Active clinical trials for "Osteomalacia"

This study will use a procedure called selective venous catheterization in patients with tumor-induced osteomalacia (TIO) or oncogenic osteomalacia (OOM) to try to locate very small tumors that produce proteins called phosphatonins. Too much phosphatonin in the blood causes the kidneys to allow large amounts of phosphorus to be excreted in the urine, leading to low blood levels of phosphorus and, in turn, to osteomalacia (a condition of soft bones). Osteomalacia can cause bone fractures requiring many surgical procedures that can leave patients in pain. Patients may also feel weak and can lose height from massive bone loss. Selective venous catheterization is a way to measure the amount of phosphatonin in the blood and may be used as a way to locate phosphatonin-producing tumors that cannot be found using standard imaging techniques. Patients with TIO or OOM are screened under NIDR Protocol 01-D-0184 with a medical history, review of medical records and routine physical examination. Other procedures may include blood tests, urine tests, and imaging tests, such as x-rays, bone densitometry, bone scan, computed tomography (CT) and magnetic resonance imaging (MRI). This study will include mostly patients whose tumors were not able to be located through imaging procedures, but also a few patients whose tumors were located. All participants, regardless of whether or not their tumor was located, undergo selective venous catheterization. For this procedure, a radiologist inserts a catheter (thin flexible tube) into the body and uses fluoroscopy (a type of x-ray) to guide the tip of the catheter to different places in the body to collect small amounts of blood from the different areas. After the procedure, the patient lies flat for 2 hours and avoids moving his or her leg on the side where the catheter was placed. The blood is analyzed to measure the amount phosphatonin is in each sample, and the amounts are compared to the average amount of phosphatonin in the general blood circulation. If a higher level of phosphatonin is found in one area and the location of the tumor is unknown, the patient undergoes imaging in that area. If a tumor is found and it is in an area where it can be removed surgically, the patient is given the option to have the surgery. If the tumor is not found by imaging done after the first catheterization procedure, the patient has the option to have a second catheterization, taking samples of blood only from the area where the phosphatonin was found to be the highest during the sampling procedure.

In this study the investigators wanted to assess vitamin D status and possible consequences of low plasma 25-hydroxyvitamin D levels in a population of healthy mothers and their infants, in the community of Aarhus, Denmark.

We aimed to determine the effect of vitamin D replacement therapy on serum FGF-23 concentrations in vitamin D deficient women and to compare the FGF-23 concentrations of vitamin D deficient patients with healthy subjects and patients with genetically-determined hypophosphatemic rickets.

Evaluate Survivorship for the Biomet® Comprehensive® Reverse Shoulder Mini Baseplate.

Oncogenic osteomalacia is rare disease predominantly caused by a small, somatostatin receptor positive mesenchymal tumor, which is frequently hidden in an unusual anatomical site and often goes undetected by conventional imaging. A permanent cure of the disease relies on exactly localizing the tumor and completely removing it. 68Ga-DOTATATE PET/CT is a novel scan that might have improved sensitivity and resolution specifically for somatostatin receptor positive tumors. The investigators will scan the suspicious and confirmed patients of oncogenic osteomalacia and compare it to 99mTc-HYNIC-TOC SPECT/CT and 18F-FDG PET/CT to see if it improves patient care.

The purpose of this study is to determine whether mass spectrometry analysis of stable (non-radioactive) calcium isotopes in plasma or urine samples can help in the diagnosis of bone and calcium disorders.

Fibroblast froth factors (FGFs) are humoral factors identified by their ability to stimulate cell proliferation1. They play different roles in the regulation of cell proliferation, differentiation and function. Most FGF family members act as paracrine factors. But FGF19(FGF19) subfamily members, including FGF19, 21, and 23, work as endocrine factors to regulate bile acid, carbohydrate and phosphate metabolism2. Of these, FGF23 plays an important role in phosphate and bone metabolism3. FGF23 gene encodes 251 amino acids, including a 24-amino acid signal peptide4. The secreted FGF23 is a protein consisted of 227 amino acids. It works by binding to a Klotho-FGF receptor 1c (FGF1c) complex5. FGF suppresses the expression of type 2a and 2c sodium-phosphate cotransporters, which mediate phosphate reabsorption in proximal tubules.6 FGF23 decreases 25-hydroxyvitamin D-1α-hydroxylase expression and enhances 25-hydroxyvitamin D-24-hydroxylase expression6. Therefore, FGF23 reduces serum 1,25-dihydroxyvitamin D〔1,25(OH)2D〕, which stimulates intestinal calcium and phosphate absorption. FGF23 decreases serum phosphate through the above mechanisms FGF23 over-expression might result in hypophosphatemic rickets and osteomalacia. Tumor induced osteomalacia (TIO) is a paraneoplastic syndrome usually caused by benign phosphaturic mesenchymal tumors. Symptoms are nonspecific, such as general weakness, fatigue, and bone pain. Sometimes fracture may occurs. The responsible tumors are sometimes small and difficult to detect. Tumors secrete FGF23. FGF23 reduced phosphate reabsorption in the proximal tubules and decrease 1,25(OH)2D levels, which result in hypophosphatemia and then osteomalacia. The investigators would like to observe the changes of FGF23 in patients who receive operation or medical treatment and hope this will benefit future treatment.

Individual patient expanded access requests may be considered for patients who have no other treatment options

The tumors that cause oncogenic osteomalacia (TIO) express and release in the circulation phosphaturic factors such as fibroblast growth factor-23 (FGF-23) that decrease renal phosphate absorption through acting in the proximal renal tubule and decreasing Type 2a and 2c sodium-phosphate co-transporter. They typically follow a benign clinical course and even in the rare malignant cases, local recurrence occurs in less than 5% and distant metastasis are very uncommon. In this study we aim to investigate the role of other molecular pathways such as ERK1, ERK2, mTOR, EGFR, MEK1, MEK2, VEGFR3, AKT1, AKT2, IGFR-1, IGFR-2, PDGFRA, PDGFRB, cMET, FGFR2, apart from FGF23, KLOTHO and PHEX, in the behavior of histopathologically benign mesenchymal phosphaturic tumors.