36 research outputs found

    Estrategias competitivas de la industria del arándano: análisis comparativo entre Chile y Perú

    Get PDF
    57 p.El mercado internacional de arándanos ha experimentado en las últimas décadas un rápido crecimiento del volumen exportado por parte de los países productores. Sin embargo, la oferta no ha podido satisfacer el rápido crecimiento de la demanda global. Lo que ha provocado una excelente oportunidad para aquellos países que cumplen con las condiciones para su producción. Con el objetivo de establecer una industria orientada en la producción y comercialización del arándano, para así satisfacer la creciente demanda de los consumidores en el mercado mundial. Lo anterior, ha permitido la aparición de nuevos competidores que otorgan un mayor dinamismo dentro del mercado, obligando a la industria a mejorar la eficiencia productiva y comercial. El objetivo de esta investigación es analizar y comparar las estrategias competitivas de la industria del arándano de Chile y Perú. La hipótesis de trabajo es que la industria chilena tiene estrategias competitivas superiores a las que presenta la industria peruana. Para este efecto se realizó un análisis ambiental de ambas industrias, mediante un análisis PEST que busca evaluar los aspectos políticos, económicos, sociales y tecnológicos que se encuentran en el macro entorno de la industria. Además, se analizan los aspectos internos y externos de la industria mediante el uso de las cinco fuerzas de Porter, con el objetivo de identificar las oportunidades, amenazas, fortalezas y debilidades dentro de la industria. Por último, mediante el uso de una matriz FODA se sintetizan las amenazas, oportunidades, fortalezas, debilidades que poseen las industrias del arándano en Chile y Perú, de manera de poder comparar con mayor facilidad las ventajas competitivas de cada industria. En conclusión, la industria del arándano chilena posee estrategias competitivas superiores a las de la industria peruana, a pesar de que Perú posee ciertas ventajas climáticas y comerciales, principalmente debido a la mayor trayectoria de la industria. Esto último, ha permitido a Chile poseer una mayor experiencia y manejo de conocimientos de importancia para la producción y comercialización del arándano. Además, esto ha permitido presentar un mayor avance en lo que respecta a la investigación y desarrollo de nuevas tecnologías, nuevas variedades, y presentan un mayor grado de incorporación de tecnologías independiente del tamaño de la empresa./ABSTRACT: The International blueberry market has experienced in recent decades a rapid growth in the volume exported by the producing countries. But the offer has not been able to meet the rapid growth of global demand. This has caused an excellent opportunity for those countries that meet the conditions for their production. With the aim of establishing an industry oriented in the production and marketing of blueberry, in order to satisfy the growing demand of the consumers in the world market. The foregoing has allowed the emergence of new competitors, thus giving greater dynamism within the market, forcing the industry to improve productive and commercial efficiency. The objective of this research is to analyze and compare the competitive strategies of the blueberry industry in Chile and Peru. The working hypothesis is that the Chilean industry has competitive strategies superior to those presented by the Peruvian industry. For this purpose an environmental analysis of both industries was carried out, through a PEST analysis that seeks to evaluate the political, economic, social and technological aspects that are found in the macro environment of the industry. In addition, the internal and external aspects of the industry are analyzed through the use of Porter's five forces, aiming to identify opportunities, threats, strengths and weaknesses within the industry. Finally, the use of a SWOT matrix summarizes the threats, opportunities, strengths, weaknesses that the blueberry industries have in Chile and Peru, so as to be able to compare the competitive advantages of each industry more easily. In conclusion, the Chilean blueberry industry possesses competitive strategies superior to those of the Peruvian industry, despite the fact that Peru has certain climatic and commercial advantages, mainly due to the greater trajectory of the industry. The latter has enabled Chile to have greater experience and management of important knowledge for the production and marketing of Blueberry. In addition, this has made it possible to present further progress in research and development of new technologies, new varieties, and have a greater degree of incorporation of technologies independent of the size of the company

    GABA and Dopamine Release from Different Brain Regions in Mice with Chronic Exposure to Organophosphate Methamidophos

    Get PDF
    Organophosphates such as methamidophos, usually used in the agricultural field, have harmful effects on humans. Exposures to insecticides has been associated with many disorders, including damage to the central and peripheral nervous system. Chronic exposure to organophosphates may lead to persistent neurological and neurobehavioral effects. This study was conducted to determine the effect of methamidophos on [3H]-dopamine (DA) and gamma aminobutyric acid (GABA) release from different brain regions after chronic exposure to it for 3, 6 or 9 months. After a six-month methamidophos treatment, the mice showed high susceptibility to convulsive seizures and a reduction in stimulated gamma aminobutyric acid release from the cerebral cortex and hippocampal slices, whereas stimulated (DA) release was slightly decreased from the striatum after three months of methamidophos exposure. The results indicate changes in gamma aminobutyric acid and dopamine neurotransmission, suggesting a specific neuronal damage

    Efecto de la recuperación nutricia en la concentración sérica de lipoperoxidos en niños con desnutrición proteínico-energética primaria grave.

    Get PDF
    Objective. The purpose is to show lipid peroxide’s serum concentration trend during a four-week nutritional recovery period in children with primary and severe protein energy malnutrition (PEM). Methods. In a clinical intervention 12 primarily and severely malnourished children (three to 48 months of age) were included. Dependent variable: Serum lipid peroxide (LPO) concentration (nmol/mL). Independent variables: non lactose starting infant formula (200 kcal/kg/d and proteins 4 g/kg/d). Age, sex, nutritional recovery, weight/age, length/age and weight/length indices calculated and expressed as Z scores were included. For statistical analysis a repeated measure ANOVA model was applied. A non-parametric Mann Whitney U-Test was used to compare groups. Null hypothesis was rejected with a p value 0.05. Results. Throughout the study the LPO concentration was higher in subjects with PEM than in the control group (p< 0.001). There was a decrease in the LPO concentration (nmol/mL) between basal vs. two weeks (12.9 vs. 7.3, p = 0.06) and basal vs. four weeks (12.9 vs. 8.16, p = 0.08). Conclusion. LPO concentrations were significantly higher in children with severe PEM at the beginning and end of the four-week nutritional recovery period. This finding was probably associated with increased metabolism of the cellular tissue and/or the high consumption of energy and nutrients compared to a control group. The null hypothesis of basal-end differences in LPO serum concentrations could not be rejected due to the great variability in serum lipoperoxides in these children with severe primary proteinenergy malnutrition

    Cervical cancer cell lines expressing NKG2D-ligands are able to down-modulate the NKG2D receptor on NKL cells with functional implications

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Cervical cancer represents the third most commonly diagnosed cancer and the fourth leading cause of cancer-related deaths in women worldwide. Natural killer (NK) cells play an important role in the defense against viruses, intracellular bacteria and tumors. NKG2D, an activating receptor on NK cells, recognizes MHC class I chain-related molecules, such as MICA/B and members of the ULBP/RAET1 family. Tumor-derived soluble NKG2D-ligands have been shown to down-modulate the expression of NKG2D on NK cells. In addition to the down-modulation induced by soluble NKG2D-ligands, it has recently been described that persistent cell-cell contact can also down-modulate NKG2D expression. The goal of this study was to determine whether the NKG2D receptor is down-modulated by cell-cell contact with cervical cancer cells and whether this down-modulation might be associated with changes in NK cell activity.</p> <p>Results</p> <p>We demonstrate that NKG2D expressed on NKL cells is down-modulated by direct cell contact with cervical cancer cell lines HeLa, SiHa, and C33A, but not with non-tumorigenic keratinocytes (HaCaT). Moreover, this down-modulation had functional implications. We found expression of NKG2D-ligands in all cervical cancer cell lines, but the patterns of ligand distribution were different in each cell line. Cervical cancer cell lines co-cultured with NKL cells or fresh NK cells induced a marked diminution of NKG2D expression on NKL cells. Additionally, the cytotoxic activity of NKL cells against K562 targets was compromised after co-culture with HeLa and SiHa cells, while co-culture with C33A increased the cytotoxic activity of the NKL cells.</p> <p>Conclusions</p> <p>Our results suggest that differential expression of NKG2D-ligands in cervical cancer cell lines might be associated with the down-modulation of NKG2D, as well as with changes in the cytotoxic activity of NKL cells after cell-cell contact with the tumor cells.</p

    MEIS1, PREP1, and PBX4 Are Differentially Expressed in Acute Lymphoblastic Leukemia: Association of MEIS1 Expression with Higher Proliferation and Chemotherapy Resistance

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The Three-amino acid-loop-extension (<it>TALE</it>) superfamily of homeodomain-containing transcription factors have been implicated in normal hematopoiesis and in leukemogenesis and are important survival, differentiation, and apoptosis pathway modulators. In this work, we determined the expression levels of <it>TALE </it>genes in leukemic-derived cell lines, in blood samples of patients with Acute lymphoblastic leukemia (ALL), and in the blood samples of healthy donors.</p> <p>Results</p> <p>Here we show increased expression of <it>MEIS1, MEIS2, </it>and <it>PREP1 </it>genes in leukemia-derived cell lines compared with blood normal cells. High levels of <it>MEIS1 </it>and <it>PREP1</it>, and low levels of <it>PBX4 </it>expression were also founded in samples of patients with ALL. Importantly, silencing of <it>MEIS1 </it>decreases the proliferation of leukemia-derived cells but increases their survival after etoposide treatment. Etoposide-induced apoptosis induces down-regulation of MEIS1 expression or <it>PREP1 </it>up-regulation in chemotherapy-resistant cells.</p> <p>Conclusions</p> <p>Our results indicate that up-regulation of <it>MEIS1 </it>is important for sustaining proliferation of leukemic cells and that down-regulation of <it>MEIS1 </it>or up-regulation of <it>PREP1 </it>and <it>PBX </it>genes could be implicated in the modulation of the cellular response to chemotherapeutic-induced apoptosis.</p

    MHC class I-related chain A and B ligands are differentially expressed in human cervical cancer cell lines

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present, one of the best-characterized activating receptors is NKG2D, which promotes the NK-mediated lysis of target cells by binding to a family of cell surface ligands encoded by the MHC class I chain-related (MIC) genes, among others. The goal of this study was to describe the expression pattern of MICA and MICB at the molecular and cellular levels in human cervical cancer cell lines infected or not with human papillomavirus, as well as in a non-tumorigenic keratinocyte cell line.</p> <p>Results</p> <p>Here we show that MICA and MICB exhibit differential expression patterns among HPV-infected (SiHa and HeLa) and non-infected cell lines (C33-A, a tumor cell line, and HaCaT, an immortalized keratinocyte cell line). Cell surface expression of MICA was higher than cell surface expression of MICB in the HPV-positive cell lines; in contrast, HPV-negative cells expressed lower levels of MICA. Interestingly, the MICA levels observed in C33-A cells were overcome by significantly higher MICB expression. Also, all cell lines released higher amounts of soluble MICB than of soluble MICA into the cell culture supernatant, although this was most pronounced in C33-A cells. Additionally, Real-Time PCR analysis demonstrated that MICA was strongly upregulated after genotoxic stress.</p> <p>Conclusions</p> <p>This study provides evidence that even when MICA and MICB share a high degree of homology at both genomic and protein levels, differential regulation of their expression and cell surface appearance might be occurring in cervical cancer-derived cells.</p

    Sensitization of U937 leukemia cells to doxorubicin by the MG132 proteasome inhibitor induces an increase in apoptosis by suppressing NF-kappa B and mitochondrial membrane potential loss

    Full text link
    Background: The resistance of cancerous cells to chemotherapy remains the main limitation for cancer treatment at present. Doxorubicin (DOX) is a potent antitumor drug that activates the ubiquitin-proteasome system, but unfortunately it also activates the Nuclear factor kappa B (NF-k{cyrillic}B) pathway leading to the promotion of tumor cell survival. MG132 is a drug that inhibits I kappa B degradation by the proteasome-avoiding activation of NF-k{cyrillic}B. In this work, we studied the sensitizing effect of the MG132 proteasome inhibitor on the antitumor activity of DOX. Methods: U937 human leukemia cells were treated with MG132, DOX, or both drugs. We evaluated proliferation, viability, apoptosis, caspase-3, -8, and -9 activity and cleavage, cytochrome c release, mitochondrial membrane potential, the Bcl-2 and Bcl-XL antiapoptotic proteins, senescence, p65 phosphorylation, and pro- and antiapoptotic genes. Results: The greatest apoptosis percentage in U937 cells was obtained with a combination of MG132 + DOX. Likewise, employing both drugs, we observed a decrease in tumor cell proliferation and important caspase-3 activation, as well as mitochondrial membrane potential loss. Therefore, MG132 decreases senescence, p65 phosphorylation, and the DOX-induced Bcl-2 antiapoptotic protein. The MG132 + DOX treatment induced upregulation of proapoptotic genes BAX, DIABLO, NOXA, DR4, and FAS. It also induced downregulation of the antiapoptotic genes BCL-XL and SURVIVIN. Conclusion: MG132 sensitizes U937 leukemia cells to DOX-induced apoptosis, increasing its anti-leukemic effectiveness. © 2014 Ortiz-Lazareno et al.; licensee BioMed Central Ltd

    Low NKp30, NKp46 and NKG2D expression and reduced cytotoxic activity on NK cells in cervical cancer and precursor lesions

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Persistent high risk HPV infection can lead to cervical cancer, the second most common malignant tumor in women worldwide. NK cells play a crucial role against tumors and virus-infected cells through a fine balance between activating and inhibitory receptors. Expression of triggering receptors NKp30, NKp44, NKp46 and NKG2D on NK cells correlates with cytolytic activity against tumor cells, but these receptors have not been studied in cervical cancer and precursor lesions. The aim of the present work was to study NKp30, NKp46, NKG2D, NKp80 and 2B4 expression in NK cells from patients with cervical cancer and precursor lesions, in the context of HPV infection.</p> <p>Methods</p> <p>NKp30, NKp46, NKG2D, NKp80 and 2B4 expression was analyzed by flow cytometry on NK cells from 59 patients with cervical cancer and squamous intraepithelial lesions. NK cell cytotoxicity was evaluated in a 4 hour CFSE/7-AAD flow cytometry assay. HPV types were identified by PCR assays.</p> <p>Results</p> <p>We report here for the first time that NK cell-activating receptors NKp30 and NKp46 are significantly down-regulated in cervical cancer and high grade squamous intraepithelial lesion (HGSIL) patients. NCRs down-regulation correlated with low cytolytic activity, HPV-16 infection and clinical stage. NKG2D was also down-regulated in cervical cancer patients.</p> <p>Conclusion</p> <p>Our results suggest that NKp30, NKp46 and NKG2D down-regulation represent an evasion mechanism associated to low NK cell activity, HPV-16 infection and cervical cancer progression.</p

    Apoptosis induction in Jurkat cells and sCD95 levels in women's sera are related with the risk of developing cervical cancer

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Currently, there is clear evidence that apoptosis plays an important role in the development and progression of tumors. One of the best characterized apoptosis triggering systems is the CD95/Fas/APO-1 pathway; previous reports have demonstrated high levels of soluble CD95 (sCD95) in serum of patients with some types of cancer. Cervical cancer is the second most common cancer among women worldwide. As a first step in an attempt to design a minimally invasive test to predict the risk of developing cervical cancer in patients with precancerous lesions, we used a simple assay based on the capacity of human serum to induce apoptosis in Jurkat cells. We evaluated the relationship between sCD95 levels and the ability to induce apoptosis in Jurkat cells in cervical cancer patients and controls.</p> <p>Methods</p> <p>Jurkat cells were exposed to serum from 63 women (20 healthy volunteers, 21 with cervical intraepithelial neoplasia grade I [CIN 1] and 22 with cervical-uterine carcinoma). The apoptotic rate was measured by flow cytometry using Annexin-V-Fluos and Propidium Iodide as markers. Serum levels of sCD95 and soluble CD95 ligand (sCD95L) were measured by ELISA kits.</p> <p>Results</p> <p>We found that serum from almost all healthy women induced apoptosis in Jurkat cells, while only fifty percent of the sera from women with CIN 1 induced cell death in Jurkat cells. Interestingly, only one serum sample from a patient with cervical-uterine cancer was able to induce apoptosis, the rest of the sera protected Jurkat cells from this killing. We were able to demonstrate that elimination of Jurkat cells was mediated by the CD95/Fas/Apo-1 apoptotic pathway. Furthermore, the serum levels of sCD95 measured by ELISA were significantly higher in women with cervical cancer.</p> <p>Conclusion</p> <p>Our results demonstrate that there is a strong correlation between low levels of sCD95 in serum of normal women and higher apoptosis induction in Jurkat cells. We suggest that an analysis of the apoptotic rate induced by serum in Jurkat cells and the levels of sCD95 in serum could be helpful during the prognosis and treatment of women detected with precancerous lesions or cervical cancer.</p
    corecore