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1.
Cell ; 184(15): 4032-4047.e31, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34171309

RESUMO

Although mutations in DNA are the best-studied source of neoantigens that determine response to immune checkpoint blockade, alterations in RNA splicing within cancer cells could similarly result in neoepitope production. However, the endogenous antigenicity and clinical potential of such splicing-derived epitopes have not been tested. Here, we demonstrate that pharmacologic modulation of splicing via specific drug classes generates bona fide neoantigens and elicits anti-tumor immunity, augmenting checkpoint immunotherapy. Splicing modulation inhibited tumor growth and enhanced checkpoint blockade in a manner dependent on host T cells and peptides presented on tumor MHC class I. Splicing modulation induced stereotyped splicing changes across tumor types, altering the MHC I-bound immunopeptidome to yield splicing-derived neoepitopes that trigger an anti-tumor T cell response in vivo. These data definitively identify splicing modulation as an untapped source of immunogenic peptides and provide a means to enhance response to checkpoint blockade that is readily translatable to the clinic.


Assuntos
Neoplasias/genética , Neoplasias/imunologia , Splicing de RNA/genética , Animais , Apresentação de Antígeno/efeitos dos fármacos , Apresentação de Antígeno/imunologia , Antígenos de Neoplasias/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Epitopos/imunologia , Etilenodiaminas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Hematopoese/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia , Inflamação/patologia , Camundongos Endogâmicos C57BL , Peptídeos/metabolismo , Isoformas de Proteínas/metabolismo , Pirróis/farmacologia , Splicing de RNA/efeitos dos fármacos , Sulfonamidas/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia
2.
Nature ; 591(7851): 652-658, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33588426

RESUMO

Limiting metabolic competition in the tumour microenvironment may increase the effectiveness of immunotherapy. Owing to its crucial role in the glucose metabolism of activated T cells, CD28 signalling has been proposed as a metabolic biosensor of T cells1. By contrast, the engagement of CTLA-4 has been shown to downregulate T cell glycolysis1. Here we investigate the effect of CTLA-4 blockade on the metabolic fitness of intra-tumour T cells in relation to the glycolytic capacity of tumour cells. We found that CTLA-4 blockade promotes metabolic fitness and the infiltration of immune cells, especially in glycolysis-low tumours. Accordingly, treatment with anti-CTLA-4 antibodies improved the therapeutic outcomes of mice bearing glycolysis-defective tumours. Notably, tumour-specific CD8+ T cell responses correlated with phenotypic and functional destabilization of tumour-infiltrating regulatory T (Treg) cells towards IFNγ- and TNF-producing cells in glycolysis-defective tumours. By mimicking the highly and poorly glycolytic tumour microenvironments in vitro, we show that the effect of CTLA-4 blockade on the destabilization of Treg cells is dependent on Treg cell glycolysis and CD28 signalling. These findings indicate that decreasing tumour competition for glucose may facilitate the therapeutic activity of CTLA-4 blockade, thus supporting its combination with inhibitors of tumour glycolysis. Moreover, these results reveal a mechanism by which anti-CTLA-4 treatment interferes with Treg cell function in the presence of glucose.


Assuntos
Antígeno CTLA-4/antagonistas & inibidores , Glicólise , Neoplasias/imunologia , Neoplasias/metabolismo , Linfócitos T Reguladores/imunologia , Animais , Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Melanoma/genética , Melanoma/imunologia , Melanoma/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL
3.
FASEB J ; 38(6): e23572, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38512139

RESUMO

Asthma is characterized by airway remodeling and hyperreactivity. Our earlier studies determined that the nitric oxide (NO)-soluble guanylyl cyclase (sGC)-cGMP pathway plays a significant role in human lung bronchodilation. However, this bronchodilation is dysfunctional in asthma due to high NO levels, which cause sGC to become heme-free and desensitized to its natural activator, NO. In order to determine how asthma impacts the various lung segments/lobes, we mapped the inflammatory regions of lungs to determine whether such regions coincided with molecular signatures of sGC dysfunction. We demonstrate using murine models of asthma (OVA and CFA/HDM) that the inflamed segments of these murine lungs can be tracked by upregulated expression of HO1 and these regions in turn overlap with regions of heme-free sGC as evidenced by a decreased sGC-α1ß1 heterodimer and an increased response to heme-independent sGC activator, BAY 60-2770, relative to naïve uninflamed regions. We also find that NO generated from iNOS upregulation in the inflamed segments has a higher impact on developing heme-free sGC as increasing iNOS activity correlates linearly with elevated heme-independent sGC activation. This excess NO works by affecting the epithelial lung hemoglobin (Hb) to become heme-free in asthma, thereby causing the Hb to lose its NO scavenging function and exposing the underlying smooth muscle sGC to excess NO, which in turn becomes heme-free. Recognition of these specific lung segments enhances our understanding of the inflamed lungs in asthma with the ultimate aim to evaluate potential therapies and suggest that regional and not global inflammation impacts lung function in asthma.


Assuntos
Asma , Heme Oxigenase-1 , Heme , Animais , Humanos , Camundongos , Alérgenos , Heme Oxigenase-1/metabolismo , Inflamação , Óxido Nítrico , Guanilil Ciclase Solúvel
4.
Bioessays ; 45(8): e2300055, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37276366

RESUMO

A natural heme deficiency that exists in cells outside of the circulation broadly compromises the heme contents and functions of heme proteins in cells and tissues. Recently, we found that the signaling molecule, nitric oxide (NO), can trigger or repress the deployment of intracellular heme in a concentration-dependent hormetic manner. This uncovers a new role for NO and sets the stage for it to shape numerous biological processes by controlling heme deployment and consequent heme protein functions in biology.


Assuntos
Hemeproteínas , Óxido Nítrico , Óxido Nítrico/metabolismo , Heme/metabolismo , Transdução de Sinais , Biologia
5.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35046034

RESUMO

Nitric oxide (NO) signaling in biology relies on its activating cyclic guanosine monophosphate (cGMP) production by the NO receptor soluble guanylyl cyclase (sGC). sGC must obtain heme and form a heterodimer to become functional, but paradoxically often exists as an immature heme-free form in cells and tissues. Based on our previous finding that NO can drive sGC maturation, we investigated its basis by utilizing a fluorescent sGC construct whose heme level can be monitored in living cells. We found that NO generated at physiologic levels quickly triggered cells to mobilize heme to immature sGC. This occurred when NO was generated within cells or by neighboring cells, began within seconds of NO exposure, and led cells to construct sGC heterodimers and thus increase their active sGC level by several-fold. The NO-triggered heme deployment involved cellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-heme complexes and required the chaperone hsp90, and the newly formed sGC heterodimers remained functional long after NO generation had ceased. We conclude that NO at physiologic levels triggers assembly of its own receptor by causing a rapid deployment of cellular heme. Redirecting cellular heme in response to NO is a way for cells and tissues to modulate their cGMP signaling and to more generally tune their hemeprotein activities wherever NO biosynthesis takes place.


Assuntos
Heme/metabolismo , Óxido Nítrico/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Cálcio , GMP Cíclico , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Guanilato Ciclase/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Camundongos , Modelos Biológicos , Ligação Proteica , Multimerização Proteica , Transporte Proteico , Transdução de Sinais , Guanilil Ciclase Solúvel/metabolismo
6.
Proc Natl Acad Sci U S A ; 119(44): e2208040119, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36279452

RESUMO

Organoid technology has provided unique insights into human organ development, function, and diseases. Patient-derived organoids are increasingly used for drug screening, modeling rare disorders, designing regenerative therapies, and understanding disease pathogenesis. However, the use of Matrigel to grow organoids represents a major challenge in the clinical translation of organoid technology. Matrigel is a poorly defined mixture of extracellular matrix proteins and growth factors extracted from the Engelbreth-Holm-Swarm mouse tumor. The extracellular matrix is a major driver of multiple cellular processes and differs significantly between tissues as well as in healthy and disease states of the same tissue. Therefore, we envisioned that the extracellular matrix derived from a native healthy tissue would be able to support organoid growth akin to organogenesis in vivo. Here, we have developed hydrogels from decellularized human and bovine endometrium. These hydrogels supported the growth of mouse and human endometrial organoids, which was comparable to Matrigel. Organoids grown in endometrial hydrogels were proteomically more similar to the native tissue than those cultured in Matrigel. Proteomic and Raman microspectroscopy analyses showed that the method of decellularization affects the biochemical composition of hydrogels and, subsequently, their ability to support organoid growth. The amount of laminin in hydrogels correlated with the number and shape of organoids. We also demonstrated the utility of endometrial hydrogels in developing solid scaffolds for supporting high-throughput, cell culture-based applications. In summary, endometrial hydrogels overcome a major limitation of organoid technology and greatly expand the applicability of organoids to understand endometrial biology and associated pathologies.


Assuntos
Neoplasias , Organoides , Feminino , Humanos , Bovinos , Animais , Organoides/metabolismo , Hidrogéis/química , Laminina/farmacologia , Laminina/metabolismo , Proteômica , Endométrio , Neoplasias/metabolismo
7.
Carcinogenesis ; 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446431

RESUMO

Long intergenic noncoding RNAs (lincRNAs) do not overlap annotated coding genes and are located in intergenic regions, as opposed to antisense and sense-intronic lncRNAs, located in genic regions. LincRNAs influence gene expression profiles and are thereby key to disease pathogenesis. In this study, we assessed the association between lincRNAs and HPV16-positive cervical cancer (CaCx) pathogenesis using weighted gene co-expression network analysis (WGCNA) with coding genes, comparing differentially expressed lincRNA and coding genes (DElincGs and DEcGs, respectively) in HPV16-positive patients with CaCx (n = 44) with those in HPV-negative healthy individuals (n = 34). Our analysis revealed five DElincG modules, co-expressing and correlating with DEcGs. We validated a substantial number of such module-specific correlations in the HPV16-positive cancer TCGA-CESC dataset. Four such modules, displayed significant correlations with patient traits, such as HPV16 physical status, lymph node involvement, and overall survival (OS), highlighting a collaborative effect of all genes within specific modules on traits. Using the DAVID bioinformatics knowledgebase, we identified the underlying biological processes associated with these modules as cancer development and progression-associated pathways. Next, we identified the top 10 DElincGs with the highest connectivity within each functional module. Focusing on the prognostic module hub genes, downregulated CTD-2619J13.13 expression was associated with poor patient OS. This lincRNA gene interacted with 25 coding genes of its module and was associated with such biological processes as keratinization loss and keratinocyte differentiation, reflecting severe disease phenotypes. This study has translational relevance in fighting various cancers with high mortality rates in underdeveloped countries.

8.
J Gen Intern Med ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424345

RESUMO

Building expertise in climate and planetary health among healthcare professionals cannot come with greater urgency as the threats from climate change become increasingly apparent. Current and future healthcare professionals-particularly internists-will increasingly need to understand the interconnectedness of natural systems and human health to better serve their patients longitudinally. Despite this, few national medical societies and accreditation bodies espouse frameworks for climate change and planetary health-related education at the undergraduate (UME), graduate (GME), and continuing (CME) medical education level. As a community of medical educators with an enduring interest in climate change and planetary health, the Society of General Internal Medicine (SGIM) recognizes the need to explicitly define structured educational opportunities and core competencies in both UME and GME as well as pathways for faculty development. In this position statement, we build from the related SGIM Climate and Health position statement, and review and synthesize existing position statements made by US-based medical societies and accreditation bodies that focus on climate change and planetary health-related medical education, identify gaps using Bloom's Hierarchy, and provide recommendations on behalf of SGIM regarding the development of climate and planetary health curricula development. Identified gaps include (1) limited systematic approach to climate and planetary health medical education at all levels; (2) minimal emphasis on learner-driven approaches; (3) limited focus on physician and learner well-being; and (4) limited role for health equity and climate justice. Recommendations include a call to relevant accreditation bodies to explicitly include climate change and planetary health as a competency, extend the structural competency framework to climate change and planetary health to build climate justice, proactively include learners in curricular development and teaching, and ensure resources and support to design and implement climate and planetary health-focused education that includes well-being and resiliency.

9.
Curr Microbiol ; 81(4): 95, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353761

RESUMO

The present work was carried out during the emergence of Delta Variant of Concern (VoC) and aimed to study the change in SARS CoV-2 viral load in Covishield vaccinated asymptomatic/mildly symptomatic health-care workers (HCWs) to find out the optimum isolation period. The SARS CoV-2 viral load was carried out in sequential samples of 55 eligible HCWs which included unvaccinated (UnV; n = 11), single-dose vaccinated (SDV, n = 20) and double-dose vaccinated [DDV, n = 24; short-interval (<6 weeks)] subjects. The mean load of envelope (E) gene on day 5 in SDV [0.42 × 105 copies/reaction] was significantly lower as compared to DDV [6.3 × 105 copies/reaction, P = 0.005] and UnV [6.6 × 105 copies/reaction, P = 0.001] groups. The rate of decline of SARS CoV-2 viral load in the initial 5 days of PCR positivity was significantly higher in SDV as compared to that in DDV (Mean log decline 0.39 vs. 0.19; P < 0.001). This was possibly due to interference of adenoviral immunity of first dose of adenovirus-vectored vaccine in double-dose vaccinated HCWs who had received vaccines within a shorter interval (<6 weeks).


Assuntos
COVID-19 , ChAdOx1 nCoV-19 , Humanos , SARS-CoV-2/genética , Carga Viral , COVID-19/prevenção & controle
10.
Am J Emerg Med ; 81: 1-9, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38613874

RESUMO

OBJECTIVE: To assess the association between ambient heat and all-cause and cause-specific emergency department (ED) visits and acute hospitalizations among Medicare beneficiaries in the conterminous United States. DESIGN: Retrospective cohort study. SETTING: Conterminous US from 2008 and 2019. PARTICIPANTS: 2% random sample of all Medicare fee-for-service beneficiaries eligible for Parts A, B, and D. MAIN OUTCOME MEASURES: All-cause and cause-specific (cardiovascular, renal, and heat-related) ED visits and unplanned hospitalizations were identified using primary ICD-9 or ICD-10 diagnosis codes. We measured the association between ambient temperature - defined as daily mean temperature percentile of summer (June through September) - and the outcomes. Hazard ratios and their associated 95% confidence intervals were estimated using multivariable Cox proportional hazards regression, adjusting for individual level demographics, comorbidities, healthcare utilization factors and zip-code level social factors. RESULTS: Among 809,636 Medicare beneficiaries (58% female, 81% non-Hispanic White, 24% <65), older beneficiaries (aged ≥65) exposed to >95th percentile temperature had a 64% elevated adjusted risk of heat-related ED visits (HR [95% CI], 1.64 [1.46,1.85]) and a 4% higher risk of all-cause acute hospitalization (1.04 [1.01,1.06]) relative to <25th temperature percentile. Younger beneficiaries (aged <65) showed increased risk of heat-related ED visits (2.69 [2.23,3.23]) and all-cause ED visits (1.03 [1.01,1.05]). The associations with heat related events were stronger in males and individuals dually eligible for Medicare and Medicaid. No significant differences were observed by climatic region. We observed no significant relationship between temperature percentile and risk of CV-related ED visits or renal-related ED visits. CONCLUSIONS: Among Medicare beneficiaries from 2008 to 2019, exposure to daily mean temperature ≥ 95th percentile was associated with increased risk of heat-related ED visits, with stronger associations seen among beneficiaries <65, males, and patients with low socioeconomic position. Further longitudinal studies are needed to understand the impact of heat duration, intensity, and frequency on cause-specific hospitalization outcomes.


Assuntos
Serviço Hospitalar de Emergência , Hospitalização , Medicare , Humanos , Serviço Hospitalar de Emergência/estatística & dados numéricos , Estados Unidos/epidemiologia , Feminino , Masculino , Idoso , Hospitalização/estatística & dados numéricos , Medicare/estatística & dados numéricos , Estudos Retrospectivos , Temperatura Alta/efeitos adversos , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Visitas ao Pronto Socorro
11.
Biol Reprod ; 108(6): 854-865, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-36917225

RESUMO

Organoid technology has provided a unique opportunity to study early human development and decipher various steps involved in the pathogenesis of disease. The technology is already used in clinics to improve human patient outcomes. However, limited knowledge of the methodologies required to establish organoid culture systems in domestic animals has slowed the advancement and application of organoid technology in veterinary medicine. This is particularly true for the field of reproduction and the application of assisted reproductive technologies (ART). Here, we have developed a platform to grow oviductal organoids from five domestic species-bovine, porcine, equine, feline, and canine. The organoids were grown progressively from single cells derived from the enzymatic digestion of freshly collected infundibular/fimbrial samples. The addition of WNT, TGFß, BMP, ROCK, and Notch signaling pathway activators or inhibitors to the organoid culture medium suggested remarkable conservation of the molecular signals involved in oviductal epithelial development and differentiation across species. The gross morphology of organoids from all the domestic species was initially similar. However, some differences in size, complexity, and growth rate were subsequently observed and described. After 21 days, well-defined and synchronized motile ciliated cells were observed in organoids. Histopathologically, oviductal organoids mimicked their respective native tissue. In summary, we have carried out a detailed cross-species comparison of oviductal organoids, which would be valuable in advancing our knowledge of oviduct physiology and, potentially, help in increasing the success of ART.


Assuntos
Organoides , Animais de Estimação , Humanos , Feminino , Animais , Gatos , Bovinos , Cavalos , Cães , Suínos , Fazendas , Tubas Uterinas , Diferenciação Celular
12.
Tumour Biol ; 45(1): 55-69, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37599552

RESUMO

BACKGROUND: Cervical cancers (CaCx), like many other cancer types, portray high molecular heterogeneity that affects response to therapy, including immunotherapy. In India and other developing countries, CaCx mortality rates are very high because women report to the clinics with advanced cancers in absence of organized screening programs. This calls for implementation of newer therapeutic regimens for CaCx, like immunotherapy, which is again not used commonly in such countries. OBJECTIVE: Therefore, we focused on dissecting tumour immune heterogeneity, if any, identify immune gene-based biomarkers of heterogeneity and subsets of such cancers with the potential for immunotherapy. We also attempted to characterize the cancer-associated phenotypes of such subsets, including viral load, to decipher the relationship of tumour immunogenicity with oncogenicity. METHODS: Employing RNA-seq analysis of 44 HPV16 positive CaCx patients, immune subtypes were identified by unsupervised hierarchical clustering of global immune-gene expression profiles. Proportions of tumor infiltrating immune cells in the tumor milieu were estimated, employing Cell-type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT), using gene expression data from RNA-seq. The oncogenic phenotypes of the immune subtypes of CaCx were deciphered through differential gene expression (DEGs) and pathway enrichment analysis. Viral load was estimated through TaqMan-based qRT-PCR analysis. RESULTS: Analysis revealed the presence of two immune subtypes of CaCx, A (26/44; 59.09%) and B (18/44; 40.90%). Compared to Subtype-A, Subtype-B portrayed overexpression of immune genes and high infiltration of immune cells, specifically CD8+ T cells (p < 0.0001). Besides, a significant correlation between PD-1 and PD-L1 co-expression among Subtype-B, as opposed to Subtype-A, confirmed the interactive roles of these immune checkpoint molecules in Subtype B. Stepwise discriminant analysis pin-pointed ten immune-genes that could classify 100% of the patients significantly (p < 0.0001) into the two immune subtypes and serve as potential biomarkers of CaCx immunity. Differential gene expression analysis between the subtypes unveiled that Subtype-B was more biologically aggressive than Subtype-A, reflecting loss of structural integrity and promotion of cancer progression. The viral load was significantly lower in Subtype-B (average viral load = 10.74/100 ng of genomic DNA) compared to Subtype-A (average viral load = 14.29/100 ng of genomic DNA). Thus viral load and the ten-gene panel underscore their association with immunogenicity and oncogenicity. CONCLUSION: Our study provides strong evidence that only a subset, about 41% of HPV16 positive CaCx patients in India, portray immune enrichment of the tumor milieu coupled with aggressive phenotypes. Such subtypes are therefore likely to benefit through checkpoint molecule-based or tumor infiltrating lymphocyte-based immunotherapy, which could be a leap forward in tackling aggressive forms of such CaCx in India and other developing countries.


Assuntos
Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/terapia , Papillomavirus Humano 16/genética , Imunoterapia , Fenótipo , Linfócitos T CD8-Positivos
13.
FASEB J ; 36(2): e22099, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34972240

RESUMO

GAPDH, a heme chaperone, has been previously implicated in the incorporation of heme into iNOS and soluble guanylyl cyclase (sGC). Since sGC is critical for myoglobin (Mb) heme-maturation, we investigated the role of GAPDH in the maturation of this globin, as well as hemoglobins α, ß, and γ. Utilizing cell culture systems, we found that overexpression of wild-type GAPDH increased, whereas GAPDH mutants H53A and K227A decreased, the heme content of Mb and Hbα and Hbß. Overexpression of wild-type GAPDH fully recovered the heme-maturation inhibition observed with the GAPDH mutants. Partial rescue was observed by overexpression of sGCß1 but not by overexpression of a sGCΔß1 deletion mutant, which is unable to bind the sGCα1 subunit required to form the active sGCα1ß1 complex. Wild type and mutant GAPDH was found to be associated in a complex with each of the globins and Hsp90. GAPDH at endogenous levels was found to be associated with Mb in differentiating C2C12 myoblasts, and with Hbγ or Hbα in differentiating HiDEP-1 erythroid progenitor cells. Knockdown of GAPDH in C2C12 cells suppressed Mb heme-maturation. GAPDH knockdown in K562 erythroleukemia cells suppressed Hbα and Hbγ heme-maturation as well as Hb dimerization. Globin heme incorporation was not only dependent on elevated sGCα1ß1 heterodimer formation, but also influenced by iron provision and magnitude of expression of GAPDH, d-aminolevulinic acid, and FLVCR1b. Together, our data support an important role for GAPDH in the maturation of myoglobin and γ, ß, and α hemoglobins.


Assuntos
Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Heme/metabolismo , Hemoglobinas/metabolismo , Chaperonas Moleculares/metabolismo , Mioglobina/metabolismo , Gliceraldeído-3-Fosfato Desidrogenases/genética , Células HEK293 , Heme/genética , Hemoglobinas/genética , Humanos , Células K562 , Chaperonas Moleculares/genética , Mutação de Sentido Incorreto , Mioglobina/genética , Sarcoglicanas/genética , Sarcoglicanas/metabolismo
14.
Langmuir ; 39(44): 15474-15486, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37874355

RESUMO

An efficient, unique, and eco-friendly biogenic synthesis of single-crystalline δ-phase manganese oxide nanoparticles (MnO2 NPs) using Gliricidia sepium leaves (GSL) extract at room temperature has been revealed for the first time. The active chemicals present in the GSL extract were found to serve as both reducing and stabilizing agents. The catalyst shows an excellent surface area of 301.13 m2 g-1, a mean pore diameter of 4.01 nm, and 39.97% w/w of active metal content. The reactivity of the synthesized catalyst was demonstrated by achieving a one-pot synthesis of benzimidazoles and quinoxalines via an acceptorless dehydrogenative coupling strategy utilizing biorenewable alcohols. The release of hydrogen gas was observed as the only side product and proven by its successful utilization for alkene reduction which supports the mechanistic elucidation. The release of hydrogen gas as a useful byproduct highlights the scientific importance of the present methodology. Additionally, gram-scale synthesis and catalyst recyclability studies are deliberated. Importantly, the δ-MnO2 NP catalyst exhibited superior catalytic activity and high durability toward hydrogen evolution reaction in alkaline media, highlighting the dual use of the catalyst. The δ-MnO2 NPs attain the current density of 10 mA/cm2 at an overpotential of 154 mV with a Tafel slope of 119 mV/dec.

15.
J Pathol ; 257(5): 593-606, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35358331

RESUMO

A thickened, white patch - leukoplakia - in the oral cavity is usually benign, but sometimes (in ~9% of individuals) it progresses to malignant tumour. Because the genomic basis of this progression is poorly understood, we undertook this study and collected samples of four tissues - leukoplakia, tumour, adjacent normal, and blood - from each of 28 patients suffering from gingivobuccal oral cancer. We performed multiomics analysis of the 112 collected tissues (four tissues per patient from 28 patients) and integrated information on progressive changes in the mutational and transcriptional profiles of each patient to create this genomic narrative. Additionally, we generated and analysed whole-exome sequence data from leukoplakia tissues collected from 11 individuals not suffering from oral cancer. Nonsynonymous somatic mutations in the CASP8 gene were identified as the likely events to initiate malignant transformation, since these were frequently shared between tumour and co-occurring leukoplakia. CASP8 alterations were also shown to enhance expressions of genes that favour lateral spread of mutant cells. During malignant transformation, additional pathogenic mutations are acquired in key genes (TP53, NOTCH1, HRAS) (41% of patients); chromosomal-instability (arm-level deletions of 19p and q, focal-deletion of DNA-repair pathway genes and NOTCH1, amplification of EGFR) (77%), and increased APOBEC-activity (23%) are also observed. These additional alterations were present singly (18% of patients) or in combination (68%). Some of these alterations likely impact immune-dynamics of the evolving transformed tissue; progression to malignancy is associated with immune suppression through infiltration of regulatory T-cells (56%), depletion of cytotoxic T-cells (68%), and antigen-presenting dendritic cells (72%), with a concomitant increase in inflammation (92%). Patients can be grouped into three clusters by the estimated time to development of cancer from precancer by acquiring additional mutations (range: 4-10 years). Our findings provide deep molecular insights into the evolutionary processes and trajectories of oral cancer initiation and progression. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias Bucais , Transcriptoma , Transformação Celular Neoplásica/genética , Exoma , Genômica , Humanos , Leucoplasia/genética , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Mutação
16.
J Chem Phys ; 159(18)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37962451

RESUMO

Metal halide perovskite nanocrystals have been under intense investigation for their promise in optoelectronic devices due to their remarkable physics, such as liquid/solid duality. This liquid/solid duality may give rise to their defect tolerance and other such useful properties. This duality means that the electronic states are fluctuating in time, on a distribution of timescales from femtoseconds to picoseconds. Hence, these lattice induced energy fluctuations that are connected to polaron formation are also connected to exciton formation and dynamics. We observe these correlations and dynamics in metal halide perovskite nanocrystals of CsPbI3 and CsPbBr3 using two-dimensional electronic (2DE) spectroscopy, with its unique ability to resolve dynamics in heterogeneously broadened systems. The 2DE spectra immediately reveal a previously unobserved excitonic splitting in these 15 nm NCs that may have a coarse excitonic structure. 2D lineshape dynamics reveal a glassy response on the 300 fs timescale due to polaron formation. The lighter Br system shows larger amplitude and faster timescale fluctuations that give rise to dynamic line broadening. The 2DE signals enable 1D transient absorption analysis of exciton cooling dynamics. Exciton cooling within this doublet is shown to take place on a slower timescale than within the excitonic continuum. The energy dissipation rates are the same for the I and Br systems for incoherent exciton cooling but are very different for the coherent dynamics that give rise to line broadening. Exciton cooling is shown to take place on the same timescale as polaron formation, revealing both as coupled many-body excitation.

17.
BMC Health Serv Res ; 23(1): 621, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37312121

RESUMO

BACKGROUND: A significant number of late middle-aged adults with depression have a high illness burden resulting from chronic conditions which put them at high risk of hospitalization. Many late middle-aged adults are covered by commercial health insurance, but such insurance claims have not been used to identify the risk of hospitalization in individuals with depression. In the present study, we developed and validated a non-proprietary model to identify late middle-aged adults with depression at risk for hospitalization, using machine learning methods. METHODS: This retrospective cohort study involved 71,682 commercially insured older adults aged 55-64 years diagnosed with depression. National health insurance claims were used to capture demographics, health care utilization, and health status during the base year. Health status was captured using 70 chronic health conditions, and 46 mental health conditions. The outcomes were 1- and 2-year preventable hospitalization. For each of our two outcomes, we evaluated seven modelling approaches: four prediction models utilized logistic regression with different combinations of predictors to evaluate the relative contribution of each group of variables, and three prediction models utilized machine learning approaches - logistic regression with LASSO penalty, random forests (RF), and gradient boosting machine (GBM). RESULTS: Our predictive model for 1-year hospitalization achieved an AUC of 0.803, with a sensitivity of 72% and a specificity of 76% under the optimum threshold of 0.463, and our predictive model for 2-year hospitalization achieved an AUC of 0.793, with a sensitivity of 76% and a specificity of 71% under the optimum threshold of 0.452. For predicting both 1-year and 2-year risk of preventable hospitalization, our best performing models utilized the machine learning approach of logistic regression with LASSO penalty which outperformed more black-box machine learning models like RF and GBM. CONCLUSIONS: Our study demonstrates the feasibility of identifying depressed middle-aged adults at higher risk of future hospitalization due to burden of chronic illnesses using basic demographic information and diagnosis codes recorded in health insurance claims. Identifying this population may assist health care planners in developing effective screening strategies and management approaches and in efficient allocation of public healthcare resources as this population transitions to publicly funded healthcare programs, e.g., Medicare in the US.


Assuntos
Depressão , Medicare , Estados Unidos/epidemiologia , Pessoa de Meia-Idade , Humanos , Idoso , Depressão/diagnóstico , Depressão/epidemiologia , Estudos Retrospectivos , Hospitalização , Medição de Risco
18.
Differentiation ; 128: 13-25, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36198237

RESUMO

SOX10 gene and SOX10 protein are responsible for the gliogenesis of neuroglia from the neural crest cells. Expression of SOX10 gene encodes SOX10 protein which binds with DNA at its minor groove via its HMG domain upon activation. SOX10 protein undergoes bending and changes its conformation after binding with DNA. Via its transactivation domain and HMG domain, it further activates several other transcription factors, these cause gliogenesis of the neural crest cells into neuroglia. In literature, it is stated that the SOX10 gene helps in the formation of schwann cells, oligodendrocytes, and enteric ganglia from neural crest cells. Altered expression of the SOX10 gene results in agliogenesis, dysmyelination, and demyelination in the nervous system as well as intestinal aganglionosis. This review highlighted that there is a role of the SOX10 gene and SOX10 protein in enteric gliogenesis from the neural crest cells.


Assuntos
Sistema Nervoso Entérico , Doença de Hirschsprung , Humanos , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Doença de Hirschsprung/genética , Fatores de Transcrição SOXE/genética , Crista Neural , Sistema Nervoso Entérico/metabolismo
19.
Entropy (Basel) ; 25(2)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36832738

RESUMO

In this article, we show that a quantum gas, a collection of massive, non-interacting, indistinguishable quantum particles, can be realized as a thermodynamic machine as an artifact of energy quantization and, hence, bears no classical analog. Such a thermodynamic machine depends on the statistics of the particles, the chemical potential, and the spatial dimension of the system. Our detailed analysis demonstrates the fundamental features of quantum Stirling cycles, from the viewpoint of particle statistics and system dimensions, that helps us to realize desired quantum heat engines and refrigerators by exploiting the role of quantum statistical mechanics. In particular, a clear distinction between the behavior of a Fermi gas and a Bose gas is observed in one dimension, rather than in higher dimensions, solely due to the innate differences in their particle statistics indicating the conspicuous role of a quantum thermodynamic signature in lower dimensions.

20.
Rep Pract Oncol Radiother ; 28(2): 217-223, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37456707

RESUMO

Background: Palliative hypofractionated radiotherapy (RT) is an effective mode of treating painful bone metastasis. While 8 Gy single fraction radiation is often effective for the same, for complicated bone metastases a protracted fractionated regimen is preferred, of which 30 Gy/10#/2weeks or 20 Gy/5#/1 week are the most common worldwide. However such schedules add to the burden of already overburdened radiation treatment facilities in a busy center, wherein alternative logistic favourable schedules with treatment on weekends are preferred. Here we compare the efficacy of a twice weekly schedule to that of standard continuous 20 Gy/5 #/1 week schedule in terms of pain relief, response and quality of life. Materials and methods: A prospective non randomized study was undertaken from Jan 2018 to May 2019, wherein eligible patients of complicated bone metastases received palliative radiotherapy of 20 Gy/5#, either continuously for 5 fractions from Monday to Saturday or twice weekly, Saturday and Wednesday, starting on a Saturday over about 2 weeks. Pain relief was assessed by the Visual Analogue Scale (VAS) and FACES pain scale recorded prior to starting palliative RT and at 4 weeks, 3 months and 6 months. Results: Thirteen patients received continuous Hypofractionated RT while 16 received it in a twice weekly schedule. Spine was the most common site receiving palliative Radiation (27/29), while breast cancer was the most common primary (16/29). The demographic and the baseline characteristics were comparable. The mean pain score decline at 4 weeks was 2.56 ± 1.1 and 2.71 ± 0.52 in the 5-day and the two-week schedule, respectively (p = 0.67). Conclusion: A twice weekly schedule over about two weeks was found to be equivalent in pain control and response to the standard fractionated palliative radiation and, thus, can be safely employed in resource constrained, busy radiotherapy centers.

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