Displaying publications 61 - 80 of 1470 in total

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  1. Nielsen SSE, Siupka P, Georgian A, Preston JE, Tóth AE, Yusof SR, et al.
    J Vis Exp, 2017 09 24.
    PMID: 28994773 DOI: 10.3791/56277
    The aim of this protocol presents an optimized procedure for the purification and cultivation of pBECs and to establish in vitro blood-brain barrier (BBB) models based on pBECs in mono-culture (MC), MC with astrocyte-conditioned medium (ACM), and non-contact co-culture (NCC) with astrocytes of porcine or rat origin. pBECs were isolated and cultured from fragments of capillaries from the brain cortices of domestic pigs 5-6 months old. These fragments were purified by careful removal of meninges, isolation and homogenization of grey matter, filtration, enzymatic digestion, and centrifugation. To further eliminate contaminating cells, the capillary fragments were cultured with puromycin-containing medium. When 60-95% confluent, pBECs growing from the capillary fragments were passaged to permeable membrane filter inserts and established in the models. To increase barrier tightness and BBB characteristic phenotype of pBECs, the cells were treated with the following differentiation factors: membrane permeant 8-CPT-cAMP (here abbreviated cAMP), hydrocortisone, and a phosphodiesterase inhibitor, RO-20-1724 (RO). The procedure was carried out over a period of 9-11 days, and when establishing the NCC model, the astrocytes were cultured 2-8 weeks in advance. Adherence to the described procedures in the protocol has allowed the establishment of endothelial layers with highly restricted paracellular permeability, with the NCC model showing an average transendothelial electrical resistance (TEER) of 1249 ± 80 Ω cm2, and paracellular permeability (Papp) for Lucifer Yellow of 0.90 10-6 ± 0.13 10-6 cm sec-1 (mean ± SEM, n=55). Further evaluation of this pBEC phenotype showed good expression of the tight junctional proteins claudin 5, ZO-1, occludin and adherens junction protein p120 catenin. The model presented can be used for a range of studies of the BBB in health and disease and, with the highly restrictive paracellular permeability, this model is suitable for studies of transport and intracellular trafficking.
    Matched MeSH terms: Blood-Brain Barrier/metabolism*; Brain/pathology*
  2. Sanchez Bornot JM, Wong-Lin K, Ahmad AL, Prasad G
    Brain Topogr, 2018 11;31(6):895-916.
    PMID: 29546509 DOI: 10.1007/s10548-018-0640-0
    The brain's functional connectivity (FC) estimated at sensor level from electromagnetic (EEG/MEG) signals can provide quick and useful information towards understanding cognition and brain disorders. Volume conduction (VC) is a fundamental issue in FC analysis due to the effects of instantaneous correlations. FC methods based on the imaginary part of the coherence (iCOH) of any two signals are readily robust to VC effects, but neglecting the real part of the coherence leads to negligible FC when the processes are truly connected but with zero or π-phase (modulus 2π) interaction. We ameliorate this issue by proposing a novel method that implements an envelope of the imaginary coherence (EIC) to approximate the coherence estimate of supposedly active underlying sources. We compare EIC with state-of-the-art FC measures that included lagged coherence, iCOH, phase lag index (PLI) and weighted PLI (wPLI), using bivariate autoregressive and stochastic neural mass models. Additionally, we create realistic simulations where three and five regions were mapped on a template cortical surface and synthetic MEG signals were obtained after computing the electromagnetic leadfield. With this simulation and comparison study, we also demonstrate the feasibility of sensor FC analysis using receiver operating curve analysis whilst varying the signal's noise level. However, these results should be interpreted with caution given the known limitations of the sensor-based FC approach. Overall, we found that EIC and iCOH demonstrate superior results with most accurate FC maps. As they complement each other in different scenarios, that will be important to study normal and diseased brain activity.
    Matched MeSH terms: Brain/physiology*; Brain Mapping/methods
  3. Bhatt S, Kanoujia J, Mohana Lakshmi S, Patil CR, Gupta G, Chellappan DK, et al.
    CNS Neurol Disord Drug Targets, 2023;22(2):276-288.
    PMID: 35352640 DOI: 10.2174/1871527321666220329140804
    The human gut microbiota plays a significant role in the pathophysiology of central nervous system-related diseases. Recent studies suggest correlations between the altered gut microbiota and major depressive disorder (MDD). It is proposed that normalization of the gut microbiota alleviates MDD. The imbalance of brain-gut-microbiota axis also results in dysregulation of the hypothalamicpituitary- adrenal (HPA) axis. This imbalance has a crucial role in the pathogenesis of depression. Treatment strategies with certain antibiotics lead to the depletion of useful microbes and thereby induce depression like effects in subjects. Microbiota is also involved in the synthesis of various neurotransmitters (NTs) like 5-hydroxy tryptamine (5-HT; serotonin), norepinephrine (NE) and dopamine (DA). In addition to NTs, the gut microbiota also has an influence on brain derived neurotrophic factor (BDNF) levels. Recent research findings have exhibited that transfer of stress prone microbiota in mice is also responsible for depression and anxiety-like behaviour in animals. The use of probiotics, prebiotics, synbiotics and proper diet have shown beneficial effects in the regulation of depression pathogenesis. Moreover, transplantation of fecal microbiota from depressed individuals to normal subjects also induces depression-like symptoms. With the precedence of limited therapeutic benefits from monoamine targeting drugs, the regulation of brain-gut microbiota is emerging as a new treatment modality for MDDs. In this review, we elaborate on the significance of brain-gut-microbiota axis in the progression of MDD, particularly focusing on the modulation of the gut microbiota as a mode of treating MDD.
    Matched MeSH terms: Brain
  4. Yeo XY, Chae WR, Lee HU, Bae HG, Pettersson S, Grandjean J, et al.
    Gut Microbes, 2023 Dec;15(2):2283911.
    PMID: 38010368 DOI: 10.1080/19490976.2023.2283911
    The complex symbiotic relationship between the mammalian body and gut microbiome plays a critical role in the health outcomes of offspring later in life. The gut microbiome modulates virtually all physiological functions through direct or indirect interactions to maintain physiological homeostasis. Previous studies indicate a link between maternal/early-life gut microbiome, brain development, and behavioral outcomes relating to social cognition. Here we present direct evidence of the role of the gut microbiome in brain development. Through magnetic resonance imaging (MRI), we investigated the impact of the gut microbiome on brain organization and structure using germ-free (GF) mice and conventionalized mice, with the gut microbiome reintroduced after weaning. We found broad changes in brain volume in GF mice that persist despite the reintroduction of gut microbes at weaning. These data suggest a direct link between the maternal gut or early-postnatal microbe and their impact on brain developmental programming.
    Matched MeSH terms: Brain
  5. Baharuddin A, Musa MN, Salleh SS
    Malays J Med Sci, 2016 Jan;23(1):1-3.
    PMID: 27540319 MyJurnal
    Muslim relies on the structure or guideline of shari'ah or the maqasid al-shariah, which consist of five essential values, namely preservation/protection of faith, life, intellect, property, and dignity/lineage - to guide them in discovering guiding principles for new concerns such as posed by neuroscience. Like in the case of brain imaging technology, there is in need for proper explanation within Islamic and among the Muslim scientists/scholars on how Islamic beliefs, values, and practices might cumulatively provide 'different' meanings to the practice and application of this technology, or whether it is in line with the shari'ah - in the context of preservation of health and protection of disease. This paper highlights the Islamic mechanism for neuroethics as basis for a holistic ethical framework of neuroscience to cope with its new, modern, and emerging technologies in the globalised world, and how Muslim should response to such changes.
    Matched MeSH terms: Brain
  6. Robert M, Wastie M
    Biomed Imaging Interv J, 2008 Jan;4(1):e3.
    PMID: 21614314 MyJurnal DOI: 10.2349/biij.4.1.e3
    Glioblastoma multiforme (GBM) is the most aggressive form of primary brain tumours known collectively as gliomas. Gliomas are graded by their microscopic appearance. As a rule, their behaviour can be predicted from histology: Grade I (pilocytic astrocytomas) and Grade II (benign astrocytomas) tumours are of low grade and grow slowly over many years. Grade IV tumours (GBM) are the most aggressive and, unfortunately, also the most common in humans, growing rapidly, invading and altering brain function. These tumours arise from the supporting glial cells of the brain during childhood and in adulthood.These growths do not spread throughout the body like other forms of cancer, but cause symptoms by invading the brain. Untreated GBMs are rapidly lethal. Most patients with GBM die of their disease in less than a year and none have long term survival.Extracranial metastases from GBM are extremely rare, with a reported frequency of only 0.44% because of the absence of lymphatics in the brain and the difficulty of tumours to penetrate blood vessels. A case of glioblastoma multiforme with the rare features of extensive liver and bone metastases is presented in this paper.
    Matched MeSH terms: Brain; Brain Neoplasms
  7. Finsterer J, Rettensteiner J, Stellamor V, Stöphasius E
    Med J Malaysia, 2013;68(1):86-7.
    PMID: 23466778
    Severe post-hemorrhaghic internal hydrocephalus with almost complete atrophy of the cerebral parenchyma, as in the following case, is rare.
    Matched MeSH terms: Brain*
  8. Tamijani SM, Karimi B, Amini E, Golpich M, Dargahi L, Ali RA, et al.
    Seizure, 2015 Sep;31:155-64.
    PMID: 26362394 DOI: 10.1016/j.seizure.2015.07.021
    Thyroid hormones (THs) L-thyroxine and L-triiodothyronine, primarily known as metabolism regulators, are tyrosine-derived hormones produced by the thyroid gland. They play an essential role in normal central nervous system development and physiological function. By binding to nuclear receptors and modulating gene expression, THs influence neuronal migration, differentiation, myelination, synaptogenesis and neurogenesis in developing and adult brains. Any uncorrected THs supply deficiency in early life may result in irreversible neurological and motor deficits. The development and function of GABAergic neurons as well as glutamatergic transmission are also affected by THs. Though the underlying molecular mechanisms still remain unknown, the effects of THs on inhibitory and excitatory neurons may affect brain seizure activity. The enduring predisposition of the brain to generate epileptic seizures leads to a complex chronic brain disorder known as epilepsy. Pathologically, epilepsy may be accompanied by mitochondrial dysfunction, oxidative stress and eventually dysregulation of excitatory glutamatergic and inhibitory GABAergic neurotransmission. Based on the latest evidence on the association between THs and epilepsy, we hypothesize that THs abnormalities may contribute to the pathogenesis of epilepsy. We also review gender differences and the presumed underlying mechanisms through which TH abnormalities may affect epilepsy here.
    Matched MeSH terms: Brain/metabolism
  9. Dai W, Chen J, Guo X, Su Z
    Tumour Biol., 2015 Jun;36(6):4089.
    PMID: 26025112 DOI: 10.1007/s13277-015-3481-4
    With great interest, we read the article "Relationships between PTEN gene mutations and prognosis in glioma: a meta-analysis" (by Xiao et al. Tumor Biol 35(7):6687-6693, 2014), which has reached important conclusions that the phosphatase and tensin homolog (PTEN) gene mutations were closely related to poor prognosis of glioma patients. Through quantitative analysis, the investigators (Xiao WZ et al.) showed that glioma patients with PTEN gene mutations exhibited a significantly shorter overall survival (OS) than those without PTEN gene mutations (HR = 3.66, 95 % CI = 2.02∼5.30, P  0.05). The meta-analysis results are encouraging. Nevertheless, some deficiencies still existed that we would like to raise.
    Matched MeSH terms: Brain Neoplasms/genetics*
  10. Delilkan AE
    Med J Malaysia, 1989 Dec;44(4):361-2.
    PMID: 2520051
    Comment on: Adam BA, Kin LC, Wahab AS. Therapeutic intervention scoring system in medical intensive care. Med J Malaysia. 1989 Jun;44(2):134-9
    Matched MeSH terms: Brain Death/diagnosis*
  11. Idris Z, Zakaria Z, Yee AS, Fitzrol DN, Ghani ARI, Abdullah JM, et al.
    Brain Sci, 2021 Apr 28;11(5).
    PMID: 33925002 DOI: 10.3390/brainsci11050558
    The concept of wholeness or oneness refers to not only humans, but also all of creation. Similarly, consciousness may not wholly exist inside the human brain. One consciousness could permeate the whole universe as limitless energy; thus, human consciousness can be regarded as limited or partial in character. According to the limited consciousness concept, humans perceive projected waves or wave-vortices as a waveless item. Therefore, human limited consciousness collapses the wave function or energy of particles; accordingly, we are only able to perceive them as particles. With this "limited concept", the wave-vortex or wave movement comes into review, which also seems to have a limited concept, i.e., the limited projected wave concept. Notably, this wave-vortex seems to embrace photonic light, as well as electricity and anything in between them, which gives a sense of dimension to our brain. These elements of limited projected wave-vortex and limitless energy (consciousness) may coexist inside our brain as electric (directional pilot wave) and quantum (diffused oneness of waves) brainwaves, respectively, with both of them giving rise to one brain field. Abnormality in either the electrical or the quantum field or their fusion may lead to abnormal brain function.
    Matched MeSH terms: Brain; Brain Waves
  12. Foo LS, Larkin JR, Sutherland BA, Ray KJ, Yap WS, Hum YC, et al.
    Magn Reson Med, 2021 04;85(4):2188-2200.
    PMID: 33107119 DOI: 10.1002/mrm.28565
    PURPOSE: To assess the correlation and differences between common amide proton transfer (APT) quantification methods in the diagnosis of ischemic stroke.

    METHODS: Five APT quantification methods, including asymmetry analysis and its variants as well as two Lorentzian model-based methods, were applied to data acquired from six rats that underwent middle cerebral artery occlusion scanned at 9.4T. Diffusion and perfusion-weighted images, and water relaxation time maps were also acquired to study the relationship of these conventional imaging modalities with the different APT quantification methods.

    RESULTS: The APT ischemic area estimates had varying sizes (Jaccard index: 0.544 ≤ J ≤ 0.971) and had varying correlations in their distributions (Pearson correlation coefficient: 0.104 ≤ r ≤ 0.995), revealing discrepancies in the quantified ischemic areas. The Lorentzian methods produced the highest contrast-to-noise ratios (CNRs; 1.427 ≤ CNR ≤ 2.002), but generated APT ischemic areas that were comparable in size to the cerebral blood flow (CBF) deficit areas; asymmetry analysis and its variants produced APT ischemic areas that were smaller than the CBF deficit areas but larger than the apparent diffusion coefficient deficit areas, though having lower CNRs (0.561 ≤ CNR ≤ 1.083).

    CONCLUSION: There is a need to further investigate the accuracy and correlation of each quantification method with the pathophysiology using a larger scale multi-imaging modality and multi-time-point clinical study. Future studies should include the magnetization transfer ratio asymmetry results alongside the findings of the study to facilitate the comparison of results between different centers and also the published literature.

    Matched MeSH terms: Brain Neoplasms*
  13. Hassan ST, Khaw WF, Rosna AR, Husna J
    JNMA J Nepal Med Assoc, 2011 Jan-Mar;51(181):53-5.
    PMID: 22335097
    Traumatic brain injury (TBI) is an increasingly major world health problem. This short review using the most pertinent articles on TBI caregiving problems and needs highlights the pressing issues. Articles focusing on both TBI-caregivers' problems and needs are rarely found, especially for developing countries. Most TBI-caregiving is done by family members, whose altered lives portend burden and stresses which add to the overwhelming demand of caring for the TBI-survivor. Lack of information, financial inadequacy, anxiety, distress, coping deficits, poor adaptability, inadequate knowledge and skills, and a poor support system comprise the major problems. Dysfunctional communication between caregivers and care-receivers has been little researched. The major needs are focused on health and rehabilitation information, financial advice and assistance, emotional and social support, and positive psychological encouragement. In time, health information needs may be met, but not emotional support. Information on TBI caregiving problems and unmet needs is critical to all relevant healthcare stakeholders.
    Matched MeSH terms: Brain Injuries/therapy*
  14. Harun MSR, Marsh V, Elsaied NA, Webb KF, Elsheikha HM
    Brain Res, 2020 11 01;1746:147002.
    PMID: 32592740 DOI: 10.1016/j.brainres.2020.147002
    Toxoplasma gondii can cause parasitic encephalitis, a life-threatening infection that predominately occurs in immunocompromised individuals. T. gondii has the ability to invade the brain, but the mechanisms by which this parasite crosses the blood-brain-barrier (BBB) remain incompletely understood. The present study reports the changes associated with infection and replication of T. gondii within human brain microvascular endothelial cells (BMECs) in vitro. Our results indicated that exposure to T. gondii had an adverse impact on the function and integrity of the BMECs - through induction of cell cycle arrest, disruption of the BMEC barrier integrity, reduction of cellular viability and vitality, depolarization of the mitochondrial membrane potential, increase of the DNA fragmentation, and alteration of the expression of immune response and tight junction genes. The calcium channel/P-glycoprotein transporter inhibitor verapamil was effective in inhibiting T. gondii crossing the BMECs in a dose-dependent manner. The present study showed that T. gondii can compromise several functions of BMECs and demonstrated the ability of verapamil to inhibit T. gondii crossing of the BMECs in vitro.
    Matched MeSH terms: Blood-Brain Barrier/drug effects; Blood-Brain Barrier/metabolism; Blood-Brain Barrier/physiopathology*; Brain/drug effects; Brain/metabolism; Brain/physiopathology
  15. Arumugasamy N
    Med J Malaya, 1969 Mar;23(3):169-73.
    PMID: 4240068
    Matched MeSH terms: Brain Neoplasms/pathology*
  16. Arumugasamay N, Sarvananthan K, Rudralingam V, Pillay RP
    Med J Malaya, 1972 Mar;26(3):168-72.
    PMID: 5031011
    Matched MeSH terms: Brain/pathology
  17. Hanani Abdul Manan, Zamzuri Idris, Jafri Malin Abdullah, Mohammed Faruque Reza, Hazim Omar
    MyJurnal
    Neuroplasticity has been subjected to a great deal of research in the last century. Recently, significant emphasis has been
    placed on the global effect of localized plastic changes throughout the central nervous system, and on how these changes
    integrate in a pathological context. The present study aimed to demonstrate the functional cortical reorganization before
    and after surgery using magnetoencephalography (MEG) in a participant with brain tumor. Results of Visual Evoked
    Magnetic Field (VEF) based on functional MEG study revealed significantly different of MEG N100 waveforms before and
    after surgery. Larger and additional new locations for visual activation areas after the surgery were found suggesting
    neuroplasticity. The present study highlight a physiological plasticity in a teenage brain and the alterations regarding
    neural plasticity and network remodeling described in pathological contexts in higher-order visual association areas.
    Matched MeSH terms: Brain; Brain Neoplasms
  18. Awais MA, Yusoff MZ, Khan DM, Yahya N, Kamel N, Ebrahim M
    Sensors (Basel), 2021 Sep 30;21(19).
    PMID: 34640888 DOI: 10.3390/s21196570
    Motor imagery (MI)-based brain-computer interfaces have gained much attention in the last few years. They provide the ability to control external devices, such as prosthetic arms and wheelchairs, by using brain activities. Several researchers have reported the inter-communication of multiple brain regions during motor tasks, thus making it difficult to isolate one or two brain regions in which motor activities take place. Therefore, a deeper understanding of the brain's neural patterns is important for BCI in order to provide more useful and insightful features. Thus, brain connectivity provides a promising approach to solving the stated shortcomings by considering inter-channel/region relationships during motor imagination. This study used effective connectivity in the brain in terms of the partial directed coherence (PDC) and directed transfer function (DTF) as intensively unconventional feature sets for motor imagery (MI) classification. MANOVA-based analysis was performed to identify statistically significant connectivity pairs. Furthermore, the study sought to predict MI patterns by using four classification algorithms-an SVM, KNN, decision tree, and probabilistic neural network. The study provides a comparative analysis of all of the classification methods using two-class MI data extracted from the PhysioNet EEG database. The proposed techniques based on a probabilistic neural network (PNN) as a classifier and PDC as a feature set outperformed the other classification and feature extraction techniques with a superior classification accuracy and a lower error rate. The research findings indicate that when the PDC was used as a feature set, the PNN attained the greatest overall average accuracy of 98.65%, whereas the same classifier was used to attain the greatest accuracy of 82.81% with the DTF. This study validates the activation of multiple brain regions during a motor task by achieving better classification outcomes through brain connectivity as compared to conventional features. Since the PDC outperformed the DTF as a feature set with its superior classification accuracy and low error rate, it has great potential for application in MI-based brain-computer interfaces.
    Matched MeSH terms: Brain-Computer Interfaces*
  19. Ismail NA, Leong Abdullah MFI, Hami R, Ahmad Yusof H
    Growth Factors, 2021 01 11;38(3-4):210-225.
    PMID: 33427532 DOI: 10.1080/08977194.2020.1864347
    Brain-derived neurotrophic factor (BDNF) is a neurotrophin that is highly expressed in the brain. It influences neuronal survival, growth and acts as a control centre for neurotransmitters. It also plays a crucial role in learning and memory. Current evidence indicates that BDNF may be a possible neurotrophic factor that controls cognitive functions under normal and neuropathological conditions. Recent findings indicate a reduction in cognitive performance in individuals with Alzheimer's disease (AD). This relationship between cognitive performance and AD is important for investigating both the time they overlap and the pathophysiological mechanism in each case. Therefore, this study reviewed the existing knowledge about BDNF and cognitive performance in the AD population. The findings support the idea that this tropic factor may be a potential biomarker for evaluating the changes in cognitive performance in AD.
    Matched MeSH terms: Brain-Derived Neurotrophic Factor*
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