Search

Objective: Peripheral nerve injury is a clinical problem that may cause sensory and motor inabilities. Sesamol is an antioxidant that can help in repairing damaged central nervous system (CNS) and other organs. The present study aimed to investigate whether the antioxidant effects of sesamol could improve the function, structure, and myelination in rats' damaged peripheral nervous system (PNS). Materials and Methods: In this study, 28 adult male Wistar rats were randomly divided into four groups. In the sham group, the sciatic nerve was exposed and restored to its place without inducing crush injury. The control received DMSO (solvent) and the two experimental groups received 50 or 100 mg/kg sesamol intraperitoneally for 28 days after sciatic nerve crush injury, respectively. Next, sciatic function index (SFI), superoxide dismutase (SOD) activity, malondialdehyde (MDA) level, expression of nerve growth factor (NGF) and myelin protein zero (MPZ) proteins in the sciatic nerve, and histological indices of the sciatic nerve and gastrocnemius muscle were evaluated. Results: The results showed that sesamol reduced oxidative stress parameters, increased expression of NGF and MPZ proteins, and improved function and regeneration of the damaged sciatic nerve. Furthermore, a significant regeneration was observed in the gastrocnemius muscle after treatment with sesamol. Although administration of both doses of sesamol was useful, the 100 mg/kg dose was more effective than the 50 mg/kg one. Conclusion: The results suggest that sesamol may be effective in improving damaged peripheral nerves in rats by reducing oxidative stress and increasing the expression of NGF and MPZ proteins. [ABSTRACT FROM AUTHOR]

Introduction: Parkinson disease (PD) results from the destruction of dopaminergic neurons in the brain. This study aimed to investigate the protective effects of natural antioxidants such as caffeic acid phenethyl ester (CAPE) to maintain these neurons. Methods: CAPE is one of the main ingredients of propolis. Intranasal administration of 1-methyl-4-phenyl-2;3;4;6-tetrahydropyridine (MPTP) was used to generate a PD model in rats. A total of 2xbone marrow stem cells (BMSCs) were injected from the tail vein. Behavioral tests, immunohistochemistry, DiI, cresyl fast violet, and TUNEL staining were used to evaluate the rats 2 weeks after treatment. Results: In all treatment groups with stem cells, the DiI staining method revealed that the cells migrated to the substantia nigra pars compacta after injection. Treatment with CAPE significantly protects dopaminergic neurons from MPTP. The highest number of tyrosine hydroxylase (TH) positive neurons was seen in the pre-CAPE+PD+stem cell (administration of CAPE, then the creation of PD, finally injection of stem cells) group. The number of TH+cells in all groups that received CAPE was significant compared to groups that received the stem cells only (P<0.001). Intranasal administration of MPTP significantly increases the number of apoptotic cells. The lowest number of apoptotic cells was in the CAPE+PD+stem cell group. Conclusion: The results showed that the use of CAPE and stem cells in Parkinson rats caused a significant reduction in the apoptotic cells. [ABSTRACT FROM AUTHOR]

Background: Alumina-titanium (Al2O3-Ti) biocomposites have been recently developed with improved mechanical properties for use in heavily loaded orthopedic sites. Their biological performance, however, has not been investigated yet. Methods: The aim of the present study was to evaluate the in vivo biological interaction of Al2O3-Ti. Spark plasma sintering (SPS) was used to fabricate Al2O3-Ti composites with 25 vol.%, 50 vol.%, and 75 vol.% Ti content. Pure alumina and titanium were also fabricated by the same procedure for comparison. The fabricated composite disks were cut into small bars and implanted into medullary canals of rat femurs. The histological analysis and scanning electron microscopy (SEM) observation were carried out to determine the bone formation ability of these materials and to evaluate the bone-implant interfaces. Results: The histological observation showed the formation of osteoblast, osteocytes with lacuna, bone with lamellar structures, and blood vessels indicating that the healing and remodeling of the bone, and vasculature reconstruction occurred after 4 and 8 weeks of implantation. However, superior bone formation and maturation were obtained after 8 weeks. SEM images also showed stronger interfaces at week 8. There were differences between the composites in percentages of bone area (TB%) and the number of osteocytes. The 50Ti composite showed higher TB% at week 4, while 25Ti and 75Ti represented higher TB% at week 8. All the composites showed a higher number of osteocytes compared to 100Ti, particularly 75Ti. Conclusions: The fabricated composites have the potential to be used in load-bearing orthopedic applications. [ABSTRACT FROM AUTHOR]

Background: L-carnitine (Lc) as a type of flavonoid antioxidants and bone marrow stromal cells (BMSCs) as a type of mesenchymal stem cells may recover damaged ovaries. It seems that Lc has favorable effects on differentiation, increasing lifespan and decreasing apoptosis in BMSCs. The aim of this study was to investigate effects of co-administration of BMSC+Lc on damaged ovaries after creating a chemotherapy model with cyclophosphamide in rats. Materials and Methods: In this experimental study, cyclophosphamide was intraperitoneally (IP) injected to forty female wistar rats for 14 days, in terms of chemotherapy-induced ovarian destruction. The rats were then randomly divided into four groups: control, Lc, BMSCs and co-administration of BMSC+Lc. Injection of BMSCs into bilateral ovaries and intraperitoneal injection of Lc were performed individually and together. Four weeks later, levels of serum estradiol (E2) and follicle-stimulating hormone (FSH) using enzyme-linked immunosorbent assay (ELISA) kit, number of ovarian follicles at different stages using hematoxylin and eosin (H&E) staining and expression of ovarian Bcl-2 and Bax proteins using western blot were assessed. Results: Co-administration of BMSC+Lc increased E2 and decreased FSH levels compared to the control group (P<0.001). The number of follicles was higher in the co-administrated group compared to the control group (P<0.001). Co-administration of BMSC+Lc increased Bcl-2 protein level, decreased Bax protein level and increased Bcl-2/Bax ratio (P<0.001). Conclusion: The effect of co-administration of BMSC+Lc is probably more effective than the effect of their separate administration on the recovery of damaged ovaries by chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Apigenin is a plant-derived compound belonging to the flavonoids category and bears protective effects on different cells. The aim of this study was to evaluate the effect of apigenin on the number of viable and apoptotic blastomeres, the zona pellucida (ZP) thickness and hatching rate of pre-implantation mouse embryos exposed to H2O2 and actinomycin D. Materials and Methods: In this experimental study, 420 two-cell embryos were randomly divided into six groups: i. Control, ii. Apigenin, iii. H2O2, iv. Apigenin+H2O2, v. Actinomycin D, and vi. Apigenin+Actinomycin D. The percentage of blastocysts and hatched blastocysts was calculated. Blastocyst ZP thickness was also measured. In addition, viable blastomeres quantity was counted by Hoechst and propidium iodide staining and the number of apoptotic blastomeres was counted by TUNEL assay. Results: The results of viable and apoptotic blastomeres quantity, the ZP thickness, and the percentage of blastocysts and hatched blastocysts were significantly more favorable in the apigenin group, rather than the control group (P<0.05). The results of the apigenin+H2O2 group were significantly more favorable than the H2O2 group (P<0.05); and the results of apigenin+actinomycin D group were significantly more favorable than actinomycin D group (P<0.05). Conclusion: The results suggest that apigenin may protect mouse embryos against H2O2 and actinomycin D. So that it increases the number of viable blastomeres and decreases the number of apoptotic blastomeres, which may cause expanding the blastocysts, thinning of the ZP thickness and increasing the rate of hatching in mouse embryos. [ABSTRACT FROM AUTHOR]

Objective(s): Granulocyte-colony stimulating factor (G-CSF) is used in clinical practice for the treatment of neutropenia and to stimulate generation of hematopoietic stem cells in bone marrow donors. In the present study, the ability of G-CSF in mobilizing exogenous bone marrow stem cells (BMSCs) from peripheral blood into the brain was tested. We for the first time injected a small amount of BMSCs through the tail vein. Materials and Methods: We choose 25 male Wistar rats (200–250 g) were lesioned by 6-OHDA injected into the left substantia nigra, pars compacta (SNpc). G-CSF (70 µg/kg/day) was given from the 7th day after lesion for five days. The BMSCs (2×105) were injected through the dorsal tail vein on the 7th day after lesion. Results:The number of rotations was significantly lower in the stem cell therapy group than in the control group. In the third test in the received G-CSF and G-CSF+stem cells groups, animals displayed significant behavioral recovery compared with the control group (P<0.05). There was a significant difference in the average of dopaminergic neurons in SNpc between the control group and G-CSF and G-CS+stem cells groups. We didn't detect any labeling stem cells in SNpc. Conclusion: G-CSF can't mobilize low amounts of exogenous BMSCs from the blood stream to injured SNpc. But G-CSF (70 µg/kg) is more neuroprotective than BMSCs (2×105 number of BMSCs). Results of our study suggest that G-CSF alone is more neuroprotective than BMSCs. [ABSTRACT FROM AUTHOR]

Objective(s): The main characteristic of mesenchymal stem cells (MSCs) is their ability to produce other cell types. Electromagnetic field (EMF) stimulates differentiation of MSCs into other cells. In this study, we investigated whether EMF can effect on the differentiation of MSCs into dopaminergic (DA) neurons. Materials and Methods: An EMF with a frequency of 50 Hz and two intensities of 40 and 400 μT 1hr/day was generated around the cells for a week. Afterwards, these cells were injected into the left ventricle of Parkinsonian rats. The rats survived for 2 weeks, and then sampling was performed. Results: The injected cells differentiated into DA neurons and sporadically settled in the substantia nigra pars compacta (SNpc). Transplanted rats exhibited significant partial correction apomorphine-induced rotational behavior compared to Parkinsonian rats (5.0±0.1 vs 7.57±0.08). Results demonstrated that endogenous serum and brain derived neurotrophic factor (BDNF) were altered in all experimental groups. The greatest increase was in group of 400 μT EMF in comparison with Parkinsonian rats (398±15 vs. 312±11.79 pg / mg). Current study have shown that 6-Hydroxydopamine can cause severe loss of dopaminergic neurons (68±6.58), but injected MSCs that exposed to 40 and 400 μT EMF increased dopaminergic neurons in SNpc ( 108±2.33 & 126±3.89) (P<0.001). Conclusion: Electromagnetic fields with particular frequencies stimulate MSCs. So, these cells had anti-Parkinsonian properties in our studies. [ABSTRACT FROM AUTHOR]

Objective(s): The effect of maternal voluntary exercise on hippocampal BDNF level in rat offspring was studied. In addition, the possible role of hippocampal BDNF receptors in maternal exercise induced enhancement of learning in the rat pups was investigated. Materials and Methods: Pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. Each of the exercising pregnant rats was given access to a cage that was equipped with a running wheel until the end of their pregnancy. On post natal day (PND) 36, two groups consisted of 7 male rat pups in each group from sedentary or exercised mothers were sacrificed and the hippocampus was dissected for BDNF proteins level determination. Also, bilateral injection of K252a to the hippocampus was used to block the hippocampal BDNF action on PND59 in the rat pups. Results: Voluntary exercise during pregnancy significantly increased the level of BDNF protein in the hippocampus of the rat pups on PND36 compared to the control group (P=0.048). Inhibiting BDNF action abolished the exercise-induced improvement of learning acquisition in offspring in training trials (P=0.0001). No difference was observed in the platform location latency and the time spent in the target in the probe test between two groups. Conclusion: This study demonstrates that voluntary exercise during pregnancy via a TrkBmediated mechanism enhances the spatial learning acquisition, however, not the retention of memory in the rat pups. [ABSTRACT FROM AUTHOR]

Postnatal hypoxia is a main cause of neuronal damage in newborn. However, our understanding of the possible preventive or therapeutic methods to reduce the harmful effects of hypoxia is still primary. Pregnant rats were provided with running wheels during their pregnancy. On PND4 (postnatal day 4)to PND8, the rat pups were exposed to postnatal chronic hypoxia (11% O2, 89% N2) in an air-tight plastic chamber for a period of six hours per day. The number of neurons and also angiogenesis in hippocampus were studied. Postnatal exposure to mild hypoxia decreased the number of the neurons in all studied regions of the hippocampus CA1, CA3(cornu ammonis), DG(dentate gyrus) and SUB(cubiculum) in rat pups. In other words the number of the neurons in rat pups born from voluntary exercise group was not significantly less than control group in CA1, CA3 and DG regions. So maternal Voluntary exercise during pregnancy increases the blood vessel density in the DG region of the hippocampus of the rat pups. In this study for the first time we provide evidences that show the protective effect of maternal voluntary exercise during pregnancy on rat offspring against postnatal hypoxia. We revealed that maternal exercise during pregnancy increases the hippocampal neuron number and angiogenesis in offspring. [ABSTRACT FROM AUTHOR]

Introduction: Traditional teaching methods cannot keep up with the new knowledge in medical students anymore. There are several challenges between traditional and new teaching methods in different courses .This study has tried to compare the effects of two teaching approaches on education of osteology( lecture VS work in small groups). Methods: In a quasi experimental study, 54 medical students of Semnan Medical University who had selected anatomy of head and neck were randomly divided into small groups of experiment in two sequent semesters . Theoretical and practical sessions of Osteology were simultaneously held for the first four sessions in groups with 5 member. Results of mid term and final exams of these groups were compared with those of the past two semesters in which the medical students had been educated only by lecture in a theory and practice combination method as a control group. Data were analyzed by SPSS software. Results: The mean scores of midterm and final exams in combined theory and practice experimental groups were significantly higher than controls in which classes were held just by lecture with separate theoretical and practical issues . Conclusion: In small groups, the level of learning osteology, compared to traditional method, was more. This increase is possibly due to the sense of team work and a better student and teacher relationship resulting in a more motivation of studying. [ABSTRACT FROM AUTHOR]

Background: Bone marrow stromal cells (BMSCs), as a type of mesenchymal stem cells, and the granulocyte colony-stimulating factor (G-CSF), as a type of growth factor, may recover damaged ovaries. The aim of the present study was to investigate the effects of the coadministration of BMSCs and the G-CSF on damaged ovaries after creating a chemotherapy model with cyclophosphamide (CTX) in rats. Methods: The present study was performed in Semnan, Iran, in the late 2016 and the early 2017. BMSCs were cultured and were confirmed using the CD markers of stromal cells. Forty female Wistar rats were randomly divided into 4 groups. The rats were injected intraperitoneally with CTX for 14 days to induce chemotherapy and ovarian destruction. Then, the BMSCs were injected into bilateral ovaries and the G-CSF was injected intraperitoneally, individually and together. Four weeks later, the number of ovarian follicles using H&E staining, the number of apoptotic granulosa cells using the TUNEL assay, the number of produced oocytes from the ovaries, and the levels of serum E2 and FSH using an ELISA reader were assessed. Statistical analysis was done using one-way ANOVA with SPSS, version 16.0. Results: The results showed that the effects of the coadministration of 2x106 BMSCs and 70 µg/kg of the G-CSF were significantly more favorable than those in the control group (P<0.001), the BMSC group (P=0.016), and the G-CSF group (P<0.001) on the recovery of damaged ovaries. Conclusion: The efficacy ofthe coadministration of BMSCs and the G-CSF in the recovery of ovaries damaged by chemotherapy was high by comparison with the administration of either of them separately. [ABSTRACT FROM AUTHOR]

Background: Quercetin is a flavonoid with the ability to improve the growth of embryos in vitro, and actinomycin D is an inducer of apoptosis in embryonic cells. Objective: The aim was to evaluate the effect of quercetin on the number of viable and apoptotic cells, the zona pellucida (ZP) thickness and the hatching rate of preimplantation embryos exposed to actinomycin D in mice. Materials and Methods: Two-cell embryos were randomly divided into four groups (Control, Quercetin, actinomycin D, and Quercetin + actinomycin D group). Blastocysts percentage, hatched blastocysts, and ZP thickness of blastocysts was measured. The number of blastomeres was counted by Hoechst and propidium iodide staining and the apoptotic cells number was counted by TUNEL assay. Results: The results showed that the use of quercetin significantly improved the growth of embryos compared to the control group (p=0.037). Moreover, quercetin reduced the destructive effects of actinomycin D on the growth of embryos significantly (p=0.026). Conclusion: quercetin may protect the embryos against actinomycin D so that increases the number of viable cells and decreases the number of apoptotic cells, which can help the expansion of the blastocysts, thinning of the ZP thickness and increasing the hatching rate in mouse embryos. [ABSTRACT FROM AUTHOR]

L-carnitine (LC) is an antioxidant with the ability to promote the growth in vitro embryo. Objective: The goal was to evaluate the effect of LC on some indicators of embryo development and blastocyst quality including zona pellucid (ZP) thickness, the hatching of blastocysts and their cell numbers. Materials and Methods: Mouse embryos were randomly divided into five groups and incubated with different concentrations of LC (I; 0, II; 0.5, III; 1, IV; 2 and V; 4 mg/ml) from 2-cell to hatched blastocyst. The percentage of blastocysts and hatched blastocysts was calculated. Blastocysts ZP thickness was measured and the number of blastocyst cells was counted using Hoechst and propidium iodide (PI) staining. Results: The results showed concentration of 0.5 mg/ml of LC had an antioxidant effect as in this group, the percentage of blastocysts and hatched blactocysts (p=0.01), the ZP thickness (p=0.00) and the number of blastocyst inner cell mass were significantly more favorable than the control group (p=0.03); and concentration of 4 mg/ml of LC had a toxic effect on embryo development and blastocyst quality (p=0.00). Conclusion: The results suggest that LC may increase the number of blastocyst cells, which probably helps to expand the blastocyst and thinning of the ZP thickness and, therefore, creating a successful hatching for implantation. [ABSTRACT FROM AUTHOR]

Objective: Transplants of multipotent stem cells have been shown to have a neuroprotective effect after central nervous system injury. The bulge region of the hair follicle has been reported as a putative source of hair follicle stem cells (HFSC) for many years; however, few studies have documented the properties of bulge derived cells in vitro until now. This study was conducted to isolate and culture bulge cells from rat hair follicles and to determine the morphological and biological features of the cultured cells. Materials and Methods: The bulge region of the rat whisker was isolated and cultured in Dulbecco's modified eagle medium: nutrient mixture F-12 (DMEM/F12) supplemented with epidermal growth factor (EGF), cholera toxin. Dissociated bulge stem cells were differentiated on coated substrates together with NT-3. The morphological and biological features of cultured bulge cells were observed by light microscopy and immunocytochemistry methods. Results: Our results showed that newly proliferated cells could be observed on the 4th day after explantation. The expression of a neural progenitor marker, nestin, was seen before differentiation of the bulge cells. The differentiated cells expressed βIII-Tubulin and RIP, which are the markers of neural and glial lineages. Conclusion: The results indicated that the bulge cells cultured from the rat hair follicle had the characteristics of stem cells and could differentiate into neural and glial lineages. [ABSTRACT FROM AUTHOR]

Objective: Bone marrow and umbilical cord stromal cells are multipotential stem cells that have the ability to produce growth factors that play an important role in survival and generation of axons. The goal of this study was to evaluate the effects of the two different mesenchymal stem cells on peripheral nerve regeneration. Materials and Methods: In this experimental study, a 10 mm segment of the left sciatic nerve of male Wistar rats (250-300 g) was removed with a silicone tube interposed into this nerve gap. Bone marrow stromal cells (BMSCs) and human umbilical cord stromal cells (HUCSCs) were respectively obtained from rat and human. The cells were separately cultured and transplanted into the nerve gap. The sciatic nerve regeneration was evaluated by immunohistochemistry, and light and electron microscopy. Moreover, histomorphology of the gastrocnemius muscle was observed. Results: The nerve regeneration in the BMSCs and HUCSCs groups that had received the stem cells was significantly more favorable than the control group. In addition, the BMSCs group was significantly more favorable than the HUCSCs group (P<0.05). Conclusion: The results of this study suggest that both homograft BMSCs and heterograft HUCSCs may have the potential to regenerate peripheral nerve injury and transplantation of BMSCs may be more effective than HUCSCs in rat. [ABSTRACT FROM AUTHOR]

Objective(s): The effect of maternal voluntary exercise on hippocampal BDNF level in rat offspring was studied. In addition, the possible role of hippocampal BDNF receptors in maternal exercise induced enhancement of learning in the rat pups was investigated., Materials and Methods: Pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. Each of the exercising pregnant rats was given access to a cage that was equipped with a running wheel until the end of their pregnancy. On post natal day (PND) 36, two groups consisted of 7 male rat pups in each group from sedentary or exercised mothers were sacrificed and the hippocampus was dissected for BDNF proteins level determination. Also, bilateral injection of K252a to the hippocampus was used to block the hippocampal BDNF action on PND59 in the rat pups., Results: Voluntary exercise during pregnancy significantly increased the level of BDNF protein in the hippocampus of the rat pups on PND36 compared to the control group (P=0.048). Inhibiting BDNF action abolished the exercise-induced improvement of learning acquisition in offspring in training trials (P=0.0001). No difference was observed in the platform location latency and the time spent in the target in the probe test between two groups. Conclusion : This study demonstrates that voluntary exercise during pregnancy via a TrkB-mediated mechanism enhances the spatial learning acquisition, however, not the retention of memory in the rat pups.