Search PubMed⌕ Search

Biomedical subjects

Michael Gross

Publications and source records attributed to Michael Gross.

89 records · Page 5Linked to original sources
PubMed2002

UK report calls for protection of genetic privacy.

DNA gathered from a used coffee mug could lead to serious breaches of a person's genetic privacy. The UK government's Human Genetics Commission now recommends making theft of genetic information a criminal offence, writes Michael Gross.

Advisory Committees↗
PubMed2002

Relation of stent design and stent surface material to subsequent in-stent intimal hyperplasia in coronary arteries determined by intravascular ultrasound.

A variety of different stent designs and coatings have become available. This study sought to determine the impact of stent design and gold-coating of stents on intimal hyperplasia (IH) in human atherosclerotic coronary arteries in relation to known predictors of restenosis. Angiographic and intravascular ultrasound (IVUS) studies were performed at 6-month follow-up on 311 native coronary lesions of 311 patients treated with 99 Multi-Link stents, 74 InFlow steel stents, 73 InFlow gold-coated stents, 41 Palmaz-Schatz stents, 12 NIR steel stents, and 12 gold-coated NIR Royal stents. Lumen and stent cross-sectional area (CSA) were measured at 1-mm axial increments. Mean IH CSA (stent CSA - lumen CSA) and mean IH thickness were calculated and averaged over the total stent length. IVUS demonstrated different levels of IH for the 6 stents. Mean IH thickness ranged from 0.20 +/- 0.13 mm for Multi-Link stents to 0.43 +/- 0.14 mm for InFlow goal-coated stents (p <0.001). Multivariate analysis proved non-Multi-Link stent design (odds ratio 3.45, 95% confidence intervals 1.13 to 11.11, p <0.034) and gold coating (odds ratio 3.78, 95% confidence intervals 1.88 to 7.54, p <0.001) to be the only independent predictors of IH thickness >0.3 mm. In conclusion, stent design and surface material have an important impact on the IH response to stents implanted in human coronary arteries. However, the differences in IH thickness between the analyzed stents were relatively small compared with the absolute lumen dimensions.

Analysis of Variance↗
PubMed2002

Effects of gold coating of coronary stents on neointimal proliferation following stent implantation.

Experimental studies suggest a reduced neointimal tissue proliferation in vascular stainless steel stents coated with gold. This prospective multicenter trial evaluated the impact of gold coating on neointimal tissue proliferation in patients undergoing elective stent implantation. The primary end point was the in-stent tissue proliferation measured by intravascular ultrasound at 6 months comparing stents of identical design with or without gold coating (Inflow). Two hundred four patients were randomized to receive uncoated (group A, n = 101) or coated (group B, n = 103) stents. Baseline parameters did not differ between the groups. Stent length and balloon size were comparable, whereas inflation pressure was slightly higher in group A (14 +/- 3 vs 13 +/- 3 atm, p = 0.013). Procedural success was similar (A, 97%; B, 96%). The acute angiographic result was better for group B (remaining stenosis 4 +/- 12% vs 10 +/- 11%, p = 0.002). Six-month examinations revealed more neointimal proliferation in group B. By ultrasound, the neointimal volume within the stent was 47 +/- 25 versus 41 +/- 23 mm(3) (p = 0.04), with a ratio of neointimal volume-to-stent volume of 0.45 +/- 0.12 versus 0.40 +/- 0.12 (p = 0.003). The angiographic minimal luminal diameter was smaller in group B (1.47 +/- 0.57 vs 1.69 +/- 0.70 mm, p = 0.04), with a higher late luminal loss of 1.17 +/- 0.51 versus 0.82 +/- 0.56 mm (p = 0.001). Thus, gold coating of the tested stent type resulted in more neointimal tissue proliferation.

Aged↗
PubMed2002

Surgical management of overactive bladder.

The majority of patients with overactive bladder (OAB) can be managed with office-based techniques. When medical therapy fails as treatment for OAB, surgical intervention ranging from electric stimulation administered in the office to extensive procedures, such as augmentation or urinary diversion, may be needed. Any surgical intervention should be tailored to the patient with consideration of the degree of his or her discomfort, underlying pathology, general health, and obviously, the patient's own motivation.

Electric Stimulation Therapy↗
PubMed2002

Revascularization during acute myocardial infarction: risks and benefits revisited.

BACKGROUND: Indication for immediate revascularization during acute myocardial infarction (MI) is debated. Drug-resistant crescendo angina, as well as hemodynamic compromise, however, often requires acute operation. In this study the differential risks of acute coronary artery bypass grafting with and without MI were stratified. METHODS: Five hundred eighteen patients undergoing isolated coronary artery bypass grafting were investigated. Thirty-nine patients underwent acute revascularization because of enzyme-proven or electrocardiogram-proven MI accompanied by crescendo angina, hemodynamic compromise, or both. They were compared with 33 emergent, 63 urgent, and 383 elective patients without MI. Preoperative risk factors for early mortality and necessity of continuous venovenous hemofiltration were analyzed by means of logistical regression analysis. Perioperative data were compared. RESULTS: Early mortality of the MI cohort was 15.4%, in contrast to 15.2% in emergent, none in urgent, and 2.1% in elective patients. Left internal thoracic artery was used in 87% of MI, 97% of emergent, 94% of urgent, and 97% of elective patients. Intraaortic balloon pump was necessary in 50% of MI patients, 27% of emergent, 6.3% of urgent, and 3.1% of elective cases. Continuous venovenous hemofiltration was performed in 29% of MI patients, 15% of emergent, 4.9% of urgent, and 3.4% of elective patients. Hemodynamic instability significantly increased the odds ratio for early mortality and continuous venovenous hemofiltration. CONCLUSIONS: Patients undergoing acute revascularization carried an elevated risk to die early notwithstanding the presence or absence of acute MI. Liberal use of left internal thoracic artery grafts was not detrimental in acute patients whereas liberal use of intraaortic balloon pump was beneficial. In almost 30% of MI patients, continuous venovenous hemofiltration was not necessary, implying a severely impaired perioperative hemodynamic condition. Immediate revascularization in the presence of acute MI is therefore indicated although it may be addressed as a separate high-risk group.

Aged↗
PubMed2002

The E-selectin SER128ARG gene polymorphism and restenosis after successful coronary angioplasty.

OBJECTIVES: Coronary angioplasty remains plagued by the problem of restenosis. Genetic polymorphisms may contribute to the development of restenosis by mediating exaggerated inflammatory responses of the endothelium to angioplasty-induced injury. BACKGROUND: The serine (Ser)-128-arginine (Arg) gene polymorphism of E-selectin has been implicated in the pathogenesis of coronary artery disease (CAD). We sought to explore whether allelic variants relate to post-angioplasty restenosis. METHODS: The 128Arg allele was analyzed by PCR in 101 (derivation study, age 54+/-1 years, all mean+/-S.E.M.) and 92 (validation study, age 62+/-1 years) patients with CAD who underwent successful angioplasty. RESULTS: Restenosis, defined as >50% luminal diameter reduction at the target lesion at follow-up angiography, was found in 54/101 (53%) and 43/92 (47%) patients during follow-up. The 128Arg allele frequency in the derivation study was 10.39% and was 11.96% in the validation study. The 128Arg allele was more prevalent in the restenosis groups (14.81% and 17.44%, respectively) than in the restenosis-free groups (5.32% and 7.14%, respectively, p=0.027 and p=0.031). In multivariate logistic regression, the 128Arg allele emerged as a predictor of restenosis in both studies (p<0.05). There were no differences in the level of soluble E-selectin according to genotype, gender, age (p>0.20), and between patients with restenosis and those without (43.8+/-3.2 vs. 47.4+/-3.1 ng/ml, p>0.20). CONCLUSIONS: The 128Arg allele of E-selectin may be related to increased endothelial responses to injury, thereby potentially serving as a risk factor for post-angioplasty restenosis in patients with CAD.The development of restenosis remains a problem in patients with CAD. The Ser128Arg polymorphism of E-selectin was analyzed in 101 (derivation) and 92 (validation) CAD patients. Patients with restenosis (54/101 and 43/92) had a higher frequency of the 128Arg allele (14.81 and 17.44%) than those without (5.32%, p=0.027 and 7.14%, p=0.031). In logistic regression, the 128Arg allele emerged as a predictor of restenosis in both studies (p<0.05). The E-selectin 128Arg allele may serve as a risk factor for the development of restenosis.

Angioplasty, Balloon, Coronary↗
PubMed2002

Dobutamine induced myocardial perfusion reserve index with cardiovascular MR in patients with coronary artery disease.

Currently, adenosine or dipyridamole is commonly used for the assessment of perfusion reserve. With intolerance to these agents, dobutamine can be used alternatively or it can be used for a combined examination of wall motion and perfusion. The aim of the study was to analyze the feasibility of cardiovascular magnetic resonance (CMR) to assess perfusion reserve with dobutamine. Alterations of myocardial perfusion were noninvasively assessed in 23 patients with and 4 without significant coronary artery disease by calculation of a myocardial perfusion reserve index from the upslope of the signal intensity curves of a first pass gadolinium bolus before and during dobutamine infusion (20 micrograms/min/kg). An ischemic threshold value of perfusion reserve index was determined from patients without significant coronary artery disease. Significant differences were found between ischemic and remote to ischemic segments in patients with single vessel disease (0.90 +/- 0.18 vs. 1.73 +/- 0.32, p < 0.0001). Differences between nonischemic segments in patients without and ischemic segments in patients with coronary artery disease were significant (2.0 +/- 0.39 vs. 0.97 +/- 0.20, p < 0.001). A cut-off value for myocardial perfusion reserve index of 1.22 for the detection of significant coronary artery stenosis yielded a sensitivity, specificity, and diagnostic accuracy of 81, 73, and 77%, respectively. Dobutamine MR is feasible in the evaluation of myocardial perfusion and can be used for the detection of myocardial ischemia alternatively to adenosine or dipyridamole in patients with coronary artery disease.

Cardiotonic Agents↗
PubMed2002

Comparison of a nomogram and physician-adjusted dosage of warfarin for prophylaxis against deep-vein thrombosis after arthroplasty.

BACKGROUND: Warfarin is an effective agent for prophylaxis against deep-vein thrombosis following total hip or knee arthroplasty. However, management with warfarin in the postoperative setting is problematic because of the need for anticoagulant monitoring. We developed a nomogram for the dosing of warfarin that was specific for joint arthroplasty. The objective of this study was to compare the performance of this nomogram with that of physician-adjusted dosing of warfarin for patients undergoing total hip or knee arthroplasty. METHODS: The study involved two cohort trials. The historical control group consisted of 1024 patients who underwent total hip or knee arthroplasty during the course of a clinical trial (the Post-Arthroplasty Screening Study [PASS]) in which all warfarin dose adjustments were made by two hematologists. The first dose of warfarin was given on the evening of the surgery, and the warfarin dose was adjusted daily on the basis of the international normalized ratio and was discontinued at the time of discharge from the hospital. In the PASS study, the dosage of warfarin was designed to prolong the international normalized ratio to 1.7 by postoperative day 4 and to maintain it between 1.8 and 2.5 until discharge from the hospital. Subsequently, a warfarin nomogram was developed on the basis of the dose adjustments used in the PASS study, and it was used prospectively to manage a cohort of 729 patients undergoing total hip or knee arthroplasty. In the nomogram cohort, the initial dose of warfarin was given on the evening of the surgery. Both cohorts were followed for twelve weeks after the surgery to determine if any venous thromboembolic complications had developed. RESULTS: The nomogram cohort and the control cohort had similar daily doses of warfarin (mean, 3.2 versus 3.3 mg) and levels of international normalized ratio on postoperative day 4 (mean, 1.9 versus 1.9) (p > 0.2). The average number of days to achieve an international normalized ratio of >1.7 was 4.0 for the nomogram cohort compared with 4.3 for the control cohort (p = 0.01). The percentage of days that the international normalized ratio was between 1.8 and 2.5 was 61% for the nomogram cohort and 58% for the control cohort (p < 0.01), and the percentage of days that the international normalized ratio was >3.0 was only 6.5% for the nomogram cohort and 6.0% for the control cohort (p > 0.2). Eighty-two percent of the patients managed with the nomogram achieved an international normalized ratio of >1.7 by the time of discharge from the hospital compared with 92% in the control cohort (p = 0.01). In the three-month follow-up period, a deep-vein thrombosis or a nonfatal pulmonary embolism developed in nineteen patients (2.6%; 95% confidence interval, 1.6% to 4.0%) in the nomogram cohort compared with fourteen patients (1.4%; 95% confidence interval, 0.7% to 2.3%) in the control cohort. No major bleeding event or fatal pulmonary embolism was observed in the patients managed with use of the nomogram. CONCLUSION: This study demonstrated that the administration of warfarin during hospitalization with use of a nomogram designed for the prevention of deep-vein thrombosis following total hip or knee arthroplasty provided effective and safe prophylaxis that was comparable with that provided by physician-adjusted dosing of warfarin.

Anticoagulants↗
PubMedDate not supplied

The Internet as a research tool in complementary and alternative medicine: a pilot study.

Information on the use of complementary and alternative medical (CAM) therapies is sometimes difficult to obtain from consumers. The purpose of this study was to evaluate the Internet as a research tool in CAM to obtain information from these consumers about the use of psychotropic herbs and drugs. A survey on psychotropic herb and drug usage was posted on 138 mental-health newsgroups on the Internet. After 38 days, 72 (71%) of the 102 respondents reported usage of psychotropic medication and 68 (67%) reported usage of psychotropic herbs during the preceding 12 months. The Internet is a potential tool to reach consumers of CAM for research purposes. The study design requires modification, and the findings need cautious interpretation for further research using the Internet as a venue.

Attitude to Health↗