جستجوی مقالات مرتبط با کلیدواژه "brain" در نشریات گروه "پزشکی"

Since brain temperature fluctuations are related to cognitive disorders, regulating brain temperature has become a key focus in cognitive studies. This study examined the effect of frontopolar cortical cooling on working memory using a cortical thermal stimulation device (CTSD).  This phase II, randomized, controlled trial included twenty participants randomly divided into two groups to receive 30 minutes of frontopolar cortical cooling across four sessions. The control group received sham cooling, while the intervention group received real cooling. Spatial working memory tests were recorded from both groups before and after the first and after the fourth sessions. The cortical thermal stimulation device used for cooling operates through the flow of water and alcohol in a closed loop. After four sessions of frontopolar cortical cooling, a significant improvement in working memory was observed. The analysis of working memory results, based on an ANCOVA test, showed an improvement in the Spatial Working Memory (SWM) test in the intervention group compared to the control group (p < 0.05). Considering the positive effect of frontopolar cortical cooling on working memory capacity, the results suggest that using an appropriate tool for cooling the cerebral cortex could become a practical approach in cognitive rehabilitation.

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women of reproductive age, which may affect various organs, including the brain and liver.

This study aimed to investigate the potential ameliorating effects of black seed (Nigella sativa) hydroethanolic extract on the liver and brain tissues in a rat model of polycystic ovary.

In this experimental study, eighteen female rats were divided into three groups: Control (PCO rats on day 0 after induction of PCO), vehicle (PCO rats receiving saline via gavage for 28 days), and black seed extract (BSE) (PCO rats receiving BSE via gavage for 28 days). Polycystic ovary was induced by a single intraperitoneal injection of 2 mg/kg estradiol valerate. Liver tissue was evaluated for the average number of damaged hepatocytes (segmented nucleus and cytoplasm shrinkage), number of Kupffer cells, and number of lipid droplets, while brain tissue was assessed for vacuolization, apoptosis, and cell shrinkage.

In the BSE group, liver weight significantly decreased, while brain weight increased compared to the vehicle and control groups. Moreover, there was a significant decrease in the number of damaged hepatocytes and Kupffer cells in the BSE group compared to the vehicle group in the liver tissue. In the brain tissue, there was a significant reduction in the number of vacuolations in the BSE group compared to the vehicle group.

Black seed extract demonstrated potential ameliorating effects on the adverse impacts of PCO in the liver (reducing damaged hepatocytes and Kupffer cells) and brain (reducing vacuolations). Further histologic and molecular analyses are needed to investigate the protective effects of BSE thoroughly.

During university life, students often face significant changes in relationships and academic pressures. Given the stressors faced by nursing students and the importance of their academic success, the study aimed to assess the impact of Super Brain Yoga on nursing students’ concentration, memory, and academic progress. This quasi-experimental study was conducted on 59 nursing students at Near East University in Cyprus from February to June 2023. The intervention group (N=29) performed Super Brain Yoga three times a week for two months, while the control group (N=30) continued the usual routines. Data were collected using the demographic questionnaire, Wechsler’s memory test, Concentration test, and the semester grade point average. Data analysis was performed using independent and paired t-test, chi-square, and ANCOVA using SPSS software version 26, with a significance level of P˂0.05. The study revealed a significant difference in total memory scores (P<0.001) and its subscales including personal and public information (P<0.001), orientation (P<0.001), mental control (P<0.001), logical memory (P=0.002), repeating numbers (P<0.001), visual memory (P<0.001), and learning associations (P=0.003) between the experimental and control groups after the intervention. Findings revealed a significant difference between the two groups in the reaction time (P=0.003) and the error of the reverse counting (P=0.021) following the intervention. After the intervention, based on ANCOVA test with adjusting the baseline values, there was no statistically significant difference in the semester mean of Grade Point Average between the two groups (95% confidence interval, P=0.657) Super Brain Yoga is a non-invasive intervention that can improve memory, concentration, and cognitive abilities in nursing students.

Radiation therapy is associated with a risk of long-term adverse effects. Ginger extract has several components that have many biological activities and vitamin c has also been recognized for protection against radiation-induced cell damage. The present study is designed to investigate the possible ameliorating effect of ginger extract and vitamin C on radiation-induced oxidative body damage.  Ginger extract and vitamin C were daily given to rats during 14 days before starting irradiation.

Rats were exposed to gamma radiation (6 Gray).

the result revealed that the levels of lipid peroxidation measured in brain tissues such as malondialdehyde (MDA), acetylcholinesterase (AChE) were significantly increased, while reduced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) content, dopamine (DA) and serotonin (ST) levels were significantly decreased in the brain homogenate of irradiated rats. Gamma-irradiation (6 Gy) resulted in a significant elevation in inflammatory markers of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-12 (IL-12) and C-reactive protein (CRP) compared to the control group. The rats that were administrated combined treatment with ginger extract and vitamin C showed significantly less severe damage and remarkable improvement in all of the last mentioned parameters when compared to irradiated rats.

According to the results obtained it could be concluded that a combined treatment with ginger extract by its antioxidant constituents, and vitamin C might be a useful candidate against radiation-induced oxidative stress, enzyme activities in the brain and metabolic disorders without any toxicity.

One of the brain anomalies that typically affects the elderly is Alzheimer’s disease (AD) and its frequency has greatly grown during the previous few decades. AD is affected by many genetics and environmental circumstances. Environmental factors and the quantity of air pollutants are two of the most significant elements influencing the prevalence of AD.

In this study, information from articles on the effects of air and environmental pollutants on AD was utilized. Additionally, the role of machine learning in predicting diseases was examined.

Several studies, approached from various perspectives, have delved into the factors influencing the onset of AD. The development of machine learning techniques has made it possible to record information about the environmental conditions and people’s habitats to make possible the occurrence of dementia-related abnormalities. According to the reviewed studies, certain biological pollutants can significantly increase the likelihood of developing AD. Also, it indicated the use of this technique has been based on biological information recorded for various diseases. The results showed that unhealthy environmental conditions increase the odds ratio of AD several times. Therefore, using this information provides the possibility to prevent the occurrence of AD.

In general, reliable information on the living conditions of the elderly, together with other information about AD, allows for the accurate forecast needed to avert the loss of social and personal capital. The future contribution of this knowledge is something we can envision.

Parkinson's disease dementia (PDD) and Dementia with Lewy bodies (DLB) are two syndromes categorized under synucleinopathy, sharing comparable symptoms. The identification of biomarkers would offer an accurate approach for improved diagnosis, treatment, and monitoring of treatment efficacy for these distinct forms of dementia.

This study utilized spectral analysis and nonlinear dynamic analysis to compare electroencephalogram (EEG) characteristics between PDD and DLB patients. EEG data was collected from 30 PDD patients, 36 DLB patients, and 36 healthy subjects at rest. Following a conditioning phase to minimize noise and eliminate artifacts, we derived spectral and complexity features using Welch's method and sample entropy. Analysis of variance with repeated measures was performed to compare spectral features and nonlinear dynamics of brain activity between the groups.

Post hoc comparison showed that in the control group, the power of delta and theta bands was lower and the power of alpha and beta bands was higher than in patients with PDD and DLB. (P < 0.05). In the theta and alpha bands, the PDD group showed greater power than the DLB group (P < 0.05). Furthermore, there was a significant main effect of diagnosis (F = 4.67, P = 0.007), and also the diagnosis by region interaction for complexity values (F = 4.58, P = 0.009). Post hoc analysis showed that the EEG complexity of the control group was significantly higher than that of the PDD and DLB groups in the frontal, central, temporal and parietal regions (P < 0.05). Moreover, the EEG complexity of the PDD group was significantly higher than that of the DLB group in the central, temporal and parietal regions (P < 0.05).

Although both PDD and DLB had almost similar patterns compared to the control group, they showed differences in the EEG power spectrum and its nonlinear dynamics. Our findings indicated marked diffuse slowing and lower cortical complexity or activity in DLB patients compared to PDD in all regions, especially in the central, temporal and parietal areas.

Understanding neural mechanisms underlying cognitive workload is crucial for advancing our knowledge of human cognition and mental processes. In this study, we utilized electroencephalography (EEG) analysis to investigate brain activity associated with varying mental cognitive workloads from a psychological perspective.

We employed a publicly accessible EEG dataset consisting of a cohort of 36 healthy volunteers (75% female), aged 18 to 26 years, while the participants were at rest or engaged in an arithmetic task to explore mental cognitive workload. After preprocessing to reduce noise and various artifacts and to obtain a clean signal for every subject, functional connectivity and complexity features were calculated from EEGs through the coherence and permutation entropy algorithms, respectively. Then, repeated measures analysis of variance (ANOVA) was conducted to assess the differences in complexity and connectivity measures across various brain regions between the rest and task states.

Brain sites showed significant within-subject effects, and the interaction between states and channels was significant for connectivity values (F = 3.68, P = 0.034). Post hoc comparisons indicated that FP1-F7, FP1-F8 and FP1-Fz connectivity were significantly lower during the task state compared to the rest state (P < 0.05). Moreover, F4-P3, F4-P4, FP1-O1, FP2-O2, F3-O1, F4-O1, F8-O1, C4-O1, F3-O2, F4-O2, F7-O2, F8-O2, Fz-O1, Fz-O2, Cz-O1 and Fz-P4 connectivity were significantly higher during the arithmetic task state (P < 0.05). Furthermore, brain sites showed significant within-subject effects and the interaction between states and channels was significant for entropy values (F = 3.50, P = 0.041). Post hoc comparisons indicated that the permutation entropy was significantly higher in the FP1, T3, T4, P4 and Pz channels during the arithmetic task compared to the rest state (P < 0.05).

During arithmetic tasks, the increased connectivity in the frontoparietal and frontooccipital networks and heightened complexity in the prefrontal, temporal and parietal lobes reflect the collaborative engagement of brain areas specialized in numerical processing, attention, working memory, cognitive control, and visual-spatial cognition. These changes in connectivity and complexity facilitate the integration of multiple cognitive processes essential for effective arithmetic problem-solving.

Recent research has revealed the central adverse effects of Botox after intramuscular injection. The aim of this study was to examine the role of brain oxidative stress factors and circulatory cytokines as indicators of the severity of seizures following acute intramuscular (IM) injection of Botox in mice.

Botox (1, 5 and 30 U, IM) was injected 60 minutes before inducing maximal electroshock (MES) seizures. Nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels were measured in the brain. Tumor necrosis factor-alpha (TNF-α) levels were also determined in the serum. The motor coordination was assessed after Botox administration by using the chimney test.

Botox (5 and 10 U/kg, IM) significantly reduced the duration of hindlimb extension (HLE) and elevated levels of NO and MDA in the brain compared to the seizure group. Additionally, the administration of Botox (1 and 5 U, IM) increased the level of GSH in the brain, while 30 U decreased it. All Botox dosages demonstrated an enhancing effect on serum TNF-α levels compared to the seizure group. Botox at 5 and 30 U induced locomotor incoordination in mice.

Our results showed that IM injection of Botox can lead to the exacerbation of tonic-clonic seizures by stimulating oxidative stress in the brain and increasing circulating TNF-α levels in mice.

Some voxels may alter the tractography results due to unintentional alteration of noises and other unwanted factors. This study aimed to investigate the effect of local phase features on tractography results providing data are mixed by a Gaussian or random distribution noise. In this simulation study, a mask was firstly designed based on the local phase features to decrease false-negative and -positive tractography results. The local phase features are calculated according to the local structures of images, which can be zero-dimensional, meaning just one point (equivalent to noise in tractography algorithm), a line (equivalent to a simple fiber), or an edge (equivalent to structures more complex than a simple fiber). A digital phantom evaluated the feasibility current model with the maximum complexities of configurations in fibers, including crossing fibers. In this paper, the diffusion images were mixed separately by a Gaussian or random distribution noise in 2 forms: a zero-mean noise and a noise with a mean of data. The local mask eliminates the pixels of unfitted values with the main structures of images, due to noise or other interferer factors.  The local phase features of diffusion images are an innovative solution to determine principal diffusion directions.

Volumetric modulated arc therapy (VMAT) is mostly considered due to its superior tumor coverage and sparing of organs at risk (OAR) with shorter treatment delivery time. This study aimed to explore the feasibility and potential benefits of VMAT with a constant dose rate (CDR). In this analytical study, 75 cancer patients (15 from each cancer) were selected. Step and shoot intensity-modulated radiation therapy (S&S IMRT), CDR, and VDR VMAT (variable dose rate VMAT) plans were generated for each patient using the Monte Carlo algorithm on the Monaco treatment planning system for 6 MV photon energy. For dosimetric comparison, some variables were compared, including doses to the planning target volume (PTV), OAR, homogeneity index, conformity index (CI), treatment delivery time, and monitor units. CI was higher in CDR and VDR VMAT plans compared to IMRT without any significant variation for PTV coverage V95 and PTV mean dose. In the sparing of OAR, no significant variation was found between CDR, VDR, and IMRT for the brain, head-neck, oesophagus, lung, and prostate. The treatment delivery time was reduced more, i.e., by up to 72-80% in the CDR VMAT technique compared to IMRT.  CDR VMAT technique generates a clinically acceptable plan in terms of PTV coverage, dose conformity, and OAR sparing as IMRT and VDR VMAT in all five cancer sites.

High-quality images with minimum radiation dose are considered a challenge in Computed Tomography (CT) scans. The current study aimed to assess the efficacy of the Iterative Reconstruction in Image Space (IRIS) algorithm combined with Automatic Tube Current Modulation (ATCM) compared to Filtered Back Projection (FBP) in brain CT scans. In this cross-sectional study, 200 patients underwent to brain CT scan, and images were then reconstructed using both FBP and IRIS. The CT Number (CTN), noise, and Signal-to-Noise Ratio (SNR) were computed for different tissues from CT images. The performance of two algorithms under different exposure conditions was evaluated using a water phantom. Two experienced radiologists assessed the image quality. Volume CT Dose Index (CTDIvol) and Dose Length Product (DLP) were recorded for each scan. FBP reconstruction exhibited higher noise and lower SNR compared to IRIS, both with and without ATCM. Noise levels significantly increased for FBP combined with ATCM. Subjective analysis showed higher performance for IRIS without ATCM compared to other approaches. The mean CTDIvol with and without ATCM was 20.04±3.33 and 36.37±4.65 mGy, respectively. In the phantom study, the noise with IRIS remained lower than that with FBP even with a 42% dose reduction.  IRIS algorithm can preserve the image quality when radiation dose is significantly reduced by ATCM in brain CT scan. Implementation of IRIS combined with ATCM is recommended for brain CT examinations.

Interest in naturally occurring phytochemicals has been on the increase, they are believed to reduce the risk of brain disorders. Hispidulin (HN) is a phenolic flavonoid compound with various pharmacological and biological effects on the central nervous system. It belongs to the flavone class of flavonoids. It can be found in different plant materials, especially fruits and vegetables. The literature used in this review was collected from credible scientific databases including ScienceDirect, Scopus, PubMed, Google Scholar, and Hindawi without time restriction, using relevant keywords, such as HN, brain, central nervous system, flavonoids, and flavones. HN was discovered to possess pro-apoptotic properties, act as an antioxidant, inhibit cytokine production and toll-like receptor 4 expression, as well as impede nuclear factor kappa beta and mitogen-activated protein kinase B. HN was also found to inhibit lipid peroxidation in vitro and reduce brain edema in mice. These pharmacological potentials suggest that HN is a promising candidate for neuroprotection in CNS disorders like depression and epilepsy. This review provides an update on the scientific literature concerning how these activities could help provide various forms of neuroprotection in the CNS. Additional experimental data on the effects of HN in models of neurological disorders and neuroprotection should be explored further. Based on the current study, HN is a promising candidate for neuroprotection of the CNS.

The We evaluate the effects of radiofrequency electromagnetic field (RF-EMF) on rat brain and testicular tissue using histopathology, comet assay, and real-time quantitative PCR techniques. Two equal groups of fourteen rats one for sham-control and the other for exposure (n = seven) were created. For a duration of 14 days, the exposure group (2100 MHz, testicular tissue SAR values of 163 mW/kg for 10 g, brain tissue SAR values of 292 mW/kg on average) was subjected to five hours of exposure per day. Evaluations were conducted on tissue gene expression levels, histopathology, and DNA damage to brain tissue. The histological examination of brain tissue from the exposed group revealed vascular alterations and significant edema (p < 0.05). It was determined that RF radiation-induced much more cellular damage in the exposed group (18.26% tail DNA) than in the control group (4.06% tail DNA). Signs of deterioration in spermatogenic cells in the testicular tissue of the exposed group also changed significantly (p < 0.05). The Bax and bcl-2 genes showed a significant difference (p < 0.05) in the mRNA level data, whereas the p53 genes showed no significant change (p > 0.05). These findings suggest that it may cause some histopathological and cellular damage in brain and testis tissue.

Maternal separation (MS) is a well-characterized model of early life stress, based on the postnatal disruption of the mother-infant interaction. Studies on rodents have demonstrated that MS, as an early adverse life event, leads to spatial memory deficits and lasting changes in brain plasticity. Here, we review data from animal studies regarding the impact of MS on long-term potentiation (LTP). Evidence shows that animal models are useful for evaluating the effects of MS on LTP. Overall, studies suggest that MS impairs LTP.

Numerous physical and chemical agents can induce destructive effects on the brain tissue. Noise and toluene, which are some of these harmful agents, have significant adverse effects on the brain tissue. This work aimed to investigate the neurotoxic changes induced by co-exposure to toluene and noise. 

A total of 24 male white New Zealand rabbits were randomly segregated into four groups, including toluene exposure, noise exposure, co-exposure to noise and toluene, and control. This in vivo study tested the neurotoxic effects of exposure to 1000 ppm toluene and 100 dB noise during two weeks (8 h/day). The serum levels of brain-derived neurotrophic factor-α (BDNF-α), malondialdehyde (MDA), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase and total antioxidant capacity (TAC) values in the brain tissue were measured. Moreover, hematoxylin and eosin (H&E) staining was utilized for brain pathological analysis.

Exposure to noise increased TAC values in the cerebral cortex. Co-exposure to toluene and noise increased the serum levels of BDNF-α. Nevertheless, exposure to noise decreased the levels of BDNF-α in serum. On the other hand, histopathological examinations using H&E staining exhibited that different signs of inflammation, such as lymphocyte infiltration, pyknosis, vacuolization, and chromatolysis were induced by exposure to noise and toluene in the cerebellum, hippocampus, and frontal section in the brain tissue. In addition, simultaneous exposure to toluene and noise induced antagonistic and synergistic changes in some neurotoxic parameters.

Exposure to noise and toluene, which caused inflammation in the brain tissue cells, could be a noticeable risk factor for the neurological system.