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At least 793 records · Page 44Linked to original sources
PubMed1985

[Test of phagocytic activity of blood leukocytes in calves].

The 2-hydroxyethylmethacrylate-particle (HEMA) phagocytosis method in whole blood was adapted to the evaluation of the phagocytic activity of the leucocytes of calves. Several test variants were compared and the best procedure was determined, based on the following principles: keeping the heparin concentration at 10 i. u. in 1 ml of blood at the maximum, using fresh samples, incubating at 37 degrees C for 0.5 to 1 hour, thoroughly agitating the sample after incubation, with possible addition of EDTA. The phagocytic activity of nine calves, 2.5 to 3 months old, was examined by the proposed procedure and 18.6% phagocytic leucocytes were found, the phagocytic index being 7.07%.

Age Factors↗
PubMed1985

[Phagocytic activity of blood leukocytes in calves from birth to 3 months of age].

Forty-three calves of various age from the day of birth to the age of three months were subjected to the 2-hydroxyethylmethacrylate (HEMA) particle phagocytosis test. Significant differences in the phagocytic activity of blood leucocytes were recorded, all depending on age. New-born calves had very low phagocytic activity: only 16.5% of the leucocytes were found to be phagocytic, the phagocytic index being 0.39. A rapid increase in phagocytic activity was recorded during the subsequent days. At the age of three days 43% of the leucocytes of the calves were phagocytic. A decrease in phagocytic activity was found on the sixth to seventh day, and another increase was recorded only from the age of three to four weeks of age. No such changes in the development of phagocytic activity were observed in the calves reared without colostrum administration. Low values were maintained for a longer time after birth without the typical increase on the third to fifth day. Phagocytic activity increased in the zero-colostrum calves experimentally infected with rotavirus.

Age Factors↗
PubMed1985

Properties of new sorbents containing activated carbon-PHEMA-PEG.

A new immobilized powder activated carbon system was developed. In this approach, highly biocompatible hydrophilic polymer gels, namely polyHEMA and PEG, were used as support. The sorbents were produced by radiation-induced polymerization of HEMA in super-cooled media. The polymer composites obtained by using different ratios of ingredients (HEMA, PEG and AC) and by changing the radiation dose period, were in the form of, almost, spherical black gels having different elasticities. Equilibrium adsorption studies were carried out to evaluate the sorption capacities of both powder and immobilized activated carbon. The comparative performance characteristics of the hemoperfusion columns filled with either granules or immobilized carbons were obtained for creatinine. Fresh human blood was used to study the biocompatibility of immobilized carbon samples. The surface morphology and the pore structure of the gels were evaluated by means of Scanning Electron Microphotography and Optical Microphotography. According to the experimental results, it was concluded that this new type of immobilized activated carbon system seems to be more attractive for hemoperfusion applications due to having comparatively higher adsorption rates and very good blood compatibility as well as simple and uniformly reproducible method of production.

Adsorption↗
PubMed1979

[HEMA-contact lens and HEMA-dressing lens-damage to the eye (author's transl)].

3 cases in which HEMA-contact lens, and 2 cases in which HEMA-dressing lens caused corneal damage were analyzed with regard to symptomatology, etiology and sequence of events. Hyperemia of the limbus is the main symptom. Avoidable causes are exaggerated tightness, overwearing, storing up of proteins, rough surface, and incompatibility of soft-lens solutions. Irreversible and largely resistant to therapy is, damage resulting from the synthetic itself.

Acrylic Resins↗
PubMed1979

Scleral buckling with a soft xerogel implant: II. Experiments in vivo.

Experimental scleral buckling was obtained in rabbits by using soft xerogel implants placed either episclerally or intrasclerally. After implantation of 1 x 1.5 x 2 mm or 1 x 2 x 2.5 mm implants, buckle heights ranged from 1.3 to 4.0 mm. Intrascleral implantation produced a higher buckle than episcleral implantation. The follow-up period extended from 6 months to 1 year. No significant inflammatory reactions, wound dehiscence, or extrusions or intrusions of the poly(2-hydroxyethyl acrylate), PHEA, implant were observed either clinically or histologically. Our impression is that HEA can be a useful material for treatment of retinal detachment, particularly when a localized high buckle is required or for patients with thin and weak sclera.

Acrylic Resins↗
PubMed1983

[Initial observations on the biocompatibility of a polymer used as a skin dressing].

In the development of a dressing for burn wound covers, a material is required which combines good oxygen permeability, high water content and good biocompatibility with reasonable mechanical properties. One of the most important functions of the cover is to protect the burned surfaces from drying out and to constitute the first defence against microbial invasion. In this study composite sheets crosslinked either in presence of glicerol or diacetin, obtained by reinforcing PHEMA with a tricot PET net have been implanted subacute in rabbits, to test their biocompatibility. The same composites crosslinked in presence of diacetin and grafted on a polybutadene film, have been used as a skin graft on rabbits.

Animals↗
PubMed1983

[Biological and surgical aspects of the use of polymers in experimental surgery. 1: implants on the oculo-extrinsic musculature].

Composite sheets obtained reinforcing PHEMA with a tricot PET net have been implanted in rabbits to test their potential applications for cross-eye surgical correction. The mechanical characterization of the composites has been carried out both in static tension and fatigue. The clinical evaluation was performed on twelve adult New Zealand white Rabbits implanting the sheets on the rectus dorsalis muscle of the eye. The material seems to be highly compatible with the surrounding tissue, mechanical satisfying and clinically helpful in correcting many of the pathological conditions connected with strabismus. The long term behaviour of the implanted prosthesis in still under investigation.

Animals↗
PubMed1980

[The interaction of methemoglobin and modified poly-(hydroxyethylmethacrylates) studied by spectroscopic methods].

The interaction between methemoglobin (MetHb) and macroporous matrices on the basis of polymethacrylates was investigated by means of optical and e.p.r. spectroscopy. The spectroscopic data show that the adsorption of MetHb to imidazole-containing matrices occurs by complex formation between matrix-bound imidazole and the iron of the prosthetic group, with all 4 polypeptide chains of the MetHb molecule being included in the interaction. The adsorption to hydrophobic side chains containing matrices leads, via the protein-matrix interaction, to considerable disturbances of iron protoporphyrin IX in equilibrium or formed from protein-contacts, which are of general importance with respect to the functional variablity and control, respectively, of iron porphyrins in hemoproteins. In case of matrix containing n-hexyl groups deoxyHb is oxidized by O2 to MetHb, instead of being oxygenated to HbO2. Not all prosthetic groups are able to bind N-3. With the increase in hydrophobicity of the matrix a conformational change is enforced leading in the beta-chains to the direct interaction between iron and sulfur of cysteine (beta-cys 92), as it is proved in all cytochrome P-450 and other model compounds.

Animals↗