Penoscrotal Edema as a Rare Complication of Acute Pancreatitis: A Case Report.

Background and Objectives: Scrotal swelling or hydrocele is a rare complication of acute pancreatitis described in the literature. We present a case of penoscrotal swelling caused by the first attack of acute interstitial edematous alcohol-induced pancreatitis in a young male patient. Case report: A 22-year-old man was admitted to the emergency unit due to diarrhea and vomiting since morning which was followed by severe abdominal pain. Urgent abdominal multislice CT scan showed steatosis, pancreatic swelling and acute peripancreatic fluid collection (interstitial edematous pancreatitis). Also, scan showed fluid between small bowel loops and along the anterior renal fascia, while there was minimal amount of fluid in the Douglas space. There was no sign of penoscrotal swelling. On the second day of admission, the patient developed left scrotal swelling and mild pain without erythema. On the fourth day, a control CT scan showed progression to moderately severe pancreatitis (CT severity index 4). Dilated scrotal veins of the pampiniform venous plexus with an increased caliber of the testicular veins were present on both sides, from the scrotum to the level of the inguinal canal. Penoscrotal swelling was significantly reduced on discharge. Conclusions: Penoscrotal swelling is a rare complication or manifestation of acute inflammation of the pancreas. It is important to identify scrotal swelling caused by pancreatitis because in severe cases it can be related to possible infertility in the future.

Plasma Drug Values of DOACs in Patients Presenting with Gastrointestinal Bleeding: A Prospective Observational Study.

Background and Objectives: Anticoagulants are a well-known risk factor for gastrointestinal bleeding (GIB). In recent years, direct oral anticoagulants (DOACs) have taken a leading role in the treatment and prevention of thromboembolic incidents. The aim of this study was to investigate the prevalence of DOAC-treated patients with GIB whose plasma drug concentrations exceeded the cut-off values reported in the literature and to evaluate their clinical characteristics. Materials and Methods: Patients who were admitted to the Intensive Care Unit in the period 2/2020-3/2022 due to GIB were prospectively included in the study and classified into three groups according to the prescribed type of DOAC (apixaban, rivaroxaban, and dabigatran). For all participants, it was determined if the measured plasma drug levels exceeded the maximum serum concentration (Cmax) or trough serum concentration (Ctrough) obtained from the available data. A comparison of clinical parameters between the patients with and without excess drug values was performed. Results: There were 90 patients (54.4% men) included in the study, of whom 27 were treated with dabigatran, 24 with apixaban, and 39 with rivaroxaban. According to Cmax, there were 34 (37.8%), and according to Ctrough, there were 28 (31.1%) patients with excess plasma drug values. A statistically significant difference regarding excess plasma drug values was demonstrated between DOACs according to both Cmax (p = 0.048) and Ctrough (p < 0.001), with the highest rate in the group treated with dabigatran (55.6% for Cmax and 59.3% for Ctrough). Multivariate logistic regression showed that age (OR 1.177, p = 0.049) is a significant positive and glomerular filtration rate (OR 0.909, p = 0.016) is a negative predictive factor for excess plasma drug values. A total of six (6.7%) patients had fatal outcomes. Conclusions: Plasma drug concentrations exceed cut-off values reported in the literature in more than one-third of patients with GIB taking DOAC, with the highest rate in the dabigatran group. Clinicians should be more judicious when prescribing dabigatran to the elderly and patients with renal failure. In these patients, dose adjustment, plasma drug monitoring, or substitution with other, more appropriate DOACs should be considered.

Detection of Sarcopenia in Patients with Liver Cirrhosis Using the Bioelectrical Impedance Analysis.

Bioelectrical impedance analysis (BIA) is a body composition assessment method. We aimed to determine its accuracy in the detection of sarcopenia in patients with liver cirrhosis (LC), using skeletal muscle index (SMI) at the level of third lumbar vertebra (L3-SMI) obtained using multislice computed tomography as the reference method. Patients with LC were enrolled in the period October 2019-March 2022 and follow-ups were conducted until January 2023. Their BIA parameters were compared against L3-SMI, and BIA cut-off values were proposed using AUROC analysis. Patients underwent outcome analysis based on obtained clinical characteristics. A total of 106 patients were included. We found a fair correlation between BIA parameters with the L3-SMI. We determined cut-off values of ≤11.1 kg/m2 for BIA-SMI (Se 73%, Sp 66%, AUROC 0.737, p < 0.001) and ≤5.05° for phase angle (PA) (Se 79%, Sp 60%, AUROC 0.762, p < 0.001) in the detection of sarcopenia. The relative risk of death was 2.2 times higher in patients with skeletal muscle mass (SMM) ≤ 36.5 kg. SMM was significantly associated with outcome in Kaplan-Meier analysis. This non-invasive and simple method that showed fair performances and a very good outcome prediction could provide for the unmet need for fast and affordable detection of sarcopenia in patients with LC and should be further evaluated.

Assessment of Gallbladder Drainage Methods in the Treatment of Acute Cholecystitis: A Literature Review.

Gallbladder drainage is a treatment option in high-risk surgical patients with moderate or severe acute cholecystitis. It may be applied as a bridge to cholecystectomy or a definitive treatment option. Apart from the simple and widely accessible percutaneous cholecystostomy, new attractive techniques have emerged in the previous decade, including endoscopic transpapillary gallbladder drainage and endoscopic ultrasound-guided gallbladder drainage. The aim of this paper is to present currently available drainage techniques in the treatment of AC; evaluate their technical and clinical effectiveness, advantages, possible adverse events, and patient outcomes; and illuminate the decision-making path when choosing among various treatment modalities for each patient, depending on their clinical characteristics and the accessibility of methods.

Impact of hemodialysis on liver stiffness measured with real-time two-dimensional shear wave elastography.

BACKGROUND AND AIMS: The impact of hemodialysis on liver stiffness is still unclear. The aim of the study was to assess liver fibrosis by real-time two-dimensional shear wave elastography (RT 2D-SWE) and to quantify the influence of net fluid withdrawal on liver stiffness during one hemodialysis session. The second aim was to investigate the influence of systolic blood pressure and time spent on dialysis (in years) on liver stiffness measurements. METHODS: This before/after hemodialysis (HD) study in a group of end stage renal disease (ESRD) patients was carried out with patients on regular HD. Measurements of liver stiffness were done using RT 2D-SWE directly before and after a hemodialysis session. RESULTS: In this study 27 patients with mean age 69.4 ± 14.75 years were included. Mean net fluid withdrawal volume per session was 2874.07 ± 778.35 ml. Mean pre-HD and post-HD liver stiffness measurements were 8.15 kPa (95% confidence interval, CI 7.61-8.68) and 6.70 kPa (95% CI 6.10-7.30 kPa), respectively. Mean liver stiffness reduction was 1.448 ± 1.14 kPa. The amount of fluid removed correlated with the decline in liver stiffness values after HD (ρ = 0.523, P = 0.003). There was a positive but statistically not significant correlation between time spent in HD and liver stiffness (ρ = 0.151, P = 0.623) CONCLUSION: Liver stiffness significantly declined after one session of HD. The change in liver stiffness was strongly correlated with the amount of net fluid withdrawal. Random liver stiffness measurements (LSM) by RT 2D-SWE does not precisely show the degree of fibrosis, Furthermore, it is presumed that postdialysis liver stiffness values likely reflect the real degree of liver fibrosis.

Case report: successful endoscopic treatment of a large bowel perforation caused by chicken bone ingestion.

RATIONALE: Large bowel perforations by a foreign body are rarely diagnosed pre-operatively due to non-specific clinical symptoms. The safety and efficacy of foreign body removal via upper endoscopy is well-established and strongly recommended. There is far less experience of endoscopic treatment of sharp foreign bodies impacted in lower parts of gastrointestinal tract. PATIENT CONCERNS: The patient was 78-year-old female with abdominal pain and nausea. Symptoms had begun 48 hours prior to hospital admission. She had lost over 10 kg of body weight in the previous couple of months DIAGNOSIS:: A multidetector-row computed tomography (MDCT) examination of the abdomen revealed mural thickening and enhancement of the cecum with haziness and linear areas of high attenuation in the pericecal fat tissue. A colonoscopy showed, the clear presence of a sharp 5.5-cm-long chicken bone perforating the cecal wall at the antemesenteric site close to the Bauchini valve. INTERVENTIONS: A quarter of the bone that had penetrated the cecal wall was pulled out with a flexible colonoscopy using a polypectomy snare. Due to the form and length of the bone, it was withdrawn through the entire colon, using pointed end trailing. OUTCOMES: The patient was discharged three days after colonoscopy with normal laboratory results and without any pain. LESSONS: In cases where sharp foreign bodies stuck into the large bowel, it is highly advisable to try to remove them via colonoscopy, before deciding to resolve the issue through a surgical intervention.

Laugier-Hunziker syndrome in endocrine clinical practice.

Laugier-Hunziker syndrome (LHS) is a rare, benign and acquired disorder characterized by hyperpigmentation of the oral cavity and lips along with longitudinal melanonychia. No underlying systemic abnormalities or malignant predisposition is associated with it. In everyday clinical practice, an endocrinologist encounters certain endocrine conditions (e.g. Addison's disease, McCune-Albright syndrome) that present with, inter alia, mucocutaneous hyperpigmentation. Even though LHS is easily distinguished from endocrine entities mentioned earlier, diagnostic evaluation usually requires skilled and thorough practitioner. Since it is the diagnosis of exclusion, a number of systemic conditions must be ruled out prior to making the final diagnosis. However, its major differential diagnosis is primarily Peutz-Jeghers syndrome, which carries an increased risk of cancer. Here, we report a case of a young woman who was referred to the endocrinologist for diagnostic evaluation of dark-colored lesions of the oral cavity and nails. All performed laboratory tests were within reference range. Endoscopic gastrointestinal evaluation did not reveal neoplastic formations. Owing to an adult-onset, asymptomatic clinical course and negative diagnostic findings, we made a final diagnosis. In this case, target diagnostic evaluation notably reduced the need for additional expensive and invasive procedures and treatments. LEARNING POINTS: Laugier-Hunziker syndrome is a rare, acquired cause of asymptomatic, benign mucocutaneous hyperpigmentation.Prior to making a final diagnosis, certain medical entities with overlapping clinical features must be excluded.Endocrine conditions that usually present with the hyperpigmentation of the skin and mucous membranes (e.g. Addison's disease, McCune-Albright syndrome) can be easily ruled out based on clinical and laboratory findings.Its major differential diagnosis, Peutz-Jeghers syndrome is characterized by melanotic macules of the face and mouth, intestinal polyposis and significantly increased risk of different types of cancer, especially gastrointestinal.Anamnesis, physical examination and target diagnostic evaluation reduce the need for additional invasive and expensive procedures and treatment.

A Patient with Ulcerative Colitis Complicated by Systemic Vein Thrombosis.

Crohn's disease and ulcerative colitis (UC) patients have an increased risk for thromboembolic complications, the most common of them are deep venous thrombosis and pulmonary embolism. Other locations and genetic mutations of coagulation factors are not so common in these patients. Here we present a case of a young woman with exacerbation of previously diagnosed mild UC complicated by multiple thrombotic incidents due to MTHFR gene mutation.

Propofol Induces Apoptosis of Neurons but Not Astrocytes, Oligodendrocytes, or Neural Stem Cells in the Neonatal Mouse Hippocampus.

It has been shown that propofol can induce widespread apoptosis in neonatal mouse brains followed by long-term cognitive dysfunction. However, selective brain area and cell vulnerability to propofol remains unknown. This study was aimed to dissect toxic effect of propofol on multiple brain cells, including neurons, astrocytes, oligodendrocytes, and neural stem cells (NSCs). Seven-day-old mice were intraperitoneally administrated propofol or intralipid as a vehicle control for 6 hours. To identify vulnerable cells undergoing apoptosis following propofol exposure, brain sagittal sections were co-stained with antibodies against an apoptosis marker along with neuron, astrocyte, oligodendrocyte, or NSC markers using immunofluorescence staining. The results showed widespread apoptosis in propofol-treated brains (apoptotic cells: 1.55 ± 0.04% and 0.06 ± 0.01% in propofol group and intralipid-treated control group, respectively). Apoptotic cell distribution exhibits region- and cell-specific patterns. Several brain regions (e.g., cerebral cortex and hippocampus) were more vulnerable to propofol than other brain regions. Most apoptotic cells in the hippocampus were located in the cornus ammonis 1 (CA1) subfield. These apoptotic cells were only detected in neurons and not astrocytes, oligodendrocytes, or NSCs. These data demonstrate that different brain regions, subfields, and different types of neuronal cells in mice exhibit various vulnerabilities to propofol. Understanding region- and cell-specific susceptibility to propofol will help to better understand cellular contribution to developmental neurotoxicity and further develop novel therapeutic targets.

High Glucose Attenuates Anesthetic Cardioprotection in Stem-Cell-Derived Cardiomyocytes: The Role of Reactive Oxygen Species and Mitochondrial Fission.

BACKGROUND: Hyperglycemia can blunt the cardioprotective effects of isoflurane in the setting of ischemia-reperfusion injury. Previous studies suggest that reactive oxygen species (ROS) and increased mitochondrial fission play a role in cardiomyocyte death during ischemia-reperfusion injury. To investigate the role of glucose concentration in ROS production and mitochondrial fission during ischemia-reperfusion (with and without anesthetic protection), we used the novel platform of human-induced pluripotent stem-cell (iPSC)-derived cardiomyocytes (CMs). METHODS: Cardiomyocyte differentiation from iPSC was characterized by the expression of CM-specific markers using immunohistochemistry and by measuring contractility. iPSC-CMs were exposed to varying glucose conditions (5, 11, and 25 mM) for 24 hours. Mitochondrial permeability transition pore opening, cell viability, and ROS generation endpoints were used to assess the effects of various treatment conditions. Mitochondrial fission was monitored by the visualization of fragmented mitochondria using confocal microscopy. Expression of activated dynamin-related protein 1, a key protein responsible for mitochondrial fission, was assessed by Western blot. RESULTS: Cardiomyocytes were successfully differentiated from iPSC. Elevated glucose conditions (11 and 25 mM) significantly increased ROS generation, whereas only the 25-mM high glucose condition induced mitochondrial fission and increased the expression of activated dynamin-related protein 1 in iPSC-CMs. Isoflurane delayed mitochondrial permeability transition pore opening and protected iPSC-CMs from oxidative stress in 5- and 11-mM glucose conditions to a similar level as previously observed in various isolated animal cardiomyocytes. Scavenging ROS with Trolox or inhibiting mitochondrial fission with mdivi-1 restored the anesthetic cardioprotective effects in iPSC-CMs in 25-mM glucose conditions. CONCLUSIONS: Human iPSC-CM is a useful, relevant model for studying isoflurane cardioprotection and can be manipulated to recapitulate complex clinical perturbations. We demonstrate that the cardioprotective effects of isoflurane in elevated glucose conditions can be restored by scavenging ROS or inhibiting mitochondrial fission. These findings may contribute to further understanding and guidance for restoring pharmacological cardioprotection in hyperglycemic patients.

Association of Asymmetric Dimethylarginine With Acute Pancreatitis-Induced Hyperglycemia.

OBJECTIVE: The objective of this study was to investigate the relationship between asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, oxidative-nitrosative damage, and glucoregulation in acute pancreatitis (AP). METHODS: The study evaluated serum levels of ADMA, nitrotyrosine, and urinary 8-hydroxydeoxyguanosine in 40 male patients hospitalized for AP at baseline and at 2 and 10 days of treatment, respectively. The patients were classified into a mild and a moderately severe AP group (MAP and MSAP, respectively) according to Atlanta classification criteria. Glycemic status was evaluated by a 75-g oral glucose tolerance test 1 month after AP onset. Forty age-matched healthy subjects served as control subjects. RESULTS: Significant decrease of ADMA and increased levels of nitrotyrosine and urinary 8-hydroxydeoxyguanosine were found in MSAP, but not in MAP at baseline, with ADMA correction toward control levels at the 10th day of treatment. Fructosamine was found to significantly influence ADMA levels (r = -0.362, P = 0.002). After AP recovery, either impaired glucose tolerance or diabetes was identified with the oral glucose tolerance test in 10.5% and 92.8% of patients with MAP and MSAP, respectively. CONCLUSIONS: Insufficient inhibition of nitric oxide synthesis, through reduced bioavailability of ADMA, might be a novel significant contributory factor to the severity of AP and subsequent development of hyperglycemia.

Altered Mitochondrial Dynamics Contributes to Propofol-induced Cell Death in Human Stem Cell-derived Neurons.

BACKGROUND: Studies in developing animals have shown that anesthetic agents can lead to neuronal cell death and learning disabilities when administered early in life. Development of human embryonic stem cell-derived neurons has provided a valuable tool for understanding the effects of anesthetics on developing human neurons. Unbalanced mitochondrial fusion and fission lead to various pathological conditions including neurodegeneration. The aim of this study was to dissect the role of mitochondrial dynamics in propofol-induced neurotoxicity. METHODS: Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate in situ nick-end labeling staining was used to assess cell death in human embryonic stem cell-derived neurons. Mitochondrial fission was assessed using TOM20 staining and electron microscopy. Expression of mitochondrial fission-related proteins was assessed by Western blot, and confocal microscopy was used to assess opening time of the mitochondrial permeability transition pore (mPTP). RESULTS: Exposure to 6 h of 20 µg/ml propofol increased cell death from 3.18 ± 0.17% in the control-treated group to 9.6 ± 0.95% and led to detrimental increases in mitochondrial fission (n = 5 coverslips per group) accompanied by increased expression of activated dynamin-related protein 1 and cyclin-dependent kinase 1, key proteins responsible for mitochondrial fission. Propofol exposure also induced earlier opening of the mPTP from 118.9 ± 3.1 s in the control-treated group to 73.3 ± 1.6 s. Pretreatment of the cells with mdivi-1, a mitochondrial fission blocker rescued the propofol-induced toxicity, mitochondrial fission, and mPTP opening time (n = 75 cells per group). Inhibiting cyclin-dependent kinase 1 attenuated the increase in cell death and fission and the increase in expression of activated dynamin-related protein 1. CONCLUSION: These data demonstrate for the first time that propofol-induced neurotoxicity occurs through a mitochondrial fission/mPTP-mediated pathway.

MicroRNA-21 Mediates Isoflurane-induced Cardioprotection against Ischemia-Reperfusion Injury via Akt/Nitric Oxide Synthase/Mitochondrial Permeability Transition Pore Pathway.

BACKGROUND: The role of microRNA-21 in isoflurane-induced cardioprotection is unknown. The authors addressed this issue by using microRNA-21 knockout mice and explored the underlying mechanisms. METHODS: C57BL/6 and microRNA-21 knockout mice were echocardiographically examined. Mouse hearts underwent 30 min of ischemia followed by 2 h of reperfusion in vivo or ex vivo in the presence or absence of 1.0 minimum alveolar concentration of isoflurane administered before ischemia. Cardiac Akt, endothelial nitric oxide synthase (eNOS), and neuronal nitric oxide synthase (nNOS) proteins were determined by Western blot analysis. Opening of the mitochondrial permeability transition pore (mPTP) in cardiomyocytes was induced by photoexcitation-generated oxidative stress and detected by rapid dissipation of tetramethylrhodamine ethyl ester fluorescence using a confocal microscope. RESULTS: Genetic disruption of miR-21 gene did not alter phenotype of the left ventricle, baseline cardiac function, area at risk, and the ratios of phosphorylated-Akt/Akt, phosphorylated-eNOS/eNOS, and phosphorylated-nNOS/nNOS. Isoflurane decreased infarct size from 54 ± 10% in control to 36 ± 10% (P < 0.05, n = 8 mice per group), improved cardiac function after reperfusion, and increased the ratios of phosphorylated-Akt/AKT, phosphorylated-eNOS/eNOS, and phosphorylated-nNOS/nNOS in C57BL/6 mice subjected to ischemia-reperfusion injury. These beneficial effects of isoflurane were lost in microRNA-21 knockout mice. There were no significant differences in time of the mPTP opening induced by photoexcitation-generated oxidative stress in cardiomyocytes isolated between C57BL/6 and microRNA-21 knockout mice. Isoflurane significantly delayed mPTP opening in cardiomyocytes from C57BL/6 but not from microRNA-21 knockout mice. CONCLUSIONS: Isoflurane protects mouse hearts from ischemia-reperfusion injury by a microRNA-21-dependent mechanism. The Akt/NOS/mPTP pathway is involved in the microRNA-21-mediated protective effect of isoflurane.

BURNOUT SYNDROME AMONG EDUCATORS IN PRE-SCHOOL INSTITUTIONS.

INTRODUCTION: The occurrence of burnout syndrome (BS) has been recognized in many professions (pilots, firefighters, police officers, doctors…) that during their work are subjected to high levels of stress. For educators in preschool institutions stress level is very high thus creating the possibility of developing BS. MATERIAL AND METHODS: For this research is selected preschool institution - kindergarten "Radost" (Joy) in Split, in which by use of questionnaires (modified scale by Freudenberger and modified scales by Girdin, Everly and Dusek) during 2014 among educators (100 respondents) is conducted a survey regarding the frequency of burnout syndrome. RESEARCH RESULTS: According to questionnaires by Girdin, Everly and Dusek there is no statistically significant difference between the number of educators who feel good and those that are under significant stress (χ2=1.04; p=0.307). According to questionnaire by Freudenberg educators are classified into 3 categories and distribution of educators by the groups is almost uniform (χ2=2.76; p=0.250), which means that one third of a teacher is in good condition, a third is in the risk area for burn-out syndrome, while one third are candidates for development of this syndrome. Comparing a teacher in good condition compared to other (at risk and those who are candidates for the burn-out syndrome) is up to 1.5 times higher in those who are at risk and the candidates for development of this syndrome than in others (χ2=4.5; p=0.033). CONCLUSION: The occurrence of burnout syndrome is very high for the group of educators (half of the educators!) in pre-school institutions which should be taken into account by the institutions management. For this purpose, it is necessary to organize regular medical check-ups with particular reference to burnout syndrome with signs of the syndrome to prevent its further development.

Cdk1, PKCδ and calcineurin-mediated Drp1 pathway contributes to mitochondrial fission-induced cardiomyocyte death.

Myocardial ischemia-reperfusion (I/R) injury is one of the leading causes of death and disability worldwide. Mitochondrial fission has been shown to be involved in cardiomyocyte death. However, molecular machinery involved in mitochondrial fission during I/R injury has not yet been completely understood. In this study we aimed to investigate molecular mechanisms of controlling activation of dynamin-related protein 1 (Drp1, a key protein in mitochondrial fission) during anoxia-reoxygenation (A/R) injury of HL1 cardiomyocytes. A/R injury induced cardiomyocyte death accompanied by the increases of mitochondrial fission, reactive oxygen species (ROS) production and activated Drp1 (pSer616 Drp1), and decrease of inactivated Drp1 (pSer637 Drp1) while mitochondrial fusion protein levels were not significantly changed. Blocking Drp1 activity with mitochondrial division inhibitor mdivi1 attenuated cell death, mitochondrial fission, and Drp1 activation after A/R. Trolox, a ROS scavenger, decreased pSer616 Drp1 level and mitochondrial fission after A/R. Immunoprecipitation assay further indicates that cyclin dependent kinase 1 (Cdk1) and protein kinase C isoform delta (PKCδ) bind Drp1, thus increasing mitochondrial fission. Inhibiting Cdk1 and PKCδ attenuated the increases in pSer616 Drp1, mitochondrial fission, and cardiomyocyte death. FK506, a calcineurin inhibitor, blocked the decrease in expression of inactivated pSer637 Drp1 and mitochondrial fission. Our findings reveal the following novel molecular mechanisms controlling mitochondrial fission during A/R injury of cardiomyocytes: (1) ROS are upstream initiators of mitochondrial fission; and (2) the increased mitochondrial fission is resulted from both increased activation and decreased inactivation of Drp1 through Cdk1, PKCδ, and calcineurin-mediated pathways, respectively.

Epoxyeicosatrienoic acids pretreatment improves amyloid ß-induced mitochondrial dysfunction in cultured rat hippocampal astrocytes.

Amyloid-ß (Aß) has long been implicated as a causative protein in Alzheimer's disease. Cellular Aß accumulation is toxic and causes mitochondrial dysfunction, which precedes clinical symptoms of Alzheimer's disease pathology. In the present study, we explored the possible use of epoxyeicosatrienoic acids (EETs), epoxide metabolites of arachidonic acid, as therapeutic target against Aß-induced mitochondrial impairment using cultured neonatal hippocampal astrocytes. Inhibition of endogenous EET production by a selective epoxygenase inhibitor, MS-PPOH, caused a greater reduction in mitochondrial membrane potential in the presence of Aß (1, 10 µM) exposure versus absence of Aß. MS-PPOH preincubation also aggravated Aß-induced mitochondrial fragmentation. Preincubation of the cells with either 14,15- or 11,12-EET prevented this mitochondrial depolarization and fragmentation. EET pretreatment also further improved the reduction observed in mitochondrial oxygen consumption in the presence of Aß. Preincubation of the cells with EETs significantly improved cellular respiration under basal condition and in the presence of the protonophore, carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP). The uncoupling of ATP synthase from the electron transfer chain that occurred in Aß-treated cells was also prevented by preincubation with EETs. Lastly, cellular reactive oxygen species production, a hallmark of Aß toxicity, also showed significant reduction in the presence of EETs. We have previously shown that Aß reduces EET synthesis in rat brain homogenates and cultured hippocampal astrocytes and neurons (Sarkar P, Narayanan J, Harder DR. Differential effect of amyloid beta on the cytochrome P450 epoxygenase activity in rat brain. Neuroscience 194: 241-249, 2011). We conclude that reduction of endogenous EETs may be one of the mechanisms through which Aß inflicts toxicity and thus supplementing the cells with exogenous EETs improves mitochondrial dynamics and prevents metabolic impairment.

Ketamine enhances human neural stem cell proliferation and induces neuronal apoptosis via reactive oxygen species-mediated mitochondrial pathway.

BACKGROUND: Growing evidence indicates that ketamine causes neurotoxicity in a variety of developing animal models, leading to a serious concern regarding the safety of pediatric anesthesia. However, if and how ketamine induces human neural cell toxicity is unknown. Recapitulation of neurogenesis from human embryonic stem cells (hESCs) in vitro allows investigation of the toxic effects of ketamine on neural stem cells (NSCs) and developing neurons, which is impossible to perform in humans. In the present study, we assessed the influence of ketamine on the hESC-derived NSCs and neurons. METHODS: hESCs were directly differentiated into neurons via NSCs. NSCs and 2-week-old neurons were treated with varying doses of ketamine for different durations. NSC proliferation capacity was analyzed by Ki67 immunofluorescence staining and bromodeoxyuridine assay. Neuroapoptosis was analyzed by TUNEL staining and caspase 3 activity measurement. The mitochondria-related neuronal apoptosis pathway including mitochondrial membrane potential, cytochrome c distribution within cells, mitochondrial fission, and reactive oxygen species (ROS) production were also investigated. RESULTS: Ketamine (100 µM) increased NSC proliferation after 6-hour exposure. However, significant neuronal apoptosis was only observed after 24 hours of ketamine treatment. In addition, ketamine decreased mitochondrial membrane potential and increased cytochrome c release from mitochondria into cytosol. Ketamine also enhanced mitochondrial fission as well as ROS production compared with no-treatment control. Importantly, Trolox, a ROS scavenger, significantly attenuated the increase of ketamine-induced ROS production and neuronal apoptosis. CONCLUSIONS: These data for the first time demonstrate that (1) ketamine increases NSC proliferation and causes neuronal apoptosis; (2) mitochondria are involved in ketamine-induced neuronal toxicity, which can be prevented by Trolox; and (3) the stem cell-associated neurogenesis system may provide a simple and promising in vitro model for rapidly screening anesthetic neurotoxicity and studying the underlying mechanisms as well as prevention strategies to avoid this toxic effect.

Acute, food-induced moderate elevation of plasma uric acid protects against hyperoxia-induced oxidative stress and increase in arterial stiffness in healthy humans.

We examined the effects of acute, food-induced moderate increase of plasma uric acid (UA) on arterial stiffness and markers of oxidative damage in plasma in healthy males exposed to 100% normobaric oxygen. Acute elevation of plasma UA was induced by consumption of red wine, combination of ethanol and glycerol, or fructose. By using these beverages we were able to separate the effects of UA, wine polyphenols and ethanol. Water was used as a control beverage. Ten males randomly consumed test beverages in a cross-over design over the period of 4 weeks, one beverage per week. They breathed 100% O(2) between 60(th) and 90(th)min of the 4-h study protocol. Pulse wave augmentation index (AIx) at brachial and radial arteries, plasma antioxidant capacity (AOC), thiobarbituric acid-reactive substances (TBARS), lipid hydroperoxides (LOOH) assessed by xylenol orange method, UA and blood ethanol concentrations were determined before and 60, 90, 120, 150 and 240 min after beverage consumption. Consumption of the beverages did not affect the AIx, TBARS or LOOH values during 60 min before exposure to hyperoxia, while AOC and plasma UA increased except in the water group. Significant increase of AIx, plasma TBARS and LOOH, which occurred during 30 min of hyperoxia in the water group, was largely prevented in the groups that consumed red wine, glycerol+ethanol or fructose. In contrast to chronic hyperuricemia, generally considered as a risk factor for cardiovascular diseases and metabolic syndrome, acute increase of UA acts protectively against hyperoxia-induced oxidative stress and related increase of arterial stiffness in large peripheral arteries.