PubMed Health⌕ Search

Biomedical subjects

T Ammitzbøll

Publications and source records attributed to T Ammitzbøll.

At least 19 recordsLinked to original sources
PubMed1991

Collagen and uronic acid distribution in the human sclera.

In the normal adult eye the content of uronic acid, hydroxyproline, hydroxylysine and proline from different parts of sclera was examined. Scleral samples from the posterior eyeball showed a higher content of uronic acid than the scleral samples from papilla, equator and limbus. Apart from a lower concentration of hydroxyproline in sclera from equator, no major differences in concentration of hydroxyproline, hydroxylysine or proline was found in sclera samples.

Aged↗
PubMed1991

The effect of hyaluronic acid on cartilage in the immobilized rabbit knee.

Out of 30 adult rabbits, 20 had one knee immobilized with a plaster of Paris cast for 6 or 12 weeks, and 10 rabbits were used as untreated controls. Prior to immobilization, 10 knees were injected with high-molecular weight hyaluronic acid. The articular cartilage of the femoral condyles was studied by light microscopy, whereas that of the patella and tibia was analyzed biochemically. Degenerative changes of the articular cartilage similar to those seen in arthrosis were observed after 6 weeks. The intraarticular injection of hyaluronic acid did not prevent these changes; instead, the reparative processes seemed inhibited.

Animals↗
PubMed1990

Regional glycosaminoglycans composition of the human sclera.

Human sclera from different parts of the normal adult eye was analyzed for content of uronic acid and the distribution of specific glycosaminoglycan types. Uronic acid is widely determined as representative of glycosaminoglycans in biological substances and variations of about 2-fold were found. Differences of up to 50% were detected in the relative abundance of hyaluronic acid and of dermatan sulphate, depending on the site on the globe from which the sample was taken. Sclera from around the papilla was found to be rich in content of dermatan sulphate. Sclera from the posterior eyeball showed a higher percentage of chondroitin sulphate as compared with sclera from equator and limbus. Equatorial sclera was richer in hyaluronic acid than posterior sclera. Sclera from the posterior eyeball showed a higher content of uronic acid as compared with sclera from equator and limbus. This work is an addition to the understanding of the scleral biochemistry and this finding may have some relevance in connection with ocular disease, as the proteoglycans and their content of glycosaminoglycans play a key role in the regulation of collagen fibril assembly and in the biomechanical strength of collagen fibrils.

Aged↗
PubMed1988

Electrically-induced collagen calcification in pig skin. A histopathologic and histochemical study.

Deposition of calcium salts on collagen fibres in skin of fully anaesthetized pigs was induced by exposure to direct current (d.c.). In biopsies obtained from cathode areas successively from day 1 to day 7 after exposure the histopathologic and histochemical changes before and after the initial deposition of calcium salts have been examined. For comparison skin sites with intradermal injected calcium hydroxyapatite crystals were studied in addition. Small areas of calcified collagen and elastic fibres were noted in viable tissue 2 days after d.c. exposure. In succeeding days the calcified areas enlarged with new deposits always more superficial and closer to the epidermis than the original calcium deposits. Preconditions for calcification appear to be (1) a pH change in basic direction and/or the electrochemical processes specific to the cathode area and (2) a viable tissue. Elastic fibres appear to have a lower calcification threshold than collagen fibres. A positive staining for glycoproteins (PAS) and glycosaminoglycans (alcian blue pH 2.5) was noted in the calcified collagen fibres simultaneously with the calcification. In succeeding days the intensity of the staining reactions increased. Whether changes in the glycoproteins, collagen and its intimately bound glycosaminoglycans precede the calcification or the staining reactions develop secondarily to this deposition is not known. However, seven days after intradermal injections of Ca-apatite crystals in pig skin small and large crystals were observed ultrastructurally without any relation to collagen fibrils, but the calcified tissue presented a positive PAS and alcian blue reaction from day 2. Thus the PAS and alcian blue stainings in this model develop secondary to the deposition of calcium salts.

Animals↗
PubMed1988

Excretion of urinary collagen metabolites correlates to severity of pulmonary disease in cystic fibrosis.

The urinary excretion of collagen metabolites (hydroxylysine, hydroxyproline and proline) was significantly increased in 10 patients with cystic fibrosis and chronic broncho-pulmonary Pseudomonas aeruginosa infection as compared with 14 age matched controls. The increase was significantly correlated to impaired pulmonary function (FVC and FEV1). The results indicate that urinary collagen metabolites reflect degradation of lung connective tissue and may be an indicator of the severity of pulmonary disease in cystic fibrosis. Parts of the excreted hydroxyproline may be degradation products of elastin.

Adolescent↗
PubMed1988

Glycosaminoglycans in human breast cancer.

Abnormal concentrations of glycosaminoglycans (GAG) have been reported for various types of tumors, suggesting that they may play a role in neoplasia. The correlation between the content of individual GAGs was studied in breast tumor tissues. The total content of GAG was estimated by uronic acid analysis. The relative distributions of dermatan sulphate, heparan sulphate, hyaluronic acid and chondroitin sulphate were measured after cellulose acetate electrophoresis. Mammary tissue samples were obtained at the time of surgery from 11 women, 6 with fibroadenomata and 5 with carcinoma. From each patient, biopsies were obtained centrally in the tumor and perilesional areas adjacent to the tumor, and also from clinically uninvolved tissue in the same region. In the central areas, it was found that carcinoma had a significant increase in chondroitin sulphate and uronic acid content, and a significant decrease in dermatan sulphate content, as compared with fibroadenoma. The chondroitin sulphate content in perilesional carcinomatous tissue was significantly greater than in clinically uninvolved tissue.

Adenofibroma↗
PubMed1988

Serum and urinary aminoterminal type III procollagen peptide in progressive systemic sclerosis: relationship to sclerodermal involvement, serum hyaluronan and urinary collagen metabolites.

Increased serum values of aminoterminal type III procollagen peptide and hyaluronan (hyaluronate) and enhanced urinary content of hydroxyproline and hydroxylsine containing polypeptides were demonstrated in patients with progressive systemic sclerosis (PSS). The serum propeptide level and the relative urinary excretion of hydroxyproline as polypeptides were related to the extent of cutaneous involvement. Elevated serum propeptide and hyaluronan values were seen in patients who progressed within the following 6 months. Patients with CREST syndrome had normal propeptide values. Reduced renal propeptide clearance is a likely cause of high serum levels of propeptide degradation products demonstrated in PSS. Serum propeptide seems to be a useful novel marker for disease activity and progression in PSS because of its linkage to the actual connective tissue metabolism.

Adult↗
PubMed1987

Bioavailability of D-penicillamine in relation to gastrointestinal involvement of generalized scleroderma.

The bioavailability of D-penicillamine was measured in 24 patients with generalized scleroderma (Progressive Systemic Sclerosis, PSS). Esophageal changes characteristic of generalized scleroderma were present in 15 of the patients, and 3 of those patients had duodenal involvements as well. The plasma concentrations of D-penicillamine were measured at 0 h, 1 h, 2 h, and 4 h after an oral dose of 300 mg D-penicillamine. Patients with duodenal and/or esophageal changes specific for scleroderma had significantly lower bioavailability of D-penicillamine than scleroderma patients without gastrointestinal manifestations. The decreased plasma D-penicillamine in scleroderma patients with involvement of the gastrointestinal tract may be due to an increased degradation of D-penicillamine in the gastrointestinal tract and/or an impaired absorption of the drug. Since the plasma level of D-penicillamine is so sensitive to pathological changes of the gastrointestinal tract, it may be advisable to adjust the dose of D-penicillamine on the basis of measurements of the plasma concentration of D-penicillamine.

Administration, Oral↗
PubMed1986

Enterocyte-labelling index in the duodenal mucosa of patients with progressive systemic sclerosis (PSS).

Ten patients with progressive systemic sclerosis (PSS), 4 patients with other gastro-intestinal diseases and 5 normal controls, underwent small intestinal biopsy procedure. The biopsy material was incubated with tritiated thymidine and processed for auto-radiography. The labelling index (LI) in the small intestinal mucosa was estimated. The LI in PSS patients with duodenal involvement was significantly higher than the LI in PSS patients without duodenal involvement. In the latter group, the LI was at the same level as in normal controls. The LI in patients with other gastro-intestinal diseases, with diarrhoea as a main symptom, was not significantly different from the LI found in duodenal PSS.

Adult↗
PubMed1986

Bioavailability of D-penicillamine in a patient with gastrointestinal progressive systemic sclerosis.

D-penicillamine pharmacokinetics were studied in a patient with gastrointestinal progressive systemic sclerosis possibly complicated by malabsorption. D-penicillamine bioavailability was examined after oral, duodenal, intravenous and rectal administration. No D-penicillamine was detectable in plasma after administration to the gastrointestinal tract. The pharmacokinetics after intravenous administration agreed closely with the corresponding situation in healthy volunteers.

Administration, Oral↗
PubMed1986

Collagen components in the duodenal and rectal mucosa in progressive systemic sclerosis and other diseases.

Small intestinal mucosa from 14 patients suffering from progressive systemic sclerosis and 22 patients with various other diseases was analysed for collagen components. There was no significant difference in the concentration of hydroxyproline, hydroxylysine and proline between the two groups. Rectal mucosa from 11 progressive systemic sclerosis patients, 5 patients with ulcerative colitis and 7 patients with various other diseases was analysed for collagen components. No significant difference was demonstrated in the concentration of hydroxyproline, hydroxylysine and proline between progressive systemic sclerosis patients and patients with various other diseases, but in patients with ulcerative colitis the concentration of hydroxyproline, hydroxylysine and proline were found to be significantly lower than in the two other groups.

Adolescent↗
PubMed1986

Non-specific binding of protein-stabilized gold sols as a source of error in immunocytochemistry.

The observation that protein-A conjugated gold sols bound to fibronectin-collagen (FNC) fibres in human fibroblast cultures prompted a series of studies on the binding of gold particles stabilized in various ways (Staphylococcal protein A, bovine serum albumin, avidin, streptavidin, gelatin, hemoglobin, polyethylene glycol (MW 20 000), methylcellulose and the nonionic detergent Tween 20) to cell and tissue components, to protein dot blots and SDS-PAGE blots on nitrocellulose paper. We found that binding of gold particles to certain cell and tissue components and to various immobilized proteins did occur irrespective of the stabilizing agent. We argue that, albeit gold sols are stabilized against salt coagulation by adsorption of proteins and other stabilizing agents, "naked areas" are (constantly or intermittently) present on particle surfaces, available for interaction with cell and tissue components that have a high electrostatic affinity for the charged gold surface under prevailing experimental conditions. Non-specific binding may be reduced or abolished by competing proteins (i.e. proteins with a higher affinity for gold than any component in the object studied) provided the proteins and the gold conjugate are present concomitantly during incubation. We found gelatin (Bloom number 60-100) to be an effective competitive protein probably due to its high affinity for gold over a wide pH range. Further, gelatin did not appreciably inhibit the specific interaction in dot blots between SpA and IgG except at very low IgG concentrations. A protocol for the use of gold-protein conjugates to circumvent the hazards of unspecific gold binding is suggested.

Cell Line↗
PubMed1985

Glycosaminoglycans in localized scleroderma (morphoea).

The composition of glycosaminoglycans (GAGs) was analyzed in skin samples of eight patients suffering from localized scleroderma, i.e., three having generalized morphoea and five localized morphoea plaques. From each patients, biopsies were obtained from sclerotic and perilesional areas, and from clinically uninvolved skin of the same region. In the perilesional areas hyaluronic acid concentration was increased (p less than 0.05), while it was decreased (p less than 0.01) in sclerotic areas. Dermatan sulfate concentration was increased in the perilesional (p less than 0.05) as well as in the sclerotic (p less than 0.01) areas. Chondroitin 4/6 sulfate was increased in the sclerotic areas (p less than 0.05). Heparan sulfate showed no changes. No major differences were found in the total concentrations of uronic acid and hexosamine. This study demonstrates that changes in GAG composition in localized scleroderma follow previously described sequences of events of inflammation and fibrosis of connective tissue.

Adolescent↗