Phosphaturic Mesenchymal Tumor.

Phosphaturic mesenchymal tumors (PMTs) are neoplasms associated with tumor-induced osteomalacia. Patients typically present with pathologic fractures in the setting of chronic hypophosphatemic hyperphosphaturic osteomalacia, as well as gradual muscle weakness, bone pain, and difficulty walking. Because of their rarity and nonspecific symptomatology, phosphaturic mesenchymal tumors often go undiagnosed for years.

Morbidity and mortality associated with Paget's disease of bone: a population-based study.

Introduction: Limited information is available about the clinical features of Paget's disease of bone among unselected patients in the community. We examined morbidity and mortality associated with this condition in a large inception cohort of Olmsted County, MN, residents with a new diagnosis of Paget's disease from 1950 through 1994.

Materials And Methods: Survival was estimated using the Kaplan-Meier method.

Identification and molecular characterization of a novel splice-site mutation (G1205C) in the SQSTM1 gene causing Paget's disease of bone in an extended American family.

Paget's disease of bone (PDB) is a common late-onset bone disorder characterized by focal areas of abnormal bone remodeling. Positional cloning efforts resulted in the identification of seven genetic loci (PDB1-7) with putative involvement in the pathogenesis of PDB. Meanwhile, the PDB-causing gene from the PDB3 region on chromosome 5q35 has been identified as the SQSTM1 gene.

Formal procedural skills training using a fresh frozen cadaver model: a pilot study.

Graduating medical students are expected to be proficient in a number of procedural skills. A structured curriculum is infrequently available. In addition, the use of a mannequin tends to be unrealistic and students continue to have some anxiety when performing procedures on patients.

Parathyroid carcinoma: is there a role for adjuvant radiation therapy?

Background: The authors proposed to determine risk factors associated with postoperative progression of parathyroid carcinoma within the neck (locoregional) and to assess the efficacy of postoperative adjuvant radiation therapy in preventing disease progression within the neck.

Methods: A retrospective review of patients with pathologically confirmed parathyroid carcinoma who underwent surgical resection was performed. Risk factors identified on univariate analysis were applied in a proportional hazards analysis to identify significant independent predictors of locoregional disease progression and cause-specific survival after surgical resection.

Corrective osteotomy for deformity in Paget disease.

Background: Severe deformity resulting from Paget disease is not uncommon. Malalignment of the extremity may lead to intractable pain, mechanical overload of the neighboring joints, limitation of motion and function, and dysmorphic appearance. Although corrective osteotomy has been used to treat osseous deformities, the outcome of corrective osteotomy for long-bone deformities resulting from Paget disease remains largely unknown.

Etidronate for osteoporosis in primary biliary cirrhosis: a randomized trial.

Background/aim: Osteoporosis is a common complication of primary biliary cirrhosis but there is no accepted therapy for the osteoporosis. In this randomized controlled trial, we compared the effects of etidronate to placebo on the treatment of osteoporosis associated with primary biliary cirrhosis.

Methods: Sixty-seven patients with primary biliary cirrhosis and osteopenia, defined by bone mineral density criteria (T-score < -2.

Fracture risk among patients with Paget's disease: a population-based cohort study.

Localized disruption of bone architecture leads to an increased risk of pathological fractures in patients with Paget's disease, but the impact of the disease on overall fracture risk is unknown. We addressed this issue among 236 Olmsted County, Minnesota residents (107 women and 129 men) first diagnosed with Paget's disease from 1950 through 1994. These subjects (mean +/- SD age at diagnosis, 69.

Long-term trends in the incidence of Paget's disease of bone.

Existing data on the epidemiology of Paget's disease of bone are limited by the lack of directly determined secular trends in clinically diagnosed Paget's disease. In the current study, we examine trends in Paget's disease incidence in Olmsted County, MN, using data from the Rochester Epidemiology Project medical records linkage system. During the period 1950 through 1994, 236 Olmsted County, MN residents were diagnosed for the first time with Paget's disease of bone at a mean age of 69.

Insulin-like growth factor system abnormalities in hepatitis C-associated osteosclerosis. Potential insights into increasing bone mass in adults.

Hepatitis C-associated osteosclerosis (HCAO) is a rare disorder characterized by a marked increase in bone mass during adult life. Despite the rarity of HCAO, understanding the mediator(s) of the skeletal disease is of great interest. The IGFs-I and -II have potent anabolic effects on bone, and alterations in the IGFs and/or IGF-binding proteins (IGFBPs) could be responsible for the increase in bone formation in this disorder.

Paget's disease of bone: indications for treatment and goals of therapy.

Paget's disease of bone is a common disorder of unknown etiology characterized by increased bone remodeling and abnormal bone architecture. The pathologic process is initiated by an increase in osteoclast-mediated bone resorption, accompanied by a compensatory increase in bone formation. The increased bone remodeling results in a disorganized mosaic of woven and lamellar bone.

Paget's disease is associated with changes in the immunohistochemical distribution of noncollagenous matrix proteins in bone.

Paget's disease of bone is characterized histologically by abnormal architecture of bone matrix. Extensive areas of woven bone and numerous scalloped cement lines occur as a result of increased irregular remodeling. Noncollagenous proteins (NCP) play an important role in the organization and mineralization of bone matrix and promote distinct cell-matrix interactions necessary for normal remodeling.

Comparative study of alendronate versus etidronate for the treatment of Paget's disease of bone.

Alendronate, an aminobisphosphonate, is much more potent than etidronate, an older bisphosphonate, in inhibiting osteoclast-mediated bone resorption, and unlike etidronate, therapeutic doses of alendronate are not associated with abnormal mineralization. In the present study, we compared the effectiveness, safety, and tolerability of 6 months of daily oral administration of alendronate (40 mg) with those of etidronate (400 mg) in 89 patients with clinically active Paget's disease. The primary efficacy end point was the percent change in serum alkaline phosphatase.

A review of corrective osteotomies for deformity in Paget's disease.

Corrective diaphyseal osteotomies for pagetic deformities may require a long time for union. However, metaphyseal osteotomies healed uneventfully. The use of plate fixation was associated with a lower rate of complications in diaphyseal osteotomies in Paget's disease.

Medullary thyroid carcinoma: clinicopathologic features and long-term follow-up of 65 patients treated during 1946 through 1970.

We retrospectively reviewed the medical records of 65 consecutive patients with medullary thyroid carcinoma, who had had their primary surgical treatment at the Mayo Clinic during the years 1946 through 1970. Of these patients, 58 had sporadic and 7 had familial medullary thyroid carcinoma. Thyroid nodules were the most common initial manifestation.

Effects of altered calcium intake on diurnal and calcium-stimulated plasma calcitonin in normal women.

We sought to determine if any protective effect of dietary calcium (Ca) or Ca supplements on bone could be at least partially mediated by increased calcitonin (CT) secretion. First we studied 10 healthy premenopausal women (median age, 35.5 years) who were randomized to high or low dietary Ca intake (1752 versus 391 mg elemental Ca per day) for 2 weeks and then crossed over.

Effects of oral contraceptive and estrogen administration on plasma calcitonin in pre- and postmenopausal women.

Estrogen (E) therapy and administration of oral contraceptives (OC) reportedly increase plasma calcitonin (CT) concentrations in women, effects said to mediate in part the beneficial actions of E on bone. To further examine this theory, we tested the effects of three cycles of OC therapy in 12 young women, comparing them to 10 healthy women before and after three normal menstrual cycles. We also determined the effects of 3 months of E therapy (ethinyl estradiol, 20 micrograms/day, 25 of 30 days) in 14 healthy postmenopausal women, using a crossover design (studied after 3 months with and 3 months without E).

Cosecretion of calcitonin gene products: studies with a C18 cartridge extraction method for human plasma PDN-21 (katacalcin).

PDN-21, the carboxyl-terminal flanking peptide encoded by the calcitonin (CT) gene, has been found in plasma of patients with medullary thyroid carcinoma and reportedly is cosecreted with CT. To test whether PDN-21 and CT are cosecreted in normal subjects, we developed a RIA for PDN-21 and measured immunoreactive CT and PDN-21 in whole plasma and silica or C18 cartridge extracts of plasma (exCT, exPDN-21) before and after calcium (Ca) infusion (2 mg Ca/kg over 5 min) in nine normal men and nine normal women. Plasma CT and immunoreactive PDN-21 levels were often below the assay detection limits.

Axial and appendicular bone mineral density in patients with long-term deficiency or excess of calcitonin.

Whether calcitonin deficiency causes and calcitonin excess prevents bone loss is controversial. We therefore measured plasma calcitonin levels and bone mineral density at the radius (by single photon absorptiometry) and lumbar spine (dual photon absorptiometry) in patients with an excess or deficiency of calcitonin. We studied 21 patients who had undergone subtotal thyroidectomy 6.

Plasma calcitonin in primary hyperparathyroidism: failure of C-cell response to sustained hypercalcemia.

An acute increase in serum calcium stimulates calcitonin (CT) secretion, but the effects of chronic hypercalcemia are controversial. Histopathological studies have shown C-cell hyperplasia in primary hyperparathyroidism (1 degree HPT), although circulating levels of CT have been variously reported to be normal, elevated, or depressed. We reexamined this relationship using CT RIA in conjunction with a silica extraction technique that conveys improved sensitivity and specificity for monomeric CT.

Secretion and metabolism of monomeric human calcitonin: effects of age, sex, and thyroid damage.

Some data suggest that human calcitonin (CT) secretion is lower in women than in men, decreases with age and the menopause, and is absent in thyroidectomized persons. To further explore CT secretory physiology, we have studied basal and calcium-stimulated plasma immunoreactive CT (iCT) and silica-extractable monomeric CT concentrations in 148 healthy volunteers and 33 patients with a history of thyroid damage (total or subtotal thyroidectomy, radioiodine treatment for thyrotoxicosis). Both whole-plasma iCT and extractable CT levels were lower basally and after calcium infusion in women than in men, basal levels being reduced about 50% and calcium-stimulated values about 75% from those of male subjects.