background: niche cells, regulating spermatogonial stem cells (sscs) fate are believed to have a reciprocal communication with sscs. the present study was conducted to evaluate the effect of ssc elimination on the gene expression of glial cell line-derived neurotrophic factor (gdnf), fibroblast growth factor 2 (fgf2) and kit ligand (kitlg), which are the main growth factors regulating sscs deve...

introduction: to evaluate the camp -mediated ibmx (3-isobutyle -1-methyl xanthin) and db-camp (dibutyryl camp) effects on differentiation of human embryonic stem cells (hescs) into nerve cells were the objectives of this study. methods: we have used royan h1 hesc- derived embryoid bodies with four treatment groups: six days treatment with ibmx (5×10 -4m) and db-camp (10 -9m) (referred to as cam...

background: the aim of this study was to investigate the percentage of the stem cells population in human endometrial tissue sections and cultured cells at fourth passage. methods: human endometrial specimens were divided into two parts, one part for morphological studies and the other part for in vitro culture. full thickness of human normal endometrial sections and cultured endometrial cells ...

background homocysteine is a sulfur-containing amino acid which formed (mainly in the liver) during the metabolism of methionine. prior studies indicated the important role of hyperhomocysteinemia in pathogenesis and progression of alcoholic liver disease, liver steatosis and cirrhosis. one of the most important mechanisms by which homocysteine promote the development of hepatic injury is oxida...

objectives : stem cell (sc) therapy is a promising technique for tissue regeneration. this study aimed to compare the viability and proliferation ability of periodontal ligament stem cells (pdlscs) isolated from the periodontium of healthy and periodontitis-affected teeth to obtain an autologous, easily accessible source of scs for tissue regeneration in periodontitis patients. materials and me...

naturally the brain is ineffective in regenerating functional tissue after disease or injury, so to overcome these defects innovative curative strategies such as stem cell transplantation and tissue engineering have to be considered. researchers investigate the use of strategies to attain better functional repair results. one of the important challenges of effective transplantation is the deliv...

dendritic cells (dcs) are a heterogeneous family of professional apcs involved in priming adaptive immune responses. donor dcs (direct pathway of allorecognition) and recipient dcs presenting processed donor major histocompatibility complex (mhc) as peptides (indirect pathway of allorecognition) participate actively in graft rejection by stimulating recipient t cell responses following organ tr...

objective: helicobacter pylori has a well-established role in the development of gastric cancer. in vitro studies reveal increased proliferation of the gastric mucosa in the presence of h. pylori infection. it has been also shown that production of some cytokines, such as interleukin-1 beta (il-1b) is increased in h. pylori infection. in addition, il-1b increases proliferation of gastric epithe...

tuberculosis is an important opportunistic disease among hiv- infected persons worldwide; from march 1999 to feburery 2001 we had seventeen patients with hiv-infection and tuberculosis. here we are presenting the clinical manifestations, diagnosis, treatment and outcome of them. all of them were male, 11 patients had pulmonary and 5 patients had extrapulmonary (pleural effusion 1, hepatic granu...

introduction: cytokines are a large group of proteins play a key role in inflammation. down-regulation of pro-inflammatory cytokines has beneficial effect on heart function. propranolol, as a non selective beta-adrenergic blocker, has been extensively used for treatment of many cardiovascular problems such as arrhythmias and heart malfunction. in addition anti-inflammatory effects of propranolo...