346 research outputs found

    An efficient spectral method for solving third-kind Volterra integral equations with non-smooth solutions

    Full text link
    This paper is concerned with the numerical solution of the third kind Volterra integral equations with non-smooth solutions based on the recursive approach of the spectral Tau method. To this end, a new set of the fractional version of canonical basis polynomials (called FC-polynomials) is introduced. The approximate polynomial solution (called Tau-solution) is expressed in terms of FC-polynomials. The fractional structure of Tau-solution allows recovering the standard degree of accuracy of spectral methods even in the case of non-smooth solutions. The convergence analysis of the method is studied. The obtained numerical results show the accuracy and efficiency of the method compared to other existing methods

    The Effect of Noise Pollution Exposure during Pregnancy on Long Term Potentiation Induction in Pyramidal Neurons of Hippocampus CA1 area in Male Rat Offsprings

    Get PDF
    Abstract: Background: It is believed that cognitive processing is easily disturbed by incompatible environmental stimulations. Many studies have shown that prenatal stress affects fetal brain development. The aim of this study was to evaluate the effect of noise pollution exposure during conception period on neural activity of hippocampus CA1 area in male rat offspring. Methods: Four groups of rats including a control group with natural pregnancy and without any stress and three groups of pregnant rats exposed to daily noise stress (intensity >95 dB, between 8 A.M - 2 P.M) with durations of 1, 2 and 4 hour (s) in the last week of pregnancy were included in the study. Then, in male offsprings of these groups, fEPSP resulted from Schaffer collateral neurons of CA1 were recorded and evaluated in baseline state and after LTP induction with tetanic stimulation. Results: Our results showed that prenatal exposure to traffic noise pollution at 3rd gestational week, reduces amplitude (P<0.0001) and slope of baseline synaptic activity in hippocampus CA1 area (P<0.0001) and furthermore interferes in hippocampal LTP in comparison with control group. The serum level of corticostrone in the two stressed groups (2 and 4 hours) of rats in comparison to the control showed significant increase. But, prenatal exposure to 1- hour noise pollution caused no significant difference in serum corticostrone level. Conclusions: Based on the obtained results, daily exposure to noise pollution in the third trimester of pregnancy for 1, 2 and 4 hour (s), attenuates fEPSP features of hippocampus CA1 area pyramidal neurons of offsprings. Keywords: Noise pollution, Pregnancy, Long-term potentiation, Hippocampus, Offspring, Ra

    Intravenous immunoglobulin for inflammatory demyelinating polyneuropathy

    Get PDF
    Intravenous immunoglobulin (IVIg) plays a key role in treatment of inflammatory demyelinating polyneuropathies such as Guillain–Barre syndrome (GBS). However, individual response to treatment can be unpredictable, and for those most severely affected, a second dose of IVIg (SIV) is commonly administered despite limited evidence for efficacy. In this month’s journal club, we review two studies which explore the efficacy of second dosing and a third study exploring neurophysiological factors predicting relapse in chronic inflammatory polyneuropathy

    Improved Differentiation of Mesenchymal Stem Cells into Hepatocyte-like Cells using FGF4 and IGF-1 in 3D Culture

    Get PDF
    Human Umbilical Cord Mesenchymal Stem Cells (UCMSCs) are considered as an excellent candidate for cell therapy to treat end-stage liver disease. Fibroblast Growth Factor-4 (FGF4), Hepatocyte Growth Factor, and Insulin-like Growth Factor-1 are some of the critical cytokines involved in liver development and regeneration. To evaluate the differentiation potency of cells into hepatocyte-like cells we used these cytokines. UCMSCs were isolated from Wharton's jelly of fullterm infants. The cells were characterized as MSCs by flow-cytometry and their multilineage differentiation capacity. Then, UCMSCs were cultured in 3D collagen scaffold and hepatogenic media with or without FGF4 for 21 days and the data were compared to control. The expression of liver specific genes was evaluated by real-time quantitative RT-PCR and immunocytochemistry. These cells expressed MSC markers and could differentiate into adipocytes and osteocytes. A non–significant higher level of liver specific genes, such as cytokeratin-18 and 19, alpha-fetoprotein and albumin, and also a significant higher level of CYP2B6 expressed by UCMSCs in hepatogenic medium containing FGF4 compared with control. In some specimens, cytokeratin-19-positive cells surrounded a luminal space within collagen scaffolds. Liver-specific marker expression was increased by pre-exposing the cells to FGF4 before treating with IGF-1 and HGF in 3D collagen scaffold. Abbreviations: UCMSCs: Human Umbilical Cord Mesenchymal Stem Cells; FGF4: Fibroblast Growth Factor 4; HGF: Hepatocyte Growth Factor; IGF-1: Insulin-like Growth Factor-1; MSCs: Mesenchymal Stem Cells; ICG: Indocyanine green; PAS: periodic acid Schiff; CK-18: cytokeratin-18; CK-19: Cytokeratin-19; AFP: alpha-fetoprotein; G6P: glucose 6 phosphatase; PEPCK: phosphoenolpyruvate carboxykinase; TAT: tyrosine amino transferase; FBS: Fetal Bovine Serum; OSM: oncostatin M; RT-PCR: Reverse Transcription Polymerase Chain Reaction; PBS: Phosphate-Buffered Saline; Hep- Par1: Hepatocyte paraffin 1; DAB: Diaminobenzidine; CYP2B6: Cytochrome P450 2B6

    Evaluation of the effects of morphine consumption during lactation period on learning and memory of rat�s offspring

    Get PDF
    Background and Aim: The frequent use of opioids changes function and plasticity of neural circuits. Exposing the immature nervous system to opioids can have deeper and more extensive impacts. The aim of this study was to investigate the effects of morphine consumption during lactation period on learning and memory of rats offspring. Material and Methods: This experimental study included 40 male Wistar rats with age range of 45-50 days. Animals were divided into control group (CO) and 3 experimental groups of rats whose mothers had received subcutaneous injections of 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during lactation period. Spatial learning was evaluated by Morris water maze (MWM) on 4 consecutive days (4 trials/day). Spatial memory retrieval was also evaluated on the last day. Results: Our results indicated that the rats whose mothers had received morphine during lactation period spent more time and traveled more distance to find the hidden platform than the controls in the learning stage. These differences were statistically significant when doses of 10 and 20 mg/kg morphine (P<0.001) were used. Also, they spent less time and passed less distance in the target quadrant in probe trial (P<0.001). Conclusion: Morphine consumption during lactation period impairs spatial learning and memory of the rats' offspring in a dose dependent manner. © 2018, Kurdistan University of Medical Sciences. All rights reserved

    The protective effect of bone marrow mesenchymal stem cells in a rat model of ischemic stroke via reducing the C-Jun N-terminal kinase expression

    Get PDF
    Ischemic stroke is the main cause of disability and mortality worldwide. Apoptosis and inflammation have an important role in ischemic brain injury. Mesenchymal stem cells (MSCs) have protective effects on stroke treatment due to anti-inflammatory properties. The inhibition of the C-Jun N-terminal kinase (JNK) pathway may be one of the molecular mechanisms of the neuroprotective effect of MSCs in ischemic brain injury. Twenty-eight male Wistar rats were divided randomly into 3 groups. Except the sham group, others subjected to transient middle cerebral artery occlusion (tMCAO). Bone marrow MSCs or saline were injected 3 h after tMCAO. Sensorimotor behavioral tests were performed 24 and 72 h after ischemia and reperfusion (I/R). The rats were sacrificed 72 h after I/R and infarct volume was measured by TTC staining. The number of apoptotic neurons and astrocytes in the peri-infarct area was assessed by TUNEL assay. The morphology of cells was checked by Nissl staining, and the expression of p-JNK was detected by immunohistochemistry and Western blot. Behavioral scores were improved and infarct volume was reduced by MSCs 24 h and 72 h after tMCAO. TUNEL assay showed that neuronal apoptosis and astroglial activity in the penumbra region were reduced by MSCs. Also, Nissl staining showed lower neuronal apoptosis in BMSCs-treated rats compared to controls. JNK phosphorylation which was profoundly induced by ischemia was significantly decreased after MSCs treatment. We concluded that anti-apoptotic and anti-inflammatory effects of MSCs therapy after brain ischemia may be associated with the down-regulation of p-JNK. © 2019 Elsevier Gmb

    The effects of nanoemulsion cream containing lavender essential oil and licorice extract on healing of deep skin wound in rats

    Get PDF
    Background: Despite the very good medicinal properties of lavender essential oil and licorice extract, some factors, such as allergic reaction and being biodegradable, limit the application of them as candidates for pharmacotherapeutic treatments. Nano-emulsification is one of the ways to overcome these limitations. The aim of this study was to investigate the effects of nanoemulsion cream containing lavender essential oil and licorice extract on healing of deep skin wound in rat model. Methods: In this experimental study, nanoemulsion cream containing lavender essential oil and licorice extract was made using self-emulsifying method. To investigate its effect on wound healing process, a full-thickness skin wound was produced on 85 male Wistar rats. The wound area was digitally photographed at 2 nd , 5 th , 7 th , 10 th , and 14 th days after surgery using a digital camera; then, the area was quantified using an image analysis system (Image J). Moreover, the expression of transforming growth factor-beta1 (TGF-β1), type I collagen (Col I), and Col III genes was evaluated using real-time polymerase chain reaction (real-time PCR) at days 2, 7, and 14. Findings: Nanoemulsion cream significantly decreased the surface area of the wounds faster than lavender essential oil and licorice extract cream (P &lt; 0.010) and phenytoin (P &lt; 0.050). Moreover, real-time PCR showed that topical treatment of wounds with nanomulsion cream increased the expression of TGF-β1, Col I, and Col III genes in rat�s skin (P &lt; 0.01). Conclusion: Nanoemulsion cream containing lavender essential oil and licorice extract exhibits a promising wound healing potential towards excisional wound models in rats. © 2019, Isfahan University of Medical Sciences(IUMS). All rights reserved

    Neurological complications of COVID-19: a preliminary review

    Get PDF

    Behavioral and electrophysiological aspects of cognition in neonate rats lactated by morphine addicted mothers

    Get PDF
    Objective(s): In addition to genetic factors, environmental phenomena during postnatal age highly affect development and, in turn, function of the brain. The present work evaluates if morphine consumption during lactation period influences the spatial performances and synaptic plasticity in rats at neonatal period of age. Materials and Methods: Three groups of mothers were subcutaneously administered by 5 (M5), 10 (M10) or 20 (M20) mg/kg morphine every 12 hours during the lactation period. At 45 days old, their offspring were introduced to Morris water maze for assessment of spatial learning and memory. Basic field excitatory post-synaptic potentials (fEPSPs) were recorded in the CA1 area of hippocampus and, then, long term potentiation (LTP) was induced by tetanic stimulation. Results: We found that the M10 and M20 rats spent more time and traveled longer distance to find the hidden platform of maze when compared to the control animals (P<0.05 for all comparisons). Similarly, these two morphine-exposed groups were inferior in the memory consolidation compared to their control counterparts. Comparing control and M20 rats revealed that morphine exposure decreases the mean amplitude and slope 10-90 of fEPSPs about 30 percent (P<0.001 for both comparisons) and inhibits the LTP induction in the CA1 area circuits. Conclusion: The present study provides behavioral and electrophysiological proofs for negative effect of morphine on the hippocampal-related function in the neonatally morphine-exposed rats. © 2019, Mashhad University of Medical Sciences. All rights reserved
    • …
    corecore