Giant sacral chondrosarcoma in an elderly male : a case report.

UNLABELLED: Primary sacral tumours are rare, therefore experience of managing their associated complications are very limited. Effective surgical treatment of pelvic chondrosarcoma remains a major challenge for orthopaedic surgeons, due to the complex anatomic structure of the pelvis, the lack of defined compartment borders, the close vicinity to vital structures, and the risk of jeopardizing pelvic structural stability. We report a rare case of a giant sacral chondrosarcoma (100cm x 80cm) in an elderly male who successfully underwent tumour resection with good functional outcome and recovery. Long term follow up is essential in view of the possibility of local tumour recurrence. KEY WORDS: Giant Chondrosarcoma, Sacrum, Surgery, Elderly Male.

The role of reactive oxygen species in arsenite and monomethylarsonous acid-induced signal transduction in human bladder cells: acute studies.

Arsenicals are known to induce ROS, which can lead to DNA damage, oxidative stress, and carcinogenesis. A human urothelial cell line, UROtsa, was used to study the effects of arsenicals on the human bladder. Arsenite [As(III)] and monomethylarsonous acid [MMA(III)] induce oxidative stress in UROtsa cells after exposure to concentrations as low as 1 microM and 50 nM, respectively. Previous research has implicated ROS as signaling molecules in the MAPK signaling pathway. As(III) and MMA(III) have been shown to increase phosphorylation of key proteins in the MAPK signaling cascade downstream of ErbB2. Both Src phosphorylation (p-Src) and cyclooxygenase-2 (COX-2) are induced after exposure to 50 nM MMA(III) and 1 microM As(III). These data suggest that ROS production is a plausible mechanism for the signaling alterations seen in UROtsa cells after acute arsenical exposure. To determine importance of ROS in the MAPK cascade and its downstream induction of p-Src and COX-2, specific ROS antioxidants (both enzymatic and non-enzymatic) were used concomitantly with arsenicals. COX-2 protein and mRNA was shown to be much more influenced by altering the levels of ROS in cells, particularly after MMA(III) treatment. The antioxidant enzyme superoxide dismutase (SOD) effectively blocked both As(III)-and MMA(III)- associated COX-2 induction. The generation of ROS and subsequent altered signaling did lead to changes in protein levels of SOD, which were detected after treatment with either 1 microM As(III) or 50 nM MMA(III). These data suggest that the generation of ROS by arsenicals may be a mechanism leading to the altered cellular signaling seen after low-level arsenical exposure.

BK-viruria and haemorrhagic cystitis are more frequent in allogeneic haematopoietic stem cell transplant patients receiving full conditioning and unrelated-HLA-mismatched grafts.

The influence of conditioning regimen, donor background and HLA matching on development of BK virus (BKV)-associated haemorrhagic cystitis (HC) was examined in 175 allogeneic haematopoietic stem cell transplant (HSCT) patients, undergoing 179 HSCT events. Twenty-seven patients presented late-onset HC, and BK viruria was verified in 23/27 HC events. Seventy-one (40%) HSCTs were performed with myeloablative conditioning (MC), 108 (60%) were performed with reduced intensity conditioning (RIC), 66 (37%) were performed with a related donor (RD) grafts and 113 (63%) with an unrelated donor (URD) graft. BK viruria was more common during HC, than non-HC events, after MC as compared to RIC (both P<0.001), and with an HLA-mismatched donor (P<0.01). By multivariate logistical regression analysis, independent risk factors for HC were BKV (OR 6.7; 95% CI 2.0-21.7; P=0.001), MC (OR 6.0; 95% CI 2.1-17.3; P<0.001) and URD (OR 3.4; 95% CI 1.1-10.6; P=0.03). However, when analysing HSCT performed with URD or RD grafts separately, BKV (OR 8.5; 95% CI 1.8-19.3; P=0.004) and MC (OR 5.9; 95% CI 1.3-11.3; P=0.009) increased the risk for HC only with a URD, but not with an RD graft.

The effect of geometric and recording system unsharpness in mammography.

Modulation transfer functions (MTFs) and test object radiographs were used to study the effect of geometric and recording system unsharpness in mammography with the CGR Senographe x-ray unit. Results show that geometric unsharpness can be a significant factor in the detection of microcalcifications within the breast, depending on the size and shape of the focal spot, the focal spot-to-recording system distance, and the object-to-recording system distance (o.r.d.). A new recording system for mammography, the DuPont Lo-dose system, requires approximately 1/15th the exposure of a direct x-ray film, such as Kodak RP/M, to provide mammograms with comparable photographic density. With the Lo-dose system, geometric unsharpness can be reduced by use of a specially designed long cone with an increased focal spot-to-recording system distance. This cannot be accomplished with direct x-ray films because the x-ray unit is operating at near-maximum output conditions even when short cones are used. Although direct x-ray films have a higher resolution than the Lo-dose system, at certain o.r.d.s total resolution is found to be affected more significantly by geometric unsharpness than by the Lo-dose recording system. In several cases, clinical results show improved detection of microcalcifications at larger o.r.d.s by the Lo-dose system with a long one, combined with a reduction by a factor of 15 in patient exposure.