Okadaic acid enhances NfKB, TLR-4, caspase 3, ERK ½, c-FOS, and 8-OHdG signaling pathways activation in brain tissues of zebrafish larvae.

This study was designed to investigate the potential neuronal damage mechanism of the okadaic acid (OA) in the brain tissues of zebrafish embryos by evaluating in terms of immunofluorescence of Nf KB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG signaling pathways. We also evaluated body malformations. For this purpose, zebrafish embryos were exposed to 0.5 µg/ml, 1 µg/ml and 2.5 µg/ml of OA for 5 days. After application, FITC/GFP labeled protein-specific antibodies were used in immunofluorescence assay for NfKB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG respectively. The results indicated that OA caused immunofluorescence positivity of NfKB, TLR-4, caspase 3, ERK ½, c-FOS and 8-OHdG in a dose-dependent manner in the brain tissues of zebrafish embryos. Pericardial edema (PE), nutrient sac edema (YSE) and body malformations, tail malformation, short tail and head malformation (BM) were detected in zebrafish embryos. These results suggest that OA induces neuronal damage by affecting the modulation of DNA damage, apoptotic, and inflammatory activities in the brain tissues of zebrafish embryos. The increase in signaling pathways shows that OA can cause damage in the structure and function of brain nerve cells. Our results provide a new basis for the comprehensive assessment of the neural damage of OA and will offer enable us to better understand molecular the mechanisms underlying the pathophysiology of OA toxicity.

Comparison of pre-operative platelet functions by thromboelastogram in patients selective serotonin reuptake inhibitors user and non-user.

BACKGROUND: The use of antidepressant drugs, in particular selective serotonin reuptake inhibitors (SSRIs), has increased in recent years. Using SSRIs can cause changes in serotonin metabolism. Serotonin provides platelet aggregation and plays a role in the regulation of vascular tone and coagulation processes. The aim of this study was to evaluate the effects of SSRI use on coagulation functions with thromboelastogram (TEG) in patients undergoing surgical operation and to compare with non-user cases. METHODS: The study was designed for 60 patients whose physical status was classified according to the American Society of Anes-thesiology (ASA) classification as ASA I-II were included in the study. During routine pre-operative blood tests, 2 ml complete blood sample used and TEG performed. The cases were divided into two groups as SSRI user and non-user and analyzed. RESULTS: R value was higher in SSRI user patients than in non-user patients. The MA value was significantly lower in SSRI user. There was no statistically significant difference in other parameters. In the evaluation based on duration of SSRI use, there was no statistically significant difference between those whose duration of use was more than 1 year and <1 year. CONCLUSION: When the coagulation process was evaluated by TEG method, it was seen that the onset of clotting was prolonged and thrombus formation was slowed down in SSRI users. The results did not reveal that SSRI alone was the cause of bleeding, but it was concluded that slowing the process might be important, especially for surgical operations.

Investigation of the effect of ultrasonography-guided bilateral erector spinae plane block on postoperative opioid consumption and pain scores in patients undergoing hepatectomy: a prospective, randomized, controlled study

ABSTRACT BACKGROUND: There is still a debate about what constitutes effective and safe postoperative analgesia in hepatectomy surgery. Erector spinae plane (ESP) block may be an important part of multimodal analgesia application in hepatectomy surgery. OBJECTIVES: To compare the effects of ultrasound-guided bilateral erector spinae plane block combined with intravenous (iv) patient-controlled analgesia (iv PCA), in comparison with iv PCA alone, in hepatectomy surgery. DESIGN AND SETTINGS: Randomized prospective single-blinded study in a tertiary university hospital. METHODS: Fifty patients scheduled for elective hepatectomy surgery were included in the study. Patients were randomized into the ESP group or the control group. In the ESP group, bilateral ESP block was performed preoperatively and iv PCA was used. In the control group, only iv PCA was used. Numerical rating scale (NRS) scores at rest and coughing, analgesic requirements and occurrences of nausea and vomiting were recorded. RESULTS: Intraoperative and postoperative opioid consumption, rescue analgesia requirement and resting and dynamic NRS scores were significantly lower in the ESP group (P < 0.05). There was no significant difference between two groups in terms of the presence of dynamic pain after the first postoperative hour. While all patients in the control group had nausea and vomiting, 24% of the patients in the ESP group did not have nausea and vomiting. CONCLUSION: This study showed that ESP block can be used as a part of multimodal analgesia, with the benefit of reducing opioid consumption and postoperative nausea and vomiting in hepatectomy surgery. CLINICAL TRIAL REGISTRATION: ACTRN12620000466943.

Investigation of the effect of ultrasonography-guided bilateral erector spinae plane block on postoperative opioid consumption and pain scores in patients undergoing hepatectomy: a prospective, randomized, controlled study.

BACKGROUND: There is still a debate about what constitutes effective and safe postoperative analgesia in hepatectomy surgery. Erector spinae plane (ESP) block may be an important part of multimodal analgesia application in hepatectomy surgery. OBJECTIVES: To compare the effects of ultrasound-guided bilateral erector spinae plane block combined with intravenous (iv) patient-controlled analgesia (iv PCA), in comparison with iv PCA alone, in hepatectomy surgery. DESIGN AND SETTINGS: Randomized prospective single-blinded study in a tertiary university hospital. METHODS: Fifty patients scheduled for elective hepatectomy surgery were included in the study. Patients were randomized into the ESP group or the control group. In the ESP group, bilateral ESP block was performed preoperatively and iv PCA was used. In the control group, only iv PCA was used. Numerical rating scale (NRS) scores at rest and coughing, analgesic requirements and occurrences of nausea and vomiting were recorded. RESULTS: Intraoperative and postoperative opioid consumption, rescue analgesia requirement and resting and dynamic NRS scores were significantly lower in the ESP group (P < 0.05). There was no significant difference between two groups in terms of the presence of dynamic pain after the first postoperative hour. While all patients in the control group had nausea and vomiting, 24% of the patients in the ESP group did not have nausea and vomiting. CONCLUSION: This study showed that ESP block can be used as a part of multimodal analgesia, with the benefit of reducing opioid consumption and postoperative nausea and vomiting in hepatectomy surgery. CLINICAL TRIAL REGISTRATION: ACTRN12620000466943.

Evaluation of coagulation with TEG in patients diagnosed COVID-19.

BACKGROUND: A high D-dimer level may indicate the risk of coagulopathy and mortality in COVID-19 patients. T hromboelastography (TEG) is a test that evaluates clot formation and fibrinolysis in real-time, unlike routine coagulation tests. The study aimed to investigate the coagulation process with TEG in patients diagnosed with COVID-19. METHODS: The study was performed at our university hospital, chest diseases outpatient clinic as a cross-section study. A total of 51 patients with 23 high D-dimer levels group (HDG) and 28 low D-dimers group (LDG) were included in the study. TEG analysis was performed at the pretreatment evaluation in these two groups. RESULTS: D-dimer and fibrinogen levels of the HDG were higher than those of the LDG (550 vs. 90 ng/mL, p < 0.001; 521 vs. 269 mg/ dL, p < 0.001, respectively). In TEG analysis, HDG's R and K values were lower than LDG, and HDG's Angle, MA, and CI values were higher than LDG (p = 0.037; p < 0.001; p < 0.001; p < 0.001; p < 0.001, respectively). ROC curve analysis suggested that the optimum TEG parameters cut-off points for thrombosis risk were as below: for K was ≤2.1 min, for R was ≤6.1 min, for Angle was >62°, MA was 60.4 mm.

How does elevated water temperature affect fish brain? (A neurophysiological and experimental study: Assessment of brain derived neurotrophic factor, cFOS, apoptotic genes, heat shock genes, ER-stress genes and oxidative stress genes).

Water temperature is one of the most important environmental factors affecting the growth and survival of fish. Increased water temperature became a global problem and it is estimated that there will be an increase in water temperature due to global climate change. The physiological mechanism for the effects of high water temperature on the fish brain is not fully known. In the present study, fish were exposed to different temperatures (10 °C/15 °C/20 °C/25°) and brain tissues were sampled 2 h-4h-6h-8h per hour respectively and then we investigated transcriptional changes of BDNF, cFOS, apoptotic genes (caspase 3, Bax, Bcl2), heat shock genes (Hsp70 and Hsp 90) ER-Stress genes (grp78, atf6, and ire1) and oxidative stress genes (CAT, SOD, and GPx) and also immunoflourescence changes of BDNF and cFOSin rainbow trout brain. The results indicated that high temperature stress lead to physiological changes in the fish brain by causing a decrease in mRNA expression levels of CAT, SOD, GPx and Bcl2 and by causing an increase in mRNA expression of BDNF, cFOS, apoptotic genes (caspase 3, Bax), heat shock genes (Hsp70 and Hsp 90) ER-Stress genes (grp78, atf6, and ire1). This study will provide important information to elucidate the physiological mechanisms related to the effects of high water temperature on the fish brain.

Assessment of oxidative DNA damage, oxidative stress responses and histopathological alterations in gill and liver tissues of Oncorhynchus mykiss treated with linuron.

We investigated changes in 8-hydroxy-2-deoxyguanosine (8-OHdG) activity which is a product of oxidative DNA damage, histopathological changes and antioxidant responses in liver and gill tissues of rainbow trout, following a 21-day exposure to three different concentrations of linuron (30 µg/L, 120 µg/L and 240 µg/L). Our results indicated that linuron concentrations caused an increase in LPO levels of liver and gill tissues (p < 0.05). While linuron induced both increases and decreases in GSH levels and SOD activity, CAT activity was decreased by all concentrations of linuron (p < 0.05). The immunopositivity of 8-OHdG was detected in the hepatocytes of liver and in the epithelial and chloride cells of the secondary lamellae of the gill tissues. Our results suggested that linuron could cause oxidative DNA damage by causing an increase in 8-OHdG activity in tissues, and it induces histopathological damage and alterations in the antioxidant parameters of the tissues.

Is sodium carboxymethyl cellulose (CMC) really completely innocent? It may be triggering obesity.

The toxicity of sodium carboxymethyl cellulose (CMC), which has GRAS status and has been determined as "ADI non specified", was re-evaluated with a new modelling and molecular-based data. For this purpose, CMC, a food additive, was injected to the yolk sac (food) of the zebrafish embryo by the microinjection method at the 4th hour of fertilization at different concentrations. As a result, it was found that CMC showed no toxic effects within the framework of the parameters studied. But, we determined increasing lipid accumulation in zebrafish embryos exposed to CMC in a dose-dependent manner. To elucidate the mechanism underlying this lipid accumulation, the expression levels of genes related to obesity-linked lipid metabolism were examined. Our findings show that while CMC does not cause a toxic effect in zebrafish embryos, it can lead important effects on lipid metabolism by causing changes in the expression of some genes associated with obesity.

The role of right ventricular volumes and inferior vena cava diameters in the evaluation of volume status before colonoscopy

Background/aim: Ultrasonographic measurements of inferior vena cava (IVC) diameters and right ventricle (RV) volumes are important tools for the evaluation of intravascular volume. The current study investigates the association of IVC diameters and RV volumes before colonoscopy in prediction of postanesthesia hypotension. Materials and methods: Seventy patients scheduled for colonoscopy were included in the study. Preoperatively, expirium (dIVC max) and inspirium (dIVC min) IVC diameters were measured using M-mode ultrasonography and the collapsibility index (IVC-CI) was calculated. Ventricular volumes and areas were also measured using transthoracic echocardiography. Postanesthesia hypotension was defined as mean arterial blood pressure of <60 mmHg or a decrease of >30% in the mean arterial pressure after sedation. Results: Minimum and maximum IVC diameters were significantly lower (P = 0.005 and P < 0.001, respectively) and IVC-CI was significantly higher (P < 0.001) in patients who developed hypotension. Similarly, right ventricular end-diastolic area (RV-EDA), right ventricular end-systolic area (RV-ESA), right ventricular end-diastolic volume (RV-EDV), right ventricular end-systolic volume (RVESV), and left ventricular end-systolic volume (LV-ESV) values were significantly lower in patients with hypotension (P < 0.05). Logistic regression analysis showed that dIVC min and RV-ESA were independent predictors of hypotension. Conclusion: IVC diameters and RV-ESA, RV-EDA, RV-ESV, and RV-EDV are good indicators of preoperative volume status and can be used to predict the patients at risk of developing hypotension.

The protective effect exerted by dietary borax on toxicity metabolism in rainbow trout (Oncorhynchus mykiss) tissues.

The aim of this study was to evaluate the effectiveness of borax (BX) against heavy metal exposure on the transcriptional and biochemical reaction in vivo and alleviating effect on gill and liver tissues of rainbow trout. Due to this aim, fish were fed with different level of BX and/or copper (Cu) (1.25, 2.5 and 5 mg/kg of BX; 500 and 1000 mg/kg of Cu) for 21·days in pre- and co-treatment options. The transcriptional parameters [(heat-shock protein 70 (hsp70), and cytochromes P450 (cyp1a), glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT))], antioxidant enzyme activities (SOD, CAT and GPx), malondialdehyde (MDA), oxidative DNA damage (8-hydroxy-2'-deoxyguanosine (8-OHdG) and caspase-3 levels were investigated in different tissues samples of treated and control fish. Our results revealed that antioxidant enzyme activity was increased and levels of 8-OHdG, Caspase-3 and MDA were decreased in the BX and BX combined groups as compared to the copper combination group and to copper-only application during pre- and co-treatment (p < 0.05). Similarly, hsp70 and cyp1a gene expressions were decreased after treatment with BX. As conclusion, we suggest that borax itself is not an antioxidant it supportes antioxidant defense mechanism of fish disrupted by heavy metals.

Neurophysiological responses in the brain tissues of rainbow trout (Oncorhynchus mykiss) treated with bio-pesticide.

The aim of this study was to investigate neurophysiological responses in rainbow trout brain tissue exposed to natural/botanical pesticides. Fish were exposed to botanical and synthetic pesticides over a 21-day period. At the end of the treatment period, oxidative DNA damage (indicated by 8-OHdG (8-hydroxy-2'-deoxyguanosine), AChE activity (acetylcholinesterase) and transcriptional parameters (gpx (glutathione peroxidase), sod (superoxide dismutase), cat (catalase), HSP70 (heat shock protein 70) and CYP1A (cytochromes P450)) was investigated in control and application groups. Our results indicated that brain AChE activities decreased very significantly in fish treated with both insecticide types when compared with control (p < 0.05). 8-OHdG activity increased in a dose/time-dependent situation in the brain tissues of Oncorhynchus mykiss (p < 0.05). In addition, with regards to gene expression, gpx sod and, cat expressions were down-regulated, whereas CYP1A and HSP70 gene expression were up-regulated in fish treated with both insecticides when compared to the control group (p < 0.05). The data for this study suggests that bio-pesticides can cause neurophysiological changes in fish brain tissue.

Research on the efficacy of the rectus sheath block method.

OBJECTIVES: We aimed to retrospectively investigate the efficacy of ultrasound guided rectus sheath block (RSB) method in our study. METHODS: We scanned 235 patient files operated for abdominal pathology. Patients meeting the criteria were evaluated for intra-operative rectus sheath block and two different groups were formed. In these two groups of patients visual analogue scale (VAS) values recorded from the postoperative pain follow-up form and analgesic delivery (DEL) and analgesic demand (DEM) values recorded from patient controlled analgesia (PCA) device were compared. In addition, complaints of nausea, vomiting and constipation were evaluated. RESULTS: Postoperative VAS values (Postoperative 1, 12 and 24 hours p<0.001), DEM values (Postoperative 1, 12 and 24 hours p<0.001) and total amount of morphine consumed (Postoperative 1, 12 and 24 hours p<0.001) were lower in patients with RSB. Also, in patients with RSB nausea (p=0.014) and vomiting was less seen postoperatively (p=0.007). In the first 24 hours after surgery, constipation was seen in 8 patients with RSB and constipation was seen in 30 patients without RSB (p=0.00). CONCLUSION: Ultrasound guided rectus sheath block is an effective method for postoperative pain control.

Immunofluorescence/fluorescence assessment of brain-derived neurotrophic factor, c-Fos activation, and apoptosis in the brain of zebrafish (Danio rerio) larvae exposed to glufosinate.

In this study, we investigated the potential neuro-toxicological mechanism of the glufosinate in the brain of zebrafish larvae in terms of BDNF and c-Fos proteins by evaluating apoptosis, immunofluorescence BDNF, and c-FOS activation. We also measured survival rate, hatching rate, and body malformations during 96 h exposure time. For this purpose, zebrafish embryos were treated with graded concentrations of dosing solutions (0.5, 1, 3, and 5 ppm) of glufosinate. End of the treatment, acridine orange staining was used to detect apoptotic cells in the brain of zebrafish larvae at 96 hpf. Texas Red and FITC/GFP labeled protein-specific antibodies were used in immunofluorescence assay for BDNF and c-FOS, respectively. The results have indicated that exposure to glufosinate caused to embryonic death, hatching delay, induction of apoptosis, increasing of c-FOS activity and the level of BDNF in a dose-dependent manner. As a conclusion, we suggested that c-Fos might play a role in the regulation of BDNF which responses to prevent the cell from apoptosis even in case of unsuccessful in zebrafish larvae exposed to glufosinate.

Neuroprotective effects of dietary borax in the brain tissue of rainbow trout (Oncorhynchus mykiss) exposed to copper-induced toxicity.

We aimed to investigate the modulating effects of dietary borax on the pathways in rainbow trout brain exposed to copper. For this aim, a comprehensive assessment was performed including biochemical (acetylcholinesterase (AChE), malondialdehyde (MDA), oxidative DNA damage (8-hydroxy-2'-deoxyguanosine (8-OHdG), and caspase-3 levels) and transcriptional parameters (heat shock protein 70 (HSP70) and cytochromes P450 (CYP1A), glutathione peroxidase (gpx), superoxide dismutase (sod), and catalase (cat)) parameters and immunohistochemically staining of 8-OHdG. Special fish feed diets were prepared for the trial. These diets contained different concentrations of borax (1.25, 2.5, and 5 mg/kg) and/or copper (500 and 1000 mg/kg) at the period of pre- and co-treatment strategies for 21 days. At the end of the treatment periods, brain tissue was sampled for each experimental group. As a result, the biochemical parameters were increased and AChE activity decreased in the copper and copper-combined groups in comparison with the control group and also with only borax applications (p < 0.05). We observed an increase or decrease in particular biochemical parameters for the borax group in every application and we established that borax had protective effect against copper toxicity by decreasing and/or increasing the relevant biochemical parameters in brain tissue of fish. The biochemical results of borax and its combinations corresponded to the observations of gene expression data, which similarly concluded that HSP70 and CYP1A genes were strongly induced by copper (p < 0.05). In addition, the expression levels of the sod, cat, and gpx genes in the fish brains exposed to borax and the borax combination groups were significantly higher than the only copper-treated groups. In conclusion, borax supplementation provided significant protection against copper-induced neurotoxicity in trout.

Force and time-dependent self-assembly, disruption and recovery of supramolecular peptide amphiphile nanofibers.

Biological feedback mechanisms exert precise control over the initiation and termination of molecular self-assembly in response to environmental stimuli, while minimizing the formation and propagation of defects through self-repair processes. Peptide amphiphile (PA) molecules can self-assemble at physiological conditions to form supramolecular nanostructures that structurally and functionally resemble the nanofibrous proteins of the extracellular matrix, and their ability to reconfigure themselves in response to external stimuli is crucial for the design of intelligent biomaterials systems. Here, we investigated real-time self-assembly, deformation, and recovery of PA nanofibers in aqueous solution by using a force-stabilizing double-pass scanning atomic force microscopy imaging method to disrupt the self-assembled peptide nanofibers in a force-dependent manner. We demonstrate that nanofiber damage occurs at tip-sample interaction forces exceeding 1 nN, and the damaged fibers subsequently recover when the tip pressure is reduced. Nanofiber ends occasionally fail to reconnect following breakage and continue to grow as two individual nanofibers. Energy minimization calculations of nanofibers with increasing cross-sectional ellipticity (corresponding to varying levels of tip-induced fiber deformation) support our observations, with high-ellipticity nanofibers exhibiting lower stability compared to their non-deformed counterparts. Consequently, tip-mediated mechanical forces can provide an effective means of altering nanofiber integrity and visualizing the self-recovery of PA assemblies.

Probe microscopy methods and applications in imaging of biological materials.

Atomic force microscopy is an emerging tool for investigating the biomolecular aspects of cellular interactions; however, cell and tissue analyses must frequently be performed in aqueous environment, over rough surfaces, and on complex adhesive samples that complicate the imaging process and readily facilitate the blunting or fouling of the AFM probe. In addition, the shape and surface chemistry of the probe determine the quality and types of data that can be acquired from biological materials, with certain information becoming available only within a specific range of tip lengths or diameters, or through the assistance of specific chemical or biological functionalization procedures. Consequently, a broad range of probe modification techniques has been developed to extend the capabilities and overcome the limitations of biological AFM measurements, including the fabrication of AFM tips with specialized morphologies, surface coating with biologically affine molecules, and the attachment of proteins, nucleic acids and cells to AFM probes. In this review, we underline the importance of probe choice and modification for the AFM analysis of biomaterials, discuss the recent literature on the use of non-standard AFM tips in life sciences research, and consider the future utility of tip functionalization methods for the investigation of fundamental cell and tissue interactions.

Biocompatible Electroactive Tetra(aniline)-Conjugated Peptide Nanofibers for Neural Differentiation.

Peripheral nerve injuries cause devastating problems for the quality of patients' lives, and regeneration following damage to the peripheral nervous system is limited depending on the degree of the damage. Use of nanobiomaterials can provide therapeutic approaches for the treatment of peripheral nerve injuries. Electroactive biomaterials, in particular, can provide a promising cure for the regeneration of nerve defects. Here, a supramolecular electroactive nanosystem with tetra(aniline) (TA)-containing peptide nanofibers was developed and utilized for nerve regeneration. Self-assembled TA-conjugated peptide nanofibers demonstrated electroactive behavior. The electroactive self-assembled peptide nanofibers formed a well-defined three-dimensional nanofiber network mimicking the extracellular matrix of the neuronal cells. Neurite outgrowth was improved on the electroactive TA nanofiber gels. The neural differentiation of PC-12 cells was more advanced on electroactive peptide nanofiber gels, and these biomaterials are promising for further use in therapeutic neural regeneration applications.

Multivalent Presentation of Cationic Peptides on Supramolecular Nanofibers for Antimicrobial Activity.

Noncovalent and electrostatic interactions facilitate the formation of complex networks through molecular self-assembly in biomolecules such as proteins and glycosaminoglycans. Self-assembling peptide amphiphiles (PA) are a group of molecules that can form nanofibrous structures and may contain bioactive epitopes to interact specifically with target molecules. Here, we report the presentation of cationic peptide sequences on supramolecular nanofibers formed by self-assembling peptide amphiphiles for cooperative enhanced antibacterial activity. Antibacterial properties of self-assembled peptide nanofibers were significantly higher than soluble peptide molecules with identical amino acid sequences, suggesting that the tandem presentation of bioactive epitopes is important for designing new materials for bactericidal activity. In addition, bacteria were observed to accumulate more rapidly on peptide nanofibers compared to soluble peptides, which may further enhance antibacterial activity by increasing the number of peptide molecules interacting with the bacterial membrane. The cationic peptide amphiphile nanofibers were observed to attach to bacterial membranes and disrupt their integrity. These results demonstrate that short cationic peptides show a significant improvement in antibacterial activity when presented in the nanofiber form.