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1.
Cell ; 185(14): 2591-2608.e30, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35803246

RESUMEN

Melanoma brain metastasis (MBM) frequently occurs in patients with advanced melanoma; yet, our understanding of the underlying salient biology is rudimentary. Here, we performed single-cell/nucleus RNA-seq in 22 treatment-naive MBMs and 10 extracranial melanoma metastases (ECMs) and matched spatial single-cell transcriptomics and T cell receptor (TCR)-seq. Cancer cells from MBM were more chromosomally unstable, adopted a neuronal-like cell state, and enriched for spatially variably expressed metabolic pathways. Key observations were validated in independent patient cohorts, patient-derived MBM/ECM xenograft models, RNA/ATAC-seq, proteomics, and multiplexed imaging. Integrated spatial analyses revealed distinct geography of putative cancer immune evasion and evidence for more abundant intra-tumoral B to plasma cell differentiation in lymphoid aggregates in MBM. MBM harbored larger fractions of monocyte-derived macrophages and dysfunctional TOX+CD8+ T cells with distinct expression of immune checkpoints. This work provides comprehensive insights into MBM biology and serves as a foundational resource for further discovery and therapeutic exploration.


Asunto(s)
Neoplasias Encefálicas , Melanoma , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/secundario , Linfocitos T CD8-positivos/patología , Ecosistema , Humanos , RNA-Seq
2.
Health Expect ; 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37749963

RESUMEN

INTRODUCTION: The importance of including people affected by research (e.g., community members, citizens or patient partners) is increasingly recognized across the breadth of institutions involved in connecting research with action. Yet, the increasing rhetoric of inclusion remains situated in research systems that tend to reward traditional dissemination and uphold power dynamics in ways that centre particular (privileged) voices over others. In research explicitly interested in doing research with those most affected by the issue or outcomes, research teams need to know how to advance meaningful inclusion. This study focused on listening to voices often excluded from research processes to understand what meaningful inclusion looks and feels like, and asked what contributes to being or feeling tokenized. METHODS: In this deliberative dialogue study, 16 participants with experience of navigating social exclusions and contributing to research activities reflected on what makes for meaningful experiences of inclusion. Using a co-production approach, with a diversely representative research team of 15 that included patient and community partners, we used critically reflective dialogue to guide an inclusive process to study design and implementation, from conceptualization of research questions through to writing. RESULTS: We heard that: research practices, partnerships and systems all contribute to experiences of inclusion or exclusion; the insufficiency or absence of standards for accountability amplifies the experience of exclusion; and inclusive practices require intention, planning, reflection and resources. CONCLUSIONS: We offer evidence-informed recommendations for the deeply relational work and practices for inclusivity, focused on promising practices for cultivating welcoming systems, spaces and relationships. PATIENT OR PUBLIC CONTRIBUTION: This work reflects a co-production approach, where people who use and are affected by research results actively partnered in the research process, including study design, data-generating activities, analysis and interpretation, and writing. Several of these partners are authors of this manuscript.

3.
Glycobiology ; 32(6): 469-482, 2022 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-34939124

RESUMEN

Acute myocardial infarction (AMI) is a leading cause of mortality and morbidity worldwide. Diagnostic challenges remain in this highly time-sensitive condition. Using capillary electrophoresis-laser-induced fluorescence, we analyzed the blood plasma N-glycan profile in a cohort study comprising 103 patients with AMI and 69 controls. Subsequently, the data generated was subjected to classification modeling to identify potential AMI biomarkers. An area under the Receiving Operating Characteristic curve (AUCROC) of 0.81 was obtained when discriminating AMI vs. non-MI patients. We postulate that the glycan profile involves a switch from a pro- to an anti-inflammatory state in the AMI pathophysiology. This was supported by significantly decreased levels in galactosylation, alongside increased levels in sialylation, afucosylation and GlcNAc bisection levels in the blood plasma of AMI patients. By substantiating the glycomics analysis with immunoglobulin G (IgG) protein measurements, robustness of the glycan-based classifiers was demonstrated. Changes in AMI-related IgG activities were also confirmed to be associated with alterations at the glycosylation level. Additionally, a glycan-biomarker panel derived from glycan features and current clinical biomarkers performed remarkably (AUCROC = 0.90, sensitivity = 0.579 at 5% false positive rate) when discriminating between patients with ST-segment elevation MI (n = 84) and non-ST-segment elevation MI (n = 19). Moreover, by applying the model trained using glycomics information, AMI and controls can still be discriminated at 1 and 6 months after baseline. Thus, glycomics biomarkers could potentially serve as a valuable complementary test to current diagnostic biomarkers. Additional research on their utility and associated biomechanisms via a large-scale study is recommended.


Asunto(s)
Infarto del Miocardio , Biomarcadores , Estudios de Cohortes , Glicómica , Humanos , Inmunoglobulina G/metabolismo , Infarto del Miocardio/diagnóstico
4.
J Environ Manage ; 309: 114676, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35151142

RESUMEN

We are facing a high risk of exposure to emerging contaminants and increasing environmental pollution with the concomitant growth of industries. Persistence of these pollutants is a major concern to the ecosystem. Laccases, also known as "green catalysts" are multi-copper oxidases which offers an eco-friendly solution for the degradation of these hazardous pollutants to less or non-toxic compounds. Although various other biological methods exist for the treatment of pollutants, the fact that laccases catalyze the oxidation of broad range of substrates in the presence of molecular oxygen without any additional cofactor and releases water as the by-product makes them exceptional. They have a good possibility of utilization in various industries, especially for the purpose of bioremediation. Besides this, they have also been used in medical/health care, food industry, bio-bleaching, wine stabilization, organic synthesis and biosensors. This review covers the catalytic behaviour of laccases, their immobilization strategies, potential applications in bioremediation of recalcitrant environmental pollutants and their engineering. It provides a comprehensive summary of most factors to consider while working with laccases in an industrial setting. It compares the benefits and drawbacks of the current techniques. Immobilization and mediators, two of the most significant aspects in working with laccases, have been meticulously discussed.


Asunto(s)
Contaminantes Ambientales , Biodegradación Ambiental , Catálisis , Ecosistema , Lacasa/metabolismo
5.
Health Care Women Int ; 43(9): 1095-1104, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-34520333

RESUMEN

The researchers explore the stigma of postpartum depression and role of lady health workers in bringing the women to the health facility and following up on their treatment. In-depth interviews were conducted from the registered patients (n = 22), Lady Health Visitors (n = 2) and Lady Health Workers (LHWs) (n = 2) in a public primary and tertiary healthcare facility in peri-urban areas of district Rawalpindi, Pakistan. Stigma of depression and lack of awareness was perceived as one of the major reasons for women to struggle with the label of postpartum depression and seeking medical treatment. Lady health workers played a significant role in health education and bringing them to the health facility. The services rendered by LHWs can be enhanced through comprehensive training as they can play an effective role in spreading awareness and educating the patients of postpartum depression in peri-urban areas and their families, consequently, ensuring their treatment and its follow-up.


Asunto(s)
Depresión Posparto , Atención a la Salud , Femenino , Instituciones de Salud , Personal de Salud , Humanos , Pakistán , Investigación Cualitativa
6.
Am J Dermatopathol ; 43(1): 57-59, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-32568833

RESUMEN

ABSTRACT: Papillary digital adenocarcinoma (PDA) is a rare eccrine tumor that is most often found on the digits. Few case reports have described PDAs located on atypical sites. It is now accepted that PDAs cannot be distinguished from benign adenomas based on histological features, and it is recommended to excise all of these lesions. Even with excision, recurrence and metastasis rates are high. Only limited genomic analyses have been performed to date, and no driver mutations have been identified. We report a case of a 63-year-old woman with a PDA on the right forearm. Biopsy showed moderate cytologic atypia and mitotic figures. Next-generation DNA sequencing of the tumor showed a BRAFV600E mutation and high tumor mutational burden (5.51 mutations/Mb). This mutation is known for its response to small molecular inhibitors of BRAF and Mitogen-activated protein kinase kinase. Such therapy may be a consideration should our patient develop recurrent unresectable disease.


Asunto(s)
Adenocarcinoma Papilar/genética , Biomarcadores de Tumor/genética , Mutación , Proteínas Proto-Oncogénicas B-raf/genética , Neoplasias de las Glándulas Sudoríparas/genética , Adenocarcinoma Papilar/patología , Adenocarcinoma Papilar/cirugía , Análisis Mutacional de ADN , Femenino , Antebrazo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Persona de Mediana Edad , Neoplasias de las Glándulas Sudoríparas/patología , Neoplasias de las Glándulas Sudoríparas/cirugía
7.
Psychiatr Q ; 92(1): 147-159, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32488820

RESUMEN

This study explores the pre-diagnosis perceptions and experiences of semi-urban women regarding maternal depression and the issues in the follow-up of its treatment. Using the patient's end of Kleinman's Explanatory Model of Illness, it documents the whole episode of maternal depression in women. The main focus group of this study includes the women diagnosed with maternal depression and registered in the health facilities of Rawalpindi. Research was conducted in one primary health facility i.e. rural health centre of Khayaban e Sir Syed and one secondary health facility i.e. the Tehsil Headquarter Hospital of Taxila that were subject to the Mother and Child Health Program under the Rural Health Sector Reform Project in Punjab. The data shows that the socio-cultural setting of the women affects their perspectives and beliefs regarding maternal depression as well as shapes their health-seeking behavior, as there seemed to be a preference of religious and cultural coping mechanisms resulting in poor compliance with medical services and hurdles in the follow-up of medical treatment. Through understanding the illness beliefs of these women, effective measures can be taken for the provision of better health facilities and ensuring their follow-up.


Asunto(s)
Depresión/epidemiología , Depresión/psicología , Madres/psicología , Narración , Población Rural/estadística & datos numéricos , Depresión Posparto/epidemiología , Depresión Posparto/psicología , Femenino , Humanos , India/epidemiología , Recién Nacido , Servicios de Salud Rural
8.
Curr Oncol Rep ; 22(10): 104, 2020 07 28.
Artículo en Inglés | MEDLINE | ID: mdl-32725406

RESUMEN

PURPOSE OF REVIEW: Uveal melanoma is a distinct subtype of melanoma characterized by a unique biology and divergent response to immune therapies. In this review, we will discuss our current understanding of the pathophysiology of uveal melanoma, systemic treatment options for advanced disease, and potential future therapeutic directions. RECENT FINDINGS: Although treatment with single-agent checkpoint blockade has been generally disappointing, the results of combined checkpoint blockade are modestly more promising. Several alternative systemic therapeutic approaches have been or are currently being investigated, including two agents that have been taken into registration-intent clinical trials: tebentafusp, a T cell redirecting agent, and IDE196, an oral protein kinase C inhibitor. Treatment of advanced uveal melanoma remains challenging, however, encouraging results from novel agents offer hope for improvement in the near future.


Asunto(s)
Melanoma/tratamiento farmacológico , Neoplasias de la Úvea/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Humanos , Inmunoterapia , Melanoma/diagnóstico , Melanoma/genética , Melanoma/fisiopatología , Melanoma/terapia , Pronóstico , Medición de Riesgo , Neoplasias de la Úvea/diagnóstico , Neoplasias de la Úvea/genética , Neoplasias de la Úvea/fisiopatología
9.
Curr Oncol Rep ; 21(11): 97, 2019 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-31696329

RESUMEN

PURPOSE OF REVIEW: In this article, we will briefly review the current treatment landscape for metastatic melanoma and provide a comprehensive update on emerging novel treatment strategies. RECENT FINDINGS: Over the past decade, remarkable advances in immunotherapy and targeted therapy have greatly improved outcomes for patients with advanced melanoma. Although a subset of patients is able to achieve durable responses, the majority experience eventual disease progression on existing therapies. Trials evaluating novel combinatorial strategies, checkpoint inhibitors, immune agonists, T cell-based therapies, intratumoral agents, and others are ongoing. While strides have been made in the treatment of advanced melanoma, further research is needed to identify alternative immune and molecular targets in order to overcome resistance and achieve better clinical outcomes.


Asunto(s)
Antineoplásicos Inmunológicos/uso terapéutico , Factores Inmunológicos/uso terapéutico , Inmunoterapia , Melanoma/terapia , Terapia Molecular Dirigida , Biomarcadores de Tumor/agonistas , Biomarcadores de Tumor/antagonistas & inhibidores , Resistencia a Antineoplásicos , Humanos , Melanoma/inmunología , Melanoma/patología , Microambiente Tumoral/efectos de los fármacos , Microambiente Tumoral/inmunología
10.
J Pak Med Assoc ; 69(6): 899-901, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31201401

RESUMEN

Treatment of Cushing syndrome depends on diagnosis of etiology responsible for hypercortisolism in the body, which sometimes presents with a challenge. Inferior petrosal sinus sampling for ACTH levels, followed by peripheral venous sampling is a proven tool to be a gold standard for differentiating between peripheral and central cause of ACTH dependent Cushing syndrome. This case report is of an elderly female who presented as an outpatient in the endocrinology clinic of Aga Khan university hospital on 22/6/2017 with clinical features of hypercortisolism. After workup she was found to have cushing syndrome secondary to ACTH secreting bronchial carcinoid tumour.


Asunto(s)
Hormona Adrenocorticotrópica/metabolismo , Neoplasias de los Bronquios/diagnóstico por imagen , Tumor Carcinoide/diagnóstico por imagen , Síndrome de Cushing/diagnóstico , Anciano , Neoplasias de los Bronquios/complicaciones , Neoplasias de los Bronquios/metabolismo , Tumor Carcinoide/complicaciones , Tumor Carcinoide/metabolismo , Síndrome de Cushing/etiología , Síndrome de Cushing/metabolismo , Femenino , Humanos , Hidrocortisona/orina , Tomografía Computarizada por Rayos X
11.
J Proteome Res ; 17(4): 1559-1574, 2018 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-29451981

RESUMEN

Comprehensive characterization of the N-glycome of a therapeutic is challenging because glycans may harbor numerous modifications (e.g., phosphorylation, sulfation, sialic acids with possible O-acetylation). The current report presents a comparison of two chromatographic platforms for the comprehensive characterization of a recombinant human erythropoietin (rhEPO) N-glycome. The two platforms include a common workflow based on 2-AB-derivatization and hydrophilic interaction chromatography (HILIC) and a native N-linked glycan workflow employing high performance anion exchange (HPAE) chromatography. Both platforms were coupled to an Orbitrap mass spectrometer, and data dependent HCD fragmentation allowed confident structural elucidation of the glycans. Each platform identified glycans not revealed by the other, and both exhibited strengths and weaknesses. The reductive amination based HILIC workflow provided better throughput and sensitivity, had good isomer resolution, and revealed the presence of O-acetylated sialic acids. However, it exhibited poor performance toward phosphorylated glycans and did not reveal the presence of sulfated glycans. Furthermore, reductive amination introduced dehydration artifacts and modified the glycosylation profile in the rhEPO glycome. Conversely, HPAE provided unbiased charge classification (sialylation levels), improved isomer resolution, and revealed multiple phosphorylated and sulfated structures, but delivered lower throughput, had artifact peaks due to epimer formation, and loss of sialic acid O-acetylation. The MS2 based identification of phosphorylated and sulfated glycans was not possible in HILIC mode due to their poor solubility caused by the high acetonitrile concentrations employed at the beginning of the gradient. After analyzing the glycome by both approaches and determining the glycans present, a glycan library was created for site specific glycopeptide analyses. Glycopeptide analyses confirmed all the compositions annotated by the combined use of 2-AB- and native glycan workflows and provided site specific location of the glycans. These two platforms were complementary and in combination delivered a more thorough and comprehensive characterization of the rhEPO N-glycome, supporting regulatory conformance for the pharmaceutical industry.


Asunto(s)
Técnicas de Química Analítica/métodos , Eritropoyetina/química , Polisacáridos/análisis , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Espectrometría de Masas , Fosforilación , Proteínas Recombinantes/química , Ácidos Siálicos , Sulfatos , Flujo de Trabajo
12.
Rapid Commun Mass Spectrom ; 32(11): 882-888, 2018 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-29575162

RESUMEN

RATIONALE: N-linked glycan analysis of recombinant therapeutic proteins, such as monoclonal antibodies, Fc-fusion proteins, and antibody-drug conjugates, provides valuable information regarding protein therapeutics glycosylation profile. Both qualitative identification and quantitative analysis of N-linked glycans on recombinant therapeutic proteins are critical analytical tasks in the biopharma industry during the development of a biotherapeutic. METHODS: Currently, such analyses are mainly carried out using capillary electrophoresis/laser-induced fluorescence (CE/LIF), liquid chromatography/fluorescence (LC/FLR), and liquid chromatography/fluorescence/mass spectrometry (LC/FLR/MS) technologies. N-linked glycans are first released from glycoproteins by enzymatic digestion, then labeled with fluorescence dyes for subsequent CE or LC separation, and LIF or MS detection. Here we present an on-line CE/LIF/MS N-glycan analysis workflow that incorporates the fluorescent Teal™ dye and an electrokinetic pump-based nanospray sheath liquid capillary electrophoresis/mass spectrometry (CE/MS) ion source. RESULTS: Electrophoresis running buffer systems using ammonium acetate and ammonium hydroxide were developed for the negative ion mode CE/MS analysis of fluorescence-labeled N-linked glycans. Results show that on-line CE/LIF/MS analysis can be readily achieved using this versatile CE/MS ion source on common CE/MS instrument platforms. CONCLUSIONS: This on-line CE/LIF/MS method using Teal™ fluorescent dye and electrokinetic pump-based nanospray sheath liquid CE/MS coupling technology holds promise for on-line quantitation and identification of N-linked glycans on recombinant therapeutic proteins.


Asunto(s)
Electroforesis Capilar/métodos , Colorantes Fluorescentes/química , Espectrometría de Masas/métodos , Polisacáridos/análisis , Hidróxido de Amonio/química , Tampones (Química) , Diseño de Equipo , Fluorescencia , Rayos Láser , Espectrometría de Masas/instrumentación , Nanoestructuras , Sistemas en Línea , Polisacáridos/química , Pirenos/química , Flujo de Trabajo
13.
Electrophoresis ; 38(13-14): 1788-1799, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28426178

RESUMEN

Analysis of N-glycan structures has been gaining attentions over the years due to their critical importance to biopharma-based applications and growing roles in biological research. Glycan profiling is also critical to the development of biosimilar drugs. The detailed characterization of N-glycosylation is mandatory because it is a nontemplate driven process and that significantly influences critical properties such as bio-safety and bio-activity. The ability to comprehensively characterize highly complex mixtures of N-glycans has been analytically challenging and stimulating because of the difficulties in both the structure complexity and time-consuming sample pretreatment procedures. CE-LIF is one of the typical techniques for N-glycan analysis due to its high separation efficiency. In this paper, a 16-capillary DNA analyzer was coupled with a magnetic bead glycan purification method to accelerate the sample preparation procedure and therefore increase N-glycan assay throughput. Routinely, the labeling dye used for CE-LIF is 8-aminopyrene-1,3,6-trisulfonic acid, while the typical identification method involves matching migration times with database entries. Two new fluorescent dyes were used to either cross-validate and increase the glycan identification precision or simplify sample preparation steps. Exoglycosidase studies were carried out using neuramididase, galactosidase, and fucosidase to confirm the results of three dye cross-validation. The optimized method combines the parallel separation capacity of multiple-capillary separation with three labeling dyes, magnetic bead assisted preparation, and exoglycosidase treatment to allow rapid and accurate analysis of N-glycans. These new methods provided enough useful structural information to permit N-glycan structure elucidation with only one sample injection.


Asunto(s)
Electroforesis Capilar/métodos , Polisacáridos/análisis , Polisacáridos/aislamiento & purificación , Electroforesis Capilar/instrumentación , Colorantes Fluorescentes/química , Glicosilación , Humanos , Inmunoglobulina G/química , Microesferas , Polisacáridos/química , Pirenos/química , Reproducibilidad de los Resultados
14.
Anal Bioanal Chem ; 409(12): 3089-3101, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28280844

RESUMEN

Characterization of glycans present on glycoproteins has become of increasing importance due to their biological implications, such as protein folding, immunogenicity, cell-cell adhesion, clearance, receptor interactions, etc. In this study, the resolving power of high-performance anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) was applied to glycan separations and coupled to mass spectrometry to characterize native glycans released from different glycoproteins. A new, rapid workflow generates glycans from 200 µg of glycoprotein supporting reliable and reproducible annotation by mass spectrometry (MS). With the relatively high flow rate of HPAE-PAD, post-column splitting diverted 60% of the flow to a novel desalter, then to the mass spectrometer. The delay between PAD and MS detectors is consistent, and salt removal after the column supports MS. HPAE resolves sialylated (charged) glycans and their linkage and positional isomers very well; separations of neutral glycans are sufficient for highly reproducible glycoprofiling. Data-dependent MS2 in negative mode provides highly informative, mostly C- and Z-type glycosidic and cross-ring fragments, making software-assisted and manual annotation reliable. Fractionation of glycans followed by exoglycosidase digestion confirms MS-based annotations. Combining the isomer resolution of HPAE with MS2 permitted thorough N-glycan annotation and led to characterization of 17 new structures from glycoproteins with challenging glycan profiles.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Cromatografía por Intercambio Iónico/métodos , Glicoproteínas/química , Espectrometría de Masas/métodos , Polisacáridos/análisis , Aniones/química , Humanos , Inmunoglobulina G/química
15.
Clin Adv Hematol Oncol ; 15(1): 75-82, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28212372

RESUMEN

Gastroesophageal (GE) malignancies make up a significant and growing segment of newly diagnosed cancers. Approximately 80% of patients who have GE cancers die within 5 years of diagnosis, which means that effective treatments for these malignancies need to be found. Currently, targeted therapies have a minimal role in this disease group. Intensive study of the molecular biology of GE cancers is a relatively new and ongoing venture, but it has already led to a significant increase in our understanding of these malignancies. This understanding, although still limited, has the potential to enhance our ability to develop targeted therapies in conjunction with the ability to identify actionable gene mutations and perform genomic profiling to predict drug resistance. Several cell surface growth factor receptors have been found to play a prominent role in GE cancer cell signaling. This discovery has led to the approval of 2 agents within the last few years: trastuzumab, an anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibody used in the first-line treatment of HER2-positive GE cancers, and ramucirumab, an anti-vascular endothelial growth factor receptor 2 (VEGFR2) monoclonal antibody that is currently used in later lines of therapy. This review discusses the current state of molecular testing in GE cancers, along with the known molecular biology and current and investigational treatments. The development of trastuzumab and ramucirumab represents a significant advance in our ability to make use of GE tumor molecular profiles. As our understanding of the impact of molecular aberrations on drug effectiveness and disease outcomes increases, we anticipate improved therapy for patients with GE cancers.


Asunto(s)
Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/terapia , Unión Esofagogástrica/patología , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/terapia , Humanos , Transducción de Señal
16.
PLoS One ; 19(1): e0296793, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38227597

RESUMEN

Ceramics are the oxides of metals and nonmetals with excellent compressive strength. Ceramics usually exhibit inert behavior at high temperatures. Magnesium aluminate (MgAl2O4), a member of the ceramic family, possesses a high working temperature up to 2000°C, low thermal conductivity, high strength even at elevated temperatures, and good corrosion resistance. Moreover, Magnesium Aluminate Nanoparticles (MANPs) can be used in the making of refractory crucible applications. This study focuses on the thermal behavior of Magnesium Aluminate Nanoparticles (MANPs) and their application in the making of refractory crucibles. The molten salt method is used to obtain MANPs. The presence of MANPs is seen by XRD peaks ranging from 66° to 67°. The determination of the smallest crystallite size of the sample is achieved by utilizing the Scherrer formula and is found to be 15.3 nm. The SEM micrographs provided further information, indicating an average particle size of 91.2 nm. At 600°C, DSC curves show that only 0.05 W/g heat flows into the material, and the TGA curve shows only 3% weight loss, which is prominent for thermal insulation applications. To investigate the thermal properties, crucibles of pure MANPs and the different compositions of MANPs and pure alumina are prepared. During the sintering, cracks appear on the crucible of pure magnesium aluminate. To explore the reason for crack development, tablets of MgAl2O4 are made and sintered at 1150°C. Ceramography shows the crack-free surfaces of all the tablets. Results confirm the thermal stability of MANPs at high temperatures and their suitability for melting crucible applications.


Asunto(s)
Compuestos de Aluminio , Óxido de Aluminio , Compuestos de Magnesio , Nanopartículas , Óxido de Magnesio
17.
Curr Probl Cardiol ; 49(2): 102152, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37852560

RESUMEN

The interplay between HDL-C and LDL levels are closely intertwined with the cardiovascular system. High-Density Lipoprotein Cholesterol (HDL-C) is a well-known biomarker traditionally being interpreted as higher the HDL-C levels, minimal the risk of adverse cardiovascular disease (CVD) outcomes. However, recent research has unveiled a more complex relationship between HDL-C levels and cardiovascular outcomes, including genetic influences and potential risks associated with extremely high HDL-C levels. Intriguingly, extremely high HDL-C levels have been linked to unexpected cardiovascular risks. Up To date research suggests that individuals with genetically linked ultra-high HDL-C levels may depict an increased susceptibility to CVD, challenging the conventional realm that higher HDL-C is always beneficial. The mechanisms underlying this mystery are not fully understood but may involve HDL particle functionality and composition. In a nutshell, the relationship between HDL-C levels and cardiovascular outcomes is multifactorial. While low HDL-C remains a recognized risk factor for CVD, the genetic determinants of HDL-C levels add complexity to this association. Furthermore, extremely high HDL-C levels may not exhibit the expected protective benefits and may even pose unprecedented cardiovascular risks. A comprehensive understanding of these dynamics is essential for advancing our knowledge of CVD risk assessment and developing targeted therapeutic interventions. Further studies are needed to unravel the intricacies of HDL-C's role in cardiovascular health and disease.


Asunto(s)
Enfermedades Cardiovasculares , Sistema Cardiovascular , Humanos , HDL-Colesterol , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/prevención & control , Factores de Riesgo , Biomarcadores
18.
Dis Colon Rectum ; 56(2): 150-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23303142

RESUMEN

BACKGROUND: Anatomic site is a predictive factor in subtypes of cutaneous and mucosal melanoma. OBJECTIVE: The aim of this study was to examine the clinical relevance of location of origin of anorectal melanoma as a prognostic factor. DESIGN: With the use of a prospectively maintained database, clinical characteristics, management, and outcomes were compared according to the site of origin. SETTINGS, PATIENTS, INTERVENTIONS: A retrospective review was conducted of patients diagnosed with anorectal melanoma from 1994 to 2010. Tumors were defined as anal, anorectal, or rectal melanoma according to their anatomic relationship to the dentate line. MAIN OUTCOME MEASURES: Clinicopathologic factors were compared by χ2 test. Time-to-event analysis was performed by Kaplan-Meier analysis. RESULTS: Of the 96 patients included (41 with anal melanoma, 32 with anorectal melanoma, 23 with rectal melanoma), patients with rectal and anorectal mucosal melanoma had advanced primary tumors (median Breslow thickness, 12 mm and 8 mm, p = 0.002), whereas anal lesions could be found at earlier depths (median thickness, 6.5 mm). Patients with anal tumors more commonly underwent transanal excision (p < 0.02) and sentinel lymph node biopsy (p = 0.004) versus anorectal and rectal tumors. Patterns of recurrence were also distinct; nearly two-thirds of anorectal and rectal tumors recurred systemically, whereas anal melanoma more often recurred within the lymph nodes first (63%; p < 0.02). Recurrence occurred in 24 (59%) patients with anal tumors, 23 (72%) patients with anorectal tumors, and 16 (70%) patients with rectal tumors. Median overall survival was 22 months for anal melanoma, 28 months for anorectal melanoma, and 27 months for rectal melanoma. Recurrence and survival were not statistically different between the groups. LIMITATIONS: This study is limited by small sample size and its retrospective nature. CONCLUSIONS: This study represents the only series describing the outcomes of anorectal melanoma by anatomic location. Lesions at or proximal to the dentate line present with more advanced disease, possibly related to a delay in diagnosis. Lesions distal to the dentate line more commonly recur within lymph nodes, which may represent differences in nodal drainage. Irrespective of location, the long-term prognosis remains poor for all cases of anorectal melanoma.


Asunto(s)
Melanoma/patología , Neoplasias del Recto/patología , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias del Ano/mortalidad , Neoplasias del Ano/patología , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Melanoma/mortalidad , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Pronóstico , Neoplasias del Recto/mortalidad , Estudios Retrospectivos , Biopsia del Ganglio Linfático Centinela
19.
JMIR Form Res ; 7: e43096, 2023 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-38064266

RESUMEN

BACKGROUND: Tobacco use has shifted in recent years, especially with the introduction of e-cigarettes. Despite the current variable and intersecting tobacco product use among tobacco users, most want to quit, which necessitates cessation programs to adapt to these variable trends (vs focusing on combustible cigarettes alone). The use of web-based modalities for cessation support has become quite popular in recent years and has been compounded by the COVID-19 pandemic. Therefore, understanding the current strengths and limitations of existing programs to meet the needs of current various tobacco users is critical for ensuring the saliency of such programs moving forward. OBJECTIVE: The purpose of this study was to understand the strengths and limitations of web-based cessation support offered through QuitNow to better understand the needs of a variety of end users who smoke, dual use, or vape. METHODS: Semistructured interviews were conducted with 36 nicotine product users in British Columbia. Using conventional content analysis methods, we inductively derived descriptive categories and themes related to the strengths and limitations of QuitNow for those who smoke, dual use, or vape. We analyzed the data with the support of NVivo (version 12; QSR International) and Excel (Microsoft Corporation). RESULTS: Participants described several strengths and limitations of QuitNow and provided suggestions for improvement, which fell under 2 broad categories: look and feel and content and features. Shared strengths included the breadth of information and the credible nature of the website. Individuals who smoke were particularly keen about the site having a nonjudgmental feeling. Moreover, compared with individuals who smoke, individuals who dual use and individuals who vape were particularly keen about access to professional quit support (eg, quit coach). Shared limitations included the presence of too much text and the need to create an account. Individuals who dual use and individuals who vape thought that the content was geared toward older adults and indicated that there was a lack of information about vaping and personalized content. Regarding suggestions for improvement, participants stated that the site needed more interaction, intuitive organization, improved interface esthetics, a complementary smartphone app, forum discussion tags, more information for different tobacco user profiles, and user testimonials. Individuals who vape were particularly interested in website user reviews. In addition, individuals who vape were more interested in an intrinsic approach to quitting (eg, mindfulness) compared with extrinsic approaches (eg, material incentives), the latter of which was endorsed by more individuals who dual use and individuals who smoke. CONCLUSIONS: The findings of this study provide directions for enhancing the saliency of web-based cessation programs for a variety of tobacco use behaviors that hallmark current tobacco use.

20.
J Biomol Struct Dyn ; : 1-10, 2023 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-37418235

RESUMEN

Myeloid Cell Leukemia 1 (MCL1) is an anti-apoptotic protein that plays a critical role in regulating cell survival, particularly in cancer cells. It is a member of the BCL-2 family of proteins, which control the intrinsic pathway of apoptosis. MCL1 has emerged as a promising target for cancer therapy because it is overexpressed in a wide range of cancers, including breast, lung, prostate, and hematologic malignancies. Due to its remarkable role in cancer progression, it has been reflected as a promising drug target for cancer therapy. A few MCL1 inhibitors have been identified previously, but further research is needed to develop novel, effective and safe MCL1 inhibitors that can overcome resistance mechanisms and minimize toxicity in normal cells. In this study, we aim to search for compounds that target the critical binding site of MCL1 from phytoconstituent library from the IMPPAT database. To accomplish this, a multitier virtual screening approach involving molecular docking and molecular dynamics simulations (MDS) were used to evaluate their suitability for the receptor. Notably, certain screened phytoconstituents have appreciable docking scores and stable interactions toward the binding pocket of MCL1. The screened compounds underwent ADMET and bioactivity analysis to establish their anticancer properties. One phytoconstituent, Isopongaflavone, was identified that exhibiting higher docking and drug-likeness than the already reported MCL1 inhibitor, Tapotoclax. Isopongaflavone and and Tapotoclax, along with MCL1, were subjected to 100 nanoseconds (ns) MDS study to verify their stability inside the binding site of MCL1. The MDS findings demonstrated a strong binding affinity between Isopongaflavone and the MCL1 binding pocket, resulting in reduced conformational fluctuations. This investigation proposes Isopongaflavone as a promising candidate for the development of innovative anticancer therapeutics, pending the necessary validation procedures. Also, the findings provide valuable information for designing MCL1 inhibitors based on the protein's structure.Communicated by Ramaswamy H. Sarma.

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