جستجوی مقالات مرتبط با کلیدواژه « alzheimer » در نشریات گروه « پزشکی »

 Alzheimer’s disease (AD) is a neurodegenerative disease specified by chronic and irreversible destruction of neurons. This study aimed to evaluate the effects of different extracts(aqueous, hydroalcoholic, hexane, and ethyl acetate) and manna of Echinops cephalotes (EC) on impaired cognitive function induced by scopolamine in mice. EC is shown to have anti-cholinesterase-butyrylcholinesterase activities.

Experimental approach:

 In this study, aqueous and hydroalcoholic extracts, hexane and ethyl acetate fractions of EC (25, 50, 100 mg/kg, i.p.), and the manna (25, 50, 100 mg/kg, gavage) were administered for 14 days alongside scopolamine (0.7 mg/kg, i.p.). Rivastigmine (reference drug) was administered for 2 weeks i.p. Mice were tested for their memory function using two behavioral models, object recognition test (ORT) and passive avoidance test (PAT).

 Administration of scopolamine significantly impaired memory function in both behavioral models. In the PAT model, all extracts at 50 and 100 mg/kg significantly reversed the effect of memory destruction caused by scopolamine. At a lower dose of 25 mg/kg, however, none of the extracts were able to significantly change the step-through latency time. In the ORT model, however, administration of all extracts at 50 and 100 mg/kg, significantly increased the recognition index. Only the manna and the aqueous extract at 25 mg/kg were able to reverse scopolamine-induced memory impairment.

Conclusions and implications:

 These results suggest that all forms of EC extracts improve memory impairment induced by scopolamine comparably to rivastigmine. Whether the effects are sustained over a longer period remains to be tested in future work.

Alzheimer’s disease (AD) is a neurodegenerative condition characterized by a gradual onset and progressive deterioration. Recent studies have demonstrated that certain antihyperglycemic drugs can slow down the progression of AD.

This study aimed to investigate the effects of sitagliptin (SG) and metformin (MTF) on scopolamine (SCP)-induced learning and memory impairment in both diabetic and non-diabetic mice.

This experimental study was conducted with two subgroups of mice, one diabetic and one non-diabetic. Over a 14-day period, the animals received different doses of SG and MTF in addition to a combination of these two drugs. On the 14th day, SCP was administered, followed by a memory impairment test (passive avoidance learning) conducted 45 minutes later. Subsequently, the animals were sacrificed, and brain samples were collected to measure oxidative stress biomarkers, including malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD).

The obtained findings revealed that intraperitoneal injection of SCP impaired learning and memory function and caused brain oxidativedamagein both diabeticand healthy mice. In healthy mice, the administration of high doses of MTF(500 mg/kg) and SG (20 mg/kg), in addition to the combination of these two drugs, significantly reduced memory impairment and oxidative stress. However, in the diabetic groups, only MTF and the combination of MTF with SG could reduce memory impairment and oxidative stress.

The authors concluded that these antidiabetic drugs ameliorated oxidative stress by increasing antioxidant capacity and improved scopolamine-induced memory impairment. Furthermore, the combination of these two drugs yielded more favorable results.

Published data obtained from in vitro and in vivo studies was reviewed systematically and analyzed critically to evaluate the effect of oral cavity-derived stem cells (OCDSCs) on the recovery or therapy of neurodegenerative diseases (NDs), such as Alzheimer disease (AD), amyotrophic lateral sclerosis (ALS), Huntington (HD) diseases, and Parkinson disease (PD). 

An electronic search was accomplished. References of included articles were also manually searched. Studies were critically evaluated for suitability against the inclusion/exclusion criteria and the data was extracted. Bias risk evaluation of the studies and evidence synthesis were conducted. 

A total of 14 in vivo and 10 in vitro studies met the inclusion criteria. PD was induced in 10 in vivo and 7 in vitro studies, while AD was induced in 2 in vivo and 4 in vitro studies. Two studies (1 in vitro and 1 in vivo) evaluated ALS disease and 1 in vivo study evaluated HD. Moderate evidence was found for in vitro studies reporting the positive effect of OCDSCs on PD or AD recovery. Strong evidence was found for in vivo studies in which PD animal models were used; meanwhile, moderate evidence was found for the impact of OCDSCs on AD recovery. Limited evidence was found for in vivo studies evaluating HD and ALS. 

Although studies reported favorable data regarding the OCDSCs on NDs, they presented a considerable risk of bias. Because of heterogeneous study characteristics, the current study recommends improving standardized methods to evaluate the therapeutic effects of OCDSCs on the NDs.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 led to the global coronavirus disease 2019 (COVID-19) pandemic with a wide range of clinical symptoms. Neurological complications have been a significant concern, with diverse symptoms and potential neuroinvasive mechanisms. The pandemic has also impacted individuals with mental health conditions, such as migraines, bipolar disorder (BD), and schizophrenia, highlighting the complex interconnections between physical and mental health during these challenging times.

This retrospective report from the Iranian Network for Research in Viral Diseases (INRVD) study aimed to investigate the multifaceted interactions between COVID-19, neurological complications, and mental health disorders (e.g., migraines, BD, and schizophrenia) to better understand their collective impact on individuals’ health and well-being.

This study involved 63 individuals who tested positive for COVID-19, including 32 females (50.8%) and 31 males (49.2%). The participants were categorized into different groups based on their underlying conditions: 7 individuals with schizophrenia, 8 with BD, 6 with migraines, 12 with Alzheimer’s disease, and 30 with COVID-19 without any underlying neurologic disorder. This investigation was carried out in 12 hospitals supervised by the INRVD between March 2020 and May 2021. The study used frequencies and percentages to describe the data and employed chi-square tests, including the contingency coefficient, to explore associations between COVID-19 symptoms and disease groups.

The analysis of clinical manifestations revealed distinctive patterns. Cough was the most prevalent symptom across the entire sample, affecting over 79% of participants. Fever followed as the second most common symptom, with approximately 62% of individuals reporting it. Fatigue ranked third, impacting 57% of the subjects. In contrast, vomiting was the least frequently reported symptom, with an incidence of only 14.3%. In terms of specific conditions, a notable discrepancy was observed in the prevalence of headaches. Although present in 71.4% of individuals with schizophrenia, this symptom was reported by only 50% of those with BD, followed by 66.7% with migraines and 83.3% with Alzheimer’s. The patients without neurologic disorders exhibited a lower incidence of neurological manifestations, with only 23.3% reporting headaches.

This study provides insights into the clinical manifestations of COVID-19 in individuals with distinct underlying conditions. The prevalence and presentation of symptoms varied significantly across the different groups, and neurological symptoms exhibited a higher prevalence in this patient group than those without any underlying neurologic disorders. This study aimed for a more comprehensive understanding of the probable intricate interplay between COVID-19, underlying health conditions, and clinical manifestations. Understanding these differences is crucial for tailoring effective clinical interventions.

One of the negative effects of the COVID-19 illness, which has affected people all across the world, is Alzheimer's disease. Oblivion after COVID-19 has created a variety of issues for many people. Predicting this issue in COVID-19 patients can considerably lessen the severity of the problem.

Alzheimer's disease was predicted in Iranian persons with COVID-19 in using three algorithms: Nave Bayes, Random Forest, and KNN. Data collected by private questioner from hospitals of Tehran Province, Iran, during Oct 2020 to Sep 2021. For ML models, performance is quantified using measures such as Precision, Recall, Accuracy, and F1-score.

The Nave Bayes, Random Forest algorithm has a prediction accuracy of higher than 80%. The predicted accuracy of the random forest algorithm was higher than the other two algorithms.

The Random Forest algorithm outperformed the other two algorithms in predicting Alzheimer's disease in persons using COVID-19. The findings of this study could help persons with COVID-19 avoid Alzheimer's problems.

Alzheimer is the most prevalent cognitive disturbance with a high spread rate among the elderly. The current research aims to investigate the impact of cognitive rehabilitation on the memory improvement of Alzheimer disease patients.

This was a semi-experimental design with pre-test and post-test designs. The statistical population in Baghdad City, Iraq, in 2021 included 60 patients with Alzheimer and was divided into an experimental (n=30) and a control group (n=30). The patient’s cognitive abilities were assessed before the intervention (pre-test), promptly after the intervention (post-test), and 2 months later (follow-up). The experimental group had twenty-eight 45-min sessions of training based on the Montessori method (2 sessions per week). The data were analyzed via the SPSS software, version 19, using the independent t-test and repeated measures analysis of variance. The results had a P<0.05.

The findings of the independent t-test demonstrated no significant difference between the scores of both groups during the pre-test stage (P>0.05); however, the difference was significant during the post-test and follow-up stages (P<0.001). In addition, the findings of the repeated measure analysis of variance indicated a significant difference between both groups’ mean scores in the post-test and follow-up (P<0.001).

Cognitive rehabilitation can help patients with memory disorders and positively affect their memory performance.

Alzheimer’s disease (AD) is an advanced and devastating neurodegenerative illness. It is an important reason for dementia in the world’s quickly aging population. The spread of AD cases positions serious problems on relations, society, and the family. MicroRNAs are endogenous ∼22 nucleotides non-coding RNAs that could control gene expression nearby a length of RNA or DNA that has been transcribed respectively from a DNA or RNA template or translation suppression. AD is a multifactorial disorder and a progressive disease beginning with mild memory loss that micoRNAs show a serious character in the pathogenesis of AD. In this review, we will focus on the outcome of microRNAs in diverse pathological manners during AD development.

Evidence Acquisition: 

miRNAs are small noncoding endogenous RNA sequences active in the regulation of protein expression; change of miRNA expression can cause abnormal adjustment in key genes and pathways that contribute to disease development. The role of exosomal miRNAs has been proven in various neurodegenerative diseases, and this opens the possibility that dysregulated exosomal miRNA profiles may influence AD disease. However, most abnormally expressed miRNAs recognized in AD are not triggered by synaptic activity. Some findings showed that synaptic-related miRNA mediates synaptic/memory deficits in AD via the protein signaling pathway, illuminating a potential therapeutic strategy for AD. Data were obtained by inhibiting miRNA and blocking the phosphorylation on mediated protein.

The pieces of evidence show that microRNAs play a critical role in the pathogenesis of AD, but they do not have the same role in the disease. For example, miRNA-134 and miRNA-146 show downregulation in the brain of AD mice while miRNA-138 can regulate the evolution of synapse and size of the spine.

The data on miRNAs in in vitro and in vivo AD animal models must be established by educations in the human brain. This feature is critical for forming the real the role of micRNA in AD miRNAs in AD.

The production of figurative expressions, particularly idioms, and proverbs, is negatively affected by damage to the left hemisphere and subcortical area of the brain. Alzheimer patients, thanks to the preservation of basal ganglia, can produce these expressions. In contrast, compared to Alzheimer’s patients, Parkinson’s patients cannot produce these expressions due to the malfunction of the basal ganglia. This study attempts to compare the linguistic and cognitive performance of Persian-speaking patients with Alzheimer’s disease, Parkinson’s disease, and healthy counterparts regarding the production and comprehension of these figurative expressions.

In doing so, by selecting a sample of participants composed of 10 Alzheimer’s patients, 10 Parkinson’s patients, and 10 healthy individuals matched with each other regarding age and education. Then, different tests, including Arizona battery for communication disorders of dementia, famous names, and face test, structured conversation, figurative expression completion, elicitation of response based on situational context, Northridge evaluation of idioms and proverbs in situational context, conventional and figurative expression evaluation were condcuted to analyze their performance.

The results of Arizona battery for communication disorders of dementia indicated that Alzheimer’s patients were in the middle stage of the disease while Parkinson’s participants were classified as non-dementia patients. Although the result of the Renown face and name recognition test demonstrated a significant difference between Alzheimer’s patients and the healthy group regarding cognition and confidence levels, the same result was not observed between healthy control and Alzheimer’s patients. Furthermore, in the test of structured conversation, the proportion of produced words by Alzheimer’s patients was more than that of Parkinson’s patients. However, the results of sentence and figurative expression completion tests corroborated the weaker performance of Alzheimer’s patients compared to their Parkinson and healthy counterparts. Furthermore, notwithstanding in the test of Elicitation of response based on Situational Context, Parkinson’s patients performed more poorly than their Alzheimer and healthy counterparts, in the tests of conventional and figurative expression evaluation, Alzheimer’s patients’ pattern of performance was different from that of other groups as they performed more weakly than Parkinson patients.

The observed dissociation in the performance of Alzheimer as well as Parkinson’s patients in the linguistic production and comprehension tests shed light on the significant role of the subcortical area of the brain in the production of idioms and proverbs.

Properties of Alzheimer's disease, can be caused by several reasons and there is no definite treatment for it. We aimed to study the effect of the hydroalcoholic extract, methanolic and n-hexane fractions of brown algae Sargassum angustifolium on memory impairment in mice and rats. 

Experimental approach:

 Hydroalcoholic extract (25, 50, 100, 200 mg/kg), methanolic (20 and 40 mg/kg) and n-hexane (40 and 60 mg/kg) fractions of S. angustifolium were administered for 21 days intraperitoneally before scopolamine injection (2 mg/kg) on day 21. Rivastigmine was administered for 3 weeks intraperitoneally as well. Then, cognitive function was evaluated by three behavioral tests: passive avoidance, object recognition, and the Morris Water Maze test.

Scopolamine induced memory impairment and rivastigmine significantly reversed the memory dysfunction in all three tests. Hydroalcoholic extract and methanolic fraction significantly reversed scopolamine-induced memory impairment in passive avoidance by 64% and 55% and enhanced the recognition index in the object recognition test. In the Morris water maze test probe trial and training session, on days 3 and 4, the hydroalcoholic extract showed a significant decrease in time spent in the target quadrant and path length, respectively. Also, hydroalcoholic extract and methanolic fraction decreased escape latency time in training sessions on days 3 and 4, by 50% and 31% in comparison to scopolamine. N-hexane fractions had no significant effect on scopolamine-induced cognitive impairment. 

Conclusion and implications:

 Although the n-hexane fraction wasn’t effective, the administration of hydroalcoholic extract and the methanolic fraction of S. angustifolium enhanced scopolamine-induced memory impairment.

Each year, twice as many women than men are diagnosed with Alzheimer’s Disease (AD). As there is no known cure for AD, preventing it has become a vital public health issue. One lifestyle intervention that may reduce the risk of AD is physical activity (PA). This scoping review aimed to examine the existing literature on PA and AD risk to identify whether PA has a sex-specific effect on AD risk in women.

A scoping review was conducted based on PRISMA-ScR guidelines. Cochrane recommended databases, MEDLINE, Embase, and PsycINFO were searched via Ovid between May and June 2022. Articles were screened at the title, abstract, and full-text level for inclusion criteria (female participants, results reported by sex, PA, or exercise reported separately from other variables, and participants with no known cognitive impairment). For each study, sample characteristics, PA and AD measures, follow-up times, and results were summarized.

Ten studies met the inclusion criteria, and their results were assessed for quality using the Cochrane GRADE tool. Most studies (80%) reported significant results for females. When broken down by sex, six studies reported differences in result significance with some studies finding that PA can reduce AD risk in women but not in men. Increased weekly PA sessions, duration, and intensity all significantly reduced AD risk for women.

While there are some limitations, including reliance on self-report, short follow-up times, and variations in AD and PA measures, the results have important implications. Findings may facilitate the development of tailored interventions that target women with unique lifestyle recommendations and inspire future research on the specifics of PA type, timing, and duration.

Advanced stages of dementia interfere with elderly self‑care. Consequently, they need caregivers who take responsibility for their care in the long‑term. Restrictions to the caregiver’s access to information, resources, and organizational support have created problems in their caregiver role, which is why the World Health Organization (WHO) emphasizes caring for caregivers by providing evidence‑based information and training programs. As there is no clinical practice guideline for home care in the Islamic Republic of Iran, this study aims to develop a home health care guideline for the elderly with dementia.

The ADAPTE process provided by the Guidelines International Network was considered as the basis. In order to identify the care needs of Iranian patients with dementia, semi‑structured interviews were added to this guideline.

The identification and implementation of the perspectives of patients and caregivers during the process of guidelines adaptation increase the applicability of the guidelines. Improved quality of life for the patients in their place of residence is one of the expected consequences of this guideline’s implementation. The developed guidelines will be used at home health care centers, and dementia and Alzheimer’s associations in Iran.

Carveol is a naturally occurring terpenoid with antispasmodic, carminative, astringent, indigestion, and dyspepsia properties, as well as anti-diabetic, anti-oxidant, anti-hyperlipidemia, and anti-inflammatory properties in the liver. Research also suggests that it has memory-enhancing and anti-oxidant properties. The purpose of this research was to see whether carveol could protect rats against scopolamine-induced memory loss in a rat model. 

Thirty male Sprague-Dawley rats (200–250 g) were grouped as the saline group receiving saline, disease group receiving scopolamine, and four treatment groups among which three groups received scopalamine+carveol and one group received scopalamine+donepezil for 28 days. Followed by in vitro, behavioral, anti-oxidant, and molecular studies were done. P<0.005 was considered  statistically significant.

The in vitro assay showed that carveol caused diphenyl-1-picrylhydrazyl inhibition. In-vivo findings revealed that carveol (50, 100, and 200 mg/kg) significantly improved dementia by reducing escape latency and spending more time in the targeted quadrant in the Morris water maze test. Increased number of entries and percent spontaneous alterations were observed in rats’ Y-maze test. In animal brain tissues, i.e., cortex and hippocampus, carveol enhanced glutathione, glutathione-s-transferase, catalase, and reduced lipid peroxide levels. Carveol also improved cellular architecture in histopathological examinations and decreased expression of inflammatory markers such as amyloid-beta, nuclear factor kappa light chain activated B cells, tumor necrosis factor-alpha, cyclooxygenase 2, prostaglandin E2, and interleukin-18, as evidenced by immunohistochemistry and enzyme-linked immunosorbent assays, as well as molecular investigations. 

This study suggests that the compound could be potent against amnesia mediated through anti-oxidant, amyloid-beta inhibition, and anti-inflammatory pathways.