Explainable artificial intelligence prediction-based model in laparoscopic liver surgery for segments 7 and 8: an international multicenter study.

BACKGROUND: Artificial intelligence (AI) is becoming more useful as a decision-making and outcomes predictor tool. We have developed AI models to predict surgical complexity and the postoperative course in laparoscopic liver surgery for segments 7 and 8. METHODS: We included patients with lesions located in segments 7 and 8 operated by minimally invasive liver surgery from an international multi-institutional database. We have employed AI models to predict surgical complexity and postoperative outcomes. Furthermore, we have applied SHapley Additive exPlanations (SHAP) to make the AI models interpretable. Finally, we analyzed the surgeries not converted to open versus those converted to open. RESULTS: Overall, 585 patients and 22 variables were included. Multi-layer Perceptron (MLP) showed the highest performance for predicting surgery complexity and Random Forest (RF) for predicting postoperative outcomes. SHAP detected that MLP and RF gave the highest relevance to the variables "resection type" and "largest tumor size" for predicting surgery complexity and postoperative outcomes. In addition, we explored between surgeries converted to open and non-converted, finding statistically significant differences in the variables "tumor location," "blood loss," "complications," and "operation time." CONCLUSION: We have observed how the application of SHAP allows us to understand the predictions of AI models in surgical complexity and the postoperative outcomes of laparoscopic liver surgery in segments 7 and 8.

Factors associated with poor adherence to medication in patients with diabetes and hypertension in Peru: findings from a pooled analysis of six years of population-based surveys.

OBJECTIVE: To evaluate the factors associated with poor medication adherence in patients with DM and HTN in Peru. STUDY DESIGN: A cross-sectional study. METHODS: We analyzed data from the Peruvian Demographic and Family Health Survey from 2014 to 2019. Adjusted prevalence ratios (aPR) and their respective 95% confidence intervals (CI) were estimated to determine the factors associated with poor medication adherence. RESULTS: We included 15,184 participants with a known diagnosis of DM and HTN. The frequency of poor medication adherence was 37.1%, with 36.7% among individuals with HTN and 29.2% among individuals with DM. Those belonging to age groups above 30 years (aPR: 0.77; 95% CI: 0.74-0.80, for the group ≥ 60 years) had a lower frequency of poor medication adherence. Meanwhile, being male (aPR: 1.03; 95% CI: 1.01-1.05), lacking health insurance (aPR: 1.08; 95% CI: 1.05-1.10), belonging to lower wealth quintiles (aPR: 1.12; 95% CI: 1.08-1.17, for the first quintile), and living in the mountain region (aPR: 1.09; 95% CI: 1.06-1.12) were associated with a higher frequency of poor medication adherence. These findings were consistent when stratifying by the type of disease. CONCLUSION: This study showed that poor medication adherence is common in patients with HTN and DM in Peru and is associated with sociodemographic factors, highlighting the importance of public health approaches to improve adherence.

Management of small subepithelial tumors by endoscopic banding without resection and single-incision needle-knife-assisted biopsy sampling: a prospective multicenter study.

BACKGROUND AND AIMS: Endoscopic band ligation (EBL) without resection combined with single-incision needle-knife (SINK) biopsy sampling may have a positive impact on small GI subepithelial tumor (SET) management, but the method needs to be tested. The aim was to evaluate the feasibility of this strategy in small-sized SETs. METHODS: This prospective multicenter observational cohort study in 7 centers included patients with SETs ≤15 mm (confirmed by EUS) between March 2017 and March 2020. The primary outcome was clinical success at 4 weeks, defined as complete SET disappearance on EUS. Secondary outcomes were long-term (1-year) clinical success, technical difficulty level, clinical impact, yield pathology, and safety. RESULTS: Of 273 patients screened, 122 (62.3% women; mean age, 60.9 ± 13.2 years) were included with SETs (mean size, 9 ± 2.8 mm; gastric location, 77%; superficial layer dependence, 63%). The primary endpoint was achieved in 73.6% of patients (95% confidence interval [CI], 64.8-81.2). At the 1-year follow-up, the success rate was 68.4% (95% CI, 59.1-76.8). A favorable clinical impact was observed in 97 cases (79.5%; 95% CI, 71.3-86.3). Pathology diagnosis was known in 70%. Potentially malignant lesions were present in 24.7%. The related adverse events rate was 4.1% (95% CI, 1.3-9.3; all mild: 2 bleeding, 2 abdominal pain). On multivariable analysis, the ≤10-mm SET group was associated with a greater success rate (1 year, 87%; relative risk, 5.07; 95% CI, 2.63-9.8) and clinical impact rate (92.7%; relative risk, 6.15; 95% CI, 2.72-13.93). CONCLUSIONS: EBL plus SINK biopsy sampling seems to be feasible and safe, and it may offer a favorable clinical impact in small-sized SETs. In particular, SETs ≤10 mm are the best candidates. (Clinical trial registration number: NCT03247231.).

Organ xenotransplantation acceptance in veterinary students: A multicentric opinion study in Spain.

BACKGROUND: The shortage of available transplant organs has made it necessary to search for alternatives, one of which is xenotransplantation. However, the use of animal organs could face rejection from society and the personnel involved in its implementation. OBJECTIVES: (a) to analyze the attitudes of Veterinary Degree students in six Spanish Universities towards xenotransplantation; and (b) to determine the factors that affect its acceptance. METHODS: Of the 2815 students surveyed in the degree program, 2683 valid surveys were obtained. Attitudes towards organ xenotransplantation were evaluated using a validated questionnaire of organ donation. RESULTS: If xenotransplantation was confirmed as a clinical reality, 93% (n = 2493) of those surveyed would accept a xenotransplanted organ, whilst 7% would not. If the results of xenotransplantation were worse than those obtained with human donors and it entailed more risk, 12% (n = 318) would be in favor. 56% (n = 1497) of the students would accept a xenotransplantation provisionally pending the arrival of a human organ. Attitudes towards xenotransplantation were affected by the academic year in which a student was studying, with more favorable attitudes among students in the last year (88% in first year vs. 95% in fifth year; p < .001). More favorable attitudes are also observed depending on the attitude they have towards organ transplantation, with those students being more in favor of donating their organs when they die (94% vs. 88%; p < .001). CONCLUSION: Veterinary students would have a very favorable attitude toward xenotransplantation if these animal organs functioned as well as human organs. Therefore, these students could play an important role in the future promotion of this technique.

New challenges in cholangiocarcinoma candidates for elective surgery: harnessing the microbiome dysbiosis.

BACKGROUND: The gut microbiota, composed by several species of microorganisms, works to preserve the liver-gut homeostasis and plays an important role during digestion and absorption of nutrients, and in the immune response of the host. In this review, we analyzed the influence of microbiota in patients with cholangiocarcinoma (CCA) who were candidates for elective surgery. METHODS: A literature review was conducted to identify papers that provided empiric evidence to support that the altered microbiota composition (dysbiosis) is related also to CCA development. RESULTS: Bacteria such as Helicobacter pylori, Helicobacter hepaticus, and Opisthorchis viverrini increase the risk of CCA. The most abundant genera were Enterococcus, Streptococcus, Bacteroides, Klebsiella, and Pyramidobacter in CCA's biliary microbiota. Additionally, levels of Bacteroides, Geobacillus, Meiothermus, and Anoxybacillus genera were significantly higher. An enrichment of Bifidobacteriaceae, Enterobacteriaceae, and Enterococcaceae families has also been observed in CCA tumor tissue. Microbiota is related to postoperative outcomes in abdominal surgery. The combination of caloric restriction diets in liver cancer or CCA increases the effect of the chemotherapy treatment. CONCLUSION: The correct use of nutrition for microbiota modulation according to each patient's needs could be a therapeutic tool in combination with elective surgery and chemotherapy to diminish side effects and improve prognosis. Further investigations are needed to fully understand the mechanisms by which they are related.

Testis formation in XX individuals resulting from novel pathogenic variants in Wilms' tumor 1 (WT1) gene.

Sex determination in mammals is governed by antagonistic interactions of two genetic pathways, imbalance in which may lead to disorders/differences of sex development (DSD) in human. Among 46,XX individuals with testicular DSD (TDSD) or ovotesticular DSD (OTDSD), testicular tissue is present in the gonad. Although the testis-determining gene SRY is present in many cases, the etiology is unknown in most SRY-negative patients. We performed exome sequencing on 78 individuals with 46,XX TDSD/OTDSD of unknown genetic etiology and identified seven (8.97%) with heterozygous variants affecting the fourth zinc finger (ZF4) of Wilms' tumor 1 (WT1) (p.Ser478Thrfs*17, p.Pro481Leufs*15, p.Lys491Glu, p.Arg495Gln [x3], p.Arg495Gly). The variants were de novo in six families (P = 4.4 × 10-6), and the incidence of WT1 variants in 46,XX DSD is enriched compared to control populations (P < 1.8 × 10-4). The introduction of ZF4 mutants into a human granulosa cell line resulted in up-regulation of endogenous Sertoli cell transcripts and Wt1Arg495Gly/Arg495Gly XX mice display masculinization of the fetal gonads. The phenotype could be explained by the ability of the mutated proteins to physically interact with and sequester a key pro-ovary factor ß-CATENIN, which may lead to up-regulation of testis-specific pathway. Our data show that unlike previous association of WT1 and 46,XY DSD, ZF4 variants of WT1 are a relatively common cause of 46,XX TDSD/OTDSD. This expands the spectrum of phenotypes associated with WT1 variants and shows that the WT1 protein affecting ZF4 can function as a protestis factor in an XX chromosomal context.

Teenagers, Audio-Visual Prosumers and Audience Generators in the Field of Organ Donation.

The creation of audio-visual content and the increase in the use of social networks by society have provided new opportunities for promoting health and the benefits of organ donation. This study analyzes the influence of audiovisual content produced by adolescents in the context of an educational program related to the promotion of organ donation with diffusion through social media. The program was implemented in the fourth year (mainly 15 and 16 year olds) in ten high schools in Spain. In the first phase, students learn about donation and create audio-visual messages about its benefits for society; in the second phase, they share this content on social networks. The influence of the content was measured using YouTube Analytics. In addition, a questionnaire was administered after the program to measure the way in which they shared the content on social networks. A total of 391 students participated in program, submitting 63 short films that obtained 104,912 views. The short films focused on appealing to society about the need for organs and the benefits of the organ donation and transplantation process. The social network that was used most frequently to share the content was WhatsApp (81.8%). Educating teenagers and turning them into prescribers of the health benefits of the organ donation and transplantation process through the use of social networks could be a good tool that can be exported to other fields of health.

A quantile panel examination of the moderation effects of guardianship on residential burglary.

Do informal and formal mechanisms of guardianship work together to reduce residential burglary? In this article we argue that informal guardianship moderates the relationship between formal mechanisms of guardianship and residential burglary. Formal guardianship requires some level of social cohesion and trust to be effective against residential burglary. We test this argument with the use of robust panel quantile methods controlling for time effects, spatial effects, and alternative explanations. Using Mexico City neighborhood crime and census data, we show evidence of a moderating weakening effect of informal guardianship on the previous relationship, particularly in deprived neighborhoods and only in the upper quantiles of the residential burglary distribution. In addition, the moderation effects seem to have weakened over time. In sum, the combination of guardianship mechanisms seems to have been more effective in high burglary risk deprived neighborhoods, although their combination seems to have become less relevant.

Abdominal normothermic regional perfusion in controlled donation after circulatory determination of death liver transplantation: Outcomes and risk factors for graft loss.

Postmortem normothermic regional perfusion (NRP) is a rising preservation strategy in controlled donation after circulatory determination of death (cDCD). Herein, we present results for cDCD liver transplants performed in Spain 2012-2019, with outcomes evaluated through December 31, 2020. Results were analyzed retrospectively and according to recovery technique (abdominal NRP [A-NRP] or standard rapid recovery [SRR]). During the study period, 545 cDCD liver transplants were performed with A-NRP and 258 with SRR. Median donor age was 59 years (interquartile range 49-67 years). Adjusted risk estimates were improved with A-NRP for overall biliary complications (OR 0.300, 95% CI 0.197-0.459, p < .001), ischemic type biliary lesions (OR 0.112, 95% CI 0.042-0.299, p < .001), graft loss (HR 0.371, 95% CI 0.267-0.516, p < .001), and patient death (HR 0.540, 95% CI 0.373-0.781, p = .001). Cold ischemia time (HR 1.004, 95% CI 1.001-1.007, p = .021) and re-transplantation indication (HR 9.552, 95% CI 3.519-25.930, p < .001) were significant independent predictors for graft loss among cDCD livers with A-NRP. While use of A-NRP helps overcome traditional limitations in cDCD liver transplantation, opportunity for improvement remains for cases with prolonged cold ischemia and/or technically complex recipients, indicating a potential role for complimentary ex situ perfusion preservation techniques.

Liver Transplantation as a New Standard of Care in Patients With Perihilar Cholangiocarcinoma? Results From an International Benchmark Study.

OBJECTIVE: To define benchmark values for liver transplantation (LT) in patients with perihilar cholangiocarcinoma (PHC) enabling unbiased comparisons. BACKGROUND: Transplantation for PHC is used with reluctance in many centers and even contraindicated in several countries. Although benchmark values for LT are available, there is a lack of specific data on LT performed for PHC. METHODS: PHC patients considered for LT after Mayo-like protocol were analyzed in 17 reference centers in 2 continents over the recent 5-year period (2014-2018). The minimum follow-up was 1 year. Benchmark patients were defined as operated at high-volume centers (≥50 overall LT/year) after neoadjuvant chemoradiotherapy, with a tumor diameter <3 cm, negative lymph nodes, and with the absence of relevant comorbidities. Benchmark cutoff values were derived from the 75th to 25th percentiles of the median values of all benchmark centers. RESULTS: One hundred thirty-four consecutive patients underwent LT after completion of the neoadjuvant treatment. Of those, 89.6% qualified as benchmark cases. Benchmark cutoffs were 90-day mortality ≤5.2%; comprehensive complication index at 1 year of ≤33.7; grade ≥3 complication rates ≤66.7%. These values were better than benchmark values for other indications of LT. Five-year disease-free survival was largely superior compared with a matched group of nodal negative patients undergoing curative liver resection (n=106) (62% vs 32%, P <0.001). CONCLUSION: This multicenter benchmark study demonstrates that LT offers excellent outcomes with superior oncological results in early stage PHC patients, even in candidates for surgery. This provocative observation should lead to a change in available therapeutic algorithms for PHC.

International Population Study in Spain, Cuba, and the United States of Attitudes Toward Organ Donation Among the Cuban Population.

Cuban immigrants constitute an important group in both the United States and Spain, with different behaviors toward organ donation having been described among the different Latin American nationalities. We analyzed the attitude toward organ donation among the Cuban populations in Cuba, Spain, and Florida. The study population was Cuban immigrants over 15 years of age residing in Cuba, Spain, and Florida, with samples randomly stratified by age and sex. A validated questionnaire on psychosocial aspects of organ donation (PCID-DTO Rios) was used. Census was used as the sampling base in all 3 countries; however, additionally, in Spain and the United States (Florida), we sought the support of immigration support associations to determine the Cuban population without legal documentation. The questionnaire was completed anonymously and self-administered. The completion rate of the study was 74% (4123/5574) among 424 surveyed in Spain, 1224 in Florida, and 2475 in Cuba. The attitude in favor of donating their own organs upon death was 60.6% of those surveyed in Spain, 37.6% in Florida, and 68.9% in Cuba, or 58% of the global sample. Multivariate analysis showed that country of residence was an independent factor associated with attitude toward organ donation (odds ratio, 1.929). Other factors associated with attitude were sex, educational level, performance of prosocial activities, knowledge of the brain death concept, religion, the couple's opinion toward donation, fear of mutilation after donation, and attitude toward manipulation of the body after death. The attitude toward organ donation among Cubans in their country of origin and immigrants in Spain was similar, being significantly different from those who emigrate to Florida, where the attitude is much less favorable.

The Willingness to Donate Organs in Medical Students From an International Perspective: A Meta-Analysis.

Attitude toward organ donation mobilizes donation behavior and makes transplant surgery possible. As future health professionals, medical students will be a relevant generating opinion group and will have an important role in the organ requesting process. The goals of this meta-analysis were to obtain polled rates of medical students who are in favor, against, or indecisive toward cadaveric organ donation in the studies conducted around the world, and to explore sociocultural variables influencing the willingness to donate. Electronic search and revision of references from previous literature allowed us to locate 57 studies fulfilling the inclusion criteria. Data extraction and risk of bias assessment were performed by two independent investigators. Pooled estimations were computed assuming a random-effects model. Despite the fact that willingness to donate was elevated in medical students, estimated rates in studies from different geographical areas and sociocultural backgrounds exhibited significant differences. The age and the grade of the students also influenced the rate of students in favor. Donation campaigns should take into account cultural factors, especially in countries where certain beliefs and values could hamper organ donation. Also, knowledge and skills related to organ donation and transplant should be acquired early in the medical curriculum when a negative attitude is less resistant to change.

Emerging Role of NLRP3 Inflammasome and Pyroptosis in Liver Transplantation.

The nucleotide-binding domain leucine-rich repeat-receptor, pyrin domain-containing-3 (NLRP3) inflammasome contributes to the inflammatory response by activating caspase-1, which in turn participates in the maturation of interleukin (IL)-1ß and IL-18, which are mainly secreted via pyroptosis. Pyroptosis is a lytic type of cell death that is controlled by caspase-1 processing gasdermin D. The amino-terminal fragment of gasdermin D inserts into the plasma membrane, creating stable pores and enabling the release of several proinflammatory factors. The activation of NLRP3 inflammasome and pyroptosis has been involved in the progression of liver fibrosis and its end-stage cirrhosis, which is among the main etiologies for liver transplantation (LT). Moreover, the NLRP3 inflammasome is involved in ischemia-reperfusion injury and early inflammation and rejection after LT. In this review, we summarize the recent literature addressing the role of the NLRP3 inflammasome and pyroptosis in all stages involved in LT and argue the potential targeting of this pathway as a future therapeutic strategy to improve LT outcomes. Likewise, we also discuss the impact of graft quality influenced by donation after circulatory death and the expected role of machine perfusion technology to modify the injury response related to inflammasome activation.

Chronic wound healing by controlled release of chitosan hydrogels loaded with silver nanoparticles and calendula extract.

As the skin is the main protective organ of the body, it is exposed to wounds or injuries which carry out a healing process during a period of approximately 15 days depending on the severity of the injury. In the present research, the development of chitosan-based hydrogels loaded with silver nanoparticles and calendula extract (Ch-AgNPs-Ce) was proposed. This can be used to fulfill the hemostatic, anti-infective, antibacterial, healing and anti-inflammatory functions through controlled release of the nanoparticles and calendula extract in substitution of commonly used drugs. The physical properties of the silver nanoparticles were analyzed by UV-visible spectroscopy, scanning and transmission electron microscopy, showing a size between 50 and 100 nm. The antibacterial properties were evaluated by the agar well diffusion method. Antimicrobial testing of the hydrogels showed that the inclusion of silver nanoparticles provides concentration-dependent antibacterial behavior against E. coli and S. aureus. The healing properties of the system were tested in two diabetic patients to whom said hydrogels were placed, obtaining a positive curative result after a few weeks. Therefore, it can be concluded that Ch-AgNPs-Ce hydrogels can achieve healing in chronic or exposed wounds after a period of time which can be used in alternative treatments in patients with poor healing capacity.

Epidemiological pattern, incidence, and outcomes of COVID-19 in liver transplant patients.

BACKGROUND & AIMS: The incidence and outcomes of coronavirus disease 2019 (COVID-19) in immunocompromised patients are a matter of debate. METHODS: We performed a prospective nationwide study including a consecutive cohort of liver transplant patients with COVID-19 recruited during the Spanish outbreak from 28 February to 7 April, 2020. The primary outcome was severe COVID-19, defined as the need for mechanical ventilation, intensive care, and/or death. Age- and gender-standardised incidence and mortality ratios (SIR and SMR) were calculated using data from the Ministry of Health and the Spanish liver transplant registry. Independent predictors of severe COVID-19 among hospitalised patients were analysed using multivariate Cox regression. RESULTS: A total of 111 liver transplant patients were diagnosed with COVID-19 (SIR = 191.2 [95% CI 190.3-192.2]). The epidemiological curve and geographic distribution overlapped widely between the liver transplant and general populations. After a median follow-up of 23 days, 96 patients (86.5%) were admitted to hospital and 22 patients (19.8%) required respiratory support. A total of 12 patients were admitted to the ICU (10.8%). The mortality rate was 18%, which was lower than in the matched general population (SMR = 95.5 [95% CI 94.2-96.8]). Overall, 35 patients (31.5%) met criteria of severe COVID-19. Baseline immunosuppression containing mycophenolate was an independent predictor of severe COVID-19 (relative risk = 3.94; 95% CI 1.59-9.74; p = 0.003), particularly at doses higher than 1,000 mg/day (p = 0.003). This deleterious effect was not observed with calcineurin inhibitors or everolimus and complete immunosuppression withdrawal showed no benefit. CONCLUSIONS: Being chronically immunosuppressed, liver transplant patients have an increased risk of acquiring COVID-19 but their mortality rates are lower than the matched general population. Upon hospital admission, mycophenolate dose reduction or withdrawal could help in preventing severe COVID-19. However, complete immunosuppression withdrawal should be discouraged. LAY SUMMARY: In liver transplant patients, chronic immunosuppression increases the risk of acquiring COVID-19 but it could reduce disease severity. Complete immunosuppression withdrawal may not be justified. However, mycophenolate withdrawal or temporary conversion to calcineurin inhibitors or everolimus until disease resolution could be beneficial in hospitalised patients.

Mid-term follow-up of balloon pulmonary angioplasty for inoperable chronic thromboembolic pulmonary hypertension: An experience in Latin America.

OBJECTIVES: To describe the characteristics of patients who undergo balloon pulmonary angioplasty (BPA) for inoperable chronic thromboembolic pulmonary hypertension (CTEPH) and report the mid-term outcomes. BACKGROUND: BPA has been recently introduced in Latin America. Mid-term results have not been published. METHODS: Prospective Chilean Registry of inoperable CTEPH patients who underwent BPA. Clinical variables were analyzed at baseline, after each procedure and at follow-up. Hemodynamic variables were recorded before and after the last BPA. RESULTS: Between August 2016 and September 2019, 22 patients (17 women), 59 ± 12.7 years, underwent 81 BPA and were followed for as long as 33.1 months (mean 17.3 ± 7.5). Mean pulmonary artery pressure decreased by 17.4% (51.1 ± 12 vs. 42.2 ± 13 mmHg, p = .001), pulmonary vascular resistance by 23.9% (766.7 ± 351 vs. 583 ± 346 dynes/s/cm-5 , p = .001), cardiac index increased by 8% (2.3 ± 0.54 vs. 2.5 ± 0.54 L/min/m2 , p = .012), N-terminal pro-B-type natriuretic peptide decreased by 73.8% (1,685 ± 1,045 vs. 441.8 ± 276 pg/dl, p = .006), and 6-min walk distance improved by 135 m (316.7 ± 94 vs. 451.1 ± 113 m, p = .001). One patient (4.5%) developed lung reperfusion injury and four patients (18.2%) had minor bleeding (hemoptysis), after the procedure. There was no mortality associated with BPA. CONCLUSIONS: Our results confirm that BPA for inoperable CTEPH is a relatively safe procedure that improves clinical and hemodynamic parameters in the mid-term. This therapy should be considered as an alternative, mainly in places where access to PAH therapy or surgery is restricted.

SARS-CoV-2 identified by transmission electron microscopy in lymphoproliferative and ischaemic intestinal lesions of COVID-19 patients with acute abdominal pain: two case reports.

BACKGROUND: SARS-CoV-2 may produce intestinal symptoms that are generally mild, with a small percentage of patients developing more severe symptoms. The involvement of SARS-CoV-2 in the physiopathology of bowel damage is poorly known. Transmission electron microscopy (TEM) is a useful tool that provides an understanding of SARS-CoV-2 invasiveness, replication and dissemination in body cells but information outside the respiratory tract is very limited. We report two cases of severe intestinal complications (intestinal lymphoma and ischaemic colitis) in which the presence of SARS-CoV-2 in intestinal tissue was confirmed by TEM. These are the first two cases reported in the literature of persistence of SARS-CoV-2 demonstrated by TEM in intestinal tissue after COVID 19 recovery and SARS-CoV-2 nasopharyngeal clearance. CASE PRESENTATION: During the first pandemic peak (1st March-30th April 2020) 932 patients were admitted in Hospital Universitari Mútua Terrassa due to COVID-19, 41 (4.4%) required cross-sectional imaging techniques to assess severe abdominal pain and six of them (0.64%) required surgical resection. SARS-CoV-2 in bowel tissue was demonstrated by TEM in two of these patients. The first case presented as an ileocaecal inflammatory mass which turned to be a B-cell lymphoma. Viral particles were found in the cytoplasm of endothelial cells of damaged mucosa. In situ hybridization was negative in tumour cells, thus ruling out an oncogenic role for the virus. SARS-CoV-2 remained in intestinal tissue 6 months after nasopharyngeal clearance, suggesting latent infection. The second patient had a severe ischaemic colitis with perforation and SARS-CoV-2 was also identified in endothelial cells. CONCLUSIONS: Severe intestinal complications associated with COVID-19 are uncommon. SARS-CoV-2 was identified by TEM in two cases, suggesting a causal role in bowel damage.

Usefulness of an organ donation opinion survey as a tool to promote organ donation among the adolescent population.

Opinion surveys on health issues are considered health promotion tools. However, no studies have confirmed this in deceased organ donation for transplantation. This study aimed to analyse the impact of completing an opinion questionnaire about deceased organ donation on the attitude towards organ donation among the adolescent population. This longitudinal study with repeated measurements of attitude towards deceased organ donation was conducted with an adolescent population. The measurement instrument was a validated questionnaire of the attitude towards organ donation (PCID-DTO-Ríos). The study process involved the application of the questionnaire at an initial time, 1 month later, and 6 months later. A total of 1374 adolescents participated in this study. The favourable attitude towards donation was 43.1%, which fell to 41.4% at 1 month (P = 0.145), and to 39.7% at 6 months (P = 0.019). Changes in the attitude were observed in all groups, both 1 and 6 months after the questionnaire was completed. There was no objective relationship between the adolescent's socio-family environment and the effect of completing the questionnaire on their attitude towards deceased organ donation. In conclusion, the opinion questionnaire was not useful for promoting organ donation and did not have a positive effect on adolescents' attitudes towards organ donation in the medium or long term.

Efficiency of Machine Learning Algorithms for the Determination of Macrovesicular Steatosis in Frozen Sections Stained with Sudan to Evaluate the Quality of the Graft in Liver Transplantation.

Liver transplantation is the only curative treatment option in patients diagnosed with end-stage liver disease. The low availability of organs demands an accurate selection procedure based on histological analysis, in order to evaluate the allograft. This assessment, traditionally carried out by a pathologist, is not exempt from subjectivity. In this sense, new tools based on machine learning and artificial vision are continuously being developed for the analysis of medical images of different typologies. Accordingly, in this work, we develop a computer vision-based application for the fast and automatic objective quantification of macrovesicular steatosis in histopathological liver section slides stained with Sudan stain. For this purpose, digital microscopy images were used to obtain thousands of feature vectors based on the RGB and CIE L*a*b* pixel values. These vectors, under a supervised process, were labelled as fat vacuole or non-fat vacuole, and a set of classifiers based on different algorithms were trained, accordingly. The results obtained showed an overall high accuracy for all classifiers (>0.99) with a sensitivity between 0.844 and 1, together with a specificity >0.99. In relation to their speed when classifying images, KNN and Naïve Bayes were substantially faster than other classification algorithms. Sudan stain is a convenient technique for evaluating ME in pre-transplant liver biopsies, providing reliable contrast and facilitating fast and accurate quantification through the machine learning algorithms tested.

[Percutaneous implantation of an aortic prosthetic valve on a degenerated mitral bioprosthesis. Report of one case]. / Implantación percutánea transeptal de válvula protésica aórtica sobre bioprótesis mitral degenerada.

Reintervention of a mitral degenerated bioprosthesis has a high surgical risk, especially in elderly patients with multiple comorbidities. We report a 74 years old female with two previous cardiac surgical procedures and a new structural mitral bioprosthesis deterioration with severe mitral regurgitation. Considering her high-surgical risk, a fully percutaneous treatment was performed with a balloon-expandable aortic valve in mitral position (valve-in-valve) through a transseptal approach with a favorable outcome. This technique is an attractive and effective option with a relatively low rate of complications that could solve this challenging and complex disease.