Ersin Ogus

Clinical and radiographic evaluations of chitosan gel in periodontal intraosseous defects: A pilot study

Periodontitis is a chronic infection in the supportive tissue of the teeth which eventually leads to tooth loss. Various grafting materials and barrier membranes have been used to repair periodontal intraosseous lesions. Chitosan is a derivative of chitin, a natural biopolymer, which is biologically safe, biodegradable, and nontoxic and has been applied in a variety of forms in dentistry. It also exerts bioactive properties such as wound healing, antimicrobial, tissue regeneration, and hemostatic activities. The aim of this study was to evaluate effects of chitosan on periodontal regeneration. Twenty chronic periodontitis patients were recruited. Following initial therapy, the patients were divided into four groups: group A, receiving chitosan gel (1% w/v); group B, receiving chitosan gel + demineralize bone matrix; group C: receiving chitosan gel + collagenous membrane; and group D, receiving flap only (control group). Clinical and radiographic measurements were recorded at baseline, day 90 (3rd month), and day 180 (6th month) after surgery. For clinical data, no significant differences were obtained among the treatment groups. However, radiographic data revealed that except control group, all the other groups showed statistically significant bone fills when compared with baseline indicating that chitosan gel alone or its combination with demineralize bone matrix/collagenous membrane is promising for periodontal regeneration.

Which is responsible for the haemodynamic response due to laryngoscopy and endotracheal intubation? Catecholamines, vasopressin or angiotensin?

Background and objective: We have investigated the concentrations of epinephrine, norepinephrine, vasopressin and angiotensin converting enzyme activity to explore the role of these mediators in the neuroendocrine response to laryngoscopy and tracheal intubation. Methods: One hundred (50 male, 50 female) ASA I patients aged 20‐50 yr (mean ± SEM; 35.59 ± 0.99) were included in the study. They were undergoing elective surgery under standard anaesthesia induction and maintenance using tracheal intubation. Plasma concentrations of epinephrine, norepinephrine and vasopressin as well as plasma angiotensin converting enzyme activity were determined at four time points, before (T1) and after (T2) induction, and 2 (T3) and 5 min (T4) after intubation. Blood pressure and heart rate were recorded at corresponding times to reveal if any correlation existed between haemodynamic parameters and neuroendocrine response. Results: Heart rate increased after induction and intubation (P < 0.05) and decreased significantly at T4 (P < 0.05). Systolic blood pressure decreased significantly (P < 0.05) after induction and increased slightly after intubation decreasing to below baseline value (P < 0.05) at T4. Diastolic blood pressure increased slightly after intubation and decreased significantly (P < 0.05) at T4. Plasma epinephrine and norepinephrine concentrations decreased after induction and increased at T3 and T4 without reaching significance. Vasopressin concentrations increased slightly at T2 and T3 and decreased significantly at T4 (P < 0.05). Angiotensin converting enzyme activity was unaffected when compared with baseline values. Conclusions: Blood pressure, heart rate, plasma epinephrine, norepinephrine and vasopressin concentrations increased slightly in response to laryngoscopy and intubation, all returning to or below baseline 5 min later with no change in angiotensin converting enzyme activity in normotensive patients.

Push-out bond strength and SEM evaluation of new polymeric root canal fillings

OBJECTIVE The objective of this study was to compare the interfacial strengths and failure modes of new polymeric endodontic obturation systems consisting of different material combinations. STUDY DESIGN Extracted human single-rooted teeth (n = 105) were instrumented using HERO Shaper rotary instruments and obturated with different combinations of core and sealer as follows: group 1, RealSeal/Resilon; group 2, RealSeal/Herofill; group 3, Hybrid Root Seal/Resilon; group 4, Hybrid Root Seal/Herofill; group 5, MM-Seal/Resilon; group 6, MM-Seal/Herofill; group 7 (control). Failure modes of root slices (1.00 +/- 0.05-mm thick) after push-out testing were examined with stereomicroscope and scanning electron microscopy. RESULTS Hybrid Root Seal/Resilon combination had significantly greater bond strength than all the other groups (P < .001); RealSeal/Resilon combination proved to have the second highest bond strength (P < .001). Bond failure was mainly mixed failure in both adhesive and cohesive modes at the dentin/sealer interface. CONCLUSION The push-out bond strengths of methacrylate-based sealers (Hybrid Root Seal and RealSeal) and thermoplastic synthetic-polymer-based core material (Resilon) combinations were higher than epoxy-resin-based sealer (MM-Seal) and gutta-percha (Herofill) combination.

Elevated CK-MB mass and plasma brain-type natriuretic peptide concentrations following convulsive seizures in children and adolescents: Possible evidence of subtle cardiac dysfunction

Purpose:  To evaluate the presence of myocardial injury during convulsive seizures in children and adolescents by determining serum concentrations of cardiac troponin I (cTnI), creatine kinase‐MB mass (CK‐MB mass), and plasma brain‐type natriuretic peptide (BNP).

Minocycline treatment inhibits lipid peroxidation, preserves spinal cord ultrastructure, and improves functional outcome after traumatic spinal cord injury in the rat.

Study design. A prospective, randomized experimental research. Objective. To evaluate the short- and long-term neuroprotective effects of minocycline on the secondary injury process of an experimental traumatic spinal cord injury (SCI) model. Summary of Background Data. Traumatic SCI is a devastating problem of health that results in high morbidity and mortality rates. The loss of function after SCI results from both the primary mechanical insult and the subsequent, multifaceted secondary response. Methods. A total of 80 adult male Spraque-Dawley rats (breeded by the Baskent University Animal Research Center) were randomly divided into 4 groups. A T10 contusion injury was produced by using modified Allen technique in all groups except the control group. No medication was administered to the rats in the trauma group. Minocycline was administered intraperitoneally and intravenously to the treatment groups. Short-term and/or long-term neuroprotective effects of minocycline on the lipid peroxidation (malondialdehyde, glutathione), apoptosis (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end labeling), ultrastructure of spinal cord (tissue electron microscopy), and behavioral assessments (Basso-Beattie-Bresnahan) were evaluated. Results. As compared with the trauma group, tissue malondialdehyde and glutathione levels demonstrated that minocycline significantly diminishes lipid peroxidation. Electromicroscopic study showed that minocycline preserves the ultrastructure of spinal cord tissue in the early post-traumatic period. Minocycline treatment significantly reduced the number of terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate-biotin nick end labeling positive cells both 1 day and 28 days after SCI. Behavioral assessments showed significant improvement in the hind limb functions of minocycline receiving rats starting 7 days after the SCI. Any statistically significant difference was not found between intraperitoneal or intravenous routes for minocycline injection. Conclusion. Minocycline is neuroprotective and contributes to functional improvement after traumatic SCI by eliminating the destructive process of secondary injury. Having both satisfying anti-inflammatory and antiapoptotic effects in experimental models, it promises to be of therapeutic use in human SCI.

Increased Vulnerability to Oxidative Stress in Pediatric Migraine Patients

Little is known about the role of oxidative stress in the pathogenesis of pediatric migraine. The objective of the present study was to investigate, during a headache-free period, the activities of erythrocyte antioxidant enzymes in children and adolescents diagnosed with migraine. In all, 47 migraine patients (age range, 8-17 years; mean, 14.1 +/- 2.4 years, 14 with aura) and 35 control subjects were included. Superoxide dismutase, glutathione peroxidase, and catalase activities were measured in erythrocytes. Although superoxide dismutase activities did not differ between groups, both catalase and glutathione peroxidase activities were significantly lower in migraine patients (P = 0.001 and P = 0.009, respectively). Activities of all three antioxidant enzymes were similar across migraine subgroups; there was no correlation with age and sex. These results confirm vulnerability to oxidative stress in pediatric migraine. Further studies and search for new therapeutic agents with antioxidant properties are needed.

Ultrastructural Examination of Glomerular and Tubular Changes in Renal Allografts with Cyclosporine Toxicity

The introduction of cyclosporine (CsA) has improved the clinical results of renal transplantation significantly; however, these improvements were closely associated with an increased incidence of renal dysfunction. The present study sought to examine the ultrastructural changes in renal allografts with CsA nephrotoxicity. Nine patients who underwent renal transplantation at the Baskent University Faculty of Medicine between 2001 and 2002 were examined; 26 biopsies of these nine patients who had received their first renal allograft were included in this study. All patients with CsA toxicity showed some form of glomerular endothelial cell injury. The swelling of mitochondria was present in three of nine renal allografts with CsA toxicity, and podocyte changes were found significantly more frequently among patients with CsA toxicity. In addition, focal segmental thickening and the duplication of glomerular basement membrane were observed statistically more frequently. In conclusion, these findings could help differentiate CsA toxicity from other conditions and develop better treatment strategies.

Evaluating the Significance Test When the Correlation Coefficient is Different from Zero in the Test of Hypothesis

Sample size and correlation coefficient of populations are the most important factors which influence the statistical significance of the sample correlation coefficient. It is observed that for evaluating the hypothesis when the observed value of the correlation coefficients r is different from zero, Fishers Z transformation may be incorrect for small samples especially when population correlation coefficient ρ has big values. In this study, a simulation program has been generated for to illustrate how the bias in the Fisher transformation of the correlation coefficient affects estimate precision when sample size is small and ρ has big value. By the simulation results, 90 and 95% confidence intervals of correlation coefficients have been created and tabled. As a result, it is suggested that especially when ρ is greater than 0.2 and sample sizes of 18 or less, Tables 1 and 2 can be used for the significance test in correlations.

Comparison of the intraoperative transfusion requirements and arterial blood gases in hetero-versus orthotopic liver transplantation.

SINCE its introduction in 1963, orthotopic liver transplantation (OLT) has become the ultimate therapy for all patients with end-stage or intractable liver disease. Although OLT is well established, the operative trauma is prohibitive in many patients with end-stage liver cirrhosis because of the severe changes in intraoperative homodynamics, especially during the anhepatic phase. In heterotopic liver transplantation (HLT), or auxiliary partial liver transplantation, the diseased native liver is left in situ, and the graft is transplanted to a position that differs from the normal anatomic position. This technique has several theoretical advantages over OLT; total hepatectomy is avoided and the recipient has the chance to benefit from the residual functional capacity of the diseased native liver. Because total hepatectomy is not carried out in HLT, it is conceivable that intraoperative transfusion requirements may be less. Also, due to the above mentioned reasons, acid-base disturbances may be less frequent and less severe. We carried out this retrospective study to investigate these possibilities.

Comparison between corneal cross-linking, topical antibiotic and combined therapy in experimental bacterial keratitis model.

Purpose This study was conducted to investigate the effects of an experimental bacterial keratitis model on the corneal collagen cross-linking treatment (CXL), and also to compare topical antibiotic treatment with the combined treatment. Methods The study involved 40 young adult female Sprague Dawley rats, which had a 2 mm scraped defect of the central corneal epithelium in both eyes. The rats were divided into two equal groups. The first group was inoculated in both eyes with standard Pseudomonas Aeruginosa (PA) from a strain suspension prepared from 0.05 ml (Group 1), and the second group was inoculated with standard Methicillin Resistance Staphylococcus Aureus (MRSA) strains from a suspension prepared from 0.05 ml (Group 2). Group 1 was divided into four sub-groups: Group 1A was treated by collagen cross-linking (CXL), Group 1C was treated with topical tobramycin drops CXL and also treated by collagen cross-linking (CXL), Group 1D was treated with topical tobramycin drops, and Group 1B was left untreated in order to create a control group. Similarly, Group 2 was also divided into four sub-groups: Group 2A was treated by CXL, Group 2C was treated with topical 5% fortified vancomycin drops CXL and also treated by CXL, Group 2D was treated with topical 5% fortified vancomycin drops, and Group 2B was left untreated in order to create a control group. CXL was performed on the third day following the inoculation and topical drop therapy. Biomicroscopy and microbiologic assessments were performed on the third and seventh days following the inoculation of microorganisms. Results In the treatment, which compared baselines in all groups before treatment, the diameter of keratitis infiltrations, corneal clouding, and corneal swab samples were obtained from the reduction in reproduction. The results were statistically significant (p < 0.01). Keratitis infiltration groups were conducted on the seventh day for Groups 1C and 1D according to Group 1B, whilst Groups 2A, 2C and 2D were conducted according to Group 2B, which showed a significant statistical reduction (p < 0.01). On the seventh day, focal groups were conducted in corneal clouding Group 1D according to Group 1B and in Groups 2A, 2C and 2D according to Group 2B, which revealed a significant statistical reduction (p < 0.01). On the seventh day, reproduction in culture was obtained from corneal swab samples in Groups 1C and 1D according to Group 1B; in Groups 1C and 1D according to Group 1A; in Groups 2A, 2C and 2D according to Group 2B; and in Group 2C according to Group 2A, where a significant statistical reduction was observed (p < 0.01). Conclusions The clinical and microbiological efficacy of the CXL treatment is evaluated in our study. In accordance with the conclusion reached an effective reduction in the density and severity of (infection), occurred as a result of CXL treatment, CXL treatment combined with topical antibiotic treatment and topical antibiotic treatment of Pseudomonas Aeruginosa (PA) and Metisilin Rezistant Staphylococcus Aureus (MRSA) keratitis infections. From these results, it is shown that topical antibiotics and CXL potentiate each other’s effects in the treatment of resistant bacterial keratitis.