Coronary and systemic hemodynamic effects of sildenafil citrate: from basic science to clinical studies in patients with cardiovascular disease

Sildenafil citrate is the first oral phosphodiesterase type 5 inhibitor approved for the treatment of erectile dysfunction. The wide use of sildenafil by patients with erectile dysfunction and cardiovascular disease has resulted in a considerable number of independent studies investigating the cardiovascular safety and functional role of the phosphodiesterase type 5-cyclic guanosine monophosphate-nitric oxide pathway in the cardiovascular system. Endothelial dysfunction, defined as a reduction in the bioavailability of nitric oxide, is associated with many of the common risk factors for cardiovascular disease and erectile dysfunction. Sildenafil has been demonstrated to improve the vasomotor aspect of endothelial dysfunction in patients with heart failure and diabetes. Hemodynamic studies suggest that sildenafil is a modest vasodilator with the potential to increase coronary blood flow and coronary flow reserve. In patients with ischemic heart disease, sildenafil is associated with reductions in mean arterial and pulmonary pressure with little effect on heart rate, cardiac output, and systemic or pulmonary vascular resistance. The absence of an effect on cardiac output supports the lack of an inotropic effect of sildenafil. This is consistent with the finding that sildenafil has no effect on cyclic adenosine monophosphate levels in the vasculature. Finally, exciting reports have emerged from clinical experience with the use of phosphodiesterase type 5 inhibitors in patients with pulmonary hypertension.     

Mapping T2 relaxation time in the pediatric knee: feasibility with a clinical 1.5-T MR imaging system

PURPOSE: To determine the feasibility of mapping the spatial variation of cartilage T2 relaxation time in vivo in the pediatric knee with a 1.5-T clinical magnetic resonance (MR) imaging system and the manufacturer's body gradient coil. MATERIALS AND METHODS: Twenty-five children and adolescents (age range, 5-17 years; mean age, 11.8 years) underwent a multisection-multiecho MR sequence for T2 relaxation time mapping. Quantitative transverse T2 maps of the patellar cartilage were calculated for 15 of the subjects. Sagittal T2 maps were calculated for the remaining 10 subjects. T2 profiles were generated for the patellar and distal femoral weight- and non-weight-bearing unossified epiphyseal and articular hyaline cartilage and for the distal femoral and proximal tibial physes. The Mann-Whitney U test was used to test for differences between paired profiles. RESULTS: Femoral non-weight-bearing unossified epiphyseal and articular cartilage showed spatial variation similar to that of weight-bearing unossified epiphyseal and articular cartilage, but with increased T2 values (P <.001). T2 spatial variations of the distal femoral and proximal tibial physes were similar to those of epiphyseal and articular cartilage but had a different pattern and increased magnitude (P <.001). The highest T2 values were measured in the distal femoral physis. CONCLUSION: T2 spatial variation of patellar hyaline cartilage in children is similar to that of patellar articular cartilage in adults. Mapping of spatial variation of T2 relaxation time of cartilage in the pediatric knee in vivo is feasible with a clinical 1.5-T MR imaging system and a body gradient coil.     

Analysis of subtraction methods in three-dimensional contrast-enhanced peripheral MR angiography

PURPOSE: To compare the effectiveness of three image subtraction algorithms designed to improve arterial conspicuity in first-pass contrast-enhanced magnetic resonance (MR) angiography. MATERIALS AND METHODS: Three subtraction methods were analyzed through computer simulations, phantom studies, and clinical studies. These algorithms were: complex subtraction, magnitude subtraction, and maximum intensity projection subtraction. RESULTS: In high resolution three-dimensional imaging, maximum intensity projection subtraction generally yields the best background suppression. Complex subtraction is effective in reducing partial volume effects in low resolution imaging. Magnitude subtraction works better in high resolution, low contrast concentration protocols. CONCLUSION: Choosing the appropriate subtraction method according to the protocol is helpful in optimizing image quality.     

The pancake phenomenon contributes to the inaccuracy of margin assessment in patients with breast cancer

BACKGROUND: To determine the effect on margin evaluation for patients with breast cancer, we prospectively quantified the "flattening" of the breast specimen after surgical removal. METHODS: The volume and height of 100 consecutive breast biopsy specimens were recorded independently by the operating surgeon and the pathologist. Five factors were analyzed that were thought to contribute to changes in specimen dimensions: patient age, breast tissue density, mammographic lesion type, specimen size, and the use of compression during specimen radiography. RESULTS: After surgical removal, mean volume and height of the breast specimens decreased from 46 cm(3) to 29 cm(3) (30%) and from 2.6 cm to 1.4 cm (46%), respectively. Flattening of the breast specimens occurred in all subgroups studied. CONCLUSIONS: Breast specimens are flattened after surgical removal, losing almost 50% of their original height. This "pancake" phenomenon has important implications for the accuracy of margin analysis.     

Adductor myositis as a cause of childhood hip pain

Two cases of bacterial adductor myositis that presented as painful hips in boys aged 4 and 9 years are reported. Clinically, there was severe pain and a high pyrexia, a raised C-reactive protein and positive blood cultures but a negative hip ultrasound. Urgent magnetic resonance imaging demonstrated changes throughout the adductor muscles in keeping with bacterial myositis. Both boys settled with intravenous antibiotic therapy. We propose that magnetic resonance imaging is a valuable tool in the assessment of infection around the hip and should be indicated when other investigations have excluded a septic arthritis but the child remains unwell.     

Ovarian cancer: patterns of care in Victoria during 1993-1995

OBJECTIVE: To describe the management of and outcomes in patients with newly diagnosed ovarian cancer during 1993, 1994 and 1995 in Victoria. DESIGN AND SETTING: Retrospective cohort study conducted by surveying doctors involved in managing incident ovarian cancer cases identified from the population-based Victorian Cancer Registry. The survey was conducted in 1997 and the cohort was followed up until the end of 1999 to obtain at least four years of follow-up data on all patients. PATIENTS: All women with invasive epithelial ovarian cancer diagnosed during 1993, 1994 and 1995. MAIN OUTCOME MEASURES: Reported management in terms of staging, treatment and survival. RESULTS: Management details were obtained for 84.5% (562/665) of eligible patients. Median age at diagnosis was 66 years (range, 22-98 years). Surgery was the primary therapy in 77.2% of women (434/562). Only one in three women had adequate surgery, which was less likely to be performed by general gynaecologists and general surgeons than gynaecological oncologists (21.3% [35/164] v 13.3% [8/60] v 52% [105/202]). After surgery 78.6% of women (341/434) received chemotherapy, usually with platinum-based regimens. The overall five-year relative survival was 46% for women treated surgically; poor survival was related to increasing age, later tumour stage, presence of ascites, residual disease > 2 cm and poorer histological differentiation of the tumour. CONCLUSIONS: For optimal care a preoperative carcinoma antigen (CA)-125 assay, chest x-ray and pelvic ultrasound should be performed, and early referral to a multi-disciplinary unit for definitive surgery is advised. Every effort should be made to adequately stage or debulk the tumour. Women with high-risk early-stage and advanced disease should be considered for platinum-based chemotherapy.