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1.
Food Chem Toxicol ; 152: 112188, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33836210

RESUMO

This study aimed to evaluate the long-term low-dose effects of exposure to a mixture of 6 pesticide active substances (diquat, imazamox, imazethapyr, tepraloxydin, bentazone, acifluorfen) and to elucidate if chronic vitamin deficiency can influence their toxicity. Two hundred Wistar rats were divided in 4 groups: a vitamin-sufficiency control group, a vitamin-deficiency control group, a vitamin sufficiency test group and a vitamin-deficiency test group. The test groups were treated with the aforementioned pesticides at doses 100 times lower than the corresponding NOAEL. After 6 months, ten rats from each group were sacrificed and a complete evaluation of blood and urine biochemistry, biomarkers of oxidative stress, xenobiotic detoxification enzymes and lysosomal enzymes and organ histopathology was performed. The pesticides mixture and vitamin deficiency determined an increase in alkaline phosphatase levels and urinary calcium levels, abnormal serum lipid profile, and a decrease of total blood proteins levels, red blood cells, haematocrit and haemoglobin. The combination of the two stressors up-regulated CYP1A1, CYP1A2, CYP2B1 and GST levels. This study provides a new proof for the need to move forward from single chemical testing to a more complex approach to account for the multitude of stressors that can challenge the setting of real safety levels.

2.
Int J Mol Med ; 47(6)2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33846767

RESUMO

The Coronavirus Disease 2019 (COVID­19) pandemic has forced the scientific community to rapidly develop highly reliable diagnostic methods in order to effectively and accurately diagnose this pathology, thus limiting the spread of infection. Although the structural and molecular characteristics of the severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2) were initially unknown, various diagnostic strategies useful for making a correct diagnosis of COVID­19 have been rapidly developed by private research laboratories and biomedical companies. At present, rapid antigen or antibody tests, immunoenzymatic serological tests and molecular tests based on RT­PCR are the most widely used and validated techniques worldwide. Apart from these conventional methods, other techniques, including isothermal nucleic acid amplification techniques, clusters of regularly interspaced short palindromic repeats/Cas (CRISPR/Cas)­based approaches or digital PCR methods are currently used in research contexts or are awaiting approval for diagnostic use by competent authorities. In order to provide guidance for the correct use of COVID­19 diagnostic tests, the present review describes the diagnostic strategies available which may be used for the diagnosis of COVID­19 infection in both clinical and research settings. In particular, the technical and instrumental characteristics of the diagnostic methods used are described herein. In addition, updated and detailed information about the type of sample, the modality and the timing of use of specific tests are also discussed.


Assuntos
/métodos , /diagnóstico , Animais , Técnicas Biossensoriais/métodos , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Humanos , Invenções , Microscopia Eletrônica/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , /isolamento & purificação , Cultura de Vírus/métodos
3.
Biomolecules ; 11(3)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800172

RESUMO

The tumor microenvironment (TME) is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded by the components of the extracellular matrix (ECM). Glycosaminoglycans (GAGs), natural biomacromolecules, essential ECM, and cell membrane components are extensively altered in cancer tissues. During disease progression, the GAG fine structure changes in a manner associated with disease evolution. Thus, changes in the GAG sulfation pattern are immediately correlated to malignant transformation. Their molecular weight, distribution, composition, and fine modifications, including sulfation, exhibit distinct alterations during cancer development. GAGs and GAG-based molecules, due to their unique properties, are suggested as promising effectors for anticancer therapy. Considering their participation in tumorigenesis, their utilization in drug development has been the focus of both industry and academic research efforts. These efforts have been developing in two main directions; (i) utilizing GAGs as targets of therapeutic strategies and (ii) employing GAGs specificity and excellent physicochemical properties for targeted delivery of cancer therapeutics. This review will comprehensively discuss recent developments and the broad potential of GAG utilization for cancer therapy.

4.
Environ Res ; 197: 111083, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33775680

RESUMO

Over the last few decades, nanotechnology has risen to the forefront of both the research and industrial interest, resulting in the manufacture and utilization of various nanomaterials, as well as in their integration into a wide range of fields. However, the consequent elevated exposure to such materials raises serious concerns regarding their effects on human health and safety. Existing scientific data indicate that the induction of oxidative stress, through the excessive generation of Reactive Oxygen Species (ROS), might be the principal mechanism of exerting their toxicity. Meanwhile, a number of nanomaterials exhibit antioxidant properties, either intrinsic or resulting from their functionalization with conventional antioxidants. Considering that their redox properties are implicated in the manifestation of their biological effects, we propose an integrated approach for the assessment of the redox-related activities of nanomaterials at three biological levels (in vitro-cell free systems, cell cultures, in vivo). Towards this direction, a battery of translational biomarkers is recommended, and a series of reliable protocols are presented in detail. The aim of the present approach is to acquire a better understanding with respect to the biological actions of nanomaterials in the interrelated fields of Redox Biology and Toxicology.

5.
Oncol Rep ; 45(4)2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33649849

RESUMO

Subsequently to the publication of the above paper, the authors have realized that they should have credited a Professor René Csuk [Martin­Luther­Universität Halle­Wittenberg, Halle (Saale), Germany] for the use of a compound that his group synthesized in the study. Therefore, the authors wish to include the following text in the Acknowledgements' section of the Declarations: 'The authors are grateful to Professor Rene Csuk, Department of Organic Chemistry, Martin­Luther University Halle­Wittenberg, for providing us with the rhodamine B­conjugated oleanolic acid derivative (RhodOA)'. All the named authors agree to this Corrigendum, and apologize to Professor Csuk for the upset and inconvenience caused. [the original article was published in Oncology Reports 44: 1169­1183, 2020; DOI: 10.3892/or.2020.7666].

6.
J Cell Mol Med ; 25(10): 4523-4533, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33734600

RESUMO

The outbreak of the coronavirus disease 2019 (COVID-19) has gathered 1 year of scientific/clinical information. This informational asset should be thoroughly and wisely used in the coming year colliding in a global task force to control this infection. Epidemiology of this infection shows that the available estimates of SARS-CoV-2 infection prevalence largely depended on the availability of molecular testing and the extent of tested population. Within molecular diagnosis, the viability and infectiousness of the virus in the tested samples should be further investigated. Moreover, SARS-CoV-2 has a genetic normal evolution that is a dynamic process. The immune system participates to the counterattack of the viral infection by pathogen elimination, cellular homoeostasis, tissue repair and generation of memory cells that would be reactivated upon a second encounter with the same virus. In all these stages, we still have knowledge to be gathered regarding antibody persistence, protective effects and immunological memory. Moreover, information regarding the intense pro-inflammatory action in severe cases still lacks and this is important in stratifying patients for difficult to treat cases. Without being exhaustive, the review will cover these important issues to be acknowledged to further advance in the battle against the current pandemia.

7.
Biomed Rep ; 14(5): 47, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33786176

RESUMO

The objective of the present study was to evaluate the circulating serum amino acid levels in children with attention deficit/hyperactivity disorder (ADHD). A total of 71 children with untreated ADHD and 31 neurotypical controls aged 7-14 years old were examined. Serum amino acid levels were evaluated using high-performance liquid chromatography (HPLC) with UV-detection. Laboratory quality control was performed with reference materials of human plasma amino acid levels. The obtained data demonstrated that children with ADHD were characterized by 29, 10 and 20% lower serum histidine (His), glutamine (Gln) and proline (Pro) levels compared with neurotypical children, respectively. In contrast, circulating aspartate (Asp), glutamate (Glu) and hydroxyproline (Hypro) levels exceeded the respective control values by 7, 7 and 42%. Correspondingly, the Gln-to-Glu and Pro-to-Hypro ratios were 28% and 49%, respectively, lower in ADHD cases compared with the controls. Total Gln/Glu levels were also significantly lower in ADHD patients. No significant group differences were observed between the groups in the other amino acids analyzed, including phenylalanine. Multiple linear regression analysis revealed significant associations between circulating serum Gln, lysine (Lys) (both negative) and Glu (positive) levels with total ADHD Rating Scale-IV scores. The observed alterations in Pro/Hypro and Gln/Glu levels and ratios are likely associated with the coexisting connective tissue pathology and alterations in glutamatergic neurotransmission in ADHD, respectively. Altered circulating levels of His, Lys and Asp may also be implicated in ADHD pathogenesis. However, further in vivo and in vitro studies are required in order to investigate the detailed mechanisms linking amino acid metabolism with ADHD pathogenesis.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33557243

RESUMO

Increasing contamination of the environment by toxic compounds such as endocrine disrupting chemicals (EDCs) is one of the major causes of reproductive defects in both sexes. Estrogen/androgen pathways are of utmost importance in gonadal development, determination of secondary sex characteristics and gametogenesis. Most of the EDCs mediate their action through respective receptors and/or downstream signaling. The purpose of this review is to highlight the mechanism by which EDCs can trigger antagonistic or agonistic response, acting through estrogen/androgen receptors causing reproductive defects that lead to infertility. In vitro, in vivo and in silico studies focusing on the impact of EDCs on estrogen/androgen pathways and related proteins published in the last decade were considered for the review. PUBMED and PUBCHEM were used for literature search. EDCs can bind to estrogen receptors (ERα and ERß) and androgen receptors or activate alternative receptors such as G protein-coupled receptors (GPCR), GPR30, estrogen-related receptor (ERRγ) to activate estrogen signaling via downstream kinases. Bisphenol A, dichlorodiphenyltrichloroethane, dichlorodiphenyldichloroethylene, polychlorinated biphenyls and phthalates are major toxicants that interfere with the normal estrogen/androgen pathways leading to infertility in both sexes through many ways, including DNA damage in spermatozoids, altered methylation pattern, histone modifications and miRNA expression.


Assuntos
Disruptores Endócrinos , Androgênios/toxicidade , Disruptores Endócrinos/toxicidade , Estrogênios/toxicidade , Feminino , Masculino , Receptores Androgênicos , Receptores Estrogênicos
9.
Environ Res ; 195: 110832, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33549619

RESUMO

Male infertility is a major problem with important socioeconomic consequences. It is associated with several pathological factors, including but not limited to endocrine disruption as a result of environmental pollution and the alarming decline in sperm count over the decades is indicative of involvement of many environmental and lifestyle changes around the globe. Organochlorine pollutants such as dichlorodiphenyltrichlorethanes (DDTs), polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) disrupt male reproductive system but the exact effect of environmental exposure on semen parameters in human is still not clear. This study was designed to monitor PCBs, DDTs and HCB in hair, urine and serum samples of infertile and healthy fertile men. Solid-phase microextraction gas chromatography-mass spectrometry (SPME/GC-MS) was used to monitor analytes. All tested compounds were detected, indicating recent use/persistent accumulation. Hair samples revealed no significant association with serum/urine concentrations of the analytes, while serum/urine concentrations were significantly correlated positively. Concentrations were higher in serum compared to other samples. The levels of organochlorine pollutants were higher in infertile men compared to controls with few exceptions. Among PCBs, and DDTs, PCB-153 and pp'-DDT were detected in highest concentrations, respectively. op'-DDT and pp'-DDT levels were significantly higher in infertile men compared to controls. HCB was significantly correlated negatively with sperm motility in all samples. Serum concentrations of all compounds were higher in men with defective semen parameters compared to normospermics. Serum was the best biological sample for assessing health outcomes in relation to exposure levels.


Assuntos
Poluentes Ambientais , Hidrocarbonetos Clorados , Bifenilos Policlorados , DDT/análise , Poluentes Ambientais/análise , Humanos , Hidrocarbonetos Clorados/análise , Masculino , Paquistão , Bifenilos Policlorados/análise , Sêmen/química , Motilidade Espermática
10.
Food Chem Toxicol ; 148: 111974, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33421462

RESUMO

The coronavirus disease (COVID)-19 pandemic is a major challenge for the health systems worldwide. Acute respiratory distress syndrome (ARDS), is one of the most common complications of the COVID-19 infection. The activation of the coagulation system plays an important role in the pathogenesis of ARDS. The development of lung coagulopathy involves thrombin generation and fibrinolysis inhibition. Unfractionated heparin and its recently introduced counterpart low molecular weight heparin (LMWH), are widely used anticoagulants with a variety of clinical indications allowing for limited and manageable physio-toxicologic side effects while the use of protamine sulfate, heparin's effective antidote, has made their use even safer. Tissue-type plasminogen activator (tPA) is approved as intravenous thrombolytic treatment. The present narrative review discusses the use of heparin and tPA in the treatment of COVID-19-induced ARDS and their related potential physio-toxicologic side effects. The article is a quick review of articles on anticoagulation in COVID infection and the potential toxicologic reactions associated with these drugs.


Assuntos
/fisiopatologia , Hemostasia/efeitos dos fármacos , Heparina/uso terapêutico , Trombose/complicações , Ativador de Plasminogênio Tecidual/uso terapêutico , Heparina/farmacologia , Humanos , Ativador de Plasminogênio Tecidual/farmacologia
11.
Int J Mol Med ; 47(1): 92-100, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33416113

RESUMO

As the coronavirus disease 2019 (COVID­19) continues to spread worldwide, it has become evident that the morbidity and mortality rates clearly vary across nations. Although several factors may account for this disparity, striking differences within and between populations indicate that ethnicity might impact COVID­19 clinical outcomes, reflecting the 'color of disease'. Therefore, the role of key biological variables that could interplay with viral spreading and severity indices has attracted increasing attention, particularly among non­Caucasian populations. Although the links between vitamin D status and the incidence and severity of COVID-19 remain elusive, several lines of emerging evidence suggest that vitamin D signaling, targeting several immune­mediated pathways, may offer potential benefits at different stages of SARS-CoV-2 infection. Given that the vitamin D status is modulated by several intrinsic and extrinsic factors, including skin type (pigmentation), melanin polymers may also play a role in variable COVID­19 outcomes among diverse population settings. Moreover, apart from the well­known limiting effects of melanin on the endogenous production of vitamin D, the potential crosstalk between the pigmentary and immune system may also require special attention concerning the current pandemic. The present review article aimed to shed light on a range of mostly overlooked host factors, such as vitamin D status and melanin pigments, that may influence the course and outcome of COVID­19.


Assuntos
/epidemiologia , Melaninas/imunologia , Pandemias , Deficiência de Vitamina D/imunologia , Vitamina D/imunologia , Vitaminas/imunologia , /imunologia , /virologia , Humanos , Transdução de Sinais , Vitamina D/sangue , Vitaminas/sangue
12.
Metabolites ; 10(12)2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302528

RESUMO

Autoimmune diseases (ADs) are chronic disorders characterized by the loss of self-tolerance, and although being heterogeneous, they share common pathogenic mechanisms. Self-antigens and inflammation markers are established diagnostic tools; however, the metabolic imbalances that underlie ADs are poorly described. The study aimed to employ metabolomics for the detection of disease-related changes in autoimmune diseases that could have predictive value. Quantitative analysis of 28 urine organic acids was performed using Gas Chromatography-Mass Spectrometry in a group of 392 participants. Autoimmune thyroiditis, inflammatory bowel disease, psoriasis and rheumatoid arthritis were the most prevalent autoimmune diseases of the study. Statistically significant differences were observed in the tricarboxylate cycle metabolites, succinate, methylcitrate and malate, the pyroglutamate and 2-hydroxybutyrate from the glutathione cycle and the metabolites methylmalonate, 4-hydroxyphenylpyruvate, 2-hydroxyglutarate and 2-hydroxyisobutyrate between the AD group and the control. Artificial neural networks and Binary logistic regression resulted in the highest predictive accuracy scores (66.7% and 74.9%, respectively), while Methylmalonate, 2-Hydroxyglutarate and 2-hydroxybutyrate were proposed as potential biomarkers for autoimmune diseases. Urine organic acid levels related to the mechanisms of energy production and detoxification were associated with the presence of autoimmune diseases and could be an adjunct tool for early diagnosis and prediction.

13.
Hum Exp Toxicol ; : 960327120975828, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33272061

RESUMO

BACKGROUND: Following the implementation of the European Union Tobacco Product Directive (EU TPD) regulations on e-cigarette products in 2016, we assessed the current profile of e-cigarette liquid exposure incidents and their associated health outcomes. METHODS: De-identified data were received from poison centers in eight EU Member States (Sweden, the Netherlands, Italy, Hungary Austria, Finland, Spain and Croatia) reporting on e-cigarette liquid exposure incidents between August 2018 to December 2019. Descriptive analysis was conducted to present incident characteristics and health outcomes. Chi-square tests and multivariable logistic regression analysis were used to test associations. RESULTS: Of the 223 e-liquid exposure incidents recorded by poison centers in multiple EU MS, 64.7% of the cases were unintentional exposures, ranging from 48.4% among adults aged ≥19 years to 100.0% among children aged 0-5 years (p < 0.05). The most frequent route of exposure was ingestion (73.5%) while55.2% experienced any clinical symptoms, including nausea (16.6%), vomiting (11.1%), and dizziness (9.0%). 57.8% of the cases were treated at the residence or on-site. CONCLUSION: Further monitoring is warranted, using uniform reporting requirements, to ensure the continued compliance to the EU TPD and assess its long-term impact on related incident characteristics.

14.
Toxicol Rep ; 7: 1571-1577, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33304826

RESUMO

Glyoxal (GO), a by-product of glucose auto-oxidation, is involved in the glycation of proteins/ lipids and formation of advanced glycation (AGE) and lipoxidation (ALE) end products. AGE/ALE were shown to contribute to diabetic complications development/progression such as nephropathy. Diabetic nephropathy progression has an oxidative nature. Given the antioxidant effects of polyphenols, potential protective effects of resveratrol, curcumin and gallic acid, in rat renal cells treated with GO, were evaluated in the present work. According to our results, incubation of GO with the cells reduced their viability and led to membrane lysis, reactive oxygen species (ROS) formation, lipid peroxidation, mitochondrial membrane potential collapse, and lysosomal membrane leakage. These findings were prevented by pre-treatment with resveratrol, curcumin and gallic acid. Mitochondrial and lysosomal toxic interactions appear to worsen oxidative stress/cytotoxicity produced by GO. Resveratrol, curcumin and gallic acid inhibited ROS formation and attenuated GO-induced renal cell death.

15.
Int J Mol Med ; 46(5): 1599-1602, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33000193

RESUMO

In response to the SARS­CoV­2 outbreak, and the resulting COVID­19 pandemic, a global competition to develop an anti­COVID­19 vaccine has ensued. The targeted time frame for initial vaccine deployment is late 2020. The present article examines whether short­term, mid­term, and long­term vaccine safety can be achieved under such an accelerated schedule, given the myriad vaccine­induced mechanisms that have demonstrated adverse effects based on previous clinical trials and laboratory research. It presents scientific evidence of potential pitfalls associated with eliminating critical phase II and III clinical trials, and concludes that there is no substitute currently available for long­term human clinical trials to ensure long­term human safety.

16.
Toxicol Rep ; 7: 1448-1458, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33110761

RESUMO

A degraded/dysfunctional immune system appears to be the main determinant of serious/fatal reaction to viral infection (for COVID-19, SARS, and influenza alike). There are four major approaches being employed or considered presently to augment or strengthen the immune system, in order to reduce adverse effects of viral exposure. The three approaches that are focused mainly on augmenting the immune system are based on the concept that pandemics/outbreaks can be controlled/prevented while maintaining the immune-degrading lifestyles followed by much of the global population. The fourth approach is based on identifying and introducing measures aimed at strengthening the immune system intrinsically in order to minimize future pandemics/outbreaks. Specifically, the four measures are: 1) restricting exposure to virus; 2) providing reactive/tactical treatments to reduce viral load; 3) developing vaccines to prevent, or at least attenuate, the infection; 4) strengthening the immune system intrinsically, by a) identifying those factors that contribute to degrading the immune system, then eliminating/reducing them as comprehensively, thoroughly, and rapidly as possible, and b) replacing the eliminated factors with immune-strengthening factors. This paper focuses on vaccine safety. A future COVID-19 vaccine appears to be the treatment of choice at the national/international level. Vaccine development has been accelerated to achieve this goal in the relatively near-term, and questions have arisen whether vaccine safety has been/is being/will be compromised in pursuit of a shortened vaccine development time. There are myriad mechanisms related to vaccine-induced, and natural infection-induced, infections that could adversely impact vaccine effectiveness and safety. This paper summarizes many of those mechanisms.

17.
J Clin Med ; 9(9)2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899768

RESUMO

Skin cancer represents the most common type of cancer among Caucasians and presents in two main forms: melanoma and non-melanoma skin cancer (NMSC). NMSC is an umbrella term, under which basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and Merkel cell carcinoma (MCC) are found along with the pre-neoplastic lesions, Bowen disease (BD) and actinic keratosis (AK). Due to the mild nature of the majority of NMSC cases, research regarding their biology has attracted much less attention. Nonetheless, NMSC can bear unfavorable characteristics for the patient, such as invasiveness, local recurrence and distant metastases. In addition, late diagnosis is relatively common for a number of cases of NMSC due to the inability to recognize such cases. Recognizing the need for clinically and economically efficient modes of diagnosis, staging, and prognosis, the present review discusses the main etiological and pathological features of NMSC as well as the new and promising molecular biomarkers available including telomere length (TL), telomerase activity (TA), CpG island methylation (CIM), histone methylation and acetylation, microRNAs (miRNAs), and micronuclei frequency (MNf). The evaluation of all these aspects is important for the correct management of NMSC; therefore, the current review aims to assist future studies interested in exploring the diagnostic and prognostic potential of molecular biomarkers for these entities.

18.
Toxicol Rep ; 7: 1090-1094, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32953461

RESUMO

Genotoxicity of the mixture of generic pesticides imidacloprid + imazalil + tebuconazole in a ratio of 14.0/1.7/1.0 by weight was assessed using Ames test (Salmonella typhimurium) and micronucleus test in vivo on mammalian bone marrow erythrocytes (CD-1 mice) supporting the data creation for the Real Life Risk Simulation (RLRS) approach. This pesticides' combination is used in the commercial formulation for seed treatment in advance of or immediately before sowing. Tested pesticides' technical grade active ingredients (TGAIs) showed no evidence of genotoxicity upon separate treatments. In combination, the three pesticides demonstrated negative results in the Ames test but induced a statistically significant, dose-depended increase in MN-PCEs in mice bone marrow at doses lower than those used separately. The observed effect may be mediated by the synergistic action of the tested TGAIs, their metabolites or impurities.

19.
Curr Treat Options Neurol ; 22(11): 37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32994698

RESUMO

Purpose of Review: To describe the possible neuroinvasion pathways of Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV-2), the virus responsible for the Coronavirus disease-19 (Covid-19) pandemic. Recent Findings: We present data regarding the family of Coronaviruses (CoVs) and the central nervous system (CNS), and describe parallels between SARS-CoV-2 and other members of the family, which have been investigated in more depth and combine these findings with the recent advancements regarding SARS-CoV-2. Summary: SARS-CoV-2 like other CoVs is neuroinvasive, neurotropic and neurovirulent. Two main pathways of CNS penetration seem to be the strongest candidates, the hematogenous and the neuronal. Τhe olfactory route in particular appears to play a significant role in neuroinvasion of coronaviruses and SARS-CoV-2, as well. However, existing data suggest that other routes, involving the nasal epithelium in general, lymphatic tissue and the CSF may also play roles in SARS-CoV-2 invasion into the CNS.

20.
Exp Ther Med ; 20(5): 78, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32968435

RESUMO

The coronavirus pandemic and its unprecedented consequences globally has spurred the interest of the artificial intelligence research community. A plethora of published studies have investigated the role of imaging such as chest X-rays and computer tomography in coronavirus disease 2019 (COVID-19) automated diagnosis. Οpen repositories of medical imaging data can play a significant role by promoting cooperation among institutes in a world-wide scale. However, they may induce limitations related to variable data quality and intrinsic differences due to the wide variety of scanner vendors and imaging parameters. In this study, a state-of-the-art custom U-Net model is presented with a dice similarity coefficient performance of 99.6% along with a transfer learning VGG-19 based model for COVID-19 versus pneumonia differentiation exhibiting an area under curve of 96.1%. The above was significantly improved over the baseline model trained with no segmentation in selected tomographic slices of the same dataset. The presented study highlights the importance of a robust preprocessing protocol for image analysis within a heterogeneous imaging dataset and assesses the potential diagnostic value of the presented COVID-19 model by comparing its performance to the state of the art.

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