Neuroprotective effect of magnesium sulfate and dexamethasone on intrauterine ischemia in the fetal rat brain: ultrastructural evaluation.

AIM: The aim of this study was to investigate the neuroprotective effect of magnesium sulfate and dexamethasone on oxidative damage in intrauterine ischemia. MATERIAL AND METHODS: In this study, 19-day pregnant rats were divided into five groups. Fetal brain ischemia was achieved in the ischemia/ reperfusion (I/R) group by bilaterally closing the utero-ovarian artery with aneurysm clips for 30 min and subsequently removing the aneurysm clips for 60 min for reperfusion. Mg (600 mg/kg) and dexamethasone (0.25 mg/kg) were administered 20 min before the I/R insult. The lipid peroxidation in the brain tissue was determined by the concentration of thiobarbituric acid reactive substances (TBARS). The mitochondrial score was calculated after an evaluation with electron microscopy. RESULTS: Both the electron microscope and TBARS data showed a significant difference between the control and I/R groups. The Mg and dexamethasone treatment groups exhibited significantly lower TBARS values compared to the IR group. Similarly, the mitochondrial scores in the Mg and dexamethasone treatment groups were significantly lower than those in the I/R group. CONCLUSION: Result showed that magnesium sulfate and dexamethasone prevent lipid peroxidation and reduce mitochondrial injury thus suggests neuroprotective effects in fetal rat brain in intrauterine ischemia-reperfusion (I/R) injury.

Analysis of human mesenchymal stem cells on a cross-linked collagen-based surgical implant material.

Biomimetic scaffolds, delivered to the patient with or without cell loading, can offer improved treatments for a range of damaged or diseased tissues. In this work we evaluated the capacity of a cross-linked collagen-based implant material (Permacol™) to support the survival and growth of multipotent stromal cells or mesenchymal stem cells (MSCs) for potential applications in soft-tissue reconstruction and compared it to uncross-linked collagen. We showed, using confocal imaging, histology, quantitative analysis of seeding efficiencies by the MTT assay and Live/Dead analysis, that Permacol™ supported the adherence, growth and survival of MSCs preserving a healthy cell phenotype. MSCs infiltrated both matrices, although migration rates were significantly higher on uncross-linked matrices for some donors. Our work demonstrates that Permacol™ could maintain human MSCs in long-term culture supporting its use as a cell-seeded biomaterial for durable and strong repair in tissue reconstruction.

Neuroprotective effects of propofol, thiopental, etomidate, and midazolam in fetal rat brain in ischemia-reperfusion model.

PURPOSE: The aim of this study was to investigate the neuroprotective effects of propofol, thiopental, etomidate, and midazolam as anesthetic drugs in fetal rat brain in the ischemia-reperfusion (IR) model. METHODS: Pregnant rats of day 19 were randomly allocated into eight groups. Fetal brain ischemia was induced by clamping the utero-ovarian artery bilaterally for 30 min and reperfusion was achieved by removing the clamps for 60 min. In the control group, fetal rat brains were obtained immediately after laparotomy. In the sham group, fetal rat brains were obtained 90 min after laparotomy. In the IR group, IR procedure was performed. No treatment was given in the IR group. One milliliter intralipid solution, 40 mg/kg propofol, 3 mg/kg thiopental, 0.1 mg/kg etomidate, and 3 mg/kg midazolam was administered intraperitoneally in the vehicle group, propofol group, thiopental group, etomidate group, and midazolam group, respectively, 20 min before IR procedure. At the end of the reperfusion period, the whole brains of the fetal rats were removed for evaluation of thiobarbituric acid reactive substances and for examination by electron microscopy. RESULTS: According to lipid peroxidation data, all the anesthetic drugs provide neuroprotection; however, ultrastructural findings and mitochondrial scoring confirms that only propofol and midazolam provides a strong neuroprotective effect. CONCLUSIONS: Propofol and midazolam may be used to protect fetal brain in case of acute fetal distress and hypoxic injury as a first choice anesthetic drug in cesarean delivery.

Magnesium sulfate protects fetal skin from intrauterine ischemia reperfusion injury.

Intrauterine ischemia-reperfusion (I/R) injury in fetus occurs with multifactorial pathogenesis and results with multiorgan injury including skin. Magnesium has widespread use in obstetric practice. Inn addition to magnesium's tocolytic and neuroprotective properties, it also has free radical reducing effects. The aim of the present study was to demonstrate whether magnesium sulfate could have protective effect on fetal rat skin in intrauterine ischemia-reperfusion (I/R) injury. Fetal skin ischemia was induced by clamping the utero-ovarian arteries bilaterally for 30 min, and reperfusion was achieved by removing the clamps for 60 min in 19-day pregnant rats. Magnesium Sulfate (MgSO(4)) was given to pregnant rats 20 min before I/R injury at the dose of 600 mg/kg in magnesium treatment group. No ischemia reperfusion was applied to control and sham-operated groups. Lipid peroxidation from the skin tissues was determined as thiobarbituric acid reactive substances (TBARS). Myeloperoxidase (MPO) activity was determined for neutrophil activation. The results showed that the levels of TBARS and MPO increased significantly in the fetal rat skin after I/R injury compared to control group. Levels of TBARS and MPO were significantly lower than those of I/R group in Magnesium-treated group. In conclusion, intrauterine ischemia-reperfusion may produce considerable fetal skin injury. Increased TBARS and MPO activity can be inhibited by magnesium treatment. This suggests that magnesium treatment may have protective effect on fetal rat skin in intrauterine I/R injury.

Generating 3D tissue constructs with mesenchymal stem cells and a cancellous bone graft for orthopaedic applications.

Bone matrix (BM) is an acellular crosslinked porcine-derived cancellous bone graft, and therefore may provide advantages over other synthetic and naturally derived materials for use in orthopaedic surgery. Here, we analysed the potential of BM to support the growth and differentiation of primary human multipotent stromal cells/mesenchymal stem cells (MSCs) in order to predict in vivo bone regeneration events. Imaging with laser scanning confocal microscopy and scanning electron microscopy showed that 1 day after static seeding, a dense population of viable MSCs could be achieved on scaffolds suggesting they could be used for in vivo delivery of cells to the implant site. Long-term growth analysis by confocal imaging and histology demonstrated that BM was permissive to the growth and the 3D population of primary MSCs and an enhanced green fluorescent protein expressing osteosarcoma cell line, eGFP.MG63s, over several days in culture. Measurement of alkaline phosphatase (ALP) activities and mRNA expression levels of osteogenic markers (Runx-2, ALP, collagen type I, osteonectin, osteocalcin and osteopontin) indicated that BM supported osteogenesis of MSCs when supplemented with osteogenic stimulants. Upregulation of some of these osteogenic markers on BM, but not on tissue culture plastic, under non-osteogenic conditions suggested that BM also had osteoinductive capacities.