View clinical trials related to Osteomalacia.
Filter by:The objective of this study is to assess the safety and tolerability of KRN23 after a single subcutaneous (SC) administration in subjects with X-linked hypophosphatemic rickets/osteomalacia (XLH) in Japan or Korea.
Evaluate Survivorship for the Biomet® Comprehensive® Reverse Shoulder Mini Baseplate.
Background: - Hypophosphatemia is a condition where a person has low levels of phosphorus in the blood. Low blood phosphorus can cause muscle and bone weakness (such as rickets) and teeth problems. One cause of the condition is having too much fibroblast growth factor 23 (FGF23). FGF23 is a hormone that causes the kidney to get rid of phosphorus in the urine. It can also prevent the body from making vitamin D, which helps the body absorb phosphorus in food. - Many people with low blood phosphorus take high doses of phosphorus and calcium medications. However, one side effect of these drugs is increased blood levels of parathyroid hormone (PTH). The drug cinacalcet can help lower PTH levels, which may decrease the amount of phosphorus lost in the urine and increase the phosphorus levels in the blood. Researchers want to see if cinacalcet can help blood phosphorus and decrease the amount of phosphorus supplements that people need to take. Objectives: - To see if cinacalcet can be a safe and effective treatment for people with low phosphorus conditions due to high FGF23. Eligibility: - Individuals between 18 and 70 years of age who have different forms of hypophosphatemic rickets and tumor-induced hypophosphatemia Design: - Participants will have up to 25 study visits over about 28 weeks. - Participants will be screened with a physical exam and medical history. Blood and urine samples will be collected. - Up to three more lab visits for blood and urine tests will be required before treatment. Imaging studies of the bones, spine, and kidneys will be performed. - Participants will have a 3-night hospital stay to start treatment. They will take cinacalcet once a day. Treatment will be monitored with frequent blood tests and imaging studies. - Participants will continue to take cinacalcet once a day for 3 weeks. They will have regular study visits to monitor the treatment. - There will be up to two other overnight hospital stays (1 to 3 nights) to adjust cinacalcet doses. The dose will increase until the maximum dose is reached, or side effects develop. - After the end of the cinacalcet study, participants will have several more followup visits to monitor the effects of treatment.
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.
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.
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.
Because of its high sun exposure, Israel was traditionally supposed to be protected from vitamin D deficiency, and the country food products hardly contain vitamin D supplements. However the Jerusalem ultra-Orthodox population, which constitutes a significant fraction of the city population, is at risk of developing vitamin D deficiency due to low sun exposure, as consequence of its dressing code covering most of the body and very limited time of outside activities. The investigators aim is to check whether vitamin D deficiency is found more frequently in the ultra-Orthodox male population in comparison to a non-ultra-Orthodox male population, and to study its eventual consequences. Correlation between vitamin D levels and PTH levels will be examined, according to age and to creatinine levels. Bone mineral density (BMD) will be evaluated in 2 selected subgroups of subjects (with lowest and highest vitamin D levels), and re-evaluated after 6 months of vitamin D supplementation in vitamin D-deficient subjects. An increase in BMD within 6 months would suggest osteomalacia as the main cause of low BMD in these subjects.
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.
This study has four objectives: 1) to provide investigators the opportunity to study bone specimens from patients with various skeletal diseases; 2) to treat patients with skeletal diseases at the NIH; 3) to expose NIH trainees to certain skeletal diseases; and 4) to gain more knowledge about skeletal diseases and stimulate further study of bone biology. Anyone with a disease that affects the skeleton may be eligible for this study. All evaluations, tests, procedures and treatments given study participants are used in the standard care of skeletal diseases. No experimental evaluations or treatments are offered. Patient evaluations include a medical history, review of medical records and routine physical examination. Based on the findings, other procedures may be recommended, including blood tests, urine tests, and imaging tests, such as X-rays, bone densitometry, bone scan, computed tomography (CT) and magnetic resonance imaging (MRI). Bone specimens from participants will be collected for research use. Specimens will be obtained from bone removed during a patient s planned surgical procedure performed for medical care, or patients may be requested to have a bone biopsy removal of a small piece of bone tissue as part of the patient evaluation procedure.
Patients with confirmed or suspected states with resistance to vitamin D or parathyroid hormone (PTH) will be admitted for diagnosis, treatment review with suggestions for modifications to the current or new treatment and for inclusion in other protocols. These states include hypocalcemia, rickets, osteomalacia, pseudohypoparathyroidism. Resistance to a factor is manifested by deficient bioeffect despite high levels of the factor in blood. Patients will be tested with multiple indices of mineral metabolism to establish the diagnosis and examine the spectrum of the underlying disorder. The principal therapies will be combinations of calcium, phosphate, and a vitamin D analog. Selected patients will have localization and surgery to remove a tumor that causes renal wasting of phosphate. Patients will also be considered for entry into other research protocols.