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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Studies were conducted in a patient with idiopathic hypophosphatemic osteomalacia to delineate the roles of parathyroid hormone (PTH), vitamin D and renal tubular function. A 43-year-old woman presented with progressive skeletal pains resulting in severe incapacity. Workup revealed: hypophosphatemia with a low tubular maximal phosphate reabsorption per glomerular filtrate (TmP/GFR) of 1.05 mg/dl, normocalcemia, hypocalciuria, elevated alkaline phosphatase and glycinuria. PTH and urinary cyclic AMP (UcAMP) were normal, while calcitriol was low. Renal tubular acidosis or other transport defects were not present and no tumor was found. Biopsy was diagnostic for osteomalacia, and the patient responded to 1-alpha OHD3 and phosphate therapy. Hyperparathyroidism was ruled out by 1) normocalcemia persisting after 1-alpha OHD3 and calcium loading and 2) normal PTH and UcAMP challenged by phosphate supplements. Combined calcium and 1-alpha OHD3 administration resulted in hypercalciuria, decreased UcAMP and increased, but not corrected, TmP/GFR. These findings suggest that the osteomalacia was due to hypophosphatemia caused by a renal leak. PTH is only contributory to the phosphaturia. Low calcitriol level contributes to the osteomalacia directly and indirectly through impaired mineral absorption and, therefore, is also responsible for the hypocalciuria.
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PMID:Metabolic studies in a patient with idiopathic hypophosphatemic osteomalacia. 334 50

We present evidence that calcitriol (1,25-dihydroxycholecalciferol) decreases tumor takes and tumor growth of subcutaneous retinoblastomas in athymic mice. Histopathologic studies showed that the calcitriol also induced necrosis of the retinoblastomas. The calcitriol, however, did not induce tumor calcification. Unfortunately, the dose of calcitriol used in this experiment caused significant toxic effects. If the toxicity of vitamin D can be alleviated without compromising its antineoplastic effect, vitamin D may be a useful chemotherapeutic agent against retinoblastoma.
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PMID:Further studies of the effect of vitamin D on retinoblastoma. Inhibition with 1,25-dihydroxycholecalciferol. 335 24

We recently reported that the steroid hormone, 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) can inhibit growth, alter morphology, and increase cell associated and medium concentrations of fibronectin (FN) in MG-63 human osteosarcoma cells (Franceschi, R. T., James, W., and Zerlauth, G. (1985) J. Cell. Physiol. 123, 401-409). In the present study, we have tested the hypothesis that 1,25-(OH)2D3 increases cellular adhesion by stimulating FN synthesis. Hormone treatment altered cell morphology and increased cell/substratum adhesion in MG-63 cells, effects which could be mimicked by exogenously added FN. 1,25-(OH)2D3-dependent increases in FN production were due to a rapid (within 12 h) increase in FN synthesis. Maximal (2 to 5-fold) stimulation was observed after 48 h. Hormone treatment did not alter apparent FN stability or distribution during this time. The FN response was specific to 1,25-(OH)2D3 when compared with other vitamin D metabolites. In contrast, triamcinolone acetonide, another known inducer of FN synthesis in certain cells, was only slightly stimulatory up to a concentration of 1 microM. FN mRNA, as measured by Northern blot hybridization, increased within 6 h of 1,25-(OH)2D3 addition with maximal (5-fold) induction seen at 24 h. 1,25-(OH)2D3 also stimulated FN synthesis in several other transformed cell lines (TE-85 human osteosarcomas, SW-480 human colon carcinomas, and HL-60 myeloid leukemia cells). These results may be related to known actions of 1,25-(OH)2D3 on cell differentiation and tumor metastasis.
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PMID:Regulation of cellular adhesion and fibronectin synthesis by 1 alpha,25-dihydroxyvitamin D3. 347 Feb 94

A squamous cell carcinoma of 33-yr-old patient who developed marked leukocytosis and hypercalcemia was transplanted into nude mice in which more marked leukocytosis and hypercalcemia also developed. This tumor (LJC-1-JCK) produced a colony-stimulating factor (CSF) and formed a cyst in the tumor from which a CSF-producing cell line (T3M-1) was established. The CSF causes predominantly formation of granulocytic colonies in addition to macrophage colonies. Bone-resorbing activity (BRA) was detected in the cystic fluid and was eluted as two separate peaks with proteins of an apparent molecular weight of 30,000-50,000 and 10,000-20,000. Colony-stimulating activity (CSA) was eluted at an apparent 30,000 mol wt. The conditioned medium of the T3M-1 cells also contained a BRA with an apparent 14,000 mol wt, whereas CSA eluted at an apparent 30,000 mol wt. PTH, epidermal growth factor, transforming growth factor-alpha, prostaglandin Es, and vitamin D could not account for the powerful BRA. In contrast to CSA, BRA was not inactivated by trypsin and more stable at 70 degrees C. When T3M-1 cells were transplanted into nude mice, marked hypercalcemia developed in addition to granulocytosis. Our findings suggest that the tumor produces and secretes a powerful BRA in vivo and in vitro, which is different from CSA in terms of molecular weight, heat stability, and trypsin treatment. We speculate that the synergistic action of CSF that stimulates macrophage colony formation and recruits osteoclast precursors, and BRA, which stimulates mononuclear phagocytes and/or osteoclasts were responsible for a marked increase in osteoclastic bone resorption and humoral hypercalcemia in the patient.
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PMID:Production of bone-resorbing activity and colony-stimulating activity in vivo and in vitro by a human squamous cell carcinoma associated with hypercalcemia and leukocytosis. 348 54

There are a variety of water and electrolyte disorders in patients with cancer. These disorders occur during the growth of tumors, generally as a consequence of inadequate intake and absorption of electrolytes, renal failure secondary to tumor or rapid tumor destruction and production of metabolically active substances by the tumor. In this paper, the electrolyte abnormalities associated with cancer were reviewed. Hyponatremia is one of the most common clinical electrolyte abnormalities in advanced cancer. Some patients may have hyponatremia, in spite of increased total body sodium and absence of a defect in water diuresis. This status is designated as "sick cell syndrome" or "essential hyponatremia". In addition, the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in association with various tumors has been described. This syndrome is principally due to water retention, but can also be due to continuous urinary loss of sodium, and hypo-osmolality. Hypercalcemia is associated with coexistent primary hyperparathyroidism, prostaglandin (PGE2) or osteoclast-activating factor. It now seems likely that ectopic PTH is rarely the cause of hypercalcemia in nonparathyroid cancer. There are no data supporting the ectopic production of vitamin D-like substance as an important factor in the hypercalcemia of cancer. There are three general categories in which patients with hypercalcemia and cancer may be placed: those with bone metastases, those without bone metastases of solid tumors and those with hematologic malignancies. Hypokalemia is associated with ectopic ACTH- and insulin--producing tumors, and is often found in patients with mucin-secreting, potassium-losing adenocarcinoma of the colon.
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PMID:[Electrolyte abnormalities associated with cancer: a review]. 352 93

Case records from 21 dogs with hypercalcemia and hyperparathyroidism were evaluated. The dogs were greater than or equal to 7 years old, and 6 were Keeshonds. The most common clinical signs were polydipsia/polyuria, listlessness, and muscle weakness. The serum calcium concentrations were 12.1 to 19.6 mg/dl. Serum phosphorus concentrations were low in 5 dogs, within the reference range in 13 dogs, and high in 3 dogs that also had high concentrations of BUN. Twenty dogs had a parathyroid adenoma, and 1 had a parathyroid carcinoma. Nineteen dogs had their parathyroid tumor surgically removed. Within 5 days of tumor removal, 11 of the 19 dogs became hypocalcemic and the remaining 8, normocalcemic. Nine of the 11 hypocalcemic dogs developed clinical signs. Iatrogenic hypercalcemia was induced in 7 of 16 dogs treated orally with calcium carbonate plus vitamin D. Only 1 of 19 dogs that had their parathyroid tumor excised died in hypocalcemic tetany. Two additional dogs died within 2 weeks of surgery, one because of pancreatitis, the other due to renal failure. Eight dogs died 9 to 37 months after surgery of unrelated problems. Eight dogs were alive for at least 7 to 28 months after surgery.
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PMID:Primary hyperparathyroidism in dogs: 21 cases (1976-1986). 365 3

Two patients with mesenchymal tumors had osteomalacia associated with marked hypophosphatemia and renal phosphate wasting. Their serum calcium and parathyroid hormone levels were normal. The first patient also had aminoaciduria and glucosuria in addition to phosphaturia. Both patients were treated with very large doses of vitamin D2 and phosphate without improvement in the osteomalacia or normalization of the serum phosphate. Complete removal of a low-grade fibrosarcoma in the second patient and removal of an ossifying fibroma in the first patient resulted in a cure in both patients despite no further therapy with vitamin D or phosphate. The excessive aminoaciduria and glucosuria of the first patient also remitted. During a 14-year follow-up period, there has been no evidence of tumor recurrence, hypophosphatemia, or osteomalacia in either patient. The levels of 1,25-dihydroxycholecalciferol remain within the normal range in both patients.
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PMID:Tumor-induced osteomalacia: long-term follow-up of two patients cured by removal of their tumors. 368 38

In a 71-year-old patient with osteomalacia, masked primary hyperparathyroidism was detected by vitamin D therapy for hypercalcemia. Surgery revealed a parathyroid tumor. Interpretation of total plasma calcium may be difficult unless the 25-hydroxyvitamin D levels are outside the normal range.
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PMID:[Hyperparathyroidism masked by osteomalacia. Is vitamin D administration in every case of osteomalacia problem-free?]. 371 42

Three patients with hypercalcemia associated with malignant lymphoma and elevations in plasma 1,25-dihydroxyvitamin D [1,25-(OH)2D] are described. In addition to the elevation of circulating 1,25-(OH)2D, these three patients were characterized by suppressed immunoreactive PTH levels and urinary cAMP excretion, elevated fasting urinary excretion of calcium, and absence of adenylate cyclase-stimulating activity in the tumor extracts. Bone marrow biopsy and skeletal radionuclide scans were negative for lymphoma in two patients. Surgical excision of a solitary splenic lymphoma in one patient and medical therapy in another patient resulted in rapid normalization of the serum calcium and plasma 1,25-(OH)2D levels. These findings confirm an earlier observation that elevated plasma levels of 1,25-(OH)2D may occur in certain patients with lymphoma and suggest that this vitamin D metabolite may act as a humoral or systemic mediator of hypercalcemia. Proof that this is the case and identification of the source of 1,25-(OH)2D production will require further study.
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PMID:Elevations in circulating 1,25-dihydroxyvitamin D in three patients with lymphoma-associated hypercalcemia. 387 Oct 92

We reviewed 4 patients with urothelial bladder cancer and hypercalcemia but without evidence of bony metastasis. Of the patients 2 presented with a leukemoid reaction (1 also had thrombocytosis). None of the patients had evidence of bone metastases or other causes of hypercalcemia, such as hyperparathyroidism, sarcoidosis or vitamin D intoxication. All 4 patients received aggressive therapy for the tumors. In each instance the serum calcium returned to normal following radiation therapy or tumor removal, lending support to the theory of humoral hypercalcemia of cancer. A diagnostic and therapeutic approach to such patients is outlined.
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PMID:Nonmetastatic bladder cancer associated with hypercalcemia, thrombocytosis and leukemoid reaction. 394 66


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