Fatih Özkan

Antioxidant Effects of Propofol on Tourniquet-Induced Ischemia-Reperfusion Injury: An Experimental Study

PURPOSE This experimental study aimed to investigate the antioxidant effects of propofol anesthesia at induction doses in a rat skeletal muscle ischemia/reperfusion injury model. METHODS Twenty-six rats were randomly divided into three groups to receive one of the following interventions: sham operation (n = 6), ischemia/reperfusion (I/R) injury (n = 10), or propofol administration in addition to I/R injury (n = 10). I/R injury was attained by 2-h clamping of femoral artery followed by 3-h perfusion. Then blood and tissue samples were collected for biochemical analysis and histopathologic examination. Glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) enzyme activities and nitric oxide (NO) and malondialdehyde (MDA) levels were measured in both plasma and muscle tissue. In addition, catalase (CAT) activity and protein carbonyl (PC) content were measured in muscle tissue. RESULTS I/R group had significantly higher SOD activity (9.05 versus 5.63 and 6.18 U/mL, P < 0.05) and NO level (46.77 versus 30.62 and 33.90 μmol/L, P < 0.05) compared with sham-operated group and I/R plus propofol group. In addition, GSH-Px activity of the I/R group was significantly higher than sham-operated group (1.26 versus 1.05 U/mL, P < 0.05). I/R group had significantly higher tissue activities of CAT (0.11 versus 0.06 and 0.04 k/g protein, P < 0.05) and SOD (0.12 versus 0.08 and 0.07 U/mg protein, P < 0.05) compared with the sham and I/R plus propofol group. Histopathologic examination showed that I/R plus propofol group had significantly lower degeneration (P = 0.021) and inflammation (P = 0.028) scores compared with I/R group. CONCLUSION Propofol anesthesia seems to enhance the antioxidant capacity against tourniquet induced ischemia-reperfusion injury.

Comparison of Three Different Analgesic Protocols During Shockwave Lithotripsy

BACKGROUND AND PURPOSE Shockwave lithotripsy (SWL) is one of the most important treatment modalities for urinary stone disease. The procedure may cause pain, and patient relaxation and cooperation are crucial in maintaining stone localization for optimal fragmentation and patient comfort during the procedure. As yet, there is not a standard analgesic protocol for patients undergoing SWL. We aimed to use three different analgesic agents and compare their efficacy during SWL in this study. PATIENTS AND METHODS Written informed consents were obtained from 95 patients with kidney stones, and they were randomized to receive lornoxicam (group L, n=32 patients), paracetamol (group P, n=31 patients), and tramadol with a patient-controlled analgesia device (group T, n=32 patients). All groups received patient-controlled analgesia with tramadol during the SWL procedure. The intensity of pain was evaluated with a visual analog scale (VAS). RESULTS The mean age of the patients was 41.87 ± 16.53 years, 44.07 ± 11.48 years, and 41.24 ± 14.82 years in group L, group P, and group T, respectively. No significant differences were found between the three groups concerning patient age, stone location, or session duration (P>0.05). The mean VAS scores and analgesic consumption were lower in group L compared with other groups (P<0.05). CONCLUSION The results of this study showed that additional administration of analgesics was decreased with intravenous lornoxicam in comparison with paracetamol and only tramadol.

Immunohistochemical Analysis of Reconstructed Sheep Mandibles: Transport Distraction Osteogenesis Versus Autogenous Bone Grafting

PURPOSE Although many studies have been conducted that related to growth factor expression in mandibular distraction osteogenesis, to our knowledge, no study comparing the immunohistochemical outcomes of autologous bone grafting (ABG) and transport distraction osteogenesis has been conducted up to now. The aim of this study was to histologically and immunohistochemically analyze newly formed bone in the resected mandible reconstructed by transport distraction osteogenesis and iliac crest bone grafting in a sheep model. MATERIALS AND METHODS Mandibular discontinuity defects created in the jaws of sheep were reconstructed by distraction osteogenesis (n = 7) and bone grafting (n = 7) and allowed to heal for 3 mos. The animals were then sacrificed and their jaws resected and prepared for decalcification. Histological and immunohistochemical examinations of transforming growth factor-beta 1 (TGF-β1) and bone morphogenetic protein (BMP) -2, -4 were performed in the newly formed bone in the defect area. RESULTS Positive staining for BMP-2, -4, and TGF-β was observed in the cells and matrix components. BMP is present in both processes, but the expression of BMP-2, -4, and TGF-β in the distraction regenerate is stronger when compared with bone graft healing. CONCLUSIONS The only limitation of the present study was that it evaluated the role of BMP-2, -4, and TGF-β expressions in bone repair process at 3 mo postoperatively. Determination of growth factor expression at more than 1 time point would be ideal in elucidating the role of these factors during bone healing.

Stereologic analysis of bone produced by distraction osteogenesis or autogenous bone grafting in mandible.

To our knowledge, in the literature, any other investigation that numerically compared osteoblasts retrieved from transport distraction osteogenesis and bone grafting procedures using stereological methods is not reported. The purpose of this study was to compare the total number of osteoblast cells at 3 months in bone produced by distraction osteogenesis and that in autogenous bone graft. A total of 19 growing sheep (male aged 7 or 8 mo; weighing between 21 and 28 kg) were used in this study. Mandibular discontinuity defects created in mandibles of sheep were reconstructed by transport distraction osteogenesis and iliac crest bone graft and allowed to heal for 3 months. The animals were then killed, and the jaws were resected and prepared to be decalcified. Stereological and histologic examinations were performed. Intramembranous ossification and osteoid and trabecular formations were observed in both groups. In the distraction group, the mean ± standard deviation (SD) numerical density of the osteoblasts was found to be higher (0.0004866 ± [0.000044])when compared with those of both the graft (0.0003458 ± [0.000030]) and control groups (0.0002714 ± [0.000022]). Statistically significant differences were found among the groups (P < 0.05). Stereologic evaluation of bone in the sheep model demonstrated significantly greater osteoblast density in bone formed through transport distraction osteogenesis when compared with bone grafting and the control. Therefore, further studies should be conducted to evaluate the differences in both osteoblastic and osteoclastic cellular activities at different time points in distraction osteogenesis and autogenous bone grafting to assess the healing process of bone for clinical applications.