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At least 307 records · Page 17Linked to original sources
PubMed2004

The expanded transposition flap: shifting paradigms based on experience gained from two decades of pediatric tissue expansion.

The authors present their experience with the design of expanded skin flaps gained over the past two decades in a large series of 995 expanded flap reconstructions performed in 626 operations in 430 patients. The indications for tissue expansion were giant congenital pigmented nevi (72.7 percent), scar contractures (11.2 percent), and a remainder for a variety of congenital and acquired deformities. Surgical strategies were reviewed retrospectively to determine the location in the body where the tissue expansion was performed, the number of procedures required to accomplish the reconstructive goal, and the design of the expanded flap that was used to reconstruct the involved area. Specific points that were noticed included contour deformities (such as webbing, dog-ears, or decreased limb circumference) following flap reconstruction, anatomic distortions (such as distortion of the eyebrow or the distance from the brow to hairline) following reconstruction, final position of the scars in relation to anatomic landmarks, borders of aesthetic units, and relaxed skin tension lines, and the potential for later scar contracture. Careful examination of reconstruction by region of involvement demonstrated significant advantages in the use of expanded transposition flaps over pure advancement. These advantages and the modifications in the design of expanded flaps for each body region are discussed in a series of representative cases. They emphasize the ability of transposition flaps to dissipate tension away from the flap apex and distribute it more proximally, thus redirecting the tension lines so there is less likelihood of anatomic distortion in the reconstructed area. Also, flaps designed in this manner allow improved contour by avoiding webbing, tenting across concavities, and bunching of skin laterally. The authors conclude that restricting the expanded flap design to advancement alone to minimize potential scarring severely limits the reconstructive capabilities of the added tissue and distracts from the surgeon's ability to accomplish the initial reconstructive goal. The cost of additional incisions is worthwhile to achieve better final contour of the reconstructed part, lesser risk of anatomic distortion, better position of the scars, and lowered risk of scar contracture.

Child↗
PubMed2003

Paradigm shift in the management of gastroesophageal reflux disease.

OBJECTIVE: To compare the short-term results of the radiofrequency treatment of the gastroesophageal junction known as the Stretta procedure versus laparoscopic fundoplication (LF) in patients with gastroesophageal reflux disease (GERD). SUMMARY BACKGROUND DATA: The Stretta procedure has been shown to be safe, well tolerated, and highly effective in the treatment of GERD. METHODS: All patients presenting to Vanderbilt University Medical Center for surgical evaluation of GERD between August 2000 and March 2002 were prospectively evaluated under an IRB-approved protocol. All patients underwent esophageal motility testing and endoscopy that documented GERD preoperatively, either by a positive 24-hour pH study or biopsy-proven esophagitis. Patients were offered the Stretta procedure if they had documented GERD and did not have a hiatal hernia larger than 2 cm, LES pressure less than 8 mmHg, or Barrett's esophagus. Patients with larger hiatal hernias, LES pressure less than 8 mmHg, or Barrett's were offered LF. All patients were studied pre- and postoperatively with validated GERD-specific quality-of-life questionnaires (QOLRAD) and short-form health surveys (SF-12). Current medication use and satisfaction with the procedure was also obtained. RESULTS: Results are reported as mean +/- SEM. Seventy-five patients (age 49 +/- 14 years, 44% male, 56% female) underwent LF and 65 patients (age 46 +/- 12 years, 42%, 58% female) underwent the Stretta procedure. Preoperative esophageal acid exposure time was higher in the LF group. Preoperative LES pressure was higher in the Stretta group. In the LF group, 41% had large hiatal hernias (>2 cm), 8 patients required Collis gastroplasty, 6 had Barrett's esophagus, and 10 had undergone previous fundoplication. At 6 months, the QOLRAD and SF-12 scores were significantly improved within both groups. There was an equal magnitude of improvement between pre- and postoperative QOLRAD and SF-12 scores between Stretta and LF patients. Fifty-eight percent of Stretta patients were off proton pump inhibitors, and an additional 31% had reduced their dose significantly; 97% of LF patients were off PPIs. Twenty-two Stretta patients returned for 24-hour pH testing at a mean of 7.2 +/- 0.5 months, and there was a significant reduction in esophageal acid exposure time. Both groups were highly satisfied with their procedure. CONCLUSIONS: The addition of a less invasive, endoscopic treatment for GERD to the surgical algorithm has allowed the authors to stratify the management of GERD patients to treatment with either Stretta or LF according to size of hiatal hernia, LES pressure, Barrett's esophagus, and significant pulmonary symptoms. Patients undergoing Stretta are highly satisfied and have improved GERD symptoms and quality of life comparable to LF. The Stretta procedure is an effective alternative to LF in well-selected patients.

Adult↗
PubMed2005

Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training.

SUMMARY BACKGROUND DATA: To inform surgeons about the practical issues to be considered for successful integration of virtual reality simulation into a surgical training program. The learning and practice of minimally invasive surgery (MIS) makes unique demands on surgical training programs. A decade ago Satava proposed virtual reality (VR) surgical simulation as a solution for this problem. Only recently have robust scientific studies supported that vision METHODS: A review of the surgical education, human-factor, and psychology literature to identify important factors which will impinge on the successful integration of VR training into a surgical training program. RESULTS: VR is more likely to be successful if it is systematically integrated into a well-thought-out education and training program which objectively assesses technical skills improvement proximate to the learning experience. Validated performance metrics should be relevant to the surgical task being trained but in general will require trainees to reach an objectively determined proficiency criterion, based on tightly defined metrics and perform at this level consistently. VR training is more likely to be successful if the training schedule takes place on an interval basis rather than massed into a short period of extensive practice. High-fidelity VR simulations will confer the greatest skills transfer to the in vivo surgical situation, but less expensive VR trainers will also lead to considerably improved skills generalizations. CONCLUSIONS: VR for improved performance of MIS is now a reality. However, VR is only a training tool that must be thoughtfully introduced into a surgical training curriculum for it to successfully improve surgical technical skills.

Attention↗
PubMed2003

Multiple paradigm shifts in multiple sclerosis.

PURPOSE OF REVIEW: The present article reviews the currently ongoing scientific debate of our changing views on the pathogenesis of multiple sclerosis and the therapeutic strategies currently available for multiple sclerosis. RECENT FINDINGS: The most important observations include that (a) axonal loss accounts for permanent disability in multiple sclerosis, (b) remyelination should be possible in theory but fails for unknown reasons in the multiple sclerosis lesion, (c) inflammation can be beneficial, (d) treatment should be initiated early, and (e) immunosuppressive strategies exhibit beneficial effects in progressive forms of the disease. SUMMARY: Our current understanding of the immunopathogenesis of multiple sclerosis has changed in the past. Whereas demyelination was originally thought to be relevant for the lasting neurological deficit, it is nowadays commonly accepted that the extent of axonal loss dictates the degree of permanent clinical disability. How axonal damage can be prevented remains elusive. The interaction between the myelinating cell and the neuron gains increasing attention, however the evolving knowledge has not yet yielded new treatment concepts. Hence for the time being, it seems prudent to make optimal use of current approved therapies. Recent trials underlined the need for early initiation of treatment with immunomodulatory drugs. The superiority of one of the interferons is still a matter of debate, and a conclusive answer cannot be given at present. Finally, with mitoxantrone we have a drug at hand which can be used in progressive forms of multiple sclerosis, especially when other disease modifying drugs are not or no longer effective.

Adjuvants, Immunologic↗
PubMed2005

Mixing in seasonally stratified shelf seas: a shifting paradigm.

Although continental shelf seas make up a relatively small fraction (ca 7%) of the world ocean's surface, they are thought to contribute significantly (20-50% of the total) to the open-ocean carbon dioxide storage through processes collectively known as the shelf sea pump. The global significance of these processes is determined by the vertical mixing, which drives the net CO(2) drawdown (which can occur only in stratified water). In this paper, we focus on identifying the processes that are responsible for mixing across the thermocline in seasonally stratified shelf seas. We present evidence that shear instability and internal wave breaking are largely responsible for thermocline mixing, a clear development from the first-order paradigm for the water column structure in continental shelf seas. The levels of dissipation observed are quantitatively consistent with the observed dissipation rates of the internal tide and near-inertial oscillations. It is perhaps because these processes make such a small contribution to the total energy dissipated in shelf seas that they are not well represented in current state-of-the-art numerical models of continental shelf seas. The results thus present a clear challenge to oceanographic models.

Carbon Dioxide↗
PubMed2005

Regime, phase and paradigm shifts: making community ecology the basic science for fisheries.

Modern fishery science, which began in 1957 with Beverton and Holt, is ca. 50 years old. At its inception, fishery science was limited by a nineteenth century mechanistic worldview and by computational technology; thus, the relatively simple equations of population ecology became the fundamental ecological science underlying fisheries. The time has come for this to change and for community ecology to become the fundamental ecological science underlying fisheries. This point will be illustrated with two examples. First, when viewed from a community perspective, excess production must be considered in the context of biomass left for predators. We argue that this is a better measure of the effects of fisheries than spawning biomass per recruit. Second, we shall analyse a simple, but still multi-species, model for fishery management that considers the alternatives of harvest regulations, inshore marine protected areas and offshore marine protected areas. Population or community perspectives lead to very different predictions about the efficacy of reserves.

Animals↗
PubMed2003

Perspective: sexual conflict and sexual selection: chasing away paradigm shifts.

Traditional models of sexual selection propose that partner choice increases both average male and average female fitness in a population. Recent theoretical and empirical work, however, has stressed that sexual conflict may be a potent broker of sexual selection. When the fitness interests of males and females diverge, a reproductive strategy that increases the fitness of one sex may decrease the fitness of the other sex. The chase-away hypothesis proposes that sexual conflict promotes sexually antagonistic, rather than mutualistic, coevolution, whereby manipulative reproductive strategies in one sex are counteracted by the evolution of resistance to such strategies in the other sex. In this paper, we consider the criteria necessary to demonstrate the chase-away hypothesis. Specifically, we review sexual conflict with particular emphasis on the chase-away hypothesis; discuss the problems associated with testing the predictions of the chase-away hypothesis and the extent to which these predictions and the predictions of traditional models of sexual selection are mutually exclusive; discuss misconceptions and mismeasures of sexual conflict; and suggest an alternative approach to demonstrate sexual conflict, measure the intensity of sexually antagonistic selection in a population, and elucidate the coevolutionary trajectories of the sexes.

Animals↗
PubMedDate not supplied

Paradigm shift of staging and treatment for early breast cancer in the sentinel lymph node era.

Lymph node status is the most reliable prognostic indicator for the clinical outcome of patients with most solid cancers. Because it is the first node draining the primary cancer, the sentinel lymph node (SLN) is most likely to harbor metastatic cancer cells. The tumor size of primary breast cancer is highly correlated with SLN metastasis. If the SLN is negative, the negative predictive value of the remaining nodal basin exceeds 95%. It appears that even using different techniques from different institutions, the successful rate to harvest the SLN is more than 95%. The false-negative rate is about 5-10% in most series. Breast cancer patients with early detection and a negative SLN have a significantly improved survival rate. The SLN data in breast cancer is so convincing that SLN information has been incorporated into the new American Joint Committee on Cancer (AJCC) classification of breast cancer. The therapeutic value of additional lymph node dissection after a positive SLN for breast cancer is still controversial. Follow-up data from breast cancer patients is somewhat limited, but available information shows that patients with negative SLNs fare much better. In summary, several important patterns of metastasis can be established based on the current SLN experience: 1) The earlier the breast cancer is found, the less the metastatic potential. 2) In most cases, breast cancer follows an orderly progression of metastasis to the SLN. 3) A small subgroup of patients may develop systemic dissemination without SLN involvement. Since metastatic cancer is usually incurable, it is important for oncologists to detect and resect an early breast cancer without delay. The challenge in the future will be to dissect these different patterns of metastasis based on molecular or genetic markers. Such information will be critical to select high-risk patients for adjuvant therapy.

Biomarkers, Tumor↗
PubMed2004

Paradigm shifts in medical and dental education: behavioural sciences and behavioural medicine.

Psychosomatic and behavioural medicine have a long tradition in Hungary. In this paper, we highlight the possibilities of teaching behavioural medicine and behavioural science in the medical and dental curricula, particularly in the field of health promotion and prevention. There are a number of possibilities for dentists in the fields of behavioural science in both research and health policy. There is a need for closer integration of teaching, research and health policy in both general medicine and dentistry, and both doctors and dentists must approach their patients in a holistic way.

Behavioral Medicine↗
PubMed2006

Gillies Lecture: ocular motility in a time of paradigm shift.

Abstract Recent progress in understanding of the structure and function of extraocular muscles, and our ability to image them clinically, allows prediction of revolutionary progress in diagnosis and treatment of strabismus in the coming decades. This perspective memorializes a lecture given in honour of Dr William Gillies, who has for decades been the paternal leader of strabismology in southern Australia.

Australia↗
PubMedDate not supplied

Difficult cases in heart failure. Novel diagnostic markers in heart failure: an emerging paradigm shift?

The differential diagnosis of dyspnea can be overwhelming in the presence of competing diseases. The recent advent of the peptide marker brain natriuretic peptide has ushered in an era of refined diagnostic capability in heart failure. We present a clinical scenario to illustrate the usefulness of this new biomarker assay in directing appropriate therapy for heart failure. (c)2001 CHF, Inc.

Journal Article↗