Effects of different bleaching methods on shear bond strengths of orthodontic brackets

Objective:To evaluate the effects of different bleaching methods on the shear bond strength (SBS) of orthodontic brackets.Materials and Methods:Forty-five freshly extracted premolars were randomly divided into three groups (n  =  15 per group). In group I, bleaching was performed with the office bleaching method. In group II, bleaching was performed with the home bleaching method. Group III served as the control. Orthodontic brackets were bonded with a light cure composite resin and cured with an LED light. After bonding, the SBS of the brackets were tested with a Universal testing machine.Results:Analysis of variance indicated a significant difference between groups (P < .001). The highest values for SBS were measured in group III (20.99 ± 2.32 MPa). The SBS was significantly lower in groups I and II than in group III (P < .001). The lowest values for SBS were measured in group II (6.42 ± 0.81 MPa). SBS was significantly higher in group I than in group II (P < .001).Conclusions:Both of the bleaching methods significantly affected the SBS of orthodontic brackets on human enamel. Bleaching with the home bleaching method affected SBS more adversely than did bleaching with the office bleaching method.     

The effect of the modes of delivery on the maternal and neonatal dynamic thiol–disulfide homeostasis

Abstract

Background: Thiols are organic compounds containing sulfhydryl groups which exert antioxidant effects via dynamic thiol–disulfide homeostasis. The shift towards disulfide indicates the presence of oxidative environment. The thiol–disulfide homeostasis has not been studied in different mode of delivery before.

Aims: To investigate the effects of mode of parturition on the thiol–disulfide homeostasis in mothers and term infants.

Study design: The participants were grouped according to the mode of their delivery: group vaginal delivery (VD, n?=?40) and group cesarean section (C/S, n?=?40). Three serum samples were collected: from mothers at the beginning of labor, from the cord blood (CB), and from the infants at the 24th hour after birth. The dynamic thiol–disulfide homeostasis in both groups were compared.

Results: The levels of native-thiol and total-thiol in CB were significantly higher in VD group than those with C/S group. The levels of disulfide were higher in infants born by C/S compared with those born by VD. The disulfide-to-native thiol ratio, disulfide-to-total thiol ratio, and native thiol-to-total thiol ratio were similar between two groups.

Conclusion: Our results showed that the dynamic thiol–disulfide homeostasis of the neonate was greatly influenced by the way of delivery and supported that vaginally delivered infants have less oxidative stress.     

Thiol–disulphide balance in infertility secondary to varicocele

Oxidative stress plays an important role in the development of infertility secondary to varicocele. We aimed to investigate the dynamic thiol–disulphide homeostasis as an oxidative stress marker in the spermatic vein of infertility secondary to varicocele. Sixty‐one patients with varicocele were included in the study. Blood was drawn from the median cubital vein and the testicular venous return side before the spermatic vein was separated during surgery. Total thiol, native thiol, disulphide, ischaemia modified albumin (IMA) and albumin values were measured from both the dilated spermatic vein and the median cubital vein. The disulphide/native thiol, disulphide/total thiol and native thiol/total thiol ratios were determined. The mean age of the patients was 27.0 ± 6.68 (15–50) years. While the albumin, native thiol and total thiol values and the native thiol/total thiol ratio were significantly lower (p = 0.004, p < 0.001, p < 0.001, p < 0.001 respectively), the IMA value and the disulphide/native thiol and disulphide/total thiol ratios were significantly higher (p < 0.001, p < 0.001, p < 0.001 respectively) in the samples taken from spermatic venous blood. Thiol–disulphide balance had deteriorated towards disulphide formation in the spermatic vein compared with the peripheral vein. Abnormal thiol–disulphide balance may be an independent risk factor for infertility secondary to varicocele.     

Clinical importance of micrometastasis in sentinel lymph nodes

Introduction

We evaluated the incidence of micrometastasis and nonsentinel lymph node metastasis as well as local and axillary recurrence rates after level I-II axillary lymph node dissection.

Materials and methods

Patients (n = 760) with early-stage breast cancer underwent sentinel lymph node biopsy, and 45 patients (6.0%) with micrometastasis (0.2-2.0 mm) were included in this study. Data concerning tumor, patients’ characteristics and adjuvant treatments were recorded.

Results

The median age was 46 (26-67) years, median breast tumor size was 20 (1-50) mm, and median number of excised sentinel lymph nodes were 2 (1-5). All patients with micrometastasis underwent further level I-II axillary lymph node dissection. Eleven of 45 (24.4%) patients with micrometastasis in their sentinel lymph node biopsy had nonsentinel lymph node metastasis after an axillary lymph node dissection. There was no factor related to nonsentinel lymph node metastasis. Stage migration occurred in 4 of 45 patients (8.8%) due to the detection of micrometastases or macrometastases in nonsentinel lymph nodes.

Discussion

The classical treatment after detection of micrometastasis in sentinel lymph nodes is further axillary dissection. However, nonrandomized, nonprospective studies with 4-5 years follow up showed 0.6% axillary recurrence without further axillary lymph node dissection, although we still need the results of randomized controlled studies.     

Ventral Hernia Repair: a Practical Point of View

Purpose: To evaluate the effect of PVP-I liposome hydrogel on intraperitoneal postoperative adhesions. Material and Methods: Thirty Wistar-Albino male rats were randomly divided into three groups. After midline laparotomy, a 1 cm² area of the caecum was abraded with a sterile gauze until subserosal haemorrhage had developed. A 1 χ 1 cm patch of peritoneum located opposite of caecal abrasion was completely dissected. In group 1 (control group, C) adhesion induction was performed and nothing was applied to the wounds. In group 2 and 3, PVP-I solution (3%) (group 2, PI) and PVP-I liposome hydrogel (group 3, PIL) were applied to the caecal abrasion areas and peritoneal defects. Adhesions were classified according to a classification system based on the evaluation of the appearance, extent and strength of the adhesions on postoperative 21^st day.

Results: There was no significant difference of the adhesion scores between the groups (U1 = 45, p > 0.05; U2 = 48, p > 0.05; U3 = 47.5, p > 0.05).

Conclusions: We found that PVP liposome hydrogel did not influence postoperative intraabdominal adhesions and should be further explored for its potential use in various intraabdominal procedures.     

Low ERCC1 expression is associated with prolonged survival in patients with bladder cancer receiving platinum-based neoadjuvant chemotherapy

PurposeExcision repair cross-complementation group 1 enzyme (ERCC1) plays a key role in the removal of platinum induced DNA adducts and cisplatin resistance. Prognostic role of ERCC1 expression in the neoadjuvant setting in bladder cancer has not been reported before. We evaluated the prognostic role of ERCC1 expression in bladder cancer receiving platinum-based neoadjuvant chemotherapy.Materials and methodsThirty-eight patients with muscle invasive bladder cancer who received neoadjuvant platinum-based chemotherapy were included. Clinical and histopathologic parameters along with immunohistochemical ERCC1 staining were examined and correlated with response rates and survival.ResultsPathologic complete response rates were similar between patients with low and high ERCC1 expression. Median disease-free survival (DFS) was 9.3 vs. 20.5 months (P = 0.186) and median overall survival (OS) was 9.3 vs. 26.7 months (P = 0.058) in patients with high ERCC1 expression compared with those with low expression, respectively. In multivariate Cox regression analysis: pathological complete response (pCR) after chemotherapy (hazard ratio (HR) 0.1, 95% CI 0.012–0.842, P = 0.034) and high ERCC1 expression (HR 3.7, 95% CI 1.2–11.2, P = 0.019) were significantly associated with DFS. Patient age (>60 vs. ≤60 years) (HR 3.4, 95% CI 1.2–9.4, P = 0.018), the presence of pCR (HR 0.11, 95% CI 0.014–0.981, P = 0.048) and high ERCC expression (HR 6.1, 95 CI 1.9–19.9, P = 0.002) were significantly associated with OS.ConclusionsOur results showed that high ERCC1 expression was independently associated with shorter disease-free and overall survival in patients with bladder cancer who received neoadjuvant platinum-based chemotherapy. ERCC1 may represent a potential predictive marker for platinum-based treatment in bladder cancer.     

The incremental value of magnetic resonance imaging for breast surgery planning

Purpose

The aim of this study was to evaluate the effect of breast magnetic resonance imaging (MRI) on preoperative or intraoperative surgical planning.

Methods

One hundred and sixty females with breast cancer were enrolled in the study. The contribution of MRI compared to MMG and USG, their histopathological concordance, and their impact on surgical treatment were evaluated prospectively.

Results

In 48 (30.0%) of the patients, MRI identified suspicious lesions that were not detected by MMG and USG. The diagnosis by MRI was accurate in 17 (10.6%) of them, while in remaining 31 patients (19.4%) the additional lesions found by MRI and interpreted as malignant were found not to be malignant. The pathological accordance of MRI and MMG compared with USG were 69.3 and 70.0%, respectively, whereas individually, MMG and USG were in accordance with the pathological examination in 52.9 and 67.9% of the cases, respectively.

Conclusions

Assessment of the tumor size, multifocality, multicentricity, and presence of ductal carcinoma in situ by MRI may lead to misinterpretations in the majority of patients. The surgical approach should not be changed based solely on MRI findings. An accurately interpreted MMG combined with USG may be sufficient in most cases.     

Biocompatibility of heparin-coated cardiopulmonary bypass circuits in coronary patients with left ventricular dysfunction is superior to PMEA-coated circuits

BACKGROUND: Several coating techniques for extracorporeal circulation have been developed to diminish the systemic inflammatory response during cardiopulmonary bypass (CPB). The aim of this study was to evaluate the clinical effectiveness and biocompatibility of heparin-coated and poly-2-methoxyethylacrylate (PMEA)-coated CPB circuits on coronary patients with left ventricular systolic dysfunction. METHODS: Thirty-six patients who underwent elective coronary artery bypass grafting were divided into two equal groups: group H (n = 18), heparin-coated; group P (n = 18), PMEA coated. Clinical outcomes, hematologic variables, cardiac enzymes, malondialdehyde (MDA), and acute phase inflammatory response (including myeloperoxidase (MPO), catalase, hsCRP, and IL-8) were analyzed perioperatively. RESULTS: Demographic, CPB, and clinical outcome data were similar for both groups. Plasma fibrinogen, total protein, albumin, and platelet count decreased, neutrophil count, MDA, IL-8, MPO, and catalase levels increased during CPB. During CPB, MPO and catalase values were significantly higher in group P (p = 0.02 and p = 0.01) and postoperative MDA concentration was lower in group H (p = 0.03). Platelet counts were better preserved in group H during and after CPB but neutrophil count and IL-8 level did not differ between the groups. Postoperative total protein, albumin, and fibrinogen levels were higher in group H (p < 0.05). The postoperative first day levels of troponin-I, CK-MB, and CRP increased in both groups without any significant differences between the groups. CONCLUSIONS: Heparin-coated circuit provided better suppression of perioperative inflammatory markers and exhibited more favorable effects on hematologic variables than PMEA-coated circuit.     

Total thyroidectomy en bloc or not? prospective,randomized clinical trial: Cerrahpasa experience

Aim-Background

While significant changes in the last century have enabled safe and effective total thyroidectomy, the utility and reliability of techniques for patients with benign diseases is debatable. The purpose of this study was to compare the complication rates of division of the isthmus vs. non-division in thyroid surgery performed for bilateral multinodular goiter by experienced endocrine surgeons. To the best of our knowledge, no such study has been published in the literature to date.

Methods

This prospective study includes 60 consecutive serial patients who underwent total thyroidectomy. Patients were randomly assigned to a thyroidectomy technique by the arbitrary draw from a bag of paper tags marked as ‘U’ (thyroidectomy without dividing the isthmus) classified as Group 1 or ‘D’ (thyroidectomy by dividing the isthmus) as Group 2. Patients in Group 1 (n=30) had a total thyroidectomy without dividing the isthmus (en bloc), patients in Group 2 (n=30) had total thyroidectomy by dividing the isthmus.

Results

Postoperative serum mean calcium and parathyroid hormone (PTH) levels, operation period, visual analogue pain score and recurrent laryngeal nerve paralysis did not differ between the groups. Permanent hypocalcaemia and permanent recurrent laryngeal nerve paralysis were not observed in either group, but total morbidity in Group 1 was higher (p=0.038). Postoperative PTH levels were significantly lower than preoperative PTH levels in both groups; (respectively, p=0.007, p=0.011). No surgical mortality was recorded.

Conclusion

Thyroidectomy without dividing the isthmus can be qualified as a safe and applicable surgical method.