120 research outputs found
Unimodular cosmology and the weight of energy
Some models are presented in which the strength of the gravitational coupling
of the potential energy relative to the same coupling for the kinetic energy
is, in a precise sense, adjustable. The gauge symmetry of these models consists
of those coordinate changes with unit jacobian.Comment: LaTeX, 23 pages, conclusions expanded. Two paragraphs and a new
reference adde
The fast-growing Brucella suis Biovar 5 depends on phosphoenolpyruvate carboxykinase and pyruvate phosphate dikinase but not on Fbp and GlpX fructose-1, 6-bisphosphatases or isocitrate lyase for full virulence in laboratory models
Bacteria of the genus Brucella infect a range of vertebrates causing a worldwide extended zoonosis. The best-characterized brucellae infect domestic livestock, behaving as stealthy facultative intracellular parasites. This stealthiness depends on envelope molecules with reduced pathogen-associated molecular patterns, as revealed by the low lethality and ability to persist in mice of these bacteria. Infected cells are often engorged with brucellae without signs of distress, suggesting that stealthiness could also reflect an adaptation of the parasite metabolism to use local nutrients without harming the cell. To investigate this, we compared key metabolic abilities of Brucella abortus 2308 Wisconsin (2308W), a cattle biovar 1 virulent strain, and B. suis 513, the reference strain of the ancestral biovar 5 found in wild rodents. B. suis 513 used a larger number of C substrates and showed faster growth rates in vitro, two features similar to those of B. microti, a species phylogenomically close to B. suis biovar 5 that infects voles. However, whereas B. microti shows enhanced lethality and reduced persistence in mice, B. suis 513 was similar to B. abortus 2308W in this regard. Mutant analyses showed that B. suis 513 and B. abortus 2308W were similar in that both depend on phosphoenolpyruvate synthesis for virulence but not on the classical gluconeogenic fructose-1, 6-bisphosphatases Fbp-GlpX or on isocitrate lyase (AceA). However, B. suis 513 used pyruvate phosphate dikinase (PpdK) and phosphoenolpyruvate carboxykinase (PckA) for phosphoenolpyruvate synthesis in vitro while B. abortus 2308W used only PpdK. Moreover, whereas PpdK dysfunction causes attenuation of B. abortus 2308W in mice, in B. suis, 513 attenuation occurred only in the double PckA-PpdK mutant. Also contrary to what occurs in B. abortus 2308, a B. suis 513 malic enzyme (Mae) mutant was not attenuated, and this independence of Mae and the role of PpdK was confirmed by the lack of attenuation of a double Mae-PckA mutant. Altogether, these results decouple fast growth rates from enhanced mouse lethality in the brucellae and suggest that an Fbp-GlpX-independent gluconeogenic mechanism is ancestral in this group and show differences in central C metabolic steps that may reflect a progressive adaptation to intracellular growth
Depth Dependent Relationships between Temperature and Ocean Heterotrophic Prokaryotic Production
9 páginas, 2 figuras, 1 tabla.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these termsCorrigendum: Depth Dependent Relationships between Temperature and Ocean Heterotrophic Prokaryotic Production, Frontiers in Marine Science 4: 91 (2017) https://doi.org/10.3389/fmars.2017.00091Marine prokaryotes play a key role in cycling of organic matter and nutrients in the ocean. Using a unique dataset (>14,500 samples), we applied a space-for-time substitution analysis to assess the temperature dependence of prokaryotic heterotrophic production (PHP) in epi- (0–200 m), meso- (201–1000 m) and bathypelagic waters (1001–4000 m) of the global ocean. Here, we show that the temperature dependence of PHP is fundamentally different between these major oceanic depth layers, with an estimated ecosystem-level activation energy (Ea) of 36 ± 7 kJ mol−1 for the epipelagic, 72 ± 15 kJ mol−1 for the mesopelagic and 274 ± 65 kJ mol−1 for the bathypelagic realm. We suggest that the increasing temperature dependence with depth is related to the parallel vertical gradient in the proportion of recalcitrant organic compounds. These Ea predict an increased PHP of about 5, 12, and 55% in the epi-, meso-, and bathypelagic ocean, respectively, in response to a water temperature increase by 1°C. Hence, there is indication that a major thus far underestimated feedback mechanism exists between future bathypelagic ocean warming and heterotrophic prokaryotic activityFinancial support for this project was provided by the Australian Institute of Marine Science (AIMS) and a grant from the Carlsberg Foundation to CL. XA, XM and JG were funded by the Malaspina expedition 2010 (grant n° CSD2008–00077) and HOTMIX (grant n° CTM2011–30010–C02–02) projects. TR was supported by the PADOM project (Austrian Science Fund grant n° P23221-B11). GH was funded by the Austrian Science Fund (FWF) project I486-B09 and by the European Research Council under the European Community's Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement No. 268595 (MEDEA project).Peer reviewe
Early imaging and molecular changes with neoadjuvant bevacizumab in stage ii/iii breast cancer
This prospective, phase II study evaluated novel biomarkers as predictors of response to bevacizumab in patients with breast cancer (BC), using serial imaging methods and gene expression analysis. Patients with primary stage II/III BC received bevacizumab 15 mg/kg (cycle 1; C1), then four cycles of neoadjuvant docetaxel doxorubicin, and bevacizumab every 3 weeks (C2–C5). Tumour proliferation and hypoxic status were evaluated using18F-fluoro-3'-deoxy-3'-L-fluorothymidine (FLT)-and18F-fluoromisonidazole (FMISO)-positron emission tomography (PET) at baseline, and during C1 and C5. Pre-and post-bevacizumab vascular changes were evaluated using dynamic contrastenhanced magnetic resonance imaging (DCE-MRI). Molecular biomarkers were assessed using microarray analysis. A total of 70 patients were assessed for treatment efficacy. Significant decreases from baseline in tumour proliferation (FLT-PET), vascularity, and perfusion (DCE-MRI) were observed during C1 (p = 0.001), independent of tumour subtype. Bevacizumab treatment did not affect hypoxic tumour status (FMISO-PET). Significant changes in the expression of 28 genes were observed after C1. Changes in vascular endothelial growth factor receptor (VEGFR)-2p levels were observed in 65 patients, with a > 20% decrease in VEGFR-2p observed in 13/65. Serial imaging techniques. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
A randomized phase II trial of platinum salts in basal-like breast cancer patients in the neoadjuvant setting. Results from the GEICAM/2006-03, multicenter study
Este artículo ha sido publicado en Breast Cancer Research and Treatment
Siguiendo las instruciones y dado que la revista dice que el artículo fue publicado tal cual se envió, hacemos un postprint copiando dicho texto enviado por la revista en un documento Word y luego convertido a PDF para así respetar el contenido, y sin dar acceso a los "extras" de la versión publicada.
Esta versión tiene Licencia Creative Commons CC-BY-NC-NDAbstract Chemotherapy remains as the only systemic treatment option available for basal-like breast cancer (BC) patients. Preclinical models and several phase II studies suggested that platinum salts are active drugs in this BC subtype though there is no randomized study supporting this hypothesis. This study investigates if the addition of carboplatin to a combination of an alkylating agent together with anthracyclines and taxanes is able to increase the efficacy in the neoadjuvant treatment context. Patients with operable breast cancer and immunophenotypically defined basal-like disease (ER-/PR-/HER2- and cytokeratin 5/6?
or EGFR?) were recruited. Patients were randomized to receive EC (epirubicin 90 mg/m2 plus cyclophosphamide
600 mg/m2 for 4 cycles) followed either by D (docetaxel 100 mg/m2 9 4 cycles; EC–D) or DCb (docetaxel 75 mg/
m2 plus carboplatin AUC 6 9 4 cycles; EC–DCb). The primary end point was pathological complete response
(pCR) in the breast following the Miller and Payne criteria. Ninety-four patients were randomized (46 EC–D, 48 EC–
DCb). pCR rate in the breast was seen in 16 patients (35 %) with EC–D and 14 patients (30 %) with EC–DCb
(P value = 0.61). pCR in the breast and axilla was seen in 30 % of patients in both arms. The overall clinical response
rate was 70 % (95 % CI 56–83) in the EC–D arm and 77 % (95 % CI 65–87) in the EC–DCb arm. Grade 3/4 toxicity
was similar in both arms. The addition of carboplatin to conventional chemotherapy with EC–D in basal-like breast
cancer patients did not improve the efficacy probably because they had already received an alkylating agent.
These findings should be taken into consideration when developing new agents for this disease.This trial was partially supported by Pfizer S.L.U
A new scenario in metastatic renal cell carcinoma: a SOG‑GU consensus
[Abstract]
Background This article describes and compares approved targeted therapies and the newer immunotherapy agents.
Materials and methods This article especially performs an in-depth review of currently available data for tivozanib, explaining its mechanism of action, its safety profle and its role as an efcacy drug in the management of renal cancer.
Results Despite the fact that the treatment of advanced RCC has been dramatically modifed in recent years, durable remissions are scarce and it remains a lethal disease. For frst- and second-line therapy, there is now growing evidence to guide
the selection of the appropriate treatment.
Conclusions Several TKIs are standard of care at diferent settings. Among those approved TKIs, tivozanib has similar
efcacy than others with a better safety profle. The use of prognostic factors is critical to the selection of optimal therapy
Effects of Vivifrail multicomponent intervention on functional capacity: a multicentre, randomized controlled trial
Background: physical exercise is an effective strategy for preserving functional capacity and improving the symptoms of frailty in older adults. In addition to functional gains, exercise is considered to be a cornerstone for enhancing cognitive function in frail older adults with cognitive impairment and dementia. We assessed the effects of the Vivifrail exercise intervention for functional capacity, cognition, and well-being status in community-dwelling older adults. Methods: in a multicentre randomized controlled trial conducted in three tertiary hospitals in Spain, a total of 188 older patients with mild cognitive impairment or mild dementia (aged >75 years) were randomly assigned to an exercise intervention (n = 88) or a usual-care, control (n = 100) group. The intervention was based on the Vivifrail tailored multicomponent exercise programme, which included resistance, balance, flexibility (3 days/week), and gait-retraining exercises (5 days/week) and was performed for three consecutive months (http://vivifrail.com). The usual-care group received habitual outpatient care. The main endpoint was change in functional capacity from baseline to 1 and 3 months, assessed with the Short Physical Performance Battery (SPPB). Secondary endpoints were changes in cognitive function and handgrip strength after 1 and 3 months, and well-being status, falls, hospital admission rate, visits to the emergency department, and mortality after 3 months. Results: the Vivifrail exercise programme provided significant benefits in functional capacity over usual-care. The mean adherence to the exercise sessions was 79% in the first month and 68% in the following 2 months. The intervention group showed a mean increase (over the control group) of 0.86 points on the SPPB scale (95% confidence interval [CI] 0.32, 1.41 points; P 0.05). Conclusions: the Vivifrail exercise training programme is an effective and safe therapy for improving functional capacity in community-dwelling frail/prefrail older patients with mild cognitive impairment or mild dementia and also seems to have beneficial effect on cognition, muscle function, and mood status.This study has been funded by a Gobierno de Navarra projectgrant and fondos FEDER (Resolución 426/2016, del 30 deseptiembre 28/16). Mikel Izquierdo is funded by a researchgrant PI17/01814 of the Ministerio de Economía, Industria yCompetitividad (ISCIII, FEDER)
Health-related quality of life with palbociclib plus endocrine therapy versus capecitabine in postmenopausal patients with hormone receptor–positive metastatic breast cancer: Patient-reported outcomes in the PEARL study
Background: The PEARL study showed that palbociclib plus endocrine therapy (palbociclib/ET) was not superior to capecitabine in improving progression-free survival in postmenopausal patients with metastatic breast cancer resistant to aromatase inhibitors, but was better tolerated. This analysis compared patient-reported outcomes. Patients and methods: The PEARL quality of life (QoL) population comprised 537 patients, 268 randomised to palbociclib/ET (exemestane or fulvestrant) and 269 to capecitabine. Patients completed the European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-BR23 and EQ-5D-3L questionnaires. Changes from the baseline and time to deterioration (TTD) were analysed using linear mixed-effect and stratified Cox regression models, respectively. Results: Questionnaire completion rate was high and similar between treatment arms. Significant differences were observed in the mean change in global health status (GHS)/QoL scores from the baseline to cycle 3 (2.9 for palbociclib/ET vs. -2.1 for capecitabine (95% confidence interval [CI], 1.4–8.6; P = 0.007). The median TTD in GHS/QoL was 8.3 months for palbociclib/ET versus 5.3 months for capecitabine (adjusted hazard ratio, 0.70; 95% CI, 0.55–0.89; P = 0.003). Similar improvements for palbociclib/ET were also seen for other scales as physical, role, cognitive, social functioning, fatigue, nausea/vomiting and appetite loss. No differences were observed between the treatment arms in change from the baseline in any item of the EQ-5D-L3 questionnaire as per the overall index score and visual analogue scale. Conclusion: Patients receiving palbociclib/ET experienced a significant delay in deterioration of GHS/QoL and several functional and symptom scales compared with capecitabine, providing additional evidence that palbociclib/ET is better tolerated. Trial registration number: NCT02028507 (ClinTrials.gov). EudraCT study number: 2013-003170-27. © 2021 The Author(s
Anthracological evidence suggests naturalness of Pinus pinaster in inland southwestern Iberia
The study of well-preserved archaeological charcoals in the pre-Roman Iron Age settlement of Castillejos II (Badajoz, Spain) is used to reconstruct environmental conditions and land-use practices in vegetation landscapes in the southwest of the Iberian Peninsula before the arrival of Roman civilization. The results support that, while evergreen Quercus forests dominated during the Holocene, Pinus pinaster existed as a natural element of southwestern Iberian Peninsula vegetation. Although its presence could be linked to anthropogenic disturbance or fire history, it is suggested that P. pinaster populations survived during the Holocene in the region, mixed with oaks or in monospecific stands in mountain enclaves. This hypothesis contrasts with previous assumptions that P. pinaster was not autochthonous in the area
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