Biomedical subjects

A Kerr

Publications and source records attributed to A Kerr.

118 records · Page 7Linked to original sources

PubMedDate not supplied

A safety net to prevent embolization during interventional procedures: work in progress.

PURPOSE: In vitro evaluation of three prototype devices designed to trap emboli that are generated by intravascular procedures. MATERIALS AND METHODS: Three prototypes of the safety net were tested in a water flow model. Angioplasty of human endarterectomy specimens was performed upstream of the device (n = 8). In other tests, polyvinyl alcohol particles were injected into the water flow model upstream of the device (n = 15). The safety nets and the effluent that passed through them were examined for embolic particles. A third prototype was tested (n = 5) to evaluate whether the device could be deployed and retrieved as designed. RESULTS: The safety net was able to trap debris released by angioplasty of endarterectomy specimens in every case. Most, but not all, polyvinyl alcohol particles were trapped by the safety net. Four of five devices tested were deployed and retrieved as designed. One became caught in the introducing valve, which prevented deployment. CONCLUSION: The vascular safety net is effective in trapping small volumes of emboli. It can be deployed and retrieved as designed.

Angioplasty↗

PubMedDate not supplied

Phenotypic characterization of immature lymphoid cells in human umbilical cord blood.

The antigenic phenotype of neonatal lymphoid cells isolated from umbilical cord blood was investigated using monoclonal antibodies and flow cytometry. Although the majority of cells expressed mature T or B cell differentiation antigens, small subpopulations of phenotypically immature lymphocytes were detected. A small proportion (mean 2.8%) of cells expressed the common acute lymphoblastic leukaemia antigen (CD-10), a significantly higher figure than that detected on adult peripheral blood lymphocytes. The cortical thymocyte antigen (CD-1) was detected on a very small subset of cord lymphoid cells, but was also present on adult lymphocytes at approximately the same frequency. The nuclear enzyme terminal deoxynucleotidyl transferase (TdT), a marker of early lymphoid differentiation, was detected by immunofluorescence on 0.031% of mononuclear cells in cytocentrifuge preparations, representing an approximate 10-fold increase in frequency over expression in childhood or adult blood. These circulating TdT+ cells were shown in double labelling experiments to predominantly express markers of B cell differentiation (CD-24, CD-10, MHC Class 2), although occasional cells co-expressing the T lineage marker CD-2 were also seen. These findings are consistent with the circulation of B cell precursors in neonatal blood. The nature of the CD-1+ cells is unclear, although the absence of CD-1+ TdT+ double labelled cells mitigates against the possible presence of immature thymus-processed lymphocytes in these samples.

Adult↗

PubMedDate not supplied

Surgical correction of hypertrophic obstructive cardiomyopathy: seventeen-year Green Lane experience.

Between 1977 and 1994, 42 patients were treated surgically for hypertrophic obstructive cardiomyopathy (HOCM). Patients have been followed up between 2 months to 17 years, mean of 107 months. There were 26 (62%) males and 16 (38%) females. There was only one pediatric case. There was no correlating factor among the ethnic groups (Maori, European, Indian, Asian, etc.). Family history was noted in 12% of the cases. Seventy-one percent of patients had aortic/left ventricular (LV) combined approach while 29% had aortic approach alone at the time of surgery. Five patients underwent other procedures, along with coronary artery bypass grafting in 3, mitral valve replacement in 1, and aortic valve replacement in 1. Persistent postoperative arrhythmias were found in 7 cases, atrial fibrillation (AF) in 3, and left bundle branch block in 4.

Adult↗

PubMedDate not supplied

Subendothelial proteoglycan synthesis and transforming growth factor beta distribution correlate with susceptibility to atherosclerosis.

Coronary bypass vessels, saphenous vein (SV) and internal thoracic artery (ITA), differ in susceptibility to atherosclerosis and medium- to long-term patency. Whereas most ITA remain patent (90% at 10 years), 20% of SV grafts fail in the first year and approximately 45% fail within 10 years. Reasons for these differences are not fully understood. Loss of SV patency may reflect early metabolic events, particularly increased proteoglycan (PG) synthesis which contributes to intimal volume and promotes atherogenesis through retention of atherogenic lipoproteins. We determined, in vitro, the PG metabolic activity of SV, ITA, and human coronary arteries through autoradiographic detection of incorporated [3H]glucosamine. SV had significantly higher levels of PG synthesis than ITA, especially in the subendothelial zone and after time (7 days) in culture. Patterns of synthesis in coronary vessels were similar to SV with high levels of incorporation in the subendothelial zone of thickened intima (> 100 microm). Increased subendothelial labelling in SV was due to increased PG synthesis, not decreased degradation. ITA showed no propensity for upregulation of subendothelial PG synthesis. Immunohistochemistry showed TGF-beta1 and TGF-beta2 localised primarily to the subendothelial zone of SV and coronary arteries. With time in culture immunostaining increased in parallel with increased PG synthesis. Subendothelial TGF-beta1 and TGF-beta2 were absent in ITA. A panspecific TGF-beta neutralising antibody reduced subendothelial PG synthesis in SV and coronary arteries by 50 and 60%, respectively. These results support the idea that vessels susceptible to atherosclerosis show increased accumulation of subendothelial PG mediated by TGF-beta.

Aged↗

PubMedDate not supplied

Diabetes initiatives: community education.

The second article in our focus on initiatives in diabetes education for nurses describes a research project which aimed to identify the training needs of district nurses working in a community trust in Belfast. The research has enabled the authors to propose a programme of education to help bridge the skills and knowledge deficits the nurses identified.

Community Health Nursing↗

PubMedDate not supplied