Association of Blood Amyloid Beta-Protein 1-42 with Poststroke Cognitive Impairment: A Systematic Review and Meta-Analysis

Background

Increases in blood of amyloid beta-protein (Aβ) have been noted in patients with Alzheimer's dementia (AD). Recent studies have shown that blood amyloid beta-protein 1-42 (Aβ1-42) level is closely related to poststroke cognitive impairment (PSCI), which may be the influencing factor and even a predictor of PSCI. The aim of this systematic review was to synthesize the evidence for the association of cognitive impairment among PSCI.

Methods

PubMed (MEDLINE), EMBASE, Cochrane Library, the Cochrane Central Register of Controlled Trial (CENTRAL), CNKI, and WanFang data were searched. Case-control, cohort, and cross-sectional studies that evaluated the association between blood Aβ1-42 and PSCI were included irrespective of language and date of publication. The outcomes of this review consisted of (1) any dementia, (2) any cognitive impairment, and (3) any cognitive impairment no dementia, which were assessed at least 3 months (90 days) after stroke. Exposure of interest was blood Aβ1-42 level (including serum and plasma).

Results

Of 617 records retrieved, 8 studies (6 case-control and 2 cohort studies) involving 931 stroke patients were included for further analysis. 8 studies with 931 subjects explored the correlation between Aβ1-42 and PSCI. PSCI was reported in 457 patients, and the pooled SMD of amyloid beta-protein 1-42 was -0.96 (95% CI -1.10~-0.82, I² = 15%, P < 0.01). The results remained robust in sensitivity analysis adjusting for study quality, sample source, and cognitive scale score in analysis of studies, as well as in analysis adjusted for publication bias.

Conclusions

Blood Aβ1-42 level was significantly negatively related to the risk for PSCI, and more prospective studies with large sample size are needed to define a precise threshold value of blood Aβ1-42 level to predict PSCI in the future. This study is registered with PROSPERO, registration number: CRD42021246165.

[Cerebrovascular disease with neurocognitive impairment]

In the International Classification of Diseases 11th revision in the section «Diseases of the nervous system», it is proposed to distinguish «Cerebrovascular disorder with neurocognitive impairment», which corresponds to both discirculatory encephalopathy (DEP) or chronic cerebral ischemia (CCI) accepted in our country, and also vascular cognitive impairments. The terminology, prevalence, risk factors and pathological basis of the disease are discussed, in particular multiple infarctions, strategic infarctions, cerebral small vessel disease, specific microangiopathies, intracerebral hemorrhage and global hypoperfusion. Post-stroke cognitive impairments are discussed in detail. The article presents relevant data on the pathogenesis of the disease, highlights the issues of clinical and neuroimaging diagnostics. Based on the data presented in the article, we can conclude that the diagnosis of DEP, CCI should be based on the presence of cerebrovascular disease with neurocognitive impairment, which implies the verification of vascular cognitive impairments and reliable neuroimaging signs of cerebrovascular pathology while excluding other causes. Early diagnosis and effective treatment of cerebrovascular disease with neurocognitive impairment (DEP, CCI) is becoming increasingly important, since treatment can slow the progression of the disease and lead to a decrease in the incidence of stroke and dementia.

Antiamnestic effect of new nicotinic acid derivatives

Introduction: The search for new drugs for the prevention and treatment of vascular cognitive disorders continues to be a relevant task of pharmacology. In this regard, the aim of this work is to study the antiamnestic effect of five new nicotinic acid derivatives in comparison with the well-known drug mexidol (ethylmethylhydroxypyridine succinate) in animals.

Materials and methods: The experiments were carried out on white male mice using conditioned passive avoidance reflex (CPAR). Electroconvulsive shock (ECS), scopolamine administration, and acute hypoxia in a hermetic chamber were used as amnesic effects. Testing for the safety of CPAR was performed 24 h after amnesic exposure. The new substances, reference drug mexidol, and a 0.9% sodium chloride solution (control group) were administered once intraperitoneally 60 min before mice training.

Results and discussion: Three of the five new nicotinic acid derivatives, LKhT 4-19 (100 mg/kg), LKhT 6-19 (25, 50, and 100 mg/kg), and LKhT 7-19 (100 mg/kg), have antiamnestic properties on models of amnesia in mice induced by ESC, scopolamine, and acute hypoxia in a hermetic chamber. At the same time, the most efficient substance – LKhT 6-19 – exceeds the reference drug mexidol on all three models used. In addition, this compound is also more efficient than two other new compounds, LKhT 4-19 and LKhT 7-19, on the model of ESC-induced amnesia and LKhT 7-19 on the scopolamine-induced amnesia model.

Conclusion: Compound LKhT 6-19 is promising for further advanced preclinical studies as a potential drug with antiamnestic activity.

Graphical abstract:

The influence of circadian variation in ischemic stroke onset on the evolution of cognitive status

Introduction. It is already known and accepted that cerebrovascular disease onset has a temporal variation pattern, the best documented being the circadian variation pattern, with a frequency peak in the morning and a second lower peak during afternoon. The impact of this circadian variation on post-stroke cognitive status has been little studied. Materials and method. The study included a cohort of 63 patients with ischemic stroke, admitted to the Neurology Departments I and II of the Rehabilitation Hospital in Cluj-Napoca between 1 June 2008 and 1 June 2009, who were evaluated for their cognitive status over 2 years, during 5 successive visits. The onset time of ischemic stroke was assigned to one of the six-hour intervals: 00.01-06.00 (night), 06.01-12.00 (morning), 12.01-18.00 (afternoon), and 18.01-24.00 (evening). Statistical analysis was performed using Excel Microsoft, descriptive and ANOVA test. Results and conclusions. The circadian variation pattern of stroke onset is confirming in our study the known incidence pattern of ischemic stroke, with the morning peak. There are differences in the evolution during dynamics of the MMSE score depending on the time of the day when stroke occurs. Patients with stroke onset during the night have seems to have a less favorable cognitive evolution in the second year after ischemic stroke compared to patients with stroke onset during the other intervals of the day.

Animal-derived medicinal products in Russia: Current nomenclature and specific aspects of quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Animal-derived medicinal products (ADMP) had been extensively used in Russia and became a part of officinal medicine in 1778.

AIM OF THE STUDY

The aim of the current review was to analyse the ADMPs authorised in the Russian Federation and to identify specific aspects of quality evaluation of these medicinal products.

MATERIALS AND METHODS

Information of ADMPs was extracted from the online State Register of Medicinal Products of the Russian Federation. At the next stage, we systematically searched library catalogues, E-library.ru, Medline/PubMed, Scopus, Web of Science and Google Scholar databases to find data related to ADMP quality evaluation, clinically proven efficacy and safety.

RESULTS

For classification of ADMP, we propose an approach based on the raw material used: ADMPs derived from marine organisms, ADMPs from cattle and pigs and ADMPs from other terrestrial animals. The majority of ADMPs authorised in Russia are produced by local manufacturers. ADMPs are available in dosage forms of solution for parenteral administration (35% of all products) and lyophilisates for parenteral use (19%), tablets and capsules (17% and 11%, respectively), ointments (5%) and powders (3%). ADMPs belong to the following pharmacotherapeutic groups: medicines for tissue regeneration and repair stimulators (30%), digestive enzyme products (22%), anticoagulants (17%), proteolytic agents (6%) and medicines for the treatment of chronic prostatitis (5%). The most important approaches to standardisation of ADMPs are implementation of modern requirements for registration dossiers, development of risk-oriented approaches for evaluation of impurities, elaboration of advanced instrumental and in vitro test methods capable of replacing in vivo methods and harmonisation of the potency units used for standardisation.

CONCLUSIONS

The key features of ADMPs that help them retain their leading position in the pharmaceutical market are as follows: (i) their unique composition usually represented by a complex of biologically active substances; (ii) a high degree of affinity of the active ingredient of an ADMP to the human body and (iii) proved safety and clinical efficiency. Variability in the quality of raw ingredients, epidemiological situation and other conditions pose additional challenges for the development of ADMPs and for the standardisation.

[Restoring of the speech functions in patients with aphasia in the early rehabilitation period of ischemic stroke]

AIM

To study the efficacy of combined therapy including daily sessions and two 10-day injections of the drug cellex in patients with aphasia in the early rehabilitation period of ischemic stroke (II).

MATERIAL AND METHODS

Forty patients in the early rehabilitation period of II in the basin of the left middle cerebral artery with moderate to severe aphasia were studied. Twenty patients received combined therapy, including daily sessions with a speech therapist-aphasiologist within 10 days using the improved method, then a self-study using educational materials and two 10-day injections of cellex. Other 20 patients received only speech therapy. To assess the efficacy of therapy, the automated "Program of examination of patients with aphasia", Goodglass-Kaplan scale, modified Rankin scale were used.

RESULTS

There was a significant improvement of speech functions, communicative abilities and functional recovery (p<0.01) in patients of both groups. However, a significantly greater level of rehabilitation (p<0.05) was noted in patients treated with combined therapy included two courses of cellex.

CONCLUSION

The results allow to recommend the inclusion of cellex in the complex rehabilitation of patients with post-stroke speech disorders.

Use of Primary Macrophages for Searching Novel Immunocorrectors

In this mini-review, the role of macrophage phenotypes in atherogenesis is considered. Recent studies on distribution of M1 and M2 macrophages in different types of atherosclerotic lesions indicate that macrophages exhibit a high degree of plasticity of phenotype in response to various conditions in microenvironment. The effect of the accumulation of cholesterol, a key event in atherogenesis, on the macrophage phenotype is also discussed. The article presents the results of transcriptome analysis of cholesterol-loaded macrophages revealing genes involved in immune response whose expression rate has changed the most. It turned out that the interaction of macrophages with modified LDL leads to higher expression levels of pro-inflammatory marker TNF-α and antiinflammatory marker CCL18. Phenotypic profile of macrophage activation could be a good target for testing of novel anti-atherogenic immunocorrectors. A number of anti-atherogenic drugs were tested as potential immunocorrectors using primary macrophage-based model.

Macrophages and Their Contribution to the Development of Atherosclerosis

Atherosclerosis can be regarded as chronic inflammatory disease driven by lipid accumulation in the arterial wall. Macrophages play a key role in the development of local inflammatory response and atherosclerotic lesion growth. Atherosclerotic plaque is a complex microenvironment, in which different subsets of macrophages coexist executing distinct, although in some cases overlapping functions. According to the classical simplified nomenclature, lesion macrophages can belong to pro-inflammatory or anti-inflammatory or alternatively activated types. While the former promote the inflammatory response and participate in lipid accumulation, the latter are responsible for the inflammation resolution and plaque stabilisation. Atherosclerotic lesion dynamics depends therefore on the balance between these macrophages populations. The diverse functions of macrophages make them an attractive therapeutic target for the development of novel anti-atherosclerotic treatments. In this chapter, we discuss different types of macrophages and their roles in atherosclerotic lesion dynamics and describe the results of several experiments studying macrophage polarisation in atherosclerosis.