SEARCH · PubMed Health

Results for “Paradigm shift”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

PubMed2001

Minimally invasive and robotic surgery.

Advances in surgery have focused on minimizing the invasiveness of surgical procedures, such that a significant paradigm shift has occurred for some procedures in which surgeons no longer directly touch or see the structures on which they operate. Advancements in video imaging, endoscope technology, and instrumentation have made it possible to convert many procedures in many surgical specialties from open surgeries to endoscopic ones. The use of computers and robotics promises to facilitate complex endoscopic procedures by virtue of voice control over the networked operating room, enhancement of dexterity to facilitate microscale operations, and development of virtual simulator trainers to enhance the ability to learn new complex operations. Future research will focus on delivery of diagnostic and therapeutic modalities through natural orifices in which investigation is under remote control and navigation, so that truly "noninvasive" surgery will be a reality.

Forecasting↗

PubMed2002

beta-Blocker therapy in heart failure: scientific review.

CONTEXT: Care of patients with heart failure has been revolutionized throughout the past decade. A paradigm shift in the strategy for treating heart failure caused by systolic dysfunction is in progress. Despite the initial perception about beta-blockers' safety, they are now the most extensively studied class of agents in the treatment of heart failure and have emerged as an important intervention to improve the clinical outcomes of heart failure patients. OBJECTIVE: To provide scientific rationale for the use of beta-blockers for patients with heart failure. DATA SOURCES: All English-language articles of large, randomized controlled clinical trials assessing the mortality benefits of beta-blockers in patients with heart failure were identified to provide the scientific rationale for the use of beta-blockers in heart failure. Basic science studies were reviewed to provide an overview of the potential physiologic role of beta-blockers in heart failure. Finally, clinical guidelines for the treatment of patients with heart failure were assessed to determine current recommendations for the use of these agents. STUDY SELECTION AND DATA EXTRACTION: Randomized controlled clinical trials of beta-blockers that included more than 300 subjects and assessed mortality as a primary end point. DATA SYNTHESIS: Of the 4 beta-blockers tested in large randomized controlled clinical trials of patients with heart failure, 3 are available in the United States, bisoprolol, carvedilol, and metoprolol; 2 of these, carvedilol and metoprolol, have Food and Drug Administration indications for the treatment of heart failure. Compared with placebo treatment, beta-blocker use is associated with a consistent 30% reduction in mortality and a 40% reduction in hospitalizations in patients with class II and III heart failure. CONCLUSIONS: Tested in more than 10,000 patients, beta-blockers reduce morbidity and mortality in class II through IV heart failure. Along with angiotensin-converting enzyme inhibitors, digoxin, and diuretics, beta-blockers have strengthened the armamentarium to improve clinical outcomes of heart failure patients. The science supporting beta-blockers must be translated into practice safely and rationally if the agents are to achieve their full potential.

Adrenergic beta-Antagonists↗

PubMed1996

Fatherhood reconsidered: a critical review.

The purpose of this critical review is to examine the three central foci around which the research on North American fatherhood has been concentrated. These foci include socialization theories relating to father's role enactment, development theories relating to the growth and development of fathers and children; and descriptions of actual paternal conduct. Since past decades have been marked by an unprecedented paradigm shift in expectations for fathers, a commentary on cultural images of fatherhood examining the empirical research on participatory and absent fathers is included. A research approach based on the social construction of gender, including avenues for future theory development, research, and social policy is proposed.

Child↗

PubMed2000

Randomized population trials and screening for lung cancer: breaking the cure barrier.

BACKGROUND: At the current time, there is nearly universal agreement that screening for the early detection of lung carcinoma is not justified. This is based on the fact that, to the author's knowledge, no randomized population trial (RPT) to date has demonstrated a significant reduction in lung carcinoma mortality as a result of any screening intervention. METHODS: To date, four RPTs, which have included a total of 37,724 male cigarette smokers, have been conducted. Studies at Memorial Sloan-Kettering Cancer Center and Johns Hopkins demonstrate no incremental effect by the addition of sputum cytology to annual chest X-ray (CXR) screening alone. However, CXR screening in all participants likely was responsible for stage and long term survival rates that were two-to three-fold higher than predicted based on contemporary statistics. Studies at the Mayo Clinic and in Czechoslovakia demonstrated significantly superior stage distribution and survival, but slightly inferior mortality in experimental populations that underwent periodic CXR screening. Such contradictory findings were made possible by a higher cumulative incidence rate of lung carcinoma in experimental populations. The constellation of improved survival, higher rate of incidence, and similar mortality led to the hypothesis that CXR screening leads to the overdiagnosis of lung carcinoma. RESULTS: Abundant evidence based on epidemiologic, pathologic, and clinical considerations conclusively demonstrate that CXR screening does not lead to the significant overdiagnosis of lung carcinoma. Moreover, overdiagnosis is the only way to reconcile the results of existing RPTs with the conclusion that CXR screening is ineffective. The alternative conclusion is that significant stage, resectability, and long term survival advantages reflected the ability of CXR screening to improve cure rates. Population heterogeneity accounts for the failure of mortality to reflect screening efficacy accurately in these trials. There is direct evidence that population heterogeneity was responsible for the trend toward increased lung carcinoma mortality in the Czech study. Moreover, review of all RPTs demonstrates a consistent pattern in which population heterogeneity confounds the ability of mortality to represent an accurate measure of screening effectiveness. CONCLUSIONS: Systematic analysis of RPTs supports two major conclusions: 1) an improvement in the cure rate rather than a reduction is cause specific mortality is the proper measure of screening effectiveness in the RPT setting and 2) CXR screening is associated with a two- to three-fold improvement in lung carcinoma cure rates. A paradigm shift is mandatory for the proper evaluation of conventional and newer screening modalities. Indeed, hundreds of thousands of lives would be saved annually on a global basis if CXR screening were offered to individuals at high risk for lung carcinoma.

Bias↗

PubMed2001

Artificial neural networks: opening the black box.

Artificial neural networks now are used in many fields. They have become well established as viable, multipurpose, robust computational methodologies with solid theoretic support and with strong potential to be effective in any discipline, especially medicine. For example, neural networks can extract new medical information from raw data, build computer models that are useful for medical decision-making, and aid in the distribution of medical expertise. Because many important neural network applications currently are emerging, the authors have prepared this article to bring a clearer understanding of these biologically inspired computing paradigms to anyone interested in exploring their use in medicine. They discuss the historical development of neural networks and provide the basic operational mathematics for the popular multilayered perceptron. The authors also describe good training, validation, and testing techniques, and discuss measurements of performance and reliability, including the use of bootstrap methods to obtain confidence intervals. Because it is possible to predict outcomes for individual patients with a neural network, the authors discuss the paradigm shift that is taking place from previous "bin-model" approaches, in which patient outcome and management is assumed from the statistical groups in which the patient fits. The authors explain that with neural networks it is possible to mediate predictions for individual patients with prevalence and misclassification cost considerations using receiver operating characteristic methodology. The authors illustrate their findings with examples that include prostate carcinoma detection, coronary heart disease risk prediction, and medication dosing. The authors identify and discuss obstacles to success, including the need for expanded databases and the need to establish multidisciplinary teams. The authors believe that these obstacles can be overcome and that neural networks have a very important role in future medical decision support and the patient management systems employed in routine medical practice.

Decision Theory↗

PubMed2006

Anatomy of learning: instructional design principles for the anatomical sciences.

Teaching anatomy is becoming increasingly challenging due to the progressive evolution of university teaching missions, student populations, medical and undergraduate curricula, coupled with a paucity of empirically tested evidence-based instructional practices in the anatomical and medical education literature. As a mechanism to confront these pedagogical challenges, recent advances in educational psychology are analyzed for developing a framework to guide educational reform efforts. Extensive research in educational psychology over the last 100 years has resulted in four major theories on human learning that have facilitated a paradigm shift from teacher-centered to learner-centered classrooms and are described here in temporal order of development: behavioral theory, information processing theory, metacognitive theory, and social constructivist theory. Each theory is analyzed in detail and is used to construct instructional design principles for enhancing anatomical education research and practice. An example of a cognitively based learning environment for an undergraduate anatomy course is presented. Preliminary results suggest that intentionally drawing on different theories of learning when making instructional decisions gave students the learning support they needed to be successful and nearly doubled the course's student retention rate over a 3-year period.

Anatomy↗

PubMed2004

Genetic modules and networks for behavior: lessons from Drosophila.

Behaviors are quantitative traits determined through actions of multiple genes and subject to genome-environment interactions. Early studies concentrated on analyzing the effects of single genes on behaviors, often generating views of simplified linear genetic pathways. The genome era has generated a profound paradigm shift enabling us to identify all the genes that contribute to expression of a behavioral phenotype, to investigate how they are organized as functional ensembles and to begin to identify polymorphisms that contribute to phenotypic variation and are targets for natural selection. Recent studies show that the genetic architecture of behavior is determined by dynamic and plastic modular networks of pleiotropic genes and that the behavioral phenotype manifests itself as an emergent property of such networks. Such networks are exquisitely sensitive to genetic background and sex effects. This review describes how Drosophila can serve as a model for uncovering fundamental principles of the genetic architecture of behavior.

Animals↗

PubMed2026

Bridging Organ-on-a-Chip and Omics: A Multi-Dimensional Frontier in Biomedical Research.

Organ-on-a-Chip (OOC) technology offers a powerful platform for replicating human tissue-specific microenvironments, thereby narrowing the translational gap between conventional biomedical models and actual human physiology. Concurrently, omics technologies deliver comprehensive molecular-level insights into biological systems. This review highlights the transformative potential of integrating OOC platforms with high-throughput omics methodologies. We systematically examine the classification, structural configurations, and engineering principles underlying OOC systems, alongside the defining attributes of key omics domains-genomics, transcriptomics, proteomics, and metabolomics. The convergence of dynamic OOC models with advanced omics technologies enables high-resolution, multi-dimensional analyses across numerous biomedical applications, including drug metabolism, disease mechanisms, environmental toxicity assessments, and host-microbiome interactions. This interdisciplinary integration is driving a paradigm shift in precision and translational medicine. However, several challenges remain to be addressed, such as the development of whole-organ mimetics, adaptation of sample collection techniques, and real-time artificial intelligence-based integration of biosensor data with multi-omics datasets. Addressing these hurdles will be vital for unlocking the full potential of this technological synergy in biomedical science.

Multiomics↗

PubMed2005

Ethics, transplantation, and the changing role of anatomists.

Anatomists are regarded as custodians of cadaveric material donated to science. Almost every facet of medical science has experienced explosive advances. This has impacted directly on anatomists and their role. Increasingly, anatomists are raising concerns with regard to the treatment of human tissue (Jones,2002, Clin. Anat. 15:436-440). The Korperwelten (Bodyworlds) of Gunther von Hagens et al. (1987, Anat. Embryol. 175:411-421) has evoked considerable debate about the treatment of human cadavers. Thus far clinical anatomists have had little role to play in policy formulation, legislation, and ethical imperatives as applied to cadaveric donation for organ transplantation. Anatomists play an even more negligible role in the raging ethical controversy around live related/unrelated organ transplantation. Due to the critical international shortage of cadaveric donors, boundaries are being pushed to meet the needs of potential recipients (Ohler,2001, Prog. Transplant. 11:160-161). Constant reappraisal of these ethical and moral issues is therefore appropriate. Issues that relate to cultural and economic imperialism and pronouncements of international transplant societies may also require re-evaluation. The legislature governing the donation of human tissue in various countries is usually governed by a Human Tissue Act or its equivalent. In general, such acts are congruent with the Human Tissue Act (South Africa: Government Gazette 9, November 2001; No. 22824) that states "It is an offense to charge a fee in relation to the donation of human organs." In many countries, however, various lay press report that "the sale of body parts is now coming of age." Terms such as "rewarded gifting" and "donors" being transformed into "vendors" are opening a Pandora's Box (Nelson et al.,1993, "Financial incentives for organ donation: a report on the UNOS ethics committee payment subcommittee"). Cameron and Hoffenberg (1999, Kidney Int. 55:724-732) feel strongly that arguments in favour of the sale of organs are sufficiently cogent to warrant further discussion. Equally disturbing is the use of executed prisoners as organ donors. In the developing world there are additional socio-economic, indigenous and cultural, religious, and ethical issues to consider. In addition, strategies that are ethically sound and morally acceptable to expand the pool of living donors must keep pace with recent advances in medicine. A paradigm shift is required for anatomists to contribute to the international ethical debate, not only as custodians of the dead but also as protectors of the living. Their voices should be heard in transplantation and other forums, and contribute to the ethical debate as well as relevant evolving legislature.

Anatomy↗

PubMed2001

Interleukin-6 and acute coronary syndrome.

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Plasma concentrations of interleukin-6 (IL-6) and its hepatic by-product C-reactive protein (CRP) appear to reflect the intensity of occult plaque inflammation and by inference may determine vulnerability to rupture. Indeed, circulating IL-6 levels are elevated in patients with acute myocardial infarction (AMI), and also in patients with unstable, but not with stable angina. Coronary sinus IL-6 concentrations are also increased after percutaneous coronary intervention (PCI), and late restenosis correlates with an increase in IL-6 concentration after the procedure, indicating that IL-6 expression may be not only related to instability of atheromatous plaques, but also to the formation of restenotic lesions after PCI. These observations suggest the advantage of screening for circulating IL-6 concentration and the use of anti-inflammatory treatment for those thought be at high risk to reduce the risk of future AMI.

Angina Pectoris↗

PubMed2002

Monocyte chemoattractant protein-1 and coronary artery disease.

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the recruitment and activation of monocytes and thus in the development of atherosclerosis. Enhanced MCP-1 expression has been detected in macrophages, endothelial cells, and vascular smooth muscle cells in the atheromatous plaque. Activation of macrophages by MCP-1 also appears to be involved in the vulnerability of the plaque. Indeed, circulating MCP-1 levels are elevated in patients with acute myocardial infarction and in those with unstable angina, but not in patients with stable angina. Production of MCP-1 and macrophage accumulation are also observed after coronary angioplasty or grafting, indicating that MCP-1 expression may be related not only to instability of atheromatous plaques, but also to the formation of restenotic lesions. The development of therapeutic drugs for atherosclerosis targeted specially against MCP-1 may be useful in the prevention of plaque formation and future myocardial infarction.

Angina, Unstable↗

PubMed2006

Relevance of extracapsular extension of pelvic lymph node metastasis in patients with bladder cancer treated in the contemporary era.

BACKGROUND: Previous reports have suggested that extracapsular extension (ECE) is a prognostic factor in patients with urothelial carcinoma who have positive lymph nodes at the time of radical cystectomy. In the current study, the relevance of ECE in patients treated in the contemporary era was evaluated. METHODS: A database search from 1993 to 2003 revealed 150 patients with pN+M0 disease detected after radical cystectomy; of these, 108 patients did not receive neoadjuvant chemotherapy and form the basis of the current report. Overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) data were analyzed by the Kaplan-Meier method, with log-rank tests used to evaluate associations between survival and variables studied. RESULTS: Five-year OS, DSS, and RFS rates were 30.9%, 45.5%, and 29.7%, respectively. Adjuvant chemotherapy was administered to 70% of patients. On multivariate analysis, adjuvant chemotherapy was significantly associated with prolonged OS, DSS, and RFS (P </= .01). For patients overall and when stratified by pN status, the presence of ECE of lymph node metastasis was not found to be significantly associated with OS (P = .52), DSS (P = .43), or RFS (P = .83). CONCLUSIONS.: The current study suggests that ECE is not an independent prognostic factor in a contemporary series of patients with positive lymph nodes at radical cystectomy. This might be reflective of a paradigm shift that encompasses the adoption of multimodal therapy.

Aged↗

PubMed2006

Special Populations Networks--how this innovative community-based initiative affected minority and underserved research programs.

The Special Populations Networks (SPN) Program was created to address both community needs for cancer information and NCI's desire to obtain community-based answers to research questions and promote training opportunities for racial/ethnic minority and underserved researchers in populations with an unequal burden of cancer. The SPN program included 3 components: 1) infrastructure and capacity building combined with cancer awareness, 2) community-based research, and 3) community-centered training. The 18 SPN grantees conducted more than 1000 cancer awareness activities. More than 2000 community lay health workers were trained. Communities formalized more than 300 partnerships with Memoranda of Understanding (MOU). More than 255 pilot research project applications were submitted by junior researchers and over 135 were funded. Approximately 90% of the applications were submitted by minority junior researchers; of which more than 100 were funded. More than 290 scientific publications thus far have resulted from the work of the SPNs. In the first 3 years of the program, the SPNs also secured an additional $20 million in outside funding. The SPN program effected a paradigm shift for minority research programs by combining community-based cancer awareness, research, and training into a single program. By engaging research leaders of minority and underserved populations to aid their own, train their own, and develop research to help their own, the SPN program activated the power of their commitment to their own. That commitment was reflected in the trust and participation offered by their communities. Cancer 2006. (c) 2006 American Cancer Society.

Community Networks↗

PubMed2001

Paradigms and research programmes: is it time to move from health care economics to health economics?

As an applied subdiscipline of economics, health economics has flourished, defining itself as the study of how scarce health care resources may be used to meet our needs. This evolutionary pathway has led to health economists adopting a very 'medical' model of health, in which the predominant production function for health is health care. This paper sets out policy challenges to health economics which have arisen in light of growing recognition by governments of the socioeconomic determinants of health and their stated commitment to tackle inequalities in health. It reviews Thomas Kuhn's theory of paradigm shift and Imre Lakatos' theory of scientific research programmes in the natural sciences, favouring the latter as an explanation of the evolution of the subdiscipline of health economics. The paper brings together four recently published visions of the future of health economics-visions that are almost exclusively focused on the production, organization and distribution of health care. In contrast to these visions, in Lakatosian terms, this paper challenges the subdiscipline's core 'positive heuristic', i.e. the set of imperatives which determines how the research programme should unfold, how it may be defended, its scope and boundaries. This paper argues that health economics will need to evolve to embrace a more socioeconomic model of health and, to this end, offers for debate an expansion of Williams' diagrammatic representation of the subdiscipline. It concludes by asking whether the magnitude and the magnetism of health care policy issues will continue to prove too strong to allow health economists, should they wish, to steer their research and educational programmes more directly towards 'health' rather than 'health care' as the relevant social want.

Delivery of Health Care↗

PubMed2006

The unfinished legacy of liver transplantation: emphasis on immunology.

Liver transplantation radically changed the philosophy of hepatology practice, enriched multiple areas of basic science, and had pervasive ripple effects in law, public policy, ethics, and theology. Why organ engraftment was feasible remained enigmatic, however, until the discovery in 1992 of donor leukocyte microchimerism in long-surviving liver, and other kinds of organ recipients. Following this discovery, the leukocyte chimerism-associated mechanisms were elucidated that directly linked organ and bone marrow transplantation and eventually clarified the relationship of transplantation immunology to the immunology of infections, neoplasms, and autoimmune disorders. We describe here how the initially controversial paradigm shift mandated revisions of cherished dogmas. With the fresh insight, the reasons for numerous inexplicable phenomena of transplantation either became obvious or have become susceptible to discriminate experimental testing. The therapeutic implications of the "new immunology" in hepatology and in other medical disciplines, have only begun to be explored. Apart from immunology, physiologic investigations of liver transplantation have resulted in the discovery of growth factors (beginning with insulin) that are involved in the regulation of liver size, ultrastructure, function, and the capacity for regeneration. Such studies have partially explained functional and hormonal relationships of different abdominal organs, and ultimately they led to the cure or palliation by liver transplantation of more than 2 dozen hepatic-based inborn errors of metabolism. Liver transplantation should not be viewed as a purely technologic achievement, but rather as a searchlight whose beams have penetrated the murky mist of the past, and continue to potentially illuminate the future.

Animals↗

PubMed2006

Therapy of hepatitis B -- viral suppression or eradication?

The practicing clinician is currently faced with a number of treatment options for chronic hepatitis B. Beginning in 1998 with the licensing of lamivudine and subsequently adefovir, the treatment paradigm shifted from 4 to 6 months of conventional alfa interferon to a year of nucleoside analog therapy. However, prolonged treatment with nucleoside analogs is often needed to optimize virological response. Recently, a 48-week regimen of pegylated interferon for hepatitis B e antigen (HBeAg)-positive and HBeAg-negative chronic hepatitis B has been shown to be effective, and long-term nucleoside analog therapy has been demonstrated to maintain viral suppression. These findings have added to the complexity of decision-making and have raised questions about whether a finite course of pegylated interferon or nucleoside analog therapy, with possible long-term maintenance, is better as first-line therapy. Each of these fundamentally different approaches has advantages and limitations, and both have a place in the therapeutic armamentarium against chronic hepatitis B. Long-term therapy with nucleoside analogs, however, raises a number of practical concerns that have not been fully addressed as of yet. I will present evidence in support of the recommendation that antiviral therapy should ideally be directed toward achieving the highest rate of viral clearance with the shortest interval of treatment.

Adult↗

PubMedDate not supplied

New ways of financing and organizing health care in Sweden.

The health care system in Sweden has been undergoing radical change since 1991. The mainly public financed (90%) system with 26 autonomous counties spent 8.5% of its gross domestic product on health care in 1991. The main features of the 'paradigm shift' are: separation of production and financing; resource allocation to health districts in relation to the needs of the population; and introduction of public competition between health districts (purchasers) and hospitals (providers). The health district boards are responsible for the health care of the population in their district hospitals financed by their activities (e.g. through diagnosis-related groups (DRGs)) and quality aspects monitored by central authorities. A parliamentary committee (HSU 2000) is investigating how Sweden's health care system can be organized and financed in the future. Three models are analyzed: a reformed county council court model, a primary care-managed model, and a compulsory insurance model. Each model must be consistent with equity and public financing. From 1992 in the Stockholm county, five surgical specialties were paid for their activities according to DRGs for inpatient care and another system for outpatient care. The number of treated patients during 1992 increased by 8% in inpatient care, 50% in day surgery and by 15% in outpatient care. Taken together, the activities increased by 11%, which is slightly more than the expected 10% increase in productivity. (There was a 10% decrease in DRG prices from 1 January 1992.) The total costs decreased by 1% due to fewer personnel. Nothing has been reported concerning the quality of care, neither before nor after the model was introduced. From 1993, all somatic acute specialties are paid by DRGs and the equivalent outpatient classification systems. The results from 1993 will be presented in the autumn of 1994.

Cost-Benefit Analysis↗

PubMed1995

Helicobacter pylori and gastrointestinal disease.

New paradigms are few and far between. The discovery that peptic ulcer disease is the result of an infection by a previously unrecognized microorganism rather than the consequence of excess secretion of gastric acid aptly qualifies as a paradigm shift. Eradication of Helicobacter pylori from the stomach by antibacterial agents heals ulcers at least as effectively as H2-blockers. Further, eradication of the organism results in long-term cures of peptic ulcers. In contrast, the relapse rate in patients successfully treated with H2-blockers exceeds 50% in the first year after healing. Also of interest is the role of H. pylori in gastric cancer.

Anti-Bacterial Agents↗