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Biomedical subjects

I Lorenzen

Publications and source records attributed to I Lorenzen.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Systemic lupus erythematosus. 1. Disease manifestations, infections, thrombotic episodes, causes of death and survival in a case load of 173 patients followed for 13.9 years].

One hundred and seventy-three patients had systemic lupus erythematosus according to the 1982-ARA-criteria. The mean disease duration at the time of the study was 16.4 years, and the patients were followed by three Copenhagen clinics for a mean of 13.9 years until 1987/88 or death. Half of the patients had nephropathy, 61 patients developed severe infections, and 39 patients had thrombotic episodes. Fifty-six patients died during the observation period, 24 due to active lupus (12 of kidney failure), 12 because of infections, and 11 because of atherosclerotic cardio-vascular disease. The patients had 10-, 15- and 20-year survival rates of 80, 65 and 48 per cent. The deaths were evenly distributed throughout the observation period.

Adult↗
PubMed1991

[Systemic lupus erythematosus. 2. Factors of predictive significance for survival].

Sixty-one of 173 patients with systemic lupus erythematosus followed for a mean of 13.9 years had severe infections which influenced their survival more than could be accounted for by the mortality (20 per cent) caused by the infections. Patients with infections had more SLE manifestations than patients without infections, and they died of lupus manifestations more often than patients without infections. Patients who went into a permanent remission and patients who died of lupus differed most markedly by the rates of infection. The rate of infection was increased more than tenfold in patients treated with high dosages of glucocorticoid compared with patients who received low dosages. Treatment with cytostatics influenced the rate of infections to a moderate degree. Nephropathy also influenced survival but half of the patients with nephropathy maintained a normal plasma creatinine in spite of the long observation period. 16 per cent of the patients with nephropathy died of kidney failure or are receiving chronic hemodialysis.

Adult↗
PubMed1991

Hepatic extraction of the aminoterminal propeptide of type III procollagen before and after bile duct ligation in pigs.

The aminoterminal propeptide of type III procollagen is extracted from the circulation by the liver, and PIIINP is found in bile. This study was performed in order to investigate whether biliary excretion contributes substantially to the hepatic extraction of circulating PIIINP. Hepatic extraction before and during a 4-h period after ligation of the common bile duct was assessed from serum PIIINP concentrations in a systemic artery, the portal vein and a hepatic vein of seven healthy anaesthetized pigs. Seven sham-operated anaesthetized pigs served as controls. Ligation of the bile duct did not cause a decrease in the hepatic extraction ratio of circulating PIIINP. The PIIINP serum levels of the cholestatic pigs and of the controls were similar throughout the investigation period. The PIIINP concentrations in bile were only 10% of the corresponding serum values. Gel filtration of sera showed that the lower PIIINP concentration in the hepatic vein, as compared to the artery and the portal vein was due to a selective decrease in the concentration of the intact propeptide. The study shows that biliary excretion does not contribute significantly to the hepatic extraction of circulating PIIINP in the normal liver. Furthermore, the hepatic extraction of circulating PIIINP preferentially affects the intact propeptide, rather than the somewhat larger PIIINP related molecule in serum.

Animals↗
PubMed1991

Type I and III procollagen propeptides in growth hormone-deficient patients: effects of increasing doses of GH.

The effect of increasing doses of growth hormone on collagen synthesis in GH-treated GH-deficient patients was determined in a short-term study. The synthesis of type I and III collagen was estimated by measurements of the carboxyterminal propeptide of type I procollagen and the aminoterminal propeptide of type III procollagen. Type I collagen is mainly found in bone and type III collagen in loose connective tissue. We observed a GH dose dependency of both procollagen propeptides. Serum type I procollagen propeptide was significantly higher following GH doses of 4 and 6 IU/day for 14 days compared with 2 IU/day (normal replacement dose) (p = 0.04). Withdrawal of GH therapy for 14 days resulted in wider variation, but not significantly different from the levels at 2, 4 and 6 IU/day. A dose dependency was found regarding type III procollagen propeptide, showing significantly higher serum concentrations at a GH dose of 4 IU/day compared with 2 IU/day (p = 0.001), and of 6 IU/day compared with 4 IU/day (p = 0.001). Withdrawal of GH therapy resulted in significantly lower type III procollagen propeptide concentrations compared with those at a GH dose of 4 and 6 IU/day (p = 0.03). Serum type III procollagen propeptide increased twice as much as type I procollagen propeptide, by 47 vs 25%, at a GH dose of 6 IU/day compared with 2 IU/day. The differences between the effects on type I and type III collagen may reflect differences in secretion or turn-over rate of collagen in bone and loose connective tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Inflammation as a basic biological mode of reaction].

The inflammatory reaction is a fundamental biological defence reaction which ensures the survival of the organism. Reaction of the organism to trauma includes local and systemic reactions which are integrated and which are often the basis for the clinical and paraclinical manifestations of disease. The reactions of the organism to trauma are, by and large, nonspecific and independent of the nature of the precipitating factor. This explains the similarity between the clinical and paraclinical manifestations in a series of inflammatory diseases. The basal inflammatory reaction pattern may be identified in apparently very different conditions: healing of wounds, infectious disease, non-infectious inflammatory disease, atherosclerosis, neoplastic disease and growth and regeneration. Identification of a series of humoral inflammation mediators and growth factors and the possibilities for direct monitoring of the inflammatory and reparative processes of connective tissue have increased the possibilities for identification of the etiological/pathogenetic factors and the possibilities for rational therapeutic pharmacological and immunological modulation of disease.

Humans↗
PubMed1990

Splanchnic and renal extraction of circulating type III procollagen aminoterminal propeptide in patients with normal liver function and in patients with alcoholic cirrhosis.

Splanchnic and renal extraction of circulating aminoterminal propeptide of type III procollagen and related antigens were studied in 12 patients with normal liver function and in 19 patients with alcoholic cirrhosis during catheterization. Type III procollagen peptide in serum was measured in two assays: the Type III Procollagen Peptide Radioimmunoassay Kit, a new assay that selectively determines the intact propeptide (and larger type III propeptide-holding antigens) and the Type III procollagen Fab assay that measures both the intact propeptide and the smaller fragments that quantitatively dominate in serum. A significant decrease in the concentration of the intact propeptide between the artery and the hepatic vein was found in the group with normal liver function (p less than 0.01) and in patients with cirrhosis (p less than 0.01). In patients with cirrhosis, however, the splanchnic extraction ratio of the intact propeptide (median = 0.04, range = -0.03 to 0.16) was significantly lower than in patients with normal liver function (median = 0.17, range = 0.05 to 0.36, p less than 0.01). The concentration of the intact propeptide in the hepatic vein was positively correlated to hepatic pressure (n = 18, r = 0.51, p less than 0.05) and inversely correlated to indocyanine green clearance (n = 15, r = -0.61, p less than 0.05). No splanchnic extraction could be demonstrated in the Type III propeptide Fab assay. A significant renal extraction was found in the Fab assay, but not in Type III Procollagen Peptide Radioimmunoassay Kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1990

Collagen distribution in developing experimentally induced granulation tissue. A morphometric study.

Viscose cellulose sponges were implanted subcutaneously on the back of full-grown Sprague-Dawley rats. Seven, 14, 21, 28, 42, 60 and 90 days after implantation, groups of 12 animals decapitated and the sponges were removed and processed for light microscopy. Five microns sections were stained with Picro-Sirius Red. Morphometry was performed on the zone of ingrowth and the collagen. The intersectional variation in the morphometrically determined collagen density within the sponges was below 20%. The hydroxyproline content was determined biochemically in 5 microns sections of sponges implanted for 14, 42, 60 and 90 days. A positive correlation (rho = 0.79, p less than 0.0001) was observed between the biochemically and morphometrically determined collagen contents. The morphometric determinations showed a steady increase in the granulation tissue ingrowth. At day 60 the ingrowth was complete. There was an increasing collagen density from days 7 and 14 through days 21 and 28, followed by a nearly steady state up to day 90 and a significantly higher collagen density peripherally than centrally in the day 42 sponges. The study has shown that morphometric collagen determination at light microscopical level using Sirius Red-stained sections may add quantitative data describing the dynamic changes in collagen content and distribution within developing granulation tissue.

Animals↗
PubMed1990

Serum aminoterminal type III procollagen peptide reflects repair after acute myocardial infarction.

In 16 patients with acute myocardial infarction and in 15 controls, procollagen type III aminoterminal peptide in serum (PIIINP) was measured consecutively. Serum PIIINP was increased on the second to third postinfarction day (p less than 0.01) and remained elevated for more than 4 months. Peak values were observed on the third to seventh postinfarction day. The individual peak changes were correlated to infarction size calculated from serum CK-MB and serum lactate dehydrogenase (p = 0.60, p = 0.02). The changes in distribution of PIIINP-related antigens in serum after gel chromatography were similar to changes observed during wound healing in humans. PIIINP is cleaved off procollagen type III during the biosynthesis of type III collagen, which characterizes the early stages of repair and inflammation. Our findings suggest that serum PIIINP reflects the repair processes and scar formation following acute myocardial infarction. The serum PIIINP alterations in acute myocardial infarction differ essentially from the changes in myocardial enzymes reflecting myocardial injury. Serum PIIINP may therefore provide new and clinically relevant information on the healing of myocardial infarction.

Adult↗
PubMed1990

Different effects of thyroid disease on serum levels of procollagen III N-peptide and hyaluronic acid.

Serum levels of procollagen III N-peptide (PIIINP) and hyaluronic acid (HA) reflect secretion of procollagen III and HA from fibroblasts, a cell type sensitive to thyroid hormones. Serum PIIINP and HA concentrations were measured in different thyroid function states, the former by two different assays, one detecting intact and aggregated PIIINP (PIIINP assay) and another detecting low mol wt degradation products of PIIINP as well (Fab-PIIINP assay). Two thirds of 28 hyperthyroid patients had elevated serum PIIINP values (mean, 192% in the PIIINP assay and 243% in the Fab-PIIINP assay) compared to age- and sex-matched controls (P less than 0.001). Normalization was seen after medical treatment (n = 16). In contrast, serum HA levels increased from 49 +/- 30 to 68 +/- 37 ng/mL (P less than 0.01) when a euthyroid state was achieved. Hypothyroid patients (n = 23) had increased serum HA levels (mean, 162%; P less than 0.05), which normalized after L-T4 treatment (71 +/- 50 before and 41 +/- 20 ng/mL after treatment (n = 16; P less than 0.02). L-T4 treatment also increased serum PIIINP levels significantly. Subjects with familial dysalbuminemic hyperthyroxinemia (n = 8), representing a situation with elevated circulating levels of T4 due to enhanced protein binding, and patients with nontoxic goiter with serum TSH levels ranging from 3.6-0.05 mU/L had normal serum levels of PIIINP and HA. Our data suggest that the secretion of procollagen III and that of HA from fibroblasts are influenced differently by thyroid hormones, since the secretion of procollagen III seems enhanced by thyroid hormones, whereas the secretion of HA seems reduced. Neither euthyroidism with enhanced serum T4 levels (familial dysalbuminemic hyperthyroxinemia) nor euthyroidism with reduced serum TSH levels (nontoxic goiter) seems associated with alterations at the connective tissue level.

Adolescent↗
PubMed1990

External thoracic duct-venous shunt in conscious pigs for long term studies of connective tissue metabolites in lymph.

An experimental animal model for lymph studies is described. Thoracic duct-venous shunt was established in 12 pigs. Shunt patency averaged 5.5 days. The composition of connective tissue metabolites in lymph and serum were investigated during a standardized surgical operation (thoracotomy) under general anesthesia. We measured the carboxyterminal propeptide of type I procollagen (PICP), the aminoterminal propeptide of type III procollagen (PIIINP) hyaluronan (HA) and total protein. During surgery/anesthesia lymph PICP (p less than 0.04), lymph PIIINP (p less than 0.03) and serum PIIINP (p less than 0.01) and serum PIIINP (p less than 0.03) increased. The changes may be explained by the inactive physical state of the animals. HA showed wide variations, with a tendency like PIIINP. In conscious animals the lymph/serum ratio of PIIINP and HA were 10 and 35, respectively, indicating that lymph is a major route of tissue clearance for these components. The lymph/serum ratio of PICP was 1.0 in conscious pigs, indicating a direct release into the circulation. Total protein in lymph decreased (p less than 0.04) during surgery/anesthesia, whereas no changes were observed in serum. Pigs can be used instead of dogs and sheep in studies on lymph. The effect of surgery/anesthesia must be taken into consideration.

Anastomosis, Surgical↗
PubMed1989

Injury and repair of smaller muscular and elastic arteries. Immunohistochemical demonstration of fibronectin and fibrinogen/fibrin and their degradation products in rabbit femoral and common carotid arteries following a dilatation injury.

Indirect immunoperoxidase staining for fibrinogen/fibrin and fibronectin was performed on normal and healing arterial tissue of muscular and smaller elastic arteries. Fibronectin was observed in the wall of the normal arteries, whereas fibrinogen/fibrin could not be demonstrated. Fibronectin was observed in the intima as well as the media deposited in a similar fashion in the femoral and carotid artery during repair. Apart from the early occurrence of fibrin/fibrinogen in the media of both arteries the distribution of fibrinogen/fibrin and degradation products differed. In the femoral artery a progressively weakening positive reaction for fibrinogen/fibrin and degradation products towards the lumen was observed in the intima and the media 7 and 14 days after the lesion. By 28 days the reaction in the media was negative. No thrombus formation was observed. In contrast, all the specimens examined from the common carotid arteries were obliterated by luminal thrombi 28 days after the lesion. The thrombus as well as the damaged intimal thickening and the compressed media were loaded with fibrinogen/fibrin and degradation products. The deposition of fibronectin, fibrinogen, and degradation products in the carotid artery was similar to that previously reported in experimental aortic arteriosclerosis in rabbits as well as in giant cell arteritis.

Animals↗
PubMed1989

Hepatic and renal extraction of circulating type III procollagen amino-terminal propeptide and hyaluronan in pig.

Hepatic and renal clearance of the amino-terminal propeptide of type III procollagen (PIIINP) and of the glycosaminoglycan, hyaluronan (HA) were investigated in a catheterization study of seven healthy anesthetized pigs. Two assays were used, in order to distinguish between the metabolism of different PIIINP-related antigens. One was the PIIINP RIA Kit, which measures the intact propeptide. The other was the PIIINP Fab assay, in which the antibody has an equal affinity to the intact propeptide and to smaller fragments, of which the latter constitutes most of the antigenic activity in serum. Hepatic and gastrointestinal extraction were evaluated from measurements of serum concentrations in the artery, the portal vein and the hepatic vein. We found a significant hepatic extraction of the intact propeptide (extraction ratio 0.14) and of HA (extraction ratio 0.23), but not of smaller PIIINP fragments. No gastrointestinal extraction of any of the tested substances could be demonstrated. Only smaller PIIINP fragments (such as the col 1 fragment) were extracted by the kidneys (the extraction ratio in the PIIINP Fab assay was 0.19). The renal extraction ratio of HA was 0.14. The amounts of PIIINP fragments and of HA extracted by the kidneys were 50- and 3-times the amounts found in urine, respectively, indicating that the col 1 fragment and HA are degraded in the kidneys in addition to urinary excretion. Our results suggest a dynamic turnover of connective tissue-related components with a fast catabolism of circulating components in liver and kidneys.

Animals↗
PubMed1988

The aminoterminal-type-III procollagen peptide and proteoglycans in serum and synovial fluid of patients with rheumatoid arthritis or reactive arthritis.

The concentrations of aminoterminal-type-III procollagen (procollagen N-) peptide, and of proteoglycans were measured in knee-joint synovial fluid and serum from patients with rheumatoid arthritis or reactive arthritis. All synovial fluids contained large amounts of intact propeptide. The synovial fluid: serum propeptide ratios were high, suggesting local propeptide liberation. A correlation was demonstrated between the propeptide concentration in synovial fluid and in serum. In rheumatoid arthritis, the propeptide concentration in synovial fluid was related to local inflammatory activity, and the serum concentration was correlated with the presence of nonspecific markers of inflammation. The presence of smaller propeptide fragments in synovial fluid indicated that some degradation occurred locally. The local metabolic changes were most prominent in patients with joint erosions. Patients with nonerosive rheumatoid arthritis and reactive arthritis had similar synovial fluid propeptide concentrations. The proteoglycan content of synovial fluid was inversely related to the degree of joint destruction, and was highest in patients with reactive arthritis. No correlation was observed between the concentrations of propeptide and proteoglycan in synovial fluid. Intraarticular glucocorticoid injection reduced the levels of propeptide and proteoglycan in synovial fluid.

Adult↗
PubMed1988

Serum aminoterminal type III procollagen peptide in inflammatory and degenerative rheumatic disorders.

Measurement of the aminoterminal type III procollagen peptide in serum has been suggested as a marker of the biosynthesis of collagen type III, a major connective tissue component in repair processes. In the present study the propeptide level correlated with the inflammatory synovial mass in rheumatoid arthritis and osteoarthritis. This implies that the propeptide level reflects the collagen type III synthesis occurring in the synovial repair processes, whether they were caused by inflammatory or degenerative rheumatic disorders. Physical activity did not enhance the transition of the propeptide from the synovial fluid or the inflamed synovial membrane to the blood. Normal serum propeptide values were observed in most patients with ankylosing spondylitis and degenerative diseases of the spine. This may reflect the lower amount of inflammatory tissue in these diseases and hence the sensitivity of the assays.

Adult↗
PubMed1988

Is the aminoterminal propeptide of type III procollagen degraded in the liver? A study of type III procollagen peptide in serum during liver transplantation in pigs.

The aminoterminal propeptide of type III collagen was monitored in serum during liver transplantation in nine pigs. The aim was to investigate whether removal of the liver causes any changes in the serum concentration of the propeptide. Another connective tissue component, hyaluronan, a glycosaminoglycan known to be degraded in the liver endothelial cells, was also measured. Removal of the liver caused a significant increase in the concentration of the intact propeptide as well as of hyaluronan. Gel filtration confirmed the increase in the amount of intact propeptide. However, another large propeptide-related antigen, eluted near the void volume, appeared in the antigen profile during the anhepatic phase. This peak probably represents the propeptide still attached to the collagen molecule (pN collagen). The findings indicate that the liver is involved in the degradation of the propeptide and of larger propeptide-holding proteins.

Animals↗
PubMed1988

Collagen type IV and procollagen type III during granulation tissue formation: a serological, biochemical, immunohistochemical and morphometrical study on the viscose cellulose sponge rat model.

The serum concentrations of collagen type IV,7S, collagen type IV,nc1, and aminoterminal type III procollagen peptide immunoreactive components were measured by means of specific radioimmunoassays during development of granulation tissue in rats. The results were compared with tissue deposition of basement membranes and interstitial collagens in the granulation as measured morphometrically. A parallel sequential pattern in tissue deposition of collagen types III and IV, and serum increase of collagen types III- and IV-related fragments, was observed. Serum collagen type IV was less sensitive as a marker for development of granulation tissue than the serum procollagen type III N-peptide. This was in accordance with a low collagen type IV/interstitial collagen ratio in the granulation tissue. However, a cross-sectional study showed that serum collagens types IV,7S and IV,nc1 may be useful as early quantitative indicators of granulation tissue formation. Simultaneously, measurement of collagen type IV- and procollagen type III N-peptide-related antigens in serum provides a differentiated reflection of the dynamic matrix processes in developing granulation tissue.

Animals↗
PubMed1988

Serum amino terminal type III procollagen peptide and serum hyaluronan in rheumatoid arthritis: relation to clinical and serological parameters of inflammation during 8 and 24 months' treatment with levamisole, penicillamine, or azathioprine.

Increased serum levels of the amino terminal type III procollagen peptide and serum hyaluronan were demonstrated in patients with rheumatoid arthritis. In patients with active disease a significant correlation was shown between serum levels of the propeptide and hyaluronan and the clinical signs of synovitis reflecting the extent of synovial inflammation. During recovery the serum propeptide and serum hyaluronan showed a delayed decline as compared with the clinical signs of synovitis and the acute phase protein response. This probably reflects the presence of persistent subclinical chronic inflammation. Normal serum propeptide levels in rheumatoid arthritis were associated with a good prognosis without progression of erosive joint lesions. Azathioprine reduced the number of patients with progression of erosive joint lesions and caused a more marked suppression of the serum propeptide than levamisole and penicillamine.

Adult↗