PubMed Health⌕ Search

Biomedical subjects

S L Karonen

Publications and source records attributed to S L Karonen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Is brain uptake of leptin in vivo saturable and reduced by fasting?

Leptin is a peptide hormone produced by adipocytes which provides a negative feedback signal to control the amount of body fat. The action of leptin on food intake and weight loss is thought to be mediated by interaction with its hypothalamic receptor. We examined the biodistribution and brain uptake of radioiodinated leptin (123I-leptin) by dynamic gamma imaging in six anaesthetized New Zealand white rabbits. Leptin uptake was seen in the brain, lungs, liver and kidneys. In the brain, increase in radioactivity as a function of time was seen in the choroid plexus area. The choroid plexus to brain radioactivity ratio (CP/BR) was used as the target to background ratio. The CP/BR ratio increased up to approximately 40-60 min, after which a steady state in CP/BR was achieved. The steady state uptake ratio was higher in the rabbits that had fasted for only 6-8 h before the experiment (CP/BR approximately 2.5) than in those that had fasted for 25-27 h before the experiment (CP/BR approximately 1.8). Thus, leptin uptake in vivo occurs in the choroid plexus region of the brain and in the lungs, kidney and the liver. The uptake of leptin in the choroid plexus appears to be saturable, as indicated by the achieved steady state in the CP/BR radioactivity curve 40-60 min following 123I-leptin injection. The lower steady state CP/BR after prolonged fasting may be the result of the downregulation of leptin receptors in the choroid plexus.

Animals↗
PubMed1998

Circulating leptin has saturable transport into intrathecal space in humans.

BACKGROUND: Leptin is an adipocyte-derived hormone that is thought to provide a negative feedback signal to control body fat mass by interacting with its hypothalamic receptor. The present study was undertaken to examine the uptake of leptin in cerebrospinal fluid (CSF) space in humans and whether the transport of leptin into CSF space is an active phenomenon or due to free access through the blood-CSF barrier. METHODS: We determined serum and CSF leptin concentrations by radioimmunoassay in 17 men [42 +/- 4 years, mean +/- SE; body mass index (BMI) 27.3 +/- 1.8 kg m-2] and 22 women (40 +/- 3 years, BMI 25.1 +/- 1.0 kg m-2). The function of the blood-CSF barrier was evaluated by determining the CSF/serum albumin ratio. RESULTS: Serum leptin concentration was lower in male (5.8 +/- 1.6 microgram L-1) than in female subjects (13.1 +/- 1.7 microgram L-1, P = 0. 001), whereas the concentrations of leptin in CSF were virtually identical in male (0.34 +/- 0.03 microgram L-1) and female (0.36 +/- 0. 03 microgram L-1) subjects. Serum leptin was correlated positively with BMI both in men (r = 0.89, P < 0.01, n = 10) and in women (r = 0.61, P < 0.05, n = 14), whereas no correlation between CSF leptin concentration and BMI was found in either group. The CSF/serum leptin ratio correlated negatively with serum leptin concentration both in men (r = -0.93, P < 0.001) and in women (r = -0.77, P < 0. 001) and with BMI both in men (r = -0.75, P = 0.02, n = 10) and in women (r = -0.64, P < 0.02, n = 14). The CSF/serum albumin ratio was not correlated with the CSF/serum leptin ratio in either group. CSF leptin concentrations and the CSF/serum leptin ratio were virtually identical in subjects with impaired and normal blood-CSF barrier function. CONCLUSION: Thus, our data support the presence of a saturable and active transporter of leptin from circulation into intrathecal space.

Adipose Tissue↗
PubMed1998

Expression profile of vascular cell adhesion molecule-1 (CD106) in inflammatory foci using rhenium-188 labelled monoclonal antibody in mice.

Rhenium (Re)-188 is a generator (W-188/Re-188) produced high energy beta-emitter suitable for radionuclide therapy (T1/2 is 16.9 hrs and Emax 2.1 MeV (range 11 mm)). We have labelled monoclonal antibody (MAb) raised against vascular cell adhesion molecule-1 (VCAM-1) with Re-188 using glucoheptonate chelation technique and SnCl2 as reducing agent. The labelling efficiency, free perrhenate and reduced Re were controlled with thin layer chromatography and the purification of Re-188-MoAbs was performed using gel filtration. Our results indicate that Re-188-labelled antibodies remain in vitro stable and the labelling purity is > 90%. We also have applied these Re-188-MoAbs for detection of inflammatory disease in a mouse. The effective half-lives of organs of interest after an injection of Re-188-anti-VCAM1 were as follows: blood 5.2 hr, kidney 4.7 hr, and liver 9.6 hr. Re-188-anti-VCAM-1 was found to accumulate mainly in kidney and liver. One hour after the injection, the kidney contained in average as high as 12.5% and the liver 2.8 ID/g tissue. After 6 hr, the kidney contained 5.5% ID/g and the liver 2.6% ID/g. At 24 hr, the kidney uptake was 0.5% ID/g and the liver uptake 0.8% ID/g, respectively. The inflamed foci, subcutaneous lesions in the footpad skin, were visualized using gamma camera. From the distribution data the uptakes in the inflamed foci as follows: at 1 hr 2.18 (inflammation) and 1.72% ID/g (control), at 6 hr 1.42 (inflammation) and 0.85% ID/g (control), and at 24 hr 0.17 (inflammation) and 0.084% ID/g (control), respectively. Anti-VCAM-1 MAb showed better targeting as compared to control MoAbs in inflammation (caused by E.coli lipoplysaccaride). In conclusion, Re-188 is suitable for MAb labelling, and MAb against VCAM-1 may be used for detection of local inflammatory disease.

Animals↗
PubMed1997

Radioiodinated estramustine phosphate and estramustine binding protein antibody accumulate in the prostate of a mouse.

BACKGROUND: The purpose of this study was to determine the distribution of radioiodinated estramustine (RI-EMP) and a radioiodinated antibody against estramustine binding protein (RI-EMBP-AB) in mice. METHODS: RI-EMP and RI-EMBP-AB were injected in male mice intravenously, and the activities of tissue samples were measured 1-31 hr from the injection. Pure iodine-125 (RI) was used as a control. RESULTS: RI-EMP accumulated in the prostate, which contained 2.6% of injected activity (ID) per gram tissue at 7 hr. The liver had an activity of 21.4% ID/g at 1 hr, which decreased as RI-EMP was secreted in bile. The lung contained 2.3% ID/g at 7 hr, and it retained the activity longer than the prostate. RI-EMBP-AB accumulated in the prostate: The activity was 2.9% ID/g at 7 hr. The gallbladder contained 6.5% ID/g at 7 hr. CONCLUSIONS: Due to its cytotoxic and radiosensitizing properties, RI-EMP can possibly be used for treating prostate cancer and other tumors.

Animals↗
PubMed1997

Relation between plasma leptin levels and measures of body fat in identical twins discordant for obesity.

BACKGROUND: Plasma levels of leptin, the recently discovered satiety hormone, are associated with adiposity in humans. OBJECTIVE: To determine whether genetic factors or body fat distribution affect the association between leptin levels and obesity. PARTICIPANTS: 23 healthy identical twin pairs (9 male pairs and 14 female pairs, 33 to 59 years of age) who were discordant for obesity (average weight difference, 18 kg). MEASUREMENTS: Fasting plasma leptin levels were measured by radioimmunoassay. Distribution of abdominal fat into visceral and subcutaneous compartments was estimated by use of magnetic resonance imaging. RESULTS: Plasma leptin levels were threefold higher in obese twins than in lean twins (mean +/- SD, 18.7 +/- 12.5 micrograms/L compared with 6.4 +/- 4.8 micrograms/L; P < 0.001); a similar difference was seen when the entire study group was divided according to sex. Compared with lean twins, plasma leptin levels were 3.7-fold higher in the obese twins who had visceral fat accumulation greater than the median and 2.1-fold higher in the obese twins who had visceral fat accumulation less than the median. The intrapair differences in leptin levels correlated with the corresponding differences in percentage of body fat in women (r = 0.73; P = 0.003) but not in men and correlated with differences in visceral fat area in men (r = 0.79; P = 0.019) and women (r = 0.73; P = 0.007). In multiple regression analyses that included intrapair differences in visceral fat area and total body fat, the association between differences in visceral fat area and leptin levels was significant in men (P = 0.029) but not in women. CONCLUSIONS: Plasma leptin levels are increased in obese persons, independent of genetic background. Visceral fat may be of special importance in the regulation of leptin levels, but it is probably less important in women than in men.

Adipose Tissue↗
PubMed1997

The aminoterminal propeptide of type I procollagen: evaluation of a commercial radioimmunoassay kit and values in healthy subjects.

OBJECTIVES: Evaluation of the performance of a radioimmunoassay kit for measuring serum concentrations of the aminoterminal extension peptide of human type I procollagen, S-PINP. DESIGN AND METHODS: S-PINP concentrations in 229 healthy subjects, 140 females, aged 3.8-81 years, and 89 males, aged 0.9-71 years, were measured with the kit. Because PINP and PICP (the carboxy-terminal propeptide of type I procollagen) are formed in equimolar concentrations, we also calculated the PICP/PINP ratio and compared the S-PINP values to those of S-PICP, which have been shown to correlate with bone formulation rate. RESULTS: The sensitivity of the assay was 2.3 micrograms/L, the spiking recovery ranged from 95.5 to 100.3%, the dilution recovery from 79.3 to 103.1%. The intra-assay imprecision was 2.3 to 3.5% (CV), the interassay imprecision within one reagent lot 2.5-5.2% and, between several reagent lots, 2.7 to 6.1% (CV). S-PINP in females over 20 years old ranged from 12 to 90 micrograms/L (x = 39.7, SD = 14.7), in males over 25 years old, from 22 to 89 micrograms/L (x = 49.9, SD = 15.8); the PICP/PINP ratio ranged from 1.5 to 5.2 and from 1.8 to 4.9, respectively. In females under 20 years old, S-PINP ranged from 52 to 820 micrograms/L, in males aged 25 years or younger from 35 to 1404 micrograms/L; the PICP/PINP ratio was 0.44-2.3 and 0.38-2.8. In females under 20 years and males under 25 years, there was a significant negative correlation between S-PINP and age: r = -0.70, p < 0.001 for females, r = -0.52, p = 0.004 for males. In different groups of healthy subjects, the correlation of S-PINP and S-PICP was significant (r = 0.67-0.86, p < 0.001). CONCLUSION: The assay performance is good. The significant positive relationship between S-PINP and S-PICP suggests that S-PINP also reflects bone formation rate. Because the clearance of PINP is probably less sensitive to hormonal changes, PINP may prove to be superior to PICP as a marker of bone formation.

Adolescent↗
PubMed1997

Leptin concentration in cord blood correlates with intrauterine growth.

Leptin is an adipocyte-derived peptide hormone regulating energy balance in experimental animals. Although the physiological function of leptin in humans is still unclear, its secretion is closely related to fat mass in adult humans. To examine how fetal growth correlates with leptin levels at birth, an umbilical cord venous blood sample was obtained at the delivery from 50 term newborn infants. Twenty-eight of the newborn infants had birth weights appropriate for gestational age (AGA; mean +/- SEM, 3362 +/- 90 g; relative birth weight, -0.08 +/- 0.2 SD), 9 were large for gestational age (birth weight, 4655 +/- 165 g; relative birth weight, 3.2 +/- 0.3 SD; P < 0.001 vs. AGA newborn infants), and 13 were small for gestational age (SGA; birth weight, 2385 +/- 69 g; relative birth weight, -2.2 +/- 0.08 SD; P < 0.001 vs. AGA newborn infants). Leptin concentrations were higher in large for gestational age (35.7 +/- 8.0 micrograms/L; P < 0.005), but lower in SGA (3.3 +/- 0.5 micrograms/L; P < 0.001) than in AGA infants (14.5 +/- 2.8 micrograms/L). When adjusted for differences in body weight, mean leptin levels were similar in the three newborn groups. Leptin concentration correlated closely with both absolute and relative birth weights (r = 0.71; P < 0.001 in both), with cord blood insulin concentration (r = 0.67; P < 0.001), and with placental weight (r = 0.60; P < 0.001). These data suggest that leptin is synthesized in utero, and that the circulating leptin concentration relates to the intrauterine growth pattern.

Amniotic Fluid↗
PubMed1996

Insulin increases plasma leptin concentrations in normal subjects and patients with NIDDM.

Insulin is known to increase expression of the ob gene product leptin in adipose tissue of rodents. We determined whether insulin increases circulating leptin concentrations in humans, and whether this effect might be altered in patients with noninsulin-dependent diabetes mellitus (NIDDM). Plasma leptin concentrations were determined during an 8.5-h hyperinsulinaemic clamp (serum free insulin approximately 480 pmol/l) and during an 8.5-h infusion of physiological NaCl solution (saline) in eight normal subjects (age 51 +/- 3 years, BMI 26.3 +/- 0.6 kg/m2, fasting plasma glucose 5.6 +/- 0.2 mmol/l) and seven patients with NIDDM (age 54 +/- 2 years, 27.0 +/- 0.9 kg/m2, 11.1 +/- 0.8 mmol/l). Fasting serum insulin level correlated with plasma leptin (r = 0.72, p < 0.005), even after adjusting for the percentage of body fat (p < 0.005). During the insulin infusion, a significant increase in the plasma leptin concentration was observed after 6 h (37 +/- 14%; 5.2 +/- 0.8. vs 3.9 +/- 0.6 ng/ml, 6 vs 0 h, p < 0.05) in the normal subjects and after 8.5 h (38 +/- 11%; 7.1 +/- 1.0 vs 5.5 +/- 0.9 ng/ml, 8.5 vs 0 h, p < 0.05) in the patients with NIDDM. During the saline infusion, plasma leptin concentrations decreased significantly in the normal subjects by 11 +/- 1% (p < 0.005) and in the patients with NIDDM by 14 +/- 1% (p < 0.01) after 2 h. During the infusion of insulin as compared to saline, plasma leptin concentrations were 32 +/- 13 (p < 0.05), 53 +/- 14 (p < 0.001), 106 +/- 15 (p < 0.001) and 165 +/- 21 (p < 0.001) % higher at 2, 4, 6 and 8.5 h in the normal subjects, and 11 +/- 9 (p < 0.05), 27 +/- 10 (p < 0.05), 58 +/- 7 (p < 0.001) and 106 +/- 13 (p < 0.001) % higher in the patients with NIDDM, respectively. No differences were observed in plasma leptin concentrations between the normal subjects and patients with NIDDM, under any conditions. We conclude that prolonged exposure to insulin increases plasma leptin concentrations in humans implying a role for insulin in chronic but not acute regulation of plasma leptin concentrations. The decrease in plasma leptin concentrations during saline infusion was greater than that expected on the basis of change in serum insulin concentrations, suggesting that factors other than insulin also contribute to regulation of plasma leptin concentrations.

Diabetes Mellitus, Type 2↗
PubMed1995

Exercise-induced hypoglycaemia in IDDM patients treated with a short-acting insulin analogue.

In order to examine the effect of short-acting insulin analogue on the exercise-induced hypoglycaemia in insulin-dependent diabetes mellitus (IDDM) patients we compared the glycaemic response of 40 min cycle ergometer exercise performed either shortly (40 min) or later (180 min) after a breakfast meal and subcutaneous injection of either short-acting insulin analogue [Lys(B28) Pro(B29)] or soluble human insulin (Humulin Regular) in ten IDDM patients with long duration of the disease. Both preparations had been used 1 month before respective studies. Changes in blood glucose, insulin and counterregulatory hormones were assayed. As compared to human insulin, after the analogue injection the peak insulin concentration came earlier, was 56% higher (p < 0.05) and disappeared faster, and the postprandial blood glucose response was lower (p < 0.05). In the analogue-treated patients the exercise-induced hypoglycaemia was 2.2-fold greater (p < 0.01) during the early exercise, but 46% less (p < 0.05) during late exercise as compared to the treatment with human insulin. Serum insulin or analogue concentration at the beginning of the exercise correlated closely with the fall in blood glucose during exercise (r = 0.74, p < 0.01; r = 0.73, p < 0.02, respectively). In the analogue-treated patients, fasting serum glucagon and adrenalin concentrations were higher than during human insulin therapy (p < 0.05) and remained so throughout the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

CSF biochemistries, glucose metabolism, and diurnal activity rhythms in alcoholic, violent offenders, fire setters, and healthy volunteers.

BACKGROUND: There is an extensive literature describing a central serotonin deficit in alcoholic, impulsive, violent offenders and fire setters. In the present study, we investigated biochemical concomitants of impulsivity and aggressiveness, and the physiological consequences of reduced central serotonin turnover. METHODS: Forty-three impulsive and 15 nonimpulsive alcoholic offenders and 21 healthy volunteers were studied in the forensic psychiatry ward of a university psychiatric department. The subjects underwent lumbar punctures and oral glucose and aspartame challenges, and their diurnal activity rhythm was measured with physical activity monitors. Discriminant function analyses were used to investigate psychophysiological and biochemical concomitants of aggressive and impulsive behaviors. RESULTS: Alcoholic, impulsive offenders with antisocial personality disorder had low mean cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) and corticotropin levels and high mean CSF testosterone concentrations. Compared with healthy volunteers, they showed increased physical activity during the daytime. Alcoholic, impulsive offenders with intermittent explosive disorder had a low mean CSF 5-HIAA concentration and blood glucose nadir after an oral glucose challenge, and desynchronized diurnal activity rhythm. Healthy volunteers had mean CSF 5-HIAA concentrations that were intermediate between those of alcoholic, impulsive and nonimpulsive offenders. Alcoholic, nonimpulsive offenders had a significantly higher mean CSF 5-HIAA concentration than all the other groups, including healthy volunteers. CONCLUSIONS: In the present sample, a low CSF 5-HIAA concentration was primarily associated with impulsivity and high CSF testosterone concentration, with aggressiveness or interpersonal violence.

Adrenocorticotropic Hormone↗
PubMed1994

Personality profiles and state aggressiveness in Finnish alcoholic, violent offenders, fire setters, and healthy volunteers.

BACKGROUND: Based on clinical observations in a series of studies on Finnish alcoholic, violent offenders, we asserted that the impulsive offenders represented an extreme group of type 2 alcoholics. We also observed that these subjects were vulnerable to hypoglycemia after the administration of oral glucose load. Furthermore, we believe that while being hypoglycemic, the impulsive offenders are particularly irritable and aggressive. In the present study, we addressed these issues by studying psychological trait and state variables in a new group of violent offenders and fire setters, and age- and sex-matched healthy volunteers. METHODS: Fifty-eight alcoholic, violent offenders and impulsive fire setters and 21 healthy volunteers were administered the Karolinska scales of personality and the Rosenzweig picture frustration test after an oral aspartame and glucose challenge. RESULTS: The psychological test results and the criminal histories of the offenders, together with biochemical measurements, suggest that a low 5-hydroxyindoleacetic acid concentration in cerebrospinal fluid in the alcoholic offenders is associated with irritability and impaired impulse control, and a high free testosterone concentration in cerebrospinal fluid is associated with increased aggressiveness, monotony avoidance, sensation seeking, suspiciousness, and reduced socialization. CONCLUSION: Finnish alcoholic, impulsive offenders have personality profiles characteristic of Scandinavian early-onset male alcoholics with antisocial traits, who have been also referred to as type 2 alcoholics.

Adult↗
PubMed1994

Suriclone enhances the actions of chlorpromazine on human psychomotor performance but not on memory or plasma prolactin in healthy subjects.

Twelve healthy subjects received single oral doses of 0.4 mg suriclone (SU), 7.5 mg zopiclone (ZO) and placebo, alone and together with 50 mg chlorpromazine (CP), double blind and crossover, in Latin square order, at one-week intervals. Performance tests administered before and 1.5, 3.5 and 6 h after drug intake included digit symbol substitution and simulated driving combined in a "Global test", flicker fusion frequency, body balance and memory and subjective assessments. Changes from baseline were examined statistically. Performance and memory data were analysed from only 11 subjects. Compared to placebo, SU minimally affected "global" performance, although it slowed reactions and tended to impair digit substitution. ZO impaired "global" performance at 1.5 h, affected performance in several separate tests, and produced subjective muzziness. CP did not impair "global" performance, although it did impair digit substitution and render the subjects drowsy, weak and dreamy. The combinations SU + CP and ZO + CP definitely impaired "global" performance more than CP alone. This difference was also found in most objective tests but less so in the subjective tests. CP and its combinations produced similar increases in plasma prolactin. Active drugs and their combinations variably lowered blood pressure and increased heart rate, and one subject collapsed after CP. The treatments irregularly impaired spatial memory and learning acquisition. No pharmacokinetic interactions were seen in the plasma levels of suriclone, zopiclone and chlorpromazine. The impairment of performance after these combinations resembles that previously encountered after 2.5 mg lorazepam, or 15 mg diazepam + 100 mg remoxipride.

Adult↗
PubMed1994

Nocturnal rise in markers of bone resorption is not abolished by bedtime calcium or calcitonin.

As assessed by urine pyridinium cross-links, bone resorption increases at night. This has been ascribed to either the nocturnal rise of serum parathyroid hormone (PTH) or immobilization. ICTP is the carboxyterminal telopeptide region of type I collagen in bone, cross-linked via pyridinium cross-links and liberated during the degradation of type I collagen. To study whether the nocturnal rise in bone resorption is seen also in serum type I collagen carboxyterminal telopeptide (ICTP) and whether this rise is abolished by bedtime calcium or calcitonin, nine healthy postmenopausal women participated in three 24 hour sessions. At 2200 hours, either 1 g of oral calcium or 200 IU of intranasal calcitonin or no treatment (control session) were given. The participants were recumbent from 2200 hours to 0600 hours. Like urinary pyridinolines, serum ICTP showed a clearcut nocturnal rise during the control session, increasing from 3.7 +/- 0.3 micrograms/liter (mean +/- SE) at 2000 hours to 4.9 +/- 0.4 micrograms/liter at 0600 hours (P < 0.001). Administration of calcium did not affect either serum ICTP or urinary pyridinolines, although it decreased serum intact PTH by 18% (P < 0.001) as assessed by areas under curve (AUC) after 2200 hours. Serum ICTP and urinary pyridinolines remained unchanged also after administration of calcitonin which increased the AUC for serum intact PTH by 9% (P < 0.05). In conclusion, serum ICTP follows a circadian rhythm in healthy postmenopausal women. The nocturnal rise in markers of bone resorption is not due to PTH, and its dependency on the function of osteoclasts is open to question.

Administration, Intranasal↗
PubMed1994

Pheochromocytoma expressing adrenocorticotropin and corticotropin-releasing hormone; regulation by glucocorticoids and nerve growth factor.

A pheochromocytoma from a 59-year-old woman was found to be immunoreactive to adrenocorticotropin (ACTH), chromogranin, neurofilament-200, neuron-specific enolase and S-100 protein. Northern blot analysis showed that both proopiomelanocortin (POMC) and corticotropin-releasing hormone (CRH) genes were expressed in the pheochromocytoma but not in the surrounding adrenal cortex. In primary culture, the POMC and CRH mRNAs were increased by dexamethasone (500 micrograms/l for 3 days) up to 10- and 15-fold of the control, respectively. The secretion of ACTH also was stimulated eightfold with the same treatment. The stimulatory effect of dexamethasone on POMC gene expression was inhibited 70% by nerve growth factor (NGF, 200 micrograms/l), 30% by 12-O-tetradecanoyl phorbol 13-acetate (TPA, 160 nmol/l) (a protein kinase-C activator) and 30% by (Bu)2cAMP (1 mmol/l). On the other hand, NGF alone increased the CRH mRNA accumulation up to 10-fold, and further enhanced the stimulatory effect of dexamethasone on the CRH mRNA twofold, and TPA inhibited (30%) the dexamethasone-induced CRH mRNA accumulation. Furthermore, the conditioned medium of the pheochromocytoma cells increased secretion of corticosterone fourfold in the primary culture of rat fetal adrenal cells. Our results indicate abnormal expression and regulation of POMC and CRH genes in this pheochromocytoma.

Adrenal Gland Neoplasms↗
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↗
PubMed1994

Ability of two new thyrotropin (TSH) assays to separate hyperthyroid patients from euthyroid patients with low TSH.

We evaluated the ability of new thyrotropin (TSH) assays to separate hyperthyroid (n = 50) patients from clinically euthyroid subjects with low TSH values (nodular goiter, n = 20, and nonthyroidal illness, n = 22). Only patients whose serum TSH was < 0.1 mIU/L by immunoradiometric assay were included. We used a new immunofluorometric method based on time-resolved fluorescence (TR-IFMA) and a new immunochemiluminometric assay (ICMA) to measure TSH in serum. Although the differences between the hyperthyroid patients and the euthyroid patients differed from each other by both methods (P = 0.0012 for TR-IFMA and P < 0.0001 for ICMA), there was no cutoff point that could definitely separate the groups. Thus, it is not possible to draw any definite conclusions on whether a patient is hyperthyroid or not, solely on the basis of TSH concentration measured with these new TSH assays.

Adult↗
PubMed1993

Radioimmunoimaging of non-small cell lung cancer with 111In- and 99mTc-labeled monoclonal anti-CEA-antibodies.

Radiolabeled monoclonal anti-CEA antibodies were used for radioimmunolocalization (RIL) of non-small cell lung cancer; in 30 patients with 111In labeled anti CEA F(ab')2 fragment (BW 431/31) and in 16 with 99mTc-labeled intact MoAb (BW 431/26). RIL results were compared with those of other imaging modalities. Paraffin sections from some patients were also studied immunohistochemically using anti-CEA antibody. Patients with 111In labeled MoAB were imaged twice 1-4 days after injection and for image enhancement pulmonary and liver/spleen subtraction were performed. Twenty-seven of 28 primary tumors were positive and metastases were detected in all patients. The total number of lesions was 78 of which 61 (78%) could be detected by RIL. For verification CT was applied to the study of 46 lesions detected by RIL. We found 6 unknown lesions subsequently verified histologically. Using subtraction techniques we detected 9 lesions in 4 patients, later verified as pulmonary metastases, not detected in unprocessed images. Pleural, mediastinal and pericardial lesions were also better delineated in subtracted images than in unprocessed images. Imaging of non-small cell lung cancer with 99mTc-labeled MoAB was performed twice 4-24 h after injection. RIL results were compared with other imaging methods; CT US, conventional radiography, and immunohistochemistry. Twelve out of 16 patients with suspected or known lung cancer had positive immunoscintigrams; 19 of 25 lesions could be detected by RIL. There were 5 false positive and 2 true negative findings. Immunoperoxidase (IP) stainings of paraffin sections of the tumours from 7 patients were performed using two different anti-CEA antibodies; BW 431/26 and ZCEA1. None of the seven tumors examined by immunohistochemistry were negative when stained by BW 431/26, which was the antibody used for immunoscintigraphy.

Adult↗