Abstract. Currently, culture and growth keratinocytes are important stages in achieving a reliable and reproducible skin tissue. In the present study, two different methods, enzymatic and explant methods, for keratinocytes isolation from human foreskin were compared. Foreskins were cut into 2-3 mm pieces and placed in trypsin at 4˚C overnight for separation of the epidermis from the dermis. Subsequently, these samples were divided into two groups: i) Keratinocytes separated from the epidermis by trypsin and ii) by the explant method. These keratinocytes were divided into two groups: i) With no feeder layer and ii) onto a type I collagen scaffold. The cells were evaluated using immunocytochemistry and 4',6-diamidine-2'-phenylindole dihydrochloride (DAPI) staining. In the enzymatic treatment, after 7-10 days no attached cells were found in the cell culture dishes. In the explant method, keratinocytes were separated after ~24 h, attached rapidly and formed big colonies into a collagen scaffold. In the absence of a feeder layer, small colonies were developed with rapid loss of proliferation within 2-3 days. Keratinocytes showed positive immunoreactivity for the pan-cytokeratin marker and keratinocytes' nuclei were clearly observed. This method could be applied and developed as a component of skin substitutes to treat burns and wounds and also in laboratory testing. IntroductionThe skin is the largest organ in the body that is divided into two anatomically distinct regions, the dermis and epidermis. The normal structure and function of this organ is dependent on the intact epidermis anchored to its vascular, elastic dermis (1,2). Fibroblasts are the most prevalent cell types in the dermis, which produce different growth factors that induce proliferation of keratinocytes in vivo and in vitro (3). The principal cell type of the epidermis is the keratinocyte (1,4), which is a small epithelial cell, located at the top of the epidermal basal membrane and characterized by a low division rate (5,6).Thus far, various enzymatic methods for dermal-epidermal separation have been applied (6-8). For instance, trypsin separates suprabasal hemidesmosomes that causes the basal layer cells to attach to the dermal layer (6). Thermolysin is another enzyme that selectively separates desmosomes (5,9) and is able to separate the epidermis at the basal membrane zone level (5,10).Although the dissociation method of keratinocytes in primary culture is well-established, attempts to acquire purified adult stem-cell like⁄progenitor keratinocytes from whole human skin are still ongoing. In particular, different techniques are currently being applied to achieve high purity or homogeneous primary cultures enriched in keratinocyte progenitor⁄precursor cells. These include filtration, density gradient centrifugation and fluorescence-activated cell sorting using cell surface antibodies, as well as differential adhesion to enrich the cells that rapidly attach to particular substrates (11).A previous study showed that when keratinocytes/precursor cells...

Our results suggest that LC could protect SH-SY5Y cells from caffeine-induced injury through the inhibition of oxidative damage, mitochondria dysfunction and inhibition of cell apoptosis. Our results indicate that LC therapy may be a valuable approach for the suppression of oxidative stress-related apoptosis in various neural diseases.

Metformin is currently the first drug of choice for treatment of type II diabetes. The primary function of metformin is to decrease hepatic glucose production mainly by inhibiting gluconeogenesis. The aim of the present study was to investigate the effects of glucose alone (control groups) and glucose and metformin (treatment groups) on pancreatic islets functions. Pancreatic islets were isolated by collagenase digestion and incubated for 24 or 48 h in RPMI-1640 containing 5 mmol/l glucose (control groups 1 and 2, respectively) or 24 h with 25 mmol/l glucose (control group 3) and 15 µmol/l metformin (treatment groups 1, 2 and 3, corresponding to the control groups, respectively). Subsequently, the rate of insulin output from islets, pancreatic and duodenal homeobox 1 () and insulin genes expression and islet viability were assayed. The rate of insulin secretion in a 5 mmol/l glucose concentration in the 48 h treatment group increased significantly compared with that of the 24 h treatment group (P<0.05). An increase of the glucose concentration (25 mmol/l) caused insulin secretion to increase compared with that of 5 mmol/l glucose. gene expression in treatment group 2 significantly decreased compared with the control group 2 (P<0.05). The the gene expression in treatment group 2 decreased compared with that of the treatment group 1. The expression of the insulin gene in treatment group 1 increased compared with control group 1, and in treatment group 2, there was a 2-fold increase in insulin gene expression compared with control group 2. The insulin gene expression in treatment group 2 increased compared with treatment group 1. The percentage of islet cell viability was increased in treatment group 3 by ~40% compared with the islet cells of treatment groups 1 and 2 (P<0/05). These data indicate that glucose and metformin have direct effects on β-cell function.

The service quality in sports organisations has become one of the important aspects which can affect the success of these organisations. On the other hand, the costumers’ intention to purchase the services of fitness centres has also attracted the attention of many researchers. This study aims to determine the effect of peripheral service quality on the purchase intention of fitness centre customers through the mediating role of the organisational brand. The sample consisted of a total of 386 users of fitness centres in Tehran. An online questionnaire was used for data collection which involved 44 items from five separate scales. Smart PLS-SEM software was used for confirmatory factor analysis and to test a structural equation model. The findings provide an insight into the importance of peripheral service quality in the creation and development of brand personality, brand trust and brand equity. Further, with regard to intention to repurchase, the results show that the variables of brand personality, brand trust and brand equity have a subsequent direct effect. This study provides an important advance in the academic literature related to the significance of service quality (especially peripheral services) in the fitness industry, and the results facilitate a better understanding of the consumer’s intention to purchase.