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T Helenius

Publications and source records attributed to T Helenius.

At least 19 recordsLinked to original sources
PubMed2000

Growth hormone and cortisol in serum and saliva.

Salivary diagnosis is a developing area in clinical chemistry and dentistry. Cortisol analyses from saliva have been used in pediatric practice and as doping tests. Growth hormone (hGH), also a stress hormone, has not been analyzed from saliva. We studied the serum and saliva of 51 healthy subjects. The samples were taken at 8:00 in the morning after 12 h fasting. Cortisol concentrations were analyzed using RIA. An immunoradiometric assay was applied for analyzing serum and salivary hGH. The validity of this method developed in our laboratory was found to be good. The results showed correlation of salivary cortisol with that of serum (r = 0.47, P < 0.001). Salivary hGH concentrations were 1000-fold lower than the respective values in serum, but a clear correlation was found between salivary and serum hGH levels (r = 0.59, P < 0.001).

Adult↗
PubMed1998

Serum N-terminal atrial natriuretic peptide (NT-ANP) in the cardiac follow-up in children with cancer.

BACKGROUND: We studied serum N-terminal atrial natriuretic peptide (NT-ANP) in children during and after chemotherapy for cancer to determine its applicability in detecting cardiac dysfunction. Forty-three patients were receiving chemotherapy for malignancy. Forty-eight patients were off chemotherapy and survived between 0.9 and 13 (median 5) years after the diagnosis, receiving cumulative anthracycline doses between 0 and 600 (median 225) mg/m2. PROCEDURE AND RESULTS: Cardiac evaluation of the patients included measurement of serum NT-ANP, recording of ECG, and assessment of systolic and diastolic function of the heart by echocardiography. During chemotherapy, serum NT-ANP levels were higher than in controls but varied markedly in the same individuals. Serum NT-ANP levels showed no consistent increase in the weeks following anthracycline administration. In late follow-up, serum NT-ANP levels were higher than in age-matched controls (median (range), 0.22 (0.06-0.47) vs. 0.14 (0.06-0.27) nmol/l, respectively, P < .001). The subgroup of patients with bone marrow transplantation and/or cardiac irradiation had the highest NT-ANP concentrations (0.30 (0.20-0.45) nmol/l). CONCLUSIONS: Thus, serum NT-ANP measurements seemed to represent a useful contribution in the long-term cardiac follow-up of children after cancer. This blood test can readily be included to laboratory follow-up, is reasonably inexpensive and may decrease the need for more laborious tests of cardiac function. When there is ongoing chemotherapy, NT-ANP levels are influenced by a variety of factors that invalidate its routine use during this period.

Adolescent↗
PubMed1997

Associations between atrial natriuretic peptides, echocardiographic findings and mortality in an elderly population sample.

OBJECTIVES: To examine associations of N-terminal and C-terminal components of the proatrial natriuretic peptide [ANP (1-98) and ANP (99-126), respectively], with echocardiographic measurements of left ventricular structure and performance and with the function of the aortic and mitral valves in old age. To compare the predictive value of the atrial peptides and echocardiographic data for short-term mortality. DESIGN: A population based survey with 1.5-year mortality follow-up. SETTING: University hospital. SUBJECTS: Three-hundred and thirty-three people aged 78-88 years. MAIN OUTCOME MEASURES: (i) Plasma ANP (1-98) and ANP (99-126); (ii) M-mode and Doppler echocardiographic measurements of left atrial diameter; left ventricular diameters, mass and fractional shortening; peak transmitral velocities; aortic valve area, aortic regurgitation jet length and mitral regurgitant jet area; (iii) total and cardiovascular 1.5-year mortality. RESULTS: ANP (1-98) correlated with left atrial diameter (r = 0.33; P < 0.001), left ventricular mass (r = 0.19; P < 0.001), fractional shortening (r = -0.16; P < 0.01) and the early-to-atrial peak transmitral velocity ratio (r = 0.23; P < 0.001). Also, ANP (1-98) predicted the degree of aortic valve obstruction and the severity of aortic and mitral regurgitation. Associations of ANP (99-126) with echocardiographic data were much weaker. Aortic valve stenosis and ANP (1-98) were independent predictors of age- and sex-adjusted total and cardiovascular mortality at 1.5 years of entry. CONCLUSIONS: Circulating ANP (1-98) correlates with left atrial size, with left ventricular mass and performance and with the severity of aortic and mitral valve dysfunction in persons representing the general elderly population. ANP (1-98) also predicts both total and cardiovascular mortality.

Aged↗
PubMed1994

Automated and manual serum free thyroxine assays evaluated with equilibrium dialysis.

Two fully automated serum FT4 assays (Ciba Corning: ACS-180; Abbott Diagnostics: IMx) and two manual/semiautomated assays (Wallac: Delfia; Diagnostic Products Corp.: Coat-A-Count) were compared with a FT4 reference method based on equilibrium dialysis (ED) using routine clinical samples (n = 105-150). For the full range of FT4 concentrations the correlation with ED was good (r = 0.932-0.959), except for Coat-A-Count (r = 0.852), a single-step analogue-type method. Analytical inaccuracy of the automated methods at low FT4 concentrations was revealed by the differential plot: the IMx assay overestimated concentrations < 10 pmol l-1 and the ACS-180 assay concentrations < 6 pmol l-1. The between-assay CVs for the automated methods were not better than for the non-automated assays indicating problems of calibration curve stability for the automated assays.

Autoanalysis↗
PubMed1993

Increased urinary polyamine excretion after starting a very low calorie diet.

Urinary polyamine excretion has been suggested to reflect hypermetabolism or catabolism in different illnesses. In the present study, the excretion of urinary polyamines was examined in 12 obese subjects (3 men, 9 women aged 32-55 y, body mass index 33.3-64.7 kg m-2) before and during a very low calorie diet (the total calorie intake 2100-3350 kJ). In addition, nitrogen balance, basal energy expenditure (BEE) and serum thyroid hormone levels were examined. During the first week on a very low calorie diet (VLCD) the mean body weight declined from 121.8 +/- 27.3 to 117.4 +/- 26.2 kg (mean +/- SD, p < 0.001), and after 12 weeks of treatment body weight was 106.6 +/- 24.6 kg. Immediate reduction of BEE from 1.44 +/- 0.24 to 1.34 +/- 0.24 kcal min-1 (p < 0.001) was found within the first week of therapy and BEE measured on weight-maintaining diet remained lower at 12 weeks (1.25 +/- 0.27 kcal min-1, p < 0.01). Serum free T3 decreased and reverse T3 increased significantly after starting VLCD. Nitrogen balance remained negative during the first 2 weeks on VLCD. A significant increase in total (38%), and in N1-acetyl- and N8-acetylspermidine excretions in the urine (40% and 27%, respectively, p < 0.05) was found during the first week, but later on the levels were not significantly different from the baseline levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Fatty acid-induced increase in serum dialyzable free thyroxine after physical exercise: implication for nonthyroidal illness.

In 14 healthy males, prolonged running exercise resulted in a mean 25% increase in serum free T4 (FT4) concentration (P less than 0.001) which was significantly correlated (P less than 0.01-0.02) with an over 5-fold increase in the concentration of serum FFA and the FFA/albumin molar ratio. Hemoconcentration, as reflected in a mean 19% increase in serum albumin, caused an increase in serum T4-binding globulin and therefore also in serum total T4. As there was no change in the serum T4/T4-binding globulin molar ratio, the rise in serum FT4 was probably not caused, or only partly caused, by an exercise-induced shift of T4 from the extravascular to the intravascular compartment. Neither is it likely that the mean 41% increase in serum TSH observed after exercise, partly owing to hemoconcentration, was the reason for the increase in serum FT4 and T4 as there was no correlation between the increases in the TSH and thyroid hormone levels. Further support for the assumption that the elevation in serum FT4 after exercise was FFA-induced was provided by the observation that addition of 2.5 mmol/L oleic acid to normal serum in vitro resulted in a 33% increase in serum FT4 (P less than 0.001). There is an association between increased concentrations of serum FT4 and unsaturated FFA in patients with various nonthyroidal illnesses according to earlier observations, but it is unlikely, in the light of the present data from healthy subjects, that FFA are directly involved in raising the serum FT4 concentration in nonthyroidal illnesses patients unless the serum FFA concentration exceeds 2 mmol/L or the FFA/albumin molar ratio rises above 2.5.

Adult↗
PubMed1990

Concentrations of somatomedin-C and triiodothyronine in patients with thyroid dysfunction and nonthyroidal illnesses.

We studied the possibility of an association between serum somatomedin-C (Sm-C) and thyroid hormone concentrations. For this purpose 34 hyperthyroid patients, 39 patients with primary hypothyroidism, 36 patients with severe nonthyroidal illnesses (NTI), and 63 euthyroid healthy control subjects were examined. The mean concentration of serum dialyzable free triiodothyronine (FT3) was 26.6 +/- 15.4 pmol/l (+/- SD) in hyperthyroidism, 2.8 +/- 1.2 in hypothyroidism, 4.2 +/- 1.1 in NTI, and 5.3 +/- 0.7 in controls. The lowest mean concentration of serum Sm-C (10.1 +/- 3.0 nmol/l) was found in the NTI group and the highest in the hyperthyroid group (16.8 +/- 3.2): these concentrations differed significantly from the mean control level (12.2 +/- 2.2). In NTI patients the serum FT3 and T3 levels correlated significantly with the serum Sm-C levels (r = 0.63; p less than 0.001, r = 0.65; p less than 0.001, respectively). In hypothyroid patients there was a weak correlation between the serum FT3 and Sm-C levels (r = 0.36; p less than 0.05), but no correlations were found in hyperthyroid and healthy subjects. We conclude that the lowered Sm-C levels in NTI do not reflect a hypothyroid state, as normal Sm-C levels were found in hypothyroidism, and that impaired nutritional state of the patients is the most likely explanation for the association between Sm-C and FT3 (and T3) in NTI.

Adult↗
PubMed1987

Free thyroxine, free triiodothyronine, and thyrotropin concentrations in hypothyroid and thyroid carcinoma patients receiving thyroxine therapy.

Free thyroxine (FT4) and free triiodothyronine (FT3) concentrations in serum were measured by direct equilibrium dialysis methods in patients receiving thyroxine replacement or suppression therapy. Four of 50 hypothyroid patients euthyroid on replacement therapy (mean thyroxine dose 120 micrograms/day) had supranormal FT4 concentrations, whereas the FT3 concentrations were normal in all. Forty-one of 56 operated thyroid carcinoma patients on suppressive therapy (mean thyroxine dose 214 micrograms/day) had raised FT4 concentrations, whereas the FT3 concentrations was elevated in only one patient. There was a large difference in mean FT4 values for hypothyroid and thyroid carcinoma patients (17.2 vs 29.5 pmol/l), whereas the difference in mean FT3 values was small (5.0 vs 6.1 pmol/l), suggesting a decreased peripheral conversion of T4 to T3 with increasing concentrations of FT4. Serum TSH concentrations, as determined by an immunoradiometric assay, varied from less than 0.02 to 11.9 mU/l in treated hypothyroid patients; 21 patients (42%) had values outside the reference limits. As a single test, serum TSH is therefore not very useful for the assessment of adequate thyroxine dosage in patients with primary hypothyroidism. In thyroid carcinoma patients, the TSH concentrations were less than 0.18 mU/l; 45 patients had values less than 0.02 mU/l indicating sufficient suppression of TSH secretion in the majority of cases. On the basis of these results we recommend the combination of FT3 and TSH tests for monitoring thyroxine replacement and suppression therapy. FT4 appears less useful than FT3 for this purpose even if special reference values values were adopted for each patient group.

Adult↗
PubMed1987

Concentrations of iodothyronines in serum of patients with chronic renal failure and other nonthyroidal illnesses: role of free fatty acids.

The mean concentration of free thyroxin (FT4) in serum, as determined by direct equilibrium dialysis, was decreased in patients with chronic renal failure (CRF) and increased in patients with various other nonthyroidal illnesses (NTI). The mean concentration of dialyzable free triiodothyronine (FT3) in serum was equally low in both groups of patients. Patients with CRF of various etiology but a similar degree of renal failure as estimated from serum creatinine assay had very similar concentrations of FT4 and FT3 in their serum. Mean thyroxin (T4) and triiodothyronine (T3) concentrations in serum were decreased in CRF and NTI, whereas the mean reverse-T3 concentration in serum was normal in CRF and increased in NTI. T4-binding globulin and albumin were markedly decreased in CRF and NTI; T4-binding prealbumin was increased in CRF and decreased in NTI. The mean concentration of nonesterified free fatty acids (FFA) in serum was increased in NTI but not in CRF. The weak, but significant, positive correlation observed between FT4 and FFA in serum (r = 0.34, P less than 0.01) in NTI indicates that the increase in serum FT4 in this group of patients could be an effect, at least in part, of FFA competing with T4 for binding sites on serum proteins. The stronger correlation detected between the serum FT4 concentration and the FFA/albumin molar ratio in serum (r = 0.60, P less than 0.001) demonstrates the importance of a low albumin concentration for expression of the effect of FFA on FT4 in severe systemic illnesses.

Adult↗
PubMed1987

Performance of direct equilibrium dialysis and analogue-type free thyroid hormone assays, and an immunoradiometric TSH method in patients with thyroid dysfunction.

Direct equilibrium dialysis and analogue-type radio-immunoassays for free triiodothyronine (FT3) and free thyroxine (FT4) in serum were compared in 168 subjects with various states of thyroid function. A good diagnostic efficacy for FT3 and FT4 by either type of assay was observed in hyperthyroidism. In hypothyroidism the free thyroid hormone assays, particularly the FT3 assays, performed diagnostically less well, partly because patients with mild disease were included in the study. No significant differences in the percentages of misclassifications of thyroid dysfunction patients by corresponding dialysis and analogue assays were found. We observed a good linear correlation between dialysis and analogue methods for FT3 (r = 0.98) and FT4 (r = 0.97) in this study comprising out-patients not suffering from severe non-thyroidal disease, known from earlier studies in this and other laboratories to interfere in these assays. It is concluded that analogue assays may be used on out-patients in whom severe systemic diseases are less frequent than in hospitalized patients. There are, however, other limitations to the use of analogue assays than systemic diseases. We observed two euthyroid patients with thyroxine auto-antibodies causing very high FT4 concentrations as determined by analogue assay; their dialysable FT4 concentrations were normal. We also tested a recently developed immunoradiometric serum TSH assay, which was found to perform well in primary hypo- and hyperthyroidism. Serum TSH was elevated in one patient hyperthyroid because of a TSH-producing pituitary adenoma, and within the reference limits in a patient with secondary hypothyroidism.

Adult↗
PubMed1986

Assessment of thyroxine suppression in thyroid carcinoma patients with a sensitive immunoradiometric TSH assay.

Serum TSH was determined with a sensitive radioimmunometric method (TSH IRMA) in 57 patients on suppression therapy with T4 after operation for differentiated thyroid carcinoma. When using a conventional RIA technique basal TSH was not detectable and remained so even after stimulation with TRH. With the TSH IRMA method 46 patients had a basal TSH below the detection limit (0.02 mU/l) (81%) and in seven patients the values were between 0.02 and 0.05 mU/l (12%). In 23 of these patients there was a small increment of 0.01-0.15 mU/l. In two patients the basal TSH was 0.08 and 0.09 mU/l, and the increment after TRH was less than 0.7 mU/l. In two other patients with basal values close to 0.2 mU/l the increment after TRH was more than 1.0 mU/l. An undetectable basal TSH value did not thus predict an absent response to TRH. The responses were, however, in all but two cases, so small that they could be regarded as clinically insignificant. Therefore, the authors conclude that a basal TSH of 0.1 mU/l, as measured with a TSH IRMA method with a detection limit of 0.05, is a sufficient indication of TSH suppression in carcinoma patients on T4 therapy and that further testing with the TRH-stimulation test is unnecessary.

Humans↗
PubMed1986

A sensitive and practical immunoradiometric assay of thyrotropin.

We describe a two-site immunoradiometric assay for thyrotropin (TSH) in serum, based on use of two monoclonal antibodies directed against two separate antigenic determinants on the TSH molecule. One antibody is immobilized on polystyrene beads; the other is radioiodinated by a modified Chloramine T method. The detection limit of the assay is 0.02 milli-int. unit/L. The working range (CV less than 10%) is from 0.1 to greater than 50 milli-int. units/L. The log mean concentration of TSH in sera collected from 100 euthyroid subjects between 08:00 and 11:00 hours was 1.9 milli-int. units/L, the range 0.4-5.4 milli-int. units/L. Values for hyperthyroid patients and thyroid-cancer patients being treated with thyroxin were much lower than those for euthyroid persons. Results by this new assay correlated excellently with those by our conventional radioimmunoassay (r = 0.99) and also with a sensitive immunofluorometric TSH method (Delfia TSH) (r = 0.99).

Adult↗
PubMed1985

Free thyroxin and free triiodothyronine as measured by equilibrium dialysis and analog radioimmunoassay in serum of patients taking phenytoin and carbamazepine.

We measured free thyroxin (FT4) and free triiodothyronine (FT3) in serum of patients taking the anti-epileptic drugs phenytoin and carbamazepine, both by equilibrium dialysis procedures and analog-type radioimmunoassays. By either assay, the mean concentration of FT4 was significantly decreased in patients receiving either drug, whereas their FT3 concentrations were normal or only slightly decreased. Adding therapeutic concentrations of these drugs in vitro to control sera had a small or no incremental effect on FT4 and FT3 as measured by either method, but adding greater concentrations of the drugs in vitro markedly increased the concentrations of the free hormones. These results indicate that the main mechanism of the decrease in concentrations of free thyroid hormones in serum during therapy with anticonvulsant drugs is not the displacement of hormones from their binding to plasma proteins. We also determined, using a new and sensitive immunoradiometric assay, that patients taking carbamazepine, but not those taking phenytoin, had significantly less thyrotropin in the serum.

Adolescent↗
PubMed1984

Discrepancies between serum free triiodothyronine and free thyroxin as measured by equilibrium dialysis and analog radioimmunoassay in nonthyroidal illnesses.

We determined free triiodothyronine (FT3) and free thyroxin (FT4) in serum of patients with various nonthyroidal illnesses (NTI), by both commercial analog-type radioimmunoassays (A) and new equilibrium dialysis procedures (D). The mean FT3 was significantly lower in NTI by both techniques, but the decreases were of different magnitudes. The FT3(D):FT3(A) ratio was 1.96, vs 1.11 for healthy controls. In NTI the mean FT4(D) was somewhat increased, whereas the mean FT4(A) was much lower than normal, the above ratio being 1.70, vs 0.92 for controls. We ascribe these discrepancies, at least in part, to binding of radiolabeled T3- and T4-analog tracers to serum albumin.

Adolescent↗
PubMed1983

Improved dialysis method for free thyroxin in serum compared with five commercial radioimmunoassays in nonthyroidal illness and subjects with abnormal concentrations of thyroxin-binding globulin.

We describe a method for free thyroxin (FT4) in serum, based on radioimmunoassay of T4 in serum dialysate, FT4(D). The method is analytically accurate, sensitive, reproducible, and suitable for routine use in the clinical laboratory. We compared results by this method with those obtained with five commercial FT4 assays (Amerlex, GammaCoat, ImmoPhase, LiquiSol, Spiria) and the free T4 index (FT4I). In several of the patients with nonthyroidal illness FT4(D) was above normal and FT4 as measured with the commercial assays was subnormal. In the third trimester of pregnancy all the FT4 methods gave decreased mean values, though the decreases were of various magnitudes: FT4(D) 32%, Amerlex 44%, GammaCoat 40%, Spiria 19%, LiquiSol 16%, and ImmoPhase 13%, respectively. FT4I was significantly higher than normal during late pregnancy. In women taking oral contraceptives the mean FT4I was increased, but there was no significant effect on the results obtained with the various FT4 methods. All subjects with hereditarily high or low serum thyroxin-binding globulin had normal FT4(D) and abnormal FT4I. Amerlex, ImmoPhase, and LiquiSol misclassified some of the subjects with hereditarily abnormal thyroxin-binding globulin.

Adult↗