Análisis a largo plazo del cartílago producido por injertos libres de periostio tibial en lesiones articulares del cóndilo femoral del conejo

Propósito de estudio: Analizar la reparación de lesiones del cartílago articular con injertos libres de periostio. Material y Métodos: 36 conejos de Nueva Zelanda, de 4 a 6 semanas. Creación de úlcera condral en cóndilo femoral interno. Evolución espontánea en 18 animales. Tratamiento con injerto libre de periostio tibial fijado con Tissucol R en otros 18 animales. Sacrificio en grupos de 67 animales a las 8, 12 y 24 semanas. Valoración de resultados macroscópicos, histológicos e histoquímicos. Análisis estadístico mediante el Test de la "U" de Mann-Whitney. Resultados: La evolución espontánea de la lesión no conllevó, en ningún caso, su reparación completa. El injerto libre de periostio tibial proporcionó una reparación completa de la lesión y una restauración de la superficie articular con diferencia estadísticamente significativa. Conclusiones: El presente estudio pone de manifiesto, en el conejo, la escasa capacidad de reparación espontánea del cartílago articular y el potencial condrogénico de injertos libres de periostio tibial, con mantenimiento a largo plazo de las características macroscópicas, histológicas e histoquímicas del neocartílago. Se discute la posibilidad de su utilización como método alternativo en la reparación de lesiones osteocondrales circunscritas en pacientes jóvenes.Purpose of the study: To analyze the healing capacity of articular cartilage lesions treated with periostium free grafos. Material and Methods: 36 New Zealand rabbits, 4-6 weeks old were used. A chondral defect was created in the medial femoral condyle and a free graft of tibial periostium filling the defect was fixed with Tissucol in 18 animals. The other 18 rabbits were used as controls. The specimens for laboratory study were harvested at 8, 12 and 24 weeks. Evaluation included macroscopic, histological and histochemical results. Mann-Whitney test was used for statistical analysis. Results: Spontaneous evolution of the lesion did not lead to complete repair of cartilage lesions and restoration of the articular surface that was statistically significant. Conclusions: the study confirms, in the rabbit, the scarce spontaneous repair of articular cartilage and the chondrogenic potential of tibial periosteum free implants, with long term maintenance of the macroscopic, histologic and histochemical characteristics of neocartilage. The potential for its use as an alternative method in repair of circumscribed osteochondral lesions in young patients is discussed

Strategies for cancer gene-delivery improvement by non-viral vectors

Lack of selectivity together with severe side effects in conventional cancer treatment have afforded the devel- opment of new strategies based on gene therapy. Nowadays, gene therapy is employed through both viral and non-viral vectors. In spite of the high transfection activity of viral vectors, some drawbacks have pointed out to non-viral vectors as a safer alternative. To overcome low efficiency as well as other issues associated with the use of non-viral vectors, complexes formed by lipids and polymers with DNA, named lipoplexes and polyplexes respectively, have been modified in order to improve its features. Suitability of cancer gene therapy also requires the capacity to distinguish between normal and tumoral cells. This requirement has been solved by the addition of specific ligands that enable receptor binding and subsequent endocytosis. In this article we review the most recent approaches in structure modification of non-viral vectors through different methods comprising conjugation, addition of helper lipids or changes in design and synthesis as well as the strategy based on exploiting receptors that are usually overexpressed in malignancies. Such improvements confer specificity, efficient gene delivery, condensation, protection of DNA and low levels of toxicity avoiding off-target effects which turn into a potential tool to treat cancer

Lipaza iz plijesni Mucor griseocyanus: proizvodnja, karakterizacija i istraživanje nekih katalitičkih svojstava imobiliziranog enzima

The aim of this work is to study the production of extracellular lipase by Mucor griseocyanus 55.1.1 strain on different substrates in order to select the ideal one for lipase synthesis. The carbon sources used were: olive oil, glycerol, coconut oil, sunflower oil, glucose, starch and sucrose. The obtained results indicate that the synthesis of the enzyme was possible in the presence of all substrates. Lipase activities in the range of 0.04 to 0.1 IU/mL were obtained. It was found that the most suitable carbon source for the production of the enzyme was a combination of coconut oil and sucrose at 0.5 and 1.5 % (m/V), respectively, and the level of activity reached under this condition was 0.113 IU/mL. The optimum pH and temperature for enzymatic extract activities were identified in a pH range of 4 to 6 and at a temperature of 60 °C. Enzymatic extract was stable for a period of 5 h in neutral and weakly acidic media (pH=6) at moderate temperatures between 20 and 40 °C. Studies on the catalytic properties (stereoselectivity and enantioselectivity) of the immobilized lipase using the esters of methyl phenyl glycinic and (R,S)-methyl mandelic acid showed excellent properties of the enzyme compared to commercial lipases tested. M. griseocyanus lipase exhibited a greater stereoselectivity towards the R-isomer of methyl phenyl glycinic acid ester. However, with the esters of methyl mandelic acid, the enzyme showed a certain preference toward the S-isomer and it was hydrolysed 20 times faster than the R-isomer.Svrha je ovoga rada bila proučiti proizvodnju ekstracelularne lipaze iz soja Mucor griseocyanus 55.1.1. na raznim podlogama radi odabira najboljeg načina sinteze lipaze. Upotrijebljeni su ovi izvori ugljika: maslinovo ulje, glicerol, kokosovo i suncokretovo ulje, te škrob i saharoza. Rezultati su pokazali da se sinteza enzima odvijala na svim podlogama, te da je postignuta aktivnost lipaze u rasponu od 0,04 do 0,1 IU/mL. Utvrđeno je da su najbolji rezultati dobiveni s podlogom koja sadržava 0,5 % (m/V) kokosova ulja i 1,5 % (m/V) saharoze, pri čemu je aktivnost enzima iznosila 0,113 IU/mL. Optimalna pH-vrijednost bila je od 4 do 6, a temperatura 60 ºC. Ekstrakt enzima bio je stabilan tijekom 5 sati u neutralnoj ili slabo kiseloj sredini (pH=6), pri temperaturama od 20 do 40 ºC. Istraživanjem katalitičkih svojstava (stereoselektivnosti i enantioselektivnosti) imobilizirane lipaze pomoću metilfenilnog estera glicinske kiseline i (R,S)-metilnog estera bademove kiseline dokazana su odlična svojstva tog enzima u usporedbi s komercijalnim lipazama. Lipaza iz plijesni M. griseocyanus ima veću stereoselektivnost prema R-oblicima metilfenilnog estera glicinske kiseline i S-izomeru metilnog estera bademove kiseline (kojeg hidrolizira 20 puta brže od R-izomera)

Time-Dependent Framework for Analyzing Emergency Intervention Travel Times and Risk Implications due to Earthquakes. Bucharest Case Study

Earthquakes can generate a significant number of casualties within seconds, as well as high economic losses. The lack of rapid and coordinated emergency intervention can contribute to much greater losses. In this paper we develop a framework taking advantage of the ArcGis Network Analyst extension, able to account for post-earthquake conditions and reflect travel times. By combining 1) network characteristics with 2) direct seismic damage information, 3) models to determine road obstruction potential, 4) traffic information and time-dependent post-earthquake modeling but also 5) emergency intervention facilities (hospitals or fire stations) and considerations regarding their functional limitations, this framework can provide important support for the management of emergency intervention but also for risk reduction planning. Main results consist of maps showing travel times for various scenarios and moments after an earthquake, inaccessible areas, vital roads for access or an identification of important facilities. As case study we chose Bucharest, one of Europe’s most endangered capitals considering the seismic risk level. The city was and could be considerably affected by earthquakes in the Vrancea Seismic Zone, being characterized by a high number of vulnerable buildings and by one of the greatest typical traffic congestion levels in the world. Compared to previous network studies for Bucharest, the new approach is more complex and customable, providing means for real-time integration and time-dependent analysis. Results, for a worst-case scenario, prove that the risks could be even greater than expected, but also what should be done to mitigate them, such as the construction of a new hospital in the western part of the city, ensuring safe delimited routes for emergency vehicles or expanding the treatment capacity of actual hospitals—some of which also need seismic retrofitting. Results of this study will be integrated in the revised version of the National Conception for Post-Earthquake Response—an operational framework which will lead to risk mitigation through the improvement of post-disaster reaction

Gestión para la mejora continua del consejo técnico y su impacto en la práctica educativa del docente de educación especial

Trabajo en el que se plantea una estrategia para atender a la problemática del poco impacto que tienen en las aulas los aprendizajes que se generan en el consejo técnico consultivo del centro de educación especial CAM Niños Héroes. Se propone un plan de intervención que implica adentrarse en las experiencias del consejo y situarlas en el referente teórico correspondiente para mejorar los aprendizajes y su implementación en las clases a través del seguimiento al desempeño docente

Electronic Descriptors for Supervised Spectroscopic Predictions

Spectroscopic properties of molecules holds great importance for the description of the molecular response under the effect of an UV/Vis electromagnetic radiation. Computationally expensive ab initio (e.g. MultiConfigurational SCF, Coupled Cluster) or TDDFT methods are commonly used by the quantum chemistry community to compute these properties. In this work, we propose a (supervised) Machine Learning approach to model the absorption spectra of organic molecules. Several supervised ML methods have been tested such as Kernel Ridge Regression (KRR), Multiperceptron Neural Networs (MLP) and Convolutional Neural Networks. The use of only geometrical descriptors (e.g. Coulomb Matrix) proved to be insufficient for an accurate training. Inspired on the TDDFT theory, we propose to use a set of electronic descriptors obtained from low-cost DFT methods: orbital energy differences, transition dipole moment between occupied and unoccupied Kohn-Sham orbitals and charge-transfer character of mono-excitations. We demonstrate that with this electronic descriptors and the use of Neural Networks we can predict not only a density of excited states, but also getting very good estimation of the absorption spectrum and charge-transfer character of the electronic excited states, reaching results close to the chemical accuracy (~2 kcal/mol or ~0.1eV)

A basic electro-topological descriptor for the prediction of organic molecule geometries by simple machine learning

This paper proposes a machine learning (ML) method to predict stable molecular geometries from their chemical composition. The method is useful for generating molecular conformations which may serve as initial geometries for saving time during expensive structure optimizations by quantum mechanical calculations of large molecules. Conformations are found by predicting the local arrangement around each atom in the molecule after trained from a database of previously optimized small molecules. It works by dividing each molecule in the database into minimal building blocks of different type. The algorithm is then trained to predict bond lengths and angles for each type of building block using an electro-topological fingerprint as descriptor. A conformation is then generated by joining the predicted blocks. Our model is able to give promising results for optimized molecular geometries from the basic knowledge of the chemical formula and connectivity. The method trends to reproduce interatomic distances within test blocks with RMSD under 0.05

A Case Study of Malignant Edema in Postpartum Mediterranean Buffaloes (Bubalus bubalis)

The paper describes for the first time four cases of postparturient malignant edema in water buffaloes due to Clostridium septicum (Cl. septicum). The study was carried out on four primiparous buffaloes that showed swelling of perineal and perivulvar areas, fever and agalactia a few hours after calving. Two of them died within 20 hours after calving. The other two developed edema in the skeletal muscles of one leg and were treated with sulfadiazine-trimethoprim for 10 days. The clinical signs completely resolved. Culture and molecular investigations identified the pathogen isolated from exudate taken from the vulva as Cl. septicum. The isolate showed multi-drug resistance. In the management of infection due to Cl. septicum, timely diagnosis and the chirurgic curettage, associated with a broad-spectrum antibiotic therapy, were found to be sufficient for the survival and recovery of the infected animals

Circumventing Traditional Conditioning Protocols in Polymer Membrane-Based Ion-Selective Electrodes

Preparation of ion-selective electrodes (ISEs) often requires long and complicated conditioning protocols limiting their application as tools for in-field measurements. Herein, we eliminated the need for electrode conditioning by loading the membrane cocktail directly with primary ion solution. This proof of concept experiment was performed with iodide, silver, and sodium selective electrodes. The proposed methodology significantly shortened the preparation time of ISEs, yielding functional electrodes with submicromolar detection limits. Moreover, it is anticipated that this approach may form the basis for the development of miniaturized all-solid-state ion-selective electrodes for in situ measurements