Multimethod imaging, staging, and spectrum of manifestations of metastatic melanoma.

The incidence of melanoma has been steadily increasing. Imaging plays an important role in tumour assessment as metastatic melanoma can involve multiple organs. Computed tomography (CT) is currently the most widely used technique for tumour staging, surveillance and assessment of therapeutic response, but ultrasound, magnetic resonance imaging (MRI) and positron-emission tomography (PET)-CT also play important roles in the imaging of this tumour. In this article, we review the pathways of spread, staging according to the recently updated TNM classification, pathology, typical and atypical imaging features at common and uncommon sites, and treatment of metastatic melanoma.

Uterine Carcinosarcomas.

Uterine carcinosarcoma (UCS) is a rare and aggressive variant of endometrial cancer, distinguished by its containment of both epithelial and sarcomatous elements. This article reviews the epidemiology, pathologic classification and staging of UCS, along with the typical findings seen on different imaging modalities. Prognosis and therapies will also be discussed.

Tumor markers: myths and facts unfolded.

OBJECTIVE: The purpose of this article is to review the most commonly used tumor markers in abdominal and pelvic tumors, describe their limitations and explain how to use them in the context of known cancer in order to optimize multidisciplinary care of oncologic patients. CONCLUSION: Tumor markers are important for the diagnosis, staging, monitoring of treatment and detection of recurrence in many cancers. This knowledge is crucial in the daily interpretation of images of oncologic and non-oncologic patients. However, radiologists should also be aware of the limitations of the most commonly used tumor markers and they should not be used solely, but interpreted in conjunction with diagnostic imaging, clinical history and physical examination that will help optimize the multidisciplinary care and management of oncologic patients.

Dual lipid modification motifs in G(alpha) and G(gamma) subunits are required for full activity of the pheromone response pathway in Saccharomyces cerevisiae.

To establish the biological function of thioacylation (palmitoylation), we have studied the heterotrimeric guanine nucleotide-binding protein (G protein) subunits of the pheromone response pathway of Saccharomyces cerevisiae. The yeast G protein gamma subunit (Ste18p) is unusual among G(gamma) subunits because it is farnesylated at cysteine 107 and has the potential to be thioacylated at cysteine 106. Substitution of either cysteine results in a strong signaling defect. In this study, we found that Ste18p is thioacylated at cysteine 106, which depended on prenylation of cysteine 107. Ste18p was targeted to the plasma membrane even in the absence of prenylation or thioacylation. However, G protein activation released prenylation- or thioacylation-defective Ste18p into the cytoplasm. Hence, lipid modifications of the G(gamma) subunit are dispensable for G protein activation by receptor, but they are required to maintain the plasma membrane association of G(betagamma) after receptor-stimulated release from G(alpha). The G protein alpha subunit (Gpa1p) is tandemly modified at its N terminus with amide- and thioester-linked fatty acids. Here we show that Gpa1p was thioacylated in vivo with a mixture of radioactive myristate and palmitate. Mutation of the thioacylation site in Gpa1p resulted in yeast cells that displayed partial activation of the pathway in the absence of pheromone. Thus, dual lipidation motifs on Gpa1p and Ste18p are required for a fully functional pheromone response pathway.

Results of three to 10 year follow up of balloon dilatation of the pulmonary valve.

BACKGROUND: The results of immediate and short term follow up of balloon dilatation of the pulmonary valve have been well documented, but there is limited information on long term follow up. OBJECTIVE: To evaluate the results of three to 10 year follow up of balloon dilatation of the pulmonary valve in children and adolescents. SETTING: Tertiary care centre/university hospital. DESIGN: Retrospective study. METHODS AND RESULTS: 85 patients (aged between 1 day and 20 years, mean (SD) 7.0 (6.4) years) underwent balloon dilatation of the pulmonary valve during an 11 year period ending August 1994. There was a resultant reduction in the peak to peak gradient from 87 (38) to 26 (22) mm Hg. Immediate surgical intervention was not required. Residual gradients of 29 (17) mm Hg were measured by catheterisation (n = 47) and echo Doppler (n = 82) at intermediate term follow up (two years). When individual results were scrutinised, nine of 82 patients had restenosis, defined as a peak gradient of 50 mm Hg or more. Seven of these patients underwent repeat balloon dilatation of the pulmonary valve: peak gradients were reduced from 89 (40) to 38 (20) mm Hg. Clinical evaluation and echo Doppler data of 80 patients showed that residual peak instantaneous Doppler gradients were 17 (15) mm Hg at long term follow up (three to 10 years, median seven), with evidence for late restenosis in one patient (1.3%). Surgical intervention was necessary to relieve fixed infundibular stenosis in three patients and supravalvar pulmonary stenosis in one. Repeat balloon dilatation was performed to relieve restenosis in two patients. Actuarial reintervention free rates at one, two, five, and 10 years were 94%, 89%, 88%, and 84%, respectively. Pulmonary valve regurgitation was noted in 70 of 80 patients at late follow up, but neither right ventricular dilatation nor paradoxical interventricular septal motion developed. CONCLUSIONS: The results of late follow up of balloon dilatation of the pulmonary valve are excellent. Repeat balloon dilatation was performed in 11% of patients and surgical intervention for subvalvlar or supravalvar stenosis in 5%. Most patients had mild residual pulmonary regurgitation but right ventricular volume overload was not required. Balloon dilatation is the treatment of choice in the management of moderate to severe stenosis of the pulmonary valve. Further follow up studies should be undertaken to evaluate the significance of residual pulmonary regurgitation.