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Biomedical subjects

E Bonucci

Publications and source records attributed to E Bonucci.

At least 73 records · Page 4Linked 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↗
PubMed1991

Endosteal surfaces in hyperparathyroidism: an enzyme cytochemical study on low-temperature-processed, glycol-methacrylate-embedded bone biopsies.

Alkaline phosphatase (AlP) and tartrate-resistant acid phosphatase (TRAP) activities have been studied comparatively in needle biopsies of the iliac crest of four cases of secondary hyperparathyroidism (renal osteodystrophy). AlP activity was associated with the plasma membrane of osteoblasts and their processes, of reticular cells of bone marrow and of young osteocytes of osteoid borders and woven bone. Moreover, it was detected in the fibroblast-like cells of the endosteal "fibrosis". These cells were orderly in arrangement and were parallel to the endosteal surfaces near zones of bone formation. They were disorderly near zones of bone resorption. A strong TRAP-positive reaction was present in osteoclasts and mononuclear cells of endosteal "fibrosis" and in osteocytes located near active osteoclasts and in woven bone. These results suggest that the so-called fibrosis of hyperparathyroidism, rather than representing reparative, inert tissue, consists of osteoblast-like cells, probably precursors of osteoblasts derived by parathormone-stimulated proliferation of AlP-positive stromal cells of bone marrow, and of TRAP-positive, mononuclear cells, probably preosteoclasts. Moreover, they show that TRAP activity can be present in osteocytes, probably under stimulation by the same factors which stimulate osteoclast activity. The histochemical demonstration of AlP and TRAP facilitates the morphological diagnosis of metabolic bone disease and may improve knowledge of bone physiopathology.

Acid Phosphatase↗
PubMed1991

Plasma insulin-like growth factor-1 and bone formation parameters in predialysis chronic renal failure.

Insulin-like growth factor-1 (IGF-1), produced by osteoblasts following parathormone (PTH) stimulation, is a local hormone with autocrine and paracrine functions on bone formation. To evaluate whether circulating IGF-1 is also important in stimulating bone formation, a study was carried out on 28 patients with slowly progressing nondialytic chronic renal failure. 9 patients were treated with 1,25(OH)2D3, while 19 did not receive vitamin D metabolites. In all patients a transiliac bone biopsy for histomorphometric studies was obtained, and the following determinations were made: immunoreactive PTH (iPTH), osteocalcin, alkaline phosphatase, IGF-1, serum calcium, phosphate and creatinine. Serum IGF-1 levels were similar in the two groups of patients, and higher than normal. iPTH and osteocalcin were positively correlated with serum creatinine, osteoblast surface and the eroded surface, but did not correlate with IGF-1. A negative (n.s.) relationship was found between dynamic bone parameters and circulating IGF-1, with the mineral apposition rate reaching a significant level (p less than 0.05). In conclusion, the circulating levels of IGF-1 are not correlated with bone formation parameters, thus apparently showing no role in bone turnover or dependency on bone production of the growth factor. The results may favor the hypothesis of a negative feedback control of circulating IGF-1 by suppressive signals originating from active bone metabolic units.

Aged↗
PubMed1990

High turnover osteoporosis in acro-osteolysis (Hajdu-Cheney syndrome).

Acro-osteolysis with diffuse osteoporosis in the absence of other associated diseases is named Hajdu-Cheney syndrome. Reduced bone formation rather than enhanced bone resorption has been indicated as the mechanism of osteoporosis. On the assumption that in this syndrome the active bone resorption which produces distal osteolysis must also predominate in generalized osteoporosis, we investigated bone histology, calcium kinetics, calciotropic hormones and bone markers in a patient suffering from sporadic Hajdu-Cheney syndrome. A radius bone biopsy taken far from the osteolytic lesions showed severe osteoporosis with a marked increase in osteoclastic bone resorption and reduced bone formation. Total body calcium clearance, performed through an analysis of the kinetics of calcium infusion, was 2.8 times higher than in normal controls, indicating the presence of active osteoclastic bone resorption. Serum parathormone, 1,25-dihydroxycholecalciferol, alkaline phosphatase and urinary hydroxiproline were in the normal range. These data indicate that in Hajdu-Cheney syndrome trabecular osteoporosis is produced by the same mechanism that induces distal osteolysis, which suggests that it may be sustained by local acting factors stimulating osteoclastic resorption.

Adult↗
PubMed1990

Technical variability of bone histomorphometric measurements.

Effects of main sources of bone biopsy sample variability have been examined. Variability was assessed in double iliac crest biopsies of 12 subjects with normal or pathological bone. Components of variance were estimated as follows: two biopsies per patient; three specimens at different distances from compact bone; three sections per specimen; three microscopic fields per section. The following indicators were measured: bone volume (BV/TV); osteoid volume (OV/BV); osteoid surface (OS/BS); osteoblast surface (Ob.S/BS); eroded surface (ES/BS); osteoclast surface (Oc.S/BS); osteoid thickness (O.Th). Sources of variability were assessed by ANOVA for random effects. On the basis of the results, between fields variation gave the main contribution to the error of single measures (BV/TV, 50%; O.Th, 70%; OV/BV, Ob.S/BS, OS/BS, Oc.S/BS, ES/BS more than 80%). Distance from compact bone affected mostly the BV/TV (40%) and the O.Th (10%) error. When bone specimens at intermediate distance from cortical bone are examined, variations due to different biopsies, different section and different microscopic field are largely reduced by measuring 12 microscopic fields for BV/TV (14%) and 48 microscopic fields for the other indicators (O.Th 16%; OV/BV, Ob.S/BS, OS/BS, Oc.S/BS, ES/BS more than 30%). The precision can be only slightly improved by further increasing the number of the microscopic fields.

Biopsy↗
PubMed1990

Bone histomorphometric reference values in 88 normal Italian subjects.

The study deals with bone histomorphometric results obtained from 88 normal subjects (38 women and 50 men; range: 20-89 years), in order to establish control values in an Italian population. Bone specimens were obtained at autopsy from a standardized area of the iliac crest. The following indicators were measured: bone volume (BV/TV), osteoid volume, osteoid surface, osteoblast surface, eroded surface, osteoclast surface, osteoid thickness. Dependence of histomorphometric indicators on sex and age was evaluated by multiple regression analysis, including sex, age, and also a quadratic term (age2) and two interaction terms (sex x age, sex x age2). BV/TV was mainly affected by age. In fact, a decrease in the amount of bone was found with increasing age in both males and females. The reduction appeared rather regular, with negligible differences between males and females. The other indicators were found to be age- and sex-independent. As a consequence, they did not give information on the possible changes of bone apposition and resorption processes due to aging. On the whole, histomorphometric indicators of trabecular bone of the normal Italian population do not greatly differ from those reported for most other caucasian people.

Adult↗
PubMed1990

Bone loss in response to long-term glucocorticoid therapy.

A number of studies have shown that an excess of glucocorticoids induces osteoporosis, but the mechanism(s) and the time course of the reduction of bone mass remain uncertain. In order to clarify this issue we carried out a longitudinal clinical and histomorphometric study of patients requiring long-term glucocorticoid treatment. In 23 patients (9 men, 10 post- and 4 premenopausal women) biochemical and bone histomorphometric investigations were carried out before and during treatment with 10-25 mg/day of prednisone. Histomorphometric analysis of bone biopsies of the iliac crest showed that the decrease of TBV (up to -27%, P less than 0.001) occurs predominantly within the first 5-7 months of treatment; during the subsequent stages, which include observations after 12 months of treatment, only minor changes were observed. Therefore trabecular bone loss can be satisfactorily described by a negative exponential function. None of the other histomorphometric parameters (osteoid surfaces, resorption surfaces, etc.) showed significant changes. However, the histological features of the bone biopsies during steroid therapy, showing a virtual lack of osteoblastic activity, ruled out an increase of bone resorption. Moreover, the dynamic study of the bone formation by double tetracycline labelling showed, in a small subgroup of patients, a decrease of the apposition rates (from 0.763 +/- 0.053 to 0.305 +/- 0.074 microns/day (mean +/- SE) after treatment). No significant changes, at any time during steroid treatment, were observed in serum alkaline phosphatase, 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, 1,25-dihydroxyvitamin D, parathyroid hormone or urinary calcium excretion. Serum calcium increased significantly within the first 1-2 months of therapy and then it returned to baseline. Urinary hydroxyproline excretion decreased significantly within the first 1-2 months and continued to fall throughout the treatment. Thus, both biochemical and histological findings suggest that long-term glucocorticoid therapy causes a reduction of bone turnover, that the bone loss occurs predominantly within the first 6 months of treatment and that patients with lower bone mass have a lower rate of bone loss.

Adult↗
PubMed1990

Osteocalcin, iPTH, alkaline phosphatase and hand X-ray scores as predictive indices of histomorphometric parameters in renal osteodystrophy.

To evaluate the relationship between hyperparathyroid bone X-ray lesion, biochemical parameters and bone histology in chronic renal failure, 59 patients (52 +/- 14.9 years; Crs 4.7 +/- 2.2 mg/dl, mean +/- SD) on conservative treatment and 103 (48 +/- 14 years) on hemodialysis (from 48.4 +/- 36.7 months) were studied. Right-hand X-ray was carried out for evaluation of the scores (0-3) of acroosteolysis (score A) and subperiosteal resorption (score B). Serum iPTH, osteocalcin and alkaline phosphatase (AP) were measured. In addition in a subset of 53 patients, 30 in predialysis and 23 in dialysis, a bone biopsy was performed for histomorphometry. In predialysis the scores A and B correlated with bone GLA protein (BGP) (p less than 0.01), AP (p less than 0.05) and osteoid surface (p less than 0.05) and 0.01 respectively). In hemodialysis the same level of significant correlation (p less than 0.001) was found between the scores and the three humoral parameters. Score A correlated with active osteoblastic surface and active resorption surface while score B correlated with active osteoblastic surface (p less than 0.01), osteoid surface and active resorption surface (p less than 0.05). Multiple regression analysis carried out to establish the predictive variables of bone histologic lesions (active resorption surface and active osteoblastic surface) singled out BGP in predialysis and AP and the two scores in dialysis. We conclude that serum BGP, as compared to PTH and AP, prevails as a valid marker of hyperparathyroid bone lesion in predialysis, while in dialysis it does not seem to add further information to that carried by other variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Ultrastructural morphological study of supragingival tartar].

Specimens of old supragingival calculus, collected from 5 patients with periodontitis, were examined electron-microscopically. Both intracellular and extracellular calcification were found. Intracellular calcification began as needle-shaped crystals or minute amorphous deposits within microorganisms. Extracellular calcification originated within the interbacterial matrix.

Dental Calculus↗
PubMed1989

Sensitivity of bone histomorphometry in the diagnosis of metabolic bone diseases.

Diagnostic sensitivity of bone histomorphometry was assessed in different metabolic bone diseases, after fixing the specificity at 75%, 90% and 95% reference levels. Sensitivity was particularly high in cases with greatly increased osteoid and/or resorption features, as in renal osteodystrophy (ROD). All the remodeling indicators were highly sensitive toward advanced or severe forms of mixed ROD (mROD). Osteoid indicators were the most sensitive parameters in ROD with predominant osteomalacia (oROD). Osteoclastic and several osteoid indicators were very sensitive in all grades of ROD with predominant hyperparathyroidism (hROD). Sensitivity was generally low in uremic patients without bone changes (wROD) and also in patients with idiopathic osteoporosis (OP). It is our recommendation, however, that for each individual patient the definite diagnosis should be based on both morphological, clinical and metabolic parameters.

Adult↗
PubMed1989

Distribution of aluminium following intraperitoneal injection of aluminium lactate in the rat.

An animal experiment was performed to evaluate the absorption and distribution of aluminium in serum and tissues of normal rats. The animals were intraperitoneally injected with an aluminium lactate solution at a pH adjusted to 7.0. Before starting, a short preliminary study was carried out in order to verify the validity of the treatment with aluminium lactate instead of aluminium chloride at endogenous pH 3.4. Thirty-one rats were used in the main experiment, divided in four groups. In treated animals, the total Al-administered dose was 75.6 mg during 78 days of treatment. Furthermore, to evaluate the influence of the parathyroid hormone on Al absorption and/or distribution, 200 USP/rat of parathyroid hormone extract (PTH) were also administered during the last 5 days of the experiment. Aluminium content in serum, tibia, rib, brain, liver, muscle, kidney and spleen was determined. Calcium analysis in serum and bone was also performed. The highest concentrations of aluminium were found in liver and spleen, whereas the lowest level was found in the brain. The PTH effect on Al absorption was evident in brain and bone.

Aluminum↗
PubMed1989

Histochemical properties of the "crystal ghosts" of calcifying epiphyseal cartilage.

The crystal ghosts represent a crystal associated organic material which is stained by acidic phosphotungstic acid, periodic acid-silver methenamine and periodic acid-thiosemicarbazide-osmium, and is reactive with cations and with colloidal iron at pH 2.0, and unreactive after methylation and saponification. These results suggest that crystal ghosts are, or derive from, proteoglycans of calcifying matrix.

Animals↗