[Comparative Analysis of MPTP Neurotoxicity in Mice with a Constitutive Knockout of the α-Synuclein Gene].

Aggregated forms of α-synuclein are core components of pathohistological inclusions known as Lewy bodies in substantia nigra (SN) neurons of patients with Parkinson's disease (PD). The role of α-synuclein in selective loss of SN dopaminergic neurons (DNs) in PD is studied in mice knocked out in the α-synuclein gene. The new mouse strain delta flox KO with a constitutive knockout of the α-synuclein gene models the end point of in vivo deletion of the α-synuclein gene in mice with a conditional knockout and has no foreign sequence in the modified genomic locus, thus differing from all other α-synuclein knockout mouse strains. The effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which is used to model PD, was compared between delta flox KO mice and mice of the well-known α-synuclein knockout strain AbKO. Subchronic MPTP administration, which models early PD, was found to reduce the dopamine content and to change the ratio of dopamine metabolites in the striatum to the same levels in delta flox KO, АbKO, and wild-type mice. Overt locomotor defects were not observed after MPTP treatment, but gait testing in a CatWalk XT (Noldus) system revealed identical gait deviations in mice of the two strains and control wild-type mice. Based on the findings, a similar mechanism of neurotoxic damage to DNs was assumed for delta flox KO and AbKO mice.

[Spatial and temporary changes in sensitivity of murine proliferative system and energy exchange to typhoid fever infection]. / Prostranstvennye i vremennye izmeneniia chuvstvitel'nosti sistem proliferatsii i énergeticheskogo obmena u myshei k vozdeistviiu briushnotifoznoi infektsii.

The authors studied the spatial and temporary organization of the proliferative system and energy exchange in the small intestinal epithelium, as well as spatial and temporary changes in the sensitivity of these systems in mice to typhoid fever infection (cultured Salmonella typhi, 4446) at day and night. The small intestinal epithelial systems were found to show a spatial and time organization and a close correlation between their temporary and spatial changes after infection. The temporary organization of the proliferative system in the esophageal epithelium is more sensitive to infection in the day-time and that of the small intestinal epithelial proliferative system is more marked at night. Thus, these changes are tissue-specific. Typhoid fever infection causes a negative effect on the proliferative system of the small intestine at night and on its energy exchange in the day-time, which shows the system-specific response of the temporary organization of a biological process within the same organ. The changes in the spatial proliferative and energy exchange parameters in the small intestinal epithelium, which have been caused by the infection of animals, depend on the time of a day.

[Changes in the level of DNA synthesis in a culture of Ehrlich ascites tumor cells under the action of different concentrations of a chalone-containing preparation]. / Izmenenie urovnia sinteza DNK v kul'ture kletok astsitnoi opukholi Erlikha pod deistviem razlichnykh kontsentratsii keilonsoderzhashchego preparata.

The study was made of the effect of various concentrations of chalone-containing preparation from ascitic Ehrlich tumor on DNA synthesis in the tumor. The preparation was shown to suppress DNA synthesis in dose-dependent manner. The dose dependence was characterized by the effect of saturation which is likely to reflect binding of chalone molecules with specific cell receptors.

[Fractionation of a chalone-containing substance from Ehrlich's ascites tumor using high pressure chromatography]. / Fraktsionirovanie keilonsoderzhashchego preparata iz astsitnoi opukholi érlikha s pomoshch'iu khromatografii vysodogo davleniia.

The effect of various fractions of chalone--containing preparation from ascyte Ehrlich's tumour obtained by high performance liquid chromatography (HPLC) on mitotic activity and DNA synthesis in the tumour has been studied. After filtration the division of active chalone component which inhibits entering cells into M-phase and S-phase took place. The component inhibiting DNA synthesis eluated with G1-chalone.

[Effects of propranolol on mitosis-inhibiting activity of G2-chalone and adrenaline in cell culture of Ehrlich's ascites tumor]. / Vliianie propranolola na mitozingibiruiushchuiu aktivnost' G2-keilona i adrenalina v kul'ture kletok astsitnoi opukholi Erlikha.

Chalone-containing preparation from ascite Ehrlich's tumour blocks these cell transition from G2-phase to mitosis and its motion in mitosis in vitro (G2-block, M-block). Adrenaline blocks these cell transition from G2-phase to mitosis. Propranolol raises G2-block of chalone or adrenaline. Consequently this way of chalones action on cell division includes beta-adrenergic receptors influence of preparation on cell motion in mitosis doesn't change with addition of propranolol. Consequently this way of chalone system action on mitosis doesn't include beta-adrenergic receptors.