Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vitro effect of parathyroid hormone (PTH) on RNA and heme synthesis by embryonic mouse liver erythroid precursors was examined. PTH produced a dose-dependent effect on RNA synthesis. A maximal increase of 60 +/- 16% (p less than 0.02) was observed with 1.0 U PTH/ml, whereas with higher concentrations a significant decline was found. Furthermore, PTH stimulated heme synthesis after 24 h of incubation. The maximal enhancement of 32 +/- 7% (p less than 0.01) was observed with 0.5 U PTH/ml, a lower effect was obtained with 1.0 U PTH/ml, while 2.0 U PTH/ml caused a pronounced decrease of heme synthesis. These data indicate that PTH affects directly the erythroid precursors by a mechanism similar to that of erythropoietin. The inhibitory effect on the RNA synthesis observed with large doses of PTH may explain at least one of the causes of the anemia reported in patients with primary hyperparathyroidism.
 ...
PMID:Increased RNA and heme synthesis in mouse erythroid precursors by parathyroid hormone. 10 88

Anemia has been recognized recently as a possible complication of primary hyperparathyroidism. If the hyperparathyroid state can induce anemia in patients with normal kidney function, the extremely high levels of circulating parathyroid hormone usually observed in hyperparathyroidism secondary to chronic renal failure may have an unfavorable influence on the anemia of uremic patients. We investigated the influence of subtotal parathyroidectomy on the severity of the anemia of 18 uremic subjects undergoing long-term hemodialysis therapy. Subtotal parathyroidectomy resulted in a significant increase of mean hematocrit value. RBC count, and hemoglobin level. Serial bone biopsies suggested a relationship between the amount of marrow fibrosis and the improvement of anemia after surgery, but the precise mechanism of this phenomenon is still unknown.
 ...
PMID:Anemia and secondary hyperparathyroidism. 71 13

Although anemia has not been widely appreciated as a complication of primary hyperparathyroidism, 5.1% of the individuals with this disorder seen at the Massachusetts General Hospital since 1962 had a normochromic, normocytic anemia that could not be related to blood loss,a deficiency state, or uremia. The anemic group had more advanced bone disease and higher levels of serum calcium, alkaline phosphatase, and parathyroid hormone than the nonanemic group. Results of bone marrow biopsies performed in five patients showed variable degrees of myelofibrosis. However, none of the patients had hepatosplenomegaly, a myelophthisic peripheral blood smear, leukopenia, or thrombocytopenia. Removal of the abnormal parathyroid glands led to improvement or correction of the anemia.
 ...
PMID:Anemia in primary hyperparathyroidism. 85 57

A series of patients with primary hyperparathyroidism showed a high incidence of anemia. Red cell morphology and indices, iron, folate and B12 were generally normal and reticulocyte counts inappropriately low. Focal fibrosis of the marrow space was observed in marrow biopsies from two patients, but no patient showed overt signs of a myelophthisic process. Anemia tended to occur in those with more severe hyperparathyroidism (higher serum calcium level or radiographic osteitis fibrosa cystica). Since severe hyperparathyroidism frequently compromises renal function, it is not always clear whether the anemia should be attributed to renal failure or to the metabolic disease. In nine of the 24 anemic patients, however, renal function was normal. Hyperparathyroidism may cause a hyporegenerative anemia, the mechanisms for which have not been elucidated.
 ...
PMID:Hyporegenerative anemia in primary hyperparathyroidism. 91 Jan 74

The frequency of anemia associated with primary hyperparathyroidism is uncertain. When anemia does occur, its mechanisms are obscure. Two patients with primary hyperparathyroidism and moderate normochromic, normocytic, reticulocytopenic anemia were studied in detail. Both had results of ferrokinetic studies that were consistent with the anemia of chronic disease; one had low serum iron concentrations and reduced normoblastic iron incorporation. Anemia in both patients resolved after parathyroidectomy. Clinical records of 100 nonuremic patients with primary hyperparathyroidism were reviewed and three other anemic patients were found. The cause of anemia in two of these individuals was bleeding in the upper gastrointestinal system, and the third had folate deficiency attributable to chronic alchoholism.
 ...
PMID:Primary hyperparathyroidism and anemia. 94 88

The seventh case in the world literature of primary hyperparathyroidism in a neonate is reported. This is the fifth case in which an autopsy was performed. The clinical and anatomic findings in all seven cases are reviewed and compared. Neonates with primary hyperparathyroidism show diffuse hyperplasia of the parathyroid glands. The bones show disturbed osteogenesis, bone resorption, and widespread fibrosis of the marrow cavities. Bony cysts are not appreciated. Pathologic fractures are common. Marked hypercalciuria or hyperphosphaturia is usually not observed, perhaps because the immature renal tubules fail to respond to the influence of excess parathormone. Aminoaciduria and anemia are commonly observed. The prognosis is grave, and the etiology of this syndrome remains unexplained.
 ...
PMID:Primary neonatal hyperparathyroidism. Report of a case and review of the literature. 110 78

A patient with primary hyperparathyroidism who presented with hypokalaemia and hypertension is described. Renal potassium wasting was documented and cured by removal of a parathyroid adenoma. Possible mechanisms for this unusual manifestation of hyperparathyroidism are mentioned. Other features of the case were severe anaemia, nephrocalcinosis, pseudogout and postoperative acidosis.
 ...
PMID:An unusual hormonal cause of hypertension and hypokalaemia. 116 32

Primary as well as secondary hyperparathyroidism may be associated with anemia, and parathyroidectomy (PTx) may improve or even heal it. The precise link between the two conditions is still matter of discussion. The purpose of the present study was to investigate possible effects of PTx on serum immunoreactive erythropoietin (iEPO) in secondary (group I, n = 23), and primary (group II, n = 16) hyperparathyroidism patients, and in 3 patients undergoing cervicotomy for thyroid mass removal (group III). In group I patients, circulating iEPO levels rose from 23.1 +/- 4.8 mU/ml before PTx to 28.2 +/- 5.0 and 245 +/- 125 mU/ml (mean +/- SEM) at day 7 (p = NS) and 14 after PTx (p less than 0.003), respectively. Reticulocyte count increased 2 weeks after PTx: from 61,000 +/- 13,317 to 86,533 +/- 13,462/mm3 (p less than 0.05, n = 23). In 4 of these patients serum iEPO levels could be measured again 12-24 months after PTx. They were slightly higher than those determined before PTx: 37.0 +/- 8.4 versus 31.8 +/- 13.5 mU/ml. Their hematocrits were also higher than before PTx: 12.8 +/- 0.9 versus 11.0 +/- 0.9 g/dl. In group II patients, serum iEPO levels remained unchanged after PTx: 17.5 +/- 2.0 mU/ml before PTx and 20.0 +/- 3.0 mU/ml 14 days PTx. The reticulocyte count, however, increased significantly 2 weeks after PTx: from 25,103 +/- 3,000 to 40,827 +/- 4,080/mm3 (p less than 0.01). In group III patients, serum iEPO, reticulocyte count, and hemoglobin remained stable after surgery. Since all group I patients had received vitamin D supplementation after PTx, we studied an additional group of 14 chronic dialysis patients (group IV) who received either calcitriol (1 micrograms/day, n = 7) or placebo (n = 7) during 14 days. The patients on calcitriol treatment, but not those on placebo, had a significant decrease of serum iEPO: 18.6 +/- 4.9 versus 16.0 +/- 4.2 mU/ml (p less than 0.03). In conclusion, PTx led to a striking increase of serum iEPO and blood reticulocytes in uremic patients with secondary hyperparathyroidism, and an increase of reticulocyte count, but not of iEPO, in patients with primary hyperparathyroidism. Marked changes of circulating PTH, extra-or intracellular calcium and phosphorus concentrations as well as of tissue sensitivity to EPO after PTx could all be responsible. In contrast, the surgical procedure and the therapeutic increase in plasma calcitriol do not appear to be involved.
 ...
PMID:Serum erythropoietin and erythropoiesis in primary and secondary hyperparathyroidism: effect of parathyroidectomy. 175 26

It is generally accepted that some patients affected by mild asymptomatic primary hyperparathyroidism need not be treated with surgery, but may be medically managed without risk. However, our experience regarding 5 of these cases observed in the last two years, suggests a different approach. These patients, initially diagnosed as having mild hyperparathyroidism based on only moderately elevated serum concentrations of calcium and followed medically for years, were referred to us for a sudden worsening of their clinical course. One 35-year-old man presented hemorrhagic gastritis with severe anemia and type II AV block with syncopal attacks. Three women, aged 51, 64 and 65 years, presented with severe hypercalcemia associated with renal failure in two and with marked bone disease in another. In all these cases parathyroid neoplasms were preoperatively localized (by ultrasonography, CT scan and radioactive 201-Tl 99-Tc scan) and surgically removed. Histological examination showed a parathyroid carcinoma in the male patient and single gland enlargements in the three females. A fifth patient, a 65-year-old woman, was referred to us in critical condition: severe hypercalcemia, osteopenia with femur fracture, myocardial infarction and renal failure. She died in a few days, in spite of intensive medical care. These cases suggest that patients with hyperparathyroidism initially diagnosed as "mild" need close medical observation and preferably, in our opinion, should undergo surgery.
 ...
PMID:Acute complications in the course of "mild" hyperparathyroidism. 180 15

Parathyroid hormone (PTH) has been shown in vitro to enhance erythrocyte osmotic fragility (EOF) and has been incriminated as a factor in the anaemia seen in patients with primary hyperparathyroidism and in patients with renal disease and secondary hyperparathyroidism. Enhanced EOF has also been shown in patients with chronic renal failure but did not correlate with PTH levels. We studied a group of patients with primary hyperparathyroidism with and without anaemia, and patients with secondary hyperparathyroidism and anaemia. We found that EOF studies in these patients did not differ from normal control groups and that there was no relation between PTH, EOF, and haematocrit in either study group. We conclude that PTH over a range of concentrations seen in vivo does not affect erythrocyte osmotic fragility or cause anaemia.
 ...
PMID:Parathyroid hormone and anaemia--an erythrocyte osmotic fragility study in primary and secondary hyperparathyroidism. 281 31


1 2 3 Next >>