Biomedical subjects
Publications and source records attributed to Mitchell Smith.
Explore the source record for details and available documents.
BACKGROUND: This study was conducted to evaluate the clinical performance of the ventricular automatic capture feature as implemented in the Insignia I Ultra pacemaker system (Guidant) utilizing a variety of ventricular leads. Currently, the optimal programming of the pacemaker output considers both pacemaker efficiency (prolonging battery longevity) and patient safety (adequate safety margin). The ability of a pacemaker to automatically adjust the ventricular output above the pacing threshold while maintaining the appropriate safety margin has been explored since the early 1970s and is only available today in conjunction with a specific low polarization lead system. METHODS: One hundred and five patients were enrolled from 17 European centers utilizing 31 different types of ventricular leads were followed through their 3-month follow-up visit. There were no restrictions on the type of ventricular leads used. RESULTS: The average mean difference between the commanded autothreshold test (0.652 + 0.335 V) and the manual threshold test (0.651 + 0.335 V) was 0.001 + 0.49 (P < 0.0001). The average mean difference between the ambulatory autothreshold test (0.696 + 0.322 V) and the commanded autothreshold test (0.682 + 0.315 V) was 0.002 + 0.74 (P < 0.0001). Holter recordings confirmed that there were no loss of capture incidences without a backup pulse being delivered. In addition, the mean number of backup pulses delivered in a 24-hour period was less than 0.1% of the total number of paced beats. CONCLUSIONS: This study provided that the automatic capture feature while using a variety of leads accurately determines the ventricular stimulation threshold and safely delivers a backup pulse when required.
Nurses played a significant role in providing care to Kosovar and East Timorese refugees at the East Hills Reception Centre in Sydney, Australia, during Operation Safe Haven in 1999-2000. To ascertain the needs of nurses in this setting, 13 nurses participated in two focus group interviews, and two in-depth interviews were conducted with nursing managers. Qualitative thematic analysis was conducted on the resulting transcripts. Nurses reported that, overall, they had the necessary clinical skills but needed specific refugee health profiles and training in culturally competent and trauma-sensitive care. The nurses experienced trauma-related, cultural, environmental and role-related stressors. They used a variety of informal psychosocial supports but reported the need for ongoing counselling and debriefing. While clinical skills were considered important, nurses identified other factors as having more impact on their ability to provide comprehensive care for traumatized refugees, particularly their role as client advocates.
The histologic diagnosis of cutaneous lymphoid lesions remains one of the most challenging areas of dermatopathology and is augmented by incorporation of immunophenotypic and genotypic data. To improve the analysis of surface Ig light chain expression and to increase the yield of immunophenotypic data obtained from skin biopsies, we evaluated the utility of flow cytometry in cutaneous lymphoid infiltrates. Flow cytometric immunophenotypic analyses were performed on skin specimens of 19 patients as a part of diagnostic procedures. We found that skin biopsy specimens, including a routine punch biopsy, yield sufficient material for diagnostic flow cytometry. One reactive lymphoid hyperplasia showed polyclonal B cells and no aberrant T cell populations. Ig light chain restriction was detected by flow cytometry and contributed to the diagnosis in 88% (15 of 17) of cutaneous primary or secondary B cell lymphomas, compared to 37% (three of eight) by immunohistochemistry. Nearly one-third of these cases were histologically suspicious but difficult lesions due to processing artifact, mixed cellular infiltrate, or paucity of abnormal cells. Additional markers (3-23) were analyzed by flow cytometry on 15 specimens, and contributed to subclassification of the lymphomas. Our experience demonstrates that flow cytometry can be successfully applied to routine skin biopsies and contributes to the diagnosis and subclassification of cutaneous lymphoid lesions.
PURPOSE: We conducted a Phase II trial of bryostatin-1, an inhibitor of protein kinase C, in advanced renal cell carcinoma to measure toxicity, response rate, time to progression, and induction of cytokines. EXPERIMENTAL DESIGN: A total of 32 patients (26 male and 6 female) received bryostatin-1 at 35-40 microg/m(2) i.v. over 1 h on days 1, 8, and 15 of each 4-week cycle. Plasma interleukin-6, tumor necrosis factor-alpha, and C-reactive protein levels were assayed pretreatment, 1 and 23 h after completion of bryostatin-1 infusion at weeks 1 and 5. RESULTS: Cycles (102) of bryostatin-1 were given (median 2, range 1-8). The most common grade 1 or 2 toxicities were myalgias (46.8%), fatigue (59.3%), and dyspnea (18.8%). Grade 3-4 toxicity included myalgias (40.6%), ataxia (9.3%), and dyspnea (15.6%). Four (12%) patients experienced cardiac events while on study (cardiac arrhythmias and congestive heart failure occurred in 2 patients, and 2 patients had fatal cardiac arrests). Of 32 patients evaluable for response, 2 (6.3%) had partial responses lasting 9 with 6 months. A total of 15 patients (46.8%) had stable disease, and 6 (18.8%) patients had stable disease for >or=6 months. Plasma interleukin-6 increased >or=2-fold over baseline measurements in 5 of 17 patients (29.4%) but did not correlate with response or toxicity. CONCLUSIONS: Although weekly bryostatin-1 at 35-40 microg/m(2) produced a low proportion of objective responses, prolonged (>6 months) stable disease or partial remission in 25% of patients suggests that this agent, or other inhibitors of protein kinase C, may have a role in the treatment of renal cell carcinoma, perhaps in combination with other agents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.