Search PubMed⌕ Search

Biomedical subjects

I Mandl

Publications and source records attributed to I Mandl.

At least 37 records · Page 2Linked to original sources
PubMed1983

Glycosaminoglycan synthesis in bleomycin-induced pulmonary fibrosis: biochemistry and autoradiography.

At 5, 15, and 45 days following induction of interstitial pulmonary fibrosis by intratracheal administration of bleomycin in hamsters, glycosaminoglycan synthesis was measured, using [35S]sulfate. Total labeled sulfate incorporation into lung glycosaminoglycans was maximally increased over that of saline-instilled controls at 5 days (P less than or equal to 0.05), declined markedly at 15 days, and returned to control values at 45 days. Separation of the various labeled glycosaminoglycans by chondroitinase digestion and chromatography revealed a transient rise from controls (P less than or equal to 0.05) in the proportion of labeled chondroitin 4-sulfate at 5 days, followed by an increase from controls (P less than or equal to 0.05) in proportionate labeling of dermatan sulfate at 15 and 45 days postbleomycin. Autoradiography, using [35S]sulfate, performed at 21 days postbleomycin, revealed an increase from controls in film grain formation in areas of interstitial reaction. Grain formation was greatly reduced by pretreatment of the slide sections with hyaluronidase and chondroitinase, demonstrating the specificity of the label for glycosaminoglycans. The results indicate that glycosaminoglycan synthesis is significantly altered from normal in this model of interstitial lung disease and that dermatan sulfate is preferentially synthesized during the fibrotic phase of the lung reaction.

Animals↗
PubMed1983

Glycosaminoglycan synthesis in endotoxin-induced lung injury.

Endotoxin-induced lung injury has previously been shown to produce lesions that resemble emphysema morphologically and biochemically as demonstrated by the reduction in the content of lung elastin. The purpose of this study was to define the changes in one other connective tissue component, glycosaminoglycans, during the acute phase of the lung injury. Intravenous administration of a single dose of endotoxin in rats resulted in an increase in the total synthesis of glycosaminoglycans by the pulmonary parenchyma. There was a significant increase in the proportion of dermatan sulfate synthesized during the first 48 hr and a concomitant decrease in heparin/heparan sulfate synthesis. At 48 hr the increased synthesis of dermatan sulfate had reached 7.3 times control values and began to decline, whereas the synthesis of chondroitin-4-sulfate rose from 4.1 to 10.7 times control values between 48 and 72 hr. Analysis of the rates of synthesis revealed that the total amount of heparin/heparan sulfate remained constant while the synthesis of chondroitin-6-sulfate increased proportionally to the overall synthesis of glycosaminoglycans. These findings indicate that dramatic changes in glycosaminoglycan synthesis are an integral part of endotoxin lung injury.

Animals↗
PubMed1982

A simple procedure for the isolation of pulmonary parenchyma free of major blood vessels and airways for biochemical studies.

A new method of preparation of lung parenchyma free from small and medium sized airways and blood vessels is described. The lung is frozen in the inflated state and cut into thin slices to facilitate visualization and separation of large blood vessels and airways. With the aid of a special steel brush mounted on a kitchen blender most of the smaller as well as medium sized blood vessels and airways are easily shaved off and subsequently separated from the parenchyma by sieving through a 20-mesh sieve. The fall-through portion consists almost entirely of alveoli. Amino acid analysis of elastin separated from the sieved fragments is similar to lung parenchymal elastin isolated and dissected from fresh lung tissue.

Animals↗
PubMed1982

Bacterial collagenases and their clinical applications.

Clostridium histolyticum cultures secrete a specific collagenase which can be precipitated from the medium in relatively large amounts. The enzyme is a metalloproteinase capable of cleaving native collagen types I, II, III, IV and V. In addition to being a valuable tool in the laboratory the bacterial collagenase has found clinical applications in the treatment of third degree burns and decubitus, diabetic or arterial ulcers. Several cases of successful topical use of the crude enzyme in an ointment base are illustrated. More recently direct injection of a highly purified form of the enzyme has been proposed in the treatment of herniated discs and keloids and as an adjunct in vitrectomy. Preliminary results of the two latter interventions are described.

Animals↗
PubMed1981

Heparin facilitates the extraction of tissue fibronectin.

Extraction of fibronectin from two human tissues, lung parenchyma and placental villi, was facilitated by the incorporation of heparin into extraction media. The effect of heparin was additive to the effect of urea which is known to extract fibronectin. These experiments provide further evidence that fibronectin and glycosaminoglycans are associated in connective tissues and the use of heparin forms the basis for a simple method for extraction and quantitation of tissue fibronectin.

Dermatan Sulfate↗
PubMed1981

Separation of elastin components by thin layer chromatography and electrophoresis.

Several methods are described which employ thin layer chromatography and electrophoresis for investigations into the structure and synthesis of crosslinked elastin. These procedures are more sensitive and involve less elaborate equipment than separation on paper. The methods described include an electrophoretic procedure for detecting the cross-linking amino acids in elastin hydrolysates, a method for completely separating desmosine, isodesmosine and merodesmosine in these hydrolysates, and a method for producing two-dimensional peptide maps of elastase digests of elastin.

Amino Acids↗
PubMed1980

Human basement membrane antigens from lung, placenta and kidney.

Three human basement membranes, glomerular basement membrane (GBM) from renal cortex, alveolar basement membrane (ABM) from lung parenchyma and trophoblast basement membrane (TBM) from the terminal villi of placenta have been isolated by sieving and sonication techniques. Canine GBM and ABM were also prepared. There were marked differences among the membranes from human tissues. Compared to GBM, TBM had very little collagen but contained high concentrations of charged amino acids. ABM was intermediate in composition between GBM and TBM and contained desmosine and isodesmosine indicative of the presence of elastin. Canine ABM (c-ABM) did not contain desmosine or isodesmosine. In the canine system an antigen was detected in ABM which was not present in GBM. The membrane preparations were analyzed for fibronectin content using a specific antiserum to fibronectin. This glycoprotein could not be detected in GBM whereas it was present in ABM in amounts up to 0.8% and in TBM in amounts as high as 7.2%. All the membranes induced the formation of precipitating antibodies in rabbits. Soluble material obtained from the membranes by alkali extraction, reduction of disulfide bonds, enzymatic digestion with elastase, plasmin or collagenase provided immunologically reactive fragments. These soluble fragments gave reactions of identity among the three basement membranes in immunodiffusion reactions in gels with antisera raised to all three BMs. The finding that plasmin digests basement membranes suggests that it may play a role in connective tissue remodeling. The fact that elastase degrades basement membranes provides an endogenous system for injury which may be triggered by infections.

Amino Acids↗