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Biomedical subjects

C Dotzenrath

Publications and source records attributed to C Dotzenrath.

At least 19 recordsLinked to original sources

Operative treatment of renal autonomous hyperparathyroidism: cause of persistent or recurrent disease in 304 patients.

BACKGROUND: Subtotal parathyroidectomy (SPTX) and total parathyroidectomy with autotransplantation (TPTX and AT) are standard procedures in the treatment of renal autonomous hyperparathyroidism. In contrast to primary hyperparathyroidism, the persistence/recurrence rate is reported of up to 12.0%. PATIENTS AND METHODS: Between 1986 and 2000 we operated on 304 patients with renal autonomous hyperparathyroidism including 14 patients who were admitted after a primary operation in an outside hospital. Mean observation period was 51.4+/-38.9 months. RESULTS: The overall persistence/recurrence rate in our patients was 9.0% (26/290). After SPTX, excluding patients with an incomplete operation, it was 3.7%, and after TPTX and AT it was 6.0%. Reasons for developing recurrent or persistent disease in these patients were removal of less than 3.5 glands ( n=12), hyperplastic autograft ( n=5), and supernumerary gland ( n=4). After the first reoperation 7 patients (26.9%) had persistent or recurrent disease. CONCLUSIONS: An incomplete primary operation caused by missed cervical glands was the major reason for persistent ( n=8) or recurrent ( n=4) disease after different operative strategies in renal autonomous hyperparathyroidism.

Adult↗

Is there any consensus in diagnostic and operative strategy with respect to medullary thyroid cancer? A questionnaire answered by 73 endocrine surgical units.

BACKGROUND: The purpose of this investigation was to analyze the individual diagnostic and operative strategy in the treatment of medullary thyroid carcinoma (MTC) in international specialized centers and to assess whether standard procedures are carried out in practice everywhere. METHODS: A questionnaire concerning diagnosis and treatment of patients with primary, persistent, or recurrent sporadic or familial MTC was sent to 263 members of the International Association of Endocrine Surgeons. RESULTS: Primary treatment of MTC does not show significant differences for patients with sporadic or familial disease (Chi-square, n.s.), and standard procedures are performed in only 25-40% of patients. Computed tomography scan is the most common localization procedure in persistent or recurrent disease (52-72%), followed by scintigraphy (43-71%), ultrasonography (41-56%), and magnetic resonance imaging (31-49%). In case of negative localization studies, 68-86% of colleagues do not recommend reoperation. In symptomatic patients with stage-IV tumors, however, 84% of colleagues advocate reoperation to provide relief from the tumor burden. CONCLUSIONS: Even with experienced endocrine surgeons, a consensus to uni- and/or bilateral neck dissection in primary MTC is lacking. The majority of authors supports at least total thyroidectomy with central lymph-node dissection. In recurrent disease, there is a general tendency to reoperate in case of positive localization studies and in case of symptomatic disease.

Carcinoma, Medullary↗

Parathyroid carcinoma: problems in diagnosis and the need for radical surgery even in recurrent disease.

INTRODUCTION: From 1986 to 1999 we operated on 963 patients with primary hyperparathyroidism (pHPT). METHODS AND RESULTS: Parathyroid carcinoma was diagnosed clinically and histologically in four patients (0.4%). In two of these patients diagnosis of parathyroid cancer was delayed by misinterpretation of the histopathology leading to an autotransplantation of malignant parathyroid tissue in one case. In two patients multivisceral surgery was performed: beside thyroidectomy, neck dissection, tracheal wall resection and resection of the muscular layer of the oesophagus one patient received oesophagectomy and gastric transposition and one patient a lung wedge resection. Both patients had a temporary palliation of tumour-associated symptoms after multivisceral surgery. The first patient died 2 years after oesophagectomy and 12 years after primary diagnosis from local tumour recurrence and cachexia. The second patient is living with tumour recurrence presenting a serum calcium level of 4.2 mmol/l (normal range 2.0 to 2.5 mol/l) and multiple brown tumours 2 years after lung resection and 6 years after the primary diagnosis. CONCLUSIONS: We conclude that parathyroid carcinomas, being difficult to diagnose, warrant radical surgery, including multivisceral resection to prolong survival and reduce tumour and hypercalcaemia associated symptoms.

Adolescent↗

Malignant endocrine tumors in patients with MEN 1 disease.

BACKGROUND: In contrast with multiple endocrine neoplasia type 2, malignancies are of minor importance in multiple endocrine neoplasia type 1 (MEN 1) syndrome. METHODS: The data for 42 patients with MEN 1 syndrome were evaluated. Twelve patients (29%) had 1 or more associated malignancies: malignant gastrinoma (1 patient), neuroendocrine tumors of the thymus (2 patients), neuroendocrine tumors of the lung (3 patients), neuroendocrine tumor of the ileum (1 patient), adrenocortical carcinomas (2 patients), and a combination of neuroendocrine tumors of thymus, lung or pancreas (3 patients). RESULTS: Despite suspected MEN 1 syndrome in 7 patients, malignancies were detected late in 4 patients and could not be resected curatively. The survival rates for 5 years and 10 years after operation of the malignant tumor were 66% +/- 14% (SE) and 33% +/- 15% (SE), respectively. CONCLUSIONS: In patients at risk for the MEN 1 syndrome, genetic screening is indispensable. Gene carriers have to be followed up closely with hormone analysis and routine examination of the thorax, pancreas, and adrenal glands to detect malignancies as early as possible.

Adolescent↗

Long-term biochemical results after operative treatment of primary hyperparathyroidism associated with multiple endocrine neoplasia types I and IIa: is a more or less extended operation essential?

OBJECTIVE: To analyse our long term results in patients operated on for primary hyperparathyroidism associated with multiple endocrine neoplasia types I and IIa. DESIGN: Retrospective (data collection) and prospective (follow-up) analysis. SETTING: University hospital, Germany. SUBJECTS: 39 patients with MEN type I-associated and 7 patients with MEN-type-IIa-associated primary hyperparathyroidism. INTERVENTIONS: Subtotal parathyroidectomy (n = 25 with MEN I and 1 with MEN IIa), total parathyroidectomy and autotransplantation (one in each group) and removal of only enlarged glands (13 with MEN type I and 5 with MEN type IIa). MAIN OUTCOME MEASUREMENTS: Recurrence rate of hyperparathyroidism and permanent hypocalcaemia postoperatively. RESULTS: Subtotal parathyroidectomy in patients with MEN type I gave a significantly lower recurrence rate than removal of only enlarged glands (3/25 compared with 3/13, log rank, p = 0.04). Permanent hypocalcaemia developed in 3/25 compared with 3/13, respectively. 2/5 patients with MEN type IIa developed recurrences after removal of only enlarged glands and the rate was higher than expected. CONCLUSIONS: A more extensive operation is essential for patients with MEN type I; the rate of permanent hypocalcaemia is not increased, but the recurrence rate is reduced. Patients with MEN type IIa should be treated by excision of enlarged glands alone, but this may be extended to subtotal parathyroidectomy in patients with severe symptoms.

Adenoma↗

Growth regulation of thyroid and thyroid tumors in humans.

In a study of growth regulation of the human thyroid gland and thyroid tumors we investigated the impact of iodine and that of the thyroid-specific growth-stimulating hormone TSH. Further studies included locally active growth factors such as the epidermal growth factor, insulin-like growth factor, and tissue transforming growth factors alpha and beta. In addition to studies of growth regulation by the various growth factors in mostly normal thyrocytes, the impact of tumor-specific mutations in oncogenes and tumor-suppressor genes was investigated. The results demonstrated distinct changes in tissue specificity and sensitivity to external stimuli. This rather complex view on thyrocyte growth regulation may be confusing, but it describes the biologic reality more precisely. Increased knowledge of the regulatory processes may lead to the development of new tumor- and patient-specific therapeutic approaches, especially for preventing benign goiter recurrence and for treating follicular and papillary thyroid cancers.

Genes, Tumor Suppressor↗

Surgery for Graves' disease: total versus subtotal thyroidectomy-results of a prospective randomized trial.

The effect of surgery on Graves' orbitopathy (GO) is still controversial. Retrospective analyses of many authors (including our own group) demonstrated GO improvement after subtotal thyroid resection in up to 70% of operated patients, so the question arose whether total thyroidectomy could add anything to this pronounced positive effect on GO. We therefore performed a prospective randomized trial on 150 patients with Graves' disease (125 women, 25 men; mean thyroid volume 80.5 ml) comparing three surgical procedures (bilateral subtotal thyroid resection-total remnant < 4 ml; unilateral hemithyroidectomy with contralateral subtotal thyroid resection-remnant < 4 ml; total thyroidectomy) and their effect on postoperative GO changes, postoperative thyroid-stimulating hormone receptor (TSH-R) antibody titers, and postoperative complication rates. After a period of at least 6 months (6-36 months) GO had improved in 71% to 74% of all patients regardless of whether total or subtotal thyroidectomy was performed. TSH-R antibody titers showed no differences for the three surgical groups. Postoperative recurrent hyperthyroidism occurred in two patients with subtotal resections, and early postoperative hypoparathyroidism was more frequently detected in patients with total thyroidectomy than in those with subtotal thyroid resection (28% vs. 12%; p < 0.002). In respect to possible postoperative hypoparathyroidism and a lack of difference in postoperative GO changes, we do not advocate total thyroidectomy for patients with Graves' disease and Graves' orbitopathy but prefer radical subtotal thyroid resection with a remnant of less than 4 ml.

Adolescent↗

Therapeutic experience of 65 cases with organic hyperinsulinism.

INTRODUCTION: The treatment for insulinoma is enucleation or resection, which are associated with various degrees of morbidity, including fistulas, pseudocysts, and necessity for reoperations. PATIENTS: We evaluated the outcome of 65 patients operated on for organic hyperinsulinism at an experienced university hospital (Department of Surgery, Heinrich-Heine University, Düsseldorf, Germany) between 1990 and 1998. Procedures included enucleation (n=37), left-sided resection (n=19), combination of enucleation from the head and left-sided resection (n=4), subtotal left pancreatectomy (n=2), and pancreaticoduodenectomy (n=3). RESULTS: In 47 out of the 65 patients (72%), the expected benign solitary insulinoma was found. Seven patients had malignant tumors and another eight had multiple tumors (including two with multiple endocrine neoplasia type 1 (MEN-1)), and three had nesidioblastosis. In total, 20 patients (31%) developed postoperative drainage of high amylase containing fluid, which in all but three cases resolved with conservative therapy. The three patients who developed fistulas and the three patients who developed pseudocysts underwent reoperative surgery. Seventeen (41%) of the patients who underwent enucleation (10 from the pancreatic head; 50%) and six (25%) of the resected patients demonstrated these complications. Postoperative glucose metabolism was normalized in all patients. CONCLUSION: Resection, especially in the head of the pancreas, demonstrates lower complication rates than enucleation. We propose resection for tumors that are large, malignant, situated close to pancreatic duct, and are multiple, including in MEN-1. For tumors in the head, pancreaticoduodenectomy may be an occasional choice.

Adolescent↗

Surgical treatment of postoperative, incidentally diagnosed small sporadic C-cell carcinomas of the thyroid.

BACKGROUND AND AIMS: The surgical strategy in small sporadic C-cell carcinomas of the thyroid that are incidentally diagnosed after goiter resection for benign disease is controversial. It remains unclear whether a completion thyroidectomy should be performed in every case. PATIENTS AND METHODS: We present nine patients who were operated on between October 1992 and October 1997 in whom an unexpected, small sporadic C-cell carcinoma (seven with pT1, two with pT2) was found in the postoperative histology. RESULTS: All patients were calcitonin negative and there were no signs of the disease being inherited (no familial history, negative RET proto-oncogene). No patient underwent a completion thyroidectomy. All patients had a follow-up with pentagastrin-stimulated calcitonin and carcinoembryonic antigen (CEA) 3 months, 6 months and annually after the operation. No patient became calcitonin positive or showed any other signs of tumor recurrence after a follow-up period of 2-7 years. CONCLUSION: A completion thyroidectomy is not necessary in small sporadic C-cell carcinoma that is incidentally diagnosed after resection for benign disease if there is no sign of familial cancer and if calcitonin is negative. A close follow-up is necessary.

Adult↗

Lack of MEN1 gene mutations in 27 sporadic insulinomas.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant familial cancer syndrome characterized by tumours of the parathyroids, anterior pituitary gland and endocrine pancreas. Since the cloning of the MEN1 gene (encoding menin) on chromosome 11q13 by Chandrasekharappa et al. in 1997, it has become possible to identify mutations that are responsible. We examined whether MEN1 gene mutations are present in sporadic insulinomas, a rare sporadic tumour that is seen more frequently in patients with the MEN 1 syndrome. PATIENTS AND METHODS: We sequenced the coding part of the MEN1 gene (exons 2-10) in tumour tissue of 27 patients suffering from an insulinoma (24 benign, three malignant). To validate our methods we also examined tumour tissue from five patients with primary hyperparathyroidism (HPT) at a younger age and/or multiple gland disease, with increased risk of MEN 1. RESULTS: We found no mutations in the nine coding exons of the MEN1 gene in the insulinoma tissues. We could confirm three benign polymorphisms (S145S, R171Q, D418D) reported previously. In the control patients we found two new point mutations (one mis-sense, one non-sense mutation) and one deletion. CONCLUSION: Mutations of the MEN1 gene do not play an important role in the pathogenesis of sporadic insulinomas. Therefore genetic screening is not cost effective in sporadic insulinoma patients without other indicators of MEN 1. Patients with primary HPT at a younger age and/or multiple gland disease should be screened for MEN1 gene mutations.

Adolescent↗

Sequence analysis of the MEN I gene in two patients with multiple cutaneous lipomas and endocrine tumors.

The discovery of mutations of the menin gene in a few multiple endocrine neoplasma type 1 (MEN I)-associated lipomas and loss of heterozygosity (LOH) on chromosome 11q13 in some sporadic lipomas has stimulated the hypothesis that lipomas may belong to the group of sporadic tumors caused by defects of the gene responsible for MEN I. Since it is unclear if the above hypothesis applies to all patients with lipoma or just to specific subsets, we searched to enlarge the database on this topic. For this purpose, we identified two patients with multiple cutaneous lipomas. One had an additional pituitary adenoma and familial presentation of multiple lipomas, the other had recurrent goiter in the setting of a family history of adenomatous goiter. Deoxyribonucleic acid (DNA) was analyzed by complete direct DNA sequencing of all coding exons and splice junctions of the MEN I gene. No mutation was identified in the coding exons of the menin gene. In contrast to former data on sporadic lipomas, these data are the first to render evidence that mutations of the MEN I gene may not be responsible for the formation of multiple lipomas, even if they appear in the context of other endocrine tumors.

Adenoma↗

Induction of cellular immunity in a parathyroid carcinoma treated with tumor lysate-pulsed dendritic cells.

BACKGROUND: Cytotoxic T-lymphocyte-mediated tumor immunity against major histocompatibility antigen class II-negative tumors requires help from CD4(+) T-cells. The major antigen presenting cells for CD4(+) cell activation are dendritic cells. Studies in mice and humans have demonstrated the potent capacity of these cells to induce specific antitumor immunity. OBJECTIVE: To control the growth of a metastasized parathyroid carcinoma, by immunizing a patient with tumor lysate and parathyroid hormone-pulsed dendritic cells. DESIGN AND METHODS: Mature dendritic cells were generated from peripheral blood monocytes in the presence of granulocyte/macrophage colony-stimulating factor, interleukin-4 and tumor necrosis factor alpha. Antigen-loaded dendritic cells were delivered by subcutaneous and intralymphatical injections. After five cycles, we added keyhole limpet hemocyanin (KLH) as a CD4(+) helper antigen. RESULTS: After 10 vaccinations, a specific cellular immune response to tumor lysate was observed. In vitro T-cell proliferation assays revealed a dose-dependent stimulation index of 1.8-5.7 compared with 0.9-1.1 before vaccination. In vivo immune response was demonstrated by positive delayed-type hypersensitivity toward tumor lysate. Intradermal injection of tumor lysate resulted in an erythema and induration, suggesting the efficient generation of tumor lysate-specific memory T-cells. CONCLUSIONS: These data indicate that dendritic cell vaccination can induce in vitro and in vivo responses in a highly malignant endocrine carcinoma. Regardless of the clinical outcome of our patient, this approach might be generally applicable to other advanced, radio- and chemotherapy-resistant endocrine malignancies, such as adrenal carcinomas and metastasized medullary and anaplastic thyroid carcinomas.

CD4-Positive T-Lymphocytes↗

Studies of oncogenes and tumor-suppressor genes in human thyroid carcinomas, and their clinical implications.

INTRODUCTION AND DISCUSSION: Molecular genetic investigations relating to thyroid cancer have started to gain clinical importance, with discovery of the tumor-specific oncogenes PTC 1-3 in papillary thyroid cancer and the syndrome-specific mutations of the RET protooncogene in MEN-2a, MEN-2b and familial MTC patients. Furthermore, the thyroid-specific sodium-iodine symporter, causing iodine accumulation in thyroid tissue, has been cloned and now offers studies to enhance iodine and radioiodine uptake in thyroid cancer, which could soon prove to be clinically applicable.

Carcinogens↗

[Laparoscopy in abdominal trauma].

Laparoscopy is very useful in penetrating abdominal trauma, in particular to exclude intraabdominal lesions in stab wounds. In blunt abdominal trauma laparoscopy is not the first choice of diagnostic means though it warrants comparable good results to CTscan and ultrasound. Invasiveness, high costs, and time consuming procedure require a critical and specific application making it suitable especially in unclear clinical situations and equivocal diagnostic findings. Without doubt laparoscopy is only useful in hemodynamically stable patients and is of secondary value in polytraumatized patients. In the future it has to be thought about laparoscopy in local anesthesia and in bedside procedure e.g. on the intensive care unit. Laparoscopy should be regarded as an integral part of diagnostic spectrum in blunt abdominal trauma.

Abdominal Injuries↗

Genetic and biochemical screening for endocrine disease.

The development of biochemical and genetic screening tests for inherited endocrine diseases has dramatically changed our approach to surgical patients with endocrine tumors. Among more than 1800 patients with endocrine tumors and a possible inherited disease operated on between 1986 and 1997, there were 6.1% to 7.3% who were found to have a familial disease associated with familial medullary thyroid cancer, (MTC), multiple endocrine neoplasia type IIa (MEN-IIa), MEN-IIb, or MEN-I. Genetic testing for the RET proto-oncogene is therefore recommended for all patients with MTC, and testing for the MEN-I gene is recommended in patients with suspected MEN-I and in specific clinical subgroups with an increased probability of endocrine tumor heredity. Early treatment based on early diagnosis by genetic testing appears to improve survival and to decrease morbidity in these patients.

Biomarkers↗

Point mutations of the human parathyroid calcium receptor gene are not responsible for non-suppressible renal hyperparathyroidism.

The calcium-dependent secretion of parathyroid hormone (PTH) is mediated through an extracellular G protein-coupled calcium receptor (CaR). Inactivating point mutations of this receptor have been found in familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism. These diseases feature a decreased calcium sensitivity of the parathyroid glands, resulting in a rightward shift of the Ca2(+)-PTH relationship. Severe non-suppressible renal hyperparathyroidism (rHPT) is often characterized by similar setpoint shifts to the right. Thus, point mutations of the CaR gene could contribute to non-suppressible rHPT. We examined genomic DNA of hyperplastic or mainly nodular tissues of 39 parathyroids from 25 rHPT-patients with resistance to calcitriol therapy. Amplification of the six exons of the CaR gene was followed by single-strand conformation polymorphism (SSCP) analysis. DNA sequencing was performed where band shifts were observed. No point mutations in the coding sequence of the CaR gene were detected using the PCR-SSCP strategy. Point mutations in the coding regions of the CaR gene probably play no role in the evolution of renal HPT and are not responsible for the calcitriol resistance of PTH secretion.

Adolescent↗

[Geographical differences of thyroid carcinoma and basic molecular principles].

Geographical differences have been demonstrated for the cancer incidence and histology of differentiated thyroid cancer. Iodine intake and specific external noxes, such as nitrosamine ingestion or external radiation are important factors. It is still questionable whether histologically identical differentiated thyroid cancers are prognostically different in low and rich iodine areas. Despite increased knowledge of molecular and genetic changes in differentiated cancer, the present therapy is primarily related to patient age, tumor stage and histology.

Cell Transformation, Neoplastic↗