Plasma marinobufagenin-like and ouabain-like immunoreactivity during saline volume expansion in anesthetized dogs

OBJECTIVES: This study investigated effects of acute plasma volume expansion on plasma levels and urinary output of two endogenous Na,K-ATPase inhibitors, marinobufagenin-like and ouabain-like immunoreactive substances. METHODS: Plasma volume was expanded for 3 h via intravenous saline infusion in three groups of anesthetized dogs--nontreated (n = 5); pretreated with rabbit antidigoxin (n = 5); and pretreated with rabbit antimouse (control) antibody (n = 4). RESULTS: Plasma marinobufagenin-like immunoreactivity increased to 11.87 +/- 3.16 nmol.l-1 (vs. 0.30 +/- 0.16 nmol.l-1) within 10 min of volume expansion, in parallel with a 15% increase in LVdP/dt, then decreased to 2.21 +/- 0.59 nmol.l-1, and in 90 min increased to 11.8 +/- 2.8 nmol.l-1, in parallel with the maximal natriuretic response. Plasma concentrations of ouabain-like immunoreactive material were increased after 90 min of saline infusion (0.019 +/- 0.004 nmol.l-1 vs. 0.139 +/- 0.056 nmol.l-1). Pretreatment of the animals with antidigoxin antibody blocked the positive inotropic and reduced natriuretic response to volume expansion, and decreased the urinary release of marinobufagenin-like, but not ouabain-like, material. CONCLUSIONS: These results show the presence of marinobufagenin-like immunoreactive substance in dog plasma and suggest that mammalian EDLF may have a bufodienolide nature. Endogenous marinobufagenin-like immunoreactive substance, which is likely to cross-react with antidigoxin antibody, is involved in the natriuretic and positive inotropic responses to plasma volume expansion.     

UVS112—A gene involved in excision repair of yeast

In this study we show that the previously described uvs112 (uvs12) mutation blocks one of the steps of the excision repair pathway. The properties of this mutation permit the assignment of the UVS112 gene to the RAD3 epistasis group. It was established that the uvs112 mutation caused a 2·5-fold reduction in the number of recombinants produced by conversion and also significantly increased the frequency of mitotic crossing-over in interplasmid recombination. Tetrad analysis placed the UVS112 gene on the left arm of chromosome IX, approximately 20 cM from HIS5. The analysis of mitotic recombination revealed that UVS112 lies between HIS6 and HIS5, and is an allele of the RAD25 gene.     

Barium–Strontium and Nickel–Cobalt Solid-State Interdiffusion between the Hexagonal Z-Ferrites Ba3Co2Fe24O41, Sr3Co2Fe24O41, and Ba3Ni2Fe24O41

The Ni, Co, Ba, and Sr profiles in the diffusion zones produced between hexagonal Z-ferrites (Sr₃Co₂Fe₂₄O₄₁/Ba₃Co₂Fe₂₄O₄₁, Ba₃Co₂Fe₂₄O₄₁/Ba₃Ni₂Fe₂₄O₄₁, and Sr₃Co₂Fe₂₄O₄₁/Ba₃Ni₂Fe₂₄O₄₁) by annealing at 1420–1520 K were used to evaluate the cation interdiffusion coefficients by the Boltzmann–Matano method over the whole composition range.     

A new method for evaluating the rheological properties of the erythrocytes in surgical patients with endogenous intoxication

An examination of 30 patients against the background of using both the operative and conservative methods of treatment was performed in order to study the rheological properties of blood and selection of the most informative tests for diagnosis of microcirculatory disturbances in diseases of the gastrointestinal tract and gastroduodenal area. The authors propose methods of investigation of deformability and viscosity of erythrocytes in patients with the surgical diseases in question. The methods are simple, quite handy for any surgical hospital and polyclinic laboratories. In addition to being used in investigations of the aggregative ability of erythrocytes and viscosity of the whole blood, these methods can be of use in express diagnosis of rheological disorders. The endogenous intoxication in patients with the diseases in question was found to be accompanied by deep rheological disturbances. The deformability of erythrocytes and their viscosity index which can pass ahead of the shifts in other parameters characterizing the hemocoagulative and rheological properties of blood are changed. A conclusion is drawn that the parameters of the erythrocyte deformability and viscosity can be an additional criteria of the adequacy of therapy used for patients with the diseases in question.     

Transmission Spectra of Shallow-Layered Semiconductor‒Insulator Structure

The features of transmission spectra characterizing the layers of a shallow-layered semiconductor?insulator medium are investigated under the action of a magnetic field. In this case, n- and p-type semiconductors are analyzed. It is demonstrated that, at H₀ ≠ 0, the frequency gap, i.e., the zone eliminating wave transmission through a structure, is formed in the spectrum. In the absence of absorption near the lower zone edge (resonance frequency), the system of alternating narrow transmission and nontransmission zones concentrating with an approach to the resonance frequency is established to appear in the spectrum. It is revealed that oscillations arising near the frequency gap are smoothed with allowance for absorption in the structure.     

Wave properties of shallow-layer semiconductor–insulator medium in the presence of magnetic field

Expressions for effective permittivity of a periodic semiconductor–insulator structure with both n- and p-type semiconductor layers are derived in the approximation of shallow-layer medium. Dispersion relations are obtained for the TM wave that is controlled by external magnetic field with allowance for different propagation directions of the wave relative to the periodicity axis of the structure. Specific features of the transmission spectrum of wave are revealed for a layer of shallow-layer medium with finite thickness at several ratios of layer thicknesses in the period of structure.