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B Saller

Publications and source records attributed to B Saller.

At least 19 recordsLinked to original sources

The value of fluorine-18 fluorodeoxyglucose PET in patients with medullary thyroid cancer.

The early detection of metastases from medullary thyroid cancer (MTC) is important because the only curative therapy consists in surgical removal of all tumour tissue. There is no single sensitive diagnostic imaging modality for the localization of all metastases in patients with MTC. Therefore, in many cases several imaging modalities (e.g. ultrasonography, magnetic resonance imaging, computerized tomography and scintigraphy using pentavalent technetium-99m dimercaptosuccinic acid, thallium-201 chloride, indium-111 pentetreotide, anti-CEA antibodies or metaiodobenzylguanidine) must be performed consecutively in patients with elevated calcitonin levels until the tumour is localized. In this prospective study, we investigated the value of fluorine-18 fluorodeoxyglucose positron emission tomography ([18F]FDG PET) in the follow-up of patients with MTC. [18F]FDG PET examinations of the neck and the chest were performed in 20 patients with elevated calcitonin levels or sonographic abnormalities in the neck. Positive [18F]FDG findings were validated by histology, computerized tomography or selective venous catheterization. [18F]FDG PET detected tumour in 13/17 patients (nine cases were validated by histology, four by computerized tomography). Five patients showed completely negative PET scans (of these cases, one was true-negative and four false-negative). One patient with [18F]FDG accumulation in pulmonary lesions from silicosis and one patient with a neck lesion that was not subjected to histological validation had to be excluded. Considering all validated localizations, [18F]FDG PET detected 12/14 tumour manifestations in the neck, 6/7 mediastinal metastases, 2/2 pulmonary metastases and 2/2 bone metastases. In two patients with elevated calcitonin levels, no diagnostic modality was able to localize a tumour. The sensitivity of [18F]FDG PET in the follow-up of MTC was 76% (95% confidence interval 53%-94%); this is encouraging. [18F]FDG PET promises to be a valuable diagnostic method, especially for the detection of lymph node metastases, surgical resection of which can result in complete remission.

Adult↗

Neuroendocrine response to film-induced sexual arousal in men and women.

The psychoneuroendocrine responses to sexual arousal have not been clearly established in humans. However, we have demonstrated previously that masturbation-induced orgasm stimulates cardiovascular activity and induces increases in catecholamines and prolactin in blood of both males and females. We presently investigated the role of orgasm in producing these effects. Therefore, in this study parallel analysis of prolactin, adrenaline, noradrenaline, and cortisol concentrations, together with cardiovascular variables of systolic/diastolic blood pressure and heart rate were undertaken during film-induced sexual arousal in nine healthy adult men and nine healthy adult women. Blood was drawn continuously via an indwelling cannula and connected tubing system passed through a mini-pump. In parallel, the cardiovascular parameters were recorded continuously via a computerised finger-cuff sensor. Subjective sexual arousal increased significantly in both men and women during the erotic film, with sexual arousal eliciting an increase in blood pressure in both males and females, and plasma noradrenaline in females only. In contrast, adrenaline, cortisol and prolactin levels were unaffected by sexual arousal. These data further consolidate the role of sympathetic activation in sexual arousal processes. Furthermore, they demonstrate that increases in plasma prolactin during sexual stimulation are orgasm-dependent, suggesting that prolactin may regulate a negative-feedback sexual-satiation mechanism.

Adult↗

Evaluation of chemiluminescence immunoassays for detecting thyroglobulin (Tg) and thyroid peroxidase (TPO) autoantibodies using the IMMULITE 2000 system.

The chemiluminescence assays for detection of autoantibodies to thyroid peroxidase (TPO) and thyroglobulin (Tg) implemented on the IMMULITE 2000 system (Diagnostic Products Corporation) were evaluated. These were immunometric assays with antigen-coated beads and monoclonal murine anti-IgG antibodies conjugated with alkaline phosphatase. Precision was satisfactory with an intraassay precision of 5.3-5.5% for anti-Tg and 4.8-5.3% for anti-TPO and an interassay precision of 5.7-7.3% for anti-TPO and 5.2-7.5% for anti-Tg. The lower detection limit was determined as 5 IU/ml for anti-TPO and 2.2 IU/ml for anti-Tg. The average dilution linearities of 102% for anti-TPO and 100% for anti-Tg and the average recovery of 80-127% for anti-TPO and 93-112% for anti-Tg were acceptable. The findings of the tests were compared with the systems from Pharmacia & Upjohn, ORGenTec, Roche Diagnostics, Byk Sangtec Diagnostica and BRAHMS Diagnostica. Taking the respective cutoff value into account, concordance was 87-96% for anti-Tg and 87-97% for anti-TPO. Summarizing all results from the different methods revealed a clinical agreement of 95% for anti-TPO and 93% for anti-Tg. A good agreement was found with the IMMULITE anti-TPO and anti-Tg assays, which are closely related as regards method and biochemistry. Regression analysis gave the following results: anti-TPO IMMULITE 2000 vs anti-TPO IMMULITE: anti-TPO IMMULITE 2000 = 0.99 x IMMULITE anti-TPO - 1.43 IU/ml (r = 0.99, n = 144). anti-Tg IMMULITE 2000 vs anti-Tg IMMULITE: anti-Tg IMMULITE 2000 = 0.98 x IMMULITE anti-Tg + 1.63 IU/ml (r = 0.99, n = 86). Further age-dependent normal ranges were evaluated. A higher prevalence of elevated autoantibody titers was found for patients older than 50 years. The rate of elevated antibody titer can be reduced by using an age-dependent reference range: < or = 50 years anti-TPO < 35 IU/ml, anti-Tg < 40 IU/ml and > 50 years anti-TPO < 100 IU/ml, anti-Tg < 80 IU/ml. Further samples from clinically diagnosed Hashimoto's thyroiditis and Graves' disease were investigated. The levels of positive anti-Tg values and anti-TPO values accorded with those stated in the literature and were comparable to those measured with a reference assay. In the tested INSTAND e. V. interlaboratory samples there was high-level accordance with the expected clinical results.

Antibodies, Monoclonal↗

Subtotal adrenalectomy by the posterior retroperitoneoscopic approach.

The retroperitoneoscopic approach offers an established operative procedure for primary adrenal gland tumors. It allows a detailed view of the adrenal gland and its surrounding region. Therefore clear differentiation between normal and neoplastic adrenal tissue is sometimes possible, permitting a planned, unilateral, subtotal resection of the gland. Between July 1994 and August 1997 primary benign adrenal gland tumors (11 Conn adenomas, 4 phenochromocytomas, 4 Cushing adenomas, 3 hormonally inactive tumors; 2.4 +/- 1.2 cm in size; 8 on the right, 14 on the left) were removed from 22 patients by the posterior retroperitoneoscopic approach maintaining tumor-free portions of the ipsilateral adrenal gland. Two patients suffered from bilateral pheochromocytomas associated with multiple endocrine neoplasia (MEN-IIa) syndrome and had previously undergone complete adrenalectomy of the contralateral gland. Following subtotal resection the operating time and blood loss did not differ significantly (p > 0.05) from that seen with complete extirpation (46 patients operated during the same period). All patients with Conn adenomas and pheochromocytomas were biochemically and clinically cured (follow-up 11 months; range 1-31 months). The four patients with Cushing adenoma currently require decreasing cortisol substitution. In the two MEN-II patients adrenal gland cortical function could be maintained; one patient is on low-dose steroid supplementation and the other on none. No local recurrence of tumors has been observed. In selected cases the retroperitoneoscopically performed subtotal adrenal gland resection is a safe procedure that can potentially maintain the function of the adrenal gland cortex.

Adolescent↗

T3-release from autonomously functioning thyroid nodules in vitro.

Toxic thyroid nodules have been shown to be of clonal origin. In a portion of them, point mutations affecting either the gene of the TSH receptor (TSHr) or the alpha-subunit of stimulating G-protein, consecutively leading to enhanced cAMP levels, which may enhance growth or functional activity of the thyrocyte or both, were recently found. To complement these studies, we evaluated hormone response (i.e. T3 release) in vitro from tissues derived from toxic thyroid nodules as compared directly to the surrounding paranodular tissues as well as tissues derived from euthyroid goiter and from patients with Graves' disease. Experiments were conducted in the presence and absence of bTSH or Graves' immunoglobulines. Tissues obtained during surgery were incubated over 5 h, followed by equilibrium dialysis for 24 h, and determination of free T3 in an aliquot by RIA. Basal T3 release in nodular tissues (n = 10) was significantly higher (median: 7.3 ng/l) compared to paranodular tissues (3.2 ng/l; P < 0.01), tissues derived from euthyroid goiter (1.3 ng/l; n = 12; P < 0.001) and thyroid tissues derived from patients with Graves' disease (2.5 ng/l; n = 6; P < 0.001). Upon stimulation with bTSH (1 IU/l), median T3 concentrations markedly increased to 11.5 ng/l (P < 0.05), 7.3 ng/l (P < 0.05), 4.2 ng/l (P < 0.01) and 3.2 ng/l (P = N.S.), respectively. Stimulation over basal values was 1.6-fold in nodular tissues, 2.3-fold in paranodular tissues, 3.2-fold in euthyroid goiter and 1.3-fold in Graves' disease. In toxic thyroid nodules basal hormone-releasing activities were stimulated by fifteen out of twenty (75%) Graves' sera tested. For comparison, stimulation in other tissues occurred in 45% (paranodular), 80% (euthyroid goiter) and 35% (Graves' disease), respectively. In conclusion, tissue derived from toxic thyroid nodules exhibits enhanced basal hormone release as compared to both, the surrounding paranodular tissues and tissues from euthyroid goiter in vitro, which may reflect constitutional activation of TSHr, alpha-subunit of stimulating G-protein or other so far unknown intermediate by point mutations affecting the respective genes. Hyperactivities in toxic thyroid nodules may be even further enhanced by external stimulators such as TSH or TSH receptor antibodies. The first stimulator may have clinical relevance in patients with toxic thyroid nodules and not yet suppressed TSH; the latter could play a role in the rare Marine Lenhart syndrome.

Adult↗

Kinetics of acute and chronic iodine excess.

Iodine plays an important role in thyroid physiology resulting from its importance as a requisite substrate for the synthesis of thyroid hormones and from its action as a regulator of thyroid function. Following intestinal absorption, inorganic iodide is largely confined to the extracellular fluid. Serum concentrations of inorganic iodide well reflect the amount of iodine present in the extracellular compartment. Since serum inorganic iodide levels are important determinants of thyroid iodine uptake, serum iodide measurement offers a valuable tool for the investigation of many basic and clinical aspects of thyroid iodine metabolism. Here we summarize important aspects of iodine metabolism and focus selectively on technical aspects of serum inorganic iodide measurement and on the kinetics of inorganic iodide in various states of iodine excess. Presently, paired-ion, reversed-phase HPLC with electrochemical detection is obviously the best method for measurement of serum inorganic iodide being highly sensitive, easy to perform, and almost completely insensitive to interfering substances. Using this method, we could demonstrate an acute increase of serum inorganic iodide during the administration of large amounts of iodide as Lugol's solution given preoperatively in patients with Graves' hyperthyroidism. In patients under treatment with the iodine containing drug amiodarone (n=37), serum inorganic iodide levels were highly elevated (range 3.5-208.2 microg/dl, median 36.6 microg/dl). Serum concentrations of inorganic iodide were correlated neither to the daily amiodarone dose, nor to the serum levels of amiodarone.

Acute Disease↗

Utility of third generation thyrotropin assays in thyroid function testing.

Determination of thyrotropin (TSH) by sensitive immunometric assays is currently judged as the most sensitive and also most cost-effective first-line approach to thyroid function testing. Further improvement of assay sensitivity has led to the description of third generation TSH assays with a functional sensitivity in the range of 0.01 to 0.02 mU/l. In the present study, we analyzed interassay precision profiles of a commercially available third generation assay (ACS:180 TSH-3) and documented the critical role of the time span used for the assessment of a method's functional sensitivity. By using a standardized approach with five serum pools measured in 30 different runs across a 6-week period, functional sensitivity was calculated as 0.015 mU/l. The TSH concentrations measured by two different third generation assays (ACS: 180 TSH-3 and Elecsys TSH) in samples from healthy blood donors were highly correlated (r = 0.76, n = 252). In some samples, however, discordant results were obtained. Euthyroid reference intervals were determined as 0.30-3.68 mU/l for the ACS:180 TSH-3 assay and as 0.36-3.64 mU/l for the Elecsys TSH assay. Reevaluation of reference intervals including only TPOAb or TgAb negative samples resulted in almost the same reference ranges. Measuring TSH concentrations in various patient populations, third generation assay turned out to be advantageous in the following clinical situations. (a) In patients with mildly suppressed but well detectable TSH concentrations due to functional thyroid autonomy (0.03-0.3 mU/l), overt hyperthyroidism can be excluded by third generation TSH measurement alone without the need of additional thyroid hormone measurements; (b) in patients receiving long term suppressive T4 treatment after thyroidectomy for differentiated thyroid cancer, measurement of basal TSH by third generation assays allow accurate monitoring of hormone therapy without the need for TRH testing; (c) in most patients with severe nonthyroidal illnesses and decreased TSH levels, TSH concentrations measured by third generation assays are only moderately suppressed and can be clearly discriminated from undetectable levels in overt hyperthyroidism. In conclusion, the use of third generation TSH assays is recommended in specialized clinical laboratories frequently analyzing samples taken in one of those clinical situations.

Adult↗

A new hot spot for mutations in the ret protooncogene causing familial medullary thyroid carcinoma and multiple endocrine neoplasia type 2A.

One hundred and eighty-one families with multiple endocrine neoplasia type 2A (MEN-2A) or familial medullary thyroid carcinoma (FMTC) have been investigated for mutations in the ret protooncogene in Germany. In 8 families with FMTC or MEN-2A, no mutation could be detected in the cysteine-rich domain encoded in exons 10 and 11 of the ret protooncogene. DNA sequencing of additional exons (no. 13-15) revealed rare noncysteine mutations in 3 families (codons 631, 768, and 844). In contrast to these rare events, heterozygous missense mutations in exon 13, codons 790 and 791, were found in 5 families (4 with MTC only; 1 family with MTC and pheochromocytoma) and 11 patients with apparently sporadic tumors. Two different mutations in codon 790 (TTG-->TTT, TTG-->TTC; Leu790Phe) and one mutation in codon 791 (TAT-->TTT; Tyr791Phe) created a phenylalanine residue. We conclude that codons 790 and 791 of the ret protooncogene represent a new hot spot for FMTC/MEN-2A causing mutations. With the discovery of these considerably common mutations in codons 790 and 791 and the identification of some rare mutations, 100% of the German FMTC/MEN-2A families could be characterized by a mutation in the ret protooncogene.

Adult↗

Effect of small doses of iodine on thyroid function in patients with Hashimoto's thyroiditis residing in an area of mild iodine deficiency.

OBJECTIVE: Several studies have suggested that iodine may influence thyroid hormone status, and perhaps antibody production, in patients with autoimmune thyroid disease. To date, studies have been carried out using large amounts of iodine. Therefore, we evaluated the effect of small doses of iodine on thyroid function and thyroid antibody levels in euthyroid patients with Hashimoto's thyroiditis who were living in an area of mild dietary iodine deficiency. METHODS: Forty patients who tested positive for anti-thyroid (TPO) antibodies or with a moderate to severe hypoechogenic pattern on ultrasound received 250 microg potassium iodide daily for 4 months (range 2-13 months). An additional 43 patients positive for TPO antibodies or with hypoechogenicity on ultrasound served as a control group. All patients were TBII negative. RESULTS: Seven patients in the iodine-treated group developed subclinical hypothyroidism and one patient became hypothyroid. Three of the seven who were subclinically hypothyroid became euthyroid again when iodine treatment was stopped. One patient developed hyperthyroidism with a concomitant increase in TBII titre to 17 U/l, but after iodine withdrawal this patient became euthyroid again. Only one patient in the control group developed subclinical hypothyroidism during the same time period. All nine patients who developed thyroid dysfunction had reduced echogenicity on ultrasound. Four of the eight patients who developed subclinical hypothyroidism had TSH concentrations greater than 3 mU/l. In 32 patients in the iodine-treated group and 42 in the control group, no significant changes in thyroid function, antibody titres or thyroid volume were observed. CONCLUSIONS: Small amounts of supplementary iodine (250 microg) cause slight but significant changes in thyroid hormone function in predisposed individuals.

Adult↗

[Subtotal retroperitoneoscopic adrenal gland resection--an alternative to adrenalectomy?].

Primary adrenal tumors were removed in 24 patients by the posterior retroperitoneoscopic approach, maintaining tumor-free parts of the ipsilateral adrenal gland. These partial adrenal resections did not cause a significantly different operating time or blood loss compared to 58 complete adrenalectomies performed during the same period. All 20 patients with hormonally active tumors are biochemically and clinically cured (mean follow-up 18 months). In selected cases the retroperitoneoscopic subtotal adrenal gland resection is a safe procedure, which can potentially maintain the function of the adrenal gland's cortex.

Adrenal Gland Neoplasms↗

[Unilateral neck exploration in primary hyperparathyroidism].

Within a prospective case control study from 1993 to 1996, in 85 first operations for primary hyperparathyroidism the neck exploration was ended unilaterally when an adenoma (also histologically proven) and one normally small parathyroid gland were found. Otherwise or in case of simultaneous surgery of the thyroid gland, a bilateral exploration was performed. The primary success rate with this strategy, additionally based on 69.4% correct results of cervical ultrasound, was 95.3%, with a significant saving of an average of 30 min. operating time.

Adenoma↗

Systemic iodine absorption during endoscopic application of radiographic contrast agents for endoscopic retrograde cholangiopancreaticography.

Hyperthyroidism induced by contrast agents in a major problem in patients with pre-existing thyroid disease, particularly in patients with functional thyroid autonomy. The present study was undertaken to evaluate whether contrast media applied during endoscopic retrograde cholangiopancreaticography (ERCP) may result in a significant increase of serum iodine levels and thus may be associated with the risk of iodine-induced hyperthyroidism. The courses of serum concentrations of total iodine and free iodide, as well as of urinary iodine excretion, were measured in 15 patients before and up to 21 days after ERCP. During ERCP, the non-ionic contrast medium iopamidol was instilled in amounts resulting in a total iodine load of 57.4 +/- 22.8 mmol (7.3 +/- 2.9 g). In all patients, ERCP resulted in a highly significant increase in serum levels of total iodine from 0.8 +/- 0.5 to 85.2 +/- 116.9 mumol/l 4 h after application of the contrast agent. In parallel, serum iodide levels were raised from 0.06 +/- 0.04 to 5.42 +/- 6.09 mumol/l and urinary iodine excretion from 71.1 +/- 35.7 mumol/mol creatinine to 621,620.9 +/- 636,492.2 mumol/mol creatinine. Peak concentrations of serum iodine are well related to the total amount of iodine applied (p < 0.05). During follow-up, iodine levels returned to pre-exposure levels within 2-3 weeks. Levels of thyrotropin, free thyroxine, and free triiodothyronine remained unchanged during the follow-up period. In conclusion, endoscopic application of iodinated contrast agents during ERCP leads to significant increases of serum levels of total iodine and free iodide and of urinary iodine excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

Increased binding capacity of receptors for the epidermal growth factor in benign thyroid nodules and thyroid malignancies.

To determine the role of epidermal growth factor (EGF) receptors in thyroid tumorigenesis, EGF binding was compared in membranes from malignant and from benign thyroid tumors. Surgical specimens were obtained from 28 patients with thyroid carcinomas (3 papillary, 13 follicular, 6 undifferentiated, and 6 medullary carcinomas) and from 30 patients with benign thyroid tumors (15 scintigraphically functional and 15 nonfunctional nodules). In 30 cases normal tissue adjacent to the tumor was also obtained. EGF binding was seen to be increased not only in thyroid carcinomas but also in benign thyroid tumors, particularly in functional thyroid adenomas. The highest EGF binding was found in undifferentiated carcinomas. A direct comparison of the EGF binding characteristics in tumor and adjacent normal thyroid tissue revealed that the increased binding of EGF is due mainly to an increase in the number of binding sites rather than an alteration in receptor affinities. EGF binding capacities were 18.4 +/- 16.7 fmol/mg protein in thyroid carcinomas and 10.5 +/- 5.2 fmol/mg in the corresponding normal tissue (P < 0.05, Kd 0.84 +/- 0.26 nM, n = 11). In autonomously functioning thyroid adenomas binding capacities were 14.2 +/- 8.2 fmol/mg in the nodules and 8.9 +/- 4.8 fmol/mg in normal tissue (P < 0.01, Kd 0.73 +/- 0.62 nM, n = 15). In conclusion, EGF receptor levels are increased not only in malignant thyroid tumors but also in well-differentiated benign thyroid nodules.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Molecular heterogeneity of human chorionic gonadotropin in serum and urine from patients with trophoblastic tumors.

Many studies on the structure and function of human chorionic gonadotropin (hCG) have relied on purified hCG preparations obtained from pregnancy urine. In the present studies, in order to demonstrate possible differences between the hCG species present in serum and those released into urine, we examined serum and urinary samples derived from patients with trophoblastic tumors and of pregnancy origin by sodium dodecyl sulfate electrophoresis, isoelectric focusing, and two-dimensional electrophoresis including immunostaining with a specific hCG antibody and densitometry of the protein bands. This type of analysis was presently feasible only in patients presenting with extremely high serum levels of hCG and was therefore limited to seven patients with testicular cancers, one woman with a hydatidiform mole, and one pregnancy sample. We found marked differences in the isoelectric focusing pattern between urinary and serum hCG samples, with the urinary hCG consisting of more alkaline pI variants than that present in the serum of the same patients. Tumor hCG differed from pregnancy hCG in that it contained more acidic variants, and this was true for urinary and serum-derived materials. In some tumor and pregnancy samples an hCG immunoreactive material of lower molecular weight than hCG itself was found. In conclusion, the present studies, extending previous findings on the microheterogeneity of hCG, indicate that serum and urinary-derived hCG may differ in the composition of the isoform spectrum, as does tumor and pregnancy hCG. Further, in some patients hCG immunoreactive molecules exist that differ markedly from hCG in size and charge. These observations suggest that, whenever possible, serum-derived hCG materials should be used to define the molecular structure of hCG and assess its biological activities.

Adult↗

Clinical use of HCG and hCG beta determinations.

Recent advances in our understanding of hCG/hCG beta synthesis by trophoblastic and nontrophoblastic tissues together with improved techniques for measuring hCG have helped to define the role of hCG as a clinical marker. HCG determination by sensitive immunometric assay enables detection of hCG immunoreactivity in normal men and women. It facilitates early detection of normal pregnancy and significantly contributes to the diagnosis of various pregnancy-related disorders, such as ectopic pregnancy, spontaneous abortion, hydatidiform mole, choriocarcinoma or Trisomy 21. Further, determination of this marker is immensely helpful to guide curative intervention in testicular cancer. For diagnosis and follow-up of patients with testicular cancer, a method measuring both hCG and hCG beta or separate methods for each component are recommended, because a significant portion of seminoma exclusively secrete free hCG beta. Also, hCG beta production by other than trophoblastic malignancies has been well recognized. A possible clinical use of hCG beta as a marker of cancers of the bladder, pancreas or biliary tract is currently debated.

Biomarkers, Tumor↗