1/30. Severe hypomagnesaemia-induced hypocalcaemia in a patient with Gitelman's syndrome.Gitelman's syndrome (GS) is characterized by hyperreninaemic hyperaldosteronism, hypokalaemia, metabolic alkalosis, hypomagnesaemia and hypocalciuria and is due to a defect of the Na-Cl cotransporter at the distal tubule, which may appear in a sporadic or in a familial form. It is an autosomal recessive disorder associated with normal or reduced blood pressure. We report a case of severe hypomagnesaemia-induced hypocalcaemia in a 39-year-old Caucasian woman with GS. The patient had impaired parathormone (PTH) responsiveness to peripheral stimuli, as proved by the marked PTH increase and normalization of plasma calcium levels after acute and chronic administration of magnesium salts. Secondary normotensive hyperreninaemic hyperaldosteronism with hypokalaemia and metabolic alkalosis was also present. Normal plasma renin activity (PRA) and aldosterone levels were restored by administration of an inhibitor of prostaglandin synthesis. The electrolyte imbalance was successfully corrected with chronic treatment with magnesium and potassium salts. Genetic analysis identified a compound heterozygous mutation in the Na-Cl cotransporter gene (NCCT), confirming the diagnosis of GS. The striking feature of this case of GS was impaired PTH responsiveness to peripheral stimuli determined by hypomagnesaemia and the resulting severe hypocalcaemia, which had not previously been described in this syndrome.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
2/30. hypocalcemia following pamidronate administration for bone metastases of solid tumor: three clinical case reports.Bisphosphonates, such as pamidronate, are a new class of drugs, initially described for treatment of neoplasic hypercalcemia. Currently, they also may be used in the treatment of bone metastases from solid tumor, even without hypercalcemia. hypocalcemia is a potential adverse effect of these drugs, which is considered infrequent and rarely symptomatic. We describe three cases of severe hypocalcemia following one injection of pamidronate. The three patients had bone metastases from solid tumors (breast in two cases, prostate in one), at least partially osteoblastic, and none had hypercalcemia. The induced hypocalcemia was rapid in onset, severe, and durable. The mechanism seems to be multiple and may include both the expected reduction of osteolysis and also a rapid and direct action on parathyroid glands followed by resistance to parathormone. Some elements could amplify the phenomenon, such as latent hypoparathyroidism after surgery, cervical radiotherapy, hypomagnesemia, or low 25 hydroxy vitamin d (25OH D). For patients who have such risk factors, it may be useful to check calcium several days after the first injection.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
3/30. hypocalcemia after therapeutic use of magnesium sulfate.It is now recognized that magnesium plays an important role in calcium homeostasis. Although the effects of hypomagnesemia have been frequently reported, little has been written to suggest a clinically important role for hypermagnesemia. A case is reported in which severe hypocalcemia, with a low plasma parathyroid hormone (PTH) concentration, resulted from the therapeutic use of magnesium sulfate for toxemia of pregnancy. Following recovery, the parathyroid glands were shown to respond normally to a phosphate load. It is suggested that the hypermagnesemia directly suppressed PTH secretion, resulting in symptomatic hypocalcemia.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
4/30. Hungry bone syndrome in a child following parathyroid surgery.The rare hungry bone syndrome was encountered in a 15-year-old child after the removal of a parathyroid adenoma. Contrary to the hypocalcemias caused by the removal of all parathyroid glands or transient ischemia after parathyroid surgery, in which the serum inorganic phosphorus level is usually normal, both serum calcium and inorganic phosphorus levels are decreased in hungry bone syndrome in the early postoperative period. Vigorous calcium supplementation and vitamin d are required for prolonged periods.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
5/30. Unexpected prolonged extreme hypocalcaemia and an inadequate PTH response in a patient with metastatic breast carcinoma.Although hypercalcaemia is often encountered during the course of malignant disease, hypocalcaemia appears to be rather rare. We describe a 37-year-old patient with metastatic carcinoma of the breast, who developed extreme hypocalcaemia (as low as 0.75 mmol calcium per litre) after chemotherapy. This is caused by a combination of hungry-bone syndrome and an insufficient parathyroid response. The latter may be the result of a direct toxic effect of chemotherapy on parathyroid hormone (PTH) synthesis possibly in combination with microscopic tumour infiltration in the parathyroid glands. Correction of the extreme hypocalcaemia over a period of 100 days by oral and intravenous calcium supplementation, corresponding to a total of 352 gram elemental calcium (1/3 of the total body calcium), resulted in gradual symptomatic relief. The possible mechanisms for these findings are discussed and the literature is briefly reviewed.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
6/30. Maternal activating mutation of the calcium-sensing receptor: implications for calcium metabolism in the neonate.Two infants were studied born of a mother with autosomal dominant hypocalcemia who is heterozygous for an activating mutation in the calcium-sensing receptor gene. Both infants had serum calcium levels in the low-normal range and parathyroid hormone levels in the high-normal range and were healthy. The mother's hypocalcemia had been treated with calcium carbonate and calcitriol and she has nephrocalcinosis and mild renal insufficiency. By genetic testing, both infants were shown to have normal calcium-sensing receptor gene alleles, i.e., they had not inherited the activating mutation from their mother. This provided reassurance to the family and ensured that treatment to correct apparent hypocalcemia would not be necessary. The fact that the infants had high normal parathyroid hormone levels with normal calcium may be due to the fact that with a normal calcium-sensing receptor their parathyroid glands responded in utero to the maternal hypocalcemia with an increase in parathyroid hormone.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
7/30. pregnancy in a woman suffering from type 1 diabetes associated with Addison's disease and Hashimoto's thyroiditis (fully developed Autoimmune Polyglandular Syndrome Type 2).In this article the pregnancy of a woman suffering from the complete triad typical of Autoimmune Polyglandular Syndrome Type 2 (Addison's disease type 1 diabetes Hashimoto's thyroiditis) is reported. By using insulin pump therapy with insulin lispro, it was possible to balance diabetes control with changes of steroid replacement therapy. pregnancy was uneventful until week 27, when signs of preeclampsia occurred. The boy was born without difficulty at gestational age 37 weeks by planned cesarean section but signs of diabetic fetopathy (macrosomia, hypoglycaemia and hypocalcaemia) were expressed. He required a short course of hydrocortisone therapy. He made a good and rapid recovery. The mother made a good post-operative recovery too, but 4 months after the delivery microalbuminuria as well as mild hyperuricemia are still present. Interdisciplinary approach and very careful observation of the mother as well as of the child enabled successful outcome of this highly risky pregnancy.- - - - - - - - - - ranking = 5keywords = gland (Clic here for more details about this article) |
8/30. infarction of mediastinal parathyroid gland causing spontaneous remission of secondary hyperparathyroidism.Secondary hyperparathyroidism is a serious complication in long-term hemodialysis patients. The authors report on 2 patients on long-term hemodialysis who suffered from persistent secondary hyperparathyroidism due to missed mediastinal parathyroid gland after total parathyroidectomy with forearm autograft. reoperation was planned. In both cases, severe hypocalcemia suddenly developed; serum parathyroid hormone (PTH) level decreased markedly after this episode. The serum calcium level increased gradually in response to administration of vitamin D and calcium carbonate, but serum PTH level remained low. A follow-up computed tomography scan showed that the formerly enlarged mediastinal parathyroid gland was markedly reduced in size. Moreover, a hot spot formerly detected by technetium 99m-MIBI (methoxy-isobutyl-isonitrile) scintigraphy in the mediastinum disappeared after this episode. The authors considered that necrosis of the enlarged ectopic parathyroid gland, probably due to infarction, resulted in hypocalcemia. To the authors' knowledge, this is the first case report of spontaneous mediastinal parathyroid autoinfarction after parathyroidectomy in hemodialysis patients.- - - - - - - - - - ranking = 7keywords = gland (Clic here for more details about this article) |
9/30. A case of chromosome 22q11 deletion syndrome diagnosed in a 32-year-old man with hypoparathyroidism.Congenital hypoparathyroidism typically manifests with hypocalcemia with or without associated characteristic physical findings and is usually diagnosed during the neonatal period. This report describes an African-American male who was diagnosed at age 32 yr to have dysgenesis of the parathyroid glands due to chromosome 22 microdeletion. Symptomatic hypocalcemia did not develop until age 14 yr, a few weeks after initiation of anticonvulsant therapy for generalized tonic-clonic seizures. Because of the timing for onset of symptomatic hypocalcemia, it was presumed that the patient had anticonvulsant-induced hypocalcemia, and he carried that diagnosis for 18 yr. Chromosome 22q11 deletion syndrome was first suspected at age 32 yr, based on the findings of subtle dysmorphic facial features and a history of learning disability in a patient with PTH-deficient hypocalcemia. The diagnosis was confirmed by fluorescence in situ hybridization analysis.This case underscores the variable clinical presentation of this congenital form of hypoparathyroidism. Chromosome 22q11 microdeletions are relatively common, and the diagnosis should be considered even in adults with hypoparathyroidism because of the potential benefit of genetic counseling.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
10/30. kinetics of the circulating levels of bone alkaline phosphatase in a case of hungry bone disease following total parathyroidectomy.We present the case of a 55-year-old patient who underwent total parathyroidectomy for severe hyperparathyroidism unresponsive to medical therapy, 4 years after having started hemodialysis treatment. It was decided to perform total parathyroidectomy because at macroscopic evaluation the parathyroid glands appeared completely compromised. After surgery, the patient developed hungry bone disease, characterized by severe hypocalcemia and hypophosphatemia. After parathyroidectomy, serial measurements were made for the long-term monitoring of the calcemia, phosphatemia and the serum levels of intact parathormone and bone alkaline phosphatase, a marker of bone turnover that mainly expresses bone formation. There was initially a slight decrease in the circulating levels of bone alkaline phosphatase as the calcemia dropped dramatically, then a new increase that anticipated the subsequent calcemia increase and finally, 6 months later, a decrease to very low values. We believe that the calcemia and blood bone alkaline phosphatase could be useful for the laboratory monitoring of the hungry bone state, providing information which may be useful to avoid excessive calcium administration and the dangerous consequences such as soft-tissue calcification.- - - - - - - - - - ranking = 1keywords = gland (Clic here for more details about this article) |
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