PubMed Health⌕ Search

Biomedical subjects

V Velebný

Publications and source records attributed to V Velebný.

At least 19 recordsLinked to original sources

[Sodium hyaluronate and an iodine complex--Hyiodine--new method of diabetic defects treatment].

UNLABELLED: Complicated diabetic defects are difficult to heal and frequently result in leg amputation. We have developed a new and unique system for wound treatment, which is based on combination of high molecular weight sodium hyaluronate with an iodine complex--Hyiodine. The aim of our study was to assess the effect of this new method of wound dressing on infected diabetic defects healing. METHODS: The effect of Hyiodine was studied on 22 patients suffering from complicated foot diabetic wounds. Hyiodine was either spread directly over the wound, or (more frequently) gauze was immersed in Hyiodine and then put on/into the wound. Then several layers of dry gauze covered the wound. RESULTS: Within 2-6 weeks after the onset of treatment all but two defects were filled with granulation tissue. Complete healing was evident in 18 patients within 6-20 weeks after the start of treatment, depending on the wound character, localization and extent. Two patients are still treated by Hyiodine, and significant improvement is apparent on their wound. Treatment was not successful in two subjects with ischemic defects due to simultaneous arterial occlusion. CONCLUSIONS: We can conclude that the hyaluronan-iodine complex Hyiodine is efficient method for treatment of difficult to heal diabetic defects without complete arterial occlusion.

Anti-Infective Agents, Local↗

The effects of hyaluronan on bone resorption and bone mineral density in a rat model of estrogen deficiency-induced osteopenia.

Hyaluronan, or hyaluronic acid (HA), is an essential component of extracellular matrices. HA of appropriate molecular weight and concentration can induce osteoblast differentiation and bone formation in vitro. The aim of our study was to evaluate the effects of HA of different molecular weights on ovariectomy (OVX)-induced bone loss in rats. Adult female Sprague Dawley rats were subjected to bilateral OVX or sham surgical procedure (sham). OVX rats were treated with: HA of molecular weight of 0.75 MDa at a dose of 1 mg/kg/day and with HA of molecular weight of 1.62 MDa at a dose of both 0.5 mg/kg/day and 1 mg/kg/day. HA was applied orally once a day during the 8-week period after ovariectomy. Body weight, urinary pyridinoline (Pyr), deoxypyridinoline (DPyr) corrected for urinary creatinine, serum nitrite/nitrate concentrations and whole body and femoral bone mineral density (BMD) were measured. HA treatment had no effect on the body weight gain in OVX rats. Excretion of urinary Pyr and Dpyr significantly increased in OVX rats compared to sham controls. The higher molecular weight HA (1.62 MDa) significantly reduced urinary Pyr and DPyr concentrations measured on day 28 after ovariectomy (p < 0.001). Serum concentrations of nitric oxide metabolites, nitrite/nitrate significantly decreased in OVX rats in comparison with sham controls (p < 0.001). HA of both 0.75 MDa and 1.62 MDa molecular weights significantly enhanced serum nitrite/nitrate concentrations in OVX rats. There was a clear reduction of whole body and femoral BMD in untreated OVX rats. The higher molecular weight HA decreased both whole body and femoral BMD loss. Our results show that orally applied HA of high molecular weight (1.62 MDa) inhibits bone resorption and provides a protective effect on bone density in ovariectomized rats.

Amino Acids↗

Elastin content in human fibrotic and cirrhotic liver.

Human liver tissue obtained at autopsy was extracted with hot 0.1 M NaOH. Determination of amino acids desmosine and isodesmosine was used to quantify elastin in the insoluble residue. Hydroxyproline content was used as an index of collagen content in the liver. Hydroxyproline content was twofold in fibrotic liver and threefold in cirrhotic liver when compared to normal liver, while the sum of desmosine and isodesmosine increased threefold and sixfold, respectively. Elastin content is low in normal liver when compared to collagen but appears to grow much faster in diseased liver.

Aged↗

Elastin powder produced for cosmetic purposes does not affect formation of granulation tissue.

A suspension of elastin powder that is produced for cosmetic purposes has been applied on open skin wounds made in rats. Elastin particles (diameter smaller than 0.1 mm) prepared by extraction of bovine nuchal ligament with alkali had no effect on wet weight and dry weight of granulation tissue formed in the wound within 6 days. Hydroxyproline content which indicates collagen content of the granulation tissue was not also changed.

Animals↗

Formation of collagen-like fibrils from alpha-elastin.

Collagen-like structures were formed in solutions of alpha-elastin after heating to 57 degrees C and after treatment with absolute ethanol. A complex between acetyl-alpha-elastin and cetyltrimethylammonium bromide showed a similar structure. Thick fibrils (diameter approximately 100 nm), resembling those described by Volpin, et al.12 revealed transversal banding with periodicity of 39 to 62 nm. A possible mechanism for the formation of these fibers is suggested based on hydrophobic interactions.

Animals↗

Fibrillar structure of alpha-elastin methylester complexes with glycoproteins and proteoglycans.

alpha-Elastin methylester forms with proteoglycan subunits and structural glycoproteins water-insoluble complexes which after staining with phosphotungstic acid (pH 7.0), reveal at large magnification bundles of slender smooth fibrils with a diameter from 4 to 5 nm. Similar fibrils can be observed after interaction of alpha-elastin methylester with chondroitin sulfate, but only if fixation with glutaraldehyde is used prior to staining. Phosphotungstic acid alters the organization of the complexes, in particular those formed with ligands of low molecular weight. The possible biological significance of the interactions studied is discussed.

Animals↗

Desmosine and isodesmosine contents and elastase activity in normal and cirrhotic rat liver.

The contents of desmosine and isodesmosine, the cross-linking amino acids of elastin, were increased 4-fold in rat liver with carbon tetrachloride-induced cirrhosis, which suggests that insoluble elastin accumulates in cirrhosis. Elastase activity in the cirrhotic liver, as determined with 3-carboxypropionyl-L-alanyl-L-alanyl-L-alanine p-nitroanilide, was 17% less than in the normal liver; no change was found when Congo Red-elastin was used as a substrate.

Amino Acids↗

Interaction of a tropoelastin model with connective tissue components.

It has been suggested that tropoelastin interacts with macromolecular components of connective tissue during the formation of elastic fibers. alpha-Elastin, used traditionally as a model of tropoelastin and mature elastin, is not suitable for the monitoring of this interaction in vitro. Therefore a new model of tropoelastin, the methyl ester of alpha-elastin, was synthesized and the interaction of this modified elastin with hyaluronic acid, chondroitin sulfate, proteoglycan subunits, solubilized structural glycoproteins and collagen was studied by turbidimetric measurement. Results indicate that alpha-elastin methyl ester is a better model of tropoelastin than alpha-elastin especially in those experiments where ionic interactions are believed to occur. It was also found that alpha-elastin methyl ester formed aggregates with hyaluronic acid, chondroitin sulfate, proteoglycan subunits and solubilized structural glycoproteins at room temperature and under conditions close to physiological ones. Alpha-elastin does not interact with these compounds under similar conditions. The character of the bonds involved in the interaction and the possible biological significance of the experiments are discussed.

Animals↗