CALCIUM INFUSION IN THE DETECTION OF BONE DISEASE IN PARATHYROID DISORDERS

1963 ◽  
Vol 43 (2) ◽  
pp. 170-183 ◽  
Author(s):  
Heinrich G. Haas ◽  
John J. Canary ◽  
Laurence H. Kyle ◽  
Daniel H. Mintz
Keyword(s):  
Alkaline Phosphatase ◽  
Calcium Absorption ◽  
Osteitis Fibrosa ◽  
Idiopathic Hypercalciuria ◽  
Calcium Excretion ◽  
List Type ◽  
Elevated Alkaline Phosphatase ◽  
Calcium Retention ◽  
High Calcium ◽  
Wide Range

ABSTRACT The retention of an infused load of calcium was determined under standard conditions in 25 patients with various parathyroid disorders, in 12 normal control subjects, and in 3 patients with idiopathic hypercalciuria. A normal range of 40–60 per cent calcium-retention was found, and there was some support to the thesis that hypercalciuria per se may lower the retention of calcium. Patients with primary hyperparathyroidism showed a wide range of calcium retention reflecting on one side probably hypercalciuria (low calcium retention) and on the other osteitis fibrosa generalisata (high calcium retention). In detecting early bone involvement in parathyroid hyperfunction, the calcium retention test was of equal or greater value than alkaline phosphatase determination in the serum. In secondary hyperparathyroidism due to severe renal insufficiency, a high calcium retention was seen pointing either to delayed calcium excretion (low GFR) or increased avidity of the skeleton for calcium as a consequence of an admixture of osteomalacia and osteitis fibrosa. All hypoparathyroid patients retained large quantities of calcium. In three of these cases, an elevated alkaline phosphatase level indicated osteomalacia, possibly following inadequate calcium absorption from the gut, while in two patients a low filtered load of calcium accounted for the apparent high calcium retention.

scholarly journals Hypocalcemia in Setting of Malignancy of Unknown Origin: A Case Report

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A200-A201
Author(s):  
Russell K Fung ◽  
Marilu Margarita Jurado-Flores
Keyword(s):  
Alkaline Phosphatase ◽  
Bone Destruction ◽  
Unknown Origin ◽  
Metastatic Carcinoma ◽  
Common Finding ◽  
Lytic Lesion ◽  
Calcium Excretion ◽  
Elevated Alkaline Phosphatase ◽  
Normal Vitamin ◽  
Calcium Infusion

Abstract Background: Hypercalcemia is a common finding well-recognized in up to 30% of cases of malignancy, associated with poor prognosis and advanced disease state. Hypocalcemia, while uncommon, can also be found in cases of malignancy facilitated by its own unique mechanism and etiologies. We present a case of severe hypocalcemia in the setting of malignancy of unknown origin. Clinical Case: 72-year-old female with a history of metastatic carcinoma of unknown origin, followed actively by Oncology, presented acutely with shortness of breath, chest pain, stiff hands and clenched fist. Patient had reported a 20 lbs weight loss over three months with a “knot” in the epigastric area affecting appetite and interfering with eating. Prior CT showed diffuse adenopathy with diffuse permeative bone destruction highly suspicious for malignancy. Follow up PET-CT showed mixed lytic lesion and sclerotic changes throughout the entire skeleton from the skull to mid thighs compatible with osseous metastatic. Initial tests show severe hypocalcemia with appropriately PTH elevation and normal vitamin D25 (calcium 5.5 mg/dL, albumin 3.9 g/dL, phosphorus (PO4) 2.3 mg/dL, magnesium (Mg) 1.5 mg/dL, PTH 243 pg/mL, vitamin D25 31.44 ng/mL). Further workup shows normal creatinine levels (0.88 mmol/L) and elevated alkaline phosphatase (1140 IU/L). Physical exam revealed bilaterally clenched fist and positive Chvostek sign. After two doses of 2 grams calcium gluconate, calcium had improved up to 7.2 mg/dL (corrected 7.76 mg/dL, albumin 3.3 g/dL) with plans to replete Mg and PO4. Patient was started on Calcium-Vitamin-D 500-200 mg-units (Oscal) two tabs trice daily. However, calcium continues to drop the next day with levels at 5.7 mg/dL (corrected 6.42 mg/dL, albumin 3.1 g/dL). A calcium infusion of 10 grams was then given over 16 hours. Calcitriol 0.25 mg twice daily was started. 24-hour urine study showed low calcium excretion (<0.8 mg/dL), normal Mg excretion (6.5 mg/dL) with an adequate creatinine collected (0.6 grams) showing no deficiencies in kidney resorption. Prior to discharge, patient’s calcium had stabilized (corrected 8.2 mg/dL, albumin 3.4 g/dL) and her associated symptoms had resolved. She was discharged on Oscal 2 tabs 4 times daily and Calcitriol 1 mcg twice daily. Conclusion: Given these biochemical results and imaging evidence of bone metastases, this case highlights the uncommon findings of hypocalcemia in the setting of malignancy. With the combination of low 24-hour urine calcium, elevated PTH, normal vitamin D25, low PO4, normal kidney function and increased alkaline phosphatase, these findings most likely indicate hypocalcemia secondary to osteoblastic bone metastasis, resulting from deposition of calcium in osteoblastic lesions. References: Schattner A, Dubin I, Huber R, Gelber M. Hypocalcaemia of malignancy. Neth J Med. 2016 Jul;74(6):231–9. PMID: 27571720

scholarly journals Severe hypercalcemia and hypernatremia in a patient treated with canagliflozin

2015 ◽  
Vol 2015 ◽  
Author(s):  
Arshpreet Kaur ◽  
Stephen J Winters
Keyword(s):  
Mental Status ◽  
Water Loss ◽  
Calcium Absorption ◽  
Free Water ◽  
Intestinal Calcium Absorption ◽  
Calcium Excretion ◽  
List Type ◽  
Close Monitoring ◽  
Osmotic Diuresis ◽  
Severe Hypercalcemia

Summary Drugs that inhibit the sodium-glucose co-transporter-2 (SGLT2) are an exciting novel, insulin-independent treatment for diabetes that block glucose reabsorption from the proximal tubules of the kidney, leading to increased glucose excretion and lower blood glucose levels. Inhibition of SGLT2 activity also reduces sodium reabsorption, which together with glycosuria produces a mild diuretic effect with the potential for dehydration and hyperkalemia. We report on a 60-year-old man with uncontrolled type 2 diabetes treated with insulin, glimepiride, metformin and canagliflozin, who was admitted with altered mental status after a syncopal episode. He had a 1-week history of ingestion of Tums for heartburn followed by poor appetite and lethargy. Laboratory work-up showed acute kidney injury, diabetic ketoacidosis (DKA), and parathyroid hormone-independent severe hypercalcemia of 17.4 mg/dl. DKA resolved with insulin treatment, and saline hydration led to improvement in hypercalcemia and renal function over 48 h, but was accompanied by a rapid increase in the serum sodium concentration from 129 to 162 mmol/l despite changing fluids to 0.45% saline. Urine studies were consistent with osmotic diuresis. Hypernatremia was slowly corrected with hypotonic fluids, with improvement in his mental status over the next 2 days. This is the first report of hypercalcemia associated with the use of a SLGT2 inhibitor. Although the exact mechanism is unknown, canagliflozin may predispose to hypercalcemia in patients ingesting excessive calcium because of dehydration from osmotic diuresis, with reduced calcium excretion and possible increased intestinal calcium absorption. Saline therapy and osmotic diuresis may lead to hypernatremia from electrolyte-free water loss. Learning points Canagliflozin, an SGLT2 inhibitor, may cause hypercalcemia in susceptible patients. Although the exact mechanisms are unknown, dehydration from osmotic diuresis and increased intestinal calcium absorption play a role. Close monitoring of serum calcium levels is recommended in patients treated with SGLT2 inhibitors who are elderly, have established hypercalcemia, or take oral calcium supplements. Saline therapy and osmotic diuresis may lead to hypernatremia from electrolyte-free water loss in susceptible patients.

Effects of chlorothiazide on 1,25-dihydroxyvitamin D3, parathyroid hormone, and intestinal calcium absorption in the rat

1982 ◽  
Vol 242 (6) ◽  
pp. G575-G581 ◽  
Author(s):  
M. J. Favus ◽  
F. L. Coe ◽  
S. C. Kathpalia ◽  
A. Porat ◽  
P. K. Sen ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Calcium Absorption ◽  
Intestinal Calcium Absorption ◽  
Idiopathic Hypercalciuria ◽  
Calcium Excretion ◽  
Dihydroxyvitamin D3 ◽  
Ussing Chambers ◽  
1,25 Dihydroxyvitamin D3 ◽  
Descending Colon

Previous studies have shown that thiazide diuretic agents reverse secondary hyperparathyroidism and reduce circulating 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and intestinal calcium absorption rates in patients with idiopathic hypercalciuria of the renal-leak variety. We have investigated whether thiazides can reverse the secondary increase in serum parathyroid hormone (PTH) and 1,25(OH)2D3 levels or intestinal calcium absorption induced by feeding rats a diet low in calcium (LCD, 0.02% calcium) but adequate in phosphorus and vitamin D. We found that LCD increased circulating immunoreactive PTH [chow vs. LCD, 0.52 +/- 0.06 vs. 1.06 +2- 0.1 (SE) ng/ml, P less than 0.001], 1,25(OH)2D3 (chow vs. LCD, 101 +/- 15 vs. 325 +/- 38 pg/ml, P less than 0.001), calcium uptake by everted gut sacs from duodenum, ileum, and descending colon, and net calcium absorption by descending colon studied in Ussing chambers in vitro. Chlorothiazide (CTZ) prevented the increase in PTH during LCD (chow + CTZ vs. LCD + CTZ, 0.69 +/- 0.07 vs. 0.73 +/- 0.06, NS) but not the increase in 1,25(OH)2D3 (chow + CTZ vs. LCD + CTZ, 88 +/- 10 vs. 277 +/- 31, P less than 0.002) or intestinal calcium transport. The drug caused no change in serum 1,25(OH)2D3 or intestinal calcium absorption in rats fed normal chow. In rats given exogenous 1,25(OH)2D3 to stimulate intestinal calcium absorption, CTZ reduced urine calcium excretion greatly but did not alter intestinal calcium absorption.

THE ROLE OF THE PARATHYROID GLANDS IN THE ABSORPTION OF CALCIUM FROM THE SMALL INTESTINE

1970 ◽  
Vol 47 (1) ◽  
pp. 65-72 ◽  
Author(s):  
M. WINTER ◽  
E. MORAVA ◽  
G. SIMON ◽  
J. SÓS
Keyword(s):  
Small Intestine ◽  
Calcium Absorption ◽  
Normal Diet ◽  
Calcium Excretion ◽  
Deficient Diet ◽  
High Calcium ◽  
Low Phosphorus ◽  
Loop Technique

SUMMARY The absorption of calcium from duodenal and jejunal segments of the small intestine was studied in rats using an in-vivo loop technique. Previous parathyroidectomy decreased calcium absorption from both segments in rats fed a normal diet. Reduced calcium transport was greater in rats fed a calcium-deficient diet after parathyroidectomy. The slower clearance of radioactive calcium from the lumen of the intestine was not due to increased endogenous calcium excretion. Thyroidectomy, either alone or combined with parathyroidectomy, decreased calcium absorption but the effect of thyroidectomy alone requires further study. The decrease in calcium absorption after removal of the parathyroids was minimal or absent when the animals were fed a high calcium, low phosphorus, vitamin D-deficient diet or fasted 48 hr. before the experiment.

Mucosal calcium uptake by rat cecum: identity with transcellular calcium absorption

1983 ◽  
Vol 244 (6) ◽  
pp. G618-G622
Author(s):  
H. N. Nellans ◽  
R. S. Goldsmith
Keyword(s):  
Calcium Binding ◽  
Calcium Uptake ◽  
Calcium Absorption ◽  
Calcium Influx ◽  
Maximal Velocity ◽  
Similar Reduction ◽  
High Calcium ◽  
Wide Range ◽  
Rat Cecum

Unidirectional intestinal calcium uptake (JCame) at the mucosal surface of rat cecum was investigated in vitro with intact tissue. Uptake is linear for 2–3 min with no indication of rapid calcium binding. Kinetic parameters reveal a maximal velocity of 333 nmol . cm-2 . h-1 with a half-maximal concentration of 0.98 mM. High-calcium diet decreased JCame by more than 60% with respect to both control and low-calcium diets; 1 mM N-ethylmaleimide caused a similar reduction. The activation energy of JCame is significantly less than that of transepithelial mucosal-to-serosal calcium absorption. Mucosal uptake was compared with transepithelial calcium fluxes in rat cecum and revealed a 1:1 correlation over a wide range of transport rates. These results are interpreted to implicate a feedback control system between basolateral calcium efflux and brush-border calcium influx.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Triply-periodic nanostructures in surfactant, block copolymer, and biomembrane systems, and simulation of TEMs

1993 ◽  
Vol 51 ◽  
pp. 884-885
Author(s):  
David M. Anderson ◽  
Tomas Landh
Keyword(s):  
Liquid Crystalline ◽  
Diblock Copolymers ◽  
Cubic Phase ◽  
List Type ◽  
Interpenetrating Networks ◽  
Triply Periodic ◽  
Wide Range ◽  
Bicontinuous Cubic ◽  
Phase Liquid ◽  
Dividing Surface

First discovered in surfactant-water liquid crystalline systems, so-called ‘bicontinuous cubic phases’ have the property that hydropnilic and lipophilic microdomains form interpenetrating networks conforming to cubic lattices on the scale of nanometers. Later these same structures were found in star diblock copolymers, where the simultaneous continuity of elastomeric and glassy domains gives rise to unique physical properties. Today it is well-established that the symmetry and topology of such a morphology are accurately described by one of several triply-periodic minimal surfaces, and that the interface between hydrophilic and hydrophobic, or immiscible polymer, domains is described by a triply-periodic surface of constant, nonzero mean curvature. One example of such a dividing surface is shown in figure 5.The study of these structures has become of increasing importance in the past five years for two reasons:1)Bicontinuous cubic phase liquid crystals are now being polymerized to create microporous materials with monodispersed pores and readily functionalizable porewalls; figure 3 shows a TEM from a polymerized surfactant / methylmethacrylate / water cubic phase; and2)Compelling evidence has been found that these same morphologies describe biomembrane systems in a wide range of cells.

PARATHYROID HORMONE SECRETION IN DISORDERS OF CALCIUM METABOLISM STUDIED BY MEANS OF EDTA

1974 ◽  
Vol 75 (2) ◽  
pp. 286-296 ◽  
Author(s):  
J. H. Lockefeer ◽  
W. H. L. Hackeng ◽  
J. C. Birkenhäger
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Calcium Metabolism ◽  
Hormone Secretion ◽  
Parathyroid Tissue ◽  
Small Mass ◽  
Idiopathic Hypercalciuria ◽  
List Type ◽  
Immunoreactive Parathyroid Hormone ◽  
Pth Level

ABSTRACT In 22 of 28 cases of primary hyperparathyroidism (PHP) the rise in the serum immunoreactive parathyroid hormone (IRPTH or PTH) level observed in response to lowering of the serum calcium by EDTA, exceeded that obtained in 8 control subjects. In 5 of these 22 patients who were studied again after parathyroidectomy the supranormal response was abolished. Fifteen of these 22 hyper-responsive PHP patients had basal IRPTH levels not exceeding the highest level in the controls and that of other groups of patients investigated (idiopathic hypercalciuria, non-parathyroid hypercalcaemia, operated PHP). Fourteen of the 22 hyper-reactive patients with PHP did not show hypocalcaemia during the infusion of EDTA. The extent of the release of PTH elicited by EDTA in cases of PHP does not as yet allow a prediction of the amount of pathological parathyroid tissue present, although all the PHP patients showing a normal release of PTH had a relatively small mass of parathyroid tissue (up to about 1 g) subsequently removed. In 9 cases of nephrolithiasis (8 of whom had idiopathic hypercalciuria) and in 7 cases of non-parathyroid hypercalcaemia, a normal PTH release was found.

A multifactorial analysis of prognostic factors in patients with liver metastases from colorectal carcinoma.

1983 ◽  
Vol 1 (11) ◽  
pp. 720-726 ◽  
Author(s):  
C J Lahr ◽  
S J Soong ◽  
G Cloud ◽  
J W Smith ◽  
M M Urist ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Colorectal Carcinoma ◽  
Survival Rates ◽  
Elevated Serum ◽  
Hepatic Metastases ◽  
Lactic Dehydrogenase ◽  
Serum Bilirubin Level ◽  
Elevated Alkaline Phosphatase ◽  
Multifactorial Analysis ◽  
Primary Colorectal Tumor

A multifactorial analysis was used to identify the dominant prognostic variables predicting survival rates of 175 patients with hepatic metastases from colorectal carcinoma. Seven of 22 parameters examined simultaneously were found to independently influence the median survival rate in these patients: (1) elevated alkaline phosphatase (p = 0.0004), (2) elevated serum bilirubin level (p = 0.0005), (3) location of hepatic metastases (unilateral or bilateral, p = 0.0022), (4) number of metastatic nodes involved (0, 1-5, greater than 5; p = 0.0148), (5) depressed serum albumin (p = 0.0217), (6) whether or not the primary colorectal tumor was resected (p = 0.0013), and (7) chemotherapy (given or withheld, p = 0.0439). The prothrombin time, serum lactic dehydrogenase, and the number of hepatic metastases also correlated with survival, but they did not independently predict survival rates after other more dominant factors were accounted for. A mathematical equation for predicting an individual patient's clinical course once they developed hepatic metastases was derived from this statistical analysis. In addition, a simple and clinically useful guide for predicting outcome was developed that integrated the two most important risk factors, alkaline phosphatase and bilirubin.

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