560 research outputs found
Significado geológico de las anomalías geofísicas del suroeste del macizo ofiolítico Moa-Baracoa (Cuba Ooriental)
A partir del procesamiento e interpretación de la información geofísica y geológica del suroeste del macizo ofiolítico Moa-Baracoa, se delimitaron nuevas áreas de desarrollo de lateritas Fe+Ni+Co, y de otros tipos de rocas, se esclarecieron aspectos relacionados con los procesos que tienen lugar en los diferentes tipos de rocas, tales como grado de meteorización, arcillosidad, contenido organógeno y acidez. También se evidenciaron las principales deformaciones tectónicas en las ofiolitas y rocas asociadas, algunas de ellas ya reportadas y otras propuestas en esta investigación, las cuales deben ser objetos de estudio en futuras investigaciones en el territorio. Con la combinación del comportamiento del campo magnético y las características aerogamma espectrométricas, se delimitaron zonas con predominio en superficie y en la profundidad de rocas serpentinizadas y por ende las variaciones de espesores de las mismas y de los dos niveles fundamentales del corte ofiolítico en esta región. También se definió el basamento de las rocas que afloran
Evaluación de tres herbicidas en el control pre emergente de arvenses en caña de azúcar (Original)
During the period february-june 2017, a trial was established in plots of commercial areas, in shoot stock, applied before the outbreak of the foliage on a Fluvisol soil (Alluvial). The experiment was carried out in a random block design, with 4 treatments and 4 replications, the area of the plot of 0.009 ha (90 m2) per treatment in the Agricultural Production Cooperative (CPA) "Omar Rivero Fonseca", of the Base Business Unit (UEB) Bartolomé Masó, located in the town of Vuelta del Caño, municipality of Manzanillo, Granma province, with the objective of evaluating the effect of three herbicides on the variety of sugarcane CP 52-43, suckers. The herbicides evaluated were the Mayoral LS 35 at 0,600 L / ha p.c applied in pre-emergence before germination irrigation; Herbicide MerlinGD 75 at 0.270 kg / ha p.c; In addition, the total Merlin 60 SC was used at 0.250 L / ha p.c and finally a Control A (absolute) was used where the effectiveness of each herbicide treated in the cover of weeds could be compared. The product was applied with Matabi backpack hand sprayer five days after the cut (5 DDC), under dry soil conditions, where the results were obtained at the beginning of 2018.Durante el período febrero-junio 2017, se estableció un ensayo en parcelas de áreas comerciales, en cepa de retoño, aplicadas antes del brote del follaje sobre un Fluvisol. El experimento se realizó en un diseño de bloque al azar, con cuatro tratamientos y cuatro réplicas, el área de la parcela de 0,009 ha (90m2) por tratamento en la Cooperativa de Producción Agropecuaria (CPA) “Omar Rivero Fonseca”, de la Unidad Empresarial de Base (UEB) Bartolomé Masó, ubicada en el poblado Vuelta del Caño, municipio de Manzanillo, provincia Granma, con el objetivo de evaluar el efecto de tres herbicidas en la variedad de caña de azúcar CP 52-43, retoños. Los herbicidas evaluados fueron El Mayoral LS 35a 0,600 L/ha p. c aplicado en preemergencia antes del riego de germinación; el herbicida Merlin GD 75 a 0.270 kg/ha p.c; además se utilizó el Merlin total 60 SC a 0.250 L/ha p.c y por último se utilizó un Testigo A (absoluto) donde se pudiera comparar la eficacia de cada herbicida tratado en la cobertura de arvenses. El producto se aplicó con asperjadora manual Mochila Matabia los cincodías después del corte (5 DDC), en condiciones de suelo seco, donde se obtuvieron los resultados a principios del año 2018
Magnetska susceptibilnost i prirodna gama radioaktivnost kao neizravni faktori za karakterizaciju pješčenjaka i vapnenaca zavalja Sabinas
An analysis of magnetic susceptibility and natural gamma radioactivity is presented as indirect proxies of the characteristics of sandstones and limestones of the Sabinas basin. These rocks are located in the sedimentary sequence ranging from the Upper Jurassic to the Cretaceous. The magnetic susceptibility indicates changes in the magnetic composition of these rocks and suggests changes in their weathering degree. Ranges of values of magnetic susceptibility in sandstones and limestones allow classifying them into different groups, suggesting variability regarding conditions of origin and evolution. High values of magnetic susceptibility in limestones can be linked to sedimentation in anoxic or reducing environment, as well as with its siliciclastic content. The natural gamma radioactivity expressed in the contents of Th and relationships U/K and Th/U also suggest the degree of weathering of these rocks, mainly in the sandstones. These relations also highlight others characteristics in the sandstones related the probable provenance of sediments, its distance, degree of weathering and transport dynamics. Using the values of U/K ratio in the sandstones, it is possible to suggest the probable quartzfeldspar relationships. These ratio values classified rocks as arkose or quartzarenite, indicating the maturity of the sandstones. According to the U/K ratio values, most of these rocks which show little maturity are called arkose. Using the values of the Th/U ratio, it is possible to suggest the textures of quartzarenites, classifying them as rocks with fabric that is clast-supported or matrix-supported.U radu je prikazana analiza magnetske susceptibilnosti i prirodne gama radioaktivnosti kao neizravnih faktora svojstava pješčenjaka i vapnenca zavalja Sabinas. Ove se stijene nalaze u sedimentnom slijedu, od gornje jure do krede. Magnetska susceptibilnost ukazuje na promjene u magnetskom sastavu ovih stijena i upućuje na promjene u stupnju njihovog trošenja. Raspon vrijednosti magnetske susceptibilnosti u pješčenjaku i vapnencu omogućuje njihovo razvrstavanje u različite skupine, što upućuje na promjenljivost obzirom na uvjete nastanka i evolucije. Visoke vrijednosti magnetske susceptibilnosti u vapnencima mogu se povezati sa sedimentacijom u anoksičnom ili reduktivnom okolišu, kao i siliciklastičnim sadržajem. Prirodna gama-radioaktivnost izražena u sadržaju torija (Th) i omjeru koncentracija urana i kalija (U / K) te torija i urana (Th / U) također upućuju na stupanj trošenja tih stijena, uglavnom u pješčenjacima. Ovi odnosi ukazuju i na druge karakteristike pješčenjaka vezane uz vjerojatno podrijetlo sedimenata, njegovu udaljenost od izvorišta, stupanj trošenja i dinamiku transporta. Koristeći vrijednosti omjera U / K u pješčenjacima moguće je predložiti vjerojatne proporcije kvarca i feldspata. Temeljem ovih vrijednosti omogućena je klasifikacija stijena kao arkoza ili kvarcarenit, a što ukazuje na zrelost pješčenjaka. Prema vrijednostima omjera U/K većina tih stijena, koji pokazuju malu zrelost, zovu se arkoze. Koristeći vrijednosti Th/U omjera moguće je predložiti teksture kvarcarenita, klasificirajući ih kao klast potporne stijene ili one s matriksom
Magnetic Susceptibility and Natural Gamma Radioactivity as Indirect Indicators of Impurities in Limestones of the Sabinas Basin: Possible Relationships with the Sedimentation Environment
This study presents an analysis of magnetic susceptibility and natural gamma radioactivity as indirect indicators of impurities in Cretaceous limestones of the Sabinas basin, as well as of the possible relation of these physical proper- ties with the changes in the sedimentation environment. Both of these physical properties indicate changes in the degree of impurities and the mineralogical composition of this rock, principally in its organic matter and detritus content. Considering that the sedimentation environment determines the impurities in these rocks, possible environmental conditions at different levels of the Cretaceous were suggested using the magnetic susceptibility, total gam- ma radiation and potassium values, as well as the uranium and thorium concentration in the limestones. The analyses suggest variations in the depth of water table of the basin, which are mainly related to transgressions and marine regressions
Comparison of body mass index (BMI) with the CUN-BAE body adiposity estimator in the prediction of hypertension and type 2 diabetes
Background Obesity is a world-wide epidemic whose prevalence is underestimated by BMI measurements, but CUN-BAE (Clínica Universidad de Navarra - Body Adiposity Estimator) estimates the percentage of body fat (BF) while incorporating information on sex and age, thus giving a better match. Our aim is to compare the BMI and CUN-BAE in determining the population attributable fraction (AFp) for obesity as a cause of chronic diseases. Methods We calculated the Pearson correlation coefficient between BMI and CUN-BAE, the Kappa index and the internal validity of the BMI. The risks of arterial hypertension (AHT) and diabetes mellitus (DM) and the AFp for obesity were assessed using both the BMI and CUN-BAE. Results 3888 white subjects were investigated. The overall correlation between BMI and CUN-BAE was R2 = 0.48, which improved when sex and age were taken into account (R2 > 0.90). The Kappa coefficient for diagnosis of obesity was low (28.7 %). The AFp was 50 % higher for DM and double for AHT when CUN-BAE was used. Conclusions The overall correlation between BMI and CUN-BAE was not good. The AFp of obesity for AHT and DM may be underestimated if assessed using the BMI, as may the prevalence of obesity when estimated from the percentage of BF
The C Allele of ATM rs11212617 Associates With Higher Pathological Complete Remission Rate in Breast Cancer Patients Treated With Neoadjuvant Metformin
Background: The minor allele (C) of the single-nucleotide polymorphism (SNP) rs11212617, located near the ataxia telangiectasia mutated (ATM) gene, has been associated with an increased likelihood of treatment success with metformin in type 2 diabetes. We herein investigated whether the same SNP would predict clinical response to neoadjuvant metformin in women with early breast cancer (BC). Methods: DNA was collected from 79 patients included in the intention-to-treat population of the METTEN study, a phase 2 clinical trial of HER2-positive BC patients randomized to receive either metformin combined with anthracycline/taxane-based chemotherapy and trastuzumab or equivalent regimen without metformin, before surgery. SNP rs11212617 genotyping was assessed using allelic discrimination by quantitative polymerase chain reaction. Results: Logistic regression analyses revealed a significant relationship between the rs11212617 genotype and the ability of treatment arms to achieve a pathological complete response (pCR) in patients (odds ratio [OR](genotypexarm) = 10.33, 95% confidence interval [CI]: 1.29-82.89, p = 0.028). In the metformin-containing arm, patients bearing the rs11212617 C allele had a significantly higher probability of pCR (ORA/C,C/C = 7.94, 95% CI: 1.60-39.42, p = 0.011). Conversely, no association was found between rs11212617 and clinical response in the reference arm (ORA/C,C/C = 0.77, 95% CI: 0.20-2.92, p = 0.700). After controlling for tumor size and hormone receptor status, the rs11212617 C allele remained a significant predictor of pCR solely in the metformin-containing arm. Conclusions: If reproducible, the rs11212617 C allele might warrant consideration as a predictive clinical biomarker to inform the personalized use of metformin in BC patients
Metformin induces a fasting- and antifolate-mimicking modification of systemic host metabolism in breast cancer patients
Certain dietary interventions might improve the therapeutic index of cancer treatments. An alternative to the "drug plus diet" approach is the pharmacological reproduction of the metabolic traits of such diets. Here we explored the impact of adding metformin to an established therapeutic regimen on the systemic host metabolism of cancer patients. A panel of 11 serum metabolites including markers of mitochondria! function and intermediates/products of folate-dependent one-carbon metabolism were measured in paired baseline and post-treatment sera obtained from HER2-positive breast cancer patients randomized to receive either metformin combined with neoadjuvant chemotherapy and trastuzumab or an equivalent regimen without metformin. Metabolite profiles revealed a significant increase of the ketone body beta-hydroxybutyrate and of the TCA intermediate alpha-ketoglutarate in the metformin-containing arm. A significant relationship was found between the follow-up levels of homocysteine and the ability of treatment arms to achieve a pathological complete response (pCR). In the metformin-containing arm, patients with significant elevations of homocysteine tended to have a higher probability of pCR. The addition of metformin to an established anticancer therapeutic regimen causes a fasting-mimicking modification of systemic host metabolism. Circulating homocysteine could be explored as a clinical pharmacodynamic biomarker linking the antifolate-like activity of metformin and biological tumor response
Neoadjuvant Metformin Added to Systemic Therapy Decreases the Proliferative Capacity of Residual Breast Cancer
The proliferative capacity of residual breast cancer (BC) disease indicates the existence of partial treatment resistance and higher probability of tumor recurrence. We explored the therapeutic potential of adding neoadjuvant metformin as an innovative strategy to decrease the proliferative potential of residual BC cells in patients failing to achieve pathological complete response (pCR) after pre-operative therapy. We performed a prospective analysis involving the intention-to-treat population of the (Metformin and Trastuzumab in Neoadjuvancy) METTEN study, a randomized multicenter phase II trial of women with primary, non-metastatic (human epidermal growth factor receptor 2) HER2-positive BC evaluating the efficacy, tolerability, and safety of oral metformin (850 mg twice-daily) for 24 weeks combined with anthracycline/taxane-based chemotherapy and trastuzumab (arm A) or equivalent regimen without metformin (arm B), before surgery. We centrally evaluated the proliferation marker Ki67 on sequential core biopsies using visual assessment (VA) and an (Food and Drug Administration) FDA-cleared automated digital image analysis (ADIA) algorithm. ADIA-based pre-operative values of high Ki67 (>= 20%), but not those from VA, significantly predicted the occurrence of pCR in both arms irrespective of the hormone receptor status (p = 0.024 and 0.120, respectively). Changes in Ki67 in residual tumors of non-pCR patients were significantly higher in the metformin-containing arm (p = 0.025), with half of all patients exhibiting high Ki67 at baseline moving into the low-Ki67 (<20%) category after neoadjuvant treatment. By contrast, no statistically significant changes in Ki67 occurred in residual tumors of the control treatment arm (p = 0.293). There is an urgent need for innovative therapeutic strategies aiming to provide the protective effects of decreasing Ki67 after neoadjuvant treatment even if pCR is not achieved. Metformin would be evaluated as a safe candidate to decrease the aggressiveness of residual disease after neoadjuvant (pre-operative) systemic therapy of BC patients
A phase 2 trial of neoadjuvant metformin in combination with trastuzumab and chemotherapy in women with early HER2-positive breast cancer: the METTEN study
The METTEN study assessed the efficacy, tolerability, and safety of adding metformin to neoadjuvant chemotherapy plus trastuzumab in early HER2-positive breast cancer (BC). Women with primary, non-metastatic HER2-positive BC were randomized (1:1) to receive metformin (850 mg twice-daily) for 24 weeks concurrently with 12 cycles of weekly paclitaxel plus trastuzumab, followed by four cycles of 3-weekly FE75C plus trastuzumab (arm A), or equivalent regimen without metformin (arm B), followed by surgery. Primary endpoint was the rate of pathological complete response (pCR) in the per-protocol efficacy population. pCR rate was numerically higher in the metformin-containing arm A (19 of 29 patients [65.5%, 95% CI: 47.3-80.1]) than in arm B (17 of 29 patients [58.6%, 95% CI: 40.7-74.5]; OR 1.34 [95% CI: 0.46-3.89], P = 0.589). The rate of breast-conserving surgery was 79.3% and 58.6% in arm A and B (P = 0.089), respectively. Blood metformin concentrations (6.2 μmol/L, 95% CI: 3.6-8.8) were within the therapeutic range. Seventy-six percent of patients completed the metformin-containing regimen; 13% of patients in arm A dropped out because of metformin-related gastrointestinal symptoms. The most common adverse events (AEs) of grade ≥3 were neutropenia in both arms and diarrhea in arm A. None of the serious AEs was deemed to be metformin-related. Addition of anti-diabetic doses of metformin to a complex neoadjuvant regimen was well tolerated and safe. Because the study was underpowered relative to its primary endpoint, the efficacy data should be interpreted with caution
The C Allele of ATM rs11212617 Associates With Higher Pathological Complete Remission Rate in Breast Cancer Patients Treated With Neoadjuvant Metformin
Background: The minor allele (C) of the single-nucleotide polymorphism (SNP) rs11212617, located near the ataxia telangiectasia mutated (ATM) gene, has been associated with an increased likelihood of treatment success with metformin in type 2 diabetes. We herein investigated whether the same SNP would predict clinical response to neoadjuvant metformin in women with early breast cancer (BC).Methods: DNA was collected from 79 patients included in the intention-to-treat population of the METTEN study, a phase 2 clinical trial of HER2-positive BC patients randomized to receive either metformin combined with anthracycline/taxane-based chemotherapy and trastuzumab or equivalent regimen without metformin, before surgery. SNP rs11212617 genotyping was assessed using allelic discrimination by quantitative polymerase chain reaction.Results: Logistic regression analyses revealed a significant relationship between the rs11212617 genotype and the ability of treatment arms to achieve a pathological complete response (pCR) in patients (odds ratio [OR]genotype×arm = 10.33, 95% confidence interval [CI]: 1.29–82.89, p = 0.028). In the metformin-containing arm, patients bearing the rs11212617 C allele had a significantly higher probability of pCR (ORA/C,C/C = 7.94, 95%CI: 1.60–39.42, p = 0.011). Conversely, no association was found between rs11212617 and clinical response in the reference arm (ORA/C,C/C = 0.77, 95%CI: 0.20–2.92, p = 0.700). After controlling for tumor size and hormone receptor status, the rs11212617 C allele remained a significant predictor of pCR solely in the metformin-containing arm.Conclusions: If reproducible, the rs11212617 C allele might warrant consideration as a predictive clinical biomarker to inform the personalized use of metformin in BC patients.Trial Registration: EU Clinical Trials Register, EudraCT number 2011-000490-30. Registered 28 February 2011, https://www.clinicaltrialsregister.eu/ctr-search/trial/2011-000490-30/ES
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