Evaluation of the Applicability of 3d Models as Perceived by the Students of Health Sciences.

The methodology and style of teaching anatomy in the faculties of Health Sciences is evolving due to the changes being introduced as a result of the application of new technologies. This brings a more positive attitude in the students, enabling an active participation during the lessons. One of these new technologies is the creation of 3D models that reliably recreates the anatomical details of real bone pieces and allow access of anatomy students to bone pieces that are not damaged and possess easily identifiable anatomical details. In our work, we have presented previously created 3D models of skull and jaw to the students of anatomy in the Faculties of Health Sciences of the University of Salamanca, Spain. The faculties included were odontology, medicine, occupational therapy nursing, health sciences and physiotherapy. A survey was carried out to assess the usefulness of these 3D models in the practical study of anatomy. The total number of students included in the survey was 280.The analysis of the results presents a positive evaluation about the use of 3D models by the students studying anatomy in different Faculties of Health Sciences.

Different Digitalization Techniques for 3D Printing of Anatomical Pieces.

The use of different technological devices that allow the creation of three-dimensional models is in constant evolution, allowing a greater application of these technologies in different fields of health sciences and medical training. The equipment for digitalization is becoming increasingly sophisticated allowing obtaining three-dimensional which are more defined and similar to real image and original object. In this work, different modalities of designing 3D anatomical models of bone pieces are presented, for use by students of different disciplines in Health Sciences. To do this we digitalized bone pieces, with different models of scanners, producing images that can be transformed for 3D printing, with a Colido X 3045 printer by digital treatment with different software.

3D Models of Female Pelvis Structures Reconstructed and Represented in Combination with Anatomical and Radiological Sections.

We present a computer program designed to visualize and interact with three-dimensional models of the main anatomical structures of the female pelvis. They are reconstructed from serial sections of corpse, from the Visible Human project of the Medical Library of the United States and from serial sections of high-resolution magnetic resonance. It is possible to represent these three-dimensional structures in any spatial orientation, together with sectional images of corpse and magnetic resonance imaging, in the three planes of space (axial, coronal and sagittal) that facilitates the anatomical understanding and the identification of the set of visceral structures of this body region. Actually, there are few studies that analysze in detail the radiological anatomy of the female pelvis using three-dimensional models together with sectional images, making use of open applications for the representation of virtual scenes on low cost Windows® platforms. Our technological development allows the observation of the main female pelvis viscera in three dimensions with a very intuitive graphic interface. This computer application represents an important training tool for both medical students and specialists in gynecology and as a preliminary step in the planning of pelvic floor surgery.

The Role of CYP2E1 in the Drug Metabolism or Bioactivation in the Brain.

Organisms have metabolic pathways that are responsible for removing toxic agents. We always associate the liver as the major organ responsible for detoxification of the body; however this process occurs in many tissues. In the same way, as in the liver, the brain expresses metabolic pathways associated with the elimination of xenobiotics. Besides the detoxifying role of CYP2E1 for compounds such as electrophilic agents, reactive oxygen species, free radical products, and the bioactivation of xenobiotics, CYP2E1 is also related in several diseases and pathophysiological conditions. In this review, we describe the presence of phase I monooxygenase CYP2E1 in regions of the brain. We also explore the conditions where protein, mRNA, and the activity of CYP2E1 are induced. Finally, we describe the relation of CYP2E1 in brain disorders, including the behavioral relations for alcohol consumption via CYP2E1 metabolism.

Genetic diversity and patterns of population structure in Creole goats from the Americas.

Biodiversity studies are more efficient when large numbers of breeds belonging to several countries are involved, as they allow for an in-depth analysis of the within- and between-breed components of genetic diversity. A set of 21 microsatellites was used to investigate the genetic composition of 24 Creole goat breeds (910 animals) from 10 countries to estimate levels of genetic variability, infer population structure and understand genetic relationships among populations across the American continent. Three commercial transboundary breeds were included in the analyses to investigate admixture with Creole goats. Overall, the genetic diversity of Creole populations (mean number of alleles = 5.82 ± 1.14, observed heterozygosity = 0.585 ± 0.074) was moderate and slightly lower than what was detected in other studies with breeds from other regions. The Bayesian clustering analysis without prior information on source populations identified 22 breed clusters. Three groups comprised more than one population, namely from Brazil (Azul and Graúna; Moxotó and Repartida) and Argentina (Long and shorthair Chilluda, Pampeana Colorada and Angora-type goat). Substructure was found in Criolla Paraguaya. When prior information on sample origin was considered, 92% of the individuals were assigned to the source population (threshold q ≥ 0.700). Creole breeds are well-differentiated entities (mean coefficient of genetic differentiation = 0.111 ± 0.048, with the exception of isolated island populations). Dilution from admixture with commercial transboundary breeds appears to be negligible. Significant levels of inbreeding were detected (inbreeding coefficient > 0 in most Creole goat populations, P < 0.05). Our results provide a broad perspective on the extant genetic diversity of Creole goats, however further studies are needed to understand whether the observed geographical patterns of population structure may reflect the mode of goat colonization in the Americas.

Adaptive fuzzy modeling of the hypnotic process in anesthesia.

This paper addresses the problem of patient model synthesis in anesthesia. Recent advanced drug infusion mechanisms use a patient model to establish the proper drug dose. However, due to the inherent complexity and variability of the patient dynamics, difficulty obtaining a good model is high. In this paper, a method based on fuzzy logic and genetic algorithms is proposed as an alternative to standard compartmental models. The model uses a Mamdani type fuzzy inference system developed in a two-step procedure. First, an offline model is obtained using information from real patients. Then, an adaptive strategy that uses genetic algorithms is implemented. The validation of the modeling technique was done using real data obtained from real patients in the operating room. Results show that the proposed method based on artificial intelligence appears to be an improved alternative to existing compartmental methodologies.

Expansion of quiescent lung adenocarcinoma CD8+ T cells by MUC1-8-mer peptide-T2 cell-ß2 microglobulin complexes.

Adoptive immunotherapy requires the isolation of CD8+ T cells specific for tumor-associated antigens, their expansion in vitro and their transfusion to the patient to mediate a therapeutic effect. MUC1 is an important adenocarcinoma antigen immunogenic for T cells. The MUC1-derived SAPDTRPA (MUC1-8-mer) peptide is a potent epitope recognized by CD8+ T cells in murine models. Likewise, the T2 cell line has been used as an antigen-presenting cell to activate CD8+ T cells, but so far MUC1 has not been assessed in this context. We evaluated whether the MUC1-8-mer peptide can be presented by T2 cells to expand CD25+CD8+ T cells isolated from HLA-A2+ lung adenocarcinoma patients with stage III or IV tumors. The results showed that MUC1-8-mer peptide-loaded T2 cells activated CD8+ T cells from cancer HLA-A2+ patients when anti-CD2, anti-CD28 antibodies and IL-2 were added. The percentage of CD25+CD8+ T cells was 3-fold higher than those in the non-stimulated cells (P=0.018). HLA-A2+ patient cells showed a significant difference (2.3-fold higher) in activation status than HLA-A2+ healthy control cells (P=0.04). Moreover, 77.6% of MUC1-8-mer peptide-specific CD8+ T cells proliferated following a second stimulation with MUC1-8-mer peptide-loaded T2 cells after 10 days of cell culture. There were significant differences in the percentage of basal CD25+CD8+ T cells in relation to the cancer stage; this difference disappeared after MUC1-8-mer peptide stimulation. In conclusion, expansion of CD25+CD8+ T cells by MUC1-8 peptide-loaded T2 cells plus costimulatory signals via CD2, CD28 and IL-2 can be useful in adoptive immunotherapy.

Synthesis and characterization of self-curing hydrophilic bone cements for protein delivery.

New formulations of acrylic bone cements for bone defect reparation, based on self-hardening methyl methacrylate (MMA)/methacrylic acid (MAA), with a high capacity for protein delivery, have been developed. The self-curing formulations were prepared by partial substitution of solid phase PMMA microparticles by newly obtained PMAA microspheres. The PMAA microspheres were prepared by inverse suspension polymerization of their monomer and were cross-linked with N,N'-methylene-bis-acrylamide (MBA) (10-15 wt %) to produce stable systems in contact with aqueous media. PMAA microspheres were loaded with hydrolyzed collagen (HC) as a model protein to simulate bone morphogenetic protein delivery useful for hard tissue reconstruction. Solid phase PMMA microparticles in the formulation were partially substituted by new PMAA-HC microspheres and were characterized to determine viability as an acrylic bone cement in minimally invasive surgery. The incorporation of PMAA-HC microspheres decreased peak temperature by 20°C, which minimized thermal necrotic risk after implantation. Mechanical compression tests revealed a behavior, under dry conditions, close to ISO 5833 standard requirements. However, a drastic drop in mechanical strength, ∼64%, was obtained after 15 days of immersion in simulated physiological conditions (37°C and pH 7.4) and was attributed to water absorption and a subsequent plasticizing effect. The increase in water uptake and retention enhanced the capability for controlled protein delivery. Finally, the biocompatibility of the cements was determined; some toxicity of the material during the first hours of culture incubation was observed. Later, toxicity was observed to decrease due to nonreacted monomer leaching, which ensured the low toxicity of the already polymerized phase.

High reflectance ta-C coatings in the extreme ultraviolet.

The extreme ultraviolet (EUV) reflectance of amorphous tetrahedrally coordinated carbon films (ta-C) prepared by filtered cathodic vacuum arc was measured in the 30-188-nm range at near normal incidence. The measured reflectance of films grown with average ion energies in the ~70-140-eV range was significantly larger than the reflectance of a C film grown with average ion energy of ~20 eV and of C films deposited by sputtering or evaporation. The difference is attributed to a large proportion of sp3 atom bonding in the ta-C film. This high reflectance is obtained for films deposited onto room-temperature substrates. The reflectance of ta-C films is higher than the standard single-layer coating materials in the EUV spectral range below 130 nm. A self-consistent set of optical constants of ta-C films was obtained with the Kramers-Krönig analysis using ellipsometry measurements in the 190-950 nm range and the EUV reflectance measurements. These optical constants allowed calculating the EUV reflectance of ta-C films at grazing incidence for applications such as free electron laser mirrors.

Design and implementation of a closed-loop control system for infusion of propofol guided by bispectral index (BIS).

BACKGROUND: This study describes the design of a hypnosis closed-loop control system with propofol. The controller used a proportional-integral (PI) algorithm with the bispectral index (BIS) as the feedback signal. Our hypothesis was that a PI closed-loop control could be applied in clinical practice safely keeping the BIS within a pre-determined target range. METHODS: The adjustment of the PI parameters was based on simulation. The procedure had three steps: obtaining a patient model using data from 12 patients, designing and adjusting the controller in simulation, and fine tuning the PI parameters in a pilot study (10 patients). The resulting controller was tested in 24 American Society of Anesthesiology (ASA) I-II patients. The controller directly decides the infusion rate of propofol, and no model is necessary in its online operation. The BIS target was set to 50. Remifentanil was used for analgesia. RESULTS: We evaluated the efficiency and safety of the automatic feedback system. It worked properly in all the patients. The median performance error was -1.62, and the median absolute performance error was 11.03. Average propofol-normalized consumption was 5.3 ± 1.8 mg/kg/h. Mean percentage of BIS in the range 40-60 was 83%. Mean time to open eyes was 8 ± 4 min. Time to extubation was 9 ± 5 min. Hemodynamic adverse event or intraoperative awareness were not recorded. CONCLUSIONS: The closed-loop system was able to maintain the BIS within an acceptable range of levels. The control of a propofol infusion guided by the BIS is feasible without hemodynamic instability in ASA I/II patients.

Cerebrospinal fluid volume and nerve root vulnerability during lumbar puncture or spinal anaesthesia at different vertebral levels.

Cerebrospinal fluid (CSF) and nerve root volumes within the lumbosacral dural sac were estimated at various vertebral levels, in an attempt to determine any possible relevance to the incidence of nerve root trauma during lumbar puncture or spinal anaesthesia. Magnetic resonance images from seven patients were studied. Volumes were calculated by semi-automatic threshold segmentation combined with manual editing of each slice. The mean dural sac volume from S1 to T12 was 42.8±5.8 ml and the mean CSF volume 34.3±5.1 ml with the mean root volume being 10.4±2.2 cm(3). The mean CSF volume per vertebral segment ranged from 4.3±0.7 ml at L5, to 5.8±2.5 ml at L1, with high inter-individual variability. The mean root volume ranged from 0.6±0.1 cm(3) at L5 to 2.4±0.5 cm(3) at T12. The conus medullaris was located at L1 in four of the five patients scanned at upper lumbar levels, and at the lower border of L2 in the other. Vulnerability to nerve root damage was expressed as the Vulnerability Index (%), being defined as the ratio of root volume to dural sac volume (CSF volume + root volume). The value ranged between 7 and 14% at L5, increasing rostrally to 30 to 43% at T12. Caution is obviously required in high punctures to avoid contact with the conus medullaris, but the cauda equina is also vulnerable to contact with more caudal punctures and had a Vulnerability Index of about 25% at L4, that increased rostrally.

[Use of an external fixator in open tibial shaft fractures as definitive treatment]. / Uso de fijador externo en fracturas diafisarias de tibia expuestas como tratamiento definitivo.

BACKGROUND: We conducted a study evaluating the clinical and radiologic results of the open tibial shaft fractures using an external fixator as definitive treatment. METHODS: Clinical, observational, descriptive, prospective and longitudinal study. Forty-six patients were included, 40 males (87%) and 6 females (13%), whose age was 31.02 +/- 14.62 years; the time elapsed from the accident to admission in the Emergency Room was 1-16 hours, with a mean of 5.1 +/- 3.35 hours. Ten patients (21.74%) had a Gustilo grade I open fracture, and 36 patients (78.26%) a Gustilo grade II fracture. They were also classified according to the AO classification, with the following resulting groups: 13 (28.9%) patients were A3, 12 (26.1%) were B3, 8 (17.4%) B1, 8 (17.4%) were B2, and 5 (10.9%) were A2. The dynamization of the fixator was done at a mean of 11.56 +/- 1.10 weeks. RESULTS: Forty-three patients had healing at 23.51 +/- 3.62 weeks; Gustilo I fractures healed at 22.8 +/- 3.5 weeks; Gustilo II fractures at 23.7 +/- 3.7 weeks, with a P value of 0.48. In 3 patients (6.53%), due to absence of healing, the external fixator was exchanged for an intramedullary nail with a bone graft, with healing occurring at 18 weeks. Six infections (13%) were reported at the nail insertion site; angulations ranged from 0 degrees to 8 degrees, which is tolerable. CONCLUSIONS: This fixator is safe in properly selected patients, since the few complications that occurred are similar to other reports using different internal fixation methods.

Valores de referencia del antígeno prostático específico (PSA) en 63.926 trabajadores sin síntomas prostáticos que participaron en el cribado de cáncer de próstata desarrollado por la Sociedad de Prevención de Ibermutuamur durante el año 2006 / Reference values of prostate specific antigen (PSA) in 63926 workers without prostatic symptoms who participated in prostate screening cancer developed by the Ibermutuamur Prevention Society in 2006

Objetivo: Determinar los valores de referencia de PSA en trabajadores españoles sin antecedentes de problemas prostáticos y compararlos con otras latitudes geográficas. Métodos: Estudio observacional, retrospectivo, multicéntrico y con base poblacional realizado entre 01 de enero y 31 de diciembre de 2006. De los 65.303 trabajadores que participaron en el Programa de cribado del cáncer de próstata realizada por la Sociedad de Prevención de Ibermutuamur en diferentes regiones españolas. De ellos, fueron seleccionados para este informe, 63926: 149 fueron excluidos por historia personal de problemas prostáticos y 1.328 por ser mayores de 64 años. Las determinaciones de PSA se realizaron mediante la prueba de Abbott. Se especificaron los valores de PSA para cada edad y para los rangos de edad: menores de 40 años, 40–49 años, 50–59 años y 60–64 años. También se calcularon las medias de los valores de PSA por Comunidades Autónomas. Los datos fueron expresados como media (±DE), los intervalos de confianza al 95%, error estándar de la media (SEM) y en los percentiles 5, 25, 50, 75 y 95. Los resultados obtenidos fueron comparados con los de otras zonas del mundo. Todos los datos fueron analizados utilizando el programa estadístico GraphPad Quick Calculs. Resultados: Valor medio de PSA: para todos los casos fue de 1,06ng/ml (95% IC: ±1,18); por grupos de edades: menores de 40 años, 0,67ng/ml (95% IC: ±0,49), 40–49 años, 0,77ng/ml (95% IC: ±0,66), 50–59 años, 1,11ng/ml (95% IC: ±1,22) y 60–64 años, 1,57ng/ml (95% IC: ±1,72). Según la edad, osciló entre 0,67ng/ml menores de 40 años y 1,70 en los 64 años. Por Comunidades Autónomas, el valor más bajo se registró en el País Vasco con 0,98ng/ml (95% CI: 1,02) y mayor en Asturias con 1,28ng/ml (95% CI: 1,32). Valores del PSA según percentil: el límite superior (percentil 95) fue de 1,40ng/ml en aquellos menores de 40 años, 1,70ng/ml en 40–49 años, 3,30ng/ml en 50–59 años y 5,18ng/ml en el grupo de 60–64 años. Conclusiones: Los valores de PSA recogidos en este estudio podrían servir de referencia para población española en edad, utilizando el rango descrito por décadas, o mejor aún, los correspondientes a cada edad (AU)

Objective: To determine the values of PSA in Spanish workers without history of prostate problems and compare them with other geographical latitudes. Methods: Observational, retrospective, multicenter and population-based study, conducted between January 1 and December 31, 2006. A total of 65303 workers participated in the Programme of prostate cancer screening conducted by the Ibermutuamur Prevention Society in different Spanish regions. Of these, were selected for this report, 63926: 149 were excluded by personal history of prostate problems and 1328 for being over 64 years. PSA determinations were performed using the Abbott test. Were specified PSA values for each age and for the following age ranges: younger than 40 years, 40–49 years, 50–59 years and 60–64 years. Also calculated the mean PSA values by Autonomous Communities. The data were expressed as mean (±SD), confidence intervals 95%, standard error of the mean (SEM) and in the percentiles 5, 25, 50, 75 and 95. The results obtained were compared with those in other areas of the world. All data were analysed using the statistical software GraphPad Quick Calcs. Results: Mean PSA value: for all cases was 1.06ng/ml (95% CI: ±1,18) and age groups: under 40 years, 0.67ng/ml (95% CI: ±0.49), 40–49 years, 0, 77ng/ml (95% CI: ±0.66), 50–59 years, 1.11ng/ml (95% CI: ±1.22) and 60–64 years, 1.57ng/ml (95% CI: ±1.72). Depending on the age ranged between 0.67ng/ml under age 40 and 1.70 in the 64 years. According to region, the lowest value was recorded in the País Vasco with 0.98ng/ml (95% CI: 1.02) and higher in Asturias with 1.28ng/ml (95% CI: 1.32). Percentile value PSA: the upper normal limit (95th percentile) was 1.40ng/ml in those younger than 40 years, 1.70ng/ml in 40–49 years, 3.30ng/ml in 50–59 years and 5.18ng/ml in the group 60–64 years. Conclusions: PSA values collected in this study may serve as a reference for the Spanish working population, using the range described for decades, or even better, those relating to each age (AU)

[Reference values of prostate specific antigen (PSA) in 63926 workers without prostatic symptoms who participated in prostate screening cancer developed by the Ibermutuamur Prevention Society in 2006]. / Valores de referencia del antígeno prostático específico (PSA) en 63.926 trabajadores sin síntomas prostáticos que participaron en el cribado de cáncer de próstata desarrollado por la Sociedad de Prevención de Ibermutuamur durante el año 2006.

OBJECTIVE: To determine the values of PSA in Spanish workers without history of prostate problems and compare them with other geographical latitudes. METHODS: Observational, retrospective, multicenter and population-based study, conducted between January 1 and December 31, 2006. A total of 65303 workers participated in the Programme of prostate cancer screening conducted by the Ibermutuamur Prevention Society in different Spanish regions. Of these, were selected for this report, 63926: 149 were excluded by personal history of prostate problems and 1328 for being over 64 years. PSA determinations were performed using the Abbott test. Were specified PSA values for each age and for the following age ranges: younger than 40 years, 40-49 years, 50-59 years and 60-64 years. Also calculated the mean PSA values by Autonomous Communities. The data were expressed as mean (+/-SD), confidence intervals 95%, standard error of the mean (SEM) and in the percentiles 5, 25, 50, 75 and 95. The results obtained were compared with those in other areas of the world. All data were analysed using the statistical software GraphPad Quick Calcs. RESULTS: Mean PSA value: for all cases was 1.06 ng/ml (95% CI: +/-1,18) and age groups: under 40 years, 0.67 ng/ml (95% CI: +/-0.49), 40-49 years, 0, 77 ng/ml (95% CI: +/-0.66), 50-59 years, 1.11 ng/ml (95% CI: +/-1.22) and 60-64 years, 1.57 ng/ml (95% CI: +/-1.72). Depending on the age ranged between 0.67 ng/ml under age 40 and 1.70 in the 64 years. According to region, the lowest value was recorded in the País Vasco with 0.98 ng/ml (95% CI: 1.02) and higher in Asturias with 1.28 ng/ml (95% CI: 1.32). Percentile value PSA: the upper normal limit (95th percentile) was 1.40 ng/ml in those younger than 40 years, 1.70 ng/ml in 40-49 years, 3.30 ng/ml in 50-59 years and 5.18 ng/ml in the group 60-64 years. CONCLUSIONS: PSA values collected in this study may serve as a reference for the Spanish working population, using the range described for decades, or even better, those relating to each age.

Evaluation of the influence of the addition of biodegradable polymer matrices in the formulation of self-curing polymer systems for biomedical purposes.

The solid phase of self-curing formulations of poly(methyl methacrylate) was modified by different biodegradable polymer matrices, such as poly(l-lactic acid), poly(beta-hydroxybutyrate) and thermoplastic starches (TPSs). The aim of this modification was the acquisition of a short- to medium-term drug delivery system to release bisphosphonates for hard tissue treatment. Different physico-chemical characterization techniques were used in order to determine the influence of these matrices and their mechanical capacity, in vitro behaviour, curing parameters, residual monomer content and surface topography for the preparation of the self-curing formulations. The incorporation of the polyesters did not induce an increase in water uptake capacity of the system due to their apolar aliphatic character. On the other hand, TPSs exhibited values of water absorption up to 15.3%, related with their hydrophilic chemical structure, dependent on the commercial formulation and the particle size distribution of the powder. The modifications of the solid phase led in all cases to a decrease in the mechanical behaviour of the material, although the formulations modified with TPS were in the range of accepted values according to standard specifications. The immersion of TPS formulations in a simulated physiological environment (phosphate buffer solution, pH 7.4, 37 degrees C) conducted to a surface porosity related with release of plasticizers of the domains of the biodegradable component of the formulation. Finally drug release capacity was studied by loading the material with Ibandronate, observing high dependence with the kind of TPS added, as well as its particle size.

Enhanced glutamatergic phenotype of mesencephalic dopamine neurons after neonatal 6-hydroxydopamine lesion.

There is increasing evidence that a subset of midbrain dopamine (DA) neurons uses glutamate as a co-transmitter and expresses vesicular glutamate transporter (VGLUT) 2, one of the three vesicular glutamate transporters. In the present study, double in situ hybridization was used to examine tyrosine hydroxylase (TH) and VGLUT2 mRNA expression during the embryonic development of these neurons, and postnatally, in normal rats and rats injected with 6-hydroxydopamine (6-OHDA) at P4 to destroy partially DA neurons. At embryonic days 15 and 16, there was a regional overlap in the labeling of TH and VGLUT2 mRNA in the ventral mesencephalon, which was no longer found at late embryonic stages (E18-E21) and postnatally. In normal pups from P5 to P15, only 1-2% of neurons containing TH mRNA in the ventral tegmental area (VTA) and substantia nigra, pars compacta, also displayed VGLUT2 mRNA. In contrast, after the cerebroventricular administration of 6-OHDA at P4, 26% of surviving DA neurons in the VTA of P15 rats expressed VGLUT2. To search for a colocalization of TH and VGLUT2 protein in axon terminals of these neurons, the nucleus accumbens of normal and 6-OHDA-lesioned P15 rats was examined by electron microscopy after dual immunocytochemical labeling. In normal rats, VGLUT2 protein was found in 28% of TH positive axon terminals in the core of nucleus accumbens. In 6-OHDA-lesioned rats, the total number of TH positive terminals was considerably reduced, and yet the proportion also displaying VGLUT2 immunoreactivity was modestly but significantly increased (37%). These results lead to the suggestion that the glutamatergic phenotype of a VTA DA neurons is highly plastic, repressed toward the end of normal embryonic development, and derepressed postnatally following injury. They also support the hypothesis of co-release of glutamate and DA by mesencephalic neurons in vivo, at least in the developing brain.

Combining TiO2-photocatalysis and wetland reactors for the efficient treatment of pesticides.

In the present work the photocatalytic and biological degradation of two commercial mixtures of pesticides (Folimat and Ronstar) and two fungicides (pyrimethanil and triadimenol) has been studied. The evolution of some components of these commercial products (dicofol, tetradifon and oxadiazon) and that of the two fungicides has been monitored by means of HPLC, GC-MS, TOC and toxicity (Lemna minor toxicity test) measurements. The photocatalytic method was able to degrade dicofol, tetradifon, pyrimethanil, triadimenol and the components of Ronstar with the exception of oxadiazon. In addition to this, the photocatalytic method eliminated pyrimethanil toxicity and reduced that of triadimenol by a 90%, Ronstar by a 78% and Folimat by an 87%. Nevertheless, the wetland reactors alone could reduce the toxicity of only the former. Finally, the proper dosage of the water containing the pesticides to a photocatalytic reactor followed by a wetland reactor resulted to be the most successful strategy for the detoxification of the studied compounds and their mixtures.

Chemical modification of jute fibers for the production of green-composites.

Natural fiber reinforced composites is an emerging area in polymer science. Fibers derived from annual plants are considered a potential substitute for non-renewable synthetic fibers like glass and carbon fibers. The hydrophilic nature of natural fibers affects negatively its adhesion to hydrophobic polymeric matrices. To improve the compatibility between both components a surface modification has been proposed. The aim of the study is the chemical modification of jute fibers using a fatty acid derivate (oleoyl chloride) to confer hydrophobicity and resistance to biofibers. This reaction was applied in swelling and non-swelling solvents, pyridine and dichloromethane, respectively. The formation of ester groups, resulting from the reaction of oleoyl chloride with hydroxyl group of cellulose were studied by elemental analysis (EA) and Fourier Transform infrared spectroscopy (FTIR). The characterization methods applied has proved the chemical interaction between the cellulosic material and the coupling agent. The extent of the reactions evaluated by elemental analysis was calculated using two ratios. Finally electron microscopy was applied to evaluate the surface changes of cellulose fibers after modification process.

Injectable self-curing bioactive acrylic-glass composites charged with specific anti-inflammatory/analgesic agent.

Injectable bioactive acrylic formulations based on poly(methyl methacrylate) (PMMA) and different amounts of bioactive glasses in the system SiO2-CaO-Na2O-P2O5 have been prepared in the presence of the anti-inflammatory analgesic drug fosfosal, the sodium salt of 2-phosphonoxibenzoic acid, to be used in minimally invasive surgery. The injectability of the formulations evaluated according to the established protocol was around 80%. The experimental formulations provided maximum temperatures in the range 50-60 degrees C, which were lower than those of commercial acrylic bone cements currently used in percutaneous vertebroplasty (PVP). Residual monomer content of any formulation was inferior to 5%. Compressive yield strength of dry specimens was in the range 80-95 MPa, but it decreased after immersion in SBF to values in the range 30-50 MPa, due to the dissolution of the bioactive glasses and the drug in the medium. The release of fosfosal was evaluated in vitro (pH = 7.0). The release profile against time obtained from a PMMA cement was quasi-linear and the 80% of the initial amount of drug was released in 175 h. However, for bioactive cements, the 80-100% of the fosfosal charged was released in approximately 48 h, due to the dissolution of the glasses in the medium. Values of weight loss of the cements determined gravimetrically ranged between 16% and 26% depending on the initial amount of fosfosal, i.e. 20 or 30 wt%, respectively. The weight loss and the water uptake were simultaneous processes, and values of hydration degree were around 10-14%. The formation of an apatite-like layer was detected on the surface of the cements at different periods of time depending on the composition of the bioactive glasses. The cements containing the glasses with P2O5 produced the growth of the apatite layer in shorter periods of time. The presence of fosfosal accelerated the precipitation of this layer independently on the glasses. The in vivo biocompatibility studied by intramuscular implantation in rats showed the absence of an anti-inflammatory response and a fibrous layer around the implant for the cement prepared with PMMA/fosfosal which is attributed to the therapeutic action of fosfosal acting in situ. The response to cements prepared with bioactive glasses and fosfosal showed a mild inflammatory reaction with the formation of the typical fibrous capsule around the implanted material.

Partially resorbable acrylic bone cements based on self-curing acrylic/phosphate glass formulations.

Partially resorbable self-curing cements based on poly(methyl methacrylate)/phosphate glasses were prepared by mixing methyl methacrylate monomer with poly(methyl methacrylate) powder in different proportions (20-60 wt-%) of phosphate glass (BV11) in the system 44.5-P2 O5 , 44.5-CaO, 11-Na2 O (mol-%). The curing of these formulations showed a reduction of 10 degrees C in the maximum temperature and an increase of 10 minutes in the setting time although the content of residual monomer in the cured materials was unaltered. The presence of the inorganic particles did not significantly change the glass transition temperature of the cement. Static mechanical properties were evaluated in compression. The compressive yield strength of PM-MA/BV11 cements were in the range 110-118 MPa, superior to those of the control for dry specimens. When the test was conducted with wet specimens, a decrease in strength was observed due to the dissolution of the glasses in the medium, but the composites prepared with 20 or 40 wt-% BV11 had the compressive yield strengths required by the international standard for acrylic bone cements (ISO 5833). The dynamic mechanical properties of the formulation containing 60 wt-% BV11 and the corresponding control were evaluated through a fatigue crack propagation test. The results showed that both formulations followed a Paris-Erdogan model in the stable crack propagation, with no significant differences in the value of the exponent m of the mentioned law. Finally, the presence of the phosphate glasses in the acrylic composite did not change the wear damage of the pair UHMWPE/Ti6Al4V produced by the PMMA formulations. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 48-57).