Sahar Omar | Ain Shams University (original) (raw)

Papers by Sahar Omar

Journal of Stem Cell Research & Therapeutics

Background & objectives: One of the major challenges facing the surgeons is replacing a full-thic... more Background & objectives: One of the major challenges facing the surgeons is replacing a full-thickness skin loss successfully. This study aimed at testing the efficacy of decellularized dermal matrix seeded with bone marrow-mesenchymal stem cells (BM-MSCs) as a scaffold for the repair of skin defects in rats comparison to using acellular dermal matrix (ADM) alone. Methods: A 2×2 cm2 size full thickness skin defect was created on the dorsum of thirty male Wister rats (200- 250g) under xylazine (5 mg/kg) and ketamine (50 mg/kg) anesthesia. The animals were then randomly divided into three equal groups: group I; The defect was left for spontaneous recovery, group II; The defect was repaired with ADM alone, and group III;Tthe defect was repaired with ADM seeded with labeled BM-MSCs. The healing rate of the defect in all groups was assessed by measuring wound area and healing percentage twice weekly. The specimens from the wound site were obtained from all groups on day 14 and day 28 pos...

Introduction: With the onset of menopause, reduced estrogen levels and decreased physical activit... more Introduction: With the onset of menopause, reduced estrogen levels and decreased physical activity created serious problems with resultant osteoporosis and fractures. Recent moves away from hormone replacement therapy suggested exercise, as the simplest and cheapest strategy to treat and prevent osteoporosis. Aim of the Work: The present study aimed to focus (from the histological point of view )on the efficacy of exercise in the amelioration of osteoporotic bone loss in ovariectomized rats with special reference to bone mineral density and bone histomorphometry. Materials and Methods: Forty adult female albino rats were used and divided into four groups. Group I (control group) which were further subdivided into 2 equal subgroups, Ia: received no intervention. Subgroup Ib included nonovariectomized rats experiencing daily exercise training program. Group II (overiectomized rats) which were further subdivided into 2 equal subgroups. Subgroup IIa: were ovariectomized on day 1 of the ...

This is an open-access article distributed under the terms of the Creative

Background & objectives: Despite surgical advances, recovery of peripheral nerve injuries has oft... more Background & objectives: Despite surgical advances, recovery of peripheral nerve injuries has often been poor, leading to irreversible impairment. This study aimed to differentiate adipose-derived stem cells (ASCs) into Schwann-like cells (SCs) in vitro and assess their role versus the undifferentiated ASCs in the regeneration of crushed sciatic nerves in adult male albino rats. Materials & Methods: We performed a simple and less costly method to differentiate ASCs into SCs. Forty rats, weighing 200-250 g, were randomly divided to 4 equal groups. Group I (control) subjected to sham operation. Group II subjected to crush injury of the sciatic nerve. Group III subjected to crush injury with local transplantation of ASCs. Group IV subjected to crush injury with local transplantation of differentiated Schwannlike cells. The rats were sacrificed 4 weeks later. We studied the nerves using H&E and Masson’s Trichrome stain. Immuno-histochemical studies using S-100 and neurofilament-H (NF-H)...

Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential... more Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential use in tissue engineering applications. Bone marrow (BM) had been extensively investigated as a source of adult stem cells. Adipose tissue (AT) is emerging as a source of stem cells that can be obtained by a less invasive method. Aim of the work The aim of the present study was to compare the MSCs derived from BM and AT in terms of their characterization, osteogenic differentiation, and proliferative capacity. Materials and methods In this study, 20 young albino rats were used. Their limb bones (femora and tibiae) and AT (from the inguinal groove) were extracted. MSCs were isolated from BM and AT, then cultured and subcultured to third passage. Characterization and osteogenic potentiality were determined for the cultured cells from both sources. Moreover, population doubling time was calculated, and then statistically compared to assess their proliferative potential. Results MSCs derive...

Background Today, about half of the world's population, even at a very young age, owns microw... more Background Today, about half of the world's population, even at a very young age, owns microwave-producing mobile phones. As mobile phones are held in close proximity to the head, the microwaves emitted may exert many effects on the brain. Aim of the study This study aimed to evaluate the effects of long-term exposure to mobile phone emissions on the thalamic neurons and the integrity of its blood barrier. This study also aimed to investigate whether ascorbic acid could ameliorate microwave-induced thalamic changes. Materials and methods Forty adult male albino rats were used; they were divided into four equal groups. Group I served as a control group. In group II, rats were exposed to 0.043–0.135 W/kg for 42 days (4 h/day in the light). The microwave radiation was produced by a mobile test phone (model NOKIA 3110). Rats of group III were subjected to mobile waves as in group II and they concomitantly received oral ascorbic acid at a dose of 250 mg/kg/day. Group IV received asco...

QJM: An International Journal of Medicine

Background Repairing urinary bladder (UB) defect by enterocystoplasty remains the gold standard s... more Background Repairing urinary bladder (UB) defect by enterocystoplasty remains the gold standard surgical bladder reconstruction procedure to increase the capacity and compliance of dysfunctional bladders. However, many complications were recorded. Aim of the work This work aimed to compare the consequences of reconstruction of urinary bladder defect using untreated small intestinal submucosal (SIS) matrix versus seeded and unseeded decellularized SIS matrix. Material and Methods Fifty female albino rats were used in this study. The animals were divided into three groups: Group I (Control) included ten adult rats from which ileal tissue was obtained. Group II included ten adult rats in which their UB defect was repaired by untreated cellular SIS. Group III included twenty adult rats that were subdivided into two subgroups, 10 rats each; Subgroup IIIA where rats had their UB defect repaired by acellular SIS and subgroup IIIb where rats had their UB defect repaired by acellular SIS see...

BioMed Research International

Objectives. Assessing the therapeutic efficacy of superparamagnetic iron oxide nanoparticles (SPI... more Objectives. Assessing the therapeutic efficacy of superparamagnetic iron oxide nanoparticles (SPIO) labeled bone marrow-derived mesenchymal stem cells (BM-MSCs) on experimental liver fibrosis and associated dysplasia. Materials and Methods. MSCs were obtained from 10 male Sprague-Dawley rats while 50 female rats were divided into control (CG), liver fibrosis (CCL4, intraperitoneal injection of CCl4 for 8 weeks), and CCL4 rats treated with SPIO-labeled MSCs (MSCs/CCl4) with and without continuing CCL4 injection for another 8 weeks. Assessment included liver histopathology, liver function tests, transmission electron microscopic tracing for homing of SPIO-MSCs, immunofluorescence histochemistry for fibrosis and dysplasia markers (transforming growth factor-beta (TGF-β1), proliferation nuclear antigen (PCNA), glypican 3)), and quantitative gene expression analysis for matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Results. SPIO-labeled MSCs wer...

The Egyptian Journal of Histology, 2015

The Egyptian Journal of Histology, 2015

Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential... more Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential use in tissue engineering applications. Bone marrow (BM) had been extensively investigated as a source of adult stem cells. Adipose tissue (AT) is emerging as a source of stem cells that can be obtained by a less invasive method. Aim of the work The aim of the present study was to compare the MSCs derived from BM and AT in terms of their characterization, osteogenic differentiation, and proliferative capacity. Materials and methods In this study, 20 young albino rats were used. Their limb bones (femora and tibiae) and AT (from the inguinal groove) were extracted. MSCs were isolated from BM and AT, then cultured and subcultured to third passage. Characterization and osteogenic potentiality were determined for the cultured cells from both sources. Moreover, population doubling time was calculated, and then statistically compared to assess their proliferative potential. Results MSCs derived from the AT possess higher proliferation potential than MSCs derived from BM. Even though, both cells have the same marker expression and osteogenic potentiality. Conclusion and recommendation AT can be an attractive alternative to BM as a source for isolating MSCs.

The Egyptian Journal of Histology, 2010

Introduction: Chromium was believed to be an essential trace element in human nutrition. Evidence... more Introduction: Chromium was believed to be an essential trace element in human nutrition. Evidence suggested that it played an important role in carbohydrate metabolism, mainly co‐acting with insulin, improving glucose tolerance. It was also hypothesized that it could lower the risk of diabetic micro vascular complications. Aim of the Work: Was to evaluate the efficacy of chromium picolinate in ameliorating diabetes‐induced histological skin alterations. Materials and Methods: Twenty five adult male albino rats were used in the current study. The rats were divided into two main groups, the control group (10 rats) and the diabetic group (15 rats). The control group was divided in 2 equal subgroups. Group II in which diabetes was induced using streptozotocin (STZ) and was divided into 3 subgroups, 5 rats each. Subgroup IIa formed of diabetic rats. Subgroup IIb formed of diabetic rats that received insulin. Subgroup IIc formed of diabetic rats that received insulin and chromium. The duration of experiment was 8 weeks. At the end of the experiment, an area from dorsal thin skin was dissected out and prepared for H&E stain, electron microscopic study and immunohistochemistry for CD34 of vascular endothelial cells. Results: Thin skin of subgroup IIa showed significant reduction in the mean thickness of nucleated epidermal keratinocytes as compared to control. Most of epidermal cells appeared with deeply‐ stained shrunken nuclei and vacuolated cytoplasm. Immunohistochemical analysis revealed significant reduction in CD34 area % of papillary and reticular vascular network. Ultra‐thin sections revealed focal absence of hemidesmosomes. Disruption of desmosomes and widening in intercellular spaces were frequently detected. Treatment with chromium showed signs of improvement manifested by significant increase in thickness of nucleated keratinocytes and CD34 area % compared to subgroup IIa & IIb. Most of keratinocytes preserved their LM & EM characteristic appearance. Conclusion: Chromium picolinate could play an important role in the long term protection of skin affection that might result from diabetes mellitus.

BMC Ophthalmology, 2015

Mesenchymal stem cells (MSC) have become a promising tool for cell therapy in regenerative medici... more Mesenchymal stem cells (MSC) have become a promising tool for cell therapy in regenerative medicine. They are readily available, demonstrate powerful differentiation capabilities and present immunosuppressive properties that aid them in surviving from host immune rejection for its great potential use in allograft. Currently clinical trials are underway using MSC, both culture-expanded allogeneic and autologous, for the treatment of a range of diseases not treatable by conventional therapies. A vast array of studies has dedicated towards the use of MSC for treating corneal diseases with very promising outcomes. MSC have successfully differentiated into keratocytes both in vitro and in vivo, and corneal epithelial cells in vitro, but it is uncertain if MSC can assume corneal epithelial cells in vivo. However, to date few studies have unequivocally established the efficacy of MSC for treating corneal endothelial defects. Currently, the diversity in protocols of the isolation and expansion of MSC are hindering to the assessment of cell treatment ability and the further development of treatment regimens. Therefore, future studies should develop international standards for MSC isolation and characterization. In this review, we discuss recent advances in MSC for treating ocular surface diseases.

The Egyptian Journal of Histology, 2015

The Egyptian Journal of Histology, 2014

The Egyptian Journal of Histology, 2011

Background Today, about half of the world's population, even at a very young age, owns microw... more Background Today, about half of the world's population, even at a very young age, owns microwave-producing mobile phones. As mobile phones are held in close proximity to the head, the microwaves emitted may exert many effects on the brain. Aim of the study This study aimed to evaluate the effects of long-term exposure to mobile phone emissions on the thalamic neurons and the integrity of its blood barrier. This study also aimed to investigate whether ascorbic acid could ameliorate microwave-induced thalamic changes. Materials and methods Forty adult male albino rats were used; they were divided into four equal groups. Group I served as a control group. In group II, rats were exposed to 0.043–0.135 W/kg for 42 days (4 h/day in the light). The microwave radiation was produced by a mobile test phone (model NOKIA 3110). Rats of group III were subjected to mobile waves as in group II and they concomitantly received oral ascorbic acid at a dose of 250 mg/kg/day. Group IV received ascorbic acid only. Results The thalamic neurons of wave-exposed animals showed significant morphological necrotic changes. Some appeared markedly vacuolated; others were irregular in shape, with densely stained nuclei. Ultrastructurally, the cytoplasm of some neurons showed prominent cytoplasmic vacuolization. A significant decrease in the mean area percentage of tight junction protein occludin expression in thalamic microvessels was also detected. In contrast, sections obtained from rats of group III showed a significant improvement of the microwave-produced changes but never reverted to the same state as the controls. Conclusion Chronic microwave exposure could have a marked effect on the thalamic neurons and its blood barrier. Administration of ascorbic acid resulted in a significant improvement, but it was not sufficient to gain a normal histological appearance.

The Egyptian Journal of Histology, 2012

The Egyptian Journal of Histology, 2014

Background Vascular endothelial growth factor (VEGF) plays an important role in bone angiogenesis... more Background Vascular endothelial growth factor (VEGF) plays an important role in bone angiogenesis, whereas transforming growth factor-&bgr;1 (TGF-&bgr;1) modulates bone differentiation, matrix formation, and cytokine expression. Aim of the work The aim of the study was to assess the immune expression of VEGF and TGF-&bgr;1 in cells lining the bone trabeculae among postmenopausal wom&egr;&ngr; in relation to bone histomorphometry and their association with osteoporosis. Patients and methods A total of 30 postmenopausal women were recruited for the study. Bone mineral density was measured using DEXA. On the basis of the results of the DEXA scan, they were divided as follows: group I comprised 14 (46.7%) women with normal bone mineral density; group II comprised five (16.7%) women with osteopenia; and group III comprised 11 (36.7%) women with osteoporosis. Iliac crest bone biopsy was taken from each of them. Histomorphometrical study was carried out using H&E stain to evaluate the trabecular microarchitecture in addition to immunohistochemistry for both VEGF and TGF-&bgr;1. Results Histomorphometric analysis was statistically and significantly different among the three groups. The area percentage of both TGF-&bgr;1 protein and VEGF expression in cells lining the bone trabeculae was statistically and significantly lower in the osteoporotic group compared with the other two groups. A statistically significant negative correlation was found between age and menopause duration and TGF-&bgr;1 only. A significant positive correlation was found between trabecular bone thickness and both VEGF (r=0.762, P=0.000) and TGF-&bgr;1 (r=0.785, P=0.000). Regression analysis showed only VEGF (t=2.537, P=0.018), and not TGF-&bgr;1 (t=0.326, P=0.747), to have independent association with trabecular bone thickness. Conclusion The results of the current study support that VEGF and TGF-&bgr;1 may contribute to the pathogenesis of postmenopausal osteoporosis. Further studies on the role of both TGF-&bgr;1 and VEGF in postmenopausal osteoporotic patients will be helpful to clarify the etiopathogenesis and treatment of postmenopausal osteoporosis.

Background: Many investigations have reported that mesenchymal stem cell (MSC) transplantation ca... more Background: Many investigations have reported that mesenchymal stem cell (MSC) transplantation can ameliorate the structure and function of injured tissues. The purpose of this study was to explore the therapeutic potency of MSC transplantation for chemotherapy-induced ovarian damage. Methods: MSC were isolated and cultured in vitro. The cytokines, including vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1), were detected in the MSC cultures using enzyme-linked immunosorbent assay (ELISA). Phosphoramide mustard (PM) was added to the media of granulosa cells (GC) cultured alone or co-cultured with MSC. GC apoptosis was assayed by Annexin-V and DNA fragmentation analysis. Chemotherapy-induced ovarian damage was induced in rats by intraperitoneal injection of cyclophosphamide (CTX). After the injection, MSC labeled with green fluorescent protein (GFP) were transplanted directly into bilateral ovaries. The rats were killed at 2, 4, 6 and 8 weeks after transplantation. Ovarian function was evaluated by estrous cycle changes and sexual hormone levels. The follicle number was counted, and GC apoptosis was analyzed by TUNEL. The expressions of Bcl-2 and Bax proteins were detected by Western blotting. Results: MSC released VEGF, HGF and IGF-1 in vitro. The GC apoptosis was diminished by co-culture with MSC, which also resulted in increased Bcl-2 expression. The ovarian function of the rats exposed to CTX injection was improved after MSC transplantation. MSC reduced apoptosis of GC and induced up-regulation of Bcl-2 in vivo. Discussion: MSC transplantation can improve ovarian function and structure damaged by chemotherapy. The paracrine mediators secreted by MSC might be involved in the repair of damaged ovaries.

The Egyptian Journal of Histology, 2014

Journal of Stem Cell Research & Therapeutics

Background & objectives: One of the major challenges facing the surgeons is replacing a full-thic... more Background & objectives: One of the major challenges facing the surgeons is replacing a full-thickness skin loss successfully. This study aimed at testing the efficacy of decellularized dermal matrix seeded with bone marrow-mesenchymal stem cells (BM-MSCs) as a scaffold for the repair of skin defects in rats comparison to using acellular dermal matrix (ADM) alone. Methods: A 2×2 cm2 size full thickness skin defect was created on the dorsum of thirty male Wister rats (200- 250g) under xylazine (5 mg/kg) and ketamine (50 mg/kg) anesthesia. The animals were then randomly divided into three equal groups: group I; The defect was left for spontaneous recovery, group II; The defect was repaired with ADM alone, and group III;Tthe defect was repaired with ADM seeded with labeled BM-MSCs. The healing rate of the defect in all groups was assessed by measuring wound area and healing percentage twice weekly. The specimens from the wound site were obtained from all groups on day 14 and day 28 pos...

Introduction: With the onset of menopause, reduced estrogen levels and decreased physical activit... more Introduction: With the onset of menopause, reduced estrogen levels and decreased physical activity created serious problems with resultant osteoporosis and fractures. Recent moves away from hormone replacement therapy suggested exercise, as the simplest and cheapest strategy to treat and prevent osteoporosis. Aim of the Work: The present study aimed to focus (from the histological point of view )on the efficacy of exercise in the amelioration of osteoporotic bone loss in ovariectomized rats with special reference to bone mineral density and bone histomorphometry. Materials and Methods: Forty adult female albino rats were used and divided into four groups. Group I (control group) which were further subdivided into 2 equal subgroups, Ia: received no intervention. Subgroup Ib included nonovariectomized rats experiencing daily exercise training program. Group II (overiectomized rats) which were further subdivided into 2 equal subgroups. Subgroup IIa: were ovariectomized on day 1 of the ...

This is an open-access article distributed under the terms of the Creative

Background & objectives: Despite surgical advances, recovery of peripheral nerve injuries has oft... more Background & objectives: Despite surgical advances, recovery of peripheral nerve injuries has often been poor, leading to irreversible impairment. This study aimed to differentiate adipose-derived stem cells (ASCs) into Schwann-like cells (SCs) in vitro and assess their role versus the undifferentiated ASCs in the regeneration of crushed sciatic nerves in adult male albino rats. Materials & Methods: We performed a simple and less costly method to differentiate ASCs into SCs. Forty rats, weighing 200-250 g, were randomly divided to 4 equal groups. Group I (control) subjected to sham operation. Group II subjected to crush injury of the sciatic nerve. Group III subjected to crush injury with local transplantation of ASCs. Group IV subjected to crush injury with local transplantation of differentiated Schwannlike cells. The rats were sacrificed 4 weeks later. We studied the nerves using H&E and Masson’s Trichrome stain. Immuno-histochemical studies using S-100 and neurofilament-H (NF-H)...

Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential... more Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential use in tissue engineering applications. Bone marrow (BM) had been extensively investigated as a source of adult stem cells. Adipose tissue (AT) is emerging as a source of stem cells that can be obtained by a less invasive method. Aim of the work The aim of the present study was to compare the MSCs derived from BM and AT in terms of their characterization, osteogenic differentiation, and proliferative capacity. Materials and methods In this study, 20 young albino rats were used. Their limb bones (femora and tibiae) and AT (from the inguinal groove) were extracted. MSCs were isolated from BM and AT, then cultured and subcultured to third passage. Characterization and osteogenic potentiality were determined for the cultured cells from both sources. Moreover, population doubling time was calculated, and then statistically compared to assess their proliferative potential. Results MSCs derive...

Background Today, about half of the world's population, even at a very young age, owns microw... more Background Today, about half of the world's population, even at a very young age, owns microwave-producing mobile phones. As mobile phones are held in close proximity to the head, the microwaves emitted may exert many effects on the brain. Aim of the study This study aimed to evaluate the effects of long-term exposure to mobile phone emissions on the thalamic neurons and the integrity of its blood barrier. This study also aimed to investigate whether ascorbic acid could ameliorate microwave-induced thalamic changes. Materials and methods Forty adult male albino rats were used; they were divided into four equal groups. Group I served as a control group. In group II, rats were exposed to 0.043–0.135 W/kg for 42 days (4 h/day in the light). The microwave radiation was produced by a mobile test phone (model NOKIA 3110). Rats of group III were subjected to mobile waves as in group II and they concomitantly received oral ascorbic acid at a dose of 250 mg/kg/day. Group IV received asco...

QJM: An International Journal of Medicine

Background Repairing urinary bladder (UB) defect by enterocystoplasty remains the gold standard s... more Background Repairing urinary bladder (UB) defect by enterocystoplasty remains the gold standard surgical bladder reconstruction procedure to increase the capacity and compliance of dysfunctional bladders. However, many complications were recorded. Aim of the work This work aimed to compare the consequences of reconstruction of urinary bladder defect using untreated small intestinal submucosal (SIS) matrix versus seeded and unseeded decellularized SIS matrix. Material and Methods Fifty female albino rats were used in this study. The animals were divided into three groups: Group I (Control) included ten adult rats from which ileal tissue was obtained. Group II included ten adult rats in which their UB defect was repaired by untreated cellular SIS. Group III included twenty adult rats that were subdivided into two subgroups, 10 rats each; Subgroup IIIA where rats had their UB defect repaired by acellular SIS and subgroup IIIb where rats had their UB defect repaired by acellular SIS see...

BioMed Research International

Objectives. Assessing the therapeutic efficacy of superparamagnetic iron oxide nanoparticles (SPI... more Objectives. Assessing the therapeutic efficacy of superparamagnetic iron oxide nanoparticles (SPIO) labeled bone marrow-derived mesenchymal stem cells (BM-MSCs) on experimental liver fibrosis and associated dysplasia. Materials and Methods. MSCs were obtained from 10 male Sprague-Dawley rats while 50 female rats were divided into control (CG), liver fibrosis (CCL4, intraperitoneal injection of CCl4 for 8 weeks), and CCL4 rats treated with SPIO-labeled MSCs (MSCs/CCl4) with and without continuing CCL4 injection for another 8 weeks. Assessment included liver histopathology, liver function tests, transmission electron microscopic tracing for homing of SPIO-MSCs, immunofluorescence histochemistry for fibrosis and dysplasia markers (transforming growth factor-beta (TGF-β1), proliferation nuclear antigen (PCNA), glypican 3)), and quantitative gene expression analysis for matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1). Results. SPIO-labeled MSCs wer...

The Egyptian Journal of Histology, 2015

The Egyptian Journal of Histology, 2015

Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential... more Background Mesenchymal stem cells (MSCs) received widespread attention because of their potential use in tissue engineering applications. Bone marrow (BM) had been extensively investigated as a source of adult stem cells. Adipose tissue (AT) is emerging as a source of stem cells that can be obtained by a less invasive method. Aim of the work The aim of the present study was to compare the MSCs derived from BM and AT in terms of their characterization, osteogenic differentiation, and proliferative capacity. Materials and methods In this study, 20 young albino rats were used. Their limb bones (femora and tibiae) and AT (from the inguinal groove) were extracted. MSCs were isolated from BM and AT, then cultured and subcultured to third passage. Characterization and osteogenic potentiality were determined for the cultured cells from both sources. Moreover, population doubling time was calculated, and then statistically compared to assess their proliferative potential. Results MSCs derived from the AT possess higher proliferation potential than MSCs derived from BM. Even though, both cells have the same marker expression and osteogenic potentiality. Conclusion and recommendation AT can be an attractive alternative to BM as a source for isolating MSCs.

The Egyptian Journal of Histology, 2010

Introduction: Chromium was believed to be an essential trace element in human nutrition. Evidence... more Introduction: Chromium was believed to be an essential trace element in human nutrition. Evidence suggested that it played an important role in carbohydrate metabolism, mainly co‐acting with insulin, improving glucose tolerance. It was also hypothesized that it could lower the risk of diabetic micro vascular complications. Aim of the Work: Was to evaluate the efficacy of chromium picolinate in ameliorating diabetes‐induced histological skin alterations. Materials and Methods: Twenty five adult male albino rats were used in the current study. The rats were divided into two main groups, the control group (10 rats) and the diabetic group (15 rats). The control group was divided in 2 equal subgroups. Group II in which diabetes was induced using streptozotocin (STZ) and was divided into 3 subgroups, 5 rats each. Subgroup IIa formed of diabetic rats. Subgroup IIb formed of diabetic rats that received insulin. Subgroup IIc formed of diabetic rats that received insulin and chromium. The duration of experiment was 8 weeks. At the end of the experiment, an area from dorsal thin skin was dissected out and prepared for H&E stain, electron microscopic study and immunohistochemistry for CD34 of vascular endothelial cells. Results: Thin skin of subgroup IIa showed significant reduction in the mean thickness of nucleated epidermal keratinocytes as compared to control. Most of epidermal cells appeared with deeply‐ stained shrunken nuclei and vacuolated cytoplasm. Immunohistochemical analysis revealed significant reduction in CD34 area % of papillary and reticular vascular network. Ultra‐thin sections revealed focal absence of hemidesmosomes. Disruption of desmosomes and widening in intercellular spaces were frequently detected. Treatment with chromium showed signs of improvement manifested by significant increase in thickness of nucleated keratinocytes and CD34 area % compared to subgroup IIa & IIb. Most of keratinocytes preserved their LM & EM characteristic appearance. Conclusion: Chromium picolinate could play an important role in the long term protection of skin affection that might result from diabetes mellitus.

BMC Ophthalmology, 2015

Mesenchymal stem cells (MSC) have become a promising tool for cell therapy in regenerative medici... more Mesenchymal stem cells (MSC) have become a promising tool for cell therapy in regenerative medicine. They are readily available, demonstrate powerful differentiation capabilities and present immunosuppressive properties that aid them in surviving from host immune rejection for its great potential use in allograft. Currently clinical trials are underway using MSC, both culture-expanded allogeneic and autologous, for the treatment of a range of diseases not treatable by conventional therapies. A vast array of studies has dedicated towards the use of MSC for treating corneal diseases with very promising outcomes. MSC have successfully differentiated into keratocytes both in vitro and in vivo, and corneal epithelial cells in vitro, but it is uncertain if MSC can assume corneal epithelial cells in vivo. However, to date few studies have unequivocally established the efficacy of MSC for treating corneal endothelial defects. Currently, the diversity in protocols of the isolation and expansion of MSC are hindering to the assessment of cell treatment ability and the further development of treatment regimens. Therefore, future studies should develop international standards for MSC isolation and characterization. In this review, we discuss recent advances in MSC for treating ocular surface diseases.

The Egyptian Journal of Histology, 2015

The Egyptian Journal of Histology, 2014

The Egyptian Journal of Histology, 2011

Background Today, about half of the world's population, even at a very young age, owns microw... more Background Today, about half of the world's population, even at a very young age, owns microwave-producing mobile phones. As mobile phones are held in close proximity to the head, the microwaves emitted may exert many effects on the brain. Aim of the study This study aimed to evaluate the effects of long-term exposure to mobile phone emissions on the thalamic neurons and the integrity of its blood barrier. This study also aimed to investigate whether ascorbic acid could ameliorate microwave-induced thalamic changes. Materials and methods Forty adult male albino rats were used; they were divided into four equal groups. Group I served as a control group. In group II, rats were exposed to 0.043–0.135 W/kg for 42 days (4 h/day in the light). The microwave radiation was produced by a mobile test phone (model NOKIA 3110). Rats of group III were subjected to mobile waves as in group II and they concomitantly received oral ascorbic acid at a dose of 250 mg/kg/day. Group IV received ascorbic acid only. Results The thalamic neurons of wave-exposed animals showed significant morphological necrotic changes. Some appeared markedly vacuolated; others were irregular in shape, with densely stained nuclei. Ultrastructurally, the cytoplasm of some neurons showed prominent cytoplasmic vacuolization. A significant decrease in the mean area percentage of tight junction protein occludin expression in thalamic microvessels was also detected. In contrast, sections obtained from rats of group III showed a significant improvement of the microwave-produced changes but never reverted to the same state as the controls. Conclusion Chronic microwave exposure could have a marked effect on the thalamic neurons and its blood barrier. Administration of ascorbic acid resulted in a significant improvement, but it was not sufficient to gain a normal histological appearance.

The Egyptian Journal of Histology, 2012

The Egyptian Journal of Histology, 2014

Background Vascular endothelial growth factor (VEGF) plays an important role in bone angiogenesis... more Background Vascular endothelial growth factor (VEGF) plays an important role in bone angiogenesis, whereas transforming growth factor-&bgr;1 (TGF-&bgr;1) modulates bone differentiation, matrix formation, and cytokine expression. Aim of the work The aim of the study was to assess the immune expression of VEGF and TGF-&bgr;1 in cells lining the bone trabeculae among postmenopausal wom&egr;&ngr; in relation to bone histomorphometry and their association with osteoporosis. Patients and methods A total of 30 postmenopausal women were recruited for the study. Bone mineral density was measured using DEXA. On the basis of the results of the DEXA scan, they were divided as follows: group I comprised 14 (46.7%) women with normal bone mineral density; group II comprised five (16.7%) women with osteopenia; and group III comprised 11 (36.7%) women with osteoporosis. Iliac crest bone biopsy was taken from each of them. Histomorphometrical study was carried out using H&E stain to evaluate the trabecular microarchitecture in addition to immunohistochemistry for both VEGF and TGF-&bgr;1. Results Histomorphometric analysis was statistically and significantly different among the three groups. The area percentage of both TGF-&bgr;1 protein and VEGF expression in cells lining the bone trabeculae was statistically and significantly lower in the osteoporotic group compared with the other two groups. A statistically significant negative correlation was found between age and menopause duration and TGF-&bgr;1 only. A significant positive correlation was found between trabecular bone thickness and both VEGF (r=0.762, P=0.000) and TGF-&bgr;1 (r=0.785, P=0.000). Regression analysis showed only VEGF (t=2.537, P=0.018), and not TGF-&bgr;1 (t=0.326, P=0.747), to have independent association with trabecular bone thickness. Conclusion The results of the current study support that VEGF and TGF-&bgr;1 may contribute to the pathogenesis of postmenopausal osteoporosis. Further studies on the role of both TGF-&bgr;1 and VEGF in postmenopausal osteoporotic patients will be helpful to clarify the etiopathogenesis and treatment of postmenopausal osteoporosis.

Background: Many investigations have reported that mesenchymal stem cell (MSC) transplantation ca... more Background: Many investigations have reported that mesenchymal stem cell (MSC) transplantation can ameliorate the structure and function of injured tissues. The purpose of this study was to explore the therapeutic potency of MSC transplantation for chemotherapy-induced ovarian damage. Methods: MSC were isolated and cultured in vitro. The cytokines, including vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1), were detected in the MSC cultures using enzyme-linked immunosorbent assay (ELISA). Phosphoramide mustard (PM) was added to the media of granulosa cells (GC) cultured alone or co-cultured with MSC. GC apoptosis was assayed by Annexin-V and DNA fragmentation analysis. Chemotherapy-induced ovarian damage was induced in rats by intraperitoneal injection of cyclophosphamide (CTX). After the injection, MSC labeled with green fluorescent protein (GFP) were transplanted directly into bilateral ovaries. The rats were killed at 2, 4, 6 and 8 weeks after transplantation. Ovarian function was evaluated by estrous cycle changes and sexual hormone levels. The follicle number was counted, and GC apoptosis was analyzed by TUNEL. The expressions of Bcl-2 and Bax proteins were detected by Western blotting. Results: MSC released VEGF, HGF and IGF-1 in vitro. The GC apoptosis was diminished by co-culture with MSC, which also resulted in increased Bcl-2 expression. The ovarian function of the rats exposed to CTX injection was improved after MSC transplantation. MSC reduced apoptosis of GC and induced up-regulation of Bcl-2 in vivo. Discussion: MSC transplantation can improve ovarian function and structure damaged by chemotherapy. The paracrine mediators secreted by MSC might be involved in the repair of damaged ovaries.

The Egyptian Journal of Histology, 2014