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Biomedical subjects

E Bonucci

Publications and source records attributed to E Bonucci.

At least 109 records · Page 6Linked to original sources
PubMed1986

Treatment of secondary hyperparathyroidism of predialysis chronic renal failure with low doses of 1,25(OH)2D3: humoral and histomorphometric results.

Treatment of secondary hyperparathyroidism and the osteodystrophy of predialysis chronic renal failure (CRF) with 1,25(OH)2D3 has been advocated by several authors, but also opposed by others for alleged renal toxicity. However, current concepts of the pathogenesis of the early occurrence of secondary hyperparathyroidism in predialysis CRF point to deficiency of 1,25(OH)2D3 as a primary factor. The aim of this study was to evaluate if administration of 1,25(OH)2D3 (0.25 microgram daily) in a dose which would not induce hypercalcemia, would improve humoral and bone histomorphometric parameters in predialysis CRF. 15 patients with predialysis CRF (mean age 51.2 +/- 16.9 years, range 13-73 years), serum creatinine 4.93 +/- 1.7 mg/dl, were treated with the vitamin D metabolite for an average of 16.2 +/- 11.3 months, at the end of which a transiliac bone biopsy for histomorphometry was performed. In addition, 23 patients comparable for age, serum creatinine and causes of renal failure, served as controls. Treatment did not induce hypercalcemia nor adversely modify the rate of decline of renal function. Alkaline phosphatase fell significantly while immunoreactive parathyroid hormone (iPTH) and osteocalcin showed a moderate, not significant, decrease. Compared to the control patients, the bone histomorphometric parameters active resorption surface and active osteoblastic surface were significantly lower and almost normalized by treatment. In conclusion, the study provides conclusive evidence of the absence of toxicity of the metabolite at the low doses employed, together with good therapeutic response on bone histology. Treatment at this dosage could be made in the early stages of predialysis CRF without need of close and continuous monitoring of serum biochemical parameters.

Adolescent↗
PubMed1986

Organic-inorganic relationships, and immunohistochemical localization of amelogenins and enamelins in developing enamel.

The organic-inorganic relationships in calf molar immature enamel, and the localization of amelogenins and enamelins in its matrix, have been studied by post-embedding decalcification and staining (PEDS) method and the immunohistochemical protein A-gold technique, respectively. Filament- and ribbon-like organic structures similar in shape, location and orientation to untreated crystals (crystal ghosts) were shown by PEDS method in immature enamel matrix. Immunohistochemical technique showed that amelogenins were not masked by inorganic substance, because they were reactive both in undecalcified and decalcified sections, gold particles being mainly located at intercrystallite regions; on the contrary, enamelins were masked by inorganic substance because they were reactive only in decalcified sections, gold particles being sometimes closely related to filament- and ribbon-like crystal ghosts. These results are in agreement with those of previous morphologic studies, showing that crystals of immature enamel are organic-inorganic structures, and with biochemical findings suggesting that amelogenins are placed in intercrystallite regions and enamelins in crystallite regions. The hypothesis is advanced that enamelins are part of the crystal ghosts of immature enamel.

Ameloblasts↗
PubMed1985

Osteonectin and Gla-protein in calf bone: ultrastructural immunohistochemical localization using the Protein A-gold method.

Osteonectin and bone Gla-protein have been localized at the ultrastructural level in calf scapula bone tissue. Post-embedding-decalcified thin sections of paraformaldehyde-fixed and Araldite-embedded specimens of calf scapula were incubated with rabbit antisera to bovine osteonectin and bone Gla-protein, and the sites of antigen-antibody reaction were demonstrated using the Protein A-gold technique. Specific labelling of the bone matrix was obtained with both antisera. The collagen fibers were labelled particularly intensely. Filamentous structures visible at the sites of early mineralization were labelled by rows of gold particles after incubation with anti-osteonectin antiserum. These findings are consistent with biochemical data available on the localization and properties of these non- collagenous proteins. 'Crystal ghost'-like structures are immunoreactive to anti-osteonectin antiserum.

Animals↗
PubMed1985

Bone GLA protein in predialysis chronic renal failure. Effects of 1,25(OH)2D3 administration in a long-term follow-up.

Serum bone GLA protein (BGP) was measured by radioimmunoassay in 42 patients (age, 47.5 +/- 16.6 years; serum creatinine, 4.32 +/- 1.9 mg/dl) with predialysis chronic renal failure (CRF). Nineteen patients were studied within a short period of time, while 23 were followed with repeated measurements of serum BGP, creatinine, iPTH, and alkaline phosphatase (AP) for a mean period of 17.1 +/- 8.1 months. Eleven of these patients were treated with 1,25(OH)2D3 for a mean of 16.8 +/- 6.4 months. In 23 patients at various stages of CRF, a transiliac bone biopsy was performed for histomorphometric evaluation. In the untreated patients, serum BGP was higher than normal and showed a positive correlation with creatinine levels (P less than 0.001). Serum BGP was also positively correlated with iPTH, AP, serum phosphate, active resorption surface, active osteoblastic surface, osteoid surface, and volume. During treatment with 1,25(OH)2D3, BGP, iPTH, and AP were significantly lower than in the untreated patients. The reduction in iPTH and BGP was proportional, while BGP and AP no longer correlated. Repeated measurements of BGP during the long-term follow-up showed a progressive rise in the untreated patients and a downward course of BGP levels during treatment. In conclusion, serum BGP increases progressively in CRF, rising with advancing renal damage in close correlation with iPTH, AP, and the severity of renal osteodystrophy. Treatment with 1,25(OH)2D3 causes a parallel decline in BGP and iPTH levels and dissociation between BGP and AP can be observed. Compared to AP, BGP seems to be a more reliable index of secondary hyperparathyroidism and potentially more useful in the long-term monitoring of treatment with 1,25(OH)2D3.

Adolescent↗
PubMed1984

Bone histology and calcium metabolism in patients with nephrotic syndrome and normal or reduced renal function.

Bone histology and its relationship with calcium metabolism was evaluated in adult patients with nephrotic syndrome: 29 had normal renal function (GFR 103 +/- 4 ml/min/1.73 m2) (group 1) and 20 had renal insufficiency (GFR 31 +/- 4 ml/min/1.73 m2) (group 2). In group 1, serum PTH, 1.25-HCC and 24.25-HCC levels were normal, while 25-HCC values were reduced. Bone histology was normal in 76% of the patients, while 17% had isolated osteomalacia and 7% an associated bone resorption. Group 2 showed a higher incidence of bone resorption when compared with a matched group of patients with renal failure and no proteinuria (40% vs. 13%) and a comparable frequency of isolated mineralization defect (25% vs. 34%). PTH levels were definitely increased and serum total calcium and all the vitamin D metabolites were reduced. A significant correlation between the apparent duration of the disease and the severity of osteodystrophy was found only in group 2. In conclusion, no constant derangement of calcium metabolism and bone histology is evident in patients with nephrotic syndrome and normal renal function, while patients with persistent proteinuria are at high risk of osteodystrophy even in the early phases of renal failure.

Adolescent↗
PubMed1984

Basic and 'special' stains for plastic sections in bone marrow histopathology, with special reference to May-Grünwald Giemsa and enzyme histochemistry.

A battery of morphological, histochemical, and enzyme histochemical stains have been experimented on semithin sections of glycol-methacrylate-embedded bone marrow biopsies. We have been able to reproduce on sections the typical 'Romanowsky effect' which characterizes May-Grünwald Giemsa-stained smears of bone marrow or peripheral blood. This appears to be of critical importance for proper routine morphological evaluation of bone marrow biopsies. Conventional histochemical stains, and the enzyme histochemistry reactions that are most useful and widely used in the study of marrow aspiration smears have been successfully applied to plastic sections: in this way the evaluation of the cytochemical profiles of marrow diseases, especially leukemias, may be included in the histopathologist's diagnostic approach, with the additional advantage of preserving the architecture of the tissue and the relationship between haemapoietic cells and stromal components.

Biopsy, Needle↗
PubMed1984

Eosinophilic leukemia with prominent visceral involvement: histopathological and histochemical observations.

Evidence supporting the view that eosinophilic leukemia exists as a separate entity among myeloproliferative disorders was found in the pathological and histochemical findings in a case of hypereosinophilic disease. Blast cells and eosinophils in all stages of maturity, including unusual atypical eosinophil precursors, were seen in a prominent infiltration of the spleen and the liver. Blasts were far more numerous in the viscera, especially in the liver, than in the marrow and peripheral blood. Enzyme histochemical studies of plastic sections showed that blasts were reactive for cyanide-resistant peroxidase, which is specific for eosinophils, and could therefore be regarded as part of an eosinophilic leukemic proliferation. Some eosinophils showed aberrant reactivity for chloroacetate esterase. The existence of a neoplastic proliferation of eosinophils is consistent with the view that eosinophils represent a distinct marrow line. The possibility that hypereosinophilic patients may harbor a far more prominent blastosis in the viscera than is apparent from marrow and blood picture is also stressed. Finally, a chromosomic abnormality previously described in acute nonlymphocytic leukemia with atypical eosinophils in the marrow is for the first time reported in a patient with hypereosinophilic disease.

Adult↗
PubMed1983

Osteoclast changes induced by lead poisoning (saturnism).

This paper reports the results of histological, histochemical and electron microscopic investigations, and of electron probe analysis, carried out on bone cells of tibiae and femurs of lead-poisoned collie puppies. The most important changes were found in osteoclasts. They were increased in number, showed intranuclear and intracytoplasmic inclusion bodies, and frequently had shrunk, pyknotic nuclei and were detached from bone matrix. Organic components were histochemically demonstrable in the inclusion bodies, which consisted of a central core, peripheral filaments and intrinsically electron-dense granules. Lead was detected in the inclusion bodies by electron probe elemental analysis: Pb-L alpha pulses in the regions with inclusions are four times higher than those in the cytoplasm. Osteoblasts and osteocytes did not contain inclusion bodies, probably because in them lead does not reach a concentration sufficiently high to induce inclusion formation. On the contrary, this concentration can be reached in the osteoclasts when, during bone resorption, they accumulate the lead salts previously incorporated in the bone matrix.

Animals↗
PubMed1982

The tensile properties of single osteonic lamellae: technical problems and preliminary results.

An investigation on the tensile properties of osteonic lamellae whose fiber bundles have an almost transversal spiral course has been carried out, using samples obtained from alternately structured osteons by applying a procedure described in detail by Ascenzi et al. (1973). A very sensitive microwave extensometer based on cavity and pulse technique was employed in order to record the tensile curve from each lamellar sample. The inhomogeneity in thickness within, and between, single lamellae has ruled out any form of comparison between the curves recorded for ultimate tensile strength and modulus of elasticity. This result is in agreement with the morphological finding that there is usually a wide, continuous range of variation in thickness even along the length of single osteonic lamellae.

Bone and Bones↗
PubMed1982

Effect of chronic propranolol treatment on bone changes of secondary hyperparathyroidism in dialysis patients.

To assess the effect of long-term propranolol therapy on uremic osteodystrophy, we evaluated retrospectively the biochemical, X-ray, and bone histological changes in 9 dialysed hypertensives who had been on propranolol treatment for periods ranging from 1 to 8 years. The control group included 9 well-matched dialysed uremics never treated with beta-blockers. The two groups did not differ in serum ionized calcium or iPTH levels. The incidence of bone resorption evaluated on X-ray findings and on bone biopsy specimens was of a comparable degree in the two groups. Our data show that propranolol even if started early in the course of renal failure, is of no benefit in preventing uremic bone disease.

Bone Resorption↗