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1.
J Chem Phys ; 160(13)2024 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-38557847

RESUMO

Heterogeneous nucleation is the main path to ice formation on Earth. The ice nucleating ability of a certain substrate is mainly determined by both molecular interactions and the structural mismatch between the ice and the substrate lattices. We focus on the latter factor using molecular simulations of the mW model. Quantifying the effect of structural mismatch alone is challenging due to its coupling with molecular interactions. To disentangle both the factors, we use a substrate composed of water molecules in such a way that any variation on the nucleation temperature can be exclusively ascribed to the structural mismatch. We find that a 1% increase in structural mismatch leads to a decrease of ∼4 K in the nucleation temperature. We also analyze the effect of orientation of the substrate with respect to the liquid. The three main ice orientations (basal, primary prism, and secondary prism) have a similar ice nucleating ability. We finally assess the effect of lattice flexibility by comparing substrates where molecules are immobile to others where a certain freedom to fluctuate around the lattice positions is allowed. Interestingly, we find that the latter type of substrate is more efficient in nucleating ice because it can adapt its structure to that of ice.

2.
Food Res Int ; 181: 114125, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38448103

RESUMO

The perception of orosensory stimuli, which includes flavor, can vary between individuals. These individual variations in oral sensations can be due to genetic factors and it would appear that they can predict food liking and consumption. The most studied source of variation is related to bitter taste perception associated with 6-n-propylthiouracil (PROP) responsiveness. In this context, humans can be classified as non-tasters (NT), medium tasters (MT) and supertasters (ST). Evidence suggests that genetic variation in bitter taste perception contributes to differences in the level of irritation caused by alcohol perception in solutions. The aim of this investigation was to study the bitter taste sensitivity among a group of mezcal consumers and its relationship with sensory perception and preference through PROP taster status. The tests were carried out in the state of Oaxaca in Mexico. A total of 83 mezcal consumers were classified by their PROP taster status and were asked to provide sensory descriptors for five mezcal samples and rate them according to the level of liking. The three-solution test was used to classify the subjects as NT, MT, and ST, while a Multiple Factor Analysis (MFA) was used to visualize the sensory descriptors provided by these three groups. The proportion of MT subjects was 16%, while the proportion of NT and ST was 34 and 51%, respectively. The MT provided higher liking ratings for at least three mezcal samples. According to MFA, the mezcal samples were organized in a similar configuration along the two dimensions. However, NT mentioned a limited number of simple terms (strong flavor, tasteless, burning in the mouth) to describe the samples, whereas ST used a more complex vocabulary (astringent, smoky, scratchy aftertaste). These data suggest that the preference for mezcal samples was similar for non-taster and supertasters, but there are indications that the sensory perception of mezcal differs between groups.


Assuntos
Percepção Gustatória , Paladar , Humanos , Sensação , Adstringentes , Emoções
3.
Adv Biol (Weinh) ; : e2400069, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38548661

RESUMO

Engagement in physical activity, across various sports, promotes a diverse microbiota in active individuals. This study examines the gut microbiota of Colombian athletes, specifically weightlifters (n = 16) and road cyclists (n = 13), compared to non-athletes (n = 15). Using Kruskal-Wallis tests, the physical activity level of a group of non-athletic individuals and the sports experience of a group of professional athletes is analyzed. The median age of participants is 24 years, comprising 25 men and 19 women. The microbiota is collected using fecal samples. Participants provided these samples during their pre-competitive stage, specifically during the concentration phase occurring two weeks prior to national competitions. This timing is chosen to capture the microbial composition during a period of heightened physical preparation. Questionnaire responses and microbial composition assessments identify disparities among groups. Microbial composition analysis explores core microbiome, abundance, and taxonomy using Pavian, MicrobiomeAnalyst 2.0, and GraPhlAn. ANCOM-BC2 reveals differentially abundant species. Road cyclists exhibit decreased Bacteria and increased Archaea abundance. Phylum-level variations included Planctomycetes, Acidobacteria, and Proteobacteria, while Bacteroidetes prevailed. Key families influencing gut microbiota are Bacteroidaceae, Muribaculaceae, and Selenomonadaceae. Weightlifters exhibit unique viral and archaeal community connections, while cyclists showed specialized microbial interplay influenced by endurance exercise. Correlation network analysis emphasizes distinctive microbial interactions within athlete groups, shedding light on the impact of physical activities on gut microbiota and athlete health.

4.
Nat Mater ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514844

RESUMO

Electrocaloric effects have been experimentally studied in ferroelectrics and incipient ferroelectrics, but not incipient ferroelectrics driven ferroelectric using strain. Here we use optimally oriented interdigitated surface electrodes to investigate extrinsic electrocaloric effects in low-loss epitaxial SrTiO3 films near the broad second-order 243 K ferroelectric phase transition created by biaxial in-plane coherent tensile strain from DyScO3 substrates. Our extrinsic electrocaloric effects are an order of magnitude larger than the corresponding effects in bulk SrTiO3 over a wide range of temperatures including room temperature, and unlike electrocaloric effects associated with first-order transitions they are highly reversible in unipolar applied fields. Additionally, the canonical Landau description for strained SrTiO3 films works well if we set the low-temperature zero-field polarization along one of the in-plane pseudocubic <100> directions. In future, similar strain engineering could be exploited for other films, multilayers and bulk samples to increase the range of electrocaloric materials for energy efficient cooling.

5.
Protein Sci ; 33(4): e4941, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38501490

RESUMO

Tardigrades are microscopic animals that survive desiccation by inducing biostasis. To survive drying tardigrades rely on intrinsically disordered CAHS proteins, which also function to prevent perturbations induced by drying in vitro and in heterologous systems. CAHS proteins have been shown to form gels both in vitro and in vivo, which has been speculated to be linked to their protective capacity. However, the sequence features and mechanisms underlying gel formation and the necessity of gelation for protection have not been demonstrated. Here we report a mechanism of fibrillization and gelation for CAHS D similar to that of intermediate filament assembly. We show that in vitro, gelation restricts molecular motion, immobilizing and protecting labile material from the harmful effects of drying. In vivo, we observe that CAHS D forms fibrillar networks during osmotic stress. Fibrillar networking of CAHS D improves survival of osmotically shocked cells. We observe two emergent properties associated with fibrillization; (i) prevention of cell volume change and (ii) reduction of metabolic activity during osmotic shock. We find that there is no significant correlation between maintenance of cell volume and survival, while there is a significant correlation between reduced metabolism and survival. Importantly, CAHS D's fibrillar network formation is reversible and metabolic rates return to control levels after CAHS fibers are resolved. This work provides insights into how tardigrades induce reversible biostasis through the self-assembly of labile CAHS gels.


Assuntos
Proteínas Intrinsicamente Desordenadas , Tardígrados , Animais , Dessecação , Tardígrados/metabolismo , Proteínas Intrinsicamente Desordenadas/metabolismo , Géis/metabolismo
6.
Histochem Cell Biol ; 161(5): 409-421, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38402366

RESUMO

Cancer is understood as a multifactorial disease that involve multiple cell types and phenotypes in the tumor microenvironment (TME). The components of the TME can interact directly or via soluble factors (cytokines, chemokines, growth factors, extracellular vesicles, etc.). Among the cells composing the TME, mesenchymal stem cells (MSCs) appear as a population with debated properties since it has been seen that they can both promote or attenuate tumor progression. For various authors, the main mechanism of interaction of MSCs is through their secretome, the set of molecules secreted into the extracellular milieu, recruiting, and influencing the behavior of other cells in inflammatory environments where they normally reside, such as wounds and tumors. Natural products have been studied as possible cancer treatments, appealing to synergisms between the molecules in their composition; thus, extracts obtained from Petiveria alliacea (Anamu-SC) and Caesalpinia spinosa (P2Et) have been produced and studied previously on different models, showing promising results. The effect of plant extracts on the MSC secretome has been poorly studied, especially in the context of the TME. Here, we studied the effect of Anamu-SC and P2Et extracts in the human adipose-derived MSC (hAMSC)-tumor cell interaction as a TME model. We also investigated the influence of the hAMSC secretome, in combination with these natural products, on tumor cell hallmarks such as viability, clonogenicity, and migration. In addition, hAMSC gene expression and protein synthesis were evaluated for some key factors in tumor progression in the presence of the extracts by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Multiplex, respectively. It was found that the presence of the hAMSC secretome did not affect the cytotoxic or clonogenicity-reducing activities of the natural extracts on cancer cells, and even this secretome can inhibit the migration of these tumor cells, in addition to the fact that the profile of molecules can be modified by natural products. Overall, our findings demonstrate that hAMSC secretome participation in TME interactions can favor the antitumor activities of natural products.


Assuntos
Células-Tronco Mesenquimais , Extratos Vegetais , Secretoma , Humanos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Secretoma/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Células Cultivadas , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais
7.
Mycotoxin Res ; 40(2): 269-277, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38421516

RESUMO

This experiment was conducted to determine the effect of an adsorbent material based on powdered alfalfa leaves added in the aflatoxin B1 (AFB1)-contaminated diet of turkey poults on production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology. For this purpose, three hundred and fifty female Nicholas-700 poults were randomly assigned into five treatments: (1) Control, AFB1-free diet; (2) AF, diet contaminated with 250 ng AFB1/g; (3) Alfalfa, AFB1-free diet + 0.5% (w/w) adsorbent; (4) AF+alfalfa, diet contaminated with 250 ng AFB1/g + 0.5% (w/w) adsorbent, and (5) AF+ yeast cell wall (YCW), diet contaminated with 250 ng AFB1/g + 0.5% (w/w) of yeast cell wall (a commercial mycotoxin binder used as reference material). The in vivo efficacy of powdered alfalfa leaves was assessed during a 28-day period. In general, the addition of powdered alfalfa leaves in the AFB1-free diet gave the best performance results (body weight, body weight gain, and feed intake) and improved the values of total protein, glucose, calcium, creatinine, and blood urea nitrogen. Moreover, the addition of powdered alfalfa leaves in the AFB1-contaminated diet enhanced body weight and body weight gain and significantly reduced the feed intake, compared to the AF and AF+YCW groups. Additionally, significant alterations in serum parameters were observed in poults intoxicated with the AFB1, compared to the Control group. Furthermore, typical histopathological lesions were observed in the liver of the AF group, which were significantly ameliorated with the addition of powdered alfalfa leaves. Conclusively, these results pointed out that low inclusion of powdered alfalfa leaves in the contaminated feed counteracted the adverse effects of AFB1 in turkey poults.


Assuntos
Aflatoxina B1 , Ração Animal , Medicago sativa , Folhas de Planta , Perus , Animais , Aflatoxina B1/toxicidade , Medicago sativa/química , Folhas de Planta/química , Ração Animal/análise , Feminino , Fígado/efeitos dos fármacos , Fígado/patologia , Dieta/veterinária , Pós , Peso Corporal/efeitos dos fármacos
8.
Forensic Sci Int Genet ; 70: 103022, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38309257

RESUMO

DNA methylation has become a biomarker of great interest in the forensic and clinical fields. In criminal investigations, the study of this epigenetic marker has allowed the development of DNA intelligence tools providing information that can be useful for investigators, such as age prediction. Following a similar trend, when the origin of a sample in a criminal scenario is unknown, the inference of an individual's lifestyle such as tobacco use and alcohol consumption could provide relevant information to help in the identification of DNA donors at the crime scene. At the same time, in the clinical domain, prediction of these trends of consumption could allow the identification of people at risk or better identification of the causes of different pathologies. In the present study, DNA methylation data from the UK AIRWAVE study was used to build two binomial logistic models for the inference of smoking and drinking status. A total of 348 individuals (116 non-smokers, 116 former smokers and 116 smokers) plus a total of 237 individuals (79 non-drinkers, 79 moderate drinkers and 79 drinkers) were used for development of tobacco and alcohol consumption prediction models, respectively. The tobacco prediction model was composed of two CpGs (cg05575921 in AHRR and cg01940273) and the alcohol prediction model three CpGs (cg06690548 in SLC7A11, cg0886875 and cg21294714 in MIR4435-2HG), providing correct classifications of 86.49% and 74.26%, respectively. Validation of the models was performed using leave-one-out cross-validation. Additionally, two independent testing sets were also assessed for tobacco and alcohol consumption. Considering that the consumption of these substances could underlie accelerated epigenetic ageing patterns, the effect of these lifestyles on the prediction of age was evaluated. To do that, a quantile regression model based on previous studies was generated, and the potential effect of tobacco and alcohol consumption with the epigenetic age was assessed. The Wilcoxon test was used to evaluate the residuals generated by the model and no significant differences were observed between the categories analyzed.


Assuntos
Metilação de DNA , Fumar , Humanos , Fumar/efeitos adversos , Consumo de Bebidas Alcoólicas/genética , DNA , Hábitos
9.
Phys Rev E ; 109(1-1): 014304, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38366525

RESUMO

We analyze the percolation threshold of square lattices comprising a combination of sites with regular and extended neighborhoods. We found that the percolation threshold of these composed systems smoothly decreases with the fraction of sites with extended neighbors. This behavior can be well-fitted by a Tsallis q-Exponential function. We found a relation between the fitting parameters and the differences in the gyration radius among neighborhoods. We also compared the percolation threshold with the critical susceptibility of nearest and next-to-nearest neighbor monoculture plantations vulnerable to the spread of phytopathogen. Notably, the critical susceptibility in monoculture plantations can be described as a linear combination of two composite systems. These results allow the refinement of mathematical models of phytopathogen propagation in agroecology. In turn, this improvement facilitates the implementation of more efficient computational simulations of agricultural epidemiology that are instrumental in testing and formulating control strategies.

10.
Artigo em Inglês | MEDLINE | ID: mdl-38194380

RESUMO

In the field of coordination and bioorganometallic chemistry, a notable shift is occurring. This mini-review explores a new generation of carefully 3D-crafted coordination and organometallic complexes that differ from conventional structures. Emphasizing disease intervention and microbial control, these compounds, incorporate noble and transition metals, and aim to enhance therapeutic efficacy while minimizing potential health risks. The mini-review covers diverse applications, showcasing their effectiveness against bacteria, viruses, fungi, and as potential tools in cancer treatment. Additionally, it sheds light on the inventive aspects of these complexes within biological systems. By highlighting advancements in bioorganometallic chemistry, the review offers insights and guidance for future developments in safer and more effective therapeutics.

11.
Clin Infect Dis ; 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214897

RESUMO

BACKGROUND: Advancements in access to antiretroviral therapy (ART) and human immunodeficiency virus (HIV) care have led to a decline in acquired immunodeficiency syndrome (AIDS)-related deaths among people with HIV (PWH) in Switzerland. However, data on the ongoing changes in causes of death among PWH over the past 15 years is scarce. METHODS: We investigated all reported deaths in the Swiss HIV Cohort Study between 2005-2022. Causes of death were categorized using the Coding Causes of Death in HIV protocol. The statistical analysis included demographic stratification to identify time trends and logistic regression models to determine associated factors for the underlying cause of death. RESULTS: In total, 1630 deaths were reported, with 23.7% of individuals assigned female at birth. Out of these deaths, 147 (9.0%) were HIV/AIDS-related, 373 (22.9%) due to non-AIDS, non-hepatic (NANH) cancers, 166 (10.2%) liver-related, and 158 (9.7%) cardiovascular-related. The median age at death increased from 45.0 [40.0,53.0] years in 2005-2007 to 61.0 [56.0,69.5] years in 2020-2022. HIV/AIDS and liver-related causes of death decreased, whereas deaths from NANH cancers increased, and cardiovascular-related deaths remained relatively stable. CONCLUSION: The proportionally decreasing HIV/AIDS and liver-related deaths showcase the effectiveness of ART, comprehensive HIV patient care, and interventions targeting hepatitis C virus co-infection. Future research should focus on managing cancer and cardiovascular-related conditions as the new leading causes of death among PWH. Comprehensive healthcare strategies focusing on non-AIDS-related comorbidities, cancer management, and sustaining liver and cardiovascular health are needed to bridge the ongoing health disparities between PWH and the general population.

12.
Electrophoresis ; 45(1-2): 69-100, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37259641

RESUMO

Proteins are important molecules involved in an immensely large number of biological processes. Being capable of manipulating proteins is critical for developing reliable and affordable techniques to analyze and/or detect them. Such techniques would enable the production of therapeutic agents for the treatment of diseases or other biotechnological applications (e.g., bioreactors or biocatalysis). Microfluidic technology represents a potential solution to protein manipulation challenges because of the diverse phenomena that can be exploited to achieve micro- and nanoparticle manipulation. In this review, we discuss recent contributions made in the field of protein manipulation in microfluidic systems using different physicochemical principles and techniques, some of which are miniaturized versions of already established macro-scale techniques.


Assuntos
Técnicas Analíticas Microfluídicas , Nanopartículas , Microfluídica/métodos , Técnicas Analíticas Microfluídicas/métodos , Nanopartículas/química , Dispositivos Lab-On-A-Chip
13.
Forensic Sci Int Genet ; 67: 102937, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37812882

RESUMO

We have adapted an established Ampliseq microhaplotype panel for nanopore sequencing with the Oxford Nanopore Technologies (ONT) system, as a cost-effective and highly scalable solution for forensic genetics applications. For this purpose, we designed a protocol combining direct PCR amplification from unextracted DNA with ONT library construction and sequencing using the MinION device and workflow. The analysis of reference samples at input amounts of 5-10 ng of DNA demonstrates stable coverage patterns, allele balance, and strand bias, reaching profile completeness and concordance rates of ∼95%. Similar levels were achieved when using direct-PCR from blood, buccal and semen swabs. Dilution series results indicate sensitivity is maintained down to 250 pg of input DNA, and informative profiles are produced down to 62.5 pg. Finally, we demonstrated the forensic utility of the nanopore workflow by analyzing two third degree pedigrees that showed low likelihood ratio values after the analysis of an extended panel of 38 STRs, achieving likelihood ratios 2-3 orders of magnitude higher when testing with the MinION-based haplotype data.


Assuntos
Sequenciamento por Nanoporos , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , DNA/genética , DNA/análise , Reação em Cadeia da Polimerase , Técnicas de Amplificação de Ácido Nucleico , Análise de Sequência de DNA/métodos
14.
mBio ; : e0208723, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37874146

RESUMO

Membrane fusion mediated by herpes simplex virus 1 (HSV-1) is a complex, multi-protein process that is receptor triggered and can occur both at the cell surface and in endosomes. To deconvolute this complexity, we reconstituted HSV-1 fusion with synthetic lipid vesicles in vitro. Using this simplified, controllable system, we discovered that HSV-1 fusion required not only a cognate host receptor but also low pH. On the target membrane side, efficient fusion required cholesterol, negatively charged lipids found in the endosomal membranes, and an optimal balance of lipid order and disorder. On the virion side, the four HSV-1 entry glycoproteins-gB, gD, gH, and gL-were sufficient for fusion. We propose that low pH is a biologically relevant co-trigger for HSV-1 fusion. The dependence of fusion on low pH and endosomal lipids could explain why HSV-1 enters most cell types by endocytosis. We hypothesize that under neutral pH conditions, other, yet undefined, cellular factors may serve as fusion co-triggers. The in vitro fusion system established here can be employed to systematically investigate HSV-1-mediated membrane fusion.IMPORTANCEHSV-1 causes lifelong, incurable infections and diseases ranging from mucocutaneous lesions to fatal encephalitis. Fusion of viral and host membranes is a critical step in HSV-1 infection of target cells that requires multiple factors on both the viral and host sides. Due to this complexity, many fundamental questions remain unanswered, such as the identity of the viral and host factors that are necessary and sufficient for HSV-1-mediated membrane fusion and the nature of the fusion trigger. Here, we developed a simplified in vitro fusion assay to examine the fusion requirements and identified low pH as a co-trigger for virus-mediated fusion in vitro. We hypothesize that low pH has a critical role in cell entry and, potentially, pathogenesis.

17.
Int J Neural Syst ; 33(8): 2350041, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37470777

RESUMO

Parkinson's Disease (PD) is the second most prevalent neurodegenerative disorder among adults. Although its triggers are still not clear, they may be due to a combination of different types of biomarkers measured through medical imaging, metabolomics, proteomics or genetics, among others. In this context, we have proposed a Computer-Aided Diagnosis (CAD) system that combines structural and functional imaging data from subjects in Parkinson's Progression Markers Initiative dataset by means of an Ensemble Learning methodology trained to identify and penalize input sources with low classification rates and/ or high-variability. This proposal improves results published in recent years and provides an accurate solution not only from the point of view of image preprocessing (including a comparison between different intensity preservation techniques), but also in terms of dimensionality reduction methods (Isomap). In addition, we have also introduced a bagging classification schema for scenarios with unbalanced data. As shown by our results, the CAD proposal is able to detect PD with [Formula: see text] of balanced accuracy, and opens up the possibility of combining any number of input data sources relevant for PD.


Assuntos
Doença de Parkinson , Adulto , Humanos , Doença de Parkinson/diagnóstico , Aprendizado de Máquina , Diagnóstico por Computador , Imageamento por Ressonância Magnética/métodos
18.
Langenbecks Arch Surg ; 408(1): 206, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37221304

RESUMO

PURPOSE: Surgery of primary thyroid lymphoma (PTL) has been mostly limited to diagnostic work-up. This study aimed to further study its potential role. METHODS: This was a retrospective study from a multi-institutional registry of PTL patients. Clinical, diagnostic work-up (fine needle aspiration, FNA; core needle biopsy, CoreNB), contribution of surgery (open surgical biopsy, OpenSB; thyroidectomy), histology subtype, and outcome data were evaluated. RESULTS: Some 54 patients were studied. Diagnostic work-up included FNA in 47 patients, CoreNB in 11, and OpenSB in 21. CoreNB yielded the best sensitivity (90.9%). Thyroidectomy was performed in 14 patients with other diagnosis (incidental PTL), in 4 for diagnosis and in 4 for elective treatment of PTL. Incidental PTL was associated with not performed FNA nor CoreNB (OR 52.5; P = 0.008), mucosa-associated lymphoid tissue (MALT) subtype (OR 24.3; P = 0.012), and Hashimoto's thyroiditis (OR 11.1; P = 0.032). Lymphoma-related death (10 cases) mostly occurred within the first year after diagnosis and was associated with diffuse large B-cell (DLBC) subtype (OR 10.3; P = 0.018) and older patients (OR 1.08 for every 1-year increase; P = 0.010). There was a trend towards lower mortality rate in patients receiving thyroidectomy (2/22 versus 8/32, P = 0.172). CONCLUSION: Incidental PTL accounts for most of thyroid surgery cases and are associated with incomplete diagnostic work-up, Hashimoto's thyroiditis and MALT subtype. CoreNB appears to be the best tool for diagnosis. Most of PTL deaths occurred during the first year after diagnosis and mostly related to systemic treatment. Age and DLBC subtype are poor prognostic factors.


Assuntos
Linfoma , Neoplasias da Glândula Tireoide , Tireoidite , Humanos , Estudos Retrospectivos
19.
Steroids ; 197: 109256, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37217088

RESUMO

Diosgenin and its derivatives have proved a huge importance in diverse biological activities. The optimized production of the diastereoisomers of the epoxide of diosgenin acetate by means of mCPBA is reported herein. This transformation had a previous design of experiments using the application of a statistical factorial DoE of 4 parameters (nk), where one variable is varied at a time, while others stay constant. The temperature showed the greatest effect on the reaction yield; so, at 298 K the diastereomeric ratio 3:1 of α and ß-epoxides, normally found, was raised to 1:1. Time was the second significant variable, but due to its high correlation with temperature, 30 min were required for a global 90% conversion at least. These diastereoisomers were characterized both isolated and in the mixtures obtained, to determine their antioxidant, antimicrobial and antiproliferative activity, finding a low antioxidant capacity by DPPH, but antimicrobial activity at the level of penicillin in gram negative bacteria by 1ß better to 1α. The antiproliferative capacity was higher for diastereoisomer ß, agreeing with the proportion of the mixture obtained by different conditions, increasing this in relation to the amount of this diastereoisomer present in hormone-dependent cancer cell lines such as Hela, PC-3 and MCF-7, with 10.0 µM obtained values of viability at 21.8 %, 35.8 % and 12.3 % respectively. DoE optimization allows to manipulate the ratio between diastereoisomers with the minimum number of experiments, extending the analysis of the effect of the ratio between diastereoisomers and the in silico potential as well as the biological activity.


Assuntos
Anti-Infecciosos , Diosgenina , Humanos , Antioxidantes/farmacologia , Antioxidantes/química , Diosgenina/química , Linhagem Celular Tumoral , Anti-Infecciosos/química , Células HeLa
20.
Cancer Lett ; 561: 216156, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37019172

RESUMO

Despite the clinical success of the programmed death ligand 1 (PD-L1) blocking therapy in cancer treatment, only a subset of patients exhibits durable responses, therefore further exploration of other immunotherapeutic alternatives are needed. This paper reported the development of the PKPD-L1Vac vaccine, a new protein vaccine candidate that uses aluminum phosphate as an adjuvant and as an antigen the extracellular domain of human PD-L1 fused to a 47 amino-terminal portion of the LpdA protein from N. meningitides (PKPD-L1). The PKPD-L1 antigen has different physical and biological characteristics than those found in the natural molecule and in others PD-L1 vaccine candidates. The quimeric protein has a reduced binding capacity to the PD-1 and CD80 receptors to decrease their pro-tumoral activity. Besides, the distinctive feature of the PKPD-L1 polypeptide to be structurally aggregated could be desirable for its immunogenic properties. PKPD-L1Vac elicited anti-PD-L1-specific IgG antibodies and T lymphocyte-mediated immunity in mice and non-human primates. The vaccine administration demonstrated antitumor activity on CT-26 and B16-F10 primary tumor models in mice. Moreover, the immunization with PKPD-L1Vac increased the tumor-infiltrating lymphocytes and decreased the proportion of CD3+CD8+PD1+high anergic T cells in CT-26 tumor tissues, suggesting that the vaccine may remodel the tumor microenvironment. In summary, the PKPD-L1Vac vaccine exhibits very promising preclinical results and deserves to move forward to a phase I clinical trial.


Assuntos
Linfócitos B , Imunoterapia , Neoplasias , Animais , Humanos , Camundongos , Antígeno B7-H1 , Linfócitos T CD8-Positivos , Tolerância Imunológica , Imunoterapia/métodos , Neoplasias/terapia , Primatas/metabolismo , Microambiente Tumoral , Vacinação , Linfócitos B/imunologia
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