a higher risk of death. We then prospectively validated the index in a cohort of 625 patients, with death from any cause and from respiratory causes as the outcome variables. results There were 25 deaths among the first 207 patients and 162 deaths (26 percent) in the validation cohort. Sixty-one percent of the deaths in the validation cohort were due to respiratory insufficiency, 14 percent to myocardial infarction, 12 percent to lung cancer, and 13 percent to other causes. Patients with higher BODE scores were at higher risk for death; the hazard ratio for death from any cause per one-point increase in the BODE score was 1.34 (95 percent confidence interval, 1.26 to 1.42; P<0.001), and the hazard ratio for death from respiratory causes was 1.62 (95 percent confidence interval, 1.48 to 1.77; P<0.001). The C statistic for the ability of the BODE index to predict the risk of death was larger than that for the FEV 1 (0.74 vs. 0.65).

3,688 citations


Journal ArticleDOI
TL;DR: The optimism of the early period of antimicrobial discovery has been tempered by the emergence of bacterial strains with resistance to these therapeutics, and today, clinically important bacteria are characterized not only by single drug resistance but also by multiple antibiotic resistance.
Abstract: The optimism of the early period of antimicrobial discovery has been tempered by the emergence of bacterial strains with resistance to these therapeutics. Today, clinically important bacteria are characterized not only by single drug resistance but also by multiple antibiotic resistance--the legacy of past decades of antimicrobial use and misuse. Drug resistance presents an ever-increasing global public health threat that involves all major microbial pathogens and antimicrobial drugs.

3,526 citations


Journal ArticleDOI
TL;DR: In patients with severe, nonischemic dilated cardiomyopathy who were treated with ACE inhibitors and beta-blockers, the implantation of a cardioverter-defibrillator significantly reduced the risk of sudden death from arrhythmia and was associated with a nonsignificant reduction in the riskof death from any cause.
Abstract: background Patients with nonischemic dilated cardiomyopathy are at substantial risk for sudden death from cardiac causes. However, the value of prophylactic implantation of an implantable cardioverter–defibrillator (ICD) to prevent sudden death in such patients is unknown. methods We enrolled 458 patients with nonischemic dilated cardiomyopathy, a left ventricular ejection fraction of less than 36 percent, and premature ventricular complexes or nonsustained ventricular tachycardia. A total of 229 patients were randomly assigned to receive standard medical therapy, and 229 to receive standard medical therapy plus a single-chamber ICD. results Patients were followed for a mean (±SD) of 29.0±14.4 months. The mean left ventricular ejection fraction was 21 percent. The vast majority of patients were treated with angiotensin-converting–enzyme (ACE) inhibitors (86 percent) and beta-blockers (85 percent). There were 68 deaths: 28 in the ICD group, as compared with 40 in the standard-therapy group (hazard ratio, 0.65; 95 percent confidence interval, 0.40 to 1.06; P=0.08). The mortality rate at two years was 14.1 percent in the standard-therapy group (annual mortality rate, 7 percent) and 7.9 percent in the ICD group. There were 17 sudden deaths from arrhythmia: 3 in the ICD group, as compared with 14 in the standardtherapy group (hazard ratio, 0.20; 95 percent confidence interval, 0.06 to 0.71; P=0.006). conclusions In patients with severe, nonischemic dilated cardiomyopathy who were treated with ACE inhibitors and beta-blockers, the implantation of a cardioverter–defibrillator significantly reduced the risk of sudden death from arrhythmia and was associated with a nonsignificant reduction in the risk of death from any cause.

1,870 citations


Journal ArticleDOI
TL;DR: Five physiological mechanisms that regulate hormone release during stress that should be useful to ecologists and conservationists are summarized.
Abstract: Increasingly, levels of the ‘stress hormones’ cortisol and corticosterone are being used by ecologists as indicators of physiological stress in wild vertebrates. The amplitude of hormonal response is assumed to correlate with the overall health of an animal and, by extension, the health of the population. However, much of what is known about the physiology of stress has been elucidated by the biomedical research community. I summarize five physiological mechanisms that regulate hormone release during stress that should be useful to ecologists and conservationists. Incorporating these physiological mechanisms into the design and interpretation of ecological studies will make these increasingly popular studies of stress in ecological settings more rigorous. Vertebrates cope with unpredictable and noxious stimuli (STRESSORS; see Glossary) by mounting a STRESS RESPONSE

1,276 citations


Journal ArticleDOI
17 Dec 2004-Cell
TL;DR: It is demonstrated that point mutant p53 alleles expressed under physiological control have enhanced oncogenic potential beyond the simple loss of p53 function.

1,216 citations


Journal Article
Andrew S. Levey1, Michael V. Rocco2, Sharon Anderson3, Sharon P. Andreoli4, George R. Bailie5, George L. Bakris6, Mary Beth Callahan, Jane H. Greene7, Cynda Ann Johnson8, James P. Lash9, Peter A. McCullough10, Edgar R. Miller11, Joseph V. Nally12, John D. Pirsch13, Ronald J. Portman14, Mary Ann Sevick15, Domenic A. Sica16, Donald E. Wesson17, Lawrence Y. Agodoa18, Kline Bolton19, Jeffrey A. Cutler18, Tom Hostetter18, Joseph Lau1, Katrin Uhlig1, Priscilla Chew1, Annamaria T. Kausz1, Bruce Kupelnick1, Gowri Raman1, Mark J. Sarnak1, Chenchen Wang1, Brad C. Astor11, Garabed Eknoyan, Adeera Levin, Nathan W. Levin, George R. Bailie5, Bryan N. Becker, Gavin J. Becker, Jerrilynn D. Burrowes, Fernando Carrera, David N. Churchill, Allan J. Collins, Peter W. Crooks, Dick DeZeeuw, Thomas A. Golper, Frank A. Gotch, Antonio M. Gotto, Roger Greenwood, Joel W. Greer, Richard H. Grimm, William E. Haley, Ronald J. Hogg, Alan R. Hull, Lawrence G. Hunsicker, Michael J. Klag, Saulo Klahr, Norbert Lameire, Francesco Locatelli, Sally McCulloch, Maureen Michael, John M. Newmann, Allen R. Nissenson, Keith C. Norris, Gregorio T. Obrador, William F. Owen, Thakor G. Patel, Glenda Payne, Claudio Ronco, Rosa A. Rivera-Mizzoni, Anton C. Schoolwerth, Robert A. Star, Michael W. Steffes, Theodore I. Steinman, John Pierre Wauters, Nanette K. Wenger, Josephine P. Briggs, Sally Burrows-Hudson, Derrick Latos, Donna Mapes, Edith Oberley, Brian J.G. Pereira, Kerry Willis, Anthony Gucciardo, Donna Fingerhut, Margaret Klette, Elicia Schachne 
TL;DR: The purpose of the Executive Summary is to provide a "stand-alone" summary of the background, scope, methods, and key recommendations, as well as the complete text of the guideline statements.

1,145 citations


Journal ArticleDOI
TL;DR: This paper reviews studies performed to date that have employed cluster or factor analysis to empirically derive eating patterns to further establish eating patterns as a sound dietary assessment method.
Abstract: This paper reviews studies performed to date that have employed cluster or factor analysis to empirically derive eating patterns. Since 1980, at least 93 studies were published that used cluster or factor analysis to define dietary exposures, of which 65 were used to test hypotheses or examine associations between patterns and disease outcomes or biomarkers. Studies were conducted in diverse populations across many countries and continents and suggest that patterns are associated with many different biomarkers and disease outcomes, whether measured by cluster or factor analysis. Despite clear differences in approaches and interpretations, there is some evidence that underlying eating patterns are revealed by either method. Although the research considered herein has created a meaningful body of literature, refining both the factor and cluster analysis methods will help to further establish eating patterns as a sound dietary assessment method.

1,101 citations


Journal ArticleDOI
TL;DR: It is shown by light and electron microscopy that HGPS is associated with significant changes in nuclear shape, including lobulation of the nuclear envelope, thickening of thenuclear lamina, loss of peripheral heterochromatin, and clustering of nuclear pores.
Abstract: Hutchinson–Gilford progeria syndrome (HGPS) is a premature aging disorder, commonly caused by a point mutation in the lamin A gene that results in a protein lacking 50 aa near the C terminus, denoted LAΔ50. Here we show by light and electron microscopy that HGPS is associated with significant changes in nuclear shape, including lobulation of the nuclear envelope, thickening of the nuclear lamina, loss of peripheral heterochromatin, and clustering of nuclear pores. These structural defects worsen as HGPS cells age in culture, and their severity correlates with an apparent increase in LAΔ50. Introduction of LAΔ50 into normal cells by transfection or protein injection induces the same changes. We hypothesize that these alterations in nuclear structure are due to a concentration-dependent dominant-negative effect of LAΔ50, leading to the disruption of lamin-related functions ranging from the maintenance of nuclear shape to regulation of gene expression and DNA replication.

1,017 citations


Journal ArticleDOI
TL;DR: This review of the life cycle of the Epstein–Barr virus explains how EBV establishes lifelong infection in a host with protective immunity against the virus.
Abstract: This review of the life cycle of the Epstein–Barr virus (EBV) explains how EBV establishes lifelong infection in a host with protective immunity against the virus. The authors also discuss the role of EBV in the development of post-transplantation lymphoma, Hodgkin's disease, and Burkitt's lymphoma.

964 citations


Journal ArticleDOI
01 Jan 2004-Nature
TL;DR: The ‘SOS response’ to DNA damage alleviates this repression, increasing the expression of genes necessary for SXT transfer and hence the frequency of transfer, and presents a mechanism by which therapeutic agents can promote the spread of antibiotic resistance genes.
Abstract: Mobile genetic elements have a crucial role in spreading antibiotic resistance genes among bacterial populations. Environmental and genetic factors that regulate conjugative transfer of antibiotic resistance genes in bacterial populations are largely unknown1. Integrating conjugative elements (ICEs) are a diverse group of mobile elements that are transferred by means of cell–cell contact and integrate into the chromosome of the new host2. SXT is a ∼100-kilobase ICE derived from Vibrio cholerae that encodes genes that confer resistance to chloramphenicol, sulphamethoxazole, trimethoprim and streptomycin3. SXT-related elements were not detected in V. cholerae before 1993 but are now present in almost all clinical V. cholerae isolates from Asia4. ICEs related to SXT are also present in several other bacterial species and encode a variety of antibiotic and heavy metal resistance genes4,5,6,7. Here we show that SetR, an SXT encoded repressor, represses the expression of activators of SXT transfer. The ‘SOS response’ to DNA damage alleviates this repression, increasing the expression of genes necessary for SXT transfer and hence the frequency of transfer. SOS is induced by a variety of environmental factors and antibiotics, for example ciprofloxacin, and we show that ciprofloxacin induces SXT transfer as well. Thus, we present a mechanism by which therapeutic agents can promote the spread of antibiotic resistance genes.

Journal ArticleDOI
TL;DR: Digital hyperemic response, as measured by RH-PAT, is attenuated in patients with coronary microvascular endothelial dysfunction, suggesting a role for RH- PAT as a noninvasive test to identify patients with this disorder.

Journal ArticleDOI
TL;DR: Three fabrication techniques were used to form porous three-dimensional silk biomaterial matrixes and the results suggest that silk-based 3D matrixes can be formed for utility in biomaterial applications.

Journal ArticleDOI
16 Apr 2004-Science
TL;DR: Genome analysis identifies extremely streamlined metabolic pathways and a reliance on the host for nutrients in the parasite, which lacks an apicoplast and its genome, and possesses a degenerate mitochondrion that has lost its genome.
Abstract: The apicomplexan Cryptosporidium parvum is an intestinal parasite that affects healthy humans and animals, and causes an unrelenting infection in immunocompromised individuals such as AIDS patients. We report the complete genome sequence of C. parvum, type II isolate. Genome analysis identifies extremely streamlined metabolic pathways and a reliance on the host for nutrients. In contrast to Plasmodium and Toxoplasma, the parasite lacks an apicoplast and its genome, and possesses a degenerate mitochondrion that has lost its genome. Several novel classes of cell-surface and secreted proteins with a potential role in host interactions and pathogenesis were also detected. Elucidation of the core metabolism, including enzymes with high similarities to bacterial and plant counterparts, opens new avenues for drug development.

Journal ArticleDOI
TL;DR: The causes of death in the study were consistent with those expected in patients with septic shock, although there was a higher proportion of cardiovascular deaths and a lower incidence of deaths caused by multiple organ failure in the 546C88 group.
Abstract: Objective: To assess the safety and efficacy of the nitric oxide synthase inhibitor 546C88 in patients with septic shock. The predefined primary efficacy objective was survival at day 28. Design: Multiple-center, randomized, two-stage, double-blind, placebo-controlled, safety and efficacy study. Setting: A total of 124 intensive care units in Europe, North America, South America, South Africa, and Australasia. Patients: A total of 797 patients with septic shock diagnosed for <24 hrs. Interventions: Patients with septic shock were allocated to receive 546C88 or placebo (5% dextrose) for up to 7 days (stage 1) or 14 days (stage 2) in addition to conventional therapy. Study drug was initiated at 0.05 mL·kg 1 ·hr 1 (2.5 mg·kg 1 ·hr 1 546C88) and titrated up to a maximum rate of 0.4 mL·kg 1 ·hr 1 to maintain mean arterial pressure between 70 and 90 mm Hg while attempting to withdraw concurrent vasopressors. Measurements and Main Results: Hemodynamic variables, organ function data, microbiological data, concomitant therapy, and adverse event data were recorded at baseline, throughout treatment, and at follow-up. The primary end point was day-28 survival. The trial was stopped early after review by the independent data safety monitoring board. Day-28 mortality was 59% (259/439) in the 546C88 group and 49% (174/358) in the placebo group (p < .001). The overall incidence of adverse events was similar in both groups, although a higher proportion of the events was considered possibly attributable to study drug in the 546C88 group. Most of the events accounting for the disparity between the groups were associated with the cardiovascular system (e.g., decreased cardiac output, pulmonary hypertension, systemic arterial hypertension, heart failure). The causes of death in the study were consistent with those expected in patients with septic shock, although there was a higher proportion of cardiovascular deaths and a lower incidence of deaths caused by multiple organ failure in the 546C88 group. Conclusions: In this study, the nonselective nitric oxide synthase inhibitor 546C88 increased mortality in patients with septic shock. (Crit Care Med 2004; 32:21‐30)


Journal ArticleDOI
18 Nov 2004-Nature
TL;DR: A novel mechanism of p53 regulation through lysine methylation by Set9 methyltransferase is reported, which specifically methylates p53 at one residue within the carboxyl-terminus regulatory region.
Abstract: p53 is a tumour suppressor that regulates the cellular response to genotoxic stresses. p53 is a short-lived protein and its activity is regulated mostly by stabilization via different post-translational modifications. Here we report a novel mechanism of p53 regulation through lysine methylation by Set9 methyltransferase. Set9 specifically methylates p53 at one residue within the carboxyl-terminus regulatory region. Methylated p53 is restricted to the nucleus and the modification positively affects its stability. Set9 regulates the expression of p53 target genes in a manner dependent on the p53-methylation site. The crystal structure of a ternary complex of Set9 with a p53 peptide and the cofactor product S-adenosyl-l-homocysteine (AdoHcy) provides the molecular basis for recognition of p53 by this lysine methyltransferase.

Journal ArticleDOI
TL;DR: Once‐daily oral valganciclovir was as clinically effective and well‐tolerated as oral ganciclovIR tid for CMV prevention in high‐risk SOT recipients and the safety profile was similar for both drugs.

Journal ArticleDOI
TL;DR: Noninvasive positive-pressure ventilation does not prevent the need for reintubation or reduce mortality in unselected patients who have respiratory failure after extubation.
Abstract: background The need for reintubation after extubation and discontinuation of mechanical ventilation is not uncommon and is associated with increased mortality. Noninvasive positivepressure ventilation has been suggested as a promising therapy for patients with respiratory failure after extubation, but a single-center, randomized trial recently found no benefit. We conducted a multicenter, randomized trial to evaluate the effect of noninvasive positive-pressure ventilation on mortality in this clinical setting. methods Patients in 37 centers in eight countries who were electively extubated after at least 48 hours of mechanical ventilation and who had respiratory failure within the subsequent 48 hours were randomly assigned to either noninvasive positive-pressure ventilation by face mask or standard medical therapy. results A total of 221 patients with similar baseline characteristics had been randomly assigned to either noninvasive ventilation (114 patients) or standard medical therapy (107 patients) when the trial was stopped early, after an interim analysis. There was no difference between the noninvasive-ventilation group and the standard-therapy group in the need for reintubation (rate of reintubation, 48 percent in both groups; relative risk in the noninvasive-ventilation group, 0.99; 95 percent confidence interval, 0.76 to 1.30). The rate of death in the intensive care unit was higher in the noninvasive-ventilation group than in the standard-therapy group (25 percent vs. 14 percent; relative risk, 1.78; 95 percent confidence interval, 1.03 to 3.20; P=0.048), and the median time from respiratory failure to reintubation was longer in the noninvasive-ventilation group (12 hours vs. 2 hours 30 minutes, P=0.02). conclusions Noninvasive positive-pressure ventilation does not prevent the need for reintubation or reduce mortality in unselected patients who have respiratory failure after extubation.

Journal ArticleDOI
TL;DR: A reciprocal relationship between medial prefrontal cortex and amygdala function in PTSD and opposing associations between activity in these regions and symptom severity consistent with current functional neuroanatomic models of this disorder are suggested.
Abstract: Context: Theoretical neuroanatomic models of posttraumatic stress disorder (PTSD) and the results of previous neuroimaging studies of PTSD highlight the potential importance of the amygdala and medial prefrontal regions in this disorder. However, the functional relationship between these brain regions in PTSD has not been directly examined. Objective: To examine the relationship between the amygdala and medial prefrontal regions during symptom provocation in male combat veterans (MCVs) and female nurse veterans (FNVs) with PTSD. Design: Case-control study. Setting: Academic medical center. Participants: Volunteer sample of 17 (7 men and 10 women) Vietnam veterans with PTSD (PTSD group) and 19 (9 men and 10 women) Vietnam veterans without PTSD (control group). Main Outcome Measures: We used positron emission tomography and the script-driven imagery paradigm to study regional cerebral blood flow (rCBF) during the recollection of personal traumatic and neutral events. Psychophysiologic and emotional self-report data also were obtained to confirm the intended effects of script-driven imagery. Results: The PTSD group exhibited rCBF decreases in medial frontal gyrus in the traumatic vs neutral comparison. When this comparison was conducted separately by subgroup, MCVs and FNVs with PTSD exhibited these medial frontal gyrus decreases. Only MCVs exhibited rCBF increases in the left amygdala. However, for both subgroups with PTSD, rCBF changes in medial frontal gyrus were inversely correlated with rCBF changes in the left amygdala and the right amygdala/ periamygdaloid cortex. Furthermore, in the traumatic condition, for both subgroups with PTSD, symptom severity was positively related to rCBF in the right amygdala and negatively related to rCBF in medial frontal gyrus. Conclusions: These results suggest a reciprocal relationship between medial prefrontal cortex and amygdala function in PTSD and opposing associations between activity in these regions and symptom severity consistent with current functional neuroanatomic models of this disorder. Arch Gen Psychiatry. 2004;61:168-176


Journal ArticleDOI
TL;DR: The results of these studies provide insight into the sol-gel transitions that silk fibroin undergoes in glands during aqueous processing while also providing important insight in the in vitro processing of these proteins into useful new materials.

Journal ArticleDOI
TL;DR: In subjects with low HDL cholesterol levels, CETP inhibition with torcetrapib markedly increased HDL cholesterol Levels and also decreased LDL cholesterol Levels, both when administered as monotherapy and when administered in combination with a statin.
Abstract: background Decreased high-density lipoprotein (HDL) cholesterol levels constitute a major risk factor for coronary heart disease; however, there are no therapies that substantially raise HDL cholesterol levels. Inhibition of cholesteryl ester transfer protein (CETP) has been proposed as a strategy to raise HDL cholesterol levels. methods We conducted a single-blind, placebo-controlled study to examine the effects of torcetrapib, a potent inhibitor of CETP, on plasma lipoprotein levels in 19 subjects with low levels of HDL cholesterol (<40 mg per deciliter [1.0 mmol per liter]), 9 of whom were also treated with 20 mg of atorvastatin daily. All the subjects received placebo for four weeks and then received 120 mg of torcetrapib daily for the following four weeks. Six of the subjects who did not receive atorvastatin also participated in a third phase, in which they received 120 mg of torcetrapib twice daily for four weeks. results Treatment with 120 mg of torcetrapib daily increased plasma concentrations of HDL cholesterol by 61 percent (P<0.001) and 46 percent (P=0.001) in the atorvastatin and non-atorvastatin cohorts, respectively, and treatment with 120 mg twice daily increased HDL cholesterol by 106 percent (P<0.001). Torcetrapib also reduced low-density lipoprotein (LDL) cholesterol levels by 17 percent in the atorvastatin cohort (P=0.02). Finally, torcetrapib significantly altered the distribution of cholesterol among HDL and LDL subclasses, resulting in increases in the mean particle size of HDL and LDL in each cohort.

Journal ArticleDOI
17 Dec 2004-Science
TL;DR: The amygdala was more responsive to fearful (larger" eye whites than to happy (smaller) eye whites presented in a masking paradigm that mitigated subjects' awareness of their presence and aberrant nature.
Abstract: The amygdala was more responsive to fearful (larger) eye whites than to happy (smaller) eye whites presented in a masking paradigm that mitigated subjects' awareness of their presence and aberrant nature. These data demonstrate that the amygdala is responsive to elements of.

Journal ArticleDOI
TL;DR: It is conceivable that the beneficial effects of many of the treatments currently available for PAH result at least in part from restoring the balance between these mediators, such as the use of prostacyclin, NO, and ET antagonists.
Abstract: The pathogenesis of pulmonary hypertension (PH) involves a complex and multifactorial process. Endothelial dysfunction seems to play an integral role in mediating the structural changes in the pulmonary vasculature. Disordered endothelial cell proliferation along with concurrent neoangiogenesis, when exuberant, results in the formation of glomeruloid structures known as the plexiform lesions, which are common pathological features of the pulmonary vessels of patients with pulmonary arterial hypertension (PAH). In addition, an altered production of various endothelial vasoactive mediators, such as NO, prostacyclin, endothelin-1 (ET-1), serotonin, and thromboxane, has been increasingly recognized in patients with PH. Because most of these mediators affect the growth of the smooth muscle cells, an alteration in their production may facilitate the development of pulmonary vascular hypertrophy and structural remodeling characteristic of PH. It is conceivable that the beneficial effects of many of the treatments currently available for PAH, such as the use of prostacyclin, NO, and ET antagonists, result at least in part from restoring the balance between these mediators. However, the ultimate cellular and physiological targets of these treatments remain unknown. In addition to the potential consequences of an imbalance in the endothelial production of various mediators, injury to the endothelium may expose the underlying vascular tissue to diverse blood-borne factors that may further promote pathological changes. Endothelial dysfunction may also have adverse consequences on pulmonary vascular hemostasis by altering the production of anticoagulant factors. Recent reports of genetic mutations in the endothelial cells of patients with PH further underscore the role of these cells in the disease pathogenesis. The endothelium lining the normal lung is characterized by significant heterogeneity. Not only is it vastly different from systemic endothelium in ultrastructure and function, but it varies in various vessel types in the pulmonary vasculature itself.1 The main functions of the pulmonary endothelium include maintenance …

Journal ArticleDOI
20 Aug 2004-Cell
TL;DR: The results reveal the presence of alternative mechanisms that allow cell cycle progression in a cyclin D-independent fashion and shows that cells lacking D-cyclins display reduced susceptibility to the oncogenic transformation.

Journal ArticleDOI
TL;DR: A comprehensive update of the diagnostic and therapeutic approaches focusing on endocrine and radiological features as well as surgical options for clinically inapparent adrenal masses is provided.
Abstract: Clinically inapparent adrenal masses are incidentally detected after imaging studies conducted for reasons other than the evaluation of the adrenal glands. They have frequently been referred to as adrenal incidentalomas. In preparation for a National Institutes of Health State-of-the-Science Conference on this topic, extensive literature research, including Medline, BIOSIS, and Embase between 1966 and July 2002, as well as references of published metaanalyses and selected review articles identified more than 5400 citations. Based on 699 articles that were retrieved for further examination, we provide a comprehensive update of the diagnostic and therapeutic approaches focusing on endocrine and radiological features as well as surgical options. In addition, we present recent developments in the discovery of tumor markers, endocrine testing for subclinical disease including autonomous glucocorticoid hypersecretion and silent pheochromocytoma, novel imaging techniques, and minimally invasive surgery. Based on the statements of the conference, the available literature, and ongoing studies, our aim is to provide practical recommendations for the management of this common entity and to highlight areas for future studies and research.

Journal ArticleDOI
TL;DR: The ability of electrospun silk matrices to support BMSC attachment, spreading and growth in vitro, combined with a biocompatibility and biodegradable properties of the silk protein matrix, suggest potential use of these biomaterial matrices as scaffolds for tissue engineering.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the simultaneous effects of learning intent, learning capacity (LC), knowledge ambiguity, and its two key antecedents ( tacitness and partner protectiveness) on technological knowledge transfer.
Abstract: This research proposes and tests a basic model of organizational learning that captures the process of knowledge transfer in international strategic alliances. Based on a cross-sectional sample of 147 multinationals and a structural equation methodology, this study empirically investigates the simultaneous effects of learning intent, learning capacity (LC), knowledge ambiguity, and its two key antecedents – tacitness and partner protectiveness – on technological knowledge transfer. In the interest of expanding our understanding of the organizational mechanisms that both hinder and facilitate learning, the concept of LC is refined into three distinct components: resource-, incentive-, and cognitive-based LC. Further, the strength of the relationships between these theoretical constructs and knowledge transfer is examined in light of the possible moderating effects of organizational culture, firm size, and the form and competitive regime of the alliance. Consistently, learning intent (as a driver) and knowledge ambiguity (as an impediment) emerge as the most significant determinants of knowledge transfer. Moreover, the effects of partner protectiveness and LC on the learning outcome are moderated by the firm's own culture towards learning, the size of the firm, the structural form of the alliance, and the fact that partners may or may not be competitors.

Journal ArticleDOI
TL;DR: This is the first prospective, randomized, controlled trial of an extracorporeal liver support system, demonstrating safety and improved survival in patients with fulminant/subfulminant hepatic failure.
Abstract: Objective: The HepatAssist liver support system is an extracorpo-real porcine hepatocyte-based bioartificial liver (BAL). The safety and efficacy of the BAL were evaluated in a prospective. random-ized, controlled, multicenter trial in patients with severe acute liver failure. Summary Background Data: In experimental animals with acute liver failure, we demonstrated beneficial effects of the BAL. Similarly, Phase I trials of the BAL in acute liver failure patients yielded promising results. Methods: A total of 171 patients (86 control and 85 BAL) were enrolled. Patients with fulminant/subfulminant hepatic failure and primary nonfunction following liver transplantation were included. Data were analyzed with and without accounting for the following confounding factors: liver transplantation, time to transplant, disease etiology, disease severity, and treatment site. Results: For the entire patient population, survival at 30 days was 71% for BAL versus 62% for control (P = 0.26). After exclusion of primary nonfunction patients, survival was 73% for BAL Versus 59% for control (it = 147; P= 0.12). When Survival was analyzed accounting for confounding factors. in the entire patient Population, there was no difference between the 2 groups (risk ratio = 0.67; P = 0.13). However, survival in fulminant/subfulminant hepatic failure patients was significantly higher in the BAL compared with the control group (risk ratio 0.56: P = 0.048). Conclusions: This is the first prospective, randomized, controlled trial of an extracorporeal liver support system, demonstrating safety and improved survival in patients with fulminant/subfulminant hepatic failure.