Mapping of the ceruloplasmin gene on human and laboratory mouse chromosomes by direct in situ hybridization

Mapping of ceruloplasmin gene in human and mouse chromosomes was carried out using the cloned fragments of rat chromosomal ceruloplasmin gene and of ceruloplasmin cDNA as specific hybridization probes. DNA probes were nick-translated with 125I-dCTP up to the high specific capacity. The number of silver grains as well as their distribution along the differentially stained chromosomes were analyzed in 120 metaphase plates from bone marrow cells of laboratory mice and in 181 plates from human lymphocyte cultures. The most probable localization of human ceruloplasmin gene is centromeric region q11-13 of chromosome 15(14?). In laboratory mice ceruloplasmin gene is assigned to the euchromatic part of D-disc of chromosome 9. The possible causes for gene synteny in laboratory mouse and in man as well as its evolutionary implication are discussed.     

Study of the Lpm-system of mink allotypes in relation to Aleutian mink disease

Data on comparative study of the Lpm system of allotypes in minks of sovkhoz populations affected and nonaffected by Aleutian disease are presented. Significant interpopulational differences for frequencies of several Lpm genes of the second category (of corresponding haplo-, allo- and phenotypes) are revealed. This category includes genes species-specific for Mustela vison which make the main contribution to Lpm polymorphism. Seven minks with Lpm 3, 4, 6, 9, 10, 11 and Lpm 3, 4, 6, 7, 9, 10, 11 phenotypes, unknown earlier, have been found in the stationary hotbeds of Aleutian disease. They are most probably caused by the appearance and spreading of the recombinant haplotype Lpm in these populations. The data obtained are discussed from the point of view of their possible connection with epizootic of Aleutian disease.     

Microvascular fluid filtration capacity (Kf) assessed with cumulative small venous pressure steps and with various degrees of tilt

Tilt procedures are frequently used to test central and peripheral cardio-vascular reflexes. We have previously used venous congestion strain gauge plethysmography for measurement of fluid filtration capacity (Kf) in human legs and have shown that, providing small cumulative venous congestion pressure steps are applied, venous congestion pressure can be increased to arterial diastolic pressure without activating peripheral vasoconstrictor mechanisms. We have also studied the effect of passive tilting on Kf and have shown that the procedure does not influence the measured value Kf indicating that passive tilting does not after the total surface area available for fluid filtration, but rather the blood flow in the microvessels of the tissue under study. In the present protocol we compared the fluid filtration (Jv) resulting from small (7-10 mmHg) cumulative pressure steps with those obtained by altering hydrostatic load with progressive increases and decreases of head down tilt of -8 degrees -15 degrees and -30 degrees, followed by a similar pattern of 15 degrees, 30 degrees and 70 degrees of head up tilt. The values of Jv obtained in response to these procedures were compared with those deduced from the relationship between fluid filtration and venous congestion pressure (Pcuff) obtained during the small cumulative pressure step protocol. It was reasoned that reflex activation, by the tilt induced pressure load, would cause a reduction in local blood flow and enhanced microvascular fluid extraction. The resulting local increase in colloid osmotic pressure would give rise to lower values of Jv than those predicted on the basis of the Kf slope.     

The Database of Ribosomal Cross-links: an update.

The Database of Ribosomal Cross-links (DRC) was created in 1997. Here we describe new data incorporated into this database and several new features of the DRC. The DRC is freely available via World Wide Web at http://visitweb.com/database/ or http://www. mpimg-berlin-dahlem.mpg.de/ approximately ag_ribo/ag_brimacombe/drc/     

Analysis of association of Col1a1 gene alleles with the development of osteoporosis

Allele frequencies of the G-->T polymorphism at the regulatory region of the Collal gene in the population of the northwestern Russia (control group) and in osteoporotic patients were estimated by the RFLP method based on PCR-mediated site-directed mutagenesis. Three patient groups with radiologically confirmed osteoporosis were examined. Group 1 consisted of 64 patients with severe osteoporosis complicated by fractures (SO); group 2 included 15 children with idiopathic osteoporosis (IO); group 3 consisted of 98 women with postmenopausal osteoporosis developed at the background of estradiol-deficiency state (PMO). The frequency of functionally defective allele s in the control group was 16.7%. It was statistically different from that in the SO patients (48.4%) (P < 0.01) and in the IO children (40%) (P < 0.01). The frequency of allele s in the PMO patients constituted 23.0% and it was similar to that in the control group (P > 0.05). Analysis of the Collal alleles provides early detection of the individuals with hereditary predisposition to osteoporosis and prophylaxis of the disease at the presymptomatic stage.     

Identification of the nature of reading frame transitions observed in prokaryotic genomes

Our goal was to identify evolutionary conserved frame transitions in protein coding regions and to uncover an underlying functional role of these structural aberrations. We used the ab initio frameshift prediction program, GeneTack, to detect reading frame transitions in 206 991 genes (fs-genes) from 1106 complete prokaryotic genomes. We grouped 102 731 fs-genes into 19 430 clusters based on sequence similarity between protein products (fs-proteins) as well as conservation of predicted position of the frameshift and its direction. We identified 4010 pseudogene clusters and 146 clusters of fs-genes apparently using recoding (local deviation from using standard genetic code) due to possessing specific sequence motifs near frameshift positions. Particularly interesting was finding of a novel type of organization of the dnaX gene, where recoding is required for synthesis of the longer subunit, τ. We selected 20 clusters of predicted recoding candidates and designed a series of genetic constructs with a reporter gene or affinity tag whose expression would require a frameshift event. Expression of the constructs in Escherichia coli demonstrated enrichment of the set of candidates with sequences that trigger genuine programmed ribosomal frameshifting; we have experimentally confirmed four new families of programmed frameshifts.     

Theoretical study of hydrophobicity and hydrophilicity of uracil and its dimers

The influence of hydrophilic and hydrophobic properties of the uracil elementary nucleic acid bases on its solubility and structure in aqueous solution was studied. Complexes of uracil with water molecules (from 1 to 14) were then calculated. The geometrical parameters of the hydrogen bridge of uracil and the changes in the frequency of valence vibrations of the bonds participating directly in hydrogen bond formation were calculated. It is shown that for the hydrogen bonds O_w?HN₁ and O_w?HN₃ the hydrogen atom can tear off, it may lead to tautomeric transformation of uracil. The results obtained having calculated the structure of uracil dimers, formed with the hydrogen bonds, in an isolated state and water solution, energy, dipole moments and the hydrogen bridge parameters made it possible to explain low solubility of uracil in water at room temperature. It is shown that water molecules with increase in their number are located mainly at one side of the plane of a pyrimidine uracil ring, that leads to the formation of stacking. Of two possible variants of stacking formation, the most profitable grouping is when a dipole moment of the formed dimer is equal to zero (anti-parallel stacking).     

Effect of the body antiorthostatic posture on various circulation and respiration parameters in anesthetised cats

In anaesthetised cats, antiorthostatic posture of the body with an inclination angle of 30 degrees increased pressure in the vena cava superior and in jugular vein. The rest of the cardio-respiratory parameters were changed insignificantly. Physical and physiological mechanisms of the blood regional redistribution in alteration of the body gravitation orientation, are discussed.     

Multifunctional morphology of the chick chorioallantoic membrane

The chicken chorioallantoic membrane is assessed between days 7 and 20 of incubation using light and electron microscopy with morphometric analysis. The completion of its formation by the middle of embryogenesis is observed, after that a rapid increase in the embryo body mass continues. The bloodstream combines chorionic epithelium, mesoderm, and allantoic epithelium into the single multifunctional organ. The ordered antiparallel arrangement of afferent and efferent vessels within the mesoderm as well as their specialized endothelium assist in partial blood fluid filtration into the interstitium. The unique structure of the capillary network within and over the chorionic epithelium that provide for the effective gas exchange is depicted. It is revealed that the ultrastuctural specialization of the chorionic epithelial cells through which an active calcium transport from the eggshell takes place. The ultrastructure peculiarities of the allantoic epithelium concerning the water-salt balance maintaining in the growing embryo, are discussed.