Assessment of burnout syndrome and associated factors among medical students during the COVID-19 pandemic.

Background: Overwhelming requirements, a high degree of work, and prolonged exposure to emotionally demanding circumstances in work and life settings can lead to burnout syndrome. The purpose of the study is to assess burnout syndrome and its associated factors among medical students during the COVID-19 pandemic. Methods: A cross-sectional, prospective, descriptive study was conducted in a Mexican medical school during the last week of the spring semester of 2021 using the Maslach Burnout Inventory-Student Survey (MBI-SS) and an associated factors survey. Results: Based on the MBI-SS definition, most students (54.2%, n = 332) had burnout symptoms and high emotional exhaustion (79.6%, n = 448), high cynicism (57.3%, n = 351), and low academic effectiveness (36.4%, n = 223). After adjusting the associated factors, a significant correlation between the school year and the presence of burnout was identified (OR 1.127, 95% CI [1.023-1.241], p<0.05). Regarding the current pandemic, the death of a family member by COVID-19 also put students at risk of developing burnout (OR 1.598*, 95% CI [1.080-2.363, p<0.05]). Limitations: The main limitation of this study was the lack of a control group (before the pandemic); therefore, the high prevalence of burnout can only be hypothesized due to the pandemic but cannot be objectively evidenced. A prospective study after the pandemic is needed to resolve this question. Conclusion: The coronavirus pandemic represents a challenge to the academic and psychological stability of students. It essential to continue assessing burnout levels in medical students and the general population to treat them in time and improve mental health.

Single Dose of Tranexamic Acid Effectively Reduces Blood Loss in Patients Undergoing Spine Surgery: A Prospective Randomized Controlled Trial.

OBJECTIVE: To evaluate the efficacy of oral administration of tranexamic acid (TXA) in spine surgery to achieve blood loss reduction. METHODS: Sixty patients undergoing major surgery of the spine were randomly assigned into 2 groups. Group 1 was assigned as the control group and the other group comprised patients who received oral administration of TXA 2 hours before surgery. Outcome measures included intraoperative blood loss, postoperative blood loss, hematologic parameters, blood transfusion needed, and surgical complications. RESULTS: Sixty patients linked up with the inclusion criteria. Intraoperative blood loss was significantly lower in the TXA oral group than in the control group; total blood loss in the TXA group was 930.66 ± 614 mL, which was lower than in the control group, with 1075.66 ± 956.11 mL. The mean reduction of hemoglobin was almost the same in both groups. Similarly, the total transfusion package received was lower, and the number of complications and length of stay were akin in both groups. A logistic regression model was performed with patients who had blood loss >1000 mL and surgery time >230 minutes. This result was related to the risk of bleeding, with an odds ratio of 1.31, 95% confidence interval, 1.004-1.023, P = 0.004, independent of the group. CONCLUSIONS: Oral TXA is as an effective measure for reducing total blood loss among patients undergoing elective spine surgery.

Payment with knowledge: A method for a training of anatomy near-peer teachers and formation of future anatomists.

Near-peer teaching has been widely implemented in medical schools and the benefits for the near-peer teachers (NPTs), the students, and the institution have been well documented. However, NPT training methods and perceptions of such have been limited. A four-year clinical anatomy and surgical training program was established (est. 2019) as part of the continuous training timeline for NPTs (n > 60 total) formation at the Universidad Autónoma de Nuevo León, in Mexico. The program provides various training courses for the NPTs according to their hierarchy, including teaching skills, professional development, psychosocial aspects, and career objectives. A "Clinical Anatomy and Surgical Training Diploma" was planned with 12 modules to aid in developing these abilities, along with a higher understanding of clinical anatomy shared by expert clinical specialists, and diverse clinical and surgical skills such as suturing, catheterization, and basic surgical procedures. The program has a completion rate of approximately 15 NPTs/year. All, while creating an environment with a sense of belonging, and facilitating mentorship between fellow NPTs and educators. Near-peer teachers develop leadership, communication, and teaching skills. The program has provided a constant source of anatomy educators, avoiding any shortage.

Trendelenburg position for internal jugular vein catheterization: A systematic review and meta-analysis.

To determine the effect of Trendelenburg position on the diameter or cross-section area of the internal jugular vein (IJV) a systematic review and metanalysis was performed. Studies that evaluated the cross-sectional area (CSA) and anteroposterior (AP) diameter of the right internal jugular vein (RIJV) with ultrasonography in supine and any degree of head-down tilt (Trendelenburg position) were analyzed. A total of 22 articles (613 study subjects) were included. A >5° Trendelenburg position statistically increases RIJV CSA and AP diameter. Further inclination from 10° does not statistically benefit IJV size. This position should be recommended for CVC placement, when patient conditions allow it, and US-guided cannulation is not available.

Characteristics and outcome of incidental hepatocellular carcinoma after liver transplantation: a cohort study.

INTRODUCTION: despite advances in imaging diagnostic modalities, hepatocellular carcinoma is sometimes incidentally diagnosed on histological examination of the liver explant. The objectives of the study were: a) to compare the characteristics between incidental and known hepatocellular carcinoma; and b) to estimate survival and tumor recurrence after liver transplantation. MATERIAL AND METHODS: a retrospective, single-center study was performed. The inclusion criteria were: a) cirrhotic patients, age ≥ 18 years; b) liver transplantation between 1998 and 2018; and c) hepatocellular carcinoma diagnosed via histopathologic examination of the explanted liver. Cholangiocarcinoma and patients with early retransplantation were excluded. Multivariate analysis was performed using binomial logistic regression to assess the factors associated with incidental hepatocellular carcinoma. Kaplan-Meier curves were plotted to explore the impact on overall survival and recurrence free survival. RESULTS: two hundred and sixty-nine patients were enrolled. The prevalence of incidental hepatocellular carcinoma was 4.18 % (95 % CI: 2.89-6.01 %) of all liver transplants performed in cirrhotic patients. The median diameter of the main nodule was smaller in incidental hepatocellular carcinoma (20 vs 27 mm, p = 0.004), although they were more likely to be beyond the Up-to-Seven criteria on explant examination (22.2 % vs 7.5 %, p = 0.001), with no differences in any other histological features. No differences were found in overall survival rates (incidental 70.2 % vs 70.4 %, p = 0.87) or recurrence-free survival (incidental 100 % vs 83.8 %, p = 0.07) at five years. CONCLUSION: incidental hepatocellular carcinoma are smaller in size and are more frequently found to be beyond the Up-to-Seven criteria. However, no differences were found in overall survival rates or recurrence-free survival, although there was no tumor recurrence in the incidental hepatocellular carcinoma group.

Factors Influencing Scientific Achievements of Medical Students in the Anatomy Research Group: An Analysis From the Autonomous University of Nuevo León in Mexico.

Scientific research and student involvement are critical to the formation of physicians, yet the number of medical researchers has decreased over time. To implement corrective strategies, the variables associated with positive research attitudes and productivity among medical students must be identified. The aim of this study was to evaluate the variables associated with students interested or involved in research. A validated questionnaire was applied to the student members of an established anatomy research group in a Mexican medical school with a six-year medical program. Data were collected and analyzed. A total of 85.5% (n = 77/90) students answered the survey with most respondents being second-year medical students. The majority of respondents indicated that the important component of conducting research was a contribution to the new knowledge (45.5%) and to the scientific community (42.9%). More than half of respondents mentioned a professor or a peer as the initial motivation to become involved in research. Lack of time was the main limitation (59.7%) to research involvement. Perceived benefits were knowledge and team work skills. Of those involved, most (85.7%) wished to continue participating in research as a complement to their clinical work. Professors and student colleagues were found to play an important motivational and recruitment role for medical research. These efforts in turn have developed into long-lasting mentor-mentee relationships. Students also anticipated that early involvement in research will positively influence the likelihood of future physicians' contribution and collaboration in research.

Immune mechanisms of Texel sheep to adult and egg stages of Haemonchus contortus.

Experimental Haemonchus contortus (Hc) infections revealed that Texel sheep have faecal egg counts (FEC) comparable to parasite-resistant St. Croix but adult worm burden comparable to parasite-susceptible Suffolk sheep. The aim of these studies was to further investigate the mechanism causing this disparity. Cellular and humoral immune responses to adult- and egg stage Hc were compared amongst St. Croix, Texel and Suffolk sheep. Adult worms and eggs were exposed to peripheral blood mononuclear cells (PBMC) and serum from the three breeds in vitro. There was a greater IgA binding to eggs when treated with St. Croix and Texel serum (p < .05), and these eggs exhibited a lower hatch rate (p < .05) when exposed to serum and PBMC. Adult worms exposed to St. Croix and Texel-derived PBMC, and serum had greater binding around the head and reproductive structures than worms exposed to Suffolk-derived cells and serum. Consequently, egg release tended to be affected by breed (p = .09). To further examine differences, Suffolk and Texel lambs (n = 5/breed) were infected with 10,000 Hc L3 for 30 days. Suffolk sheep had greater egg release per worm than Texel (3.8 vs. 2.1 eggs/worm). Taken together, these data would indicate one of the mechanisms in Texel's targeting adult-stage Hc reducing worm fecundity.

Behind the Adaptive and Resistance Mechanisms of Cancer Stem Cells to TRAIL.

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), also known as Apo-2 ligand (Apo2L), is a member of the TNF cytokine superfamily. TRAIL has been widely studied as a novel strategy for tumor elimination, as cancer cells overexpress TRAIL death receptors, inducing apoptosis and inhibiting blood vessel formation. However, cancer stem cells (CSCs), which are the main culprits responsible for therapy resistance and cancer remission, can easily develop evasion mechanisms for TRAIL apoptosis. By further modifying their properties, they take advantage of this molecule to improve survival and angiogenesis. The molecular mechanisms that CSCs use for TRAIL resistance and angiogenesis development are not well elucidated. Recent research has shown that proteins and transcription factors from the cell cycle, survival, and invasion pathways are involved. This review summarizes the main mechanism of cell adaption by TRAIL to promote response angiogenic or pro-angiogenic intermediates that facilitate TRAIL resistance regulation and cancer progression by CSCs and novel strategies to induce apoptosis.

Comparison of suturing models: the effect on perception of basic surgical skills.

BACKGROUND: Acquisition of Basic Surgical Skills (BSS) are essential for medical students. The objective was to determine it's fidelity impact. METHODS: Using four suturing models (SM) (pigskin, sponge, commercial pad, and orange), SM-quality and student-SM interaction were evaluated. After a 1-h class, participants were divided into groups and randomly assigned exercises in SM in 15-min intervals. The experiment included completing three individual simple stitches and a 3-stitch continuous suture in each SM. RESULTS: Eighty-two medical students participated. Suturing quality was better in pigskin and sponge, which were also the preferred models (p < 0.001). Significant differences in quality between the insertion and exit point, and firmness of knots (p < 0.05) in both simple and continuous sutures, as well as between length and distance in continuous ones (p < 0.001) were identified. CONCLUSIONS: Acquisition and quality of BSS are influenced by the intrinsic characteristics of SM. An adequate degree of resistance, consistency, and elasticity are necessary.

Back from the past: Molecular and morphological support for Simulium mutucuna Nunes de Mello & Vieira da Silva, 1974 (Diptera: Simuliidae) as a valid species.

Simulium mutucuna, a species described based on a single female from Roraima state, was previously synonymized with Simulium paynei and currently is considered a synonym of Simulium rubrithorax. In the present paper we present morphological and molecular evidence supporting the validity of S. mutucuna based on analysis of specimens from Brazil, Venezuela and Mexico. We redescribe the female and describe, for the first time, the male, pupa and larva of S. mutucuna and discuss the morphological differences between this species and the others that are already considered as its senior synonyms. Currently, the distribution of S. mutucuna is restricted to Roraima state. The distribution record for S. rubrithorax in Brazil's North region needs to be removed, since the previous records were based on occurrence of S. mutucuna. Finally, we present new evidence of cryptic diversity in the S. paynei complex based on molecular information.

Mexican Educators Survey on Anatomical Sciences Education and a Review of World Tendencies.

Anatomical sciences curricula have been under constant reform over the years, with many countries having to reduce course hours while trying to preserve laboratory time. In Mexico, schools have historically been autonomous and unregulated, and data regarding structure and methods are still lacking. A national survey was sent by the Mexican Society of Anatomy to 110 anatomical sciences educators. The questionnaire consisted of 50 items (open and multiple choice) for gross anatomy, microscopic anatomy, neuroanatomy, and embryology courses in medical schools across Mexico. A clinical approach was the most common course approach in all disciplines. Contact course hours and laboratory hours were higher in Mexican anatomy education compared to other countries, with the highest reported contact hours for embryology (133.4 ± 44.1) and histology (125 ± 33.2). There were similar contact hours to other countries for gross anatomy (228.5 ± 60.5). Neuroanatomy course hours (43.9 ± 13.1) were less than reported by the United States and similar to Saudi Arabia and higher than the United Kingdom. Dissection and microscopy with histological slides predominate as the most common laboratory activities. Traditional methods prevail in most of the courses in Mexico and only a few educators have implemented innovative and technological tools. Implementation of new methods, approaches, and curricular changes are needed to enhance anatomical sciences education in Mexico.

Assessing Immunity by Quantitative Measurement of SARS-CoV-2 IgG Antibodies in Fingerstick Samples.

COVID-19 has affected billions of people around the world directly or indirectly. The response to the pandemic has focused on preventing the spread of the disease and improving treatment options. Diagnostic technologies have played a key role in this response since the beginning of the pandemic. As vaccines and other treatments have been developed and deployed, interest in understanding and measuring the individual level of immune protection has increased. Historically, use of antibody titers to measure systemic immunity has been constrained by an incomplete understanding of the relationship between antibodies and immunity, the lack of international standards for antibody concentration to enable cross-study comparisons, and insufficient clinical data to allow for the development of robust antibody-immunity models. However, these constraints have recently shifted. With a deeper understanding of antibodies, the promulgation of WHO antibody standards, and the development of immunity models using datasets from multiple COVID-19 vaccine trials, certain types of quantitative antibody tests may now provide a way to monitor individual or community immunity against COVID-19. Specifically, tests that quantitate the concentration of anti-RBD IgG -antibodies that target the receptor binding domain of the S1 spike protein component of the SARS-CoV-2 virus - show promise as a useful and scalable measure of the COVID-19 immunity of both individuals and communities. However, to fulfill this promise, a rapid and easy-to-administer test is needed. To address this important clinical need, Brevitest deployed its point-of-care-capable technology platform that can run a rapid (<15 minute), quantitative antibody test with a sample of 10 µl of whole blood from a fingerstick. The test we validated on this platform measures the concentration of anti-RBD IgG in Binding Antibody Units per milliliter (BAU/mL) per WHO Reference Standard NIBSC 20/136. In this paper, we present studies used to characterize the Brevitest anti-RBD IgG assay and evaluate its clinical performance, lower limits of measurement, precision, linearity, interference, and cross-reactivity. The results demonstrate the ability of this assay to measure a patient's anti-RBD IgG concentration. This information, together with models developed from recent COVID-19 vaccine clinical trials, can provide a means of assessing the current level of immune protection of an individual or community against COVID-19 infection.

Salivary anti-SARS-CoV-2 IgA as an accessible biomarker of mucosal immunity against COVID-19.

Background: Mucosal immunity, including secretory IgA (sIgA), plays an important role in early defenses against respiratory pathogens. Salivary testing, the most convenient way to measure sIgA, has been used to characterize mucosal immune responses to many viral infections including SARS, MERS, influenza, HIV, and RSV. However, its role has not yet been characterized in the COVID-19 pandemic. Here, we report development and validation of a rapid immunoassay for measuring salivary IgA against the SARS-CoV-2 virus, and report quantitative results in both pre-COVID-19 and muco-converted subjects. Methods: We developed and refined a specific test for salivary IgA against SARS-CoV-2 on the Brevitest platform, a rapid immunoassay system designed for point-of-care use. A qualitative test was validated as per FDA guidelines with saliva obtained from subjects prior to the emergence of COVID-19, and from PCR-confirmed COVID-19 patients. We also generated a quantitative measure of anti-SARS-CoV-2 salivary IgA. Time taken for saliva self-collection was measured and its ease-of-use assessed. Results: We successfully validated a qualitative salivary assay for SARS-CoV-2 IgA antibodies, with positive and negative predictive values of 92% and 97%, respectively, and no observable cross-reactivity with any of seven potential confounders. Pre-COVID-19 saliva samples showed an 8-fold range of IgA concentrations, suggesting a broad continuum of natural antibody resistance against the novel virus, though at levels lower than that observed in COVID-19 PCR-confirmed subjects. Samples from muco-positive subjects also shown a ~9-fold variation in salivary IgA levels, with elevated salivary IgA observed beyond three months after onset of symptoms. We observed a correlation (r=0.4405) between salivary IgA levels and COVID-19 disease severity. In anecdotal observations, we observed individuals who exhibited antibodies early in the course of their disease, contemporaneously with a positive PCR test, as well as individuals who muco-converted despite no known direct exposure to a COVID-19 patient, no symptoms, and negative molecular and/or serum antibody tests. Salivary collection took 5-10 minutes, and was reported as being easy (mean of 1.1 on a scale of 1 to 10). Implications: Mucosal immunity, including secretory IgA, plays an important role in host defense against respiratory pathogens, and our early data suggest it may do so in COVID-19. Salivary IgA, an accessible marker of mucosal immunity, may be a useful indicator of several key parameters including individual and community immune response, disease severity, clinical risk, and herd immunity. The non-invasive nature and ease of saliva collection facilitates its potential use as a biomarker for ongoing patient assessment and management, as well as a community surveillance tool. By measuring mucosal immune responses directly and systemic immune responses indirectly, salivary IgA could be useful in developing and deploying a vaccine(s) against COVID-19. Quantitative IgA assessment could also potentially serve as a tool to segment the population into different risk categories and inform individual and collective decisions relating to appropriate activities and vaccine prioritization/delivery. These data reinforce the importance of further investigation into the role of mucosal immunity and IgA in host responses against COVID-19.

Biology, Epidemiology, and Control of Gastrointestinal Nematodes of Small Ruminants.

Strongylid gastrointestinal nematodes are an important cause of disease and economic loss in small ruminants. These parasites are important in most of the United States, with the bloodsucking parasite Haemonchus contortus being the predominant species of concern. Sheep and goats are infected while grazing, and the biology of infective larvae on pastures is important in the design of parasite management programs. Widespread resistance to anthelmintics requires strategies designed to preserve remaining drug activity; these include combination treatments with multiple classes of anthelmintics and targeted treatments.

Luschka Duct Leak: An Unexpected Cause of Choleperitoneum After Liver Transplant.

The anatomic variabilities in ducts of Luschka put patients at risk during hepatobiliary surgery. Clinically relevant bile leakage is the cause of 0.4% to 1.2% of complications of cholecystectomies, with almost one-third of complications caused by an inadvertent injury to the duct of Luschka. However, bile leakage from a duct of Luschka after liver transplant is rare, and only one previously published report has been found. Here, we report a case of a 67-year-old male patient who underwent liver transplant for cirrhosis due to hepatitis C virus infection. After transplant, the patient had a choleperitoneum caused by bile leakage from a duct of Luschka. The donor surgery had been performed by surgeons from another institution, and they had also performed the previous cholecystectomy. Fifteen days after surgery, a cholangiography showed bile leakage near the anastomosis. A new intervention was decided. After confirmation of the integrity of the anastomosis, methylene blue was injected through the Kehr's tube, which escaped from a duct of Luschka. The duct was closed, and an intraoperative cholangiography confirmed that the biliary tree was intact. After this intervention, a new bile leakage was observed, resulting in an endoscopic retrograde cholangiopancreatography scan and sphincterotomy. The Kehr's tube was kept open until leak resolution. Although unusual after liver transplant, this complication should be considered in cases of bile leakage. The ducts of Luschka are difficult to see during cholecystectomy in the graft due to perivesicular edema.

Neutrophils rapidly produce Th2 cytokines in response to larval but not adult helminth antigen.

Host protective immunity to Haemonchus contortus (Hc) infection in parasite-resistant St. Croix (STC) sheep is initiated early and characterized by an influx of innate cells and robust interleukin-4 (IL-4) production, resulting in T-helper type 2 immune (Th2) responses. The purpose of these studies was to elucidate the source of early IL-4 production. Neutrophils were isolated from whole blood, and populations >98% purity were cultured with larval or adult antigen to access cytokine production. Interleukin-4 and IL-13 were measured in sample supernatant using an ovine-specific enzyme-linked immunosorbent assay (ELISA). Neutrophils exposed to HcLA peaked in IL-4 production at 30 minutes (STC, 3153.65 pg/mL and SUF, 4665.22 pg/mL). A similar trend was observed in IL-13 production by 6 hours (STC, 391.02 pg/mL and SUF, 419.6 pg/mL). Adult antigen stimulation resulted in low cytokine production when compared to HcLA stimulation (STC IL-4, 6.04 pg/mL and SUF, 8.05 pg/mL, respectively; STC IL-13, 10 pg/mL and 12.5 pg/mL; P < .001), and no breed differences were observed. Mixed immune cell assays revealed an ability of neutrophils to induce IL-4 production in peripheral blood mononuclear cell (PBMC). Taken together, these data implicate neutrophils as a potential effector cell responsible for Th2 initiation.

Heller myotomy versus endoscopic balloon dilatation for achalasia: A single center experience.

This study aimed to compare clinical results, symptom relief, quality of life and patient satisfaction after the 2 most common procedures for achalasia treatment: laparoscopic Heller myotomy (LHM) and endoscopic balloon dilatation (EBD).Patients treated at University Hospital of Heidelberg with LHM or EBD were included. A retrospective chart review of perioperative data and a prospective follow-up of therapeutic efficiency, Gastrointestinal Quality of Life Index (GIQLI) and patient satisfaction was conducted.Follow-up data (mean follow-up: 75.1 ±â€Š53.9 months for LHM group and 78.9 ±â€Š45.6 months for EBD) were obtained from 36 patients (19 LHM; 17 EBD). Eckardt score (median (q1,q3): 2 (1,4) in both groups, P = .91, GIQLI (LHM: 117 (91.5, 126) vs EBD: 120 (116, 128), P = .495) and patient satisfaction (3 (2,3) vs 3 (2,4), P = .883) did not differ between groups. Fifteen patients (78.9%) in LHM group and 11 (64.7%) in EBD group (P = .562) stated they would undergo the intervention again. All patients with EBD had at least 2 dilatations (100%), whilst only 2 patients (10.5%) had dilatation after LHM (P < .001). There were no complications after EBD, but 2 after LHM (10.5%, P = .517).Both LHM and EBD are able to control symptoms and provide similar quality of life and patient satisfaction. However, reintervention rate was higher following EBD, hence LHM provided a more sustained treatment than EBD.

A SERS aptasensor for sensitive and selective detection of bis(2-ethylhexyl) phthalate.

Bis(2-ethylhexyl) phthalate (DEHP) is an endocrine disruptor commonly present in plastic products, such as PVC tubes and water bottles. In this work, a surface enhanced Raman spectroscopy (SERS) based aptasensor was developed and utilized for rapid, easy, sensitive, and specific detection of trace DEHP. A DEHP aptamer was immobilized on magnetic particles. Raman reporter molecule conjugated silver nanoparticles were clustered and coated with silica to provide a stable SERS signal. The SERS silica particle was then functionalized with 1,2,4-benzenetricarboxylic acid 1,2-bis(2-ethylhexyl) ester to increase its affinity to the DEHP aptamer. In the presence of a sample with DEHP, the high-affinity SERS silica particle competes with the DEHP molecule to bind with the aptamer on the magnetic particle. By measuring the signal of free SERS silica particles in the supernatant after magnetic separation, the concentration of DEHP in the sample was quantitatively determined. The developed DEHP aptasensor had a detection range from 0.008 to 182 nM and a limit of detection (LOD) of 8 pM. The aptasensor also showed high selectivity when exposed to interferents with analogous structures. The aptasensor was successfully tested for the detection of DEHP spiked in tap water, bottled water, and a carbonate beverage. The developed SERS-based aptasensor provides a rapid, sensitive, and easy-to-use method for the quantitative detection of DEHP in environmental and food analysis.