Application of Raman spectroscopy for the determination of proteins denaturation and amino acids decomposition temperature.

Raman spectroscopy was employed to study the thermal denaturation of three different proteins, bovine serum albumin (BSA), lysozyme, ovalbumin; and the decomposition temperature of three amino acids, l-glutamine, l-cysteine, and l-alanine, all of them as lyophilized powders. All the Raman bands observed in the spectra obtained were recorded and analyzed at preset heating temperatures. The results obtained for either protein denaturation temperature TD and amino acid decomposition temperatures TM-dc, were compared with those measured by differential scanning calorimetry (DSC). The DSC and Raman results were additionally corroborated with a thermogravimetric analysis (TGA) for the case of proteins. This exercise indicated almost complete coincidence in the determination of these transition temperatures between the three techniques, evidencing the applicability of Raman spectroscopy in the study of denaturation and decomposition temperatures of proteins and amino acids.

Caracterización de la mortalidad por fractura de cadera como causa básica en el periodo 2017-2022 en Chile / Characterization of mortality due to hip fracture as the underlying cause in the period 2017-2022 in Chile

Introducción: La fractura de cadera (FC) es una solución de continuidad en el extremo proximal del fémur, con consecuencias significativas para quien la padece. Este estudio busca comparar descriptivamente la tasa de mortalidad por FC en el periodo 2017-2022, en Chile. Metodología: Estudio descriptivo observacional sobre defunciones por FC entre 2017 y 2022, en Chile (n= 3.190), según datos del Departamento de Estadísticas e Información de Salud de Chile. Se calcularon tasas de mortalidad por FC por variable, índice de sobremortalidad e índice de Swaroop, utilizando datos del Censo 2017. No requirió comité de ética. Resultados: La mayor tasa de mortalidad por FC se observó en el año 2018 (3,23), en el grupo de 100 años y más (2.264,15), la región de Valparaíso (28,31) y el sexo femenino (4,32) reflejandose en su índice de sobremortalidad (2,589). La menor tasa de mortalidad por FC ocurrió en el año 2021 (2,76), en el grupo de entre 0 y 19 años (0,04) y en la región de Atacama (12,58). El índice de Swaroop fue 100% en la mayoría de las regiones. Discusión: La tendencia a la baja desde el año 2019 podría explicarse por el confinamiento por COVID-19 que limitó la movilidad de las personas mayores. Los cambios postmenopausicos y un mayor riesgo de caídas podrían explicar una mayor tasa de mortalidad por FC en mujeres y pacientes de edad avanzada, respectivamente. El análisis por región podría relacionarse con la proporción demográfica de personas mayores.

Introduction: The hip fracture (HF) is a discontinuity in the proximal end of the femur, with significant consequences for those who suffer from it. This study aims to descriptively compare the HF mortality rate in the period 2017-2022 in Chile. Methodology: This is an observational descriptive study on deaths due to HF between 2017 and 2022 in Chile (n=3,190), according to data from the Department of Statistics and Health Information of Chile. HF mortality was calculated by variable, excess mortality rate, and Swaroop index, using data from the 2017 Census. No ethics committee was required. Results: The highest HF mortality rate was in 2018 (3,23), in the age group of 100 years and older (2.264,15), the Valparaíso region (28,31) and the female sex (4,32) reflected in its excess mortality rate (2,589). The lowest HF mortality rate occurred in 2021 (2,76), in the group between 0 and 19 years (0,04) and in the Atacama region (12,58). The Swaroop index was 100% in most regions. Discussion: The downward trend since 2019 could be explained by the COVID-19 lockdown that limited the mobility of elderly adults. Postmenopausal changes and a higher risk of falls could explain higher HF mortality rate in women and old people patients, respectively. The regional analysis could be related to the demographic proportion of elder people.

Application of Processing Guidance: Case Study of Cleaning Validations on Flexible Endoscopes.

In 2015, the Food and Drug Administration (FDA) updated its guidance on test methods for cleaning validations for reusable medical devices. The changes include the condition and contamination of devices, test samples and controls, cleaning process performed during validation, extraction methods, and endpoints. This article reviews the FDA's changes to cleaning validations. Examples are presented using flexible endoscopes in order to provide a practical guide to performing cleaning validations.

Tumores fibroóseos de cavidades paranasales: experiencia en el Hospital Clínico de la Universidad de Chile y revisión de la literatura / Fibro-osseous tumors of paranasal cavities: experience in the Hospital Clínico de la Universidad de Chile and review of the literature

Los tumores de cavidades paranasales presentan una baja frecuencia. Dentro de éstos, entre los benignos destacan las lesiones fibroóseas que se caracterizan por el reemplazo de hueso normal por estroma celular fibroso. Dentro de estas lesiones se describen osteoma, displasia fibrosa y fibroma osificante. Se revisan 3 casos de pacientes del Hospital Clínico de la Universidad de Chile y se presenta una revisión bibliográfica en cuanto a las lesiones fibroóseas, su clínica, diagnóstico, imagenología y tratamiento.

The tumors of paranasal cavities present a low frequency. Among the benign tumors are fibro-osseous lesions characterized by the replacement of normal bone by fibrous cell stroma. Osteoma, fibrous dysplasia, and ossifying fibroma are described within these lesions. Three cases of patients from the Hospital Clínico de la Universidad de Chile are reviewed and a bibliographic review is presented regarding the fibro-osseous lesions, their clinical features, diagnosis, imaging and treatment.

Dimensionality-Driven Photoproduction of Massive Dirac Pairs near Threshold in Gapped Graphene Monolayers.

Generation of quasiparticle-hole pairs in gapped graphene monolayers in the combined field of two counterpropagating light waves is studied. The process represents an analog of electron-positron pair production from the vacuum of quantum electrodynamics (QED) by the Breit-Wheeler effect. We show, however, that the two-dimensional structure of graphene causes some striking differences between both scenarios. In particular, contrary to the QED case, it allows for nonzero pair production rates at the energy threshold when the Breit-Wheeler reaction proceeds nonlinearly with absorption of three photons.

Dilatación precoz de estenosis subglótica adquirida posintubación utilizando tubos endotraqueales / Early dilatation of acquired post-intubation subglottic stenosis using endotracheal tubes

RESUMEN Introducción: La estenosis subglótica adquirida es una causa importante de estridor persistente después de una intubación endotraqueal. El diagnóstico y manejo tempranos pueden llevar a procedimientos menos invasivos con altas tasas de éxito. Si las lesiones agudas posintubación evolucionan hacia una estenosis, las dilataciones endoscópicas usando instrumentos romos o balones podrían lograr restablecer un lumen adecuado. Los balones son efectivos, pero caros y obstruyen la vía respiratoria al momento de la dilatación. Objetivo: Presentar nuestra experiencia con la dilatación progresiva de estenosis subglótica adquirida posintubación utilizando tubos endotraqueales. Material y método: Revisión retrospectiva de las dilataciones realizadas como tratamiento primario en estenosis subglótica pediátrica adquirida. Resultados: Se incluyeron 16 pacientes con estenosis de grados I a III, con una edad promedio de 2 años y 4 meses. El tiempo promedio de intubación fue de 6,6 días. El número de procedimientos promedio fue de 2, con un rango de 1 a 6. El éxito clínico se logró en todos los pacientes, con resolución de los síntomas respiratorios y evitando la traqueostomía. No hubo complicaciones ni mortalidad asociadas. Conclusión: En esta cohorte, la dilatación subglótica con tubos endotraqueales fue eficaz y segura. Estos están ampliamente disponibles y permiten ventilar al paciente mientras se realiza el procedimiento.

ABSTRACT Introduction: Acquired post-intubation subglottic stenosis is one of the most important complications causing persistent stridor after endotracheal intubation. Early diagnosis and management can lead to less-invasive procedures with high success rates. If the acute post-intubation injuries progress into a stenosis, endoscopic dilatations can be attempted to reestablish an adequate lumen. These can be performed using blunt instrument or balloons. Balloons are effective but expensive, and obstruct the airway while dilatating. Aim: Present our experience with progressive blunt dilatation of acquired post-intubation subglottic stenosis using endotracheal tubes. Material and method: Retrospective chart review of dilatations performed as the primary treatment in early acquired pediatric subglottic stenosis. Results: 16 patients with grades I to III stenosis were included. Average age was 2 years 4 months, and average intubation time was 6.6 days. The number of procedures ranged between 1 and 6, with a mean of 2. Clinical success was achieved in all patients, with resolution of respiratory symptoms and avoidance of tracheostomy. There were no complications or mortality. Conclusion: In this cohort, subglottic dilatation using endotracheal tubes was effective and safe. Endotracheal tubes are easily available and allow to ventilate the patient while performing the procedure.

Evaluation of the effect of 1,3-bis-(4-phenyl-[1,2,3] triazole-1-il)2-propanol in comparison with metronidazole in an in vitro culture of Blastocystis in samples of patients with irritable bowel syndrome.

Metronidazole is the most-used pharmaceutical for the treatment of infection by Blastocystis. However, studies have reported resistance of the microorganism towards this pharmaceutical. In Mexico, studies concerning the prevalence of this parasite and its relationship to Irritable Bowel Syndrome have been carried out. To evaluate the in vitro effect of metronidazole and the compound 1,3-bis-(4-phenyl-[1,2,3] triazole-1-il)2-propanol over Blastocystis, as well as the prevalence of Blastocystis in patients with Irritable Bowel Syndrome. A prospective, transversal design study (April 2016-April 2017) of 51 samples of patients with Irritable Bowel Syndrome, obtained from the ISSEMyM Medical Center in Toluca, Mexico. For the identification of Blastocystis was done in three serial stool samples through direct microscopic examination and the Ritchie technique. The in vitro susceptibility test towards metronidazole and the triazolic compound was done through a microculture in concentrations of 1 to 1000 µg/mL, each one in triplicate. A 31.3% prevalence of Blastocystis was observed in the population, with greater prevalence in women (30.2%) than in men (25%). In the susceptibility test, a CL50 of 64 µg/mL was obtained for metronidazole, in comparison to the CL50 of 250 µg/mL for 1,3-bis-(4-phenyl-[1,2,3] triazole-1-il)2-propanol. This molecule in development has an effect for the treatment of infection by Blastocystis in vitro in patients with IBS and therefore, more studies should be performed.

Nanocarrier-based systems for wound healing.

In general, the systems intended for the treatment and recovery of wounds, seek to act as a coating for the damaged area, maintaining an adequate level of humidity, reducing pain, and preventing the invasion and proliferation of microorganisms. Although many of the systems that are currently on the market meet the purposes mentioned above, with the arrival of nanotechnology, it has sought to improve the performance of these coatings. The variety of nano-systems that have been proposed is very extensive, including the use of very different materials (natural or synthetic) ranging from polymers or lipids to systems derived from microorganisms. With the objective of improving the performance of the systems, seeking to combat several of the problems that arise in a wound, especially when it is chronic, these materials have been combined, giving rise to nanocomposites or scaffolds. In recent years, the interest in the development of systems for the treatment of wounds is notable, which is reflected in the increase in publications related to the subject. Therefore, this document presents generalities of systems involving nanocarriers, mentioning some examples of representative systems of each case.

Fasceítis necrotizante cervical: consideraciones para el manejo precoz / Cervical necrotizing fascitis: considerations for early management

RESUMEN La fasceítis necrotizante cervical (FNC) es una infección que afecta la fascia cervical y tejido subcutáneo, diseminándose rápidamente a través de los planos fasciales con una alta tasa de mortalidad. Si bien, las imágenes son una herramienta de apoyo fundamental para el diagnóstico, éste sigue siendo eminentemente clínico, presentando una rápida progresión de síntomas en pocas horas. El objetivo de esta presentación fue identificar factores descritos con peor pronóstico en el diagnóstico precoz de la FNC. Se realizó un estudio descriptivo de serie de casos de pacientes con diagnóstico de FNC en los últimos 10 años en el Servicio de Otorrinolaringología del Hospital Barros Luco Trudeau (HBLT). Se identificaron 5 pacientes, dentro de los cuales, los parámetros clínicos y de laboratorio a destacar fueron el dolor desproporcionado y rápido deterioro de exámenes de laboratorio. En los casos que había signos sugerentes de FNC en la tomografía computarizada, se favoreció el manejo quirúrgico agresivo, mientras que, en quienes no había imágenes sugerentes de FNC, se postergó el diagnóstico y su manejo precoz, provocando un desenlace fatal. La FNC constituye un cuadro grave en el que la sospecha clínica y rapidez de inicio del tratamiento resultan fundamental en el pronóstico.

ABSTRACT Cervical necrotizing fasciitis (CNF) is an infection that affects the cervical fascia and subcutaneous tissue. It is characterized by a rapid dissemination trough the fascial planes, with a high rate of mortality. Even tough imaging results a fundamental diagnostic tool, it is still made by clinic signs with rapid progression of symptoms in few hours. Here, we identify worse prognostic factors in the precocious diagnosis of CNF, from five cases presented in our center. A descriptive case-series study was performed in patients with CNF in the last ten years in the Otolaryngology Department of Barros Luco Trudeau Hospital. Five patients were identified, between the clinical and laboratory parameters. A disproportional pain and rapid deterioration of the laboratory exams were the most highlighted features. In the cases with suggestive signs of CFN in the CT scan, allowed an aggressive surgical management, while in those that had no suggestive images the diagnosis was delayed and therefore their management ended in a fatal outcome. CFN constitutes a severe picture in wich clinical suspicion and a prompt initiation of treatment are fundamental in its prognosis.

Verapamilo en conjunto con las prendas de compresión en el tratamiento de la cicatriz patológica causada por quemadura / Verapamil in conjunction with pressure therapy in the treatment of pathologic scar due burn injury

Abstract Introduction: Keloids and hypertrophic scars are dermal fibro-proliferative disorders unique to humans. Their treatment is a true challenge with multiple options, but not all the time with good results. Unfortunatelythis problem is not uncommon in patients with history of burn injury. Aim: To evaluate use of verapamil andpressure garments in patients with hypertrophic or keloid scar caused by burn injury. methods: We includedpatients with a hypertrophic or keloid scar caused by burn injury that report non-response to treatment withpressure garment. The pathologic scars were evaluated by serial photographic records, Vancouver and Posasscales. The scales of Vancouver and Posas were compared with t Student. Results: We included 13 scars in11 patients. Four scars were located in the legs, 4 in the arms, 4 in the face-neck and 1 in the abdomen. Thedose of verapamil was calculated 0.03 mg per kg. Injections were scheduled every 7 to 10 days until complete 6 sessions. Taking in count Posas scale, patients referred improvement in pigmentation (0.01), thickness(0.005), pliability (0.01), pruritus (0.003) and irregular surface (0.004). In the Vancouver scale the observers mentioned improvement in elevation (0.008), pigmentation (0.014), vascularity (0.022) and flexibility (0.014).No adverse effects were found in verapamil injection. Conclusion: Verapamil was useful in conjunction withpressure garment to improve the condition of the keloid and hypertrophic scar caused by burn.

Resumen Introducción: La cicatriz queloide o la cicatriz hipertrófica son desórdenes fibro-proliferativos únicos de los humanos, cuyo tratamiento representa un reto en donde existen pocas opciones con buenos resultados.Objetivo: Evaluar el uso de verapamilo y las prendas de compresión en pacientes con cicatrización patológicacomo consecuencia de quemadura. material y método: Incluimos pacientes con cicatrización patológica,ya sea queloide o hipertrófica, causada por quemadura que mencionaron no haber tenido beneficio con el usode prendas de compresión. La cicatriz fue evaluada con fotografías seriadas, escala de Vancouver y Posas.Los resultados fueron comparados con la prueba de t de Student. Resultados: Incluimos 13 cicatrices en 11pacientes. La localización de las cicatrices fue en brazos 4, piernas 4, cara y cuello 1, y abdomen 1. La dosisde verapamilo se calculó a 0,03 mg por kg. Las inyecciones se aplicaron intralesionales y se administraroncada 7 a 10 días hasta completar 6 sesiones. Encontramos mejoría en los siguientes parámetros de la escalade Posas: pigmentación (0,01), pliabilidad (0,01), endurecimiento o grosor (0,005), prurito (0,003) e irregular (0,004). En la escala de Vancouver elevación (0,008), pigmentación (0,014), vascularidad (0,022) yflexibilidad (0,014). No encontramos efectos adversos con la administración de verapamilo. Conclusión: Elverapamilo fue útil en conjunto con las prendas de compresión para mejorar las condiciones de la cicatrizqueloide e hipertrófica causadas por lesiones por quemadura.

Graph-based symbolic technique and its application in the frequency response bound analysis of analog integrated circuits.

A new graph-based symbolic technique (GBST) for deriving exact analytical expressions like the transfer function H(s) of an analog integrated circuit (IC), is introduced herein. The derived H(s) of a given analog IC is used to compute the frequency response bounds (maximum and minimum) associated to the magnitude and phase of H(s), subject to some ranges of process variational parameters, and by performing nonlinear constrained optimization. Our simulations demonstrate the usefulness of the new GBST for deriving the exact symbolic expression for H(s), and the last section highlights the good agreement between the frequency response bounds computed by our variational analysis approach versus traditional Monte Carlo simulations. As a conclusion, performing variational analysis using our proposed GBST for computing the frequency response bounds of analog ICs, shows a gain in computing time of 100x for a differential circuit topology and 50x for a 3-stage amplifier, compared to traditional Monte Carlo simulations.

Intake estimation of horses grazing tall fescue (Lolium arundinaceum) or fed tall fescue hay.

Six mature geldings of light horse breeds (557 ± 37 kg) were randomly assigned to a nontoxic endophyte-infected tall fescue hay (n = 3) or pasture treatment (n = 3) in a crossover design with 14-d periods to estimate DMI with alkane markers and to compare DMI of hay and pasture. When fed pasture, horses were housed in stalls from 0700 to 1300 h daily with access to water and then grazed pasture as a group in a single 0.4 ha pasture from 1300 to 0700 h. When fed hay, horses were maintained individually in stalls and given access to hay ad libitum from 1300 to 0700 h. All horses were individually fed 225 g oats twice daily treated with hexatriacontane (C36; external marker) and fecal samples were collected at 0700 and 1900 h on d 10 to 14. Fecal samples were mixed, dried, subsampled, and analyzed for tritriacontane (C33) and hentriacontane (C31) as internal markers and C36 as the external marker using gas chromatography. Estimated hay DMI using either C33 (1.75 kg/100 kg BW) or C31 (1.74 kg/100 kg BW) as internal alkane marker did not differ (P = 0.55) from measured hay DMI (1.70 kg/100 kg BW). Pasture DMI and DM digestibility (DMD) estimated with C31 (2.24 kg/100 kg BW and 53.1 g/100 g DMI) or with C33 (2.34 kg/100 kg BW and 56.2 g/100 g DMI) was greater (P = 0.05) than hay DMI and DMD (1.74 kg/100 kg BW and 44.5 g/100 g DMI). Intake estimated with C33 or C31 did not differ (P = 0.35) during hay or pasture. In conclusion, alkanes can be used to estimate pasture or hay DMI and DMD, and pasture intake exceeded hay intake when offered ad libitum.

Bilateral symmetry of breast tissue composition by magnetic resonance in young women and adults.

BACKGROUND: Some reports suggest that there is a slightly higher frequency of breast cancer in the left breast compared with the right in middle-aged women. The reasons for this association are unknown. The water and fat content of both breasts was compared using magnetic resonance (MR). Breast water by MR reflects fibro-glandular tissue and is strongly positively correlated with percent mammographic density, a strong risk factor for breast cancer. METHODS: Magnetic resonance was used to measure fat and water content of the breast in 400 young women aged 15-30 years and a random sample of 100 of their mothers. All MR examinations were carried out using a 1.5T MR system, and 45 contiguous slices were obtained in the sagittal plane. One reader identified the breast tissue in the image, and subsequently, fat and water content was calculated using a three-point Dixon technique. Left- and right-sided images were read independently in random order. RESULTS: In young women, mean percent water was on average 0.84 % higher in the right compared with the left breast (p < 0.001) and total breast water was on average 6.42 cm(3) greater on the right side (p < 0.001). In mothers, there were no significant differences in any breast measure between right and left sides. CONCLUSION: The small differences in breast tissue composition in young women are unlikely to be associated with large differences in breast cancer risk between sides. The reported excess of left-sided breast cancer in older women is unlikely to be explained by differences in breast tissue composition.

Pedagogía de la fraternidad en situaciones de riesgo, formación integral para la vida / Pedagogy of fraternity in situations of risk, all round formation for life

El presente artículo pretende aportar en la fundamentación de la pedagogía de la Fraternidad en Situaciones de Riesgo, como una nueva visión de la pedagogía en la que están presentes muchos elementos de otras teorías pero que se asumen desde una perspectiva diferente, cuya meta es: primero, permitir que los procesos educativos lleven a generar una sociedad más justa y fraterna en la que se genere un espacio de amistad, confianza y estima recíproca; segundo, que el conocimiento aumente siempre por el deseo de dar respuestas a las problemáticas de la sociedad y tercero generar un espacio en el que se sienta la familia.

This article aims to contribute to the foundation of the pedagogy of fraternity in situations of risk, as a new vision of the pedagogy in which many elements of other theories are present, but which are taken from a different perspective, whose goal is to allow educational processes that make a fairer and more fraternal society possible, by generating friendship, trust, and reciprocal esteem, in the first place, that knowledge is always increased as a manner to solve the answers to the issues of society, in the second place, and in the third place, it can generate a space in which the family can be felt.

[Midazolam versus dexmedetomidine for sedation for upper gastrointestinal endoscopy]. / Midazolam versus dexmedetomidina en sedación para procedimientos endoscópicos de tubo digestivo alto.

BACKGROUND: The diagnostic upper gastrointestinal endoscopy (UGI) is a safe procedure although 50% to 60% morbidity and mortality due to cardiopulmonary complications. OBJECTIVE: To compare safety and efficacy of dexmedetomidine vs. midazolam in UGI. METHODS: We conducted a randomized controlled, double-blind, clinical trial to compare the two drugs. Patients with an indication of UGI were randomized to receive sedation with dexmedetomidine or midazolam during the procedure. We compared age, sex, physical status (ASA), body mass index (BMI), degree of sedation (Ramsay scale), recovery time and degree of satisfaction with the procedure. RESULTS: Forty patients with an indication of UGI were included (20 in each arm). Both groups showed a similar distribution by sex, age, BMI and ASA physical status. The level of sedation was similar starting and ending the procedure according to the Ramsay scale. The dexmedetomidine group had a shorter recovery time (7.1 vs. 15.8 min, p <0.05) and satisfaction (9.9 vs. 9.0, p <0.05). Adverse effects occurred in similar proportions in both groups. CONCLUSIONS: Midazolam and dexmedetomidine are suitable for endoscopic procedures of upper digestive tract. Dexmedetomidine offers shorter recovery time and better patient's satisfaction.

Quality of fruits in Mexican tomato (Lycopersicon esculentum Mill) landraces / Calidad de frutos en variedades nativas mexicanas de tomate (Lycopersicon esculentum Mill)

Mexico is a center of domestication and diversification of tomatoes, with various landrace cultivated populations and wild varieties, but the documentation is poor in terms of their physical, chemical and nutritional characteristics. Thirteen accessions were collected and then sown and transplanted in greenhouse conditions under a randomized complete block design with four replications. This process was performed in order to evaluate the lycopene content, ascorbic acid and other physicochemical characteristics, as well as the effect of storage conditions on lycopene loss of a sample of tomato fruits native from different regions of Mexico. The analysis of variance shows significant differences (P < 0.05) among accessions for titratable acidity, pH, lycopene on wet and dry basis, in the CIE chromaticity coordinates L*, a* b*, and in the maturity index. GTO-11, OAX-115, PH-102 and PH-96 accessions stood out for their lycopene content on wet and dry basis with values above 20 and 300 mg 100 g-1, respectively. Lycopene content in samples of ground tomato fruits decreased after storing them at -20ºC; it also decreased in the scalded samples immersed in boiling water.

México es un centro de domesticación y diversificación del tomate con diversas poblaciones nativas cultivadas y variantes silvestres, pero poco documentadas en términos de sus características físicas, químicas y nutricionales. Con el objetivo de evaluar el contenido de licopeno, ácido ascórbico y otras características fisicoquímicas de los frutos de una muestra de tomate originaria de diferentes regionesde México, y evaluar el efecto de almacenamiento sobre la pérdida de licopeno, se hizo una colecta yposteriormente la siembra y trasplante en invernadero de trece accesiones bajo un diseño de bloques completos al azar con cuatro repeticiones. El análisis de varianza detecta diferencias significativas(P < 0.05) entre accesiones para acidez titulable, pH, licopeno en base húmeda y seca, en las coordenadas cromáticas CIE L*, a* y b*, y en el índice de madurez. Las accesiones GTO-11, OAX-115, PH-102 y PH-96 sobresalen en contenido de licopeno en base húmeda y seca con valores mayores a 20 y 300 mg 100 g-1, respectivamente. El contenido de licopeno en muestras molidas de frutos de tomate y almacenadas a -20ºC, decreció a medida que se incrementó el tiempo de almacenamiento, aún en las muestras escaldadas, inmersión en agua en ebullición.

New rabies virus variant found during an epizootic in white-nosed coatis from the Yucatan Peninsula.

In February 2008, three white-nosed coatis (Nasua narica) were found dead in a recreational park in Cancun, Mexico. The diagnosis of rabies virus (RABV) infection was confirmed by direct immunofluorescence test. The phylogenetic analysis performed with the complete RABV nucleoprotein gene positioned this isolate close to a sequence of a human rabies case reported during 2008 from Oaxaca, Mexico, sharing 93% similarity. In turn, these two variants are related to another variant found in rabid Tadarida brasiliensis mexicana bats across North America. Anti-RABV neutralizing activity (1.3 IU/ml) was found in the serum of one white-nosed coati captured with another five that cohabited with the dead animals. Enhanced rabies surveillance and pathogenesis studies should be conducted in coatis and insectivorous bats of the region to clarify the role of these species as potential emergent or long-term unidentified RABV reservoirs.

The isolation and characterization of a novel telomerase immortalized first trimester trophoblast cell line, Swan 71.

Studies using first trimester trophoblast cells may be limited by the inability to obtain patient samples and/or adequate cell numbers. First trimester trophoblast cell lines have been generated by SV40 transformation or similar methods, however, this approach is known to induce phenotypic and karyotypic abnormalities. The introduction of telomerase has been proposed to be a viable alternative for the immortalization of primary human cells. To investigate whether telomerase-induced immortalization might be a more feasible approach for the generation of first trimester trophoblast cell lines, we isolated primary trophoblast cells from a 7-week normal placenta and infected the cells with human telomerase reverse transcriptase (hTERT), the catalytic subunit of telomerase. Although this hTERT-infected first trimester trophoblast cell line, which we have named Swan 71, has been propagated for more than 100 passages, it still has attributes that are characteristic of primary first trimester trophoblast cells. The Swan 71 cells are positive for the expression of cytokeratin 7, vimentin and HLA-G, but do not express CD45, CD68 or the Fibroblast Specific Antigen (FSA), CD90/Thy-1. In addition, we also demonstrated that the Swan 71 cells secrete fetal fibronectin (FFN) as well as low levels of human Chorionic Gonadotrophin (hCG). Moreover, the Swan 71 cells exhibit a cytokine and growth factor profile that is similar to primary trophoblast cells and are resistant to Fas, but not TNF-alpha-induced apoptosis. This suggests that the Swan 71 cells may represent a valuable model for future in vitro trophoblast studies.

Robust correction of spike noise: application to diffusion tensor imaging.

Echo-planar imaging (EPI) -based diffusion tensor imaging (DTI) is particularly prone to spike noise. However, existing spike noise correction methods are impractical for corrupted DTI data because the methods correct the complex MRI signal, which is not usually stored on clinical MRI systems. The present work describes a novel Outlier Detection De-spiking technique (ODD) that consists of three steps: detection, localization, and correction. Using automated outlier detection schemes, ODD exploits the data redundancy available in DTI data sets that are acquired with a minimum of six different diffusion-weighted images (DWIs) with similar signal and noise properties. A mathematical formulation, describing the effects of spike noise on magnitude images, yields appropriate measures for an outlier detection scheme used for spike detection while a normalization-dependent outlier detection scheme is used for spike localization. ODD performs accurately on diverse DTI data sets corrupted by spike noise and can be used for automated control of DTI data quality. ODD can also be extended to other MRI applications with data redundancy, such as dynamic imaging and functional MRI.

[Diagnosis and clinical presentations of celiac disease: a multicenter study]. / Estado actual del diagnóstico y presentaciones clínicas de enfermedad celíaca: Estudio multicéntrico.

BACKGROUND: Ample use of serological markers of high sensitivity and specificity led to relevant changes in the epidemiology of celiac disease. The impact of these changes in our country is poorly known. AIM: To assess the diagnostic procedures, clinical presentations and follow up of celiac disease as conducted in current pediatric practice. MATERIAL AND METHODS: A multicentric retrospective study of patients diagnosed between 2000 and 2005 in five pediatric hospitals in Santiago, Chile. Data was obtained from clinical records, recorded in electronic spreadsheets and analyzed by descriptive statistics. RESULTS: Seventy four of 83 identified patients fulfilled the inclusion criteria and were analyzed. Mean time to reach the diagnosis was 2.1 years. Cases younger than 10 years presented digestive manifestations such as chronic diarrhea and abdominal distension. Twenty one percent of older patients had atypical presentations (mainly short stature, refractory anaemia). Ten percent of cases were screened because a first degree relative had celiac disease. All patients had significant duodenal/jejunal lesion. IgA-antiendomysial antibodies (n =65) and IgA-antigliadin antibodies (n =23) were the most commonly used screening tests used but often, they were not available for follow up. A second biopsy was planned in all patients but only 26 had it due to repeated dietary transgressions, often due to unnoticed consumption of gluten in poorly labeled products. CONCLUSIONS: Digestive manifestations were the main presentation form for celiac disease among patients under 10 years of age. Atypical symptoms become relevant in patients older than 10 years. Antiendomysial and antitransglutaminase antibody measurement should be incorporated for routine screening and follow up of celiac disease in public hospitals. To improve food labeling about their gluten content is needed.