Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
1.
BMC Infect Dis ; 24(1): 1191, 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39438823

RESUMO

BACKGROUND: One of the main risks of infection after hematopoietic stem cell transplantation (HSCT) is infection by gram-positive bacteria, including vancomycin-resistant enterococci (VRE). Based on the format of a global review and meta-analysis study, this study aims to investigate the incidence of VRE bloodstream infection (BSI) after HSCT in colonized individuals. METHODS: The keywords of the systematic search included vancomycin-resistant enterococci and HSCT. These words were searched in Google Scholar, PubMed/Medline, Scopus, and Web of Science databases from January 1, 2000, to March 1, 2024. Studies that reported the prevalence of vancomycin-resistant enterococci in patients undergoing HSCT were included. The random effects model was used for the meta-analyses. Investigations were conducted according to PRISMA guidelines, and the protocol was registered in PROSPERO: CRD42024543491. RESULTS: Out of 1100 screened papers, 28 were eligible. The random effects model was established to analyze the incidence of VRE BSI after HSCT. The pooled prevalence of co-infection for Allo-HSCT recipients was 3.023 (95% CI, Z-value = -3.5, p-value < 0.0001), and this value for Auto-HSCT recipients was 11.89 (95% CI, Z-value = -2.923, p-value < 0.001). These results showed that the rate of BSI due to vancomycin-resistant enterococcus in Auto-HSCT recipients is higher than Allo-HSCT. CONCLUSIONS: The prevalence of vancomycin-resistant enterococci in Auto-HSCT recipients is higher than that of Allo-HSCT, possibly due to colonization of the intestines of these people with vancomycin-resistant enterococci before transplantation. VRE Colonization before transplantation increases the likelihood of post-transplant VRE BSI and other bacterial infections, including Gram-negative. The strains should be analyzed by sequencing before and after HSCT for a more detailed investigation.


Assuntos
Infecções por Bactérias Gram-Positivas , Transplante de Células-Tronco Hematopoéticas , Enterococos Resistentes à Vancomicina , Humanos , Enterococos Resistentes à Vancomicina/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Incidência , Prevalência , Bacteriemia/epidemiologia , Bacteriemia/microbiologia
2.
Stem Cell Res Ther ; 15(1): 264, 2024 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-39183334

RESUMO

OBJECTIVE: Neurological and functional impairments are commonly observed in individuals with spinal cord injury (SCI) due to insufficient regeneration of damaged axons. Exosomes play a crucial role in the paracrine effects of mesenchymal stem cells (MSCs) and have emerged as a promising therapeutic approach for SCI. Thus, this study aimed to evaluate the safety and potential effects of intrathecal administration of allogeneic exosomes derived from human umbilical cord MSCs (HUC-MSCs) in patients with complete subacute SCI. METHODS: This study was a single-arm, open-label, phase I clinical trial with a 12-month follow-up period. HUC-MSCs were extracted from human umbilical cord tissue, and exosomes were isolated via ultracentrifugation. After intrathecal injection, each participant a underwent complete evaluation, including neurological assessment using the American Spinal Injury Association (ASIA) scale, functional assessment using the Spinal Cord Independence Measure (SCIM-III), neurogenic bowel dysfunction (NBD) assessment using the NBD score, modified Ashworth scale (MAS), and lower urinary tract function questionnaire. RESULTS: Nine patients with complete subacute SCI were recruited. The intrathecal injection of allogeneic HUC-MSCs-exosomes was safe and well tolerated. No early or late adverse event (AE) attributable to the study intervention was observed. Significant improvements in ASIA pinprick (P-value = 0.039) and light touch (P-value = 0.038) scores, SCIM III total score (P-value = 0.027), and NBD score (P-value = 0.042) were also observed at 12-month after the injection compared with baseline. CONCLUSIONS: This study demonstrated that intrathecal administration of allogeneic HUC-MSCs-exosomes is safe in patients with subacute SCI. Moreover, it seems that this therapy might be associated with potential clinical and functional improvements in these patients. In this regard, future larger phase II/III clinical trials with adequate power are highly required. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT20200502047277N1. Registered 2 October 2020, https://en.irct.ir/trial/48765 .


Assuntos
Exossomos , Injeções Espinhais , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Traumatismos da Medula Espinal , Cordão Umbilical , Humanos , Traumatismos da Medula Espinal/terapia , Exossomos/metabolismo , Masculino , Feminino , Adulto , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Pessoa de Meia-Idade , Transplante de Células-Tronco Mesenquimais/métodos , Transplante de Células-Tronco Mesenquimais/efeitos adversos , Cordão Umbilical/citologia , Transplante Homólogo/métodos , Adulto Jovem
3.
Vet Res Forum ; 15(5): 223-229, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39022576

RESUMO

In recent years, the use of probiotics and their metabolites, known as postbiotics as natural preservatives has received increasing attention in the food industry. This study aimed to prepare and characterize postbiotics of Lactiplantibacillus sakei and to investigate its application as an anti-Listeria solution on beef fillets using an aerosolization technique. The functional groups, including organic acids, polysaccharides and other minor metabolites, were identified by Fourier transform infrared (FTIR) in the postbiotics. The 2, 2'-diphenyl-1-picrylhydrazyl radical scavenging activity of the postbiotics was reported as 0.82 mg mL-1. The antimicrobial test using the agar well diffusion method revealed a zone of inhibition of 27.00 ± 1.20 mm. Application of an aerosolized postbiotics solution resulted in a significant reduction in Listeria monocytogenes counts on beef fillets, reaching 3.30 log10 CFU g-1 over a 15-day storage period at 4.00 ± 1.00 ˚C. The results of this study revealed that the postbiotics of L. sakei was an effective antimicrobial additive for controlling foodborne pathogens in beef fillets and aerosolization is a promising method for developing an antimicrobial coating on meat to enhance meat safety.

4.
Mol Biol Rep ; 51(1): 737, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874790

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common type of cancer among children, presenting significant healthcare challenges for some patients, including drug resistance and the need for targeted therapies. SiRNA-based therapy is one potential solution, but problems can arise in administration and the need for a delivery system to protect siRNA during intravenous injection. Additionally, siRNA encounters instability and degradation in the reticuloendothelial system, off-target effects, and potential immune system stimulation. Despite these limitations, some promising results about siRNA therapy in ALL patients have been published in recent years, showing the potential for more effective and precise treatment, reduced side effects, and personalized approaches. While siRNA-based therapies demonstrate safety and efficacy, addressing the mentioned limitations is crucial for further optimization. Advancements in siRNA-delivery technologies and combination therapies hold promise to improve treatment effectiveness and overcome drug resistance. Ultimately, despite its challenges, siRNA therapy has the potential to revolutionize ALL treatments and improve patient outcomes.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , RNA Interferente Pequeno , Humanos , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Terapia Genética/métodos , Animais , Resistencia a Medicamentos Antineoplásicos/genética
5.
Am J Disaster Med ; 19(2): 151-160, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38698514

RESUMO

AIMS: The Arbaeen procession is one of the largest religious gatherings in which tens of millions of people participate every year. The presence of many people in this religious gathering highlights the necessity of planning to reduce incidents related to pilgrims in the field of health and to ensure their timely access to health and treatment services. The current research was conducted with the aim of investigating and analyzing the health field in the Arbaeen procession of 2022. METHODOLOGY: This was a qualitative study, in which in-depth and semistructured interviews were conducted. The target population comprised healthcare policymakers, managers, and providers of the Arbaeen procession in 2022. The interview and data collection guide were developed using the World Health Organization's recommendations. Data collection was continued till data saturation. Directed content analysis was used to analyze the data. Different strategies were applied to increase the validity and reliability of the results of this study. FINDING: Data saturation was reached after 33 interviews. In total, eight main topics were identified, including follow-up of disease and trauma, promotion of public health, education and health system, cooperation and coordination in the field of health, information and communication management, response operations, support and resource management, and security and safety. CONCLUSION: Essential health issues in Arbaeen procession were identified in this research, which may be considered as an evidence-based guide for planners, planners, and executive managers of this religious community. The findings of this research may be used in other marches and public gatherings.


Assuntos
Pesquisa Qualitativa , Humanos , Entrevistas como Assunto , Planejamento em Desastres/organização & administração , Irã (Geográfico) , Islamismo
6.
Microsc Res Tech ; 87(7): 1615-1626, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38445461

RESUMO

Acute lymphoblastic leukemia (ALL) is a life-threatening disease that commonly affects children and is classified into three subtypes: L1, L2, and L3. Traditionally, ALL is diagnosed through morphological analysis, involving the examination of blood and bone marrow smears by pathologists. However, this manual process is time-consuming, laborious, and prone to errors. Moreover, the significant morphological similarity between ALL and various lymphocyte subtypes, such as normal, atypic, and reactive lymphocytes, further complicates the feature extraction and detection process. The aim of this study is to develop an accurate and efficient automatic system to distinguish ALL cells from these similar lymphocyte subtypes without the need for direct feature extraction. First, the contrast of microscopic images is enhanced using histogram equalization, which improves the visibility of important features. Next, a fuzzy C-means clustering algorithm is employed to segment cell nuclei, as they play a crucial role in ALL diagnosis. Finally, a novel convolutional neural network (CNN) with three convolutional layers is utilized to classify the segmented nuclei into six distinct classes. The CNN is trained on a labeled dataset, allowing it to learn the distinguishing features of each class. To evaluate the performance of the proposed model, quantitative metrics are employed, and a comparison is made with three well-known deep networks: VGG-16, DenseNet, and Xception. The results demonstrate that the proposed model outperforms these networks, achieving an approximate accuracy of 97%. Moreover, the model's performance surpasses that of other studies focused on 6-class classification in the context of ALL diagnosis. RESEARCH HIGHLIGHTS: Deep neural networks eliminate the requirement for feature extraction in ALL classification The proposed convolutional neural network achieves an impressive accuracy of approximately 97% in classifying six ALL and lymphocyte subtypes.


Assuntos
Linfócitos , Redes Neurais de Computação , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/classificação , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Linfócitos/patologia , Linfócitos/citologia , Processamento de Imagem Assistida por Computador/métodos , Algoritmos , Microscopia/métodos
7.
bioRxiv ; 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38464246

RESUMO

EAG1 depolarization-activated potassium selective channels are important targets for treatment of cancer and neurological disorders. EAG1 channels are formed by a tetrameric subunit assembly with each subunit containing an N-terminal Per-Arnt-Sim (PAS) domain and C-terminal cyclic nucleotide-binding homology (CNBH) domain. The PAS and CNBH domains from adjacent subunits interact and form an intracellular tetrameric ring that regulates the EAG1 channel gating, including the movement of the voltage sensor domain (VSD) from closed to open states. Small molecule ligands can inhibit EAG1 channels by binding to their PAS domains. However, the allosteric pathways of this inhibition are not known. Here we show that chlorpromazine, a PAS domain small molecule binder, alters interactions between the PAS and CNBH domains and decreases the coupling between the intracellular tetrameric ring and the pore of the channel, while having little effect on the coupling between the PAS and VSD domains. In addition, chlorpromazine binding to the PAS domain did not alter Cole-Moore shift characteristic of EAG1 channels, further indicating that chlorpromazine has no effect on VSD movement from the deep closed to opened states. Our study provides a framework for understanding global pathways of EAG1 channel regulation by small molecule PAS domain binders.

8.
Appl Radiat Isot ; 204: 111124, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38029638

RESUMO

The aim of this study is to evaluate organ-at-risk (OAR) doses obtained from different designs of intracavitary cylinder applicators during high-dose-rate (HDR) brachytherapy of an asymmetric vaginal tumor. Dose distributions around five cylinder applicators were obtained using the Geant4 toolkit. Three of these applicators are commercially available: single-channel, multi-channel, and shielded. Additionally, two proposed sub-configurations were evaluated: (I) a combination of the multichannel applicator with a central shield and (II) a dynamically modulated cylinder (DMC). The dose distributions of the proposed applicators were compared to those of the single-channel cylinder applicator. The results showed that using a cylindrical applicator with a higher degree of freedom in plan optimization can improve OAR, sparing up to 60% for the rectum and 20% for the bladder. In conclusion, this work suggests using a new design of a cylindrical applicator to enhance the therapeutic ratio of brachytherapy for asymmetric and irregularly shaped vaginal tumors.


Assuntos
Braquiterapia , Neoplasias Vaginais , Feminino , Humanos , Braquiterapia/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Vaginais/radioterapia
9.
J Med Phys ; 48(3): 268-273, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37969149

RESUMO

Purpose: According to the revised Task Group number 43 recommendations, a brachytherapy source must be validated against a similar or identical source before its clinical application. The purpose of this investigation is to verify the dosimetric data of the high dose rate (HDR) BEBIG 192Ir source (Ir2.A85-2). Materials and Methods: The HDR 192Ir encapsulated seed was simulated and its main dosimetric data were calculated using Geant4 Application for Tomographic Emission (GATE) simulation code. Cubic cells were used for the calculation of dose rate constant and radial dose function while for anisotropy function ring cells were used. DoseActors were simulated and attached to the respective cells to obtain the required data. Results: The dose rate constant was obtained as 1.098 ± 0.003 cGy.h - 1.U - 1, differing by 1.0% from the reference value reported by Granero et al. Similarly, the calculated values for radial dose and anisotropy functions presented good agreement with the results obtained by Granero et al. Conclusion: The results of this study suggest that the GATE Monte Carlo code is a valid toolkit for benchmarking brachytherapy sources and can be used for brachytherapy simulation-based studies and verification of brachytherapy treatment planning systems.

10.
J Biol Chem ; 299(12): 105391, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37898402

RESUMO

Ether-a-go-go (EAG) channels are key regulators of neuronal excitability and tumorigenesis. EAG channels contain an N-terminal Per-Arnt-Sim (PAS) domain that can regulate currents from EAG channels by binding small molecules. The molecular mechanism of this regulation is not clear. Using surface plasmon resonance and electrophysiology we show that a small molecule ligand imipramine can bind to the PAS domain of EAG1 channels and inhibit EAG1 currents via this binding. We further used a combination of molecular dynamics (MD) simulations, electrophysiology, and mutagenesis to investigate the molecular mechanism of EAG1 current inhibition by imipramine binding to the PAS domain. We found that Tyr71, located at the entrance to the PAS domain cavity, serves as a "gatekeeper" limiting access of imipramine to the cavity. MD simulations indicate that the hydrophobic electrostatic profile of the cavity facilitates imipramine binding and in silico mutations of hydrophobic cavity-lining residues to negatively charged glutamates decreased imipramine binding. Probing the PAS domain cavity-lining residues with site-directed mutagenesis, guided by MD simulations, identified D39 and R84 as residues essential for the EAG1 channel inhibition by imipramine binding to the PAS domain. Taken together, our study identified specific residues in the PAS domain that could increase or decrease EAG1 current inhibition by imipramine binding to the PAS domain. These findings should further the understanding of molecular mechanisms of EAG1 channel regulation by ligands and facilitate the development of therapeutic agents targeting these channels.


Assuntos
Canais de Potássio Éter-A-Go-Go , Imipramina , Fenômenos Eletrofisiológicos , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Canais de Potássio Éter-A-Go-Go/química , Canais de Potássio Éter-A-Go-Go/genética , Imipramina/química , Imipramina/farmacologia , Ligação Proteica , Animais , Domínios Proteicos , Camundongos , Xenopus
11.
Sci Rep ; 13(1): 14920, 2023 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-37691039

RESUMO

This study aimed to investigate the diagnostic performance of machine learning-based radiomics analysis to diagnose coronary artery disease status and risk from rest/stress Myocardial Perfusion Imaging (MPI) single-photon emission computed tomography (SPECT). A total of 395 patients suspicious of coronary artery disease who underwent 2-day stress-rest protocol MPI SPECT were enrolled in this study. The left ventricle myocardium, excluding the cardiac cavity, was manually delineated on rest and stress images to define a volume of interest. Added to clinical features (age, sex, family history, diabetes status, smoking, and ejection fraction), a total of 118 radiomics features, were extracted from rest and stress MPI SPECT images to establish different feature sets, including Rest-, Stress-, Delta-, and Combined-radiomics (all together) feature sets. The data were randomly divided into 80% and 20% subsets for training and testing, respectively. The performance of classifiers built from combinations of three feature selections, and nine machine learning algorithms was evaluated for two different diagnostic tasks, including 1) normal/abnormal (no CAD vs. CAD) classification, and 2) low-risk/high-risk CAD classification. Different metrics, including the area under the ROC curve (AUC), accuracy (ACC), sensitivity (SEN), and specificity (SPE), were reported for models' evaluation. Overall, models built on the Stress feature set (compared to other feature sets), and models to diagnose the second task (compared to task 1 models) revealed better performance. The Stress-mRMR-KNN (feature set-feature selection-classifier) reached the highest performance for task 1 with AUC, ACC, SEN, and SPE equal to 0.61, 0.63, 0.64, and 0.6, respectively. The Stress-Boruta-GB model achieved the highest performance for task 2 with AUC, ACC, SEN, and SPE of 0.79, 0.76, 0.75, and 0.76, respectively. Diabetes status from the clinical feature family, and dependence count non-uniformity normalized, from the NGLDM family, which is representative of non-uniformity in the region of interest were the most frequently selected features from stress feature set for CAD risk classification. This study revealed promising results for CAD risk classification using machine learning models built on MPI SPECT radiomics. The proposed models are helpful to alleviate the labor-intensive MPI SPECT interpretation process regarding CAD status and can potentially expedite the diagnostic process.


Assuntos
Doença da Artéria Coronariana , Diabetes Mellitus , Imagem de Perfusão do Miocárdio , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Aprendizado de Máquina , Tomografia Computadorizada de Emissão de Fóton Único , Masculino , Feminino
12.
FEMS Microbiol Lett ; 3702023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-37697675

RESUMO

Previous research has demonstrated promising outcomes regarding the advantageous impact of probiotics in both cancer prevention and treatment. Nevertheless, the precise molecular mechanisms underpinning these effects remain elusive. Recent investigations have proposed a potential involvement of micro ribonucleic acids (miRNAs) in mediating the favorable influence of probiotics on cancerous cells. This study was designed to evaluate the effect of Lactobacillus casei condition medium on miR-21 relative expression in HT-29 colorectal cancer cells. Lactobacillus casei condition medium mixed with RPMI in different proportions (1:1, 1:3, and 1:7) and utilized to treat HT-29 cells for 24 and 48 h. Subsequently, percentage of early and late apoptotic cells were identified using a flow cytometry instrument. A real-time polymerase chain reaction was carried out to determine the relative expression of miR-21. Our findings revealed that L. casei condition medium induces apoptosis in a time- and dose-dependent manner in HT-29 cells. Furthermore, we found a significantly downregulated miR-21 after treatment with high doses of L. casei condition medium after 48 h. Overall, our results provide valuable insights into a potential mechanism through which L. casei condition medium mediates its apoptotic effect in colorectal cancer cells through downregulation of miR-21. However, further investigations are required to unravel its therapeutic, diagnostic, and treatment monitoring potential.

13.
J Phys Chem B ; 127(31): 6887-6895, 2023 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-37527428

RESUMO

Conformational dynamics in proteins can give rise to aggregation prone states during folding, and these kinetically stable states could form oligomers and aggregates. In this study, we investigate the intermediate states and near-folded states of ß2-microglobulin and their physico-chemical properties using molecular dynamics and Markov state modeling. Analysis of hundreds of microseconds simulation show the importance of the edge strands in the misfolded states that give rise to a high exposure of hydrophobic residues in the core of the protein that could initiate oligomerization and aggregate formation. Our study sheds light on the first step of aggregation of ß2m monomers and gave a better picture of the landscape of protein misfolding and aggregation.


Assuntos
Simulação de Dinâmica Molecular , Microglobulina beta-2 , Microglobulina beta-2/química , Conformação Molecular , Amiloide/química , Dobramento de Proteína
14.
Noncoding RNA ; 9(4)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37624036

RESUMO

Lymphoid cells play a critical role in the immune system, which includes three subgroups of T, B, and NK cells. Recognition of the complexity of the human genetics transcriptome in lymphopoiesis has revolutionized our understanding of the regulatory potential of RNA in normal lymphopoiesis and lymphoid malignancies. Long non-coding RNAs (lncRNAs) are a class of RNA molecules greater than 200 nucleotides in length. LncRNAs have recently attracted much attention due to their critical roles in various biological processes, including gene regulation, chromatin organization, and cell cycle control. LncRNAs can also be used for cell differentiation and cell fate, as their expression patterns are often specific to particular cell types or developmental stages. Additionally, lncRNAs have been implicated in lymphoid differentiation, such as regulating T-cell and B-cell development, and their expression has been linked to immune-associated diseases such as leukemia and lymphoma. In addition, lncRNAs have been investigated as potential biomarkers for diagnosis, prognosis, and therapeutic response to disease management. In this review, we provide an overview of the current knowledge about the regulatory role of lncRNAs in physiopathology processes during normal lymphopoiesis and lymphoid leukemia.

15.
J Med Signals Sens ; 13(2): 101-109, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37448543

RESUMO

Background: Diagnosis of the stage of COVID-19 patients using the chest computed tomography (CT) can help the physician in making decisions on the length of time required for hospitalization and adequate selection of patient care. This diagnosis requires very expert radiologists who are not available everywhere and is also tedious and subjective. The aim of this study is to propose an advanced machine learning system to diagnose the stages of COVID-19 patients including normal, early, progressive, peak, and absorption stages based on lung CT images, using an automatic deep transfer learning ensemble. Methods: Different strategies of deep transfer learning were used which were based on pretrained convolutional neural networks (CNNs). Pretrained CNNs were fine-tuned on the chest CT images, and then, the extracted features were classified by a softmax layer. Finally, we built an ensemble method based on majority voting of the best deep transfer learning outputs to further improve the recognition performance. Results: The experimental results from 689 cases indicate that the ensemble of three deep transfer learning outputs based on EfficientNetB4, InceptionResV3, and NasNetlarge has the highest results in diagnosing the stage of COVID-19 with an accuracy of 91.66%. Conclusion: The proposed method can be used for the classification of the stage of COVID-19 disease with good accuracy to help the physician in making decisions on patient care.

16.
Anal Bioanal Chem ; 415(23): 5681-5694, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37507464

RESUMO

Aflatoxins (AFs), an important category of pollutants, are formed in many foods and adversely affect human health. Therefore, their determination is critical to ensuring human food health. An efficient dispersive solid-phase microextraction technique was developed as a simple and straightforward sample preparation technique for determination of four aflatoxins using a high-performance liquid chromatography (HPLC) fluorescence detector. A novel efficient, green sorbent for extracting AFs was synthesized based on hydrothermal and chemical strategies. The amounts of three sorbent components were optimized using a mixture design (simplex lattice design), including 14 experiments. The optimal amount of amino-bimetallic Fe/Ni-MIL-53 nanospheres, chitosan, and magnetic Fe3O4 nanoparticles as sorbent components was 0.87, 0.67, and 0.47 g, respectively. Also, various factors affecting the process of AF determination were studied and optimized in two successive experimental designs, including the definitive screening design and the Box-Behnken design. Under optimal conditions, the linear ranges for measuring aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 were 0.05-82.6, 0.07-86.4, 0.08-85.7, and 0.07-89.5 ng mL-1, respectively. The relative standard deviations under inter-day and intra-day conditions for measuring AFs at three analyte concentrations were determined in triplicate analysis and were in the ranges of 3.7-4.6% and 4.9-6.1% for water sample analysis, respectively. The qualitative detection limits for determining AFs were between 0.01 and 0.05 ng mL-1. The pre-concentration factor of the method for measuring AFs ranged from 739.7 to 802.1. The proposed method was used for determining AFs in several real samples, including herbal distillate, black tea, corn, and real water samples. The relative recovery and standard deviation were 87.8-97.8% and 4.10-6.82%, respectively.

17.
Sci Rep ; 13(1): 8041, 2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37198168

RESUMO

Microorganisms do not live as dispersed single cells but rather they form aggregates with extracellular polymeric substances at interfaces. Biofilms are considered efficient life forms because they shield bacteria from biocides and collect dilute nutrients. This is a big concern in industry since the microorganisms can colonize a wide range of surfaces, accelerating material deterioration, colonizing medical devices, contaminating ultrapure drinking water, increasing energy costs and creating focus of infection. Conventional biocides that target a specific component of the bacteria are not effective in the presence of biofilms. Efficient biofilm inhibitors are based on a multitarget approach interacting with the bacteria and the biofilm matrix. Their rationale design requires a thorough understanding of inhibitory mechanisms that are still largely lacking today. Herein we uncover via molecular modelling the inhibition mechanism of cetrimonium 4-OH cinnamate (CTA-4OHcinn). Simulations show that CTA-4OH micelles can disrupt symmetric and asymmetric bilayers, representative of inner and outer bacterial membranes, following three stages: adsorption, assimilation, and defect formation. The main driving force for micellar attack is electrostatic interactions. In addition to disrupting the bilayers, the micelles work as carriers facilitating the trapping of 4OH cinnamate anions within the bilayer upper leaflet and overcoming electrostatic repulsion. The micelles also interact with extracellular DNA (e-DNA), which is one of the main components of biofilms. It is observed that CTA-4OHcinn forms spherical micelles on the DNA backbone; which hinders their ability to pack. This is demonstrated by modelling the DNA along the hbb histone-like protein, showing that in the presence of CTA-4OHcinn, DNA does not pack properly around hbb. The abilities of CTA-4OHcinn to cause cell death through membrane disruption and to disperse a mature, multi-species biofilm are also confirmed experimentally.


Assuntos
Desinfetantes , Micelas , Cetrimônio/farmacologia , Biofilmes , Bactérias , DNA/farmacologia , Desinfetantes/farmacologia , DNA Bacteriano/farmacologia
18.
Neurochem Res ; 48(8): 2335-2344, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37037995

RESUMO

Peripheral neuropathies caused by the peripheral nervous system (PNS) damage can occur due to trauma and other disorders. They present as altered sensation, weakness, autonomic symptoms, and debilitating pain syndrome with a wide range of clinical signs. Acetyl-L-Carnitine (ALCAR) is a biological compound with essential roles in mitochondrial oxidative metabolism and anti-oxidant effects that protects mitochondria from oxidative damage and inhibits apoptosis caused by mitochondrial damage. This study is a systematic review and meta-analysis of the effects of ALCAR on peripheral nerve injuries. This review examines studies on treating traumatic peripheral neuropathies in which ALCAR is administered to rats with sciatic nerve injury with an appropriate control group. The articles were divided based on the mode of ALCAR administration. If one method was used in more than one article, their results were entered in the "Revman5.4" software and were meta-analyzed. Studies were selected from 1994 to 2018 on rats with varying physical injuries to their sciatic nerves. In one study, ALCAR was provided to rats in their drinking water, while in other studies, ALCAR was injected intra-peritoneally. Different mechanisms of ALCAR actions have been suggested in this study, but the underpinnings of the neuroprotective effects of ALCAR are still unclear. Further studies are mandatory to clarify the actual mechanisms of the neuroprotective activity of ALCAR. Based on the results of existing studies, ALCAR effectively increases the tolerance threshold of thermal and mechanical stimuli, reduces latency, and reduces apoptosis; finally, adjusting the dose and duration of administration may increase the dose and duration axon diameter.


Assuntos
Acetilcarnitina , Traumatismos dos Nervos Periféricos , Animais , Ratos , Acetilcarnitina/farmacologia , Regeneração Nervosa , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Nervo Isquiático/lesões
19.
Crit Rev Anal Chem ; 53(6): 1285-1312, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34955046

RESUMO

Antidepressants are an important class of drugs to treat various types of depression. The determination of antidepressants is crucial in biological samples to control adverse effects in humans and study pharmacokinetics and bioavailability. Direct measurement of antidepressants in biological and water samples is a considerable challenge for analysts due to their low concentration, the high matrix effects of real samples, and the presence of metabolites of these drugs in biological samples. The challenge leads to using sample preparation processes as a critical step in determining antidepressants. Extraction and microextraction procedures have been widely utilized as sample preparation procedures for these drugs. The purposes of extraction or microextraction methods for antidepressant medications are to preconcentrate the analyte, reduce the matrix effects, increase the selectivity of the procedures, and convert the sample to a suitable format for introducing it into detection systems. In the review, the various extraction and microextraction methods of these drugs in biological, real water, and wastewater samples were investigated. The theory of each technique was briefly addressed to understand the features and factors affecting each method. The extraction and microextraction methods were classified based on their application for antidepressants, and the advantages and disadvantages of each technique were reviewed. The new developments to overcome the limitations of each procedure were discussed. The investigation indicated the number of applications of liquid-phase microextraction for extracting antidepressants has been almost equal to that of solid-phase microextraction.


Assuntos
Antidepressivos , Microextração em Fase Líquida , Humanos , Microextração em Fase Líquida/métodos , Microextração em Fase Sólida/métodos , Manejo de Espécimes , Água
20.
Rep Pract Oncol Radiother ; 28(5): 571-581, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38179292

RESUMO

Background: Radiotherapy has a significant side effect known as radiation-induced secondary cancer. This study aims to evaluate the dose and secondary cancer risk for women with rectal cancer treated with three-dimensional conformal radiation therapy (3D-CRT) to the organs at risk (OARs) and some sensitive organs using different types of radiation-induced cancer risk prediction models, including Biological Effects of Ionizing Radiation (BEIRVII), Environmental Protection Agency (EPA) and International Commission on Radiological Protection (ICRP), and compare the results of the different models for same organs. Materials and methods: Thirty female patients with rectal cancer were considered and dose calculations were based on the PCRT-3D treatment planning system, while the radiotherapy of the patients had been performed using Shinva linear accelerator with a total dose of 45 Gy at 25 fractions. Planning target volume (PTV), OARs, and some sensitive organs were contoured, three models were used to evaluate secondary cancer risk (SCR) using the excess relative risk (ERR) and excess absolute risk (EAR). Results: The bladder presents the highest risk, in terms of ERR, and the femur head and uterus in terms of EAR from the three models (BEIR VII, EPA, and ICRP). Conclusion: Based on the obtained results, radiotherapy of rectal cancer is relatively higher for the bladder and femur head, compared to the risk for other organs, the kidney risk is significantly lower. It was observed that the SCR from the ICRP model was higher compared to BEIR VII and EPA models.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA