Colonization of surfaces by phenolic compounds utilizing microorganisms.

The aim of the present study is to determine optimal adhesive interaction of phenolic compounds utilizing Candida maltosa and Rhodococcus erythropolis when adhering to kaolin, silicone, synthetic foil (Steriking R40) and fluorinated silicones, comparing cell and support surface hydrophobicity. In parallel, the interfering effect of detergents was investigated. Data obtained show that the less hydrophobic supports display high initial cell adhesion when contacted with the cell type with a lower surface hydrophobicity (yeast cell) but most stable yeast biofilms are those formed on highly hydrophobic fluorinated silicones. On the other hand, support hydrophobicity has no effect on bacterial cell detachment; however, bacterial biofilms are denser when growing on more hydrophobic supports. Both detergents interfere (independently on the cell type) with the early and late phases of biofilm development.

Silicone rubber-hydrogel composites as polymeric biomaterials. IX. Composites containing powdery polyacrylamide hydrogel.

A composite material has been prepared consisting of a silicone rubber matrix and particulate lightly cross-linked polyacrylamide hydrogel. The material, resembling common silicone rubber, is hydrophilic and swells in water like hydrogels. The polyacrylamide has a high specific surface area, a relatively low content of water-soluble low-molecular-weight compounds and, owing to its non-ionogenic character, a pH-independent swelling degree. For the composite material consisting of the silicone rubber and very fine powdery cross-linked polyacrylamide, we have measured the rate of swelling in water, the mechanical properties (tensile strength, break elongation, hardness, resilience), biological properties (implantation test, cytotoxicity, cell cultivation) and UV absorption of its water extracts. The polyacrylamide and polysiloxane purity, as the composite material starting components, has been determined to be satisfactory. As a result, a high swelling rate of the prepared composite material has been observed, resulting in reaching more than 70% wt of water of the equilibrium swelling. The results show that the composite material is suitable for biological and medical use.

Medulloepithelioma in a cat.

Castrated male of European cat, bastard, 16 month-old suffered from a grayish-pink tumour in the anterior chamber of the right eyeball in the course of last six months. After enucleation, the eye was examined by histology, immunohistochemistry (NSE, NPF, S-100 protein) and electronmicroscopy. The tumour was classified as malignant medulloepithelioma. Existence of neuroblastoma in animals and frequency of neuroblastoma and medulloepithelioma in humans and animals is discussed.

Silicone rubber-hydrogel composites as polymeric biomaterials. IV. Silicone matrix-hydrogel filler interaction and mechanical properties.

Composite materials consisting of a silicone rubber matrix and particulate synthetic hydrogels were prepared and their mechanical properties were studied. The influence of the size, shape, aggregation of hydrogel particles, chemical reactions of polymer phases on tensile properties and tear strength of the composite materials were investigated. The relations between the properties, structure and chemical composition of polymer phases of the composite materials and their mechanical properties are discussed.

[Anesthesia in dogs and cats with althesin]. / Narkóza psa a kocky althesinem.

Tests of the effect of the new steroid anaesthetic alfadion in the drug Althesin are described. Experiments were carried out in three experimental groups. Intramuscular administration of Althesin to dogs at doses 5 to 15 mg. kg-1 does not induce required anaesthesia. After intravenous administration of Althesin to dogs at a dose of 2 mg. kg-1 after diazepam pre-medication at a dose of 0.25 mg.kg-1 i. m., anaesthesia started without excitations immediately after completed application. Anaesthesia lasted on the average 10 minutes and at the time of recovery excitations and side effects occurred. After intravenous administration of Althesin at a dose of 6 mg. kg-1 with diazepam pre-medication 0.25 mg. kg-1 i.m., the course of narcosis in cats was similar to that in dogs, only its duration was on the average 29 minutes.