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Biomedical subjects

R Stanescu

Publications and source records attributed to R Stanescu.

At least 37 records · Page 2Linked to original sources
PubMed1987

Histopathology of arthritis induced in rats by active immunization to mycobacterial antigens or by systemic transfer of T lymphocyte lines. A light and electron microscopic study of the articular surface using cationized ferritin.

We analyzed the histopathologic findings of arthritis in 3 rat models: adjuvant arthritis induced by active immunization to Mycobacterium tuberculosis (MT) antigens, arthritis produced by passive transfer of an intrinsically arthritogenic line of anti-MT T lymphocytes, and bystander arthritis produced by intraarticular injection of a foreign antigen, ovalbumin, into rats with T lymphocyte line cells specific for the ovalbumin antigen. The histopathology of the tibiotarsal and knee joints was studied by light microscopy and the articular surface of the cartilage by electron microscopy after labeling with cationized ferritin. The lesions in the 3 models of arthritis were compared. In active adjuvant arthritis, inflammatory lesions and cartilage destruction were found as early as 9 days after immunization, and persisted for as long as 11 months. Similar, but somewhat milder, lesions were found in arthritis produced by transfer of anti-MT T lymphocytes. Inflammatory signs were present at 4 days, when there was no evidence of joint edema. Severe inflammatory lesions were found in arthritis induced by transfer of anti-ovalbumin T lymphocytes that was followed by ovalbumin injection into the knee. Pathologic changes were found to be similar in all 3 models. Thus, the changes could be attributed to the action of T lymphocytes, irrespective of whether the target antigen was intrinsic to the joint.

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

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↗
PubMed1985

Effects of enzymatic digestions on the negative charge of articular cartilage surfaces.

The articular surface of adult BALB/c mouse femoral heads is covered by a fine granular electron dense material containing negative charges that bind electrostatically cationized ferritin. The material is of proteidic nature being digested by trypsin and chymopapain and resistant to testicular and microbial hyaluronidase, keratanase, chondroitinase ABC and AC. Mammalian collagenase disrupted the surface without digesting the material and allowed the penetration of cationized ferritin in the subsurface layers, where the label was bound on residual fibers. Sequential digestion with collagenase and chondroitinase ABC showed that the charges associated with the subsurface fibers are proteoglycans.

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↗
PubMed1984

Opsismodysplasia: a new type of chondrodysplasia with predominant involvement of the bones of the hand and the vertebrae.

The name opsismodysplasia is proposed for a new chondrodysplasia, which was studied in three patients. Clinically, the condition is recognized at birth on the basis of shortness, short hands, and facial abnormalities with a short nose and a depressed bridge of nose. The most characteristic radiographic signs are: very retarded bone maturation; marked shortness of the bones of the hands and of the feet with concave metaphyses; and thin, lamellar vertebral bodies. The growth cartilage studied in one case showed a wide hypertrophic area containing thick connective tissue septa, irregular provisional calcification, and vascular invasion. Type I collagen was detected in the hypertrophic area by immunohistochemical and microchemical tests. The transmission of opsismodysplasia is probably autosomal recessive.

Abnormalities, Multiple↗
PubMed1984

Labeling of articular cartilage surface with cationized ferritin: aged human normal and osteoarthritic cartilage.

The labeling of the articular surface with cationized ferritin (CF), an electron-dense marker, visualizes the anionic sites and may disclose abnormal penetration of the large CF molecule into the subsurface layers. Various areas of cartilage selected by unaided eye examination were taken from femoral heads excised in three cases of osteoarthritis and two cases of hip fracture. The fragments were examined by optical microscopy and by electron microscopy after labeling with CF. The labeling with and the penetration of CF were correlated with the morphological features of the surface. The surfaces belonging to the erosion border were disrupted and the CF penetrated approximately 2 microns into the matrix along the collagen fibers and in areas containing a patchy dense material. Prefixation with Karnovsky's fixative prevents CF penetration. The fragments taken at a distance from the erosion border showed at electron microscopical examination either an intact appearance of the surface that was labeled without penetration or a disrupted surface with penetration of the label. The osteophytes and the regeneration buds surface were labeled showing little or no penetration. The fragments from cartilage of hip fractures had either an intact surface regularly labeled or a slightly or moderately disrupted surface with moderate penetration of CF. The penetration of large molecules of CF in damaged cartilage demonstrates important permeability changes that may be significant for the pathogenetic mechanism of osteoarthritis. Similar permeability changes were previously shown in mice femoral heads treated in vitro with collagenase or trypsin and labeled with CF.

Age Factors↗
PubMed1984

Pathogenic mechanisms in osteochondrodysplasias.

UNLABELLED: We performed histochemical, immunohistochemical, electron-microscopic, and microchemical studies on cartilage growth plates from sixty-eight patients with nineteen different forms of human osteochondrodysplasia. Cartilage biopsies were obtained during orthopaedic procedures. Postmortem specimens were obtained within a short time after death. The combined morphological and biochemical studies revealed specific abnormalities suggestive of a particular biochemical defect in several chondrodysplasias. In pseudoachondroplasia, non-collagenous protein accumulated in the rough endoplasmic reticulum of chondrocytes and a proteoglycan species that normally is present in the extracellular matrix was not detected by gel electrophoresis. The accumulated material was stained with antibodies against the core protein of proteoglycan. This strongly suggested that in this syndrome an abnormal core protein of a proteoglycan species is not properly transferred to the Golgi system. In Kniest syndrome, intracytoplasmic accumulation of metachromatic material, dilatation of rough endoplasmic reticulum, and an abnormal gel-electrophoretic pattern of cartilage proteoglycans suggested an abnormality of cartilage proteoglycan metabolism. Abnormalities that probably are related to degradative lysosomal processes of proteoglycans in chondrocytes were found in spondylometaphyseal dysplasia of the Kozlowski type. An abnormal organization of type-II collagen was found in fibrochondrogenesis. In diastrophic dysplasia, an abnormal organization of collagen was found in areas of interterritorial matrix and around many degenerated cells, but also in the lacunae of cells without ultrastructural signs of degeneration. The segment-long-spacing form of collagen prepared from cartilage of three patients with diastrophic dysplasia showed an abnormal cross-striation pattern in a portion between bands 42 and 45, corresponding to the position of the alpha 1(II) cyanogen-bromide-derived 10,5 peptide. This suggested that in this syndrome there is a structural alteration of the type-II collagen molecule. There was an accumulation of intracellular lipid in pyknodysostosis and in hypochondrogenesis, and of glycoproteins in several atypical cases of spondyloepiphyseal dysplasia. In a pair of twins with an atypical form of spondyloepiphyseal dysplasia, the presence of many multinucleated chondrocytes suggested a primary impairment of cell division. CLINICAL RELEVANCE: A knowledge of the pathogenic mechanisms in osteochondrodysplasias might improve the classification; aid in diagnosis, prognosis, and genetic counseling; and contribute to the understanding of normal endochondral growth.(ABSTRACT TRUNCATED AT 400 WORDS)

Achondroplasia↗
PubMed1984

[Spondyloepiphyseal dysplasia with an accumulation of glycoproteins in chondrocytes].

A case presenting a peculiar type of spondylo-epiphyseal dysplasia was studied. Clinically, the normal height was striking. The X-rays showed large epiphysis and wide metaphysis. Bilateral coxa valga with very large femoral necks was present. The height of the vertebral bodies was slightly reduced. The study of the upper tibial growth cartilage showed glycoprotein inclusions in the chondrocytes and large dilatations of the rough endoplasmic reticulum. The gel electrophoresis of the non collagenous proteins extracted from the growth cartilage had an abnormal densitometric tracing. The type of inheritance of this syndrome is unknown, the patient being an isolated case in a normal family.

Adolescent↗
PubMed1983

The distribution of proteoglycans of high electrophoretic mobility in cartilages from different species and of different ages.

The distribution of small proteoglycans of high relative electrophoretic mobility in cartilage of various species and of different ages was studied. Proteoglycans extracted by 4 M guanidinium chloride were purified by ion-exchange chromatography and assessed by gel electrophoresis. Proteoglycans fractionated by equilibrium density gradient centrifugation under 'dissociative' conditions were similarly purified and assessed. A rapid migrating population was found in articular cartilages of young humans, baboons, calves, pigs, rabbits, rats, chickens and in mandibular and vertebral cartilages of dog-fish. It was not detected in unfractionated proteoglycans extracted from fetal rat, pig, calf, baboon and human cartilages. In baboon and human fetal cartilages of advanced gestational age, however, small amounts of the rapid population were present being detected in the low density fractions of dissociative gradients. The rapid migrating population was not found either in unfractionated or in fractionated proteoglycans obtained from articular cartilages of humans aged over 40. It was also absent from human osteoarthritic cartilages but was detected even at advanced age in cartilages covering osteophytes.

Adult↗
PubMed1983

Hypochondrogenesis.

Three clinicopathological observations of a mild form of type II achondrogenesis are presented. The cases were selected from a group of 21 similar cases to illustrate the various degrees of clinical and roentgenological signs that can be found. The cases had various survival periods after birth but not exceeding several months. The roentgenological signs were less severe than those of type II achondrogenesis. Some cases similar to case no. 3 have roentgenological signs very close to spondylo-epiphyseal dysplasia congenita and probably were confused previously with the latter. The name of hypochondrogenesis was proposed for these cases because the lesions of the growth plate are similar although less marked to those found in type II achondrogenesis: high cellularity with poor matrix development; irregular columnization and vascular penetration; large chondrocytes and even more enlarged lacunae; large sclerotic cartilage canals. The clinical and roentgenological diagnosis of hypochondrogenesis could be difficult especially in the less severe forms. The delay in vertebral ossification, the absence of all the epiphyseal nuclei and of the tarsal bones might suggest the diagnosis of hypochondrogenesis, rather than that of spondyloepiphyseal dysplasia. The evolution which seems to be always lethal in a period of several weeks or months would make the diagnosis still more likely and it could be confirmed by histopathological examination. Cases of spondylo-epiphyseal dysplasia congenita might have at birth, roentgenological signs indistinguishable from those of hypochondrogenesis, as was illustrated by case no. 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Achondroplasia↗
PubMed1982

Noncollagenous proteins in cartilage of normal subjects and patients with degenerative joint disease. A gel electrophoretic study.

Normal articular cartilage from subjects of various ages and cartilage from patients with degenerative joint disease were extracted with 4M guanidinium chloride. After dialysis against 8M urea pH 6.8, a 0.2M NaCl fraction was obtained by ion exchange chromatography on DE-52 in 8M urea. This fraction was concentrated, reduced, and analyzed by sodium dodecyl sulfate--polyacrylamide gel electrophoresis (7% gels). Six major noncollagenous protein bands (P1-P6) were found; 2 were identified as the link proteins. The approximate molecular weights of P1-P6 were: 87,000, 64,000, 56,000, 46,000, 41,000, and 27,000. A similar sodium dodecyl sulfate-polyacrylamide gel electrophoresis pattern of P1-P6 was found in young baboons, in normal young and aged humans, and in patients with degenerative joint disease. Peaks corresponding to extracted collagen were decreased in older patients and increased in patients with degenerative joint disease, even those of advanced age.

Adolescent↗
PubMed1982

[Heterogeneity of formes frustes of Morquio's disease].

Two children presenting with a mild form of Morquio's syndrome are reported. Clinically, there was a characteristic brevity of the trunk and slit lamp examination showed discrete corneal opacities. On X-ray films, generalized plastyspondylia was moderate but it was associated with hypoplasia of the odontoid process. Acetabula were enlarged with coxa valga; obliquity of inferior radio-cubital extremity was associated with a sharp pattern of the proximal end of metacarpi. Epiphyseal cartilage chondrocytes also looked like those of Morquio's syndrome: large cells containing numerous vacuoles, limited by a single smooth membrane. On the other hand, no keratosulfate was found in urines and N-acetylgalactosamine-6-sulfate-sulfatase and beta-galactosidase assays in fibroblasts were normal. Thus, this mild form is different from the so-called Morquio's syndromes types A and B.

Child↗