PubMed Health⌕ Search

Biomedical subjects

U Cordes

Publications and source records attributed to U Cordes.

At least 19 recordsLinked to original sources
PubMed1998

Aberrant expression of tissue-specific proteins in the thymus: a hypothesis for the development of central tolerance.

Herein we present the case for the existence of a thymic cortical epithelial cell that possesses an unusual gene transcription. It produces tissue-specific proteins that have their usual physiological functions outside the thymus and presents them, as well as household proteins, to the differentiating thymocytes. We suggest that this specialized cell enforces tolerance to most self-proteins by causing release of a signal for programmed cell death to thymocytes that express receptors for these self-antigens.

Animals↗
PubMed1997

Murine thymic nurse cells express ICAM-1 on caveolar and vacuolar membranes.

The thymic nurse cell is a unique type of epithelial cell in the thymic cortex. It is in intimate contact with the developing thymocytes by harbouring up to 200 thymocytes in distinct vacuoles, called caveoles. This investigation is concerned with the nurse cell expression of the intercellular adhesion molecule ICAM-1, the ligand for thymocyte LFA-1. Nurse cells from young Balb/c mice were isolated in a density gradient. ICAM-1 expression was studied by using two different immunotechniques: alkaline phosphatase labelled cryosections, and immunogold electron microscopy. The specific antibody was a monoclonal rat anti-mouse ICAM-1. Immunostaining of cryosections demonstrated that ICAM-1 is expressed on the surface membrane and in the internal caveolar membranes of thymic nurse cells. Electron microscopy of immunogold labelled sections revealed ICAM-1 on the surface membrane of thymic nurse cells and on the membranes of the caveoles, the small cytoplasmic vesicles, as well as on the Golgi apparatus.

Animals↗
PubMed1997

[Prediction of pharmacological effect of octreotide in acromegaly by means of 111In-pentetreotide scintigraphy and calculation of a pituitary uptake index].

AIM: The aim of our prospective study was to optimize the determination of the pituitary somatostatin receptor status by means of 111-In-pentetreotide scintigraphy and to compare it intraindividually with the pharmacological effect of octreotide in active acromegaly. METHODS: In n = 22 patients with growth hormone (GH) secreting pituitary adenoma, 111-In-pentetreotide scintigraphy was performed, and the specific radionuclide accumulation in the pituitary area (evaluation visually as well as semiquantitatively by means of ROI technique and calculation of various uptake indices) was correlated with the acute drop of GH after administration of 100 micrograms octreotide s. c. (octreotide acute test). RESULTS: The uptake index we propose (cts/pixel-ratio circular pituitary ROI: irregular cerebrum ROI after background correction in the sagittal SPECT slice with maximum pituitary uptake 24 h p.i.) correlates best with the pharmacological effect (acute decrease of GH levels) of octreotide; its upper normal limit amounts of 3.5. CONCLUSION: As often the normal pituitary gland can be visualized scintigraphically, the purely visual differentiation between a normal and a pathological receptor status sometimes is equivocal. A pituitary uptake index, calculated by means of a standardized ROI technique, facilitates this discrimination and so contributes to select possible responders for a treatment with octreotide.

Acromegaly↗
PubMed1995

Gynaecomastia in a patient with a hCG producing giant cell carcinoma of the lung. Case report.

Gynaecomastia, or enlargement of the male breast may result from various endocrine dysfunctions and often reflects ectopic production of substances such as hCG and estradiol. We report on the case of a 30 year old man who presented with gynaecomastia and elevated plasma levels of hCG, estradiol and testosterone. As a result of several diagnostic procedures such as selective venous sampling and magnetic resonance tomography (MRT), a hCG producing tumor of the upper lobe of the left lung was found. This hormonal overproduction induced an enhanced secretion of estradiol and testosterone in the testicular tissue. Histology revealed a giant cell carcinoma with positive immunostaining for hCG. This case report further underlines the necessity of an intensive search for ectopic beta-hCG production due to malignant tumours, in particular in the adult.

Adult↗
PubMed1993

[Quantitative determination of echogenicity of diffuse inflammatory thyroid gland diseases].

Grey level was measured in 93 ultrasonic scans of the thyroid gland in order to quantify hypoechogenicity in diffuse inflammatory thyroid disease. Using a modern ultrasound device (256 grey-scale steps and 7.5-MHz parallel scan), grey levels were measured in normal thyroid glands and euthyreotic goiters as well as in thyroiditis or Graves' disease using a programmed setting of the device. Highly significant differences were found between normal thyroid glands and thyroiditis or Graves' disease. Sensitivity of the method was 65% in discriminating Graves' disease and 91% in discriminating thyroiditis; specificity was 95%. The clinical value of the method for follow-up studies in inflammatory diseases of the thyroid gland still has to be established.

Adolescent↗
PubMed1993

[Sports therapy in Bechterew's disease--presentation of a new treatment concept].

Bechterew's disease is a chronic-inflammatory condition of the spine, with a tendency toward stiffening and relatively frequent involvement also of the hip, knee and shoulder joints. Contrary to most other rheumatic diseases, drug therapy plays a rather minor role. The focus is on movement, in line with the motto that "Bechterew patients need movement". The sports therapy concept of the Münster University Bechterew group as well as initial experience are set out.

Disability Evaluation↗
PubMed1992

The influence of testosterone substitution on bone mineral density in patients with Klinefelter's syndrome.

The aim of this study was to clarify the extent of bone mineral deficiency in patients with Klinefelter's syndrome on the premise that testosterone substitution could prevent this deficiency. Bone mineral density was measured by single-photon absorptiometry in 42 patients with Klinefelter's syndrome, (21 patients without therapy, 10 with testosterone substitution before the age of 20 and 11 patients with testosterone substitution beginning after the age of 20). We found significantly lower bone mineral density in patients without therapy and in patients when the therapy began later compared to normal individuals. Patients with early therapy showed a high proportion of normal values of bone mineral density. We found a positive correlation between bone mineral density and plasma testosterone and a negative correlation between plasma testosterone and age for patients without therapy. These findings suggest that low testosterone levels before or during puberty cause inadequate bone development and low bone mineral density in Klinefelter's syndrome. Only early testosterone substitution may prevent bone mineral deficiency. Later substitution no longer affects bone mineral density.

Adult↗
PubMed1991

Subcutaneous gonadotropin therapy in male patients with hypogonadotropic hypogonadism.

OBJECTIVE: The response to subcutaneous (SC) gonadotropin replacement therapy, using human chorionic gonadotropin (hCG) and human menopausal gonadotropin (hMG) or hCG alone, was evaluated in male hypothalamic hypogonadism. DESIGN: Sixteen patients with hypothalamic hypogonadism were treated with gonadotropins for induction of puberty and normalization of spermatogenesis. The results were analyzed retrospectively. SETTING: The study was carried out in a clinical endocrinology department providing tertiary care and in private practices of endocrinology. PATIENTS: Eight patients with idiopathic hypogonadotropic hypogonadism and eight patients with Kallmann's syndrome in prepubertal or early pubertal stages. INTERVENTIONS: Human chorionic gonadotropin and hMG were administered SC in individual dosages. MAIN OUTCOME MEASURES: Increase of serum testosterone (T), testicular volume, semen volume, and sperm count were evaluated. RESULTS: Normalization of serum T and complete sexual maturation was achieved in all patients. Spermatogenesis was induced in all but two patients. Seven patients showed normal findings in semen volume and sperm count, and two patients had semen quality close to normal. In five patients sperm count remained less than 10 x 10(6)/mL. CONCLUSIONS: The results obtained by SC gonadotropin replacement prove this mode of administration to be effective in stimulating steroidogenesis and spermatogenesis in hypogonadotropic males.

Adolescent↗
PubMed1990

The influence of penbutolol and placebo on blood sugar levels and insulin consumption in the glucose-controlled insulin infusion system ("artificial endocrine pancreas").

The aim of the study was to investigate the influence of 40 mg of the beta-blocker penbutolol (Betapressin TM; Hoechst Ltd., Frankfurt/Main) in comparison to placebo on the insulin consumption on the blood sugar profile in twelve insulin-dependent diabetes (IDDM) patients. The patients were treated with penbutolol and placebo for a period of three days, and then were examined with the help of the glucose-controlled insulin infusion system. The blood sugar profile and insulin consumption over a 24 hour period was not affected by either penbutolol or placebo, nor could any changes be measured in these parameters when measured after food intake. After a submaximal exercise load on the bicycle ergometer (1 watt per kg body weight) following an evening meal, no difference could be observed between penbutolol and placebo in the above-mentioned parameters. The same was also true for hormonal parameters as STH, ACTH, cortisol, and catecholamines. These findings demonstrated that medication of penbutolol over a three-day period has no influence on the baseline blood sugar profile and insulin consumption or on insulin consumption after food intake during rest and physical exercise.

Adolescent↗
PubMed1989

[Long-term study of endocrine ophthalmopathy and retrospective assessment of therapeutic measures].

The follow-up of Graves' ophthalmopathy was analysed regarding to clinical and chemical data on the one hand and to dependence on different therapeutic alternatives on the other. 297 patients (44 +/- 14 years, 249 female, 48 men) were observed with inclusion of data from the history and clinical data as well (computer tomography and orbital sonography). At the onset of therapy 253 patients were hyperthyroid, 36 euthyroid and eight showed hypothyroidism. The staging was: I 13, II 54, III 113, IV 95, V five, VI eight patients. The HLA-typing in 89 patients showed the following results: B8 in 32%, DR3 in 42%, B8 as well as DR3 in 24% of the patients. In about 50% of the cases there were raised microsomal and in about 18% there were raised thyroglobuline antibodies. 63% of the patients received immunosuppressive medication: corticosteroids in 100% (more than one time in 43%), cyclosporine A in 11%, ciamexone in 10%, other non-steroid immunosuppressants in 5% of the cases. The retrobulbar irradiation was performed in 9%, and total thyroidectomy in 7%. During therapy the inflammatory process was clearly ameliorated, however exophthalmos and diplopia were more resistant to treatment. In the group of patients with combined cyclosporine and prednisone therapy and in the group of patients with total thyroidectomy and partly retrobulbar radiotherapy, significant differences were observed regarding to visual acuity and Hertel values. None of the therapies applied constitutes an optimal treatment with the regard to the long-term course. Under therapy an improvement can be reached, but no complete healing.

Adolescent↗
PubMed1988

Evaluation of the clonidine-suppression test in the diagnosis of pheochromocytoma.

In this study we examined the preoperative value of the clonidine-suppression test in 15 patients with surgically proved pheochromocytomas. The result of the clonidine-suppression test was pathological (epinephrine plus norepinephrine above 500 ng/l 3 h after clonidine) in 10 of 15 patients (66%). These patients had relatively large tumors and higher basal norepinephrine plasma levels. Out of the 5 cases without a pathological clonidine test 4 had normal basal plasma catecholamine levels with the result that the clonidine test could not be properly applied and 1 case produced a false negative result. These 5 cases generally had smaller tumors and lower plasma catecholamine levels. Two of these cases had basally raised epinephrine values. The other three cases had either a paradoxical increase or a suspiciously low fall (less than 25%) in norepinephrine within the normal range. We conclude that the clonidine-suppression test is only reliable for the diagnosis of relatively large pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1987

[Type II multiple endocrine neoplasms. Diagnosis, therapy and prognosis].

From 1979 to 1986, seven patients with multiple endocrine neoplasia (MEN) type IIa and three with type IIb were treated. Nine had a C-cell carcinoma, one had C-cell hyperplasia. None had hyperparathyroidism. Three patients had multiple mucous neuromas. Six patients had proven pheochromocytoma: adrenalectomy was performed in these six (unilateral or bilateral depending on whether the tumor was uni- or bilateral). All ten patients had a total thyroidectomy--three later required neck dissection for regional lymphnode metastases. One patient died from the consequences of diffuse liver metastases of a C-cell carcinoma. Extensive family screening is necessary with patients who have MEN type II, in order to discover early any occult disease carriers. In addition, MEN type II should be excluded in all patients who have C-cell carcinoma, pheochromocytoma or hyperparathyroidism.

Adolescent↗
PubMed1985

Comparison of 131I-metaiodobenzylguanidine scintigraphy with urinary and plasma catecholamine determinations in the diagnosis of pheochromocytoma.

In a retrospective study of 31 patients with suspected pheochromocytoma we examined the preoperative results of 131I-metaiodobenzylguanidine (131-I-MIBG) scintigraphy and a fluorimetric urine catecholamine determination test. An additional radioenzymatic plasma catecholamine determination test was performed in 25 patients. In 14 of the 31 patients the diagnosis of pheochromocytoma was later histologically confirmed. In the remaining 17 patients the suspected diagnosis was finally rejected after a clinical decision had been made on the basis of clinical history, symptoms, laboratory and imaging tests. 131-I-MIBG scintigraphy apparently had a very high specificity (no false-positive results among the patients with rejected diagnosis), but showed the least sensitivity (3 of 14 tumours were not detected). Urine catecholamines showed two false-negative and three false-positive results. Plasma catecholamines had the highest sensitivity and gave only one false-positive result. Because of its high pathognomonic value 131-MIBG scintigraphy can be helpful not only for localization, but also for confirmation of diagnosis when catecholamine determination tests are contradictory. On the basis of our experience with false-positive results after interfering medication therapy, urine and plasma catecholamine determination tests should only be carried out after purification with thin layer chromatography or high performance liquid chromatography.

3-Iodobenzylguanidine↗
PubMed1985

Selective blood sampling in adrenal hypertension.

Selective venous blood sampling was performed in 89 patients with hypertension (14 pheochromocytoma, 10 Conn's syndrome, 8 Cushing's disease, 57 essential hypertension). We looked for diagnostic criteria and the valuability of blood sampling from the adrenal veins in such diseases. Defining a norepinephrine concentration of more than 8,000 ng/l as pathological, we had an accuracy of 94.6%. Defining an aldosterone concentration of more than 1,400 pg/ml as pathological, we had an accuracy of 97.4%. In Cushing's disease this method was not very helpful due to overlapping results.

Adrenal Gland Diseases↗
PubMed1983

[CEA determination to differentiate between pheochromocytoma with ectopic calcitonin formation and type-II multiple endocrine neoplasms].

Plasma levels of calcitonin and carcinoembryonic antigen (CEA) were determined pre-operatively and two months postoperatively in ten patients with C-cell carcinoma as part of multiple endocrine neoplasia type II. In addition, CEA was measured in extracts from 20 different phaeochromocytomas (five from patients with multiple endocrine neoplasia type II, 15 from patients with sporadic phaeochromocytoma). In comparison, CEA concentration was determined in extracts from five C-cell carcinomas of patients with multiple endocrine neoplasia type II. When correlating pre- and postoperative calcitonin and CEA levels, there was a significant linear relationship (P less than 0.001). CEA concentration in extracts from phaeochromocytomas was at the lower level of sensitivity (4.7 +/- 12.2 pg/mg tumour wet-weight). In extracts from C-cell carcinomas they were much higher (6402 +/- 4570 pg/mg tumour wet-weight). The results suggest that it is possible, in patients with phaeochromocytoma and high calcitonin levels, to differentiate by additional CEA determination between C-cell carcinoma in the course of multiple endocrine neoplasia type II and sporadic phaeochromocytoma with ectopic calcitonin liberation.

Adrenal Gland Neoplasms↗