It has been suggested that glycosaminoglycans are involved in the pathogenesis of liver fibrosis. Furthermore, recent studies have reported that one of them, hyaluronate, was mainly taken up and degraded by the liver. Using an enzymoimmunological assay, based on hyaluronate-hyaluronectin interaction, serum levels of hyaluronate were measured in 113 patients with various liver diseases. Patients were divided into six groups according to clinical, biological and histological data: Group 1-alcoholic cirrhosis (n = 47) including alcoholic cirrhosis with alcoholic hepatitis (n = 24); Group 2-primary biliary cirrhosis (n = 21); Group 3-cirrhosis related to viral hepatitis (n = 10); Group 4-idiopathic hemochromatosis (n = 17); Group 5-alcoholic fatty liver (n = 8); and Group 6-viral or drug acute hepatitis (n = 10). Ninety-four blood donors were studied as controls. Levels of hyaluronate were found to be strikingly elevated in Group 1 (1,225 +/- 1,137 micrograms per liter), Group 2 (792 +/- 739 micrograms per liter), Group 3 (649 +/- 373 micrograms per liter), and Group 4 (246 +/- 242 micrograms per liter), whereas patients in Group 5 (94 +/- 63 micrograms per liter) and Group 6 (73 +/- 57 micrograms per liter) had values close to controls (23 +/- 17 micrograms per liter). There was a significant correlation between serum hyaluronate and serum albumin, prothrombin time, factor V concentration and serum gamma-globulins. It is suggested that hyaluronate levels reflect both active fibrosis and hepatic failure and may be a quantitative marker of severity of hepatic injury.

Adult↗

PubMedDate not supplied

Hyaluronan digestion and synthesis in an experimental model of metastatic tumour.

To approach the question of hyaluronan catabolism in tumours, we have selected the cancer cell line H460M, a highly metastatic cell line in the nude mouse. H460M cells release hyaluronidase in culture media at a high rate of 57 pU/cell/h, without producing hyaluronan. Hyaluronidase was measured in the H460M cell culture medium at the optimum pH 3.8, and was not found above pH 4.5, with the enzyme-linked sorbent assay technique and zymography. Tritiated hyaluronan was digested at pH 3.8 by cells or cell membranes as shown by gel permeation chromatography, but no activity was recorded at pH 7 with this technique. Hyaluronan was digested in culture medium by tumour slices, prepared from tumours developed in nude mice grafted with H460M cells, showing that hyaluronan could be digested in complex tissue at physiological pH. Culture of tumour slices with tritiated acetate resulted in the accumulation within 2 days of radioactive macromolecules in the culture medium. The radioactive macromolecular material was mostly digested by Streptomyces hyaluronidase, showing that hyaluronan was its main component and that hyaluronan synthesis occurred together with its digestion. These results demonstrate that the membrane-associated hyaluronidase of H460M cells can act in vivo, and that hyaluronan, which is synthesised by the tumour stroma, can be made soluble and reduced to a smaller size by tumour cells before being internalised and further digested.

Animals↗

PubMedDate not supplied

Lysosomal hydrolases in long term cultures of human gliomas: total enzyme activities and rate of extracellular accumulation.

A number of investigations have suggested a fundamental role for lysosomal enzymes in growth control of normal cells and in the loss of growth control which occurs in neoplasia and in cell cultures transformed by oncogenic viruses. In this investigation total enzyme activities and rates of extracellular accumulation of enzyme were measured in long term cultures of gliomas and normal human astrocytes. Marked differences were found between the cultures with regard to total enzyme activity. Exocytosis rates of the enzymes also showed differences, with one group of tumours demonstrating low or intermediate rates and another smaller group with high rates. There was no positive correlation between the enzyme profile of the cultures and their tumorigenicity in nude mice.

Acetylglucosaminidase↗

PubMedDate not supplied

Effects of diabetes and insulin treatment of diabetic rats on hyaluronan and hyaluronectin production in injured aorta.

The present study was conducted to determine the effect of diabetes with and without insulin treatment on the production of hyaluronen (HA) and distribution of hyaluronectin (HN) in the rat aorta 14 days after injury with a catheter balloon. Injury increased intima-media wet weight (+11%) and DNA content (+37.5%). This increase was slightly enhanced in untreated diabetic rats (+14.7% for wet weight and +48.9% for DNA content) and was significantly greater in diabetic rats treated with insulin (+28.9% for wet weight and +54% for DNA content). HA content increase in the injured aorta of nondiabetic rats (+43.6%) was similar in untreated diabetic (+44.7%) and more pronounced in diabetic rats treated with insulin (+91.3%). HA was markedly expressed in the neointima of nondiabetic rats, particularly near the lumen of the aorta. In untreated diabetic rats, HA was present throughout the neointima and not mainly close to the lumen. HA staining in the neointima of diabetic rats treated with insulin was similar to that in nondiabetic rats. HN was strongly expressed throughout the neointima of all groups. Injury enhanced the production of a high molecular mass HN (>400 kDa); this was not observed either in untreated or in insulin-treated diabetic rats. In conclusion, insulin treatment promoted the proliferative response of aorta to injury and this was associated mainly with increased HA production. This finding suggests that HA, which has been shown to play a crucial role in smooth muscle cell proliferation and migration, may be involved in the promoting effect of insulin treatment on arterial wall reaction to injury.

Animals↗

PubMedDate not supplied

[Methods for study of soluble antigens in pathological anatomy].

The authors restate their personal researches about several antigen systems, viz. ACE, neurospecific antigens. They point out the complementarity of immunochemistry and immunohistochemistry which implicates a very precise methodology and utilization of rigorously monospecific immune serums with regard to the studied antigen. This conduces to reproducible, responsive and reliable techniques in optic microscopy but much less easily so in electron microscopy. These techniques are still partly experimental; but their application to the study of pathological tissues and especially of tumors may however be considered. The identification of histological types and the correlated evolution is suggested on hand of concrete examples.

Adenocarcinoma↗

PubMedDate not supplied

Simultaneous quantitation of cytokine mRNAs in interleukin-1 beta stimulated U373 human astrocytoma cells by a polymerisation chain reaction method involving co-amplification with an internal multi-specific control.

The measurement of cytokine mRNA levels is of fundamental importance in the understanding of diverse pathological states. We present a simplification of a polymerase chain reaction-based technique which permits the simultaneous measurement of up to 20 cytokine mRNAs, together with those of several other cellular products, including beta 2-microglobulin and beta-actin. The technique makes use of internal standards bearing multiple PCR primer sites which are identical to those on the mRNAs to be assayed. Known quantities of the standards are added to the cellular RNA and the mixture is co-reverse transcribed and co-amplified. The simplifications described here are based on the fact that each pair of amplicons accumulates in a constant ratio even in the plateau phase of amplification. As a result, no preliminary experiments to determine the limits of the exponential phase of amplification are necessary; the same number of cycles may be chosen for all the mRNAs to be measured, whatever their level in the mixture might be; pipetting errors are avoided since all calculations are based upon the relative quantities of co-amplified material. Here we illustrate the method through a quantitative study of the expression of cytokine mRNAs in U373 human astrocytoma cells before and after stimulation with IL-1 beta. Quantitation was carried out either by incorporating radioactivity in the amplicons or by fluorescence measurements after propidium iodide staining. Only very low numbers of transcripts for IL-6, IL-8, CSF-1, MCP-1 and either Gro alpha or Gro beta were detectable in unstimulated cells. The levels of these cytokine mRNAs increased dramatically following IL-1 beta stimulation and, in addition, transcription of IL-1 beta, TNF alpha, GM-CSF, G-CSF, Gro gamma and MCP-1, some of which have not previously been detected in U373, was initiated in the stimulated cells. At the same time we found that transcripts for IL-2, IL-3, IL-4, IL-5, IFN gamma, huMlP1 alpha and huMlP1 beta were totally absent in this cell line. These results suggest a potentially important role for astrocytes in the local amplification of inflammatory responses in the brain.

Astrocytes↗

PubMedDate not supplied

In vitro immunological activity of a dextran-boronated monoclonal antibody.

Explore the source record for details and available documents.

Antibodies, Monoclonal↗

PubMedDate not supplied

[Immunocytochemical localization of gliofibrillary proteins (GDAP) in human cerebral tumors. Histological and in vitro studies].

On the basis of studies utilizing antibody to GFAP (glial fibrillary acidic protein) in the indirect immunofluorescent and immunoperoxydase methods we report the presence of GFAP in 5 astrocytomas, 1 ependymoma and 1 medulloblastoma. The GFAP was evidenced on cryostat sections of frozen material and in short-term tissue culture. Five others tumors including 1 oligodendrocytoma, 1 choroid-plexus papilloma, 1 meningioma and 2 secondary sarcomas were negative. Possible applications of antibodies to GFAP for localization and therapy of brains tumors were considered.

Antigens↗