17 research outputs found
Effect of the mycotoxin, ochratoxin A, on hormone-stimulated ion transport in a cultured cell model of the renal principal cell
The mycotoxin ochratoxin A (OTA) is a common contaminant of many foodstuffs and, consequently, is present in a large proportion of tested populations of humans and commercial animals. The predominant effects of OTA are manifested in the kidney where the severity varies from salt wasting to renal carcinoma formation in a concentration-dependent fashion. The MDCK-C7 renal cell culture model responds to various hormones known to regulate electrolyte and fluid balance and was used as a model to study the chronic effects of an acute exposure to low dose OTA. The natriferic hormones aldosterone and insulin-like growth factor 1 (IGF1) both stimulate Na(+) flux in a reabsorptive direction via activation of the epithelial Na(+) channel (ENaC). In contrast, anti-diuretic hormone (ADH) stimulates three separate and temporally distinct ion transport responses, one of which is Na(+) reabsorption. Treatment of MDCK-C7 cells with OTA (100 nM) for 48 h selectively and irreversibly inhibits hormone-stimulated Na(+) reabsorption via ENaC. This effect was retained for 48 cell passages after the removal of the toxin and mimics the OTA-induced salt-wasting that has been documented in clinical studies. These studies indicate that the effect of the toxin is genomic and therefore, likely to be long lasting in exposed animals and humans
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Effect of the mycotoxin, ochratoxin A, on hormone-stimulated ion transport in a cultured cell model of the renal principal cell
The mycotoxin ochratoxin A (OTA) is a common contaminant of many foodstuffs and, consequently, is present in a large proportion of tested populations of humans and commercial animals. The predominant effects of OTA are manifested in the kidney where the severity varies from salt wasting to renal carcinoma formation in a concentration-dependent fashion. The MDCK-C7 renal cell culture model responds to various hormones known to regulate electrolyte and fluid balance and was used as a model to study the chronic effects of an acute exposure to low dose OTA. The natriferic hormones aldosterone and insulin-like growth factor 1 (IGF1) both stimulate Na(+) flux in a reabsorptive direction via activation of the epithelial Na(+) channel (ENaC). In contrast, anti-diuretic hormone (ADH) stimulates three separate and temporally distinct ion transport responses, one of which is Na(+) reabsorption. Treatment of MDCK-C7 cells with OTA (100 nM) for 48 h selectively and irreversibly inhibits hormone-stimulated Na(+) reabsorption via ENaC. This effect was retained for 48 cell passages after the removal of the toxin and mimics the OTA-induced salt-wasting that has been documented in clinical studies. These studies indicate that the effect of the toxin is genomic and therefore, likely to be long lasting in exposed animals and humans
Predicting and Testing Physical Locations of Genetically Mapped Loci on Tomato Pachytene Chromosome 1
Predicting the chromosomal location of mapped markers has been difficult because linkage maps do not reveal differences in crossover frequencies along the physical structure of chromosomes. Here we combine a physical crossover map based on the distribution of recombination nodules (RNs) on Solanum lycopersicum (tomato) synaptonemal complex 1 with a molecular genetic linkage map from the interspecific hybrid S. lycopersicum Ă S. pennellii to predict the physical locations of 17 mapped loci on tomato pachytene chromosome 1. Except for one marker located in heterochromatin, the predicted locations agree well with the observed locations determined by fluorescence in situ hybridization. One advantage of this approach is that once the RN distribution has been determined, the chromosomal location of any mapped locus (current or future) can be predicted with a high level of confidence
Childrenâs psychological and behavioral responses following pediatric intensive care unit hospitalization: the caring intensively study
Abstract
Background
Pediatric intensive care unit (PICU) hospitalization places children at increased risk of persistent psychological and behavioral difficulties following discharge. Despite tremendous advances in medical technology and treatment regimes, approximately 25% of children demonstrate negative psychological and behavioral outcomes within the first year post-discharge. It is imperative that a broader array of risk factors and outcome indicators be explored in examining long-term psychological morbidity to identify areas for future health promotion and clinical intervention. This study aims to examine psychological and behavioral responses in children aged 3 to 12Â years over a three year period following PICU hospitalization, and compare them to children who have undergone ear, nose and/or throat (ENT) day surgery.
Methods/Design
This mixed-methods prospective cohort study will enrol 220 children aged 3 to 12Â years during PICU hospitalization (study group, nâ=â110) and ENT day surgery hospitalization (comparison group, nâ=â110). Participants will be recruited from 3 Canadian pediatric hospitals, and followed for 3Â years with data collection points at 6Â weeks, 6Â months, 1Â year, 2Â years and 3Â years post-discharge. Psychological and behavioral characteristics of the child, and parent anxiety and parenting stress, will be assessed prior to hospital discharge, and again at each of the 5 subsequent time points, using standardized measures. Psychological and behavioral response scores for both groups will be compared at each follow-up time point. Multivariate regression analysis will be used to adjust for demographic and clinical variables at baseline. To explore baseline factors predictive of poor psychological and behavioral scores at 3Â years among PICU patients, correlation analysis and multivariate linear regression will be used. A subgroup of 40 parents of study group children will be interviewed at years 1 and 3 post-discharge to explore their perceptions of the impact of PICU hospitalization on their children and enhance our understanding of findings generated from standardized measures in the larger cohort study. An interpretive descriptive approach will guide qualitative data collection and analysis.
Discussion
This study aims to generate new information regarding the magnitude and duration of psychological and behavioral disturbances among children admitted to PICUs, potentially leading to remedial or preventive interventions
Correlations among morphological and biochemical traits in highâcannabidiol hemp (Cannabis sativa L.)
Abstract Cannabis sativa is cultivated for multiple uses including the production of cannabinoids. In developing improved production systems for highâcannabinoid cultivars, scientists and cultivators must consider the optimization of complex and interacting sets of morphological, phenological, and biochemical traits, which have historically been shaped by natural and anthropogenic selection. Determining factors that modulate cannabinoid variation within and among genotypes is fundamental to developing efficient production systems and understanding the ecological significance of cannabinoids. Thirtyâtwo highâcannabinoid hemp cultivars were characterized for traits including flowering date and shootâtip cannabinoid concentration. Additionally, a set of plant architecture traits, as well as wet, dry, and stripped inflorescence biomass were measured at harvest. One plant per plot was partitioned postâharvest to quantify intraâplant variation in inflorescence biomass production and cannabinoid concentration. Some cultivars showed intraâplant variation in cannabinoid concentration, while many had a consistent concentration regardless of canopy position. There was both intraâ and interâcultivar variation in architecture that correlated with intraâplant distribution of inflorescence biomass, and concentration of cannabinoids sampled from various positions within a plant. These relationships among morphological and biochemical traits will inform future decisions by cultivators, regulators, and plant breeders
A comparison of the frequencies of risk factors for depression in older black and white participants in a study of indicated prevention
BACKGROUND: To compare the frequencies of risk factors, we describe risks for depression as a function of race among consecutively admitted participants in a randomized clinical trial of indicated depression prevention in later life. METHODS: Seventy-two black and 143 white participants were screened for risk factors for depression. RESULTS: Black participants were more likely to have fewer years of education and lower household income. They were more likely to be obese, live alone, experience functional disability, have a history of alcohol and drug abuse, and have lower scores on the Mini-mental State Examination and the Executive Interview (EXIT). White participants were not found to have greater prevalence or higher mean score on any risk factor. On average, black participants experienced approximately one more risk factor than white participants (t(213) = 3.32, p = 0.0011). CONCLUSIONS: In our sample, black participants had higher frequencies of eight risk factors for depression and a greater mean number of risk factors compared to white participants.http://dx.doi.org/10.1017/S104161021000152