Universidad del Desarrollo

About: Universidad del Desarrollo is a education organization based out in Santiago, Chile. It is known for research contribution in the topics: Population & Entrepreneurship. The organization has 2695 authors who have published 3578 publications receiving 52302 citations.

Suicide HSVtk gene delivery by neurotensin-polyplex nanoparticles via the bloodstream and GCV Treatment specifically inhibit the growth of human MDA-MB-231 triple negative breast cancer tumors xenografted in athymic mice.

Abstract: The human breast adenocarcinoma cell line MDA-MB-231 has the triple-negative breast cancer (TNBC) phenotype, which is an aggressive subtype with no specific treatment. MDA-MB-231 cells express neurotensin receptor type 1 (NTSR1), which makes these cells an attractive target of therapeutic genes that are delivered by the neurotensin (NTS)-polyplex nanocarrier via the bloodstream. We addressed the relevance of this strategy for TNBC treatment using NTS-polyplex nanoparticles harboring the herpes simplex virus thymidine kinase (HSVtk) suicide gene and its complementary prodrug ganciclovir (GCV). The reporter gene encoding green fluorescent protein (GFP) was used as a control. NTS-polyplex successfully transfected both genes in cultured MDA-MB-231 cells. The transfection was demonstrated pharmacologically to be dependent on activation of NTSR1. The expression of HSVtk gene decreased cell viability by 49% (P<0.0001) and induced apoptosis in cultured MDA-MB-231 cells after complementary GCV treatment. In the MDA-MB-231 xenograft model, NTS-polyplex nanoparticles carrying either the HSVtk gene or GFP gene were injected into the tumors or via the bloodstream. Both routes of administration allowed the NTS-polyplex nanoparticles to reach and transfect tumorous cells. HSVtk expression and GCV led to apoptosis, as shown by the presence of cleaved caspase-3 and Apostain immunoreactivity, and significantly inhibited the tumor growth (55–60%) (P<0.001). At the end of the experiment, the weight of tumors transfected with the HSVtk gene was 55% less than that of control tumors (P<0.05). The intravenous transfection did not induce apoptosis in peripheral organs. Our results offer a promising gene therapy for TNBC using the NTS-polyplex nanocarrier.

Diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration for mediastinal staging in lung cancer*

Abstract: OBJECTIVE: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive diagnostic test with a high diagnostic yield for suspicious central pulmonary lesions and for mediastinal lymph node staging. The main objective of this study was to describe the diagnostic yield of EBUS-TBNA for mediastinal lymph node staging in patients with suspected lung cancer. METHODS: Prospective study of patients undergoing EBUS-TBNA for diagnosis. Patients ≥ 18 years of age were recruited between July of 2010 and August of 2013. We recorded demographic variables, radiological characteristics provided by axial CT of the chest, location of the lesion in the mediastinum as per the International Association for the Study of Lung Cancer classification, and definitive diagnostic result (EBUS with a diagnostic biopsy or a definitive diagnostic method). RESULTS: Our analysis included 354 biopsies, from 145 patients. Of those 145 patients, 54.48% were male. The mean age was 63.75 years. The mean lymph node size was 15.03 mm, and 90 lymph nodes were smaller than 10.0 mm. The EBUS-TBNA method showed a sensitivity of 91.17%, a specificity of 100.0%, and a negative predictive value of 92.9%. The most common histological diagnosis was adenocarcinoma. CONCLUSIONS: EBUS-TBNA is a diagnostic tool that yields satisfactory results in the staging of neoplastic mediastinal lesions.

Acquisition, Maintenance and Relapse-Like Alcohol Drinking: Lessons from the UChB Rat Line.

Abstract: This review addresses the biological factors that influence (i) the acquisition of alcohol intake, (ii) the maintenance of chronic alcohol intake and (iii) alcohol relapse-like drinking behavior in animals bred for their high-ethanol intake. Data from several rat strains/lines strongly suggest that catalase-mediated brain oxidation of ethanol into acetaldehyde is an absolute requirement (up 80-95%) for rats to display ethanol’s reinforcing effects and to initiate chronic ethanol intake. Acetaldehyde binds non-enzymatically to dopamine forming salsolinol, a compound that is self-administered. In UChB rats, salsolinol (a) generates marked sensitization to the motivational effects of ethanol and (b) strongly promotes binge-like drinking. The specificity of salsolinol actions is shown by the finding that only the R-salsolinol enantiomer but not S-salsolinol accounted for the latter effects. Inhibition of brain acetaldehyde synthesis does not influence the maintenance of chronic ethanol intake. However, a prolonged ethanol withdrawal partly returns the requirement for acetaldehyde synthesis/levels both on chronic ethanol intake and on alcohol relapse-like drinking. Chronic ethanol intake, involving the action of lipopolysaccharide diffusing from the gut, and likely oxygen radical generated upon catechol/salsolinol oxidation, leads to oxidative stress and neuro-inflammation, known to potentiate each other. Data show that the administration of N-acetyl cysteine a strong antioxidant inhibits chronic ethanol maintenance by 60-70%, without inhibiting its initial intake. Intra-cerebroventricular administration of mesenchymal stem cells, known to release anti-inflammatory cytokines, to elevate superoxide dismutase levels and to reverse ethanol-induced hippocampal injury and cognitive deficits, also inhibited chronic ethanol maintenance; further, relapse-like ethanol drinking was inhibited up to 85% for 40 days following intracerebral stem cell administration. Thus: (i) ethanol must be metabolized intracerebrally into acetaldehyde, and further into salsolinol, which appear responsible for promoting the acquisition of the early reinforcing effects of ethanol; (ii) acetaldehyde is not responsible for the maintenance of chronic ethanol intake, while other mechanisms are indicated; (iii) the systemic administration of N-acetyl cysteine, a strong antioxidant markedly inhibits the maintenance of chronic ethanol intake; (iv) the intra-cerebroventricular administration of anti-inflammatory and antioxidant mesenchymal stem cells inhibit both the maintenance of chronic ethanol intake and relapse-like drinking.

Relation between suicidal ideation and parenting styles among a group of Chilean adolescents

Abstract: The relation between suicidal ideation and parenting styles was assessed in a random sample of 2,346 Chilean school attending adolescents aged 13 to 20 years old (59% women) from three cities: Antofagasta (Northern Chile, II Region), Santiago (Central, Metropolitan Region) and Concepcion (Southern, VIII Region) Participants were tested with the Chilean adaptation of the Cross National Adolescents Program (CNAP) Plus questionnaire developed by Barber et al The relation between suicidal ideation and parenting styles was assessed using regression analyses

Predicting City Poverty Using Satellite Imagery

Abstract: Reliable data about socio-economic conditions of individuals, such as health indexes, consumption expenditures and wealth assets, remain scarce for most countries. Traditional methods to collect such data include on site surveys that can be expensive and labour intensive. On the other hand, remote sensing data, such as high-resolution satellite imagery, are becoming largely available. To circumvent the lack of socio-economic data at high granularity, computer vision has already been applied successfully to raw satellite imagery sampled from resource poor countries. In this work we apply a similar approach to the metropolitan areas of five different cities in North and South America, starting from pre-trained convolutional models used for poverty mapping in developing regions. Applying a transfer learning process we estimate household income from visual satellite features. The urban environment we consider is characterized by different features with respect to the resource-poor training environment, such as the high heterogeneity in population density. By leveraging both official and crowd-sourced data at city scale, we show the feasibility of estimating the socio-economic conditions of different neighborhoods from satellite data.