Cerebrovascular Disease in the Young Adult: Examining Melatonin's Possible Multiple Roles

Cerebrovascular mortality: trend and seasonality in Brazilian capitals, 2000-2019

OBJECTIVE

To evaluate the trend and seasonality of cerebrovascular mortality rates in the adult population of Brazilian capitals from 2000 to 2019.

METHODS

This is an ecological and descriptive study of a time series of mortality due to cerebrovascular causes in adults (≥ 18 years) living in Brazilian capitals from 2000 to 2019, based on the Brazilian Mortality Information System. Descriptive statistical techniques were applied in the exploratory analysis of data and in the summary of specific, standardized rates and ratios by sociodemographic characteristics. The jointpoint regression model was used to estimate the trend of cerebrovascular mortality rates by gender, age groups, and geographic regions. The seasonal variability of rates by geographic regions was estimated using the generalized additive model by smoothing cubic splines.

RESULTS

People aged over 60 years comprised 77% of all cerebrovascular deaths. Women (52%), white individuals (47%), single people (59%), and those with low schooling (57%, elementary school) predominated in our sample. Recife (20/1,000 inhab.) and Vitória (16/1,000 inhab.) showed the highest crude mortality rates. Recife (49/10,000 inhab.) and Palmas (47/10,000 inhab.) prevailed after we applied standardized rates. Cerebrovascular mortality rates in Brazil show a favorable declining trend for adults of all genders. Seasonality influenced rate increase from July to August in almost all region capitals, except in the North, which rose in March, April, and May.

CONCLUSIONS

Deaths due to cerebrovascular causes prevailed in older single adults with low schooling. The trend showed a tendency to decline and winter, the greatest risk. Regional differences can support decision-makers in implementing public policies to reduce cerebrovascular mortality.

The Effect of Task-Oriented Activities Training on Upper-Limb Function, Daily Activities, and Quality of Life in Chronic Stroke Patients: A Randomized Controlled Trial

This randomized controlled study aimed to investigate the effects of 8-week task-oriented activities of daily living (T-ADL) training on upper limb functions, activities of daily living (ADL), and quality of life (QoL) in chronic stroke patients. The 33 patients were randomly assigned to the T-ADL training or conventional occupational therapy (OT) group. The respective interventions were provided for 45-min a day, five times a week for eight weeks. To compare the upper-limb function before and after the intervention, the manual function test (MFT), box and block test (BBT), and grasp power test were performed; to compare the level of ADL performance, the modified-Barthel index (MBI) was measured. To evaluate QoL, stroke-specific QoL was measured. There was a significant group-by-time interaction in the affected side MFT score and both sides of BBT scores, but no significant interaction was found in the unaffected side MFT score, ADL, and QoL. Both groups showed a significant main effect of time in their ADL and QoL after the intervention (p < 0.001). The results of this study indicate that the eight-week T-ADL training has a positive effect on upper limb functions and gross manual dexterity, and both T-ADL training and conventional OT are effective in improving ADL and QoL in chronic stroke patients.

Melatonin Protects Against Ischemic Brain Injury by Modulating PI3K/AKT Signaling Pathway via Suppression of PTEN Activity

Stroke is one of the leading causes of death and disability worldwide with limited therapeutic options. Melatonin can attenuate ischemic brain damage with improved functional outcomes. However, the cellular mechanisms of melatonin-driven neuroprotection against post-stroke neuronal death remain unknown. Here, distal middle cerebral artery occlusion (dMCAO) was performed in C57BL/6j mice to develop an ischemic stroke in vivo model. Melatonin was injected intraperitoneally immediately after ischemia, and 24 and 48 hours later. Melatonin treatment, with 5 to 20 mg/kg, elicited a dose-dependent decrease in infarct volume and concomitant increase in sensorimotor function. At the molecular level, phosphorylation of PTEN and Akt were increased, whereas PTEN activity was decreased in melatonin treated animals 72 hours after dMCAO. At the cellular level, oxygenglucose deprivation (OGD) challenge of neuronal cell line Neuro-2a (N2a) and primary neurons supported melatonin’s direct protection against neuronal cell death. Melatonin treatment reduced LDH release and neuronal apoptosis at various time points, markedly increased Akt phosphorylation in neuronal membrane, but significantly suppressed it in the cytoplasm of post-OGD neurons. Mechanistically, melatonin-induced Akt phosphorylation and neuronal survival was blocked by Wortmannin, a potent PIP3 inhibitor, exposing increased PI3K/Akt activation as a central player in melatonin-driven neuroprotection. Finally, PTEN knock-down through siRNA significantly inhibited PI3K/Akt activation and cell survival following melatonin treatment, suggesting that melatonin protection against ischemic brain damage, is at least partially, dependent on modulation of the PTEN/PI3K/Akt signaling axis.

Melatonin and Melatonergic Influence on Neuronal Transcription Factors: Implications for the Development of Novel Therapies for Neurodegenerative Disorders

Melatonin is a multifunctional signalling molecule that is secreted by the mammalian pineal gland, and also found in a number of organisms including plants and bacteria. Research has continued to uncover an ever-increasing number of processes in which melatonin is known to play crucial roles in mammals. Amongst these functions is its contribution to cell multiplication, differentiation and survival in the brain. Experimental studies show that melatonin can achieve these functions by influencing transcription factors which control neuronal and glial gene expression. Since neuronal survival and differentiation are processes that are important determinants of the pathogenesis, course and outcome of neurodegenerative disorders; the known and potential influences of melatonin on neuronal and glial transcription factors are worthy of constant examination. In this review, relevant scientific literature on the role of melatonin in preventing or altering the course and outcome of neurodegenerative disorders, by focusing on melatonin's influence on transcription factors is examined. A number of transcription factors whose functions can be influenced by melatonin in neurodegenerative disease models have also been highlighted. Finally, the therapeutic implications of melatonin's influences have also been discussed and the potential limitations to its applications have been highlighted.

Lp-PLA2 evaluates the severity of carotid artery stenosis and predicts the occurrence of cerebrovascular events in high stroke-risk populations

Background

Lipoprotein‐associated phospholipase A2 (Lp‐PLA2) is an independent risk factor for cardiovascular disease. However, relationship between carotid artery stenosis and cerebrovascular events in high stroke‐risk populations is still unclear.

Methods

A total of 835 people at a high risk of stroke were screened from 15,933 people aged >40 years in April 2013 and followed at 3, 6, 12, and 24 months. Finally, 823 participants met the screening criteria, and the clinical data and biochemical parameters were investigated.

Results

Among the 823 participants, 286 had varying degrees of carotid artery stenosis and 18 had cerebrovascular events. The level of Lp‐PLA2 in the carotid artery stenosis group was higher than that in the no stenosis group, and the level in the event group was higher than that in the no event group (p < 0.05). Spearman correlation analysis showed that Lp‐PLA2 was positively correlated with the degree of carotid artery stenosis (r = 0.093, p = 0.07) and stenosis involvement (r = 0.094, p = 0.07). The correlation coefficient between Lp‐PLA2 and lipoprotein was the highest on the levels of sdLDL (r = 0.555, p < 0.001), followed by non‐HDL, LDL, TC, and TG. Cox multivariate regression analysis revealed that, compared with the first quantile of Lp‐PLA2 level (Q1, low level), the risk of cerebrovascular events in the fourth quantile of Lp‐PLA2 was 10.170 times that of the first quantile (OR = 10.170, 95% CI 1.302–79.448, p = 0.027).

Conclusions

Lp‐PLA2 levels can evaluate carotid artery stenosis and predict the occurrence of cerebrovascular events in high stroke‐risk populations and provide scientific guidance for risk stratification management.

A retrospective review of speech-language therapy services provided to adult inpatients at a central-level hospital in Gauteng, South Africa

Background

The quadruple burden of disease (BoD) and multimorbidity reflected in South Africa’s public health sector challenges speech-language therapists (SLTs) to optimise patient management in this context. For planning and delivery of appropriate services, it is important to understand the profile of speech-language therapy (SLT) patients and the public healthcare services provided by SLTs.

Objectives

This study aimed to describe the prevalence of inpatient adult speech, language and swallowing disorders associated with various medical conditions and South Africa’s BoD, in addition to the target areas and duration of SLT interventions provided at a central public hospital.

Method

A retrospective review was conducted on records of 2549 adult inpatients who received SLT services between January 2014 and December 2015 at Chris Hani Baragwanath Academic Hospital. Data, including demographics, medical and SLT diagnoses, and treatment recommendations, were analysed using descriptive and inferential statistics.

Results

Non-communicable diseases (NCDs) were most prevalent (77.48%), with multimorbidity of BoD categories in 29.27% of patients. Cerebrovascular disease (CeVD) comprised 52.45% patients, with CeVD, traumatic brain injury, other neurological conditions, cancer and burns comprising 88.74% patients. More than a third of the patients with CeVD were < 56 years (n = 486; 36.35%). Dysphagia (48.96%), aphasia (30.95%) and dysarthria (23.62%) were the most common, with 44.68% of patients having multiple SLT diagnoses. The number of SLT sessions significantly correlated with SLT comorbidity (r_s = 0.4200; p = 0.0000), but not BoD comorbidity (r_s = 0.0049; p = 0.8058).

Conclusion

Speech-language therapy patients reflected a heavy NCD burden and multimorbidity. Provision of SLT services should take into consideration a profile of increased complexity of medical conditions and SLT diagnoses.

A Potent Antioxidant Endogenous Neurohormone Melatonin, Rescued MCAO by Attenuating Oxidative Stress-Associated Neuroinflammation

Ischemic stroke is an acute neurological syndrome either due to permanent or temporary obstruction of blood. Such obstruction immediately triggers abrupt pathological cascading processes, which collectively lead to neuronal cell death. Oxidative stress and neuroinflammation in ischemic stroke are critical regulating events that ultimately lead to neuronal death. Complicated interplay exists between the two processes which occur through several stages. Most often, oxidative stress precedes the inflammatory mechanisms and includes several interconnected cascades that underlie the ischemic stroke pathology. In continuation of the previously published data, here, we further ruled out the protective role of melatonin in focal cerebral ischemic injury model. Administration of 5 mg/kg dose of melatonin 30 min prior to ischemia reduced brain infarction associated with sequentially rescued neuronal apoptosis. Furthermore, melatonin attenuated neuroinflammatory markers and reactive oxygen species (ROS), induced by ischemic stroke, via halting the key players of mitogen stress family (p38/JNK). Besides, melatonin modulated the endogenously produced antioxidant enzyme, thioredoxin (Trx) pathway. These broader therapeutic efficacies of melatonin suggest that melatonin could be further investigated for its diverse therapeutic actions with multiple targets in recovering, preventing and halting the detrimental outcomes of MCAO, such as elevated oxidative stress, neuroinflammation, and neurodegeneration.

Melatonin protects against ischemic stroke by modulating microglia/macrophage polarization toward anti-inflammatory phenotype through STAT3 pathway

AIMS

Microglia and infiltrated macrophages play important roles in inflammatory processes after ischemic stroke. Modulating microglia/macrophage polarization from pro-inflammatory phenotype to anti-inflammatory state has been suggested as a potential therapeutic approach in the treatment of ischemic stroke. Melatonin has been shown to be neuroprotective in experimental stroke models. However, the effect of melatonin on microglia polarization after stroke and underlying mechanisms remain unknown.

METHODS

In vivo, cerebral ischemia was induced by distal middle cerebral artery occlusion (dMCAO) in C57BL/6J mice. Melatonin was injected intraperitoneally (20 mg/kg) at 0 and 24 hours after ischemia. In vitro, the microglial cell line BV2 was stimulated to the pro-inflammatory state with conditioned media (CM) collected from oxygen-glucose deprivation (OGD) challenged neuronal cell line Neuro-2a (N2a). Real-time PCR was utilized to detect the mRNA expression of microglia phenotype markers. Activation of signal transducer and activator of transcription 3 (STAT3) pathway was determined by Western blot of phosphorylated STAT3 (pSTAT3). A neuron-microglia co-culture system was used to determine whether melatonin can inhibit the neurotoxic effect of pro-inflammatory microglia to post-OGD neurons.

RESULTS

Melatonin treatment reduced brain infarct and improved neurological functions 3 days after dMCAO, which was accompanied by decreased expression of pro-inflammatory markers and increased expression of anti-inflammatory markers in the ischemic brain. In vitro studies confirmed that melatonin directly inhibited the pro-inflammatory responses in BV2 cells upon exposure to OGD neuron CM. The microglia possessing pro-inflammatory phenotype exacerbated post-OGD N2a cells death, whereas melatonin reduced such neurotoxic effect. Further, melatonin enhanced the otherwise inhibited pSTAT3 expression in BV2 cells treated with OGD neuron CM. STAT3 blockade significantly reduced the effect of melatonin on microglial phenotype shift.

CONCLUSION

Melatonin treatment ameliorates brain damage at least partially through shifting microglia phenotype from pro-inflammatory to anti-inflammatory polarity in a STAT3-dependent manner.