Hepatopathy secondary to infiltration by malignant melanoma: diagnostic value of liver biopsy.

We present the case of a 61-year-old male with no relevant history of interest who was admitted to hospital due to constitutional syndrome and discomfort in the right hypochondrium. On admission, abdominal ultrasound was performed with findings of chronic liver disease and innumerable well-defined hypoechogenic lesions of small size. Although the study was extended with other imaging tests, they did not provide more information than what was available at the time. Subsequently, an ultrasound-guided liver biopsy was performed with pathological anatomy compatible with infiltration by malignant melanoma. Subsequently, a search for the primary origin of the melanoma was performed and it was found in the right thigh. Hepatic involvement by melanoma is infrequent and both the symptoms and the findings in the complementary tests are non-specific, characteristics that make diagnosis difficult. Therefore, in these cases liver biopsy plays a fundamental role in the diagnosis.

Gastrointestinal bleeding due to Heyde's syndrome resolved by transcatheter aortic valve implantation (TAVI).

We introduce the case of an 82-year-old woman with Heyde's syndrome (HS) whose gastrointestinal bleeding was refractory to medical and endoscopic therapy, for which a percutaneous aortic valve implantation (TAVI) was performed. The outcome after TAVI was good, gastrointestinal bleeding ceased and Hb remained stable during follow-up in the following 3 months. Currently, although SH is not an indication for TAVI, it could be an indication for TAVI in patients with recurrent gastrointestinal bleeding or refractory anemia to other therapies, using the percutaneous route in those with high surgical risk.

Open wound and cutaneous fistulization after microwave ablation of hepatocarcinoma.

A 64-year-old male with a history of HBV Child A MELD 9 cirrhosis on treatment with oral entecavir 0.5 mg/day. Diagnosed with 2 cm hepatocarcinoma in segment 6 treated by radiofrequency in April 2016 with complete response until June 2021, when an increase in the size of the solid component of the treated lesion (28 x 20 mm in diameter) was detected with early enhancement after the administration of paramagnetic contrast, suggestive of local tumor recurrence. Microwave ablation is a percutaneous thermal treatment that creates an electromagnetic field around a monopolar electrode, inducing homogeneous heating and coagulative tissue necrosis. It allows treating several lesions simultaneously and in less time than radiofrequency ablation with low morbidity and mortality. The incidence of adverse events ranges between 2.6% and 7.5%. The most frequent complications are bleeding and hematoma. Ablation tract fistulization is an infrequent complication, with a higher risk of appearing in subcapsular or peripheral hepatic lesions, as was the case in our patient.

Upper gastrointestinal bleeding secondary to toxicity by anthracyclines, cytarabine and methotrexate in a patient with acute lymphoblastic leukemia.

A 60-year-old male patient with no medical history but acute lymphoblastic leukemia was admitted in the hematology ward for chemotherapy treatment (methotrexate, cytarabine, fludarabine and idarubicin). Approximately six days after finishing this chemotherapy, the patient began with symptoms of upper gastrointestinal bleeding (hematemesis and melena). Gastroscopy revealed erosive esophagitis, gastritis and duodenitis, as well as Forrest III ulcers in the duodenal bulb and multiple Forrest IIb ulcers in the second portion of the duodenum. Given the multiplicity of lesions, medical treatment with high doses of folinic acid, intravenous omeprazole, and transfusion of blood products was decided, with favorable evolution of the gastrointestinal bleeding. However, the patient died of respiratory infection.

Charting molecular free-energy landscapes with an atlas of collective variables.

Collective variables (CVs) are a fundamental tool to understand molecular flexibility, to compute free energy landscapes, and to enhance sampling in molecular dynamics simulations. However, identifying suitable CVs is challenging, and is increasingly addressed with systematic data-driven manifold learning techniques. Here, we provide a flexible framework to model molecular systems in terms of a collection of locally valid and partially overlapping CVs: an atlas of CVs. The specific motivation for such a framework is to enhance the applicability and robustness of CVs based on manifold learning methods, which fail in the presence of periodicities in the underlying conformational manifold. More generally, using an atlas of CVs rather than a single chart may help us better describe different regions of conformational space. We develop the statistical mechanics foundation for our multi-chart description and propose an algorithmic implementation. The resulting atlas of data-based CVs are then used to enhance sampling and compute free energy surfaces in two model systems, alanine dipeptide and ß-D-glucopyranose, whose conformational manifolds have toroidal and spherical topologies.

Reverse engineering the euglenoid movement.

Euglenids exhibit an unconventional motility strategy amongst unicellular eukaryotes, consisting of large-amplitude highly concerted deformations of the entire body (euglenoid movement or metaboly). A plastic cell envelope called pellicle mediates these deformations. Unlike ciliary or flagellar motility, the biophysics of this mode is not well understood, including its efficiency and molecular machinery. We quantitatively examine video recordings of four euglenids executing such motions with statistical learning methods. This analysis reveals strokes of high uniformity in shape and pace. We then interpret the observations in the light of a theory for the pellicle kinematics, providing a precise understanding of the link between local actuation by pellicle shear and shape control. We systematically understand common observations, such as the helical conformations of the pellicle, and identify previously unnoticed features of metaboly. While two of our euglenids execute their stroke at constant body volume, the other two exhibit deviations of about 20% from their average volume, challenging current models of low Reynolds number locomotion. We find that the active pellicle shear deformations causing shape changes can reach 340%, and estimate the velocity of the molecular motors. Moreover, we find that metaboly accomplishes locomotion at hydrodynamic efficiencies comparable to those of ciliates and flagellates. Our results suggest new quantitative experiments, provide insight into the evolutionary history of euglenids, and suggest that the pellicle may serve as a model for engineered active surfaces with applications in microfluidics.

Modeling and enhanced sampling of molecular systems with smooth and nonlinear data-driven collective variables.

Collective variables (CVs) are low-dimensional representations of the state of a complex system, which help us rationalize molecular conformations and sample free energy landscapes with molecular dynamics simulations. Given their importance, there is need for systematic methods that effectively identify CVs for complex systems. In recent years, nonlinear manifold learning has shown its ability to automatically characterize molecular collective behavior. Unfortunately, these methods fail to provide a differentiable function mapping high-dimensional configurations to their low-dimensional representation, as required in enhanced sampling methods. We introduce a methodology that, starting from an ensemble representative of molecular flexibility, builds smooth and nonlinear data-driven collective variables (SandCV) from the output of nonlinear manifold learning algorithms. We demonstrate the method with a standard benchmark molecule, alanine dipeptide, and show how it can be non-intrusively combined with off-the-shelf enhanced sampling methods, here the adaptive biasing force method. We illustrate how enhanced sampling simulations with SandCV can explore regions that were poorly sampled in the original molecular ensemble. We further explore the transferability of SandCV from a simpler system, alanine dipeptide in vacuum, to a more complex system, alanine dipeptide in explicit water.

Poisoning cases in Catalonia: characteristics according to age groups in the Intox.28 study. / Características de las intoxicaciones agudas atendidas en Cataluña y diferencias según grupos de edad: Estudio Intox-28.

OBJECTIVES: The Toxicology Working Group of the Catalan Society of Emergency Medicine (SoCMUETox) began the Intox-28 study in 2013. The aim was to identify differences in poisoning cases between 3 age groups. MATERIAL AND METHODS: Descriptive observational study of poisoning cases managed in 8 hospital emergency departments on the 28th day of each month from 2013 to 2019. We gathered information on patient particulars, type of poison, clinical data, and discharge destination. The patient sample was distributed into 3 groups for comparison: minors under the age of 17 years, adults aged 17 to 65 years, and adults over the age of 65 years. RESULTS: The hospitals registered 1088 cases: 132, 859, and 97 in each age group. In comparisons between the minors and the adults aged 65 years or younger, the minors had more females (58.3% vs 46.1%), fewer recreational poisonings (22% vs 46.1%) more poisonings inside the home (67.4% vs 51.1%), more medication poisonings (49.2% vs 31.1%), and less often received treatment (43.2% vs 73%) (P .001, all comparisons). The proportion of older adults receiving treatment (73.2%) was similar to that of the younger adults. CONCLUSION: The characteristics of poisonings vary according to age. Differences lie in gender, intentionality, and type of poison.

OBJETIVO: El Grupo de Trabajo de Toxicología de la Societat Catalana de Medicina d'Urgències i Emergències (SoCMUETox) inició en 2013 el estudio Intox-28. El objetivo de este trabajo es evaluar las diferencias existentes en las características de las intoxicaciones según la edad de los pacientes. METODO: Estudio descriptivo observacional de las intoxicaciones atendidas en 8 servicios de urgencias hospitalarios (SUH) el día 28 de cada mes durante el periodo 2013-19. Se recogieron datos demográficos, tipo de tóxico, datos clínicos y destino al alta. Los pacientes se dividieron en 3 grupos: menores de 17 años, adultos (entre 17 y 65 años) y mayores de 65 años. RESULTADOS: Se registraron 1.088 intoxicaciones: 132 (12,1%), 859 (78,9%) y 97 (8,9%) en cada grupo de edad respectivamente. En comparación a los pacientes adultos, en los menores de 17 años hubo más mujeres (58,3% vs 46,1%; p 0,001), menos intoxicaciones de tipo recreativo (22% vs 46,1%; p 0,001) y acontecieron más frecuentemente en el domicilio (67,4% vs 51,1%; p 0,001). El tipo de tóxico más implicado fueron los fármacos (49,2% vs 31,1%; p 0,001) y precisaron tratamiento con menor frecuencia (43,2% vs 73%; p 0,001). Los mayores de 65 años precisaron tratamiento en porcentaje similar a los pacientes de 17 a 65 años (73,2%). CONCLUSIONES: Existen diferencias entre los grupos de edad, entre las que destacan el sexo predominante, la intencionalidad de la intoxicación y el tipo de tóxico implicado.

[Prehospital emergency care of patients exposed to poisoning: Assessment of epidemiological, clinical characteristics and quality of care]. / Atención prehospitalaria urgente de los pacientes pediátricos expuestos a tóxicos: características epidemiológico-clínicas y evaluación de la calidad asistencial.

OBJECTIVE: To describe the characteristics of paediatric patients with suspected poisoning treated by advanced life support (ALS) units, and to evaluate quality indicators (QI) for the prehospital emergency care of these patients. METHOD: A one-year observational study of patients under 18 years of age exposed to poisoning and treated by an ALS unit of the Medical Emergency System in Catalonia. Severe clinical criteria were defined, with 8 QI being evaluated for prehospital emergency care of poisoned paediatric patients. RESULTS: The study included a total of 254 patients, with a median age of 14 years-old (p25-75 = 7-16), with intentional poisoning in 50.8% of cases. The most frequently involved toxic agent was carbon monoxide (CO) (33.8%). Poisoning was found in 48.8% of those patients, being serious in 16.5%. Intentionally (OR 5.1; 95% CI: 1.9-13.8) and knowledge of the time of exposure (OD 3.1; 95% CI: 1.3-7.3) were independent risk factors associated with the appearance of severe clinical symptoms. Five QI did not reach the quality standard and included, availability of specific clinical guidelines, activated charcoal administration in selected patients, oxygen therapy administration at maximum possible concentration in carbon monoxide poisoning, electrocardiographic assessment in patients exposed to cardiotoxic substances, and recording of the minimum data set. CONCLUSIONS: Paediatric patients attended by ALS units showed specific characteristics, highlighting the involvement of CO and adolescents with voluntary poisoning. The QI assessment was useful to detect weak points in the quality of care of these patients and to develop strategies for improvement.

Efficient pipeline for image-based patient-specific analysis of cerebral aneurysm hemodynamics: technique and sensitivity.

Hemodynamic factors are thought to be implicated in the progression and rupture of intracranial aneurysms. Current efforts aim to study the possible associations of hemodynamic characteristics such as complexity and stability of intra-aneurysmal flow patterns, size and location of the region of flow impingement with the clinical history of aneurysmal rupture. However, there are no reliable methods for measuring blood flow patterns in vivo. In this paper, an efficient methodology for patient-specific modeling and characterization of the hemodynamics in cerebral aneurysms from medical images is described. A sensitivity analysis of the hemodynamic characteristics with respect to variations of several variables over the expected physiologic range of conditions is also presented. This sensitivity analysis shows that although changes in the velocity fields can be observed, the characterization of the intra-aneurysmal flow patterns is not altered when the mean input flow, the flow division, the viscosity model, or mesh resolution are changed. It was also found that the variable that has the greater impact on the computed flow fields is the geometry of the vascular structures. We conclude that with the proposed modeling pipeline clinical studies involving large numbers cerebral aneurysms are feasible.