A true singles list-mode data acquisition system for a small animal PET scanner with independent crystal readout.

We present a unique data acquisition system designed to read out signals from the MADPET-II small animal LSO-APD PET tomograph. The scanner consists of 36 independent detector modules arranged in a dual-radial layer ring (phi 71 mm). Each module contains a 4 x 8 array of optically isolated, 2 x 2 mm LSO crystals, coupled one-to-one to a 32 channel APD.

A prototype high-resolution animal positron tomograph with avalanche photodiode arrays and LSO crystals.

To fully utilize positron emission tomography (PET) as a non-invasive tool for tissue characterization, dedicated instrumentation is being developed which is specially suited for imaging mice and rats. Semiconductor detectors, such as avalanche photodiodes (APDs), may offer an alternative to photomultiplier tubes for the readout of scintillation crystals. Since the scintillation characteristics of lutetium oxyorthosilicate (LSO) are well matched to APDs, the combination of LSO and APDs seems favourable, and the goal of this study was to build a positron tomograph with LSO-APD modules to prove the feasibility of such an approach.

Regeneration of autotransplanted splenic tissue at different implantation sites.

Inbred animals (Lewis rats) were used to investigate the regeneration of autologously implanted splenic tissue at intra-omental and subcutaneous sites. Quantitative immunohistology with monoclonal antibodies against lymphocytes and macrophages was performed to analyse the cell density of red pulp (RP), periarteriolar lymphoid sheath (PALS), marginal zone (MZ) and follicle, 7-180 days after transplantation. Antigenic, allogeneic and mitogenic stimulation and Northern blotting were also performed.

Immunoarchitecture and specific functions of splenic autotransplants at different implantation sites.

The present study deals with the morphological and functional development of intraomentally and subcutaneously implanted splenic tissue. Spleens and splenic transplants from 138 Lewis rats were investigated with immunohistological, immunological and molecular biological methods at different times after operation (up to 200 days postoperatively). The analysis of the development revealed a nonsignificant reduction concerning the weight of subcutaneous replants and a nonsignificant decrease of the weight of female transplants of both groups at different phases after operation.

[Autotransplantation of the spleen in rats: development, function and cytokine expression in intra-omental and subcutaneous regeneration].

The implantation of splenic tissue at different implantation sites (intraomental and subcutaneous) into one animal (Lewis rats) results in the development of splenic nodules at both sites. In a quantitative immunohistological analysis of splenic compartments such as red pulp (RP), periarteriolar lymphoid sheaths (PALS), marginal zone (MZ) and follicles (F) the T-cell reduction was related to the T(helper) cells in the MZ and T(supp/cyt) cells in the PALS. In contrast, the cell density of B cells and ED-1+ macrophages in the PALS and T(supp/cyt) cells in the MZ was increased.

[Reconstruction-plasty of iatrogenic choledochal stenoses using human pericardium. An experimental study in the domestic pig].

The effect of human pericardial patch plastic for reconstruction of iatrogenic common bile duct stenosis was investigated in experiments performed in pigs. All patches (n = 8) were overgrown with immature biliary epithelium detectable on light and electron microscopy within 6 weeks. No restenosis nor any fistula developed during this observation period.

[Extracorporeal shock wave treatment of calcium containing gallbladder calculi].

A total of 50 patients--37 female and 13 male--with an average age of 50 +/- 27 years (23-86 years), suffering from rim-calcified gallbladder stones, underwent extracorporeal shock-wave lithotripsy (ESWL), using an ultrasound-guided overhead module of Lithostar Plus (Siemens Company). The total number of stones was 87, with an average diameter of 16 +/- 7 (7-38) mm. 29 patients had a solitary stone, 13 had two and 8 patients three or more stones.

[A combined endoscopic surgical treatment concept in acute biliary pancreatitis].

This paper presents the results of a combined endoscopic-surgical approach with management of acute biliary pancreatitis in 91 patients. The diagnosis was always made by means of endoscopic-retrograde cholangiography. Papillary or bile duct stones, or unmistakable signs of previous stone passage, and in exceptional cases flow obstruction due to preiampullary diverticuli were considered criteria for a positive diagnosis.

[Laparoastoma (open packing) in the treatment concept of infected pancreatic necroses].

Out of 284 patients with acute pancreatitis 73 (26%) had pancreas necrosis. Of these 73 cases 43 patients with infected pancreas necrosis were treated surgically, whereas conservative treatment proved successful in the remaining 30 cases with so-called sterile necrosis. Our interdisciplinary treatment combined delayed surgery for the better demarcation of the necrotic tissue, with extended intensive care therapy and epigastral laparostomy; through this laparostomy surgical revision with necrosectomy and peritoneal lavage was performed daily for 15 (+/- 6) days, necessitating long-term artificial respiration for an average of 15 (4/168) days.

[Technique of recurrent laryngeal nerve exposure within the scope of interventions of the thyroid gland].

In anatomical preparations performed during autopsy we developed a well-defined approach for the identification of the recurrent laryngeal nerve during surgery on the thyroid gland. The principle of this concept is to visualize the nerve near the branching of the inferior thyroid artery, where it shows a 30 degree angle to the trachea in a direction running from caudal lateral to cranial medial and lies in front of, behind, or between the branches of the artery. This preparation mode has been prospectively performed in 100 patients undergoing thyroid surgery.

[Value of preoperative fine needle puncture cytology in the diagnosis of highly malignant thyroid tumors].

Highly malignant thyroid tumours are frequently diagnosed only at an advanced stage where radical resection is no longer feasible. By the wide application of fine needle aspiration biopsy as a diagnostic tool in nodular thyroid diseases occasionally early stages of these tumours can be diagnosed. Despite early detection in 23% of our patients with anaplastic carcinomas and sarcomas of the thyroid gland and subsequent radical resection an improvement in the long-term outcome was not achieved.

[Therapy of suspicious fine needle puncture from nodular struma with reference to thyroid function and morphology].

A suspicious preoperative cytology (= class "III") may be the result of various disorders of the thyroid presenting with cell atypia. For example hyperthyroidism or thyroiditis can show a cytological aspect, mimicing a differentiated carcinoma. Our study, comprising 231 patients with cytology "III" revealed a low malignancy rate (1%) in cases of concurrent hyperthyroidism or thyreoiditis.

Immunocytochemical localization of estrogen and progesterone receptors in human thyroid.

The presence of steroid hormone receptors has previously been suggested in thyroid tissue by biochemical means. Our studies were designed to confirm these results and to localize the specific receptor-containing cell type using a novel immunocytochemical method. Monoclonal antibodies specific to estrogen receptors (ER) and progesterone receptors (PgR) were used to localize these steroid hormone receptors in the human thyroid gland.

Alteration of proliferation and subtle changes of protein synthesis in autologous transplanted spleens.

In the case of massive splenic rupture, heterotopic autologous transplantation of splenic tissue into the omentum majus may be used to restore splenic function. Yet little is known about specific functions of the transplants compared to the normal spleen. The goal of this study was to get more information about immunologic functions and protein expression in splenic transplants.

The role of serotonin in the canine secretory response to cholera toxin in vivo.

This study was initiated to evaluate the role of serotonin in cholera toxin-induced jejunal secretion of water and electrolytes. Chronic Thiry-Vella loops, constructed in six dogs, were perfused with an isosmotic neutral perfusate containing [14C]polyethylene glycol as the recovery marker. Fluxes of water, sodium, chloride and potassium were calculated and immunoreactive serotonin levels were measured in blood and effluent perfusates.

Emergency endoscopy: a basis for therapeutic decisions in the treatment of severe gastroduodenal bleeding.

This prospective study compares 3 different consecutive treatment protocols of gastroduodenal hemorrhage. Three hundred sixty-one patients underwent emergency endoscopy as the basis for further treatment. Clinical and endoscopic findings, such as site and type of the bleeding source, bleeding activity and intensity, age, and concomitant diseases of the patient were scored between 0 and 6 points, the higher number indicating a higher risk.

Hyperthyroidism and concurrent thyroid malignancies.

In a 17-year period 1848 patients with hyperthyroidism were operated on. Fourteen (0.76%) had a coexisting thyroid malignancy.

Incidence of septic and thromboembolic-related deaths after splenectomy in adults.

In a review of 37,012 autopsies over the last 20 years 202 deceased adults who had had a splenectomy were investigated. The incidence of infections and thromboembolic complications related to death in these patients was compared with that of a matched deceased population (n = 403) who had not undergone splenectomy. Death-related pneumonia was diagnosed frequently in the splenectomy group and to a lesser extent in the control group (57.

Selective ERCP and preoperative stone removal in bile duct surgery.

This project was undertaken to evaluate in a prospective fashion the effects of selective preoperative endoscopic-retrograde cholangiography and stone extraction (ERCP-ST EXTR) on the results of biliary tract surgery. Over a 6-year period, 728 patients with primary or secondary biliary tract disease were admitted to the First Surgical Department, landeskrankenanstalten, Salzburg, Austria. If, based on preoperative screening, the possibility of common bile duct stones (CBDS) existed, the patients were subjected to ERCP-ST EXTR.

[Current aspects of prevention of struma recurrence].

Prevention of struma recurrence is a major aspect in postoperative management, following struma surgery. Prophylaxis is based on substitution of L-thyroxine, depending on TSH levels. The latter should be somewhere between 0.

[Can the rate of recurrent laryngeal nerve paralysis be reduced by a modified surgical technic in struma surgery?].

The surgical technique used in thyroidectomy is of decisive importance for the rate of recurrent nerve injury. The latter was reduced from 4.9 to 2.