Kuzey Aydinuraz

In vitro S. epidermidis and S. aureus adherence to composite and lightweight polypropylene grafts.

BACKGROUND Despite the significant risk of infection, prosthetic graft materials have become indispensable for incisional hernia repair. Composite and lightweight grafts have been developed to overcome adhesion and rigidity. The aim of this study was to evaluate in vitro S. epidermidis and S. aureus adherence to these new generation grafts, which have modified composition and textile properties. MATERIALS AND METHODS In this experimental study, sterile samples of multifilament polypropylene, multifilament lightweight composite, monofilament composite, and monofilament polypropylene grafts were incubated with slime positive S. epidermidis and S. aureus strains for 24 h. The grafts were washed and vortexed in saline. The saline was passaged to blood agar and incubated for 24 h. The colonies were counted. Naïve and incubated graft materials were examined by scanning electron microscopy to reveal both textile properties and biofilm formation. Physicochemical properties were evaluated. Wilcoxon signed ranks test and Friedman test were used for statistical analysis. RESULTS S. epidermidis showed a significantly decreased adherence to monofilament polypropylene graft, and increased adherence to multifilament polypropylene graft (P<0.05). S. aureus showed a significant affinity for monofilament composite graft (P<0.05). SEM studies showed that biofilm formation was present on multifilament polypropylene graft. CONCLUSIONS Both S. epidermidis and S. aureus had significantly less adherence to multifilament lightweight composite than multifilament polypropylene graft. S. epidermidis showed a greater affinity to monofilament composite graft compared with monofilament polypropylene graft. Overall S. epidermidis adherence for multifilament lightweight composite and monofilament composite was less than multifilament polypropylene and higher than monofilament polypropylene. S. epidermidis and S. aureus showed different adherence for each graft. Changes in material composition and textile properties may well influence bacterial adherence.

Similar effects of general and spinal anaesthesia on perioperative stress response in patients undergoing haemorrhoidectomy.

Surgery induces release of neuroendocrine hormones (cortisol), cytokines (interleukin-6: IL-6, tumour necrosis factor-α: TNF-α), acute phase proteins (C-reactive protein: CRP, leptin). We studied the effects of general and spinal anaesthesia on stress response to haemorrhoidectomy. Patients were assigned to general and spinal anaesthesia groups (n = 7). Blood samples were drawn before induction and 24 hours after surgery. Perioperative levels of IL-6, TNF-α, CRP, cortisol, and leptin were comparable among the groups. Twenty four hours after surgery, TNF-α and cortisol did not change; IL-6 and CRP increased significantly in all patients. Significant increase in leptin levels was found in patients undergoing spinal anaesthesia. Except for the increase in leptin levels, there was no significant difference related to the effects of general and spinal anaesthesia.

A RAT MODEL OF POLYPROPYLENE GRAFT INFECTION CAUSED BY STAPHYLOCOCCUS EPIDERMIDIS

Background:  The aim of this study was to constitute a valid graft infection model with Staphylococcus epidermidis in rats.

Effect of Carnitine on Cutaneous Wound Healing in Immunosuppressed Rats

BACKGROUND The wound is ischemic in nature. Chronic steroid administration impairs wound healing by changing enzymes in the glycolytic pathway. Carnitine supplementation may help to restore the energy deficiency caused by chronic steroid administration in the wound. The aim of this study was to evaluate the effect of carnitine on impaired wound healing. METHODS The study was conducted in three groups. Surgical intervention was a 4 cm long midline skin incision at the back. In Group A, eight rats received methylprednisolone for 7 d prior to surgical intervention, and it was continued until the end of the experiment. In Group B, 12 rats received methylprednisolone for 7 d prior to surgical intervention. After surgery, methylprednisolone injection was continued and carnitine was supplemented until the end of the experiment. In Group C, eight rats received no medication. The wound of half of the animals in each group was harvested on the seventh day after surgical intervention and the remaining on the 14th d. Tensile strength and hydroxyproline content were measured in all groups. RESULTS There was no significant difference in parameters in any of the groups on day seven. On day 14, all parameters were statistically different between methylprednisolone and control groups (P < 0.05). Values for tensile strength were higher in the methylprednisolone/carnitine group compared with methylprednisolone group (P < 0.05). Carnitine administration had also increased hydroxyproline levels in the methylprednisolone/carnitine group compared with the control group (P < 0.05). CONCLUSIONS Carnitine is shown to increase tensile strength of the wound when supplemented to immunosuppressed rats in which wound healing is impaired by methylprednisolone.

The effects of scalpel, harmonic scalpel and monopolar electrocautery on the healing of colonic anastomosis after colonic resection

Purpose In our study, the effects of harmonic scalpel, scalpel, and monopolar electrocautery usage on the health and healing of colon anastomosis after resection was investigated. Methods In this study, 120 female albino Wistar rats were divided into 3 groups each containing 40 rats. Group A, resection with scalpel; group B, resection with monopolar electrocautery; group C, resection with harmonic scalpel. The groups were divided into 4 subgroups consisting of 10 rats and analysed in the postoperative 1st, 3rd, 5th, and 7th days. Anastomotic bursting pressures, hydroxyproline levels and histopathological parameters were surrogate parameters for evaluating wound healing. Results The tissue hydroxyproline levels did not show any significant difference between the groups and subgroups. The mean bursting pressure of group A on the 5th day was significantly higher than groups B and C (P < 0.001). When the fibroblast and fibrosis scores were evaluated, scores of group C on the 5th day were significantly higher than the other groups, but the results of bursting pressures and biochemical parameters did not support the fibroblast and fibrosis scores. There were not any significant differences between the groups in other histopathologic parameters. Conclusion The use of monopolar electrocautery needs more attention since the device causes tissue destruction. The obliterating effect of harmonic scalpel on luminal organs is an important problem, especially if an anastomosis is planned. Despite the disadvantages of scalpel, its efficacy on early wound healing is better than the other devices.

Effect of hypothermia on apoptosis in traumatic brain injury and hemorrhagic shock model

INTRODUCTION The neuroprotective mechanisms of therapeutic hypothermia against trauma-related injury have not been fully understood yet. In this study, we aimed to investigate the effects of therapeutic hypothermia on biochemical and histopathological markers of apoptosis using Traumatic brain injury (TBI) and hemorrhagic shock (HS) model. METHODS A total of 50 male albino-wistar rats were divided into five groups: Group isolated TBI, Group NT (HT+HS+normothermia), Group MH (HT+HS+mild hypothermia), Group MoH (HT+HS+moderate hypothermia) and Group C (control). Neurological deficit scores were assessed at baseline and at 24h. The rats were, then, sacrificed to collect serum and brain tissue samples. Levels of Caspase-3,6,8, proteoglycan-4 (PG-4), malondialdehyde (MDA), and nitric oxide (NO) were measured in serum and brain tissue samples. Histopathological examination was performed in brain tissue. RESULTS There were significant differences in the serum levels of Caspase-3 between Group NT and Group C (p=0.018). The serum levels of Caspase-6 in Group NT (0.70±0.58) were lower than Group MH (1.39±0.28), although the difference was not statistically significant (p=0.068). There were significant differences in the brain tissue samples for Caspase-3 levels between Group NT and Group C (p=0.049). A significant difference in the Caspase-8 brain tissue levels was also observed between Group NT and Group C (p=0.022). Group NT had significantly higher scores of all the pathological variables (for edema p<0.017; for gliosis p<0.001; for congestion p<0.003, for hemorrhage p<0.011) than Group C. CONCLUSION Our study results suggest that hypothermia may exert its neuroprotective effects by reducing markers of apoptotic pathway, particularly Caspase-3 on TBI and HS.

The effect of thymoquinone coating on adhesive properties of polypropylene mesh

BackgroundAn incisional hernia is a common complication following abdominal surgery. Polypropylene mesh is frequently used in the repair of such defects and has nearly become the standard surgical treatment modality. Though they are very effective in reducing recurrence, mesh materials exhibit a strong stimulating effect for intraabdominal adhesion. The thymoquinone (TQ) extracted from Nigella sativa seeds has potential medical properties. TQ has anti-inflammatory, antioxidant and antibacterial properties. The aim of this study is to coat polypropylene mesh with TQ in order to investigate the effect of surface modification on intraabdominal adhesions.MethodsTQ-coated polypropylene mesh material was tested for cytotoxicity, contact angle, surface spectroscopy, TQ content, sterility, and electron microscopic surface properties. An experimental incisional hernia model was created in study groups, each consisting of 12 female Wistar rats. The defect was closed with uncoated mesh in control group, with polylactic acid (PLA) coated mesh and PLA-TQ coated mesh in study groups. Adhesion scores and histopathologic properties were evaluated after sacrifice on postoperative 21th day.ResultsGranuloma formation, lymphocyte and polymorphonuclear leukocyte infiltration, histiocyte fibroblast and giant cell formation, capillary infiltration, collagen content were significantly reduced in the PLA-TQ coated mesh group (p < 0.05). Though not statistically significant, likely due to the limited number of study animals, adhesion formation was also reduced in the PLA-TQ coated mesh group (p: 0.067).ConclusionTQ coated mesh is shown to reduce adhesion formation and TQ is a promising coating material for mesh surface modification.