Numerical solutions for a model of tissue invasion and migration of tumour cells.

The goal of this paper is to construct a new algorithm for the numerical simulations of the evolution of tumour invasion and metastasis. By means of mathematical model equations and their numerical solutions we investigate how cancer cells can produce and secrete matrix degradative enzymes, degrade extracellular matrix, and invade due to diffusion and haptotactic migration. For the numerical simulations of the interactions between the tumour cells and the surrounding tissue, we apply numerical approximations, which are spectrally accurate and based on small amounts of grid-points. Our numerical experiments illustrate the metastatic ability of tumour cells.

Upregulating CD59: a new strategy for protection of neurons from complement-mediated degeneration.

An increasing number of studies have shown a critical role for the membrane attack complex, synthesized on activation of the terminal pathway of the complement system, in causing demyelination and neuronal death in neurodegeneration. The aim of this study was to develop a strategy to increase the resistance of neurons to complement damage by modulating the expression of membrane complement regulatory protein CD59, the only inhibitor of the terminal pathway of the complement cascade. We exploited our recent finding that CD59 expression is regulated by the neural-restrictive silencer factor (REST) and designed a novel REST-derived peptide (REST5) containing the nuclear localization domain of the wild-type protein. The effect of REST5 and the mechanism by which it modulates CD59 expression were modelled in neuroblastoma cells transfected with expression constructs, and then confirmed in human neurons differentiated from neural progenitor cells. REST5 increased the expression of CD59 in neurons by fivefold and protected them from complement-mediated lysis spontaneously triggered by neurons. As a source of complement, we used either human serum or conditioned medium from primary human oligodendroglia. This study brings new insight into immunopharmacological research that may serve to inhibit neuronal death triggered by the terminal pathway of complement activation.

[Mutagenic effect of the cytostatic drug thaliblastine on rat bone marrow cells when administered alone and in combination with radiation]. / Issledovanie mutagennogo éffekta tsitostatika taliblastina na kletkakh kostnogo mozga krys pri razdel'nom i sochetannom s oblucheniem vozdeistviiakh.

The cytogenetic analysis was performed in the bone marrow cells of Wistar rats treated with a therapeutic dose of thaliblastine (250 mg/kg) and exposed to gamma-rays (2 Gy). Thaliblastine alone induced chromosome aberrations and polyploid cells. The latter were the result of the stathmokinetic effect of the drug. In contrast to gamma-radiation of 2 Gy thaliblastine elicited a minor mutagenic effect. The cytogenetic effect of the combined treatment is greater than the sum of the two agents delivered separately, the maximum effect of radiation and thaliblastine being exhibited on the 8th and the 12th hour, respectively. The difference between the sum of aberrations after separate treatments and the yield of aberrations after the combined treatment is due to chromatid fragments.

[Causes of death in chicks in the 1st days after hatching]. / Prouchvane na prichinite za smurtnostta po piletata prez purvite dni sled izliupvaneto.

Scientific and productional experiments and complex investigations were carried out on breeding eggs, chick embryos, newly hatched birds, and ecologic habitats of two broiler dressing combines. It was found that the basic reasons for the morbidity and mortality of chicks in the first days following hatching were: the eggs chosen for hatching were of a lower biologic value due to deficient feeding (1); the veterinary, sanitary, and hygiene requirements with regard to the production, shipping, storing, and hatching of breeding eggs were overlooked (2); the little birds were offered feed mixtures of low value, along with admission of other drawback in their feeding (3); during the first days of raising the birds were kept at lower temperatures and lower relative humidity on the premises.

[Microclimate and the mortality among turkey poult broilers]. / Prouchvaniia vurkhu mikroklimatata i smurtnostta pri puicheta broilers.

Zoohygiene studies have been carried out in the course of two years, following up periodically at 20--25-day intervals the concentration of ammonia gas and hydrogen sulfide, the relative humidity, and the temperature within the houses of an industrial animal-breeding complex for the production of broiler turkey-poults. Parallel investigations have aimed at following up the morbidity and mortality rates among the birds. Part of them divided into age groups, have likewise been studied in terms of total protein and protein fractions of the blood serum along with the establishing of the blood bactericidal titer. Dependable values have been found of the interrelationship between the age of the turkey-poults and their mortality rate. The same have proved to be the values expressing the correlation between the air concentration of ammonia gas in the farm houses and the mortality rate shown. It is concluded that the mortality rates established in the turkey combine might probably be due to the action of comlex factors, mainly to inappropriate microclimate and incomplete raising technology that contribute to the appearance and development of pathogenic and occasionally pathogenic agents as well as of some noninfectious diseases.

[Fluorescent microscopy in the diagnosis of Dictyocaulus infection in sheep]. / Fluorestsentnata mikroskopiia pri diagnostikata na diktiokaulozata po ovtsete

Fluorescence microscopy was employed to study Dictyocaulus infection in 15 experimentally infected lambs each given 2000 D. filaria larvae. Studied were also the sera of 10 control lambs and of 20 sheep and goats infected with other helminths. Antibodies were established after the 14th day in 53 per cent of the lambs, the 20th day in 86.6 per cent, and the 27th day in all animals infected with the parasite. Antigens were found mainly in the wall of the digestive and reproductive organs, and in the cuticle of the larvae. As a method of early diagnosis fluorescence microscopy is simple, precise, and readily applicable in establishing Dictyocaulus infections.

[Influence of tissue emulsions on the phagocytic activity of the RES]. / Vliianie na t'kannata emulsiia v'rkhu fagotsitarnata aktivnost na RES

Radiometric, microbiologic, biochemical and morphologic investigations were carried out with a total of 95 guinea pigs and 20 rabbits in order to study the effect of the biogenic stimulants after Filatov on the phagocytic activity of the reticulo-endothelial system. Use was made of a tissue emulsion of swine embryos with biologic activity up to 160 per cent and a microbial stain - Escherichia coli 078. The labeling of the microorganisms was effected by means of 32P as obtained from Na2 H32PO4. It was found that the parenteral treatment of the animals with tissue emulsion after Filatov leads to the enhancement of the phagocytic activity and the lysing of the phagocytised bacteria by the elements of the reticulo-endothelial system by 7 to 10 per cent more than was observed with the use of control animals. The biogenic stimulants after Filatov activate the plasmocytic reaction of the body and the development of ribonucleoproteids in the parenchymal organs, and raise the level of properdin and gamma-globulins in the blood of the treated animals.