Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Sensors (Basel) ; 24(7)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38610475

RESUMO

The growing popularity of social media has engendered the social problem of spam proliferation through this medium. New spam types that evade existing spam detection systems are being developed continually, necessitating corresponding countermeasures. This study proposes an anomaly detection-based framework to detect new Twitter spam, which works by modeling the characteristics of non-spam tweets and using anomaly detection to classify tweets deviating from this model as anomalies. However, because modeling varied non-spam tweets is challenging, the technique's spam detection and false positive (FP) rates are low and high, respectively. To overcome this shortcoming, anomaly detection is performed on known spam tweets pre-detected using a trained decision tree while modeling normal tweets. A one-class support vector machine and an autoencoder with high detection rates are used for anomaly detection. The proposed framework exhibits superior detection rates for unknown spam compared to conventional techniques, while maintaining equivalent or improved detection and FP rates for known spam. Furthermore, the framework can be adapted to changes in spam conditions by adjusting the costs of detection errors.

2.
BMC Psychiatry ; 23(1): 594, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582725

RESUMO

BACKGROUND: Medical care avoidance affects individuals' health status. Previous studies on medical care avoidance have mainly focused on medical costs and people's satisfaction with medical services. This study investigates whether an individual's sense of policy alienation toward medical care policy (SPA-M) affects behavioral intention of medical care avoidance, and to what extent an intermediary variable-medical financial risk perception-mediates the relationship between SPA-M and medical care avoidance. METHODS: A cross-sectional survey was conducted involving 434 people aged 35-59 years from Wuhu, a city in China's Anhui province. A moderated mediation model was constructed to investigate the research question and sex (biological: male and female) was used as a moderating variable between SPA-M and medical financial risk perception. RESULTS: We found that SPA-M significantly impacted medical care avoidance, and that medical financial risk perception played a complete mediating role in this relationship, while sex moderated the relationship between SPA-M and medical financial risk perception. CONCLUSION: This study contributes to the literature by enhancing our understanding of the factors that influence behavioral intention regarding medical care avoidance, deepening our understanding of the role of SPA-M in medical care policy, and expanding the role of sex differences in the analysis of the relationship between SPA-M, medical financial risk perception, and medical care avoidance, offering implications for public and community health.


Assuntos
Emoções , Intenção , Humanos , Masculino , Feminino , Estudos Transversais , Políticas , Percepção
3.
Sensors (Basel) ; 23(8)2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37112202

RESUMO

Over the last decade, the Short Message Service (SMS) has become a primary communication channel. Nevertheless, its popularity has also given rise to the so-called SMS spam. These messages, i.e., spam, are annoying and potentially malicious by exposing SMS users to credential theft and data loss. To mitigate this persistent threat, we propose a new model for SMS spam detection based on pre-trained Transformers and Ensemble Learning. The proposed model uses a text embedding technique that builds on the recent advancements of the GPT-3 Transformer. This technique provides a high-quality representation that can improve detection results. In addition, we used an Ensemble Learning method where four machine learning models were grouped into one model that performed significantly better than its separate constituent parts. The experimental evaluation of the model was performed using the SMS Spam Collection Dataset. The obtained results showed a state-of-the-art performance that exceeded all previous works with an accuracy that reached 99.91%.

4.
Dev World Bioeth ; 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37584521

RESUMO

Predatory journals and conferences are an emerging problem in scientific literature as they have financial motives, without guaranteeing scientific quality and exposure. The main objective of the ASGLOS project is to investigate the predatory e-email characteristics, management, and possible consequences and to analyse the extent of the current problem at each academic level. To collect the personal experiences of physicians' mailboxes on predatory publishing, a Google Form® survey was designed and disseminated from September 2021 to April 2022. A total of 978 responses were analysed from 58 countries around the world. A total of 64.8% of participants indicated the need for 3 or fewer emails to acquire a criticality view in distinguishing a real invitation from a spam, while 11.5% still have doubt regardless of how many emails they get. The AGLOS Study clearly highlights the problem of academic e-mail spam by predatory journals and conferences. Our findings signify the importance of providing academic career-oriented advice and organising training sessions to increase awareness of predatory publishing for those conducting scientific research.

5.
Molecules ; 28(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36838880

RESUMO

Ruta chalepensis L., commonly known as Shazab in Saudi Arabia, is one of the famous culinary plants belonging to the Rutaceae family. It is commonly used in ethnomedicine in treating numerous diseases. This study was performed to characterize the essential oil isolated from Saudi species using a relatively new advanced headspace solid-phase microextraction technique. Following that, the antioxidant activity of the extracted oil was assessed using in vitro techniques such as the DPPH and nitric oxide scavenging tests, as well as the reducing power FRAP study and the molecular docking tool. The essential oil yield of the dried plant was 0.83% (v/w). Gas chromatography joined with a mass spectrometer was used to determine the chemical composition of the pale-yellow essential oil. Sixty-eight constituents were detected, representing 97.70% of the total oil content. The major constituents were aliphatic ketones dominated by 2-undecanone (37.30%) and 2-nonanone (20.00%), with minor constituents of mono and sesquiterpenoids chemical classes. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is one of the major causes of many contemporary diseases due to its ability to create a reactive oxygen species (ROS). Thus, molecular docking was used to confirm that some oil phytoconstituents have good docking scores compared to the standard antioxidant drug (Vitamin C), indicating great binding compatibility between the (NADPH) oxidase receptor site and the ligand. In conclusion, our findings suggest that the oil could be used safely and as a cost-effective remedy in treating various modern diseases caused by free radical formation.


Assuntos
Óleos Voláteis , Ruta , Antioxidantes , Ruta/química , Simulação de Acoplamento Molecular , NADP , Arábia Saudita , Óleos Voláteis/química , Oxirredutases
6.
Geriatr Nurs ; 51: 202-208, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37011492

RESUMO

We aimed to clarify whether health literacy (HL)  impacts medical care avoidance through an underexplored mediator: a sense of policy alienation towards medical care policy for residents (SPA-M). A moderated mediation model with control perception as a moderator was used to analyze the inner relationship between HL and SPA-M. A cross-sectional survey of 470 people ≥ 60 years old, revealed a significant negative association between HL and medical care avoidance intention, which bootstrapped moderated mediation analysis confirmed is partially mediated by SPA-M. When older people's control perception was high, HL had a significant negative impact on medical care avoidance intention through SPA-M; for low control perception, the effect was insignificant. This study elucidates HL's impact of HL on medical care avoidance, highlighting control perception's relevance to medical care policymaking for older people.


Assuntos
Letramento em Saúde , Humanos , Idoso , Estudos Transversais , Emoções , Inquéritos e Questionários
7.
Br J Neurosurg ; 36(6): 792-795, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35867035

RESUMO

BACKGROUND: We describe a novel progressive neurological syndrome complicating traumatic spinal cord injury (TSCI). Based on clinical and radiological features, we propose the term 'Chronic Relapsing Ascending Myelopathy' (CRAM). We distinguish between the previously described sub-acute progressive ascending myelopathy (SPAM) and post-traumatic syringomyelia (PTS), which may lie on a spectrum with CRAM. CASE REPORT: A 60-year-old man sustained a T4 ASIA-A complete TSCI. Four months post-injury, he developed a rapidly progressive ascending sensory level to C4. Clinical and radiological evaluation revealed ascending myelopathy with progressive T2 hyper-intense cord signal change. He underwent cord detethering and expansion duroplasty. Following an initial dramatic resolution of symptoms, the patient sustained two relapses, each 1-month post-discharge characterised by recurrence of disabling ascending sensory changes, each correlating with the radiological recurrence of cord signal change. Symptoms and radiological signal change permanently resolved with more extensive detethering and expansion duroplasty. There is radiological and clinical resolution at 1-year follow-up. CONCLUSION: Acute neurological deterioration post-TSCI may be due to SPAM or may occur after years due to PTS. We propose CRAM as a previously unrecognised phenomenon. The radiological characteristics overlap with SPAM. However, CRAM presents later and, clinically, behaves like PTS, but without cord cystic change. Cord detethering with expansion duroplasty are an effective treatment.


Assuntos
Traumatismos da Medula Espinal , Siringomielia , Masculino , Humanos , Pessoa de Meia-Idade , Assistência ao Convalescente , Alta do Paciente , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/cirurgia , Siringomielia/diagnóstico por imagem , Siringomielia/etiologia , Siringomielia/cirurgia , Laminectomia/efeitos adversos , Doença Crônica , Medula Espinal/diagnóstico por imagem , Medula Espinal/cirurgia , Imageamento por Ressonância Magnética
8.
Int J Mol Sci ; 23(24)2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36555637

RESUMO

The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) exerts effective neuroprotective activity through its specific receptor, PAC1-R. We accidentally discovered that as a positive allosteric modulator (PAM) of PAC1-R, the small-molecule PAM (SPAM1) has a hydrazide-like structure, but different binding characteristics, from hydrazide for the N-terminal extracellular domain of PAC1-R (PAC1-R-EC1). SPAM1 had a significant neuroprotective effect against oxidative stress, both in a cell model treated with hydrogen peroxide (H2O2) and an aging mouse model induced by D-galactose (D-gal). SPAM1 was found to block the decrease in PACAP levels in brain tissues induced by D-gal and significantly induced the nuclear translocation of PAC1-R in PAC1R-CHO cells and mouse retinal ganglion cells. Nuclear PAC1-R was subjected to fragmentation and the nuclear 35 kDa, but not the 15 kDa fragments, of PAC1-R interacted with SP1 to upregulate the expression of Huntingtin (Htt), which then exerted a neuroprotective effect by attenuating the binding availability of the neuron-restrictive silencer factor (NRSF) to the neuron-restrictive silencer element (NRSE). This resulted in an upregulation of the expression of NRSF-related neuropeptides, including PACAP, the brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH), and synapsin-1 (SYN1). The novel mechanism reported in this study indicates that SPAM1 has potential use as a drug, as it exerts a neuroprotective effect by regulating NRSF.


Assuntos
Fármacos Neuroprotetores , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Cricetinae , Camundongos , Animais , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Fármacos Neuroprotetores/farmacologia , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Cricetulus , Peróxido de Hidrogênio
9.
Sensors (Basel) ; 21(8)2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33916964

RESUMO

On a crowdsourcing platform, in order to cheat for rewards or sabotage the crowdsourcing processes, spam workers may submit numerous erroneous answers to the tasks published by requesters. This type of behavior extremely reduces the completion rate of tasks and the enthusiasm of honest users, which may lead a crowdsourcing platform to a failure. Defending against malicious attacks is an important issue in crowdsourcing, which has been extensively addressed by existing methods, e.g., verification-based defense mechanisms, data analysis solutions, trust-based defense models, and workers' properties matching mechanisms. However, verification-based defense mechanisms will consume a lot of resources, and data analysis solutions cannot motivate workers to provide high-quality services. Trust-based defense models and workers' properties matching mechanisms cannot guarantee the authenticity of information when collusion requesters publish shadow tasks to help malicious workers get more participation opportunities. To defend such collusion attacks in crowdsourcing platforms, we propose a new defense model named TruthTrust. Firstly, we define a complete life cycle system that from users' interaction to workers' recommendation, and separately define the trust value of each worker and the credence of each requester. Secondly, in order to ensure the authenticity of the information, we establish a trust model based on the CRH framework. The calculated truth value and weight are used to define the global properties of workers and requesters. Moreover, we propose a reverse mechanism to improve the resistance under attacks. Finally, extensive experiments demonstrate that TruthTrust significantly outperforms the state-of-the-art approaches in terms of effective task completion rate.

10.
Hum Factors ; 63(1): 124-150, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-31560575

RESUMO

OBJECTIVE: To examine evidence of sensitivity, predictiveness, and methodological concerns regarding direct, objective measures of situation awareness (SA). BACKGROUND: The ability to objectively measure SA is important to the evaluation of user interfaces and displays, training programs, and automation initiatives, as well as for studies that seek to better understand SA in both individuals and teams. A number of methodological criticisms have been raised creating significant confusion in the research field. METHOD: A meta-analysis of 243 studies was conducted to examine evidence of sensitivity and predictiveness, and to address methodological questions regarding Situation Awareness Global Assessment Technique (SAGAT), Situation Present Assessment Technique (SPAM), and their variants. RESULTS: SAGAT and SPAM were found to be equally predictive of performance. SPAM (64%) and real-time probes (73%) were found to have significantly lower sensitivity in comparison to SAGAT (94%). While SAGAT was found not to be overly memory reliant nor intrusive into operator performance, SPAM resulted in problems with intrusiveness in 40% of the studies examined, as well as problems with speed-accuracy tradeoffs, sampling bias, and confounds with workload. Concerns about memory reliance, the utility of these measures for assessing Team SA, and other issues are also addressed. CONCLUSION: SAGAT was found to be a highly sensitive, reliable, and predictive measure of SA that is useful across a wide variety of domains and experimental settings. APPLICATION: Direct, objective SA measurement provides useful and diagnostic insights for research and design in a wide variety of domains and study objectives.


Assuntos
Conscientização , Carga de Trabalho , Humanos
11.
Solid State Nucl Magn Reson ; 108: 101668, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32645557

RESUMO

In solid-state NMR, multiple-quantum MAS (MQMAS) and satellite-transition MAS (STMAS) experiments are well-established techniques to obtain high-resolution spectra of half-integer quadrupolar nuclei. In 2004 and 2005, a soft-pulse-added-mixing (SPAM) concept was introduced by Gan and Amoureux to enhance the S/N ratio of MQMAS and STMAS experiments. Despite their robustness and simplicity, SPAM approaches have not yet been widely applied. Here, we further exploit SPAM concepts for sensitivity enhancement upon acquisition of two-dimensional MQMAS and STMAS spectra and also establish a general procedure upon implementation of SPAM-MQMAS and SPAM-STMAS NMR. Its effectiveness and ease in experimental setup are demonstrated using simulations and experiments performed on I â€‹= â€‹3/2 (23Na, 87Rb), 5/2 (27Al, 85Rb) and 9/2 (93Nb) nuclei with a variety of quadrupolar coupling constants (CQ). Compared to the conventional z-filter methods, sensitivity enhancements in between 2 and 4 are achievable with SPAM. We recommend to use SPAM with a ratio of 4:1 for the number of echoes and antiechoes to safely maximize the sensitivity and resolution simultaneously. In addition, a comparison of the experimental approaches is made in the context of SPAM-MQMAS and SPAM-STMAS NMR with respect to repetition delay and spinning frequency, aiming to discuss the precautions upon making a judicious choice of high-resolution NMR methods of half-integer quadrupolar nuclei.

12.
Morphologie ; 104(346): 151-157, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32224028

RESUMO

OBJECTIVE: To investigate the role of Spam1 hyaluronidase in age-related bone and cartilage changes in the mouse knee. DESIGN: Spam1-/- and WT mice were euthanised at different ages from 10 to 52 weeks. The right hindlimbs were dissected, scanned with peripheral Quantitative Computed Tomography (pQCT) and then decalcified for histological analysis (modified Mankin score). In other mice, cartilages of both tibiae were sampled at 10, 30 and 52 weeks of age for RNA extraction and qPCR analysis. We assessed the expression of hyaluronidases Hyal1 and Hyal2, hyaluronan synthase HAS2, extracellular matrix proteases Mmp13 and Adamts-5, and type 2 collagen. RESULTS: Spam1-/- mice did not exhibit specific morphological characters up to 52 weeks of age. From 20 weeks, the proximal tibia of Spam1-/- mice had a significantly lower bone mineral density than WT mice. At 52 weeks, the modified Mankin score was significantly lower in Spam1-/- than WT mice. Spam1-/- chondrocytes expressed significantly less Hyal2 than WT ones at all ages and less Mmp13 at 52 weeks. Through all the experiment, the Hyal1 expression of Spam1-/- chondrocytes remained similar as that of WT chondrocytes. CONCLUSION: Spam1 knockout reduced significantly cartilage degradation in mouse knee whereas the chondrocyte expression of Hyal 1, Hyal 2 and Mmp13 was modified, suggesting a role of this hyaluronidase in cartilage metabolism.


Assuntos
Cartilagem , Hialuronoglucosaminidase , Animais , Camundongos , Camundongos Knockout
13.
Ergonomics ; 62(8): 983-994, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31056018

RESUMO

This study explored distinct perceptual and decisional contributions to spam email mental construal. Participants classified spam emails according to pairings of three stimulus features - presence or absence of awkward prose, abnormal message structure, and implausible premise. We examined dimensional interactions within general recognition theory (GRT; a multidimensional extension of signal detection theory). Classification accuracy was highest for categories containing either two non-normal dimension levels (e.g. awkward prose and implausible premise) or two normal dimension levels (e.g. normal prose and plausible premise). Modelling indicated both perceptual and decisional contributions to classification responding. In most cases, perceptual discriminability was higher along one dimension when stimuli contained a non-normal level of the paired dimension (e.g. prose discriminability was higher with abnormal structure). Similarly, decision criteria along one dimension were biased in favour of the non-normal response when stimuli contained a non-normal level of the paired dimension. Potential applications for training are discussed. Practitioner summary: We applied general recognition theory (i.e. multivariate signal detection theory) to spam email classification at low or high levels of three stimulus dimensions: premise plausibility, prose quality, and email structure. Relevant to training, this approach helped identify perceptual and decisional biases that could be leveraged to individualise training.


Assuntos
Correio Eletrônico , Fraude/psicologia , Adolescente , Adulto , Tomada de Decisões , Feminino , Humanos , Julgamento , Masculino , Pessoa de Meia-Idade , Teoria Psicológica , Reconhecimento Psicológico , Adulto Jovem
14.
Sci Eng Ethics ; 24(2): 655-668, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28397175

RESUMO

Invalid journals are recent challenges in the academic world and many researchers are unacquainted with the phenomenon. The number of victims appears to be accelerating. Researchers might be suspicious of predatory journals because they have unfamiliar names, but hijacked journals are imitations of well-known, reputable journals whose websites have been hijacked. Hijacked journals issue calls for papers via generally laudatory emails that delude researchers into paying exorbitant page charges for publication in a nonexistent journal. This paper presents a method for detecting hijacked journals by using a classification algorithm. The number of published articles exposing hijacked journals is limited and most of them use simple techniques that are limited to specific journals. Hence we needed to amass Internet addresses and pertinent data for analyzing this type of attack. We inspected the websites of 104 scientific journals by using a classification algorithm that used criteria common to reputable journals. We then prepared a decision tree that we used to test five journals we knew were authentic and five we knew were hijacked.


Assuntos
Algoritmos , Enganação , Fraude/prevenção & controle , Internet , Publicações Periódicas como Assunto , Editoração , Registros , Árvores de Decisões , Correio Eletrônico , Humanos , Roubo de Identidade , Organizações , Publicações Periódicas como Assunto/classificação , Publicações Periódicas como Assunto/normas , Pesquisa , Pesquisadores , Roubo
15.
Sensors (Basel) ; 18(1)2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29271913

RESUMO

In this work we present the design and implementation of WARCProcessor, a novel multiplatform integrative tool aimed to build scientific datasets to facilitate experimentation in web spam research. The developed application allows the user to specify multiple criteria that change the way in which new corpora are generated whilst reducing the number of repetitive and error prone tasks related with existing corpus maintenance. For this goal, WARCProcessor supports up to six commonly used data sources for web spam research, being able to store output corpus in standard WARC format together with complementary metadata files. Additionally, the application facilitates the automatic and concurrent download of web sites from Internet, giving the possibility of configuring the deep of the links to be followed as well as the behaviour when redirected URLs appear. WARCProcessor supports both an interactive GUI interface and a command line utility for being executed in background.

16.
Hum Factors ; 57(8): 1417-26, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26314878

RESUMO

OBJECTIVE: The objective of this article is to examine the extent to which interruptions negatively impact situation awareness and long-term performance in a submarine track management task where pre- and postinterruption display scenes remained essentially identical. BACKGROUND: Interruptions in command and control task environments can degrade performance well beyond the first postinterruption action typically measured for sequential static tasks, because individuals need to recover their situation awareness for multiple unfolding display events. Participants in the current study returned to an unchanged display scene following interruption and therefore could be more immune to such long-term performance deficits. METHOD: The task required participants to monitor a display to detect contact heading changes and to make enemy engagement decisions. Situation awareness (Situation Present Assessment Method) and subjective workload (NASA-Task Load Index) were measured. The interruption replaced the display for 20 s with a blank screen, during which participants completed a classification task. RESULTS: Situation awareness after returning from interruption was degraded. Participants were slower to make correct engagement decisions and slower and less accurate in detecting heading changes, despite these task decisions being made at least 40 s following the interruption. CONCLUSION: Interruptions negatively impacted situation awareness and long-term performance because participants needed to redetermine the location and spatial relationship between the displayed contacts when returning from interruption, either because their situation awareness for the preinterruption scene decayed or because they did not encode the preinterruption scene. APPLICATION: Interruption in work contexts such as submarines is unavoidable, and further understanding of how operators are affected is required to improve work design and training.


Assuntos
Atenção/fisiologia , Conscientização/fisiologia , Navios , Carga de Trabalho/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
17.
Cureus ; 16(2): e54189, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38496146

RESUMO

Background Predatory journals are an emerging problem in scientific literature, as they have financial motives without guaranteeing scientific quality. Therefore, the scientific community needs to establish how this issue can be solved in the long term. Objective The study aims to provide information that can be used to take action against predatory journals and to guide future change. Methods A Google Forms (Google LLC, Mountain View, California, United States) survey was designed and disseminated between September 2021 and April 2022. Reflexive thematic analysis was used as a qualitative analysis technique in this study, with the assistance of the NVivo software (Lumivero LLC, Denver, Colorado, United States) to manage and support the analysis process. Results A total of 978 responses from 58 countries worldwide, achieving a response rate of 19.9%, were analyzed. Five key themes emerged regarding participants' suggestions on techniques to cope with the detrimental impact of predatory journals: "Checking," "Increasing education and awareness," "Responsibility," "Use of technology," and "Obstacles to the solution." Conclusion The outcomes of this study will help us focus and channel efforts in the future to combat predatory journals and aid us in understanding what needs to be done. We hope that this study will influence management strategies and encourage more education and awareness on a global scale.

18.
IUCrJ ; 11(Pt 1): 16-22, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38096039

RESUMO

Molecular structures can be determined in vitro and in situ with cryo-electron microscopy (cryo-EM). Specimen preparation is a major obstacle in cryo-EM. Typical sample preparation is orders of magnitude slower than biological processes. Time-resolved cryo-EM (TR-cryo-EM) can capture short-lived states. Here, Cryo-EM sample preparation with light-activated molecules (C-SPAM) is presented, an open-source, photochemistry-coupled device for TR-cryo-EM that enables millisecond resolution and tunable timescales across broad biological applications.

19.
Cureus ; 16(5): e60990, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38910751

RESUMO

Myocarditis is an inflammatory disease of the cardiac muscle that manifests as chest pain, dyspnea, and other signs of heart failure. ST segment changes with elevated cardiac biomarkers mimic acute coronary syndromes. It is most commonly caused by viruses like the Epstein-Barr virus (EBV) and Coxsackie B virus, but it can also be due to cardiotoxic drugs like cyclophosphamide and cocaine or caused by a systemic infiltrative process like sarcoidosis or collagen vascular diseases. One relatively common bacterial cause of myocarditis is beta-hemolytic Group A Streptococcus, which is well known to lead, two to three weeks later, to rheumatic fever and pancarditis. Less commonly, it can cause non-rheumatic myocarditis, which occurs faster, with the pathogenesis not very well understood. We will be reporting a case series of two brothers suffering at the same time from non-rheumatic streptococcal A-isolated myocarditis, questioning the possibility of bacterial toxin-mediated myocarditis or inter-linked genetic predisposition.

20.
Cells ; 13(14)2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39056785

RESUMO

Hyaluronan (HA) is a large polysaccharide that is broadly distributed and highly abundant in the soft connective tissues and embryos of vertebrates. The constitutive turnover of HA is very high, estimated at 5 g per day in an average (70 kg) adult human, but HA turnover must also be tightly regulated in some processes. Six genes encoding homologues to bee venom hyaluronidase (HYAL1, HYAL2, HYAL3, HYAL4, HYAL6P/HYALP1, SPAM1/PH20), as well as genes encoding two unrelated G8-domain-containing proteins demonstrated to be involved in HA degradation (CEMIP/KIAA1199, CEMIP2/TMEM2), have been identified in humans. Of these, only deficiencies in HYAL1, HYAL2, HYAL3 and CEMIP have been identified as the cause or putative cause of human genetic disorders. The phenotypes of these disorders have been vital in determining the biological roles of these enzymes but there is much that is still not understood. Deficiencies in these HA-degrading proteins have been created in mice and/or other model organisms where phenotypes could be analyzed and probed to expand our understanding of HA degradation and function. This review will describe what has been found in human and animal models of hyaluronidase deficiency and discuss how this has advanced our understanding of HA's role in health and disease.


Assuntos
Ácido Hialurônico , Hialuronoglucosaminidase , Humanos , Ácido Hialurônico/metabolismo , Animais , Hialuronoglucosaminidase/metabolismo , Hialuronoglucosaminidase/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA