Donald R Bertolini

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When leukocytes are exposed to mitogens or antigens in vitro, they release bone-resorbing activity into the culture supernatants which can be detected by bioassay. Like many lymphocyte-monocyte products, this activity has been difficult to purify because of its low abundance in activated leukocyte cultures and the unwieldy bioassay required to detect(More)
We report molecular cloning and initial functional characterization of a novel member of the low density lipoprotein receptor (LDLR) gene family. The cDNA was isolated from a human osteoblast cDNA library and encoded a 1,615 amino acids protein designated as LR3. It has, in the extracellular region, a cluster of three LDLR ligand binding repeats at a(More)
Myeloma cells destroy bone by producing an osteoclast-stimulating factor that has chemical and biological characteristics similar to the bone-resorbing activity present in the supernatants of activated leukocyte cultures. Recently, a number of bone-resorbing leukocyte cytokines have been identified, including interleukin-1, lymphotoxin, and tumor necrosis(More)
The culture media of three cell lines, a human prostate carcinoma (PC3), a rat Leydig cell tumor (Rice-500), and a rat carcinosarcoma (WRC-256), that were derived from tumors associated with humoral hypercalcemia of malignancy (HHM), were examined for stimulation of adenylate cyclase in ROS 17/2.8 osteoblastic cells and for bone resorptive activity in(More)
Interconversion of estrogens by osteoblasts may play a role in regulating bone mass. As a first step toward exploring this possibility, we investigated the expression and activity of 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) in cultured human osteoblasts (HOB) and osteoblast-like osteosarcoma cells (MG63, TE85, and SaOS-2). Significant 17beta-HSD(More)
The precise mechanisms responsible for increased calcium levels in patients with cancer are not fully understood. In a recent study, the participation of interleukin (IL)-6 as an important mediator of key parameters of cancer cachexia in the colon-26 adenocarcinoma was reported. Here, we show that in addition to cachexia, C-26 tumour bearing mice also(More)
UNLABELLED To investigate the role of leptin in bone formation, the skeleton of the obese female leptin receptor-deficient Zucker rat was examined using pQCT, microCT, and histomorphometry. A trend toward decreasing structural and bone formation parameters in these rats as they age suggest that leptin has a small positive effect on bone. INTRODUCTION(More)
Data from several laboratories suggest a role for a variety of cytokines in the process of bone resorption. SK&F 86002 [5-(4-pyridyl)-6(4-fluorophenyl)-2,3-dihydroimidazo(2,1-b) thiazole], a potent cytokine-suppressive anti-inflammatory agent, has been shown to inhibit cyclooxygenase (CO) and 5-lipoxygenase (LO) activity and to inhibit the production of(More)
The human T cell lymphotrophic virus type I (HTLV-I) has recently been identified in a T cell lymphoma associated with hypercalcemia and increased bone turnover. Since increased serum concentrations of 1,25-dihydroxyvitamin D have been reported in this disease, we have examined the capacity of HTLV-I-infected cord blood lymphocytes to metabolize(More)