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Biomedical subjects

Z Deyl

Publications and source records attributed to Z Deyl.

At least 19 recordsLinked to original sources
PubMed1992

Silver staining of collagen type I after sodium dodecylsulphate polyacrylamide gel electrophoresis: effect of Maillard reaction.

Differences in the acidic silver staining, after sodium dodecylsulphate polyacrylamide gel electrophoresis, between the alpha 1 and alpha 2 collagen chains, as well as between rat-tail tendon and calf-skin collagen type I, were observed. The staining conditions at which the staining differences are both most expressed and reproducible were characterized. Age differences between staining of the alpha 1 CB6 fragment from young rats (2 and 12 months) and old rats (29 months) indicated that different susceptibilities of collagen species to the silver staining can be the result of different extents of some age-dependent post-translational modification, such as glycation. In vitro incubation of acid-soluble rat-tail tendon collagen with various sugars led to an increase in silver staining compared with samples incubated in the absence of sugar. This effect was inhibited by sodium cyanoborohydride, diethylenetriamine pentaacetic acid and aminoguanidine, i.e. compounds inhibiting the Maillard reaction at various stages. It can be concluded that the enhanced silver susceptibility of glycated collagen is related to advanced-phase Maillard reaction products attached to collagen.

Animals↗
PubMed1992

Altered ratio of collagen chains in bone of a patient with non-lethal osteogenesis imperfecta.

Bone from a patient with osteogenesis imperfecta contained type III collagen which was absent in control bone. The ratio of alpha 1(I)/alpha 2(I) in type I collagen of patient's bone was increased (2.9 vs. 2.3 +/- 0.2 in controls) and the ratio of dimers beta 11/beta 12/beta 22 was altered due to the increased beta 22 content. No abnormality was observed in collagen from the patient's skin. The altered composition of collagen in bone, but the normal composition in skin suggests that the disease in the patient is due to impaired regulation of the synthesis of collagens in bone, rather than by a mutation in one of the two type I collagen genes. Unlike in skin, all the type III collagen in patient's bone was pepsin-soluble indicating an inability of the bone to incorporate type III collagen into mature highly cross-linked extracellular matrix.

Bone and Bones↗
PubMed1991

Capillary zone electrophoresis: its applicability and potential in biochemical analysis.

Recent developments in capillary zone electrophoresis (CZE) are reviewed, starting with available instrumentation, a description of different operational modes and the most commonly used detection systems. Appropriate attention is paid to CZE-mass spectrometry coupling and coupling of electrophoretic and chromatographic procedures. The possibility of separating chiral molecules is also discussed. Examples of applications concern mainly amino acids, peptides, proteins, nucleic acids and their constituents.

Amino Acid Sequence↗
PubMed1991

Separation of elastin cross-links as phenylisothiocyanate derivatives.

A method has been developed for the separation and quantitation of desmosines in tissue samples. The tissue is treated with cold 10% trichloroacetic acid to remove collagen and hydrolysed in HCl vapours in sealed vials. Preseparation of desmosines from tissue acid hydrolysates is performed on a cellulose column, first eluted with n-butanol-acetic acid-water to wash out other amino acids and then with water to recover desmosines. Separated desmosines are then derivatized with phenylisothiocyanate and determined by reversed-phase high-performance liquid chromatography using a gradient system with sodium acetate pH 6.4 and acetonitrile. Desmosines were detected spectrophotometrically at 254 nm. The method was applied to the determination of desmosine in elastin, rat aorta and bovine ligamentum nuchae.

Animals↗
PubMed1991

Change with age of UV absorbance and fluorescence of collagen and accumulation of epsilon-hexosyllysine in collagen from Wistar rats living on different food restriction regimes.

Accumulation of glycation products (as revealed by the thiobarbituric test and hexosyllysine assay) and the pigmented products (350 nm UV absorbance and 370ex/440em nm fluorescence) in aortal and skin collagen was investigated under the conditions of different nutritional regimes. Four groups of animals were tested: (1) ad libitum fed controls, (2) animals which were food restricted throughout their whole life (50% food intake), (3) animals fed ad libitum during their first year of life and then food restricted and (4) animals food restricted when young and fed ad libitum from the age of 1 year onwards. It was shown that all food-restricted animals showed lower levels of glycation and pigmentation products in collagen preparations from skin and aorta. The lowest accumulation was observed in group 4 which exhibited the longest 50% survival (29.4 months, as compared with 18.3 months in normally-fed controls). Of particular interest is the fact that in this group the decreased rate of accumulation of the glycated and pigmented products was preserved even after 1 year of life, i.e., when the animals had a free access to food. Though not directly supporting the glycation theory of aging (Cerami, 1985), our data are indicative of the involvement of glucose metabolism in the ageing process. Correlation between the levels of glycated and pigmented products in aortal and skin collagen as well as the correlation between the rate of accumulation of these products and 50% survival was impossible to establish. Nevertheless, each time that food restriction was imposed on the animals it always resulted in decreased accumulation of glycated and pigmented products and increased 50% survival. Possible mechanisms for this process are discussed.

Aging↗
PubMed1991

Change in the amount of epsilon-hexosyllysine, UV absorbance, and fluorescence of collagen with age in different animal species.

Skin and aorta collagen specimens of Wistar rats, white mice, beagle dogs, cats, horses, and human necropsies of different ages were examined with respect to the content of glycated products. The data presented show that (a) glycation and accumulation of the chromophore(s) are comparable in collagen samples from different species of comparable age; (b) glycation and pigmented accumulation increase markedly during the first 5-10 years of age; (c) the extent of glycation is different in different tissues (in particular, glycation of aortal collagen is about twice that of skin collagen); and (d) collagen pigmentation as followed by fluorescence is comparable in aortal and skin collagen (except below 10 years); pigmentation measured by absorbance at 350 nm is, on the contrary, lower in aortal than in skin collagen. Based on the assumption of constant blood glucose level during the life span, it appears feasible to conclude that the degree of nonenzymatic collagen glycation reflects the time period for which the protein was exposed to the action of sugars. This period, because of increased cross-linking, is likely to be extended in older animals. Other factors, such as differences in collagen turnover between different tissues and the intensity of the removal process of the glycated products, should be taken into consideration as well.

Aging↗
PubMed1990

Separation and partial characterization of Maillard reaction products by capillary zone electrophoresis.

Capillary zone electrophoresis proved useful for separating small amounts of both charged and uncharged solutes that are otherwise difficult to analyse. A typical complex mixture that had previously resisted all analytical approaches, including reversed-phase separations, is the products arising from the reaction of free amino acids with aldehydic sugars (Maillard reaction products). By using capillary zone electrophoresis [untreated capillary 50 cm x 75 microns I.D., 18 kV, 0.02 mol/l phosphate buffer (pH 7.5)], a number of products resulting from the reaction of glucose or ribose with glycine, alanine and isoleucine were separated and partially characterized. They were separated (1) without derivatization (and profiles of compounds absorbing at 220 nm were obtained), (2) as phenylthiocarbamyl derivatives in a search for reactive amino groups and (3) after derivatzation with 2,4-dinitrophenylhydrazine in a search for a method for compounds with a free aldehydic group. Phenylthiocarbamyl derivatives were separated in 0.005 mol/l borate buffer (pH 9.6) at 20 kV and 25 microA. Separation of 2,4-dinitrophenylhydrazones was effected by electrokinetic micellar chromatography in the same apparatus using a 50 cm x 75 microns I.D. capillary at 10 kV in 0.01 mol/l Na2HPO4-0.006 mol/l tetraborate, 0.050 mol/l with respect to sodium dodecyl sulphate. The results are compared with those given by high-performance liquid and thin-layer chromatography.

Amino Acids↗
PubMed1990

Increased glycation and pigmentation of collagen in aged and young parabiotic rats and mice.

Changes of non-enzymatic collagen glycosylation were followed in 2- and 24-month-old rats and mice and in parabiotic animals of the same age. With advancing age increased glycation of collagen was observed in both old male Wistar rats and white mice. Further it was demonstrated that both aortal and skin collagen of young animals is rapidly non-enzymatically glycosylated in the common milieu created by parabiotic animals and the proportion of non-enzymatically incorporated glucose approaches in the young counterparts the level found in old individuals. Similar trends as with non-enzymatic glycosylation were found with a fluorescent (370/440 nm) product present in both categories of collagen preparations. This fluorescence was higher in old animals and was considerably increased in the young counterpart of the parabiotic couple 6 weeks after operation. The nature of the fluorescent product appears different from pyridinoline and remains to be elucidated.

Aging↗
PubMed1990

[The effect of chronic exposure to lead on lysosomal levels in amniotic fluid in an experimental model].

Groups of female rats were exposed for prolonged periods to different lead concentrations in drinking water; in one group was also added to the drinking water, in the amniotic fluid of exposed females greatly reduced lysozyme values were found, as compared with controls. Concurrent Zn administration considerably reduced the effect of lead. Long-term exposure to low concentrations of lead caused a greater drop of lysozyme levels in amniotic fluid than that found in previous experiments after short-term exposure to higher lead concentration.

Amniotic Fluid↗
PubMed1989

Separation of collagens by capillary zone electrophoresis.

Collagen (types I, II, V, IX and XI) constituting polypeptide chains and their polymers and cyanogen bromide-cleaved peptides of collagen type I and type III were investigated by means of capillary zone electrophoresis. Separations were effected in 2.5 mM sodium tetraborate buffer in less than 15 min. A 50 cm x 0.1 mm I.D. fused-silica capillary was used. The separations were run at 18 kV per capillary. The results of the separation were monitored at 220 nm with an on-tube detection system. Using the Offord equation, relative retention times of cyanogen bromide cleavage fragments were plotted against M(2-3)/Z, where M is the molecular mass of a polypeptide and Z its valency. A linear relationship was observed. Collagen alpha-chains and their polymers were also satisfactorily resolved.

Collagen↗
PubMed1989

Simple apparatus for capillary zone electrophoresis and its application to protein analysis.

The construction of a simple apparatus for capillary zone electrophoresis is described, consisting of an optical system allowing direct absorbance measurement in the capillary in UV light, an evaluating electronic module and a high-potential source. An attempt was made to achieve maximum sensitivity with a simple construction. In the electronics, care was taken to obtain a quiet baseline and to optimize the signal-to-noise ratio. That part of the noise which is of the frequency band of the signal is filtered off. Both suction and electrophoretic sample introduction are possible. According to operator's choice, the apparatus can be run under constant voltage or current and is protected against overloading. The high-potential electrode chamber contains separate buffer and sample compartments and its construction offers an easy interchange between the running and sampling positions. The applicability of the system to the separation of amino acids as phenylthiocarbamyl derivatives, peptides and both artificial and naturally occurring protein mixtures is demonstrated.

Adsorption↗
PubMed1989

Separation methods for the study of collagen and treatment of collagen disorders.

Liquid chromatographic and electrophoretic methods applicable to the separation of collagen and its fragments are reviewed. Special attention is paid to the separation of both stabile and labile crosslinking elements. Identification procedures exploiting the mapping of either collagen alpha-chains or of cyanogen bromide fragments are discussed. These methods can be used for diagnosing inborn errors of collagen metabolism using bioptic or necroptic samples. Analysis of urinary hydroxyproline-containing peptides or the determination of peptidically bound pyridinoline is suitable for measuring the intensity of collagen metabolism.

Amino Acids↗
PubMed1989

[Experimental models of arthritis induced by various cartilage collagen type].

To laboratory rats of Wistar strain (Ipcv: Wist) native collagenous types of pig cartilage--II, IX and XI and the denatured type XI were administered. The first immunization dose, 0.5 mg collagen per experimental animal, was administered in incomplete Freund adjuvant and the second immunization dose (collagen in solution) followed after 7 days and was administered by the i.p. route. Inflammatory arthritis of the small interphalangeal, metatarsophalangeal and tarsal joints developed between the 11th and 17th day of the experiment in rats immunized with native collagen type II and XI--60% of the animals were affected. The histological findings corresponded to the course of arthritis, however, the articular destructive changes after administration of collagen type XI were more severe than after type II. The changes were evaluated by X-ray and by means of thermovision. The antibody levels against different types of collagen assessed by means of the ELISA test reached peak values between the 13th and 20th day of the experiment. In the group of rats immunized by collagen type IX and the denatured type XI arthritis did not develop. The antibody response in the group of rats immunized with type IX was similar as in the group immunized with types II and XI. Histological examination confirmed some changes in the joints of rats immunized with collagen type IX, while in the joints of rats immunized with denatured collagen type XI no changes were found.

Animals↗
PubMed1989

[The effect of a gold complex on experimental arthritis induced by immunization with type II collagen].

Gold complexes are used in the treatment of rheumatoid arthritis for some 60 years by now. The authors used therefore a gold complex, sodium aurothiosulphate (ATSS) to influence the experimental model of arthritis induced by immunization with type II collagen in laboratory rats. To the first group of laboratory rats ATSS was administered concurrently with the first immunization dose, to the second group with the second immunization dose and to the third group in the course of arthritis. ATSS was administered to individual groups every week by the i. m. route, 20 mg/kg body weight. In all three groups a reduction of arthritic symptoms was observed, however, in group three to a much lesser extent than in groups one and two. The results of the experiment indicate clearly that ATSS was able to suppress the development of collagen induced arthritis, if administered not later than with the second immunization dose. As the formation of antibodies against type II collagen was not suppressed, it may be assumed that the activation of the complement system was blocked by the bond of the gold complex with the C1q component. It has been proved already previously that the interaction of C1q with gold complexes is very rapid.

Animals↗
PubMed1989

Effects of dietary trans-fatty acids on reproductive performance of Wistar rats.

1. Wistar rats were fed for three successive generations on a semi-purified diet, in which the fat was provided by butter, sunflower oil, rapeseed oil or hydrogenated vegetable fat, differing in the content of cis,cis-18:2 and trans-18:1 fatty acids. Effects of these fats on the composition of adipose tissue and reproductive performance were studied. Fatty acids were analysed using high-performance liquid chromatography. 2. The fatty acid pattern of adipose tissue was closely related to dietary fat composition and, established in the first generation, did not change significantly in successive generations of rats. 3. Hydrogenated fat adversely affected litter size, sperm morphology and regularity of oestrous cycle, and prolonged the period of gestation in experimental animals. Differences observed between the generations were not significant. 4. Hydrogenated fat decreased the level of serum testosterone in males, but the differences observed in levels of serum progesterone in females were not apparently related to the dietary trans-fatty acids.

Adipose Tissue↗
PubMed1989

The contribution of discrimination analysis to the diagnostic decision in patients with lung carcinoma.

A set of 620 patients was examined. Out of them, 245 suffered from lung carcinoma of different type and stage, 28 suffered from other malignant tumors, 37 were affected with benign tumors, and 166 were suffering from a nonmalignant respiratory disease (tuberculosis, nonspecific pneumonia, chronic bronchitis, abscesses, cysts, asthma, lung fibrosis, bronchiectasis and sarcoidosis). In addition to these patients, 144 blood donors were examined who represented the control group of healthy individuals. In a blind test another set of 266 persons was examined. By completing the values of selected markers (orosomucoid, prealbumin, glycoprotein electrophoresis, erythrocyte sedimentation, age of the individual, and the number of smoked cigarettes) into the discrimination rule and by calculating the discrimination function, a sensitivity of 80.6% and a specificity of 75.6% were obtained. A comparative cytological examination of the same set revealed lower sensitivity (61.0%) but higher specificity (98.0%). These values were verified in a blind test, as the patients were admitted to the hospital. Sensitivity in lung cancer was found to be 83.9%; in nonmalignant diseases the respective value was 77.1%. This approach can be applied to individuals suspect of cancer, in secondary prevention and in individuals with a high risk of lung cancer.

Adult↗
PubMed1979

The presence of gamma-carboxyglutamic acid-containing protein in atheromatous aortae.

It has been established that a gamma-carboxyglutamic acid-containing protein is present in rat aortae after long term atherogenic diet administration. A similar protein was proven to be present in turkey tibial tendons that are predisposed to undergo physiological calcification. The molecular weight and amino acid composition of both proteins were identical. They contained six glutamic acid residues per molecule, three of which were gamma-carboxylated. The proteins studied were also identical in their N-terminal sequence over six residues. This sequence was fully coincident with that published for osteocalcin (Price, P.A., Poser, J.W. and Raman, N. (1976) Proc. Natl. Acad. Sci. U.S.A. 73, 3374--3375). In the region corresponding to residues 20--26 in osteocalcin, a single replacement of valine for isoleucine was found in turkey tendon protein. From the physiological point of view it should be mentioned that the level of the gamma-carboxyglutamic acid containing protein in atherogenic diet fet rat aortae exceeds that found normally in bone or in tissues predisposed for physiological calcification.

1-Carboxyglutamic Acid↗