62 research outputs found
Secondary structure of Ac-Ala-LysH polyalanine peptides (=5,10,15) in vacuo: Helical or not?
The polyalanine-based peptide series Ac-Ala_n-LysH+ (n=5-20) is a prime
example that a secondary structure motif which is well-known from the solution
phase (here: helices) can be formed in vacuo. We here revisit this conclusion
for n=5,10,15, using density-functional theory (van der Waals corrected
generalized gradient approximation), and gas-phase infrared vibrational
spectroscopy. For the longer molecules (n=10,15) \alpha-helical models provide
good qualitative agreement (theory vs. experiment) already in the harmonic
approximation. For n=5, the lowest energy conformer is not a simple helix, but
competes closely with \alpha-helical motifs at 300K. Close agreement between
infrared spectra from experiment and ab initio molecular dynamics (including
anharmonic effects) supports our findings.Comment: 4 pages, 4 figures, Submitted to JPC Letter
Exploiting the potential of autophagy in cisplatin therapy: A new strategy to overcome resistance
Resistance to cisplatin is a major challenge in the current cancer therapy. In
order to explore new therapeutic strategies to cisplatin resistance, we evaluated,
in a model of lung cancer (H1299 and H460 cell lines), the nature of the pathways
leading to cell death. We observed that H1299 displayed a natural resistance to
cisplatin due to an inability to trigger an apoptotic response that correlates with
the induction of autophagy. However, pharmacological and genetic approaches
showed how autophagy was a mechanism associated to cell death rather than to
resistance. Indeed, pro-autophagic stimuli such as mTOR or Akt inhibition mediate
cell death in both cell lines to a similar extent. We next evaluated the response to
a novel platinum compound, monoplatin, able to promote cell death in an exclusive
autophagy-dependent manner. In this case, no differences were observed between
both cell lines. Furthermore, in response to monoplatin, two molecular hallmarks
of cisplatin response (p53 and MAPKs) were not implicated, indicating the ability
of this pro-autophagic compound to overcome cisplatin resistance. In summary,
our data highlight how induction of autophagy could be used in cisplatin resistant
tumours and an alternative treatment for p53 mutated patient in a synthetic lethally
approach.This work was supported by grants from FundaciĂłn
Leticia Castillejo Castillo and Ministerio de EconomĂa y
Competitividad (grant SAF2012-30862 to RSP and grant
CTQ2011-24434 to FAJ). RSP Research Institute, and the
work carried out in his laboratory receive support from the
European Community through the regional development
funding program (FEDER). JGC received funding from
the Regional Ministry of Education and Science of
CastillaâLa Mancha (FPI-JCCM) and from FundaciĂłn
Leticia Castillejo Castillo. MCC and RSP have a contract
from the INCRECYT progra
Exploiting the potential of autophagy in cisplatin therapy: a new strategy to overcome resistance
Resistance to cisplatin is a major challenge in the current cancer therapy. In order to explore new therapeutic strategies to cisplatin resistance, we evaluated, in a model of lung cancer (H1299 and H460 cell lines), the nature of the pathways leading to cell death. We observed that H1299 displayed a natural resistance to cisplatin due to an inability to trigger an apoptotic response that correlates with the induction of autophagy. However, pharmacological and genetic approaches showed how autophagy was a mechanism associated to cell death rather than to resistance. Indeed, pro-autophagic stimuli such as mTOR or Akt inhibition mediate cell death in both cell lines to a similar extent. We next evaluated the response to a novel platinum compound, monoplatin, able to promote cell death in an exclusive autophagy-dependent manner. In this case, no differences were observed between both cell lines. Furthermore, in response to monoplatin, two molecular hallmarks of cisplatin response (p53 and MAPKs) were not implicated, indicating the ability of this pro-autophagic compound to overcome cisplatin resistance. In summary, our data highlight how induction of autophagy could be used in cisplatin resistant tumours and an alternative treatment for p53 mutated patient in a synthetic lethally approach
TRIB1 regulates tumor growth via controlling tumor-associated macrophage phenotypes and is associated with breast cancer survival and treatment response
Methods: Bioinformatic analysis was used to investigate the link between TRIB1 expression in breast cancer and therapeutic response to chemotherapy. In vivo models of breast cancer included immune-competent mice to characterize the consequences of altered (reduced or elevated) myeloid Trib1 expression on tumor growth and composition of stromal immune cell populations.
Results: TRIB1 was highly expressed by TAMs in breast cancer and high TRIB1 expression correlated with response to chemotherapy and patient survival. Both overexpression and knockout of myeloid Trib1 promote mouse breast tumor growth, albeit through different molecular mechanisms. Myeloid Trib1 deficiency led to an early acceleration of tumor growth, paired with a selective reduction in perivascular macrophage numbers in vivo and enhanced oncogenic cytokine expression in vitro. In contrast, elevated levels of Trib1 in myeloid cells led to an increased late-stage mammary tumor volume, coupled with a reduction of NOS2 expressing macrophages and an overall reduction of macrophages in hypoxic tumor regions. In addition, we show that myeloid Trib1 is a previously unknown, negative regulator of the anti-tumor cytokine IL-15, and that increased myeloid Trib1 expression leads to reduced IL-15 levels in mammary tumors, with a consequent reduction in the number of T-cells that are key to anti-tumor immune responses.
Conclusions: Together, these results define a key role for TRIB1 in chemotherapy responses for human breast cancer and provide a mechanistic understanding for the importance of the control of myeloid TRIB1 expression in the development of this disease
Vaccination adjuvated against hepatitis B in Spanish National Healthcare System (SNS) workers typed as non-responders to conventional vaccines
[EN] Trial Design: An interventional, phase 4, single group assignment, without masking (open label), preventive clinical trial was carried out in health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B. Methods: 67 health workers with biological risk in their tasks, who have been filed as non-responders to conventional vaccination against Hepatitis B, were enrolled in the Clinical Trial. All participants were from 18 years up to 64 years old. Inclusion Criteria: NHS workers -including university students doing their internships in health centres dependent on the National Health System (inclusion of students is regulated and limited by specific instructions on labour prevention in each autonomous community)- classified as non-responders. The criteria defining them as non-responders to the conventional hepatitis B vaccine is anti HBsAb titers < 10 mUI/ml following the application of six doses of conventional vaccine at 20 lg doses (two complete guidelines). The objective of this study was to provide Health workersstaff with an additional protection tool against hepatitis B infection, and to evaluate the efficacy of the adjuvanted vaccine in healthy non-responders to conventional hepatitis B vaccine. The primary outcome was the measurement of antibody antiHBs before the first Fendrix dose and a month after the administration of each dose. Other outcome was collection of adverse effects during administration and all those that could be related to the vaccine and that occur within 30 days after each dose. In this study, only one group was assigned. There was no randomization or masking.
Results: The participants were recruited between April 13, 2018 and October 31, 2019. 67 participants
were enrolled in the Clinical Trial and included the analyses. The primary immunisation consists of 4 separate
0.5 ml doses of Fendrix , administered at the following schedule: 1 month, 2 months and 6 months from the date of the first dose. Once the positivity was reached in any of the doses, the participant finished the study and was not given the following doses. 68.66% (46 out 67) had a positive response to first dose of Fendrix. 57.14% (12 out 21) had a positive response to second dose of Fendrix . 22.22% (2 out 9) had a positive response to third dose of Fendrix and 42.96% (3 out 7) had a positive response to last dose of Fendrix. Overall, 94.02% (64 out 67) of participants had a positive response to Fendrix . No serious adverse event occurred. Conclusions: The use of Fendrix , is a viable vaccine alternative for NHS workers classified as âânonrespondersâ. Revaccination of healthy non-responders with Fendrix, resulted in very high proportions
of responders without adverse events. Trial registration: The trial was registered in the Spanish National Trial Register (REEC), ClinicalTrials.gov and inclusion has been stopped (identifier NCT03410953; EudraCT-number 2016-004991-23). Funding: GRS 1360/A/16: Call for aid for the financing of research projects in biomedicine, health management and socio-health care to be developed in the centres of the Regional Health Management of Autonomous Community of Castile-Leon. In addition, this work has been supported by the Spanish Platform for Clinical Research and Clinical Trials, SCReN (Spanish Clinical Research Network), funded by the Subdirectorate General for Research Evaluation and Promotion of the Carlos III Health Institute (ISCIII), through the project PT13/0002/0039 and project PT17/0017/0023 integrated in the State Plan for R&D&I 2013â2016 and co-financed by and the European Regional Development Fund (ERDF)
Endocrine and Growth Abnormalities in 4H Leukodystrophy Caused by Variants in POLR3A, POLR3B, and POLR1C.
CONTEXT: 4H or POLR3-related leukodystrophy is an autosomal recessive disorder typically characterized by hypomyelination, hypodontia, and hypogonadotropic hypogonadism, caused by biallelic pathogenic variants in POLR3A, POLR3B, POLR1C, and POLR3K. The endocrine and growth abnormalities associated with this disorder have not been thoroughly investigated to date. OBJECTIVE: To systematically characterize endocrine abnormalities of patients with 4H leukodystrophy. DESIGN: An international cross-sectional study was performed on 150 patients with genetically confirmed 4H leukodystrophy between 2015 and 2016. Endocrine and growth abnormalities were evaluated, and neurological and other non-neurological features were reviewed. Potential genotype/phenotype associations were also investigated. SETTING: This was a multicenter retrospective study using information collected from 3 predominant centers. PATIENTS: A total of 150 patients with 4H leukodystrophy and pathogenic variants in POLR3A, POLR3B, or POLR1C were included. MAIN OUTCOME MEASURES: Variables used to evaluate endocrine and growth abnormalities included pubertal history, hormone levels (estradiol, testosterone, stimulated LH and FSH, stimulated GH, IGF-I, prolactin, ACTH, cortisol, TSH, and T4), and height and head circumference charts. RESULTS: The most common endocrine abnormalities were delayed puberty (57/74; 77% overall, 64% in males, 89% in females) and short stature (57/93; 61%), when evaluated according to physician assessment. Abnormal thyroid function was reported in 22% (13/59) of patients. CONCLUSIONS: Our results confirm pubertal abnormalities and short stature are the most common endocrine features seen in 4H leukodystrophy. However, we noted that endocrine abnormalities are typically underinvestigated in this patient population. A prospective study is required to formulate evidence-based recommendations for management of the endocrine manifestations of this disorder
Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.
BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden
Mullite macro-needles for reinforcement of refractory castables
Abstract Ceramic macro-needles incorporation as reinforcement in commercial refractory castable was studied. Ceramic macro-needles (Ă2x20 mm) were made from kaolinite clay and gibbsite to obtain mullite as the main crystalline phase. Specimens with the ceramic reinforcement were evaluated by compression after being treated at two temperatures (815 and 1400 °C). The results were compared with those obtained using the same commercial concrete but reinforced with steel fibers and without reinforcement. Compression values presented by specimens with ceramic macro-needles were 74% and 50% higher than specimens with steel fibers after exposition to 815 and 1400 °C, respectively. Based on these results, it was established that ceramic macro-needles are a feasible solution to improve the mechanical resistance of castables exposed to high temperatures
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