Right ventricular outflow tract reconstruction using a valved biological conduit (Hancock conduit) late after Tetralogy of Fallot surgical correction

OBJECTIVES: The most appropriate strategy in the management of right ventricular outflow tract (RVOT) reconstruction in patients with tetralogy of Fallot early repair and late failure of right ventricle to pulmonary artery continuity is still debated. This study addresses this issue by evaluating retrospectively 12 years experience in this kind of reconstruction, focusing exclusively on the performance of Hancock conduits. METHODS: Data from 32 patients with an early repaired Tetralogy of Fallot, 23 males and 9 females, who underwent 34 RVOT reconstruction (2 were reinterventions) with Hancock conduit at Fondazione Toscana "G. Monasterio" Pediatric Cardiac Surgery department, Massa, Italy between February 2003 and May 2015 were retrospectively reviwed. Median age was 17,6 +/- 11,32 years (range 13 months to 41 years and 8 months), mean BSA 1,4 +/- 0,54m2 (0,34 m2 minimum and 2,12 m2 most), mean height 148,1 +/- 33,6 cm (range 61 cm to 195 cm) and mean weight 49,5 +/- 26,35 Kg (range 6,9 Kg to 96 Kg). The RV-PA peak gradient, RV mean pressure and pulmonary regurgitation were measured before and after the surgical conduit implantation and on follow-up, in addition RV end-diastolic volume index was measured, when feasible, before and after Hancock implantation. RESULTS: The early 30 days mortality was 6,25% and not related to conduit failure. Complete follow-up was feasible in 27 patients and the mean duration was 31,6 +/- 34,42 months. The observed RV-PA peak gradient means were 60,4 +/- 30,06 mmHg preoperatively, 29,1 +/- 11,48 mmHg postoperatively and 45,3 +/- 26,02 mmHg on the last follow-up; RV mean pressures were 53,3 +/- 27,73 mmHg preoperatively 41,6 +/- 12,71 mmHg postoperatively and 53,6 +/- 18,8 mmHg on the last follow-up; RV end-diastolic volume index means were 218,3 +/- 57,94 ml/m2 before surgery and 126,1 +/- 14,49 ml/m2 after surgery. Conduit failure was observed in 5 patients in which the the mean freedom from conduit failure was 70,56 +/- 15,02 months (mean age at failure 6,86 +/- 1,78 years), in 4 of them percutaneous intervention were attempted (2 ballooning and 2 melody), 2 successful. DISCUSSION: From our series the Hancock conduit can be actually considered as a valuable solution for RVOT reconstruction in already operated patients with ToF, considering good RV pressures and gradients values even after up to 9 years of follow up

Cytogerontology since 1881: A reappraisal of August Weismann and a review of modern progress

Cytogerontology, the science of cellular ageing, originated in 1881 with the prediction by August Weismann that the somatic cells of higher animals have limited division potential. Weismann's prediction was derived by considering the role of natural selection in regulating the duration of an organism's life. For various reasons, Weismann's ideas on ageing fell into neglect following his death in 1914, and cytogerontology has only reappeared as a major research area following the demonstration by Hayflick and Moorhead in the early 1960s that diploid human fibroblasts are restricted to a finite number of divisions in vitro. In this review we give a detailed account of Weismann's theory, and we reveal that his ideas were both more extensive in their scope and more pertinent to current research than is generally recognised. We also appraise the progress which has been made over the past hundred years in investigating the causes of ageing, with particular emphasis being given to (i) the evolution of ageing, and (ii) ageing at the cellular level. We critically assess the current state of knowledge in these areas and recommend a series of points as primary targets for future research

Evaluation of Interferon-Gamma Release Assays in the Diagnosis of Recent Tuberculosis Infection in Health Care Workers

BACKGROUND:Health care workers (HCWs) are a group at risk of latent tuberculosis infection (LTBI). The aims of this study were to determine IFN-gamma response by QuantiFERON-TB GOLD In Tube (QFN-G-IT) and T-SPOT.TB in HCWs, comparing the results with tuberculin skin test (TST); and to analyze the capacity of IFN-gamma tests to detect recent versus remote LTBI with a prolonged stimulation test (PST). METHODOLOGY/PRINCIPAL FINDINGS:A total of 147 HCWs were enrolled; 23 of whom were BCG vaccinated. 95 HCWs (64.6%) had a previous positive TST and were not retested; and 52 HCWs had a previous negative TST or were tested for the first time. When we analysed individuals without previous positive TST, the number of positive results for T-SPOT.TB was 12/52 (23.1%); and for QFN-G-IT, 9/52 (17.3%). The global concordance (kappa) between T-SPOT.TB and QFN-G-IT with TST was 0.754 and 0.929 respectively. Of individuals with previous positive TST, T-SPOT.TB and QFN-G-IT were negative in 51.6% (49/95) and 62.1% (59/95) respectively, decreasing the concordance to 0.321 and 0.288, respectively. In non-BCG vaccinated HCWs with previous positive TST a positive IFN-gamma test was associated with degree of exposure and diameter of TST. PST was performed in 24 HCW with previous positive TST and negative IFN-gamma tests. PST was developed in 3 cell cultures stimulated with medium alone, ESAT-6 and CFP-10, respectively. In the third and sixth day of incubation period, part of the supernatants were replaced with complete medium supplemented with (rIL)-2. On day 9, ELISPOT assay was performed. In 14 samples PST was not valid due to not having enough cells. In 8 cases, the response was negative, and in 2 cases positive, suggesting that these patients were infected with Mycobacterium tuberculosis in some point in the past. CONCLUSIONS:Both IFN-gamma tests showed a similar number of positive results, and concordance between the tests was excellent. None of the tests was affected by prior BCG vaccination. IFN-gamma tests are a useful tool for detecting recent infection in HCW population

Phagocytosis and digestion of pH-sensitive fluorescent dye (Eos-FP) transfected E. coli in whole blood assays from patients with severe sepsis and septic shock

The function of phagocytic and antigen presenting cells is of crucial importance to sustain immune competence against infectious agents as well as malignancies. We here describe a reproducible procedure for the quantification of phagocytosis by leukocytes in whole blood. For this, a pH-sensitive green-fluorescent protein- (GFP) like dye (Eos-FP) is transfected into infectious microroganisms. After UV-irradiation, the transfected bacteria emit green (≈5160 nm) and red (≈581 nm) fluorescent light at 490 nm excitation. Since the red fluorescent light is sensitive to acidic pH, the phagocytosed bacteria stop emitting red fluorescent light as soon as the phagosomes fuse with lysosomes. The green fluorescence is maintained in the phagolysosome until pathogen degradation is completed. Fluorescence emission can be followed by flow cytometry with filter settings documenting fluorescence 1 (FL 1, FITC) and fluorescence 2 (FL 2, phycoerythrin, PE). Eos-FP transfected bacteria can also be traced within phagocytes using microscopical techniques. A standardized assay has been developed which is suitable for clinical studies by providing clinicians with syringes pre-filled with fixed and appropriately UV-irradiated Eos-FP E. coli (TruCulture™). After adding blood or body fluids to these containers and starting the incubation at 37°C, phagocytosis by granulocytes proceeds over time. Cultures can be terminated at a given time by lysing red blood cells followed by flow cytometry. A pilot study demonstrated that Eos-FP E. coli phagocytosis and digestion was up-regulated in the majority of patients with either severe sepsis or septic shock as compared to healthy donors (p < 0.0001 after o/n incubation). Following treatment with recombinant human granulocyte colony-stimulating factor (rhG-CSF) in selected patients with sepsis, phagolysosome fusion appeared to be accelerated