Abnormally high level of calcium in the blood.
A ubiquitously expressed, secreted protein with bone resorption and renal calcium reabsorption activities that are similar to PARATHYROID HORMONE. It does not circulate in appreciable amounts in normal subjects, but rather exerts its biological actions locally. Overexpression of parathyroid hormone-related protein by tumor cells results in humoral calcemia of malignancy.
A condition of abnormally elevated output of PARATHYROID HORMONE (or PTH) triggering responses that increase blood CALCIUM. It is characterized by HYPERCALCEMIA and BONE RESORPTION, eventually leading to bone diseases. PRIMARY HYPERPARATHYROIDISM is caused by parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. SECONDARY HYPERPARATHYROIDISM is increased PTH secretion in response to HYPOCALCEMIA, usually caused by chronic KIDNEY DISEASES.
A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.
A class of G-protein-coupled receptors that react to varying extracellular CALCIUM levels. Calcium-sensing receptors in the PARATHYROID GLANDS play an important role in the maintenance of calcium HOMEOSTASIS by regulating the release of PARATHYROID HORMONE. They differ from INTRACELLULAR CALCIUM-SENSING PROTEINS which sense intracellular calcium levels.
Syndromes resulting from inappropriate production of HORMONES or hormone-like materials by NEOPLASMS in non-endocrine tissues or not by the usual ENDOCRINE GLANDS. Such hormone outputs are called ectopic hormone (HORMONES, ECTOPIC) secretion.
Tumors or cancer of the PARATHYROID GLANDS.
Reduction of the blood calcium below normal. Manifestations include hyperactive deep tendon reflexes, Chvostek's sign, muscle and abdominal cramps, and carpopedal spasm. (Dorland, 27th ed)
Excision of one or more of the parathyroid glands.
Organic compounds which contain P-C-P bonds, where P stands for phosphonates or phosphonic acids. These compounds affect calcium metabolism. They inhibit ectopic calcification and slow down bone resorption and bone turnover. Technetium complexes of diphosphonates have been used successfully as bone scanning agents.
A pair of anal glands or sacs, located on either side of the ANUS, that produce and store a dark, foul-smelling fluid in carnivorous animals such as MEPHITIDAE and DOGS. The expelled fluid is used as a defensive repellent (in skunks) or a material to mark territory (in dogs).
A condition of abnormally elevated output of PARATHYROID HORMONE due to parathyroid HYPERPLASIA or PARATHYROID NEOPLASMS. It is characterized by the combination of HYPERCALCEMIA, phosphaturia, elevated renal 1,25-DIHYDROXYVITAMIN D3 synthesis, and increased BONE RESORPTION.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Two pairs of small oval-shaped glands located in the front and the base of the NECK and adjacent to the two lobes of THYROID GLAND. They secrete PARATHYROID HORMONE that regulates the balance of CALCIUM; PHOSPHORUS; and MAGNESIUM in the body.
The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.
A VITAMIN D that can be regarded as a reduction product of vitamin D2.
In patients with neoplastic diseases a wide variety of clinical pictures which are indirect and usually remote effects produced by tumor cell metabolites or other products.
Bone loss due to osteoclastic activity.
Derivatives of ERGOSTEROL formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. They differ from CHOLECALCIFEROL in having a double bond between C22 and C23 and a methyl group at C24.
Abnormally elevated PARATHYROID HORMONE secretion as a response to HYPOCALCEMIA. It is caused by chronic KIDNEY FAILURE or other abnormalities in the controls of bone and mineral metabolism, leading to various BONE DISEASES, such as RENAL OSTEODYSTROPHY.
Urination of a large volume of urine with an increase in urinary frequency, commonly seen in diabetes (DIABETES MELLITUS; DIABETES INSIPIDUS).
Tumors or cancer of the anal gland.
A transient increase in the number of leukocytes in a body fluid.
A rare, metallic element designated by the symbol, Ga, atomic number 31, and atomic weight 69.72.
Pathological processes of the PARATHYROID GLANDS. They usually manifest as hypersecretion or hyposecretion of PARATHYROID HORMONE that regulates the balance of CALCIUM; PHOSPHORUS; and MAGNESIUM in the body.
A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions.
A condition caused by a deficiency of PARATHYROID HORMONE (or PTH). It is characterized by HYPOCALCEMIA and hyperphosphatemia. Hypocalcemia leads to TETANY. The acquired form is due to removal or injuries to the PARATHYROID GLANDS. The congenital form is due to mutations of genes, such as TBX1; (see DIGEORGE SYNDROME); CASR encoding CALCIUM-SENSING RECEPTOR; or PTH encoding parathyroid hormone.
A condition in which the death of adipose tissue results in neutral fats being split into fatty acids and glycerol.
A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults.
An idiopathic systemic inflammatory granulomatous disorder comprised of epithelioid and multinucleated giant cells with little necrosis. It usually invades the lungs with fibrosis and may also involve lymph nodes, skin, liver, spleen, eyes, phalangeal bones, and parotid glands.
Benign and malignant tumors of the HYPOTHALAMUS. Pilocytic astrocytomas and hamartomas are relatively frequent histologic types. Neoplasms of the hypothalamus frequently originate from adjacent structures, including the OPTIC CHIASM, optic nerve (see OPTIC NERVE NEOPLASMS), and pituitary gland (see PITUITARY NEOPLASMS). Relatively frequent clinical manifestations include visual loss, developmental delay, macrocephaly, and precocious puberty. (From Devita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2051)
A condition characterized by calcification of the renal tissue itself. It is usually seen in distal RENAL TUBULAR ACIDOSIS with calcium deposition in the DISTAL KIDNEY TUBULES and the surrounding interstitium. Nephrocalcinosis causes RENAL INSUFFICIENCY.
Disorders in the processing of calcium in the body: its absorption, transport, storage, and utilization.
Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.
A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.
Tumors or cancer located in bone tissue or specific BONES.
Agents that inhibit BONE RESORPTION and/or favor BONE MINERALIZATION and BONE REGENERATION. They are used to heal BONE FRACTURES and to treat METABOLIC BONE DISEASES such as OSTEOPOROSIS.
Inorganic salts of phosphoric acid.
A historical and cultural entity dispersed across the wide geographical area of Europe, as opposed to the East, Asia, and Africa. The term was used by scholars through the late medieval period. Thereafter, with the impact of colonialism and the transmission of cultures, Western World was sometimes expanded to include the Americas. (Dr. James H. Cassedy, NLM History of Medicine Division)
Form of radioimmunoassay in which excess specific labeled antibody is added directly to the test antigen being measured.
A benign epithelial tumor with a glandular organization.
Cell surface proteins that bind PARATHYROID HORMONE with high affinity and trigger intracellular changes which influence the behavior of cells. Parathyroid hormone receptors on BONE; KIDNEY; and gastrointestinal cells mediate the hormone's role in calcium and phosphate homeostasis.
Small organic molecules that act as allosteric activators of the calcium sensing receptor (CaSR) in the PARATHYROID GLANDS and other tissues. They lower the threshold for CaSR activation by extracellular calcium ions and diminish PARATHYROID HORMONE (PTH) release from parathyroid cells.
A diphosphonate which affects calcium metabolism. It inhibits bone resorption and soft tissue calcification.
Excretion of abnormally high level of CALCIUM in the URINE, greater than 4 mg/kg/day.
Aggressive T-Cell malignancy with adult onset, caused by HUMAN T-LYMPHOTROPIC VIRUS 1. It is endemic in Japan, the Caribbean basin, Southeastern United States, Hawaii, and parts of Central and South America and sub-Saharan Africa.
Hydroxy analogs of vitamin D 3; (CHOLECALCIFEROL); including CALCIFEDIOL; CALCITRIOL; and 24,25-DIHYDROXYVITAMIN D 3.
Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.
A large multinuclear cell associated with the BONE RESORPTION. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in CEMENTUM resorption.
Compounds that specifically inhibit STEROL 14-DEMETHYLASE. A variety of azole-derived ANTIFUNGAL AGENTS act through this mechanism.
Hormones released from neoplasms or from other cells that are not the usual sources of hormones.
Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.
A condition of an abnormally low level of PHOSPHATES in the blood.
A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.

22-oxacalcitriol suppresses secondary hyperparathyroidism without inducing low bone turnover in dogs with renal failure. (1/967)

BACKGROUND: Calcitriol therapy suppresses serum levels of parathyroid hormone (PTH) in patients with renal failure but has several drawbacks, including hypercalcemia and/or marked suppression of bone turnover, which may lead to adynamic bone disease. A new vitamin D analogue, 22-oxacalcitriol (OCT), has been shown to have promising characteristics. This study was undertaken to determine the effects of OCT on serum PTH levels and bone turnover in states of normal or impaired renal function. METHODS: Sixty dogs were either nephrectomized (Nx, N = 38) or sham-operated (Sham, N = 22). The animals received supplemental phosphate to enhance PTH secretion. Fourteen weeks after the start of phosphate supplementation, half of the Nx and Sham dogs received doses of OCT (three times per week); the other half were given vehicle for 60 weeks. Thereafter, the treatment modalities for a subset of animals were crossed over for an additional eight months. Biochemical and hormonal indices of calcium and bone metabolism were measured throughout the study, and bone biopsies were done at baseline, 60 weeks after OCT or vehicle treatment, and at the end of the crossover period. RESULTS: In Nx dogs, OCT significantly decreased serum PTH levels soon after the induction of renal insufficiency. In long-standing secondary hyperparathyroidism, OCT (0.03 microg/kg) stabilized serum PTH levels during the first months. Serum PTH levels rose thereafter, but the rise was less pronounced compared with baseline than the rise seen in Nx control. These effects were accompanied by episodes of hypercalcemia and hyperphosphatemia. In animals with normal renal function, OCT induced a transient decrease in serum PTH levels at a dose of 0.1 microg/kg, which was not sustained with lowering of the doses. In Nx dogs, OCT reversed abnormal bone formation, such as woven osteoid and fibrosis, but did not significantly alter the level of bone turnover. In addition, OCT improved mineralization lag time, (that is, the rate at which osteoid mineralizes) in both Nx and Sham dogs. CONCLUSIONS: These results indicate that even though OCT does not completely prevent the occurrence of hypercalcemia in experimental dogs with renal insufficiency, it may be of use in the management of secondary hyperparathyroidism because it does not induce low bone turnover and, therefore, does not increase the risk of adynamic bone disease.  (+info)

The elevated serum alkaline phosphatase--the chase that led to two endocrinopathies and one possible unifying diagnosis. (2/967)

A 39-year-old Chinese man with hypertension being evaluated for elevated serum alkaline phosphatase (SAP) levels was found to have an incidental right adrenal mass. The radiological features were characteristic of a large adrenal myelolipoma. This mass was resected and the diagnosis confirmed pathologically. His blood pressure normalised after removal of the myelolipoma, suggesting that the frequently observed association between myelolipomas and hypertension may not be entirely coincidental. Persistent elevation of the SAP levels and the discovery of hypercalcaemia after surgery led to further investigations which confirmed primary hyperparathyroidism due to a parathyroid adenoma. The patient's serum biochemistry normalised after removal of the adenoma. The association of adrenal myelolipoma with primary hyperparathyroidism has been reported in the literature only once previously. Although unconfirmed by genetic studies this association may possibly represent an unusual variation of the multiple endocrine neoplasia type 1 syndrome.  (+info)

Pamidronate reduces skeletal morbidity in women with advanced breast cancer and lytic bone lesions: a randomized, placebo-controlled trial. Protocol 18 Aredia Breast Cancer Study Group. (3/967)

PURPOSE: To assess whether pamidronate can reduce the frequency of skeletal morbidity in women with lytic bone metastases from breast cancer treated with hormone therapy. PATIENTS AND METHODS: Three hundred seventy-two women with breast cancer who had at least one lytic bone lesion and who were receiving hormonal therapy were randomized to receive 90 mg of pamidronate or placebo as a 2-hour intravenous infusion given in double-blind fashion every 4 weeks for 24 cycles. Patients were evaluated for skeletal complications: pathologic fractures, spinal cord compression, irradiation of or surgery on bone, or hypercalcemia. The skeletal morbidity rate (the ratio of the number of skeletal complications to the time on trial) was the primary efficacy variable. Bone pain, use of analgesics, quality of life, performance status, bone tumor response, and biochemical parameters were also evaluated. RESULTS: One hundred eighty-two patients who received pamidronate and 189 who received placebo were assessable. The skeletal morbidity rate was significantly reduced at 12, 18, and 24 cycles in patients treated with 90 mg of pamidronate (P = .028, .023, and .008, respectively). At 24 cycles, the proportion of patients having had any skeletal complication was 56% in the pamidronate group and 67% in the placebo group (P = .027). The time to the first skeletal complication was longer for patients receiving pamidronate than for those given placebo (P = .049). There was no statistical difference in survival or in objective bone response rate. Pamidronate was well tolerated. CONCLUSION: Treatment with 90 mg of pamidronate as a 2-hour intravenous infusion every 4 weeks in addition to hormonal therapy significantly reduces skeletal morbidity from osteolytic metastases.  (+info)

Inhibition of prostate cancer metastasis in vivo: a comparison of 1,23-dihydroxyvitamin D (calcitriol) and EB1089. (4/967)

The steroid hormone 1,25-dihydroxyvitamin D [1,25(OH)2D, also known as calcitriol] is known to inhibit the proliferation and to promote the differentiation of human prostate cancer cells. Additionally, we showed that 1,25(OH)2D markedly inhibits the invasiveness of human prostate cancer cells in vitro (G. G. Schwartz et al., Cancer Epidemiol. Biomark. Prev., 6: 727-732, 1997). These properties support the use of 1,25(OH)2D as differentiation therapy in prostate cancer. However, the use of 1,25(OH)2D in vivo is limited by the risk of hypercalcemia. We therefore compared the effects of 1,25(OH)2D and of EB1089, an analogue of 1,25(OH)2D with reduced calcemic effects, in an in vivo model of androgen-insensitive metastatic prostate cancer, the rat Dunning MAT LyLu prostate cancer model. Tumor growth and metastasis were studied using Copenhagen rats given s.c. injections of MAT LyLu cells. Fifty male rats were divided into five groups of 10 rats each. Four experimental groups received i.p. injections of low and high doses of 1,25(OH)2D and EB1089 (0.5 and 1.0 microg/kg, low and high, respectively). A control group received injections of vehicle only. Tumor volumes were measured three times per week. Rats were weighed weekly. The number of metastases to the lungs and the extent of hypercalcemia were evaluated. Compared with controls, tumor volumes were significantly smaller in all experimental groups. Similarly, the number of lung metastases (number of foci/lung) was reduced markedly by both 1,25(OH)2D and EB1089. Control rats developed 22.7 (+/- 1.98 SE) tumor foci per lung. Rats treated with 1,25(OH)2D and with EB1089 (1.0 microg/kg) developed 10.4 (+/- 2.81) and 7.70 (+/- 1.29) tumor foci, respectively (P < 0.001 and P < 0.0001, respectively; drug versus control). Compared with controls (10.79 +/- 0.1 mg/dl), serum calcium levels were significantly elevated in both 1,25(OH)2D and EB1089-treated rats (P < 0.01). However, EB1089 was significantly less calcemic than 1,25(OH)2D (12.59 +/- 0.21 mg/dl versus 14.47 +/- 0.46 mg/dl; 1.0 microg/kg; P < 0.001). Rats treated with 1,25(OH)2D showed marked weight loss: 20.0 +/- 1.9% and 26.3 +/- 1.7% of their initial weight (low and high doses, respectively, P < 0.001). Weight loss was significantly lower in rats treated with EB1089 at the high dose 8.4 (+/- 2.9) %. Moreover, rats treated with low-dose EB1089 gained 5.2 (+/- 3.7) % of their initial weight. In conclusion, 1,25(OH)2D and EB1089 showed marked and equivalent inhibition of prostate cancer metastasis in vivo. EB1089 was significantly less calcemic than 1,25(OH)2D and did not induce severe weight loss. This is the first report of a vitamin D analogue that significantly inhibits prostate cancer metastasis in vivo and that does so without producing cachexia or unacceptable hypercalcemia.  (+info)

Renal biopsy in the milk-alkali syndrome. (5/967)

In milk-alkali syndrome the degree of renal impairment varies greatly. Few reports have been published describing structural changes on renal biopsy. In three illustrative cases, impairment of renal function was related to morphological changes shown on percutaneous biopsy. Milk-alkali syndrome should be considered as a cause of renal dysfunction in patients with a long history of dyspensia.  (+info)

A large intrathoracic parathyroid adenoma. (6/967)

A case is described in which an unusually large parathyroid adenoma was visible on the plain chest radiograph taken during the investigation of hypercalcaemia. This was diagnosed preoperatively and a scheme is suggested whereby such a disgnosis can now readily be made. The differential diagnosis is discussed ant the literature is reviewed.  (+info)

Promoter structure of mouse RANKL/TRANCE/OPGL/ODF gene. (7/967)

Receptor activator of NF-kappa B ligand (RANKL)/tumor necrosis factor-related activation induced cytokine (TRANCE)/osteoprotegerin ligand (OPGL)/osteoclast differentiation factor (ODF) is a membrane-bound signal transducer responsible for differentiation and maintenance of osteoclasts. To elucidate the mechanism regulating RANKL/TRANCE/OPGL/ODF gene expression, we cloned the 5'-flanking basic promoter region of the mouse RANKL/TRANCE/OPGL/ODF gene and characterized it by transient transfection studies and genomic Southern blot analysis. Inverted TATA- and CAAT-boxes and a putative Cbfa1/Osf2/AML3 binding domain constituted the basic promoter structure. The repeated half-sites for the vitamin D3 (VitD3) and glucocorticoid receptors were located at -935 and -640, respectively. Transient transfection studies revealed that short-term treatment with 1alpha,25(OH)2 VitD3 or dexamethasone increased luciferase activity up to 204% and 178%, respectively; on the other hand, treatment with dibutyryl cyclic AMP did not affect the promoter activity. Since the expression of Cbfa1/Osf2/AML3 is also regulated by VitD3, 1alpha,25(OH)2 VitD3 might affect RANKL/TRANCE/OPGL/ODF gene expression both directly and indirectly. CpG methylation was observed dominantly in mouse stromal cells, ST2, of a later passage which ceased to support in vitro osteoclastogenesis, suggesting that the methylation status of the CpG loci in the RANKL/TRANCE/OPGL/ODF gene promoter may be one of the influential cis-regulating factors.  (+info)

Excessive Ca and P intake during early maturation in dogs alters Ca and P balance without long-term effects after dietary normalization. (8/967)

Calcium (Ca) and phosphorus (P) balance is important for skeletal development. Although the effects of deficiencies are well known, reports on the effects of excessive Ca and P supply are relatively scarce. Epidemiologic data and a few controlled studies have shown that skeletal abnormalities may develop when Ca intake is excessive, particularly in periods of rapid growth. Changes in Ca and P balance during and/or after a high Ca intake are thought to underlie this phenomenon. In this study, the effects of excessive Ca (3.1 g/kg dry matter) or Ca and P (Ca 3.1 g/kg, P 2.8 g/kg) intake on Ca and P balance in young, rapidly growing dogs during (for the period from 3 to 17 wk of age) and after (for the period from 17 to 27 wk of age) high Ca and P intake were compared with findings in age-matched controls with normal Ca and P intakes (Ca 1.0 g/kg, P 0.8 g/kg). Dogs fed a high Ca diet developed hypercalcemia, and food intake and fractional absorption of Ca and P were significantly lower at 15 wk of age, whereas endogenous fecal and renal Ca excretion were significantly higher than in controls. This resulted in significantly higher Ca retention than in controls only at 9 wk of age, and in disproportionate absorption of Ca and P. In dogs fed a high Ca and P diet, normocalcemia was maintained, fractional absorption of Ca and P were significantly lower at 9 and 15 wk of age, but retention of both was significantly higher at 9 wk than in controls. The endogenous fecal Ca and renal P losses were significantly higher, but renal Ca excretion was not different from that in controls. After normalization of Ca and P intake, Ca and P balance did not differ among groups. In conclusion, excessive Ca and P intake during early maturation alters Ca and P balance, but does not influence Ca and P balance after dietary normalization.  (+info)

Hypercalcemia is a medical condition characterized by an excess of calcium ( Ca2+ ) in the blood. While the normal range for serum calcium levels is typically between 8.5 to 10.2 mg/dL (milligrams per deciliter) or 2.14 to 2.55 mmol/L (millimoles per liter), hypercalcemia is generally defined as a serum calcium level greater than 10.5 mg/dL or 2.6 mmol/L.

Hypercalcemia can result from various underlying medical disorders, including primary hyperparathyroidism, malignancy (cancer), certain medications, granulomatous diseases, and excessive vitamin D intake or production. Symptoms of hypercalcemia may include fatigue, weakness, confusion, memory loss, depression, constipation, nausea, vomiting, increased thirst, frequent urination, bone pain, and kidney stones. Severe or prolonged hypercalcemia can lead to serious complications such as kidney failure, cardiac arrhythmias, and calcification of soft tissues. Treatment depends on the underlying cause and severity of the condition.

Parathyroid Hormone-Related Protein (PTHrP) is a protein that is encoded by the PTHLH gene in humans. It is structurally similar to parathyroid hormone (PTH) and was initially identified due to its role in humoral hypercalcemia of malignancy, a condition characterized by high levels of calcium in the blood caused by certain types of cancer.

PTHrP has a variety of functions in the body, including regulation of calcium and phosphate homeostasis, cell growth and differentiation, and bone metabolism. It acts through a specific G protein-coupled receptor called the PTH/PTHrP receptor, which is found in many tissues throughout the body, including bone, kidney, and cartilage.

In contrast to PTH, which is primarily produced by the parathyroid glands and regulates calcium levels in the blood, PTHrP is produced by many different types of cells throughout the body. Its expression is regulated in a tissue-specific manner, and its functions can vary depending on the context in which it is produced.

Overall, PTHrP plays important roles in normal physiology as well as in various disease states, including cancer, bone disorders, and developmental abnormalities.

Hyperparathyroidism is a condition in which the parathyroid glands produce excessive amounts of parathyroid hormone (PTH). There are four small parathyroid glands located in the neck, near or within the thyroid gland. They release PTH into the bloodstream to help regulate the levels of calcium and phosphorus in the body.

In hyperparathyroidism, overproduction of PTH can lead to an imbalance in these minerals, causing high blood calcium levels (hypercalcemia) and low phosphate levels (hypophosphatemia). This can result in various symptoms such as fatigue, weakness, bone pain, kidney stones, and cognitive issues.

There are two types of hyperparathyroidism: primary and secondary. Primary hyperparathyroidism occurs when there is a problem with one or more of the parathyroid glands, causing them to become overactive and produce too much PTH. Secondary hyperparathyroidism develops as a response to low calcium levels in the body due to conditions like vitamin D deficiency, chronic kidney disease, or malabsorption syndromes.

Treatment for hyperparathyroidism depends on the underlying cause and severity of symptoms. In primary hyperparathyroidism, surgery to remove the overactive parathyroid gland(s) is often recommended. For secondary hyperparathyroidism, treating the underlying condition and managing calcium levels with medications or dietary changes may be sufficient.

Parathyroid hormone (PTH) is a polypeptide hormone that plays a crucial role in the regulation of calcium and phosphate levels in the body. It is produced and secreted by the parathyroid glands, which are four small endocrine glands located on the back surface of the thyroid gland.

The primary function of PTH is to maintain normal calcium levels in the blood by increasing calcium absorption from the gut, mobilizing calcium from bones, and decreasing calcium excretion by the kidneys. PTH also increases phosphate excretion by the kidneys, which helps to lower serum phosphate levels.

In addition to its role in calcium and phosphate homeostasis, PTH has been shown to have anabolic effects on bone tissue, stimulating bone formation and preventing bone loss. However, chronic elevations in PTH levels can lead to excessive bone resorption and osteoporosis.

Overall, Parathyroid Hormone is a critical hormone that helps maintain mineral homeostasis and supports healthy bone metabolism.

Calcium-sensing receptors (CaSR) are a type of G protein-coupled receptor that play a crucial role in the regulation of extracellular calcium homeostasis. They are widely expressed in various tissues, including the parathyroid gland, kidney, and bone.

The primary function of CaSR is to detect changes in extracellular calcium concentrations and transmit signals to regulate the release of parathyroid hormone (PTH) from the parathyroid gland. When the concentration of extracellular calcium increases, CaSR is activated, which leads to a decrease in PTH secretion, thereby preventing further elevation of calcium levels. Conversely, when calcium levels decrease, CaSR is inhibited, leading to an increase in PTH release and restoration of normal calcium levels.

In addition to regulating calcium homeostasis, CaSR also plays a role in other physiological processes, including cell proliferation, differentiation, and apoptosis. Dysregulation of CaSR has been implicated in various diseases, such as hyperparathyroidism, hypoparathyroidism, and cancer. Therefore, understanding the function and regulation of CaSR is essential for developing new therapeutic strategies to treat these conditions.

Paraneoplastic endocrine syndromes refer to a group of hormonal and related disorders that occur as remote effects of cancer. They are caused by substances (like hormones, peptides, or antibodies) produced by the tumor, which may be benign or malignant, and can affect various organs and systems in the body. These syndromes can occur before the cancer is diagnosed, making them an important consideration for early detection and treatment of the underlying malignancy.

Examples of paraneoplastic endocrine syndromes include:

1. Syndrome of Inappropriate Antidiuretic Hormone (SIADH): This occurs when a tumor, often small cell lung cancer, produces antidiuretic hormone (ADH), leading to excessive water retention and low sodium levels in the blood.
2. Cushing's Syndrome: Excessive production of adrenocorticotropic hormone (ACTH) by a tumor, often a small cell lung cancer or pancreatic neuroendocrine tumor, can lead to increased cortisol levels and symptoms such as weight gain, muscle weakness, and mood changes.
3. Ectopic Production of Parathyroid Hormone-Related Peptide (PTHrP): This occurs when a tumor, often a squamous cell carcinoma, produces PTHrP, leading to increased calcium levels in the blood and symptoms such as bone pain, kidney stones, and confusion.
4. Hypercalcemia of Malignancy: Excessive production of calcitriol (active vitamin D) by a tumor, often a lymphoma or myeloma, can lead to increased calcium levels in the blood and symptoms such as bone pain, kidney stones, and confusion.
5. Carcinoid Syndrome: This occurs when a neuroendocrine tumor, often in the gastrointestinal tract, produces serotonin and other substances, leading to symptoms such as flushing, diarrhea, and heart problems.

It is important to note that these syndromes can also be caused by non-cancerous conditions, so a thorough evaluation is necessary to make an accurate diagnosis.

Parathyroid neoplasms refer to abnormal growths in the parathyroid glands, which are small endocrine glands located in the neck, near or within the thyroid gland. These neoplasms can be benign (non-cancerous) or malignant (cancerous).

Benign parathyroid neoplasms are typically called parathyroid adenomas and are the most common type of parathyroid disorder. They result in overproduction of parathyroid hormone (PTH), leading to a condition known as primary hyperparathyroidism. Symptoms may include kidney stones, osteoporosis, fatigue, depression, and abdominal pain.

Malignant parathyroid neoplasms are called parathyroid carcinomas. They are rare but more aggressive than adenomas, with a higher risk of recurrence and metastasis. Symptoms are similar to those of benign neoplasms but may also include hoarseness, difficulty swallowing, and enlarged lymph nodes in the neck.

It is important to note that parathyroid neoplasms can only be definitively diagnosed through biopsy or surgical removal and subsequent histopathological examination.

Hypocalcemia is a medical condition characterized by an abnormally low level of calcium in the blood. Calcium is a vital mineral that plays a crucial role in various bodily functions, including muscle contraction, nerve impulse transmission, and bone formation. Normal calcium levels in the blood usually range from 8.5 to 10.2 milligrams per deciliter (mg/dL). Hypocalcemia is typically defined as a serum calcium level below 8.5 mg/dL or, when adjusted for albumin (a protein that binds to calcium), below 8.4 mg/dL (ionized calcium).

Hypocalcemia can result from several factors, such as vitamin D deficiency, hypoparathyroidism (underactive parathyroid glands), kidney dysfunction, certain medications, and severe magnesium deficiency. Symptoms of hypocalcemia may include numbness or tingling in the fingers, toes, or lips; muscle cramps or spasms; seizures; and, in severe cases, cognitive impairment or cardiac arrhythmias. Treatment typically involves correcting the underlying cause and administering calcium and vitamin D supplements to restore normal calcium levels in the blood.

Parathyroidectomy is a surgical procedure for the removal of one or more of the parathyroid glands. These glands are located in the neck and are responsible for producing parathyroid hormone (PTH), which helps regulate the levels of calcium and phosphorus in the body.

Parathyroidectomy is typically performed to treat conditions such as hyperparathyroidism, where one or more of the parathyroid glands become overactive and produce too much PTH. This can lead to high levels of calcium in the blood, which can cause symptoms such as weakness, fatigue, bone pain, kidney stones, and mental confusion.

There are different types of parathyroidectomy procedures, including:

* Partial parathyroidectomy: removal of one or more, but not all, of the parathyroid glands.
* Total parathyroidectomy: removal of all four parathyroid glands.
* Subtotal parathyroidectomy: removal of three and a half of the four parathyroid glands, leaving a small portion of one gland to prevent hypoparathyroidism (a condition where the body produces too little PTH).

The choice of procedure depends on the underlying condition and its severity. After the surgery, patients may need to have their calcium levels monitored and may require calcium and vitamin D supplements to maintain normal calcium levels in the blood.

Diphosphonates are a class of medications that are used to treat bone diseases, such as osteoporosis and Paget's disease. They work by binding to the surface of bones and inhibiting the activity of bone-resorbing cells called osteoclasts. This helps to slow down the breakdown and loss of bone tissue, which can help to reduce the risk of fractures.

Diphosphonates are typically taken orally in the form of tablets, but some forms may be given by injection. Commonly prescribed diphosphonates include alendronate (Fosamax), risedronate (Actonel), and ibandronate (Boniva). Side effects of diphosphonates can include gastrointestinal symptoms such as nausea, heartburn, and abdominal pain. In rare cases, they may also cause esophageal ulcers or osteonecrosis of the jaw.

It is important to follow the instructions for taking diphosphonates carefully, as they must be taken on an empty stomach with a full glass of water and the patient must remain upright for at least 30 minutes after taking the medication to reduce the risk of esophageal irritation. Regular monitoring of bone density and kidney function is also recommended while taking these medications.

Anal sacs, also known as scent glands or scent sacs, are small paired sac-like structures located on either side of the anus in many mammals, including dogs and cats. These sacs produce a foul-smelling liquid that is used for marking territory and communication with other animals. In some cases, the ducts leading from the anal sacs can become blocked, causing discomfort or infection, which may require medical intervention.

Primary hyperparathyroidism is a medical condition characterized by excessive secretion of parathyroid hormone (PTH) from one or more of the parathyroid glands in the neck. These glands are normally responsible for regulating calcium levels in the body by releasing PTH, which helps to maintain an appropriate balance of calcium and phosphate in the bloodstream.

In primary hyperparathyroidism, the parathyroid gland(s) become overactive and produce too much PTH, leading to elevated calcium levels (hypercalcemia) in the blood. This can result in a variety of symptoms, such as fatigue, weakness, bone pain, kidney stones, and cognitive impairment, although some individuals may not experience any symptoms at all.

The most common cause of primary hyperparathyroidism is a benign tumor called an adenoma that develops in one or more of the parathyroid glands. In rare cases, primary hyperparathyroidism can be caused by cancer of the parathyroid gland(s) or by enlargement of all four glands (four-gland hyperplasia). Treatment typically involves surgical removal of the affected parathyroid gland(s), which is usually curative.

Calcium is an essential mineral that is vital for various physiological processes in the human body. The medical definition of calcium is as follows:

Calcium (Ca2+) is a crucial cation and the most abundant mineral in the human body, with approximately 99% of it found in bones and teeth. It plays a vital role in maintaining structural integrity, nerve impulse transmission, muscle contraction, hormonal secretion, blood coagulation, and enzyme activation.

Calcium homeostasis is tightly regulated through the interplay of several hormones, including parathyroid hormone (PTH), calcitonin, and vitamin D. Dietary calcium intake, absorption, and excretion are also critical factors in maintaining optimal calcium levels in the body.

Hypocalcemia refers to low serum calcium levels, while hypercalcemia indicates high serum calcium levels. Both conditions can have detrimental effects on various organ systems and require medical intervention to correct.

The parathyroid glands are four small endocrine glands located in the neck, usually near or behind the thyroid gland. They secrete parathyroid hormone (PTH), which plays a critical role in regulating calcium and phosphate levels in the blood and bones. PTH helps maintain the balance of these minerals by increasing the absorption of calcium from food in the intestines, promoting reabsorption of calcium in the kidneys, and stimulating the release of calcium from bones when needed. Additionally, PTH decreases the excretion of calcium through urine and reduces phosphate reabsorption in the kidneys, leading to increased phosphate excretion. Disorders of the parathyroid glands can result in conditions such as hyperparathyroidism (overactive glands) or hypoparathyroidism (underactive glands), which can have significant impacts on calcium and phosphate homeostasis and overall health.

Calcitriol is the active form of vitamin D, also known as 1,25-dihydroxyvitamin D. It is a steroid hormone that plays a crucial role in regulating calcium and phosphate levels in the body to maintain healthy bones. Calcitriol is produced in the kidneys from its precursor, calcidiol (25-hydroxyvitamin D), which is derived from dietary sources or synthesized in the skin upon exposure to sunlight.

Calcitriol promotes calcium absorption in the intestines, helps regulate calcium and phosphate levels in the kidneys, and stimulates bone cells (osteoblasts) to form new bone tissue while inhibiting the activity of osteoclasts, which resorb bone. This hormone is essential for normal bone mineralization and growth, as well as for preventing hypocalcemia (low calcium levels).

In addition to its role in bone health, calcitriol has various other physiological functions, including modulating immune responses, cell proliferation, differentiation, and apoptosis. Calcitriol deficiency or resistance can lead to conditions such as rickets in children and osteomalacia or osteoporosis in adults.

Dihydrotachysterol is a synthetic form of vitamin D that is used as a medication to treat hypocalcemia (low levels of calcium in the blood) in people with certain medical conditions, such as hypoparathyroidism and vitamin D deficiency. It works by increasing the absorption of calcium from the gut and promoting the release of calcium from bones into the bloodstream.

Dihydrotachysterol is available in tablet form and is typically taken once or twice a day, with the dosage adjusted based on the individual's response to treatment and serum calcium levels. Common side effects of dihydrotachysterol include hypercalcemia (high levels of calcium in the blood), nausea, vomiting, and constipation. It is important to monitor serum calcium levels regularly while taking this medication to prevent toxicity.

Paraneoplastic syndromes refer to a group of rare disorders that are caused by an abnormal immune system response to a cancerous (malignant) tumor. These syndromes are characterized by symptoms or signs that do not result directly from the growth of the tumor itself, but rather from substances produced by the tumor or the body's immune system in response to the tumor.

Paraneoplastic syndromes can affect various organs and systems in the body, including the nervous system, endocrine system, skin, and joints. Examples of paraneoplastic syndromes include Lambert-Eaton myasthenic syndrome (LEMS), which affects nerve function and causes muscle weakness; cerebellar degeneration, which can cause difficulty with coordination and balance; and dermatomyositis, which is an inflammatory condition that affects the skin and muscles.

Paraneoplastic syndromes can occur in association with a variety of different types of cancer, including lung cancer, breast cancer, ovarian cancer, and lymphoma. Treatment typically involves addressing the underlying cancer, as well as managing the symptoms of the paraneoplastic syndrome.

Bone resorption is the process by which bone tissue is broken down and absorbed into the body. It is a normal part of bone remodeling, in which old or damaged bone tissue is removed and new tissue is formed. However, excessive bone resorption can lead to conditions such as osteoporosis, in which bones become weak and fragile due to a loss of density. This process is carried out by cells called osteoclasts, which break down the bone tissue and release minerals such as calcium into the bloodstream.

Ergocalciferols are a form of vitamin D, specifically vitamin D2, that is found in some plants. They are not produced by the human body and must be obtained through diet or supplementation. Ergocalciferols can be converted into an active form of vitamin D in the body, which is important for maintaining healthy bones and calcium levels. However, vitamin D3 (cholecalciferol), which is produced by the body in response to sunlight exposure, is generally considered to be more effective at raising and maintaining vitamin D levels in the body than ergocalciferols.

Secondary hyperparathyroidism is a condition characterized by an overproduction of parathyroid hormone (PTH) from the parathyroid glands due to hypocalcemia (low levels of calcium in the blood). This condition is usually a result of chronic kidney disease, where the kidneys fail to convert vitamin D into its active form, leading to decreased absorption of calcium in the intestines. The body responds by increasing PTH production to maintain normal calcium levels, but over time, this results in high PTH levels and associated complications such as bone disease, kidney stones, and cardiovascular calcification.

Polyuria is a medical term that describes the production of large volumes of urine, typically defined as exceeding 2.5-3 liters per day in adults. This condition can lead to frequent urination, sometimes as often as every one to two hours, and often worsens during the night (nocturia). Polyuria is often a symptom of an underlying medical disorder such as diabetes mellitus or diabetes insipidus, rather than a disease itself. Other potential causes include kidney diseases, heart failure, liver cirrhosis, and certain medications. Proper diagnosis and treatment of the underlying condition are essential to manage polyuria effectively.

Anal gland neoplasms, also known as anal sac tumors, are abnormal growths that develop from the cells lining the anal glands. These glands are located on either side of the anus in dogs and some other animals, and they produce a scent used for marking territory.

Anal gland neoplasms can be benign or malignant (cancerous). Malignant tumors are more common and tend to grow quickly, invading surrounding tissues and spreading to other parts of the body (metastasis). Common symptoms of anal gland neoplasms include straining to defecate, bleeding from the rectum, and a firm mass that can be felt near the anus.

Treatment for anal gland neoplasms typically involves surgical removal of the tumor. In some cases, radiation therapy or chemotherapy may also be recommended. The prognosis for animals with anal gland neoplasms depends on several factors, including the size and location of the tumor, whether it has spread to other parts of the body, and the overall health of the animal.

Leukocytosis is a condition characterized by an increased number of leukocytes (white blood cells) in the peripheral blood. A normal white blood cell count ranges from 4,500 to 11,000 cells per microliter of blood in adults. Leukocytosis is typically considered present when the white blood cell count exceeds 11,000 cells/µL. However, the definition might vary slightly depending on the laboratory and clinical context.

Leukocytosis can be a response to various underlying conditions, including bacterial or viral infections, inflammation, tissue damage, leukemia, and other hematological disorders. It is essential to investigate the cause of leukocytosis through further diagnostic tests, such as blood smears, differential counts, and additional laboratory and imaging studies, to guide appropriate treatment.

Gallium is not a medical term, but it's a chemical element with the symbol Ga and atomic number 31. It is a soft, silvery-blue metal that melts at a temperature just above room temperature. In medicine, gallium compounds such as gallium nitrate and gallium citrate are used as radiopharmaceuticals for diagnostic purposes in nuclear medicine imaging studies, particularly in the detection of inflammation, infection, and some types of cancer.

For example, Gallium-67 is a radioactive isotope that can be injected into the body to produce images of various diseases such as abscesses, osteomyelitis (bone infection), and tumors using a gamma camera. The way gallium distributes in the body can provide valuable information about the presence and extent of disease.

Therefore, while gallium is not a medical term itself, it has important medical applications as a diagnostic tool in nuclear medicine.

Parathyroid diseases refer to conditions that affect the parathyroid glands, which are small endocrine glands located in the neck, near or attached to the back surface of the thyroid gland. The primary function of the parathyroid glands is to produce and secrete parathyroid hormone (PTH), a crucial hormone that helps regulate calcium and phosphorus levels in the blood and bones.

There are four parathyroid glands, and they can develop various diseases, including:

1. Hyperparathyroidism: A condition where one or more parathyroid glands produce excessive amounts of PTH. This can lead to an imbalance in calcium and phosphorus levels, resulting in symptoms such as fatigue, weakness, bone pain, kidney stones, and increased risk of osteoporosis. Hyperparathyroidism can be primary (caused by a benign or malignant tumor in the parathyroid gland), secondary (due to chronic kidney disease or vitamin D deficiency), or tertiary (when secondary hyperparathyroidism becomes autonomous and continues even after correcting the underlying cause).
2. Hypoparathyroidism: A condition where the parathyroid glands do not produce enough PTH, leading to low calcium levels in the blood (hypocalcemia) and high phosphorus levels (hyperphosphatemia). Symptoms of hypoparathyroidism may include muscle spasms, tingling sensations in the fingers, toes, or lips, anxiety, cataracts, and seizures. Hypoparathyroidism can be caused by surgical removal of the parathyroid glands, autoimmune disorders, radiation therapy, or genetic conditions.
3. Parathyroid tumors: Abnormal growths in the parathyroid glands can lead to hyperparathyroidism. Benign tumors (adenomas) are the most common cause of primary hyperparathyroidism. Malignant tumors (carcinomas) are rare but can also occur, leading to more severe symptoms and a worse prognosis.
4. Parathyroid dysfunction in genetic disorders: Some genetic syndromes, such as multiple endocrine neoplasia type 1 (MEN1), multiple endocrine neoplasia type 2A (MEN2A), and hyperparathyroidism-jaw tumor syndrome (HPT-JT), can involve parathyroid gland abnormalities, leading to hyperparathyroidism or other related conditions.

Proper diagnosis and management of parathyroid disorders are crucial for maintaining optimal calcium homeostasis and preventing complications associated with hypocalcemia or hypercalcemia. Treatment options may include surgery, medication, dietary modifications, and monitoring hormone levels.

Phosphorus is an essential mineral that is required by every cell in the body for normal functioning. It is a key component of several important biomolecules, including adenosine triphosphate (ATP), which is the primary source of energy for cells, and deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), which are the genetic materials in cells.

Phosphorus is also a major constituent of bones and teeth, where it combines with calcium to provide strength and structure. In addition, phosphorus plays a critical role in various metabolic processes, including energy production, nerve impulse transmission, and pH regulation.

The medical definition of phosphorus refers to the chemical element with the atomic number 15 and the symbol P. It is a highly reactive non-metal that exists in several forms, including white phosphorus, red phosphorus, and black phosphorus. In the body, phosphorus is primarily found in the form of organic compounds, such as phospholipids, phosphoproteins, and nucleic acids.

Abnormal levels of phosphorus in the body can lead to various health problems. For example, high levels of phosphorus (hyperphosphatemia) can occur in patients with kidney disease or those who consume large amounts of phosphorus-rich foods, and can contribute to the development of calcification of soft tissues and cardiovascular disease. On the other hand, low levels of phosphorus (hypophosphatemia) can occur in patients with malnutrition, vitamin D deficiency, or alcoholism, and can lead to muscle weakness, bone pain, and an increased risk of infection.

Hypoparathyroidism is a medical condition characterized by decreased levels or insufficient function of parathyroid hormone (PTH), which is produced and released by the parathyroid glands. These glands are located in the neck, near the thyroid gland, and play a crucial role in regulating calcium and phosphorus levels in the body.

In hypoparathyroidism, low PTH levels result in decreased absorption of calcium from the gut, increased excretion of calcium through the kidneys, and impaired regulation of bone metabolism. This leads to low serum calcium levels (hypocalcemia) and high serum phosphorus levels (hyperphosphatemia).

Symptoms of hypoparathyroidism can include muscle cramps, spasms, or tetany (involuntary muscle contractions), numbness or tingling sensations in the fingers, toes, and around the mouth, fatigue, weakness, anxiety, cognitive impairment, and in severe cases, seizures. Hypoparathyroidism can be caused by various factors, including surgical removal or damage to the parathyroid glands, autoimmune disorders, radiation therapy, genetic defects, or low magnesium levels. Treatment typically involves calcium and vitamin D supplementation to maintain normal serum calcium levels and alleviate symptoms. In some cases, recombinant PTH (Natpara) may be prescribed as well.

Fat necrosis is a medical condition that refers to the death (necrosis) of fat cells, typically due to injury or trauma. This can occur when there is an interruption of blood flow to the area, leading to the death of fat cells and the release of their contents. The affected area may become firm, nodular, or lumpy, and can sometimes be mistaken for a tumor.

Fat necrosis can also occur as a result of pancreatic enzymes leaking into surrounding tissues due to conditions such as pancreatitis. These enzymes can break down fat cells, leading to the formation of calcium soaps that can be seen on imaging studies.

While fat necrosis is not typically a serious condition, it can cause discomfort or pain in the affected area. In some cases, surgical intervention may be necessary to remove the affected tissue.

Calcitonin is a hormone that is produced and released by the parafollicular cells (also known as C cells) of the thyroid gland. It plays a crucial role in regulating calcium homeostasis in the body. Specifically, it helps to lower elevated levels of calcium in the blood by inhibiting the activity of osteoclasts, which are bone cells that break down bone tissue and release calcium into the bloodstream. Calcitonin also promotes the uptake of calcium in the bones and increases the excretion of calcium in the urine.

Calcitonin is typically released in response to high levels of calcium in the blood, and its effects help to bring calcium levels back into balance. In addition to its role in calcium regulation, calcitonin may also have other functions in the body, such as modulating immune function and reducing inflammation.

Clinically, synthetic forms of calcitonin are sometimes used as a medication to treat conditions related to abnormal calcium levels, such as hypercalcemia (high blood calcium) or osteoporosis. Calcitonin can be administered as an injection, nasal spray, or oral tablet, depending on the specific formulation and intended use.

Sarcoidosis is a multi-system disorder characterized by the formation of granulomas (small clumps of inflammatory cells) in various organs, most commonly the lungs and lymphatic system. These granulomas can impair the function of the affected organ(s), leading to a variety of symptoms. The exact cause of sarcoidosis is unknown, but it's thought to be an overactive immune response to an unknown antigen, possibly triggered by an infection, chemical exposure, or another environmental factor.

The diagnosis of sarcoidosis typically involves a combination of clinical evaluation, imaging studies (such as chest X-rays and CT scans), and laboratory tests (including blood tests and biopsies). While there is no cure for sarcoidosis, treatment may be necessary to manage symptoms and prevent complications. Corticosteroids are often used to suppress the immune system and reduce inflammation, while other medications may be prescribed to treat specific organ involvement or symptoms. In some cases, sarcoidosis may resolve on its own without any treatment.

Hypothalamic neoplasms refer to tumors that originate in the hypothalamus, a small region of the brain that is located at the base of the brain and forms part of the limbic system. The hypothalamus plays a critical role in regulating many bodily functions, including hormone release, temperature regulation, hunger, thirst, sleep, and emotional behavior.

Hypothalamic neoplasms can be benign or malignant and can arise from various cell types within the hypothalamus, such as neurons, glial cells, or supportive tissue. These tumors can cause a variety of symptoms depending on their size, location, and rate of growth. Common symptoms include endocrine disorders (such as diabetes insipidus or precocious puberty), visual disturbances, headaches, behavioral changes, and cognitive impairment.

The diagnosis of hypothalamic neoplasms typically involves a combination of clinical evaluation, imaging studies (such as MRI or CT scans), and sometimes biopsy or surgical removal of the tumor. Treatment options depend on the type, size, and location of the tumor but may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Regular follow-up care is essential to monitor for recurrence or progression of the tumor.

Nephrocalcinosis is a medical condition characterized by the deposition of calcium salts in the renal parenchyma, specifically within the tubular epithelial cells and interstitium of the kidneys. This process can lead to chronic inflammation, tissue damage, and ultimately impaired renal function if left untreated.

The condition is often associated with metabolic disorders such as hyperparathyroidism, distal renal tubular acidosis, or hyperoxaluria; medications like loop diuretics, corticosteroids, or calcineurin inhibitors; and chronic kidney diseases. The diagnosis of nephrocalcinosis is typically made through imaging studies such as ultrasound, CT scan, or X-ray. Treatment usually involves addressing the underlying cause, modifying dietary habits, and administering medications to control calcium levels in the body.

Calcium metabolism disorders refer to a group of medical conditions that affect the body's ability to properly regulate the levels of calcium in the blood and tissues. Calcium is an essential mineral that plays a critical role in many bodily functions, including bone health, muscle contraction, nerve function, and blood clotting.

There are several types of calcium metabolism disorders, including:

1. Hypocalcemia: This is a condition characterized by low levels of calcium in the blood. It can be caused by various factors such as vitamin D deficiency, hypoparathyroidism, and certain medications. Symptoms may include muscle cramps, spasms, and tingling sensations in the fingers and toes.
2. Hypercalcemia: This is a condition characterized by high levels of calcium in the blood. It can be caused by various factors such as hyperparathyroidism, cancer, and certain medications. Symptoms may include fatigue, weakness, confusion, and kidney stones.
3. Osteoporosis: This is a condition characterized by weak and brittle bones due to low calcium levels in the bones. It can be caused by various factors such as aging, menopause, vitamin D deficiency, and certain medications. Symptoms may include bone fractures and loss of height.
4. Paget's disease: This is a condition characterized by abnormal bone growth and deformities due to disordered calcium metabolism. It can be caused by various factors such as genetics, age, and certain medications. Symptoms may include bone pain, fractures, and deformities.

Treatment for calcium metabolism disorders depends on the underlying cause of the condition. It may involve supplements, medication, dietary changes, or surgery. Proper diagnosis and management are essential to prevent complications such as kidney stones, bone fractures, and neurological damage.

A fatal outcome is a term used in medical context to describe a situation where a disease, injury, or illness results in the death of an individual. It is the most severe and unfortunate possible outcome of any medical condition, and is often used as a measure of the severity and prognosis of various diseases and injuries. In clinical trials and research, fatal outcome may be used as an endpoint to evaluate the effectiveness and safety of different treatments or interventions.

Vitamin D is a fat-soluble secosteroid that is crucial for the regulation of calcium and phosphate levels in the body, which are essential for maintaining healthy bones and teeth. It can be synthesized by the human body when skin is exposed to ultraviolet-B (UVB) rays from sunlight, or it can be obtained through dietary sources such as fatty fish, fortified dairy products, and supplements. There are two major forms of vitamin D: vitamin D2 (ergocalciferol), which is found in some plants and fungi, and vitamin D3 (cholecalciferol), which is produced in the skin or obtained from animal-derived foods. Both forms need to undergo two hydroxylations in the body to become biologically active as calcitriol (1,25-dihydroxyvitamin D3), the hormonally active form of vitamin D. This activated form exerts its effects by binding to the vitamin D receptor (VDR) found in various tissues, including the small intestine, bone, kidney, and immune cells, thereby influencing numerous physiological processes such as calcium homeostasis, bone metabolism, cell growth, and immune function.

Bone neoplasms are abnormal growths or tumors that develop in the bone. They can be benign (non-cancerous) or malignant (cancerous). Benign bone neoplasms do not spread to other parts of the body and are rarely a threat to life, although they may cause problems if they grow large enough to press on surrounding tissues or cause fractures. Malignant bone neoplasms, on the other hand, can invade and destroy nearby tissue and may spread (metastasize) to other parts of the body.

There are many different types of bone neoplasms, including:

1. Osteochondroma - a benign tumor that develops from cartilage and bone
2. Enchondroma - a benign tumor that forms in the cartilage that lines the inside of the bones
3. Chondrosarcoma - a malignant tumor that develops from cartilage
4. Osteosarcoma - a malignant tumor that develops from bone cells
5. Ewing sarcoma - a malignant tumor that develops in the bones or soft tissues around the bones
6. Giant cell tumor of bone - a benign or occasionally malignant tumor that develops from bone tissue
7. Fibrosarcoma - a malignant tumor that develops from fibrous tissue in the bone

The symptoms of bone neoplasms vary depending on the type, size, and location of the tumor. They may include pain, swelling, stiffness, fractures, or limited mobility. Treatment options depend on the type and stage of the tumor but may include surgery, radiation therapy, chemotherapy, or a combination of these treatments.

Bone density conservation agents, also known as anti-resorptive agents or bone-sparing drugs, are a class of medications that help to prevent the loss of bone mass and reduce the risk of fractures. They work by inhibiting the activity of osteoclasts, the cells responsible for breaking down and reabsorbing bone tissue during the natural remodeling process.

Examples of bone density conservation agents include:

1. Bisphosphonates (e.g., alendronate, risedronate, ibandronate, zoledronic acid) - These are the most commonly prescribed class of bone density conservation agents. They bind to hydroxyapatite crystals in bone tissue and inhibit osteoclast activity, thereby reducing bone resorption.
2. Denosumab (Prolia) - This is a monoclonal antibody that targets RANKL (Receptor Activator of Nuclear Factor-κB Ligand), a key signaling molecule involved in osteoclast differentiation and activation. By inhibiting RANKL, denosumab reduces osteoclast activity and bone resorption.
3. Selective estrogen receptor modulators (SERMs) (e.g., raloxifene) - These medications act as estrogen agonists or antagonists in different tissues. In bone tissue, SERMs mimic the bone-preserving effects of estrogen by inhibiting osteoclast activity and reducing bone resorption.
4. Hormone replacement therapy (HRT) - Estrogen hormone replacement therapy has been shown to preserve bone density in postmenopausal women; however, its use is limited due to increased risks of breast cancer, cardiovascular disease, and thromboembolic events.
5. Calcitonin - This hormone, secreted by the thyroid gland, inhibits osteoclast activity and reduces bone resorption. However, it has largely been replaced by other more effective bone density conservation agents.

These medications are often prescribed for individuals at high risk of fractures due to conditions such as osteoporosis or metabolic disorders that affect bone health. It is essential to follow the recommended dosage and administration guidelines to maximize their benefits while minimizing potential side effects. Regular monitoring of bone density, blood calcium levels, and other relevant parameters is also necessary during treatment with these medications.

Phosphates, in a medical context, refer to the salts or esters of phosphoric acid. Phosphates play crucial roles in various biological processes within the human body. They are essential components of bones and teeth, where they combine with calcium to form hydroxyapatite crystals. Phosphates also participate in energy transfer reactions as phosphate groups attached to adenosine diphosphate (ADP) and adenosine triphosphate (ATP). Additionally, they contribute to buffer systems that help maintain normal pH levels in the body.

Abnormal levels of phosphates in the blood can indicate certain medical conditions. High phosphate levels (hyperphosphatemia) may be associated with kidney dysfunction, hyperparathyroidism, or excessive intake of phosphate-containing products. Low phosphate levels (hypophosphatemia) might result from malnutrition, vitamin D deficiency, or certain diseases affecting the small intestine or kidneys. Both hypophosphatemia and hyperphosphatemia can have significant impacts on various organ systems and may require medical intervention.

I'm sorry for any confusion, but the term "Western World" is a geopolitical and cultural term, rather than a medical one. It generally refers to societies or countries in Europe, North America, Australia, and New Zealand that share common cultural and historical roots. It does not have a specific medical definition. However, it is often used in medical literature to compare and contrast health statistics, disease prevalence, and healthcare systems between Western and non-Western countries.

An Immunoradiometric Assay (IRMA) is a type of radioimmunoassay (RIA), which is a technique used in clinical laboratories to measure the concentration of specific analytes, such as hormones, drugs, or vitamins, in biological samples. In an IRMA, the sample containing the unknown amount of the analyte is incubated with a known quantity of a labeled antibody that specifically binds to the analyte.

The labeled antibody is usually radiolabeled with a radioisotope such as iodine-125 (^125^I) or tritium (^3^H). During the incubation, the labeled antibody binds to the analyte in the sample, forming an immune complex. The unbound labeled antibody is then separated from the immune complex by a variety of methods such as precipitation, centrifugation, or chromatography.

The amount of radioactivity in the pellet (immune complex) is measured using a gamma counter (for ^125^I) or liquid scintillation counter (for ^3^H). The amount of radioactivity is directly proportional to the amount of analyte present in the sample. By comparing the radioactivity in the sample to a standard curve prepared with known concentrations of the analyte, the concentration of the analyte in the sample can be determined.

IRMAs are highly sensitive and specific assays that can detect very low levels of analytes in biological samples. However, they require specialized equipment and handling procedures due to the use of radioisotopes.

An adenoma is a benign (noncancerous) tumor that develops from glandular epithelial cells. These types of cells are responsible for producing and releasing fluids, such as hormones or digestive enzymes, into the surrounding tissues. Adenomas can occur in various organs and glands throughout the body, including the thyroid, pituitary, adrenal, and digestive systems.

Depending on their location, adenomas may cause different symptoms or remain asymptomatic. Some common examples of adenomas include:

1. Colorectal adenoma (also known as a polyp): These growths occur in the lining of the colon or rectum and can develop into colorectal cancer if left untreated. Regular screenings, such as colonoscopies, are essential for early detection and removal of these polyps.
2. Thyroid adenoma: This type of adenoma affects the thyroid gland and may result in an overproduction or underproduction of hormones, leading to conditions like hyperthyroidism (overactive thyroid) or hypothyroidism (underactive thyroid).
3. Pituitary adenoma: These growths occur in the pituitary gland, which is located at the base of the brain and controls various hormonal functions. Depending on their size and location, pituitary adenomas can cause vision problems, headaches, or hormonal imbalances that affect growth, reproduction, and metabolism.
4. Liver adenoma: These rare benign tumors develop in the liver and may not cause any symptoms unless they become large enough to press on surrounding organs or structures. In some cases, liver adenomas can rupture and cause internal bleeding.
5. Adrenal adenoma: These growths occur in the adrenal glands, which are located above the kidneys and produce hormones that regulate stress responses, metabolism, and blood pressure. Most adrenal adenomas are nonfunctioning, meaning they do not secrete excess hormones. However, functioning adrenal adenomas can lead to conditions like Cushing's syndrome or Conn's syndrome, depending on the type of hormone being overproduced.

It is essential to monitor and manage benign tumors like adenomas to prevent potential complications, such as rupture, bleeding, or hormonal imbalances. Treatment options may include surveillance with imaging studies, medication to manage hormonal issues, or surgical removal of the tumor in certain cases.

Parathyroid hormone (PTH) receptors are a type of cell surface receptor that bind to and respond to parathyroid hormone, a hormone secreted by the parathyroid glands. These receptors are found in various tissues throughout the body, including bone, kidney, and intestine.

The PTH receptor is a member of the G protein-coupled receptor (GPCR) family, which consists of seven transmembrane domains. When PTH binds to the receptor, it activates a signaling pathway that leads to increased calcium levels in the blood. In bone, activation of PTH receptors stimulates the release of calcium from bone matrix, while in the kidney, it increases the reabsorption of calcium from the urine and decreases the excretion of phosphate.

In the intestine, PTH receptors play a role in the regulation of vitamin D metabolism, which is important for calcium absorption. Overall, the activation of PTH receptors helps to maintain normal calcium levels in the blood and regulate bone metabolism.

Calcimimetic agents are a type of medication that mimic the action of calcium on the calcium-sensing receptor (CaSR) in the parathyroid gland. These agents enhance the sensitivity of the CaSR to extracellular calcium, which leads to a decrease in parathyroid hormone (PTH) secretion.

Calcimimetics are primarily used in the treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD) on dialysis. By decreasing PTH levels, calcimimetics can help to prevent the development of bone disease, reduce the risk of cardiovascular calcification, and improve overall clinical outcomes in these patients.

The most commonly prescribed calcimimetic agent is cinacalcet (Sensipar/Mimpara), which has been shown to effectively lower PTH levels, as well as serum calcium and phosphorus levels, in patients with CKD on dialysis. Other calcimimetic agents include etelcalcetide (Parsabiv) and evocalcet (Rocaltrol).

It is important to note that calcimimetics should be used with caution in patients with hypocalcemia, as they can further lower serum calcium levels. Close monitoring of calcium, phosphorus, and PTH levels is necessary during treatment with these agents.

Clodronic acid is a medication that belongs to a class of drugs called bisphosphonates. It is used to treat and prevent osteoporosis in postmenopausal women and men with a high risk of fracture, as well as to treat Paget's disease of bone.

Clodronic acid works by inhibiting the activity of bone-resorbing cells called osteoclasts, which helps to slow down bone loss and increase bone density. This can help reduce the risk of fractures in people with osteoporosis.

The medication is available in several forms, including tablets and intravenous solutions. It is usually taken or administered once a day or once a week, depending on the specific formulation and the individual patient's needs.

Like all medications, clodronic acid can have side effects, including gastrointestinal symptoms such as nausea, vomiting, and diarrhea, as well as muscle pain, joint pain, and headaches. In rare cases, it can also cause more serious side effects such as esophageal ulcers and bone necrosis of the jaw. It is important for patients to follow their doctor's instructions carefully when taking this medication and to report any unusual symptoms or side effects promptly.

Hypercalciuria is a medical condition characterized by an excessive amount of calcium in the urine. It can occur when the body absorbs too much calcium from food, or when the bones release more calcium than usual. In some cases, it may be caused by certain medications, kidney disorders, or genetic factors.

Hypercalciuria can increase the risk of developing kidney stones and other kidney problems. It is often diagnosed through a 24-hour urine collection test that measures the amount of calcium in the urine. Treatment may include changes in diet, increased fluid intake, and medications to help reduce the amount of calcium in the urine.

Adult T-cell Leukemia/Lymphoma (ATLL) is a rare and aggressive type of cancer that affects the circulating white blood cells called T-lymphocytes or T-cells. It is caused by the human T-cell leukemia virus type 1 (HTLV-1), which infects CD4+ T-cells and leads to their malignant transformation. The disease can present as either acute or chronic leukemia, or as lymphoma, depending on the clinical features and laboratory findings.

The acute form of ATLL is characterized by the rapid proliferation of abnormal T-cells in the blood, bone marrow, and other organs. Patients with acute ATLL typically have a poor prognosis, with a median survival of only a few months. Symptoms may include skin rashes, lymphadenopathy (swollen lymph nodes), hepatosplenomegaly (enlarged liver and spleen), and hypercalcemia (high levels of calcium in the blood).

The chronic form of ATLL is less aggressive than the acute form, but it can still lead to serious complications. Chronic ATLL is characterized by the accumulation of abnormal T-cells in the blood and lymph nodes, as well as skin lesions and hypercalcemia. The median survival for patients with chronic ATLL is around two years.

ATLL can also present as a lymphoma, which is characterized by the proliferation of abnormal T-cells in the lymph nodes, spleen, and other organs. Lymphoma may occur in isolation or in combination with leukemic features.

The diagnosis of ATLL is based on clinical findings, laboratory tests, and the detection of HTLV-1 antibodies or proviral DNA in the blood or tissue samples. Treatment options for ATLL include chemotherapy, antiretroviral therapy, immunotherapy, and stem cell transplantation. The choice of treatment depends on several factors, including the patient's age, overall health, and the stage and type of ATLL.

Hydroxycholecalciferols are metabolites of vitamin D that are formed in the liver and kidneys. They are important for maintaining calcium homeostasis in the body by promoting the absorption of calcium from the gut and reabsorption of calcium from the kidneys.

The two main forms of hydroxycholecalciferols are 25-hydroxyvitamin D (25(OH)D) and 1,25-dihydroxyvitamin D (1,25(OH)2D). 25-hydroxyvitamin D is the major circulating form of vitamin D in the body and is used as a clinical measure of vitamin D status. It is converted to 1,25-dihydroxyvitamin D in the kidneys by the enzyme 1α-hydroxylase, which is activated in response to low serum calcium or high phosphate levels.

1,25-dihydroxyvitamin D is the biologically active form of vitamin D and plays a critical role in regulating calcium homeostasis by increasing intestinal calcium absorption and promoting bone health. Deficiency in hydroxycholecalciferols can lead to rickets in children and osteomalacia or osteoporosis in adults, characterized by weakened bones and increased risk of fractures.

Calcium carbonate is a chemical compound with the formula CaCO3. It is a common substance found in rocks and in the shells of many marine animals. As a mineral, it is known as calcite or aragonite.

In the medical field, calcium carbonate is often used as a dietary supplement to prevent or treat calcium deficiency. It is also commonly used as an antacid to neutralize stomach acid and relieve symptoms of heartburn, acid reflux, and indigestion.

Calcium carbonate works by reacting with hydrochloric acid in the stomach to form water, carbon dioxide, and calcium chloride. This reaction helps to raise the pH level in the stomach and neutralize excess acid.

It is important to note that excessive use of calcium carbonate can lead to hypercalcemia, a condition characterized by high levels of calcium in the blood, which can cause symptoms such as nausea, vomiting, constipation, confusion, and muscle weakness. Therefore, it is recommended to consult with a healthcare provider before starting any new supplement regimen.

Osteoclasts are large, multinucleated cells that are primarily responsible for bone resorption, a process in which they break down and dissolve the mineralized matrix of bones. They are derived from monocyte-macrophage precursor cells of hematopoietic origin and play a crucial role in maintaining bone homeostasis by balancing bone formation and bone resorption.

Osteoclasts adhere to the bone surface and create an isolated microenvironment, called the "resorption lacuna," between their cell membrane and the bone surface. Here, they release hydrogen ions into the lacuna through a process called proton pumping, which lowers the pH and dissolves the mineral component of the bone matrix. Additionally, osteoclasts secrete proteolytic enzymes, such as cathepsin K, that degrade the organic components, like collagen, in the bone matrix.

An imbalance in osteoclast activity can lead to various bone diseases, including osteoporosis and Paget's disease, where excessive bone resorption results in weakened and fragile bones.

14-alpha Demethylase Inhibitors are a class of antifungal medications that work by inhibiting the enzyme 14-alpha demethylase, which is essential for the synthesis of ergosterol, a critical component of fungal cell membranes. By inhibiting this enzyme, the drugs disrupt the structure and function of the fungal cell membrane, leading to fungal cell death.

Examples of 14-alpha Demethylase Inhibitors include:

* Fluconazole (Diflucan)
* Itraconazole (Sporanox)
* Ketoconazole (Nizoral)
* Posaconazole (Noxafil)
* Voriconazole (Vfend)

These medications are used to treat a variety of fungal infections, including candidiasis, aspergillosis, and cryptococcosis. However, they can also have significant drug-drug interactions and toxicities, so their use must be monitored closely by healthcare professionals.

Ectopic hormone production refers to the situation when a hormone is produced in an unusual location or by a type of cell that does not typically produce it. This can occur due to various reasons such as genetic mutations, cancer, or other medical conditions. The ectopic hormone production can lead to hormonal imbalances and related symptoms, as the regulation of hormones in the body becomes disrupted.

For example, in some cases of lung cancer, the tumor cells may produce adrenocorticotropic hormone (ACTH), which is typically produced by the pituitary gland. This ectopic ACTH production can result in Cushing's syndrome, a condition characterized by symptoms such as weight gain, muscle weakness, and high blood pressure.

It's important to note that ectopic hormone production is relatively rare and usually occurs in the context of specific medical conditions. If you suspect that you or someone else may have ectopic hormone production, it's important to seek medical attention from a healthcare professional who can provide appropriate evaluation and treatment.

Proteins are complex, large molecules that play critical roles in the body's functions. They are made up of amino acids, which are organic compounds that are the building blocks of proteins. Proteins are required for the structure, function, and regulation of the body's tissues and organs. They are essential for the growth, repair, and maintenance of body tissues, and they play a crucial role in many biological processes, including metabolism, immune response, and cellular signaling. Proteins can be classified into different types based on their structure and function, such as enzymes, hormones, antibodies, and structural proteins. They are found in various foods, especially animal-derived products like meat, dairy, and eggs, as well as plant-based sources like beans, nuts, and grains.

Hypophosphatemia is a medical condition characterized by abnormally low levels of phosphate (phosphorus) in the blood, specifically below 2.5 mg/dL. Phosphate is an essential electrolyte that plays a crucial role in various bodily functions such as energy production, bone formation, and maintaining acid-base balance.

Hypophosphatemia can result from several factors, including malnutrition, vitamin D deficiency, alcoholism, hormonal imbalances, and certain medications. Symptoms of hypophosphatemia may include muscle weakness, fatigue, bone pain, confusion, and respiratory failure in severe cases. Treatment typically involves correcting the underlying cause and administering phosphate supplements to restore normal levels.

"Bone" is the hard, dense connective tissue that makes up the skeleton of vertebrate animals. It provides support and protection for the body's internal organs, and serves as a attachment site for muscles, tendons, and ligaments. Bone is composed of cells called osteoblasts and osteoclasts, which are responsible for bone formation and resorption, respectively, and an extracellular matrix made up of collagen fibers and mineral crystals.

Bones can be classified into two main types: compact bone and spongy bone. Compact bone is dense and hard, and makes up the outer layer of all bones and the shafts of long bones. Spongy bone is less dense and contains large spaces, and makes up the ends of long bones and the interior of flat and irregular bones.

The human body has 206 bones in total. They can be further classified into five categories based on their shape: long bones, short bones, flat bones, irregular bones, and sesamoid bones.

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