Fatal ventricular arrhythmia as a complication of transesophageal echocardiography.

AIM: To report a case of serious ventricular arrhythmia during transesophageal echocardiography. METHODS AND RESULTS: A 58-year-old woman with previous mitral and tricuspid valve replacement and permanent pacemaker implantation suffered from recurrent fever and Staphylococcus aureus bacteremia. Transesophageal echocardiography was performed as part of the assessment for infective endocarditis. During this procedure the patient developed sustained ventricular tachycardia and subsequently ventricular flutter. She was successfully resuscitated. Subsequently the procedure was undertaken under general anesthesia with no complications. CONCLUSION: The increasing use of TEE in a wider spectrum of patients, many of whom are seriously ill, may result in serious side-effects.     

Assessment of the coagulation profile in hemato-oncological patients receiving ATG-based conditioning treatment for allogeneic stem cell transplantation

Antithymocyte globulin (ATG) is increasingly used in pre-allogeneic stem cell transplantation (allo-SCT) conditioning regimens to prevent graft rejection and graft-versus-host disease. However, ATG was also found to be associated with increased incidence of thrombosis during organ transplantation. In the present study, we tested the coagulation status of 21 patients with hematologic malignancies undergoing allo-SCT who received ATG-based (11 patients) or non-ATG-based (10) conditioning treatment. We assessed several thrombophilia markers as well as circulating total and endothelial microparticles (TMP/EMP) and soluble CD40 ligand (CD40L). No significant difference in the mean values of prothrombin time, partial thromboplastin time, fibrinogen, antithrombin, protein C, protein S, thrombin-antithrombin III complex, homocysteine levels, prevalence of genetic thrombophilia markers and levels of EMP, TMP or CD40L was observed between the ATG-treated and ATG-untreated patients, as well as before and after conditioning in each group separately. Platelet counts decreased significantly in ATG-treated patients; however, this decrease was not associated with clinical or laboratory evidence of disseminated intravascular coagulation. No patient developed thromboembolic event or veno-occlusive liver disease. Our results suggest that allo-SCT is not associated with increased hypercoagulability and addition of ATG to conditioning regimen has no significant procoagulant effect.     

A cell-based multifactorial approach to angiogenesis

We here propose an alternative cell therapy approach to induce angiogenesis. We prepared small organ fragments whose geometry allows preservation of the natural epithelial/mesenchymal interactions and ensures appropriate diffusion of nutrients and gases to all cells. Fragments derived from lung are shown to behave as fairly independent units, to undergo a marked upregulation of angiogenic factors and to continue to function for several weeks in vitro in serum-free media. When implanted into hosts, they transcribe a similar array of angiogenic factors that specifically induce the formation of a potent vascular network. The angiogenic induction capacity of these fragments was also tested in a mouse and rat model of limb ischemia. We report that such fragments, when implanted in the vicinity of the ischaemic area, induce an angiogenic response which can rescue the ischaemia-induced damage. The approach presented differs from single factor application, gene therapy and other cell therapy methods in that it exploits the complex behaviour of autologous cells in their near to normal environment in order to achieve secretion of a whole range of angiogenic stimuli continuously and in an apparently coordinated fashion.     

Ordered intracellular RecA-DNA assemblies: a potential site of in vivo RecA-mediated activities

The inducible SOS response increases the ability of bacteria to cope with DNA damage through various DNA repair processes in which the RecA protein plays a central role. Here we present the first study of the morphological aspects that accompany the SOS response in Escherichia coli. We find that induction of the SOS system in wild-type bacteria results in a fast and massive intracellular coaggregation of RecA and DNA into a lateral macroscopic assembly. The coaggregates comprise substantial portions of both the cellular RecA and the DNA complement. The structural features of the coaggregates and their relation to in vitro RecA-DNA networks, as well as morphological studies of strains carrying RecA mutants, are all consistent with the possibility that the intracellular assemblies represent a functional entity in which RecA-mediated DNA repair and protection activities occur.     

Ibritumomab tiuxetan (Zevalin) combined with reduced-intensity conditioning and allogeneic stem-cell transplantation (SCT) in patients with chemorefractory non-Hodgkin's lymphoma

Allogeneic SCT is an effective therapy for lymphoma. Reduced-intensity conditioning (RIC) reduces non-relapse mortality (NRM) associated with myeloablative conditioning but relapse rates are high when performed in active disease. This study was designed to explore the safety and outcome of ibritumomab tiuxetan (Zevalin) combined with RIC in patients with advanced lymphoma. The study included 12 patients, median age 54 years (37-62), with a median of four prior treatments (2-6) and active disease documented on PET-CT. Zevalin 0.4 mCi/kg was given on day -14 and fludarabine combined with BU (n=6) or melphalan (n=6) was started on day -6. GVHD prevention was tapered 3 months after SCT to augment the graft-versus-lymphoma effect. All patients engrafted, a median of 14 days after SCT. Eighty-three percent achieved CR/PR. With a median follow-up of 21 months (12-37), 2-year PFS is 33%. Only three patients relapsed; cumulative incidence 25%. NRM was 42%, predominantly due to acute GVHD. Zevalin-RIC is feasible with consistent engraftment, acceptable organ toxicity, but high rates of acute GVHD. The low incidence of relapse suggests augmented anti-lymphoma effect. Zevalin-RIC merits further study. Better results may be achieved in patients earlier in disease course and with longer duration of immune-suppression.     

Comparison between two fludarabine-based reduced-intensity conditioning regimens before allogeneic hematopoietic stem-cell transplantation: fludarabine/melphalan is associated with higher incidence of acute graft-versus-host disease and non-relapse mortality and lower incidence of relapse than fludarabine/busulfan.

Reduced-intensity conditioning (RIC) regimens are increasingly used in allogeneic stem-cell transplantation (SCT). There are no data whether any of these regimens has advantage and in what setting. We retrospectively analyzed SCT outcomes in 151 patients given fludarabine-based RIC for various hematological malignancies; 72 conditioned with fludarabine and intravenous-busulfan (FB) and 79 with fludarabine and melphalan (FM). FM was more myelosuppressive. Grade III-IV organ toxicity occurred in 31 and 53% of FB and FM recipients (P=0.005) and acute graft-versus-host disease grade II-IV in 33 and 53%, respectively (P=0.01). Non-relapse mortality rate (NRM) was 16 and 40%, respectively (P=0.003). Active disease (HR 2.2, P=0.003) and prior autologous SCT (HR 1.7, P=0.04) predicted inferior overall survival (OS). Among patients transplanted in remission, OS was 72 and 36% after FB and FM, respectively (P=0.03) due to increased NRM with FM. Similarly, patients transplanted in active disease experienced higher NRM with FM, however lower relapse rates resulted in equivalent OS. In conclusion, there are marked differences in outcome between RIC regimens that are theoretically dose-equivalent. The FM regimen is more myelosuppressive and toxic but controls disease better. FB was associated with improved survival in patients transplanted in remission. These observations merit further study in prospective studies.