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Biomedical subjects

V Stanescu

Publications and source records attributed to V Stanescu.

At least 73 records · Page 4Linked to original sources
PubMed1980

The mild form of pseudoachondroplasia. Identity of the morphological and biochemical alterations of growth cartilage with those of typical pseudoachondroplasia.

A 9-year-old boy from an incestuous union presented with mild clinical and roentgenological manifestations of pseudoachondroplasia. Tibial growth cartilage was obtained during a routine orthopedic procedure. Microscopic, histochemical and biochemical analysis showed changes identical to those of 6 sporadic cases of typical pseudoachondroplasia. The results support a concept of pathogenetic homogeneity of pseudoachondroplasia.

Achondroplasia↗
PubMed1980

[Dysplasia spondylo-epiphysealis congenita: its heterogeneity (author's transl)].

A study of epiphyseal cartilage in two children presenting with all the clinical and radiologic features of the dysplasia spondylo-epiphysealis congenita showed abnormalities different from those usually described. In addition to dilatations of the endoplasmic reticulum, there were two types of inclusions observed in the chondrocytes, granules and spirilla, which were limited by a smooth membrane. The intercellular matrix consisted of a dense tangle of fine fibers and numerous dense granules. These findings suggest a heterogeneity for this disease.

Cartilage↗
PubMed1980

[A syndrome of congenital diabetes with disordered epiphyseal growth with autosomal recessive inheritance (author's transl)].

A child is described with insulin dependent diabetes of neonatal onset and a disorder of endochondral growth. Radiological and histological bone appearances differ from those observed in other types of chondrodysplasia. The association of diabetes and chondrodysplasia is not likely to occur by chance but is probably a genuine clinical entity. The condition is probably inherited as a autosomal recessive and its possible pathogenesis is discussed.

Child↗
PubMed1979

Link-proteins and non-collagenous proteins from normal and chondrodysplastic cartilages.

Baboon and human articular and growth cartilage was extracted with 4M guanidinium chloride in the presence of proteolysis inhibitors. After dialysis against 8M urea pH 6.8 the proteins were separated from proteoglycans by ion-exchange chromatography. The concentrated and reduced protein fractions was analyzed by SDS-PAGE. Bands corresponding to collagen and to 6 major non-collegenous proteins were found. Two of the latter were identified with the link-proteins. By using small columns and microconcentration procedures, a gel-electrophoretic analysis of link-proteins extracted from small pieces of cartilage was performed and ten cases of osteochondrodysplasias were studied. No abnormalities were detected in the following syndromes: achondroplasia, diastrophic dwarfism, thanatophoric dwarfism, Jeune disease, spondyloepiphyseal dysplasia congenita, Kozlowski syndrome, osteogenesis imperfecta, polyepiphyseal dysplasia with diabetes mellitus.

Achondroplasia↗
PubMed1979

[A new method for extraction of cartilage proteoglycans: the electrical extraction (author's transl)].

Sections (40 mu thick) or fine powder of baboon articular cartilage were submitted to electric current (40-60 V/cm) in a free zone electrophoretic system and the extraction of proteoglycans from cartilage was followed by histochemical and biochemical methods. An extraction of about 40 per cent of the total hexuronic acid was obtained in 5 hours. The metachromasia showed that the proteoglycans resistant to electrical extraction are found in the chondrocytes lacunae and in the calcified zone. Gel electrophoretic studies showed the absence of proteoglycan aggregates and a material with a migration similar or a little faster than that of proteoglycan subunits. In some experiments a material with the migration of chondroitin sulphate was found. The electrical extraction could give information about the relationship between collagen framework and proteoglycans in the cartilage matrix itself and about proteoglycan organization.

Animals↗
PubMed1978

[Fibrochondrogenesis].

Fibrochondrogenesis is a lethal form of dwarfism similar to thanatophoric dwarfism. It is distinguished radiologically by the widening of the metaphyses of the long bones, and, on lateral x-ray of the spine, by a median fissure of the body of the vertebra without any loss of vertebral height. The condition is inherited an autosomal recessive. A study of growing cartilage confirms that this disease is a distinct entity as there is fibrosis of the cartilage which is never present in thanatophoric dwarfism or in the different forms of achondrogenesis.

Bone Diseases, Developmental↗
PubMed1977

Proteoglycan populations of baboon (Papio papio) articular cartilage.

1. Gel electrophoresis of proteoglycans extracted with use of 4 M-guanidinium chloride from baboon (Papio papio) articular cartilage and purified on DEAE-cellulose in 8 M-urea yielded three bands on electrophoresis in polyacrylamide/agarose gels: two wide bands close together (I and II) and a third, thinner and more rapidly moving band (III). 2. Gel electrophoresis of fractions from direct 'dissociative' gradients showed that these bands were partially separated (buoyant density of I greater than II greater than III). 3. Reduction and alkylation of proteoglycans did not alter either the gel-electrophoretic pattern or the distribution of the bands in the fractions of the gradient. 4. Band III was found in the upper third of 'associative' gradients but not in the bottom fraction, which yielded after dissociation only bands I and II. 5. The third band was completely extracted for 24h with an iso-osmotic solution, but was contaminated with bands I and II. The second extraction step with 4M-guanidinium chloride yielded only bands I and II. 6. The data strongly suggest the presence in the articular cartilage of several populations of dissociated proteoglycans differing in gel-electrophoretic migration, buoyant density and aggregation capacity.

Animals↗
PubMed1976

[Differences in distribution of type I and type II collagens in the superficial and intermediary zones of articular cartilage].

Undecalcified frozen sections, 40 mu thick, were cut from the knee articular cartilage of young adult Baboons (Papio papio). The sections were freeze dried and the superficial and the intermediate zones were separated by microdissection under a binocular dissecting microscope. The material of each zone was cleaved with CNBr and the major peptides were analyzed by discelectrophoresis in SDS polyacrylamide. Peptides alpha, CB 3,5 and alpha, (II) CB 10 were used as characteristic markers for type I and type II collagen respectively. The method could detect as little as 5-10% of type I collagen of total collagen in mixtures. The thin superficial zone contains type I and type II collagen. The intermediate zone contains only type II collagen. The possible biological significance of this different anatomical distribution of the two types of collagen is discussed. This special distribution could explain the contradictory data from the literature concerning the presence of type I collagen in the articular cartilage.

Animals↗
PubMed1976

[Study by gel electrophoresis, of alpha chains and of CNBr peptides of collagen from epiphyseal cartilage in chondrodysplasia].

The alpha chains and the major CNBr - derived peptides of collagen of growth cartilage were studied in the following syndromes: thanatophoric dwarfism, pseudothanatophoric dwarfism, achondroplasia, pseudoachondroplasia, diastrophic dwarfism, metatropic dwarfism, Kniest disease, parastremmatic dwarfism, multiple exostoses, Blount disease and pycnodysostosis. After extraction of proteoglycans the collagen was solubilized by limited pepsin digestion purified, and the alpha chains were analysed by electrophoresis. The major CNBr - derived peptides were obtained by cleaving directly the cartilage after proteoglycan extraction. In some syndromes purified collagen was also cleaved. The CNBr peptides were analyzed by disc electrophoresis in SDS-polyacrylamide. Human normal growth cartilage and baboon cartilage were used as controls. The pattern of alpha chains and of major CNBr peptides was similar in all the cases studied, except one case of lethal diastrophic dwarfism in which the pattern of peptides showed the presence of type I collagen in quantities detectable by the present method. However in a milder case of diastrophic dwarfism the pattern of CNBr peptides was found normal. The present study does not exclude possible abnormalities of collagen at a higher lever of supramolecular organization in osteochondrodysplasias.

Adolescent↗
PubMed1976

Kniest syndrome.

Explore the source record for details and available documents.

Cartilage↗
PubMed1975

[Ultrastructural abnormalities of the chondrocytes in pycnodysostosis. Their relation to a disorder of lipid metabolism].

The ultrastructural study of the growth cartilage of pycnodysostosis reveals the presence of abnormal inclusions in the majority of the chondrocytes. The inclusions are single membrane bound and contain granular material and lamellar irregularly interwoven structures which at very high magnification appear to be made up of dense parallel bands. These vacuoles displace adjacent structures and some of them appear to be closely related to the Golgi apparatus. In addition, appearances are sometimes seen which suggest the expulsion of the vacuoles into the cell capsules. The abnormal chondrocyte inclusions are visible by optic microscopy and stained with Nile blue on frozen section. Thus, histochemical and ultrastructural characteristics suggest a lipid (probably phospholipid) content. Many authors have already stressed the role of lipids in the process of calcification. The abnormalities described might bear some relation to the densification of the skeleton seen in pycnodysostosis.

Cartilage↗
PubMed1975

Age-dependent change in the gel-electrophoretic pattern of proteoglycans of human growth cartilage.

The gel-electrophoretic pattern of dissociated proteoglycans was studied in 7 fetuses, 5 premature newborns, 4 term newborns, 5 infants and 5 children. The tibial growth cartilage was extracted with 4 M guanidinium chloride. After dialysis against 8 M urea at pH 7 the proteoglycans were obtained by ion chromatography in urea on DEAE cellulose and submitted to gel electrophoresis on polyacrylamide agarose gels. Gel electrophoresis of proteoglycans showed a different pattern in fetuses from that found in children. The change occurs in the first months of extrauterine life.

Adolescent↗
PubMed1975

Gel electrophoretic studies on proteoglycans and collagen of abnormal human growth cartilage: proteoglycan abnormalities in pseudoachondroplasia and in Kniest's disease.

The microchemical study of growth cartilage biopsies may improve the classification and the genetic advice of some types of growth disturbances and contribute to the understanding of biochemical defects. Small tibial growth cartilage biopsies were performed during orthopedic surgery in cases with achondroplasia, pseudoachondroplasis (three cases), Kniest's disease (two cases), diastrophic dwarfism (two cases), parastrematic dwarfism, pycnodysos tosis, mucolipidosis type III, Blount's disease, and in three normal growing children. Five human fetal cartilages were also studied. The proteoglycans were extracted with 4 M guanidinium chloride. After dialysis against 8 M urea at pH 7, the proteoglycans were obtained by ion chromatography in urea on DEAE-cellulose and submitted to gel electrophoresis on polyacrylamide-agarose gels. The gel electrophoresis of the proteoglycans of growth cartilage of normal growing children gave two metachromatic bands situated close one to another. The proteoglycans extracted from fetal growth cartilage gave a single band with a slightly slower migration. An abnormal gel electrophoretic pattern was found in pseudoachondroplasia and in Kniest's disease. In pseudoachondroplasia a single wide band was found; in overcharged tubes several thin, more rapid bands appeared in addition to the main band. In Kniest's disease three bands were found. In all of the other syndromes studied two normally or almost normally situated bands were present. Small differences in the width and intensity of the bands observed in several cases were difficult to assess. In all cases except mucolipidosis III and Kniest's disease the collagen was extracted by using limited cleavage and solubilization with pepsin, purified and analyzed by polyacrylamide gel electrophoresis. A type of collagen with a single alpha band was found.

Achondroplasia↗