Diagnóstico participativo: experiencias con grupos de campesinos en el norte de Antioquia.

El ICA en el Convenio Colombo-Holandés, desarrolló una investigación sobre el diagnóstico participativo, instrumento que busca una mayor participación de los pequeños productores en la programación y ejecución de actividades de Transferencia de Tecnología. Es necesario considerar que dentro de la concepción del proceso de enseñanza-aprendizaje, la comunicación debe operar en forma horizontal donde tanto el agente de cambio como el usuario, partiendo de una realidad objeto del conocimiento, y de los problemas de la comunidad a través de un diálogo, se dén soluciones a los mismos. El objetivo es experimentar metodologías a través de las cuales se logre una mayor participación de las comunidades rurales en la determinación y priorización de sus problemas tecnológicos. Se seleccionaron las siguientes comunidades: San Isidro en Santa Rosa de Osos, Zancudito en Belmira, El Olivo-Montañitas en Angosturas y Maldonado en el mismo municipio. En estas comunidades se ensayaron 4 tratamientos de diagnóstico participativo: restringido con diapositivas, participativo amplio con diapositivas, participativo restringido con diapositivas, participativo sin diapositivas modificado. Se concluye que el diagnóstico participativo con diapositivas y sin diapositivas, es un instrumento aplicable y funcional para lograr una mayor participación de las comunidades rurales en detectar y priorizar sus problemas tecnológicos. En las condiciones en que se realizó el trabajo, las diapositivas generan discusión más amplia y profunda que un diagnóstico sin ella

Control químico de enfermedades foliares para la producción de semilla de repollo (Brassica olerácea var. Capitata) en el oriente antioqueño.

En el Centro de Investigación La Selva del ICA, situado en Rionegro (Antioquia), a una altura de 2.100 m.s.n.m., con una temperatura media anual de 17 grados centígrados perteneciente a la formación ecológica bosque húmedo montano bajo (bh-mb), se realizó una investigación para evaluar la producción de semilla de repollo de la variedad Penn State Ballhead, mediante el control químico de enfermedades foliares. La producción máxima de semilla (198 kg/ha) se obtuvo en las plantas asperjadas con Iprodione 0.15 g/l, seguida por el control con una mezcla de Clorotalonil 1.25 cc/l y Benomyl 0.25 g/l (139 kg/ha). La semilla producida exhibió igual capacidad de germinación y vigor que el material comercial importado, el cual alcanzó un mayor peso para 100 unidades que el obtenido con la semilla producida en el estudio, excepto la proveniente de las plantas que se asperjaroncon una mezcla de Clorotalinil más Benomyl. La enfermedad conocida como mancha gris, causada por el hongo Altemaria brassicae, y otras enfermedades de la raíz se constituyeron en el factor limitante principal para la producción de semillaInstituto Colombiano Agropecuario - IC

Human CD141+ (BDCA-3)+ dendritic cells (DCs) represent a unique myeloid DC subset that cross-presents necrotic cell antigens

The characterization of human dendritic cell (DC) subsets is essential for the design of new vaccines. We report the first detailed functional analysis of the human CD141+ DC subset. CD141+ DCs are found in human lymph nodes, bone marrow, tonsil, and blood, and the latter proved to be the best source of highly purified cells for functional analysis. They are characterized by high expression of toll-like receptor 3, production of IL-12p70 and IFN-β, and superior capacity to induce T helper 1 cell responses, when compared with the more commonly studied CD1c+ DC subset. Polyinosine-polycytidylic acid (poly I:C)–activated CD141+ DCs have a superior capacity to cross-present soluble protein antigen (Ag) to CD8+ cytotoxic T lymphocytes than poly I:C–activated CD1c+ DCs. Importantly, CD141+ DCs, but not CD1c+ DCs, were endowed with the capacity to cross-present viral Ag after their uptake of necrotic virus-infected cells. These findings establish the CD141+ DC subset as an important functionally distinct human DC subtype with characteristics similar to those of the mouse CD8α+ DC subset. The data demonstrate a role for CD141+ DCs in the induction of cytotoxic T lymphocyte responses and suggest that they may be the most relevant targets for vaccination against cancers, viruses, and other pathogens

Diagnosis of biliary tract and ampullary carcinomas

Diagnostic methods for biliary tract carcinoma and the efficacy of these methods are discussed. Neither definite methods for early diagnosis nor specific markers are available in this disease. When this disease is suspected on the basis of clinical symptoms and risk factors, hemato-biochemical examination and abdominal ultrasonography are performed and, where appropriate, enhanced computed tomography (CT) and/or magnetic resonance cholangiopancreatography (MRCP) is carried out. Diagnoses of extrahepatic bile duct cancer and ampullary carcinoma are often made based on the presence of obstructive jaundice. Although rare, abdominal pain and pyrexia, as well as abnormal findings of the hepatobiliary system detected by hemato-biochemical examination, serve as a clue to making a diagnosis of these diseases. On the other hand, the early diagnosis of gallbladder cancer is scarcely possible on the basis of clinical symptoms, so when this cancer is found with the onset of abdominal pain and jaundice, it is already advanced at the time of detection, thus making a cure difficult. When gallbladder cancer is suspected, enhanced CT is carried out. Multidetector computed tomography (MDCT), in particular — one of the methods of enhanced CT — is useful for decision of surgical criteria, because MDCT shows findings such as localization and extension of the tumor, and the presence or absence of remote metastasis. Procedures such as magnetic resonance imaging, endoscopic ultrasonography, bile duct biopsy, and cholangioscopy should be carried out taking into account indications for these procedures in individual patients. However, direct biliary tract imaging is necessary for making a precise diagnosis of the horizontal extension of bile duct cancer

Flowcharts for the management of biliary tract and ampullary carcinomas

No strategies for the diagnosis and treatment of biliary tract carcinoma have been clearly described. We developed flowcharts for the diagnosis and treatment of biliary tract carcinoma on the basis of the best clinical evidence. Risk factors for bile duct carcinoma are a dilated type of pancreaticobiliary maljunction (PBM) and primary sclerosing cholangitis. A nondilated type of PBM is a risk factor for gallbladder carcinoma. Symptoms that may indicate biliary tract carcinoma are jaundice and pain in the upper right area of the abdomen. The first step of diagnosis is to carry out blood biochemistry tests and ultrasonography (US) of the abdomen. The second step of diagnosis is to find the local extension of the carcinoma by means of computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), percutaneous transhepatic cholangiography (PTC), and endoscopic retrograde cholangiopancreatography (ERCP). Because resection is the only way to completely cure biliary tract carcinoma, the indications for resection are determined first. In patients with resectable disease, the indications for biliary drainage or portal vein embolization (PVE) are checked. In those with nonresectable disease, biliary stenting, chemotherapy, radiotherapy, and/or best supportive care is selected

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Longitudinal amyloid and tau accumulation in autosomal dominant Alzheimer's disease: findings from the Colombia-Boston (COLBOS) biomarker study

Background: Neuroimaging studies of autosomal dominant Alzheimer's disease (ADAD) enable characterization of the trajectories of cerebral amyloid-beta (A beta) and tau accumulation in the decades prior to clinical symptom onset. Longitudinal rates of regional tau accumulation measured with positron emission tomography (PET) and their relationship with other biomarker and cognitive changes remain to be fully characterized in ADAD.Methods: Fourteen ADAD mutation carriers (Presenilin-1 E280A) and 15 age-matched non-carriers from the Colombian kindred underwent 2-3 sessions of A beta (11C-Pittsburgh compound B) and tau (18F-flortaucipir) PET, structural magnetic resonance imaging, and neuropsychological evaluation over a 2-4-year follow-up period. Annualized rates of change for imaging and cognitive variables were compared between carriers and non-carriers, and relationships among baseline measurements and rates of change were assessed within carriers.Results: Longitudinal measurements were consistent with a sequence of ADAD-related changes beginning with A beta accumulation (16 years prior to expected symptom onset, EYO), followed by entorhinal cortex (EC) tau (9 EYO), neocortical tau (6 EYO), hippocampal atrophy (6 EYO), and cognitive decline (4 EYO). Rates of tau accumulation among carriers were most rapid in parietal neocortex (similar to 9%/year). EC tau PET signal at baseline was a significant predictor of subsequent neocortical tau accumulation and cognitive decline within carriers.Conclusions: Our results are consistent with the sequence of biological changes in ADAD implied by cross-sectional studies and highlight the importance of EC tau as an early biomarker and a potential link between A beta burden and neocortical tau accumulation in ADAD