Ayşegül Yücel

Levels of Interleukin-8 During Tooth Movement

A host-derived neutrophil-activating cytokine interleukin-8 (IL-8) is secreted mainly by monocytes and is considered to be important in regulating alveolar bone resorption during tooth movement. The aim of this study was to evaluate the levels of IL-8 during mechanical forces on periodontal tissues at different stages of orthodontic therapy. Ten canine teeth of patients having different Angle classifications were selected for the study. After the premolars were extracted, the maxillary/mandibular canines were tipped distally. Gingival crevicular fluid was sampled from mesial and distal gingival crevices of each canine separately at baseline and one hour, 24 hours, six days, 10 days, and 30 days after the application of the force. An enzyme-linked immunosorbent assay for quantitative detection of IL-8 was used. Although there was an increase in the concentration of IL-8 at tension (mesial) sites after one hour, 24 hours, six days, and 10 days, a decrease was observed at 30 days. Pressure (distal) sites did not demonstrate such an increase at any period except at 10 days. However, the concentration of IL-8 at both sites showed a similar decrease and approached each other at day 30. We concluded that local host response toward the orthodontic forces might lead an increase in IL-8 and neutrophil accumulation, and this may be one of the triggers for bone remodeling processes.

Importance of cytokines, oxidative stress and expression of BCL-2 in the pathogenesis of non-alcoholic steatohepatitis

Objective. Non-alcoholic steatohepatitis (NASH) is a form of chronic hepatitis. The pathogenesis of NASH has been dealt with in only a few studies and so it has not been clearly identified yet. The purpose of this study was to investigate the roles of TNF-α, TGF-β, IL-6, IL-8, malondialdehyde (MDA), nitric oxide (NO) and the expression of Bcl-2 and Bax in the pathogenesis of NASH. Material and methods. The study included 92 patients, 57 of whom were diagnosed with biopsy-proven NASH, 13 with biopsy-proven hepatosteatosis and 22 with ultrasonography-diagnosed hepatosteatosis. Serum levels of TNF-α, TGF-β, IL-6 and IL-8 were measured using the ELISA method. The plasma levels of NO were studied using the Griess method. Expressions of Bcl-2 and Bax were examined in paraffin blocks of liver biopsy materials by means of immunohistochemical-staining. MDA levels were measured using the thiobarbituric acid method. Results. No significant difference was found in the levels of TNF-α, TGF-β, IL-6 or NO between the three groups (p>0.05). No difference was found in expression of Bcl-2 and expression of Bax between the biopsy-proven NASH and biopsy-proven hepatosteatosis groups (p>0.05). In the NASH group, the levels of IL-8 and MDA were found to be higher than those in the hepatosteatosis groups (p<0.05). Conclusions. The elevated levels of MDA may indicate the relationship between oxidative stress and NASH. Furthermore, IL-8 was found to be higher in the NASH group than in the hepatosteatosis group, demonstrating the importance of inflammation in the pathogenesis of NASH.

Increased Serum Levels of Epidermal Growth Factor in Children with Autism

The etiology of autism is unclear, however autism is considered as a multifactorial disorder that is influenced by neurological, environmental, immunological and genetic factors. Growth factors, including epidermal growth factor (EGF), play an important role in the celluler proliferation and the differentiation of the central and peripheral nervous system. In this study we hypothesized that EGF may play a role in the pathophysiology of autism and examined serum EGF levels in children with autism. We measured serum levels of EGF in the 27 autistic children and 28 age- matched normal controls. The serum levels of EGF in the subjects with autism were significantly higher than those of normal control subjects. However, there were no correlations between serum EGF levels and clinical variables in the subjects with autism. This is the first report demonstrating the increased serum levels of EGF in children with autism. This study suggests that increased levels of EGF might have an importance in the pathophysiology of autism.

Effect of Blood Collection Tube Types on the Measurement of Human Epidermal Growth Factor

Abstract We observed significant differences in measured human epidermal growth factor (hEGF) levels for the same individuals serum/plasma samples between different tube types (glass, polystyrene, plastic with clot activator, plastic without clot activator, plastic with EDTA, polypropylene tubes). For all individuals, hEGF levels in plasma were found to be below the detection limit. The discrepancy of the hEGF levels in serum and plasma was attributed to the platelet derived EGF by analyzing platelet lyzate with size exclusion chromotography and demonstrating the immunoreactivity of the fractions corresponding to the pre‐proEGF and/or proEGF elution time. Besides, samples of females showed much higher EGF levels than those of males in certain test tube types. As a conclusion, all blood samples should be taken and stored in the same type of test tubes in order to make precise measurements for hEGF. And, the measured hEGF level in blood is susceptible to changes with blood clotting.

Clinical significance of serum vascular endothelial growth factor, endostatin, and leptin levels in children with lymphoma.

A number of clinical studies conducted in adults have demonstrated the prognostic significance of angiogenic factors in malignancies, however, only a limited number of studies have been conducted in children. The aim of this study was to determine serum vascular endothelial growth factor (VEGF), endostatin, and leptin levels in children with lymphoma and to investigate whether these factors provide prognostic information.

Can Serum Pin1 Level Be Regarded as an Indicative Marker of Nonalcoholic Steatohepatitis and Fibrotic Stages

Background: We aimed to investigate serum Pin1 as an indicator of the presence of nonalcoholic steatohepatitis (NASH) and its association with the histopathological liver fibrosis stages. Methods: Serum samples were collected from consecutive biopsy-proven NASH patients and healthy controls, and then serum levels of Pin1 were measured. The correlations between clinical and histopathological features of NASH and Pin1 were evaluated. Patients who had fibrotic stages <2 were termed mild fibrosis group and those who had ≥2 as advanced fibrosis group. We performed univariate and multivariate logistic regression analyses to evaluate the independent predicting factors for the presence of liver fibrosis caused by NASH. Results: Fifty-six consecutive NASH patients and 56 age- and sex-matched healthy controls were enrolled in the study. Serum Pin1 levels were significantly higher in NASH patients (39.24 ± 30.94) than in controls (27.7 ± 9.56, p < 0.001). In NASH patients, serum Pin1 levels were correlated with the histopathological features. Patients with advanced fibrosis had higher serum Pin1 levels than the mild fibrosis group (53.42 ± 33.8 vs. 33.24 ± 20.90, respectively; p < 0.001). In multivariate analysis, Pin1 remained an independent predicting factor of advanced liver fibrosis (OR: 1.051, 95% CI: 1.013-1.089, p < 0.05). Conclusion: Serum Pin1 level can be used as a potential independent marker of the presence of the NASH and advanced fibrotic scores.

Short term effects of non-surgical periodontal treatment on gingival crevicular fluid levels of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 2 (PAI-2) in patients with chronic and aggressive periodontitis §

OBJECTIVE The purpose of this study was to evaluate the gingival crevicular fluid (GCF) levels of tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor 2 (PAI-2) in aggressive periodontitis (AgP), chronic periodontitis (CP) and periodontally healthy control subjects, before (BT) and after (AT) the non-surgical periodontal treatment. DESIGN Systemically healthy 12 CP and 13 AgP patients and 20 control subjects were included in this study. Plaque index, gingival index, probing depth and clinical attachment levels were recorded and GCF samples were collected BT and AT. Assays for GCF t-PA and PAI-2 levels were carried out by an enzyme linked immunosorbent assay (ELISA). The χ(2), Wilcoxon and Mann-Whitney U tests and Spearman correlation coefficient were used for data analyses. RESULTS Statistically significant reductions in clinical index scores were noted in both periodontitis groups after treatment. No significant differences were detected in GCF levels of t-PA and PAI-2 between CP and AgP groups at either BT or AT. There was a statistically significant decrease in GCF PAI-2 levels in CP after therapy (p<0.01). GCF t-PA levels in CP and AgP groups exhibited significant correlations with PD and CAL measurements at both BT and AT (p<0.01). CONCLUSION Significant decrease was detected for GCF PAI-2 levels in CP and clinical parameters in both CP and AgP by non-surgical periodontal treatment.

Proliferative response of peripheral blood lymphocytes and lymphocyte subpopulations in n-Hexane, toluen, and methyl ethyl ketone co-exposed workers.

To estimate the quantitative relation between chronic co-exposure to airborne n-hexane, toluen, methyl ethyl ketone (MEK) and various markers of immune function such as proliferative response of peripheral blood lymphocytes and lymphocyte subpopulations, a group of workers employed in a shoe factory were examined and compared with the unexposed controls. A significant increase was observed in the proliferative response of the peripheral lymphocytes to 2.5 and 5 μg PHA in the exposed group compared with that of the control group. There was no significant change in the percentage of circulating CD3(+), CD4(+), CD8(+), CD19(+), CD16(+) lymphocytes even in those workers with 3.3-fold higher mean levels of urine 2,5-hexanedione (2,5-Hxdn) and approximately twofold higher mean levels of urine hippuric acid (HA) as compared to controls. No difference was also observed between the mean granulocyte, monocyte, lymphocyte percentages of the groups, but a significant increase was observed in mean serum C3 level of the workers. Our results suggest that while lymphocyte subpopulations and leucocyte percentages are not affected, the proliferative response of the peripheral lymphocytes is stimulated after chronic co-exposure to n-hexane, toluen and MEK at the defined levels.

The effect of thyroid autoimmunity on T-cell responses in early pregnancy

Thyroid autoimmunity (TAI) is common in women of reproductive age. There is a relationship between TAI and recurrent pregnancy loss and infertility. In pregnant patients with thyroid autoimmunity, the T helper-1 (Th1)/T helper-2 (Th2) ratio may shift to a Th1-type response and these activated T lymphocytes may lead to implantation failure. The aims of this study were to investigate the serum levels of Th1-, Th2-, and T-helper-17-(Th17)-associated cytokines in pregnant patients with TAI, and to evaluate how these cytokines change with l-thyroxin treatment during pregnancy. Twenty pregnant women with TAI diagnosed in the first trimester of pregnancy who were not on l-thyroxine treatment, 14 pregnant women with known TAI before pregnancy already been on l-thyroxine treatment, and 19 pregnant patients without TAI were included in this study. Thyroid function tests, thyroid autoantibodies, and cytokine levels were measured at the first and the second trimesters. In pregnant patients who were diagnosed with TAI in the first trimester, both serum IL-2 levels and IL-17 levels were significantly higher than those of the control group. There were no significant differences between groups for serum IL-4, IL-6, IL-23, IL-10, and IFNγ levels. In the second trimester, no significant differences were found between groups for all the cytokines measured. There are significant differences in Th1- and Th17-associated cytokine levels between patients with TAI and the control group in the first trimester. In the second trimester cytokine levels were similar among all groups. This pattern may be associated with the clinical benefits of l-thyroxine treatment.

Are serum nitric oxide and vascular endothelial growth factor levels affected by packed red blood cell transfusions

Abstract Background: Nitric oxide (NO) and vascular endothelial growth factor (VEGF) are important mediators for hemodynamics and angiogenesis in the body. NO coming from endothelial cells and red blood cells is particularly effective in hypoxic vasodilation. VEGF has known effects on the induction of NO synthesis and is also known to be affected by blood product transfusions. The objectives of this study were to measure NO and VEGF levels before and after packed red blood cell (PRBC) transfusions. Study design and methods: Blood was drawn from preterm newborns before and 30 min after PRBC transfusions and samples were used for NO and VEGF measurements. NO end products nitrite and nitrate were measured by modified Greiss method, VEGF levels measured by double sandwitch ELISA method. Vital signs including heart rate and blood pressure were also recorded. Results: Thirty four newborns were included in the study and overall 54 transfusion episodes were assessed for mediator levels. No difference was observed between the mediator levels before and after PRBC transfusions. Vital signs were also unchanged. Conclusion: As there was no change in NO end product levels with PRBC transfusions, it might suggest that hypoxia was not severe enough to cause nitrite increase; however, other NO sources might still be active. VEGF levels were found to be unchanged and may reflect a delayed effect of transfusion on VEGF induction.