Study of carbon nanotubes effects on the chondrogenesis of human adipose derived stem cells in alginate scaffold

Background: Osteoarthritis is one of the most common diseases in middle-aged populations in the World and could become the fourth principal cause of disability by the year 2020. One of the critical properties for cartilage tissue engineering [TE] is the ability of scaffolds to closely mimic the extracellular matrix and bond to the host tissue. Therefore, TE has been presented as a technique to introduce the best combination of cells and biomaterial scaffold and to stimulate growth factors to produce a cartilage tissue resembling natural articular cartilage. The aim of study is to improve differentiation of adipose derived stem cells [ADSCs] into chondrocytes in order to provide a safe and modern treatment for patients suffering from cartilage damages

Methods: After functionalization, dispersions and sterilizing carbon nano-tubes [CNTs], a new type of nanocomposite gel was prepared from water-soluble CNTs and alginate. ADSCs seeded in 1.5% alginate scaffold and cultured in chondrogenic media with and without transforming growth factor-beta1 [TGF-beta1] for 7 and 14 days. The genes expression of sex determining region Y-box 9 [SOX9], types II and X collagens was assessed by real-time polymerase chain reaction and the amount of aggrecan [AGC] and type I collagen was measured by ELISA

Results: Our findings showed that the expression of essential cartilage markers, SOX9, type II collagen and AGC, in differentiated ADSCs at the concentration of 1 microg/ml CNTs in the presence of TGF-beta1 were significantly increased in comparison with the control group [P < 0.001]. Meanwhile, type X collagen expression and also type I collagen production were significantly decreased [P < 0.001]

Conclusions: The results showed that utilized three-dimensional scaffold had a brilliant effect in promoting gene expression of chondrogenesis

evaluation of perioperative safety of local anesthesia with lidocaine containing epinephrine in patients with ischemic heart disease

The use of local anesthesia with lidocaine containing epinephrine in patients with cardiac disease is controversial in the literature. The aim of our study was determining the safety of use the local anesthesia contain epinephrine in patients with ischemic heart disease that undergoing reconstructive surgery. Thirty two patients that had known ischemic heart disease and candidate to undergo reconstructive surgery for skin tumor enrolled in this study. All patients continued their medication for cardiac disease till morning of the operation. 10 ml lidocaine 2% containing 1:100,000 epinephrine was injected in patients for local anesthesia. The hemodynamic changes and electrocardiographic variables before injection were compared with them after injection, during surgery and till 6 hours postoperation period. A 12 lead electrocardiogram was recorded in all our cases for detection of myocardial ischemic changes. The mean age, weight and height were 58.2 +/- 10.4, 74.8 +/- 14.4 kg and 164.5 +/- 8 cm respectively. Twelve patients [37.5%] were diagnosed with systemic hypertension and 10 patients with diabetes [31.2%]. The comparison of change of systolic, diastolic and mean blood pressure between baseline, during procedure and after operation defined that our subjects did not have any significant disturbance in blood pressure in perioperative period. The comparison of baseline heart rate with heart rate after injection, during procedure and in postoperation period indicated a significant changes in this variable [P=0.044]. The heart rhythm during the perioperative period also failed to exhibit alterations. The ischemic change was not recorded in our patients before injection compared to after injection. None of our patients have any early complications because of infiltration of local anesthetic containing epinephrine in our patients. The use of 10 ml 2% lidocaine with epinephrine 1:100,000 in patients with cardiac disease represent a safe anesthetic procedure. These patients experienced a more profound anesthesia with hemodynamic stability and without myocardial ischemic changes.

hemodynamic effects of spinal block with low dose of bupivacaine and sufentanil in patients with low myocardial ejection fraction

The aim of this study was to assess the effect of spinal block with low dose of bupivacaine and sufentanil on patients with low cardiac output who underwent lower limb surgery. Fifteen patients who had ejection fraction less than 40% [group 1] were compared with 65 cases with ejection fraction more than 40% [group 2] in our study. Our subjects underwent spinal block with 7.5 mg hyperbaric bupivacaine 0.5% and 5 micro g sufentanil. We recorded early events such as hypotension, bradycardia, vasopressor need and ST segment change in our cases. The average mean arterial pressure decreased 13% [110 mmHg to 95.7 mmHg] in group 1 and 20% [160 mmHg to 128 mmHg] in group 2 [P<0.001]. Hypotension due to spinal anesthesia was observed in none of our subjects in both groups and none of our cases need to vasopressor support. All patients remained alert, and no ST segment changes were observed in two groups. In our study none of subjects complained of pain intraoperatively. The subjects were without complaints during the spinal anesthetic in both groups. Spinal block with low dose local anesthetic and sufentanil was a safe and effective method for lower limb surgery in patients with low ejection fraction