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Biomedical subjects

V Stanescu

Publications and source records attributed to V Stanescu.

At least 37 records · Page 2Linked to original sources
PubMed1991

Nucleolysis of the rabbit intervertebral disc using chondroitinase ABC.

The nucleolytic action of chondroitinase ABC was studied by the use of rabbit lumbar intervertebral discs. The injection of one unit of enzyme results in necrosis of the nucleus pulposus. Radiologic, histologic, and biochemical changes were evident in discs studied 2 days after injection, and consistent nucleolysis was seen in those studied after 6 days. These results show that chondroitinase ABC deserves further evaluation as a possible chemonucleolytic enzyme.

Animals↗
PubMed1990

Homozygous achondroplasia: morphologic and biochemical study of cartilage.

We have performed histochemical, immunohistochemical, electron microscopic, and biochemical studies on the upper tibial cartilage from a case of homozygous achondroplasia. The growth zone was narrow and disorganized. Columnization was absent except for a few areas with short rows of cells. Hypertrophy was reduced to scattered clusters of cells. The provisional calcification was patchy and primary trabeculae were thick and irregularly arranged. Islands of fibrous or fibrocartilagineous tissue were found along the growth zone. The matrix did not stain with safranin O and lacked metachromasia, except for pericellular rims around the hypertrophic cell clusters. Staining with antibodies against the large proteoglycan monomers and chondroitin-4-sulfate was weakly positive. Electron microscopic examination showed that only a few cells had degenerative signs. In most areas of the matrix, proteoglycan granules were absent. Areas with dense collagen fibers were seen. In contrast to the growth zone, the cartilage of the remaining epiphyses had normal histochemical, immunohistochemical, and electron microscopic appearance. The large proteoglycan monomers had a normal composition and hydrodynamic size. Type II and XI collagen, pepsin fragments of type IX collagen, and several noncollagenous proteins extracted from cartilage had a normal electrophoretic migration. It is suggested that a mutation affecting a matrix component or a regulatory pathway present only or predominantly in the growth area of the chondroepiphysis might explain the findings.

Achondroplasia↗
PubMed1990

The small proteoglycans of cartilage matrix.

The small proteoglycans (PGs) of cartilage matrix represent a small fraction of the total mass of PGs, but with a small size they can be present in equivalent moles to the large PGs. Three types of PGs with a wide skeletal and extraskeletal distribution, biglycan (PGI), decorin (PGII) and fibromodulin have distinct but homologous core proteins containing leucin-rich sequences. Carbohydrate substituants (one or two chondroitin sulfate/dermatan sulfate chains for decorin and biglycan respectively, chains of keratan sulfate for fibromodulin and oligosaccharides) present variations from tissue to tissue and with age and other factors. Decorin and fibromodulin appear to interact with collagen and to participate in the regulation of collagen matrices. In vitro experiments indicate a role for small PGs in adhesion, multiplication, differentiation, and migration of cells. Recent data on molecular biology of the small PGs contribute to a better understanding of their functions and make the evaluation of their role in hereditary diseases.

Animals↗
PubMed1990

Pseudodiastrophic dysplasia evolution with age and management. Report of two new cases and review of the literature.

Two new patients with pseudodiastrophic dysplasia are reported. Clinical and radiologic features, genetics, as well as, course and management of the disease are described for these two patients and seven others reported in the literature. Based also on histological findings, special emphasis is put on differential diagnosis with diastrophic dysplasia.

Abnormalities, Multiple↗
PubMed1988

Recessive lethal chondrodysplasia, "round femoral inferior epiphysis type".

Four cases of a sublethal form of chondrodysplasia are reported. The micromelic dwarfism is severe and on X-ray pictures the most striking feature is the shape of the lower femoral epiphysis, which is relatively well developed and rounded. The mode of inheritance is presumably autosomal recessive.

Epiphyses↗
PubMed1988

Age-related changes in small proteoglycans of low buoyant density of human articular cartilage.

Proteoglycans extracted from articular cartilage of large joints of humans aged 4, 11, 70 and 75, were fractionated on associative density gradients. The top fraction (A3) was purified by ion-exchange chromatography and subsequent gel filtration on Sepharose CL 4B in 4 M GuCl, 0.5% Triton x 100. Proteoglycans from young cartilages yielded a narrow rapid migrating band on gel electrophoresis, had a Kav of 0.43 and 0.44 on Sepharose CL 4B, a glucosamine/galactosamine ratio of 0.11 and 0.12 and a glycoprotein core rich in aspartic acid and leucine with a Mr of about 47,000. Proteoglycans from old cartilages gave a wider and slower migrating band on gel electrophoresis, had a wide peak with a Kav of 0.38 and 0.40 on Sepharose CL 4B, a glucosamine/galactosamine ratio of 5.1 and 3.2, a glycoprotein core rich in glutamic acid and glycine, and with a Mr of about 170,000-180,000. Analysis using monoclonal antibodies detected epitopes of keratarn sulfate and of hyaluronic acid binding region in the fractions from old but not in those from young cartilages. Small proteoglycans not derived from the large monomers are the major component of low-buoyant-density fractions of proteoglycans from young cartilages. Fragments of large monomers containing keratan sulfate and hyaluronic acid binding region are the major component of similar fractions from old cartilage.

Aged↗
PubMed1988

Comparative histopathology of the growth cartilage in short-rib polydactyly syndromes type I and type III and in chondroectodermal dysplasia.

The histopathology of growth cartilage of long bones was studied in two cases of chondroectodermal dysplasia (Ellis-Van Creveld syndrome), a case of short-rib polydactyly (SRP) type I (Saldino-Noonan syndrome), three cases of short-rib polydactyly (SRP) type III (Verma-Naumoff syndrome), and a case with polydactyly without other skeletal abnormalities but with visceral malformations. The lesions were qualitatively similar in chondroectodermal dysplasia and SRP I: regular concave ossification line, short, slightly irregular columns, regularly dispersed hypertrophic chondrocytes. In SRP III, the ossification line was irregular and the hypertrophic cells had a discontinuous distribution in clusters. No amylase resistant PAS intracytoplasmic inclusions were found. Short, slightly or markedly irregular primary trabeculae, some of them with wide cartilaginous cores, tongue prolongations and islands of cartilage situated along the periost were found in chondroectodermal dysplasia, SRP I and III. The case of polydactyly without other skeletal abnormalities had a normal morphology of the growth plate. These data suggest that there is a relationship between chondroectodermal dysplasia and SPR type I, and that SRP type III is distinct from SRP type I.

Ellis-Van Creveld Syndrome↗
PubMed1988

In vitro protection of the articular surface by cross-linking agents.

The effects of cross-linking agents on the resistance of the articular surface to digestion with clostridial collagenase were studied using a described in vitro system. Mouse femoral heads were treated with various concentrations of glutaraldehyde, with osmium tetraoxide and with dithiobis (succinimydil propionate), digested with the enzyme, labeled with cationized ferritin and examined by electron microscopy. Collagenase alone caused disruption of the articular surface with penetration of the large marker into the cartilage matrix. After treatment of the femoral heads with the cross-linking agents, no effects on the morphology and on the labeling of the articular surface and no penetration of the label into the cartilage matrix were observed. Increasing cross-linking at the articular surface might be a new route for therapeutic intervention. However, experiments would be needed to assess the effect of the procedure on the viability and nutrition of chondrocytes and on the functional properties of the tissue.

Animals↗
PubMed1988

[Nucleolytic action of chondroitinase ABC on the lumbar disc of the rabbit].

Nucleolysis using chondroitinase ABC was studied using the rabbit's intervertebral lumbar disc. The purpose was to find a possible alternative to chymopapain which is commonly used in the management of sciatica due to disc herniation. The injection of 1 U of the enzyme into the nucleus pulposus gave significant histological and biochemical changes in all twelve discs studied.

Animals↗
PubMed1987

Drug action on articular cartilage surface. An in vitro study using mouse femoral heads labeled with cationized ferritin.

The direct effects on the cartilage articular surface of three anti-inflammatory drugs (Diclofenac, Pirprofen and acetyl-salicylic acid) and of a polysulfated glycosaminoglycan (Arteparon), were studied using an in vitro system in which BALB-c mouse femoral heads were incubated with the drugs. After incubation and labeling of the negative charges of the articular surfaces with cationized ferritin, the femoral heads were examined by electron microscopy. In addition, the effect of the drugs on the aggressive action of collagenase on the articular surface was tested using the same in vitro system. Diclofenac, Pirprofen and the polysulfated glycosaminoglycan did not alter the structure or the charge properties of the surface. Acetyl salicylic acid produced a slight disruption of the articular surface. The drugs studied had no effect on the disruptive action of collagenase.

Animals↗
PubMed1987

Preparative electrophoresis on agarose submerged gels of two aggregating proteoglycan monomers from articular cartilage.

Analytical electrophoresis on polyacrylamide-agarose gels of aggregating proteoglycan monomers from baboon articular cartilage produces two distinct bands, corresponding to two different aggregating monomer populations. A preparative electrophoresis procedure is described for isolating the two monomers. Proteoglycans were extracted from young baboon articular cartilage in 4 M guanidinium chloride containing proteolysis inhibitors and aggregated after hyaluronic acid addition. The aggregates were separated from non-aggregated proteoglycans by isopycnic centrifugation, followed by gel chromatography on Sepharose CL-2B. The monomers of the aggregates were obtained by isopycnic centrifugation under dissociative conditions. Two monomers were separated by preparative electrophoresis on 0.8 % agarose submerged gels. Approximately 60 % of the proteoglycans were recovered from the gel using a freeze-squeeze procedure. Aliquots of the separated monomers gave single bands when submitted to analytical polyacrylamide-agarose gel electrophoresis. Their migration and appearance were similar to that of the two bands present in the non separated preparation of monomers.

Animals↗
PubMed1987

Proteoglycan electrophoresis on horizontal submerged polyacrylamide-agarose gels.

A method of proteoglycan electrophoresis on submerged horizontal polyacrylamide-agarose gels is described. Several preparations of purified proteoglycans extracted from fetal and young baboon articular cartilage and from mandibular dog-fish cartilage were analyzed. Discrete bands corresponding to proteoglycan monomers of different size were obtained. The results were similar to those obtained using the more tedious electrophoretic separation on cylindrical gel rods.

Animals↗
PubMed1987

The protein core of the largest proteoglycan monomer of articular cartilage. Gel electrophoretic pattern and tryptophanyl peptide bond cleavage.

The largest proteoglycan monomer of baboon (Papio papio) articular cartilage was isolated and the protein rich core was obtained after chondroitinase AC II and keratanase digestions. On SDS-PAGE the core yielded a single band with apparent Mr of 290,000. Tryptophanyl peptide bond cleavage of the core with N-chlorosuccinimide/urea gave 4 peptides with apparent Mr of 105,000, 66,000, 62,000 and 56,000

Animals↗
PubMed1987

Pathologic features of the femoral heads in a patient aged 14 1/2 years with spondyloepiphyseal dysplasia with osteoarthritis.

We describe a patient with spondyloepiphyseal dysplasia and precocious hip osteoarthritis. Bilateral hip arthroplasty was performed at the age of 14 1/2 years. Pathologic examination revealed severe osteoarthritic deformities: flattened and deformed femoral heads, were almost completely covered by abnormal cartilaginous, fibrocartilaginous and fibrous tissues showing intense degenerative and regenerative processes. The electron microscopic examination of chondrocytes showed large intracytoplasmic accumulations of glycogen and of microfilaments and many small vesicles suggesting intense micropinocytosis and/or microexocytosis.

Adolescent↗
PubMed1986

Acromicric dysplasia.

We describe a new type of bone dysplasia, the "acromicric dysplasia," based on the study of six patients. This dysplasia is characterized clinically by mild facial anomalies, markedly shortened hands and feet, and growth retardation that is severe in most of cases. Roentgenograms of the hands are characteristic: the metacarpals and the phalanges are short and stubby, the proximal portion of the last four metacarpals are slightly pointed with an external notch on the 2nd metacarpal and an internal notch on the 5th metacarpal, similar to pseudo-epiphysis. The shape of the epiphysis and the metaphysis of the long bones is almost normal, except for a slight deformation of the femoral heads in some patients. No signs of visceral storage were found, which rules out geleophysic dwarfism. The histological, histochemical, and electron microscopical examination of the growth cartilage in two cases showed similar lesions: disorganization of the growth zone with islands of cells, some of them degenerated; abnormal organization of collagen forming thick rims around the cells and wide fibers in the interterritorial matrix; large accumulation of glycogen in most chondrocytes. Both sexes are affected; all patients are isolated cases from normal families.

Biopsy↗
PubMed1986

Gel electrophoresis of proteoglycan monomers of baboon articular cartilage separated by zonal rate centrifugation in sucrose gradients.

Proteoglycan monomers from articular cartilage of young baboons and of a baboon foetus were submitted to zonal rate centrifugation in sucrose gradients. The peaks obtained were analyzed by gel electrophoresis on polyacrylamide-agarose gels. The proteoglycan monomers corresponding to the bands obtained by gel-electrophoresis of unfractionated proteoglycans were separated in the gradients and the sedimentation distance correlated with the electrophoretic mobility.

Animals↗
PubMed1985

[Cellular aspects of chondrodysplasia].

Studies of growing cartilage in cases of chondrodysplasia have demonstrated chondrocytic abnormalities, in particular the presence of abnormal inclusions. The histochemical and microchemical analysis of these inclusions provide valuable information concerning the pathophysiology of these diseases, which involves a variety of mechanisms: disorders of the metabolism of proteoglycans and glycosaminoglycans, collagen, lipids, glycoproteins, disorders of cell division.

Cell Division↗