PubMed Health⌕ Search

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 541 records · Page 30Linked to original sources

The surgical management of allograft coronary disease: a paradigm shift.

The surgical options for heart transplant recipients who develop obstructive coronary artery disease in their allograft have historically been limited to retransplantation. Given the worse outcome in recipients of second grafts, often caused by recurrence of coronary disease, coupled with the significant increase in the number of patients on the transplantation waiting lists, has made retransplantation a limited option. However, as heart transplant recipients continue to live longer, there are an increasing number of patients who develop allograft coronary disease. Coronary bypass surgery has not been offered to these patients because of numerous pathology reports describing uniform involvement of the coronary vessel from its origin to the distal intramural branches, thereby eliminating any reasonable runoff vascular bed to handle increased flow that might be delivered with bypass conduits. However, new diagnostic techniques such as measurement of coronary flow reserve by Doppler flow wire can define the physiological vasodilating capacity or reserve which, if normal, should allow conventional bypass surgery if adequate target epicardial vessels are present. This approach would allow a more reasonable alternative to many patients who otherwise would die of this disease without any intervention. Other alternatives such as transmyocardial laser revascularization are discussed.

Coronary Disease↗

A challenge to develop a new paradigm shift in nursing education.

The failure of American society to integrate all segments of its population is discussed in this paper as well as how the profession of nursing has followed national patterns, what these patterns of exclusion mean to the health care of ethnic communities as well as to the nation. Recommendations are made for positive change.

Cultural Diversity↗

Paradigm shift.

Explore the source record for details and available documents.

Ethics, Dental↗

Science and the shifting paradigm in dental education.

Dental education is faced with continuing challenges to adjust to external as well as internal pressures. These pressures are coming from a variety of sources that are often inconsistent in the nature and direction of change they would bring about. Pressure on the future direction of dental education are coming from sources such as an Institute of Medicine report, Pew Health Professions Commission reports, changes in the academic health centers in response to health care reform, and expectations of parent universities. Reactions to these and other forces are bringing about changes in the nature and extent of scientific research in schools of dentistry. As the educational programs continue to evolve, research will receive greater attention, and more of it will be funded from private sources.

Academic Medical Centers↗

Sexual differentiation of the zebra finch song system: positive evidence, negative evidence, null hypotheses, and a paradigm shift.

Permanent sex differences in the brain are found in many vertebrates, and are thought to be induced by sex differences in secretion of gonadal steroid hormones during critical periods of early development. This theory has received support primarily from many experiments conducted on mammals, but also from studies on other vertebrate classes, including birds. The only avian neural dimorphism that has allowed extensive tests of this hypothesis is the neural circuit for song in passerine birds, which is much larger in males than in females. Experiments in zebra finches have yielded contradictory results. Although it is relatively easy to induce masculine patterns of development in genetic females with estrogen, it has not been possible to induce feminine patterns of development in males with any treatments, including antiestrogens and inhibitors of estrogen synthesis. Moreover, genetic females that develop with large amounts of functional testicular tissue but with virtually no ovarian tissue nevertheless have a feminine song circuit. The latter studies fail to support the idea of steroid induction of sexual differentiation. An alternative to the steroidal control hypothesis is that nonhormonal gene products expressed in the brain early in development trigger sexually dimorphic patterns of development. Although current evidence in several neural and nonneural systems indicates that sexual differentiation of some somatic phenotypes cannot be explained by the actions of gonadal steroids, the idea of direct genetic (nonhormonal) induction of sexual differentiation has yet to be proved.

Animals↗