Active clinical trials for "Hypercalcemia"

Hypothesis : Vitamin D serum concentration is decreased in the first trimester in pregnant women who will develop preeclampsia in the second or third trimester compare to a control group Primary purpose : To determine the vitamin D status in the first trimester in a large population of french pregnant women in order to evaluate the importance of the vitamin D deficiency in France and correlate this deficiency with preeclampsia

Parathyroid hormone (PTH) gland calcium sensing receptor (CASR) regulates PTH secretion. CASR is also expressed in nephron thick ascending limb (TAL). Bartter syndrome (BS), a normotensive hypokalemic tubulopathy, may be due to mutations in different TAL channels, including the potassium channel ROMK. Mutations in CASR may also cause BS through its effects on ROMK function. However, it is unknown whether ROMK mutations exert any effects on CASR function and PTH physiology. Preliminary data from our center shows that PTH levels were specifically elevated in type II (where ROMK is mutated) and not in type IV (where another gene, Barttin is defective) BS, without a common explanation. We assume that the mutation in ROMK may cause a dysregulation of PTH secretion via possible interaction with CASR. The purpose of this study is: to investigate the PT-gland function and regulation in BS. Methods: Patients with BS type II and IV and normal controls will undergo a standard protocol of controlled ionic hypo- and hypercalcemia, during which PTH secretion, phosphate balance and calcium excretion will be followed. Calcium Vs PTH response curves will be generated and compared. Expected impact and benefit: the results of this study will help understand the mechanisms of PTH regulation beyond CASR.

Familial hypocalciuric hypercalcemia (FHH) is a rare disease (ORPHA#405, www.orpha.net) and most likely underdiagnosed, that clinicians should be aware of in the differential diagnosis of a hypercalcemia. Appropriate identification of the FHH has implications in treatment and also for the family, since it is an automosal-dominant disease, due to mostly a heterozygous loss-of-function mutation of the CASR (calcium-sensing receptor) gene, but also much less freqüent mutations of another two genes (AP2S1 and GNA11). In case of clinical and biochemical suspicion of FHH, a genetic evaluation is mandatory. Nevertheless, an important number of patients, the genetic study is negative. This observational study is intended to perform a descriptive review of cases with clinical and biochemical suspicion of FHH who underwent a genetic study in the usual clinical practice. Clinical, biochemical and radiological characteristics, treatment, follow-up and comorbidities of genotype-negative participants will be compared with genotype-positive cases.

Purpose of this study is to compare the image quality and diagnostic accuracy obtained with ultrafast solid state short SPECT in comparison with the routine SPECT protocol.

Primary hyperparathyroidism (PHPT) is one of the common endocrine disorders. The major clinical symptoms involve stones, bones, abdominal groans and psychiatric moans. Increased parathyroid cell proliferation and decreased calcium-mediated control of the PTH secretion are characteristic findings. The most common cause of PHPT is adenoma followed by hyperplasia and carcinoma.The molecular mechanisms involved in parathyroid tumorigenesis are partially known. Few genes have been identified and their roles are under study. The genes which are under study by different groups are unable to give a definite direction towards the understanding of parathyroid tumorigenesis and the mechanism involved in overgrowth of parathyroid tissue. So identifying different proteins and their regulation pattern from adenomas to carcinomas will be the initial steps towards understanding the proteins involved in tumorigenesis of parathyroid tissues. By using proteomics approach one can generate protein level information. In this study, using a combined approach based on 2 D gel electrophoresis and mass spectrometry (MS), the investigators propose to study a comparative proteomics to examine the changes of protein profiles in parathyroid tumor tissues with normal and hyperplasic parathyroid tissues. This work plan will help us to understand differentially expressed proteins in patients with PHPT. This will help in understanding the disease and identifying better diagnostic and curative measures of the disease. The investigators are also planning to access nuclear morphometry changes in sporadic parathyroid tumors. It will help in establishing cellular and nuclear change pattern variations from normal to parathyroid tumors.