scholarly journals Fractionation of proteoglycans from bovine corneal stroma

1975 ◽  
Vol 145 (3) ◽  
pp. 491-500 ◽  
Author(s):  
I Axelsson ◽  
D Heinegård
Keyword(s):  
Chondroitin Sulphate ◽  
Corneal Stroma ◽  
Molecular Size ◽  
Equal Weight ◽  
Keratan Sulphate ◽  
Before And After ◽  
Weight One ◽  
Tenfold Excess ◽  
Covalently Linked ◽  
The Individual

Proteoglycans were extracted from bovine corneal stroma with 4M-guanidinum chloride, purified by DEAE-dellulose chromatography (Antonopoulos et al., 1974) and fractionated by precipitation with ethanol into three fractions of approximately equal weight. One of these fractions consisted of a proteoglycan that contained keratan sulphate as the only glycosaminoglycan. In the othertwo fractions proteoglycans that contained chondroitin sulphate, dermatan sulphate and keratan sulphate were present. Proteoglycans which had a more than tenfold excess of galactosaminoglycans over keratan sulphate could be obtianed by further subfractionation. The gel-chromatographic patterns of the glucosaminoglycans before and after digestion with chondroitinase AC differed for the fractions. The individual chondroitin sulphate chains seemed to be larger in cornea than in cartilage. Oligosaccharides, possibly covalently linked to the protein core of the proteoglycans, could be isolated from all fractions. The corneal proteoglycans were shown to have higher protein contents and to be of smaller molecular size than cartilage proteoglycans.

scholarly journals Structural studies on sialylated and sulphated O-glycosidic mannose-linked oligosaccharides in the chondroitin sulphate proteoglycan of brain

1987 ◽  
Vol 245 (1) ◽  
pp. 229-234 ◽  
Author(s):  
T Krusius ◽  
V N Reinhold ◽  
R K Margolis ◽  
R U Margolis
Keyword(s):  
Ion Exchange ◽  
Chondroitin Sulphate ◽  
Gel Filtration ◽  
Molecular Size ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Keratan Sulphate ◽  
Size Fractions ◽  
Sulphate Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan

We have previously described the structures of neutral and sialylated O-glycosidic mannose-linked tetrasaccharides and keratan sulphate polysaccharide chains in the chondroitin sulphate proteoglycan of brain. The present paper provides information on a series of related sialylated and/or sulphated tri- to penta-saccharides released by alkaline-borohydride treatment of the proteoglycan glycopeptides. The oligosaccharides were fractionated by ion-exchange chromatography and gel filtration, and their structural properties were studied by methylation analysis and fast-atom-bombardment mass spectrometry. Five fractions containing [35S]sulphate-labelled oligosaccharides were obtained by ion-exchange chromatography, each of which was eluted from Sephadex G-50 as two well-separated peaks. The apparent Mr values of both the large- and small-molecular-size fractions increased with increasing acidity (and sulphate labelling) of the oligosaccharides. The larger-molecular-size fractions contained short mannose-linked keratan sulphate chains of Mr 3000-4500, together with some asparagine-linked oligosaccharides. The smaller tri- to penta-saccharides, of Mr 800-1400, appear to have a common GlcNac(beta 1-3)Manol core, and to contain one to two residues of sialic acid and/or sulphate.

Cell adhesion and proteoglycans. I. The effect of exogenous proteoglycans on the attachment of chick embryo fibroblasts to tissue culture plastic and collagen

1979 ◽  
Vol 40 (1) ◽  
pp. 77-88
Author(s):  
P. Knox ◽  
P. Wells
Keyword(s):  
Tissue Culture ◽  
Hyaluronic Acid ◽  
Cell Adhesion ◽  
Chick Embryo ◽  
Structural Integrity ◽  
Chondroitin Sulphate ◽  
Cell Types ◽  
Tissue Culture Plastic ◽  
Keratan Sulphate ◽  
Covalently Linked

Proteoglycan was isolated from cartilage and freed from contaminating glycoproteins and hyaluronic acid. The macromolecule consists of a protein core covalently linked to a number of glycosaminoglycan side chains, namely chondroitin sulphate and keratan sulphate. This proteoglycan retards the attachment of a variety of cell types to tissue culture plastic and to collagen. Glycosaminoglycans alone, have no significant effect on rates of attachment. Similarly, trypsinized proteoglycan is without effect. It is concluded that the structural integrity of the proteoglycan macromolecule is essential for its effect on cell adhesion.

scholarly journals Immunochemical analysis of cartilage proteoglycans. Antigenic determinants of substructures

1979 ◽  
Vol 179 (1) ◽  
pp. 35-45 ◽  
Author(s):  
J Wieslander ◽  
D Heinegård
Keyword(s):  
Hyaluronic Acid ◽  
Chondroitin Sulphate ◽  
Antigenic Site ◽  
Trypsin Digestion ◽  
Antigenic Determinants ◽  
Binding Region ◽  
Keratan Sulphate ◽  
Link Protein ◽  
Before And After ◽  
Hyaluronic Acid Binding

Antibodies were raised in rabbits by injection of cartilage proteoglycan monomers, isolated hyaluronic acid-binding region, polysaccharide-peptides prepared by trypsin digestion of proteoglycans and link-protein. The rabbits injected with the proteoglycan monomers made antibodies reacting with the intact proteoglycan. The antiserum contained antibodies specific for, and also reacting with, the isolated hyaluronic acid-binding region and the keratan sulphate-rich region. In addition there were probably antibodies reacting with other structures of the proteoglycan monomer. When isolated hyaluronic acid-binding region was used for immunization the antibodies obtained reacted specifically with the hyaluronic acid-binding region. The antibodies obtained from rabbits immunized with the polysaccharide-peptides reacted with the proteoglycan monomers and showed a reaction identical with that of the chondroitin sulphate-peptides isolated after trypsin digestion of proteoglycans. The antibodies prepared with the link-protein as the antigen reacted only with the link-protein and not with any preparation from the proteoglycan monomer. Neither did any of the antisera raised against the proteoglycan monomer or its substructures react with the link-protein. Separately it was shown that the peptide ‘maps’ prepared from trypsin digests of the link-protein and the hyaluronic acid-binding region were different. Therefore it appears that the link-protein is not structurally related to the proteoglycan or the hyaluronic acid-binding region. Digestion of proteoglycan monomers or isolated hyaluronic acid-binding region with trypsin did not destroy the antigenic sites of the hyaluronic acid-binding region. In contrast trypsin digests of previously reduced and alkylated preparations did not react with the anti-(hyaluronic acid-binding region). The trypsin digests, however, reacted with both the antibodies directed against the chondroitin sulphate-peptides and those against the keratan sulphate-peptides. Trypsin digestion of the link-proteins destroyed the antigenic site and the reactivity with the antibodies. By combining immunoassay of proteoglycan preparations before and after trypsin digestion it is feasible to quantitatively determine its substructures by using the antisera described above.

scholarly journals A comparative biochemical and ultrastructural study of proteoglycan–collagen interactions in corneal stroma. Functional and metabolic implications

1990 ◽  
Vol 270 (2) ◽  
pp. 491-497 ◽  
Author(s):  
J E Scott ◽  
T R Bosworth
Keyword(s):  
Guinea Pig ◽  
Alcian Blue ◽  
Chondroitin Sulphate ◽  
Corneal Thickness ◽  
Corneal Stroma ◽  
Human Cornea ◽  
Dermatan Sulphate ◽  
Keratan Sulphate ◽  
Cellulose Acetate Membranes ◽  
O2 Supply

1. Corneas of mouse, rat, guinea pig, rabbit, sheep, cat, dog, pig and cow were quantitatively analysed for water, hydroxyproline, nucleic acid, total sulphated polyanion, chondroitin sulphate/dermatan sulphate and keratan sulphate, several samples or pools of tissue from each species being used. Ferret cornea was similarly analysed for water and hydroxyproline on one pool of eight corneas. Pooled frog (38) and ferret (eight) corneas and a single sample of human cornea were qualitatively examined for keratan sulphate and chondroitin sulphate/dermatan sulphate by electrophoresis on cellulose acetate membranes. Nine species (mouse, frog, rat, guinea pig, rabbit, sheep, cat, pig and cow) were examined by light microscopy and six (mouse, frog, rat, guinea pig, rabbit and cow) by electron microscopy, with the use of Alcian Blue or Cupromeronic Blue in critical-electrolyte-concentration (CEC) methods to stain proteoglycans. 2. Water (% of wet weight), hydroxyproline (mg/g dry wt.) and chondroitin sulphate (mg/g of hydroxyproline) contents were approximately constant across the species, except for mouse. 3. Keratan sulphate contents (mg/g of hydroxyproline) increased with corneal thickness, whereas dermatan sulphate contents decreased. The oversulphated domain of keratan sulphate was absent from mouse and frog corneas, increasing as percentage of total keratan sulphate with increasing corneal thickness. Sulphation of dermatan sulphate was essentially complete (i.e. one sulphate group per disaccharide unit). 4. Chondroitin sulphate/dermatan sulphate proteoglycans were present at the d bands of the collagen fibrils of all species examined, orthogonally arrayed, with high frequency, and occasionally at the e bands. Keratan sulphate proteoglycans were present at the a and c bands of all species examined, but with far higher frequency in the thicker corneas, where keratan sulphate contents were high. 5. Alcian Blue CEC staining showed much higher sulphation of keratan sulphate in thick corneas, e.g. that of cow, than in thin corneas, e.g. that of mouse, in keeping with biochemical analyses. 6. It is suggested that the constancy of interfibrillar volumes is regulated via the swelling and osmotic pressure of the interfibrillar polyanions, by adjustment of the extent of sulphation in two independent proteoglycan populations, to achieve an ‘average sulphation’ of the total polyanion similar to that of fully sulphated chondroitin sulphate/dermatan sulphate. 7. The balance of synthesis of the two kinds of proteoglycans may be determined by the O2 supply to the avascular cornea. O2 supply may also determine the conversion of chondroitin sulphate into dermatan sulphate.

scholarly journals Model connective-tissue systems. A study of polyion–mobile ion and of excluded-volume interactions of proteoglycans

1974 ◽  
Vol 143 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Wayne D. Comper ◽  
Barry N. Preston
Keyword(s):  
Chondroitin Sulphate ◽  
Intervertebral Discs ◽  
Gelatin Matrix ◽  
Keratan Sulphate ◽  
Sulphate Content ◽  
Gelatin Gels ◽  
Tissue Systems ◽  
The Individual ◽  
Mobile Ions

The osmotic pressure of solutions of sulphated proteoglycans isolated from the intervertebral discs of animals of various ages was determined. The behaviour of the solutions in salt-added systems was investigated in terms of the Donnan distribution of the mobile ions. It is evident that this effect is the dominating factor in explaining the observed nonidealities. Although marked variations in the compositions of the proteoglycan, with regard to their chondroitin sulphate and keratan sulphate content and hence charge content, occur with increasing age of parent tissue, the osmotic activities of the various preparations are very similar. This is explained by the ‘fixation’ of the counterions in such a way as to counteract any change in the charge content of the polyion; an ‘osmotic buffering’ effect. The swelling behaviour of gelatin gels containing the proteoglycan preparations has been measured. In all cases pressures in excess of the sum of the osmotic pressures of the individual components are observed. However, the magnitude of the excess decreases with increasing age of the parent tissue. It is suggested that the age changes, as reflected by a decrease in water content of the gel system, are not the result of changes in the osmotic properties of the individual components but rather reflect changes in the entropic interaction of the proteoglycan with the gelatin matrix. The relevance of this observation to the situation in vivo is discussed.

scholarly journals Altered proteoglycan synthesis by micromelial limbs induced by 6-aminonicotinamide. Appearance of abnormal forms of cartilage-characteristic proteoglycan (PG-H)

1987 ◽  
Vol 246 (3) ◽  
pp. 745-753
Author(s):  
A Honda ◽  
S Kazuno ◽  
Y Mori ◽  
K Kimata ◽  
S Suzuki
Keyword(s):  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Molecular Size ◽  
Immunological Methods ◽  
Proteoglycan Synthesis ◽  
In Ovo ◽  
Keratan Sulphate ◽  
Hind Limbs ◽  
Limb Morphogenesis ◽  
Significant Difference

Since administration of 6-aminonicotinamide (10 micrograms) to day-4 chick embryos in ovo was shown to induce micromelial limbs, biosynthesis of cartilage-characteristic proteoglycan-H (PG-H) as an important index of limb chondrogenesis was examined in day-7 normal and micromelial hind limbs by biochemical and immunological methods. (1) Metabolic labelling of the micromelial limbs with [6-3H]glucosamine and either [35S]sulphate or [35S]methionine, followed by analyses of labelled PG-H by glycerol density-gradient centrifugation under dissociative conditions, showed a marked reduction in the PG-H synthesis. (2) PG-H synthesized by the micromelial limbs was much lower than that synthesized by the normal limbs in the biosynthetic ratio of chondroitin sulphate to keratan sulphate and glycoprotein-type oligosaccharide, although no significant difference was observed in the immunological properties of these proteoglycans. (3) The degree of sulphation of chondroitin sulphates of PG-H was lowered in the micromelial limbs as judged by the increase of unsulphated disaccharide (delta Di-OS) released by chrondroitinase ABC digestion, although there were no significant differences between the normal and the micromelial limbs in the average molecular size (Mr = 38,000) of labelled chondroitin sulphates of PG-H. (4) Addition of beta-D-xyloside, an artificial initiator for chondroitin sulphate synthesis, to the micromelial limbs in culture recovered the incorporation of labelled glucosamine into chondroitin sulphate to that comparable with the normal control with beta-D-xyloside, although the incorporation of [35S]sulphate was lower in the micromelia than in the control with beta-D-xyloside. These results suggest that the reduction in the biosynthesis of the PG-H as well as the production of altered forms of PG-H induced by 6-aminonicotinamide during a critical period of limb morphogenesis may be an important factor for the micromelia.

Healing of Circular Defects in the Rabbit Medial Meniscus Can Occur Spontaneously and Is not Improved by Intra-Articular Hyaluronic Acid

1996 ◽  
Vol 09 (02) ◽  
pp. 60-5 ◽  
Author(s):  
N. Hope ◽  
P. Ghosh ◽  
S. Collier
Keyword(s):  
Hyaluronic Acid ◽  
Medial Meniscus ◽  
Chondroitin Sulphate ◽  
Rabbit Model ◽  
Type Ii Collagen ◽  
Type Ii ◽  
Keratan Sulphate ◽  
Meniscal Healing ◽  
Meniscus Healing ◽  
Made In

SummaryThe aim of this study was to determine the effects of intra-articular hyaluronic acid on meniscal healing. Circular defects, 1.0 mm in diameter, were made in the anterior third of the medial meniscus in rabbits. In one joint, 0.4 ml hyaluronic acid (Healon®) was instilled, and in the contralateral (control) joint, 0.4 ml Ringer’s saline. Four rabbits were killed after four, eight and 12 weeks and the menisci examined histologically. By eight weeks most of the lesions had healed by filling with hyaline-like cartilage. Healing was not improved by hyaluronic acid treatment. The repair tissue stained strongly with alcian blue, and the presence of type II collagen, keratan sulphate, and chondroitin sulphate was demonstrated by immunohistochemical localisation. In contrast to the circular defects, longitudinal incisions made in the medial menisci of a further six rabbits did not show any healing after 12 weeks, indicating that the shape of the lesion largely determined the potential for healing.The effect of hyaluronic acid on meniscal healing was tested in a rabbit model. With one millimeter circular lesions in the medial meniscus, healing by filling with hyalinelike cartilage was not significantly affected by the application of hyaluronic acid intra-articularly at the time of surgery, compared to saline controls, as assessed histologically four, eight and 12 weeks after the operation.

Official Advice Improves Mortgage-Holders’ Perceptions of Switching: Experimental Evidence

2019 ◽  
Author(s):  
Shane Timmons
Keyword(s):  
Interest Rate ◽  
Experimental Evidence ◽  
Consumer Protection ◽  
Policy Development ◽  
Switching Process ◽  
Competitive Markets ◽  
Protection Agency ◽  
Change Perceptions ◽  
Before And After ◽  
The Individual

Encouraging consumers to switch to lower-rate mortgages is important both for the individual consumer’s finances and for functioning competitive markets, but switching rates are low. Given the complexity of mortgages, one potential regulatory intervention that may increase switching rates is to provide independent advice on how to select good mortgage products and how to navigate the switching process. Working with a government consumer protection agency, we conducted an experiment with mortgage-holders to test whether such advice alters perceptions of switching. The experiment tested how (i) the attributes of the offer, (ii) perceptions about the switching process, (iii) individual feelings of competence and (iv) comprehension of the product affect willingness to switch to better offers, both before and after reading the official advice. The advice made consumers more sensitive to interest rate decreases, especially at longer terms. It also increased consumers’ confidence in their ability to select good offers. Overall, the findings imply that advice from policymakers can change perceptions and increase switching rates. Moreover, the experiment demonstrates how lab studies can contribute to behaviourally-informed policy development.

Quality of Life for Children with Persistent Sinonasal Symptoms

2003 ◽  
Vol 128 (1) ◽  
pp. 17-26 ◽  
Author(s):  
David J. Kay ◽  
Richard M. Rosenfeld
Keyword(s):  
Quality Of Life ◽  
Clinical Care ◽  
Longitudinal Change ◽  
Good Test ◽  
Routine Clinical Care ◽  
Before And After ◽  
The Mean ◽  
The Individual ◽  
Sinonasal Symptoms

OBJECTIVE: The goal was to validate the SN-5 survey as a measure of longitudinal change in health-related quality of life (HRQoL) for children with persistent sinonasal symptoms. DESIGN AND SETTING: We conducted a before and after study of 85 children aged 2 to 12 years in a metropolitan pediatric otolaryngology practice. Caregivers completed the SN-5 survey at entry and at least 4 weeks later. The survey included 5 symptom-cluster items covering the domains of sinus infection, nasal obstruction, allergy symptoms, emotional distress, and activity limitations. RESULTS: Good test-retest reliability ( R = 0.70) was obtained for the overall SN-5 score and the individual survey items ( R ≥ 0.58). The mean baseline SN-5 score was 3.8 (SD, 1.0) of a maximum of 7.0, with higher scores indicating poorer HRQoL. All SN-5 items had adequate correlation ( R ≥ 0.36) with external constructs. The mean change in SN-5 score after routine clinical care was 0.88 (SD, 1.19) with an effect size of 0.74 indicating good responsiveness to longitudinal change. The change scores correlated appropriately with changes in related external constructs ( R ≥ 0.42). CONCLUSIONS: The SN-5 is a valid, reliable, and responsive measure of HRQoL for children with persistent sinonasal symptoms, suitable for use in outcomes studies and routine clinical care.

scholarly journals General psychopathology links burden of recent life events and psychotic symptoms in a network approach

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Linda T. Betz ◽  
◽  
Nora Penzel ◽  
Lana Kambeitz-Ilankovic ◽  
Marlene Rosen ◽  
...  
Keyword(s):  
Life Events ◽  
Childhood Trauma ◽  
Negative Symptoms ◽  
Psychotic Symptoms ◽  
Network Approach ◽  
General Psychopathology ◽  
Recent Onset ◽  
Syndrome Scale ◽  
Before And After ◽  
The Individual

AbstractRecent life events have been implicated in the onset and progression of psychosis. However, psychological processes that account for the association are yet to be fully understood. Using a network approach, we aimed to identify pathways linking recent life events and symptoms observed in psychosis. Based on previous literature, we hypothesized that general symptoms would mediate between recent life events and psychotic symptoms. We analyzed baseline data of patients at clinical high risk for psychosis and with recent-onset psychosis (n = 547) from the Personalised Prognostic Tools for Early Psychosis Management (PRONIA) study. In a network analysis, we modeled links between the burden of recent life events and all individual symptoms of the Positive and Negative Syndrome Scale before and after controlling for childhood trauma. To investigate the longitudinal associations between burden of recent life events and symptoms, we analyzed multiwave panel data from seven timepoints up to month 18. Corroborating our hypothesis, burden of recent life events was connected to positive and negative symptoms through general psychopathology, specifically depression, guilt feelings, anxiety and tension, even after controlling for childhood trauma. Longitudinal modeling indicated that on average, burden of recent life events preceded general psychopathology in the individual. In line with the theory of an affective pathway to psychosis, recent life events may lead to psychotic symptoms via heightened emotional distress. Life events may be one driving force of unspecific, general psychopathology described as characteristic of early phases of the psychosis spectrum, offering promising avenues for interventions.

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