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Cancer immunotherapies strive to overcome tumor-induced immune suppression and activate antitumor immune responses. Although cytotoxic T lymphocytes (CTLs) play a pivotal role in this process, natural killer (NK) cells have also demonstrated remarkable tumor-killing abilities, given their ability to discriminate tumor cells from normal cells and mediate specific antitumoral cytotoxicity. NK cells activation depends on a balance between activation and inhibition signals from several ligands/receptors. Among them, MICA/NKG2D axis is a master regulator of NK activation. MHC class I chain-related polypeptide A (MICA) expression is upregulated by many tumor cell lines and primary tumors and serves as a ligand for the activating NK group 2D (NKG2D) receptor on NK cells and subpopulations of T cells. However, cancer cells can cleave MICA, making it soluble and de-targeting tumor cells from NK cells, leading to tumor immune escape.In this study, we present ICOVIR15KK-MICAMut, an oncolytic adenovirus (OAdv) armed with a transgene encoding a non-cleavable MICA to promote NK-mediated cell-killing capacity and activate the immune response against cancer cells. We first demonstrated the correct MICA overexpression from infected cells. Moreover, our MICA-expressing OAdv promotes higher NK activation and killing capacity than the non-armed virus in vitro. In addition, the armed virus also demonstrated significant antitumor activity in immunodeficient mice in the presence of human PBMCs, indicating the activation of human NK cells. Finally, OAdv-MICA overexpression in immunocompetent tumor-bearing mice elicits tumor-specific immune response resulting in a greater tumor growth control.In summary, this study highlights the significance of NK cells in cancer immunotherapy and presents an innovative approach using a modified oncolytic virus to enhance NK cell activation and antitumor immune response. These findings suggest promising potential for future research and clinical applications.
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Adenoviridae , Subfamília K de Receptores Semelhantes a Lectina de Células NK , Humanos , Animais , Camundongos , Adenoviridae/genética , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Ativação Linfocitária , Genes MHC Classe I , Evasão TumoralRESUMO
Collagen expression and structure in the tumour microenvironment are associated with tumour development and therapy response. Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is a widely expressed inhibitory collagen receptor. LAIR-2 is a soluble homologue of LAIR-1 that competes for collagen binding. Multiple studies in mice implicate blockade of LAIR-1:collagen interaction in cancer as a promising therapeutic strategy. Here, we investigated the role of LAIR-1 in anti-tumour responses. We show that although LAIR-1 inhibits activation, proliferation, and cytokine production of mouse T cells in vitro, tumour outgrowth in LAIR-1-deficient mice did not differ from wild type mice in several in vivo tumour models. Furthermore, treatment with NC410, a LAIR-2-Fc fusion protein, did not result in increased tumour clearance in tested immunocompetent mice, which contrasts with previous data in humanized mouse models. This discrepancy may be explained by our finding that NC410 blocks human LAIR-1:collagen interaction more effectively than mouse LAIR-1:collagen interaction. Despite the lack of therapeutic impact of NC410 monotherapy, mice treated with a combination of NC410 and anti-programmed death-ligand 1 did show reduced tumour burden and increased survival. Using LAIR-1-deficient mice, we showed that this effect seemed to be dependent on the presence of LAIR-1. Taken together, our data demonstrate that the absence of LAIR-1 signalling alone is not sufficient to control tumour growth in multiple immunocompetent mouse models. However, combined targeting of LAIR-1 and PD-L1 results in increased tumour control. Thus, additional targeting of the LAIR-1:collagen pathway with NC410 is a promising approach to treating tumours where conventional immunotherapy is ineffective.
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Antígeno B7-H1 , Neoplasias , Animais , Humanos , Camundongos , Colágeno , Modelos Animais de Doenças , Leucócitos , Ligantes , Neoplasias/tratamento farmacológico , Microambiente TumoralRESUMO
Tumors are highly complex and heterogenous ecosystems where malignant cells interact with healthy cells and the surrounding extracellular matrix (ECM). Solid tumors contain large ECM deposits that can constitute up to 60% of the tumor mass. This supports the survival and growth of cancerous cells and plays a critical role in the response to immune therapy. There is untapped potential in targeting the ECM and cell-ECM interactions to improve existing immune therapy and explore novel therapeutic strategies. The most abundant proteins in the ECM are the collagen family. There are 28 different collagen subtypes that can undergo several post-translational modifications (PTMs), which alter both their structure and functionality. Here, we review current knowledge on tumor collagen composition and the consequences of collagen PTMs affecting receptor binding, cell migration and tumor stiffness. Furthermore, we discuss how these alterations impact tumor immune responses and how collagen could be targeted to treat cancer.
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Colágeno , Matriz Extracelular , Imunoterapia , Neoplasias , Humanos , Neoplasias/terapia , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Colágeno/metabolismo , Imunoterapia/métodos , Matriz Extracelular/metabolismo , Animais , Processamento de Proteína Pós-TraducionalRESUMO
Tissue repair is disturbed in fibrotic diseases like systemic sclerosis (SSc), where the deposition of large amounts of extracellular matrix components such as collagen interferes with organ function. LAIR-1 is an inhibitory collagen receptor highly expressed on tissue immune cells. We questioned whether in SSc, impaired LAIR-1-collagen interaction is contributing to the ongoing inflammation and fibrosis. We found that SSc patients do not have an intrinsic defect in LAIR-1 expression or function. Instead, fibroblasts from healthy controls and SSc patients stimulated by soluble factors that drive inflammation and fibrosis in SSc deposit disorganized collagen products in vitro, which are dysfunctional LAIR-1 ligands. This is dependent of matrix metalloproteinases and platelet-derived growth factor receptor signaling. In support of a non-redundant role of LAIR-1 in the control of fibrosis, we found that LAIR-1-deficient mice have increased skin fibrosis in response to repeated injury and in the bleomycin mouse model for SSc. Thus, LAIR-1 represents an essential control mechanism for tissue repair. In fibrotic disease, excessive collagen degradation may lead to a disturbed feedback loop. The presence of functional LAIR-1 in patients provides a therapeutic opportunity to reactivate this intrinsic negative feedback mechanism in fibrotic diseases.
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Colágeno , Modelos Animais de Doenças , Fibroblastos , Fibrose , Camundongos Knockout , Receptores Imunológicos , Escleroderma Sistêmico , Animais , Humanos , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia , Camundongos , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Colágeno/metabolismo , Fibroblastos/metabolismo , Bleomicina/efeitos adversos , Pele/patologia , Pele/metabolismo , Pele/imunologia , Transdução de Sinais , Masculino , Feminino , Células CultivadasRESUMO
Correction for 'Inkjet-printed O2 gas sensors in intelligent packaging' by M. D. Fernández-Ramos et al., Analyst, 2021, 146, 3177-3184, https://doi.org/10.1039/D1AN00295C.
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Correction for 'An optical sensor for the sensitive determination of formaldehyde gas based on chromotropic acid and 4-aminoazobenzene immobilized in a hydrophilic membrane' by M. D. Fernández-Ramos et al., Analyst, 2023, 148, 4533-4538, https://doi.org/10.1039/D3AN01056B.
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The food industry uses indigo carmine (IC) extensively as a blue colorant to make processed food for young children and the general population more attractive. Given that IC can act as a ligand, this raises concerns about its interactions with essential metal ions in the human body. In view of this interest, in the present investigation, the copper(II)/indigo carmine system was thoroughly investigated in aqueous solution and in the solid state, and the detailed structural characterization of the complexes formed between copper(II) and the ligand was performed using spectroscopic methods, complemented with DFT and TD-DFT calculations. NMR and UV/Vis absorption spectroscopy studies of the ligand in the presence of copper(II) show changes that clearly reveal strong complexation. The results point to the formation of complexes of 1:1, 1:2 and 2:1 Cu(II)/IC stoichiometry in aqueous solution, favored in the pH range 6-10 and stable over time. DFT calculations indicate that the coordination of the ligand to the metal occurs through the adjacent carbonyl and amine groups and that the 1:1 and the 2:1 complexes have distorted tetrahedral metal centers, while the 1:2 structure is five-coordinate with a square pyramidal geometry. FTIR results, together with EDS data and DFT calculations, established that the complex obtained in the solid state likely consists of a polymeric arrangement involving repetition of the 1:2 complex unit. These results are relevant in the context of the study of the toxicity of IC and provide crucial data for future studies of its physiological effects. Although the general population does not normally exceed the maximum recommended daily intake, young children are highly exposed to products containing IC and can easily exceed the recommended dose. It is, therefore, extremely important to understand the interactions between the dye and the various metal ions present in the human body, copper(II) being one of the most relevant due to its essential nature and, as shown in this article, the high stability of the complexes it forms with IC at physiological pH.
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*1. In many countries, eggs are not refrigerated and must be stored at room temperature. The objective of this study was to explore the effects of dietary oregano oil (275 mg/kg; ORE) versus an unsupplemented control diet (CON) on laying hens on the shelf life and fatty acid profile of eggs.2. Treatments were randomly distributed into 10 pens containing 27 birds each. A total of 200 eggs were collected from both groups on the same day and were stored for either 0, 10, 21 and 35 d. At each storage time, egg yolks were analysed for fatty acid profile and lipid peroxidation.3. The main indicator of lipid peroxidation, malondialdehyde (MDA), was significantly lower in ORE eggs compared to CON eggs (p = 0.001). Storage time had a significant impact on MDA concentrations (p = 0.023), with the highest found after 35 d. Significant differences were found for individual fatty acids, saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA). Palmitic acid, stearic acid, oleic acid, linoleic acid and arachidonic acid were significantly lower in ORE eggs compared to CON eggs (p < 0.05). Palmitoleic acid (p = 0.002), linolenic acid (p = 0.001) and docosahexaenoic acid (DHA, p = 0.001) were significantly higher in ORE eggs.4. Storage only affected oleic, linolenic, linoleic, arachidonic and docosahexaenoic acids (p < 0.05). Total SFA, MUFA, n-6 and ratio of n-3 to n-6 (n-3:n-6) PUFA were significantly higher in CON eggs (p < 0.05). The ratio of SFA to PUFA (SFA:PUFA, p = 0.005) and total n-3 PUFA (p = 0.001) were significantly higher in ORE eggs.5. The n-3:n-6 ratio was significantly impacted by treatment (p = 0.021) and storage (p = 0.031) with no significant interaction. This ratio is important for human health indication and could lead to the development of designer eggs.
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Ração Animal , Galinhas , Dieta , Suplementos Nutricionais , Ovos , Ácidos Graxos , Armazenamento de Alimentos , Óleos Voláteis , Origanum , Animais , Origanum/química , Ácidos Graxos/análise , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Ração Animal/análise , Suplementos Nutricionais/análise , Ovos/análise , Dieta/veterinária , Feminino , Óleos Voláteis/química , Distribuição Aleatória , Peroxidação de Lipídeos/efeitos dos fármacos , TemperaturaRESUMO
BACKGROUND AND OBJECTIVE: Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. PATIENTS AND METHODS: Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. RESULTS: A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19-82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0-5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. CONCLUSIONS: LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population.
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Hipertensão , Minoxidil , Masculino , Humanos , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Minoxidil/efeitos adversos , Anti-Hipertensivos/efeitos adversos , Alopecia/tratamento farmacológico , Alopecia/induzido quimicamente , Hipertensão/tratamento farmacológico , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/tratamento farmacológico , Resultado do TratamentoRESUMO
BACKGROUND AND OBJECTIVE: Systemic adverse effects (AE) are a major concern of low-dose oral minoxidil (LDOM) treatment, especially in patients with arterial hypertension or arrhythmia. The objective of this study was to evaluate the safety of LDOM in patients with hypertension or arrhythmia. PATIENTS AND METHODS: Retrospective multicenter study of patients with hypertension or arrhythmia treated with LDOM for any type of alopecia. RESULTS: A total of 254 patients with hypertension [176 women (69.3%) and 78 men (30.7%)] with a mean age of 56.9 years (range 19-82) were included. From them, the dose of LDOM was titrated in 128 patients, allowing the analysis of 382 doses. Patients were receiving a mean of 1.45 (range 0-5) antihypertensive drugs. Systemic AE were detected in 26 cases (6.8%) and included lightheadedness (3.1%), fluid retention (2.6%), general malaise (0.8%), tachycardia (0.8%) and headache (0.5%), leading to LDOM discontinuation in 6 cases (1.5%). Prior treatment with doxazosin (P<0.001), or with three or more antihypertensive drugs (P=0.012) was associated with a higher risk of discontinuation of LDOM. CONCLUSIONS: LDOM treatment showed a favorable safety profile in patients with hypertension or arrhythmia, similar to general population.
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Hipertensão , Minoxidil , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Alopecia/tratamento farmacológico , Alopecia/induzido quimicamente , Anti-Hipertensivos/efeitos adversos , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/tratamento farmacológico , Hipertensão/tratamento farmacológico , Minoxidil/efeitos adversos , Resultado do Tratamento , Estudos RetrospectivosRESUMO
BACKGROUND: Functional impairment is the main consideration when it comes to choosing therapy for infantile hemangiomas (IH). However, since most hemangiomas are treated for cosmetic reasons, it is important to know the cosmetic outcome assessed by the parents. OBJECTIVE: To evaluate the aesthetic outcomes of IH, considering the characteristics of the lesions and the treatments used. PATIENTS AND METHODS: The Spanish Infantile Hemangioma Nationwide Prospective Cohort (2016-2022) recruited all consecutive patients diagnosed with IH in 12 Spanish hospitals. The children included had 2 photos of the IH lesion (at both baseline and at the end of the study). A panel of parents blindly assessed all available photos using a scale from 0 (worst cosmetic outcomes) to 10 (best cosmetic outcomes). The different scores -both before and after treatment-as well as the outcomes percent considered excellent (> 9) were described and compared. We analyzed the effect of receiving different therapies and performed causal model analyses estimating the mean treatment effect of parents' assessments. RESULTS: The median follow-up was 3.1 years. A total of 824 photos were evaluated. Baseline aesthetic impact was higher in the propranolol group vs the topical timolol and observation treatment groups (1.85 vs 3.14 vs 3.66 respectively; p < 0.001). After treatment, the aesthetic impact was similar between both treatment groups (7.59 vs 7.93 vs 7.90; p > 0.2). The causal model could only be applied to the comparison between topical timolol and observation, revealing no differences whatsoever. CONCLUSION: This is the first prospective cohort to analyze the aesthetic outcome of IH. The final aesthetic results of the 3 therapies were similar, with nearly 40% of patients achieving excellent aesthetic outcomes.
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A new family of molecules obtained by coupling Tröger's base unit with dicyanovinylene-terminated oligothiophenes of different lengths has been synthesized and characterized by steady-state stationary and transient time-resolved spectroscopies. Quantum chemical calculations allow us to interpret and recognize the properties of the stationary excited states as well as the time-dependent mechanisms of singlet-to-triplet coupling. The presence of the diazocine unit in Tröger's base derivatives is key to efficiently producing singlet-to-triplet intersystem crossing mediated by the role of the nitrogen atoms and of the almost orthogonal disposition of the two thiophene arms. Spin-orbit coupling-mediated interstate intersystem crossing (ISC) is activated by a symmetry-breaking process in the first singlet excited state with partial charge transfer character. This mechanism is a characteristic of these molecular triads since the independent dicyanovinylene-oligothiophene branches do not display appreciable ISC. These results show how Tröger's base coupling of organic chromophores can be used to improve the ISC efficiency and tune their photophysics.
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We report on the first proton-induced single proton- and neutron-removal reactions from the neutron-deficient ^{14}O nucleus with large Fermi-surface asymmetry S_{n}-S_{p}=18.6 MeV at â¼100 MeV/nucleon, a widely used energy regime for rare-isotope studies. The measured inclusive cross sections and parallel momentum distributions of the ^{13}N and ^{13}O residues are compared to the state-of-the-art reaction models, with nuclear structure inputs from many-body shell-model calculations. Our results provide the first quantitative contributions of multiple reaction mechanisms including the quasifree knockout, inelastic scattering, and nucleon transfer processes. It is shown that the inelastic scattering and nucleon transfer, usually neglected at such energy regime, contribute about 50% and 30% to the loosely bound proton and deeply bound neutron removal, respectively. These multiple reaction mechanisms should be considered in analyses of inclusive one-nucleon removal cross sections measured at intermediate energies for quantitative investigation of single-particle strengths and correlations in atomic nuclei.
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Formaldehyde is a common contaminant in occupational and environmental atmospheres, prolonged exposure leads to health risks, and its determination is necessary to protect health. There is a great demand for portable, rapid, and sensitive methods that can be used in resource-limited settings. In this respect, a colorimetric sensor has been developed based on the colour change from pink to purple of co-immobilized chromotropic acid and 4-aminoazobenzene in hydroxypropyl methylcellulose when it is exposed to different concentrations of formaldehyde. The concentration of formaldehyde in the gas phase was quantified by measuring the change of the appropriate colour coordinates in response to the concentration of formaldehyde. A calibration curve was obtained for formaldehyde, with a useful concentration range from 0.08 to 0.6 ppmv. The detection limit was 0.016 ppmv, which is lower than the maximum exposure concentrations recommended by both the World Health Organization (WHO) and the Occupational Safety and Health Administration (OSHA). The optical sensor was found to have good reproducibility, with a relative standard deviation of 2.3 and 1.7% at 0.08 and 0.25 ppmv, respectively. The sensor can operate at room temperature and environmental humidity, 25 °C, and 50% RH, respectively. In addition, a study of interferents (acetaldehyde, toluene, methanol, ethyl acetate, acetone, acetic acid, carbon dioxide and ammonia) showed high selectivity for formaldehyde, which indicates that this membrane is a simple, fast, and economical alternative for quantifying the concentration of formaldehyde in different environments.
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Colorimetria , Formaldeído , Reprodutibilidade dos Testes , Colorimetria/métodos , NaftalenossulfonatosRESUMO
Two colorimetric nanostructured sensor phases (Color-NSPs) for the determination of low concentrations of acid vapors in the atmosphere of paper storage rooms have been designed and characterized. The acid vapor determination is based on the color change that occurs in polyaniline (PANI) in the presence of acids when it goes from its emeraldine base form (blue) to its emeraldine salt form (green). To synthesize the Color-NSPs, two methods have been used, a one-step method performed by grafting polyaniline onto a cellulose membrane (Cellu-PANI) and a two-step method in which in the first step, polyaniline is grafted onto the surface of polymeric nanoparticles (NPs-PANI), and in a second step, NPs-PANI are immobilized into the pores of a nylon membrane (Nylon-NPs PANI). The response of the sensors versus acid vapor was measured by color coordinates with a photographic camera. A linear response range from 1 ppmv to 7 ppmv was found for both sensors, and the detection limits were 0.95 ppmv (1.2 % RSD) and 0.40 ppmv (0.8 % RSD) for Cellu-PANI and Nylon-NPs PANI, respectively. In addition, both sensors showed complete reversibility and a short exposition time (5 min). The potential applicability of the Color-NSPs in the control of the exposure of paper heritage collections to outdoor- and indoor-generated gaseous pollutants was demonstrated by determining acid vapors in museums. The method was validated with an external reference method; the paired test was applied, and p-values greater than 5% were obtained, indicating an excellent correlation and showing that the Color-NSPs reported are simple, fast, and an economical alternative to control and protect cultural heritage materials in indoor environments.
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In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.
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BACKGROUND: We evaluated a new chemoimmunotherapy combination based on the anti-PD1 monoclonal antibody pembrolizumab and the pyrimidine antimetabolite gemcitabine in HER2- advanced breast cancer (ABC) patients previously treated in the advanced setting, in order to explore a potential synergism that could eventually obtain long term benefit in these patients. METHODS: HER2-negative ABC patients received 21-day cycles of pembrolizumab 200 mg (day 1) and gemcitabine (days 1 and 8). A run-in-phase (6 + 6 design) was planned with two dose levels (DL) of gemcitabine (1,250 mg/m2 [DL0]; 1,000 mg/m2 [DL1]) to determine the recommended phase II dose (RP2D). The primary objective was objective response rate (ORR). Tumor infiltrating lymphocytes (TILs) density and PD-L1 expression in tumors and myeloid-derived suppressor cells (MDSCs) levels in peripheral blood were analyzed. RESULTS: Fourteen patients were treated with DL0, resulting in RP2D. Thirty-six patients were evaluated during the first stage of Simon's design. Recruitment was stopped as statistical assumptions were not met. The median age was 52; 21 (58%) patients had triple-negative disease, 28 (78%) visceral involvement, and 27 (75%) ≥ 2 metastatic locations. Progression disease was observed in 29 patients. ORR was 15% (95% CI, 5-32). Eight patients were treated ≥ 6 months before progression. Fourteen patients reported grade ≥ 3 treatment-related adverse events. Due to the small sample size, we did not find any clear association between immune tumor biomarkers and treatment efficacy that could identify a subgroup with higher probability of response or better survival. However, patients that experienced a clinical benefit showed decreased MDSCs levels in peripheral blood along the treatment. CONCLUSION: Pembrolizumab 200 mg and gemcitabine 1,250 mg/m2 were considered as RP2D. The objective of ORR was not met; however, 22% patients were on treatment for ≥ 6 months. ABC patients that could benefit of chemoimmunotherapy strategies must be carefully selected by robust and validated biomarkers. In our heavily pretreated population, TILs, PD-L1 expression and MDSCs levels could not identify a subgroup of patients for whom the combination of gemcitabine and pembrolizumab would induce long term benefit. TRIAL REGISTRATION: ClinicalTrials.gov and EudraCT (NCT03025880 and 2016-001,779-54, respectively). Registration dates: 20/01/2017 and 18/11/2016, respectively.
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Neoplasias da Mama , Feminino , Humanos , Pessoa de Meia-Idade , Antígeno B7-H1 , Mama , Neoplasias da Mama/tratamento farmacológico , GencitabinaRESUMO
Hydrogels are polymeric biomaterials characterised by their promising biological and biomechanical properties, which make them potential alternatives for use in tendon repair. The aim of the present study was to generate in vitro, and determine the therapeutic efficacy in vivo, of novel nanostructured fibrin-based hydrogels to be used as an augmentation strategy for the surgical repair of rat Achilles tendon injuries. Fibrin, fibrin-agarose and fibrin-collagen nanostructured hydrogels (NFH, NFAH and NFCH, respectively) were generated and their biomechanical properties and cell-biomaterial interactions characterised ex vivo. Achilles tendon ruptures were created in 24 adult Wistar rats, which were next treated with direct repair (control group) or direct repair augmented with the generated biomaterials (6 rats/group). After 4 and 8 weeks, the animals were euthanised for macroscopical and histological analyses. Biomechanical characterisation showed optimal properties of the biomaterials for use in tendon repair. Moreover, biological analyses confirmed that tendon-derived fibroblasts were able to adhere to the surface of the generated biomaterials, with high levels of viability and functionality. In vivo studies demonstrated successful tendon repair in all groups. Lastly, histological analyses disclosed better tissue and extracellular matrix organisation and alignment with biomaterial-based augmentation strategies than direct repair, especially when NFAH and NFCH were used. The present study demonstrated that nanostructured fibrin-collagen hydrogels can be used to enhance the healing process in the surgical repair of tendon ruptures.
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Tendão do Calcâneo , Traumatismos dos Tendões , Tendão do Calcâneo/patologia , Tendão do Calcâneo/cirurgia , Animais , Materiais Biocompatíveis/farmacologia , Colágeno/farmacologia , Fibrina/farmacologia , Hidrogéis/farmacologia , Ratos , Ratos Wistar , Traumatismos dos Tendões/patologia , Traumatismos dos Tendões/cirurgiaRESUMO
We report the synthesis of a new conjugated polymer bearing crown ether moieties, poly[(N(1-aza-[18]crown-6)carbamido)thiophene-2,5-diyl-alt-1,4-phenylene] (BG2). In water, BG2 forms a dispersion with a slightly cloudy appearance. We have studied the effect of adding surfactants, with different polar head groups, on these polymer-polymer aggregates. Special attention is given to the system with the anionic surfactant, sodium dodecyl sulfate (SDS). The combination of photophysical techniques with electrical conductivity, NMR (1H, 13C, and 27Na), DFT calculations, molecular dynamics simulations, and small-angle neutron scattering (SANS) provides a detailed picture on the behavior of the SDS/BG2 system in aqueous solution and in thin films. NMR, electric conductivity, and DFT results suggest that hydrophilic interactions occur between the polar headgroup of the surfactant (OSO3- Na+) and the aza-[18]-crown-6 moiety. DFT calculations confirmed the capability of BG2 to form stable complexes with the Na+ cations, where the cation can be either inside the azacrown cavity or sandwiched between the cavity and the polymer chain, which seem to determine the position of the surfactant hydrocarbon chain and, therefore, be responsible for the disruption of the BG2 aggregates and subsequent increase in the photoluminescence quantum yields. SANS measurements, made with hydrogenated and deuterated SDS in D2O, clearly show how micron-sized aggregates of BG2 are broken down by SDS and then how BG2 becomes preferentially incorporated within joint colloidal particles of BG2 and SDS with increasing [SDS]/[BG2] molar ratio.
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Catalytic asymmetric Povarov protocols have undergone an explosive growth, especially in the last ten years, since the first example was published in 1996. The use of chiral Lewis and Brønsted acids and dual strategies based on their combination with catalysts acting by hydrogen bond formation, as well as covalent aminocatalysis, are reviewed. More recent variations such as the nitroso Povarov reaction and interrupted Povarov reactions as a route to chiral scaffolds other than tetrahydroquinolines are also discussed.