3D printed ventilation tubes and their effect on biological models.

BACKGROUND: Acute otitis media (AOM) causes inflammation and hearing loss. Ventilation tubes are key in treatment. 3D printing improves prostheses in otorhinolaryngology, offering precision and greater adaptability. MATERIALS AND METHODS: An experimental study was conducted with Wistar rats from July to December 2020. 3D tympanostomy tube models were designed, with technical specifications and tests performed on inexpensive 3D printers. The tympanostomy tube was inserted endoscopically. RESULTS: Procedures were performed on five rats with implants in both ears. Pre-intervention pathologies, such as atical retraction and glue ear, were found. The PLA-printed tympanostomy tube showed improvement after adjustments. Histopathological results revealed significant middle and inner ear damage. CONCLUSION: In our study, the design and 3D printing of implants fulfilled the desired functions when modified, with a height of 5 mm. Complications included PLA degradation and ear damage. There were no adverse events during observation, highlighting the need for further research on 3D-printed implants.

Carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex.

The aim of the study was to compare carcass composition and physicochemical and sensory attributes of breast and leg meat from native Mexican guajolote (Meleagris g. gallopavo) as influenced by sex. For this, slaughter weight and carcass characteristics of male (n=8) and female (n=8) guajolotes raised traditionally under extensive systems with similar housing and feeding conditions were recorded. Also, physical characteristics, proximate composition, the fatty acid profile, and sensory attributes were determined in breast and leg meat using standard procedures. The results showed that males had higher (P<0.001) slaughter weight, hot and cold carcass weights, and dressing percentage, as well as carcass part weights, while females had higher (P<0.001) abdominal fat weights than males. The lightness (L*), yellowness (b*), and drip loss values of breast meat, as well as redness (a*) and water-holding capacity values of leg meat, were significantly (P<0.05) influenced by sex. Male breast meat had higher (P<0.05) moisture content, crude protein, erucic acid (C22:1n9), ∑ MUFAs (total monounsaturated fatty acids), ∑ UFAs (unsaturated fatty acids), ∑ DFAs (desirable fatty acids), ∑ UFA / ∑ SFA (total saturated fatty acid) ratio, ∑ PUFA (total polyunsaturated fatty acid) / ∑ SFA ratio, and chewiness scores than females. Likewise, leg meat from males showed higher (P<0.05) ash content, myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), palmitoleic acid (C16:1n7), ∑ SFAs, ∑ OFAs (odd fatty acids), thrombogenic index, and atherogenic index, whereas females had high fat content. In conclusion, it would be suggested that, from a nutritional point of view, the meat from male guajolotes was preferable to the meat from females.

Diagnostic Efficacy of Chest Computed Tomography with a Dual-Reviewer Approach in Patients Diagnosed with Pneumonia Secondary to Severe Acute Respiratory Syndrome Coronavirus 2.

To compare the diagnostic effectiveness of chest computed tomography (CT) utilizing a single- versus a dual-reviewer approach in patients with pneumonia secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we conducted a retrospective observational study of data from a cross-section of 4809 patients with probable SARS-CoV-2 from March to November 2020. All patients had a CT radiological report and reverse-transcription polymerase chain reaction (PCR) results. A dual-reviewer approach was applied to two groups while conducting a comparative examination of the data. Reviewer 1 reported 108 patients negative and 374 patients positive for coronavirus disease 2019 (COVID-19) in group A, and 266 negative and 142 positive in group B. Reviewer 2 reported 150 patients negative and 332 patients positive for COVID-19 in group A, and 277 negative and 131 positive in group B. The consensus result reported 87 patients negative and 395 positive for COVID-19 in group A and 274 negative and 134 positive in group B. These findings suggest that a dual-reviewer approach improves chest CT diagnosis compared to a conventional single-reviewer approach.

Superhydrophobic SLA 3D printed materials modified with nanoparticles biomimicking the hierarchical structure of a rice leaf.

The rice leaf, combining the surface properties of lotus leaves and shark skin, presents outstanding superhydrophobic properties motivating its biomimesis. We created a novel biomimetic rice-leaf superhydrophobic surface by a three-level hierarchical structure, using for a first time stereolithographic (SLA) 3D printed channels (100µm width) with an intrinsic roughness from the printing filaments (10µm), and coated with TiO2 nanoparticles (22 and 100nm). This structure presents a maximum advancing contact angle of 165° characterized by lower both anisotropy and hysteresis contact angles than other 3D printed surfaces, due to the presence of air pockets at the surface/water interface (Cassie-Baxter state). Dynamic water-drop tests show that the biomimetic surface presents self-cleaning, which is reduced under UV-A irradiation. The biomimetic surface further renders an increased floatability to 3D printed objects meaning a drag-reduction due to reduced water/solid contact area. Numerical simulations of a channel with a biomimetic wall confirm that the presence of air is essential to understand our results since it increases the average velocity and decreases the friction factor due to the presence of a wall-slip velocity. Our findings show that SLA 3D printing is an appropriate approach to develop biomimetic superhydrophobic surfaces for future applications in anti-fouling and drag-reduction devices.

Study of racial profile of the native Guajolote (Meleagris gallopavo gallopavo) in two regions of Mexico: morphometric characterization.

The present study aimed at the morphometric characterization of the native Guajolote reared in two regions of Mexico using multivariate analysis techniques. Data from a total of 362 unrelated native Guajolotes (257 males and 105 females) were used: of these, 160 were from the Central region and 202 were from the Southeast region. The birds were also grouped according to age, as youngs (≤ 8 months; n = 150) and adults (≥ 9 months; n = 212). The body weight (BW) and nine morphometric measurements-chest circumference (CC), body length (BL), body height (BH), neck length (NL), peak length (PL), shank length (SL), shank diameter (SD), wing length (WL) and wing width (WW)-were measured. There were significant differences (p < 0.05) due to the effect of region, sex and age for most of the morphometric measurements evaluated. There was a high percentage of positive and significant correlations (p < 0.001; p < 0.01) between the variables. In each region, three principal components were extracted that represented more than 75% of the accumulated variation among the variables. The most discriminating morphometric measurements between populations were WW, PL and NL. The Mahalanobis distance between the males and females of the two populations was 37.457 and 29.310 (p < 0.001), respectively. This differentiation can contribute to the definition of the phenotypic standard of this poultry genetic resource for its official recognition as a breed, as well as in the orientation of its genetic improvement programs in the future.

Resiliencia de la cobertura vegetal en el Suroeste de México ante los efectos del cambio climático / Resilience of vegetation cover in Southwest Mexico to the climate change effects

Resumen El modelado de escenarios de cambios climáticos utilizando sistemas de información geográfica para estimar la resiliencia de la cobertura vegetal es una herramienta útil para proyectar impactos futuros e implementar estrategias de conservación o manejo. En el presente trabajo asociamos espacialmente la biodiversidad de la cobertura vegetal del Suroeste de México con su capacidad para adaptarse a los efectos del cambio climático. Para analizar esta asociación se estimaron índices de riqueza y diversidad de especies, y su relación con escenarios de clima futuro. Se utilizaron los registros geográficos del Inventario Nacional Forestal y de Suelos para ocho comunidades vegetales (arbórea, arbustiva, herbácea, palma, cactus, bejucos, helechos y xerófita) distribuidas entre Guerrero, Oaxaca y Chiapas. La proyección climática fue al 2050, con modelos de circulación global A2 (promedio CCCMA, HADCM3 y CSIRO), 19 variables bioclimáticas y una resolución de 2.5 minutos. Los escenarios de cambio climático se modelaron con el algoritmo MaxEnt y la riqueza de especies, índice de diversidad y regresiones espaciales con el software Diva-GIS v7.5. Los modelos de regresión espacial estimaron que a mayor riqueza y diversidad de especies mayor seria la resiliencia que mostraría el ecosistema. Las comunidades vegetales cactus, palma y xerófita mostraron mayor vulnerabilidad al cambio climático. Las variaciones en la estacionalidad de la temperatura resultó ser el factor que condicionaría su distribución futura. Por lo que, las estrategias de conservación o manejo deberían considerar a la diversidad como un agente del ecosistema que amortiguaría a los efectos negativos del clima futuro.

Abstract The scenarios modeling of climate changes using geographic information systems to estimate the vegetation cover resilience is a useful tool to project future impacts and implement conservation or management strategies. We associate spatially the biodiversity of the vegetation cover of Southwest Mexico with its ability to adapt to the effects of climate change. We analysis this association estimating species richness and diversity indices, and its relationship with scenarios of future climate. Geographical records of the National Forest and Soil Inventory were obtained for eight plant communities (arboreal, shrubby, herbaceous, palm, cactus, vines, ferns, and xerophyte) distributed in Guerrero, Oaxaca, and Chiapas. The climatic projection was to 2050, with global circulation A2 models (CCCMA, HADCM3 and CSIRO average), 19 bioclimatic variables and a resolution of 2.5 minutes. Climate change scenarios were modelled with the MaxEnt algorithm and species richness, diversity index, and spatial regressions with Diva-GIS v7.5 software. The spatial regression models estimated that higher richness and species diversity, the greater resilience that the ecosystem would show. The cactus, palm, and xerophytic plant communities presented greater vulnerability to climate change. Variations in temperature seasonality turned out to be the factor that would condition its future distribution. Therefore, in conservation or management strategies, diversity should be considered as an agent of the ecosystem that cushions the negative effects of future climate.

Novel Template Plasmids pCyaA'-Kan and pCyaA'-Cam for Generation of Unmarked Chromosomal cyaA' Translational Fusion to T3SS Effectors in Salmonella.

The type III secretion systems (T3SS) encoded in pathogenicity islands SPI-1 and SPI-2 are key virulence factors of Salmonella. These systems translocate proteins known as effectors into eukaryotic cells during infection. To characterize the functionality of T3SS effectors, gene fusions to the CyaA' reporter of Bordetella pertussis are often used. CyaA' is a calmodulin-dependent adenylate cyclase that is only active within eukaryotic cells. Thus, the translocation of an effector fused to CyaA' can be evaluated by measuring cAMP levels in infected cells. Here, we report the construction of plasmids pCyaA'-Kan and pCyaA'-Cam, which contain the ORF encoding CyaA' adjacent to a cassette that confers resistance to kanamycin or chloramphenicol, respectively, flanked by Flp recombinase target (FRT) sites. A PCR product from pCyaA'-Kan or pCyaA'-Cam containing these genetic elements can be introduced into the bacterial chromosome to generate gene fusions by homologous recombination using the Red recombination system from bacteriophage λ. Subsequently, the resistance cassette can be removed by recombination between the FRT sites using the Flp recombinase. As a proof of concept, the plasmids pCyaA'-Kan and pCyaA'-Cam were used to generate unmarked chromosomal fusions of 10 T3SS effectors to CyaA' in S. Typhimurium. Each fusion protein was detected by Western blot using an anti-CyaA' monoclonal antibody when the corresponding mutant strain was grown under conditions that induce the expression of the native gene. In addition, T3SS-1-dependent secretion of fusion protein SipA-CyaA' during in vitro growth was verified by Western blot analysis of culture supernatants. Finally, efficient translocation of SipA-CyaA' into HeLa cells was evidenced by increased intracellular cAMP levels at different times of infection. Therefore, the plasmids pCyaA'-Kan and pCyaA'-Cam can be used to generate unmarked chromosomal cyaA' translational fusion to study regulated expression, secretion and translocation of Salmonella T3SS effectors into eukaryotic cells.

Co-occurrence Interaction Networks of Extremophile Species Living in a Copper Mining Tailing.

Copper mining tailings are characterized by high concentrations of heavy metals and an acidic pH, conditions that require an extreme adaptation for any organism. Currently, several bacterial species have been isolated and characterized from mining environments; however, very little is known about the structure of microbial communities and how their members interact with each other under the extreme conditions where they live. This work generates a co-occurrence network, representing the bacterial soil community from the Cauquenes copper tailing, which is the largest copper waste deposit worldwide. A representative sampling of six zones from the Cauquenes tailing was carried out to determine pH, heavy metal concentration, total DNA extraction, and subsequent assignment of Operational Taxonomic Units (OTUs). According to the elemental concentrations and pH, the six zones could be grouped into two sectors: (1) the "new tailing," characterized by neutral pH and low concentration of elements, and (2) the "old tailing," having extremely low pH (~3.5) and a high concentration of heavy metals (mainly copper). Even though the abundance and diversity of species were low in both sectors, the Pseudomonadaceae and Flavobacteriaceae families were over-represented. Additionally, the OTU identifications allowed us to identify a series of bacterial species with diverse biotechnological potentials, such as copper bioleaching and drought stress alleviation in plants. Using the OTU information as a template, we generated co-occurrence networks for the old and new tailings. The resulting models revealed a rearrangement between the interactions of members living in the old and new tailings, and highlighted conserved bacterial drivers as key nodes, with positive interactions in the network of the old tailings, compared to the new tailings. These results provide insights into the structure of the soil bacterial communities growing under extreme environmental conditions in mines.

Comparison of four nonlinear growth models in Creole chickens of Mexico.

Animal growth is a complex and dynamic process that involves physiological and morphological changes from hatching to maturity. It is defined as the increase in body size per time unit. Mathematical functions, called growth models, have been used to explain growth patterns. The aim of this study was to compare the Gompertz-Laird, logistic, Richards, and Von Bertalanffy growth models to determine which best fits the data of the Creole chickens (CC). Three hundred forty-seven CC were individually weighed from hatching until 177 D of age. Birds were fed a starter diet (0-18 D of age; 19% crude protein (CP) and 3,000 kcal of ME/kg) and grower diet (19-177 D of age; 18% CP and 2,800 kcal of ME/kg). Data were analyzed using PROC NLIN to fit the nonlinear growth curve. The coefficient of determination (R2), Akaike information criteria (AIC), and Bayesian information criteria (BIC) were used to compare the goodness of fit of the models. The Von Bertalanffy (R2: 0.9382, 0.9415; AIC: 2,224.1, 2,424.8; BIC: 2,233.5, 2,434.3, for females and males, respectively) was the model that best explained growth of the birds. On the other hand, both the Gompertz-Laird and logistic models overestimated hatching BW and underestimated the final BW of CC. Females reached age of maximum growth faster than males. The asymptotic weight was higher in males (3,011 g) than in females (2,011 g). Body weight at inflection point was 892 g at 64 D of age for males and 596 g at 54 D for females. In conclusion, the best fit of the data was obtained with the Von Bertalanffy growth model; the information is intended to serve as the basis for utilizing CC.

Soybean meal substitution by dehulled lupine (Lupinus angustifolius) with enzymes in broiler diets.

OBJECTIVE: Evaluate the effects of i) dehulling of lupine seed on chemical composition and apparent metabolizable energy (AME) and ii) soybean meal substitution by dehulled lupine seed in broiler diets with enzymes on productive performance, size of digestive organs and welfare-related variables. METHODS: Experiment 1, chemical composition and AME were determined in whole and dehulled lupine seed. Experiment 2, two hundred eighty-eight one-day-old male Ross 308 broilers were used. The experimental diets were maize-soybean meal (MS), MS with enzymes (MSE) and maize-dehulled lupine seed with enzymes (MLE). Diets were assigned to the experimental units under a completely randomized design (eight replicates per diet). The body weight (BW) gain, feed intake, feed conversion, digestive organ weights, gait score, latency to lie down and valgus/varus angulation were evaluated. RESULTS: The dehulling process increased protein (25.0% to 31.1%), AME (5.9 to 8.8 MJ/kg) and amino acid contents. The BW gain of broilers fed the MLE diet was similar (p>0.05) to that of those fed the MS diet, but lower than that of those fed the MSE diet. Feed intake of broilers fed the MLE diet was higher (p<0.05) than that of those fed the MS diet and similar (p>0.05) to those fed the MSE diet. Feed conversion of broilers fed the MLE diet was 8.0% and 8.7% higher (p<0.05) than that of those fed the MS and MSE diets, respectively. Broilers fed the MLE diet had the highest (p<0.05) relative proventriculus and gizzard weights, but had poor welfare-related variables. CONCLUSION: It is possible to substitute soybean meal by dehulled lupine seed with enzymes in broiler diets, obtaining similar BW gains in broilers fed the MLE and MS diets; however, a higher feed intake is required. Additionally, the MLE diet reduced welfare-related variables.

Fnr and ArcA Regulate Lipid A Hydroxylation in Salmonella Enteritidis by Controlling lpxO Expression in Response to Oxygen Availability.

Lipid A is the bioactive component of lipopolysaccharide, and presents a dynamic structure that undergoes modifications in response to environmental signals. Many of these structural modifications influence Salmonella virulence. This is the case of lipid A hydroxylation, a modification catalyzed by the dioxygenase LpxO. Although it has been established that oxygen is required for lipid A hydroxylation acting as substrate of LpxO in Salmonella, an additional regulatory role for oxygen in lpxO expression has not been described. The existence of this regulation could be relevant considering that Salmonella faces low oxygen tension during infection. This condition leads to an adaptive response by changing the expression of numerous genes, and transcription factors Fnr and ArcA are major regulators of this process. In this work, we describe for the first time that lipid A hydroxylation and lpxO expression are modulated by oxygen availability in Salmonella enterica serovar Enteritidis (S. Enteritidis). Biochemical and genetic analyses indicate that this process is regulated by Fnr and ArcA controlling the expression of lpxO. In addition, according to our results, this regulation occurs by direct binding of both transcription factors to specific elements present in the lpxO promoter region. Altogether, our observations revealed a novel role for oxygen acting as an environment signal controlling lipid A hydroxylation in S. Enteritidis.

Suicide detection in Chile: proposing a predictive model for suicide risk in a clinical sample of patients with mood disorders

Objective: To analyze suicidal behavior and build a predictive model for suicide risk using data mining (DM) analysis. Methods: A study of 707 Chilean mental health patients (with and without suicide risk) was carried out across three healthcare centers in the Metropolitan Region of Santiago, Chile. Three hundred forty-three variables were studied using five questionnaires. DM and machine-learning tools were used via the support vector machine technique. Results: The model selected 22 variables that, depending on the circumstances in which they all occur, define whether a person belongs in a suicide risk zone (accuracy = 0.78, sensitivity = 0.77, and specificity = 0.79). Being in a suicide risk zone means patients are more vulnerable to suicide attempts or are thinking about suicide. The interrelationship between these variables is highly nonlinear, and it is interesting to note the particular ways in which they are configured for each case. The model shows that the variables of a suicide risk zone are related to individual unrest, personal satisfaction, and reasons for living, particularly those related to beliefs in one’s own capacities and coping abilities. Conclusion: These variables can be used to create an assessment tool and enables us to identify individual risk and protective factors. This may also contribute to therapeutic intervention by strengthening feelings of personal well-being and reasons for staying alive. Our results prompted the design of a new clinical tool, which is fast and easy to use and aids in evaluating the trajectory of suicide risk at a given moment.

Suicide detection in Chile: proposing a predictive model for suicide risk in a clinical sample of patients with mood disorders.

OBJECTIVE:: To analyze suicidal behavior and build a predictive model for suicide risk using data mining (DM) analysis. METHODS:: A study of 707 Chilean mental health patients (with and without suicide risk) was carried out across three healthcare centers in the Metropolitan Region of Santiago, Chile. Three hundred forty-three variables were studied using five questionnaires. DM and machine-learning tools were used via the support vector machine technique. RESULTS:: The model selected 22 variables that, depending on the circumstances in which they all occur, define whether a person belongs in a suicide risk zone (accuracy = 0.78, sensitivity = 0.77, and specificity = 0.79). Being in a suicide risk zone means patients are more vulnerable to suicide attempts or are thinking about suicide. The interrelationship between these variables is highly nonlinear, and it is interesting to note the particular ways in which they are configured for each case. The model shows that the variables of a suicide risk zone are related to individual unrest, personal satisfaction, and reasons for living, particularly those related to beliefs in one's own capacities and coping abilities. CONCLUSION:: These variables can be used to create an assessment tool and enables us to identify individual risk and protective factors. This may also contribute to therapeutic intervention by strengthening feelings of personal well-being and reasons for staying alive. Our results prompted the design of a new clinical tool, which is fast and easy to use and aids in evaluating the trajectory of suicide risk at a given moment.

EhVps32 Is a Vacuole-Associated Protein Involved in Pinocytosis and Phagocytosis of Entamoeaba histolytica.

Here, we investigated the role of EhVps32 protein (a member of the endosomal-sorting complex required for transport) in endocytosis of Entamoeba histolytica, a professional phagocyte. Confocal microscopy, TEM and cell fractionation revealed EhVps32 in cytoplasmic vesicles and also located adjacent to the plasma membrane. Between 5 to 30 min of phagocytosis, EhVps32 was detected on some erythrocytes-containing phagosomes of acidic nature, and at 60 min it returned to cytoplasmic vesicles and also appeared adjacent to the plasma membrane. TEM images revealed it in membranous structures in the vicinity of ingested erythrocytes. EhVps32, EhADH (an ALIX family member), Gal/GalNac lectin and actin co-localized in the phagocytic cup and in some erythrocytes-containing phagosomes, but EhVps32 was scarcely detected in late phagosomes. During dextran uptake, EhVps32, EhADH and Gal/GalNac lectin, but not actin, co-localized in pinosomes. EhVps32 recombinant protein formed oligomers composed by rings and filaments. Antibodies against EhVps32 monomers stained cytoplasmic vesicles but not erythrocytes-containing phagosomes, suggesting that in vivo oligomers are formed on phagosome membranes. The involvement of EhVps32 in phagocytosis was further study in pNeoEhvps32-HA-transfected trophozoites, which augmented almost twice their rate of erythrophagocytosis as well as the membranous concentric arrays built by filaments, spirals and tunnel-like structures. Some of these structures apparently connected phagosomes with the phagocytic cup. In concordance, the EhVps32-silenced G3 trophozoites ingested 80% less erythrocytes than the G3 strain. Our results suggest that EhVps32 participates in E. histolytica phagocytosis and pinocytosis. It forms oligomers on erythrocytes-containing phagosomes, probably as a part of the scission machinery involved in membrane invagination and intraluminal vesicles formation.

Evaluación serológica de Leptospira interrogans en equinos pertenecientes a un centro ecuestre de la provincia de Linares, Chile / Serological evaluation of Leptospira interrogans in horses from an equestrian center in Linares province, Chile / Avaliação serológica da Leptospira interrogans em equinos pertencentes a um centro equestre da província de Linares, Chile

Resumen La leptospirosis es una enfermedad bacteriana caracterizada por producir clínicamente en equinos signos clínicos inespecíficos como fiebre, anemia, depresión, y otros específicos, como aborto, muerte neonatal y uveítis recurrente. La finalidad del trabajo fue determinar la seroprevalencia en 55 equinos pertenecientes al Centro Ecuestre de la Escuela Artillería de Linares, Región del Maule. Las muestras (suero), fueron obtenidas de animales sin distinción de sexo o edad y analizadas mediante el método de Aglutinación Microscópica (MAT) para nueve serovares a títulos de dilución de 1/100 o superiores. Determinando una seropositividad general del 65,4%, distribuido en los serovares: Autumnalis (54,5%), Bratislava (52,7%), Canicola (20%), Copenhageni (12,7%) y Hardjo (7,3%), mientras que para Pomona, Grippothyphosa, Bataviae y Ballum no se obtuvieron sueros reaccionantes. Finalmente, no se observó diferencia estadística significativa (P≥0,05) en los individuos reaccionantes según sexo y edad, demostrándose que a mayor edad menor es la seropositividad.

Abstract Leptospirosis is a bacterial disease characterized in horses by nonspecific clinical signs such as fever, anemia, depression; and specific signs such as abortion, neonatal death, and recurrent uveitis. The objective was to determine seroprevalence in 55 horses from the equestrian center of Linares Artillery School, located in the Maule region. Serum samples were obtained from animals of both sexes and several ages. Samples were analyzed by Microscopic agglutination (MAT) for nine serovars with dilution titles of 1:100 or higher. The overall seropositivity was 65.4%, distributed in the following serovars: autumnalis (54.5%), bratislava (52.7%), canicola (20%), copenhageni (12.7%), and hardjo (7.3%); whereas reacting sera were not obtained for pomona, grippothyphosa, ballum, or bataviae. Finally, no statistically significant difference was observed between sex or age (P≥ 0.05). Seropositivity was lower in older than in younger horses.

Resumo A leptospirose é uma doença bacteriana caracterizada por produzir em equinos alguns signos clínicos inespecíficos, como febre, anemia, depressão; e outros específicos, como aborto, morte neonatal e uveíte recorrente. A finalidade deste trabalho foi determinar a soroprevalência em 55 equinos pertencentes ao Centro Equestre da Escola de Artilharia de Linares, região de Maule no Chile. As amostras (soro) foram obtidas de animais sem distinção de sexo ou idade e analisadas pelo método de aglutinação microscópica (MAT) para nove serovares a títulos de diluição de 1/100 ou superiores. Determinando uma seropositividade geral de 65,4%, distribuído nos serovares: Autumnalis (54,5%), Bratislava (52,7%), Canicola (20%), Copenhageni (12,7%) e Hardjo (7,3%), enquanto que para Pomona, Grippothyphosa, Bataviae e Ballum não se obtiveram soros reacionantes. Finalmente, não houve diferença significativa (P≥0,05) nos indivíduos reacionantes segundo sexo e idade, conferindo que a maior idade menor é a seropositividade.

Accelerating the development of a therapeutic vaccine for human Chagas disease: rationale and prospects.

Chagas disease is a leading cause of heart disease affecting approximately 10 million people in Latin America and elsewhere worldwide. The two major drugs available for the treatment of Chagas disease have limited efficacy in Trypanosoma cruzi-infected adults with indeterminate (patients who have seroconverted but do not yet show signs or symptoms) and determinate (patients who have both seroconverted and have clinical disease) status; they require prolonged treatment courses and are poorly tolerated and expensive. As an alternative to chemotherapy, an injectable therapeutic Chagas disease vaccine is under development to prevent or delay Chagasic cardiomyopathy in patients with indeterminate or determinate status. The bivalent vaccine will be comprised of two recombinant T. cruzi antigens, Tc24 and TSA-1, formulated on alum together with the Toll-like receptor 4 agonist, E6020. Proof-of-concept for the efficacy of these antigens was obtained in preclinical testing at the Autonomous University of Yucatan. Here the authors discuss the potential for a therapeutic Chagas vaccine as well as the progress made towards such a vaccine, and the authors articulate a roadmap for the development of the vaccine as planned by the nonprofit Sabin Vaccine Institute Product Development Partnership and Texas Children's Hospital Center for Vaccine Development in collaboration with an international consortium of academic and industrial partners in Mexico, Germany, Japan, and the USA.

Breakthrough performance of large proteins on ion-exchange membrane columns.

Protein adsorption of large proteins on ion-exchange membrane columns was theoretically and experimentally investigated using batch and fixed-bed systems. Thyroglobulin was used as the model protein. The study strongly suggests that part of the protein is physically retained inside the column during frontal mode operation. These experimental results were used to obtain a filtration function of the chromatographic system. In the theoretical analysis of the frontal protein adsorption, a model was integrated by the serial coupling of the membrane-transport model, the filtration model and the system-dispersion model. Two different techniques were employed in the estimation of the maximum adsorption capacity, the equilibrium desorption constant and the forward interaction rate constant, which are the parameters of the membrane-transport model. The fit of the model to the experimental data was not possible using the equilibrium parameters obtained in the batch experiments. The parameter estimation using a simplex optimization routine coupled to the solution of the partial differential model equations yields full prediction of the adsorption phenomena.

Breakthrough performance of linear-DNA on ion-exchange membrane columns.

Breakthrough performance of linear-DNA adsorption on ion-exchange membrane columns was theoretically and experimentally investigated using batch and fixed-bed systems. System dispersion curves showed the absence of flow non-idealities in the experimental arrangement. Breakthrough curves were not significantly affected by flow-rate or inlet solution concentration. In the theoretical analysis a model was integrated by the serial coupling of the membrane transport model and the system dispersion model. A transport model that considers finite kinetic rate and column dispersed flow was used in the study. A simplex optimization routine coupled to the solution of the partial differential model equations was employed to estimate the maximum adsorption capacity constant, the equilibrium desorption constant and the forward interaction rate-constant, which are the parameters of the membrane transport model. Through this approach a good prediction of the adsorption phenomena is obtained for inlet concentrations and flow rates greater than 0.2 mg/ml and 0.16 ml/min.

Lesiones impalpables del seno: localización mamográfica y biopsia: análisis de 164 anormalidades / Impalpable lesions of the breast: Mammographic localization and biopsy: analysis of 164 abnormalities

La biopsia guiada mediante mamografía en lesiones ocultas del seno es una herramienta útil para el diagnóstico temprano del cáncer y las lesiones premalignas. En esta revisión de 164 pacientes con lesiones no palpables detectadas mediante este procedimiento durante un período de dos años, a quienes se realizó marcación con arpón y resección quirúrgica, se diagnosticó malignidad en 42 pacientes (25,6%), trece de ellas con carcinoma in situ (7,9%) y 29 infiltrante (17,6%). El diagnóstico benigno más frecuente en esta serie fue fibroadenoma, seguido por otras patologías benignas comunes. La categorización mamográfica según el sistema de BI-RADS muestra muy buena correlación con el diagnóstico histopatológico definitivo, evidenciando resultados homologables a otros estudios similares. Por tales hallazgos, nos permitimos recomendar esta técnica de diagnóstico temprano en nuestro medio para lesiones no palpables del seno detectadas con mamografía.