Volumetric measurements of weak current-induced magnetic fields in the human brain at high resolution.

PURPOSE: Clinical use of transcranial electrical stimulation (TES) requires accurate knowledge of the injected current distribution in the brain. MR current density imaging (MRCDI) uses measurements of the TES-induced magnetic fields to provide this information. However, sufficient sensitivity and image quality in humans in vivo has only been documented for single-slice imaging. METHODS: A recently developed, optimally spoiled, acquisition-weighted, gradient echo-based 2D-MRCDI method has now been advanced for volume coverage with densely or sparsely distributed slices: The 3D rectilinear sampling (3D-DENSE) and simultaneous multislice acquisition (SMS-SPARSE) were optimized and verified by cable-loop experiments and tested with 1-mA TES experiments for two common electrode montages. RESULTS: Comparisons between the volumetric methods against the 2D-MRCDI showed that relatively long acquisition times of 3D-DENSE using a single slab with six slices hindered the expected sensitivity improvement in the current-induced field measurements but improved sensitivity by 61% in the Laplacian of the field, on which some MRCDI reconstruction methods rely. Also, SMS-SPARSE acquisition of three slices, with a factor 2 CAIPIRINHA (controlled aliasing in parallel imaging results in higher acceleration) acceleration, performed best against the 2D-MRCDI with sensitivity improvements for the ∆ B z , c $$ \Delta {B}_{z,c} $$ and Laplacian noise floors of 56% and 78% (baseline without current flow) as well as 43% and 55% (current injection into head). SMS-SPARSE reached a sensitivity of 67 pT for three distant slices at 2 × 2 × 3 mm3 resolution in 10 min of total scan time, and consistently improved image quality. CONCLUSION: Volumetric MRCDI measurements with high sensitivity and image quality are well suited to characterize the TES field distribution in the human brain.

Effect of Nifedipine Used in the Treatment of the Threat of Preterm Labor on Total Uterine Artery Blood Volume Flow Rate.

PURPOSE: Evaluation of the effect of maternal nifedipine treatment on total uterine artery blood volume flow rate (TVFR). METHODS: In this prospective study, 43 women who were admitted to the Perinatology Department of the University of Health Sciences Etlik Zübeyde Hanim Gynecology Training and Research Hospital, with the diagnosis of the threat of preterm labor, and 40 healthy pregnant women, who were randomly selected as the control group, were evaluated between July 1, 2018, and September 1, 2018. A transabdominal ultrasound examination of uterine arteries was performed both before and 48 hours after administration of oral nifedipine for TVFR measurement. For the final analysis, the TVFR levels of the group diagnosed with the threat of preterm labor and the control group were compared. RESULTS: There was no significant difference in either uterine artery pulsatility index or resistance index values as well as the diameters of the uterine arteries after nifedipine treatment (p>0.05 for all). Total uterine artery blood volume flow rate (TVFR) was 424.66±236.74 mL/min before and 543.39±309.68 mL/min after treatment with nifedipine and was statistically significantly higher (p < 0.05). CONCLUSIONS: Our study showed a statistically significant increase in total uterine artery blood volume flow rate 48 hours after oral nifedipine treatment.

Maternal Serum and Umbilical Cord Brain Natriuretic Peptide Levels in Fetuses with Intrauterine Growth Restriction.

Aim: We compared maternal serum and fetal cord blood proBNP levels in healthy pregnancies to those with intrauterine growth restriction (IUGR). Methods: Prospectively, maternal and cord blood samples at childbirth of 40 pregnant women with isolated IUGR and 40 healthy pregnant women were evaluated for ProBNP levels. Results: The mean serum ProBNP level was significantly higher in newborn cord blood with IUGR than in the control group (181.28 ± 145.37 vs. 91.41 ± 49.77 pg/mL, p = <0.01). Mean serum ProBNP level trended higher in women with IUGR compared to the controls, but was not statistically significant (124.21 ± 113.32 vs. 88.73 ± 85.18 pg/mL, p= >0.05). Conclusion: Third trimester mean proBNP in fetal cord blood are increased in IUGR fetuses at term birth compared to pregnancies with normal fetal growth.

On the reconstruction of magnetic resonance current density images of the human brain: Pitfalls and perspectives.

Magnetic resonance current density imaging (MRCDI) of the human brain aims to reconstruct the current density distribution caused by transcranial electric stimulation from MR-based measurements of the current-induced magnetic fields. So far, the MRCDI data acquisition achieves only a low signal-to-noise ratio, does not provide a full volume coverage and lacks data from the scalp and skull regions. In addition, it is only sensitive to the component of the current-induced magnetic field parallel to the scanner field. The reconstruction problem thus involves coping with noisy and incomplete data, which makes it mathematically challenging. Most existing reconstruction methods have been validated using simulation studies and measurements in phantoms with simplified geometries. Only one reconstruction method, the projected current density algorithm, has been applied to human in-vivo data so far, however resulting in blurred current density estimates even when applied to noise-free simulated data. We analyze the underlying causes for the limited performance of the projected current density algorithm when applied to human brain data. In addition, we compare it with an approach that relies on the optimization of the conductivities of a small number of tissue compartments of anatomically detailed head models reconstructed from structural MR data. Both for simulated ground truth data and human in-vivo MRCDI data, our results indicate that the estimation of current densities benefits more from using a personalized volume conductor model than from applying the projected current density algorithm. In particular, we introduce a hierarchical statistical testing approach as a principled way to test and compare the quality of reconstructed current density images that accounts for the limited signal-to-noise ratio of the human in-vivo MRCDI data and the fact that the ground truth of the current density is unknown for measured data. Our results indicate that the statistical testing approach constitutes a valuable framework for the further development of accurate volume conductor models of the head. Our findings also highlight the importance of tailoring the reconstruction approaches to the quality and specific properties of the available data.

Sensitivity and resolution improvement for in vivo magnetic resonance current-density imaging of the human brain.

PURPOSE: Magnetic resonance current-density imaging (MRCDI) combines MRI with low-intensity transcranial electrical stimulation (TES; 1-2 mA) to map current flow in the brain. However, usage of MRCDI is still hampered by low measurement sensitivity and image quality. METHODS: Recently, a multigradient-echo-based MRCDI approach has been introduced that presently has the best-documented efficiency. This MRCDI approach has now been advanced in three directions and has been validated by phantom and in vivo experiments. First, the importance of optimum spoiling for brain imaging was verified. Second, the sensitivity and spatial resolution were improved by using acquisition weighting. Third, navigators were added as a quality control measure for tracking physiological noise. Combining these advancements, the optimized MRCDI method was tested by using 1 mA TES for two different injection profiles. RESULTS: For a session duration of 4:20 min, the new MRCDI method was able to detect TES-induced magnetic fields at a sensitivity level of 84 picotesla, representing a twofold efficiency increase against our original method. A comparison between measurements and simulations based on personalized head models showed a consistent increase in the coefficient of determination of ΔR2 = 0.12 for the current-induced magnetic fields and ΔR2 = 0.22 for the current flow reconstructions. Interestingly, some of the simulations still clearly deviated from the measurements despite the strongly improved measurement quality. This highlights the utility of MRCDI to improve head models for TES simulations. CONCLUSION: The achieved sensitivity improvement is an important step from proof-of-concept studies toward a broader application of MRCDI in clinical and basic neuroscience research.

Comparison of the maternal serum endocan levels in preterm premature rupture of membrane and normal pregnancy.

OBJECTIVE: Endocan is a novel marker of endothelial inflammation. In this study, we aimed to show whether there was a significant difference between the endocan levels of pregnant women with and without preterm premature rupture of membranes (PPROM and non-PPROM). Also, we aimed to find a relation between endocan levels and the latent period. MATERIAL AND METHODS: Pregnant women with PPROM between 28 and 34 weeks of gestation and those without PPROM with similar gestational weeks were included in the study. A total of 88 pregnant women, 44 with PROM and 44 healthy pregnancies, were evaluated. Demographic and obstetric features, leukocyte, and endocan levels of the study and control groups were compared. RESULTS: The demographic features and obstetric history of both groups were similar. The mean leukocyte and endocan levels of the study group were higher than in the control group (p < 0.001 and 0.029, respectively). The leukocyte level was the only independent factor predicting PPROM after multivariate logistic regression analysis. CONCLUSION: Although the endocan levels were higher in patients with PPROM, multivariate analysis showed that the only independent predictive factor was the leukocyte level.

Increased serum delta neutrophil index levels are associated with intrahepatic cholestasis of pregnancy.

OBJECTIVE: This study aims to compare the maternal serum delta neutrophil index (DNI) levels in intrahepatic cholestasis of pregnancy (ICP) and healthy pregnancies. METHODS: This study consisted of a group of patients (n = 40) diagnosed with isolated ICP who gave birth in our hospital and a control group (n = 60) between December 1, 2015, and June 30, 2018. The diagnosis of ICP was made based on pruritus and elevated fasting serum bile acids and liver enzymes. Laboratory tests of both groups in the hospitalization process were retrospectively examined. Maternal and neonatal characteristics, pregnancy outcomes, and DNI values of the two groups were compared. Statistical analyses were performed using SPSS version 20. RESULTS: Mean maternal serum DNI levels were significantly higher in women with ICP than in the control group (0.49 ± 4.8 vs -3.99 ± 3.02, p = <0.01). Receiver operating characteristic (ROC) curve analysis was used to define the DNI value where ICP can be best predicted. CONCLUSION: DNI, a new inflammatory marker, was found to be higher in women with ICP than in normal pregnancies.

Can placental elasticity predict the time of delivery in cases of threatened preterm labor?

AIM: We aimed to evaluate placental elasticity for the short-time prediction of delivery in cases of threatened preterm labor (TPL). METHODS: We performed a prospective study with consented pregnant women diagnosed with TPL (24th to 34th gestational week). According to the birth time, the patients were grouped into two groups, whether the delivery happened in the following first week or not. We compared the placental strain ratio (PSR) values between these two groups. RESULTS: A total of 108 pregnant women divided into two groups according to the delivery time were enrolled in our study. The pregnant women who had a delivery in 1 week after hospitalization have increased PSR values when compared to those who have not delivered within 1 week (P < 0.001). Multivariate logistic regression analysis showed that cervical length and PSR were significantly associated with delivery in 1 week after hospitalization. When the cervical length was entered as a covariate (control) variable, PSR was significantly associated with delivery time (B = 0.504, odds ratio: 1.655, 95% confidence interval: 1.339-2.045, P < 0.001). A PSR value of 4.04 had a sensitivity of 77.78% and a specificity of 87.04% in terms of short-time prediction of the delivery time, in the receiver-operator curves analysis to determine the cut-off point PSR value. CONCLUSION: Elastography may contribute to predict the delivery time in high-risk pregnants with TPL.

Relations between second-trimester aneuploidy screening results and prediction of labour induction success in term pregnancies.

We aimed to assess whether the second-trimester maternal serum markers could be used for the prediction of labour induction success. This prospective study enrolled women planned labour induction at term. Women were assigned to one of two groups: vaginal prostaglandin or balloon dilatation. All patients were evaluated for Bishop score, maternal serum oestriol, human chorionic gonadotropin and progesterone at the time of second-aneuploidy screening. The total successful rate for induction of labour was 63.9% in both groups. Maternal serum oestriol multiple of median (MoM) values were significantly lower among the caesarean section group compared to the vaginal delivery group (p < .001). A MoM value of 0.74 for oestriol was associated with a sensitivity of 75.9%, specificity of 41.0%, a positive predictive value of 76.6% and a negative predictive value of 58.0% for a successful induction of labour. Oestriol had a good performance in the prediction of successful induction of labour at term.IMPACT STATEMENTWhat is already known on this subject? Induction of labour is a common procedure undertaken whenever the benefits of prompt delivery outweigh the risks of expectant management. Previous studies have reported that a decreased progesterone/oestradiol ratio and increased maternal plasma oestriol levels are associated with successful labour. What the results of this study add? The results of this study showed that second-trimester oestriol multiple of median (MoM) value provide a significant contribution to the efforts of the prediction of successful induction of labour in term pregnancy, having a sensitivity of 69.8%, specificity of 92.4%, positive predictive value of 83.3% and negative predictive value of 82.5%.What the implications are of these findings for clinical practice and/or further research? This finding can be used as an additional method for prediction of labour induction as well as multiparity and Bishop score. This adds new valuable data to the literature which could be used for systematic reviews and for implementing guidelines and protocols on labour induction.

Is ProBNP a New Marker for Predicting Intrauterine Growth Restriction?

PURPOSE: To evaluate the usability of first-trimester maternal serum ProBNP levels in the prediction of intrauterine growth restriction (IUGR). Methods In this prospective study, blood samples taken from 500 women who applied to our polyclinic for routine serum aneuploidy screening between the 11-14th gestational weeks were centrifuged. The obtained plasma samples were placed in Eppendorf tubes and stored at -80+°C. For the final analysis, first-trimester maternal serum ProBNP levels of 32 women diagnosed with postpartum IUGR and 32 healthy women randomly selected as the control group were compared. FGR was defined as estimated fetal weight below the 10th percentile for the gestational age. RESULTS: The mean ProBNP levels were statistically and significantly higher in the women with intrauterine growth restriction (113.73±94.69 vs. 58.33±47.70 pg/mL, p<0.01). At a cut-off level of 50.93, ProBNP accurately predicted occurrence of IUGR (AUC+= 0.794 (95% confidence interval 0.679-0.910), p+= 0.001) with sensitivity and specificity rates of 78.1 and 69.0%, respectively. Conclusion First-trimester serum ProBNP level was significantly higher in women who developed IUGR compared to healthy controls. First-trimester ProBNP level can be used as a potential marker to predict the development of IUGR in pregnant women.

Skin Color May Predict Intra-Abdominal Adhesions During Repeated Caesarean Section Deliveries.

OBJECTIVE: Caesarean rates have increased rapidly for various reasons recently. One of the important reasons among these is medicolegal problems. Our aim with this study was to preoperatively predict abdominal adhesion density by combining the scar tissue morphology formed in the post-caesarean Pfannenstiel incision line and the skin color scoring of the patients. MATERIAL AND METHODS: Patients who had undergone one caesarean section previously, completed their terms (37-39 weeks) and were under 35 years old were included in the study. Skin color scoring of the patients was performed using the Fitzpatrick skin color scale. Intra-abdominal adhesion scoring of the participant patients was performed using Nair's adhesion scoring system. RESULTS: The change in abdominal adhesion scores was evaluated based on the Fitzpatrick color scale. Adhesion scores per the Nair intra-abdominal adhesion scoring system were found to be 0.04±0.209 in the FP1 group, 0.35±0.662 in the FP2 group, 1.58±0.923 in the FP3 group, and 2.33±0.577 in the FP4 group (p<0.05). These results showed a significant increase in adhesion density with increasing skin color darkness. Based on these results, it was observed that the abdominal adhesion scores and the frequency of depressed skin scar were significantly increased with increasing Fitzpatrick scores (p<0.05). CONCLUSION: The aim of this study was to increase the prediction rates by adding the skin color scoring to the scar tissue characteristics, which have been used in previous studies. The results of this study indicate that the combination of these two parameters may be more effective in predicting intra-abdominal adhesions. Nevertheless, there is a need for studies with a much higher number of patients and multiple parameters to be able to predict intra-abdominal adhesion density preoperatively with greater accuracy.

Effects of Covid-19 outbreak on environment and renewable energy sector.

Many articles have been written in the medical field related to the Covid-19 outbreak that has surrounded the World and killed many people. However, its environmental and energy impacts have not been sufficiently studied. Some sources argue that Covid-19 outbreak reduces pollution environmentally, while others say that environmentally significant damages await us. On the other hand, it is wondered how the global flexible renewable energy sector will react to Covid-19 outbreak. In this study, the effects of Covid-19 outbreak in terms of the environment and renewable energy sector in the literature were examined in detail and the findings obtained were discussed. The main aim of this study is to shed light on the future studies of environmental and renewable energy researchers.

The effect of placental elasticity on intraoperative bleeding in pregnant women with previous cesarean section.

Background We aimed to evaluate the efficiency of placental elasticity in predicting the amount of intraoperative bleeding via real-time tissue elastography technique. Methods Pregnant women in the third trimester of pregnancy who had planned delivery via cesarean section due to the recurrent cesareans were enrolled in the research (n = 78). Elastographic measurements of placental tissues of all cases were carried out by real-time elastographic ultrasonography. It is a tissue elastography software (Esaote MyLabSeven) that uses a 8-1-MHz multifrequency AC2541 Probe. Results A significant relationship was found between placental elasticity and intraoperative bleeding. There was a significant correlation between alterations in the preoperative and postoperative hemoglobin (Hb) and hematocrit (Hct) levels and placental strain ratio (SR) (P < 0.001, r: 0.831; P < 0.001, r: 0.733, respectively). Conclusion These findings may reflect an alteration at the tissue elasticity level. We hope that the use of real-time elastographic ultrasonography technique may give an idea about the amount of bleeding during the cesarean section.

Comparison of placental elasticity in normal and intrauterine growth retardation pregnancies by ex vivo strain elastography.

OBJECTIVE: To compare the placental elasticity in fetuses with or without intrauterine growth restriction (IUGR). MATERIALS AND METHODS: One hundred pregnant women (50 IUGR and 50 healthy) with anteriorly located placenta were evaluated during the third trimester of pregnancy. Measurements were carried out by a machine that has a real-time elastographic ultrasonography feature. After obtaining the optimum image, three areas (subcutaneous tissue, center, and the edge of the placenta) were provided to identify the placental strain values. Then, the placental strain ratio (PSR) value was calculated automatically. Two groups compared in terms of their PSR values. RESULTS: There was a significant difference in placental elasticity between the groups (P < 0.001). PSR value was 2.8 ± 1.2 in the IUGR group and 1.3 ± 0.6 in the control group. A PSR value of 1.78 had an 86% sensitivity (OR 4.3) and 80% specificity (OR 0.17) in IUGR cases. The positive predictive value was 81.1% and the negative predictive value was 85.1% for this cut-off value. CONCLUSIONS: We have shown that placental strain ratio is increased during the third trimester of pregnancy in fetuses with IUGR. Increased stiffness and elasticity may be responsible for the onset of IUGR in some cases.

Comparison of automated vs. manual measurement to estimate fetal weight in isolated polyhydramnios.

Objective To understand the impact of the measurement method to predict actual birthweight in pregnancies complicated with isolated polyhydramnios in the third trimester. Methods A prospective study was conducted with 60 pregnant women between the 37th and 40th weeks of gestation. Routine biometric measurements were obtained by two-dimensional (2D) ultrasonography. When a satisfactory image was obtained, the image was frozen to get two measurements. First, calipers were placed to get the manual measurement. Then automated measurement was captured by the ultrasonography machine in the same image. The fetal weight was estimated by using the Hadlock II formula. Results The mean difference was found to be 0.03, -0.77, -0.02 and 0.17 for biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL), respectively. Pearson's correlation coefficient between automated and manual estimated fetal weights (EFWs) and the actual birthweight was 0.919 and 0.796, respectively. The mean difference between actual and manual EFW measurement values was 46.16 ± 363.81 g (range between -745 g and 685 g) (P = 0.330). Also, the mean difference between actual and automated EFW measurement values was found to be 31.98 ± 218.65 g (range between -378 g and 742 g) (P = 0.262). The Bland-Altman test results have shown that, 666 g lower or 759 g higher values were obtained when the measurement was performed manually. On the other hand, EFW results were 396 g lower or 460 g higher than the actual birthweight with automated measurement tools. Conclusion The accuracy rate of fetal weight estimation with ultrasonography is high for both automated and manual measurements. Automated tools have a higher success to predict the EFW.

A comprehensive assessment of redox balance in small for gestational age newborns and their mothers.

OBJECTIVE: The objective of this study was to assess oxidative stress in small for gestational age (SGA) newborns and their mothers by evaluating intra- and extracellular thiol homeostasis and the quantification of major oxidants and antioxidants. METHODS: A total of 75 mothers and their 75 newborns (43 SGA) were enrolled in this study. Thiol-disulfide homeostasis, serum myeloperoxidase, catalase, total oxidant, and antioxidant status were analyzed. Additionally, erythrocytic glutathione (GSH) homeostasis was measured. RESULTS: Although native and total thiol levels were decreased, disulfide levels were increased in SGA groups. Additionally, myeloperoxidase activity and total oxidant status levels were significantly elevated whereas total antioxidant status levels and enzymatic antioxidant systems were diminished in SGA groups. Similarly, intra-erythrocytic GSH homeostasis was shifted in favor of oxidants in SGA groups. CONCLUSION: Our results demonstrate that insufficient antioxidant systems in mothers and a robust source of oxidative stress in SGA might contribute to the pathophysiology of SGA births.

Impact of Short-Term Weight Loss on Hemostasis and Thrombosis after Bariatric Surgery.

Introduction: Obesity causes thrombophilia and many coagulation problems related to slowing the capillary flow. We aimed to evaluate rapid weight loss outcomes in the early period after bariatric surgery on the coagulation system. Materials and Method. A prospective study enrolled 28 patients with a BMI > 40 kg/m2 who underwent bariatric surgery. Preoperative and postoperative (first and third months) demographic criteria-such as age, gender, weight, height, and alcohol and tobacco use, and biochemical parameters such as PLT, PT, aPTT, INR, bleeding time, coagulation time, fibrinogen, D-dimer, albumin, calcium, ionized calcium, vitamin D, and PTH-were analyzed. Results: We found that both bleeding and thrombotic parameters increase in early-slowing surgery. The first-month platelet levels were significantly different from the preoperative values (p < 0.001). The prothrombin time in the first (p < 0.001) and third months (p < 0.009) was also comparable. The PTT in the first month was higher than in the preoperative period (p < 0.011). INR in the first month (p < 0.001) was higher than that in the preoperative period and the third month (p = 0.007) value was higher than in the first month. In terms of fibrinogen levels, all parameters indicated statistical significance within each other; preoperative to the first month (p < 0.001), the first month to the third month (p < 0.016). Third-month D-dimer levels were lower than the first month's values (p = 0.032). Conclusion: Thromboembolic events have crucial importance in the converse scenario of haemorrhagic diathesis during the first months of bariatric surgery. Vitamin support and antithrombotic agents may be recommended in the early postoperative period.

Programmed cell death 1 and programmed cell death ligand 1 expression in invasive breast carcinoma using CAL10 and NAT105 immunostaining.

Increased incidence of breast cancer has stimulated development of new diagnostic and therapeutic methods. The programmed cell death 1 (PD1) pathway and its inhibitors are promising avenues for investigation. PD1 includes PD ligands 1 (PDL1) and 2 (PDL2). We investigated the expression of PD1 and PDL1 in invasive breast carcinomas using immunohistochemical staining. We used 171 invasive breast carcinoma specimens from which tissue microarray blocks were created. Immunohistochemical staining of PD1 using NAT105, and PDL1 using CAL10 was performed on tissue microarray sections. NAT105 and CAL10 are useful clones for detecting expression of PD1 and PDL1. PD1 and PDL1 immunostaining was significantly stronger in carcinomas with basal-like phenotype compared to other molecular breast cancer types. PD1 and PDL1 expression also was associated with a high histologic grade and a high Ki-67 index. PD1 expression also was associated with lymphovascular invasion and axillary metastasis. PD1 and PDL1 expression is associated with aggressive tumor behavior and a basal-like phenotype in breast cancer. We suggest that inhibition of the PD1/PDL1 pathway, particularly in triple negative breast carcinomas with basal-like phenotype, might be useful for targeted immunotherapy.

Effect of Fresh Gas Flow Rate on Thiol/Disulphide Hemostasis and Ischemia-modified Albumin in Laparoscopic Cholecystectomy.

OBJECTIVE: To investigate the effects of low-flow and high-flow anesthesia techniques, administered with sevoflurane during laparoscopic cholecystectomy, on thiol/disulphide homeostasis and serum ischemia-modified albumin (IMA) levels. STUDY DESIGN: Double-blind, randomised study. PLACE AND DURATION OF STUDY: Department of Anesthesiology and Reanimation, Health Science University, Bursa Yuksek Ihtisas Training and Education hospital, Bursa, Turkey from January to October 2020. METHODOLOGY: Patients over the age of 18 years, scheduled for elective laparoscopic cholecystectomy, were included in the study. The patients were divided into two groups: Group 1 (low-flow, 1 L/min) and Group 2 (high-flow, 2 L/min). The blood samples for thiol/disulphide homeostasis and serum IMA levels were collected as follows: 5 minutes before induction of anesthesia (T0), 5 minutes after induction of anesthesia (T1) and postoperative 24th hour (T2). RESULTS: The final analysis included 104 patients. The two groups did not differ significantly in terms of any of the demographic characteristics (p >0.05). There were also no inter-group differences in terms of thiol/disulphide homeostasis parameters or serum IMA levels at T0, T1, or T2. However, in both groups, there were statistically significant changes in serum disulphide and IMA levels from T0 to T1 and T0 to T2 (p=0.000, and p=0.005, respectively). CONCLUSION: There was no difference between low-flow and high-flow anesthesia during laparoscopic cholecystectomy in terms of hemodynamics or thiol/disulphide homeostasis. Key Words: Low-flow anesthesia, High-flow anesthesia, Thiol/disulphide homeostasis, Ischemia-modified albumin (IMA), Laparoscopic cholecystectomy.

The effects of methylene blue on adhesion formation in a rat model of experimental peritonitis.

BACKGROUND: We investigated the effects of methylene blue (MB) on the early and late phases of adhesion and abscess formation in a standard colonic wall injury and fecal peritonitis model in rats. METHODS: There were four groups: Group I (only laparotomy, n=10), Group II (peritonitis + MB, n=15), Group III (peritonitis + saline, n=15), and Group IV (colon incision + saline, n=15). Mortality, morbidity, adhesion scores, histopathologic analyses, serum tumor necrosis factor-alpha (TNF-?) levels, and tissue hydroxyproline (5-HP) levels were evaluated in all animals. Descriptive statistical methods were used with Kruskal-Wallis test. When a statistical difference was obtained between groups, Mann-Whitney U test was used to confirm the difference between two groups. RESULTS: Adhesion scores of Groups I, III and IV were significantly higher than in Group II. TNF-? levels were significantly higher in Groups I, III and IV. 5-HP levels were significantly lower in Groups I and II compared to Groups III and IV. CONCLUSION: Based on these results, it appears that MB may prevent peritoneal adhesions in a peritonitis model, but wound healing could be impaired. MB should be further evaluated because of its dual effect.