Nanoblock-mediated selective oncolytic polypeptide therapy for triple-negative breast cancer.

Rationale: Broad-spectrum oncolytic peptides (Olps) constitute potential therapeutic options for treating heterogeneous triple-negative breast cancer (TNBC); however, their clinical application is limited owing to high toxicity. Methods: A nanoblock-mediated strategy was developed to induce selective anticancer activity of synthetic Olps. A synthetic Olp, C12-PButLG-CA, was conjugated to the hydrophobic or hydrophilic terminal of a poly(ethylene oxide)-b-poly(propylene oxide) nanoparticle or a hydrophilic poly(ethylene oxide) polymer. A nanoblocker, that can significantly reduce the toxicity of Olp, was screened out through hemolytic assay, and then Olps were conjugated to the nanoblock via a tumor acidity-cleavable bond to obtain the selective RNolp ((mPEO-PPO-CDM)2-Olp). The tumor acidity responsive membranolytic activity, in vivo toxicity and anti-tumor efficacy of RNolp were determined. Results: We found that the conjugation of Olps to the hydrophobic core of a nanoparticle but not the hydrophilic terminal or a hydrophilic polymer restricts their motion and drastically reduces their hemolytic activity. We then covalently conjugated Olps to such a nanoblock via a cleavable bond that can be hydrolyzed in the acidic tumor environment, yielding a selective RNolp molecule. At physiological pH (pH 7.4), RNolp remained stable with the Olps shielded by nanoblocks and exhibited low membranolytic activity. At the acidic tumor environment (pH 6.8), Olps could be released from the nanoparticles via the hydrolysis of the tumor acidity-cleavable bonds and exerted membranolytic activity against TNBC cells. RNolp is well tolerated in mice and demonstrated high antitumor efficacy in orthotopic and metastatic mouse models of TNBC. Conclusion: We developed a simple nanoblock-mediated strategy to induce a selective cancer therapy of Olps for TNBC.

A coarse-grain MD (molecular dynamic) simulation of PCL-PEG and PLA-PEG aggregation as a computational model for prediction of the drug-loading efficacy of doxorubicin.

Formulating a hydrophobic drug that is water-soluble is a pharmaceutical challenge. One way is to incorporate the drug in an amphiphilic micelle composed from an aggregation of block copolymers. Design of a good nano-micelle requires many trial-and-error attempts. In this article, we developed a computational model based on a coarse-grained molecular dynamic (MD) simulation and correlated outputs with previous studies. A good correlation shows that this model reliably simulates poly-lactic acid-poly-ethylene glycol (PLA-PEG) and poly-caprolactone (PCL)-PEG aggregation in water with and without the presence of doxorubicin. Communicated by Ramaswamy H. Sarma.

cRGD-functionalized reduction-sensitive shell-sheddable biodegradable micelles mediate enhanced doxorubicin delivery to human glioma xenografts in vivo.

Biodegradable micelles are one of the most studied systems for the delivery of hydrophobic anticancer drugs. Their therapeutic efficacy in vivo is, however, suboptimal, partly due to poor tumor cell uptake as well as slow intracellular drug release. Here, we show that cRGD-functionalized intracellularly shell-sheddable biodegradable PEG-SS-PCL micelles mediate enhanced doxorubicin (DOX) delivery to U87MG glioma xenografts in vivo, resulting in significantly improved tumor growth inhibition as compared to reduction-insensitive cRGD/PEG-PCL controls. cRGD/PEG-SS-PCL micelles revealed a small size of ca. 61nm, a decent DOX loading of 14.9wt%, and triggered drug release in a reductive environment (10mM glutathione). Flow cytometry, confocal microscopy, and MTT assays demonstrated that cRGD/PEG-SS-PCL micelles with a cRGD ligand density of 20% efficiently delivered and released DOX into αvß3 integrin overexpressing U87MG cells. The in vivo pharmacokinetics studies displayed that DOX-loaded cRGD20/PEG-SS-PCL micelles had a prolonged elimination half-life time of 3.51h, which was comparable to that of cRGD20/PEG-PCL counterparts, indicating that disulfide bonds in the PEG-SS-PCL micelles are stable in the circulation. Notably, in vivo imaging and biodistribution studies in U87MG glioma xenografts showed that cRGD20/PEG-SS-PCL micelles led to efficient accumulation as well as fast drug release in the tumor. The therapeutic outcomes demonstrated that DOX-loaded cRGD20/PEG-SS-PCL micelles exhibited little side effects and superior tumor growth inhibition as compared to non-targeting PEG-SS-PCL and reduction-insensitive cRGD20/PEG-PCL counterparts. The reduction-sensitive shell-sheddable biodegradable micelles have appeared as a fascinating platform for targeted tumor chemotherapy.

Impact of ethylene oxide gas sterilization of duodenoscopes after a carbapenem-resistant Enterobacteriaceae outbreak.

BACKGROUND AND AIMS: Carbapenem-resistant Enterobacteriaceae (CRE) outbreaks have been implicated at several medical institutions involving gastroenterology laboratories and, specifically, duodenoscopes. Currently, there are no specific guidelines to eradicate or prevent the outbreak of this bacteria. We describe ethylene oxide (ETO) gas sterilizations of duodenoscopes to address this issue. METHODS: A complete investigation of the gastroenterology laboratory and an evaluation by the Centers for Disease Control and Prevention concluded that no lapses were found in the reprocessing of the equipment. With no deficiencies to address, we began a novel cleaning process using surgical ETO gas sterilizers in addition to standard endoscope reprocessing recommendations and guidelines, all while trying to eradicate the CRE contamination and prevent future recurrences. We also instituted a surveillance system for recurrence of CRE contamination via monthly cultures of the duodenoscopes. RESULTS: Between October 2013 and April 2014, 589 ERCPs were performed with 645 ETO gas sterilizations of 6 duodenoscopes. Given the extra 16 hours needed to sterilize the duodenoscopes, our institution incurred costs resulting from purchasing additional equipment and surveillance cultures. Four duodenoscopes sustained damage during this period; however, this could not be directly attributed to the sterilization process. Furthermore, after an 18-month success period we encountered a positive CRE culture after sterilization, albeit of a different strain than originally detected during the outbreak. The duodenoscope underwent additional ETO gas sterilization, with a negative repeated culture; all potentially exposed individuals screened negative for CRE. CONCLUSIONS: Proper use of high-level disinfection alone may not eliminate multidrug-resistant organisms from duodenoscopes. In this single-center study, the addition of ETO sterilization and frequent monitoring with cultures reduced duodenoscope contamination and eliminated clinical infections. As such, ETO gas sterilization may provide benefit in further decontamination of duodenoscopes, but further investigation is necessary.

Guía de procedimientos de esterilización a baja temperatura / No disponible

No disponible

Computer-aided orbital wall defects treatment by individual design ultrahigh molecular weight polyethylene implants.

UNLABELLED: Despite of well-known advantages of high molecular weight polyethylene (Medpor, Synpore) in orbital reconstructions, the thickness of those implants significantly exceeds 0.5 mm and precise modification of thickness is limited. The aim of this study was to present the application of a self-developed method of treatment orbital wall fracture by custom implant made of ultrahigh molecular weight polyethylene (UHMW-PE). MATERIAL AND METHOD: First, the test of influence of sterilization process upon implant deformation was performed (autoclaving, ethylene oxide, gas plasma, irradiation). Next, ten cases for delayed surgical treatment of orbital fracture were included into this study (7 males, 3 females). Based on CT scan and mirrored technique, a CAD model of virtual implant for repairing orbital wall was made. Then, an implant was manufactured with a computer numerical controlled milling machine from UHMW-PE block, sterilized and used during a surgical procedure. Clinically used implants had thickness from 0.2 to 4.0 mm. RESULTS: The best method of sterilization is ethylene oxide process, and the worst is autoclaving. In this series of delayed surgical cases, functional results of orbital surgery are worse than in simpler, early treated cases, but long-term subsidence of diplopia is noticeable [10% poor results]. The results of the treatment depend on the initial level of diplopia where severe initial diplopia to be corrected requires thicker implants (p < 0.01). It also leads to longer surgical procedures (p < 0.01), but prolongation of the surgery had no negative influence upon results of any investigated follow-up examinations. Obviously, the orbital destruction intensity is related to injury-evoked initial diplopia but it also influences whole results of treatment up to 12 months post-op. Interesting result is presented by the relation of maximal implant thickness to 12-month diplopia evaluation. Thicker implants used result in lower residual diplopia (p < 0.05). This is important because of the correlation between the higher orbital destruction intensity with a thicker UHMW-PE implant (p < 0.05) applied in this series. CONCLUSION: Patient-specific ultrahigh molecular weight polyethylene implants enable precise reconstructions of orbital wall. One should not be afraid of a significant eye globe reposition caused by these thickness modulated implants, as such repositioning is essential for an efficient correction of enophthalmos.

Nanohydroxyapatite incorporated electrospun polycaprolactone/polycaprolactone-polyethyleneglycol-polycaprolactone blend scaffold for bone tissue engineering applications.

The present work is a comparative evaluation of physical and biological properties of electrospun biodegradable fibrous scaffolds based on polycaprolactone (PCL) and its blend with polycaprolactone-polyethyleneglycol-polycaprolactone (CEC) with and without nanohydroxyapatite (nHAP) particles. The fiber morphology, porosity, surface wettability, and mechanical properties of electrospun PCL were distinctly influenced by the presence of both copolymer CEC and nHAP. The degradation in hydrolytic media affected both morphological and mechanical properties of the scaffolds and the tensile strength decreased by 58% for PCL, 83% for PCL/CEC, 36% for PCL/nHAP and 75% for PCL/CEC/nHAP in 90 days of PBS ageing. MTT assay using mouse fibroblast L929 cells proved all the scaffolds to be non-cytotoxic. An overall enhanced performance was shown by PCL/CEC/nHAP scaffold in cell viability (LPH) and proliferation (Picogreen). Simultaneously, ELF assay of ALP activity (bone marker) confirmed the presence of osteogenic-induced Rabbit adipose-derived mesenchymal stem cells (ADMSCs) on all the scaffolds. In comparison, the results reveal the potential of the cytocompatible PCL/CEC/nHAP scaffold for the fabrication of living bony constructs for tissue engineering applications.

The effects of sterilization methods on lyophilized cartilage grafts in an experimental model.

BACKGROUND: Cartilage graft is an effective method for reconstructing the bony framework of the face and covering the bony defect site. As a process method of cartilages, lyophilization has the advantages of long-term storage and easy handling. We hypothesized that the type of procedure used to sterilize lyophilized cartilage may affect outcomes after implantation into the body. We compared the effects of ethylene oxide (EO) gas, γ-irradiation, and autoclaving methods on cartilage grafts. METHODS: After sterilization, lyophilized human rib cartilage was inserted into subperiosteal pockets created in New Zealand white rabbit skulls. We assessed the weights and ratios of the remaining cartilage and examined histologic changes throughout the implantation period. RESULTS: Over a 5-week period, the γ-irradiated grafts remained more than the other grafts, but after more than 5 weeks, there were no significant differences between γ-irradiated and EO gas-sterilized cartilages. Autoclave-sterilized cartilages were totally resorbed at 10 weeks. CONCLUSIONS: Over 10 weeks of follow-up, based on persistence measurements and histologic appearance, there was little difference between γ-irradiated and EO gas-sterilized lyophilized cartilage used in experimental bone grafts.

Tejido óseo esponjoso esterilizado con gas óxido de etileno / Spongy bone tissue sterilized with ethylene oxide gas

Objetivo: comprobar las propiedades esterilizantes del gas óxido de etileno sobre el hueso esponjoso empleado como implante en la clínica médica, fundamentalmente su eficacia para determinados microorganismos y el tiempo necesario de su uso en autoclave industrial.Métodos: se prepararon 54 porciones de tejido óseo esponjoso en forma de cubo separados en 3 grupos de 18 porciones cada uno. El primer grupo se empleó para evaluar un método de contaminación bacteriológica con cepas de microorganismos conocidos. El segundo y tercer grupo una vez contaminados con los microorganismos conocidos se sometieron a la acción del gas óxido de etileno en subgrupos de 6, durante 60, 90 y 120 min.Resultados: en el primer grupo el 100 por ciento de las muestras contaminadas se presentaron positivas. En los grupos segundo y tercero la efectividad del gas óxido de etileno resultó de 100 por ciento a los 120 min.Conclusión: este método es seguro, por lo que es apropiado para el empleo en la clínica médica(AU)

Objective: verify the sterilizing properties of ethylene oxide gas over the spongy bone used for implants in medical practice, mainly its efficacy against certain microorganisms and the time required for sterilization in industrial autoclaves.Methods: 54 cube-shaped spongy bone tissue samples were prepared and distributed into 3 groups, each with 18 samples. The first group was used to evaluate a bacteriological contamination method with strains of known microorganisms. Upon contamination with the known microorganisms, the second and third groups were subjected to the effect of ethylene oxide gas in subgroups of 6 samples during 60, 90 and 120 minutes.Results: in the first group 100 percent of the samples contaminated were positive. In the second and third groups, the effectiveness of ethylene oxide gas was 100 percent at 120 minutes.Conclusion: this is a safe method appropriate for use in medical practice(AU)

Tejido óseo esponjoso esterilizado con gas óxido de etileno / Spongy bone tissue sterilized with ethylene oxide gas

Objetivo: comprobar las propiedades esterilizantes del gas óxido de etileno sobre el hueso esponjoso empleado como implante en la clínica médica, fundamentalmente su eficacia para determinados microorganismos y el tiempo necesario de su uso en autoclave industrial. Métodos: se prepararon 54 porciones de tejido óseo esponjoso en forma de cubo separados en 3 grupos de 18 porciones cada uno. El primer grupo se empleó para evaluar un método de contaminación bacteriológica con cepas de microorganismos conocidos. El segundo y tercer grupo una vez contaminados con los microorganismos conocidos se sometieron a la acción del gas óxido de etileno en subgrupos de 6, durante 60, 90 y 120 min. Resultados: en el primer grupo el 100 por ciento de las muestras contaminadas se presentaron positivas. En los grupos segundo y tercero la efectividad del gas óxido de etileno resultó de 100 por ciento a los 120 min. Conclusión: este método es seguro, por lo que es apropiado para el empleo en la clínica médica(AU)

Objective: verify the sterilizing properties of ethylene oxide gas over the spongy bone used for implants in medical practice, mainly its efficacy against certain microorganisms and the time required for sterilization in industrial autoclaves. Methods: 54 cube-shaped spongy bone tissue samples were prepared and distributed into 3 groups, each with 18 samples. The first group was used to evaluate a bacteriological contamination method with strains of known microorganisms. Upon contamination with the known microorganisms, the second and third groups were subjected to the effect of ethylene oxide gas in subgroups of 6 samples during 60, 90 and 120 minutes. Results: in the first group 100 percent of the samples contaminated were positive. In the second and third groups, the effectiveness of ethylene oxide gas was 100 percent at 120 minutes. Conclusion: this is a safe method appropriate for use in medical practice(AU)

EGFR-mediated intracellular delivery of Pc 4 nanoformulation for targeted photodynamic therapy of cancer: in vitro studies.

In photodynamic therapy (PDT), the light activation of a photosensitizer leads to the generation of reactive oxygen species that can trigger various mechanisms of cell death. Harnessing this process within cancer cells enables minimally invasive yet targeted cancer treatment. With this rationale, here we demonstrate tumor-targeted delivery of a highly hydrophobic photosensitizer Pc 4 loaded within biocompatible poly(ethylene glycol)-poly(ɛ-caprolactone) block co-polymer micelles. The micelles were surface-modified with epidermal growth factor receptor (EGFR)-targeting GE11 peptides for active targeting of EGFR-overexpressing cancer cells, in vitro. Pc 4-loaded EGFR-targeted micelles were incubated with EGFR-overexpressing A431 epidermoid carcinoma cells for various time periods, to determine Pc 4 uptake by epifluorescence microscopy. The cells were subsequently photoirradiated, and PDT-induced cell death for various incubation periods was determined by MTT assay and fluorescence Live/Dead assay. Our results indicate that active EGFR targeting of the Pc 4-loaded micelles accelerates intracellular uptake of the drug. Consequently, this enhances the PDT-induced cytotoxicity within shorter time periods. FROM THE CLINICAL EDITOR: Photodynamic cancer therapy using Pc 4, a light activated and highly hydrophobic photosensitizer is demonstrated in this paper in vitro. Pc 4 was delivered in block-copolymer micelles surface-modified with GE11 peptides targeting EGFR-overexpressing cancer cells.

Comparison of sterilization of reusable endoscopic biopsy forceps by autoclaving and ethylene oxide gas.

BACKGROUND AND AIMS: Every country has standardized reprocessing guidelines for reducing the risk of microorganism transmission via reusable biopsy forceps. Sterilization is performed either by autoclaving or with the use of ethylene oxide (EO) gas. However, there are no clear standard global recommendations. The aim of this study was to determine whether EO gas or autoclaving is a safer and more effective method for the sterilization of reusable forceps. METHODS: This was a prospective study conducted at multiple tertiary referral centers. Seventy reusable biopsy forceps that had been reused at least 20 times each were collected from six endoscopy centers. In all, 61 forceps from five centers were sterilized using EO gas, and the nine forceps from the remaining center were placed in an autoclave. We performed real-time polymerase chain reaction (RT-PCR) for Mycobacterium tuberculosis and hepatitis B virus and performed bacterial cultures on the reusable forceps, which were cut into 2- to 3-cm sections. The forceps were also scanned with an electron microscope (EM) to detect surface damage and contamination. RESULTS: Escherichia coli bacteria were cultured from 2 of the 61 (3.3%) reusable biopsy forceps sterilized with EO gas. On EM scanning, abundant debris and tissue materials remained on the cup surfaces of the reused biopsy forceps and on their inner wires. No microorganisms were found on the autoclaved forceps. CONCLUSIONS: Sterilization with EO gas may be inadequate because the complicated structure of the forceps may interfere with sterilization. Therefore, for optimum safety, reusable biopsy forceps should be sterilized by autoclaving.

Apósito biológico esterilizado con gas óxido de etileno / A biological dressing sterilized using ethylene oxide gas

Objetivo: se presentó el resultado de una investigación preclínica dirigida a comprobar el poder esterilizante del gas óxido de etileno sobre la piel porcina empleada como apósito biológico. Métodos: se contaminaron 2 grupos de 60 muestras cada uno, de piel porcina liofilizada con una cepa de estafilococo coagulasa positivo y Pseudomona aeruginosa, respectivamente. El 25 por ciento de las muestras de cada grupo se envió al laboratorio de microbiología para comprobar la efectividad del método de contaminación. El 75 por ciento restante se trató durante diferentes períodos en una cámara de gas óxido de etileno y, posteriormente, se enviaron al laboratorio de microbiología para comprobar el grado de esterilidad. Resultados: se demostró la alta efectividad del gas óxido de etileno para esterilizar la piel porcina que es empleada como apósito biológico. Conclusiones: este método es seguro, por lo que es apropiado para el empleo en la clínica médica

Objective: to present the result from a preclinical research aimed to verify the sterilizing power of ethylene oxide gas on the porcine skin used as a biological dressing. Methods: two groups of 60 samples each of lyophilized porcine skin were contaminated with a strain of positive-coagulase staphylococcus and Pseudomona aeruginosa, respectively. The 25 percent of samples of each group was sent to microbiology laboratory to verify the effectiveness of contamination method. The remainder 75 percent was treated in different periods in a chamber of ethylene oxide gas and later, was sent to the above laboratory to verify the sterility degree. Results: it was demonstrated the effectiveness of the ethylene oxide gas to sterilize the porcine skin, which is used as a biological dressing. Conclusions: this method is safe, therefore it is appropriate to use in the medical clinic

Apósito biológico esterilizado con gas óxido de etileno / A biological dressing sterilized using ethylene oxide gas

Objetivo: se presentó el resultado de una investigación preclínica dirigida a comprobar el poder esterilizante del gas óxido de etileno sobre la piel porcina empleada como apósito biológico. Métodos: se contaminaron 2 grupos de 60 muestras cada uno, de piel porcina liofilizada con una cepa de estafilococo coagulasa positivo y Pseudomona aeruginosa, respectivamente. El 25 por ciento de las muestras de cada grupo se envió al laboratorio de microbiología para comprobar la efectividad del método de contaminación. El 75 por ciento restante se trató durante diferentes períodos en una cámara de gas óxido de etileno y, posteriormente, se enviaron al laboratorio de microbiología para comprobar el grado de esterilidad. Resultados: se demostró la alta efectividad del gas óxido de etileno para esterilizar la piel porcina que es empleada como apósito biológico. Conclusiones: este método es seguro, por lo que es apropiado para el empleo en la clínica médica(AU)

Objective: to present the result from a preclinical research aimed to verify the sterilizing power of ethylene oxide gas on the porcine skin used as a biological dressing. Methods: two groups of 60 samples each of lyophilized porcine skin were contaminated with a strain of positive-coagulase staphylococcus and Pseudomona aeruginosa, respectively. The 25 percent of samples of each group was sent to microbiology laboratory to verify the effectiveness of contamination method. The remainder 75 percent was treated in different periods in a chamber of ethylene oxide gas and later, was sent to the above laboratory to verify the sterility degree. Results: it was demonstrated the effectiveness of the ethylene oxide gas to sterilize the porcine skin, which is used as a biological dressing. Conclusions: this method is safe, therefore it is appropriate to use in the medical clinic(AU)

Anticoagulación del circuito extracorpóreo esterilizado con óxido de etileno y rayos gamma: ¿necesitan las mismas dosis de heparina? / Anticoagulation of the extracorporeal circuit sterilized with ethylene oxide and gamma irradiation: is the same dose of heparin needed?

Introducción: En los últimos años se han ido sustituyendo las líneas de hemodiálisis esterilizadas con óxido de etileno por las esterilizadas con rayos gamma, dado que numerosos autores han demostrado que es un método más biocompatible. Al utilizar líneas esterilizadas con rayos gamma observamos que se formaban más coágulos que con las esterilizadas con óxido de etileno. Objetivos: Observar si hay diferencia en las dosis de heparina utilizadas y en la formación de coágulos en los circuitos extracorpóreos esterilizados con rayos gamma y óxido de etileno. Material y método: Hemos realizado un estudio cuasi-experimental, longitudinal y prospectivo, utilizando en el mismo paciente líneas de hemodiálisis esterilizadas con rayos gamma y con óxido de etileno. Se realizaron en cada paciente 12 sesiones de hemodiálisis consecutivas con cada tipo de línea. Después de cada sesión se valoraron las pérdidas hemáticas en las cámaras arteriales y venosas, así como las necesidades de heparina. Resultado: Los resultados obtenidos demuestran que la formación de coágulos es mayor en las líneas esterilizadas con rayos gamma y que sí se modificó la dosis de heparina aunque no fue estadísticamente significativa. Discusión: Mantener una buena anticoagulación del circuito extracorpóreo durante la diálisis permite: realizar un tratamiento clínicamente satisfactorio durante el tiempo requerido, evitar pérdidas estimadas altas y minimizar la heparina circulante disminuyendo los efectos secundarios (AU)

Introduction: In recent years, haemodialysis lines sterilized using ethylene oxide have been replaced with lines sterilized using gamma irradiation, as several authors have proven that it is a more biocompatible method. On using lines sterilized by gamma irradiation, we observed that more clots were formed than with lines sterilized with ethylene oxide. Aims: To observe whether there is a difference in the heparin doses used and in the formation of clots in the extracorporeal circuits sterilized using gamma irradiation and ethylene oxide. Material and method: We carried out a quasiexperimental, longitudinal and prospective study using haemodialysis lines sterilized by gamma irradiation and by ethylene oxide on the same patient. On each patient, 12 consecutive haemodialysis sessions with each type of line were carried out. After each session, the blood loss in the arterial and venous chambers was evaluated, together with the heparin needs. Results: The results obtained show that clot formation is higher in the lines sterilized using gamma irradiation and that the heparin dose was indeed modified, although it was not statistically significant. Discussion: Maintaining good anticoagulation of the extracorporeal circuit during dialysis makes it possible to: carry out a clinically satisfactory treatment during the time required, prevent estimated high losses and minimize the circulating heparin, reducing the side effects (AU)

Bacterial leakage in obturated root canals-part 2: a comparative histologic and microbiologic analyses.

OBJECTIVE: In this study, presence of dentin infection in root canals, obturated with 4 techniques submitted to the bacterial leakage test, was evaluated using histologic methods. STUDY DESIGN: The canals of palatal roots of 160 molars were instrumented and divided into different groups, according to the obturation technique used (lateral condensation, MicroSeal system, Touch 'n Heat + Ultrafil, and Tagger's hybrid technique) and extent of the remaining obturation material (5 mm and 10 mm). Ten additional roots were used as control samples. The roots were sterilized in ethylene oxide and mounted on a device for evaluation of bacterial leakage using the bacteria Enterococcus faecalis for 120 days. After the leakage test, roots were microscopically analyzed for the presence of dentin infection in the root canals and dentinal tubules. RESULTS: A total of 154 specimens were analyzed using both methodologies in the experimental groups; 50 root canals (32.4%) showed bacterial leakage at the end of the experimental period, and 118 (76.6%) showed the presence of bacteria in the root canals using the histologic criteria. The lateral condensation technique allowed lower penetration of bacteria in the root canals and dentinal tubules, followed by Touch 'n Heat + Ultrafil, MicroSeal, and Tagger's hybrid technique, which allowed significantly greater penetration of bacteria. Root canals with 10 mm of remaining obturation material presented similar bacterial penetration as root canals with 5 mm. CONCLUSIONS: Even when an adequate seal of the apical foramen was shown by the absence of turbidity in the bacterial leakage test, E. faecalis dentin infection was present in a high percentage of the root canals after 120 days of root filling exposure to the bacteria. Tagger's hybrid technique presented greater quantity of bacteria in histologic sections than root canals obturated with the other techniques.

Reconstrucción craneofacial compleja: malla de titanio, hueso autólogo preservado en óxido de etileno y reconstrucciones tridimensionales en polimetilmetacrilato (HTR-PMI) / Complex craneofacial reconstruction: titanium mesh, autologous bone preserved in ethylene oxide and tridimensional polimetilmetacrilate implants (HTR-PMI)

La evolución de la Cirugía Craneofacial se inició con Jean Paul Tessier, quien en 1967 preconizó el uso de injertos autólogos de hueso fresco en gran cantidad para cubrir extensas brechas óseas en la corrección de disóstosis craneofacial. Recientemente, diferentes tipos de reconstrucción utilizando hueso autólogo preservado en óxido de etileno y materiales como el polimetilmetacrilatoporoso confeccionado a medida, han permitido también la corrección de grandes defectos óseos craneofaciales. Presentamos nuestra experiencia inicial en el uso de estas técnicas a través de un análisis retrospectivo sobre 21 pacientes operados por un equipo multidisciplinario entre Enero del 2007 y Marzo del 2009 en el Hospital Militar, Centro Panamericano de Ojos y Hospital de Diagnóstico de El Salvador, en los que se utilizaron formas alternativas pera reconstrucción de calota craneana, piso de órbita, fosa craneal anterior, área órbito-cigomática y maxilar superior. No registramos casos de infección o retirada de material de osteosíntesis aloplástico o de los injertos autólogos, ni hubo fístulas. Si se presentó una úlcera postraumática en una zona de unión de tejido desvitalizado, que se resolvió con tratamiento conservador. Los resultados estéticos obtenidos fueron de aceptables a buenos. Como conclusión, el equipo multidisciplinario, la combinación de técnicas quirúrgicas y el uso de material protésico para la reconstrucción craneofacial compleja ha dado como resultado avances significativos desde el punto de vista funcional y estético ante lesiones que involucran esta compleja área anatómica (AU)

The evolution of craniofacial surgery began with Jean Paul Tessier, who in 1967 supported the use of fresh autologous bone to cover bone defects in the craniofacial area. Recently different types of reconstructions using autologous bone preserved in ethylene oxide and advanced custom-made polimetacrilate implants that have allowed more complex and esthetically rewarding procedures to patients have suffered extensive bone loss in the craniofacial area. We report our initial experience using these techniques with a retrospective analysis of 21 patients operated from January 2007 to March 2009 by a multidisciplinary team in the Hospital Militar, Centro Panamericano de Ojos and Hospital de Diagnóstico of El Salvador, who required complex craniofacial reconstruction using one or more techniques to cover the defects. The reconstructed areas have been cranium, orbital roof and floor as well as cigomatic region, anterior cranium fossa and superior maxillary sinuous. No infections or retrieval of material for reconstruction or fistulas were reported and only one post-traumatic ulcer that resolved in a conservative way. The esthetic results in the patient soperated have been considered acceptable, to excellent. As a conclusions, multidisciplinary team, combination of surgical techniques and the acquisition of advanced prosthesis material for craniofacial reconstructions has resulted in a significant advance from the functional and aesthetic point of view in areas that involve this anatomically complex area (AU)

Evaluation of Permacol as a cultured skin equivalent.

Skin loss following severe burn requires prompt wound closure to avoid such complications as fluid and electrolyte imbalance, infection, immune suppression, and pain. In clinical situations in which insufficient donor skin is available, the development of cultured skin equivalents (dermal matrices seeded with keratinocytes and fibroblasts) may provide a useful alternative. The aim of this study was to assess the suitability of a porcine-derived dermal collagen matrix (Permacol) to function as a cultured skin equivalent in supporting the growth of keratinocytes in vitro and providing cover to full thickness wounds in the BALB C/nude mouse model. A histological comparison was against Glycerol treated-Ethylene Oxide Sterilised Porcine Dermis (Gly-EO Dermis) which has successfully been used as a cultured skin equivalent in previous studies. Both Gly-EO Dermis and to a lesser extent Permacol were able to support the growth of cultured keratinocytes following a 16-day period of cell culture, however, this study was only able to demonstrate the presence of an epidermal layer on Gly-EO dermis 2 weeks after grafting onto full-thickness wounds in the BALB C/nude mouse model.