Determination Of Calcium In Blood Research Articles

Special case of primary hyperparathyroidism late diagnosis

Primary hyperparathyroidism is a socially significant problem due to the fact that the analysis of blood calcium in Russia is not a routine biochemical test, and diagnosis is carried out at the stage of irreversible complications. So, a patient addressed to our clinic which had a clinical picture of hyperparathyroidism complications over time. In the hospital diagnostic studies were carried out, including, first of all, a determination of calcium in blood, followed by more comprehensive survey, on the basis of which hyperparathyroidism has been confirmed. An adenoma of the left lower parathyroid gland was found by the method of topical diagnosis (ultrasound of the parathyroid glands and scintigraphy with Tc-99m-technetril). After the surgical treatment a level of calcium and a level of PTH have declined significantly. The combination of calcium and vitamin D supplementation was prescribed about intensive saturation therapy was needed with intense post-operative hyperparathyroidism. Given the existence of osteo-visceral complications by hyperparathyroidism, at the moment the patient needs a long rehabilitation course. This case shows that in order to avoid late diagnostics, it seems necessary to determine the level of calcium for routine. Therefore, it is possible to prevent the development of complications of the disease and the disability of patients.

Rational use of blood calcium determinations.

This study was motivated by the recent excessive increase in requests for blood calcium determinations and laboratory tests in general, in the Hospital das Clínicas complex of Faculdade de Medicina, Universidade de São Paulo (HCFMUSP). Its aim was to suggest rules for the determination of total and ionized calcium in our intensive care units, emergency department, wards and outpatient services, thus contributing towards improving the quality of medical care and achieving more appropriate use of human and financial resources. Critical analysis on clinical and laboratory data and the pertinent scientific literature, conducted by the study group for rational clinical laboratory use, which is part of the Central Laboratory Division, HCFMUSP. The study group reviewed scientific publications, statistics and clinical and laboratory data concerning requests for total and ionized calcium determinations in the settings of intensive care units, emergency department, wards and outpatient services. From this critical analysis, clinical decision flow diagrams aimed at providing guidance for ordering these tests were constructed. Use of the proposed flow diagrams may help to limit the numbers of inappropriate requests for ionized and total calcium determinations, with consequent reductions in the number of tests, risks to patients and unnecessary costs.

Conductometric Studies of Calcium Ions with Kryptofix 221 in Mixed MeOH-DMF Solvents at Different Temperatures

On using conductometric technique, the apparent association constant (KA) of Ca (NO3)2 were measured in mixed MeOH-DMF mixed solvents at 0, 20, 40 , 60 ,80 and 100% MeOH (by volume) and different temperatures (298.15, 303.15, 308.15 and 313.15K) in absence and presence of . Kryptofix- 221 (4, 7, 13, 16, 21- pentaoxa-1.10-diazo-bicyclo (8,8,5) tricosane). From the experimental results, the molar conductivities (∧) were calculated and limiting molar conduc- tivities (∧0) were calculated by using Shedlovsky and Fouss - Kraus extrapolation methods. The molar solvated (∨), Van der Waals (∨w) and electrostriction (∨e) were evaluated. The association constants KA for Ca(NO3)2 were calculated by using simple equation derived from Ostwald, Arrhenius and Fuoss-Shedlovsky theories. From the association constants the dif- ferent thermodynamic parameters were evaluated and the results obtained were discussed. The free energy of association ( A G ∆ ), free energy necessary for complexation ( complex G ∆ ) and enthalpy (ΔH ) were determined. It was concluded that the maximum complexation between calcium ions and Kryptofix-221 were by using 80% and 100%. MeOH in the mixtures. Where as the least complexing ability at 40% and 60% by volume of MeOH .This work give data can help for the analytical determination of calcium in blood and water samples.

Simple Spectrophotometric Sequential Injection Analysis System for Determination of Serum Calcium

A sequential injection analysis (SIA) system for the determination of total calcium in blood has been implemented. The assay principle is based on the arsenazo III method, in which the indicator’s complex with calcium forms a blue-purple colour. The absorbance peak height at 650 nm was proportional to the calcium content in samples. A linear range was obtained from 2.5 - 15 mg?dL–1 (r2 = 0.999), with a detection limit of 0.430 mg?dL–1 (3σ). Magnesium, glucose, hae-moglobin, and bilirubin at 123, 1,000, 50, and 0.5 mg?dL–1, respectively, were not found to interfere with the proposed system significantly (recovery 99.1% - 104.4%). The sampling frequency was 30 h–1, in which the carry-over effect was negligible (0.69%). The proposed SIA system was successfully applied to the determination of calcium from serum samples (r2 = 0.970; n = 30).

Flow-injection analysis–fluorescence detection for the in vivo on-line determination of calcium in blood with microdialysis sampling

Due to its high selectivity for calcium, calcein can be used as fluorescent indicator for the sensitive determination of calcium. A flow-injection on-line microdialysis system for in vivo monitoring of calcium in blood is developed. A microdialysis probe, implanted in the vein of rabbit, was perfused with perfusate at a flow rate of 5 μl/min. The concentration of calcium in the dialysate was determined on-line with a flow-injection fluorescence system. The dialysate sample volume was about 15 μl. The system was linearly related to the concentration of calcium in the range 0–80 μg/ml ( r 2=0.9968) with a detection limit (3 σ) of 0.01 μg/ml and the sample throughput of 20 h −1. R.S.D. was <5% ( n=11). The validation of using the no net flux method of quantitative microdialysis to measure concentration of calcium was evaluated in vitro and in vivo. The accuracy of this method was tested in vitro under steady-state conditions for three test solutions containing known concentration of calcium. The estimated concentration of calcium were 32±2, 42±2, and 49.5±0.9 μg/ml (mean±R.S.D.) in agreement with the actual concentrations of calcium in the test solutions which were 30, 40 and 50 μg/ml, respectively. In vivo, the estimated basal of calcium in dialysis sample from probe in the test animal’s blood was 33 μg/ml.

Recent advances in parathyroid hormone research

The introduction of blood calcium determinations as part of routine health screening procedures in this country has led to the discovery of a much higher incidence of primary hyperparathyroidism than was recognized previously. Research efforts have focused on studies of the cellular defects in the regulation or parathyroid hormone biosynthesis and secretion that are characteristically found in adenomatous and hyperplastic parathyroid glands. The available evidence indicates that the secretory defect probably resides at two levels: (1) a defect in the calcium sensor of the abnormal glands ("set-point" error) and (2) an exaggeration of a small component of autonomous hormone secretion that becomes relevant due to the large mass of glandular tissue. Regulation of parathyroid hormone synthesis appears to be at the level of cell replication (hyperplasia) and at the level of intracellular turnover of hormone. Marked heterogeneity of hormone in the circulation arises as a result of both glandular and extraglandular cleavages of hormone and the predominant circulating form of the hormone are biologically inactive, COOH-terminal fragments. Because most cases of hypercalcemia that accompany cancer are caused by humoral substances other than COOH-terminal fragments should distinguish patients with hypercalcemia due to cancer from those with primary hyperparathyroidism.

Automatic determination of calcium in blood and urine using Corinth Ca

Automatic determination of calcium in blood and urine using Corinth Ca

Intramuscular Injection of Vitamins A and D Concentrates During Pregnancy: Preliminary Report

Resume There is an accelerated metabolism in the state of pregnancy. There is an obvious drain by the fetus on the maternal organism. And there is apparently some degree of vitamin A and D deficiency. With these clinical axioms in mind, an anticipatory therapeusis by the accoucheur is in order. Absorbability, effectiveness, infrequent administration, and respect for a whimsical palate and an intolerant stomach are the key desiderata in the administration of vitamins A and D in pregnant women. Intramuscular injection of a high concentrate in 1 c.c. dosages every fortnight has proved practical and safe from every angle. In this foregoing clinical investigation no morbid phenomena or postpartum pathology existed. It is not alleged that the intramuscular A and D administrations are the source of normalcy in this series of cases. The primary purpose was simply to determine whether a high concentrate of vitamins A and D from fish liver oils can be administered intramuscularly with good effect and without toxic reaction in the gravid, a state so prone to vitamin inadequacy. It has been shown that it can and with little or no local reaction at the site of injection, and with no fear of toxicity. The advantages accrued are: a. The palate and gastrointestinal tract were not goaded into rebellion. b. The dosage, 1 c.c. c. Frequency, about every two to four weeks. d. Multiplied effectiveness. e. Patient under vigilance of her attending physician, f. Increased storage of these vitamins thus forestalling a deficiency. Due to lack of space, tables of blood calcium determinations are omitted but are added to the author's reprints.

Low calcium tetany of the newborn: Review of the recent literature and report of another proved case

<h3>Summary</h3> <ul><li>1.A case of low calcium tetany in a newborn infant is reported. Facial twitchings first occurred on the second day of life during the course of aspiration pneumonia. Twitchings recurred on the seventh day of life and again on the eighth day, followed by convulsion. The blood calcium content was 7.6 mg. Intensive therapy was instituted. Although symptoms of active tetany ceased after the third day of therapy, the blood calcium content was relatively unchanged (7.5 mg.) at the end of a week of therapy and was raised to 9.3 mg. only after two weeks of intensive intravenous and oral calcium therapy. Vitamin D in the form of viosterol was given to increase the absorption of calcium through the intestinal tract.</li><li>2.This is the second proved case of low calcium tetany in the newborn during the first three weeks of life observed by the author within a period of fifteen months.</li><li>3.The presence or absence of the Chvostek phenomenon is not of diagnostic significance. Although laryngospasm and carpopedal spasm may be present, they must not necessarily form part of the symptom-complex. The occurrence of convulsions or twitchings of unexplained etiology in a newborn infant, even in the absence of other signs and symptoms of tetany, necessitates a blood calcium determination to establish or rule out low calcium tetany.</li><li>5.The increasing frequency of reports of low calcium tetany in the newborn is obviously not due to an increased incidence of the syndrome but rather to increased watchfulness on the part of the physician and routine blood calcium determinations in cases of convulsions or twitches of unexplained etiology in the newborn.</li><li>6.If the calcium content of the blood were determined routinely in all such infants, it is probable that low calcium tetany would be found much more commonly in the newborn period than has hitherto been the case.</li></ul>

Low calcium tetany in the newborn: A review of the literature and a report of a case

Summary 1.A case of low calcium tetany in a newborn infant is reported. Facial twitchings first occurred on the second day of life during the course of aspiration pneumonia. Twitchings recurred on the seventh day of life and again on the eighth day, followed by convulsion. The blood calcium content was 7.6 mg. Intensive therapy was instituted. Although symptoms of active tetany ceased after the third day of therapy, the blood calcium content was relatively unchanged (7.5 mg.) at the end of a week of therapy and was raised to 9.3 mg. only after two weeks of intensive intravenous and oral calcium therapy. Vitamin D in the form of viosterol was given to increase the absorption of calcium through the intestinal tract. 2.This is the second proved case of low calcium tetany in the newborn during the first three weeks of life observed by the author within a period of fifteen months. 3.The presence or absence of the Chvostek phenomenon is not of diagnostic significance. Although laryngospasm and carpopedal spasm may be present, they must not necessarily form part of the symptom-complex. The occurrence of convulsions or twitchings of unexplained etiology in a newborn infant, even in the absence of other signs and symptoms of tetany, necessitates a blood calcium determination to establish or rule out low calcium tetany. 5.The increasing frequency of reports of low calcium tetany in the newborn is obviously not due to an increased incidence of the syndrome but rather to increased watchfulness on the part of the physician and routine blood calcium determinations in cases of convulsions or twitches of unexplained etiology in the newborn. 6.If the calcium content of the blood were determined routinely in all such infants, it is probable that low calcium tetany would be found much more commonly in the newborn period than has hitherto been the case.

Effect of Bile Salts on the Blood Calcium.

The relation of calcium metabolism to jaundice has long been a matter of clinical observation. Changes in the bones following both cholemia and prolonged loss of bile are a matter of common knowledge. More recent work by Walters and Heyd and others has put the therapy of jaundice by the intravenous injection of calcium chloride on a very firm clinical basis so that it is used as a routine in many clinics today. While the effect aimed at has generally been the decrease in the coagulation time of the blood as a preparation for surgical therapy, the results achieved have gone further than that, and it is without a doubt true that there is also a marked temporary detoxification produced by the intravenous injection of large amounts of calcium chloride. The studies of Still have shown clearly that it is the bile salts which are the offending factor in cholemia as the other elements of the bile are nontoxic. Buchbinder and Kern have shown that in animals and man the blood calcium tends to be rather low and Cantarow, Dodek and Gordon have confirmed the early work showing a greater excretion of calcium in jaundice. Walters and Bowler show that twice the amount of calcium salt injected intravenously may be required to raise the blood calcium to a given level in a patient with jaundice as in a normal person. With these points in view the following series of experiments were undertaken. A 10% solution of bile salts was injected intraperitoneally into 4 dogs; to 3 it was administered intravenously, and the blood calcium determinations were made at short intervals thereafter.

A FURTHER AND FINAL REPORT ON A CASE OF TETANIA PARATHYREOPRIVA, TREATED FOR A YEAR WITH PARATHYROID EXTRACT (COLLIP), WITH EVENTUAL DEATH AND AUTOPSY*

Late in 1924, J. B. Collip announced “the extraction of a parathyroid hormone which will prevent or control parathyroid tetany and which regulates the level of blood calcium.” In a series of articles (1, 2, 3, 4), culminating in his Harvey Lecture (5) Collip presented convincing evidence of the potency of the extract. Suffice it to state that a stable and purified principle was obtained which, when injected subcutaneously into experimental animals, produced a rise in the blood serum calcium level, and which in overdosage resulted in an alarming and sometimes fatal hypercalcemia. It was furthermore shown that frequently repeated small doses of this extract are cumulative in action and will eventually raise the blood calcium to dangerous levels (values over 15 mgm.), due to a “pyramiding of the effect of each successive injection upon the preceding one.” Hence the importance of accurate and dependable blood calcium determinations to control the dosage, very much as one checks the administration of insulin b...

GEOGRAPHICAL FACTORS IN CALCIUM METABOLISM*

At this time I wish to call attention to the possible causitive relationship between blood calcium deficiency as a clinical entity and calcium deprivation; also to report the results of blood calcium determinations on clinical subjects. Further, I wish to point out certain geographical factors which undoubtedly bear on the question of calcium metabolism in the State of Washington.

CALCIUM IN THE BLOOD OF CHILDREN

The publication of several relatively accurate and simple micro-methods for the determination of calcium in the blood has opened the way for many interesting lines of investigation in the field of calcium metabolism. About two years ago, inspired by the acquisition of a new weapon, we embarked on the study of an old and much investigated problem, viz., the calcium metabolism of children. The obvious connection between rickets, and probably infantile tetany, and some error of calcium metabolism, has naturally led us to lay special stress on the study of patients suffering from these disorders, but we also have attempted to collect data on the calcium content of the blood of children suffering from a variety of pathological conditions. Our calcium determinations have been made by the method of Lyman, 1 which we have modified in a few minor details. Lyman's method for the determination of calcium in blood consists

The determination of calcium in blood and plasma

The method consists in a direct precipitation of the calcium without removal of the blood porteins. The only reagents necessary are ammonium chloride (to prevent the precipitation of magnesium), and ammonium oxalate, both adjusted approximately to PH 7.4.Blood.—Citrated blood (5 c.c. in a 50 c.c. centrifuge tube), is hemolyzed by the addition of four volumes (20 c.c.) of warm water and after standing 15 to 20 minutes is centrifuged to remove the stroma. An aliquot (20 c.c.) of the clear, red liquid is transferred to a 50 c.c. centrifuge tube. One c.c. of 5 per cent. ammonium chloride is added and, after mixing, 3 c.c. of 3 per cent. ammonium oxalate are added. The oxalate should be added slowly and the contents of the tube must be well mixed. After standing at least 16 hours (the much shorter time recently reported by de Waard1 results in an incomplete precipitation of the calcium), the mixture is centrifuged and the supernatant liquid siphoned off. The tube is washed by the addition of 25-30 c.c. of cold...