فهرست مطالب

  • Volume:2 Issue:1, 2014
  • تاریخ انتشار: 1393/04/25
  • تعداد عناوین: 10
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  • Zahra Nazari, Mohammad Nabiuni*, Zahra Safaei Nejad, Bahram Delfan, Saeed Irian Page 1
    Background
    Aquaporins (AQPs) are water channels that play a key role in water transport in many epithelia. Recent studies have shown that AQP1, located in the apical membrane of choroid plexus cells, has an important role in cerebrospinal fluid (CSF) production. However, the mechanism of water transport through the basolateral membrane of choroid plexus (CP) cells is yet to be determined.
    Objectives
    In this study, the expression and localization of AQP1, AQP4 and AQP5 in the rat lateral ventricle CP were investigated by immunocytochemistry, western analysis and flowcytometry.
    Materials And Methods
    Choroidal epithelial cells of the lateral ventricle in Wistar rats were isolated and grown in Dulbecco's Modified Eagle's medium (DMEM) supplement, which was refreshed every two days. After five days, the expression patterns of AQP1, AQP4 and AQP5 were determined by immunoblotting, immuncytochemistry and flowcytometry.
    Results
    The immunocytochemistry data revealed the expression of AQP1 and AQP4 in the membrane and the cytoplasmof AP cells, respectively. Through western analysis, the AQP1 antibody detected two bands of approximately 27 and 32 kDa. A single peptide of 29 kDa was recognized by the AQP4 antibody. Quantitative flowcytometry revealed CP cells exhibiting a high level of AQP1 and AQP4 proteins (95.39% and 92.21%, respectively). According to immunocytochemistry, AQP5 is weakly expressed in the cytoplasm of CP cells. Anti-AQP5 antibody recognized a pale band of approximately28 kDa by western analysis.
    Conclusions
    These observations suggested that AQP4 may have an important role in CSF secretion; however, expression of AQP4 or AQP5 was not detected in the cell membrane. Thus, how water crosses the basolateral membrane of CP cells remains to be determined.
    Keywords: Aquaporins, Cerebrospinal Fluid, Choroid Plexus Cells, Lateral Ventricle, Wistar Rats
  • Farzad Ashrafi, Alireza Baratloo, Zahra Nasiri*, Maryam Soleymani, Sina Asaadi Page 2
    Introduction
    Ischemic stroke is still a leading cause of death and long-term disability all around the world. Restoration of blood flow with thrombolytic agents like tissue plasminogen activator (t-PA) is the only way that may rescue patients exposed to cerebral ischemia. Complications of these agents are commonly related to hemorrhage, arterial reocclusion, anaphylaxis, or reperfusion damage. Recurrence of stroke in the same or other cerebral arteries only rarely causes early deterioration during or shortly after thrombolytic administration. We report a patient who experienced a second stroke despite intravenous thrombolytic therapy.
    Case Presentation
    A 68-year-old man with the history of uncontrolled hypertension and diabetes mellitus presented with acute ischemic stroke in the territory of vertebrobasilar system to the emergency department. Atrial fibrillation (AF) rhythm, high blood sugar and uncontrolled hypertension were recorded on admission. Echocardiography performed before thrombolysis, did not identify any embolic sources. Five Hours after intravenous injection of tissue Plasminogen Activator (t-PA), the patient became comatose and developed a recurrent infarction in the territory of right middle cerebral artery (MCA).
    Discussion
    It seems that thrombolysis therapy in patients with the risk factors of recurrent stroke, must be done with more preparation and readiness for concurrent processing. Regardless of normal trans-thoracic echocardiography, in patients with AF rhythm, transesophageal echocardiography may be helpful. Also performing appropriate randomized trial to compare the incidence of recurrent stroke in patients under t-PA therapy and controls were still needed.
    Keywords: Stroke, Atrial Fibrillation, Tissue Plasminogen Activator
  • Keyvan Tayebi Meybodi, Mohammad Taghvaei, Nazi Derakhshanrad, Zahid Hussain Khan, Hooshang Saberi* Page 3
    Introduction
    Neurosurgical interventions have been associated with troublesome bleeding during and after the procedures. There are cases of intractable coagulopathy with life threatening bleeding. In this study, we reported a patient with neurofibromatosis type 1, and huge cranial neurofibroma, associated with massive bleeding after excision.
    Case Presentation
    A 22 year-old man was referred to this center with facial deformity due to a large craniofacial neurofibroma. He underwent craniotomy and tumor resection, but intraoperative blood loss was massive, and epidural hematomata developed at the operative site due to coagulopathy. The drains still were draining fresh blood and the patient was severely anemic. After consultation with a hematologist, rFVIIa was administered intravenously to successfully control the bleeding.
    Conclusions
    While using recombinant rFVIIa is life-saving, it should not be a substitute for life saving urgent surgeries and should be cautiously used as a last resort in conjunction with conventional medico-surgical care.
    Keywords: Recombinant activated factor VII, Coagulopathy, Intracranial Hemorrhages
  • Zahra Tolou Ghamari *, Jafar Mehavari Habibabadi, Abbas Ali Palizban Page 4
    Background
    Due to the narrow therapeutic window of the AEDs prescription, their side effects and efficacy are the most important items that should be considered in epileptic patients.
    Objectives
    This study aimed to investigate evidence-based pharmacotherapy in epileptic patients.Patients and
    Methods
    Data were collected Cross-sectionally from patients (n = 24) registered at Kashani Epilepsy Ward in Isfahan. Demographic, clinical, hematology and biochemical data were recorded in d-base and analyzed using SPSS application for windows.
    Results
    The frequency of polypharmacy was 79% in which 50% of epileptic patients received 3 to 4 AEDs. The onset of seizure was under 16 years old in 70% of patients. Fourteen varieties of AEDs were used, among them valproic acid (Depakote) was the most administered drugs. Prescriptions of two patients consisted of 4 and 6 AEDs: patient with code No. 575 (carbamazepine, topiramate, clobasam, lamotrigine) and another one with code No. 587 (oxcarbamazepine, phenytoin, gabapentin, valproic acid, clonazepam, lamotrigine). Red blood cell counts, hemoglobin and hematocrit in patients under more than one drug treatment were significantly lower than patients with AED monotherapy.
    Conclusions
    AEDs are well-recognized to control seizure attacks. In clinical practice, the older generation of AEDs such as carbamazepine (CBZ), valporic acid (VPA), phenytoin (PHT), topiramate (TOP) and lamotrigine (LAMO) might need monitoring serum levels. Nonrational polypharmacy in terms of simultaneous using of both AEDs inducer and inhibitor could cause sedation, dizziness, and cognitive adverse effects. Further studies are needed to confirm these associations. Finally, to avoid polypharmacy that could arise side effects, a sufficient intervention for each AED to decide on its continuation, interruption or the number of drugs should be attempted. Combinations based on CBZ + VP, VP + TOP, CBZ + TOP, VP + LAMO, and TOP + LAMO could cause pharmacokinetic interactions.
    Keywords: Epilepsy, Pharmacotherpay, AEDs, Evidence, Based
  • Meng Jia, Julian Pittman* Page 5
    Background
    Anxiety and depression are common nonmotor symptoms of Parkinson’s disease (PD).
    Objectives
    We investigated whether Bisphenol A (BPA) is capable of inducing anxiety/depressive-like behaviors and neurotransmitter alterations that are similar to those observed in PD.
    Materials And Methods
    To test this hypothesis, we used a zebrafish animal model and conducted behavioral and histological assays.
    Results
    BPA produced anxiety/depression-like behavioral signs for 14 days following administration. Altered behavioral responses were accompanied by reductions of striatal dopamine transporter, and decrease in hippocampal 5-HT content.
    Conclusions
    These results suggest that the nigrostriatal pathway might play a role in the etiology of anxiety/depression. Furthermore, dopamine transporter function, in particular, might play a critical role in the pathophysiology of anxiety/depression.
    Keywords: Anxiety, Depression, Dopamine, Serotonin, Parkinson's Disease
  • Thiago Teixeira Guimaraes *, Bruno Macedo Da Costa, Lucenildo Silva Cerqueira, Allan De Carlo Andrade Serdeiro, Fernando Augusto Monteiro Saboia Pompeu, Helena Sales De Moraes, Tony Meireles Dos Santos, Andrea Camaz Deslandes Page 6
    Background
    Nowadays, one of the most important challenges of human beings is physical inactivity. There is evidence that a positively behavioral response, modulated by a single period of exercise can predict the level of engagement during the next six to 12 months.
    Objectives
    The aim of this study was to investigate the effects of three different combinations of intensity and duration of effort, on a cycle ergometer, on mood, anxiety and cortical activity of physically active young males.
    Materials And Methods
    Ten men, aged 20 to 27 years, underwent three experimental conditions randomly (submaximal, maximal and supramaximal effort). Immediately before and after the treatments, behavior was evaluated by the Profile of Mood States (POMS) and Trait Anxiety Inventory (STAI) scales. Standardized low resolution brain electromagnetic tomography (sLORETA) was performed to investigate the cortical activity.
    Results
    While submaximal effort reduced total mood disturbance, more intense efforts (maximal and supramaximal) worsened the mood (P = 0.001). This result was more prominent in supramaximal effort. Anxiety was increased in the supramaximal effort compared to others (P = 0.006), which was not significantly different. The sLORETA analysis revealed a significant increase in high alpha and beta activity in the parahippocampal gyrus of the limbic lobe, related to brain reward system, after maximal effort (P ≤ 0.05).
    Conclusion
    Acute changes in mood, anxiety and cortical activity are dependent on exercise intensity. Physically active young males, but not athletes showed positive results on subjective or neurobiological behavioral variables in submaximal and maximal efforts, respectively. This investigation could be useful to promote adherence to regular physical activity.
    Keywords: Motor Activity, Electroencephalography, Behavior
  • Julian Koenig *, Barbara Menke, Thomas K. Hillecke, Julian F. Thayer, Marc N. Jarczok Page 7
    Context: Cocaine affects the autonomic nervous system (ANS). Cardiovascular effects of cocaine have been extensively studied by measures of mean heart rate (HR) or blood pressure (BP). The present systematic review aims to summarize the current evidence on the effects of cocaine on heart rate variability (HRV) in human subjects.Evidence Acquisition: A systematic search of electronic databases (PUBMED, PSYNDEX and EMBASE) based on the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)” statement was employed. Studies were screened for eligibility based on pre-specified inclusion criteria. The search revealed a total of 48 papers after removing duplicates.Eleven studies fitting the inclusion criteria were included in the systematic review.
    Results
    Evidence on the effects of cocaine on HRV is rare. Existing studies either address the impact of acute cocaine administration in adults or the effect of prenatal cocaine exposure on infants in various age groups.
    Conclusions
    However, HRV is a promising index to study ANS function within this particular field of research. Several suggestions for future research are provided.
    Keywords: Heart Rate Variability, Cocaine, Humans
  • Mohita Shrivastava, Madhuri Behari* Page 8
    Context: Ethical issues have always been a topic of concern in basic science and clinical research. The ethical implications of neuroscience research and treatment have adopted the label “neuroethics,” with great relevance and value.Evidence Acquisition: Human subjects and patients undergoing research and treatment exhibit their naturally judgmental nature on what is "moral" or "ethical’’ and raise several questions pin pointing broader dilemmas in regarding moral and ethical issues posed by scientific research along with clinical treatment regimens.
    Results
    Neuroethics encompasses the numerous ways and diverse methodologies throughwhich developments in basic and clinical neuroscience traverse with social, legal, moral and ethical issues.
    Conclusions
    This review article puts forth emphasis on moral and ethical approaches regarding neuroscience research and treatment methodologies in the scientific arena.
    Keywords: Ethics, Neurosciences, Biomedical Research
  • Jerome Joseph Maller, Brian Lithgow, Caroline Gurvich, Saman Haghgooie, Omid Ranjbar Pouya, Paul Bernard Fitzgerald, Jayashri Kulkarni * Page 9
    Background
    Absence of quantitative techniques for objectively diagnosing many brain changes associated with mental illnesses hampers early intervention and effective treatment. Known bidirectional neural pathways closely link the vestibular system and regions involved in emotion processing.
    Objectives
    To assess whether Electrovestibulography (EVestG) can detect specific neural responses, using an ear probe and tilt chair, to provide a quantitative indirect measure assessment of brain regions and pathways frequently compromised in mental illnesses.
    Materials And Methods
    EVestG data was collected on 38 subjects with major depression, 22 with schizophrenia, 36 with bipolar disorder and 57 matched healthy controls. Data was analyzed using the NEER algorithm to generate the average field potentials and firing patterns. Characteristic features were extracted followed by AdaBoost subset feature selection and classification for separating data into four classes. To remove the bias of working on small size population, we used 10-fold cross validation to select the best diagnostic features. The accuracy of the diagnostic features’ classification was tested using nonparametric statistical analysis.
    Results
    EVestG signals were statistically different (P = 0.000 to 0.040) between the groups by using Kruskal-Wallis, and the best diagnostic accuracies for a four-way diagnostic group separation were on average (n = 100, 10 repeated 10-fold cross validations) 70.2% (SD = 9.6) using 10-fold cross validation.
    Conclusions
    Comparing vestibular driven responses has the potential to be a valid and clinically useful diagnostic tool.
    Keywords: Depression, Schizophrenia, Bipolar Disorder
  • Michael C. C. Kuo, Karen P. Y. Liu *, Michelle Bissett, Jacqueline Wesson, Nikki Tulliani, Rosalind Bye, Leung, Wing Chu Page 10
    Context: Information processing requires a series of mental operations from encoding to storage and retrieval. A large number of studies have examined the retrieval process, but less attention has been paid to the encoding process.Evidence Acquisition: The aims of this paper were to provide an overview of perceptual and semantic encoding processes as well as identify and compare the structural and functional changes in the memory encoding process of young and old adults. A review of encoding was conducted based on findings from two recent memory encoding studies and a literature search on memory encoding. It included studies published from January 1980 to December 2013 and appeared in the databases of CINAHL, MEDLINE, AMED, Journals@Ovid and the ISI Web of Science.
    Results
    Five stages of encoding were identified. They were: 1) early perceptual processing; 2) prelexical feature detection and early lexical processing; 3) initial selection of information from competing information for processing in the working memory; 4) semantic, syntactic, or lexical processing; and 5) updating of working memory with the newly created item representation and elaborate processing. Perceptual encoding appears to be modulated by sensory cortices, in which stimuli are initially perceived and processed, whereas semantic encoding involves the left prefrontal cortex temporal regions by both verbal and nonverbal stimuli.
    Conclusions
    Early perceptual processing and the selection of information processes associated with memory encoding are comparable between young and old adults. However, they showed differences in semantic processing, updating of working memory, and elaborate processing. These differences might be due to reduced volume and functional capacity of the hippocampus and frontal lobes, shrinkage in the white matter and its associated tracts, as well as inability of the aging brain to produce levels of dopamine comparable to its previous levels.
    Keywords: Memory, Perceptual, Semantic, Adults