COVID-19 Infection in Critically Ill Patients Carries a High Risk of Venous Thrombo-embolism.

OBJECTIVE: The coronavirus disease of 2019 (COVID-19) due to SARS-CoV-2 infection has been found to cause an increased risk of venous thrombo-embolism (VTE). The aims of the study were to determine the frequency of VTE in critically ill patients with COVID-19 and its correlation with D dimer levels and pharmacological prophylaxis. METHODS: This was a cohort study of critically ill patients due to COVID-19. All patients admitted to the intensive care unit on the same day of April 2020 were selected, regardless of length of stay, and a single bilateral venous duplex ultrasound in the lower extremities was performed up to 72 hours later. Pulmonary embolism (PE) was diagnosed by computed tomography angiography. Asymptomatic and symptomatic VTE were registered, including pre-screening in hospital VTE. Characteristics of patients, blood test results, doses of thromboprophylaxis received, VTE events, and mortality after seven day follow up were recorded. RESULTS: A total of 230 critically ill patients were studied. The median intensive care unit stay of these patients was 12 days (interquartile range [IQR] 5 - 19 days). After seven days follow up, the frequency of patients with VTE, both symptomatic and asymptomatic, was 26.5% (95% confidence interval [CI] 21% - 32%) (69 events in 61 patients): 45 with DVT and 16 with PE (eight of them with concomitant DVT). The cumulative frequency of symptomatic VTE was 8.3% (95% CI 4.7% - 11.8%). D dimer values ≥ 1 500 ng/mL were diagnostic of VTE, with a sensitivity of 80% and a specificity of 42%. During follow up after screening, six patients developed new VTE. Three of them developed a recurrence after a DVT diagnosed at screening, despite receiving therapeutic doses of heparin. Mortality rates at seven day follow up were the same for those with (6.6%) and without (5.3%) VTE. CONCLUSION: Patients with severe COVID-19 infection are at high risk of VTE, and further new symptomatic VTE events and recurrence can occur despite anticoagulation. The prophylactic anticoagulant dose may need to be increased in patients with a low risk of bleeding.

Enhanced carbon dioxide drainage observed in digital rock under intermediate wetting conditions.

Carbon dioxide (CO 2 ) trapping in capillary networks of reservoir rocks is a pathway to long-term geological storage. At pore scale, CO 2 drainage displacement depends on injection pressure, temperature, and the rock's interaction with the surrounding fluids. Modeling this interaction requires adequate representations of both capillary volume and surface. For the lack of scalable representations, however, the prediction of a rock's CO 2 storage potential has been challenging. Here, we report how to represent a rock's pore space by statistically sampled capillary networks (ssCN) that preserve morphological rock characteristics. We have used the ssCN method to simulate CO 2 drainage within a representative sandstone sample at reservoir pressures and temperatures, exploring intermediate- and CO 2 -wet conditions. This wetting regime is often neglected, despite evidence of plausibility. By raising pressure and temperature we observe increasing CO 2 penetration within the capillary network. For contact angles approaching 90 ∘ , the CO 2 saturation exhibits a pronounced maximum reaching 80 % of the accessible pore volume. This is about twice as high as the saturation values reported previously. For enabling validation of our results and a broader application of our methodology, we have made available the rock tomography data, the digital rock computational workflows, and the ssCN models used in this study.

Theoretical quantification of the polyvalent binding of nanoparticles coated with peptide-major histocompatibility complex to T cell receptor-nanoclusters.

Nanoparticles (NPs) coated with peptide-major histocompatibility complexes (pMHCs) can be used as a therapy to treat autoimmune diseases. They do so by inducing the differentiation and expansion of disease-suppressing T regulatory type 1 (Tr1) cells by binding to their T cell receptors (TCRs) expressed as TCR-nanoclusters (TCRnc). Their efficacy can be controlled by adjusting NP size and number of pMHCs coated on them (referred to as valence). The binding of these NPs to TCRnc on T cells is thus polyvalent and occurs at three levels: the TCR-pMHC, NP-TCRnc and T cell levels. In this study, we explore how this polyvalent interaction is manifested and examine if it can facilitate T cell activation downstream. This is done by developing a multiscale biophysical model that takes into account the three levels of interactions and the geometrical complexity of the binding. Using the model, we quantify several key parameters associated with this interaction analytically and numerically, including the insertion probability that specifies the number of remaining pMHC binding sites in the contact area between T cells and NPs, the dwell time of interaction between NPs and TCRnc, carrying capacity of TCRnc, the distribution of covered and bound TCRs, and cooperativity in the binding of pMHCs within the contact area. The model was fit to previously published dose-response curves of interferon-γ obtained experimentally by stimulating a population of T cells with increasing concentrations of NPs at various valences and NP sizes. Exploring the parameter space of the model revealed that for an appropriate choice of the contact area angle, the model can produce moderate jumps between dose-response curves at low valences. This suggests that the geometry and kinetics of NP binding to TCRnc can act in synergy to facilitate T cell activation.

[Meckel's diverticulitis, an uncommon cause of acute abdomen]. / Diverticulitis de Meckel, una causa poco frecuente de abdomen agudo.

Meckel's diverticulum corresponds to the aberrant involution of the omphalo-mesenteric canal or vitelline duct, which is located at the level of the antimesenteric border of the terminal ileum. It is the most common structural anomaly of the gastrointestinal tract, it is almost always asymptomatic and its diagnosis is usually incidental, however the complication with diverticulitis is an unusual condition. We describe the case of a 65-year-oldman, who was admitted from another institution with a diagnosis of acute abdomen. On physical examination, he presented signs of peritoneal irritation with evidence of leukocytosis and neutrophilia in the admission blood count. Computerized tomography of the abdomen with intra venous contrast was performed, which was interpreted as complicated Meckel's diverticulitis, being corroborated during the surgical act and confirmed by pathological anatomy. Meckel's diverticulitis is a rare entity, however it is important to recognize it within the differential diagnoses of acute abdomen, which will allow prompt intervention and a favorable outcome.

El divertículo de Meckel (DM) corresponde a la involución aberrante del canal onfalo-mesentérico o conducto vitelino, el cual se ubica a nivel del borde antimesentérico del íleon terminal. Es la anomalía estructural más común del tracto gastrointestinal, casi siempre es asintomático y su diagnóstico por lo general es incidental, sin embargo, la complicación con diverticulitis es una condición poco usual. Describimos el caso de un hombre de 65 años, que ingresó referido de otra institución con diagnóstico de abdomen agudo, al examen físico presentó signos de irritación peritoneal con evidencia de leucocitosis y neutrofilia en hemograma de ingreso. Se realizó tomografía computarizada de abdomen con contraste endovenoso, la cual se interpretó como diverticulitis de Meckel complicada, siendo corroborado durante el acto quirúrgico y confirmado mediante anatomía patológica. La diverticulitis de Meckel es una entidad rara, sin embargo, es importante reconocerla dentro de los diagnósticos diferenciales de abdomen agudo, lo cual permitirá una pronta intervención y un favorable desenlace.

Mortality and bleeding complications of COVID-19 critically ill patients with venous thromboembolism.

BACKGROUND: Venous thromboembolism (VTE) disease in COVID-19 patients is a remarkable issue, especially its relationship with bleeding events and mortality. The objective of this study was to describe the outcomes of critically ill patients with COVID-19, hospitalized in the Intensive Care Unit (ICU), in relationship with VTE during their stay. METHODS: This is a prospective cohort study of critically ill COVID-19 patients in two hospitals that underwent a venous ultrasound at the beginning of follow-up of both lower limbs in April 2020. In case of clinical suspicion of new VTE during the 30-day follow-up, additional ultrasound or thoracic CT were performed. Global VTE frequency, major bleeding events and survival were collected, and their predictors were studied. RESULTS: We included 230 patients. After 30 days of follow-up, there were 95 VTE events in 86 patients (37.4%). Thirteen patients (5.7%) developed major bleeding complications and 42 patients (18.3%) died. None of the comorbidities or previous treatments were related with bleeding events. D-Dimer at admission was significantly related with VTE development and mortality. Independent predictors of mortality in the regression model were older age (>66 years), D-Dimer at admission (>1.500 ng/mL) and low lymphocyte count (<0.45×109/L) with an AUC in the ROC curve of 0.81 (95% CI: 0.73-0.89). Patients presenting these three conditions presented a mortality of 100% in the predictive model. CONCLUSIONS: VTE frequency in ICU COVID-19 patients is high and risk of major bleeding is low. Comorbidities and laboratory parameters of admission in these patients can be a useful tool to predict mortality.

[Prevalence of iodine deficiency in pregnant women in the health area of Palencia (Spain)]. / Yododeficiencia en mujeres gestantes del Area Sanitaria de Palencia (España).

BACKGROUND: Iodine deficiency in pregnant women may result in substantial and irreversible impairment in fetal brain development, even from the first few weeks of pregnancy. OBJECTIVE: To assess the nutritional iodine status of pregnant women in our health area and its relationship with dietary factors and thyroid function and to suggest treatment guidelines. PATIENTS AND METHOD: A study in 164 pregnant women in early pregnancy was carried out. Data on urinary iodine concentrations were gathered from 24-hour urine samples. Data on anthropometric parameters and thyroid function were included. Information on dietary habits in the previous week was collected using a nutritional questionnaire. All data were obtained before iodine supplements were administered. RESULTS: The median urinary iodine concentration was 92 [p25-p75 range, 71-139] microg/l. Seventy-eight percent of urinary iodine values were under 150 microg/l. Women who took iodized salt had higher levels of urinary iodine concentrations than women without iodized salt intake. CONCLUSIONS: Seventy-eight percent of pregnant women in our health area were iodine deficient. Iodized salt intake is related to iodine sufficiency and to increased urinary iodine concentrations. Measures to increase intake of iodized salt among the population should be implemented. Iodized salt supplements should be systematically prescribed in women from the beginning of pregnancy.

Pilot-scale isolation and characterization of extracellular polymeric substances (EPS) from cell-free medium of Spirulina sp. LEB-18 cultures under outdoor conditions.

This objective of this work was to monitor the EPS production during the growth of Spirulina sp. LEB-18, evaluate the productivity and to characterize the exopolymers obtained on pilot-scale under outdoor conditions. The production of crude EPS occurred in all phases of biomass growth and was approximately ten folds higher than that biomass concentration of Spirulina sp. LEB-18 at the end cultivation, demonstrating the importance of the use of supernatant after harvesting of Spirulina to obtain high value bioproducts. The EPS extracted by Spirulina sp. LEB-18 are typically heteropolymers with one high molecular weight fraction (polysaccharides) with potential to be utilized as an alternative bioflocculant and another fraction of lower molecular mass (proteins). The presence of uronic acids, pyruvates and acyl groups of carbohydrates or carboxylic groups of amino acids in protein moiety is the main responsible for overall negative charge of EPS, which is also of biotechnological importance. Moreover, due to the pseudoplastic behavior of the solutions and high thermal stability, the obtained EPS can be widely applied in several industrial sectors, thus determining its technological and market potentiality.

Diverticulitis de Meckel, una causa poco frecuente de abdomen agudo / Meckel's diverticulitis, an uncommon cause of acute abdomen

Resumen El divertículo de Meckel (DM) corresponde a la involución aberrante del canal onfalo-mesentérico o conducto vitelino, el cual se ubica a nivel del borde antimesentérico del íleon terminal. Es la anomalía estructural más común del tracto gastrointestinal, casi siempre es asintomático y su diagnóstico por lo general es incidental, sin embargo, la complica ción con diverticulitis es una condición poco usual. Describimos el caso de un hombre de 65 años, que ingresó referido de otra institución con diagnóstico de abdomen agudo, al examen físico presentó signos de irritación peritoneal con evidencia de leucocitosis y neutrofilia en hemograma de ingreso. Se realizó tomografía computarizada de abdomen con contraste endovenoso, la cual se interpretó como diverticulitis de Meckel complicada, siendo corroborado durante el acto quirúrgico y confirmado mediante anatomía patológica. La diverticulitis de Meckel es una entidad rara, sin embargo, es importante reconocerla dentro de los diagnósticos diferenciales de abdomen agudo, lo cual permitirá una pronta intervención y un favorable desenlace.

Abstract Meckel's diverticulum corresponds to the aberrant invo lution of the omphalo-mesenteric canal or vitelline duct, which is located at the level of the antimesenteric border of the terminal ileum. It is the most common structural anomaly of the gastrointestinal tract, it is almost always asymptomatic and its diagnosis is usually incidental, how ever the complication with diverticulitis is an unusual con dition. We describe the case of a 65-year-oldman, who was admitted from another institution with a diagnosis of acute abdomen. On physical examination, he presented signs of peritoneal irritation with evidence of leukocytosis and neutrophilia in the admission blood count. Computerized tomography of the abdomen with intra venous contrast was performed, which was interpreted as complicated Meckel's diverticulitis, being corroborated during the surgical act and confirmed by pathological anatomy. Meckel's diverticulitis is a rare entity, however it is important to recognize it within the differential diagnoses of acute abdomen, which will allow prompt intervention and a favorable outcome.

[Nutrigenomics, obesity and public health]. / Nutrigenómica, obesidad y salud pública.

Functional genomics will change knowledge and practice in clinical nutrition in the forthcoming years. The possibility of performing an individual's genetic profile (genetic variations and epigenetic modifications) as well as the ability of its integration in a complex network of metabolic interactions represents a huge challenge in Human Nutrition. The influence of nutrigenomics in terms of prevention and treatment of chronic diseases, such as obesity, type 2 diabetes and cardiovascular disease in a population level remains undetermined for the moment. The opportunity of nutritional intervention in critical stages of development and the chance of changing genetic susceptibility to diseases through diet in a Public Health basis should lead the future of nutrigenomics beyond the mere design of "personalized" functional food or diets.

[New approaches in obesity treatment: the gastrointestinal tract as an endocrine organ]. / Nuevas perspectivas en el tratamiento de la obesidad: el aparato digestivo como órgano endocrino.

The gastrointestinal tract, besides digesting and processing nutrients, is now regarded as an endocrine organ able to modulate appetite, satiety, and carbohydrate metabolism. Several enteroendocrine cells produce numerous peptides codifying either orexigenic (ghrelin, orexins) or anorexigenic signals (pancreatic polypeptide, peptide YY, cholecystokinin, amylin, bombesin homologs, apolipoprotein A-IV, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, oxyntomodulin), which interact in a complex network with other peripheral signals of energy balance and with different neuropeptides involved in the central control of appetite and energy homeostasis. The growing knowledge of the actions of these gastrointestinal peptides on appetite regulation and carbohydrate metabolism, and subsequent synthesis of analogs, particularly those derived from amylin and incretins, herald a new era in the therapy of 2 closely related diseases, obesity and type 2 diabetes mellitus.

Divertículo de Meckel en asociación a onfalocele y tetralogía de Fallot: reporte de caso y revisión de la literatura / Meckel's diverticulum in association with omphalocele and tetralogy of Fallot: Case report and literature review

El onfalocele o exónfalos se definen como un defecto congénito de la pared abdominal, que consiste en la herniación de las vísceras abdominales a través del anillo umbilical. Esta entidad rara vez se asocia a la comunicación del divertículo de Meckel con el saco del onfalocele. Teniendo en cuenta la escasa prevalencia de dicha entidad, compartimos el reporte de caso de un paciente recién nacido, con diagnóstico de onfalocele menor, en quien se sospechaba ruptura del saco, sin embargo, de manera intraoperatoria se encontró que la aparente ruptura del saco, correspondía a la comunicación con un divertículo de Meckel. El caso además se asoció con hallazgos ecocardiográficos de tetralogía de Fallot

Omphalocele or exomphalos are defined as a congenital defect of the abdominal wall, which consists of the herniation of the abdominal viscera through the umbilical ring. This entity is rarely associated with the communication of Meckel's diverticulum with the omphalocele sac. Considering the low prevalence of this entity, we report the case of a newborn with a diagnosis of minor omphalocele, in whom rupture of the sac was suspected; however, intraoperatively it was found that the apparent rupture of the sac corresponded to a communication with a Meckel's diverticulum. The case was also associated with echocardiographic findings of tetralogy of Fallot

Consideraciones acerca del aula invertida AI (FLIPPED CLASSROOM) / Considerations about the flipped classroom

La necesidad de mejorar las competencias de los futuros profesionales en salud ha conducido a repensar la manera como se imparten los conocimientos a los estudiantes y de cómo ellos podrían aprender de manera significativa. Actualmente, el aula invertida (AI) o flipped classroom (FC) se convierte en una estrategia de enseñanza alternativa en el campo de la educación en salud. Incentiva el aprendizaje del estudiante al promover la autonomía en el abordaje de los conocimientos antes de cada clase, favorece la motivación, el aprendizaje activo, colaborativo y significativo durante las sesiones presenciales, de tal manera que permite desarrollar el pensamiento crítico para una formación profesional idónea. Al realizar una revisión de la literatura se evidenció un amplio uso del AI en educación en salud con resultados positivos frente a la educación tradicional. Además, las tecnologías juegan un papel importante para presentar contenidos y ejecutar actividades fuera y dentro del aula. Se presentan algunas evidencias de la efectividad del AI en educación médica, cómo podría implementarse en nuestras aulas y la diversidad de recursos disponibles para usar en los diferentes escenarios que plantea esta estrategia.

The need to improve the skills of future health professionals has led to rethinking how knowledge is imparted to studentsand how to make learning more meaningful. Currently the use of the flipped classroom (FC) has become an alternativeteaching strategy in the field of health education. It encourages student learning by promoting autonomy in the approachto knowledge before classroom meetings. It also favors motivation and active, collaborative and meaningful learning duringthe in-class sessions, in such a way that it allows developing critical thinking skills as part of appropriate professionaltraining. A review of the literature showed a wide use of FC in health education with positive results when compared withtraditional education. Moreover, technology plays an important role for content presentation and implementing activitiesinside or outside the classroom. Some evidence is presented on the effectiveness of the FC in medical education, how it couldbe implemented in our classrooms, and the diversity of available resources for use in the different scenarios posed by thisstrategy.

Nematophagous fungi from decomposing cattle faeces in Argentina.

BACKGROUND: Biological control of gastrointestinal nematodes of ruminants by use of nematophagous fungi would become part of any livestock parasite integral control system. Identifying autochthonous species that could then be selected for mass production is an important phase in the practical use of biological control. AIMS: To search for nematophagous fungi with potential use as biological control agents against gastrointestinal nematodes in Argentina. METHODS: Decomposing cattle faeces sampled in different locations were incubated in water agar 2% with Panagrellus sp. The developed nematophagous fungi were transferred to new water agar 2% plates and then to corn meal agar plates in order to carry out their identification. Fungal diversity and richness were also assessed. RESULTS: Seventeen species from nine genera of nematophagous fungi were found. Twelve species were nematode-trapping fungi and three species plus two fungi identified to genus level corresponded to endoparasitic fungi. Arthrobotrys conoides, Arthrobotrys oligospora, Duddingtonia flagrans, Monacrosporium doedycoides, Arthrobotrys robusta and Drechmeria coniospora were the most frequently isolated species overall in the whole study (6.6%, 5.7%, 5.7%, 5.7%, 4.7% and 4.7%, respectively) although other species were more frequently recorded at local levels such as Arthrobotrys pyriformis (18.8%). Only A. conoides has been previously isolated from ruminant faecal samples in Argentina. Five nematode-trapping fungal species are mentioned for the first time in the Americas CONCLUSIONS: D. flagrans and A. conoides, both identified in the present study, are among the most promising ones as biological control agents against gastrointestinal nematodes of ruminants.

[Functional nutrition and optimal nutrition. Near or far?]. / Alimentos funcionales y nutrición óptima. Cerca o lejos?

The concept of functional food, about which scientific agreement is still lacking, springs from the field of Optimum Nutrition, aimed at modifying genetic and physiological aspects of human life and at the prevention and treatment of a growing number of diseases, far beyond merely covering nutritional requirements. From the European Union perspective, functional foods can be natural as well as industrially processed foods. The leading functional foods regarding which the soundest scientific evidence exists are probiotics, live microbial food ingredients represented mainly by fermented dairy products. Prebiotics, such as inulin-type fructans, are the trophic substrate of probiotics and potential intestinal microflora selectors. The combination of prebiotics and probiotics is termed synbiotic. Innumerable substances are known to have functional effects: soluble and insoluble fiber, phytosterols, phytoestrogens, monounsaturated and polyunsaturated fatty acids, phenol derivatives, vitamins and other phytochemicals. Functional foods exert their actions on different systems, especially the gastrointestinal, cardiovascular and immunological ones, acting too as enhancers of development and differentiation and positively modulating nutrient metabolism, gene expression, oxidative stress and the psychic sphere. The establishment of Health Claims must be firmly based upon scientific knowledge and legal regulation. Efficient biomarkers related to biological response must be found. Furthermore, it is essential to analyze possible diet or drug interactions as well as it is indispensable to conduct valid studies on humans. The prime objective must be the diet as a whole. Thus, the future challenge of a functional diet emerges.

Guidelines for the diagnosis and treatment of adrenal insufficiency in the adult.

Adrenal insufficiency (AI) is a disease characterized by a deficient production or action of glucocorticoids, with or without deficiency in mineral corticoids and/or adrenal androgens. It can result from disease intrinsic to the adrenal cortex (primary AI), from pituitary diseases that hamper the release of corticotropin (secondary AI) or from hypothalamic disorders that impair the secretion of the corticotropin-releasing hormone (tertiary AI). It is a disease with a low prevalence but its impact on the affected individual is very high as it can be life-threathening if not treated or lead to health problems if inadequately treated. However, currently there are no specific guidelines for the management of this disease. Therefore, at the proposal of the Spanish Society of Endocrinology and Nutrition (SEEN) board, a task-force under the Neuroendocrinology Knowledge Area of the SEEN was established, with the mandate of updating the diagnosis and treatment of AI. In fulfilment of this mandate the task-force has elaborated the present guide that, based on a comprehensive review of literature, is intended to provide an answer to questions related to the management of this disease. It is, therefore, an essentially practical document, mainly aimed at guiding the health professionals involved in the care of IA patients.

Estudio de detección del riesgo en diabetes en Atención Primaria según cuestionario FINDRISC en el Municipio de Gral. Pueyrredón (Estudio DR. DIAP) / Diabetes risk detection study in Primary Care according to FINDRISC questionnaire in the Municipality of Gral. Pueyrredón (DR. DIAP STUDY)

Objetivos: conocer la magnitud del riesgo de padecer diabetes mellitus 2 (DM2) en la población del Municipio de Gral. Pueyrredón que concurre a los Centros Asistenciales de Atención Primaria. Materiales y métodos: estudio observacional para determinar el riesgo de padecer DM2 mediante una entrevista donde se indagaron sobre las ocho preguntas del cuestionario FINDRISC. Resultados: la muestra del estudio estuvo constituida por 2.784 pacientes, el 54% conformada por mujeres. La edad fue agrupada en menos de 45 años el 47,5% (1.323), de 45 a 54 años el 20,9% (582), de 55 a 64 años el 18,3% (510) y más de 64 años el 13,2% (368). El 20% de la población presentó una puntuación de la escala de riesgo del cuestionario FINDRISC igual o mayor a 15, alto riesgo a muy alto riesgo de padecer diabetes en los próximos 10 años. El 43,38% presentó un IMC>30 y el 25,97% declaró recibir medicación para la hipertensión arterial. El 55,37% refería actividad física baja, el 50,79% no ingería verduras y frutas en forma diaria y el 17,98% declaró cifras de glucemias elevadas. Las variables que con mayor frecuencia se asociaron a una escala de riesgo >15 fueron: sedentarismo (80,9%), cintura >102/88 (65,7/77,2%), antecedente de hiperglucemia (64,0%), alimentación no saludable (61,9%) e IMC>30 (61,8%). El riesgo >15 según IMC fue: IMC 30 el 45,4%. Conclusiones: el 20% de la población encuestada está en alto riesgo de padecer diabetes. Una de cada dos o tres personas sin diabetes que asisten a un centro de Atención Primaria tiene un FINDRISC >15. Esta escala de riesgo es una herramienta simple, económica, de rápida confección, no invasiva y segura para detectar individuos con alto riesgo de padecer diabetes tipo 2. También puede usarse para identificar DM2 no detectada y factores de riesgo de enfermedad cardiovascular

Xenopus development from late gastrulation to feeding tadpole in simulated microgravity.

Microgravity (microG) is known to influence cytoskeletal structure, but its effects on cell migration are not well understood. To examine the effects of altered gravity on neural crest cell (NCC) migration, we inserted Xenopus laevis embryos into two separate microG-simulating slow turning lateral vessels (STLVs) just before neurulation (stage 11-12), and exposed them until feeding stage (stage 45), when the jaws and branchial apparatus are fully functional. To evaluate apparatus-related artifacts, we used two different STLVs and a vibration control as well as a stationary control vessel. Larval growth, pattern of NCC-derived cartilage formation, and incidence of malformations were analyzed using immunolocalization and wholemount staining of cartilage with Alcian blue. Interestingly, the two STLVs often yielded different or conflicting results. Many differences, such as increased cartilage size, attenuated Hoxa2 expression, and increased cell division, may be attributed mainly to vibration of the rotating vessels. However, tadpoles that developed in simulated microgravity (both STLVs, but not the vibration control) showed significantly more skeletal abnormalities, with stronger effects on cartilages derived from NCCs than those derived mainly from mesoderm. We conclude that migrating NCCs of Xenopus are sensitive to the altered gravitational environment of STLVs, and that studies relying on bioreactors to simulate microgravity also need to take variation in apparatus into account.