Detection of TMPRSS2-ERG fusion gene in benign prostatic hyperplasia.

The Ets-related gene fusions are among the most common molecular alterations in prostate cancer (PCa) and are detected in more than 50 % of PCas. Transmembrane protease serine 2 and Ets-related gene fusion (TMPRSS2-ERG) is the most frequently identified chimeric gene and has been associated with undifferentiated and invasive phenotypes. TMPRSS2-ERG has also been detected in prostate intraepithelial neoplasia (PIN) lesions and more rarely in benign prostatic hyperplasia (BPH) regions mainly in PCa-bearing glands. The possibility that the fusion TMPRSS2-ERG may be present in BPH samples in the absence of apparent PCa was addressed. Out of 115 BPH samples, three were found positive employing RT-PCR. The presence of the fusion gene was confirmed by FISH for these samples, and an additional four samples were found to carry the TMPRSS2-ERG fusion out of 43 tested by the later approach. The presence of the TMPRSS2-ERG fusion did not result in altered expression of 12 putative downstream targets. These findings indicate that TMPRSS2-ERG may or may not lead to PCa development.

Cold storage of rat skeletal muscle free flaps and pre-ischemic perfusion with modified UW solution.

We used the rat medial gastrocnemius free flap, based on a pedicle of the femoral artery and vein, in order to test the tolerance of skeletal muscle to cold ischemia-reperfusion (IR) injury, and to determine whether tolerance can be enhanced by pre-ischemic perfusion with tissue/organ preservation solutions. Muscle flaps (n = 6 per group) were subjected to variable periods of cold storage (0, 1, 2, 3, or 4 days) and 24-h normothermic reperfusion. Muscle viability, as determined by nitroblue tetrazolium (NBT) histochemical staining of viable mitochondria and supported by histological examination, was 100%, 26%, 11%, 4%, and 1%, respectively. Using 24-h cold storage/24-h reperfusion as the experimental conditions, groups of muscle flaps (n = 5 per group) were perfused immediately before cold storage with either modified, colloid-free University of Wisconsin (UW) solution, a solution described by Kohout et al. (Br J Plast Surg 1995;48:132-144) or normal saline. Perfusion with modified UW solution or Kohout's solution increased survival to 33% (P < 0.05) and 28% (not statistically significant), respectively, compared with the 19% viability of separate groups of nonperfused or saline-perfused controls. These findings indicate that cold-stored skeletal muscle is highly susceptible to cold IR injury and that the viability can be increased by prior perfusion with a tissue preservation solution such as modified UW solution.

The beneficial effect of heparin in preischemic perfusion solutions for cold-stored skin flaps.

Storage of skin flaps in the cold before replantation increases their tolerance to ischemic damage. Rat epigastric skin flaps were perfused immediately before 2 days of cold ischemia with 3 ml of normal saline containing either 10 U per milliliter of heparin (group 1, N = 11) or normal saline (group 2, N = 10), or stored without perfusion (group 3, N = 6), and replanted. Flap viability was assessed 7 days later. The mean flap survival in groups 1, 2, and 3 was 73% (p<0.01 compared with group 2), 10%, and 33% respectively. Intravascular fibrin deposits were detected histochemically 5 minutes before reperfusion in nonperfused flaps and 5 minutes after reperfusion in saline-perfused flaps, but not in flaps perfused with heparinized saline. Angiography revealed evidence of no reflow in the first 5 minutes of reperfusion in saline-perfused flaps, but normal blood flow in heparinized saline-perfused flaps. Tissue water content, myeloperoxidase activity, and hydroperoxide levels after 1 and 24 hours of reperfusion were not significantly different in flaps perfused with heparinized saline and normal saline. These findings indicate that in skin flaps perfused before ischemia, flaps perfused with heparinized saline survive significantly better than flaps perfused with normal saline. They also survive better than nonperfused flaps but the improvement is not significant.