Dictionary-based software for proton dose reconstruction and submilimetric range verification.

Objective.This paper presents a new method for fast reconstruction (compatible with in-beam use) of deposited dose during proton therapy using data acquired from a PET scanner. The most innovative feature of this novel method is the production of noiseless reconstructed dose distributions from which proton range can be derived with high precision.Approach.A new MLEM & simulated annealing (MSA) algorithm, developed especially in this work, reconstructs the deposited dose distribution from a realistic pre-calculated activity-dose dictionary. This dictionary contains the contribution of each beam in the plan to the 3D activity and dose maps, as calculated by a Monte Carlo simulation. The MSA algorithm, usinga prioriinformation of the treatment plan, seeks for the linear combination of activities of the precomputed beams that best fits the observed PET data, obtaining at the same time the deposited dose.Main results.the method has been tested using simulated data to determine its performance under 4 different test cases: (1) dependency of range detection accuracy with delivered dose, (2) in-beam versus offline verification, (3) ability to detect anatomical changes and (4) reconstruction of a realistic spread-out Bragg peak. The results show the ability of the method to accurately reconstruct doses from PET data corresponding to 1 Gy irradiations, both in intra-fraction and inter-fraction verification scenarios. For this dose level (1 Gy) the method was able to spot range variations as small as 0.6 mm.Significance.out method is able to reconstruct dose maps with remarkable accuracy from clinically relevant dose levels down to 1 Gy. Furthermore, due to the noiseless nature of reconstructed dose maps, an accuracy better than one millimeter was obtained in proton range estimates. These features make of this method a realistic option for range verification in proton therapy.

Adaptación e implementación del modelo de prevención de consumo de sustancias Planet Youth en Chile / Adaptation and implementation of the Planet Youth substance use prevention model in Chile

Resumen El consumo de sustancias en adolescentes es altamente prevalente en varias regiones del mundo, y especialmente en Chile, siendo su prevención un importante desafío para la salud pública. Este artículo describe el modelo islandés de prevención del consumo de sustancias en adolescentes "Planet Youth", su adaptación y factibilidad de implementación en Chile, como primera experiencia en Latinoamérica. Este modelo comunitario está enfocado en la prevención ambiental y en la promoción de la salud de niños, niñas y adolescentes, basado en un diagnóstico local y oportuno de factores protectores y de riesgo, con colaboración de la autoridad local y la academia. Seis comunas de la región metropolitana en colaboración con la Universidad de Chile y el Icelandic Centre for Social Research and Analysis inician su implementación en 2018. Se tradujo y adaptó la encuesta islandesa que fue aplicada a 7354 estudiantes de 2° medio, cuyos resultados se retroalimentaron a colegios y municipalidades para trabajar en la modificación de los principales factores de riesgo y protección. En 2020, el proceso ha requerido algunas adaptaciones debido a la pandemia por COVID-19. Se discute acerca de factores socioculturales relevantes en la adaptación de estrategias basadas en evidencia internacional que se transfieren a un país diferente. La implementación del modelo Planet Youth es factible en Chile y ofrece una importante oportunidad para prevenir el consumo de sustancias en jóvenes de manera efectiva en Latinoamérica.

The prevalence of substance use is high among adolescents in several region around the world, specifically in Chile, and its prevention is an important public health challenge. We describe the adaptation and the feasibility to implement the Icelandic model of substance use prevention in adolescents "Planet Youth" in Chile as first experience in Latin America. This community prevention model focuses on the environment, culture and the promotion of health in adolescents, informed by local risk and protective factors. Implementation requires collaboration between academia and municipal authorities. Six municipalities of the Metropolitan Region, the University of Chile and the Icelandic Centre for Social Research and Analysis collaborated in the implementation of the Planet Youth model since 2018 in Chile. A substance use survey was translated, adapted, and applied to 7354 tenth grade students. The results were informed to schools and municipalities in order to work on modifications of the main risk and protective factors in their own community. In 2020, the prevention process has required some adaptation due to COVID-19 pandemic. We discuss sociocultural factors in the adaptation of this international prevention model transferred to Latin America. The implementation of the Planet Youth model is feasible in Chile and offers an opportunity to effectively prevent the substance use behaviors of adolescents in Latin America.

Drinking water treatment by multistage filtration on a household scale: Efficiency and challenges.

Universalising actions aimed at water supply in rural communities and indigenous populations must focus on simple and low-cost technologies adapted to the local context. In this setting, this research studied the dynamic gravel filter (DGF) as a pre-treatment to household slow-sand filters (HSSFs), which is the first description of a household multistage filtration scale to treat drinking water. DGFs (with and without a non-woven blanket on top of the gravel layer) followed by HSSFs were tested. DGFs operated with a filtration rate of 3.21 m3 m-2.d-1 and HSSFs with 1.52 m3 m-2.d-1. Influent water contained kaolinite, humic acid and suspension of coliforms and protozoa. Physical-chemical parameters were evaluated, as well as Escherichia coli, Giardia spp. cysts and Cryptosporidium spp. oocyst reductions. Removal was low (up to 6.6%) concerning true colour, total organic carbon and absorbance (λ = 254 nm). Nevertheless, HMSFs showed turbidity decrease above 60%, E. coli reduction up to 1.78 log, Giardia cysts and Cryptosporidium oocysts reductions up to 3.15 log and 2.24 log, respectively. The non-woven blanket was shown as an important physical barrier to remove solids, E. coli and protozoa.

Eficacia y seguridad de tres esquemas para la preparación del colon para colonoscopia (polietilenglicol (PEG) 4 litros (4 L) (dosis única) vs. PEG 4 L dividido (2 L + 2 L) vs. PEG 2 L dividido de volumen bajo (1 L + 1 L): ensayo clínico controlado aleatorizado / A randomized controlled clinical trial of the efficacy and safety of colonoscopy preparation using a single four liter dose of polyethylene glycol (PEG) vs. two 2 liter doses of PEG vs. two low volume (1L + 1L) doses of PEG

Resumen Introducción: la colonoscopia es el examen estándar de oro para evaluar la mucosa del colon. De la limpieza del colon en la preparación intestinal para colonoscopia depende el hallazgo de pólipos, que pueden ser adenomatosos con potencial maligno y con la posibilidad de degenerarse en cáncer de colon. Objetivo: comparar la eficacia y la seguridad de tres tipos de preparaciones para la limpieza del colon: dosis única de polietilenglicol (PEG) 4 litros (4 L) y dosis divididas: PEG 4 L dividido (2 L + 2 L) y PEG 2 L dividido (1 L + 1 L) de volumen bajo. Métodos: en pacientes con una colonoscopia electiva de una clínica universitaria, se realizó un ensayo clínico controlado aleatorizado y ciego (para el médico que evaluó la limpieza del colon). Se asignaron 74 pacientes para cada grupo. El parámetro principal de eficacia fue la preparación integral de calidad adecuada medida con la escala de Boston, y los parámetros secundarios fueron el porcentaje de eventos adversos, la tolerabilidad y la tasa de detección de pólipos. Resultados: la preparación completa de todo el colon fue significativamente de mayor la calidad en la alternativa de 4 L divididos (2 L + 2 L), seguida de la otra alternativa dividida (1 L + 1 L) y menor en la dosis única (79,7 %, 75,7 % y 63,5 %, respectivamente, p = 0,019); también se encontraron diferencias en la detección de pólipos (13,5 %, 24,3 % y 9,5 %, p = 0,037) y sin diferencias en la presentación de al menos un evento adverso (p = 0,254) ni en la tolerabilidad (p = 0,640). Conclusiones: las dos preparaciones de dosis dividida tienen una mayor eficacia en la limpieza del colon en comparación con la dosis única de 4 L y en la detección de pólipos, mientras que no se evidencian diferencias en las preparaciones para la ocurrencia de eventos adversos y la tolerabilidad. La dosis de PEG 2 L dividido puede ser una muy buena opción para las preparaciones de colonoscopia electiva.

Abstract Introduction: Colonoscopy is the gold standard for evaluation of the colonic mucosa. Colon cleansing in preparation for colonoscopy depends on finding of polyps which can be adenomatous with malignant potential and the possibility of degenerating into colon cancer. Objective: This study's objective was to compare the efficacy and safety of three types of preparations for colon cleansing: a single four liter dose of polyethylene glycol (PEG) vs. two 2 liter doses of PEG vs. two low volume (1L + 1L) doses of PEG. Methods: This is a randomized controlled clinical trial of patients who underwent elective colonoscopy at a University clinic. It was blinded for the doctor who evaluated colon cleansing. Seventy four patients 74 patients were randomized into each group. The main parameter of effectiveness was integral preparation of adequate quality measured on the Boston scale. Secondary parameters were the percentage of adverse events, tolerability and detection rate of polyps. Results: Complete preparation of the entire colon was achieved significantly more often with 4 liters divided into two 2 liter doses followed by the other divided alternative (1 L + 1 L). It was achieved least frequently with in the single dose: 79.7%, 75.7% and 63.5%, respectively, p = 0.019. Differences were also found in the detection of polyps (13.5%, 24.3% and 9.5%, respectively, p = 0.037). ) There were no differences in presentation of at least one adverse event (p = 0.254) or in tolerability (p = 0.640). Conclusions: The two divided dose preparations had higher colon cleansing and polyp detection efficacies than did the single 4L dose while there were no differences in occurrence of adverse events and tolerability. The divided PEG 2L dose could be a very good option for elective colonoscopy preparation.

Fast optimized Monte Carlo phase-space generation and dose prediction for low energy x-ray intra-operative radiation therapy.

Low energy x-ray intra-operative radiation therapy (IORT) is used mostly for breast cancer treatment with spherical applicators. X-ray IORT treatment delivered during surgery (ex: INTRABEAM®, Carl Zeiss) can benefit from accurate and fast dose prediction in a patient 3D volume. However, full Monte Carlo (MC) simulations are time-consuming and no commercial treatment planning system (TPS) was available for this treatment delivery technique. Therefore, the aim of this work is to develop a dose computation tool based on MC phase space information, which computes fast and accurate dose distributions for spherical and needle INTRABEAM® applicators. First, a database of monoenergetic phase-space (PHSP) files and depth dose profiles (DDPs) in water for each applicator is generated at factory and stored for on-site use. During commissioning of a given INTRABEAM® unit, the proposed fast and optimized phase-space (FOPS) generation process creates a phase-space at the exit of the applicator considered, by fitting the energy spectrum of the source to a combination of the monoenergetic precomputed phase-spaces, by means of a genetic algorithm, with simple experimental data of DDPs in water provided by the user. An in-house hybrid MC (HMC) algorithm which takes into account condensed history simulations of photoelectric, Rayleigh and Compton interactions for x-rays up to 1 MeV computes the dose from the optimized phase-space file. The whole process has been validated against radiochromic films in water as well as reference MC simulations performed with penEasy in heterogeneous phantoms. From the pre-computed monoenergetic PHSP files and DDPs, building the PHSP file optimized to a particular depth-dose curve in water only takes a few minutes in a single core (i7@2.5 GHz), for all the applicators considered in this work, and this needs to be done only when the x-ray source (XRS) is replaced. Once the phase-space file is ready, the HMC code is able to compute dose distributions within 10 min. For all the applicators, more than 95% of voxels from dose distributions computed with the FOPS+hybrid code agreed within 7%-0.5 mm with both reference MC simulations and measurements. The method proposed has been fully validated and it is now implemented into radiance (GMV SA, Spain), the first commercial IORT TPS.

Síndrome de hiperémesis por cannabinoides: caso clínico / Cannabinoid hyperemesis syndrome: clinical case

Background. The cannabinoid hyperemesis syndrome (CHS) was first described in 2004. It is considered as a functional gastrointestinal syndrome characterized by the presence of nausea, severe and cyclic morning vomiting, epigastric abdominal pain, hot water bathing for symptom relief, in patients that use cannabis regularly and has a resolution of the syndrome after cessation of cannabis consumption. Clinical Case. Report of a 29 year old male, with daily consumption of cannabis, with history of intense epigastric abdominal pain and recurrent vomiting that partially responded to the use of antispasmodics. After 4 visits to the emergency department he was hospitalized for study and treatment. Laboratory and image exploration are carried out without positive results for organic disease. Therefore, a functional gastrointestinal syndrome is thought, and a cannabinoid hyperemesis syndrome was suspected. A psychiatric evaluation is carried out, diagnosing a cannabis use disorder. Discussion and conclusion. CHS is a syndrome that has been described recently and is not usually considered as a differential diagnosis for patients with hyperemesis. However, the current high prevalence of cannabis consumption, will probably lead to a more frequent presentation of the syndrome at different health providers. Therefore, it is important to diffuse and update the knowledge about this syndrome to recognize it and develop a timely treatment, avoiding medical complications from invasive exploratory methods and the use of unnecessary resources. (AU)

Bilateral maculopathy after exposure to a laser pointer: Optical coherence tomography angiography findings. / Maculopatía bilateral por exposición a puntero láser: hallazgos en la angiografía mediante tomografía de coherencia óptica.

CASE REPORT: A 36-year-old man went to the emergency department the day after exposure to a laser pointer. Funduscopy revealed dispersed macular pigment alterations, and optical coherence tomography showed a disruption of the retinal layers. The visual acuity was counting fingers in both eyes. Nine months later, optical coherence tomography angiography showed a rarefaction in the choriocapillaris vascular flow in the area of the laser injuries. DISCUSSION: The retinal layer mainly damaged by the laser injury was the retinal pigment epithelium. However, it is suggested that the laser injury could involve tissues beyond the retinal pigment epithelium, since a rarefaction of the choriocapillaris was found after exposure to the laser.

Factores asociados al ataque cerebrovascular isquémico entre los años 2013 a 2016, un estudio de casos y controles / Factors associated with ischaemic cerebrovascular accidents between the years 2013 and 2016: A case-control study

Resumen Objetivo: Determinar los factores asociados al ataque cerebrovascular isquémico en el servicio de urgencias de la Clínica Especializada Los Andes, de la ciudad de Tunja, entre los años 2013 a 2016. Pacientes y métodos: Estudio de casos y controles; los casos correspondieron a 97 pacientes con ataque cerebrovascular isquémico (infarto cerebral isquémico y accidente isquémico transitorio) y los controles a 291 pacientes sin ataque cerebrovascular isquémico que ingresaron a urgencias entre los años 2013 a 2016. Resultados: El sexo femenino correspondió al 56,7% (55) de los casos y al 54,6% de los controles (154) (p = 0,069). La media de edad en el grupo caso fue de 73,7 años ENT#091;DE: 10,5 añosENT#093; y en los controles de 64,5 años ENT#091;DE: 11,3 añosENT#093;. Los factores asociados al ataque cerebrovascular isquémico fueron: antecedente de ataque cerebrovascular isquémico ENT#091;OR 7,7 IC 95% 3,2; 18 p= 0,000ENT#093;, tabaquismo ENT#091;OR 4,4 IC 95% 1,1; 18 p= 0,022ENT#093;, dislipidemia ENT#091;OR 3 IC 95% 1,2; 7,5 p= 0,017ENT#093;, edad igual o mayor a 70 años ENT#091;OR 2,3 IC 95% 1,3; 4,1 p= 0,002ENT#093; e hipertensión arterial ENT#091;OR 1,8 IC 95% 1,06; 3,3 p= 0,029ENT#093;. Conclusiones: Los factores asociados al ataque cerebrovascular isquémico fueron, en orden de importancia, antecedente de ataque cerebrovascular isquémico, tabaquismo, dislipidemia, edad igual o mayor a 70 años E hipertensión arterial.

Abstract Objective: To determine the factors associated with ischaemic cerebrovascular accidents (ICVA) in the Emergency Department of the Andes Specialist Clinic of the city of Tunja, between the years 2013 and 2016. Patients and methods: A case-control study was conducted in which the cases consisted of 97 patients with ICVA (ischaemic cerebral infarction and transient ischaemic accident), and the controls were 291 patients with no ICVA, who were admitted to the Emergency Department between the years 2013 and 2016. Results: There were 56.7% (55) females in the cases, and 54.6% (154) in the controls (P=.069). The mean age of the cases was 73.7 years ENT#091;SD: 10.5 yearsENT#093;, and 64.5 years ENT#091;SD: 11.3 yearsENT#093; in the controls. The factors associated with ICVA were: a history of ICVA ENT#091;OR; 7.7, 95% CI; 3.2-18, P=.000ENT#093;, smoking ENT#091;OR; 4.4, 95% CI; 1.1-18, P=.022ENT#093;, dyslipidaemia ENT#091;OR; 3, 95% CI; 1.2-7.5, P=.017ENT#093;, age equal to or greater than 70 years ENT#091;OR; 2.3, 95% CI; 1.3-4.1, P=.002ENT#093;, and arterial hypertension ENT#091;OR; 1.8, 95% CI; 1.06-3.3, P=.029ENT#093;. Conclusions: The factors associated with ischaemic cerebrovascular accident were, in order of importance, a history of ischaemic cerebrovascular accident, smoking, dyslipidaemia, age equal to or greater than 70 years, and arterial hypertension.

Integration of Membrane Distillation with solar photo-Fenton for purification of water contaminated with Bacillus sp. and Clostridium sp. spores.

Although Membrane Distillation (MD) has been extensively studied for desalination, it has other applications like removing all kinds of solutes from water and concentrating non-volatile substances. MD offers the possibility of producing a clean stream while concentrating valuable compounds from waste streams towards their recovery, or emerging contaminants and pathogens present in wastewater in order to facilitate their chemical elimination. This paper analyses the elimination of bacterial spores from contaminated water with MD and the role of MD in the subsequent treatment of the concentrate with photo-Fenton process. The experiments were performed at Plataforma Solar de Almería (PSA) using a plate and frame bench module with a Permeate Gap Membrane Distillation (PGMD) configuration. Tests were done for two different kinds of spores in two different water matrixes: distilled water with 3.5wt% of sea salts contaminated with spores of Bacillus subtilis (B. subtilis) and wastewater after a secondary treatment and still contaminated with Clostridium sp. spores. An analysis of the permeate was performed in all cases to determine its purity, as well as the concentrated stream and its further treatment in order to assess the benefits of using MD. Results showed a permeate free of spores in all the cases, demonstrating the viability of MD to treat biological contaminated wastewater for further use in agriculture. Moreover, the results obtained after treating the concentrate with photo-Fenton showed a shorter treatment time for the reduction of the spore concentration in the water than that when only photo-Fenton was used.

Prospective study of filtering blebs after XEN45 surgery. / Estudio prospectivo de las ampollas de filtración poscirugía de implante XEN45.

OBJECTIVE: To qualitatively analyse the evolution of filtering blebs after XEN surgery, by using anterior segment optical coherence tomography (AS-OCT). METHODS: A prospective study was performed on filtering blebs of 30 eyes with cataracts and glaucoma, surgically operated on using phacoemulsification and XEN45 implantation (PHACO-XEN). AS-OCT was used to analyse bleb morphology and reflectivity at 3, 6, and 12 months after surgery. Functionality was studied considering an intraocular pressure (IOP)≤18mmHg without antihypertensive medication. RESULTS: The IOP enabled the blebs to be classified into non-functional: flat (6.67%) and encapsulated (3.33%); and functional (90%), which were then divide by their morphology into cystic (5/27), diffuse (2/27), and layered (20/27). Cystic types had a mean IOP of 12.8, 12.6, and 14.0mmHg at 3, 6 and 12 months, respectively. In the diffuse type, the mean IOP was 13.0, 11.5 and 13.0mmHg at 3, 6 and 12 months, respectively. In the layers pattern the mean IOP was 14.45, 14.55 and 14.8mmHg at 3, 6 and 12 months respectively. The percentage of blebs with high reflectivity was 48.15%, 62.96%, and 77.78%, at 3, 6 and 12 months, with a mean IOP of 14.23, 14.59, and 15.14mmHg in each time period, respectively. CONCLUSION: AS-OCT could be a good predictor of bleb functionality in PHACO-XEN surgery. Those with a cystic pattern or low reflectivity seem to have better post-operative success. Nevertheless, more long-term studies are required.

Special situations in inflammatory bowel disease: First Latin American consensus of the Pan American Crohn's and Colitis Organisation (PANCCO) (Second part). / Situaciones especiales en la enfermedad inflamatoria intestinal: primer consenso latinoamericano de la Pan American Crohn's and Colitis Organisation (PANCCO) (Segunda parte).

This is the first Latin American Consensus of the Pan American Crohn's and Colitis Organisation (PANCCO) regarding special situations in patients with inflammatory bowel disease (IBD). The aim of this consensus is to raise awareness in the medical community in all Latin American countries with respect to pregnancy, vaccinations, infections, neoplasms, including colorectal cancer, and pediatric issues in patients with IBD.

Diagnosis and treatment of inflammatory bowel disease: First Latin American Consensus of the Pan American Crohn's and Colitis Organisation. / Diagnóstico y tratamiento de la enfermedad inflamatoria intestinal: Primer Consenso Latinoamericano de la Pan American Crohn's and Colitis Organisation.

The incidence and prevalence of inflammatory bowel disease (IBD) has increased in recent years in several Latin American countries. There is a need to raise awareness in gastroenterologists and the population in general, so that early diagnosis and treatment of ulcerative colitis (UC) and Crohn's Disease (CD) can be carried out. It is important for all physicians to have homogeneous criteria regarding the diagnosis and treatment of IBD in Latin America. The Pan American Crohn's and Colitis Organisation (PANCCO) is an organization that aims to include all the countries of the Americas, but it specifically concentrates on Latin America. The present Consensus was divided into two parts for publication: 1) Diagnosis and treatment and 2) Special situations. This is the first Latin American Consensus whose purpose is to promote a perspective adapted to our Latin American countries for the diagnosis, treatment, and monitoring of patients with UC and CD.

Hipovitaminosis D en pacientes hospitalizados por trastornos por consumo de sustancias en Unidad de Adicciones del Hospital Clínico Universidad de Chile / Hypovitaminosis D in patients hospitalized for substance use disorders in the Addictions Unit of the Hospital Clínico Universidad de Chile

The pathological consumption of alcohol and other drugs is associated with calcium metabolism disfunction through different pathways. Hypovitaminosis D contributes to acute a chronic neuronal injury in alcohol dependent patients. We do not have national evidence regarding the presence of hypovitaminosis D in addicted patients and there is a lack of information in the literature regarding polysubstance users. In this retrospective study, we evaluate the presence of hypovitaminosis of D in Substance Use Disorder inpatients treated in the Psychiatric Clinic of the University during the months of August to November 2017 and we described their main characteristics. 24 patients were evaluated, 19 of whom presented levels lower than 30 ng/ml of Vitamin D. Of those patients with hypovitaminosis 79% were men and 90% of them consumed alcohol, although in only 26% alcohol was the main substance. The main substance reported by the patients was cocaine (37%), smokable cocaine (32%) and marijuana (5%). Despite the methodological limitations of the study and the high prevalence of Hypovitaminosis D reported in the Chilean population, the results of this study suggest the need for a systematic evaluation of Vitamin D levels in patients hospitalized for addictions to adequately supplement those who require it. (AU)

Comparación de prácticas en salud sexual y reproductiva entre estudiantes de ciencias de la salud y de ingeniería de una institución de educación superior en Bogotá, Colombia, 2008 / Comparison of sexual and reproductive health practices between students of health sciences and students of engineering in a higher education institution in Bogotá, Colombia, 2008 / Comparação das práticas de saúde sexual e reprodutiva entre estudantes de ciências da saúde e de engenharia de uma instituição de educação superior em Bogotá, Colombia, 2008

El objetivo de este estudio de corte transversal fue comparar las prácticas en salud sexual y reproductiva de un grupo de estu\r\n-\r\ndiantes de ciencias de la salud y de ingeniería de una institución de educación superior en Bogotá, Colombia, en el año 2008. El \r\ntamaño de la muestra fue de 112 estudiantes de ciencias de la salud y 109 estudiantes de ingeniería. El 72% de los estudiantes de ingeniería y el 67,9% de ciencias de la salud tuvieron su primera relación sexual entre los 15 y 18 \r\naños. La frecuencia de embarazos es mayor en las estudiantes de ciencias de la salud (20% vs. 7,6%). El nivel de conocimientos \r\nen anticoncepción fue superior en los estudiantes de ciencias de la salud (74,1% vs. 50,5%). Se presentan similitudes en el nivel \r\nde conocimiento sobre las infecciones de transmisión sexual, 96,4% en ciencias de la salud y 92,7% en ingeniería. No se realizan \r\nla citología cervicouterina: 69,4% de las estudiantes de las ciencias de la salud y 61,9% de ingeniería. El 85,7% de los hombres \r\nen las ingenierías y el 58,3% de las ciencias de la salud no realizan el autoexamen de testículo. Se concluye que, pese a que los \r\nestudiantes de ciencias de la salud tienen un mayor nivel de conocimiento relacionado con la salud sexual y reproductiva, los \r\nresultados indican similitudes al compararlos con ingeniería; por lo tanto, tener formación en este aspecto no siempre significa \r\nque estos conocimientos sean llevados a la vida propia para el ejercicio de una sexualidad responsable.

The purpose of this cross-section study was to compare the \r\nsexual and reproductive health practices of a group of health \r\nsciences students and engineering students of a higher educa\r\n-\r\ntion institute in Bogota, Colombia in 2008. The sample size was \r\n112 health sciences students and 109 engineering students.\r\n72% of engineering students and 67.9% of health sciences \r\nstudents had their first sexual relationship between 15 and 18 \r\nyears of age. The frequency of pregnancy is greater in health \r\nsciences students (20% vs. 7.6%). The level of knowledge of \r\ncontraceptives was greater in students of health sciences (74.1% \r\nvs. 50.5%). There were similarities in the level of knowledge \r\nabout sexually transmitted diseases, 96.4% in health sciences \r\nand 92.7% in engineering. 64.4% of health sciences students \r\nand 61.9% of engineering students did not carry out a cervical \r\ncytology. 85.7% of male engineering students and 58.3% of \r\nmale health sciences students do not carry out self-exami\r\n-\r\nnation of the testicles. It is concluded that despite health \r\nsciences students having a higher level of knowledge related \r\nwith sexual and reproductive health, the results indicate simi\r\n-\r\nlarities with the behavior of engineering students; therefore, \r\nhaving formation in this aspect does not always mean that the \r\nknowledge will lead to a life proper for the exercising of sexual \r\nresponsibility.

O objetivo deste estudo de coorte transversal foi comparar \r\nas práticas na saúde sexual e reprodutiva de um grupo de \r\nestudantes de ciências da saúde e de engenharia de uma insti\r\n-\r\ntuição de educação superior em Bogotá, Colômbia, no ano de \r\n2008. O tamanho da amostra foi de 112 estudantes de ciências \r\nda saúde e 109 estudantes de engenharia.\r\n72% dos estudantes de engenharia e 67,9% de ciências da \r\nsaúde tiveram sua primeira relação sexual entre 15 e 18 anos. \r\nA frequência de gravidez é maior nas estudantes de ciên\r\n-\r\ncias da saúde (20% vs. 7,6%). O nível de conhecimento sobre \r\nanticoncepcionais foi superior nos estudantes de ciências da \r\nsaúde (74,1% vs. 50,5%). Semelhanças são apresentadas no \r\nnível de conhecimento sobre as doenças sexualmente trans\r\n-\r\nmissíveis, 96,4% em ciências da saúde e 92,7% em engenharia. \r\nNão realizam a citologia cervical: 69,4% das estudantes de \r\nciências da saúde e 61,9% de engenharia. 85,7% dos homens \r\nna engenharia e 58,3% de ciências da saúde não realizaram o \r\nautoexame dos testículos. Conclui-se que, apesar de os estu\r\n-\r\ndantes de ciências da saúde apresentarem um nível maior \r\nde conhecimento relacionado à saúde sexual e reprodutiva, \r\nos resultados indicam semelhanças ao compará-los com a \r\nengenharia. Portanto, ser formado neste assunto nem sempre \r\nsignifica que estes conhecimentos sejam levados à vida \r\npessoal para o exercício de uma sexualidade responsável.

Phase space determination from measured dose data for intraoperative electron radiation therapy.

A procedure to characterize beams of a medical linear accelerator for their use in Monte Carlo (MC) dose calculations for intraoperative electron radiation therapy (IOERT) is presented. The procedure relies on dose measurements in homogeneous media as input, avoiding the need for detailed simulations of the accelerator head. An iterative algorithm (EM-ML) has been employed to extract the relevant details of the phase space (PHSP) of the particles coming from the accelerator, such as energy spectra, spatial distribution and angle of emission of particles. The algorithm can use pre-computed dose volumes in water and/or air, so that the machine-specific tuning with actual data can be performed in a few minutes. To test the procedure, MC simulations of a linear accelerator with typical IOERT applicators and energies, have been performed and taken as reference. A solution PHSP derived from the dose produced by the simulated accelerator has been compared to the reference PHSP. Further, dose delivered by the simulated accelerator for setups not included in the fit of the PHSP were compared to the ones derived from the solution PHSP. The results show that it is possible to derive from dose measurements PHSP accurate for IOERT MC dose estimations.

Obesidad y excreción urinaria de sodio en niños y adolescentes / Obesity and urinary sodium excretion in children and adolescents

Background: Qbesity is a disease characterized by an abnormal accumulation body fat that results in neuroen-docrine changes that alter the homeostasis of sodium, producing an increased risk of hypertension in adulthood. objective: To evaluate the effect of obesity on urinary sodium excretion in children and adolescents. subjects and Methods: 266 male and female children in the age group of 5-15 years were studied: 154 obese (OB) with > 95th percentile of BMI, and 112 normal-weight patients (C) with percentile 5-85 of BMI, from the outpatient service of the Children Hospital, Posadas, Misiones, Argentina during the years 2008 -2009. The determinations of serum sodium (Na s) and 24-hour urine (Na ur) were performed using Ion Selective Electrode. The fractional excretion of sodium (FENa percent) was calculated. results: Na ur values (mEq/kg/day) and FENa percent reported significantly lower differences in the obese group compared to controls: OB Na ur 2.23 vs C Na ur 3.40 (p < 0.0001); OB FENa percent 0.59 vs C FENa percent 0.71 (p = 0.001). Conclusion: Results obtained in the present study showed that obese children have a significantly decreased urinary sodium excretion compared to normal weight children. This difference could be caused by renal retention of this ion.

Introducción: La obesidad es una enfermedad caracterizada por el aumento de grasa corporal, que genera modificaciones neuroendocrinas involucrando alteraciones en la homeostasis del sodio, que podrían generar hipertensión arterial en la adultez. Objetivo: Evaluar el efecto de la obesidad sobre la excreción urinaria de sodio en niños y adolescentes. Pacientes y Método: Se estudiaron 266 niños de ambos sexos, entre 5 y 15 años: 154 obesos (OB) definidos como IMC percentil > 95, y 112 normopeso (C), IMC percentil 5-85, provenientes del Servicio de Consultorio Externo del Hospital de Pediatría-Posadas, Misiones, Argentina, durante los años 2008-2009. Las determinaciones de sodio en suero (Na s) y orina de 24 h (Na ur) se realizaron con electrodo ion selectivo. Se calculó la excreción fraccional de sodio (EFNa por ciento). Resultados: Los valores de Naur (mEq/ kg/día) y la EFNa por ciento significativamente menores en el grupo de obesos con respecto a los controles: Na ur QB 2,23 vs Na ur C 3,40 (p < 0,0001); EFNa por ciento OB 0,59 vs EFNa por ciento C 0,71 (p = 0,001). Conclusión: En el presente estudio los resultados mostraron que los niños y adolescentes obesos presentan una disminución significativa de la excreción urinaria de sodio respecto de los niños normopeso. Dicha diferencia podría estar generada por la retención renal de dicho ion.

Prevalencia y factores asociados al Síndrome de Burnout en docentes de odontología Fundación Universitaria San Martín, año 2011 / Prevalence and associated factors in Burnout Syndrome on professors of the Fundación Universitaria San Martín, 2011

Objetivo: determinar la prevalencia y factores asociados al síndrome de Burnout en docentes de la Fundación Universitaria San Martin, Año 2011.\r\nMateriales y métodos: el tipo de estudio fue de corte transversal en una población de docentes de la Fundación Universitaria San Martin en el año de 2011. Los criterios de inclusión fueron: pertenecer a las áreas básica, preclínica y clínica, y estar vinculados a la institución. Los criterios de exclusión fueron: aquellos docentes que no quisieran participar o no se encontraran el día de la toma de los datos. La muestra fue conformada por aquellos que cumplieron con los criterios de selección. Para determinar el síndrome de Burnout se utilizó la escala de Maslach, incluyendo el APGAR familiar, variables socio demográficas y relacionadas con el trabajo.\r\nResultados: el agotamiento emocional fue alto en un 30,8% (n=24), moderado en un 43,6% (n=34) y bajo en un 25,6% (n=20). En despersonalización fue alto en un 17,1% (n=14), moderado en un 48,8% (n=40) y bajo en un 34,1% (n=28). En baja realización personal fue moderado en un 1,4% (n=1) y bajo en un 98,6% (n=72). En el análisis multivariado se encontró asociación con agotamiento emocional y el APGAR familiar leve, siendo 16,84 veces mayor frente al funcional, y en el estado civil soltero 10,54 veces mayor frente al casado. En despersonalización, el estado civil separado tuvo un riesgo 21,94 veces mayor de presentar agotamiento emocional frente al estado civil casado o unión libre.\r\nConclusión: los docentes en su mayoría presentaron un\r\ngrado alto de agotamiento emocional y despersonalización.

Objective: to determine the prevalence and the factors associated with Burnout syndrome on professors in the Fundación Universitaria San Martin, 2011.\r\nMaterials and methods: a cross-sectional type study was performed on a population of professors in the Fundación Universitaria San Martin in 2011. Inclusion criteria were professors of the basic, pre-clinical and clinical areas, and currently being part of the institution; exclusion criteria were those professors who did not want or could not be present when the data was collected. The sample was conformed for those that satisfied the selection criteria. To determine Burnout syndrome the Maslach scale was used, including the family APGAR, demographics and work-linked variables.\r\nResults: emotional exhaustion was higher in 30,8% (n = 24), moderate in 43,6% (n = 34) and low in 25,6% (n = 20). In depersonalization was higher in 17,1% (n = 14), moderate in 48,8% (n = 40) and low in 34,1% (n = 28). In low personal accomplishment was moderate in 1,4% (n = 1) and low in 98,6% (n = 72). Multivariate analysis reveled association with emotional exhaustion and mild family APGAR to 16,84 more times on the functional, and single marital status 10,54 more times against married. In depersonalization separate marital status was 21,94 times higher risk of emotional exhaustion present status against married or cohabiting.\r\nConclusion: the majority of professors had a high degree of emotional exhaustion and depersonalization.

Split-dose administration of thiopurine drugs: a novel and effective strategy for managing preferential 6-MMP metabolism.

BACKGROUND: Mercaptopurine and azathioprine (AZA) are efficacious in treating IBD. 6-tioguanine (6-TGN) levels correlate with therapeutic efficacy, whereas high 6-methylmercaptopurine (6-MMP) levels are associated with hepatotoxicity and myelotoxicity. Some IBD patients exhibit dose-limiting preferential 6-MMP production, which may lead to undesired side effects and impact efficacy. AIM: To review the outcomes of thiopurine split-dosing in patients with preferential 6-MMP metabolism. METHODS: A retrospective chart review of 179 IBD patients treated at the Cedars-Sinai IBD Center with AZA or mercaptopurine was performed. Preferential 6-MMP metabolisers with 6-MMP levels greater than 7000 pmol/8 × 10(8) erythrocytes who underwent split-dosing were identified and assessed for biochemical and clinical responses to these dose modifications. RESULTS: A total of 20 of 179 patients met the criteria for preferential 6-MMP metabolism and underwent thiopurine split-dosing. Dividing the total daily thiopurine dose led to a reduction in 6-MMP levels (11785 vs. 5324 pmol/8 × 10(8) erythrocytes; P < 0.0001) without negatively affecting clinical disease activity or 6-TGN levels (239 vs. 216 pmol/8 × 10(8) erythrocytes; P = N.S.) and led to resolution of 6-MMP associated side effects (elevated transaminases, leucopenia and flu-like symptoms) in all but two patients. After mean follow-up of 36 months, 12 patients remained in clinical remission on split-dose mercaptopurine. Five of the remaining eight patients escalated to anti-TNF therapy, two progressed to surgery, and one switched to tioguanine therapy. CONCLUSION: Split-dose administration of mercaptopurine/AZA represents an alternative option in IBD patients with preferential 6-MMP metabolism who might otherwise require steroid exposure or escalation of therapy.

Elimination of water pathogens with solar radiation using an automated sequential batch CPC reactor.

Solar disinfection (SODIS) of water is a well-known, effective treatment process which is practiced at household level in many developing countries. However, this process is limited by the small volume treated and there is no indication of treatment efficacy for the user. Low cost glass tube reactors, together with compound parabolic collector (CPC) technology, have been shown to significantly increase the efficiency of solar disinfection. However, these reactors still require user input to control each batch SODIS process and there is no feedback that the process is complete. Automatic operation of the batch SODIS process, controlled by UVA-radiation sensors, can provide information on the status of the process, can ensure the required UVA dose to achieve complete disinfection is received and reduces user work-load through automatic sequential batch processing. In this work, an enhanced CPC photo-reactor with a concentration factor of 1.89 was developed. The apparatus was automated to achieve exposure to a pre-determined UVA dose. Treated water was automatically dispensed into a reservoir tank. The reactor was tested using Escherichia coli as a model pathogen in natural well water. A 6-log inactivation of E. coli was achieved following exposure to the minimum uninterrupted lethal UVA dose. The enhanced reactor decreased the exposure time required to achieve the lethal UVA dose, in comparison to a CPC system with a concentration factor of 1.0. Doubling the lethal UVA dose prevented the need for a period of post-exposure dark inactivation and reduced the overall treatment time. Using this reactor, SODIS can be automatically carried out at an affordable cost, with reduced exposure time and minimal user input.

Lethal synergy of solar UV-radiation and H(2)O(2) on wild Fusarium solani spores in distilled and natural well water.

Environmentally-friendly disinfection methods are needed in many industrial applications. As a natural metabolite of many organisms, hydrogen peroxide (H(2)O(2))-based disinfection may be such a method as long as H(2)O(2) is used in non-toxic concentrations. Nevertheless, when applied alone as a disinfectant, H(2)O(2) concentrations need to be high enough to achieve significant pathogen reduction, and this may lead to phytotoxicity. This paper shows how H(2)O(2) disinfection concentrations could be significantly reduced by using the synergic lethality of H(2)O(2) and sunlight the first time for fungi and disinfection. Experiments were performed on spores of Fusarium solani, the ubiquitous, pytho- and human pathogenic fungus. Laboratory (250-mL bottles) and pilot plant solar reactors (2 x 14 L compound parabolic collectors, CPCs) were employed with distilled water and real well water under natural sunlight. This opens the way to applications for agricultural water resources, seed disinfection, curing of fungal skin infections, etc.