RESUMEN
Glutamate is an excitatory neurotransmitter that is released by the majority of central nervous system synapses and is involved in developmental processes, cognitive functions, learning and memory. Excessive elevated concentrations of Glu in synaptic cleft results in neural cell apoptosis which is called excitotoxicity causing neurodegenerative diseases. Hence, we investigated the possibility of extremely low frequency electromagnetic fields (ELF-EMF) as a risk factor which is able to change Glu concentration in synaptic clef. Synaptosomes as a model of nervous terminal were exposed to ELF-EMF for 15-55 min in flux intensity range from 0.1 to 2 mT and frequency range from 50 to 230 Hz. Finally, all raw data by INForm v4.02 software as an artificial neural network program was analyzed to predict the effect of whole mentioned range spectra. The results showed the tolerance of all effects between the ranges from -35 to +40 % compared to normal state when glutamatergic systems exposed to ELF-EMF. It indicates that glutamatergic system attempts to compensate environmental changes though release or reuptake in order to keep the system safe. Regarding to the wide range of ELF-EMF acquired in this study, the obtained outcomes have potential for developing treatments based on ELF-EMF for some neurological diseases; however, in vivo experiments on the cross linking responses between glutamatergic and cholinergic systems in the presence of ELF-EMF would be needed.
Asunto(s)
Campos Electromagnéticos , Ácido Glutámico/metabolismo , Redes Neurales de la Computación , Sinaptosomas/metabolismo , Animales , Microscopía Electrónica de Transmisión , Ratas Wistar , Sinaptosomas/ultraestructuraRESUMEN
In recent decades, considerable efforts have been made to understand the mechanism of memory, cognition, and relevant neurodegenerative diseases in the human brain. Several studies have shown the importance of microtubule proteins in the memory mechanism and memory dysfunction. Microtubules possess dynamicity, which is essential for functions of neuronal networks. Microtubule-associated proteins, i.e., tau, play vital roles in microtubule stability. On the other hand, the ferromagnetic mineral magnetite (Fe(3)O(4)) has been detected in the normal human brain, and elevated levels of magnetite are also observed in the brains of Alzheimer's disease patients. Therefore, we propose that a relationship between microtubule organization in axons and brain magnetite nanoparticles is possible. In this study we found alterations of microtubule polymerization in the presence of increasing concentrations of magnetite through transmission electron microscopy images and a turbidimetry method. Structural changes of microtubule and tau protein, as an essential microtubule-associated protein for tubulin assembly, were detected via circular dichroism spectroscopy, intrinsic fluorescence, and 8-anilino-1-naphthalenesulfonic acid fluorometry. We predicted three possible binding sites on tau protein and one possible binding site on tubulin dimer for magnetite nanoparticles. Magnetite also causes the morphology of PC12 cells to change abnormally and cell viability to decrease. Finally, we suggest that magnetite changes microtubule dynamics and polymerization through two paths: (1) changing the secondary and tertiary structure of tubulin and (2) binding to either tubulin dimer or tau protein and preventing tau-tubulin interaction.
Asunto(s)
Encéfalo/metabolismo , Nanopartículas de Magnetita/análisis , Tubulina (Proteína)/metabolismo , Proteínas tau/metabolismo , Enfermedad de Alzheimer/metabolismo , Animales , Supervivencia Celular , Humanos , Microtúbulos/metabolismo , Microtúbulos/ultraestructura , Células PC12 , Unión Proteica , Ratas , Ovinos , Tubulina (Proteína)/ultraestructuraRESUMEN
Establishing a robust teamwork model in the practice of neuro-oncology requires continued interdisciplinary efforts. The Neuro-Oncology Scientific Club (NOSC) initiative is an interdisciplinary clinical forum promoting the comprehensive approach across involved disciplines in the management of central nervous system (CNS) malignancies. With its provincial founding panels and national steering board, NOSC has been operational in Iran since 2011. This initiative has pursued its mission through interval strategic meetings, tumor boards, case discussions as well as publishing neuro-oncology updates, case study periodicals, and newsletters. A provincial meeting of NOSC in Shiraz put together insights from international practice guidelines, emerging evidence, and expert opinions to draw a position statement on high-grade glioma management in adults. The present report summarizes key highlights from the above clinical forum.
Asunto(s)
Neoplasias Encefálicas/terapia , Glioma/terapia , Grupo de Atención al Paciente , Adulto , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/diagnóstico por imagen , Terapia Combinada , Vías Clínicas , Glioma/diagnóstico , Glioma/diagnóstico por imagen , Humanos , Irán , Imagen por Resonancia Magnética , Oncología Médica/métodos , Oncología Médica/organización & administración , Neuroimagen , Grupo de Atención al Paciente/organización & administraciónRESUMEN
BACKGROUND: Physical exercises can influence some anthropometric and fitness components differently. The aim of present study was to evaluate how a relatively long-term training program in 11-14-year-old male Iranian students affects their anthropometric and motor performance measures. METHODS: Measurements were conducted on the anthropometric and fitness components of participants (n = 28) prior to and following the program. They trained 20 weeks, 1.5 h/session with 10 min rest, in 4 times trampoline training programs per week. Motor performance of all participants was assessed using standing long jump and vertical jump based on Eurofit Test Battery. RESULTS: The analysis of variance (ANOVA) repeated measurement test showed a statistically significant main effect of time in calf girth P = 0.001, fat% P = 0.01, vertical jump P = 0.001, and long jump P = 0.001. The ANOVA repeated measurement test revealed a statistically significant main effect of group in fat% P = 0.001. Post hoc paired t-tests indicated statistical significant differences in trampoline group between the two measurements about calf girth (t = -4.35, P = 0.001), fat% (t = 5.87, P = 0.001), vertical jump (t = -5.53, P = 0.001), and long jump (t = -10.00, P = 0.001). CONCLUSIONS: We can conclude that 20-week trampoline training with four physical activity sessions/week in 11-14-year-old students seems to have a significant effect on body fat% reduction and effective results in terms of anaerobic physical fitness. Therefore, it is suggested that different training model approach such as trampoline exercises can help students to promote the level of health and motor performance.
RESUMEN
Safranal, a component of saffron, indicates anti-tumor activities; however, the precise mechanism of this effect has remained elusive. In this study we investigated tubulin assembly and structure in the presence of safranal to open the new horizons about the potential of safranal as an anti-tumor agent via microtubule disfunction. Anti-microtubule activity of safranal was evaluated by turbidimetric method and transmission electron microscopy (TEM). Safranal (0.1-70µM) was incubated with tubulin (5µM) and tubulin structural changes was surveyed using fluorometry. Tubulin binding site with safranal was estimated by molecular docking. Microtubule polymerization decreased significantly in the presence of safranal, regardless of its concentration and the IC50 value was obtained 72.19µM. Safranal was situated between α and ß tubulin closer to α-tubulin and hydrogen bond with Gly 142 and hydrophobic interactions played critical roles for safranal molecule stabilization in binding site. It seems that decline of tubulin assembly could result from tubulin structural changes through safranal bindings between alpha and beta tubulin with ΔG(0) of -5.63kcal/mol. Safranal can be taken into account as an anticancer agent; however, in vivo experiments are required to confirm this conclusion.
Asunto(s)
Ciclohexenos/química , Terpenos/química , Tubulina (Proteína)/química , Animales , Sitios de Unión , Encéfalo/metabolismo , Ciclohexenos/metabolismo , Enlace de Hidrógeno , Microtúbulos/metabolismo , Simulación del Acoplamiento Molecular , Unión Proteica , Estructura Terciaria de Proteína , Ovinos , Terpenos/metabolismo , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/metabolismoRESUMEN
Research and practice of neuro-oncology compiles clinical neuroscience expertise from neurosurgery, radiation oncology, neuroradiology, medical oncology, neuropathology and related disciplines to optimize planning and therapy in central nervous system malignancies. Such an interdisciplinary context prompted health-care providers from all related disciplines to establish the Neuro-Oncology Scientific Club (NOSC) in Iran and let it flourish since 3 years ago. With the advent of advanced technologies and through continued share of experience, NOSC members have tried to provide more integrated diagnoses and therapeutic care to brain tumor patients across the country. NOSC activities revolve around some key tenets including dissemination of education and updates, facilitation of institutional collaborations; data registry and patients' awareness. By virtue of recent insights on molecular characterization of brain tumors such as codeletion of chromosomes 1p and 19q in anaplastic gliomas and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma, a range of translational research is being followed within NOSC. The most recent NOSC meeting which was held in Tehran, recapitulated main advances and dealt with the current debates on functional neurosurgery, biological markers and neuroimaging, risk prediction models in high grade gliomas and clinical issues in pediatric neuro-oncology. This article gives an overview of current hotspots in neuro-oncology research and practice which are pursued within NOSC.
RESUMEN
Acetylcholinesterase (AChE) is the enzyme that controls the acetylcholine (ACh) concentrations in cholinergic synaptic clefts by hydrolyzing ACh to choline and acetate. Cholinergic synapses are involved in important functions such as learning, memory and cognition. In this study, we investigated the effects of a wide range of extremely low frequency electromagnetic fields (ELF-EMFs) on synaptic ACh concentrations through AChE enzyme activity assay. Synaptosome suspensions were prepared as a neural terminus from cerebral cortex of sheep brain. Prepared synaptosomes were exposed to ELF-EMFs with frequency ranging from 50 Hz to 230 Hz for duration between 15 and 120 min and flux intensity between 0.1 mT and 1.7 mT. Consequently, AChE activity was measured by Ellman method. Raw data were analyzed by neural network based software, Inform 4.02, to predict AChE activity pattern through nine 3D curves. These curves showed that AChE activity decreases when exposed to ELF-EMFs of 1.2 mT to 1.7 mT intensity and 50 Hz to 90 Hz frequency. Thus, it is proposed that exposure to fields of in this range of frequency-intensity would be effective in clinical treatments of cholinergic disorders to increase synaptic ACh concentration. However, more in vivo experiments are needed to develop this suggested treatment.