Efectividad de dos métodos para la descelularización de arterias umbilicales.

La descelularización de las arterias umbilicales puede proporcionar una solución a la necesidad de injerto vasculares de pequeño calibre. Comparamos la efectividad entre los métodos SDS y Triton X-100. Se utilizó cordones umbilicales obtenidos a partir de embarazos a término con evolución normal y sin complicaciones evidentes del recién nacido, se micro-diseccionaron en 12 horas y se almacenaron en solución salina con fosfato sin congelación. Las arterias se procesaron para la descelularización usando los protocolos de SDS al 0.1% y 1%, y Triton X-100 al 1%. Se realizó la evaluación de material celular y nuclear, fibras de colágeno, fibras elásticas y glucosoaminoglicanos de la matriz extracelular (MEC), así como el análisis morfométrico de técnicas histológicas e inmunohistoquímicas

Comments on: Implications of structural variations in the human sacrum: why is an anatomical classification crucial?

We sincerely appreciate the work done by Mahato [1] in which a qualitative classification of the sacrum is done to determine the number of segments, position of auricular surfaces, symmetry and abnormalities. This work is of the utmost importance since it is crucial for several surgical interventions and at the same time correlates certain pathologies with the morphology, mostly low back pai

Estudio cadavérico del nervio dentario inferior.

Estudio cadavérico del nervio dentario inferior

Burnout Among First-Year Medical Students During COVID-19 Pandemic in Mexico: A Cross-Sectional Study

Background: The coronavirus pandemic is an international public health emergency without precedence in modern history. It represents a challenge to students’ academic and psychological stability due to the changes it caused in daily life. This study aimed to evaluate the prevalence and level of burnout in medical students caused by the academic and psychological instability that the pandemic represents. Methods: A prospective cross-sectional study was designed using the Maslach Burnout Inventory-Student Survey (MBI-SS). This evaluated the emotional exhaustion due to study demands, cynicism, and negative self-academic efficacy. This study was based in the school of medicine of the Universidad Autonoma de Nuevo Leon (UANL) in Monterrey, Mexico, during the Spring semester of 2020. Results: A total of 154 (93 women and 61 men) first-year medical students participated (response rate of 36.4%). Burnout was identified in 14.9% (n=23), and high emotional exhaustion in 53.9% (n=83). Burnout was almost 4 times more likely to develop in men than in women (aOR = 4.8; 95% Confidence Interval=1.7-13.3) when considering age as a covariable in the multivariable model. Conclusion: Further epidemiological studies of burnout syndrome in medical students are needed, and schools should consider promoting mental health and making programs available for their students to help overcome the emotional and social challenges during the pandemic

Anatomical Variants of Anterior Cerebral Arterial Circle: A Study by Multidetector Computerized 3D Tomographic Angiography

SUMMARY: One of the most common causes of stroke is rupture of aneurysms whose approach requires knowledge of anatomical variants. The aim of this study was to determine the prevalence of anatomical variants of the anterior cerebral artery (ACA) and the anterior communicating artery (AComA) by 3D computed tomography angiography (3D CTA) in Mexican individuals. A retrospective, observational, cross-sectional descriptive study of 283 patients, independent of sex or age, in which morphometric measurements of cerebral vessels were evaluated using contrasted 3D CTA from a period of two years was performed. We found at least one "atypical" variant in a third of the study population (33.93 %). The most common "atypical" variant was the absence of the AComA (14.1 %). A significant association between the hypoplastic variant of the right A1 segment and hypoplasia of the left A1 and the right A2 was found, while hypoplasia of the left A1 was associated with hypoplasia of the right A2. There is a difference in the prevalence of anatomical variants of the ACA-AComA complex in Mexican population in relation to other populations. The typical variant is the most prevalent form in the study population. However, the presence of atypical variants represents an important number that should be taken into account in clinical and surgical procedures. KEY WORDS: Anterior cerebral artery; Anatomical variant; Anterior communicating artery; Cerebral arterial circle; Subarachnoid hemorrhage; Cerebral endovascular surgery

Influencia del biocarbón aplicado al suelo sobre atributos de rendimiento y calidad de avena forrajera

El suelo es un recurso imprescindible para la producción agrícola y, por lo tanto, requiere de condiciones adecuadas para favorecer una nutrición adecuada de los cultivos y generar mayores rendimientos. El biocarbón (BC) ha sido propuesto ampliamente para mejorar la calidad del suelo y la productividad de los cultivos. El objetivo del estudio fue evaluar los efectos del biocarbón sobre el rendimiento y calidad de la avena forrajera, en el periodo otoño-invierno 2016-2017. Un diseño de bloques al azar con cuatro repeticiones fue usado, el cual incluía tres tratamientos y un testigo: T0 = testigo absoluto; T1 = [fertilización convencional: (120-60-00 kg ha-1)]; T2 = (2.25 Mg ha-1 de biocarbón + fertilización convencional); T3 = (4 Mg ha-1 de biocarbón + fertilización convencional). El experimento se condujo en campo abierto con una densidad de siembra de 120 kg ha-1. Las variables evaluadas fueron: altura de planta (AP), materia verde (MV), materia seca (MS); fibra detergente neutra (FDN), fibra detergente ácida (FDA), proteína cruda (PC), nutrientes digestibles totales (NDT), digestibilidad de la materia seca (DMS). Los datos registrados se sometieron a análisis de varianza y las medias se compararon con la prueba de Tukey (P < 0.05). Diferencias estadísticas significativas (≤ 0.05) se observaron para AP y MV, donde T2 registró el mayor valor de 33 y 102%, respectivamente, frente al control. Se concluye que la aplicación de biocarbón influye positivamente sobre atributos de rendimiento de avena forrajera. Sin embargo, se deben realizar estudios más detallados, considerando condiciones distintas al presente estudio

Modifications to the delivery of a gross anatomy course during the COVID-19 pandemic at a Mexican medical school

The Coronavirus disease was declared a pandemic this year, causing an impact on medical education. Following the World Health Organization’s (WHO) recommendations, Universities around the world implemented social distancing and the use of online platforms. Anatomists lead medical students, most of which are part of Generation Z. Different technological tools have been used in the gross anatomy course in combination with face-toface classes, but now are forced to move exclusively online. The Human Anatomy Department in the Medical School of the Universidad Autonoma de Nuevo León (UANL) implemented asynchronous sessions as a short-term resolution, transformed to synchronous sessions as the pandemic progressed. It is important to consider the adaptability of the student, the near-peer teacher, and academic staff, with the creation of innovative ideas to facilitate the learning for the student and to maintain the quality of the course. Their role in this modality should be assessed, as it may change medical education and the way to teach in the future for the new generation of medical students. Professors’ roles are changing and it is necessary to adapt to new situations

Standardized Classification of Aortic Arch Branching Patterns (SCAABP)

Objectives. To review current anatomical classifications for the aortic branching patterns and propose a method for standardized classification of Aortic Arch Branching Patterns (SCAABP). Methods. Through a three-stage Delphi method, expert vascular anatomists in morphology design SCAABP to report trunks, branches, and laterality of aortic arch branching patterns. Results. SCAABP is a classification that includes 7 parameters (Number of branches, and 6 types of branches [braquiocephalic trunk, common trunk, common carotid, subclavian artery, vertebral artery, and ectopic arteries]). It can integrate all reported branching patterns and allows the classification of new or unreported patterns. The classification allows standardization for future comparison of results, and improvement of evidence-based anatomy. Conclusions. SCAABP is a standardized method for classifying anatomical variants of the aortic arch. It is simple, clear, and contemplates new variants. All reported classifications can be integrated

Magnetic resonance based morphometric analysis of the tentorial notch

Background: The study of the tentorial notch can improve the understanding of brain injury mechanisms. Tentorial morphology has been analyzed primarily in cadaveric studies. However, the postmortem effect can cause variability in the measurements. The objective was to evaluate the morphometry of the tentorial notch and the third cranial nerve on living subjects using Magnetic Resonance Imaging (MRI). Materials and methods: A retrospective cross-sectional study was performed. Using consecutive cases, 60 MRI scans were analyzed for tentorial notch morphology. Maximum notch width (MNW), notch length (NL), interpedunculoclival (IC) distance, apicotectal (AT) distance, CN-III distance, and inter CN-III angle, were obtained. For the classification of the tentorial notch quartile distribution technique for MNW, NL, AT distance, and IC distance was used. Results: According to the quartile of the MNW, patients were stratified into narrow, midrange, and wide groups. Using the NL quartile groups, they were also classified as short, midrange, and long. With these, the tentorial notch could be classified into eight types. Statistical differences between genders in the MNW and inter CN-III angle were found, as well as a strong positive correlation between NL and AT distance, and between right and left CN-III distances. Conclusions: There were differences between the cadaveric samples and living subjects in the CN-III distances. This difference could be explained by the dehydration of brain volume in the postmortem process which may cause nerve elongation. Morphometry of the tentorial notch and its neurovascular relations allows a better understanding of the mechanisms of brain herniation

Neurovascular Structures at Risk During Anterolateral and Medial Arthroscopic Approaches of the Hip

To describe the safety areas for placement of 5 anterolateral portals (anterior, anterior lateral, posterior lateral, proximal anterior medial and distal anterior medial portals) and 3 recently described medial portals (anterior medial, posterior medial and distal posterior medial portals) to provide topographical description of the safety of each. A descriptive, observational and crosssectional study in which femoral triangle dissection was performed in 12 hips. 5 lateral portals and the 3 medial portals were placed. Clinically relevant neurovascular structures associated with each portal, were identified measured and documented. The lateral portal with the highest risk of injury to a nearby neurovascular structure was the anterior portal, the most adjacent to the femoral cutaneous nerve, 1.42 cm (±0.85) lateral to the portal. In the medial portals, the anterior medial portal has the narrowest margin in relation to the femoral artery, 2.14 cm (±0.35) lateral to the portal and medial to the obturator nerve by 0.87 cm (±0.62). The lateral portals have a higher safety margin; the portal with the most proximity to a neurovascular structure is the anterior portal, associated laterally with the femoral cutaneous nerve, presenting a higher risk of injury. Medial portals have a higher risk of injuring the femoral neurovascular bundle as well as the obturator nerve