Mechanisms and Functions of the Cerebral-Cognitive Reserve in Patients with Alzheimer's Disease: A Narrative Review.

Background: The need for scientific knowledge about aging is predicated on the demand of modern society to extend the active life of a person. To maintain intellectual longevity, it is necessary to take into account not only the pathological, but also compensatory mechanisms that arise during aging. The cerebral-cognitive reserve (CCR) influences the rate of transition from pre-phenomenological stages to the clinical stage of the disease, thereby changing the prognosis of Alzheimer's disease (AD).

Two clusters of mutations map distinct receptor-binding sites of echovirus 11 for the decay-accelerating factor (CD55) and for canyon-binding receptors.

In this study we present the comparative sequence analysis of the parental haemagglutinating (daf+) and mutant non-haemagglutinating (daf-) clones of echovirus 11 (EV11) isolated from the prototype strain Gregory. The sequence comparison revealed only a single amino acid substitution in the capsid protein VP2 of each mutant clone. These substitutions were located in the area of viral receptor-binding site for DAF.

[Mapping of point mutations leading to loss of virus ECH011 affinity for receptor DAF (CD55)].

Comparative sequence of the structural part of genomes pf the original daf+ clone and two derived daf- mutant clones (101 and 103) was analyzed to map mutations responsible for the loss of affinity for the receptor glycoprotein DAF (CD55). The obtained nucleotide sequences (EU167520, EU167521, EU167522) were deposited in the GenBank. There were single point mutations causing amino acid changes in VP2 protein: S145 --> N in clone 101 and G162 --> E in clone 103.

Hemoglobin heterogeneity under conditions of abnormal erythropoiesis.

Experiments on rats showed that changes in the hemoglobin profile during hypoxia are determined by switching of erythropoiesis from the "basic" to "emergency" mode. The "basic" mode of erythropoiesis is typical of the mature organism under normal conditions. The "reserve" or "emergency" mode is realized in fetuses, senile animals, and during hypoxia.

Mechanisms of changes in the hemoglobin profile during acute adaptation to extreme conditions.

We studied changes in rat hemoglobin isoforms during acute adaptation to various hypoxic conditions. Erythrocytes were heterogeneous in the content of various hemoglobin isoforms. Changes in the hemoglobin profile during hypoxia are related to variations in the ratio between populations of erythrocytes differing in the content of individual hemoglobin isoforms.