Cengiz Çetin

Protective effect of Fucoidin (a neutrophil rolling inhibitor) on ischemia reperfusion injury: Experimental study in rat epigastric island flaps

The objective of this study was to examine whether a decrease in neutrophil-mediated tissue injury using Fucoidin, a nontoxic neutrophil rolling inhibitor, would improve flap survival in an island flap model after ischemia–reperfusion. Myeloperoxidase activity (an indirect index of tissue neutrophil count) and malondialdehyde (an indicator of lipid peroxidation), the degree of neutrophil infiltration by direct counting, and macroscopic flap survival were assessed in the flap after arterial ischemia–reperfusion. Epigastric island skin flaps were elevated in 56 rats. The first group of 21 rats was subjected to 6 hours of arterial ischemia. The second group of 21 rats was subjected to 10 hours of arterial ischemia, and the rest of the rats were used as nonischemic controls (sham flaps). For inhibiting neutrophil rolling, a nontoxic polysaccharide agent—Fucoidin—was used. Each ischemic group was divided further into three subgroups: Subgroup I (control rats) received saline, subgroup II received 10 mg per kilogram Fucoidin, and subgroup III received 25 mg per kilogram Fucoidin before reperfusion. The results were evaluated as tissue neutrophil counts, tissue malondialdehyde content, tissue myeloperoxidase activity, and flap survival. Neutrophil counts and tissue myeloperoxidase activity were decreased significantly (p <0.001) in subgroup III, but lipid peroxidation by means of tissue malondialdehyde content was not affected by Fucoidin administration. The authors conclude that administration of Fucoidin before reperfusion can limit tissue injury apparently by inhibiting neutrophil rolling in a dose-dependent manner.

Effects of rolling inhibition on smoke inhalation injury

Inhalation of chemical and particulate products of smoke is one of the principal determinant of mortality following burn injury. Inflammatory responses have been implicated in the pathogenesis of lung injury after smoke inhalation. In the current study, we tested the inhibitory effect of Fucoidin on the neutrophil rolling stage of inflammatory response and determined the degree of pulmonary injury. Fifteen rats were divided into three groups: sham group (N: 5) of rats inhaled room air; control group (N: 5) inhaled smoke, and experimental group inhaled smoke and received Fucoidin. All the rats were sacrificed 24h after smoke inhalation. The trachea and lungs were removed totally; samples for histopathological and biochemical (myeloperoxidase (MPO)) analysis were taken from each lung and trachea. Morphologic studies using light and electron microscopes showed a decrease in lung parenchymal and tracheoepithelial injury in the experiment group of rats. Also, biochemical analysis of tissue MPO was significantly lower in test group than in control group. These results suggest that the inhibition of neutrophil rolling leads to a reduction of neutrophil invasion to pulmonary parenchyma and trachea, which may be beneficial for attenuating neutrophil mediated inhalation injury.

Effects of ischemic preconditioning protocols on skeletal muscle ischemia-reperfusion injury.

BACKGROUND Ischemic preconditioning (IPC) is described as brief ischemia-reperfusion (I/R) cycles to induce tolerance to subsequent in response to longer I/R insults. Various IPC protocols can be performed in four combinations as follows: at early or late phases and on local or distant organs. Although many experimental studies have been performed on IPC, no consensus has been established on which IPC protocol is most effective. The aims of the present study were as follows: (1) to compare the variables of preconditioning in different combinations (in early versus late phases; local versus remote organ implementations) and (2) to determine the most therapeutic IPC protocol(s). MATERIALS AND METHODS A subtotal hind limb amputation model with clamping an intact femoral pedicle was used for I/R injury. IPC was induced using hind limb tourniquet with 3 × 10 min I/R cycles before longer I/R insult. Forty-nine rats were divided into seven groups (n = 7), sham, IsO (ischemia only), I/R, early ischemic preconditioning (e-IPC), late ischemic preconditioning (l-IPC), early remote ischemic preconditioning (e-RIPC), and l-RIPC (late-remote) groups, respectively. In the sham group, pedicle occlusion was not performed. Six hours ischemia was challenged in the IsO group. Three hours ischemia followed by 3 h reperfusion was performed in the I/R group. The e-IPC group was immediately preconditioned, whereas the l-IPC group was preconditioned 24 h before I/R injury on the same hind limb. In the e-RIPC and l-RIPC groups, the same protocols were performed on the contralateral hind limb. At the end of the experiments, skeletal muscle tissue samples were obtained for biochemical analysis (Malondialdehyde [MDA], catalase, myeloperoxidase [MPO], and nitric oxide end products [NOx]), light microscopy, and caspase-3 immunohistochemistry for determination of apoptosis. RESULTS Tissue biochemical markers were improved in nearly all the IPC groups compared with IsO and I/R groups (P < 0.05). Similarly, the histologic damage scores were decreased in all the IPC groups (P < 0.05). The lowest damage score was in the e-RIPC group followed by the l-RIPC, e-IPC, and l-IPC groups, respectively. The apoptosis scores were significantly high in the I/R group compared with the e-RIPC and l-RIPC groups (P < 0.05). Although apoptosis scores of the e-IPC and l-IPC groups were lower than the I/R group, this finding was not statistically significant (P > 0.05). CONCLUSIONS All IPC protocols were effective in reducing I/R injury. Among these protocols, e-RIPC achieved most protection.

Do local anesthetics have antibacterial effect on Staphylococcus aureus under in vivo conditions? An experimental study.

OBJECTIVE The antimicrobial properties against Staphylococcus aureus of some common local anesthetic preparations such as prilocaine, bupivacaine, articaine, and combinations were evaluated in a live rat surgical wound model. METHODS This study was conducted at the animal research laboratory of Eskisehir Osmangazi University in 2003. Clean surgical wounds were created after local anesthetic application and inoculated with S. aureus (102 colony forming units/mL). Four days later, tissue cultures were harvested from control animals and animals given local anesthetic to determine the quantity of bacteria. RESULTS The tissue cultures demonstrated that none of the local anesthetics used in the study showed any inhibitory or bactericidal activity on S. aureus. There was no statistical difference in bacterial count between the local anesthetic–treated and control group wounds. CONCLUSION The results of the present study did not show any antimicrobial activity of above‐mentioned local anesthetics in surgically created wounds of rats. The authors have indicated no significant interest with commercial supporters.

LYOPHILISED POLYURETHANE MEMBRANE DRESSING FOR SURGICALLY-SEPARATED PSEUDOSYNDACTYLY IN EPIDERMOLYSIS BULLOSA

The results of paraffin gauze dressing and lyophilised polyurethane membrane dressing were studied in a patient with surgically-separated pseudosyndactyly of dystrophic epidermolysis bullosa. Polyurethane membrane dressing decreased the time to epithelialisation and the need for anaesthesia.

A new apparatus for standardization of experimental burn models

BACKGROUND Burns have severe economic burden for families and countries therefore its treatment modalities have utmost importance. Several study both experimental or clinic has been reported accordingly. Although contact burns were frequently used models, most of them were manually designed. The elapsed time was recorded only. However, the real time contact surface temperature (T) and weight force (WF) were fundamental characteristics of a burn model. The aim of this study is to create a standard burn model with recording real time variables on behalf of custom designed apparatus. METHODS A custom designed apparatus was manufactured in which the variables of real time T, WF and elapsed time could be set and record. A vertical angle was provided to ensure the applied WF. And hence, Sprague-Dawley rats were randomly divided into four groups: (1) Burned at 60±1°C with low WF(G60WFL), (2) Burned at 60±1°C with high WF(G60WFH), (3) Burned at 80±1°C with low WF(G80WFL), (4) Burned at 80±1°C with high WF(G80WFH). The healthy skin thickness and burn depth were measured. The percentage of burn depth to healthy skin was used for statistical analysis. RESULTS Constant variables T and WF were achieved. The pressure applied on skin was not significant between low [G60WFL vs G80WFL, (p=0.1704)] and high [G60WFH vs G80WFH (p=0.2369)] WF groups. However the percentage of burn depth was increasing owing to applied WF in 60°C group [G60WFL vs G60WFH, (p=0.0125)] and in 80°C group [G80WFL vs G80WFH (p<0.0001)]. And also the percentage was significantly increasing owing to set T, in low WF group [G60WFL vs G80WFL (p<0.0001)] and high WF group [G60WFH vs G80WFH (p<0.0001)]. Besides neither T nor WF has priority. CONCLUSION Without recording the real time T and WF, it is infeasible to achieve a standard burn model. For a standard depth of burn, variables should be under control, as if our custom designed apparatus.

Freestyle Perforator-Based Fasciocutaneous Flap Reconstruction in Nicolau Syndrome-Related Tissue Necrosis.

The actual pathology of the Nicolau syndrome (NS) is still unknown. It is thought to involve direct vascular damage and vasospasm. Many NS cases were reported in the literature but a treatment protocol is still not established. However, after demarcation of the necrotic tissue, surgical intervention is mandatory. Five NS cases with extensive tissue necrosis on the upper lateral gluteal region were analyzed retrospectively. Operative technique was described in details for freestyle perforator-based fasciocutaneous flaps from the gluteal region to reconstruct defects of NS-related tissue necrosis. Freestyle perforator-based fasciocutaneous flaps were used for defect closure in all patients. All flaps survived totally. No complications occurred during the follow-up period. Although rare, NS is a serious complication of inadvertent intramuscular injections. Prevention is the best treatment. However, in case of large-tissue necrosis, freestyle perforator-based fasciocutaneous flaps harvested from the gluteal region is a satisfactory option for reconstruction.

Imaging findings of an extradigital fibro-osseous pseudotumor.

Fibro-osseous pseudotumor (FOPT) is a rare and benign ossifying lesion. Described as the superficial variant of myositis ossificans (MO), this rare entity mostly occurs in the subcutaneous tissues of the digits. The FOPT clinicopathological features may mimic a variety of benign and malignant soft tissue lesions, and the diagnosis can be difficult when it arises in an unusual anatomic location. In this report we describe the clinical and radiological features of a case of an FOPT that involved the hypothenar region of the hand.

Can a Small Intestine Segment Be an Alternative Biological Conduit for Peripheral Nerve Regeneration

Background: Autologous nerve grafts are used to bridge peripheral nerve defects. Limited sources and donor site morbidity are the major problems with peripheral nerve grafts. Although various types of autologous grafts such as arteries, veins and muscles have been recommended, an ideal conduit has not yet been described. Aims: To investigate the effectiveness of a small intestinal conduit for peripheral nerve defects. Study Design: Animal experimentation. Methods: Twenty-one rats were divided into three groups (n=7). Following anaesthesia, sciatic nerve exploration was performed in the Sham group. The 10 mm nerve gap was bridged with a 15 mm ileal segment in the small intestinal conduit group and the defect was replaced with orthotopic nerve in autologous nerve graft group. The functional recovery was tested monthly by walking-track analysis and the sciatic functional index. Histological evaluation was performed on the 12th week. Results: Sciatic functional index tests are better in autologous nerve graft group (-55.09±6.35); however, during follow-up, progress in sciatic functional index was demonstrated, along with axonal regeneration and innervation of target muscles in the small intestinal conduit group (-76.36±12.08) (p<0.05). In histologic sections, distinctive sciatic nerve regeneration was examined in the small intestinal conduit group. The expression of S-100 and neurofilament was observed in small intestinal conduit group but was less organised than in the autologous nerve graft group. Although the counted number (7459.79±1833.50 vs. 4226.51±1063.06 mm2), measured diameter [2.19 (2.15-2.88) vs. 1.74 (1.50-2.09) µm] and myelin sheath thickness [1.18 (1.09-1.44) vs. 0.66 (0.40-1.07) µm] of axons is significantly high in the middle sections of autologous nerve graft compared to the small intestinal conduit group, respectively (p<0.05), the peripheral nerve regeneration was also observed in the small intestinal conduit group. Conclusion: Small intestinal conduit should not be considered as an alternative to autologous nerve grafts in its current form; however, the results are promising. Even though the results are no better than autologous nerve grafts, with additional procedures, it might be a good alternative due to harvesting abundant sources without donor site morbidity.