Discovery of novel drug sensitivities in T-PLL by high-throughput ex vivo drug testing and mutation profiling.

T-cell prolymphocytic leukemia (T-PLL) is a rare and aggressive neoplasm of mature T-cells with an urgent need for rationally designed therapies to address its notoriously chemo-refractory behavior. The median survival of T-PLL patients is <2 years and clinical trials are difficult to execute. Here we systematically explored the diversity of drug responses in T-PLL patient samples using an ex vivo drug sensitivity and resistance testing platform and correlated the findings with somatic mutations and gene expression profiles. Intriguingly, all T-PLL samples were sensitive to the cyclin-dependent kinase inhibitor SNS-032, which overcame stromal-cell-mediated protection and elicited robust p53-activation and apoptosis. Across all patients, the most effective classes of compounds were histone deacetylase, phosphoinositide-3 kinase/AKT/mammalian target of rapamycin, heat-shock protein 90 and BH3-family protein inhibitors as well as p53 activators, indicating previously unexplored, novel targeted approaches for treating T-PLL. Although Janus-activated kinase-signal transducer and activator of transcription factor (JAK-STAT) pathway mutations were common in T-PLL (71% of patients), JAK-STAT inhibitor responses were not directly linked to those or other T-PLL-specific lesions. Overall, we found that genetic markers do not readily translate into novel effective therapeutic vulnerabilities. In conclusion, novel classes of compounds with high efficacy in T-PLL were discovered with the comprehensive ex vivo drug screening platform warranting further studies of synergisms and clinical testing.

MiR-30a-5p connects EWS-FLI1 and CD99, two major therapeutic targets in Ewing tumor.

Ewing sarcoma is a pediatric bone tumor characterized in 85% of cases by the fusion between EWS and FLI1 genes that results in the expression of the EWS-FLI1 aberrant transcription factor. Histologically, the Ewing tumor expresses high levels of the CD99 membrane glycoprotein. It has been recently described that CD99 expression contributes to the Ewing tumor oncogenesis by modulating growth and differentiation of tumor cells. Different studies have also shown that overexpression of EWS-FLI1 induces CD99 expression in non-Ewing cells. At the opposite, the knockdown of EWS-FLI1 expression by siRNA approaches has no significant effect on CD99 mRNA level in Ewing cells. Here, by in vivo and in vitro studies, we show that while EWS-FLI1 inhibition has only slight effects on the amount of CD99 transcript, it induces a dramatic decrease of the CD99 protein expression level, hence suggesting post-transcriptional regulations, possibly mediated by microRNAs. To further investigate this issue, we identified a set of 91 miRNAs that demonstrate EWS-FLI1 modulation, three of them being predicted to bind CD99 3' untranslated region (30'UTR). Among these, we show that miR-30a-5p has the ability to interact with the 30'UTR region of CD99 and to regulate its expression. Moreover, the re-expression of miRNA-30a-5p in Ewing cell line induces decreased cell proliferation and invasion. In this study, we therefore show that miR-30a-5p constitutes a major functional link between EWS-FLI1 and CD99, two critical biomarkers and therapeutic targets in Ewing sarcoma.

Laparoscopic parastomal hernia repair.

Repair of parastomal represents a significant challenge for the hernia surgeon. Repair of these hernias is indicated because of an ill-fitting appliance, cosmetic deformity, inability to maintain proper hygiene and complications from the hernia itself such as incarceration or strangulation. Recent reports in the literature have shown that primary fascial repair can occur in 46% of patients and relocation of the stoma is associated with a 40% recurrence rate. For this reason, the use of polypropylene mesh has been applied to this repair. The recurrence rate with this open technique will still incur a failure rate of 20-29%. Additionally there are other complications such as obstruction, fistulization or mesh erosion with this biomaterial. The laparoscopic approach to this hernia may offer a new choice for this difficult problem. We have used ePTFE to repair 12 parastomal hernias with three different approaches. There have been eight colostomy, two ileostomy and two urostomy hernias. Follow-up ranges from 3-39 months (average 20 months). There has been one recurrence that required two repairs (8%). Other complications included enterotomy (one patient), ileus (one), seroma (one), and death from postoperative aspiration (one). The laparoscopic repair of parastomal hernias appears to be a promising technique for this complex dilemma.

Laparoscopic incisional and ventral hernioplasty: lessons learned from 200 patients.

Our first 100 patients and our second 100 patients who underwent a laparoscopic repair of incisional and ventral hernias were compared and evaluated. This analysis revealed that the second group was approximately 9 years older with more comorbid medical conditions. In all, 15% were incarcerated hernias, and 21% were recurrent. Seven operations were converted to the open repair because of adhesions in five patients and either a small or large bowel injury in two patients. There were no complications related to enterotomy. Older and more infirm patients in the second group did not significantly affect outcomes. The average size of the hernia defects was 111 cm2. The average size of the prosthesis was 257.5 cm2. Larger prostheses were used in the second group. With more experience, the recurrence rates have declined from 9% to 4%. The etiology of these recurrences differed in these two groups of patients. Removal of the prosthetic due to infection was a predictable recurrence in two patients. A new hernia below the original hernia has caused us to repair the entire incision that had the initial hernia. Only one technical failure was noted, due to fracture of the suture during transfascial placement and clamping of the suture. It is not recommended to grasp any suture that remains in the patient during this hernioplasty. Recurrences were reduced because of the use of an increased overlap of the biomaterial and the use of dual methods of fixation (tacks and transfascial sutures).

Tissue attachment strength of prosthetic meshes used in ventral and incisional hernia repair. A study in the New Zealand White rabbit adhesion model.

BACKGROUND: Many prosthetic materials are used in incisional hernia repair, including polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). However, PP forms severe adhesions and ePTFE has raised concerns about the adequacy of tissue attachment. METHODS: The early tissue attachment strength of PP and two new forms of ePTFE (DLM and DLMC) was compared in a rabbit model (n = 12) in which disks of the three meshes (n = 8 of each material) were implanted against the abdominal wall for 3 days. RESULTS: Tensiometer testing found that DLMC mesh had significantly greater attachment strength than PP (p = 0.02). Histologic studies indicated that this was due to cellular ingrowth. Tissue adhesions were observed with all eight PP disks, one DLMC disk, and none of the DLM disks. CONCLUSION: Modified forms of ePTFE mesh may provide abdominal wall repairs that are as strong or stronger than those obtained with PP, with early tissue attachment and without adhesions.

Laparoscopic incisional and ventral herniorraphy: our initial 100 patients.

A review of our initial 100 patients upon whom we attempted a laparoscopic repair of either a ventral and incisional hernia is presented. The average follow-up period of these individuals was 51 months. The operation was completed with the laparoscopic technique in 96 cases. The average defect size was 155 cm2 and the average prosthetic biomaterial size to repair these defects was 214.8 cm2. The major complication rate was 4.1%. The incidence of recurrence in these patients was 9.3%. In all of these cases of recurrence, the method of attachment was that of staples or spiral tacks alone. In 5 patients, it appeared that the prosthesis was too small to cover the defect adequately. We believe that this is an effective operation but one that has two technical mandates. The prosthetic biomaterial (DualMesh) must cover the fascial edges by a minimum of a three-centimeter overlap. Additionally, the attachment of the patch by staples or tacks alone is inadequate; consequently, the herniorraphy must include the use of through and through sutures to assure adequate fixation of the prosthesis.

Laparoscopic incisional and ventral herniorrhaphy in 100 patients.

BACKGROUND: Laparoscopic incisional and ventral herniorrhaphy, a procedure first described 7 years ago, continues to gain acceptance. A series of about 100 patients who underwent the operation is described. Follow-up in this series was longer (mean 51 months) than that in previously reported series. METHODS: A retrospective review was conducted of operative and follow-up records of a series of patients scheduled to undergo laparoscopic incisional or ventral herniorrhaphy between 1992 and 1997. RESULTS: Laparoscopic repair was completed in 96 of 100 patients. The complication rate was 14%, with seromas accounting for half of the postoperative problems. Mean hospital stay was 1 day. The late recurrence rate was 9%, with 4 of the 9 recurrences developing >2 years postoperatively. CONCLUSIONS: Laparoscopic incisional and ventral herniorrhaphy is safe and effective. Most patients require hospitalization for /=3 years.

Delayed posttraumatic tamponade.

Delayed cardiac tamponade is a rare phenomenon with two primary causes: delayed hemorrhage after an acute injury or delayed pericarditis with effusion. We present a case of cardiac tamponade 4 weeks after injury, with findings compatible with delayed hemorrhage and pericarditis. Our case emphasizes the need for follow-up of patients with penetrating chest trauma for several months after injury; echocardiography should be used if symptoms of tamponade appear.