An O-antigen study of Pseudomonas aeruginosa from serological group O11]

In the study of P. aeruginosa cultures, serogroup O11, strains agglutinated simultaneously by factor sera 11b and 11c have been detected. In experiments on cross agglutination and agglutinin adsorption the antigenic structure of these strains, viz. 11a, 11b and 11c, has been determined.     

Identification of HLA-B44 subtypes associated with extended MHC haplotypes

The HLA class I antigen B44 is found in each of two different extended major histocompatibility haplotypes (allele combinations of HLA-B, HLA-DR, and complement genes BF, C2, C4A, and C4B in linkage disequilibrium). Using isoelectric focusing, two variants of HLA-B44 were identified. The basic variant was found in all cell lines with the extended haplotype HLA-B44, DR7, FC31, and the acidic variant in all cell lines with the extended haplotype HLA-B44, DR4, SC30. The occurrence of each antigen variant with a unique extended haplotype explains previous observations concerning the nonrandom association of B44 variants with DR antigens.     

The use of phase diagrams in the crystallization of oligonucleotide duplexes. I. A model of crystallization of the (pGpT)n.(pApC)n + spermine system

A set of experimental phase diagrams revealing the region of existence of microcrystals in mixture "(pGpT)n.(pApC)n+spermine", n = 2,3,4, was obtained. All diagrams are wedge-like with the slope of the upper branch and the level of the lower one depending on the oligonucleotidd length. The presence of MPD, MgCl2 and NaCl changes the form of the diagrams in a different manner. A model explaining the peculiar features of the diagrams for mixture "oligonucleotide duplex+spermine" is proposed. The analysis of the diagrams was carried out on the basis of this model and the values of the binding constants for binding of spermine and Mg2+ to duplexes were estimated. Some conclusions about the types of complexes, which may form microcrystals in different regions of diagrams were made.     

The length of DNA determines the degree of regularity of crystals of the cro-repressor complex

The DNA-cro-repressor complex crystals have been obtained, five DNA fragments of the same nucleotide sequence and different length being used. The rotation function for crystals of complexes with hexamer (pGpT)3 . (pApC)3 and with octamer (pGpT)3 . (pApC)3 have been calculated. The order of cro-DNA complex crystals is shown to vary with DNA length, the crystal of the complex with octamer being the most perfect among all investigated complexes.     

Neuroendocrine and neurochemical mechanisms of the domestication of animals

A review of experimental data documenting that domestication of animals is associated with hereditary reorganization of neuro-endocrine mechanisms, responsible for basic processes of ontogeny, is presented. The data demonstrated changes in gonadal and pituitary-adrenal systems in domesticated animals. Analysis of evidence that selection for low aggressiveness towards man is, in fact, the selection for definite activity of brain neurotransmitters regulating aggressive behaviour and emotional stress response has been carried out. Supposed role of modifications in the mechanisms of domestication is discussed.     

The component composition of the human cortical motor potential during static muscle loading

In summation and averaging of sections of the EEG of sensorimotor cortex of both cerebral hemispheres recorded during human static effort of definite duration, a complex of negative-positive oscillations was observed. These oscillations appear before the beginning of the effort, accompany its execution and finishing and are also recorded after cessation of muscles activity. Before the beginning, the potential of readiness is formed. The execution of the effort is accompanied by a slow negative wave which in some people may be broken by a pronounced positivity. Further a "final" potential appears; its fast positive oscillation is formed before the end of the effort, and a slow negative wave in which it turns, appears only after muscles relaxation.     

Simple kinetic models explaining critical phenomena in enzymatic reactions with isomerization of the enzyme and substrate

Kinetic models for enzyme reactions are considered which take into account enzyme and substrate isomerization. Application of graph-theoretic methods allows to reveal fragments in schemes which may induce multiple stead-states or concentrational selfoscillations. The role of substrate isomers in the inhibition of enzyme isomers to produce critical phenomena is considered. The boundaries of parameter domains for critical phenomena are estimated. It is shown that the controlled change in concentrations of substrate and enzyme isomers may be important in regulation of enzyme systems, if different enzyme isomers are inhibited mainly by different substrate isomers. The models are used for interpretation of possible critical phenomena in the open reaction catalyzed by lactate dehydrogenase. It is shown that lactate dehydrogenase may act as a trigger in carbohydrate metabolism by changing "critically" its activity in relation to changes in pH and pyruvate fluxes. Slow enzyme inhibition by enolpyruvate is suggested as a possible reason for glycolytic oscillations.     

Pulmonary paracoccidioidomycosis in immunized mice

Paracoccidioidomycosis was induced in immunized (IM) and non-immunized (NI) mice. The histopathology, the number of fungi in the lungs, the cellular (footpad test — FPT and macrophage inhibition factor assay — MIF) and humoral (immunodiffusion test) immune response were investigated serially postinfection. In the IM mice, at days 1 and 3, there was intense and predominant macrophagic-lymphocytic alveolitis with loose granulomatous reaction; at day 30, inflammation was mild. In the NI group, up to day 3, the lesions were focal; later there was formation of extensive epithelioid granuloma. The number of fungi in IM mice were always smaller than those of NI group. Immunization alone induced positive FPT and MIF indices with low titer of antibody. After infection, there was a significant decrease of the FPT indices in the IM group, which we interpreted as desensitization due to trapping of sensitized lymphocytes in the lungs. In conclusion, (1) The lesional pattern of pulmonary paracoccidioidomycosis in IM mice was similar to that of a hypersensitivity pneumonitis. This reaction was probably effective in reducing the extension of the infection and decrease the number of fungi. (2) In this model, pulmonary resistance against P. brasiliensis seems to be related to local and systemic delayed-type hypersensitivity reaction.     

Comparative effects of a recombinant and a mutein type of granulocyte colony stimulating factor on the growth of Meth-A fibrosarcoma with 5-fluorouracil chemotherapy

The present study was designed to evaluate the effects of a recombinant human G-CSF (rhG-CSF) and a mutein G-CSF(KW-2228) on leucopenia and tumor growth in mice treated with 5-fluorouracil (5-FU). In normal mice, the number of leucocytes (white blood cell, WBC) reached the peak 12 hours after a single injection of either type of G-CSF and decreased to the normal level after 24 hours. Daily administration induced a continuous increase in the WBC count, however, administrations at intervals did not. Meth-A fibrosarcoma was subcutaneously inoculated into the backs of syngeneic BALB/c mice. The mice were treated with 5-FU alone or with G-CSFs. Chemotherapy with 5-FU alone resulted in leucopenia and an insignificant inhibition of tumor growth. The conjunctive administration of G-CSFs with 5-FU resulted in a significantly augmented inhibition of tumor growth, and leukopenia was not seen. This augmenting effect was more prominent with KW-2228.These results suggest that in 5-FU chemotherapy G-CSFs may be beneficial in restoring the number of leucocytes from leucopenic state and in augmenting the tumor inhibitory effect. Furthermore, KW-2228 may be more beneficial than the natural type rhG-CSF.