Kenan Dağlıoğlu

Effect of zoledronic acid on osseointegration of titanium implants: an experimental study in an ovariectomized rabbit model.

PURPOSE Zoledronic acid (ZA), a new-generation intravenous bisphosphonate, exhibits the greatest affinity for bone mineral with the longest retention, thereby leading to its ability to be dosed at annual intervals in the treatment of osteoporosis. The purpose of this preliminary study was to evaluate the effects of systemic administration of a single dose of ZA on osseointegration and bone healing around titanium dental implants. MATERIALS AND METHODS Thirty-six female New Zealand rabbits (aged 6-12 months) were used in this study. Rabbits were randomly assigned to 1 of 3 groups: sham control group (SH), ovariectomy group (OVX), and OVX and ZA group (OVX + ZA). Animals in the OVX and OVX + ZA groups were subjected to bilateral ovariectomy, whereas animals in the SH group were sham operated. Eight weeks later, 1 implant was placed in each tibia of the animals. ZA was administered in the OVX + ZA group during the implantation, whereas the OVX and SH groups received saline solution infusions. All of the subjects were sacrificed 8 weeks after the implantation, and tibial specimens were harvested. Histomorphometric bone-to-implant contact analysis, resonance frequency analysis, removal torque testing, and digital radiographic absorptiometry were administered, and the data were statistically analyzed. RESULTS Histomorphometric, resonance frequency, and radiodensitometric analyses showed significant improvement in osseointegration of implants in the OVX + ZA group compared with the OVX group. However, the differences in removal torque results between the groups were not statistically significant. CONCLUSIONS The results of this study suggest that systemic ZA administration may improve osseointegration of titanium implants placed in estrogen-deficient states of bone.

The effect of levetiracetam on neuronal apoptosis in neonatal rat model of hypoxic ischemic brain injury

BACKGROUND Hypoxic-ischemic brain injury (HIBI) is a common cause of neonatal mortality and morbidity. The use of levetiracetam (LEV), as a potential neuroprotective in brain ischemia, receives an increasingly high attention, and it could have a crucial role in the regulation of epileptogenesis and neuroprotection. Potential effects of LEV on neuronal apoptosis in HIBI have not previously been reported in literature. OBJECTIVES The aim of this study is to evaluate the possible effects of LEV on neuronal apoptosis in neonatal rat model of HIBI. METHODS Seven-day-old Wistar rat pups were subjected to right common carotid artery ligation and hypoxia (92% nitrogen and 8% oxygen) for 2h. The pups were treated with LEV or saline after hypoxia. In sham group rats, neither ligation, nor hypoxia was performed. Neuronal apoptosis was evaluated by the terminal deoxynucleotidyl-transferase- mediated dUTP nick-end labeling (TUNEL) methods. RESULTS The counts of apoptotic cells in both hippocampus and cerebral cortex were significantly higher in the saline treatment group than in the sham group. The counts of apoptotic cells in both hippocampus and cerebral cortex were similar to those in the sham group and in the LEV treatment group. The number of apoptotic cells decreased significantly in the LEV-treated group compared with the saline group. CONCLUSIONS These results show that LEV administration after hypoxia reduces neuronal apoptosis. Thus, we propose that LEV, as an effective antiepileptic and antiapoptotic drug, may be a viable choice for the control of seizure activity in neonates with HIBI.

The effectiveness of heliox in acute respiratory distress syndrome

INTRODUCTION: The management of acute respiratory distress syndrome (ARDS) was investigated with the use of heliox in an experimental model. OBJECTIVES: To investigate whether heliox can be considered a new therapeutic approach in ARDS. METHODS: ARDS was designed in Wistar albino male rats, 250-300 g in weight, by intratracheal instillation of physiological saline solution. Anesthezied and tracheotomized rats with ARDS were pressure-controlled ventilated. At the end of 210 min, helium gas was tried. All rats were assigned to two groups: Group 1 (n = 10) was the control group, and was given no treatment; group 2 (n = 7) was given heliox (He: O2 = 50:50). The heliox group received heliox for 1 h continously. Rats were continued to be kept on a ventilator through the experiment. Two hours after the last inhalation, both lungs of the rats were excised for both histopathological examination and immunohistochemical evaluation. STATISTICAL ANALYSIS USED: Histopathological grading were expressed as median interquartile range. Mann–Whitney U-test was used to assess the relationships between the variables. RESULTS: The infiltation of neutrophils were decreased in rats treated with heliox. Edema in the interstitial and intraalveolar areas was less than that of the control rats. Also, the diminishing of perivascular and/or intraalveolar hemorrhage was apperant. Hyaline membrane (HM) formation decreased in the heliox group compared with the control group. Decreased inducible nitric oxide synthase expression was shown via immunohistochemical examination in the heliox group. CONCLUSION: The present study histopathologically indicated the effectiveness of heliox in the decreasing of neutrophil infiltation, interstitial/intraalveolar edema, perivascular and/or intraalveolar hemorrhage and HM formation in ARDS. Besides the known effect of heliox in obstructive lung disease, inhaled heliox therapy could be associated with the improvement of inflamation in ARDS.

Preventative effect of deferoxamine on degenerative changes in the optic nerve in experimental retrobulbar haematoma

Purpose: Changes in the optic nerve due to the breakdown of blood elements and the effect of deferoxamine on these changes were evaluated.

The protective effect of hesperidin on methotrexate-induced intestinal epithelial damage in rats: an experimental study.

Objective: The purpose of this experimental study was to evaluate the efficacy of hesperidin (HES) in protecting against methotrexate (MTX)-induced intestinal damage using histopathological and immunohistochemical techniques. Materials and Methods: Seventy-eight male Wistar albino rats were divided into 4 groups that received (a) saline only (control group), n = 19; (b) HES only, n = 19; (c) MTX only, n = 19, and (d) MTX plus HES, n = 21. On the first day of the study, a single dose of MTX (20 mg/kg) was administered intraperitoneally to group 3 and 4 rats. The HES (200 mg/kg) was administered by gavage for 5 days. For the MTX plus HES group, HES (200 mg/kg) was administered by gavage for 5 days after MTX treatment. Rats were sacrificed on the 2nd, 4th and 6th day of the study. Tissue samples from the jejunum were taken for histopathological and immunohistochemical analysis. Results: On the 4th day, crypt injury in the MTX plus HES group (1.00 ± 0.00) was less than that in the MTX group (2.00 ± 0.89; p < 0.05). The small intestinal damage score was lower in the MTX plus HES group (6.33 ± 0.82) as compared to the MTX group (8.00 ± 2.37). Inducible nitric oxide synthase and interleukin-8 levels were lower in the MTX plus HES group (65 and 25%, respectively) as compared to the corresponding values of the MTX group (80 and 52.5%, respectively). On the 6th day, the Ki-67 proliferation index in the MTX group (45%) was lower than that in the MTX plus HES group (76.67%) and the control group (p < 0.05). The small intestinal damage score was high in the HES group on the 4th day due to increased cellular infiltration. On the 6th day, the Ki-67 proliferation index rose in parallel with the decrease in cellular infiltration and therefore histopathological scoring. The proliferation-enhancing effect of HES also appeared in healthy rats. Conclusion: HES seemed to have a protective effect against MTX-induced intestinal injury.

Effects of Sodium Valproate on Renal Functions in Rats

In recent years, it has been reported that sodium valproate occasionally can cause renal tubular impairment. This study was designed to demonstrate the renal tubular and glomerular functions in rats given sodium valproate as monotherapy, as well as to determine any reversibility of dysfunctions. Female rats were randomly allocated to three groups: group 1 received sodium valproate 500 mg/kg/d intraperitoneal for six weeks; after the same injection period, group 2 was housed for another six weeks, after which laboratory investigations were completed; and group 3 served as a control group made up of 20 healthy rats living in same condition without any treatment. Serum ALT, total protein, uric acid, ALP, phosphorus, sodium levels, and urine Ca/cr ratio were significantly different between groups 1 and 3 (p < 0.025), but this difference was not seen between groups 2 and 3. On the other hand, other parameters such as TRP, Ccr, NAG, and MDA were not significantly different among the three groups ( p > 0.025) These results suggest that SV does not have a significant dose- or time-related side effect on renal functions. Minor biochemical dysfunctions related to long-term sodium valproate therapy is reversible, and the minimal renal fibrosis that showed histopathologically is not clinically important. The renal tissues of rats are known to show similar metabolic and histological patterns with human renal tissues. No renal dysfunction was expected in humans because there were no clinically statistically significant renal side effects in this study.

Effects of bovine lactoferrin in surgically created bone defects on bone regeneration around implants.

The aim of this experimental study was to evaluate the effect of bovine lactoferrin (bLF)-loaded gelatin microspheres (GM) used in combination with anorganic bovine bone on bone regeneration in surgically created bone defects around tooth implants. Twenty-four uniform bone defects were created in the frontal bone via an extraoral approach in 12 domestic pigs. Twenty-four implants were placed at the center of the defects. In eight animals one of these defects was filled with 0.3 mL anorganic bovine bone while the other was left empty. In four animals, all defects were filled with 3 mg/defect bLF-loaded GM and anorganic bovine bone. All the defects were covered with collagen membranes. All animals were sacrificed after 10 weeks of healing, and the implants with the surrounding bone defects were removed en bloc. Undecalcified sections were prepared for histomorphometric analysis. The mean total area of hard tissue was 26.9 ± 6.0% in the empty defect group, 31.8 ± 8.4% in the graft group, and 47.6 ± 5.0% in the lactoferrin group (P < 0.001). The mean area of newly formed bone was 26.9 ± 6.0% in the empty defect group, 22.4 ± 8.2% in the graft group, and 46.1 ± 5.1% in the lactoferrin group (P < 0.001). The mean residual graft area was 9.4 ± 3.2% in the graft group and 1.5 ± 0.6% in the lactoferrin group (P < 0.001). The mean proportion of bone-implant contact in the defect region was 21.9 ± 8.4% in the empty defect group, 26.9 ± 10.1% in the graft group and 29.9 ± 10.3% in the lactoferrin group (P = 0.143). These data indicate that a combination of 3 mg bLF-loaded GM and bovine-derived HA promotes bone regeneration in defects around implants.

Investigating the clinical significance of mesh peritonization in abdominal vault suspension surgery using a comparative rabbit model

OBJECTIVE To investigate the clinical significance of mesh peritonization in an experimental rabbit model. STUDY DESIGN Twenty rabbits were randomly assigned to two groups. A sacrouteropexy operation was performed in both groups using a polypropylene mesh. In the first group, the pelvic peritoneum was not closed over the mesh, and in the second group, the mesh was buried throughout the pelvic retroperitoneal tunnel. One month after mesh implantation, the abdomen was opened and the previous surgical site was explored. The primary outcome was intraabdominal adhesion formation; the secondary outcome was the histologic degree of tissue remodeling. RESULTS There were no statistically significant differences between the two groups in terms of adhesion scores and collagen organization (P=0.692, P=0.097, respectively). There was a greater degree of inflammation in the second group as identified by significantly higher scores for eosinophils-neutrophils, macrophages-foreign body giant cells and mononuclear cells (P=0.002, P=0.001 and P=0.002, respectively). CONCLUSIONS Similar adhesion and collagen organization patterns were found in both groups, but indicators of the inflammatory process were significantly higher in the second group.

Straight versus S-shaped sternotomy: a histologic study in the sheep model

IntroductionStraight sternotomy is the most common access for open heart surgery. Techniques have been proposed for maximizing sternal stability in high-risk patients. This trend implies a growing need for newer surgical techniques. The aim of this experimental study in the sheep model is to evaluate median vs. S shaped sternotomy the feasibility of using a special device to accelerate the sternal instability and bone healing.Materials and methodsWe enrolled 31 sheep, weighing 18–30 kg. For all animals a midline skin incision was made. In group I (n = 16 animals), straight median sternotomy and in group II (n = 15 animals), S-shaped incision was marked on the periosteum of the sternum by new created device for standard S-shaped sternotomy. Sternum biopsies were performed on second surgery month for all survived animals from the sternum and the surrounding soft tissue.ResultsNo early superficial wound complications were observed. Overall mortality in the initial approach group was 19.3% (6 sheep). In group I; 3 sheep had died on first surgery day, the reason may be hemorrhage and in group II; 3 sheep developed intractable VF during surgery procedure or immediately afterwards so died. There were statistically significant differences in the scores of bone healing between group 1 and group 2 (4.2 vs.7.3, ANOVA, p < 0.001).DiscussionOur work is based on the use of a standard S-shaped sternotomy procedure on sheep sternum. In our experience with the sternal healing in the sheep model, the process of new bone formation was accelerated with S- shaped cut than straight sternotomy procedure.

Evaluation of paracetamol distribution and stability in case of acute intoxication in rats

Effects of different storing conditions on paracetamol concentration in biological samples of acute intoxicated rats were investigated. The stability and distribution of paracetamol was observed in postmortem serum, liver, kidney and brain tissues. The serum samples were stored for 30 days and daily changes were evaluated for paracetamol. A significant difference (p = 0.05) was noticed on the 30th experimental day. Paracetamol serum levels changed as much as 66.30% and 33.78% for 4°C and −20°C, respectively. The stability of paracetamol in liver stored at −20°C was also evaluated for 30 days. The paracetamol concentration levels taken from liver samples dramatically decreased from 30.36% on the 1st day to 94.97% on the 30th day. The paracetamol distribution in organs was as 2.68 , 1.11 and 0.68 mg/g in liver, kidney and brain samples, respectively. Meaningful difference in paracetamol in serum and liver samples was in observed in 30th day values (p = 0.05).