Interactions of lipid micelles with blood proteins

Interaction of lipid micelles (LM), containing cholesterol and hydroxycholesterol, with human serum lipoproteins was investigated. It was shown that cholesterol-containing LM interact with low density lipoproteins (LDL). Selectivity of LM-LDL interaction depended on the cholesterol content of micelles and almost did not depend on the composition of LM core. Up to 90% of LDL were bound with cholesterol-saturated LM. By means of gel chromatography it was shown that interaction of cholesterol- and 7-hydroxycholesterol-containing micelles with serum led to the partial fusion of LDL with LM and LDL-LM complex formation, as well as to the cholesterol and 7-hydroxycholesterol transfer from micelles to LDL. The obtained results indicate that cholesterol-containing LM can be used for the delivery of oxidized cholesterol to cells involving LDL and receptor-dependent pathway of their capture by peripheral cells.     

Thermohaemolysis of human erythrocytes in sucrose containing isotonic media

1. 1.|The thermohaemolysis of human erythrocytes in NaCl/sucrose isotonic media can be best accounted for in terms of the colloid-osmotic theory of haemolysis.

2. 2.|The thermohaemolysis in NaCl saline was preceded by leakage of K⁺ and cell swelling. If the inner oncotic osmoactivity was balanced with external sucrose the cells progressively shrinked losing K⁺, but the haemolysis was strongly reduced.

3. 3.|Time dependence of the shrinking of cells and one-step resealed ghosts suspended in isotonic 60 mOsm NaCl/sucrose media was studied between 50 and 58°C.

4. 4.|After a lag period for cells only, this shrinking proceeded with apparently constant rate for cells and ghosts.

5. 5.|The rate constant of shrinking for cells and ghosts obeys the Arrhenius relation, giving the value of 250 ± 15 kJ/mol for the activation energy of shrinking in both cases. This is also the case for the activation energy of the membrane ion permeability constant.

6. 6.|These results are consistent with the thermal inactivation of membrane associated protein(s) acting as a trigger for the ion permeability barrier disturbance.

7. 7.|The mid-point temperature for these membrane events was about 61°C.

Comparative study of chromosomal nonhistone proteins pp23 in cells from different types of tissue]

A specific immunoserum against nonhistone chromosomal protein pp23 from rat kidney was produced. A similar protein was obtained in cells of different tissue specificity (in the liver cells of rats submitted to a single effect of hepatocarcinogens, in rat hepatomas G-27, HTC, Zajdela, in cultivated non-tumor myogenic L6 cells and in kidney cells of newborn rats) by means of immunofluorescent method on using this immunoserum. In all cases a specific fluorescence of the nucleus and nuclear membrane was observed.     

Fractionation of chromatin of liver cell nuclei after mild micrococcal nuclease digestion

Mild micrococcal nuclease treatment of rat and mouse nuclei and fractionation were based on the method of Tata and Baker. Three chromatin fractions, S, P1, P2, were separated, and for each of these fractions the sensitivity to the DNase 1 action was determined. The relative content in these fractions of non-transcribed DNA sequences was established by hydridization with a mouse satellite DNA, and the relative content of transcribed DNA sequences--by hydridization with DNA synthesised on the total poly (A) mRNA. None of the fractions displayed the properties characteristic of active chromatin.     

Determination of the structural integrity of DNA from pathogenic enterobacteria

Among the enterobacterial strains under study, more organisms in the stationary phase of growth have been found to have nicks in their DNA than those in the exponential phase. Bacteria less sensitive to ultraviolet irradiation have the least number of nicks in each phase of growth. The number of nicks in different strains belonging to the serovar is sufficiently stable. Virulent and avirulent forms show no difference in this characteristic.     

Stereological analysis of ultrastructural changes in cardiomyocytes during adriblastina-induced cardiomyopathy

Both single and graded administration of an anthracycline antibiotic adriablastine at a dose of 20 mg/kg to white rats have resulted in cardiomyocyte volume decrease, dystrophia and lysis of myofibrils, and reduction of mitochondrial surface density volume. Accumulations of myelin bodies of different configuration and diffuse myolysis were observed. Myelin bodies and diffuse myolysis of cardiomyocytes in adriablastine-induced cardiomyopathy are believed to be a morphological sign of lipid peroxidation.     

N.P. Bochkov,Clinical Genetics: A Textbook for Students of Medical Colleges,the Second Revised Edition,Moscow: GEOTAR-MED, 2001

Russian Journal of Genetics -