What is Kindness in Science and why does it matter?

Kindness in Science is a grassroots initiative to establish a scientific community built on diversity, respect and well-being, which would ultimately lead to happier scientists and better scientific outcomes. We believe that the key areas that we can become kinder as scientists include yourself, each other, the environment and the wider community. Here, we discuss the key barriers to kindness in each of these areas, and ways we can overcome these issues to create kinder, more sustainable and harmonious research teams.

The use of mTOR inhibitors for the treatment of kaposiform hemangioendothelioma. A systematic review.

BACKGROUND: Kaposiform hemangioendothelioma (KHE) is a locally aggressive and potentially lethal vascular tumor of infancy. Current consensus recommendations include the use of vincristine and/or systemic steroids as first-line treatment. Mammalian target of rapamycin (mTOR) inhibitors represent a promising therapy for patients with KHE. The goal of our study is to critically assess the existing literature on outcomes of patients with KHE treated with mTOR inhibitors. METHODS: We conducted a literature search from 1 January 2000, to 30 April 2022. Articles reporting outcomes of patients treated with mTOR inhibitors for KHE were included. Descriptive statistics were used to describe and summarize the outcomes of the treatment. RESULTS: We included 327 patients with a mean age at diagnosis of 9.1 months (SD ± 9). Patients were treated with an mTOR inhibitor for a mean of 15.2 months (SD ± 4.1). A total of 315 (96.3%) patients had positive outcomes including improvement of the tumor size, symptoms and/or laboratory parameters in 227 (85%) and complete remission in 38 (12%). Seven (2%) patients did not respond to treatment and seven (2%) died of sepsis (4), Kasabach-Merritt phenomenon complications (1), cardiac and liver failure due to ductus arteriosus (1), or metastatic disease (1). CONCLUSION: This systematic review supports the efficacy and safety of mTOR inhibitors for KHE. Their use resulted in positive outcomes in terms of decreased symptoms, reduction in tumor size and improvement in biochemical parameters with a mortality rate of 2%. According to these findings, we suggest revised consensus treatment guidelines for KHE with mTOR inhibitors potentially considered first-line therapy.

The contribution of self-concept to sleep quality in adolescents: A cross-sectional study.

Self-concept has been associated with health-related behaviors and emotional self-regulation, which can improve sleep. However, its involvement in sleep quality in a healthy adolescent population has been little studied. This study evaluated the association between self-concept and sleep quality in adolescents adjusting for sleep/wake habits. The cross-sectional study included 1,751 adolescents, 54% females, with an age of M = 16.76 ± 1.04 years. The information was collected through an electronic survey that contained the Patient Health Questionnaire, Sleep Habits Questionnaire, Pittsburgh Sleep Quality Index, and Self-Concept Scale. A significant association between self-concept, adjustment for adolescents´ characteristics and sleep/wake habits was observed (R2 = .17, F = 26.61, p < .001). That is, in addition to the adolescent habits, self-concept also contributed to the explanation of sleep/wake habits. These results reinforce the idea that the self-concept can be an essential factor that contributes to better sleep quality, despite the habits of adolescents.

[Lack of association between the S447X variant of the lipoprotein lipase gene and plasma lipids. A preliminary study]. / Ausencia de asociación entre la variante S447X del gen de la lipoproteina lipasa y lipidos plasmáticos. Estudio preliminar.

The increase in lipid plasma values is an important cardiovascular risk factor. Lipoprotein lipase (LPL) plays an important role in the lipoprotein metabolism and metabolic and genetic factors may influence its levels and functions. The S447X variant of the lipoprotein lipase gene is associated with changes in plasma lipids in different populations. The objective of this research was to analyze the S447X variant of the LPL gene and its relation with plasma lipids of individuals in Zulia state, Venezuela. With this purpose, we studied 75 individuals (34 men and 41 women) between 20 and 60 years of age. Each subject had a medical history which included family history, anthropometric characteristics, nutritional status evaluation and biochemical tests. Genomic DNA was extracted for the molecular study and the polymerase chain reaction was used, followed by enzyme digestion, for restriction fragments length polymorphisms using the Hinf I enzyme. The individuals studied had normal levels of blood glucose, triglycerides, total cholesterol and low density lipoproteins (LDL-C) and slightly decreased levels of high density lipoproteins (HDL-C). The genotypic distribution of the LPL gene S447X variant in the studied population was 90.6% for the homozygous genotype SS447 and 9.4% for the heterozygote SX447. The genotype 447XX was not identified. The population was found in Hardy Weinberg genetic equilibrium. No association between the S447X polymorphism of lipoprotein lipase gene and plasma lipids was observed.

Generation of RRMS and PPMS specific iPSCs as a platform for modeling Multiple Sclerosis.

The advent of cellular reprogramming technology converting somatic cells into induced pluripotent stem cells (iPSCs) has revolutionized our understandings of neurodegenerative diseases that are otherwise hard to access and model. Multiple Sclerosis (MS) is a chronic demyelinating, inflammatory disease of central nervous system eventually causing neuronal death and accompanied disabilities. Here, we report the generation of several relapsing-remitting MS (RRMS) and primary progressive MS (PPMS) iPSC lines from MS patients along with their age matched healthy controls from peripheral blood mononuclear cells (PBMC). These patient specific iPSC lines displayed characteristic embryonic stem cell (ESC) morphology and exhibited pluripotency marker expression. Moreover, these MS iPSC lines were successfully differentiated into neural progenitor cells (NPC) after subjecting to neural induction. Furthermore, we identified the elevated expression of cellular senescence hallmarks in RRMS and PPMS neural progenitors unveiling a novel drug target avenue of MS pathophysiology. Thus, our study altogether offers both RRMS and PPMS iPSC cellular models as a good tool for better understanding of MS pathologies and drug testing.

Arsenic species, AS3MT amount, and AS3MT gene expression in different brain regions of mouse exposed to arsenite.

Human exposure to inorganic arsenic (iAs) has been associated with cancer and serious injury to various internal organs, as well as peripheral neuropathy, endocrine disruption and diverse effects in the central nervous system (CNS). Using rodent models, it is possible to demonstrate As accumulation in the brain that leads to defects in operant learning, behavioral changes, and affect pituitary gonadotrophins. iAs biomethylation in the CNS is a significant process, yielding products that are more reactive and toxic than the parent compound. Mice received 2.5, 5, and 10 mg/kg/day sodium arsenite orally for 9 days. We investigated the distribution of iAs and its metabolites as well as the mRNA and protein expression of arsenic (III) methyltransferase (AS3MT), which encodes the key enzyme in iAs metabolism, in the cerebral cortex, hippocampus, striatum, mesencephalon, thalamus, cerebellum, hypothalamus, pons, medulla oblongata, and pituitary of mouse brain. Our findings show that methylated As metabolites are present in all brain regions studied suggesting that AS3MT is ubiquitously expressed in the brain and it is not inducible by dose of arsenite. There is also a dose-related accumulation of As species in all brain regions, with the highest accumulation observed in the pituitary. The higher distribution of arsenicals in pituitary can help to explain the neuroendocrine effects associated with iAs exposure.

Anti-inflammatory potential of human corneal stroma-derived stem cells determined by a novel in vitro corneal epithelial injury model.

BACKGROUND: An in vitro injury model mimicking a corneal surface injury was optimised using human corneal epithelial cells (hCEC). AIM: To investigate whether corneal-stroma derived stem cells (CSSC) seeded on an amniotic membrane (AM) construct manifests an anti-inflammatory, healing response. METHODS: Treatment of hCEC with ethanol and pro-inflammatory cytokines were compared in terms of viability loss, cytotoxicity, and pro-inflammatory cytokine release, in order to generate the in vitro injury. This resulted in an optimal injury of 20% (v/v) ethanol for 30 s with 1 ng/mL interleukin-1 (IL-1) beta. Co-culture experiments were performed with CSSC alone and with CSSC-AM constructs. The effect of injury and co-culture on viability, cytotoxicity, IL-6 and IL-8 production, and IL1B, TNF, IL6, and CXCL8 mRNA expression were assessed. RESULTS: Co-culture with CSSC inhibited loss of hCEC viability caused by injury. Enzyme linked immunosorbent assay and polymerase chain reaction showed a significant reduction in the production of IL-6 and IL-8 pro-inflammatory cytokines, and reduction in pro-inflammatory cytokine mRNA expression during co-culture with CSSC alone and with the AM construct. These results confirmed the therapeutic potential of the CSSC and the possible use of AM as a cell carrier for application to the ocular surface. CONCLUSION: CSSC were shown to have a potentially therapeutic anti-inflammatory effect when treating injured hCEC, demonstrating an important role in corneal regeneration and wound healing, leading to an improved knowledge of their potential use for research and therapeutic purposes.

[Association of the vitamin D receptor gene BBAAtt haplotype with osteoporosis in post-menopausic women]. / Asociación del haplotipo BBAAtt del gen del receptor de la vitamina D con la osteoporosis en mujeres posmenopáusicas.

Osteoporosis (OP) is an important public issue affecting more than 150 millions all over the world, mainly post-menopausic women. Epidemiological studies have shown that the genetic factors could be involved in 80-90% of the bone mineral density variabiblity and therefore, related to the risk of OP manifestations. The vitamin D receptor (VRD) gene has been extensively studied, but its relationship with OP has been controversial. The aim of this investigation was to study the association of Bsm I, Apa I and Taq I VDR gene polymorphism with OP in 147 post-menopausic women; 71 with OP and 76 without the disease (control). The molecular gene analysis was performed using the polymerase chain reaction (PCR). The genotypes BB, AA, and tt were found in 56.33, 50.70 and 25.35% and in 21.05, 28.95 and 10.53% of OP patients and controls respectively. The haplotype BBAAtt was observed in 23.94% of OP patients and 5.26% of the controls. This haplotype was a risk factor for OP, since a odds ratio (OR) of 5.66 was found, while, haplotype BbaaTT was a protection factor (OR: 0.10). These findings support the association of the vitamin D receptor gene BBAAtt haplotype with OP.

Opinión de estudiantes de medicina sobre el uso de un aula virtual asincrónica durante la COVID-19 / Opinion of medical students on the use of an asynchronous virtual classroom during COVID-19

Introducción: Ante la pandemia por COVID-19, las escuelas de medicina debieron transitar de un modelo de enseñanza predominantemente presencial a la modalidad en línea, por lo que se dieron a la tarea de diseñar una serie de herramientas para dar continuidad a la formación de sus estudiantes. Objetivo: Conocer la opinión de los alumnos de medicina sobre el uso de un aula virtual asincrónica como recurso de apoyo durante su proceso de aprendizaje en el contexto de la pandemia. Sujetos y métodos: Participaron 31 alumnos de primer año de medicina en México. Se utilizó un cuestionario de nueve ítems para indagar su opinión sobre la calidad de los contenidos de una asignatura, la idoneidad de la cantidad de actividades utilizadas, así como la claridad de la introducción a cada tema, de sus objetivos y de las instrucciones para cada actividad de aprendizaje. Resultados: Más de la mitad opinó que la introducción, los objetivos y las instrucciones del aula virtual asincrónica para realizar las actividades de aprendizaje de cada tema eran fáciles de entender. Más del 70% consideró que la calidad de los contenidos era muy buena y que el número de actividades de aprendizaje utilizadas era suficiente para cubrir los objetivos. Conclusiones: Los resultados permitieron identificar el material y las actividades del aula virtual asincrónica que resultaron, en opinión de los estudiantes, enriquecedores para su proceso de aprendizaje y qué cambios realizar para mejorar esta plataforma en beneficio de su formación profesional.(AU)

Introduction: Faced with the COVID-19 pandemic, medical schools had to move from a predominantly face-to-face teaching model to the online modality, so they undertook the task of designing a series of tools to continue the training of their students. Aim: To know the opinion of medical students on the use of an asynchronous virtual classroom as a support resource during their learning process in the context of the pandemic. Subjects and methods: Thirty-one first-year medical students in Mexico participated. A nine-item questionnaire was used to find out their opinion about the quality of the contents of a subject, the suitability of the number of activities used, as well as the clarity of the introduction to each topic, its objectives and the instructions for each learning activity. Results: More than half found the introduction, objectives, and instructions of the asynchronous virtual classroom to carry out the learning activities for each topic easy to understand. Over 70% considered that the quality of the contents was very good and that the number of learning activities used was sufficient to cover the objectives. Conclusions: The results made it possible to identify the material and activities of the asynchronous virtual classroom that were, in the opinion of the students, enriching for their learning process and what changes to make to improve this platform for the benefit of their professional training.(AU)

Conventional physical therapy and physical therapy based on reflex stimulation showed similar results in children with myelomeningocele.

We aimed to investigate whether infants with myelomeningocele would improve their motor ability and functional independence after ten sessions of physical therapy and compare the outcomes of conventional physical therapy (CPT) to a physical therapy program based on reflex stimulation (RPT). Twelve children were allocated to CPT (n = 6, age 18.3 months) or RPT (n = 6, age 18.2 months). The RPT involved proprioceptive neuromuscular facilitation. Children were assessed with the Gross Motor Function Measure and the Pediatric Evaluation of Disability Inventory before and after treatment. Mann-Whitney tests compared the improvement on the two scales of CPT versus RPT and the Wilcoxon test compared CPT to RPT (before vs. after treatment). Possible correlations between the two scales were tested with Spearman correlation coefficients. Both groups showed improvement on self-care and mobility domains of both scales. There were no differences between the groups, before, or after intervention. The CPT and RPT showed similar results after ten weeks of treatment.

Evaluation of fibrin-based dermal-epidermal organotypic cultures for in vitro skin corrosion and irritation testing of chemicals according to OECD TG 431 and 439.

Reconstructed human epidermis (RhE) models have been used for in vitro testing of the potential harmful effects of exposure to chemical compounds on health. In the past, skin irritation and corrosion were evaluated in animal models; however, in recent years, due to the bioethics implications of the method and, to minimize the use of experimental animals, alternative procedures have been proposed. The Organisation for Economic Co-operation and Development (OECD) in its test guidelines (TG) 431 and 439 indicates the requirements for validating new methods for the evaluation of skin corrosion and irritation, respectively. Here, we present an in-house human dermal-epidermal model, useful for the performance of these tests. Using the methods described in this work, it was possible to obtain human fibrin-based dermal-epidermal organotypic skin cultures (ORGs) displaying similar histological characteristics to native skin and expressing specific differentiation epithelial proteins. The end points to classify a substance as irritant or corrosive were cell viability evaluated by MTT assay, and cytokine release measured by BD CBA for human inflammatory cytokines. According to the MTT test, the ORGs correctly classified irritating and corrosive substances. Moreover, the cytokine release assay was difficult to interpret in the context of testing chemical hazard classification. Further experiments are needed to validate this new model for the evaluation of surfactants because the fibrin matrix was affected in the presence of these substances.

Asociación entre actividad física y salud mental positiva en estudiantes de medicina en México: un estudio transversal / Associação entre atividade física e saúde mental positiva em estudantes de medicina do México: um estudo transversal / Association between physical activity and positive mental health in medical students in Mexico: a cross-sectional study

Esta investigación tuvo como objetivo identificar la relación entre la práctica de actividad física y aspectos positivos de la salud mental de alumnos de medicina en México. Se trata de un estudio transversal realizado con una muestra aleatoria de 190 estudiantes, con edad media de 19.0 ±1.4 años, del primero y segundo grado de una escuela de medicina en la Ciudad de México. Se aplicó una batería de pruebasde salud mental positiva que comprendía escalas para evaluar la satisfacción de los jóvenes con la vida, su resiliencia, autoconcepto y compromiso, así como el IPAQ que evalúa su práctica de actividad física. Se llevaron a cabo análisis descriptivos, comparativos y de regresión lineal múltiple. Se encontró una asociación significativa del nivel de actividad física practicada por los alumnos con su satisfacción con la vida (B= –1.64, IC95% = –2.90, –0.38, p= .011) y su capacidad de resiliencia (B= –2.41, IC95% = –3.87, –0.95, p= .001), controlando por factores sociodemográficos. La actividad física tuvouna asociación significativa con aspectos positivos de la salud mental de estudiantes de medicina en México; por ello, intervenciones orientadas a favorecer la práctica de actividad física pueden diseñarse y utilizarse no sólo en el tratamiento y prevención de trastornos mentales, sino también para promover la salud mental entre esta población. (AU)

This study aimed to identify the relationship between the practice of physical activity and positive aspects of medical students’ mental health in Mexico. This was a cross-sectional study that applied randomized sampling, and data from 190 students, with a mean age of 19.0 ±1.4 years, from the first and second grades of a medical school in Mexico City were analyzed. The questionnaire comprised scales to assess students’ satisfaction with life, resilience, self-concept, and engagement, as well as the IPAQ that evaluates their practice of physical activity. Descriptive, comparative,and multiple linear regression analyses were carried out. A significant association was found between students’ levels of physical activity, their satisfaction with life (B= –1.64, IC95% = –2.90, –0.38, p= .011) and their resilience skills (B= –2.41, IC95% = –3.87, –0.95, p= .001), controlling for sociodemographic factors. Physical activity had a significant association with positive aspects of Mexican medical students’ mental health; thus, interventions aimed at improving physical activity practice can be designed and utilized not only in the treatment and prevention of mental disorders but also to promote mental health among this population. (AU)

Este estudo teve como objetivo identificar a relação entre a prática de atividade física e aspectos positivos da saúde mental de estudantes de medicina do México. Este é um estudo transversal realizado com uma amostra aleatória de 190 alunos, com idade média de 19.0 ±1.4 anos, do primeiro esegundo ano de uma escola de medicina na Cidade do México. Foi aplicado um questionário que incluía escalas para avaliar a satisfação dos alunos com a vida, sua resiliência, autoconceito e comprometimento, além do IPAQ que avalia sua prática de atividade física. Foram realizadas análises descritivas, comparativas e de regressão linear múltipla. Foi encontrada associação significativa entre os níveis de atividade física praticados pelos alunos, a satisfação com a vida (B= –1.64, IC95% = –2.90, –0.38, p= .011) e a resiliência (B= –2.41, IC95% = –3.87, –0.95, p= .001), controlando para fatores sociodemográficos. A atividade física teve associação significativa com aspectos positivos da saúde mental de estudantes de medicina mexicanos; portanto, intervenções destinadas a promover a prática de atividade física podem ser planejadas e utilizadas não apenas no tratamento e prevenção de transtornos mentais, mas também para promover a saúde mental dessa população. (AU)

Propiedades psicométricas del cuestionario de estrés académico en la universidad (CEAU) en una muestra de estudiantes de Medicina mexicanos / Psychometric properties of the University Academic Stress Questionnaire (CEAU) in a sample of Mexican medical students

Introducción: El estrés se asocia a un pobre desempeño académico y problemas de salud mental entre los universitarios. Existen pocos instrumentos adaptados a esta población que identifiquen las fuentes de estrés académico. Objetivo: Evaluar las propiedades psicométricas del cuestionario de estrés académico en la universidad (CEAU) en estudiantes mexicanos. Sujetos y métodos: Contestaron el CEAU y la escala de malestar psicológico de Kessler (K-10) 232 alumnos de primer año de Medicina. El CEAU contiene 19 ítems sobre situaciones escolares potencialmente estresantes, mientras que la K-10 mide el malestar psicológico global inespecífico con 10 ítems. La validez de constructo se evaluó por composición factorial y por convergencia con la K-10. Las medidas de confiabilidad se obtuvieron por consistencia interna y estabilidad temporal. Resultados: Los reactivos se agruparon en los cuatro componentes de su versión original y explicaron el 45% de la varianza total, con cargas factoriales bajas en dos reactivos y uno fuera del factor propuesto inicialmente; eliminar este último reactivo produjo un mejor ajuste de los componentes y aumentó la explicación de la varianza al 57%. La consistencia interna fue de alfa = 0,88 para la puntuación total, con valores de alfa = 0,70-0,83 en sus subescalas y una estabilidad temporal de r(202) = 0,76 (p = 0,0001). La correlación del CEAU con la K-10 fue de r(232) = 0,64 (p = 0,0001). Conclusiones: El CEAU cumple con los criterios de confiabilidad y validez de constructo, se ajusta a los factores propuestos y correlaciona con el malestar psicológico en el sentido esperado.(AU)

Introduction: Stress is associated with poor academic performance and mental health problems among university students. There are few instruments adapted to this population that identify sources of academic stress. Objective: To evaluate the psychometric properties of the Academic Stress Questionnaire at University (CEAU) in Mexican students. Subjects and methods: 232 first-year medical students answered the CEAU and the Kessler psychological distress scale (K-10). The CEAU contains 19 items on potentially stressful school situations, while the K-10 measures nonspecific global psychological distress with 10 items. The construct validity was evaluated by factorial composition and by convergence with the K-10. Reliability measures were obtained by internal consistency and temporal stability. Results: The items were grouped into the four components of their original version and explained 45% of the total variance, with low factor loadings in two items and one outside the initially proposed factor; eliminating this last item produced a better fit of the components and increased the explanation of the variance to 57%. The internal consistency was α = 0.88 for the total score, with values from α = 0.70 to 0.83 in its subscales and a temporal stability of r(202) = 0.76 (p = .0001). The correlation between CEAU and K-10 was r(232) = 0.64 (p = .0001). Conclusions: The CEAU meets the reliability and construct validity criteria, adjusts to the proposed factors and correlates with psychological distress in the expected sense.(AU)

Treatment of choledochal cyst in a pediatric population. A single institution experience of 15-years. Case series.

BACKGROUND: Choledochal cyst (CC) is a rare congenital anomaly of the bile duct that approximately 75% of the patients are diagnosed in childhood. Without a standardized surgical procedure for the biliary reconstruction, we present our experience over the last 15 years and show the differences between the biliary reconstructions techniques in our population. METHODS: We did a retrospective hospital archive search for patients admitted to the pediatric surgery department with the diagnosis of a choledochal cyst from January 2000 to June 2015. RESULTS: We found 15 patients, of which, 1 was excluded because of missing data from the hospital record. Of the remaining 14, eight had hepaticojejunal (HY) anastomosis in Roux-en-Y, with a 25% rate of complications; six had hepatoduodenal (HD) anastomosis with a rate of complications of 16.6%. The average hospital length of stay in the group of HD vs. HY was 14 ± 1.6-days vs. 19 ± 8.2-days respectively. DISCUSSION: There are no standardized surgical reconstruction techniques of the biliary tract after the CC excision, there is literature that supports the biliary reconstruction with an HY and an HD without a distinct advantage over one or the other. CONCLUSION: In our series HD anastomosis represents a safe procedure with fewer complications than HY.

Shape and surface effects on the cytotoxicity of nanoparticles: Gold nanospheres versus gold nanostars.

Gold nanoparticles are materials with unique optical properties that have made them very attractive for numerous biomedical applications. With the increasing discovery of techniques to synthesize novel nanoparticles such as star-shaped gold nanoparticles for biomedical applications, the safety and performance of these new nanomaterials must be systematically assessed before use. In this study, gold nanostars (AuNSTs) with multibranched surface structures were synthesized, and their influence on the cytotoxicity of human skin fibroblasts and rat fat pad endothelial cells (RFPECs) were assessed and compared with that of gold nanospheres (AuNSPs) with unbranched surfaces. Results showed that the AuNSPs with diameters of approximately 61.46 nm showed greater toxicity with fibroblast cells and RFPECs compared with the synthesized AuNSTs with diameters of approximately 33.69 nm. The AuNSPs were lethal at concentrations of 40 µg/mL for both cell lines, whereas the AuNSTs were less toxic at higher concentrations (400 µg/mL). The calculated IC50 (50% inhibitory concentration) values of the AuNSPs exposed to fibroblast cells were greater at 1 and 4 days of culture (26.4 and 27.7 µg/mL, respectively) compared with the RFPECs (13.6 and 13.8 µg/mL, respectively), indicating that the AuNSPs have a greater toxicity to endothelial cells. It was proposed that possible factors that could be promoting the reduced toxicity effects of the AuNSTs to fibroblast cells and RFPECs, compared with the AuNSPs may be size, surface chemistry, and shape of the gold nanoparticles. The reduced cell toxicity observed with the AuNSTs suggests that AuNSTs may be a promising material for use in biomedical applications.

Karewsky syndrome: A case report and review of the literature.

INTRODUCTION: Gallstone ileus can be a lethal disease, rarely suspected in the clinical scenario. It represents about 25% of all bowel obstruction cases in patients older than 65. There is a classification of gallstone ileus based on the onset time: acute, subacute and chronic (Karewsky syndrome). We describe the first reported case of chronic gallstone ileus. CASE PRESENTATION: A 78-year-old female was admitted to the ER with a 15-day case of consistent bowel obstruction. The subject reported a five-year history of recurrent hospital admissions that resolved spontaneously after non-surgical management. Karewsky syndrome was diagnosed and managed with enterolithotomy. After five days of postoperative evolution the patient was discharged, and at six months follow up, no other hospital admission or relapse has been registered. DISCUSSION: The gallstone ileus diagnosis demands a higher clinical suspicion, there is no biochemical marker, and an abdominal CT is ideal for imaging-based diagnosis. There is no consensus on the optimal surgical approach. CONCLUSION: We describe the first case of Karewsky syndrome and a gastro-jejune and gastric-choledochus double fistula. We emphasize the importance of higher clinical suspicion for patients with bowel obstruction older than 65 years old and make evident that although there are not evidence-based guidelines for this treatment, enterolithotomy is a recommended approach.

Inclusion bodies and pH lowering: as an effect of gold nanoparticles in Streptococcus pneumoniae.

Streptococcus pneumoniae is a human pathogen whose principal virulence factor is its capsule. This structure allows the bacterium to evade the human immune system. Treatment of infections caused by this bacterium is based on antibiotics; however, the emergence of antibiotic-resistant strains makes this task increasingly difficult. Therefore, it is necessary to investigate new therapies, such as those based on gold nanoparticles, for which unfortunately the mechanisms involved have not yet been investigated. As far as we know, this study is the first that attempts to explain how gold nanoparticles destroy the bacterium Streptococcus pneumoniae. We found that the mean particle size was an important issue, and that the effect on the bacterium was dose-dependent. Cellular growth was inhibited by the presence of the nanoparticles, as was cell viability. The pH of the bacterial growth media was acidified, but interestingly the reactive species were not affected. A transmission electron microscopy analysis revealed the presence of inclusion bodies of gold nanoparticles within the bacterium. We present the first findings that attempt to explain how gold nanoparticles lyse Gram-positive bacteria.

Estrategias de afrontamiento y estrés. Estudio longitudinal con estudiantes de Medicina y Veterinaria de la Universidad Nacional Autónoma de México / Coping strategies and stress. A longitudinal study of medical and veterinary students at the National Autonomous University of Mexico

Introducción: Medicina y Veterinaria son licenciaturas con alta demanda académica que tiende a ocasionar niveles elevados de estrés entre sus estudiantes. Objetivo: El propósito de esta investigación fue indagar sobre el papel de las estrategias utilizadas por los alumnos para afrontar el estrés. Sujetos y métodos. Se aplicó una encuesta en línea a 244 estudiantes del primer año de ambas carreras en la Universidad Nacional Autónoma de México, al inicio del ciclo escolar y cuatro meses después. La encuesta incluyó la escala de estrés percibido de 10 ítems, el inventario de estilos de afrontamiento, y un apartado que indagó sobre aspectos sociodemográficos y académicos. Resultados: Se observó un incremento en el estrés de los alumnos de ambas licenciaturas, que fue estadísticamente significativo sólo en veterinaria (t(140)= –3,4; p < 0,001; d de Cohen = –0,29). El análisis estadístico mostró que mayores recursos económicos percibidos, mayor equilibrio entre la vida personal y académica, mayor resolución del problema y evitación del problema, así como menor expresión emocional, pensamiento desiderativo y autocrítica, notificados al inicio del ciclo académico, fueron los factores que se asociaron significativamente con un menor estrés percibido después de cuatromeses (F(15,228) = 14,16; p < 0,0001). Conclusión: Se destaca que las escuelas deberían incorporar actividades durante el proceso de formación de los futuros médicos y veterinarios, centradas en guiarlos y motivarlos para que desarrollen y utilicen estrategias que les permitan manejar adecuadamente situaciones desafiantes. De este modo, ellos pueden evitar el incremento de los niveles de estrés y el posible impacto negativo en su desempeño académico y salud mental.(AU)

Introduction: Medicine and Veterinary are careers with high academic demands that tend to cause high levels of stressamong students. Objective: This study investigated the role of strategies used by students to deal with stress.Subjects and methods. An online survey was administered to 244 medical and veterinary students at the National Autonomous University of Mexico, at the beginning of their first academic cycle and four months later. The survey included the perceived stress scale-10, the coping strategies inventory, as well as a section that inquired about sociodemographic and academic characteristics. Results: An increase in the stress of the students in both degrees was noted but this was only statistically significant (t(140) = –3.4, p < 0.001, Cohen’s d = –0.29) among students enrolled in veterinary. Perception of higher financial resources to cover tuition and fees, greater life and school balance, increased problem-solving and problem-avoidance, less emotional expression, wishful thinking, and self-criticism, mentioned at the beginning of the academic cycle were significantly associated with a lower perception of stress four months later (F(15,228) = 14.16, p < 0.0001).Conclusion: It is highlighted that schools should incorporate activities during the training process of future doctors and veterinarians, focused on guiding and motivating them to develop and use strategies that allow them to adequately handle challenging situations. In this way, they will be able to avoid increased stress levels and the possible negative impact on their academic performance and mental health.(AU)