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Biomedical subjects

Mark Patterson

Publications and source records attributed to Mark Patterson.

9 recordsLinked to original sources
PubMed2006

Paclitaxel-eluting versus uncoated stents in primary percutaneous coronary intervention.

BACKGROUND: Drug-eluting coronary-artery stents have been shown to decrease restenosis and therefore the likelihood that additional procedures will be required after percutaneous coronary intervention (PCI). We evaluated the use of a drug-eluting stent in patients undergoing PCI for acute myocardial infarction with ST-segment elevation. METHODS: We randomly assigned 619 patients presenting with an acute myocardial infarction with ST-segment elevation to receive either a paclitaxel-eluting stent or an uncoated stent. The primary end point was a composite of death from cardiac causes, recurrent myocardial infarction, or target-lesion revascularization at 1 year. RESULTS: Baseline clinical and angiographic characteristics in both groups were well matched. There was a trend toward a lower rate of serious adverse events in the paclitaxel-stent group than in the uncoated-stent group (8.8% vs. 12.8%; adjusted relative risk, 0.63; 95% confidence interval, 0.37 to 1.07; P=0.09). A nonsignificant trend was also detected in favor of the paclitaxel-stent group, as compared with the uncoated-stent group, in the rate of death from cardiac causes or recurrent myocardial infarction (5.5% vs. 7.2%, P=0.40) and in the rate of target-lesion revascularization (5.3% vs. 7.8%, P=0.23). The incidence of stent thrombosis during 1 year of follow-up was the same in both groups (1.0%). CONCLUSIONS: Although the use of paclitaxel-eluting stents in acute myocardial infarction with ST-segment elevation reduced the incidence of serious adverse cardiac events at 1 year by 4.0 percentage points, as compared with uncoated stents, the difference was not statistically significant. (Current Controlled Trials number, ISRCTN65027270 [controlled-trials.com].).

Angioplasty, Balloon, Coronary↗
PubMed2006

Intracoronary stent dislodgment: updated strategy enabled by the new generation of materials.

Stent dislodgment remains a vexing problem in percutaneous coronary intervention. The technological improvements in machine-crimped premounted stents have led to a reduced incidence of dislodgment but may have exacerbated the problem of stent dislodgment (SD). Previous reports describing the management of SD have concentrated predominantly on manually mounted stents. We present a case where the position of a dislodged premounted stent in the distal left main stem was unfavorable for previously described solutions. The problem was elegantly resolved by taking advantage of the improved performance of the current generation of wires and balloons to achieve a rapid first-rate clinical outcome.

Aged↗
PubMed2006

Bifurcation balloon for left main shock syndrome: facilitating the simultaneous percutaneous reperfusion of the LAD and circumflex.

Acute occlusion of the left main coronary artery frequently causes cardiogenic shock and, when this occurs with an initial TIMI 0 flow, has an extremely poor prognosis. The use of a bifurcation system has not been described previously in this situation but has advantages that may result in a simpler and quicker solution then other strategies. This case describes a distal LMCA occlusion, 2 weeks post-stenting of the proximal LAD and proximal Cx, where this strategy was successfully used as a bridge to surgery. Such a strategy may be crucially beneficial in this commonly fatal condition.

Angioplasty, Balloon, Coronary↗
PubMed2005

The PLoS community journals.

2005 will see the launch of three new open access journals from the Public Library of Science - PLoS Computational Biology, PLoS Genetics, and PLoS Pathogens.

Computational Biology↗
PubMed2005

Symptoms of musculoskeletal disorders in ophthalmologists.

OBJECTIVE: To describe the presence of musculoskeletal disorders (MSDs) of the neck, low back, and upper extremity among ophthalmologists. DESIGN: Survey. METHODS: Mail survey using a pretested instrument to 2,529 ophthalmologists in the Northeastern United States; 697 ophthalmologists (28%) returned a completed survey. RESULTS: Self-reported prevalence of neck, upper body, or lower back symptoms in the prior month was 51.8%. Low back pain was present in 39% of respondents, followed by upper extremity symptoms (32.9%) and neck pain (32.6%). Approximately 15% of ophthalmologists were slightly to moderately limited in their work as a result of these symptoms. CONCLUSION: MSD symptoms appear to be common among ophthalmologists. With a relatively low response rate, however, it is plausible that asymptomatic subjects represent a large percentage of the nonrespondents. Additional investigation is warranted to evaluate ergonomic risk factor exposure and establish injury prevention guidelines.

Back Pain↗
PubMed2004

Contrasting negative-feedback control of endogenously driven and exercise-stimulated pulsatile growth hormone secretion in women and men.

GH represses its own secretion via rapid and reversible feedback exerted at key hypothalamic loci. The primary mechanisms include stimulation of somatostatin release and inhibition of GHRH outflow. Autoinhibition is prominent in the adult male rat but diminutive in the female animal. The sex contrast reflects important differences in central neuropeptide signaling in this species. No comparable insights into gender-specific control of GH autofeedback are available in the human. To examine this issue, we quantitated acute recombinant human (rh)GH-induced inhibition of baseline (resting) and aerobic exercise-stimulated GH secretion in healthy young men (n = 8) and early follicular-phase women (n = 6). Each subject underwent four fasting, morning inpatient infusion studies in a prospectively randomized, placebo-controlled, double-blind, within-subject cross-over design. The feedback paradigm comprised 6-min bolus iv infusion of saline or rhGH (10 microg/kg) followed in 120 min by rest or submaximal aerobic (individually calibrated) bicycle ergometry for 30 min. Concomitantly, blood was sampled every 10 min for 6 h, and sera were submitted to immunochemiluminometric GH assay (sensitivity 0.005 microg/liter). Biexponential deconvolution analysis was applied to estimate stimulated GH secretory-burst mass (microg/liter per 90 min after onset of exercise or rest). Women and men had statistically comparable serum estradiol but unequal testosterone concentrations. Repeated-measures ANOVA documented a significant three-way interaction among gender, stimulus type (rest or exercise), and feedback status (saline or rhGH injection) in determining GH secretory-burst mass (P = 0.008). There were prominent two-factor interactions among gender and exercise (P < 0.001); gender and rhGH-induced negative feedback (P = 0.002); and exercise and rhGH feedback (P = 0.006). Gender comparisons disclosed that women, compared with men, maintain 20-fold higher GH secretory-burst mass at rest (P < 0.001); 40-fold less stimulation of pulsatile GH release by exercise than rest (P < 0.001); and 20-fold greater inhibition of GH secretory-burst mass by rhGH than saline at rest (P < 0.05). Observed feedback contrasts by sex were specific, inasmuch as gender did not affect absolute estimates of exercise-stimulated GH secretion (microg/liter/90 min); nadir GH concentrations (microg/liter) enforced by rhGH infusion; and the time latency (min) to manifest maximal inhibition after rhGH injection. In summary, the present clinical investigation unmasks: 1) markedly greater fractional feedback inhibition of pulsatile GH secretion by rhGH in young women than men; and 2) partial resistance of the aerobic-exercise stimulus to GH autofeedback in both women and men. We postulate that sex-steroid-specific control of somatostatin and GHRH outflow may mediate the former gender contrasts, whereas unknown (gender-independent) factors may determine the capability of exercise to significantly antagonize GH autoinhibition.

Adult↗