[Effect of mechanical stimulation on differentiation of human mesenchymal stem cells to different cell lines: a systematic review]

Stem cells due to their great potential can help in establishing tissue engineering as a new treatment modality. Numerous studies have evaluated the effect of various chemical and mechanical stimuli on these cells. In this respect, the role of mechanical loads is undeniable. This systematic review evaluated studies on the effects of mechanical loads on differentiation of mesenchymal stem cells to different cell lineages published in the past 12 years In this systematic review, PUBMED database was used to search key words namely "human mesenchymal stem cell", "strain,", "mechanical loading," and "differentiation", in the literature published from 2000 to July 2012. The inclusion criteria were the publication year, language of articles, type of cells and study objectives In total, 46 articles were evaluated qualitatively. In most studies, applied mechanical loads led to the anticipated differentiation. Studies showed that the combination of two forces increased differentiation. The amount of applied strain also influenced the type of differentiation. This review indicated that advances made on the effects of mechanical loads on stem cells can be used for improving tissue engineering treatments

[Photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution by UV irradiation in the presence of titanium dioxide nanoparticles]

Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromium and divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO[2] process in a batch system. At first, reactor was designed. Then, optimumdosage of TiO[2] was obtained equal to 1 g/L, with variation TiO[2] dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO[2] [1gr/L]. The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO[2] dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively. The results showed that UV/TiO[2] was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions

[ effect of high dose vitamin d3 on the level of serum alkaline phosphatase, calcium, phosphor and vitamin d3 in children older than 3 years old who were receiving phenobarbital]

Background and Objective: chronic use of antiepileptic drugs may influence the bones and their mineral metabolism due to deficiency of vitamin D3. In this study we investigated the effect of high dose vitamin D3 on bones and their mineral metabolism

Materials and Methods: fifty six children older than 3 years old who were affected by epilepsy and had taken the antiepileptic drugs at least for 6 months were included in the study. Levels of alkaline phosphatase [ALP], calcium, phosphorus and vitamin D3 were measured. The patients were divided into three groups; one group was provided with 1peril of 50000 units of vitamin D and the other two groups took 2 and 3 perils of vitamin D. Two months after prescription, serum level of the above parameters were measured and compared with the results before vitamin D prescription

Results: after prescription of vitamin D3, decrease of ALP [p<0/001], increase of calcium [p=0/01] and increase level of vitamin D3 in serum [p<0/001] was observed. The highest increase in the serum level of vitamin D3 was observed in the group which had received 3 perils of vitamin D [p<0/0001]

Conclusion: decrease in the serum level of vitamin D3 following long term use of antiepileptic drugs and its increase as a result of vitamin D supplementation suggests that this method of therapy can prevent the skeletal abnormalities due to side effects of these drugs