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A connection has been suggested between glucocorticoid-induced osteopenia and an increase in the apoptosis of bone cells, and between the dimerization of the glucocorticoid receptor (GR) and the development of apoptosis. On this basis, a study has been carried out on the relationships between the occurrence of apoptotic cells and their detectable GR content, and between apoptosis frequency and changes in histomorphometric variables, in the growth plate and secondary spongiosa of rat long bones after the high-dose (10 mg/day) administration of corticosterone (CORT) and after recovery. The main results of the CORT treatment were: a significant increase in apoptotic osteoblasts, and a concomitant decrease in the histomorphometric variables of bone formation, with a reversal of both values during recovery; a nonsignificant increase in the apoptosis of osteoclasts, without changes in the histomorphometric variables of bone resorption; a significant increase in apoptotic terminal hypertrophic chondrocytes; the presence of GR in all types of skeletal cells in control rats, with different (cytoplasmic and/or nuclear) immunohistochemical detection in the same type of cell; a decrease in GR detection in proliferative chondrocytes and osteocytes in CORT and recovery groups, and in the maturative/hypertrophic chondrocytes of the recovery group; a fall in growth cartilage width, possibly due to the reduced proliferation of proliferative chondrocytes and increased apoptosis in terminal hypertrophic chondrocytes. In conclusion, pharmacological doses of CORT reduce bone formation by increasing osteoblast apoptosis; they reduce growth cartilage width, probably by inhibiting chondrocyte proliferation and increasing the apoptosis of terminal hypertrophic chondrocytes, and they reduce osteocyte GR. Although these effects appear to be mediated by the presence of GR in all skeletal cells, no precise correlation between GR immunohistochemical detection and apoptosis induction has been found.

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Tuberous sclerosis is a hereditary autosomal-dominant disease characterized by hamartomas that can develop in any organ. We report herein the case of a 34-year-old female with tuberous sclerosis and a huge abdominopelvic mass that started growing quickly 2 years after its diagnosis. The patient had undergone several previous operations for hydrocephalus and cerebral tubers, and a nephrectomy for right renal angiomyolipoma. On admission, she was in poor general health with renal failure, severe anemia, and weight loss. A laparotomy revealed that the tumor occupied the pelvis, the lower and part of the upper abdomen, and was hypervascularized, with an extremely irregular surface covered in nodules, vegetations, and areas of hemorrhagic necrosis. The development of the mass and the impossibility of recognizing the internal genital organs led us to assume that the formation had originated from these. Frozen-section examination indicated an undifferentiated tumor that had not been completely resected. Her postoperative course was complicated by bronchopneumonia and progressive renal failure. The patient died 10 days after surgery due to cardiorespiratory failure. A histological diagnosis of epithelioid angiomyolipoma was confirmed. Although it is presently impossible to determine whether angiomyolipoma with predominant epithelioid cells is more aggressive than typical angiomyolipoma, it definitively demonstrated local aggressive behavior in this patient.

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The authors describe the first ever reported case of a malignant pecoma of the uterus infiltrating the ovary, the tube and two bowel loops. This extremely rare tumour usually shows a benign behaviour and seems to arise from the perivascular epithelioid cells (PEC).

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BACKGROUND: Adynamic bone disease was initially attributed too aluminum intoxication in association with low circulating levels of parathyroid hormone. More recently adynamic bone disease has been described even in the absence of aluminum intoxication. PURPOSE OF THE STUDY: It was the purpose of this retrospective analysis of 1429 iliac crest biopsies sent to our laboratory from 1985 to 1994 by 41 Italian nephrology and dialysis centres to assess the frequency of adynamic bone disease and aluminum accumulation. METHODS: Adynamic bone disease was diagnosed by histological and histodynamic (tetracycline labelling) analysis, on the basis of predetermined criteria. Aluminum accumulation was assessed by aluminon histochemical staining. RESULTS: The frequency of adynamic bone disease was fairly constant at approximately 15% from 1985 to 1994. In contrast, aluminum accumulation, defined as positive aluminon histochemical staining, decreased during the same period from 36% to 4%. CONCLUSIONS: Our data clearly show a dissociation of the incidence of adynamic bone disease and aluminium accumulation in bone. At least today, given the low prevalence of aluminium intoxication, factors other than aluminium are the main cause of adynamic bone disease.

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