RESUMO
Mycobacterium tuberculosis (M.tb.) infection leads to over 1.5 million deaths annually, despite widespread vaccination with BCG at birth. Causes for the ongoing tuberculosis endemic are complex and include the failure of BCG to protect many against progressive pulmonary disease. Host genetics is one of the known factors implicated in susceptibility to primary tuberculosis, but less is known about the role that host genetics plays in controlling host responses to vaccination against M.tb. Here, we addressed this gap by utilizing Diversity Outbred (DO) mice as a small animal model to query genetic drivers of vaccine-induced protection against M.tb. DO mice are a highly genetically and phenotypically diverse outbred population that is well suited for fine genetic mapping. Similar to outcomes in people, our previous studies demonstrated that DO mice have a wide range of disease outcomes following BCG vaccination and M.tb. challenge. In the current study, we used a large population of BCG-vaccinated/M.tb.-challenged mice to perform quantitative trait loci mapping of complex infection traits; these included lung and spleen M.tb. burdens, as well as lung cytokines measured at necropsy. We found sixteen chromosomal loci associated with complex infection traits and cytokine production. QTL associated with bacterial burdens included a region encoding major histocompatibility antigens that are known to affect susceptibility to tuberculosis, supporting validity of the approach. Most of the other QTL represent novel associations with immune responses to M.tb. and novel pathways of cytokine regulation. Most importantly, we discovered that protection induced by BCG is a multigenic trait, in which genetic loci harboring functionally-distinct candidate genes influence different aspects of immune responses that are crucial collectively for successful protection. These data provide exciting new avenues to explore and exploit in developing new vaccines against M.tb.
Assuntos
Mycobacterium bovis , Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose , Humanos , Animais , Camundongos , Vacina BCG/genética , Tuberculose/genética , Tuberculose/prevenção & controle , Tuberculose/microbiologia , Vacinas contra a Tuberculose/genética , Vacinação , Loci Gênicos , Citocinas/genética , Antígenos de BactériasRESUMO
Nanotechnology is considered a successful approach for cancer diagnosis and treatment. Preferentially, cancer cell recognition and drug targeting via nano-delivery system include the penetration of anticancer agents into the cell membrane to damage the cancer cell by protein modification, DNA oxidation, or mitochondrial dysfunction. The past research on nano-delivery systems and their target has proven the beneficial achievement in a malignant tumor. Modern perceptions using inventive nanomaterials for cancer management have been offered by a multifunctional platform based on various nano-carriers with the probability of imaging and cancer therapy simultaneously. Emerging nano-delivery systems in cancer therapy still lack knowledge of the biological functions behind the interaction between nanoparticles and cancer cells. Since the potential of engineered nanoparticles addresses the various challenges, limiting the success of cancer therapy subsequently, it is a must to review the molecular targeting of a nano-delivery system to enhance the therapeutic efficacy of cancer. This review focuses on using a nano-delivery system, an imaging system, and encapsulated nanoparticles for cancer therapy.
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Antineoplásicos , Nanomedicina , Neoplasias , Humanos , Neoplasias/tratamento farmacológico , Nanomedicina/métodos , Antineoplásicos/uso terapêutico , Antineoplásicos/administração & dosagem , Nanopartículas/química , Sistemas de Liberação de Medicamentos , Animais , Portadores de Fármacos/químicaRESUMO
The process of glycation, characterized by the non-enzymatic reaction between sugars and free amino groups on biomolecules, is a key contributor to the development and progression of both microvascular and macrovascular complications associated with diabetes, particularly due to persistent hyperglycemia. This glycation process gives rise to advanced glycation end products (AGEs), which play a central role in the pathophysiology of diabetes complications, including nephropathy. The d-ribose-mediated glycation of fibrinogen plays a central role in the pathogenesis of diabetes nephropathy (DN) and retinopathy (DR) by the generation and accumulation of advanced glycation end products (AGEs). Glycated fibrinogen with d-ribose (Rb-gly-Fb) induces structural changes that trigger an autoimmune response by generating and exposing neoepitopes on fibrinogen molecules. The present research is designed to investigate the prevalence of autoantibodies against Rb-gly-Fb in individuals with type 2 diabetes mellitus (T2DM), DN & DR. Direct binding ELISA was used to test the binding affinity of autoantibodies from patients' sera against Rb-gly-Fb and competitive ELISA was used to confirm the direct binding findings by checking the bindings of isolated IgG against Rb-gly-Fb and its native conformer. In comparison to healthy subjects, 32% of T2DM, 67% of DN and 57.85% of DR patients' samples demonstrated a strong binding affinity towards Rb-gly-Fb. Both native and Rb-gly-Fb binding by healthy subjects (HS) sera were non-significant (p > 0.05). Furthermore, the early, intermediate, and end products of glycation have been assessed through biochemical and physicochemical analysis. The biochemical markers in the patient groups were also significant (p < 0.05) in comparison to the HS group. This study not only establishes the prevalence of autoantibodies against d-ribose glycated fibrinogen in DN but also highlights the potential of glycated fibrinogen as a biomarker for the detection of DN and/or DR. These insights may open new avenues for research into novel therapeutic strategies and the prevention of diabetes-related nephropathy and retinopathy.
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Diabetes Mellitus Tipo 2 , Nefropatias Diabéticas , Doenças Retinianas , Humanos , Nefropatias Diabéticas/complicações , Autoanticorpos , Ribose , Produtos Finais de Glicação Avançada/metabolismo , Fibrinogênio , Doenças Retinianas/complicaçõesRESUMO
Tuberculosis is still the leading cause of death globally from any infectious disease, despite the widespread use of the live attenuated vaccine Bacille Calmette Guerin (BCG). While BCG has some efficacy against disseminated TB disease in children, protection wanes into adulthood resulting in over 1.8 million TB deaths per year. This has led to efforts to develop novel vaccine candidates that either replace or boost BCG, as well as to test novel delivery mechanisms to enhance BCG's efficacy. Traditional BCG vaccination is performed as an intradermal (ID) injection but delivering BCG by an alternate route may enhance the depth and breadth of protection. Previously, we demonstrated that phenotypically and genotypically disparate Diversity Outbred (DO) mice have heterogenous responses to M. tuberculosis challenge following intradermal BCG vaccination. Here, we utilize DO mice to examine BCG-induced protection when BCG is delivered systemically via intravenous (IV) administration. We find that DO mice vaccinated with IV BCG had a greater distribution of BCG throughout their organs compared to ID-vaccinated animals. However, compared to ID-vaccinated mice, M. tuberculosis burdens in lungs and spleens were not significantly reduced in animals vaccinated with BCG IV, nor was lung inflammation significantly altered. Nonetheless, DO mice that received BCG IV had increased survival over those vaccinated by the traditional ID route. Thus, our results suggest that delivering BCG by the alternate IV route enhances protection as detected in this diverse small animal model.
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Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculose , Animais , Camundongos , Vacina BCG , Camundongos de Cruzamento Colaborativo , Tuberculose/prevenção & controle , VacinaçãoRESUMO
Social determinants of health (SDoH) may impact outcomes in sickle cell disease (SCD). We conducted a comprehensive literature review of five electronic databases to elucidate the relationship between SDoH and SCD, and identify gaps in the literature. Our search yielded 59 articles, which we organized into five SDoH areas: Neighborhood and Built Environment, Health and Healthcare, Social and Community Context, Education, and Economic Stability. We found that social determinants, such as access to healthcare, were inconsistently evaluated. Improved recognition and understanding of SDoH should enhance the development of programs that directly address its detrimental effects on patients with SCD.
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Anemia Falciforme , Determinantes Sociais da Saúde , Humanos , Escolaridade , Características de Residência , Anemia Falciforme/epidemiologia , Anemia Falciforme/terapiaRESUMO
In high-income countries, premarital genetic counseling for Sickle Cell Disease (SCD) is a standard practice. However, in Nigeria, there is no formal premarital genetic counseling program available for SCD. We conducted a series of focus group discussions with health care professionals, patients with SCD, and parents of the patients with or without SCD to gain an understanding of their attitudes and beliefs towards SCD/Sickle Cell Trait and premarital genetic counseling for SCD. Data were analyzed using Charmaz's constructivist grounded theory approach. Two themes were highlighted in the analysis as follows: (1) the difference between the perception of premarital sickle cell screening among individuals with SCD versus the general population, and (2) the personal beliefs and physical challenges that could lead to the avoidance of premarital screening within the general community. Lack of disease-related knowledge, testing facilities, transportation, and stigma associated with the disease were the most commonly perceived barriers to premarital testing. Also, a willingness to receive premarital testing for SCD exists within our community to reduce the spread of the disease and advocate for improved health-related quality of life of patients with SCD. The content and structure of a premarital genetic counseling program in Kano, Northern Nigeria, needs to be developed.
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Anemia Falciforme , Aconselhamento Genético , Humanos , Nigéria/epidemiologia , Qualidade de Vida , Aconselhamento , Anemia Falciforme/epidemiologiaRESUMO
The influence of advanced glycation end products (AGEs) in the biological processes contribute to the life-changing complications such as progression of cancer, diabetes and other chronic disorders. The receptor of AGEs while interacting with its ligands causes a never-ending irregularity in the cell-signaling communication. Hence, AGEs are considered as an important link between progression and contribution to cancer. This study focuses on the presence and/or absence of oxidative and glycative stress in the serum samples of various cancer patients. During analysis of the early and intermediate glycation product in cancer patient's sera, our result indicates an increasing trend of both the adducts as compared to normal healthy subjects. Similarly, one of the AGEs i.e., carboxymethyllysine was found to be enhanced in cancer sera as compared to NHS. The binding characteristics of circulating auto-antibodies in cancer patient's sera against human serum albumin (HSA)-AGEs were assessed through ELISA and furthermore, the maximum percent inhibition against HSA-AGEs was observed as 57-63%, 46-62% and 42-64% in prostate cancer, lung cancer and head and neck cancer. Hence, our result successfully assisted the presence of AGEs in all the cancer patient's sera though it is not clear which specific cancer is more potent to AGEs.
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Produtos Finais de Glicação Avançada/metabolismo , Neoplasias/metabolismo , Albumina Sérica Humana/metabolismo , Adolescente , Adulto , Idoso , Feminino , Produtos Finais de Glicação Avançada/sangue , Glicosilação , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Oxirredução , Adulto JovemRESUMO
Impaired awareness of glycation biology in cancer initiation and progression is one of the fundamental reasons for its meticulous investigation of the molecules involved in signalling pathway. Glycation of biological macromolecules results in the progression of advanced glycation end-products (AGEs) that proliferates the process of carcinogenesis by activation of transcription factors and release of cytokines. The receptor for advanced glycation end-products (RAGEs) with the binding of its different ligands like; AGEs, HMGB1 and S100 activate the signalling arrays. The activation of downstream signalling pathway ultimately leads to the pathophysiological conditions of diabetes, ageing, neurological disorders and cancers as well as a result of the activation of transcription factors which is discussed in the main body text of this review. However, there might be a likelihood of the positive effect of the HMGB1 and S100 proteins in cancer. Still, some untouched mechanisms might be responsible for the establishment of the function of AGE-RAGE or AGE-sRAGE axis activation that leads to the friend-foe association with the cancers. The levels of RAGE and s-RAGE may be a useful biomarker of ligand-RAGE pathway activation and cancer. Thus, the possibility of providing a potential complement to carcinogenesis is very high which might be an interesting target for therapeutic interventions. This article is an insightful assessment on AGE, RAGE and s-RAGE for its possible role in cancer onset and progression. The novel therapeutic targets for cancer prevention or inhibition are also explained in brief in relation to AGE and RAGE.
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Carcinogênese/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Receptor para Produtos Finais de Glicação Avançada/sangue , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Dano ao DNA , Glicosilação , Humanos , Inflamação/metabolismo , Ligantes , Estresse Oxidativo , Transdução de SinaisRESUMO
The combine effect of oxidative and glycative stress predisposed to glycoxidation, and their outcomes that play critical role in lung cancer have been examined in different ways. The therapeutic approaches for lung cancer are still unsatisfactory. We observe some unclear and decisive pathways which might play an important role in targeting lung cancer. The roadmap of signaling pathway includes p38 MAPK, NF-ÆB, TNF-α and AGE-RAGE binding affinity play role in the cell growth, proliferation, apoptosis inhibition and metastasis. The goal of this review is to achieve a new signaling map inside the lung cancer which is mediated by glycoxidative products mainly reactive dicarbonyls and advanced glycation end products (AGEs). Additionally, AGE-RAGE binding critically regulates the suppression and promotion of lung cancer via inhibition and activation of different signaling pathways. Hence, this review suggests the role of oxidation, glycation, and glycoxidation in lung cancer.
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Produtos Finais de Glicação Avançada/metabolismo , Neoplasias Pulmonares/metabolismo , Estresse Oxidativo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Apoptose , Proliferação de Células , Glicosilação , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/fisiopatologia , Oxirredução , Receptor para Produtos Finais de Glicação Avançada/fisiologia , Transdução de SinaisRESUMO
Advanced glycation end products (AGEs) are directly related to third aging-associated diseases, such as cardiovascular diseases, arteriosclerosis, and neurodegeneration. Likewise, these irreversible and nonenzymatic products have been reported to be involved in the progression of malignant cancers. In general, aging-associated diseases and the initiation of cancer have been subjects of interest for several years. Few studies on the role of AGEs in cancer have been performed on cell lines. Moreover, past investigations in the field of glycation biology still lack the knowledge of in vivo and in vitro approaches for cancer cells. Accordingly, we aimed to focus on and establish a link between cancer and glycation with respect to all the possible AGEs. In our study, the levels of carboxymethyllysine (CML) increased by 50.94% in an animal model of glycation, whereas in an animal model of cancer, the contents of CML increased by 45.94% compared with their negative controls. Similarly, fluorescent AGEs were also examined and were found to be increased by 65.3% and 58.63% in the animal models of glycation and cancer, respectively, compared with the control subjects. The protein carbonyl contents were also found to be enhanced in the animal models of glycation and cancer. In our study, the levels of reactive oxygen species were also found to be significantly increased in the in vitro model of cancer cells as compared with the controls. Such an initial breakthrough indicated that AGEs were present in the serum of the animal models of cancer and glycation.
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Produtos Finais de Glicação Avançada/metabolismo , Neoplasias Pulmonares/metabolismo , Células A549 , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , Masculino , Camundongos , Carbonilação Proteica/fisiologia , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismoRESUMO
Human serum albumin is playing an increasing role as a drug carrier in clinical settings. Biotin molecules are often used as suitable tags in targeted anti-tumor drug delivery systems. We report on the synthesis and properties of a new multimodal theranostic conjugate based on an anti-cancer fluorinated nucleotide conjugated with a biotinylated dual-labeled albumin. Interestingly, in vitro and in vivo study revealed stronger anti-tumor activity of the non-tagged theranostic conjugate than that of the biotin-tagged conjugate, which can be explained by decreased binding of the biotin-tagged conjugate to cellular receptors. Our study sheds light on the importance of site-specific albumin modification for the design of albumin-based drugs with desirable pharmaceutical properties.
Assuntos
Antineoplásicos/farmacologia , Biotina/química , Nucleotídeos/farmacologia , Albumina Sérica Humana/química , Nanomedicina Teranóstica , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Camundongos , Camundongos SCID , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Nucleotídeos/síntese química , Nucleotídeos/química , Relação Estrutura-AtividadeRESUMO
We report on the synthesis and properties of a new multimodal theranostic conjugate based on an anticancer fluorinated nucleotide conjugated with a dual-labeled albumin. A fluorine-labeled homocysteine thiolactone has been used as functional handle to synthesize the fluorinated albumin and couple it with a chemotherapeutic agent 5-trifluoromethyl-2'-deoxyuridine 5'-monophosphate (pTFT). The conjugate allows for direct optical and 19F magnetic resonance cancer imaging and release of the drug upon addition of glutathione. Interestingly, the pTFT release from albumin conjugate could only be promoted by the increased acidity (pH 5.4). The in vitro study and primary in vivo investigations showed stronger antitumor activity than free pTFT.
Assuntos
Antineoplásicos/farmacologia , Nucleotídeos/química , Albumina Sérica/química , Nucleotídeos de Timina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração de Íons de Hidrogênio , Estrutura Molecular , Oxirredução , Relação Estrutura-Atividade , Nucleotídeos de Timina/químicaRESUMO
BACKGROUND: Complex regional pain syndrome (CRPS) is a painful condition with approximately 50,000 annual new cases in the United States. It is a major cause of work-related disability, chronic pain after limb fractures, and persistent pain after extremity surgery. Additionally, CRPS patients often experience cognitive changes, anxiety, and depression. The supraspinal mechanisms linked to these CRPS-related comorbidities remain poorly understood. METHODS: The authors used a previously characterized mouse model of tibia fracture/cast immobilization showing the principal stigmata of CRPS (n = 8 to 20 per group) observed in humans. The central hypothesis was that fracture/cast mice manifest changes in measures of thigmotaxis (indicative of anxiety) and working memory reflected in neuroplastic changes in amygdala, perirhinal cortex, and hippocampus. RESULTS: The authors demonstrate that nociceptive sensitization in these mice is accompanied by altered thigmotactic behaviors in the zero maze but not open field assay, and working memory dysfunction in novel object recognition and social memory but not in novel location recognition. Furthermore, the authors found evidence of structural changes and synaptic plasticity including changes in dendritic architecture and decreased levels of synaptophysin and brain-derived neurotrophic factor in specific brain regions. CONCLUSIONS: The study findings provide novel observations regarding behavioral changes and brain plasticity in a mouse model of CRPS. In addition to elucidating some of the supraspinal correlates of the syndrome, this work supports the potential use of therapeutic interventions that not only directly target sensory input and other peripheral mechanisms, but also attempt to ameliorate the broader pain experience by modifying its associated cognitive and emotional comorbidities.
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Ansiedade/patologia , Encéfalo/patologia , Síndromes da Dor Regional Complexa/patologia , Modelos Animais de Doenças , Transtornos da Memória/patologia , Fraturas da Tíbia/patologia , Animais , Ansiedade/psicologia , Encéfalo/fisiologia , Síndromes da Dor Regional Complexa/psicologia , Hipocampo/patologia , Masculino , Transtornos da Memória/psicologia , Camundongos , Camundongos Endogâmicos C57BL , Plasticidade Neuronal/fisiologia , Distribuição Aleatória , Fraturas da Tíbia/psicologiaRESUMO
Traditionally, successful vaccines rely on specific adaptive immunity by activating lymphocytes with an attenuated pathogen, or pathogen subunit, to elicit heightened responses upon subsequent exposures. However, recent work with Mycobacterium tuberculosis and other pathogens has identified a role for "trained" monocytes in protection through memory-like but non-specific immunity. Here, we used an in vitro co-culture approach to study the potential role of trained macrophages, including lung alveolar macrophages, in immune responses to the Live Vaccine Strain (LVS) of Francisella tularensis. F. tularensis is an intracellular bacterium that replicates within mammalian macrophages and causes respiratory as well as systemic disease. We vaccinated mice with F. tularensis LVS and then obtained lung alveolar macrophages, or derived macrophages from bone marrow. LVS infected and replicated comparably in both types of macrophages, whether naïve or from LVS-vaccinated mice. LVS-infected macrophages were then co-cultured with either naïve splenocytes, splenocytes from mice vaccinated intradermally, or splenocytes from mice vaccinated intravenously. For the first time, we show that immune (but not naïve) splenocytes controlled bacterial replication within alveolar macrophages, similar to previous results using bone marrow-derived macrophage. However, no differences in control of intramacrophage bacterial replication were found between co-cultures with naïve macrophages or macrophages from LVS-vaccinated mice; furthermore, nitric oxide levels and interferon-gamma production in supernatants were largely comparable across all conditions. Thus, in the context of in vitro co-cultures, the data do not support development of trained macrophages in bone marrow or lungs of mice vaccinated with LVS intradermally or intravenously. IMPORTANCE: The discovery of non-specific "trained immunity" in monocytes has generated substantial excitement. However, to date, training has been studied with relatively few microbes (e.g., Mycobacterium bovis Bacille Calmette-Guérin, a live attenuated intracellular bacterium used as a vaccine) and microbial substances (e.g., LPS), and it remains unclear whether training during infection is common. We previously demonstrated that vaccination of mice with Francisella tularensis Live Vaccine Strain (LVS), another live attenuated intracellular bacterium, protected against challenge with the unrelated bacterium Listeria monocytogenes. The present study therefore tested whether LVS vaccination engenders trained macrophages that contributed to this protection. To do so, we used a previous in vitro co-culture approach with murine bone marrow-derived macrophages to expand and study lung alveolar macrophages. We demonstrated that alveolar macrophages can be productively infected and employed to characterize interactions with LVS-immune lymphocytes. However, we find no evidence that either bone marrow-derived or alveolar macrophages are trained by LVS vaccination.
Assuntos
Vacinas Bacterianas , Francisella tularensis , Macrófagos Alveolares , Tularemia , Vacinas Atenuadas , Animais , Francisella tularensis/imunologia , Camundongos , Vacinas Atenuadas/imunologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/microbiologia , Tularemia/imunologia , Tularemia/prevenção & controle , Tularemia/microbiologia , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/administração & dosagem , Macrófagos/imunologia , Macrófagos/microbiologia , Feminino , Camundongos Endogâmicos C57BL , Técnicas de Cocultura , Interferon gama/metabolismo , Interferon gama/imunologia , VacinaçãoRESUMO
PURPOSE: Methylglyoxal (MG) is the most potent precursor during the formation of the advanced glycation end products (AGEs). MG-dependent glycative stress contributes to pathogenesis of diabetes, age-related disorders, and cancer. There is a great need to study the reduction process of glycative stress for effective management of metabolic disorders. From natural compounds to synthetic drugs, each element contributes to the reduction of glycative stress. Previously, it was established that the lowering of uric acid, low-density lipoprotein cholesterol, and urine albumin excretion rate, as well as reducing total oxidative stress, were all achieved more effectively with a levothyroxine regimen. Still, there is no such study found that supports the MG-dependent glycative stress reduction with thyroid hormone compound. Our study aims to investigate the effects of T3 and T4 on MG-dependent glycative stress. METHODS: The antiglycation effect was assayed through NBT assay, DNPH assay, ELISA, and fluorescence spectrophotometer. The intracellular reduction in reactive oxygen species (ROS) has been estimated through confocal microscopy. RESULTS: The results revealed an effective reduction in the formation of AGEs adducts and intracellular ROS formation. CONCLUSION: The investigation concludes AGEs formation was suppressed using these compounds, although in vivo and rigorous clinical trials are required in order to verify these findings.
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One of the goals in improving the design of compact portable micronuclear heat pipe reactors is to enhance their operating life so that they can generate maximum power within safe nuclear, thermal, and mechanical limits and with minimal human intervention. This work carries out an analysis to estimate the effect of non-uniform fuel enrichment and thermo-mechanical performance of a 1 MW thermal power uranium nitride fueled Micro Nuclear Heat Pipe Reactor (MNHPR). For neutronic and thermo-mechanical analyses, the open-source Monte Carlo code OpenMC and the COMSOL Multiphysics codes are used. The neutron flux distribution and subsequent fuel temperature, heat transport, stresses and strains are estimated. The analysis of core power distribution shows an uneven power distribution resulting in hot spots. The maximum fuel centerline temperature of 1353 K at the highest peaking factor 1.22 is within the safety limit. However, the high temperature results in higher thermal stress and subsequent displacement of 119 µm that exceeds the 100 µm fuel-clad gap. Power peaking thus significantly limits the maximum allowed operating power. In this study it is found that non-uniform placement of the fuel reduces power peaking and enhances the overall core performance. It is recommended to consider each fuel ring as a separate zone and gradually change the fuel enrichment in each zone. The non-uniform distribution of the fuel follows the gradual increase of enrichment from ring 1 to ring 5 with max enrichment in ring 5, and then a drop in the enrichment to mitigate any peaking in ring 6 due to its proximity to the reflector. From ring 1 to ring 6 fuel of 60-62-70-70-75-65 percent enrichment is recommended. The proposed fuel strategy mitigates power peaking in the core and enhances the maximum safe operating power level by 15 % from 775 kW to 893 kW without physical design change.
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Hyperglycaemia is a life-threatening risk factor that occurs in both chronic and acute phases and has been linked to causing injury to many organs. Protein modification was triggered by hyperglycaemic stress, which resulted in pathogenic alterations such as impaired cellular function and tissue damage. Dysregulation in cellular function increases the condition associated with metabolic disorders, including cardiovascular diseases, nephropathy, retinopathy, and neuropathy. Hyperglycaemic stress also increases the proliferation of cancer cells. The major areas of experimental biomedical research have focused on the underlying mechanisms involved in the cellular signalling systems involved in diabetes-associated chronic hyperglycaemia. Reactive oxygen species and oxidative stress generated by hyperglycaemia modify many intracellular signalling pathways that result in insulin resistance and ß-cell function degradation. The dysregulation of post translational modification in ß cells is clinically associated with the development of diabetes mellitus and its associated diseases. This review will discuss the effect of hyperglycaemic stress on protein modification and the cellular signalling involved in it. The focus will be on the significant molecular changes associated with severe metabolic disorders.
Assuntos
Hiperglicemia , Doenças Metabólicas , Processamento de Proteína Pós-Traducional , Transdução de Sinais , Humanos , Hiperglicemia/metabolismo , Doenças Metabólicas/metabolismo , Doenças Metabólicas/etiologia , Animais , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
BACKGROUND: Hydroxyurea is an evidence-based disease-modifying therapy for sickle cell disease (SCD) but is underutilized. The Integration of Mobile Health into Sickle Cell Disease Care to Increase Hydroxyurea Utilization (meSH) multicenter study leveraged mHealth to deliver targeted interventions to patients and providers. SCD studies often underenroll; and recruitment strategies in the SCD population are not widely studied. Unanticipated events can negatively impact enrollment, making it important to study strategies that ensure adequate study accrual. OBJECTIVE: The goal of this study was to evaluate enrollment barriers and the impact of modified recruitment strategies among patients and providers in the meSH study in response to a global emergency. METHODS: Recruitment was anticipated to last 2 months for providers and 6 months for patients. The recruitment strategies used with patients and providers, new recruitment strategies, and recruitment rates were captured and compared. To document recruitment adaptations and their reasons, study staff responsible for recruitment completed an open-ended 9-item questionnaire eliciting challenges to recruitment and strategies used. Themes were extrapolated using thematic content analysis. RESULTS: Total enrollment across the 7 sites included 89 providers and 293 patients. The study acceptance rate was 85.5% (382/447) for both patients and providers. The reasons patients declined participation were most frequently a lack of time and interest in research, while providers mostly declined because of self-perceived high levels of SCD expertise, believing they did not need the intervention. Initially, recruitment involved an in-person invitation to participate during clinic visits (patients), staff meetings (providers), or within the office (providers). We identified several important recruitment challenges, including (1) lack of interest in research, (2) lack of human resources, (3) unavailable physical space for recruitment activities, and (4) lack of documentation to verify eligibility. Adaptive strategies were crucial to alleviate enrollment disruptions due to the COVID-19 pandemic. These included remote approaching and consenting (eg, telehealth, email, and telephone) for patients and providers. Additionally, for patients, recruitment was enriched by simplification of enrollment procedures (eg, directly approaching patients without a referral from the provider) and a multitouch method (ie, warm introductions with flyers, texts, and patient portal messages). We found that patient recruitment rates were similar between in-person and adapted (virtual with multitouch) approaches (167/200, 83.5% and 126/143, 88.1%, respectively; P=.23). However, for providers, recruitment was significantly higher for in-person vs remote recruitment (48/50, 96% and 41/54, 76%, respectively, P<.001). CONCLUSIONS: We found that timely adaptation in recruitment strategies secured high recruitment rates using an assortment of enriched remote recruitment strategies. Flexibility in approach and reducing the burden of enrollment procedures for participants aided enrollment. It is important to continue identifying effective recruitment strategies in studies involving patients with SCD and their providers and the impact and navigation of recruitment challenges. TRIAL REGISTRATION: ClinicalTrials.Gov NCT03380351; https://clinicaltrials.gov/study/NCT03380351. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/16319.
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The water-based Cu and CoFe2O4 hybrid nano liquid flow across a permeable curved sheet under the consequences of inertial and Lorentz forces has been reported in this analysis. The Joule heating and Darcy Forchheimer effects on fluid flow have been also examined. In the presence of copper (Cu) and cobalt iron oxide (CoFe2O4) nanoparticles, the hybrid nano liquid is synthesized. Radiation and heat source features are additionally incorporated to perform thermodynamics analysis in detail. The second law of thermodynamics is employed in order to estimate the overall generation of entropy. The nonlinear system of PDEs (partial differential equations) is transformed into a dimensionally-free set of ODEs (ordinary differential equations) by employing a similarity framework. The Mathematica built in package ND Solve method is applied to compute the resulting set of nonlinear differential equations numerically. Along with the velocity, and temperature profiles, skin friction and Nusselt number are also computed. Figures and tables illustrate the effects of flow factors on important profiles. Evidently, the outcomes reveal that hybrid nanofluid (Cu + CoFe2O4+H2O) is more progressive than nanofluid (Cu + H2O) and base fluid (H2O) in thermal phenomena. Furthermore, the velocity profile is improved with the greater values of curvature parameter, while the inverse trend is observed against the magnetic parameters. Also, the velocity and energy distribution of hybrid nano-liquid flow boosts with the inclusion of Cu and CoFe2O4 nanoparticles into the base fluid. Velocity distribution diminishes with the increment of volume friction. For high values of inertial factor, skin friction improve while velocity and Nusselt number declines.
RESUMO
Chronic pain affects 30% to 40% of individuals with sickle cell disease (SCD) and impairs patient functioning. Clinically meaningful, practical, and valid assessment tools for investigation, evaluation, and management of chronic pain are limited, representing a barrier for advancing SCD care. We sought to determine whether patient-reported outcomes (PROs) show preliminary construct validity in identifying individuals with SCD who were a priori defined as suggestive of having chronic pain based on previously published criteria. All individuals completed the Patient-Reported Outcomes Measurement Information System (PROMIS) domains: pain interference, pain behavior, pain quality (nociceptive, neuropathic), fatigue, sleep disturbance, depression, and anxiety; the Adult Sickle Cell Quality of Life Measurement Information System (ASCQ-Me) domains: pain impact and emotional impact; and the painDETECT questionnaire. Thirty-three adults living with SCD were enrolled, and 42.4% had chronic pain. Pain-related PROs scores distinctly differentiated individuals with chronic pain from those without. Individuals with chronic pain had significantly worse pain-related PROs scores: PROMIS pain interference (64.2 vs 54.3), PROMIS pain behavior (63.2 vs 50), and ASCQ-Me pain impact (42.9 vs 53.2). According to published PROMIS clinical cut scores for the pain-related domains, individuals with chronic pain were categorized as having moderate impairment, whereas those without chronic pain had mild or no impairment. Individuals with chronic pain had PRO pain features consistent with neuropathic pain and worse scores in fatigue, depression, sleep disturbance, and emotional impact. Pain-related PROs show preliminary construct validity in differentiating individuals with and without chronic SCD pain and could be used as valuable tools for research and clinical monitoring of chronic pain.