Expression of thyroid hormone receptor isoform alpha1 in pancreatic islets.

Thyroid hormone receptors (TR) mediate the action of thyroid hormones. Genetic studies revealed that the individual TR isoforms possess different functions. In the present paper we studied the expression of the isoforms TRalpha1 and TRbeta1 in the murine pancreatic islet. TRalpha1 and TRbeta1 mRNA transcripts and proteins were detected in islets using reverse transcription-polymerase chain reaction and Western blotting analyses, respectively. In immunohistochemical studies individual cells in the periphery of islets were labelled using an anti-TRalpha1 antibody. No labelled cells were detected in the exocrine pancreas. A similar staining pattern was obtained with an anti-glucagon antibody, but not with an anti-insulin antibody, which suggests that TRalpha1 is mainly expressed in alpha-cells. In order to address a potential function of TRalpha1 in this cell type, the regulation of glucagon gene expression by triiodothyronine was studied in a glucagon-producing cell line by Northern blot analysis and transient transfection assays using glucagon promoter luciferase fusion gene constructs. In these assays, triiodothyronine did not regulate the glucagon mRNA level or the glucagon promoter activity. The predominant localization of TRalpha1 in pancreatic alpha-cells suggests that this receptor isoform mediates a specific, yet unknown, function of thyroid hormones in this cell type.

Thermoplastic stents: a new concept for endoluminal prosthesis.

BACKGROUND AND STUDY AIMS: Intraluminal stenting of organs with stenoses or fistulae in anatomically difficult locations (for instance cardia, pylorus, large bowel), with a tendency to kinking or increased motility, still carries a high risk of stent dislocation. In the search for a solution, we report on the use of a new thermoplastic stent in animal experiments. MATERIAL AND METHODS: The new stent consists of a plastic-coated wire mesh which can be heated electrically. Once it is warmed up to 55 C, its size and shape can be changed. After being expanded by a dilatation balloon across the stenosed area, the stent can be fitted onto the inner organ surface. This guarantees a low dislocation risk and high stability. In an animal experiment, stents were endoscopically placed in the trachea and the surgically stenosed esophagus of two dogs. The animals were observed for 3 months. RESULTS: The thermostents were implanted easily and without complications. It was possible to mold the thermostent evenly onto the intraluminal wall. No stent dislocation, bleeding or perforation was observed. Upon histologic evaluation, granulation tissue was found to be growing through the wire mesh of the stent. CONCLUSION: It was shown that the stent described here can be implanted without major problems. The greater effort of the implantation procedure, in comparison with self-expanding stents, is compensated by the special mechanical characteristics of the stent. These characteristics may permit implantation in anatomically difficult locations where up to now stenting has been impossible or inadequate.

Congenital nasal hemangiopericytoma: intrauterine, intraoperative, and histologic findings.

Hemangiopericytoma is a rare tumor of mesenchymal origin. To date, 91 cases of nasal or paranasal hemangiopericytoma and 59 congenital hemangiopericytomas have been reported in the literature. A congenital hemangiopericytoma arising from the nasal cavity and skull base has not yet been described. We report a case of a male newborn with a highly vascular nasal tumor diagnosed by in utero sonography with three-dimensional surface reconstruction. The tumor extended to the right anterior skull base, the right nasal cavity, and the right side of the nasal pyramid. A complete resection by neodymium:yttrium-aluminum-garnet-potassium titanyl phosphate ("Nd:YAG-KTP") laser was performed on the day of cesarean section at 33 weeks' gestation. The tumor was diagnosed as hemangiopericytoma by histologic and immunohistochemical findings. Postoperative nasal flow, feeding, and sight were unimpaired. At the 9-month follow-up, the infant remained free of disease.

Ultrafast magnetic resonance imaging improves the staging of pancreatic tumors.

OBJECTIVE: This prospective study was undertaken to evaluate the accuracy of a noninvasive "all-in-one" staging method in predicting surgical resectability in patients with pancreatic or periampullary tumors. SUMMARY BACKGROUND DATA: Despite progress in imaging techniques, accurate staging and correct prediction of resectability remains one of the chief problems in the management of pancreatic tumors. Staging algorithms designed to separate operable from inoperable patients to save the latter an unnecessary laparotomy are becoming increasingly complex, expensive, time-consuming, invasive, and not without risks for the patient. METHODS: Between August 1996 and February 1997, 58 consecutive patients referred for operation of a pancreatic or periampullary tumor were examined clinically and by 5 staging methods: 1) percutaneous ultrasonography (US); 2) ultrafast magnetic resonance imaging (UMRI); 3) dual-phase helical computed tomography (CT); 4) selective visceral angiography; and 5) endoscopic cholangiopancreatography (ERCP). The assessment of resectability by each procedure was verified by surgical exploration and histologic examination. RESULTS: The study comprised 40 male and 18 female patients with a median age of 63 years. Thirty-five lesions were located in the pancreatic head (60%), 11 in the body (19%), and 1 in the tail of the gland (2%); there were 9 tumors of the ampulla (16%) and 2 of the distal common duct (3%). All five staging methods were completed in 36 patients. For reasons ranging from metallic implants to contrast medium allergy or because investigations already had been performed elsewhere, US was completed in 57 (98%), UMRI in 54 (93%), CT in 49 (84%), angiography in 48 (83%), and ERCP in 49 (84%) of these 58 patients. Signs of unresectability found were vascular involvement in 22 (38%), extrapancreatic tumor spread in 16 (26%), liver metastases in 10 (17%), lymph node involvement in 6 (10%), and peritoneal nodules in only 2 patients (3%). These findings were collated with those of surgical exploration in 47 patients (81 %) and percutaneous biopsy in 5 (9%); such invasive verification was deemed unnecessary and therefore unethical in 6 clearly inoperable patients (10%). In assessing the four main signs of unresectability (extrapancreatic tumor spread, liver metastases, lymph node involvement, and vascular invasion), the overall accuracy of UMRI was 95.7%, 93.5%, 80.4%, as compared to 85.1%, 87.2%, 76.6% for US and 74.4%, 87.2%, 69.2% for CT. In assessing vascular invasion, the sensitivity, specificity, and overall accuracy of angiography were 42.9%, 100%, and 68.8%, respectively. There were 3 complications (12.5%) after 24 resections, 5 in 17 palliative procedures, and none after 6 explorations only. The hospital stay was 14 days after resection, 13 after palliative bypass, and 6 after exploration alone. There was no operative or hospital mortality in these 58 cases. CONCLUSIONS: Although it is by no means 100% accurate, UMRI is equal or even superior to all other staging methods. It probably will replace most of these, because it provides an "all-in-one" investigation avoiding endoscopy, vascular cannulation, allergic reactions, and x-radiation. But because even UMRI is not perfect, the final verdict on resectability of a tumor still will depend on surgical exploration in some cases.

[Resection of solitary liver metastases of malignant melanoma]. / Resektion von solitären Lebermetastasen des malignen Melanoms.

Patients with solitary metastasis of melanoma may benefit from resection, although diffuse organ involvement is common. Recent results in immunotherapy of metastatic melanoma are impaired by early local recurrence, leading to consolidation surgery. Two patients with solitary liver metastasis were treated by liver resection. In one patient in January 1993, atypical resection was performed after partial remission induced by regional adoptive immunotherapy with LAK-cells and Interleukin-2. In September 1983 right hemihepatectomy was done in one patient for large metastasis without preceding therapy. Until now there is no evidence of disease in both patients. The metastasis were 14 cm without and 3.5 cm after (5.3 cm before) immunotherapy in diameter. On histologic examination we found only a slight necrosis without marked immunological reaction like mononuclear cell infiltration or fibrotic demarcation in the specimen of the patient without forgoing therapy. In the specimen of the patient after immunotherapy, the metastasis was necrotic. It was encapsulated by fibrous tissue which was infiltrated by lymphoid cells. The microscopic evaluation revealed some clots of vital tumorcells. The resection of solitary liver metastasis of melanoma with or without immunotherapy is recommended. The rational for consolidation surgery for melanoma metastases after successful immunotherapy is based on the histologically proven vital tumor cells in necrotic metastasis, which are responsible for early local recurrence.

[Typical complications of short rib polydactyly syndrome]. / Typische Komplikationen des Kurzripp-Polydaktylie-Syndroms.

Osteochondrodysplasias are hereditary dysfunctions of the enchondral ossification with a decreased longitudinal bone-growth. We describe the case of a female child which suffered from a short rib-polydactyly-syndrome, a localised form of a osteo-chondrodysplasia, and died at the age of nine months as a result of the typical complications of this disease.

[Immunohistochemical and morphometric studies on neuroendocrine differentiation of prostate carcinomas]. / Immunhistochemische und morphometrische Untersuchungen zur neuroendokrinen Differenzierung in Prostatakarzinomen.

102 unselected and untreated prostate carcinomas were immunohistochemically analysed with regard to neuroendocrine (ne) differentiation using a monoclonal antibody against Chromogranin A. Density of ne-tumor cells/mm2 tumor area and arrangement of ne-tumor cells (single cells; small groups and large groups) were determined. We found ne-tumor cells in 90% of all carcinomas (n = 92). 70% had a low density of ne-tumor cells (< or = 1 cell/mm2). 67% of carcinomas with ne-differentiation showed only single ne-tumor cells, there were small groups in 19% and large groups in 14%. There was an association between higher densities of ne-tumor cells and arrangement in groups. In high malignancy carcinomas we found a higher density of ne-tumor cells and more often an arrangement in groups than in low grade tumors. Our results support reports in literature that ne-differentiation is of prognostic significance.

[Struma carcinoid tumor within a dermoid cyst as an incidental finding in cesarean section]. / Strumales Karzinoid innerhalb einer Dermoidzyste als Zufallsbefund bei Sectio caesarea.

A 25-year-old primigravida with breech presentation was admitted near term. During Caesarean section, a dermoid cyst of the right ovary was detected. The dermoid cyst was enucleated, preserving a plum-sized ovary. Histology revealed a strumal carcinoid within the excised dermoid cyst. From the histological point of view it was classified as a tumour of low malignancy. The clinical study provided no evidence of any metastases. On the 14th postoperative day the patient could be discharged from hospital subject to close aftercare control.