The NA49 detector is a wide acceptance spectrometer for the study of hadron production in p+p, p+A, and A+A collisions at the CERN SPS. The main components are 4 large-volume TPCs for tracking and particle identification via dE/dx. TOF scintillator arrays complement particle identification. Calorimeters for transverse energy determination and triggering, a detector for centrality selection in p+A collisions, and beam definition detectors complete the set-up. A description of all detector components is given with emphasis on new technical realizations. Performance and operational experience are discussed in particular with respect to the high track density environment of central Pb+Pb collisions.

Highly integrated readout electronics were developed and produced for the 182 000 channels of the four TPCs of the NA49 heavy-ion fixed target experiment at the CERN SPS. The large number of channels, the high packing density and required cost minimization led to the choice of a custom electronics system. The requirements, the design and the performance of the electronics components are described.

Präoperative diagnostische Methoden haben eine unterschiedliche Aussagekraft bezüglich einer zu erwartenden Malignität von Schilddrüsenknoten. Die klinische Untersuchung ist sehr zuverlässig, wenn ein Karzinom schon zur Organüberschreitung bzw. Infiltration umgebender Halsstrukturen geführt hat. Bezüglich der Frühdiagnose oder der Aussage eines Karzinomverdachtes ist sie vielfach nutzlos [6].

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. The cell composition of cell suspensions from spleen and both transplant types showed a deficiency of T, B, MHC-I+ cells and a certain macrophage subset (ED-3+ cells) in transplants. In a quantitative immunohistological analysis of compartments (red pulp, periarteriolar lymphoid sheaths, marginal zone and follicles) the T cell reduction was related to the Tsupp/cyt cells and T cell receptor bearing cells in the periarteriolar lymphoid sheaths, whereas the density of T helper cells was normal. In addition, a different homing of kappa-light chain positive and leukocyte common antigen (B cell type)-positive B cells in follicles and marginal zone was detected. The amount of two macrophage subsets (ED-1+ and ED-2+ cells) was increased in the red pulp. Only minor differences in the immunoarchitecture of transplants at different implantation sites were measured. A functional analysis of spleen compared to both transplant groups elicited a B cell defect after LPS stimulation in subcutaneous transplants and a reduced allogeneic response of both transplant types but a normal proliferation of T cells after ConA stimulation and a correct IgM antibody response against sheep red blood cells. The in vivo mRNA expression and the expression kinetics of interferon-gamma and granulocyte-macrophage colony-stimulating factor after antigen stimulation differed in both transplant groups with a remarkable permanent expression of both mediators in subcutaneous transplants. It can be summarized that the results clearly indicate a development of spleen-like immunoarchitecture of intraomental replants with subtle cellular, functional and molecular alterations. In contrast, despite a comparable development, some severe functional defects occurred in subcutaneous implants pointing out the important role of interactions between the regenerating splenic tissue and the target tissue on a functional and molecular level.

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. In 159 (= 97.6%) sides of the neck out of 163 we identified the nerve at the typical site. The topographical relation of the recurrent nerve to the inferior thyroid artery revealed the following differences for the right and left side of the neck: On the right side the nerve was found to be behind in 48%, in front in 33% and between the branches of the artery in 15% of cases. In contrast, on the left side the nerve was found to be dorsal in 53%, ventral in 23% and between the branches in 23%. Of 163 nerves at risk we observed primary nerve palsy in 2 cases (1.2%), and a definitive palsy rate of 0.6% at the 3-month follow-up. In conclusion, we recommend the described approach for the identification of the recurrent laryngeal nerve during thyroid surgery whenever complete mobilisation of the thyroid lobe (e.g. thyroidectomy, lobectomy, resection of retro-tracheal adenomas) is necessary.

The ability of splenic tissue to regenerate after avascular transplantation at different target tissues is well documented but the capacity of splenic transplants to compensate the loss of spleen and the influence of the implantation site on the functional development of replants are still discussed contradictory, because little is known about specific functions of the transplants. Therefore, we investigated splenic implants in rats at different states of development and in different target tissues (intraomental and subcutaneous implantation site).

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. Liver function tests, especially bilirubin, were not suitable parameters for the detection of biliary obstruction (preoperative value 0.38 +/- 0.09 mg/dl; 1 week after subtotal stenosis 3.36 +/- 1.53 mg/dl; 2 weeks after subtotal stenosis 1.49 +/- 0.62 mg/dl; 3 weeks after subtotal stenosis 0.50 +/- 0.27 mg/dl; 6 weeks after pericardial patch plastic 0.33 +/- 0.05 mg/dl, x +/- SD. Ultrasonographic measurement of the common bile duct diameter was the diagnostic method of choice. Preoperative dimension 4.5 +/- 0.5 mm; 1 week after subtotal stenosis 8.5 +/- 2.0 mm; 2 weeks after subtotal stenosis 10.5 +/- 1.8 mm; 3 weeks after subtotal stenosis 14.0 +/- 3.6 mm; 6 weeks afer pericardial patch plastic 9.0 +/- 1.6 mm, x +/- SD.

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. In 159 (= 97.6%) sides of the neck out of 163 we identified the nerve at the typical site. The topographical relation of the recurrent nerve to the inferior thyroid artery revealed the following differences for the right and left side of the neck: On the right side the nerve was found to be behind in 48%, in front in 33% and between the branches of the artery in 15% of cases. In contrast, on the left side the nerve was found to be dorsal in 53%, ventral in 23% and between the branches in 23%. Of 163 nerves at risk we observed primary nerve palsy in 2 cases (1.2%), and a definitive palsy rate of 0.6% at the 3-month follow-up. In conclusion, we recommend the described approach for the identification of the recurrent laryngeal nerve during thyroid surgery whenever complete mobilisation of the thyroid lobe (e.g. thyroidectomy, lobectomy, resection of retrotracheal adenomas) is necessary.

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. The mortality rate in the 43 patients with infected pancreas necrosis amounted to 16.2% (n = 7); none of the patients with sterile necrosis died. In cases of multiple organ failure the mortality rate was significantly higher (30%) than with failure of only one organ system (4.3%). The mortality rate in all cases with pancreas necrosis (n = 73) amounted therefore to 9.5%. Serious complications of laparostomy occurred in 28% (n = 12) of the 43 patients, whereby 8 of these cases were gastrointestinal fistulae, with a fatal outcome in one patient. The overall mortality rate in the total group of 284 patients with acute pancreatitis was 2.8%.

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. Transplant groups differed from spleen only in the reduced size of PALS; however, quantitative analysis demonstrated subtle differences between spleen and transplants. The cell density of B-cells and ED-1+ macrophages was reduced in the RP, Tsupp/cyt-cells were decreased and B-cells increased in PALS, and B-cells and Thelper-cells reduced in the MZ. No differences could be detected between the transplant groups. Flow-cytometric analysis of cell suspensions from spleen and transplants revealed a reduction of T-cells (OX-19+), MHC-I and transferrin-receptor-bearing cells in both transplant groups, and a decrease in the number of Thelper-cells and ED-3+ macrophages in subcutaneous transplants. Both transplant groups were defective regarding the allogeneic and pokeweed mitogen response. Aberration of the lipopolysaccharide response was restricted to subcutaneous transplants, which additionally showed abnormal expression of interferon-gamma, interleukin-5 and interleukin-6 mRNA. Thus, subtle alterations of the newly developed microenvironment and/or lymphocyte-homing may influence the regeneration of splenic tissue; the implantation site may represent an important parameter in functional reorganisation.

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. All patients received adjunct medication of 10 mg/kg body weight chenodeoxycholic and ursodeoxycholic acid 14 days prior to ESWL as a single bedtime dose. An average number of 5,300 +/- 2,200 shock waves (1,200-15,000) was applied for stone disintegration. The corresponding energy amounted to 750 bar. 29 patients needed one, 21 two or more treatments. After ESWL a variety of clinical abnormalities was observed: flank pain (15%), transient microhaematuria (33%) and transient macrohaematuria (2%). Subsequent to ESWL 5 patients suffered from complications such as biliary obstruction 3 weeks to 9 months after treatment and had to undergo ERCP. Three times endoscopic papillotomy was performed to remove stones from the common bile duct. Up to now 4 patients have undergone cholecystectomy: acute cholecystitis (n = 3), recurrent colicky pain (n = 1). 20 patients have been followed up over a 12-month period; 12 of them are completely free of stones and fragments.

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. The mortality rate in the 43 patients with infected pancreas necrosis amounted to 16.2% (n = 7); none of the patients with sterile necrosis died. In cases of multiple organ failure the mortality rate was significantly higher (30%) than with failure of only one organ system (4.3%). The mortality rate in all cases with pancreas necrosis (n = 73) amounted therefore to 9.5%. Serious complications of laparostomy occurred in 28% (n = 12) of the 43 patients, whereby 8 of these cases were gastrointestinal fistulae, with a fatal outcome in one patient. The overall mortality rate in the total group of 284 patients with acute pancreatitis was 2.8%.

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 extra-corporeal 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. All patients received adjunct medication of 10 mg/kg body weight chenodeoxycolic and ursodeoxycolic acid 14 days prior to ESWL as a single bedtime dose. An average number of 5,300 +/- 2,200 shock waves (1,200-15,000) was applied for stone disintegration. The corresponding energy amounted to 750 bar. 29 patients needed one, 21 two or more treatments. After ESWL a variety of clinical abnormalities was observed: flank pain (15%), transient microhaematuria (33%) and transient macrohaematuria (2%). Subsequent to ESWL 5 patients suffered from complications such as biliary obstruction 3 weeks to 9 months after treatment and had to undergo ERCP. Three times endoscopic papillotomy was performed to remove stones from the common bile duct. Up to now 4 patients have undergone cholecystectomy: acute cholecystitis (n = 3), recurrent colicky pain (n = 1). 20 patients have been followed up over a 12-month period; 12 of them are completely free of stones and fragments.

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. Significant differences between the implantation sites were restricted to CD5+ cells (thymocytes and T cells) in the MZ and OX-33+ cells (B cells with LCAB antigen) in the PALS. The reorganisation of the compartments of subcutaneous implants showed a delay of one week as compared with omental ones. Functional assays like haemolytic plaque assay, mitogen stimulation and mixed lymphocyte assay elicited an analogous delay of the functional maturation of IgM-positive B cells, a reduced proliferation of both transplant groups after pokeweed mitogen (PWM) stimulation, a decreased response after lipopolysaccharide (LPS) stimulation in solely subcutaneous replants and no differences concerning the mitogens concanavalin A (ConA) and phytohaemagglutinin (PHA). Both transplant groups showed a significantly reduced allogeneic response. The results of the functional analysis and the abnormal mRNA expression of Il-5, Il-6 (Interleukin 5 and 6), GMCSF (Granulocyte-Macrophage-Colony-Stimulation-Factor) and IFN-gamma (Interferon gamma) in subcutaneous replants indicate subtle molecular alterations (independent of a spleen-like immunoarchitecture) at this site.(ABSTRACT TRUNCATED AT 250 WORDS)

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. Significant differences between the implantation sites were restricted to CD5+ cells (thymocytes and T cells) in the MZ and OX-33+ cells (B cells with LCAB antigen) in the PALS. The reorganisation of the compartments of subcutaneous implants showed a delay of one week as compared with omental ones. Functional assays like haemolytic plaque assay, mitogen stimulation and mixed lymphocyte assay elicited an analogous delay of the functional maturation of IgM-positive B cells, a reduced proliferation of both transplant groups after pokeweed mitogen (PWM) stimulation, a decreased response after lipopolysaccharide (LPS) stimulation in solely subcutaneous replants and no differences concerning the mitogens concanavalin A (ConA) and phytohaemagglutinin (PHA). Both transplant groups showed a significantly reduced allogeneic response. The results of the functional analysis and the abnormal mRNA expression of Il-5, Il-6 (Interleukin 5 and 6), GMCSF (Granulocyte-Macrophage-Colony-Stimulation-Factor) and IFN-gamma (Interferon gamma) in subcutaneous replants indicate subtle molecular alterations (independent of a spleen-like immunoarchitecture) at this site. In contrast, the influence of the greater omentum seems to be able to partially compensate for these defects.

We are presently building an array of angle integrating air Cherenkov counters for the study of VHE and UHE cosmic rays. The new array will be sensitive to extended air showers of energies > 5 × 1013 meV and of zenith angles up to 35°. The determination of the incident shower direction will be performed by fast timing measurements with an angular resolution of 0.5–5 mrad. The Cherenkov counters will allow us to obtain information on the shower energy and structure higher up in the atmosphere. The array will be combined with the existing HEGRA scintillation counter matrix on La Palma. The combination of the Cherenkov data and the data from the ground level scintillator matrix will provide a powerful tool for γ/hadron discrimination. We expect to achieve hadron rejection ratios of > 103 when adding the proposed muon detectors, thereby making possible the detection of the diffuse γ radiation presumed to be coming predominantly from the galactic plane.