PubMed Health⌕ Search

Biomedical subjects

J Thode

Publications and source records attributed to J Thode.

At least 19 recordsLinked to original sources
PubMed2000

Serum-ionised magnesium in patients with acute myocardial infarction. Relation to cardiac arrhythmias, left ventricular function and mortality.

Measurement of serum-ionised magnesium has recently become available, and we report the first study of the relation of this parameter to arrhythmias, left ventricular function and mortality in patients with an acute myocardial infarction. Serum-ionised magnesium was determined in 217 consecutive patients admitted to hospital with an enzyme confirmed AMI. 70 healthy subjects acted as a control group. The main study parameters were occurrence of arrhythmias, left ventricular function estimated by echocardiography, and mortality after 10 months for the AMI patients. AMI patients had significantly lower serum-ionised magnesium compared to healthy controls but the level of serum-ionised magnesium in the acute phase of a MI was neither related to arrhythmias, left ventricular function nor mortality.

Adult↗
PubMed1998

Lack of relationship between serum and gallbladder bile calcium in patients with gallstone disease.

BACKGROUND: Recent studies suggest that alternation in serum calcium influences the level of gallbladder bile ionized calcium (Ca2+). Theoretically, this could increase the risk of calcium precipitation in the gallbladder. METHODS: We therefore measured serum and gallbladder bile minerals in patients with gallstones (n = 27) and without (n = 10, controls). The serum samples were taken just prior to induction of anaesthesia and gallbladder bile was aspirated before any manipulation of the gallbladder. RESULTS: The active molality of Ca2+ in gallbladder bile was not statistically significant different between cases and controls (0.44 +/- 0.16 vs. 0.40 +/- 0.10 mmol/kg), whereas pH was significantly lower (6.94 +/- 0.31 vs. 7.36 +/- 0.28, p < 0.0001) and cholesterol higher (4.37 +/- 2.70 vs. 1.79 +/- 1.33 mmol/l; p < 0.01) in gallbladder bile obtained from cases. Serum Ca2+ at actual pH, magnesium and phosphate were significantly higher among cases than in controls. Gallbladder bile active molality of Ca2+ was significantly correlated with bile total calcium in both groups (r = 0.72; p < 0.001 and r = 0.91; p < 0.001, respectively). In controls only, we observed a positive relationship between serum Ca2+ at actual pH and the active molality of Ca2+ in bile (r = 0.61; p < 0.05). CONCLUSION: Our study demonstrates that Ca2+ in gallbladder bile does not differ between cases and controls. The lack of correlation between serum and gallbladder bile constituents in cases compared to controls suggests that changes in calcium equilibration between bile and serum in patients with gallstone disease might be of importance for the formation of gallstones.

Adult↗
PubMed1998

Evaluation of an ionized magnesium-pH analyzer--NOVA 8.

An ion-selective analyzer (NOVA 8 [previously NOVA CRT], NOVA Biomedical Waltham, USA) for simultaneous measurement of the concentration of ionized magnesium (cMG2+) and pH is investigated for linearity and influence of calcium ions on the Mg2+ results in different Mg2+ aqueous solutions with/without added calcium. Within the cMg2+ range 0-3.0 mmol/L, which covers most clinical values, we found cMg2+ values close to the line of identity, with a sensitivity about 94%, but 0.09 mmol/L lower in the absence of Ca2+. The analytical precision (CV) for human serum control was 1.7% in the physiological range. The accuracy and precision data for the Mg2+ electrode meet the demands for reliable results within the range for clinical use. We found a reference interval (95%) for cMg2+ of between 0.43 and 0.59 mmol/L serum, with a mean value of 0.51 mmol/L for healthy adults in the non-fasting state with no relation to sex or age. The mean cMg2+ was 61% of the mean concentration of plasma total magnesium (cTMg) ranging from (95%) 49% to 73%. No significant correlation was found between cMg2+ and total protein, albumin, phosphate, Ca2+, and total CO2. No significant difference was found between mean values for cMg2+ in whole blood, plasma, and serum. Serum samples could be stored for 24 h at 4 degrees C without significant change. Storage at -20 degrees C for 7 months caused a mean cMg2+ decrease of 8.3%. The mean slope delta lgcMg2+/delta pH measured after equilibration with different pCO2 values in each serum sample from the reference population was -0.0110, indicating a close agreement between the values for actual cMg2+ and adjusted cMg2+ (pH = 7.4).

Adult↗
PubMed1996

Does the plasma concentration of 25-hydroxyvitamin D determine the level of 1,25-dihydroxyvitamin D in primary hyperparathyroidism?

In man, parathyroid hormone (PTH) is one of the main regulators of 1,25-dihydroxyvitamin D (1,25(OH)2D) production. However, conflicting results have been reported concerning the regulatory significance of PTH on 1,25(OH)2D in primary hyperparathyroidism. We measured the plasma concentrations of intact PTH, ionized calcium (pH 7.4), phosphate, creatinine, 25-hydroxyvitamin D (25(OH)D), 1,25(OH)2D and urine creatinine in a standardised regime in 17 patients with primary hyperparathyroidism. The nephrogeneous cyclic adenosine-3,5-monophosphate (NcAMP) was measured and so provides an "in vivo receptor assay' for biologically active PTH in the circulation. Multiple regression analysis was used to identify variables with a possible influence on the plasma concentration of 1,25(OH)2D. The only variable showing a significant correlation to the plasma concentration of 1,25(OH)2D was 25(OH)D (r=0.6, p < 0.03). Our results indicate that the plasma concentration of 25(OH)D may be very central for the regulation of 1,25(OH)2D production in primary hyperparathyroidism.

Adult↗
PubMed1994

[Osteoporosis-profile--a bad examination?].

A so-called osteoporosis-profile has become increasingly popular among Danish doctors. Future bone loss in peri- and postmenopausal women is estimated by means of an algorithm comprising serum osteocalcin and alkaline phosphatases as markers of bone formation and urinary calcium and hydroxyproline excretions, corrected for creatinine, as markers of bone resorption. The osteoporosis-profile, performed by Medi-Lab, was tested in six females aged 46-56 years. Three different diets were used on three successive week-ends, each ending with a collagen-free supper and an overnight fast. Individual changes in estimated bone loss of up to 200-300% were found, demonstrating that the test was useless in a single person.

Aged↗
PubMed1994

Childhood sarcoidosis presenting with hypercalcaemic crisis.

We report a case of hypercalcaemic crisis due to sarcoidosis in a 15-year-old boy. The clinical suspicion of sarcoidosis was confirmed by a liver biopsy. At admission serum calcium, 1,25(OH)2 and ACE were elevated and iPTH was suppressed. The levels of serum total and ionized calcium, iPTH, ACE, 1,25(OH)2 and 25-OH were followed and chest X-ray and pulmonary function tests were performed during systemic steroid treatment. The clinical condition improved during treatment and the paraclinical measurements normalised within 5 weeks. The mechanism whereby hypercalcaemia occurs in childhood sarcoidosis is clarified.

Adolescent↗
PubMed1993

Calcium, magnesium, and free fatty acids in the formation of gallstones: a nested case-control study.

In a nested case-control study, calcium status was assessed by measurements of serum total calcium, magnesium, phosphate, ionized calcium, parathyroid hormone, albumin, total CO2 (bicarbonate), and free fatty acids in relation to gallstone formation. The subjects were recruited from a cohort study (n = 4,581) on the epidemiology of gallstones in Denmark. The cohort was examined with ultrasonography twice, in 1983 and 1988; 63 subjects developed gallstones, and among those who did not, 122 were randomly selected as controls. Subjects with gallstones had significantly increased serum concentrations of total calcium, magnesium, and bicarbonate as compared with normal subjects. The difference was only observed in women. Age, body mass index, alcohol consumption, and smoking did not influence the results when included as covariables in a logistic regression analysis. Multivariate analysis showed increased concentrations of magnesium, bicarbonate, and parathyroid hormone to be significantly associated with gallstone disease in women. No significant association was observed between gallstone disease and serum variables in men.

Bicarbonates↗
PubMed1993

Effects of age, sex, season and diet on serum ionized calcium, parathyroid hormone and vitamin D in a random population.

OBJECTIVES: To study the influence of age, sex, season and diet on calcium status in normal subjects. DESIGN: A random population study. Setting. Institutional clinic for large population studies. SUBJECTS: The subjects were drawn randomly from the Danish Civil Registration System and represented a random sample of the background population in the area. The sample comprised 127 subjects (54 men and 73 women, aged 35-65 years). MAIN OUTCOME MEASURES: The effects of age, sex, season and diet on parathyroid hormone (PTH),1,25-dihydroxyvitamin D (1,25(OH)2D) and 25-hydroxyvitamin D (25-OHD). RESULTS: There was no statistical significant difference for the serum concentrations of ionized calcium, PTH, 1,25(OH)2D and 25-OHD between the two sexes, nor any influence by age in either sex, in contrast to serum phosphate, which declined significantly in men (P < 0.05), but tended to increase in women. Serum PTH (P < 0.009) showed seasonal fluctuations, whereas serum concentrations of 1,25(OH)2D, 25-OHD, ionized calcium, phosphate and magnesium remained stable throughout the year. Dietary intake of calcium and vitamin D were not related to any serum variables. CONCLUSIONS: In healthy subjects differences between the two sexes exist regarding phosphate metabolism. Serum PTH shows seasonal fluctuations.

Adult↗
PubMed1993

Serum ionized calcium, parathyroid hormone and phosphate in uremic patients during and between hemodialysis.

The serum concentrations of actual ionized calcium (at actual pH), adjusted ionized calcium (at pH 7.4), pH, intact parathyroid hormone (PTH) and phosphate were studied in ten patients during and between two hemodialysis sessions using a dialysate containing 1.66 mmol/l of calcium. Actual ionized calcium and adjusted ionized calcium increased during hemodialysis from 1.19 to 1.38 and 1.43 mmol/l, respectively (mean values) and returned to predialysis values within five and nine hours postdialysis. Serum PTH decreased from 165 ng/l to 55 ng/l (median values) during hemodialysis but two-hour postdialysis the level did not differ significantly from the predialysis level. Serum phosphate decreased from 2.05 mmol/l to 1.11 mmol/l during hemodialysis, and increased slowly towards the predialysis level. The level of pH increased from 7.40 to 7.47 during hemodialysis and reached predialysis level after nine hours. In a multivariate analysis including actual and adjusted ionized calcium, pH, phosphate and PTH, only actual or adjusted ionized calcium was associated with the level of PTH. We conclude that the effect of dialysate calcium on the levels of ionized calcium and PTH is of very short duration postdialysis.

Adult↗
PubMed1993

Variability of the calcium ion activity with pH in stone-forming and non-stone-forming urine.

In recurrent renal stone-formers (N = 20) and matched healthy adults (N = 20), the actual activity of ionized calcium (alpha Ca2+) and pH were determined in whole urine with an ion-selective electrode. No significant difference was found for the actual median activity of ionized calcium, however the actual median pH was significantly higher in stone-formers compared to healthy adults (pH = 5.57 vs. pH = 5.24; p < 0.005). The relationship between Ca2+ activity and pH was studied in each collected urine by titration with HCl/NaOH. In all urines the Ca2+ activity decreased with increasing pH in a typical bifasic manner. All curves showed a characteristic "breaking point" at a similar median pH in the stone-formers and in the healthy adults (pH = 6.81 vs. pH = 6.77) (NS). However the slope of the curves in the stone-formers and healthy adults changed from a median value of delta lg alpha Ca2+/delta pH of -0.139 and -0.173 (NS) respectively, to a highly significant difference of -1.326 and -1.053 (p < 0.0001) between the groups, indicating increased binding/precipitation of Ca2+ in stone-formers than in healthy adults supporting the theory of the lack of inhibitors in stone-formers. The strong relationship between the activity of ionized calcium and pH, combined with a higher actual pH and a higher decrease of ionized calcium with pH in stone-formers than in healthy adults, indicates hydrogen ion as a major factor in stone-formation. The close relationship between Ca2+ activity and pH indicates the need for simultaneous measurements of the pH in order to interpret data for the Ca2+ activity. In order to preserve a low urinary pH, where Ca2+ is predominantly in a free ionic state, our results suggest that treatment with acidifying salts could be a logical choice in order to prevent stone-formation.

Adult↗
PubMed1992

Increased activity of ionised calcium in gall bladder bile in gall stone disease.

The actual activity of ionised calcium (Ca2+) in gall bladder bile determined with an ion-selective electrode was significantly higher in patients with gall stone disease (n = 15) than in patients without gall stones (n = 10) (0.43 mmol/kg v 0.31 mmol/kg; p < 0.05). No change in the Ca2+ activity in any of the gall bladder bile samples was observed during equilibration with CO2. During titration with HCl/NaOH, however, the Ca2+ activity fell with increasing pH in a biphasic manner, with the breaking point occurring at a significantly lower median pH in patients with gall stones than in patients without (pH 7.1 v 8.2; p < 0.0001). The combination of a higher activity of calcium in bile and precipitation of bile salts taking place at a lower pH in patients with gall stone disease than in patients without gall stones suggests a major role for calcium and pH in the pathogenesis of gall stones. Strict anaerobic sampling is not necessary for the measurements of Ca2+ in gall bladder bile, because the Ca2+ was not significantly affected by the changes in pCO2. The metabolic studies suggest, however, that simultaneous measurements of the activity of Ca2+ and pH is important in order to interpret data for the calcium activity in gall bladder bile.

Adult↗
PubMed1992

Performance characteristics of creatine kinase-MB isoenzyme measured with an immunoenzymometric and an immunoinhibition assay in acute myocardial infarction with and without thrombolytic therapy.

In a time study we compared the analytical and clinical performance of the Tandem Icon QSR CK-MB enzyme-immunoassay (Hybritech) (creatine kinase-MB) and a creatine kinase-MB immunoinhibition method (Boehringer Mannheim GmbH) (creatine kinase-B). Two hundred and ninety-nine serum samples from 38 patients suspected of acute myocardial infarction were collected at regular intervals during 48 hours. Twenty-nine patients were diagnosed as having acute myocardial infarction, of whom 19 received thrombolytic therapy. Although highly correlated, the large scatter around the regression line at low values indicated a different clinical performance of the two methods. We evaluated and compared test performance at different decision levels by means of frequency distributions and predictive values of positive and negative results. For early diagnosis of acute myocardial infarction (4 hours after onset of pain) the Hybritech creatine kinase-MB method gives acceptable predictive values. In thrombolytic treated acute myocardial infarction patients, the peak creatine kinase-MB and creatine kinase-B concentrations were reached after 13.0 h and 13.6 h after the onset of pain, compared with 19.8 h and 17.8 h for patients without thrombolytic therapy.

Creatine Kinase↗
PubMed1990

Direct reading glucose electrodes detect the molality of glucose in plasma and whole blood.

It is the activity that determines the direction of chemical processes, transport, etc. and thus provides the clinically more relevant information. Direct reading glucose electrodes consume glucose at a rate proportional to the glucose activity in the sample. The activity equals the molality (mmol glucose per kg water), so results from direct reading glucose electrodes must differ from the conventionally measured glucose concentration. This was observed in 159 whole blood samples which gave higher results from a direct reading glucose electrode than by our conventional method (y = 1.21x - 0.37 mmol/l). However, adjustment for the different water concentration due to salt, plasma proteins, and hemoglobin occupying space, gave results equal to the concentrations (y = 1.00x - 0.28 mmol/l, r = 0.997). Furthermore, results for samples with constant glucose concentration and varying albumin concentration correlated with the albumin concentration (r = 0.989), but not after adjustment for water concentration (r = 0.037, n.s.).

Blood Chemical Analysis↗
PubMed1990

Ionized calcium and cyclic AMP in plasma and urine. Biochemical evaluation in calcium metabolic disease.

Measurement of ionized calcium and cAMP in plasma and urine are used as sensitive parameters for the evaluation of calcium disorders. Ionized calcium is accepted as the biologically active form of calcium in the extracellular fluid, while urine cAMP provides an in vivo receptor assay for the biologically active parathyroid hormone. When urine is included as part of the calcium metabolic investigation it usually requires 24 h urine collection with a variety of different laboratory tests. Ionized calcium and cAMP are described in the literature in terms of several derived quantities, nomenclatures, and units which are rather unsystematic. The author developed reliable techniques and proposed systematic names and symbols and reference values for these quantities. Due to the lack of guidelines for the collection of urines in calcium metabolic evaluation, the author presented a simplified protocol (4 h standardized urine collection). In clinical investigation plasma and urine cAMP have been used to differentiate idiopathic hypoparathyroidism from pseudohypoparathyroidism (PsHP) based on the results of i.v. injection of parathyroid hormone (PTH). Nephrogenous cAMP has also been used for the detection of primary and secondary hyperparathyroidism with a high nosographic sensitivity (90%) (Broadus). The author showed that measurement of cAMP after i.v. PTH was a reliable and sensitive test to establish the diagnosis of PsHP, and that the urinary cAMP was useful for the diagnosis of secondary hyperparathyroidism in patients with jejunoileal bypass, but could not confirm the high nosographic sensitivity for the diagnosis of primary hyperparathyroidism. Further data are needed for proper conclusion. Although pursued vigorously the research into idiopathic stone formation using different protocols has not prevented stone recurrence nor indicated where further progress might be made. For the evaluation of recurrent calcium disease, the author proposed a simplified 4 h standardized urine collection with plasma albumin, urinary pH, standardized excretion rate of calcium, plasma phosphate glomerular filtration rate, and nephrogenous cAMP as the most important parameters. In this way the author obtained a sensitivity of 93% and specificity of 95.6% for the diagnosis of recurrent stone former. The test may therefore be of value for predicting the risk of recurrent stone formation in the single stone former.

Calcium↗
PubMed1990

Adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood compared for clinical evaluation of patients with disorders of calcium metabolism.

We report results for adjusted ionized calcium (at pH 7.4) and actual ionized calcium (at actual pH) in capillary blood from 183 patients with disorders of calcium metabolism (primary hyperparathyroidism, secondary hyperparathyroidism of malabsorption, primary hypoparathyroidism, Paget's disease, acromegaly, hypercalcemia of malignancy, osteoporosis, sarcoidosis, idiopathic hypercalciuria, and familial hypocalciuric hypercalcemia). The correlation and the equation for the linear regression between adjusted ionized calcium (y) and actual ionized calcium (x) were y = 1.011x + 0.005 mmol/L, r = 0.992, Sy,x = 0.021 mmol/L. Results were similar within each diagnostic group. Consistent agreement between adjusted and ionized calcium was observed in 96.7% of patients representing a variety of the most frequently encountered disorders of calcium metabolism. Thus we find adjusted ionized calcium to be as useful as actual ionized calcium for evaluation of patients with such disorders. Adjusted ionized calcium may therefore also be a logical choice for establishing agreement between laboratories for reference intervals in healthy adults.

Acromegaly↗
PubMed1989

[Ionized calcium, total calcium and albumin corrected calcium in the serum in 1213 patients with suspected calcium metabolic diseases. A prospective multicenter study].

The correlation between serum ionized calcium, serum total calcium and albumin corrected total calcium was investigated in a prospective multicentre investigation of 1,213 patients with suspected calcium metabolic disease. 31.0% of the patients were misclassified when serum total calcium was measured instead of serum ionized calcium. The diagnostic discrepancy between the two methods decreased with the calculation of albumin corrected total calcium or calculated ionized calcium (17.9%). On justing for the analytical error connected with the measurement of ionized calcium, 11.2% of the patients were still misclassified. It is not possible precisely to predict serum ionized calcium from the measurement of serum total calcium and we recommend measurement of serum ionized calcium in patients believed to have calcium metabolic disease.

Calcium↗
PubMed1989

Palmitic acid stimulates glucose incorporation in the adipocyte by a mechanism likely involving intracellular calcium.

The effect of palmitic acid on basal and insulin-stimulated incorporation of glucose into rat adipocytes was studied. Palmitic acid (2.40 mM) stimulated basal as well as insulin-stimulated glucose incorporation in rat adipocytes three and twofold, respectively. Similar degrees of stimulation of basal glucose oxidation by palmitate were also observed. The ability of palmitic acid to stimulate glucose uptake was additive with respect to the stimulation induced by insulin and was proportional to the palmitic acid concentration between 0.15 mM and 2.40 mM. Stimulation of glucose incorporation by palmitic acid was inhibited by preincubating the cells with quin2-AM, which accumulates intracellularly yielding the trapped chelator form. quin2, which binds intracellular Ca2+.The concentration of quin2-AM required for half-maximal inhibition of palmitic acid stimulated glucose incorporation was 3.8 +/- 1.2 microM (mean +/- SEM). The inhibition of palmitic acid-stimulated glucose incorporation by quin2-AM (10 microM) was overcome by incubating cells with the Ca2+ ionophore, A23187, in the presence of extracellular Ca2+ (2.6 mM). Chelation of extracellular Ca2+ with EGTA did not significantly affect the magnitude of palmitic acid-stimulated glucose incorporation. Dantrolene (12.5-100 microM) failed to affect basal or palmitic acid-stimulated glucose incorporation. These findings suggest that palmitic acid stimulates incorporation of glucose in the adipocyte by a mechanism dependent upon intracellular but not extracellular Ca2+.

Adipose Tissue↗