Limitation of tuning the antibody-antigen reaction by changing the value of pH and its consequence for hyperthermia.

Distribution of the isoelectric point (pI) was calculated for the hypervariable regions of Fab fragments of the antibody molecules, which structure is annotated in the structural antibody database SabDab. The distribution is consistent with the universal for all organisms dividing the proteome into two sets of acidic and basic proteins. It shows the additional fine structure in a form of the narrow-sized peaks of pI values. This is an explanation why a small change of the environmental pH can have a strong effect on the antibody-antigen affinity. To show this, a typical enzyme-linked immunospecific assay experiment for testing the reaction of goat anti-human IgA antibodies with human IgA immunoglobulins of saliva as antigens was modified in such a way that Fe3O4magnetic nanoparticles were added to PBS buffer. The magnetic nanoparticles were remotely heated by the radio frequency magnetic field providing the local change of temperature and pH. It was observed that short times of the heating were significantly increasing the antibody-antigen binding strength while it was not the case for a longer time. The finding discussed in the study can be useful for biopharmaceuticals using antibodies, the immunoassay techniques as well as for control over the use of hyperthermia.

The role of the specialist nurse in breast cancer.

Psychosocial support is vital for women with breast cancer. The breast care nurse performs a crucial role in this support.

Mutagenic activity of 6-azido deoxyhexoses and azido alcohols in Salmonella typhimurium and its inhibition by a structure-similar carbon source in the medium.

6-Azido-6-deoxy (AZd) derivatives of D-glucose, D-mannose, D-altrose, D-allose, L-idose, D-galactose, D-galactonic acid and D-galactitol, 3-azido-1,2-propanediol (azidoglycerol), 3,1-diazido-2-propanol (diazidoglycerol) and (at much higher doses) 2-azidoethanol were mutagenic in Salmonella typhimurium strains TA100 and TA1535. The mutagenic response was similar to that induced by sodium azide, i.e., the azido compounds failed to induce mutations in strain TA98, and mutagenesis was independent of plasmid pKM101, and independent of external activation. The specific mutagenicity (his+ rev/mmole) of AZd-glucose and AZd-galactose was decreased with increasing concentrations of D-glucose or D-galactose in the minimal agar medium and enhanced 100-fold or more when 0.2% citrate rather than 0.2% glucose served as the carbon source in the medium. Similarly, the mutagenic efficiency of azidoglycerol was inhibited by glycerol but not by D-glucose or D-galactose; however, the mutagenicity of sodium azide was not influenced by any of these carbon sources in the medium. The inhibition of the mutagenic action of azido hexoses and azido alcohols by non-azido structural analogs is assumed to reside in competition in transmembrane transport or for the metabolic pathways.

Combined radioprotection by preirradiation peroral cystamine and postirradiation glucan administration.

The possibilities of combined radioprotection, using preirradiation peroral cystamine and postirradiation intraperitoneal glucan administration in sublethally and lethally whole-body gamma-irradiated mice were investigated. The results demonstrated at least additive radioprotective effects of both agents, manifested in the enhancement of postirradiation haemopoietic recovery and increased survival of irradiated mice. The effects appear to depend on the sequential cell protection mediated by cystamine and enhanced haemopoietic repopulation induced by glucan.

Interstrain differences in the responsiveness of mice to glucan with respect to hematological effects and manifestations of late damage.

A study was made of the effect of a single s.c. injection of 4 mg glucan in the mouse strains C57BL/10, C3H and a hybrid population of mice. In mice of the strain C57BL/10 high responsiveness was demonstrated, manifested in a long-term increase in the granulocyte counts in the peripheral blood. These effects were accompanied by a fall in the mean red cell volume and the mean corpuscular hemoglobin, a fall in body weight, and mortality. 10 weeks after administration of glucan histology revealed necrotic foci in the livers of animals of the C57BL/10 strain, and an increased amount of the fibrous connective component in the pulmonary interstitium. The strain C3H exhibited a low responsiveness in respect of the hematological indices, while the hybrids did not show any significant response.

High mutagenic activity of 3-azido-1,2-propanediol (azidoglycerol, AG) in strain D7 of Saccharomyces cerevisiae.

3-Azido-1,2-propanediol (azidoglycerol, AG) showed a high mutagenicity in strain D7 of Saccharomyces cerevisiae. At 5 mM it increased the spontaneous frequency of isoleucine revertants 3500 times and the frequency of gene convertants 3000 times during 24 h of growth, reducing the growth rate to 30%. In non-growth conditions, treatment with 150 mM of AG for 3 h reduced cell survival to 60% and enhanced the frequency of isoleucine revertants 490 times and tryptophan-independent convertants 50 times. At equal survival levels, AG was found to be 3000-fold more mutagenic and 200-fold more convertogenic than sodium azide.

Effect of 60amino-6-deoxy-D-glucose hydrochloride on influenza infection in mice.

A prophylactic effect of 6-amino-6-deoxy-D-glucose hydrochloride (AG) in influenza-infected mice was demonstrated. A dose of 500 mg AG per kg body-weight given intranasally 2000 mouse intranasal LD50) protected 32-40 per cent of the animals from death. The virus titres in the lungs and serum were lower in treated mice than in untreated ones. After AG administration, low interferon titres were demonstrated in the lungs and serum. The group of infected mice, untreated with AG, was examined electron microscopically. Virus was demonstrated on the surface of granular pneumocytes and in the lumen of lung alveoli.