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Biomedical subjects

E Bonucci

Publications and source records attributed to E Bonucci.

At least 19 recordsLinked to original sources
PubMed1992

Immunohistochemical investigation on the presence of chondroitin sulfate in calcification nodules of epiphyseal cartilage.

Chondroitin sulfate localization in mouse epiphyseal cartilage was studied using CS-56 monoclonal antibody immunospecific for the glycosaminoglycan portion of the molecule. For light and fluorescence microscopy, decalcified specimens were embedded in paraffin, Lowicryl, or were frozen and cryostat-sectioned, and the antigen-antibody reaction was demonstrated by treating sections with IgM-peroxidase, IgM-alkaline phosphatase, or IgM-fluorescein conjugates. For electron microscopy, decalcified and undecalcified specimens were embedded in Lowicryl; ultrathin sections from undecalcified specimens were decalcified by flotation on EDTA; sections from both types of specimens were treated with IgM-immunogold conjugate for demonstration of CS-56 reaction. Before immunoreaction, part of all decalcified sections were digested with Streptomyces or testicular hyaluronidase. Control sections were treated with either mouse and goat non-immune serum, or mouse monoclonal antiserum to human dendritic reticulum cells. Both light and electron microscopy show CS-56 reaction with cytoplasmic components of maturing and hypertrophic chondrocytes. Under the light microscope, immunoreaction was not visible in calcified matrix, and was visible in uncalcified matrix only after hyaluronidase digestion. Under the electron microscope, it was evident both in uncalcified and calcified matrix, although the latter showed few immunogold particles, usually placed on areas which appeared incompletely calcified. Gold particles were chiefly distributed at the periphery of calcification nodules and fully calcified matrix. These results show that CS-56, besides reacting with cytoplasm of maturing and hypertrophic chondrocytes, binds to crystal ghosts and other components of cartilage matrix, immunoreactivity decreasing as calcification increases. This suggests that chondroitin sulfate molecules are either degraded during calcification, or segregated into macromolecular complexes, or both degraded and segregated. The second possibility is supported by the increase of immunosensitivity induced by hyaluronidase digestion.

Animals↗
PubMed1992

Bone mineral and aluminum concentrations in patients undergoing CAPD.

CAPD results in continuous peritoneal transfer of hormones and minerals involved in the pathogenesis of renal osteodystrophy (RO). Moreover, although CAPD patients seem to have better control of serum phosphate concentration than hemodialysis patients, the need for aluminum-containing phosphate binders (ACPB) may still be present. In a prospective study meant to investigate the evolution of RO, we obtained 79 bone biopsies in 29 uremic patients (20 male, 9 female; age 25-59, mean 46). Of these, 22 were obtained at the beginning of treatment, 24 after 24 months, 23 after 36 months and 10 after 60 months. All patients were treated with CAPD (Viaflex, Baxter 2-2.5 L x 4-5 bags/day; Ca(++) + 3.5, Mg(++) 1.5 mEq/L) as the first modality of therapy and received oral calcitriol, aluminum hydroxyde and/or calcium carbonate and magnesium hydroxyde in order to maintain serum calcium (Ca) and phosphorus within the normal range. Qualitative bone histology, bone Ca and magnesium (Mg) (Flame atomic absorption spectroscopy) and aluminum (Al) concentration (Graphite furnace atomic absorption spectrometry) were determined. CAPD achieves a good control of RO as indicated by the tendency toward a decreased incidence of mixed osteodystrophy and predominant hyperparathyroid bone disease and improvement of osteoid lesions. A defective Ca content of bone is persistent in the observed period and positively correlated to bone Mg concentration. An increased level of Al was shown in the serum and bone. The highest bone Al content was found among patients with predominant osteoid bone disease. Also in CAPD, patients consuming ACPB are at risk of bone Al accumulation despite the low Al levels in the dialysate.

Adult↗
PubMed1992

Morphological and histochemical study of supragingival human calculus and dental plaque using ruthenium hexammine trichloride and acridine orange.

Ruthenium hexammine trichloride (RHT) and acridine orange were used to preserve and visualize anionic groups in human plaque and dental calculus. RHT-reacting material was present on the membrane of micro-organisms and in intermicrobial spaces of the calcifying areas, and seems to correspond to, and derive from, acidic glyco- and phospholipids of the plasma membrane of the micro-organisms. However, the presence of acidic salivary peptidoglycans cannot be ruled out. Two types of calcification were found: extramicrobial and intramicrobial. The former consisted of calcified deposits irregularly scattered in the intermicrobial matrix. They were in close relationship with RHT-reacting material, or were placed inside vesicular structures delimited by a membrane. Intramicrobial calcification consisted of small aggregates of needle-shaped crystals and/or of granular deposits; in both cases, they either masked the whole cytoplasm of the micro-organisms, or were located only over the plasma membrane. These results suggest that mineral deposition occurs in connection with acidic components of intermicrobial matrix, microbial plasma membranes, and cytoplasms. The addition of RHT and acridine orange to fixing and decalcifying solutions yields satisfactory preservation of dental calculus and plaque, and apparently reduces loss of their anionic organic components and increases their electron density. However, these substances are not sufficient to preserve all ultrastructural details in decalcified areas, probably because the inorganic substance prevents reaction of acridine orange and RHT with the organic components of the calcified matrix.

Acridine Orange↗
PubMed1979

Resorption of uncalcified cartilage in the diaphysis of the chick embryo tibia.

The resorption of the uncalcified cartilage matrix of the middle third of the diaphysis in the chick embryo tibia has been studied using histological, histochemical and electron microscopic techniques. The first stage in the resorption process affects the periosteal bone, which is breached by osteoclasts at one or several points. Capillary vessels and clear, apparently undifferentiated cells penetrate through the holes so formed and reach the cartilage. The loss of acid proteoglycans to a depth of 10--20 micrometer into the matrix is the first sign of cartilage resorption; it is followed by the digestion of collagen fibrils, the opening of cell lacunae, chondrocyte degeneration and fragmentation and, lastly, the complete dissolution of the cartilage. This process is mediated by cells which probably derive from perivascular elements. Most of these cells have an undifferentiated appearance, but they have macrophagic properties, as is shown by phagocytotic activity along their plasma membrane, by the presence of lysosome-like bodies in their cytoplasm, and by their intense acid phosphatase activity. Resorption by giant cells of chondroclastic type only occurs at a late stage.

Animals↗
PubMed1979

25-hydroxycholecalciferol in the treatment of renal osteodystrophy in haemodialysed patients.

The effects of 25-OHD3 on renal osteodystrophy have been studied in 6 patients on maintenance haemodialysis. Administration of 25-OHD3, 50 microgram/day, did not improve biochemical data and intestinal absorption of calcium. With a dose of 100 microgram/day in all patients an increase in blood calcium levels eventually reaching hypercalcemic values was observed. In two cases a fall in alkaline phosphatase toward normal values was noted. In the same cases the treatment-induced hyperphosphatemia, uncontrolled by AI(OH)3 supplementation and similarly high iPTH levels were observed. In two cases repeated bone biopsy following 8 months treatment and not show substantial improvement of bone lesions. In one case addition of 1,25-(OH)2D3 to the treatment with 25-OHD3 led to a more rapid improvement in biochemical parameters and iPTH serum levels. Doses of 25-OHD3 capable to correct blood calcium levels and intestinal absorption of calcium, may have minimal benefit on the osteitis fibrosa component of the bone lesion.

Adolescent↗
PubMed1979

A histological investigation of skin lesions in onchocerciasis patients from Southern Togo.

Specimens from unselected populations in an area of hyperendemic onchocerciasis were used to describe and quantify histological changes in the upper layers of the dermis and the findings were compared with the macroscopical lesions observed. 553 persons, the inhabitants of two villages in Southern Togo, were examined. 502 biopsies were processed histologically. Onchocerciasis prevalence was over 75% and macroscopical skin lesions were evident in 30--40% of the population examined. Histological changes typical for the infection existed in the dermis in 68.5%. A cellular infiltration was seen in 49%, changes in the elastic or collagenous fibrils in 28.9% of the specimen. The observations are described in detail. Signs of inflammatory as well as primary degenerative changes were seen in biopsies from all age-groups. When microscopic and macroscopic findings are compared, it can be noticed that atrophy may start at an early age without preceeding dermatitis and that inflammatory reactions may occur at all ages. After submersion in saline for 24 hours not all microfilariae had emerged from the skin snips as evidenced by the histological examination. In 12.1% of those that otherwise would have been diagnosed as negative, microfilariae were identified in the sections.

Adolescent↗
PubMed1979

Histochemical and electron microscopical investigations on the calcified keratin in the horn pearls of a glans carcinoma (calcified keratin).

The calcified keratin in the horn pearls of a glans carcinoma has been studied by histochemical and ultrastructural methods. The former have shown that the calcified areas contain glycoproteins and acid proteoglycans and have a concentration of sulphydryl groups greater than that of the surrounding, uncalcified keratin. Electron microscopy has shown the presence of intracellular needle- and filament-like crystals closely related to the keratinocyte filaments and similar to those found in other calcified tissues. Besides the close relationship discovered between crystals and keratinocyte filaments, the other main conclusions are that keratin calcification is an intracellular process and that keratin molecules are responsible for the induction and regulation of the process.

Aged↗
PubMed1978

X-ray diffraction and electron microscope study of osteons during calcification.

To obtain information on the changes in the inorganic bone fraction during calcification, low- and wide-angle X-ray diffraction techniques and electron microscopy have been applied to single osteon samples. The samples were cylindrically shaped and their axes corresponded to the axes of the Haversian canals. The selection was made according to the degree of calcification and the orientation of collagen bundles and inorganic particles. Osteons at both the initial and final stages of calcification were chosen. Arrangements of fiber bundles and inorganic particles in successive lamellae characteristic of three types of osteon were selected, that is, longitudinally structured osteons, transversely structured osteons, and alternately structured osteons. The results indicate that in osteonic lamellar bone there are two types of inorganic particles: (1) granules arranged in linear or needle-shapred entities with maximum width 40-45 A, which are regularly distributed at the level of the main band of the collagen fibrils where their maximum length reaches the length of the main band itself; that is , about 400 A; and (2) very long crystallites, with a diameter of 40-45 A, which grow with their crystallographic c-axis parallel to the collagen fibrils and cover much more than a major collagen period.

Adolescent↗
PubMed1977

Initial studies on the crystallinity of the mineral fraction and ash content of isolated human and bovine osteons differing in their degree of calcification.

Several groups containing 10--15 isolated osteons differing in their degree of maturity were analysed. Samples were isolated from undecalcified human and bovine bone sections. The crystallinity coefficient, defined as the ratio of the number of radiation-induced paramagnetic defects in the crystalline lattice of hydroxyapatite to the total ash content, was calculated. The results were compared with measurements performed on fragments of total cortical bone, primary periosteal bone, and inner circumferential lamellar bone. The results show a higher crystallinity of fully calcified osteons as compared with that found at the initial stage of calcification. No differences in the ash content were observed between human osteons, from different stages of calcification evaluated morphologically and by X-ray absorption. These differences were evident when bovine osteons differing in their stage of calcification were compared. Human fully calcified osteons contain 60% ash and their crystallinity coefficient is 52.1. Human osteons at the initial stage of calcification contain 57% ash and their crystallinity coefficient is 40.6. The same parameters for fully calcified bovine osteons and for bovine osteons at the initial stage of calcification are 59% ash, 62.6 crystallinity coefficient and 46% ash, 43.0 crystallinity coefficient, respectively.

Adult↗
PubMed1977

Osteocyte ultrastructure in renal osteodystrophy.

The ultrastructure of the osteocyte has been studied in 80 needle biopsies from the iliac crest of uremic subjects with renal osteodystrophy. Different types of osteocytes were present in the osseous trabeculae. Those recognizable in completely uncalcified osteoid tissue looked like normal osteocytes, even though the matrix was not mineralized. Those present in hypomineralized areas showed enlarged and irregular lacunae when examined under the light microscope; under the electron microscope these osteolytic-like changes were not evident and were found to have been produced by defective calcification of the perilacunar matrix. Osteocytes placed in matrix whose mineralization was normal were often surrounded by a border of crystals protruding side-to-side from the bone matrix into the lacunar space. Other osteocytes were placed in unusually wide lacunae. They showed evidence of osteolytic activity, chiefly consisting of irregularity of the lacunar wall, presence of flocculent, granular and filamentous material in the pericellular space, and calcification of mitochondria. Degenerating and degenerate osteocytes were also recognizable.

Adolescent↗
PubMed1977

Histologic, microradiographic and electron microscopic investigations of bone tissue in a case of craniodiaphyseal dysplasia.

The results of histologic, microradiographic and electron microscopic investigations carried out on two bone biopsies pertaining to a case of craniodiaphyseal dysplasia are reported. They show that the affected skeletal segments are chiefly characterized by enhancement of bone volume, and defective calcification of the bone matrix. Moreover, interstitial calcification of skeletal muscle has been found.

Bone Diseases, Developmental↗
PubMed1977

Ultrastructural aspects of chondrodystrophia calcificans congenita (syndrome of Conradi-Hünermann).

An ultrastructural study of chondrodystrophia calcificans congenita is reported. Foci of initial calcification of cartilage are characterized by coexistence of three different types of crystals, probably due to abnormal proteoglycan composition of cartilage matrix. The calcification process in chondrodystrophia calcificans congenita is apparently not related to 'matrix vesicles' as it is in normal cartilage.

Calcinosis↗