Evaluation of possible antioxidant and anticonvulsant effects of the ethyl acetate fraction from Platonia insignis Mart. (Bacuri) on epilepsy models

The aim of present study was to examine the effects of the ethyl acetate fraction (EAF) from Platonia insignis on lipid peroxidation level, nitrite formation, and superoxide dismutase and catalase activities in rat striatum prior to pilocarpine-induced seizures as well as to explore its anticonvulsant activity in adult rats prior to pentylenetetrazole (PTZ)- and picrotoxin (PIC)-induced seizures. Wistar rats were treated with vehicle, atropine (25 mg/kg), EAF (0.1, 1, and 10 mg/kg), pilocarpine (400 mg/kg, P400 group), PTZ (60 mg/kg, PTZ group), PIC (8 mg/kg, PIC group), atropine + P400, EAF + P400, EAF + PTZ, or EAF + PIC. Significant decreases in number of crossings and rearings were observed in the P400 group. The EAF 10 + P400 group also had significant increases in these parameters. In addition, in rats treated with P400, there were significant increases in lipid peroxidation and nitrite levels; however, there were no alterations in SOD and catalase activities. In the EAF 10 + P400 group, lipid peroxidation and nitrite levels significantly decreased and SOD and catalase activities significantly increased after pilocarpine-induced seizures. Additionally, effects of the EAF were evaluated in PTZ and PIC models. EAF did not increase the latency to development of convulsions induced with PTZ and PIC at the doses tested. Our findings strongly support the hypothesis that EAF does not have anticonvulsant activity in the different models of epilepsy studied. Our results indicate that in the in vivo model of pilocarpine-induced seizures, EAF has antioxidant activity, but not anticonvulsant properties at the doses tested.     

Effects of prenatal stress and exercise on dentate granule cells maturation and spatial memory in adolescent mice

Exposure to prenatal stress (PS) increases the risk of developing neurobehavioral disturbances later in life. Previous work has shown that exercise can exert beneficial effects on brain damage; however, it is unknown whether voluntary wheel running (VWR) can ameliorate the neurobehavioral impairments induced by PS in adolescent offspring. Pregnant CF-1 mice were randomly assigned to control (n = 5) or stressed (n = 5) groups. Pregnant dams were subjected to restraint stress between gestational days 14 and 21 (G14–21), whereas controls remained undisturbed in their home cages. On postnatal day 21 (P21), male pups were randomly assigned to the following experimental groups: control (n = 5), stressed (n = 5), and stressed mice + daily submitted to VWR (n = 4). At P52, all groups were behaviorally evaluated in the Morris water maze. Animals were then sacrificed, and Golgi-impregnated granule cells were morphometrically analyzed. The results indicate that PS produced significant behavioral and neuronal impairments in adolescent offspring and that VWR significantly offset these deleterious effects.     

Cisplatin induces platelet apoptosis through the ERK signaling pathway

Cisplatin (cis-diamminedichloroplatinum II) is one of the most widely used anti-tumor agents. However, cisplatin-based chemotherapy is usually accompanied by adverse side effects such as thrombocytopenia, and the mechanism remains unclear. Here we show that cisplatin induced several platelet apoptotic events including up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-X_L, mitochondrial translocation of Bax, mitochondrial inner transmembrane potential depolarization, caspase-3 activation and phosphatidylserine (PS) exposure. Cisplatin dose-dependently induced activation of extracellular signal-regulated protein kinase (ERK) in platelets. Caspase-3 inhibitor z-DEVD-fmk dramatically inhibited cisplatin-induced caspase-3 activation and PS exposure without affecting ERK activation. Blockade of the ERK pathway significantly prevented platelet apoptosis. Furthermore, levels of reactive oxygen species (ROS) and Ca^2 + were significantly elevated by cisplatin, and scavenging of ROS and Ca^2 + obviously inhibited platelet apoptosis induced by cisplatin. In addition, cisplatin did not induce platelet activation, whereas it obviously impaired platelet functions. These data indicate that cisplatin induces platelet apoptosis through the ERK signaling pathway, which might contribute to cisplatin-related haematological toxicity.     

Erythropoietin improves brain development in short-term hypoxia in rat embryo cultures

Background: Hypoxic ischemic encephalopathy continues to be a significant cause of death and disability worldwide. Erythropoietin (EPO) has the potential to lessen neurologic sequelae due to hypoxia–ischemia. Methods: The in vitro effects of EPO on total embryonic development and brain VEGF receptor (VEGFR) expressions were investigated in 50 rat embryos at 9.5 days of gestation that were cultured in whole rat serum (WRS). According to the study protocol, the embryos were divided into two groups. The first group is comprised hypoxia, 100 and 50 U/ml EPO after hypoxia groups. Group 2 comprised control (WRS) and WRS + EPO. After 48-h culture, the embryos from each group were harvested to be analyzed according to a morphological scoring system and also genetically to measure brain VEGFR expression. Results: The mean morphological scores for the embryos grown in control, WRS + EPO, hypoxia, and in the presence of 100 and 50 U/ml EPO in hypoxic medium were 55.30 ± 7.22, 52.10 ± 5.27, 23.0 ± 4.60, 36.20 ± 5.07, and 19.70 ± 5.07, respectively. Expressions of VEGFR-1, -2, -3 were significantly elevated in the 100 U/ml EPO and WRS + EPO groups compared to the hypoxia group (p < 0.05). Conclusions: These results support the conclusion that (1) VEGFR-1, -2, -3 may increase with EPO treatment in hypoxic conditions, (2) VEGF and EPO may be part of a self-regulated physiological protection mechanism to prevent neuronal injury including in utero neural tube defects.     

Antioxidant enzymes in cerebral cortex of immature rats following experimentally-induced seizures: upregulation of mitochondrial MnSOD (SOD2)

We have recently demonstrated the evidence of oxidative stress in brain of immature rats during seizures induced by dl-homocysteic acid (dl-HCA). The aim of the present study was to investigate the antioxidant defense mechanisms under these conditions. Seizures were induced in immature 12-day-old rats by bilateral icv infusion of dl-HCA (600 nmol/side), and the activities of the main antioxidant enzymes were examined in supernatants of the cerebral cortex during the acute phase of seizures and at several periods of survival, up to 5 weeks, following these seizures. In control animals individual antioxidant enzymes revealed different changes during the studied postnatal period (PD 12 till PD 47). Total superoxide dismutase (SOD), CuZn SOD (SOD1), Mn SOD (SOD2) and glutathione peroxidase (GPX) activities were increasing while, catalase activity decreased and the activity of glutathione reductase (GR) remained unchanged. In HCA-treated animals, the activity of total SOD, SOD1 and particularly SOD2 significantly increased at 20 h and 6 days of survival. Importantly, upregulation of SOD2 was also confirmed in mitochondria at the protein level by immunoblotting. The activities of other antioxidant enzymes including catalase and GPX did not significantly differ upon HCA treatment from the appropriate controls at any of the studied time intervals. The pronounced and selective upregulation of SOD2 points to enhanced ROS levels in the mitochondrial matrix. This may be associated with inhibition of respiratory chain complex I that we have demonstrated in our previous studies. The present findings suggest that oxidative stress occurring in the brain of immature rats during and following the seizures induced by dl-HCA is apparently due to both the increased free radical production and the limited antioxidant defense.     

Enhanced thrombin formation and fibrinolysis during acute Puumala hantavirus infection

Introduction

Nephropathia epidemica (NE) is a viral hemorrhagic fever with renal syndrome associated with thrombocytopenia and mild bleeding. We assessed activation of coagulation and fibrinolysis during the acute phase of NE.

Materials and methods

19 hospital-treated patients were involved. Plasma levels of D-dimer, prothrombin fragments 1 + 2 (F1 + 2), activated partial thromboplastin time (APTT), prothrombin time (PT%), thrombin time (TT), fibrinogen, antithrombin (AT), protein S free antigen (PS), protein C (PC) and complete blood count (CBC) were measured three times during the acute phase and once at 32-54 days after the onset of fever (recovery phase). Laboratory abnormalities were evaluated by the disseminated intravascular coagulation (DIC) scoring advocated by the International Society of Thrombosis and Haemostasis (ISTH).

Results

APTT was prolonged and D-dimer and F1 + 2 increased during the acute phase of NE. AT, PC and PS decreased, and TT was shortened, all implying increased thrombin generation. Acutely F1 + 2 was 3.4-fold and D-dimer even 24-fold higher compared with the recovery phase (median 726 vs 213 pmol/l, and median 4.8 vs 0.2 mg/l, respectively, p < 0.001 for both). Platelet count correlated with AT, PC, and PS (r = 0.73, r = 0.81, and r = 0.71, respectively, p < 0.001 for all) as well as with fibrinogen (r = 0.72, p < 0.001). Only five patients fulfilled the ISTH diagnosis of DIC.

Conclusions

During acute NE thrombocytopenia was associated with decreased natural anticoagulants, shortened thrombin time and enhanced fibrinolysis. Augmented thrombin formation and fibrinolysis characterize this hantavirus infection.     

Neurochemical evidence that 3-methylglutaric acid inhibits synaptic Na,K-ATPase activity probably through oxidative damage in brain cortex of young rats

3-Methylglutaconic aciduria (MGTA) comprehends a group of disorders biochemically characterized by accumulation of 3-methylglutaric acid (MGA), 3-methylglutaconic acid (MGT) and occasionally 3-hydroxyisovaleric acid (OHIVA). Although neurological symptoms are common in the affected individuals, the mechanisms of brain damage are poorly known. In the present study we investigated the in vitro effect MGA, MGT and OHIVA, at concentrations ranging from 0.1 to 5.0 mM, on bioenergetics and oxidative stress in synaptosomal preparations isolated from cerebral cortex of young rats. MGA significantly reduced mitochondrial redox potential (25%), as determined by resazurin reduction, and inhibited the activity of Na⁺,K⁺-ATPase (30%), whereas MGT and OHIVA did not modify these parameters. Moreover, the inhibitory effect elicited by MGA on Na⁺,K⁺-ATPase activity was totally prevented by co-incubation with the scavenging antioxidants creatine and melatonin, implying a role for reactive species in this effect. MGA also increased 2′,7′-dichlorofluorescein (DCFH) oxidation (30%), reinforcing that this organic acid induces reactive species production. The present data indicate that MGA compromises mitochondrial function, elicits reactive species production and inhibits the activity of a crucial enzyme implicated in neurotransmission. It is therefore presumed that these deleterious effects may play a role in the pathophysiology of the brain damage observed in patients affected by disorders in which MGA accumulates.     

Normal reference ranges of antithrombin,protein C and protein S: Effect of sex,age and hormonal status

Introduction

Antithrombin (AT), protein C (PC) and protein S (PS) deficiencies are risk factors for venous thromboembolism. Overlapping values between heterozygous carriers and normal individuals often make a correct classification of a deficiency difficult. The aim of this study was to investigate the effect of sex, age, menopause and hormone therapy on natural anticoagulant plasma levels in a large group of healthy individuals, and to evaluate the need of separate reference ranges.

Materials and Methods

AT and PC were measured with a chromogenic assay, antigenic free PS with an ELISA test. To evaluate the effect of sex, age, oral contraception, hormonal status (and their interaction) on AT, PC and PS levels, linear regression models were used. Biological relevance and the value of the normal deviate z were chosen as rules to decide for separate reference ranges.

Results

The study population consisted of 1837 healthy adult individuals (741 men, 1096 women), aged 18-85 years (median age: 44 years). In men AT levels decreased after the age of 50 years. Men had higher levels of PS than women, particularly at young ages. In women, after correction for menopause, only PC levels increased with age. Menopause affected AT and PS, but not PC levels. Oral contraceptive intake was associated with a decrease of AT and PS, and an increase of PC levels.

Conclusions

For AT, PC and PS, sex- and age-specific normal reference ranges can be useful, in order to better discriminate true carriers of a natural anticoagulant deficiency.     

Maternal exercise during pregnancy ameliorates the postnatal neuronal impairments induced by prenatal restraint stress in mice

Clinical and preclinical studies have demonstrated that prenatal stress (PS) induces neuronal and behavioral disturbances in the offspring. In the present study, we determined whether maternal voluntary wheel running (VWR) during pregnancy could reverse the putative deleterious effects of PS on the neurodevelopment and behavior of the offspring. Pregnant CF-1 mice were randomly assigned to control, restraint stressed or restraint stressed + VWR groups. Dams of the stressed group were subjected to restraint stress between gestational days 14 and delivery, while control pregnant dams remained undisturbed in their home cages. Dams of the restraint stressed + VWR group were subjected to exercise between gestational days 1 and 17. On postnatal day 23 (P23), male pups were assigned to one of the following experimental groups: mice born from control dams, stressed dams or stressed + VWR dams. Locomotor behavior and pyramidal neuronal morphology were evaluated at P23. Animals were then sacrificed, and Golgi-impregnated pyramidal neurons of the parietal cortex were morphometrically analyzed. Here, we present two major findings: first, PS produced significantly diminished dendritic growth of parietal neurons without altered locomotor behavior of the offspring; and second, maternal VWR significantly offset morphological impairments.     

Total oligomeric flavonoids of Cyperus rotundus ameliorates neurological deficits, excitotoxicity and behavioral alterations induced by cerebral ischemic-reperfusion injury in rats

Interactions between neurons and astrocytes play a critical role in the central nervous system homeostasis. Cyperus rotundus (family: Cyperaceae), a traditional Indian medicinal herb, used as nervine tonic and nootropic in the Ayurvedic system of medicine. The present study was undertaken to investigate the neuroprotective effect of total oligomeric flavonoids (TOFs), prepared from C. rotundus, in rat model of cerebral ischemia and reperfusion. Male Sprague Dawley rats (290-340 g) were subjected to middle cerebral artery occlusion (MCAO) for 2 h and reperfusion for 70 h. Experimental animals were divided into four groups: Group I - sham operated (n = 7); Group II - vehicle treated ischemic-reperfusion (IR) (n = 9), and Group III and IV - TOFs treated (100 and 200 mg/kg body weight, p.o., respectively; n = 7 in each group). Vehicle or TOFs were pretreated for four days before the induction of ischemia and continued for next three days after the ischemia i.e. treatment was scheduled totally for a period of 7 days. MCAO surgery was performed on day 4, 1 h after TOFs administration. Neuroprotective effect of TOFs was substantiated in terms of neurological deficits, excitotoxicity (glutamate, glutamine synthetase and Na⁺K⁺ATPase levels), oxidative stress (malondialdehyde, super oxide dismutase, and glutathione) and neurobehavioral functions in the experimental animals. TOFs decreased glutamate, glutamine synthetase (GS) and increased Na⁺K⁺ATPase activity in a dose dependent manner when compared to the IR rats. Treatment with TOFs significantly reduced the neurological deficits and reversed the anxiogenic behavior in rats. Further, it also significantly decreased MDA and increased superoxide dismutase (SOD) and glutathione content in brains of experimental rats. Histopathological examination using cresyl violet staining revealed the attenuation of neuronal loss by TOFs in stroke rats. The present study demonstrates the unswerving involvement of TOFs on ischemia-reperfusion triggered biochemical alterations in MCAO/R rats. Hence, TOFs might be an attractive candidate for further studies in the development of new drugs for cerebral stroke treatment.     

Cyanide preconditioning protects brain endothelial and NT2 neuron-like cells against glucotoxicity: role of mitochondrial reactive oxygen species and HIF-1α

The current study was undertaken to address the role of mitochondrial reactive oxygen species (ROS), and hypoxia inducible factor-1 alpha (HIF-1α) signaling pathway in the protection against high glucose levels in brain endothelial and NT2 neuron-like cells. Rat brain endothelial cells (RBE4) treated with non-toxic concentrations of cyanide (≤ 1 μM; 1 h) exhibited an increase in ROS levels, particularly hydrogen peroxide (H₂O₂). Cyanide also induced a modest mitochondrial depolarization, an increase in oxygen consumption and a structural (smaller mitochondria) and spatial (perinuclear region) reorganization of mitochondrial network. The stabilization and nuclear activation of HIF-1α in the presence of cyanide were also observed, which resulted in an increase in vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and erythropoietin (EPO) protein levels reflecting an adaptive response. Importantly, preconditioning induced by cyanide protected brain endothelial cells against high glucose-mediated damage by the prevention of apoptotic cell death. In mitochondrial DNA-depleted NT2 (NT2 ρ0) cells, cyanide (0.1 μM) was unable to stimulate ROS production and, consequently, protect against glucotoxicity. Conversely, in NT2 cells, the parental cells with functional mitochondria, cyanide significantly increased ROS levels protecting against high glucose-induced neuronal cell loss and activation of caspase-3. The free radical scavenger N-acetyl-L-cysteine and the specific HIF-1α inhibitor 2-methoxyestradiol completely abolished the protective effects of cyanide preconditioning. Altogether our results demonstrate that mitochondrial preconditioning induced by cyanide triggers a protective response mediated by mitochondrial ROS and HIF-1α activation and signaling, which render brain endothelial and neuronal cells resistant against glucotoxicity.     

Swimming training prevents pentylenetetrazol-induced inhibition of Na+, K+-ATPase activity, seizures, and oxidative stress

Purpose: In the present study we decided to investigate whether physical exercise protects against the electrographic, oxidative, and neurochemical alterations induced by subthreshold to severe convulsive doses of pentyltetrazole (PTZ). Methods: The effect of swimming training (6 weeks) on convulsive behavior induced by PTZ (30, 45, and 60 mg/kg, i.p.) was measured and different electrographic electroencephalography (EEG) frequencies obtained from freely moving rats. After EEG recordings, reactive oxygen species (ROS) generation, nonprotein sulfhydryl (NPS), protein carbonyl, thiobarbituric acid‐reactive substances (TBARS), superoxide dismutase (SOD), catalase (CAT), Na⁺, K⁺‐ATPase activity, and glutamate uptake were measured in the cerebral cortex of rats. Results: We showed that physical training increased latency and attenuated the duration of generalized seizures induced by administration of PTZ (45 mg/kg). EEG recordings showed that physical exercise decreased the spike amplitude after PTZ administration (all doses). Pearson’s correlation analysis revealed that protection of physical training against PTZ‐induced seizures strongly correlated with NPS content, Na⁺, K⁺‐ATPase activity, and glutamate‐uptake maintenance. Physical training also increased SOD activity, NPS content, attenuated ROS generation per se, and was effective against inhibition of Na⁺, K⁺‐ATPase activity induced by a subthreshold convulsive dose of PTZ (30 mg/kg). In addition, physical training protected against 2′,7′‐dichlorofluorescein diacetate (DCFH‐DA) oxidation, TBARS and protein carbonyl increase, decrease of NPS content, inhibition of SOD and catalase, and inhibition glutamate uptake induced by PTZ. Conclusions: These data suggest that effective protection of selected targets for free radical damage, such as Na⁺, K⁺‐ATPase, elicited by physical training protects against the increase of neuronal excitability and oxidative damage induced by PTZ.     

ROS-independent preconditioning in neurons via activation of mitoK(ATP) channels by BMS-191095.

Previously, we have shown that the selective mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel opener BMS-191095 (BMS) induces neuronal preconditioning (PC); however, the exact mechanism of BMS-induced neuroprotection remains unclear. In this study, we have identified key components of the cascade resulting in delayed neuronal PC with BMS using isolated rat brain mitochondria and primary cultures of rat cortical neurons. BMS depolarized isolated mitochondria without an increase in reactive oxygen species (ROS) generation and induced rapid phosphorylation of Akt and glycogen synthase kinase-3beta. Long-term (3 days) treatment of neurons with BMS resulted in sustained mitochondrial depolarization, decreased basal ROS generation, and elevated ATP levels. This treatment also elicited almost complete protection against glutamate excitotoxicity, which could be abolished using the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin, but not with the superoxide dismutase (SOD) mimetic M40401. Long-term BMS treatment induced a PI3K-dependent increase in the expression and activity of catalase without affecting manganese SOD and copper/zinc-dependent SOD. Finally, the catalase inhibitor 3-aminotriazole dose-dependently antagonized the neuroprotective effect of BMS-induced PC. In summary, BMS depolarizes mitochondria without ROS generation, activates the PI3K-Akt pathway, improves ATP content, and increases catalase expression. These mechanisms appear to play important roles in the neuroprotective effect of BMS.     

瑞香素通过抑制TXNIP/NLRP3信号通路来减轻OGD/R诱导的海马神经元炎症反应和凋亡

目的 探讨瑞香素通过抑制硫氧还蛋白结合蛋白(Thioredoxin-interacting protein,TXNIP)/核苷酸结合寡聚化结构域样受体蛋白3(Nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)信号通路来对氧糖剥夺/复氧(Oxygen-glucose deprivation/Reoxygenation,OOGD/R)诱导的海马神经元炎症反应和凋亡的影响。方法 对体外培养的小鼠海马神经元HT-22做OGD/R处理诱导建立细胞损伤模型,采用细胞计数试剂盒-8(Cell counting Kit-8,CCK-8)实验检测0、5、10、20、40、80 μmol/L的瑞香素对其细胞活力的影响,筛选出最佳作用水平; 将体外培养的HT-22细胞随机分为对照组、模型组、瑞香素(40 μmol/L)组、TXNIP空载(转染TXNIP空载质粒)组、TXNIP过表达(转染TXNIP过表达质粒)组、瑞香素(40 μmol/L)+TXNIP过表达组,以瑞香素和质粒提前处理12 h后进行OGD/R诱导建立细胞损伤模型; 采用二苯甲亚胺、三氯化氢2'-(4-羟基苯基)-5-(4-甲基-1-哌嗪基)-2,5'-二-1H-苯并咪唑(2'-(4-Hydroxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5'-bi-1H-benzimidazole,trihydrochloride,Hoechst)33258染色及流式细胞实验检测各组HT-22细胞凋亡情况; 采用试剂盒检测各组HT-22细胞线粒体膜电位; 应用酶标仪测量各组HT-22细胞肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、白细胞介素(Interleukin,IL)-6、IL-1β、IL-18、超氧化物歧化酶(Superoxide Dismutase,SOD)、过氧化氢酶(Catalase,CAT)、活性氧(Reactive oxygen species,ROS)及乳酸脱氢酶(Lactate dehydrogenase,LDH)释放水平; 采用免疫印迹实验检测各组HT-22细胞TXNIP/NLRP3通路蛋白表达水平。结果 选择40μmol/L瑞香素处理OGD/R诱导HT-22细胞进行后续实验; 与对照组比较,模型组HT-22细胞凋亡率、细胞TNF-α,IL-6,IL-1β,IL-18及ROS水平、细胞LDH释放水平、细胞TXNIP,NLRP3及天冬氨酸特异性半胱氨酸蛋白酶1(Cysteine-containing aspartate-specific proteases-1,Caspase-1)蛋白表达水平明显升高(P<0.05),线粒体膜电位、细胞SOD及CAT水平明显降低(P<0.05)。分别与模型组、瑞香素+TXNIP过表达组比较,瑞香素组HT-22细胞凋亡率、细胞TNF-α,IL-6,IL-1β,IL-18及ROS水平、细胞LDH释放水平、细胞TXNIP,NLRP3及Caspase-1蛋白表达水平均降低(P<0.05),线粒体膜电位、细胞SOD及CAT水平均升高(P<0.05); TXNIP过表达组HT-22细胞凋亡率、细胞TNF-α,IL-6,IL-1β,IL-18及ROS水平、细胞LDH释放水平、细胞TXNIP,NLRP3及Caspase-1蛋白表达水平均升高(P<0.05),线粒体膜电位、细胞SOD及CAT水平均降低(P<0.05); TXNIP空载组HT-22细胞各指标水平均无明显变化(P>0.05)。结论 瑞香素可通过抑制TXNIP/NLRP3信号通路来降低OGD/R诱导的ROS和炎性因子过量表达,抑制炎症和氧化应激反应,缓解海马神经元线粒体损伤,减轻神经元凋亡。     

Diagnosing photosensitive epilepsy: Fancy new versus old fashioned techniques in patients with different epileptic syndromes

Purpose: To demonstrate the clinical importance of using a high quality photic stimulator for recording EEGs to diagnose photosensitivity. Methods: We performed EEG examinations on 2 adult and 2 paediatric patients with a history of visually induced seizures; routinely we used a Grass PS 40 photic stimulator (rectangular Xenon lamp giving flashes of 10 μs duration, 0.7 J, 1-30 Hz, width 7 cm, length 12 cm). We repeated the IPS with a Grass PS 33 plus stimulator (round Xenon lamp giving flashes of 10 μs duration, 1 J, 1-60 Hz, diameter 14 cm). Results: Patients were affected by both benign and catastrophic epilepsies. They complained about episodes of dizziness (case 1), dizziness accompanied by a sensation in the arms and fear (case 2), absences (case 3), and myoclonic jerks (case 4). These symptoms occurred when working with neon lights, computers or ironing striped clothes (case 1), while driving (case 2), whenever there was sunlight (case 3 and 4). Only IPS performed with the Grass PS 33 plus stimulator evoked PPRs accompanied by their typical complaints. In all cases, the revised diagnosis led to changes in their treatment and the disappearance or diminishment of their complaints and PPR range. Conclusion: A PPR can occur in various types of epilepsy, can have a different meaning, and requires a different therapeutic intervention. Only an appropriate photic stimulator with diffuse white light and a flash intensity level of 1 J/flash, can reliably demonstrate whether a patient is photosensitive, or equally important exclude it.     

The Cannabinoid Receptor Agonist WIN55,212-2 Ameliorates Hippocampal Neuronal Damage After Chronic Cerebral Hypoperfusion Possibly Through Inhibiting Oxidative Stress and ASK1-p38 Signaling

Chronic cerebral hypoperfusion (CCH) is a major contributor to cognitive decline and degenerative processes leading to Alzheimer’s disease, vascular dementia, and aging. However, the delicate mechanism of CCH-induced neuronal damage, and therefore proper treatment, remains unclear. WIN55,212-2 (WIN) is a nonselective cannabinoid receptor agonist that has been shown to have effects on hippocampal neuron survival. In this study, we investigated the potential roles of WIN, as well as its underlying mechanism in a rat CCH model of bilateral common carotid artery occlusion. Hippocampal morphological changes and mitochondrial ultrastructure were detected using hematoxylin and eosin staining and electron microscopy, respectively. Various biomarkers, such as reactive oxidative species (ROS), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were used to assess the level of oxidative stress in the hippocampus. Furthermore, the expression levels of neuronal nuclei (NeuN), apoptosis signal-regulating kinase 1 (ASK1)-p38 signaling proteins, cleaved Caspase-9 and -3, and cytochrome-c (Cyt-C) were accessed by western blotting. CCH decreased the levels of NeuN, Cyt-C (mitochondrial), SOD, and CAT, and increased the levels of MDA, phosphorylated ASK1 and phosphorylated p38, cleaved Caspase-9 and -3, and Cyt-C (cytoplasm), which were reversed by WIN treatment. Chronic treatment with WIN also improved CCH-induced neuronal degeneration and mitochondrial fragmentation. These findings indicated that WIN may be a potential therapeutic agent for ischemic neuronal damage, involving a mechanism associated with the suppression of oxidative stress and ASK1-p38 signaling.     

Effects of enoxaparin in the rat hippocampus following traumatic brain injury

Purpose of this study was to investigate the effects of low molecular weight heparin, enoxaparin, on different parameters of the hippocampal damage following traumatic brain injury (TBI) in the rat. TBI of moderate severity was performed over the left parietal cortex using the lateral fluid percussion brain injury model. Animals were s.c. injected with either enoxaparin (1 mg/kg) or vehicle 1, 7, 13, 19, 25, 31, 37, and 43 h after the TBI induction. Sham-operated, vehicle-treated animals were used as the control group. Rats were sacrificed 48 h after the induction of TBI. Hippocampi were processed for spectrophotometric measurements of the products of oxidative lipid damage, thiobarbituric acid-reactive substances (TBARS) levels, as well as the activities of antioxidant enzymes, superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Moreover, the Western blotting analyses of the oxidized protein levels, expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), pro- and mature-interleukin-1β (pro-, and mature-IL-1β), and active caspase-3 were performed. COX-2 expressions were also explored by using immunohistochemistry. Glial fibrillary acidic protein immunochistochemistry was performed with the aim to assess the level of astrocytic activity. Fluoro-Jade B staining was used to identify the level and extent of hippocampal neuronal injury. TBI caused statistically significant increases of the hippocampal TBARS and oxidized protein levels as well as COX-2, pro-IL-1β, and active caspase-3 overexpressions, but it did not significantly affect the SOD and GSH-Px activities, the iNOS, and mature-IL-1β expression levels. TBI also induced hippocampal reactive astrocytosis and neurodegeneration. Enoxaparin significantly decreased the hippocampal TBARS and oxidized protein levels, COX-2 overexpression and reactive gliosis, but it did not influence the SOD and GSH-Px activities, pro-IL-1β and active caspase-3 overexpressions as well as neurodegeneration following TBI. These findings demonstrate that enoxaparin may reduce oxidative damage, inflammation and astrocytosis following TBI in the rat and could be a candidate drug for neuroprotective treatment of this injury.     

Impact of age and strain on ischemic brain injury and seizures after carotid ligation in immature mice

Stroke is an important cause of neurologic injury in the neonatal period and frequently results in lifelong neurologic impairments. We reported previously that unilateral carotid ligation on postnatal day (P)12 in CD1 mice causes acute behavioral seizures and unilateral brain injury and provides a model for neonatal stroke in human infants. In the present study we confirmed that behavioral seizures observed after ligation on P12 in the CD1 strain are associated with rhythmic ictal discharges that show temporal progression on electrocorticograms. We also examined the effects of carotid ligation performed at different ages in CD1 mice or performed in the C57Bl/6 strain. The right common carotid was ligated at P7, P10, P12 or P21 in CD1 mice or at P12 in C57Bl/6 mice. Littermate controls received sham surgery. Seizures were rated for 4 h after surgery; brain injury was scored one week later. In a separate group of P12 CD1 mice, electrocorticographic activity was recorded continuously for 4 h after carotid ligation or sham surgery. Brain injury and cumulative seizure score varied significantly with age (p < 0.001) and strain (p < 0.001). In CD1 mice, injury was greatest after ligation on P10 to P12 and seizure score was maximal at P12. Seizure scores were significantly correlated with injury after ligation on P10 or P12. C57Bl/6 mice, like C3Heb/FeJ mice examined previously, were much less vulnerable to seizures and injury than CD1 mice after ligation on P12. This study demonstrates that carotid ligation in the CD1 mouse on P12 causes acute electrographic rhythmic discharges that correlate with behavioral seizures. We also found that the age at which ligation is performed and genetic strain have a strong influence on the severity of injury.     

Effect of pentylenetetrazole and sound stimulation induced single and repeated convulsive seizures on the MDA, GSH and NO levels, and SOD activities in rat liver and kidney tissues

Objectives

The aim of our study was to evaluate the activity of superoxide dismutase (SOD) and the levels of glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) in liver and kidney tissues in a rat model of convulsive seizure induced by single and repeated doses of pentylenetetrazole (PTZ) and sound stimulation with key ringing.

Materials and methods

Male Wistar adult rats (n = 48), were used in the experiment. The animals were divided into six groups: (1) Single Seizure Control Group (SS-Control; n = 8), (2) Repeated Seizures Control Group (RS-Control; n = 8), (3) PTZ induced Single Seizure Group (SS-PTZ Group; n = 8), (4) PTZ induced Repeated Seizures Group (RS- PTZ Group; n = 8), (5) Key-Ringing Induced Single Seizure Group (SS-KEY Group; n = 8), (6) Key-Ringing Induced Repeated Seizures Group (RS-KEY Group; n = 8). Following injections rats were observed for seizure activity for 30 min. Animals were sacrificed 24 h after induced seizure (single or last seizure) or saline administration. MDA, NO, GSH levels and SOD activities were determined in liver and kidney tissues.

Results

There was no significant difference between SS-Control and RS-Control groups, SS-PTZ and SS-KEY groups, and RS-PTZ and RS-KEY groups (p > 0.05) in none of the examined 4 parameters in liver and kidney tissues.The liver and kidney levels of MDA and NO in SS-PTZ group were found to be significantly higher than the SS-Control group (p < 0.05). In SS-KEY group, the liver and kidney levels of MDA and NO were found to be significantly higher and GSH levels were significantly lower than the SS-Control group (p < 0.05).While liver and kidney levels of MDA in RS-PTZ group and RS-KEY group were found to be significantly higher than the RS-Control group (p < 0.05), liver and kidney GSH levels were significantly lower (p < 0.05). The liver levels of NO in RS-PTZ group and RS-KEY group were found to be significantly higher than the RS-Control group (p < 0.05). Kidney SOD activities in RS-PTZ group and RS-KEY group were found to be significantly lower than the RS-Control group (p < 0.05).When RS-PTZ group is compared with the SS-PTZ group, the liver SOD activity and kidney NO level were found to be significantly lower in the RS-PTZ group (p < 0.05).While the liver NO level and GSH level in RS-KEY group were significantly higher than the SS-KEY group, SOD activity was significantly lower in the RS-KEY group (p < 0.05). When RS-KEY group was compared with SS-KEY group, the kidney NO level and SOD activity were found to be significantly lower in the RS-KEY group (p < 0.05).

Conclusion

In conclusion, key-ringing or PTZ induced single and repeated seizures result in increased oxidative damage and lipid peroxidation, and decreased antioxidant defense mechanisms.