PubMed Health⌕ Search

Biomedical subjects

M Swank

Publications and source records attributed to M Swank.

14 recordsLinked to original sources
PubMed2006

Ion concentrations from hip implants.

Total hip joint arthroplasty is performed in increasing numbers--about 0.16-0.2% of population per year in industrial countries. In most cases, an implant is a metallic component articulating with a metal, ceramic, or polyethylene liner, used in the hip, knee, and spine. The metal implants release ions in vivo. Toxic concentrations of ions can lead to many adverse physiological effects, including cytotoxicity, genotoxicity, carcinogenicity, and metal sensitivity. Reference levels of ion concentrations in body fluids and tissues determined by many studies are compiled, reviewed, and presented in this article. The concentrations of ions released from different alloys--including cobalt, chromium, nickel, molybdenum titanium, aluminum, and vanadium--are also presented. This article reviews the literature pertaining to clinical data on metal ion concentrations in patients with metal joint prostheses and laboratory data on the physiological effects of the metals.

Hip Prosthesis↗
PubMed2000

Long-term outcomes of stereotactic breast biopsies.

Stereotactic core needle biopsies (SCNBs) are accurate and relatively convenient for the patient; however, the long-term follow-up of benign results has not been reported. All patients between 1993 and 1998 undergoing SCNB at a community-based hospital were entered into a registry. Follow-up was obtained by a retrospective analysis of the charts. Biopsies were performed on 865 lesions. One hundred thirty-one (15%) were malignant, 42 (5%) were suspicious for malignancy, 687 (79%) were benign, and five (1%) were lobular carcinoma in situ. Of the 42 patients with suspicious findings 38 underwent biopsy. Ten were malignant and 28 benign. Of the 687 patients with benign pathology, 377 had follow-up available with a mean length of 1.7 years. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SCNB for benign lesions in our study are all 100 per cent. Eight lesions were worrisome and await final analysis. Of 687 patients with benign lesions 310 were lost to follow-up. This study suggests that patients with a benign diagnosis should be returned to routine mammography. These data also extend the reported follow-up to 1.7 years and establish an acceptable level of accuracy for SCNB. The lost patients remind us that follow-up is essential despite a benign diagnosis.

Biopsy, Needle↗
PubMed1993

The natural history of unicompartmental arthroplasty. An eight-year follow-up study with survivorship analysis.

From 1983 to 1987, 82 unicondylar arthroplasties were performed for primary unicompartmental osteoarthrosis. Seven knees had lateral compartment arthroplasties and 75 had medial unicompartmental knee arthroplasties (UKA). At a minimum follow-up period of four years, eight patients had been revised, one patient was scheduled for revision, and one patient had died with a failed UKA, for a total failure rate of 12%. Reasons for failure were progression of tricompartmental arthritis in two patients (2.4%), polyethylene wear in two (2.3%), component failure in two (2.3%), component loosening in three (3.5%), and technical error in one (1.6%). Furthermore, 14 (17%) patients showed roentgenographic evidence of impending failure and an additional 12 (15%) patients showed a gradual decline in Hospital for Special Surgery knee scores. Unicondylar knee arthroplasty does not appear to provide as reliable pain relief as total knee arthroplasty. Progression to tricompartmental arthritis, polyethylene wear, and component loosening were seen to limit the usefulness of this arthroplasty. Unlike total knee arthroplasty, factors affecting the success or failure of UKA cannot be predictably controlled by the surgeon.

Aged↗
PubMed1992

Myelomeningocele: a review of the orthopaedic aspects of 206 patients treated from birth with no selection criteria.

Two hundred and six consecutive children with spina bifida who have been treated since the first day of life were analysed in terms of walking ability, motor level, orthopaedic deformities, operative procedures and balance deficit. The authors found that: (1) ambulation was quite delayed compared with the normal population; (2) sitting balance was a useful predictor of future walking; (3) almost all patients with quadriceps function were able to walk and were community ambulators; and (4) a significant number of congenital and acquired orthopaedic deformities required surgical intervention.

Adolescent↗
PubMed1990

Case report 593: Hemangioma of sternum.

A 38-year-old woman presented with an expansile lesion of the sternum. Plain film tomograms and computed tomography showed an expansile lesion of the sternum. Bone scanning revealed increased uptake in the sternum. The neoplasm was surgically excised and proved to be a hemangioma (Fig. 4a) and 4b). The rarity of this neoplasm in the sternum was stressed. An extensive search of the literature failed to reveal a single previous report of a sternal hemangioma. A differential list of other primary benign and malignant sternal tumors was presented.

Adult↗
PubMed1982

Coronary artery to left atrium fistula requiring revascularisation: case report and literature review.

Only 12 cases of coronary artery to left atrium fistula have been reported, with successful correction in at least seven. We describe a unique case of repair of a left main coronary artery to left atrium fistula using revascularisation with general discussion of the embryology, pathophysiology, complications, and diagnosis of these fistulae, indications for operation, and guidelines for surgical management.

Coronary Disease↗
PubMed1978

Effect of intra-aortic balloon pumping on nutrient coronary flow in normal and ischemic myocardium.

The effects of intra-aortic balloon pumping (IABP) on myocardial flow distribution were studied in 50 dogs. Cardiac output was controlled by right heart bypass. In each dog the following parameters were measured with and without IABP during normal coronary perfusion and after regional ischemia was induced by anterior descending coronary vein flow by timed collection, and endocardial/epicardial flow ratios by a previously reported thermal washout technique. In nonischemic myocardium, IABP significantly (p less than 0.05) increased mean coronary sinus flow 11.5 percent +/- 5.8 percent (S.D.) and the mean endocardial/epicardial ratio, 17.3 percent +/- 0.28 percent. In the regionally ischemic myocardium, IABP significantly (p less than 0.05) increased mean segmental coronary vein flow 13.9 percent +/- 1.23 percent but decreased the endocardial/epicardial ratio 29.9 percent +/- 1.1 percent. We conclude that in the dog, IABP enhances subendocardial blood flow in perfused but not in ischemic myocardium. Contrary to common suppositions, the increase in collateral blood flow with IABP preferentially supplies epicardial layers in segmental ischemic zones, but may be shunted from the subendocardium.

Animals↗
PubMedDate not supplied

Characterization of a 3H-arginine8-vasopressin binding site in the cingulate gyrus of the rat pup.

Autoradiographic analysis of 1, 8, 16 and 26-day-old rat brains showed 3H-arginine8-vasopressin (3H-AVP) binding to the cingulate gyrus-dorsal hippocampus (CG) only in the 8-day-old rat brain. Saturation analysis of CG membranes prepared from pups (7-10 days) and adults (90 days) revealed a small but significant increase in binding site concentration in adults compared to pups. However, the Kd of the 3H-AVP binding site increased significantly with age. The Kd of 3H-AVP binding to pup CG membranes was 0.9 +/- 0.1 nM, while the adult CG was 5.7 +/- 1.0 nM. The pharmacological specificity of 3H-AVP binding sites in the pup and adult CG was similar, but differed markedly from the profile observed in adult septal membranes. The primary specificity difference between the pup CG and septum was the reduced potency of certain V1 receptor antagonists. In competition experiments the CG binding site showed a reduced affinity for the V1 antagonist, [d(CH2)5, Tyr(Me)]AVP. This reduced affinity for the V1 antagonist was also documented autoradiographically using 3H-[d(CH2)5, Tyr(Me)]AVP. The data suggest that the 3H-AVP binding site expressed in the pup CG is not identical to the V1 type receptor present in the periphery and brain of the adult rat.

Aging↗
PubMedDate not supplied

Walking ability in spina bifida patients: a model for predicting future ambulatory status based on sitting balance and motor level.

Two-hundred six patients with spina bifida were followed from birth to an average age of 115 months. We characterized the population in terms of factors which we expected to affect walking ability. Two independent predictors of community ambulation were identified through regression analysis: sitting balance and motor level. We used these variables to develop a mathematical method to predict which groups were likely to be independent walkers into adolescence. When we tested this equation against our actual population, we correctly characterized walkers as such in 92% of the cases. Furthermore, when we applied this equation to another random population taken from our clinic, we successfully characterized walkers in 92% of the cases. The strength of these observations allows us to provide guidelines to parents about the likelihood of their children being able to walk independently as adolescents on the basis of motor level and sitting balance, which can be assessed at an early age.

Adolescent↗