Treatment of malignant gastroduodenal obstruction with a nitinol self-expanding metal stent: An international prospective multicentre registry

Background: Duodenal stenting has become a broadly accepted first line of treatment for patients with advanced malignant gastroduodenal obstruction as these patients are difficult to treat and are poor surgical candidates. Aims: To document duodenal stent performance for palliative management of malignant gastroduodenal obstruction. Methods: Multicentre, single arm, prospective registry documenting peroral endoscopic duodenal stenting procedures in 202 patients. Results: Technical success achieved in 98% (CI. 95%, 99%) of stent placements. Increase of Gastric Outlet Obstruction Score by at least 1 point compared to baseline was achieved in 91% (CI, 86%, 95%) of patients persisting for a median of 184 days (CI, 109, 266). By day 5 (CI, 4,6) after stent placement, 50% of patients experienced a score increase of at least 1 point. Improvement from 14% of patients at baseline tolerating soft solids or low residue/normal diet to 84% at 15 days, 86% at 30 days, 81% at 90 days, 79% at 180 days, and 70% at 270 days. Complications included stent ingrowth and/or overgrowth (12.4%), transient periprocedural symptoms (3%), bleeding (3%), stent migration (1.5%), and perforation (0.5%). Conclusions: Safety and effectiveness of duodenal stenting for palliation of malignant gastroduodenal obstruction was confirmed in the largest international prospective series to date. (C) 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Formation and Characterization of Oriented Micro-and Nanofibers Containing Poly (ethylene oxide) and Pectin

Formation of oriented or aligned micro- and nanofibers using biocompatible materials opens the possibility to obtain engineered tissues that can be used in medicine, environmental engineering, security and defense, among other applications. Pectin, a heteropolysaccharide, is a promising material to be incorporated into the fibers because, besides being biocompatible, this material is also biodegradable and bioactive. In this work, the formation of oriented fibers using solutions containing pectin and polyethylene oxide (biocompatible polymers), and chloroform (as the solvent) is investigated. The injection of solution into an intense electric field defined between two parallel electrodes was used to obtain oriented fibers. This novel approach is a modification of the conventional electrospinning process. The presence of pectin in the fibers was confirmed by FTIR analysis. Fibers with diameters of hundreds of nanometers and several centimeters long can be collected. The incorporation of pectin leads to a higher variation of the diameter of the fibers, and a trend to larger fiber diameters. This behavior can be related to the presence of pectin clusters in the fibers. (C) 2012 The Electrochemical Society. [DOI: 10.1149/2.057203jes] All rights reserved.

Elaboration and Characterization of Nano-Biocomposites Based on Plasticized Poly(Hydroxybutyrate-Co-Hydroxyvalerate) with Organo-Modified Montmorillonite

Nano-biocomposites based on a biodegradable bacterial copolyester, poly(hydroxybutyrate-co-hydroxyvalerate), have been elaborated with an organo-modified montmorillonite (OMMT) clay as nanofiller, and acetyl tributyl citrate as plasticizer. The corresponding (nano)structures, thermal and mechanical properties, permeability, and biodegradability have been determined. Polyhydroxyalkanoates are very thermal sensitive then to follow the degradation the corresponding matrices have been analyzed by size exclusion chromatography. The results indicate that the addition of the plasticizer decreases the thermo-mechanical degradation, during the extrusion. These nano-biocomposites show an intercalated/exfoliated structure with good mechanical and barrier properties, and an appropriated biodegradation kinetic. Intending to understand the changes in the thermal properties, the nano-biocomposites were characterized by thermal gravimetric analysis and differential scanning calorimetry. The presence of the OMMT clay did not influence significantly the transition temperatures. However, the filler not only acted as a nucleating agent which enhanced the crystallization, but also as a thermal barrier, improving the thermal stability of the biopolymer. The results indicated that the addition of the plasticizer reduces the glass transition temperature and the crystalline melting temperature. The plasticizer acts as a processing aid and increases the processing temperature range (lower melting temperature).

Compatibilization of polypropylene/poly(3-hydroxybutyrate) blends

Blending polypropylene (PP) with biodegradable poly(3-hydroxybutyrate) (PHB) can be a nice alternative to minimize the disposal problem of PP and the intrinsic brittleness that restricts PHB applications. However, to achieve acceptable engineering properties, the blend needs to be compatibilized because of the immiscibility between PP and PHB. In this work, PP/PHB blends were prepared with different types of copolymers as possible compatibilizers: poly(propylene-g-maleic anhydride) (PPMAH), poly (ethylene-co-methyl acrylate) [P(EMA)], poly(ethylene-co-glycidyl methacrylate) [P(EGMA)], and poly(ethylene-co-methyl acrylate-co-glycidyl methacrylate) [P(EMAGMA)]. The effect of each copolymer on the morphology and mechanical properties of the blends was investigated. The results show that the compatibilizers efficiency decreased in this order: P(EMAGMA) > P(EMA) > P(EGMA) > PP-MAH; we explained this by taking into consideration the affinity degree of the compatibilizers with the PP matrix, the compatibilizers properties, and their ability to provide physical and/or reactive compatibilization with PHB. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3511-3519, 2012

Silicon(IV) phthalocyanine-loaded-nanoparticles for application in photodynamic process

The aim of this study was to evaluate the potential application of biodegradable nanoparticles containing a photosensitizer in photodynamic therapy. The poly (D,L lactic-co-glycolic acid) nanoparticles were studied by steady-state techniques, time-resolved fluorescence, and laser flash photolysis. The external morphology of the nanoparticles was established by scanning electron microscopy, and the biological activity was evaluated by in vitro cell culture by 3-(4,5 dimethylthiazol-2,5 biphenyl) tetrazolium bromide assay. The particles were spherical in shape exhibiting a 435 nm diameter with a low tendency to aggregate. The loading efficiency was 77%. The phthalocyanine-loaded-nanoparticles maintained their photophysical behavior after encapsulation. The cellular viability was determined, obtaining 70% of cellular death. All the performed physical-chemical, photophysical, and photobiological measurements indicated that the phthalocyanine-loaded-nanoparticles are a promising drug delivery system for photodynamic therapy and photoprocesses. (C) 2012 Laser Institute of America.

Applying the National Institute for Clinical Excellence criteria to patients treated with the Genous (TM) Bio-engineered R stent (TM): a sub-study of the e-HEALING (Healthy Endothelial Accelerated Lining Inhibits Neointimal Growth) worldwide registry

The National Institute for Clinical Excellence (NICE) guidelines recommend the use of bare-metal stents (BMS) in non-complex lesions with a low risk of restenosis (diameter a parts per thousand yen3 mm and lesion length a parts per thousand currency sign15 mm) and the use of drug-eluting stents (DES) in more complex lesions with a high risk of restenosis (diameter < 3.0 mm or lesion length > 15 mm). However, the guidelines were created based on studies evaluating BMS and DES only. We performed an analysis of patients undergoing non-urgent percutaneous coronary intervention with the novel endothelial cell capturing stent (ECS). The ECS is coated with CD34(+) antibodies that attract circulating endothelial progenitor cells to the stent surface, thereby accelerating the endothelialization of the stented area. We analyzed all patients enrolled in the worldwide e-HEALING registry that met the NICE criteria for either low-risk or high-risk lesions and were treated with a parts per thousand yen1 ECS. The main study outcome was target vessel failure (TVF) at 12-month follow-up, defined as the composite of cardiac death or MI and target vessel revascularization (TVR). A total of 4,241 patients were assessed in the current analysis. At 12-month follow-up, TVF occurred in 7.0% of the patients with low-risk lesions and in 8.8% of the patients with high-risk lesions (p = 0.045). When evaluating the diabetic patients versus the non-diabetic patients per risk group, no significant differences were found in TVF, MI or TVR in either risk group. The ECS shows good clinical outcomes in lesions carrying either a high or a low risk of restenosis according to the NICE guidelines with comparable rates of cardiac death, myocardial infarction, and stent thrombosis. The TVF rate with ECS was slightly higher in patients with high-risk lesions, driven by higher clinically driven TLR. The risk of restenosis with ECS in patients carrying high-risk lesions needs to be carefully considered relative to other risks associated with DES. Furthermore, the presence of diabetes mellitus did not influence the incidence of TVF in either risk group.

Avaliação da mucosa sinusal do coelho à presença de implante biodegradável

Pensando em melhorar a qualidade de vida dos pacientes com doenças do humor vítreo, os oftalmologistas começaram a utilizar recentemente implantes biodegradáveis com corticoide. Estes mesmos implantes podem ser uma alternativa no tratamento da RSC e, para isso, realizamos um estudo experimental em seios maxilares de coelhos. OBJETIVO: Avaliar histologicamente a mucosa de seio maxilar de coelhos após a colocação de implante biodegradável de prednisolona. MÉTODO: Dezoito coelhos foram divididos aleatoriamente em dois grupos: Grupo 1: no seio maxilar esquerdo foi inserido um implante biodegradável com prednisolona; Grupo 2: No seio maxilar esquerdo foi inserido um implante biodegradável sem medicação. Os seios maxilares do lado direito serviram como controle. Após 7, 14 e 28 dias foram escolhidos aleatoriamente três coelhos de cada grupo e a resposta tecidual inflamatória foi avaliada. RESULTADOS: Foi encontrada diferença não significativa de inflamação na mucosa, quando comparamos o grupo de coelhos que receberam implantes com e sem medicação com o grupo controle; ou quando comparamos o grupo que recebeu implante com prednisolona com o grupo que recebeu implante sem medicação. CONCLUSÃO: Não foram observados sinais de toxicidade ou inflamação na mucosa do seio maxilar do coelho à presença do implante com ou sem prednisolona.

Effects of Different Moisture Contents on Physical Properties of PVA-Gelatin Films

In this work, it was investigated the effect of different moisture contents on PVA-gelatin films by means of dielectric properties, infrared spectroscopy, microwave response and gravimetric method. The films were elaborated from a blend of gelatin and PVA, with 0 and 25 % glycerol. The sorption isotherms were determined by gravimetric methods, at 25 A degrees C. A capacimeter was used for dielectric measurements, and a device called SOLFAN setup was used for microwave measurements. The sorption isotherms were markedly affected by the glycerol content and relative humidity, due to the hygroscopic nature of the films. The dielectric constant and the microwave response signal were also strongly affected by the moisture and glycerol content in the films. Finally, Infrared spectra showed some changes in the amide peak positions, attributed to the modifications in the interactions between the macromolecules. The behaviors obtained in this work were explained on the basis the way the water enters in the film matrix.

Strategies for Multivessel Revascularization in Patients with Diabetes

BACKGROUND In some randomized trials comparing revascularization strategies for patients with diabetes, coronary-artery bypass grafting (CABG) has had a better outcome than percutaneous coronary intervention (PCI). We sought to discover whether aggressive medical therapy and the use of drug-eluting stents could alter the revascularization approach for patients with diabetes and multivessel coronary artery disease. METHODS In this randomized trial, we assigned patients with diabetes and multivessel coronary artery disease to undergo either PCI with drug-eluting stents or CABG. The patients were followed for a minimum of 2 years (median among survivors, 3.8 years). All patients were prescribed currently recommended medical therapies for the control of low-density lipoprotein cholesterol, systolic blood pressure, and glycated hemoglobin. The primary outcome measure was a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke. RESULTS From 2005 through 2010, we enrolled 1900 patients at 140 international centers. The patients' mean age was 63.1 +/- 9.1 years, 29% were women, and 83% had three-vessel disease. The primary outcome occurred more frequently in the PCI group (P=0.005), with 5-year rates of 26.6% in the PCI group and 18.7% in the CABG group. The benefit of CABG was driven by differences in rates of both myocardial infarction (P<0.001) and death from any cause (P=0.049). Stroke was more frequent in the CABG group, with 5-year rates of 2.4% in the PCI group and 5.2% in the CABG group (P=0.03). CONCLUSIONS For patients with diabetes and advanced coronary artery disease, CABG was superior to PCI in that it significantly reduced rates of death and myocardial infarction, with a higher rate of stroke. (Funded by the National Heart, Lung, and Blood Institute and others; FREEDOM ClinicalTrials.gov number, NCT00086450.)

PLGA microspheres containing bee venom proteins for preventive immunotherapy

Bee venom (BV) allergy is potentially dangerous for allergic individuals because a single bee sting may induce an anaphylactic reaction, eventually leading to death. Currently, venom immunotherapy (VIT) is the only treatment with long-lasting effect for this kind of allergy and its efficiency has been recognized worldwide. This therapy consists of subcutaneous injections of gradually increasing doses of the allergen. This causes patient lack of compliance due to a long time of treatment with a total of 30-80 injections administered over years. In this article we deal with the characterization of different MS-PLGA formulations containing BV proteins for VIT. The PLGA microspheres containing BV represent a strategy to replace the multiple injections, because they can control the solute release. Physical and biochemical methods were used to analyze and characterize their preparation. Microspheres with encapsulation efficiencies of 49-75% were obtained with a BV triphasic release profile. Among them, the MS-PLGA 34 kDa-COOH showed to be best for VIT because they presented a low initial burst (20%) and a slow BV release during lag phase. Furthermore, few conformational changes were observed in the released BV. Above all, the BV remained immunologically recognizable, which means that they could continuously stimulate the immune system. Those microspheres containing BV could replace sequential injections of traditional VIT with the remarkable advantage of reduced number of injections. (C) 2011 Elsevier B.V. All rights reserved.

Comparison of different delivery systems of DNA vaccination for the induction of protection against tuberculosis in mice and guinea pigs

The great challenges for researchers working in the field of vaccinology are optimizing DNA vaccines for use in humans or large animals and creating effective single-dose vaccines using appropriated controlled delivery systems. Plasmid DNA encoding the heat-shock protein 65 (hsp65) (DNAhsp65) has been shown to induce protective and therapeutic immune responses in a murine model of tuberculosis (TB). Despite the success of naked DNAhsp65-based vaccine to protect mice against TB, it requires multiple doses of high amounts of DNA for effective immunization. In order to optimize this DNA vaccine and simplify the vaccination schedule, we coencapsulated DNAhsp65 and the adjuvant trehalose dimycolate (TDM) into biodegradable poly (DL-lactide-co-glycolide) (PLGA) microspheres for a single dose administration. Moreover, a single-shot prime-boost vaccine formulation based on a mixture of two different PLGA microspheres, presenting faster and slower release of, respectively, DNAhsp65 and the recombinant hsp65 protein was also developed. These formulations were tested in mice as well as in guinea pigs by comparison with the efficacy and toxicity induced by the naked DNA preparation or BCG. The single-shot prime-boost formulation clearly presented good efficacy and diminished lung pathology in both mice and guinea pigs.

Intervenção Coronariana Percutânea prévia como fator de risco para Revascularização Miocárdica

FUNDAMENTO: A Intervenção Coronariana Percutânea (ICP) vem aumentando na doença arterial coronariana crônica. Consequentemente, cada vez mais pacientes submetidos a Cirurgia de Revascularização Miocárdica (CRM) apresentam stent coronariano. OBJETIVO: Avaliar a influência do antecedente de stent coronariano na mortalidade hospitalar após CRM. MÉTODOS: Análise prospectiva com 1.099 pacientes consecutivos submetidos a CRM com circulação extracorpórea, entre maio/2007 e junho/2009. Pacientes sem ICP prévia (n = 938; 85,3%) foram comparados com pacientes com ICP prévia (n = 161; 14,6%), utilizando modelos de regressão logística e análise de pareamento de amostras. RESULTADOS: Ambos os grupos apresentavam semelhança em relação aos fatores de risco, exceto pela maior presença de pacientes com angina instável no grupo com ICP prévia (16,1% vs. 9,9%; p = 0,019). A mortalidade hospitalar após CRM foi maior entre os pacientes com ICP prévia (9,3% vs. 5,1%, p = 0,034), e foi semelhante à esperada em relação ao EuroSCORE e ao 2000 Bernstein-Parsonnet score. Na análise com regressão logística multivariada a ICP prévia emergiu como fator de risco independente para mortalidade hospitalar pós-operatória (odds ratio 1,94; IC 95% 1,02-3,68; p = 0,044) tão forte quanto diabetes (odds ratio 1,86; IC 95% 1,07-3,24; p = 0,028). Após o pareamento dos grupos, a mortalidade hospitalar continuou sendo maior entre os pacientes com ICP prévia, com odds ratio 3,46 ; IC 95% 1,10-10,93; p = 0,034. CONCLUSÃO: A ICP prévia em pacientes com doença coronariana multiarterial é fator de risco independente para mortalidade hospitalar após CRM. Tal fato deve ser considerado quando a ICP for indicada como alternativa inicial em pacientes com doença arterial coronariana mais avançada. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0)

In vitro cultivation of canine multipotent mesenchymal stromal cells on collagen membranes treated with hyaluronic acid for cell therapy and tissue regeneration

Support structures for dermal regeneration are composed of biodegradable and bioresorbable polymers, animal skin or tendons, or are bacteria products. The use of such materials is controversial due to their low efficiency. An important area within tissue engineering is the application of multipotent mesenchymal stromal cells (MSCs) to reparative surgery. The combined use of biodegradable membranes with stem cell therapy may lead to promising results for patients undergoing unsuccessful conventional treatments. Thus, the aim of this study was to test the efficacy of using membranes composed of anionic collagen with or without the addition of hyaluronic acid (HA) as a substrate for adhesion and in vitro differentiation of bone marrow-derived canine MSCs. The benefit of basic fibroblast growth factor (bFGF) on the differentiation of cells in culture was also tested. MSCs were collected from dog bone marrow, isolated and grown on collagen scaffolds with or without HA. Cell viability, proliferation rate, and cellular toxicity were analyzed after 7 days. The cultured cells showed uniform growth and morphological characteristics of undifferentiated MSCs, which demonstrated that MSCs successfully adapted to the culture conditions established by collagen scaffolds with or without HA. This demonstrates that such scaffolds are promising for applications to tissue regeneration. bFGF significantly increased the proliferative rate of MSCs by 63% when compared to groups without the addition of the growth factor. However, the addition of bFGF becomes limiting, since it has an inhibitory effect at high concentrations in culture medium.

Novo modelo de endoprótese traqueal autoexpansível de fabricação nacional: estudo experimental em coelhos

Objetivamos testar um novo modelo de endoprótese traqueal autoexpansível para que esse possa ser futuramente disponibilizado para o uso clínico. As endopróteses de nitinol revestidas de poliuretano foram alocadas no terço médio da traqueia de 25 coelhos da raça Nova Zelândia sob laringoscopia direta. Após um período de observação médio de 26 dias, avaliou-se a migração da prótese, grau de dilatação, incorporação, aderência, formação de tecido de granulação, presença de infiltrado inflamatório, envolvimento parietal e revestimento epitelial. Os resultados demonstraram completa expansibilidade radial, pouca aderência à mucosa traqueal e baixa incorporação tecidual, assim como alta taxas de formação de granulomas e de migração. Esse novo modelo demonstrou ser biocompatível e teve comportamento semelhante ao de outras próteses disponíveis no mercado.

Avaliação do stent coronário eluidor de everolimus XIENCE TM V na cpopulação feminina latino-americana do estudo de braço único SPIRIT Women: acompanhamento clínico de um ano

INTRODUÇÃO: Os estudos com stents farmacológicos têm avaliado predominantemente populações masculinas de descendência europeia. O estudo de braço único SPIRIT Women avalia o stent eluidor de everolimus XIENCE TM V em lesões de novo complexas em uma população feminina do mundo real, incluindo pacientes latino-americanas. Esta análise permite compreender como essa população responde ao implante de stent, comparativamente a pacientes não-latino-americanas. MÉTODOS: Das 1.572 pacientes matriculadas em 73 locais fora dos Estados Unidos, 138 (9%) foram recrutadas na Argentina, no Brasil e na Venezuela. RESULTADOS: As lesões-alvo tinham diâmetro de referência do vaso entre 2,25 mm e 4 mm e extensão da lesão ≤ 28 mm. As características basais foram semelhantes entre os grupos, com exceção de maior prevalência de hipertensão arterial, infarto do miocárdio (IM) de parede anterior e história familiar de doença arterial coronária na coorte latino-americana. As lesões tendiam a ser mais complexas em mulheres latino-americanas, com menor diâmetro de referência do vaso-alvo, maior extensão da lesão, maior excentricidade e angulação e mais lesões tipo B2/C. Os eventos foram adjudicados de acordo com as definições do Academic Research Consortium. Em um ano, o desfecho combinado de morte por todas as causas, IM e revascularização do vaso-alvo (RVA) foi de 12,1% na população não-latino-americana e de 10,1% na população latino-americana (P = 0,58). CONCLUSÕES: Em um ano, os baixos índices de eventos cardíacos adversos, incluindo trombose do stent, falha da lesão-alvo, morte cardíaca, IM e RVA nas mulheres latino-americanas foram comparáveis aos das mulheres não-latino-americanas, apesar da maior complexidade das lesões. Esses resultados demonstram a segurança e a eficácia do stent XIENCE TM V nessa pequena coorte de pacientes latino-americanas, à semelhança do que é observado com populações maiores e mais variadas.