45 research outputs found

    Effects of Injection of Carbon Nanotubes on EEG and Results of a Behavioral Test in Rats

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    We examined the biocompatibility of carbon nanotubes (CNTs) injected i.p. into rats (1 mg/kg body mass) by recording EEG from the frontal and occipital cortex and performing the water maze router test before and after such injection. For EEG, the energy and average power spectral density of wavelet coefficients in the β, α, and θ bands were considered the features. In the water maze router experiment, the distance, time, and speed of rats were investigated as behavioral factors. Comparison of EEG signals before and after injection showed that introduction of CNTs exerted no significant effect on electrophysiological brain indices. A comparison of behavioral factors before and after injection, however, showed that injections of CNTs increased the pacing distance and time to find the desired platform and decreased somewhat the speed in the water maze router experiment. A possible reason of this phenomenon is the possible influence of CNTs on ion fluxes in brain neurons.Ми досліджували біосумісність вуглецевих нанотрубок (ВНТ), ін’єкованих щурам (1 мг/кг маси тіла, внутрішньоочеревинно), відводячи ЕЕГ та застосовуючи поведінковий тест із водним лабіринтом перед такою ін’єкцією та після неї. Параметрами ЕЕГ вважали енергію та усереднені щільності спектральної потужності вейвлет-коефіцієнтів для бета-, тета- та альфа-ритмів. В експерименті з водним лабіринтом поведінковими факторами були відстань, час та швидкість руху щурів у пошуках цільової платформи. Порівняння сигналів ЕЕГ перед ін’єкцією ВНТ та після неї показало, що введення нанотрубок істотно не впливало на електрофізіологічні показники мозку. Порівняння ж поведінкових показників перед ін’єкцією та після неї, проте, засвідчило, що введення ВНТ викликало вірогідне збільшення шляху до платформи і тривалості її пошуків, а також деяке зменшення швидкості пересування у водному лабіринті. Можливою причиною такого феномену є вплив ВНТ на іонні токи в нейронах мозку

    Immunomodulation and Generation of Tolerogenic Dendritic Cells by Probiotic Bacteria in Patients with Inflammatory Bowel Disease

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    In inflammatory bowel diseases (IBD), the therapeutic benefit and mucosal healing from specific probiotics may relate to the modulation of dendritic cells (DCs). Herein, we assessed the immunomodulatory effects of four probiotic strains including Lactobacillus salivarius, Bifidobacterium bifidum, Bacillus coagulans and Bacillus subtilis natto on the expression of co-stimulatory molecules, cytokine production and gene expression of signal-transducing receptors in DCs from IBD patients. Human monocyte-derived DCs from IBD patients and healthy controls were exposed to four probiotic strains. The expression of co-stimulatory molecules was assessed and supernatants were analyzed for anti-inflammatory cytokines. The gene expression of toll-like receptors (TLRs), IL-12p40 and integrin \u3b1v\u3b28 were also analyzed. CD80 and CD86 were induced by most probiotic strains in ulcerative colitis (UC) patients whereas only B. bifidum induced CD80 and CD86 expression in Crohn's disease (CD) patients. IL-10 and TGF-\u3b2 production was increased in a dose-independent manner while TLR expression was decreased by all probiotic bacteria except B. bifidum in DCs from UC patients. TLR-4 and TLR-9 expression was significantly downregulated while integrin f8 was significantly increased in the DCs from CD patients. IL-12p40 expression was only significantly downregulated in DCs from CD patients. Our findings point to the general beneficial effects of probiotics in DC immunomodulation and indicate that probiotic bacteria favorably modulate the expression of co-stimulatory molecules, proinflammatory cytokines and TLRs in DCs from IBD patients

    MPTP-Treated Zebrafish Recapitulate ‘Late-Stage’ Parkinson’s-like Cognitive Decline

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    The zebrafish is a promising model species in biomedical research, including neurotoxicology and neuroactive drug screening. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) evokes degeneration of dopaminergic neurons and is commonly used to model Parkinson’s disease (PD) in laboratory animals, including zebrafish. However, cognitive phenotypes in MPTP-evoked experimental PD models remain poorly understood. Here, we established an LD50 (292 mg/kg) for intraperitoneal MPTP administration in adult zebrafish, and report impaired spatial working memory (poorer spontaneous alternation in the Y-maze) in a PD model utilizing fish treated with 200 µg of this agent. In addition to conventional behavioral analyses, we also employed artificial intelligence (AI)-based approaches to independently and without bias characterize MPTP effects on zebrafish behavior during the Y-maze test. These analyses yielded a distinct cluster for 200-µg MPTP (vs. other) groups, suggesting that high-dose MPTP produced distinct, computationally detectable patterns of zebrafish swimming. Collectively, these findings support MPTP treatment in adult zebrafish as a late-stage experimental PD model with overt cognitive phenotypes. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Funding: The experiments were implemented using the equipment and unique scientific installation “Biological collection–Genetic biomodels of neuropsychiatric disorders” (No. 493387) of the Federal State Budgetary Scientific Institution “Scientific Research Institute of Neurosciences and Medicine” theme no. AAAA-A21-121011990039-2 (2021–2025). The study partially used the facilities and equipment of the Resource Fund of Applied Genetics MIPT (support grant 075-15-2021-684)

    Prevalence and characterization of Clostridium perfringens toxinotypes among patients with antibiotic-associated diarrhea in Iran

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    Clostridium perfringens has emerged as an important cause of antibiotic-associated diarrhea (AAD), particularly in the hospital environment. Here we investigated the prevalence and molecular epidemiology of C. perfringens isolated from 2280 fecal samples from Iranian diarrheal patients suspected of having AAD. Overall, AAD was diagnosed in 13.3% (303/2280) of patients and associated with advanced age (>50 years, P = 0.001). A total of 106 C. perfringens isolates were cultured from AAD (n = 68) and non-AAD (n = 38) groups, with toxinotypes A and F comprising 84% and 16% of isolates, respectively. Notably, 41.2% of type F strains were also cpb2-positive and enterotoxigenic cpe-positive strains were detected in 13.2% of the isolates from AAD patients. Genes associated with the VirR/VirS signal transduction (virR, virS) and accessory gene regulator (agrB, agrD) systems were detected in 56.6% and 67% of the isolates, respectively, and peptides of the quorum-sensing modulator, AgrD were highly conserved across all strains. The high prevalence of C. perfringens in Iranian AAD patients suggests that diagnostic laboratories in this region should consider screening for C. perfringens in cases of suspected AAD, especially if the specimen is negative for other pathogens and/or the patients are aged >50 years

    Improving gas sensor properties of encapsulated ZnO nanorods for ethanol detection using ZnO:Cr layer as an encapsulated layer

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    In this study, encapsulated ZnO nanorods with different amount of chromium (Cr) dopant (0-4.5 at.%) were prepared with hydrothermal method, and their sensitivities as gas sensors against ethanol vapor were investigated. Morphologies of samples were explored by field emission scanning electron microscope (FESEM) which showed that encapsulation process increased the diameter of ZnO nanorods. Existence of Cr in ZnO nanorods structures was confirmed by Energy-dispersive X-ray spectroscopy (EDX). Based on X-ray diffraction (XRD) analysis, the ZnO:Cr nanorods had wurtzite crystal structure, and adding Cr did not alter the crystal structure of ZnO. Electrical measurements revealed that current levels of samples were decreased by adding Cr, while the current level of the sample with 4.5 at.% was increased. This reduction could be attributed to the presence of Cr3+ ions, which led to decrease of charge carriers. Besides, due to the catalytic properties of Cr and its lower ionization energy than Zn, it was observed that Cr dopant improved the detection sensitivity of samples, and decreased the optimum operating temperature of samples. Among all samples, the most sensitivity (14) was obtained based on the sample with 1.5 at.% of Cr for 500 ppm ethanol vapor at the optimum temperature (250 ). In fact, by encapsulating the samples, they became rougher, so the appropriate places to absorb and decompose of gas molecules are increased

    Sequence Diversity in tRNA Gene Locus A-L among Iranian Isolates of Entamoeba Dispar

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    Background: A number of methods for detecting diversity in Entamoeba have been described over the years. In the present study the genetic polymorphism of noncoding locus A-L was ana­lyzed using PCR and sequencing in order to clarify the genotypic differences among E. dispar isolates.Methods: A total of 28 E. dispar from patients with gastrointestinal symptoms were determined and the genomic DNA was extracted directly from stool. For genotype analysis; Locus A-L was amplified by PCR and PCR products were sequenced .The sequences obtained were edited ma­nually and aligned using Gene Runner software.Results: With sequencing of PCR products a reliable genetic diversity in size, number and posi­tion of the repeat units were observed among the Iranian E. dispar isolates in locus A-L gene. Se­quences showed variation in length from 448bp to 507bp and seven distinct types were identified.Conclusion: The genetic diversity of loci like A-L shows them to be suitable for epidemiological studies such as the characterization of the routes of transmission of these parasites in Iran
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