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Biomedical subjects

I Lorenzen

Publications and source records attributed to I Lorenzen.

At least 127 records · Page 7Linked to original sources

Giant-cell arteritis, temporal arteritis and polymyalgia rheumatica. A retrospective study of 63 patients.

The initial clinical symptoms, the course of the disease, and the effect of corticosteroid treatment have been analyzed in a retrospective study of 63 patients with temporal arteritis or polymyalgia rheumatica. The relationship between the physical examination of the temporal regions, the ophthalmological examination, and biopsy from the temporal artery with respect to the diagnostic value were examined. Histological examination of biopsy specimens from the temporal artery in 58 patients revealed arteritis in 46. Half of the patients had only local symptoms from the temporal regions; one fourth presented such symptoms as well as myalgias, and one fourth had myalgias only. Patients presenting local symptoms of temporal arteritis as well as of myalgias had always had myalgias as the initial symptom and developed local symptoms of temporal arteritis 1-24 months later. Permanent reduction of vision occurred in 20% of the patients. Symptoms of generalized arteritis were observed in several patients. The overlapping of the clinical symptoms, the positive biopsy findings in patients with polymyalgia rheumatica as the only local symptom and the identical reaction to corticosteroid treatment support the conception of temporal arteritis and polymyalgia rheumatica as two manifestations of the same disease. The physical and the ophthalmological examinations were of limited diagnostic value. Positive biopsy findings were seen in 25 patients with noraml palpatory findings, and in 46 patients without eye symptoms the ophthalmoscopic examination revealed no signs of arteritis. If the first biopsy from the temporal artery is negative, biopsy from the contralateral temporal artery should be performed. Correctly timed corticosteroid treatment in adequate doses can prevent reduction of vision in giant-cell arteritis. The treatment is a long-term therapy, its average duration in the present study being more than two years.

Adrenal Cortex Hormones↗

Cyclophosphamide effect on collagen metabolism in granulation tissue, skin, and aorta of rats.

Granulation tissue was produced in rats by subcutaneous implantation of viscose cellulose sponges. Cyclophosphamide 10 mg/kg was given daily intraperitoneally to 15 rats from the day of sponge implantation. Fifteen rats served as pair-fed controls, and 15 rats served as non-starved controls. After 14 days of treatment the animals were decapitated. Groups of 3 rats were given 50 muci 14C-proline intraperitoneally 1, 3, 6, 12, or 24 hours before death. The aorta, skin, and granulation tissue were examined. Cyclophosphamide caused no effect on collagen of the aorta, while in skin, the only detectable effect was a decrease in 14C-OH-proline biosynthesis. In granulation tissue, cyclophosphamide caused a fall in the dry weight, a decrease in 14C-proline uptake and 14C-OH-proline synthesis, as well as an increase in the alpha-amino nitrogen to OH-proline ratio in purified collagen. These results indicate that cyclophosphamide inhibits the synthesis of proteins, including collagen, and inhibits the hydroxylation of proline in collagen. No effect of cyclophosphamide could be detected on the amount of salt soluble OH-proline or on collagen cross-linking. The registered effects of cyclophosphamide on granulation tissue is probably of importance with regard to the anti-inflammatory action of cyclophosphamide. This action as well as the tissue differences in the sensitivity of cyclophosphamide may be of relevance to the clinical application of cytostatics in rheumatological diseases.

Animals↗

Transfer factor, sarcoidosis and cellular immunity.

A 27-year-old man with disseminated sarcoidosis was treated with repeated injections of Transfer Factor. Grossly abnormal immunological in vitro parameters were normalized, but in spite of these changes the clinical condition deteriorated.

Adult↗

Glucocorticoid and starvation effect on glycosaminoglycans in vascular connective tissue. Biochemical studies on repair processes in rabbit aorta.

Male rabbits were injured by a single mechanical dilatation injury of aorta and then injected with prednisone 2 mg/kg or saline for 14 days or subjected to starvation. The biosynthesis of the sulfated glycosaminoglycans as evaluated by the uptake of 35S-sulfate and the content of the glycosaminoglycans were measured on the intima-media layer of the descending thoracic aorta. The results indicate that prednisone may inhibit the biosynthesis of heparan and/or dermatan sulfate while starvation increases the biosynthesis of all the sulfated glycosaminoglycans. No alterations were observed in the total amount of glycosaminoglycans in aorta following glucocorticoid injection or starvation. The metabolism of aortic glycosaminoglycans during repair is less sensitive to the action of prednisone than in undamaged aorta. This contrasts with the effect of prednisone on the metabolism of aortic collagen.

Animals↗

Cytostatic treatment of glomerular diseases. III. A double-blind cross-over study of the effect of cyclophosphamide report from a copenhagen study group of renal diseases.

Fifty patients with renal glomerular diseases entered a double-blind cross-over study on the effect of cyclophosphamide; 38 had received neither corticosteroids nor cytostatic drugs before joining the study. Cyclophosphamide was given for 4 months in doses decreasing from 3 to 1.5 mg/kg b.wt. Cyclophosphamide caused a 46% decrease in the 24-hour excretion of urinary protein and a decrease in serum creatinine within the normal range. Albumin, transferrin and IgA in urine, as well as albumin clearance and the sieving coefficient of albumin, changed parallel to the total urinary protein. The initial values of proteinuria and serum complement were of prognostic significance for the effect of cyclophosphamide in serum creatinine. We were unable to demonstrate a prognostic significance for the variables: clinical diagnosis, renal histology, arterial BP, initial values of serum creatinine and IgG, IgA and IgM in serum and urine. ESR appeared to be the most reliable acute phase reactant. No differences were found between the changes in renal histology during cyclophosphamide or placebo.

Administration, Oral↗

The effects of cyclophosphamide and azathioprine on collagen in skin and granulation tissue in rats, and the effects of cyclophosphamide on collagen in human skin.

Granulation tissue was produced in rats by subcutaneous implantation of cellulose sponges. The effect of daily intraperitoneal injections of cyclophosphamide or azathioprine on rat skin and granulation tissue was examined after 14 and 42 days. Skin biopsies from patients with glomerulonephritis were analyzed before and after 42 days of treatment with cyclophosphamide or placebo. In the rats, cytostatic treatment caused an increase in the dry weight of the skin, and azathioprine increased the dry weight and the protein content of the granulomas. The increase in the dry weight was accompanied by a decrease in water percentage. The alpha-amino nitrogen/OH-proline ratio in purified acid soluble collagen from skin and granulation tissue increased with the dose and duration of cytostatic treatment. No effect on the aldehyde content was observed. Cyclophosphamide caused a decrease in the alpha/beta ratio in acid soluble collagen from granulation tissue, but not in the collagen from the skin. Salt soluble collagen was increased in the skin after 14 days of cytostatic treatment, but remained unchanged in the granulation tissue. In human skin cyclophosphamide caused no statistically significant changes in the amount of salt soluble or total collagen. It is concluded, that daily treatment of rats with cyclophosphamide or azathioprine from 14 to 42 days seems to inhibit the catabolic processes in the skin and granulation tissue, to decrease the hydroxylation of proline in collagen, and to inhibit the intermolecular cross-linking in collagen.?222

Animals↗

Glucocorticoid effect on repair processes in vascular connective tissue. Morphological examination and biochemical studies on collagen RNA and DNA in rabbit aorta.

Male rabbits were injured by a single mechanical dilatation of the aorta and then injected with prednisone 2 mg/kg saline for 14 days or starved. Morphological studies and biochemical measurements of the collagen metabolism, the content of alpha-amino nitrogen, RNA, DNA, water and fat, and the aorta to serum ratio of 125I-albumin were performed on the intima-media layer of the descending thoracic aorta. Prednisone inhibited the intimal thickening. In the media the infiltration by mononuclear cells, the proliferation and regeneration of the smooth muscle cells and the calcification were reduced. Prednisone caused a decrease in 0.45 M NaCl soluble collagen as well as in the dialysable and non-dialysable 14C-hydroxyproline fractions. The total amount of collagen, elastin and alpha-amino nitrogen was unchanged, whereas the 14C-proline incorporation in the non-dialysable protein fraction was inhibited to a greater extent than the 14C-hydroxyproline synthesis. The findings indicate that prednisone inhibits the biosynthesis of collagen, which is inhibited to a greater extent than the general protein synthesis. Prednisone increased the dialysable to non-dialysable 14C-hydroxyproline ratio consistent with a relative increase in the catabolism of newly synthesized collagen. The aortic content of RNA and DNA was reduced consistent with the inhibition of protein synthesis and cell proliferation. Finally prednisone decreased the aortic content of water when related to the wet weight and increased the aortic content of fat. The aorta to serum ratio of 125I-albumin was not influenced by prednisone. It is concluded that administration of glucocorticoid for 14 days exerts an inhibitory action on the histological reaction to injury as well as on the biosynthesis of collagen of the repair processes in vascular connective tissue. A comparison with the effects of prednisone on undamaged rabbit aorta (Manthorpe et al. 1974) demonstrates that the metabolism of collagen of vascular connective tissue during repair is more sensitive to the antianabolic effects of prednisone than collagen in the non-injured aorta. Starvation caused an increase of the aortic percentage of water but otherwise had no influence on the repair processes in the vascular connective tissue.

Animals↗