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A significant difference in behavior of ZrIV ions during their cocrystallization and sorption binding to hydroxyapatite (HAP) is demonstrated. When the concentration of doping ions exceeds 10−4 mol L−1, a chemical reaction with the formation of amorphous zirconium phosphate and complete dissolution of the sorbent occurs in the system rather than sorption. According to the X-ray diffraction and transmission electron microscopy (TEM) data, a similar reaction is also possible at lower concentrations of zirconium ions. The effect of doping ions on the morphology and structure of HAP is significantly lower for the cocrystallization introduction of Zr. In addition, according to high-resolution TEM data, doping ions can uniformly be distributed over the carrier surface or volume. Therefore, this method of binding method can be recommended for the preparation of a target HAP-Zr complex. [ABSTRACT FROM AUTHOR]

According to one hypothesis, Parkinson's disease pathogenesis is largely caused by dopamine catabolism that is catalyzed on mitochondrial membranes by monoamine oxidase. Reactive oxygen species are formed as a byproduct of these reactions, which can lead to mitochondrial damage followed by cell degeneration and death. In this study, we investigated the effects of administration of the mitochondrial antioxidant SkQ1 on biochemical, immunohistochemical, and behavioral parameters in a Parkinson-like condition caused by protoxin MPTP injections in C57BL/6 mice. SkQ1 administration increased dopamine quantity and decreased signs of sensory-motor deficiency as well as destruction of dopaminergic neurons in the substantia nigra and ventral tegmental area in mice with the Parkinson-like condition. [ABSTRACT FROM AUTHOR]

The influence of a course of medical treatment with the Semax nootropic peptide (50 and 200 μg/kg) on alcohol motivation and general behavior was studied in rats preliminarily alcoholized over six months. Semax was also included in the scheme of complex therapy of human alcohol dependence in clinical practice. Experiments with rats showed an increase in the locomotor and exploratory activity of rats and a decrease in the degree of depressive-like components. This effect compensated the behavioral changes observed in the control group exposed to alcohol deprivation. At the same time, the behavior of test groups under anxiogenic conditions showed increased anxiety. Semax in a dose of 200 μg/kg caused a significant increase in alcohol motivation, whereas its lower dose induced no proalcohol effect. Clinical trials demonstrated the safety (the absence of side effects and fairly high tolerance) of Semax in the course of alleviating the acute withdrawal syndrome and its efficacy for the recovery of mnestic functions (which was similar to the efficacy of Pyracetam). Semax did not change the frequency of cases of pathological craving for alcohol, but increased the overall intensity of behavioral reactions, which made the craving for alcohol stronger. These results allowed determination of safe course doses of Semax (to 50 μg/kg) under conditions of chronic alcoholization and inclusion of this nootropic agent in a scheme of complex therapy for patients with alcohol dependence. The mechanisms underlying the individual differences in the effects of Semax should be studied further. [ABSTRACT FROM AUTHOR]

Describes the properties of a new mouse superantigen. The antigen is maternally transmitted in milk and is probably encoded by a mammary tumor virus.

The αβreceptors on T cells (TCRs) nearly always recognize peptides from antigens bound to host major histocompatibility complex proteins (MHC). We and others have found some of the residues on TCRs that control their ability to react with MHC. The same TCR residues are used to bind both MHCI and MHCII. This property of TCRs have been inherited through evolution since in the case we test here, a TCR variable region from shark confers the same specificity for MHC on a mouse TCR as the endogenous mouse variable region does. The TCR amino acids we have studied confer generic reactivity with MHC on the TCR, that is, they contribute to binding to MHC regardless of the class or allele. However, TCRs in any individual are biased by positive selection to react only with MHC alleles present in their host. We are now trying to find out what portions of the TCR control specificity for MHC. Our results on this subject will be discussed. [ABSTRACT FROM PUBLISHER]