جستجوی مقالات مرتبط با کلیدواژه « laminin » در نشریات گروه « زیست شناسی »

In this study، we have used immunohistochemical studies to examine the effects of maternal hypothyroidism on the expression of laminin in the lung alveoli newborn Wistar rats examined. in this study we have used female virgin rat، wistar strain. Rats were divided in two experimental groups (hypothyroid and hyperthyroid treated with thyroxin) and one control group (n=12). 14 days before mating in the experimental groups، the rats respectively were exposed to Propylthiouracil (50 mg/L) as well as thyroxin (1 mg/L) and Propylthiouracil (50 mg/L) simultaneously. After 14 days، blood test was taken from mothers and in case of desired changes in hormone levels، rats were allowed to mate. After delivery، the lung of the 10 days old newborns were used for immunohistochemical studies. There was a significant reduction in laminin expression in hypothyroid group (p= 0. 001) where as no significant difference was observed in hypothyroid group treated with thyroxin compared to control group. Thyroid hormones have important role on laminin expression and development of lung، since maternal hypothyroidism causes large reduction in alveiolar laminin expression. Therefore changes in maternal thyroid hormone can cause large changes in alveolar development in newborns.

Aim and Tissue engineering is a promising area in biomedical engineering to repair or replace the function of defective or damaged tissues or organs. Recently, tissue engineering has provided a new medical therapy as an alternative to conventional transplantation methods by using polymeric biomaterials with living cells. The scaffold provides the microenvironment (synthetic temporary extracellular matrix) for regenerative cells, supporting cell attachment, proliferation, differentiation, and neo tissue genesis due to their suitable chemical, physical and biological. In this research, chitosan/laminin nanocomposite was exploited as scaffold for suitable cell proliferation. Freeze-drying technique was used to fabricate chitosan/laminin-nanocomposites for L929 fibroblast cellsseeding, proliferation and attachment. The physico-chemical properties of the scaffold were fully characterized by using scanning electron microscopy (SEM). Consequently, the biocompatibility of scaffold was evaluated by biocompatibility test. The microstructure observation with SEM suggests the formation of cylinder-shaped porous structure and interconnected porosity. Our results demonstrated that the nano-sized chitosan/laminin scaffolds are nontoxic and biocompatible which can promote proliferation and attachment of L929 fibroblast cells. And their appropriate adhesion to nanocomposite for improved tissue engineering applications.

Previous studies have shown that thyroid hormones are necessary for normal development of many tissues in the human body. So In this investigation, the effect of maternal hypothyroidism on neonatal skin development was studied using immunohistochemistry technique. Rats were divided in 4 groups hypothyroid, hyperthyroid, hypothyroid treated with thyroxin and control, each group containing 10 rats. 14 days before mating, hypothyroid, hyperthyroid and hypothyroid treated with thyroxin groups, were respectively exposed to Propylthiouracil (PTU) (50 mg/lit), levothyroxin 1 mg/lit and both PTU (50 mg/lit) and levothyroxin (1 mg/lit) simultaneously. After 14 days, blood test was taken from mothers and in the case of desired changes in hormone levels, rats were allowed to mate. After pregnancy and delivery, the dorsal skins of the 10 days old newborns were used for immunohistochemical studies. in this study, in most area of skin, significant increase of laminin expression in hypothyroid groups (p=0.002) and significant decrease of laminin expression in hyperthyroid groups (p=0.007) were observed. Also in treated hypothyroid with thyroxin rather than control group no significant difference was observed. Maternal hypothyroidism causes considerable changes in the expression of laminin in different areas of skin. While maternal hyperthyroidism causes opposite results in laminin expression. In fact, thyroid hormone causes negative regulation of laminin expression. There fore, rising of thyroid hormone levels leads to a decrease in laminin expression and overhand. So,changes in thyroid hormones level can cause various changes in different areas of newborns skin.