Prediction of clinical toxicity in locally advanced head and neck cancer patients by radio-induced apoptosis in peripheral blood lymphocytes (PBLs)

Head and neck cancer is treated mainly by surgery and radiotherapy. Normal tissue toxicity due to x-ray exposure is a limiting factor for treatment success. Many efforts have been employed to develop predictive tests applied to clinical practice. Determination of lymphocyte radio-sensitivity by radio-induced apoptosis arises as a possible method to predict tissue toxicity due to radiotherapy. The aim of the present study was to analyze radio-induced apoptosis of peripheral blood lymphocytes in head and neck cancer patients and to explore their role in predicting radiation induced toxicity. Seventy nine consecutive patients suffering from head and neck cancer, diagnosed and treated in our institution, were included in the study. Toxicity was evaluated using the Radiation Therapy Oncology Group scale. Peripheral blood lymphocytes were isolated and irradiated at 0, 1, 2 and 8 Gy during 24 hours. Apoptosis was measured by flow cytometry using annexin V/propidium iodide. Lymphocytes were marked with CD45 APC-conjugated monoclonal antibody. Radiation-induced apoptosis increased in order to radiation dose and fitted to a semi logarithmic model defined by two constants: α and β. α, as the origin of the curve in the Y axis determining the percentage of spontaneous cell death, and β, as the slope of the curve determining the percentage of cell death induced at a determined radiation dose, were obtained. β value was statistically associated to normal tissue toxicity in terms of severe xerostomia, as higher levels of apoptosis were observed in patients with low toxicity (p = 0.035; Exp(B) 0.224, I.C.95% (0.060-0.904)). These data agree with our previous results and suggest that it is possible to estimate the radiosensitivity of peripheral blood lymphocytes from patients determining the radiation induced apoptosis with annexin V/propidium iodide staining. β values observed define an individual radiosensitivity profile that could predict late toxicity due to radiotherapy in locally advanced head and neck cancer patients. Anyhow, prospective studies with different cancer types and higher number of patients are needed to validate these results

Prediction of clinical toxicity in localized cervical carcinoma by radio-induced apoptosis study in peripheral blood lymphocytes (PBLs)

<p>Abstract</p> <p>Background</p> <p>Cervical cancer is treated mainly by surgery and radiotherapy. Toxicity due to radiation is a limiting factor for treatment success. Determination of lymphocyte radiosensitivity by radio-induced apoptosis arises as a possible method for predictive test development. The aim of this study was to analyze radio-induced apoptosis of peripheral blood lymphocytes.</p> <p>Methods</p> <p>Ninety four consecutive patients suffering from cervical carcinoma, diagnosed and treated in our institution, and four healthy controls were included in the study. Toxicity was evaluated using the Lent-Soma scale. Peripheral blood lymphocytes were isolated and irradiated at 0, 1, 2 and 8 Gy during 24, 48 and 72 hours. Apoptosis was measured by flow cytometry using annexin V/propidium iodide to determine early and late apoptosis. Lymphocytes were marked with CD45 APC-conjugated monoclonal antibody.</p> <p>Results</p> <p>Radiation-induced apoptosis (RIA) increased with radiation dose and time of incubation. Data strongly fitted to a semi logarithmic model as follows: RIA = βln(Gy) + α. This mathematical model was defined by two constants: α, is the origin of the curve in the Y axis and determines the percentage of spontaneous cell death and β, is the slope of the curve and determines the percentage of cell death induced at a determined radiation dose (β = ΔRIA/Δln(Gy)). Higher β values (increased rate of RIA at given radiation doses) were observed in patients with low sexual toxicity (Exp(B) = 0.83, C.I. 95% (0.73-0.95), p = 0.007; Exp(B) = 0.88, C.I. 95% (0.82-0.94), p = 0.001; Exp(B) = 0.93, C.I. 95% (0.88-0.99), p = 0.026 for 24, 48 and 72 hours respectively). This relation was also found with rectal (Exp(B) = 0.89, C.I. 95% (0.81-0.98), p = 0.026; Exp(B) = 0.95, C.I. 95% (0.91-0.98), p = 0.013 for 48 and 72 hours respectively) and urinary (Exp(B) = 0.83, C.I. 95% (0.71-0.97), p = 0.021 for 24 hours) toxicity.</p> <p>Conclusion</p> <p>Radiation induced apoptosis at different time points and radiation doses fitted to a semi logarithmic model defined by a mathematical equation that gives an individual value of radiosensitivity and could predict late toxicity due to radiotherapy. Other prospective studies with higher number of patients are needed to validate these results.</p

Introduction of the Problem-based learning methodology in the teaching of Legal Veterinary

[ES] El aprendizaje basado en problemas (ABP) es una estrategia de enseñanza centrada en el alumno, que adquirirá conceptos complejos llevando a la práctica conocimientos previos sobre una disciplina concreta. En el campo de la Veterinaria Legal, el peritaje forense forma parte central de los conocimientos que el alumno debe adquirir. Desde el curso 2010/2011, los alumnos de Veterinaria de la Universidad de Las Palmas de Gran Canaria, realizan un peritaje forense mediante ABP. Los alumnos, divididos en grupos de 6-8 individuos, trabajan un problema desde dos puntos de vista diferentes: el del demandado y el del demandante. Durante el proceso, los alumnos son tutorizados y las dos posturas se enfrentan en el aula para defender su postura, donde el profesor ejerce de juez, y el resto de compañeros de jurado. La actividad es valorada con 1-3 puntos. Durante 5 cursos, un total de 275 alumnos han realizado la actividad, con el 50,91% de los alumnos obteniendo la máxima calificación.  Los  alumno[EN] Problem-based learning (PBL) is an educational  strategy  centered  on  the student, who will acquire complex concepts being implemented prior knowledge about a particular discipline. In the field of  Legal  Veterinary,  forensic  expertise is a central part of the knowledge that students must acquire. Since 2010/2011, veterinary students from the University of Las Palmas de Gran Canaria, complete a  forensic  expertise  through  PBL.  The students, separated in two groups of 6-8 subjects, work on a problem from two different points of view: defendant and claimant. During the process, students are tutored and the two positions facing in the classroom to defend their point. At that time, the teacher acts as judge, and the rest of students act as jury. the activity is assessed with 1-3 points. For 5 courses, a total of 275 students have completed the activity, with 50.91% of students obtaining the  highest  qualification.  Students  are satisfied with the activity. We therefore conclude Henríquez Hernández, LA.; Pérez Luzardo, O.; Domínguez Boada, L.; Almeida González, M.; Zumbado Peña, M. (2015). Aplicación de la metodología de aprendizaje basado en problemas a la docencia de Veterinaria Legal. REDU. Revista de Docencia Universitaria. 13(3):171-188. https://doi.org/10.4995/redu.2015.5456OJS171188133Albanese, M.A., Mitchell, S. (1993). Problem-based learning: A Review of literature on its outcomes and implementations issues. Academic Medicine, 68, 52-81. https://doi.org/10.1097/00001888-199301000-00012Aspy, D.N., Aspy, C.B., Quimby, P.M. (1993). What Doctors Can Teach Teachers about Problem-Based Learning. Educational Leadership, 50, 22-24.Barrows, H.S. (1971). Simulated Patients (programmed patients). The development and use of a new technique in medical education. C.C. Thomas: Springfield, USA.Barrows, H.S. (1986). A taxonomy of problem-based learning methods. Medical Education, 20, 481-486. https://doi.org/10.1111/j.1365-2923.1986.tb01386.xBarrows, H.S. (1993). An overview of the uses of standardized patients for teaching and evaluating clinical skills. Academic Medicine, 68, 399-405. https://doi.org/10.1097/00001888-199306000-00002Barrows, H.S., Tamblyn, R. (1980). Problem-Based Learning: An Approach to Medical Education. Springer Series on Medical Education Vol 1, Springer Publishing Company: New York.Biggs, J.B. (2005). Calidad del aprendizaje universitario. Narcea: Madrid.Blumberg, P., Michael, J.A. (1992). Development of self-directed learning behaviors in a partially teacher-directed problem-based learning curriculum. Teaching and Learning in Medicine, 4, 3-8. https://doi.org/10.1080/10401339209539526Bridges, E.M., Hallinger, P. (1991). Problem-Based Learning in Medical and Managerial Education. Paper presented for the Cognition and School Leadership Conference of the National Center for Educational Leadership and the Ontario Institute for Studies in Education, Nashville, USA.Dochy, F., Segers, M., Van den Bossche, P., Gijbels, D. (2003). Effects of Problem-Based Learning: A Meta-Analysis. Learning and Instruction, 13, 533-568. https://doi.org/10.1016/S0959-4752(02)00025-7Farnsworth, C.C. (1994). Using Computer Simulations in Problem-Based Learning. En M. Orey (Ed.), Proceedings of the Thirty-fifth ADCIS Conference. Nashville, USA: Omni Press.Gallagher, S.A., Stepien, W.J., Rosenthal, H. (1992). The Effects of Problem-Based Learning on Problem Solving. Gifted Child Quarterly, 36, 195-200. https://doi.org/10.1177/001698629203600405Lane, E.A. (2008). Problem-Based Learning in Veterinary Education. Journal of Veterinary Medical Education,35, 631-636. https://doi.org/10.3138/jvme.35.4.631Mennin, S.P., Friedman, M., Skipper, B., Kalishman, S., Snyder, J. (1993). Performances on the NBME I, II, and III by Medical Students in the Problem-Based Learning and Conventional Tracks at the University of New Mexico'. Academic Medicine, 68, 616-624. https://doi.org/10.1097/00001888-199308000-00012Morales, P., Landa, V. (2004). Aprendizaje basado en problemas, Theoria, 13, 145-157.Norman, G.R., Schmidt, H.G. (1992). The Psychological Basis of Problem-Based Learning: A Review of the Evidence. Academic Medicine, 67, 557-565. https://doi.org/10.1097/00001888-199209000-00002Pincus, K.V. (1995). Introductory Accounting: Changing the First Course. New Directions for Teaching and Learning, 61, 88-98. https://doi.org/10.1002/tl.37219956112Vernon, D.T., Blake, R.L. (1993). Does Problem-Based Learning Work?: A Meta-Analysis of Evaluative Research. Academic Medicine, 68, 550-563. https://doi.org/10.1097/00001888-199307000-0001

Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients

<p>Abstract</p> <p>Background</p> <p>DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed.</p> <p>Methods</p> <p>Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide.</p> <p>Results</p> <p>Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p < 0.0001 in all cases). Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). A statistically significant inverse correlation was found between initial damage to DNA and radio-induced apoptosis at 1 Gy (p = 0.034). A trend toward 2 Gy (p = 0.057) and 8 Gy (p = 0.067) was observed after 24 hours of incubation.</p> <p>Conclusions</p> <p>An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity.</p

Critical review of analytical methods for the determination of flame retardants in human matrices

Human biomonitoring is a powerful approach in assessing exposure to environmental pollutants. Flame retardants (FRs) are of particular concern due to their wide distribution in the environment and adverse health effects. This article reviews studies published in 2009-2020 on the chemical analysis of FRs in a variety of human samples and discusses the characteristics of the analytical methods applied to different FR biomarkers of exposure, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), novel halogenated flame retardants (NHFRs), bromophenols, incl. tetrabromobisphenol A (TBBPA), and organophosphorous flame retardants (PFRs). Among the extraction techniques, liquid-liquid extraction (LLE) and solid phase extraction (SPE) were used most frequently due to the good efficiencies in the isolation of the majority of the FR biomarkers, but with challenges for highly lipophilic FRs. Gas chromatography-mass spectrometry (GC-MS) is mainly applied in the instrumental analysis of PBDEs and most NHFRs, with recent inclusions of GC-MS/MS and high resolution MS techniques. Liquid chromatography-MS/MS is mainly applied to HBCD, bromophenols, incl. TBBPA, and PFRs (including metabolites), however, GC-based analysis following derivatization has also been used for phenolic compounds and PFR metabolites. Developments are noticed towards more universal analytical methods, which enable widening method scopes in the human biomonitoring of FRs. Challenges exist with regard to sensitivity required for the low concentrations of FRs in the general population and limited sample material for some human matrices. A strong focus on quality assurance/quality control (QA/QC) measures is required in the analysis of FR biomarkers in human samples, related to their variety of physical-chemical properties, low levels in most human samples and the risk of contamination.This study was part of the HBM4EU project receiving funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 733032. The authors acknowledge Berith E. Knudsen for her help with the literature search.S

Constitutive gene expression profile segregates toxicity in locally advanced breast cancer patients treated with high-dose hyperfractionated radical radiotherapy

Breast cancer patients show a wide variation in normal tissue reactions after radiotherapy. The individual sensitivity to x-rays limits the efficiency of the therapy. Prediction of individual sensitivity to radiotherapy could help to select the radiation protocol and to improve treatment results. The aim of this study was to assess the relationship between gene expression profiles of ex vivo un-irradiated and irradiated lymphocytes and the development of toxicity due to high-dose hyperfractionated radiotherapy in patients with locally advanced breast cancer. Raw data from microarray experiments were uploaded to the Gene Expression Omnibus Database (GEO accession GSE15341). We obtained a small group of 81 genes significantly regulated by radiotherapy, lumped in 50 relevant pathways. Using ANOVA and t-test statistical tools we found 20 and 26 constitutive genes (0 Gy) that segregate patients with and without acute and late toxicity, respectively. Non-supervised hierarchical clustering was used for the visualization of results. Six and 9 pathways were significantly regulated respectively. Concerning to irradiated lymphocytes (2 Gy), we founded 29 genes that separate patients with acute toxicity and without it. Those genes were gathered in 4 significant pathways. We could not identify a set of genes that segregates patients with and without late toxicity. In conclusion, we have found an association between the constitutive gene expression profile of peripheral blood lymphocytes and the development of acute and late toxicity in consecutive, unselected patients. These observations suggest the possibility of predicting normal tissue response to irradiation in high-dose non-conventional radiation therapy regimens. Prospective studies with higher number of patients are needed to validate these preliminary results

Arquitectos en Mendoza II : biografías, trayectorias profesionales y obras: 1961- 1972

En esta nueva edición se compilan las trayectorias de un conjunto de agentes graduados entre 1961 y 1972, que actuaron en la provincia de Mendoza incidiendo en sus aspectos espaciales, particularmente durante la segunda mitad del siglo XX. Esos arquitectos se formaron durante la bisagra que supuso a escala disciplinar, la incorporación de la vanguardia moderna asociada al diseño de la Arquitectura y la Ciudad. Justamente referirse a las vanguardias admite considerar en la producción una serie de aspectos innovadores y de avanzada no sólo en lo que atañe a la estética y los aspectos formales sino también a lo funcional y utilitario, y lo tecnológico constructivo. Las décadas del ´60 y ´70 abrieron en Mendoza, la puerta a una experimentación formal más cercana al regionalismo. Paralelamente al gusto por el lenguaje pintoresquista siempre vigente en la arquitectura mendocina, los proyectos ejecutados, particularmente los de arquitectura residencial, comenzaron a mostrar volúmenes puros y losas planas asociados al uso de la piedra, la madera, el acero y el ladrillo a la vista. Fue también una marca de ese momento de producción, el desarrollo de una vertiente que asoció la estética del material en bruto al sitio de emplazamiento de la obra, utilizando entre otros elementos pérgolas y parasoles como respuesta al clima desértico mendocino

Single nucleotide polymorphisms in DNA repair genes as risk factors associated to prostate cancer progression

Background Besides serum levels of PSA, there is a lack of prostate cancer specific biomarkers. It is need to develop new biological markers associated with the tumor behavior which would be valuable to better individualize treatment. The aim of this study was to elucidate the relationship between single nucleotide polymorphisms (SNPs) in genes involved in DNA repair and prostate cancer progression.Methods A total of 494 prostate cancer patients from a Spanish multicenter study were genotyped for 10 SNPs in XRCC1, ERCC2, ERCC1, LIG4, ATM and TP53 genes. The SNP genotyping was made in a Biotrove OpenArray® NT Cycler. Clinical tumor stage, diagnostic PSA serum levels, and Gleason score at diagnosis were obtained for all participants. Genotypic and allelic frequencies were determined using the web-based environment SNPator.Results SNPs rs11615 (ERCC1) and rs17503908 (ATM) appeared as risk factors for prostate cancer aggressiveness. Patients wild homozygous for these SNPs (AA and TT, respectively) were at higher risk for developing cT2b – cT4 (OR = 2.21 (confidence interval (CI) 95% 1.47 – 3.31), p < 0.001) and Gleason scores ≥ 7 (OR = 2.22 (CI 95% 1.38 – 3.57), p < 0.001), respectively. Moreover, those patients wild homozygous for both SNPs had the greatest risk of presenting D’Amico high-risk tumors (OR = 2.57 (CI 95% 1.28 – 5.16)).Conclusions Genetic variants at DNA repair genes are associated with prostate cancer progression, and would be taken into account when assessing the malignancy of prostate cancer.This work was subsidized by a grant from the Instituto de Salud Carlos III (Ministerio de Economía y Competitividad from Spain), ID: PI12/01867. Almudena Valenciano has a grant from the Instituto Canario de Investigación del Cáncer (ICIC)

Polymorphisms in DNA-repair genes in a cohort of prostate cancer patients from different areas in Spain: heterogeneity between populations as a confounding factor in association studies

Background: Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. Objective: To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. Design, Setting, and Participants: A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArrayH NT Cycler. Outcome Measurements and Statistical Analysis: Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. Results and Limitations: We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. Conclusion: Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out