3D-Imaging of cardiac structures using 3D heart models for planning in heart surgery: a preliminary study

The aim of the study was to create an anatomical correct 3D rapid prototyping model (RPT) for patients with complex heart disease and altered geometry of the atria or ventricles to facilitate planning and execution of the surgical procedure. Based on computer tomography (CT) and magnetic resonance imaging (MRI) images, regions of interest were segmented using the Mimics 9.0 software (Materialise, Leuven, Belgium). The segmented regions were the target volume and structures at risk. After generating an STL-file (StereoLithography file) out of the patient's data set, the 3D printer Ztrade mark 510 (4D Concepts, Gross-Gerau, Germany) created a 3D plaster model. The patient individual 3D printed RPT-models were used to plan the resection of a left ventricular aneurysm and right ventricular tumor. The surgeon was able to identify risk structures, assess the ideal resection lines and determine the residual shape after a reconstructive procedure (LV remodelling, infiltrating tumor resection). Using a 3D-print of the LV-aneurysm, reshaping of the left ventricle ensuring sufficient LV volume was easily accomplished. The use of the 3D rapid prototyping model (RPT-model) during resection of ventricular aneurysm and malignant cardiac tumors may facilitate the surgical procedure due to better planning and improved orientation.     

Topical negative pressure wound therapy: a review of its role and guidelines for its use in the management of acute wounds

Over the past two decades, topical negative pressure (TNP) wound therapy has gained wide acceptance as a genuine strategy in the treatment algorithm for a wide variety of acute and chronic wounds. Although extensive experimental and clinical evidence exists to support its use and despite the recent emergence of randomised control trials, its role and indications have yet to be fully determined. This article provides a qualitative overview of the published literature appertaining to the use of TNP therapy in the management of acute wounds by an international panel of experts using standard methods of appraisal. Particular focus is applied to the use of TNP for the open abdomen, sternal wounds, lower limb trauma, burns and tissue coverage with grafts and dermal substitutes. We provide evidence-based recommendations for indications and techniques in TNP wound therapy and, where studies are insufficient, consensus on best practice.     

Participation in pediatric epidemiologic research: the SEARCH for Diabetes in Youth Study experience

BackgroundWe evaluated the association of demographic and clinical characteristics with participation in an epidemiologic study of diabetes mellitus among youth.MethodsSEARCH for Diabetes in Youth is a multicenter study of physician-diagnosed diabetes in youth under the age of 20 comprising a surveillance and a cohort component. At each center, we enumerated all prevalent cases of diabetes in 2001 (n = 6266) and all incident cases between 2002 and 2004 (n = 3668). After confirmation of eligibility and validation, we invited each case to complete a survey and participate in a study visit. Here we evaluate how age, sex, race, and diabetes type are associated with participation in the survey and study visit.ResultsAmong prevalent cases, participation in the survey was 68% and 41% in the study visit. Among 2002 to 2004 incident cases, participation varied for the survey (76%, 81%, and 82%) and study visit (52%, 60%, and 60%). In multivariate logistic regression analyses among all incident cases, older age was associated with a lower odds of participation in the study visit (15–17 vs. < 10 years: OR 0.5, 95% CI 0.4–0.7; 18–19 vs. < 10 years: OR 0.3, 95% CI 0.2–0.5), as was having type 2 diabetes vs. type 1 diabetes (OR 0.5, 95% CI 0.4–0.7) and being of African American race vs. non-Hispanic White (OR 0.6, 95% CI 0.4–0.8). Results were very similar among prevalent cases.ConclusionsElucidating the relationship between individual characteristics and participation is essential for evaluating nonresponse bias, correcting for it, and for planning and implementing recruitment strategies.     

BNP-mediated vasodilatation for dialysis-dependent patient with acute heart failure syndrome in the emergency department

Acutely decompensated heart failure syndrome is a common emergency department presentation in patients with renal failure. B-type natriuretic peptide-mediated vasodilatation may provide a unique bridge in renal failure patients with acutely decompensated heart failure syndrome to treatment with dialysis. We evaluated the efficacy of B-type natriuretic peptide-mediated vasodilatation in acutely decompensated heart failure syndrome emergency department patients with hemodialysis dependent renal failure. This was a prospective, interventional trial. All patients received nesiritide infusion in addition to usual care. Outcome measures included hemodynamic parameters and dyspnea visual analog scale. Eight patients were enrolled, and all demonstrated significant improvement in their dyspnea visual analog scale (Delta 50.1 mm; p < .001 vs. pre-infusion) and APEX score (Delta 48.4%; p < .001 vs. pre-infusion). Three patients improved enough to be discharged from the emergency department for outpatient dialysis. In this hypothesis-generating initial trial, B-type natriuretic peptide-mediated vasodilatation with nesiritide improved symptoms in heart failure patients with hemodialysis-dependent renal failure and appears additive to standard treatment. Further trials are required to test this hypothesis.     

Endoscopic suture removal at gastrojejunal anastomosis after Roux-en-Y gastric bypass to prevent marginal ulceration

BACKGROUND: After Roux-en-Y gastric bypass (RYGB) surgery, marginal ulcers develop in 3-23% of patients. Marginal ulcers can occur secondary to the use of nonabsorbable sutures to create the gastrojejunostomy. The suture can elicit a foreign body reaction that exposes it to the gastric lumen, irritating the mucosa. Surgical removal is mandated when medical therapy fails to resolve matters. Because endoscopic removal would be less invasive than laparotomy, a technique for the endoscopic removal of the suture was devised. Presented are the results of 6 patients who underwent this procedure. METHODS: A computer search of all patients who had undergone laparoscopic RYGB was done and found 6 women who had undergone endoscopic suture removal. After a double-lumen endoscope was inserted through the mouth, a grasper was used to placed the suture under tension before transecting it with blunt-tip endoshears. The suture was then removed without difficulty. All patients were evaluated at 2 weeks and 6 months postoperatively. RESULTS: Of the patients who underwent laparoscopic RYGB between June 2003 and June 2005 and presented with epigastric pain, 6 women underwent endoscopic stitch removal. These women had a mean age of 57 years, a mean initial body mass index of 55 kg/m(2), and had undergone laparoscopic RYGB a mean of 18 months before presentation. The patients, who had experienced new-onset epigastric pain and "heartburn," underwent endoscopic examination of the stomach, which showed visible suture at the gastrojejunal anastomosis, no ulceration, and edema, and underwent suture removal. No complications developed. At 6 months of follow-up, all patients were without symptoms and had normal findings on upper endoscopy. CONCLUSION: The results of our study have shown that endoscopic suture removal is a feasible and effective means of treating epigastric pain and preventing the suture-induced marginal ulcers that can occur after RYGB.     

An atomistic picture of the regeneration process in dye sensitized solar cells

A highly efficient mechanism for the regeneration of the cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)-ruthenium(II) sensitizing dye (N3) by I^- in acetonitrile has been identified by using molecular dynamics simulation based on density functional theory. Barrier–free complex formation of the oxidized dye with both I^- and , and facile dissociation of and from the reduced dye are key steps in this process. In situ vibrational spectroscopy confirms the reversible binding of I₂ to the thiocyanate group. Additionally, simulations of the electrolyte near the interface suggest that acetonitrile is able to cover the (101) surface of anatase with a passivating layer that inhibits direct contact of the redox mediator with the oxide, and that the solvent structure specifically enhances the concentration of I^- at a distance which further favors rapid dye regeneration.     

Andrology: Incubation of spermatozoa from asthenozoospermic semen samples with pentoxifylline and 2-deoxyadenosine: variability in hyperactivation and acrosome reaction rates

We examined hyperactivation and acrosomal loss in asthenozoospermicpatients with a history of failed in-vitro fertilization (IVF).After selection by a Percoll gradient, spermatozoa were incubatedwith 3.6 mM pentoxifylline (PTX), 3.0 mM 2-deoxyadenosine (2-DXA)or both. Hyperactivation and ionophore A-23187-induced acrosomereaction were assessed immediately after sperm treatment andagain after 180 min. In all groups studied, the mean hyperactivationrates were found to be low. No significant differences werenoted between assessments immediately after treatment and 180min later, except after treatment with both PTX and 2-DXA. Themean hyperactivation rates were found not to improve as a resultof either PTX or 2-DXA, while the combination of both PTX and2-DXA revealed a significant enhancement of total hyperactivation.When individual hyperactivation rates between control and treatedsperm samples were compared, large differences in response wereobserved. Some sperm samples showed a marked increase in hyperactivationwith one treatment, while another treatment led to a decrease.Acrosome reaction rates assessed immediately after ionophoreA-23187 stimulation were found not to be significantly differentfrom those assessed 180 min later. No significant effect couldbe demonstrated for either treatment, although, here too, markedinterindividual variations were noted. It was concluded thatan unselective use of PTX, 2-DXA or both compounds together,may restore sperm function in certain of these patients, andperhaps improve fertilization in vitro, but in others it mayproduce no change or may even be detrimental to sperm function.