A Randomized Trial of Mesenchymal Stromal Cells for Moderate to Severe Acute Respiratory Distress Syndrome from COVID-19.

Rationale: There are limited therapeutic options for patients with coronavirus disease (COVID-19)-related acute respiratory distress syndrome with inflammation-mediated lung injury. Mesenchymal stromal cells offer promise as immunomodulatory agents. Objectives: Evaluation of efficacy and safety of allogeneic mesenchymal cells in mechanically-ventilated patients with moderate or severe COVID-19-induced respiratory failure. Methods: Patients were randomized to two infusions of 2 million cells/kg or sham infusions, in addition to the standard of care. We hypothesized that cell therapy would be superior to sham control for the primary endpoint of 30-day mortality. The key secondary endpoint was ventilator-free survival within 60 days, accounting for deaths and withdrawals in a ranked analysis. Measurements and Main Results: At the third interim analysis, the data and safety monitoring board recommended that the trial halt enrollment as the prespecified mortality reduction from 40% to 23% was unlikely to be achieved (n = 222 out of planned 300). Thirty-day mortality was 37.5% (42/112) in cell recipients versus 42.7% (47/110) in control patients (relative risk [RR], 0.88; 95% confidence interval, 0.64-1.21; P = 0.43). There were no significant differences in days alive off ventilation within 60 days (median rank, 117.3 [interquartile range, 60.0-169.5] in cell patients and 102.0 [interquartile range, 54.0-162.5] in control subjects; higher is better). Resolution or improvement of acute respiratory distress syndrome at 30 days was observed in 51/104 (49.0%) cell recipients and 46/106 (43.4%) control patients (odds ratio, 1.36; 95% confidence interval, 0.57-3.21). There were no infusion-related toxicities and overall serious adverse events over 30 days were similar. Conclusions: Mesenchymal cells, while safe, did not improve 30-day survival or 60-day ventilator-free days in patients with moderate and/or severe COVID-19-related acute respiratory distress syndrome.

Impact of diabetes on short-term outcomes in patients undergoing coronary artery bypass grafting surgery in acute coronary syndrome.

INTRODUCTION: Diabetes mellitus (DM) is associated with concomitant comorbidities, such as atherosclerosis and cardiovascular disease. Coronary artery bypass grafting (CABG) surgery is the optimal therapy in diabetic patients with triple vessel disease. DM is also known to be a relevant risk factor for higher morbidity and mortality in patients who underwent elective CABG procedures. Data regarding outcomes in diabetic patients in acute coronary syndrome (ACS) is heterogeneous. This study aimed to investigate the impact of DM on short-term outcomes in patients who underwent CABG surgery in ACS. METHODS: A retrospective propensity score matched (PSM) analysis of 1370 patients who underwent bypass surgery for ACS between June 2011 and October 2019 was conducted. All patients were divided into two groups: non-diabetic group (n = 905) and diabetic group (n = 465). In-hospital mortality was the primary outcome. Secondary outcomes were perioperative myocardial infarction, new onset dialysis, reopening for bleeding and duration of intensive care unit (ICU) stay. A subgroup analysis of patients with insulin-dependent and non-insulin dependent DM was also performed. RESULTS: After performing PSM analysis, baseline characteristics and the preoperative risk profile were comparable between both groups. The proportion of patients who underwent total arterial revascularization (p = .048) with the use of both internal thoracic arteries (p < .001) was significantly higher in the non-diabetic group. The incidence of perioperative myocardial infarction (p = .048) and new onset dialysis (p = .008) was significantly higher in the diabetic group. In-hospital mortality was statistically (p = .907) comparable between the two groups. CONCLUSION: DM was associated with a higher incidence of adverse outcomes, however with comparable in-hospital mortality in patients who underwent CABG procedure for ACS.

Chemical Characterization of Trichoderma spp. Extracts with Antifungal Activity against Cocoa Pathogens.

Ecuador is one of the major cocoa producers worldwide, but its productivity has lately been affected by diseases. Endophytic biocontrol agents have been used to minimize pathogenic effects; however, compounds produced by endophytes are minimally understood. This work presents the chemical characterization of the Trichoderma species extracts that proved inhibition against cocoa pathogens. Solid-liquid extraction was performed as a partitioning method using medium with the fungal mycelia of Trichoderma reesei (C2A), Trichoderma sp. (C3A), Trichoderma harzianum (C4A), and Trichoderma spirale (C10) in ethyl acetate individually. The extract of T. spirale (C10) exhibited the growth inhibition (32.97-47.02%) of Moniliophthora perniciosa at 10 µg/mL, while a slight stimulation of Moniliophthora roreri was shown by the extracts of T. reesei (C2A) and T. harzianum (C4A) at higher concentrations. The inhibitory activity could be related to alkaloids, lactones, quinones, flavonoids, triterpenes, and sterols, as indicated by chemical screening and antifungal compounds, such as widdrol, ß-caryophyllene, tyrosol, butyl isobutyrate, sorbic acid, palmitic acid, palmitelaidic acid, linoleic acid, and oleic acid, which were identified by gas chromatography-mass spectrometry (GC-MS). The results showed that the extracts, particularly T. spirale (C10), have the potential as biocontrol agents against witches' broom disease; however, further studies are needed to confirm their effectiveness.

LKB-1 Expression and High-Risk Histopathology are Independent Prognostic Factors for Patients with Oral Cavity Carcinoma.

BACKGROUND: The expression of liver kinase B1 (LKB-1) has been associated with prognosis in squamous cell carcinoma of the oral cavity (SCCOC). This study aimed to define the prognostic role of LKB-1 expression for patients with SCCOC and the suitability of its integration into a multivariate prognostic model. METHODS: A retrospective cohort study of patients with SCCOC was conducted in a cancer center. Expression of LKB-1 was evaluated by immunohistochemistry, and multivariate analysis defined prognostic factors associated with recurrence, recurrence-free survival (RFS), and overall survival (OS). The logistic regression model was used to construct a predictive computer software program. RESULTS: Of the 201 patients in this study, 104 (51.7%) experienced recurrence of their disease. Lower expression of LKB-1, high-risk histopathology, and advanced tumor-node-metastasis (TNM) stages were independent factors via multivariate analysis associated with the increased recurrence risk, poor RFS, and poor OS. If lack of LKB-1 expression is considered the reference category, the factors independently associated with recurrence were low (odds ratio [OR], 0.157; 95% confidence interval [CI], 0.044-0.557), intermediate (OR, 0.073; 95% CI, 0.017-0.319), and intense (OR, 0.047; 95% CI, 0.007-0.304) expression of LKB-1. This model permitted construction of a computer software program capable of prediction with receiver operating characteristic analysis (area under the curve, 0.925) and led to the definition of five prognostic groups with a biologic gradient. CONCLUSION: These results suggest that LKB-1 expression in patients with SCCOC is of robust prognostic value and complements the TNM staging system. The proposed model requires external validation in prospective observational studies.

The Mechanism of Action between Pulsed Radiofrequency and Orthobiologics: Is There a Synergistic Effect?

Radiofrequency energy is a common treatment modality for chronic pain. While there are different forms of radiofrequency-based therapeutics, the common concept is the generation of an electromagnetic field in the applied area, that can result in neuromodulation (pulsed radiofrequency-PRF) or ablation. Our specific focus relates to PRF due to the possibility of modulation that is in accordance with the mechanisms of action of orthobiologics. The proposed mechanism of action of PRF pertaining to pain relief relies on a decrease in pro-inflammatory cytokines, an increase in cytosolic calcium concentration, a general effect on the immune system, and a reduction in the formation of free radical molecules. The primary known properties of orthobiologics constitute the release of growth factors, a stimulus for endogenous repair, analgesia, and improvement of the function of the injured area. In this review, we described the mechanism of action of both treatments and pertinent scientific references to the use of the combination of PRF and orthobiologics. Our hypothesis is a synergic effect with the combination of both techniques which could benefit patients and improve the life quality.

Long-Term Financial, Psychosocial, and Overall Health-Related Quality of Life After Living Liver Donation.

BACKGROUND: To assess the impact of living liver donation (LD) in a diverse and aging population up to 20 y after donation, particularly with regard to medical, financial, psychosocial, and overall health-related quality of life (HRQOL). METHODS: Patients undergoing LD between 1999 and 2009 were recruited to respond to the Short-Form 36 and a novel Donor Quality of Life Survey at two time points (2010 and 2018). RESULTS: Sixty-eight living liver donors (LLDs) completed validated surveys, with a mean follow-up of 11.5 ± 5.1 y. Per Donor Quality of Life Survey data, physical activity or strength was not impacted by LD in most patients. All respondents returned to school or employment, and 82.4% reported that LD had no impact on school or work performance. LD did not impact health insurability in 95.6% of donors, and only one patient experienced difficulty obtaining life insurance. Overall, 97.1% of respondents did not regret LD. Short-Form 36 survey-measured outcomes were similar between LLDs and the general U.S. POPULATION: LLDs who responded in both 2010 and 2018 were followed for an overall average of 15.4 ± 2.4 y and HRQOL outcomes in these donors also remained statistically equivalent to U.S. population norms. CONCLUSIONS: This study represents the longest postdonation follow-up and offers unique insight related to HRQOL in a highly diverse patient population. Although LLDs continue to maintain excellent HRQOL outcomes up to 20 y after donation, continued lifetime follow-up is required to accurately provide young, healthy potential donors with an accurate description of the risks that they may incur on aging.

Long-term outcomes in chronic hypersensitivity pneumonitis.

INTRODUCTION: The objective of this study was to analyze mortality, possible predictors of long-term survival, and health-related quality of life of a large chronic hypersensitivity pneumonitis (CHP) patient sample. METHODS: Longitudinal study in patients diagnosed with CHP during 2004-2013, followed for at least 1 year. Patients remaining alive and consenting to participate had a follow-up visit during 2015, including a complete pulmonary function study and the EuroQol-5D and Beck Depression and Anxiety Inventories. RESULTS: Out of the 160 patients finally included, 87 remained alive. Seventy-three had died or underwent lung transplantation at the time of the study with a median survival of 7.0 (4.4-14.5) years. A Cox proportional risk model showed that factors associated with lower survival were as follows: increased age, a low percentage of lymphocytes in bronchoalveolar lavage (BAL), a decreased transfer factor of the lung for carbonmonoxide (DLCO), presence of honeycomb in the high-resolution chest scan (HRCT), and the usual interstitial pneumonia (UIP) histologic pattern. At follow-up, all patients presented an EuroQol-5D score <0.8 and 21(50%) and 9(28.6%) subjects presented a probable anxiety and depressive syndrome, respectively. CONCLUSION: CHP is a severe disease with a bad mid-term prognosis. Lymphocyte values in BAL and DLCO values at baseline, presence of honeycomb in HRCT, and UIP histologic pattern were found to be predictors of survival. Early accurate diagnosis of the disease is fundamental for prompt initiation of antigen avoidance.

Chemically Driven Oscillating Soft Pneumatic Actuation.

Pneumatic actuators are widely studied in soft robotics as they are facile, low cost, scalable, and robust and exhibit compliance similar to many systems found in nature. The challenge is to harness high energy density chemical and biochemical reactions that can generate sufficient pneumatic pressure to actuate soft systems in a controlled and ecologically compatible manner. This investigation evaluates the potential of chemical reactions as both positive and negative pressure sources for use in soft robotic pneumatic actuators. Considering the pneumatic actuation demands, the chemical mechanisms of the pressure sources, and the safety of the system, several gas evolution/consumption reactions are evaluated and compared. Furthermore, the novel coupling of both gas evolution and gas consumption reactions is discussed and evaluated for the design of oscillating systems, driven by the complementary evolution and consumption of carbon dioxide. Control over the speed of gas generation and consumption is achieved by adjusting the initial ratios of feed materials. Coupling the appropriate reactions with pneumatic soft-matter actuators has delivered autonomous cyclic actuation. The reversibility of these systems is demonstrated in a range of displacement experiments, and practical application is shown through a soft gripper that can move, pick up, and let go of objects. Our approach presents a significant step toward more autonomous, versatile soft robots driven by chemo-pneumatic actuators.

Liquid-amplified zipping actuators for micro-air vehicles with transmission-free flapping.

Flapping micro-air vehicles (MAVs) can access a wide range of locations, including confined spaces such as the inside of industrial plants and collapsed buildings, and offer high maneuverability and tolerance to disturbances. However, current flapping MAVs require transmission systems between their actuators and wings, which introduce energetic losses and additional mass, hindering performance. Here, we introduce a high-performance electrostatic flapping actuation system, the liquid-amplified zipping actuator (LAZA), which induces wing movement by direct application of liquid-amplified electrostatic forces at the wing root, eliminating the requirement of any transmission system and their associated downsides. The LAZA allows for accurate control of flapping frequency and amplitude, exhibits no variation in performance over more than 1 million actuation cycles, and delivers peak and average specific powers of 200 and 124 watts per kilogram, respectively, exceeding mammalian and insect flight muscle and on par with modern flapping MAV actuation systems. The inclusion of 50-millimeter-long passively pitching wings in a dragonfly-sized LAZA flapping system allowed the rectification of net directional thrust up to 5.73 millinewtons. This thrust was achieved while consuming only 243 milliwatts of electrical power, implying a thrust-to-power ratio of 23.6 newtons per kilowatt, similar to state-of-the-art flapping MAVs, helicopter rotors, and commercial drone motors. Last, a horizontally moving LAZA flapping system supported by a taut nylon wire was able to accelerate from at-rest and travel at speeds up to 0.71 meters per second. The LAZA enables lightweight, high-performance transmission-free flapping MAVs for long-term remote exploration and search-and-rescue missions.

IL-15:IL-15 receptor alpha superagonist complex: high-level co-expression in recombinant mammalian cells, purification and characterization.

IL-15, a promising cytokine for treating cancer and viral diseases, is presented in trans by the IL-15 receptor (IL-15R) alpha-chain to the IL-15Rßγc complex displayed on the surface of T cells and natural killer (NK) cells. We previously reported that an asparagine to aspartic acid substitution at amino acid 72 (N72D) of IL-15 provides a 4-5-fold increase in biological activity compared to the native molecule. In this report, we describe Chinese hamster ovary (CHO) cell expression of a soluble complex (IL-15 N72D:IL-15RαSu/Fc) consisting of the IL-15 N72D superagonist and a dimeric IL-15Rα sushi domain-IgG1 Fc fusion protein. A simple but readily scalable affinity and ion exchange chromatography method was developed to highly purify the complex having both IL-15 binding sites fully occupied. The immunostimulatory effects of this complex were confirmed using cell proliferation assays. Treatment of mice with a single intravenous dose of IL-15N72D:IL-15RαSu/Fc resulted in a significant increase in CD8+ T cells and NK cells that was not observed following IL-15 treatment. Pharmacokinetic analysis indicated that the complex has a 25-h half-life in mice which is considerably longer than <40-min half-life of IL-15. Thus, the enhanced activity of the IL-15N72D:IL-15RαSu/Fc complex is likely the result of the increased binding activity of IL-15N72D to IL-15Rßγc, optimized cytokine trans-presentation by the IL-15RαSu domain, the dimeric nature of the cytokine domain and its increased in vivo half-life compared to IL-15. These findings indicate that this IL-15 superagonist complex could serve as a superior immunostimulatory therapeutic agent.

Near-normal aerobic capacity in long-term survivors after lung transplantation.

The clinical course of lung transplantation (LT) is diverse: some patients present chronic lung allograft dysfunction (CLAD) and progressive decline in pulmonary function, but others maintain normal spirometric values and active lives. OBJECTIVES: The aim of this study was to elucidate whether long-term LT survivors with normal spirometry achieve normal exercise capacity, and to identify predictive factors of exercise capacity. METHODS: This was a cross-sectional multicentre study, where bilateral LT recipients who survived at least 10 years after LT, with normal spirometry, no diagnosis of CLAD and modified Medical Research Council dyspnoea degree ≤2 underwent cardiopulmonary exercise testing (CPET). RESULTS: 28 LT recipients were included with a mean±sd age of 48.7±13.6 years. Oxygen uptake (V' O2 ) had a mean±sd value of 21.49±6.68 mL·kg-1·min-1 (75.24±15.6%) and the anaerobic threshold was reached at 48.6±10.1% of the V' O2max predicted. The mean±sd heart rate reserve at peak exercise was 17.56±13.6%. The oxygen pulse increased during exercise and was within normal values at 90.5±19.4%. The respiratory exchange ratio exceeded 1.19 at maximum exercise. The median (25-75th percentile) EuroQol-5D score was 1 (0.95-1), indicating a good quality of life. The median (25-75th percentile) International Physical Activity Questionnaire score was 5497 (4007-9832) MET-min·week-1 with 89% of patients reporting more than 1500 MET-min·week-1. In the multivariate regression models, age, sex and diffusing capacity of the lung for carbon monoxide remained significantly associated with V' O2max (mL·kg-1·min-1); haemoglobin and forced expiratory volume in 1 s were significantly associated with maximum work rate (watts), after adjusting for confounders. CONCLUSION: We report for the first time near-normal peak V' O2 values during CPET and normal exercise capacity in long-term LT recipients without CLAD.

Evaluation of the sensitivity and synergistic effect of Trichoderma reesei and mancozeb to inhibit under in vitro conditions the growth of Fusarium oxysporum.

Trichoderma is a saprophytic, soil-borne fungus with a worldwide distribution that has been extensively studied due to their capacity to synthesize secondary metabolites with antimicrobial activity, parasitize other fungi and directly interact with plant roots, inducing resistance to disease and tolerance to abiotic stresses. Fusarium wilt caused by the soil-inhabiting fungus Fusarium oxysporum is considered one of the most important diseases that affect banana cultivars. Currently, more environmentally friendly alternatives to control this disease are being proposed, these strategies include the application of low doses of synthetic fungicides and the use of biocontrol agents such as Trichoderma or Xylaria. Thus, this study aimed to evaluate under in vitro conditions the synergistic effect of the biological control agent T. reesei C2A combined with low doses of mancozeb to inhibit the mycelial growth of F. oxysporum F1. To perform the synergistic essays, 0.1 mg/mL of mancozeb was suspended in PDA plates, then plugs of T. ressei C2A were placed at the center of the Petri dishes, the plates were incubated for 7 days at 28°C. Results showed that the mycoparasitic capacity of the biocontrol strain to inhibit the mycelial growth of F. oxysporum F1 was enhanced approximately 36% compared to the control plates. Although these results are promising, future studies under greenhouse and field conditions are necessary to corroborate the effectiveness of this approach.

Glass Transition in Crosslinked Nanocomposite Scaffolds of Gelatin/Chitosan/Hydroxyapatite.

The development of biopolymeric scaffolds crosslinked with nanoparticles is an emerging field. Gelatin/chitosan scaffolds are gaining interest in medical areas, e.g., bone tissue engineering, given their suitability for nano-hydroxyapatite incorporation. The glass transition temperature is a thermodynamic property of polymer scaffolds that changes with crosslinker or nanofiller concentration. Here, we report the experimental change in glass transition temperature of gelatin/chitosan scaffolds modified by hydroxyapatite nanoparticles and crosslinker concentration. Our results show synergic effects between nanoparticles and crosslinking, which leads to a non-linear behavior of the glass transition temperature. Furthermore, a theoretical model to predict glass transition is proposed. This model can be used as a mathematical tool for the design of future scaffolds used in bone tissue engineering.

[Comparación del índice de neutrófilos/linfocitos, la escala de SOFA y la concentración sérica de procalcitonina como indicadores de la gravedad de la apendicitis aguda]. / Comparison of the neutrophil-to-lymphocyte ratio, SOFA score and serum procalcitonin as biomarkers of acute appendicitis.

Introducción: La apendicitis aguda (AA) es una de las principales causas de abdomen agudo. Un retraso en su diagnóstico y tratamiento elevan la morbimortalidad. Objetivo: Evaluar el índice de neutrófilos/linfocitos (INL), la escala SOFA (Sequential Organ Failure Assessment), la procalcitonina (PCT) y la bilirrubina total (BT), y ver si existe relación como determinantes de la gravedad de la AA. Método: Estudio retrospectivo, observacional, para comparar el INL contra biomarcadores (PCT, BT) y contra escalas de gravedad (APACHE II [Acute Physiology and Chronic Health Evaluation] y SOFA) y quirúrgica (Mannheim). Resultados: 82 casos de enero a mayo de 2017. El 80.8% de los casos con peritonitis generalizada presentaron un INL > 12 (p = 0.002). El 66% de los casos con perforación apendicular presentaban un INL > 12 (p = 0.024). El 70% de los casos graves por BT mostraron un INL > 12 (p = 0.004). El 75% de los casos graves por PCT presentaban un INL > 12 (p = 0.006). El 50% de los casos con SOFA > 6 mostraron un INL > 12 (U de Mann-Whitney, p = 0.023). Conclusión: Existe una relación entre el INL tanto con SOFA, BT y PCT, lo cual indica que un INL > 12 puntos podría estar relacionado con peritonitis generalizada y apendicitis perforada.

Background: Acute appendicitis (AA) is one of the main causes of acute abdomen that requires urgent surgical treatment, a delay in its diagnosis and therapeutic increase in morbidity and mortality. Objective: To evaluate the usefulness of inflammatory markers as a tool to compare the neutrophil/lymphocyte ratio (NLR), the SOFA scale (Sequential Organ Failure Assessment) and the serum level of procalcitonin, total bilirubin, and see if there is a relationship as indicators and determinants of the severity of AA. Method: An retrospective, observational, and analytical study to evaluate the usefulness of the NLR as a diagnostic and severity indicator of AA, comparing it against biomarkers (BT and PCT), and against two severity scales ­(APACHE II [Acute Physiology and Chronic Health Evaluation] and SOFA) and a surgical scale (Mannheim). Results: We included 82 cases from January to May 2017. 80.8% of those cases with generalized peritonitis had an NLR > 12 (p = 0.002). 66% of the cases with appendiceal perforation presented an NLR > 12 (p = 0.024). 70% of severe cases due to TB showed an NLR > 12 (p = 0.004). 75% of severe cases due to PCT have an NLR > 12 (p = 0.006). 50% of the cases with SOFA > 6 showed an NLR > 12 (U Mann-Whitney, p = 0.023). Conclusions: There is a relationship between the NLR with SOFA, total bilirubin and procalcitonin, indicating that an NLR > 12 points could be related to generalized peritonitis and perforated appendicitis.

Living donor liver transplantation: post-operative imaging follow-up of right lobe liver donors.

PURPOSE: To identify long-term post-operative imaging findings resulting from right lobe liver donation. METHODS: This retrospective imaging review consisted of 42 adults (20 males, 22 females, mean age 36.6 years, range 18.7-55.9 years) who underwent right lobe liver donation with pre- and post-operative imaging between 1999 and 2006. The mean follow-up period was 30.2 months (range 12.3-69.6 months). Follow-up imaging evaluation included assessment of the biliary tree, particularly isolated bile ducts draining to and terminating at the cut surface (orphan ducts). Three-dimensional volumetry of the liver remnant was also assessed. RESULTS: After liver donation, 29/42 (69%) participants demonstrated orphan ducts on follow-up imaging (95% confidence interval 52.9% to 82.4%). In those patients with orphan ducts, the main draining ducts were normal in 70% and dilated in 69%. Nearly all right lobe liver donors with orphan ducts had no clinical symptoms on follow-up (28/29); the only liver donor with clinical symptoms on follow-up was subsequently diagnosed with primary biliary cirrhosis. Mean regenerated liver volume was approximately 93%, with mean pre-operative total liver volume of 1552 ml (median 1504 ml, range 1040-2520 ml) and mean post-operative total liver volume of 1446 ml (median 1455 ml, range 964-2090 ml). CONCLUSIONS: Orphan ducts are changes that may be seen after liver donation. The presence of these findings in the absence of clinical symptoms or abnormal hepatic chemistries does not require further work-up and should not be considered pathologic.

[Programa de entrenamiento en reparacion vascular en modelo experimental para residentes de cirugía general]. / Vascular reparation training program in experimental model for general surgery residents.

INTRODUCCIÓN: Los programas de entrenamiento simulado permiten optimizar recursos, aumentar la práctica técnica y acortar curvas de aprendizaje, y constituyen un método seguro, estandarizado y validado de aprendizaje para todos los entrenados. OBJETIVO: Desarrollar un programa de entrenamiento vascular mediante la elaboración de una anastomosis término-terminal de un vaso en un modelo experimental para residentes de cirugía general. MÉTODO: Para el desarrollo de este modelo de entrenamiento se utilizó una extremidad amputada a nivel supracondíleo libre de proceso médico-legal. Se realizó la disección de la arteria femoral, se dividió en dos porciones y se realizó una anastomosis término-terminal. Se diseño un sistema que incluye la evaluación de las siguientes variables utlizando la escalas OSATS (Objetive Structured Assesment of Technical Skills) y Likert: 1) nudo manual y punto simple; 2) permeabilidad de la anastomosis; 3) simetría de los puntos; 4) fuga de anastomosis; y 5) tiempo total de anastomosis. DISCUSIÓN: Al reconocer las ventajas del entrenamiento experimental, se propone un modelo biológico experimental reproducible, estandarizado y de bajo costo. CONCLUSIONES: El desarrollo de modelos biológicos experimentales permite al cirujano general la adquisición de habilidades y destrezas quirúrgicas, mejorando el desempeño durante un procedimiento quirúrgico y reduciendo riesgos. INTRODUCTION: Simulated training programs allow to optimize resources, increase technical practice and shorten learning curves, constituting a safe, standardized and validated method of learning for all those trained. OBJECTIVE: Develop a vascular training program through the elaboration of an end to end anastomosis of a vessel in an experimental model for General Surgery residents. METHOD: For the development of this training model, an amputated limb was used at the supracondylar level free of medical-legal process. The dissection of the femoral artery was performed, it was divided into two portions and an end to end anastomosis was performed. A system was designed that included the evaluation of the following variables using the OSATS (Objective Structured Assessment of Technical Skills) and Likert scales: 1) manual knot and single stitch; 2) permeability of the anastomosis; 3) symmetry of the stitches; 4) Anastomosis leakage; and 5) total time of the anastomosis. DISCUSSION: Recognizing the advantages of experimental training, a reproducible, standardized, and low cost experimental biological model is proposed. CONCLUSIONS: The development of experimental biological models, allows the general surgeon the acquisition of surgical skills and abilities, improving performance during a surgical procedure and reducing risks.

[Protective effect of Helianthus annuus (sunflower) on myocardial infarction in New Zealand rabbit]. / Efecto protector de Helianthus annuus (girasol) sobre el infarto de miocardio en conejos Nueva Zelanda.

OBJECTIVES: Determine the protective effect of oil Helianthus annuus (Sunflower) on myocardial infarction induced by epinephrine in New Zealand rabbits. MATERIALS AND METHODS: The rabbits were randomized into five groups (8 per group): blank, negative control, experimental 1 (10 mg / kg), experimental 2 (20 mg / kg) and three experimental (40 mg/ kg). Experimental groups 1, 2 and 3 received Helianthus annuus oil for two weeks. Epinephrine (2 mg/Kg) to the negative, Experimental Control 1, 2 and 3 groups was given over two consecutive days with an interval of 24 h after pretreatment with oil. Twenty four hours after the last administration, the rabbits were anesthetized and sacrificed. Serum troponin I and polymorphonuclear evaluated by .mu.m.sup.2. RESULTS: Significant difference between the negative control group and the experimental groups 1, 2 and 3 was found in the serum variables troponin I and polymorphonuclear by .mu.m.sup.2. CONCLUSIONS: Helianthus annuus oil at doses of 20 mg/kg has protective effect on myocardial infarction induced by epinephrine in New Zealand rabbits.

Band structure quantization in nanometer sized ZnO clusters.

Nanometer sized ZnO clusters are produced in the gas phase and subsequently deposited on clean Au(111) surfaces under ultra-high vacuum conditions. The zinc blende atomic structure of the approximately spherical ZnO clusters is resolved by high resolution scanning transmission electron microscopy. The large band gap and weak n-type conductivity of individual clusters are determined by scanning tunnelling microscopy and spectroscopy at cryogenic temperatures. The conduction band is found to exhibit clear quantization into discrete energy levels, which can be related to finite-size effects reflecting the zero-dimensional confinement. Our findings illustrate that gas phase cluster production may provide unique possibilities for the controlled fabrication of high purity quantum dots and heterostructures that can be size selected prior to deposition on the desired substrate under controlled ultra-high vacuum conditions.

Trauma perineal: parto acuático versus parto convencional en Centro Hospitalario Nuevo Sanatorio Durango en la Ciudad de México / Perineal trauma: water birth versus conventional vaginal deliveries in Hospital Center Nuevo Sanatorio Durango in Mexico City

Resumen Introducción La atención de parto acuático ha incrementado en popularidad en la Ciudad de México. El Centro Hospitalario Nuevo Sanatorio Durango ha sido pionero en ofrecer la atención de parto bajo el agua. Hasta la fecha, no se han realizado estudios sobre la conducta de los partos acuáticos en México. Objetivo Este estudio intenta evaluar si el parto bajo el agua está asociado a mayor incremento en las tasas de trauma perineal comparándolo con un grupo control de pacientes atendidas por parto convencional. Material y métodos Archivos clínicos de mujeres que se atendieron de parto acuático en el Centro Hospitalario Sanatorio Durango en la Ciudad de México en el periodo comprendido entre 2016 y 2017, revisados retrospectivamente. Los resultados de interés fueron estimar el trauma perineal (desgarros de tercer y cuarto grado) comparándolo con un grupo control de parto convencional. Resultados Se registraron 120 pacientes que se atendieron de parto acuático. Hubo diferencia significativa en los resultados en trauma perineal en el grupo de parto acuático: mayores tasas de periné intacto en mujeres atendidas bajo el agua, por lo que se propone que el parto acuático es protector del trauma perineal. Conclusiones El parto en agua en nuestro centro no parece estar asociado a incremento en los resultados adversos maternos (trauma perineal). Los resultados de este estudio establecen que el parto acuático es una alternativa aceptable para el nacimiento en mujeres de bajo riesgo obstétrico, siempre y cuando cuente con adecuada vigilancia y profesional capacitado.

Abstract Introduction Waterbirth has been increasing in popularity in Mexico City. Hospital Center Nuevo Sanatorio Durango in Mexico City is the pioneer hospital offering water births to women. To date, no studies have been done on the conduct of waterbirths in Mexico. Objective This study aims to evaluate if water immersion during delivery is associated with increased rates of perineal trauma as compared with conventional vaginal deliveries. Material and methods Clinical records of women who birthed underwater at Hospital Center Sanatorio Durango in Mexico City between 2016 and 2017 were retrospectively reviewed. The outcomes of interest were estimated perineal trauma, third or fourth degree. Outcomes were compared against a matched control group of women who had conventional vaginal deliveries. Results Records of 120 women who birthed underwater were accrued. There was a significant difference in maternal outcomes in perineal trauma in water birth: higher rates of intact perineums in women who birth underwater, proposing that water birth is protective against perineal trauma. Conclusions Water birth at our center does not appear to be associated with an increased incidence of adverse maternal outcomes (perineal trauma). The results of this study supported water birth as a birthing option for groups of low-risk women in an obstetrician led setting with good midwifery support.

Estudios sobre el virus del papiloma humano (VPH) en el Ecuador: parte I / Studies on human papillomavirus (HPV) in Ecuador: part I

Aprovechando la realización de las XL Jornadas Nacionales de Biología Espol en la ciudad de Guayaquil, se realizó una sesión dedicada a la epidemiología del virus de papiloma humano (VPH) y del cáncer cervical. Esta sesión tuvo la participación de varios investigadores provenientes de diferentes zonas del Ecuador. El presente artículo tiene como objeto presentar un resumen de estas charlas, junto a un análisis de la información mostrada además de una reflexión sobre las preguntas que quedan aún por responder en cuanto al perfil epidemiológico de esta patología en el país.

Taking advantage of the realization of theXL National Conference on Espol Biology in the city of Guayaquil, a session was held dedicated to the epidemiology of Human Papilloma Virus (HPV) and cervical cancer. This session was attended by several researchers from different areas of Ecuador. The object of this article is to present a summary of these talks, together with an analysis of the information shown in addition to a reflection on the questions still to be answered regarding the epidemiological profile of this pathology in the country.