Adsorption of haematoporphyrins on the planar bilayer membrane

Adsorption of haematoporphyrin derivatives with different hydrophobicities of peripheral groups on a planar bilayer lipid membrane (BLM) was studied in the dark and upon illumination by the visible light. Haematoporphyrin molecules were shown to adsorb on the BLM as anions. The adsorption changed the boundary potential at the membrane/water interface, in particular, it altered the potential in the diffuse part of the double layer outside the membrane and increased an additional unscreenable potential drop inside it. Illumination decreased the value of the negative potential drop due probably to the appearance of a positive charge in the haematoporphyrin macrocycle. The adsorption of haematoporphyrins affected the BLM conductivity induced by different ionophores, which can be explained by changes in membrane structure. Haematoporphyrin derivatives with higher hydrophobicities adsorbed deeper inside the membrane, caused greater changes in its structure and displayed a stronger photodynamic effect.     

Mechanism of the radiation-protective effect of indralin

Output from the interpositus nucleus can inhibit the inferior olive, probably via the GABA-ergic nucleo-olivary pathway. It has been suggested that the function of this inhibition might be to regulate synaptic plasticity resulting from parallel fibre/climbing fibre interaction in cerebellar Purkinje cells, by providing negative feedback information to the olive. Thus, when a learned response, generated by the interpositus nucleus, reaches a sufficient amplitude, the olive would be inhibited and further learning blocked. This suggestion was tested in a classical conditioning paradigm. Decerebrate ferrets were trained using electrical skin stimulation of the forelimb as the conditioned stimulus (CS) and periorbital stimulation as the unconditioned stimulus (US). Climbing fibre responses evoked in Purkinje cells by the US were recorded as surface field potentials in the part of the c3 zone controlling eyeblink. It was found that the CS did not inhibit the olive at the beginning of training, but when conditioned responses were large, the olive was inhibited by the CS in some animals. After a number of unpaired CS presentations, which caused extinction of the conditioned response, the inhibition disappeared. The size of individual conditioned responses correlated negatively with the size of the climbing fibre responses evoked by the US. Climbing fibre responses evoked by direct stimulation of the olive were also inhibited. It was concluded that cerebellar output during performance of a conditioned response inhibits the inferior olive. The results thus support the hypothesis of a cerebellar locus of conditioning and are consistent with the proposed role of cerebello-olivary inhibition.     

Possibilities of using surgical laser in the treatment of chronic tonsillitis

A novel technique of surgical treatment of chronic tonsillitis is presented. It implies the use of Ne-YAG laser in contract regimen. Good results were obtained in experiments on the exposure of distal tonsils to intralacunar laser radiation.     

Treatment of solitary subconjunctival cysts of filtration pad after fistulizing surgery of glaucoma

The clinical picture and cytostatic treatment of solitary subconjunctival cysts of filtration pad after fistula-forming antiglaucoma surgery are described. Twenty-seven eyes with hypertension which developed as a result of subconjunctival cysts formed in the early postoperative period in 7% of patients operated on for open-angle glaucoma. Probable mechanisms of the pathogenesis of the formation of solitary cysts are discussed and 3-staged therapy proposed, including beta-blockers, perforation of the cyst wall by YAG laser, and, in 10% of cases with rigid cysts, microsurgical revision of filtration pad.     

Refinement of technique for cosmonaut's body radiation loading estimation using of orbital station dosimetric monitoring system

Proposed is a technique for estimation of radiation loading of cosmonauts' body from the data of the space station radiation monitoring system by bringing the objective to a linear mathematical model. Resulted matrix ratios allow to work out the challenge; test calculations illustrating efficiency of the proposed technique are included.     

Cell activation mediated by glycosylphosphatidylinositol-anchored or transmembrane forms of CD14

CD14 is a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein which functions as a receptor on myeloid cells for ligands derived from microbial pathogens such as lipopolysaccharide (LPS). We have studied the importance of the GPI tail of CD14 in signalling with the promonocytic cell line THP-1 expressing recombinant CD14 in a GPI-anchored form (THP1-wtCD14 cells) or in a transmembrane form (THP1-tmCD14). We found that, like other GPI-anchored molecules, GPI-anchored CD14 was recovered mainly from a Triton X-100-insoluble fraction, whereas transmembrane CD14 was fully soluble in Triton X-100. LPS induced cell activation of THP1-wtCD14 and of THP1-tmCD14 (protein tyrosine kinase phosphorylation, NF-kappaB activation, and cytokine production) in a very similar manner. However, anti-CD14 antibody-induced cross-linking caused a rapid calcium mobilization signal only in GPI-anchored CD14 cells. Studies with pharmacologic inhibitors of intracellular signalling events implicate phospholipase C and protein tyrosine kinases in the genesis of this antibody-induced calcium signal. Our results suggest that GPI anchoring and CD14 targeting to glycolipid-rich membrane microdomains are not required for LPS-mediated myeloid cell activation. GPI anchoring may however be important for other signalling functions, such as those events reflected by antibody cross-linking.     

Current methods for assessing mucociliary transport disorders in the diagnosis of chronic rhinosinusitis]

This paper summarises the findings of a systematic review of research on preschool vision screening. The review concludes that the provision of such screening programmes should be reconsidered, if not abandoned.