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Biomedical subjects

M Hüfner

Publications and source records attributed to M Hüfner.

At least 19 recordsLinked to original sources
PubMed2007

[Recurrent familial cardiac myxomas and lentiginosis. Second recurrence in a 41-year-old female patient].

The case of a 41-year-old woman with recurrent cardiac myxomas and widespread lentiginosis is reported. The diagnosis of a Carney complex was established 7 and 25 years, respectively, after first manifestation of the cardiac myxomas in both the patient and her brother. This peculiar hereditary disease is commonly associated with multiple neoplasms and an endocrine overactivity, requiring a thorough examination of the patients and their relatives to detect additional typical manifestations.

Adult↗
PubMed2006

Incidence of radioiodine induced Graves' disease in patients with multinodular toxic goiter.

In this study, we assessed the incidence of Graves' disease (GD) following radioiodine therapy (RIT) in a large cohort of well characterized patients with autonomy in comparison to the clinical course of control patients with thyroidal autonomy not definitively treated with (131)I or surgery. 622 consecutive patients were treated with (131)I for autonomy (unifocal: n = 321; multifocal: n = 199; disseminated: n = 102) and followed up for at least 6 months post RIT. 108 consecutive patients with autonomy not definitively treated (unifocal: n = 49; multifocal: n = 42; disseminated: n = 11) followed up for at least 6 months served as controls. Initial evaluation and follow-up included determination of FT3, FT4, TSH, autoantibodies against the thyroid peroxidase (anti-TPO) and TSH-receptor antibodies (TRAb) by highly sensitive radio receptor-assay, quantitative thyroid scintigraphy and sonography. After 6 months, GD was newly diagnosed in 1/321 patients with unifocal autonomy, in 1/199 patients with multifocal autonomy and in 0/108 control patients. In patients with disseminated autonomy (group C), GD was diagnosed significantly more often compared to the other groups (5/102 patients; 4,1 %; p < 0.05). In conclusion, RIT may induce Graves' disease in a few cases with toxic multinodular goiter. The incidence in this population is small. Compared with patients suffering from uni- or multifocal autonomy, subjects with disseminated autonomy have a more than tenfold higher risk for the development of GD.

Adult↗
PubMed2005

Expression of the sodium iodide symporter in differentiated thyroid cancer: clinical evidence.

AIM: Molecular analysis of the expression of the sodium iodide symporter (NIS) in 32 patients with differentiated thyroid cancer (DTC) and correlation with scintigraphic findings ((131)I,(123)I) in 19 (59.4%) of them. PATIENTS, METHODS: NIS expression of 27 primary tumours, 13 lymphnodes and 18 distant metastases was determined by immunostaining using a murine monoclonal anti-NIS-antibody. NIS expression and radionuclide uptake of metastases were analysed by a semiquantitative visual score. Patients were divided into two subgroups: Group 1 (n = 8 patients): indirect correlation of radioiodine uptake (RIU) of subsequent metastases with NIS expression of 7 primary tumours and 3 metastases; Group 2 (n=11 patients): direct correlation of radionuclide uptake with NIS expression of 19 metastases which were excised after imaging. RESULTS: 49 of 58 specimens (84.5%) were NIS-positive. A preserved NIS-expression was found in 12 primary tumours and 8 of 10 (80%) synchrone and 6 of 7 (85.7%) metachrone metastases. Group 1 revealed a 100% positive predictive value (PPV) of a preserved NIS expression in the primary tumour regarding radioiodine uptake in metastases while a lack of NIS expression in the primary tumor did not reliable predict a loss of the metastases' ability to concentrate radioiodine. In group 2, only 11 of 19 (57.9%) specimens showed a concordant NIS expression and RIU whereas in the remaining 8 cases without visible RIU NIS expression was still present. CONCLUSIONS: NIS expression of the primary tumour and metastases in DTC is usually well preserved. We found a positive correlation between NIS expression of the primary and metastatic tissue but could not identify such well correspondence between NIS expression and the RIU of subsequent metastases.

Adult↗
PubMed2004

Evidence of downregulation of matrix extracellular phosphoglycoprotein during terminal differentiation in human osteoblasts.

Matrix extracellular phosphoglycoprotein (MEPE) is an extracellular matrix protein that was first detected in tumor-induced osteomalacia (TIO). Investigations in mice revealed that MEPE is expressed in bone and teeth in a maturation-dependent manner, reaching its maximum during mineralization. However, from knockout experiments, although it has become clear that MEPE might function as a mineralization inhibitor, the exact mechanism of action is still unclear. Even less is known about the regulation of MEPE in men. Therefore, we have studied the time- and maturation-dependent expression of MEPE in two human osteoblast culture systems, the osteosarcoma cell line HOS 58 and primary trabecular osteoblasts. Cells were cultured for up to 29 days, and the influence of beta-glycerophosphate (bGP), ascorbate, transforming growth factor beta (TGF-beta), BMP-2, and dexamethasone was studied. HOS 58 cells showed no significant effect on MEPE gene expression up to 5.0 mM, but a significant inhibition was revealed at 10 and 20 mM, when osteocalcin (OC) expression was maximal. Under the same conditions, primary human osteoblasts showed no effect on MEPE gene expression. However, when cultured in the presence of 5 mM beta-glycerophosphate, ascorbate, and dexamethasone for 29 days, which are similar conditions to those described by Owen in his differentiation model in rat osteoblasts, a progressive inhibition of MEPE gene expression to 20% of the maximum was observed. Increasing osteocalcin expression indicated advancing differentiation. In conclusion, in contrast to the results in mice, when MEPE was maximally expressed during mineralization, in the human system, this factor seems to be maximally active in the proliferation and early matrix maturation phase. It was, however, strongly suppressed, associated with the mineralization phase.

Adult↗
PubMed2004

Calcitonin measurement to detect medullary thyroid carcinoma in nodular goiter: German evidence-based consensus recommendation.

Serum calcitonin (CT) has become a very specific and sensitive marker for human medullary thyroid carcinoma (MTC), a neuroendocrine tumor affecting about 1 % of patients with nodular thyroid disease. MTC is characterized by early micrometastasis and a lack of curative non-surgical treatment, so that early diagnosis is desirable. Based on a systematic review of scientific evidence, we propose multidisciplinary consensus recommendations for the clinical use of CT in patients with nodular goiter. To exclude MTC, serum CT should be determined in patients with nodular thyroid disease, using a two-site CT immunoassay. If basal serum CT exceeds 10 pg/ml, CT should be analysed by pentagastrin stimulation testing, after renal insufficiency and proton pump inhibitor medication have been ruled out. As the risk for MTC is higher than 50 % in patients with stimulated CT values > 100 pg/ml, thyroidectomy is advised in these individuals. If stimulated CT exceeds 200 pg/ml, thyroidectomy and lymphadenectomy is strongly recommended. Pentagastrin-stimulated CT values < 100 pg/ml are associated with a low risk of MTC, or very rarely, non-metastasizing micro-MTC (size < 10 mm). Therefore, regular clinical and biochemical follow-up is the preferred treatment in such patients, unless thyroid malignancy is suspected otherwise.

Calcitonin↗
PubMed2003

[Macroadenoma of the pituitary gland with moderate hyperprolactinaemia].

HISTORY AND CLINICAL FINDINGS: A 46-year-old woman was referred to the neurosurgery department for treatment of a macroadenoma of the pituitary. She had complained of recurrent galactorrhoea for 7 years; a hysterectomy was performed 4 years ago. The clinical investigation was unremarkable, except for a slight galactorrheoa on both sides. INVESTIGATIONS: The endocrinological work-up revealed a moderately elevated prolactin level of 3133 mU/l (147 ng/ml) with intact pituitary functions. She had no visual impairment and the MRI depicted a pituitary tumor with a maximal diameter of 1.9 cm and both intra- and suprasellar extension. DIAGNOSIS, TREATMENT AND CLINICAL COURSE: The diagnosis of a nonfunctioning macrodenoma with functional hyperprolactinemia was made and a selective transsphenoidal adenomectomy was performed. The primary histology showed a chromophobe adenoma. However, additional immunohistological investigations revealed distinct staining for prolactin. In the meantime, because of persistent galactorrhea and elevated prolactin levels, treatment with cabergolin 0.5 mg/week was started. This stopped galactorrhea and normalized the prolactin levels. A follow-up MRI after 3 months of treatment showed a significant shrinkage of the residual tumor. CONCLUSION: This case demonstrates that the differential diagnosis of macroprolactinoma with low secretory activity and functional hyperprolactinemia is very difficult preoperatively in individual cases. This is relevant because macroprolactinomas with low secretory activity can also be treated successfully with dopamine agonists. We therefore suggest a drug treatment trial with dopamine agonists in all macroadenoms with hyperprolactinemia, particularly in those with prolactin levels above 2000 mU/l (100 ng/ml).

Cabergoline↗
PubMed2003

[Clinical evaluation of a new thyroglobulin immunoradiometric assay in the follow-up of differentiated thyroid carcinoma].

AIM: Formal and clinical comparison of a new 3 (rd) -generation-Tg-IRMA (3-G-IRMA; Dynotest Tg-plus) with a conventional Tg-IRMA (3-G-IRMA; SELco Tg-assay) for patients with differentiated thyroid carcinoma. In addition we evaluated, if thyroglobulin (Tg) levels above a specific threshold concentration indicate the need for further investigations for residual disease. PATIENTS, METHODS: Tg concentration of 105 sera of 93 consecutive patients with a differentiated thyroid cancer was determined with both assays and compared at different cut-off values (Dynotest Tg-plus: 0.2, 1, 2 ng/ml; SELco Tg-assay: 0.5, 1, 2 ng/ml) with the clinical results in respect to the corresponding TSH concentration. RESULTS: Tg concentration did not show any significant difference (SELco Tg-assay 0.5 ng/ml, Dynotest Tg-plus 0.2 ng/ml). The Tg-values of both assays correlated with 97%. However, correlation of recovery in both assays was small (40%). The sensitivities and specificities of both assays at different cut-offs and TSH values did not reveal significant differences. In patients with TSH concentration > 30 micro U/ml the functional assay sensitivity was superior to arbitrary cut-offs in the decision to start further evaluations. CONCLUSIONS: In our study neither formal nor clinical significant differences between two Tg-assays were found. In a hypothyroid patient (TSH > 30 micro U/ml, Tg concentration exceeding the functional assay sensitivity) further investigations for residual disease are warranted. Higher thresholds are of limited value, due to an unacceptably high rate of false negative results.

Carcinoma↗
PubMed2002

[Thyroid hormones in the treatment of iodine deficiency goiter. Superfluous like goiter?].

In recent years, the widespread use of iodized salt in households and industrially produced foods has considerably improved the shortage of iodine in the German diet. Recent epidemiologic studies have shown that we are now at the threshold of adequacy. Over the last decade, views on the pathogenesis of iodine deficiency goiter have changed: while TSH was previously assumed to be the major factor underlying this form of goiter, experimental data now finger the activation of local growth factors, in particular IGF1. Iodinated organic compounds, in particular iodolacton produced by iodination of unsaturated fatty acids in the thyrocyte, are the key regulators of IGF1 activity by inhibitory action, and iodine is now the therapeutic agent of first choice for iodine deficiency goiter; long-term thyroxine treatment in TSH suppressive doses has been abandoned. The recommended daily dose of iodine is 200 micrograms; higher doses may induce or aggravate autoimmune thyroiditis, and should not be used for a length of time. In pregnant women, an adequate supply of iodine is of critical importance for optimal neurophysiological development, and the general use of iodine supplementation in pregnancy therefore remains mandatory in Germany.

Adolescent↗
PubMed2001

Increase of serum estradiol in cirrhotic men treated by transjugular intrahepatic portosystemic stent shunt.

BACKGROUND/AIMS: Liver cirrhosis is frequently associated with sexual dysfunction and hormonal abnormalities. To evaluate the effect of portosystemic shunting on sex steroid serum concentrations, a prospective study was performed in cirrhotic patients treated consecutively and electively by transjugular intrahepatic portosystemic stent shunt (TIPS). METHODS: In 27 patients with liver cirrhosis we measured serum levels of testosterone (T), sexual hormone binding globulin (SHBG), luteinizing hormone, follicle-stimulating hormone, dehydroepiandrosterone sulfate, androstenedione (A), estradiol (E2), 17-OH-progesterone and the T/SHBG ratio before and 3 months after TIPS. RESULTS: In men (n = 17) 3 months after TIPS, A and E2 significantly increased, with mean serum levels rising from 4.4 +/- 2.5 to 5.6 +/- 2.9 ng/ml (P = 0.04) and from 27 +/- 9 to 40 +/- 19 pg/ml (P = 0.003), respectively. In contrast to A the increase of E2 persisted at 9 and 15 months after TIPS. Erectile dysfunction increased from 30% before TIPS to 70% after TIPS. In women (n = 10) A and E2 levels did not change significantly after TIPS. CONCLUSIONS: TIPS aggravated hormonal dysbalance of sex steroids in favor of estrogens (hyperestrogenism) in men.

Adult↗
PubMed2000

Persistent hypocalcemia with elevated parathyroid hormone levels after long-term primary hyperparathyroidism: report of a case.

We report herein the case of a 48-year-old man with long-term persistent primary hyperparathyroidism (pHPT) despite undergoing a parathyroidectomy in 1976, followed by a reoperation in 1978, for whom resection of a parathyroid adenoma in the upper mediastinum was eventually performed. His postoperative course was complicated by recurrent hypocalcemia refractory to oral calcium substitution and significantly elevated levels of parathyroid hormone (PTH). The radiological findings are presented, and we discuss the possible reasons for the coincidence of severe hypocalcemia with increased PTH levels in association with pHPT.

Adenoma↗
PubMed2000

Disseminated thyroid autonomy or Graves' disease: reevaluation by a second generation TSH receptor antibody assay.

The clinical diagnosis of disseminated autonomy (DISA) can only be established by exclusion of Graves' disease (GD). Both hyperthyroid conditions share the same scintigraphic appearance and can only be distinguished from each other clinically either by the presence or absence of endocrine ophthalmopathy (EO) or thyrotropin (TSH) binding inhibiting immunoglobulins (TBIIs). The purpose of this study was the reevaluation of thyroid autonomies originally classified as DISAs by a second-generation radioreceptor antibody assay (RAA) (DYNOtest TRAKhuman) (B.R.A.H.M.S. Diagnostika, Berlin, Germany). The analysis included 32 patients (female: n = 25, male: n = 7; mean age: 46 +/- 18 years) who were initially diagnosed with DISA. All patients were TSH receptor (TSHR) antibody (TRAb) negative by a conventional radioimmunoassay (RIA) (TSH-REZAK RIA) (Medipan Diagnostica, Selchow, Germany) during their first evaluation. The presence of EO was excluded by clinical signs in all patients. Surgery had been performed prior to our evaluation in 5 patients and after our survey in 1 patient. Four patients had been treated previously with 131I. Ten patients were treated with thionamides during our evaluation, and 13 had not been treated before. One hundred three patients who had either healthy thyroids, nontoxic goiters, or focal autonomies served as controls and were evaluated both by the TSH-REZAK assay and the DYNOtest TRAKhuman assay. Seven of thirty-two (22%) patients originally classified as DISA were TRAb positive in the second-generation assay. In this group, 5 of 7 patients had a total thyroid volume (TTV) <30 mL (positive predictive value [PPW] for TRAb positivity 71%), and 5 of 7 patients had a diffuse goiter (PPW for TRAb-positivity 71%). Six of seven patients were anti-thyroperoxidase (TPO) positive (PPW for TRAb positivity 85%). A hypoechoid pattern on ultrasound was present by visual analysis in 3 of 7 patients (PPW for TRAb positivity 43%). A 100% PPW for TRAb positivity could be obtained if a goiter <30 ml was combined with anti-TPO positivity, but this combination was present in only 4 of 7 (57%) patients. With the second-generation assay, one false positive test result was observed in the control group. Surgery was performed in 6 patients who were TRAb negative in both assays. In all these cases, the histologic findings were compatible with autonomous transformation of the thyroid. Our study demonstrates that a significant number (22%) of patients formerly classified as DISA may actually have GD. However, DISA still exists as a clinical entity, and its pathophysiological link to multifocal and unifocal autonomy should be further investigated.

Adult↗
PubMed2000

[Clinical implications of a new TSH receptor antibody assay (DYNOtest TRAKhuman) in autoimmune thyroid diseases].

AIM: Conventional radioreceptor-antibody-assays (RAAs) fail in the detection of TSH-receptor antibodies (TRAKs) in 10-30% of patients with Graves' disease (GD). The aim of this study was the evaluation of the diagnostic and clinical impact of a new RRA (DYNOtest TRAKhuman) which uses the human recombinant TSH-Receptor in the diagnosis of autoimmune thyroid disease. METHODS: Sera from 142 consecutive patients (GD: n = 50, autoimmune thyroiditis/AIT: n = 92) and from 55 controls (31 patients without any thyroid disease and 14 with euthyroid goiter) were evaluated both with the DYNOtest TRAKhuman-assay and a conventional RRA (TRAK-Assay). Thyroid in vitro parameters and thyroid sonography were performed in all patients. RESULTS: The DYNOtest TRAK-assay was significantly superior to the conventional RRA in the diagnosis of GD (p < 0.00012), especially in those who were treated by thionamides (p < 0.003) and in the diagnosis of TRAK-positive patients with AIT (p < 0.003). The majority of TRAK-positive AIT-patients suffered from hypothyroidism. One false positive result in patients with euthyroid goiter was found in the TRAK-Assay as well as in the DYNOtest TRAKhuman-Assay. Therefore the specificity of the DYNOtest TRAKhuman was not inferior compared with the conventional assay. CONCLUSION: The DYNOtest TRAK-assay is superior in the diagnostic work up of Graves' disease compared with a conventional TRAK-assay and offers an equal specificity.

Female↗
PubMed1999

Development of the osteoblast phenotype in primary human osteoblasts in culture: comparison with rat calvarial cells in osteoblast differentiation.

In rat osteoblast-like cells, a time-dependent sequence of growth and differentiation-dependent genes has been identified and a model of osteoblast differentiation in culture suggested. We investigated the expression of the bone matrix-associated proteins osteonectin and procollagen I and of the bone cell phenotype-related proteins alkaline phosphatase and osteocalcin during cell culture in primary human osteoblast like cells. Primary human explant cultures from nine young healthy donors were established under highly standardized conditions. Cells in the second passage were analyzed on different days from day 1 to 32, comparing cells growing under the influence of ascorbate with controls. Gene expression was determined by Northern blot analysis or polymerase chain reaction. Osteocalcin expression was also investigated after 1,25-(OH)(2)D(3) stimulation. On the protein level, newly synthesized collagen I, alkaline phosphatase activity, and secretion of osteocalcin were analyzed at all time points. On comparing our findings to the pattern of gene expression suggested for the rat calvarial osteoblast system, we found a similar developmental sequence for the so-called "proliferation" as well as a similar, but lengthened, sequence for the "matrix maturation stage." During "matrix maturation," we found an ongoing proliferation despite increased alkaline phosphatase and decreased procollagen I gene expression. Our study, therefore, shows that in pHOB the gene expression profile proceeded to the "matrix maturation stage," as defined by Owen and colleagues, independent of ongoing proliferation. We were unable to observe the mineralization period as demonstrated by the missing increase of osteocalcin expression and lack of nodule formation in our human osteoblast model. In contrast to the rat system, we found a proliferation stimulating influence of ascorbate, suggesting species-specific differences in response to differentiation factors. From these data, we conclude that general considerations on physiology and pathophysiology of bone cell differentiation have to be confirmed in the human osteoblastic cell system.

Adult↗
PubMed1999

1,25 dihydroxyvitamin-D3 attenuates the confluence-dependent differences in the osteoblast characteristic proteins alkaline phosphatase, procollagen I peptide, and osteocalcin.

In the present study a cell culture model of primary human osteoblasts based on degrees of confluence was investigated by measuring basal and 1,25(OH)2D3stimulated levels of the osteoblast characteristic proteins alkaline phosphatase (AP), procollagen I-peptide (PICP), and osteocalcin (OC), as well as the corresponding gene expression. Primary osteoblast-like cell cultures from seven donors were treated in the second passage with 1,25(OH)2D3 (5 x 10(-8) M for 48 hours) and investigated at four stages of confluence (stage I 50%, stage II 75%, stage III 100%, and stage IV 7 days postconfluence). In untreated cultures passing through the different stages of confluence, we saw a 1.8-fold increase of AP activity, a 2. 3-fold increase of OC secretion, but a decrease of PICP levels to 0. 36-fold. Gene expression showed only minor variation between the different confluence stages. 1,25(OH)2D3 did not significantly affect PICP production. Alkaline phosphatase protein was stimulated during proliferation until confluence, with no effect thereafter. Surprisingly, OC secretion and mRNA expression were stimulated in all four stages to the same absolute level independent of basal values. We conclude that our results correspond to other studies showing differentiation-stage dependent changes of basal levels of osteoblast-specific proteins. However, 1,25(OH)2D3 stimulation decreased the confluence-dependent difference for AP and abolished it for osteocalcin, thus leading to a more differentiated phenotype of the osteoblast. Therefore, 1,25(OH)2D3 stimulation might improve the reproducibility of results obtained at different confluence stages from cultures of clinical samples.

Alkaline Phosphatase↗