La enseñanza de la probabilidad y la geometría

Presentamos relaciones entre la enseñanza de la probabilidad y la geometría, a través del uso de un marco geométrico para calcular probabilidades teóricas en casos discretos y del cálculo de probabilidades geométricas. Mostramos cómo aparecen diferentes miradas sobre la noción de probabilidad según diferentes contextos y usos, proponiendo problemas para cada caso, y sugerimos algunas ideas para desarrollar propuestas de aula para los diferentes niveles de enseñanza

610 Fontan associated kidney and liver disease: can we predict organ involvement with echocardiographic assessment of systolic function and atrioventricular valve insufficiency?

Abstract Aims Fontan operation represents the surgical palliative option for congenital heart disease with single ventricle physiology. With the improvement of surgical and percutaneous technique, we are facing a growing population of patients with an unique pathophysiology and potential complications. Methods and results Patients that underwent Fontan palliation in our centre between 1993 and 2016 were included in this prospective study. We excluded patients with major congenital renal anomalies, those that underwent cardiac transplantation, and redo-Fontan patients. All the subjects underwent clinical evaluation, laboratory exams with complete renal and hepatic function, transient hepatic elastography, and complete cardiac evaluation. We used Schwartz equation for estimating glomerular filtration rate in patients younger than 18 years, and CDK-EPI equation for adult patients. We enrolled 35 patients, 46% female (N = 16), and 54% male (N = 19). Medium age was 17 years old, median age 15 years old (range: 10–31 years old). Medium time from Fontan completion was 160 months (range: 57–340 months). Regarding to cardiac anatomy, 10 patients had functional single left ventricle (FSLV, 28.5%) and 21 a functional single right ventricle (FSRV, 60%); 4 patients had undetermined single ventricle (11.5%). Total cavo-pulmonary connection (TCPC) with intracardiac lateral tunnel was performed in 7 patients (20%, N = 7), whereas 28 patients had TCPC with external conduit (80%). Data from echocardiographic evaluation showed a medium EF established with Simpson's method of 60% in patients with FSLV; patients with a FSRV or undetermined single ventricle had a medium FAC of 41.1%, with 15.1% having a reduced FAC < 35%. No FSLV patients had an EF < 50%. When using creatinine-based formula, data about renal function in our population showed a stage 2 chronic kidney disease (eGFR: 60–89 ml/min 1.73 mq) in 11% of total population (N = 4), that became 26% when using cystatin C-based equation (N = 9), with one patient showing a moderate reduced loss of kidney function (eGFR: 40–59 ml/min 1.73 mq). Urinalysis showed 29% (N = 10) of patients having microalbuminuria (microalbumin/creatinine ratio between 30 and 300 mg/g). Statistical analysis demonstrated a negative correlation between systolic function (TAPSE for FSRV) and cystatin C blood levels (Pearson's R −0.428, P = 0.053), and between systolic function (FAC and Simpson) and microalbuminuria (Pearson's R −0.414 with P = 0.049 and Pearson's R −0.754 with P = 0.019, respectively). Transient elastography reported 10 patients (29.4%) with abnormal hepatic stiffness for Fontan patients. That condition appeared to be more frequent in patients with higher grade of AV valve insufficiency (P < 0.05). Conclusions Our population showed an higher prevalence of FSRV Fontan patients, with an expected lower systolic function compared with FSLV. 2D evaluation of systolic function showed a linear inverse correlation with renal function, suggesting that Fontan patients need a closer renal monitoring. Hepatic stiffness, which is a warning sign of potential hepatic cirrhosis need to be monitored in all Fontan patients, especially those with a worse AV valve insufficiency

Alterazioni neurovascolari nell'epatite cronica C: uno studio caso-controllo

Summary Introduction Hepatitis C is a major health problem: approximately 170 million people are infected with the hepatitis C virus worldwide. It is unclear whether chronic hepatitis C affects atherosclerosis and whether it can cause endothelial and/or autonomic nervous system (ANS) dysfunction. Materials and methods From April 2008 through April 2009, we studied 76 patients with biopsy-confirmed chronic hepatitis C and no evidence of cirrhosis, ascites, portal hypertension, encephalopathy, or hepatocellular carcinoma. The age-, sex-, BMI- and cardiovascular risk factor-matched control group comprised 76 healthy, HCV-negative individuals with no evidence of liver, autoimmune, or immunoproliferative diseases and no history of cardiovascular events. Twenty five of the hepatitis C patients were treatment-naive; the other 51 had been treated with interferon (but only 25 had persistent virological responses). Color Doppler sonography was used to measure the intima-media-thickness (IMT) of the common and internal carotid arteries. Endothelial function was assessed in the brachial artery with the flow-mediated-dilatation (FMD) test. The ANS was assessed with the tilt, laying to standing, Valsalva, hand grip, deep breath, and stroop tests. Results The case group (mean age 52 ± 13 years) had a significantly higher internal carotid IMT (0.86 ± 0.3 vs 0.67 ± 0.1 mm for controls; p = 0.002). Chronic hepatitis C was also associated with an odds ratio for carotid plaque formation (reflected by an IMT ≥ 1.3 mm) of 2.15. Cases also had significantly reduced FMD in the brachial artery (0.46 ± 0.9 vs 0.76 ± 0.7 for controls; p = 0.005) and significantly altered sympathetic and parasympathetic function (p = 0.001 vs controls in the Valsalva, hand grip, deep breath, and stroop tests). Within the case group, all alterations were more severe in patients with significant viremia. Discussion Our findings suggest that chronic hepatitis C may be a nonclassic cardiovascular risk factor since it seems to influence the onset of pre-atherosclerotic lesions and to promote atherosclerotic plaque formation in patients with pre-existing increases in carotid IMT. It also seems to cause dysfunctions of the vascular endothelium and ANS. Conclusions Chronic hepatitis C may increase cardiovascular risk and promote ANS dysfunctions, particularly when patients have experienced treatment failure and have persistent viremia. These patients may require cardiovascular and neurologic follow-up

Advanced liver disease outcomes after hepatitis C eradication by human immunodeficiency virus infection in PITER cohort

Liver disease progression after Hepatitis C Virus (HCV) eradication following direct-acting antiviral (DAA) treatment in the real-life setting according to Human Immunodeficiency Virus (HIV) coinfection was evaluated

Aportes para la enseñanza de la Matemática : Segundo Estudio Regional Comparativo y Explicativo

El objetivo es proporcionar a los docentes orientaciones que los ayuden a mejorar sus prácticas pedagógicas en las áreas exploradas por el SERCE, para lograr que los estudiantes construyan los aprendizajes necesarios para participar plenamente en la sociedad. Esta colección es coherente con una concepción de evaluación de la calidad de la educación que no se limita a hacer diagnósticos de situación, sino que proporciona, además, elementos para favorecer las prácticas educativas y avanzar hacia una educación de calidad sin exclusiones

Natural history of hepatitis C.

Abstract Ten years after the discovery of the hepatitis C virus (HCV) and its association with NANB hepatitis as a major cause of chronic liver disease worldwide, our knowledge of the natural history of hepatitis C is still limited. The asymptomatic course of the disease in most patients, its slow and silent progression and heterogeneous outcome and the widespread use of interferon therapy during the past decade explain why many questions are still unsolved. The changing epidemiological pattern of HCV and the significant contribution of several cofactors to the severity of liver disease also complicate the development of a general model describing the natural history of hepatitis C. Available data indicate that HCV infection may resolve without any clinical signs of liver disease in individuals exposed to low dose inoculum and that these cases may develop T cell immunity even in the absence of anti-HCV seroconversion. Rates of complete biochemical and virological resolution of acute hepatitis C range between 10 and 50%, and are probably affected by the route of infection, size and type of inoculum and acute phase clinical features. Chronic HCV infection may develop with or without ALT abnormalities and with or without chronic inflammation and increasing fibrosis in the liver. Studies conducted in patients who acquired hepatitis C by blood transfusion 15-25 years ago indicate that 20-30% of them have now progressed to cirrhosis, including 5-10% with end stage liver disease and 4-8% who died of liver-related causes. Similar studies conducted in patients infected by other routes have shown a more benign course of hepatitis C, with little evidence of cirrhosis and no liver-related mortality during the first two decades. Outcomes after longer follow-up need to be assessed. In patients presenting with chronic hepatitis C, fibrosis progression is extremely variable over time and can be partially predicted by the age at infection, disease duration, liver histologic activity and stage of fibrosis and by the ALT profile. However, it is often difficult to predict clinical outcomes in individual cases. In patients who have developed cirrhosis, the 5-year risk of decompensation is between 15 and 20% and that of hepatocellular carcinoma around 10%. Several variables have been shown to influence the natural course of shown C, the most significant being age at infection, alcohol consumption and coinfection with HBV and HIV Studies are being performed to assess the role of host genetics. Viral factors, such as the HCV type and load, seem to have inconsistent or marginal effects