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1.
Cell ; 184(24): 5886-5901.e22, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34822784

RESUMO

Current therapies for Alzheimer's disease seek to correct for defective cholinergic transmission by preventing the breakdown of acetylcholine through inhibition of acetylcholinesterase, these however have limited clinical efficacy. An alternative approach is to directly activate cholinergic receptors responsible for learning and memory. The M1-muscarinic acetylcholine (M1) receptor is the target of choice but has been hampered by adverse effects. Here we aimed to design the drug properties needed for a well-tolerated M1-agonist with the potential to alleviate cognitive loss by taking a stepwise translational approach from atomic structure, cell/tissue-based assays, evaluation in preclinical species, clinical safety testing, and finally establishing activity in memory centers in humans. Through this approach, we rationally designed the optimal properties, including selectivity and partial agonism, into HTL9936-a potential candidate for the treatment of memory loss in Alzheimer's disease. More broadly, this demonstrates a strategy for targeting difficult GPCR targets from structure to clinic.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Desenho de Fármacos , Receptor Muscarínico M1/agonistas , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Doença de Alzheimer/complicações , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/patologia , Sequência de Aminoácidos , Animais , Pressão Sanguínea/efeitos dos fármacos , Células CHO , Inibidores da Colinesterase/farmacologia , Cricetulus , Cristalização , Modelos Animais de Doenças , Cães , Donepezila/farmacologia , Eletroencefalografia , Feminino , Células HEK293 , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos C57BL , Modelos Moleculares , Simulação de Dinâmica Molecular , Degeneração Neural/complicações , Degeneração Neural/patologia , Primatas , Ratos , Receptor Muscarínico M1/química , Transdução de Sinais , Homologia Estrutural de Proteína
2.
Bioinformatics ; 40(1)2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38258418

RESUMO

MOTIVATION: Scientific advances build on the findings of existing research. The 2001 publication of the human genome has led to the production of huge volumes of literature exploring the context-specific functions and interactions of genes. Technology is needed to perform large-scale text mining of research papers to extract the reported actions of genes in specific experimental contexts and cell states, such as cancer, thereby facilitating the design of new therapeutic strategies. RESULTS: We present a new corpus and Text Mining methodology that can accurately identify and extract the most important details of cancer genomics experiments from biomedical texts. We build a Named Entity Recognition model that accurately extracts relevant experiment details from PubMed abstract text, and a second model that identifies the relationships between them. This system outperforms earlier models and enables the analysis of gene function in diverse and dynamically evolving experimental contexts. AVAILABILITY AND IMPLEMENTATION: Code and data are available here: https://github.com/cambridgeltl/functional-genomics-ie.


Assuntos
Genômica , Neoplasias , Humanos , Neoplasias/genética , Mineração de Dados/métodos , PubMed , Fenótipo
3.
Small ; 20(16): e2304879, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38044307

RESUMO

The development of skin organs for studying developmental pathways, modeling diseases, or regenerative medicine purposes is a major endeavor in the field. Human induced pluripotent stem cells (hiPSCs) are successfully used to derive skin cells, but the field is still far from meeting the goal of creating skin containing appendages, such as hair follicles and sweat glands. Here, the goal is to generate skin organoids (SKOs) from human skin fibroblast or placental CD34+ cell-derived hiPSCs. With all three hiPSC lines, complex SKOs with stratified skin layers and pigmented hair follicles are generated with different efficacies. In addition, the hiPSC-derived SKOs develop sebaceous glands, touch-receptive Merkel cells, and more importantly eccrine sweat glands. Together, physiologically relevant skin organoids are developed by direct induction of embryoid body formation, along with simultaneous inactivation of transforming growth factor beta signaling, activation of fibroblast growth factor signaling, and inhibition of bone morphogenetic protein signaling pathways. The skin organoids created in this study can be used as valuable platforms for further research into human skin development, disease modeling, or reconstructive surgeries.


Assuntos
Células-Tronco Pluripotentes Induzidas , Gravidez , Humanos , Feminino , Placenta , Pele , Folículo Piloso/fisiologia , Organoides
4.
Opt Express ; 32(4): 5885-5897, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439304

RESUMO

Lensless coherent x-ray imaging techniques have great potential for high-resolution imaging of magnetic systems with a variety of in-situ perturbations. Despite many investigations of ferromagnets, extending these techniques to the study of other magnetic materials, primarily antiferromagnets, is lacking. Here, we demonstrate the first (to our knowledge) study of an antiferromagnet using holographic imaging through the 'holography with extended reference by autocorrelation linear differential operation' technique. Energy-dependent contrast with both linearly and circularly polarized x-rays are demonstrated. Antiferromagnetic domains and topological textures are studied in the presence of applied magnetic fields, demonstrating quasi-cyclic domain reconfiguration up to 500 mT.

5.
Syst Biol ; 72(6): 1247-1261, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-37561391

RESUMO

Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, "reddish" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms.


Assuntos
Rãs Venenosas , Venenos , Animais , Filogenia , Pigmentação/genética , Anuros , Pterinas/metabolismo , Evolução Biológica
6.
Nature ; 553(7686): 111-114, 2018 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-29300009

RESUMO

The complement system is a crucial component of the host response to infection and tissue damage. Activation of the complement cascade generates anaphylatoxins including C5a and C3a. C5a exerts a pro-inflammatory effect via the G-protein-coupled receptor C5a anaphylatoxin chemotactic receptor 1 (C5aR1, also known as CD88) that is expressed on cells of myeloid origin. Inhibitors of the complement system have long been of interest as potential drugs for the treatment of diseases such as sepsis, rheumatoid arthritis, Crohn's disease and ischaemia-reperfusion injuries. More recently, a role of C5a in neurodegenerative conditions such as Alzheimer's disease has been identified. Peptide antagonists based on the C5a ligand have progressed to phase 2 trials in psoriasis and rheumatoid arthritis; however, these compounds exhibited problems with off-target activity, production costs, potential immunogenicity and poor oral bioavailability. Several small-molecule competitive antagonists for C5aR1, such as W-54011 and NDT9513727, have been identified by C5a radioligand-binding assays. NDT9513727 is a non-peptide inverse agonist of C5aR1, and is highly selective for the primate and gerbil receptors over those of other species. Here, to study the mechanism of action of C5a antagonists, we determine the structure of a thermostabilized C5aR1 (known as C5aR1 StaR) in complex with NDT9513727. We found that the small molecule bound between transmembrane helices 3, 4 and 5, outside the helical bundle. One key interaction between the small molecule and residue Trp2135.49 seems to determine the species selectivity of the compound. The structure demonstrates that NDT9513727 exerts its inverse-agonist activity through an extra-helical mode of action.


Assuntos
Benzodioxóis/química , Benzodioxóis/metabolismo , Imidazóis/química , Imidazóis/metabolismo , Receptor da Anafilatoxina C5a/antagonistas & inibidores , Receptor da Anafilatoxina C5a/química , Animais , Benzodioxóis/farmacologia , Sítios de Ligação , Cristalografia por Raios X , Agonismo Inverso de Drogas , Células HEK293 , Humanos , Imidazóis/farmacologia , Modelos Moleculares , Mutação , Estabilidade Proteica , Estrutura Secundária de Proteína , Receptor da Anafilatoxina C5a/genética , Receptor da Anafilatoxina C5a/metabolismo , Receptores Adrenérgicos beta 2/química , Receptores Adrenérgicos beta 2/metabolismo , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo
7.
Bioinformatics ; 38(4): 1157-1158, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-34791027

RESUMO

SUMMARY: Many applications of chemical screening are performed in concentration or dose-response mode, and it is necessary to extract appropriate parameters, including whether the chemical/assay pair is active and if so, what are concentrations where activity is seen. Typically, multiple mathematical models or curve shapes are tested against the data to assess the best fit. There are several commercial programs used for this purpose as well as open-source libraries. A widely used system for managing high-throughput screening (HTS) concentration-response data is tcpl (ToxCast Pipeline). The current implementation of tcpl has the concentration-response modeling code tightly integrated with the data management and databasing aspects of HTS data processing. Tcplfit2 is a stand-alone version of the curve-fitting and hitcalling core of tcpl that has been extended to include a large number of standard curve classes and to use benchmark dose modeling. This package will be useful for HTS concentration-response data such as high-throughput whole genome transcriptomics. AVAILABILITY AND IMPLEMENTATION: tcplfit2 is written in R and is available from CRAN.


Assuntos
Ensaios de Triagem em Larga Escala , Software , Idioma
8.
Med Care ; 61(7): 448-455, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37289563

RESUMO

OBJECTIVE: The objectives of this study were to (1) examine demographic differences between patient portal users and nonusers; and (2) examine health literacy, patient self-efficacy, and technology usage and attitudes between patient portal users and nonusers. METHODS: Data were collected from Amazon Mechanical Turk (MTurk) workers from December 2021 to January 2022. MTurk workers completed an online survey, which asked about their health, access to technology, health literacy, patient self-efficacy, media and technology attitudes, and patient portal use for those with an account. A total of 489 MTurk workers completed the survey. Data were analyzed using latent class analysis (LCA) and multivariate logistic regression models. RESULTS: Latent class analysis models revealed some qualitative differences between users and nonusers of patient portals in relation to neighborhood type, education, income, disability status, comorbidity of any type, insurance type, and the presence or absence of primary care providers. These results were partially confirmed by logistic regression models, which showed that participants with insurance, a primary care provider, or a disability or comorbid condition were more likely to have a patient portal account. CONCLUSIONS: Our study findings suggest that access to health care, along with ongoing patient health needs, influence the usage of patient portal platforms. Patients with health insurance have the opportunity to access health care services, including establishing a relationship with a primary care provider. This relationship can be critical to a patient ever creating a patient portal account and actively engaging in their care, including communicating with their care team.


Assuntos
Exclusão Digital , Letramento em Saúde , Portais do Paciente , Humanos , Atenção à Saúde , Inquéritos e Questionários
9.
Palliat Support Care ; 21(3): 454-460, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-35678170

RESUMO

OBJECTIVES: The primary objective of this study was to co-design and conduct a pilot evaluation of a novel, immersive virtual reality (VR) experience for procedural pain and anxiety in an Australian healthcare setting. The secondary objective was to identify key parameters that can facilitate the development and implementation of VR experiences in clinical practice. METHOD: A qualitative, Design Box method was selected for co-design. It was used with adult burns survivors and adolescents and young adults (AYAs) with cancer, and healthcare professionals from these fields to identify the practical and design parameters required for the application of VR technology within the clinical setting. Results informed the development of the VR experience that was evaluated by consumers and healthcare professionals, who completed qualitative surveys. Thematic analysis was conducted on co-design notes and survey data. RESULTS: Procedural pain and management was a challenge for both cohorts, but particularly the burns cohort. Anxiety was significant challenge for both cohorts. Boredom and quality of life was a significant challenge, particularly for the AYA oncology cohort. These results informed the development of "A Wanderers Tale," an Australiana-themed, gaze-controlled VR application for Oculus Quest platforms. Thematic analysis results suggest that cultural preferences, procedural contexts of use, and agency through customization and interaction are three parameters to consider when creating or selecting VR experiences for application in health. SIGNIFICANCE OF RESULTS: This work describes a novel method for the use VR as an adjuvant pain management tool in patients with burns and cancer. The VR experience may provide a culturally, practice and procedure-appropriate tool in comparable settings of care. The study also describes interdisciplinary co-design and evaluation approaches that can help maximize the use of VR to improve healthcare approaches that address clinical challenges in pain, anxiety, and quality of life for patients while in hospital.


Assuntos
Queimaduras , Neoplasias , Dor Processual , Realidade Virtual , Adulto Jovem , Adolescente , Humanos , Qualidade de Vida , Austrália , Dor/etiologia , Queimaduras/complicações , Queimaduras/terapia , Neoplasias/complicações , Neoplasias/terapia
10.
Antimicrob Agents Chemother ; 66(1): e0171321, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34694875

RESUMO

Candida auris provides a substantial global nosocomial threat clinically. With the recent emergence that the organism can readily colonize skin niches, it will likely continue to pose a risk in health care units, particularly to patients undergoing surgery. The purpose of this study was to investigate the efficacy of antifungal-loaded calcium sulfate (CS) beads in combatting C. auris infection. We demonstrate that the CS-packed beads have the potential to interfere with planktonic and sessile C. auris.


Assuntos
Antifúngicos , Candida auris , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Biofilmes , Sulfato de Cálcio/farmacologia , Candida , Humanos
11.
Mol Phylogenet Evol ; 168: 107389, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35026428

RESUMO

The use of genome-scale data in phylogenetics has enabled recent strides in determining the relationships between taxa that are taxonomically problematic because of extensive morphological variation. Here, we employ a phylogenomic approach to infer evolutionary relationships within Ranitomeya (Anura: Dendrobatidae), an Amazonian lineage of poison frogs consisting of 16 species with remarkable diversity in color pattern, range size, and parental care behavior. We infer phylogenies with all described species of Ranitomeya from ultraconserved nuclear genomic elements (UCEs) and also estimate divergence times. Our results differ from previous analyses regarding interspecific relationships. Notably, we find that R. toraro and R. defleri are not sister species but rather distantly related, contrary to previous analyses based on smaller genetic datasets. We recover R. uakarii as paraphyletic, designate certain populations formerly assigned to R. fantastica from Peru as R. summersi, and transfer the French Guianan and eastern Brazilian R. amazonica populations to R. variabilis. By clarifying both inter- and intraspecific relationships within Ranitomeya, our study paves the way for future tests of hypotheses on color pattern evolution and historical biogeography.


Assuntos
Venenos , Animais , Anuros , Guiana Francesa , Peru , Filogenia
12.
Syst Biol ; 70(5): 1033-1045, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-33720363

RESUMO

Ancestral range estimation and projection of niche models into the past have both become common in evolutionary studies where the ancient distributions of organisms are in question. However, these methods are hampered by complementary hurdles: discrete characterization of areas in ancestral range estimation can be overly coarse, especially at shallow timescales, and niche model projection neglects evolution. Phylogenetic niche modeling accounts for both of these issues by incorporating knowledge of evolutionary relationships into a characterization of environmental tolerances. We present a new method for phylogenetic niche modeling, implemented in R. Given past and present climate data, taxon occurrence data, and a time-calibrated phylogeny, our method constructs niche models for each extant taxon, uses ancestral character estimation to reconstruct ancestral niche models, and projects these models into paleoclimate data to provide a historical estimate of the geographic range of a lineage. Models either at nodes or along branches of the phylogeny can be estimated. We demonstrate our method on a small group of dendrobatid frogs and show that it can make inferences given species with restricted ranges and little occurrence data. We also use simulations to show that our method can reliably reconstruct the niche of a known ancestor in both geographic and environmental space. Our method brings together fields as disparate as ecological niche modeling, phylogenetics, and ancestral range estimation in a user-friendly package. [Ancestral range estimation; ancestral state reconstruction; biogeography; Dendrobatidae; ecological niche modeling; paleoclimate; phylogeography; species distribution modeling.].


Assuntos
Clima , Ecossistema , Modelos Teóricos , Filogenia , Filogeografia
13.
Regul Toxicol Pharmacol ; 129: 105096, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34896478

RESUMO

In 2020, the European Commission up-classified metal cobalt as Class 1B Carcinogen (presumed to have carcinogenic potential) based primarily on data from rodent inhalation carcinogenicity studies. This up-classification requires an assessment under the Medical Device Regulations of cobalt cancer risk from medical devices. We performed a systematic review and meta-analysis to evaluate site-specific cancer risks with cobalt exposure from either total joint replacement (TJR) or occupational exposure (OC). Results were stratified by exposure type (OC or TJR), exposure level (metal-on-metal (MoM) or non-MoM), follow-up duration (latency period: <5, 5-10 or >10 years), and cancer incidence or mortality (detection bias assessment). From 30 studies (653,104 subjects, average 14.5 years follow-up), the association between TJR/OC and cancer risk was null for 22 of 27 cancer sites, negative for 3 sites, and positive for prostate cancer and myeloma. Significant heterogeneity and large estimate ranges were observed for many cancer sites. No significant increase in estimates was observed by exposure level or follow-up duration. The current evidence, including weak associations, heterogeneity across studies and no increased association with exposure level or follow-up duration, is insufficient to conclude that there exists an increased risk for people exposed to cobalt in TJR/OC of developing site-specific cancers.


Assuntos
Cobalto/análise , Prótese Articular/estatística & dados numéricos , Neoplasias/epidemiologia , Exposição Ocupacional/análise , Humanos , Medição de Risco
14.
Community Ment Health J ; 58(6): 1101-1111, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34799773

RESUMO

The purpose of the study was to identify barriers to accessing mental health services by migrant youth in a middle-sized central Canadian city. We asked participants, "What would stop you from talking to someone about mental health stress?". We interviewed 30 youth aged 16 to 22 who migrated from 10 different countries and lived in Canada for an average of 29 months. The data was analyzed using group concept mapping. The participants identified five concepts: fear of being misunderstood or ignored, desire for confidentiality, lack of trust and understanding, talking about it as not appropriate, and fear of the disclosure process. We compare these results with the literature.


Assuntos
Serviços de Saúde Mental , Migrantes , Adolescente , Canadá , Acessibilidade aos Serviços de Saúde , Humanos , Saúde Mental
15.
Artigo em Inglês | MEDLINE | ID: mdl-33753336

RESUMO

Calcium sulfate (CS) has been used clinically as a bone- or void-filling biomaterial, and its resorptive properties have provided the prospect for its use as a release mechanism for local antibiotics to control biofilms. Here, we aimed to test CS beads loaded with three antifungal drugs against planktonic and sessile fungal species to assess whether these antifungal beads could be harnessed to provide consistent release of antifungals at biofilm-inhibitory doses. A panel of different fungal species (n = 15) were selected for planktonic broth microdilution testing with fluconazole (FLZ), amphotericin B (AMB), and caspofungin (CSP). After establishing planktonic inhibition, antifungal CS beads were introduced to fungal biofilms (n = 5) to assess biofilm formation and cell viability through a combination of standard quantitative and qualitative biofilm assays. Inoculation of a hydrogel substrate, packed with antifungal CS beads, was also used to assess diffusion through a semidry material, to mimic active infection in vivo In general, antifungals released from loaded CS beads were all effective at inhibiting the pathogenic fungi over 7 days within standard MIC ranges for these fungi. We observed a significant reduction of pregrown fungal biofilms across key fungal pathogens following treatment, with visually observable changes in cell morphology and biofilm coverage provided by scanning electron microscopy. Assessment of biofilm inhibition also revealed reductions in total and viable cells across all organisms tested. These data show that antifungal-loaded CS beads produce a sustained antimicrobial effect that inhibits and kills clinically relevant fungal species in vitro as planktonic and biofilm cells.


Assuntos
Antifúngicos , Sulfato de Cálcio , Antifúngicos/farmacologia , Biofilmes , Sulfato de Cálcio/farmacologia , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana
16.
J Cell Sci ; 132(3)2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30659111

RESUMO

Intraflagellar transport (IFT), which is essential for the formation and function of cilia in most organisms, is the trafficking of IFT trains (i.e. assemblies of IFT particles) that carry cargo within the cilium. Defects in IFT cause several human diseases. IFT trains contain the complexes IFT-A and IFT-B. To dissect the functions of these complexes, we studied a Chlamydomonas mutant that is null for the IFT-A protein IFT140. The mutation had no effect on IFT-B but destabilized IFT-A, preventing flagella assembly. Therefore, IFT-A assembly requires IFT140. Truncated IFT140, which lacks the N-terminal WD repeats of the protein, partially rescued IFT and supported formation of half-length flagella that contained normal levels of IFT-B but greatly reduced amounts of IFT-A. The axonemes of these flagella had normal ultrastructure and, as investigated by SDS-PAGE, normal composition. However, composition of the flagellar 'membrane+matrix' was abnormal. Analysis of the latter fraction by mass spectrometry revealed decreases in small GTPases, lipid-anchored proteins and cell signaling proteins. Thus, IFT-A is specialized for the import of membrane-associated proteins. Abnormal levels of the latter are likely to account for the multiple phenotypes of patients with defects in IFT140.This article has an associated First Person interview with the first author of the paper.


Assuntos
Proteínas de Algas/genética , Membrana Celular/metabolismo , Chlamydomonas reinhardtii/genética , Cílios/metabolismo , Flagelos/metabolismo , Proteínas Ligadas a Lipídeos/genética , Proteínas de Algas/química , Proteínas de Algas/metabolismo , Axonema/metabolismo , Axonema/ultraestrutura , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Membrana Celular/ultraestrutura , Ataxia Cerebelar/genética , Ataxia Cerebelar/metabolismo , Ataxia Cerebelar/patologia , Chlamydomonas reinhardtii/metabolismo , Chlamydomonas reinhardtii/ultraestrutura , Cílios/ultraestrutura , Síndrome de Ellis-Van Creveld/genética , Síndrome de Ellis-Van Creveld/metabolismo , Síndrome de Ellis-Van Creveld/patologia , Flagelos/ultraestrutura , Expressão Gênica , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Proteínas Ligadas a Lipídeos/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Proteínas Monoméricas de Ligação ao GTP/genética , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Mutação , Organismos Geneticamente Modificados , Transporte Proteico , Retinose Pigmentar/genética , Retinose Pigmentar/metabolismo , Retinose Pigmentar/patologia , Transdução de Sinais , Proteína Vermelha Fluorescente
17.
Regul Toxicol Pharmacol ; 125: 104987, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34229014

RESUMO

In 2020, the European Commission up-classified pure cobalt metal to a Category 1B hazard, based primarily on data from rodent inhalation carcinogenicity studies of metallic cobalt. The European Commission review did not evaluate cobalt-containing alloys in medical devices, which have very different properties vs. pure cobalt metal and did not include a systematic epidemiologic review. We performed a systematic review and meta-analysis of published, peer-reviewed epidemiologic studies evaluating the association between overall cancer risk and exposure to orthopedic implants containing cobalt alloys or cobalt particulates in occupational settings. Study-specific estimates were pooled using random-effects models. Analyses included 20 papers on orthopedic implants and 10 occupational cohort papers (~1 million individuals). The meta-analysis summary estimates (95% confidence intervals) for overall cancer risk were 1.00 (0.96-1.04) overall and 0.97 (0.94-1.00) among high-quality studies. Results were also similar in analyses stratified by type of exposure/data sources (occupational cohort, implant registry or database), comparators (general or implant population), cancer incidence or mortality, follow-up duration (latency period), and study precision. In conclusion, meta-analysis found no association between exposure to orthopedic implants containing cobalt alloys or cobalt particulates in occupational settings and overall cancer risk, including an analysis of studies directly comparing metal-on-metal vs. non-metal-on-metal implants.


Assuntos
Ligas/química , Cobalto/análise , Equipamentos e Provisões , Neoplasias/epidemiologia , Exposição Ocupacional/análise , Carcinogênese , Humanos , Prótese Articular , Neoplasias/mortalidade , Medição de Risco , Titânio/análise
18.
South Med J ; 114(11): 692-696, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34729612

RESUMO

OBJECTIVES: Dysphagia is a common symptom in patients hospitalized with human immunodeficiency virus (HIV). There are limited data on the relation between dysphagia and important hospital outcomes. The aim of our study was to assess the impact of dysphagia on hospital costs, length of stay (LOS), mortality, and 30-day readmission rates in HIV patients hospitalized with dysphagia. METHODS: We used the Nationwide Readmissions Database to identify all adult hospitalizations with HIV between January 2010 and September 2015. We stratified cases according to the presence of dysphagia (International Classification of Diseases, Ninth Revision, Clinical Modification code 787.2) as a primary or secondary diagnosis, and compared clinical and hospital characteristics between the two groups. Multivariable regression models were used to compare LOS, total hospital costs, in-hospital mortality, 30-day mortality, and 30-day readmission rates between the two groups. RESULTS: A total of 206,332 hospitalized patients with HIV were included in the study. Of these, 8699 (4.2%) patients had dysphagia. Patients with dysphagia were more likely to have Candida esophagitis (26.8% vs 3.6%), esophageal strictures (3.1% vs 0.2%), and malnutrition (41.6% vs 17.6%); and they were more likely to undergo upper endoscopy (23.2% vs 3.8%) and percutaneous feeding tube placement (9.2% vs 0.7%), all P < 0.0001. On multivariate analysis, dysphagia was associated with longer LOS (12 vs 7.4 days; P < 0.0001), higher hospitalization cost ($32,993 vs $21,813, P < 0.0001), and increased 30-day readmissions (24% vs 20.8%, adjusted odds ratio 1.19; 95% confidence interval 1.12-1.25; P < 0.0001). Patients with dysphagia had higher in-hospital mortality (4.7% vs 3.5%) but this did not reach statistical significance (adjusted odds ratio 1.01; 95% confidence interval 0.91-1.12; P = 0.86). CONCLUSION: In hospitalized patients with HIV, dysphagia is a significant independent predictor of longer LOS, higher costs, and higher rates of 30-day readmissions. These findings highlight the importance of optimizing treatment of dysphagia in patients with HIV to mitigate its negative impact on patient and hospital outcomes.


Assuntos
Transtornos de Deglutição/complicações , Infecções por HIV/complicações , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Readmissão do Paciente/tendências , Adulto , Idoso , Transtornos de Deglutição/etiologia , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/fisiopatologia , Hospitalização/estatística & dados numéricos , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Avaliação de Resultados em Cuidados de Saúde/métodos , Readmissão do Paciente/estatística & dados numéricos , Fatores de Risco
19.
Int J Mol Sci ; 22(5)2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673626

RESUMO

Many neuroinflammatory diseases, like traumatic brain injury (TBI), are associated with an elevated level of fibrinogen and short-term memory (STM) impairment. We found that during TBI, extravasated fibrinogen deposited in vasculo-astrocyte interfaces, which was associated with neurodegeneration and STM reduction. The mechanisms of this fibrinogen-astrocyte interaction and its functional role in neurodegeneration are still unclear. Cultured mouse brain astrocytes were treated with fibrinogen in the presence or absence of function-blocking antibody or peptide against its astrocyte receptors intercellular adhesion molecule-1 (ICAM-1) or cellular prion protein (PrPC), respectively. Fibrinogen interactions with astrocytic ICAM-1 and PrPC were characterized. The expression of pro-inflammatory markers, generations of reactive oxygen species (ROS) and nitric oxide (NO) in astrocytes, and neuronal death caused by astrocyte-conditioned medium were assessed. Data showed a strong association between fibrinogen and astrocytic ICAM-1 or PrPC, overexpression of pro-inflammatory cytokines and overproduction of ROS and NO, resulting in neuronal apoptosis and death. These effects were reduced by blocking the function of astrocytic ICAM-1 and PrPC, suggesting that fibrinogen association with its astrocytic receptors induce the release of pro-inflammatory cytokines, resulting in oxidative stress, and ultimately neuronal death. This can be a mechanism of neurodegeneration and the resultant STM reduction seen during TBI.


Assuntos
Apoptose , Astrócitos/metabolismo , Fibrinogênio/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Neurônios/patologia , Proteínas PrPC/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Astrócitos/citologia , Morte Celular , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo
20.
Int J Mol Sci ; 22(21)2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34769513

RESUMO

The non-enzymatic addition of glucose (glycation) to circulatory and tissue proteins is a ubiquitous pathophysiological consequence of hyperglycemia in diabetes. Given the high incidence of periodontitis and diabetes and the emerging link between these conditions, it is of crucial importance to define the basic virulence mechanisms employed by periodontopathogens such as Porphyromonas gingivalis in mediating the disease process. The aim of this study was to determine whether glycated proteins are more easily utilized by P. gingivalis to stimulate growth and promote the pathogenic potential of this bacterium. We analyzed the properties of three commonly encountered proteins in the periodontal environment that are known to become glycated and that may serve as either protein substrates or easily accessible heme sources. In vitro glycated proteins were characterized using colorimetric assays, mass spectrometry, far- and near-UV circular dichroism and UV-visible spectroscopic analyses and SDS-PAGE. The interaction of glycated hemoglobin, serum albumin and type one collagen with P. gingivalis cells or HmuY protein was examined using spectroscopic methods, SDS-PAGE and co-culturing P. gingivalis with human keratinocytes. We found that glycation increases the ability of P. gingivalis to acquire heme from hemoglobin, mostly due to heme sequestration by the HmuY hemophore-like protein. We also found an increase in biofilm formation on glycated collagen-coated abiotic surfaces. We conclude that glycation might promote the virulence of P. gingivalis by making heme more available from hemoglobin and facilitating bacterial biofilm formation, thus increasing P. gingivalis pathogenic potential in vivo.


Assuntos
Infecções por Bacteroidaceae/metabolismo , Complicações do Diabetes/fisiopatologia , Eritrócitos/metabolismo , Heme/metabolismo , Hemoglobinas/metabolismo , Periodontite/microbiologia , Porphyromonas gingivalis/patogenicidade , Animais , Infecções por Bacteroidaceae/microbiologia , Infecções por Bacteroidaceae/patologia , Glicosilação , Hemeproteínas/química , Hemoglobinas/química , Cavalos , Periodontite/patologia , Porphyromonas gingivalis/isolamento & purificação , Porphyromonas gingivalis/metabolismo
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