Sandoglobulin immunocorrection in trauma

Twenty one patients with the long-term compression syndrome (LCS) and 12 patients with burns treated with sandoglobulin in combination with antibacterial therapy were followed up. The control groups included 14 and 18 patients, respectively. All the patients had wound infections. Increased or lowered respiratory burst of peripheral blood neutrophils and lowered contents of active T-lymphocytes were detected in the majority of the patients. The patients had also an increased respiratory burst of tissue homogenate in the primary focus. Sandoglobulin decreased the periods of normalization of the immunological indices, body temperature and leukogram shifts to the right. The most pronounced effect of the drug was recorded before radical operations, i.e. in the presence of acute microbial toxemia or in patients with severe and extended burns. The procedure of immunological monitoring developed by the authors rapidly estimates the indications to the use of sandoglobulin alone or in combination with other immunomodulators.     

Physico-chemical properties of ribonuclease A modified with pyridoxal-5'-phosphate]

The physico-chemical properties have been studied of RNase A selectively modified at the E-NH2-group of Lys-7 and Lys-41 with pyridoxal-P. Modification did not affect conformational stability of the protein globule, thus all changes in the molecule of the modified RNase A were localised around the alkylated Lys residue. In the both cases pyridoxyl-P. The residue was shown to be localized in the active site region of the (P-Pxy)-Lys-7-RNase A and its chromophore parts was highly exposed to the solvent. (P-Pxy) E-Lys-7-RNase A and its chromophore parts was highly exposed to the solvent. In the Lys-41 derivative, pyridoxamine-P was situated exactly in the active site and is partially hidden in the protein grobule. The pH-dependence of absorption spectra indicates that the chromophore of pyridoxyl-P in modified proteins is quite sensible to the ionic state of its surrounding. The usefulness of pyridoxyl-P as a reporter group was proved in the study with (P-Pxy)-Lys-7-RNase A. Some conformational changes involving His-119 were shown to take place in the course of the enzyme-nucleotide complex formation.     

Mechanism of anion-cation selectivity of amphotericin B channels

Summary Zero current potential and conductance of ionic channels formed by polyene antibiotic amphotericin B in a lipid bilayer were studied in various electrolyte solutions. Nonpermeant magnesium and sulphate ions were used to independently vary the concentration of monovalent anions and cations as well as to maintain the high ionic strength of the two solutions separated by the membrane. Under certain conditions the channels select very strongly for anions over cations. They are permeable to small inorganic anions. However, in the absence of these anions the channels are practically impermeable to any cation. In the presence of a permeant anion the contribution of monovalent cations to channel conductance grows with an increase in the anion concentration. The ratio of cation-to-anion permeability coefficients is independent of the membrane potential and cation concentration, but it does depend linearly on the sum of concentrations of a permeant anion in the two solutions. These results are accounted for on the assumption that a cation can enter only an anion-occupied channel to form an ionic pair at the center of the channel. The cation is also assumed to slip past the anion and then to leave the channel for the opposite solution. This model with only few parameters can quantitatively describe the concentration dependences of conductance and zero current potential under various conditions.     

Gamasid mites of common voles in the central Volga River region

The specific composition of gamasid mites from three species of voles (Microtus arvalis Pall., M. agrestis L., M. oeconomus Pall.) is given. Forest, field and flood-land groupings of the common vole having distinct phenotypical differences are characterized by differences in the structure of their parasite fauna. In the forest the number of meadow and meadow-field species decreases while that of forest species of mites regularly increases.     

Study of 2.5S RNA of 1,4-alpha-glucan branching enzyme by fluorescent methods using ethidium bromide

The fluorescence yield and lifetime of ethidium bromide complexes with 1,4-alpha-glucan branching enzyme and its free nucleic acid component 2.5S RNA were measured. Both fluorescence parameters showed a 10-fold increase in comparison with those characteristics for the free dye. This increase allows to suggest the existence of double-stranded regions in 2.5S RNA both in the free as well as in the protein bound state. The coefficients of fluorescence polarization were also determined for ethidium bromide complexed with free and protein bound 2.5S RNA. They proved to be 13 and 18% respectively. No concentration depolarization was observed in both types of ethidium bromide and ethidium bromide--enzyme--RNA complexes. This proves that the double-stranded regions are rather short and that two ethidium bromide molecules can't be bound to each of them. The binding isotherms were measured for ethidium bromide absorbed on 2.5S RNA and on the holoenzyme. Their parameters napp and rmax are identical in the cases of free and protein bound 2,5S RNA (rmax = 0.046 +/- 0.001). However the binding constants of ethidium bromide complexes with free and protein bound 2.5S RNA differ significantly (Kapp = 2.2 X 10(6) M-1 for free 2.5S RNA and Kapp = 1.6 X 10(6) M-1 for the holoenzyme). The quantity of nucleotides involved in the two double-stranded regions accessible for ethidium binding is estimated to be about 28%. Increasing of Mg2+ ion concentration up to 10(-3) results in a decrease of ethidium bromide binding with double stranded regions. It may be due to a more compact tertiary structure of 2.5S RNA in the presence of Mg2+ in the free as well as in protein bound state.     

Isolation and physicochemical study of the components of the new antibacterial antibiotic 2562

An antibacterial antibiotic complex consisting of 2 components designated as 2562 A and 2562 B is produced by Streptomyces griseovarabilis. The antibiotic was isolated from the mycelium and purified chromatographically on a column with aqueous silicic acid. The study of the components showed that component 2562 A was chlorbiocin, while component 2562 B differed from the known antibiotics of this group. Physicochemical assays demonstrated that component 2562 B differed from chlorbiocin by the absence of the methyl group in pyrrol, which is probably attached to sugar at beta-position. It was found that component 2562 B is a new representative of the antibiotic cumero-glycoside group.     

Spatial organization of template polynucleotides on the ribosome determined by fluorescence methods.

The spatial organization of template polynucleotides on the ribosome and the dynamics of their interaction with 30 S subunits have been studied by fluorescence spectroscopy. The topography of the mRNA in the ribosome has been determined using singlet-singlet energy transfer. This method has allowed us to estimate distances between donors and acceptors of energy which have been linked to the terminal residues of template polynucleotides (poly- and oligo(U) and oligo(A] and 16 S RNA or to SH-groups of ribosomal proteins S1 and S8. The dynamics of mRNA-ribosome interaction have been investigated by the fluorescence stopped-flow technique. It has been shown that the binding to the 30 S subunit of poly(U) with length much shorter (16 nucleotides) than that covered by the ribosome is greatly enhanced by protein S1. However, the final position of oligo(U)16 on the 30 S subunit, which probably includes the ribosomal decoding site, proves to be quite different from that occupied by oligo(U)16 on a free protein S1. Interaction of oligo- and poly(U) with the 30 S subunit occurs in at least two steps: the first one is as fast as the interaction of poly(U) with free S1, whereas the second step represents a first-order reaction. Therefore, the second step may reflect some rearrangement of the template in the ribosome after its primary binding. It is suggested that protein S1 in some cases may fulfill the role of a transient binding site for mRNA in the course of its interaction with the ribosome. The general shape of the template in the mRNA binding region of the ribosome has been studied using various synthetic ribopolynucleotides and has been shown to be similar. It can be represented by a loop(s) or "U-turn(s)". On the basis of estimation of distances from the ends of poly(U) to some well-localized points on the 30 S ribosomal surface, a tentative model of mRNA path through the ribosome is proposed.     

Recombinant core particles of hepatitis B virus exposing foreign antigenic determinants on their surface

Insertion of foreign oligopeptide sequences (40-50 amino acids in length) into the Pro144 position of hepatitis B core antigen (HBcAg) leads to the formation of chimeric capsids in Escherichia coli cells. These capsids are morphologically and immunologically similar to native HBcAg, but expose the inserted oligopeptides on their outer surface and exhibit antigenic and immunogenic characteristics of the latter. As a source of model antigenic determinants, the appropriate DNA copies excised from cloned viral genes such as the pre-S region of hepatitis B virus, the transmembrane protein gp41 of human immunodeficiency virus 1 and the envelope protein gp51 of bovine leukemia virus have been used. The localization of the inserted antigenic determinants on the surface of chimeric capsids does not depend on the presence or absence of the arginine-rich, 39 amino acid-long C terminus of HBcAg.