Left psoas abscess due to duodenal fistula as a late complication of necrotizing pancreatitis treated by endoscopic approach.

Gastrointestinal fistulas can be a complication of severe acute pancreatitis, and their incidence is low and sporadically reported in the literature. The most frequently reported site is in the colon, followed by duodenal fistulas. Psoas abscess is a rare condition. Iliopsoas abscesses are classified as primary or secondary. Secondary abscesses develop by spreading infection from contiguous anatomical structures, such as the gastrointestinal tract. We present the case of a recurrent left psoas abscess secondary to a duodenal fistula as a late complication of necrotizing pancreatitis resolved by endoscopic treatment.

Certification exams evaluated with serial case reports: theoretical and problematic approach.

The objective of this issue is a theoretical approach to the disadvantages involved in taking the certification exams of medical specializations through serial case reports and analyzing them with the Classical Test Theory (TCT). The certification exams of medical specializations correspond to criterial summative exams with high consequences. Therefore, it is imperative to maintain the highest quality standards in all the processes involved in preparing the exam. At present, it has been detected that some councils of medical specialties conduct the certification exams with tests that contain serial case reports and the psychometric analysis that they conduct is supported by the TCT; however, the structure of this type of test violates the fundamental assumptions of the TCT. The violation of the fundamental assumptions of the TCT in the tests constructed through serial case reports can lead to biases or misinterpretations of the results. Due to the above, it is advisable to use other psychometric models for the analysis of this type of test, or to avoid the use of serial case reports in the certification exams of medical specialties.

Se presenta un planteamiento teórico de las desventajas de realizar los exámenes de certificación de las especializaciones médicas mediante casos clínicos seriados y analizarlos con la Teoría Clásica del Test (TCT). Los exámenes de certificación de las especializaciones médicas corresponden a exámenes sumativos criteriales de altas consecuencias, por lo tanto, es imperativo mantener los máximos estándares de calidad en todos los procesos implicados en su elaboración. Actualmente, se ha detectado que algunos consejos de especialidades médicas realizan los exámenes de certificación con pruebas que incluyen casos clínicos seriados y que el análisis psicométrico está sustentado en la TCT; sin embargo, la estructura de este tipo de pruebas infringe los supuestos fundamentales de dicha teoría. La violación de los supuestos fundamentales de la TCT en las pruebas construidas mediante casos clínicos seriados puede conducir a sesgos o interpretación errónea de los resultados. Por lo anterior, es recomendable utilizar otros modelos psicométricos para el análisis de este tipo de pruebas, o evitar el uso de los casos clínicos seriados en los exámenes de certificación de las especialidades médicas.

Dose Escalation and Safety of Capsaicin for Cerebral Perfusion Augmentation: A Pilot Study.

Background and Purpose: Sphenopalatine ganglion (SPG) electrical stimulation has been studied in the setting of acute ischemic stroke to enhance collateral flow. Capsaicin poses an alternative to chemically stimulate the sphenopalatine ganglion. Therefore, the objective of this study was to determine the safety and effect of increasing doses of capsaicin upon serial transcranial Doppler markers of cerebral blood flow. Methods: We performed serial transcranial Doppler testing in 30 healthy volunteers divided into 5 equal groups. Capsaicin doses ranged from 33 to 165 µMol. We recorded peak systolic and end-diastolic velocities in the middle cerebral artery, arterial pressure, and perceived pungency in 5-minute intervals up to 20 minutes. We then calculated the mean velocity, the pulsatility index, and the cerebral blood flow index. Results: The participants' median age was 21 years (range, 5 years); all reported consumption of capsaicin in their diets. After and during the study, none reported side effects. Perceived pungency peaked at 5 minutes, and by the 20-minute mark, none perceived any pungency. All the tested doses produced the same pattern, consisting of augmentation of the middle cerebral artery mean velocity with the pulsatility index's diminution. The effects peaked between the 5- and the 10-minute measurements and then returned to basal levels except for the 66-µMol doses, which produced a sustained effect. We found no correlation between perceived pungency and dose, but the middle cerebral artery mean velocity was strongly correlated with the dose administered. Conclusions: This study provides evidence supporting the safety and tolerability of oral capsaicin in a population of healthy volunteers. Capsaicin appears to produce effects similar to those of sphenopalatine ganglion electrical stimulation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04545892.

Environmental Fe, Ti, Al, Cu, Hg, Bi, and Si Nanoparticles in the Atrioventricular Conduction Axis and the Associated Ultrastructural Damage in Young Urbanites: Cardiac Arrhythmias Caused by Anthropogenic, Industrial, E-Waste, and Indoor Nanoparticles.

Air pollution exposure is a risk factor for arrhythmia. The atrioventricular (AV) conduction axis is key for the passage of electrical signals to ventricles. We investigated whether environmental nanoparticles (NPs) reach the AV axis and whether they are associated with ultrastructural cell damage. Here, we demonstrate the detection of the shape, size, and composition of NPs by transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometry (EDX) in 10 subjects from Metropolitan Mexico City (MMC) with a mean age of 25.3 ± 5.9 and a 71-year-old subject without cardiac pathology. We found that in every case, Fe, Ti, Al, Hg, Cu, Bi, and/or Si spherical or acicular NPs with a mean size of 36 ± 17 nm were present in the AV axis in situ, freely and as conglomerates, within the mitochondria, sarcomeres, lysosomes, lipofuscin, and/or intercalated disks and gap junctions of Purkinje and transitional cells, telocytes, macrophages, endothelium, and adjacent atrial and ventricular fibers. Erythrocytes were found to transfer NPs to the endothelium. Purkinje fibers with increased lysosomal activity and totally disordered myofilaments and fragmented Z-disks exhibited NP conglomerates in association with gap junctions and intercalated disks. AV conduction axis pathology caused by environmental NPs is a plausible and modifiable risk factor for understanding common arrhythmias and reentrant tachycardia. Anthropogenic, industrial, e-waste, and indoor NPs reach pacemaker regions, thereby increasing potential mechanisms that disrupt the electrical impulse pathways of the heart. The cardiotoxic, oxidative, and abnormal electric performance effects of NPs in pacemaker locations warrant extensive research. Cardiac arrhythmias associated with nanoparticle effects could be preventable.

EUS-guided biliary drainage in patients with distal malignant biliary obstruction requires fewer interventions and has a lower cost compared to ERCP biliary drainage.

INTRODUCTION: Endoscopic retrograde cholangiopancreatography (ERCP) biliary drainage is considered the reference standard in patients with biliary obstruction, but it is not free of complications. EUS-guided biliary drainage (EUS-BD) is considered an alternative in patients with failed ERCP; however, data are scarce as to whether EUS-BD could be considered a first option. OBJECTIVE: The aim of our study was to compare the need for reintervention and cost between ERCP biliary drainage vs. EUS-BD. MATERIAL AND METHODS: We conducted a retrospective and comparative study of patients with distal malignant biliary obstruction with biliary drainage with ERCP + plastic stent (ERCP-PS) vs. ERCP + metal stent (ERCP-MS) vs. EUS-BD. RESULTS: 124 patients were included, divided into three groups: ERCP-PS, 60 (48.3%) patients; ERCP-MS, 40 (32.2%) patients; and EUS-BD, 24 (19.3%) patients. The need for reinterventions (67 vs. 37 vs. 4%, respectively), the number of procedures [3 (1-10) vs. 2 (1-7) vs. 1 (1-2)], and the costs (4550 ± 3130 vs. 5555 ± 3210 vs. 2375 ± 1020 USD) were lower in the EUS-BD group. No differences in terms of complications were detected. CONCLUSION: EUS-BD requires fewer reinterventions and has a lower cost compared to drainage by ERCP with metal or plastic stents.

Quantitative Assessment of Chest CT Patterns in COVID-19 and Bacterial Pneumonia Patients: a Deep Learning Perspective.

BACKGROUND: It is difficult to distinguish subtle differences shown in computed tomography (CT) images of coronavirus disease 2019 (COVID-19) and bacterial pneumonia patients, which often leads to an inaccurate diagnosis. It is desirable to design and evaluate interpretable feature extraction techniques to describe the patient's condition. METHODS: This is a retrospective cohort study of 170 confirmed patients with COVID-19 or bacterial pneumonia acquired at Yeungnam University Hospital in Daegu, Korea. The Lung and lesion regions were segmented to crop the lesion into 2D patches to train a classifier model that could differentiate between COVID-19 and bacterial pneumonia. The K-means algorithm was used to cluster deep features extracted by the trained model into 20 groups. Each lesion patch cluster was described by a characteristic imaging term for comparison. For each CT image containing multiple lesions, a histogram of lesion types was constructed using the cluster information. Finally, a Support Vector Machine classifier was trained with the histogram and radiomics features to distinguish diseases and severity. RESULTS: The 20 clusters constructed from 170 patients were reviewed based on common radiographic appearance types. Two clusters showed typical findings of COVID-19, with two other clusters showing typical findings related to bacterial pneumonia. Notably, there is one cluster that showed bilateral diffuse ground-glass opacities (GGOs) in the central and peripheral lungs and was considered to be a key factor for severity classification. The proposed method achieved an accuracy of 91.2% for classifying COVID-19 and bacterial pneumonia patients with 95% reported for severity classification. The CT quantitative parameters represented by the values of cluster 8 were correlated with existing laboratory data and clinical parameters. CONCLUSION: Deep chest CT analysis with constructed lesion clusters revealed well-known COVID-19 CT manifestations comparable to manual CT analysis. The constructed histogram features improved accuracy for both diseases and severity classification, and showed correlations with laboratory data and clinical parameters. The constructed histogram features can provide guidance for improved analysis and treatment of COVID-19.

Cutaneous Manifestations of Zika in Peru.

This article aims to describe the cutaneous manifestations observed in the Zika epidemic in Peru during 2016 and 2017, as well as discuss the potential differential diagnoses. During the outbreak, the main reason for seeking medical advice was the development of a pruriginous maculopapular rash with a marked papular component, which started on the chest and later generalized to the rest of the body. Similar manifestations were noted in adults, children, and pregnant women. Other manifestations such as conjunctivitis, edema, or petechiae on the palate were rare. We suggest that in areas that are endemic for arboviral infections, in the differential diagnosis of a rash one must consider infections such as dengue, Zika, or chikungunya viruses. In nonendemic areas, the diagnosis is more difficult, as the rash may result from other viral infections not transmitted by arthropods and/or reactive or inflammatory diseases (urticaria, atopic dermatitis, systemic lupus erythematosus). We recommend that primary care health personnel are trained in the recognition of the mucocutaneous lesions caused by Zika virus infection, which could contribute to the identification of suspicious cases, particularly pregnant women.

Permanent Indwelling Transmural Stents for Endoscopic Treatment of Patients With Disconnected Pancreatic Duct Syndrome: Long-term Results.

INTRODUCTION: Disconnected pancreatic duct syndrome (DPDS) is defined as the complete disruption of the main pancreatic duct, the result are peripancreatic fluid collections or pancreatic leaks. The aim of this study was to report the results of derivative endoscopic treatment of DPDS in a long-term follow-up period. PATIENTS AND METHODS: We performed a retrospective analysis of prospectively collected data. Endoscopic treatment consisted of transmural drainage with 2 double pigtail plastic stents (7 F and 4 cm) deployed under endoscopic ultrasound guidance. RESULTS: In total, 21 patients were included in our study. There were 15 (71%) men and the median age was 36 years (range, 23 to 86 y). The principal etiology of DPDS was acute pancreatitis. A total of 20 (95.2%) patients were diagnosed with DPDS by endoscopic pancreatography and only 1 (4.8%) patient by magnetic resonance cholangiopancreatography (MRCP). The median follow-up time was 28 months (range, 7 to 76 mo). Technique success was 100% and initial clinical success was 80.9% (17/21). Three (17.6%) of these patients required a new endoscopic procedure with success in all cases. During follow-up, 11 (52%) patients developed diabetes mellitus and 3 patients (14%) developed exocrine pancreatic insufficiency. There were 5 (15%) patients with complications. CONCLUSION: According to our data, endoscopic treatment with the placement of a permanent indwelling transmural stents is a useful and safe tool for the treatment of DPDS.

Blastocystis Hominis and Chronic Abdominal Pain in Children: Is there an Association between Them?

Chronic abdominal pain has many etiologies, one of them being parasites. The aim of this study was to find an association between chronic abdominal pain in children and Blastocystis hominis (Bh). Clinical files of patients with Bh and functional abdominal pain were reviewed. A comparison was made between patients who showed an improvement of their symptoms and those who did not. Out of the 138 patients who had functional abdominal pain and Bh, 37 patients did not receive any treatment (26.8%), while 101 received it and were treated with different antimicrobial agents (73.2%); regarding the improvement of symptoms, a statistically significant difference (p < 0.001) was observed. Chronic abdominal pain in children has different etiologies; however, we have documented through this work that it is appropriate to provide antimicrobial treatment for patients with Bh and chronic abdominal pain.

Exposures to fine particulate matter (PM2.5) and ozone above USA standards are associated with auditory brainstem dysmorphology and abnormal auditory brainstem evoked potentials in healthy young dogs.

BACKGROUND: Delayed central conduction times in the auditory brainstem have been observed in Mexico City (MC) healthy children exposed to fine particulate matter (PM2.5) and ozone (O3) above the current United States Environmental Protection Agency (US-EPA) standards. MC children have α synuclein brainstem accumulation and medial superior olivary complex (MSO) dysmorphology. The present study used a dog model to investigate the potential effects of air pollution on the function and morphology of the auditory brainstem. METHODOLOGY: Twenty-four dogs living in clean air v MC, average age 37.1 ± 26.3 months, underwent brainstem auditory evoked potential (BAEP) measurements. Eight dogs (4 MC, 4 Controls) were analysed for auditory brainstem morphology and histopathology. RESULTS: MC dogs showed ventral cochlear nuclei hypotrophy and MSO dysmorphology with a significant decrease in cell body size, decreased neuronal packing density with regions in the nucleus devoid of neurons and marked gliosis. MC dogs showed significant delayed BAEP absolute wave I, III and V latencies compared to controls. CONCLUSIONS: MC dogs show auditory nuclei dysmorphology and BAEPs consistent with an alteration of the generator sites of the auditory brainstem response waveform. This study puts forward the usefulness of BAEPs to study auditory brainstem neurodegenerative changes associated with air pollution in dogs. Recognition of the role of non-invasive BAEPs in urban dogs is warranted to elucidate novel neurodegenerative pathways link to air pollution and a promising early diagnostic strategy for Alzheimer's Disease.

Secondary node analysis as an indicator for axillary lymphadenectomy in breast cancer patients. / Ganglio secundario como indicador de linfadenectomía axilar en pacientes afectas de cáncer de mama.

INTRODUCTION: Currently, there is no agreement regarding if it would be necessary to perform an axillary lymph node dissection (ALND) in patients who have macrometastases in the sentinel lymph node (SLN). We studied the utility of the secondary node analysis (SN), defined as the following node after the SLN in an anatomical and lymphatic pathway, as a sign of malignant axillary involvement. METHODS: An observational, retrospective and multicentre study was designed to assess the utility of the SN as a sign of axillary involvement. Among 2273 patients with breast cancer, a valid sample of 283 was obtained representing those who had the SN studied. Main endpoints of our study were: the SLN, the SN and the ALND histological pattern. Sensitivity, specificity and precision of the test were also calculated. RESULTS: SN test, in cases with positive SLN, has a sensitivity of 61.1%, a specificity of 78.7%, a positive predictive value of 45.8% and a negative predictive value of 87.3% with a precision of 74.7%. CONCLUSION: The study of the SN together with the technique of the SLN allows a more precise staging of the axillary involvement, in patients with breast cancer, than just the SLN technique.

EUS-guided drainage of pancreatic pseudocysts offers similar success and complications compared to surgical treatment but with a lower cost.

BACKGROUND AND AIM: Pancreatic pseudocysts (PPC) are a complication that occurs in acute and chronic pancreatitis. They comprise 75% of cystic lesions of the pancreas. There are scarce data about surgical versus endoscopic treatment on PPC. The aim of this study was to compare both treatment modalities regarding clinical success, complication rate, recurrence, hospital stay and cost. METHODS: Retrospectively, data obtained prospectively from 2000 to 2012 were analyzed. A PPC was defined as a fluid collection in the pancreatic or peripancreatic area that had a well-defined wall and contained no solid debris or recognizable parenchymal necrosis. Clinical success was defined as complete resolution or a decrease in size of the PPC to 2 cm or smaller. RESULTS: Overall, 64 procedures in 61 patients were included: 21 (33%) cases were drained endoscopically guided by EUS and 43 (67%) cases were drained surgically. The clinical success of the endoscopic group was 90.5 versus 90.7% for the surgical group (P = 0.7), with a complication rate of 23.8 and 25.6%, respectively (P = 0.8), and a mortality rate of 0 and 2.3% for each group, respectively (P = 0.4). The hospital stay was lower for the endoscopic group: 0 (0-10) days compared with 7 (2-42) days in the surgical group (P < 0.0001). Likewise, the cost was lower in the endoscopic group (P < 0.001). The recurrence rate was similar in both groups: 9.5 and 4.5% respectively (P = 0.59). The two recurrences found in the endoscopic group were associated with stent migration, and the recurrence in the surgical group was due to the type of surgery performed (open drainage). CONCLUSION: Endoscopic treatment of PPC offers the same clinical success, recurrence, complication and mortality rate as surgical treatment but with a shorter hospital stay and lower costs.

Postoperative abdominal collections drainage: Percutaneous versus guided by endoscopic ultrasound.

BACKGROUND AND AIM: Postoperative fluid collections (POFC) have high mortality. Percutaneous drainage (PD) is the preferred treatment modality. Drainage guided by endoscopic ultrasound (EUS-GD) represents a good alternative. The aim of the present study was to compare clinical success and complication rates of EUS-GD versus PD. METHODS: Data collected prospectively were analyzed in a retrospective manner. Patients with POFC from October 2008 to November 2013 were included. All collections were drained percutaneously or by EUS-GD. RESULTS: Sixty-three procedures in 43 patients with POFC were analyzed; 13 patients were drained using EUS-GD and 32 patients with PD. Two patients assigned initially to the PD group were reassigned to EUS-GD. Surgery procedures most often related to the collections were intestinal reconnection, distal pancreatectomy, biliary-digestive bypass, and exploratory laparotomy. Technical success (100% vs 91%; P = 0.25), clinical success (100% vs 84%; P = 0.13), recurrence (31% vs 25%; P = 0.69), hospital stay days (median 22 vs 27; P = 0.35), total costs (8328 ± 1600 USD vs 11 047 ± 1206 USD; P = 0.21), complications (0% vs 6%; P = 0.3), and mortality (8% vs 6%; P = 0.9) were each evaluated in the EUS-GD and PD groups, respectively. In the PD group one death was related to the procedure. CONCLUSIONS: EUS-GD is as effective and safe as PD in patients with POFC. The advantage of not requiring external drainage and a trend to higher clinical success and lower total costs must be considered.

Enhanced Nuclei Segmentation and Classification via Category Descriptors in the SAM Model.

Segmenting and classifying nuclei in H&E histopathology images is often limited by the long-tailed distribution of nuclei types. However, the strong generalization ability of image segmentation foundation models like the Segment Anything Model (SAM) can help improve the detection quality of rare types of nuclei. In this work, we introduce category descriptors to perform nuclei segmentation and classification by prompting the SAM model. We close the domain gap between histopathology and natural scene images by aligning features in low-level space while preserving the high-level representations of SAM. We performed extensive experiments on the Lizard dataset, validating the ability of our model to perform automatic nuclei segmentation and classification, especially for rare nuclei types, where achieved a significant detection improvement in the F1 score of up to 12%. Our model also maintains compatibility with manual point prompts for interactive refinement during inference without requiring any additional training.

Attention guided multi-scale cluster refinement with extended field of view for amodal nuclei segmentation.

Nuclei segmentation plays a crucial role in disease understanding and diagnosis. In whole slide images, cell nuclei often appear overlapping and densely packed with ambiguous boundaries due to the underlying 3D structure of histopathology samples. Instance segmentation via deep neural networks with object clustering is able to detect individual segments in crowded nuclei but suffers from a limited field of view, and does not support amodal segmentation. In this work, we introduce a dense feature pyramid network with a feature mixing module to increase the field of view of the segmentation model while keeping pixel-level details. We also improve the model output quality by adding a multi-scale self-attention guided refinement module that sequentially adjusts predictions as resolution increases. Finally, we enable clusters to share pixels by separating the instance clustering objective function from other pixel-related tasks, and introduce supervision to occluded areas to guide the learning process. For evaluation of amodal nuclear segmentation, we also update prior metrics used in common modal segmentation to allow the evaluation of overlapping masks and mitigate over-penalization issues via a novel unique matching algorithm. Our experiments demonstrate consistent performance across multiple datasets with significantly improved segmentation quality.

Content preserving image translation with texture co-occurrence and spatial self-similarity for texture debiasing and domain adaptation.

Models trained on datasets with texture bias usually perform poorly on out-of-distribution samples since biased representations are embedded into the model. Recently, various image translation and debiasing methods have attempted to disentangle texture biased representations for downstream tasks, but accurately discarding biased features without altering other relevant information is still challenging. In this paper, we propose a novel framework that leverages image translation to generate additional training images using the content of a source image and the texture of a target image with a different bias property to explicitly mitigate texture bias when training a model on a target task. Our model ensures texture similarity between the target and generated images via a texture co-occurrence loss while preserving content details from source images with a spatial self-similarity loss. Both the generated and original training images are combined to train improved classification or segmentation models robust to inconsistent texture bias. Evaluation on five classification- and two segmentation-datasets with known texture biases demonstrates the utility of our method, and reports significant improvements over recent state-of-the-art methods in all cases.

Vitamin C for Photo-Stable Non-fullerene-acceptor-Based Organic Solar Cells.

The recent advent of the new class of organic molecules, the so-called non-fullerene acceptors, has resulted in skyrocketing power conversion efficiencies of organic solar cells. However, rapid degradation occurs under illumination, particularly when photocatalytic metal oxide electron transport layers are used in these devices. We introduced vitamin C (ascorbic acid) into the organic solar cells as a photostabilizer and systematically studied its photostabilizing effect on inverted PBDB-T:IT-4F devices. The presence of vitamin C as an antioxidant layer between the ZnO electron transport layer and the photoactive layer strongly suppressed the photocatalytic effect of ZnO that induces NFA photodegradation. Upon 96 h of exposure to AM 1.5G 1 Sun irradiation, the reference devices lost 64% of their initial efficiency, while those containing vitamin C lost only 38%. The UV-visible absorption, impedance spectroscopy, and light-dependent voltage and current measurements reveal that vitamin C reduces the photobleaching of NFA molecules and suppresses the charge recombination. This simple approach using a low-cost, naturally occurring antioxidant, provides an efficient strategy for improving photostability of organic semiconductor-based devices.

Treatment Approaches for Swallowing Disorders in Children.

A swallowing disorder or dysphagia is defined as a disorder in the sequence of swallowing, during the oral or pharyngeal phase, which compromises the safety and/or efficiency of transit of the food bolus to the esophagus. The evaluation of neurodevelopment, nutrition, and preventive medicine actions are as important as the clinical evaluation of dysphagia, so they must be included and systematized in all pediatric evaluations; This evaluation can be divided into different parts: bedside swallowing evaluation, instrumental swallowing evaluation, and additional studies. The management of swallowing disorders requires a multidisciplinary team approach, depending on the child's age, cognitive and physical abilities, and the specific swallowing and feeding disorder, ensuring adequate and safe nutrition and improving the patient's quality of life.