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Data on the long-term persistence of HCV resistance-associated substitutions (RASs) after treatment with direct-acting antivirals (DAAs) are limited. This study evaluated the persistence of NS3, NS5A, and NS5B RASs for up to 5 years after the end of treatment (EOT).We included samples from 678 individuals with an HCV genotype (GT) 1 or 3 infection and virologic DAA treatment failure collected in the European Resistance Database. NS3, NS5A, and NS5B were sequenced, and clinical parameters were evaluated.A total of 242 individuals with HCV GT1a (36%), 237 with GT1b (35%), and 199 (29%) with GT3 and a DAA failure were included. After protease inhibitor failure, the frequencies of NS3 RASs were 40-90% after the EOT. NS3 RASs disappeared rapidly in GT1b and GT3 after follow-up month 3 but were stable (≥60%) in GT1a owing to Q80K. The SOF-resistant NS5B RAS S282T was only found in individuals with GT3a. Non-nucleoside NS5B RASs were frequent in GT1 (56-80%) and decreased to 30% in GT1a but persisted in GT1b. NS5A RASs were very common in all GTs after NS5A inhibitor failure (88-95%), and even after follow-up month 24, their frequency was 65% and higher. However, RASs in GT1b had a stable course, whereas RASs in GT1a and GT3 declined slightly after follow-up month 24 (GT1a, 68%; GT1b, 95%; and GT3, 65%), mainly because of the slow decline of high-level resistant Y93H.We found that low-to medium-level RASs persisted, whereas high-level resistant RASs disappeared over time. Different patterns of RAS persistence according to HCV subtype could have implications for retreatment with first-generation DAAs and for global HCV elimination goals.There are little data on the long-term persistence of HCV resistance-associated substitutions (RASs) after DAA treatment failure, and RASs could have an impact on the efficacy of a rescue treatment. Especially in countries with limited availability of VOX/VEL/SOF or G/P/SOF, different patterns of RAS persistence could have implications for retreatment with first-generation DAAs and for global HCV elimination goals. The different patterns of RAS persistence identified in this study can be used to derive general rules regarding the persistence of RASs after DAA failure that could be applied by physicians in less developed countries to plan individualized HCV retreatment.

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.8 However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Background & Aims Little is known about substitutions that mediate resistance of hepatitis C virus (HCV) to direct-acting antivirals (DAAs), due to the small number of patients with treatment failure in approval studies. It is important to identify resistance patterns to select effective salvage treatments. Methods We performed a comprehensive analysis for resistance-associated substitutions (RASs) in HCV genes (nonstructural protein [NS]3, NS5A, NS5B) targeted by DAAs. We compared NS3, NS5A, and NS5B sequences from 626 patients in Europe with DAA failure with sequences from 2322 DAA-naive patients, infected with HCV genotypes 1 to 4. We considered RASs to be relevant if they were associated with DAA failure in patients or conferred a greater than twofold change in susceptibility compared with a reference strain in in vitro replicon assays. Data were collected on pretreatment status, DAA regimen, the treatment initiation date and duration, and virologic response. Patients who received at least 4 weeks of antiviral treatment were included in the analysis. Results RASs in NS3 associated with simeprevir or paritaprevir failure include R155K and D168E/V. In addition, several RASs were specifically associated with failure of simeprevir (Q80K/R in patients with genotype 1a or 4) or paritaprevir (Y56H in combination with D168V in patients with genotype 1b). Y93H in NS5A was the RAS most frequently associated with failure of daclatasvir, ledipasvir, or ombitasvir in patients with genotype 1b infection, and L31M was associated with failure of daclatasvir or ledipasvir, but not ombitasvir. RASs in NS5A were heterogeneous among patients with HCV genotype 1a or genotype 4 infections. In patients with HCV genotype 3, Y93H was associated with resistance to daclatasvir, but no RASs were associated with ledipasvir failure, pointing to a limited efficacy of ledipasvir in patients with genotype 3. Among patients failed by sofosbuvir-containing regimens, L159F was enriched in patients with genotype 1b (together with C316N) or genotype 3 infection, whereas the RAS S282T was rarely observed. Conclusions We compared RASs in NS3, NS5A, and NS5B among patients failed by DAA therapy. Theses varied with the HCV genotype and subtype, and the different drug classes. These findings might be used to select salvage therapies.

Activated factor X (FXa) and thrombin can up-regulate gene expression of connective tissue growth factor (CTGF/CCN2) on fibroblasts. Since tissue factor (TF) is expressed on these cells, we hypothesized that they may assemble the prothrombinase complex leading to CTGF/CCN2 upregulation. In addition, the effect of thrombospondin-1 (TSP1) on this reaction was evaluated. Human foreskin fibroblasts were incubated with purified factor VII (FVII), factor X (FX), factor V (FV), prothrombin and calcium in the presence and absence of TSP1. Generation of FXa and of thrombin were assessed using chromogenic substrates. SMAD pathway phosphorylation was detected via Western-blot analysis. Pre-incubation of fibroblasts with FVII led to its auto-activation by cell-surface expressed TF, which in turn in the presence of FX, FVa, prothrombin and calcium led to FXa (9.7 ± 0.8 nM) and thrombin (7.9 ± 0.04 U/mL × 10–3) generation. Addition of TSP1 significantly enhanced thrombin (23.3 ± 0.7 U/mL × 10–3) but not FXa (8.5 ± 0.6 nM) generation. FXa and thrombin generation leads to upregulation of CTGF/CCN2. TSP1 alone upregulated CTGF/CCN2, an effect mediated via activation of transforming growth factor beta (TGFβ) as shown by phosphorylation of the SMAD pathway, an event blunted by using a TGFβ receptor I inhibitor (TGFβRI). FXa- and thrombin-induced upregulation of CTGF/CCN2 was not blocked by TGFβRI. In summary, assembly of the prothrombinase complex occurs on fibroblast's surface leading to serine proteases generation, an event enhanced by TSP1 and associated with CTGF/CCN2 upregulation. These mechanisms may play an important role in human diseases associated with fibrosis.

Manufacturing systems with main and side loops that employ asynchronous, track-based workpiece holder transport with decentralised control generally allow arbitrarily small distances between workpiece holders, so that their state space is partly continuous. The considered systems show complex inter-arrival time distributions that can reduce system capacity when multiple routes share common tracks. This paper presents an analytical approach to modelling this inter-arrival time behaviour that distinguishes between different zones in parameter space by associating each zone with one specific queueing situation. For each queueing situation, a recursively defined sequence is set up that represents the inter-arrival times of workpiece holders. Two of these sequences yield inherently different types of turbulence that form characteristic patterns in phase diagrams. The emergence of these patterns is validated using a deterministic discrete-event simulation of an assembly system. A synchronisation methodology is ...

Automated manufacturing systems commonly employ track-bound work piece transport mechanisms and work piece holders. In the systems considered, the track layout comprises one main loop and multiple side loops, following common industrial practice. As soon as work piece holders simultaneously traverse common tracks on multiple routes, e.g. because the main loop serves as a buffer, such manufacturing systems normally show complex, aperiodic inter-arrival times, which may affect performance. A synchronisation method is presented that limits the number of different inter-arrival times and controls the length of inter-arrival time periods without requiring extensive mathematical modelling. It is applied to a simplified model of a manufacturing system, for which allowable parameter tolerances are derived and validated with simulation. Since these tolerances are very narrow, synchronised operation requires continuous control of inter-arrival times. The applicability of the proposed approach is also demonstrated f...

Thrombospondin-1 (TSP1/THBS1) plays a major role in the pathophysiology of rheumatoid arthritis (RA); however, its interface with the cytokine network involved in RA has not been delineated. Correlations were performed between plasma levels of TSP1 and selected cytokines from blood samples collected from 20 patients affected by RA and 13 healthy donors (control). Plasma levels of TSP1 and tissue growth factor beta (TGFbeta) were determined by standard enzyme-linked immunosorbent assay, and cytokines were measured by protein profiling rolling-circle amplification (RCA). TSP1 circulating levels in plasma were found significantly increased in the RA patients when compared with control individuals (P = 0.039). The plasma levels of TGFbeta were also increased in the RA patients, which indicates a statistical trend. Cytokine levels of interleukin (IL)-4, IL-5, IL-12, chemokine CXC 10 (CXCL10/IP10), and chemokine CC 4 (CCL4)/MIP1beta were significantly increased in the RA patients when compared with the control group. In summary, this study demonstrates increased plasma levels of TSP1, which correlated with increased levels of proinflammatory cytokines in plasma of RA patients. More detailed research is required to explore the cytokine imprint yielded by this study and its interface with TSP1 and TGFbeta.

The paradigm of hybrid automatic/manual assembly systems has recently been extended by reconfigurable systems that allow exchanging manual and automated production modules with minimum interruption of the system control and operation. However, both types of assembly systems exhibit different interarrival time patterns for layouts that employ asynchronous workpiece transport on tracks with multiple routes and loops. In this work, it has been shown analytically that for Gaussian processing time distributions the queue length follows heavy-tailed unimodal and bimodal distributions. Based on the resulting outlier probability, an analytical model for predicting the limits of allowable processing time variance for deterministic interarrival time models is proposed. This model is positively validated with simulation analysis by comparing different levels of processing time variance. It is concluded that established design practices such as cycle-time balancing and synchronization should be avoided in reconfigurable hybrid assembly system design because they introduce interarrival-time turbulence in the automated system.

Introduction Thrombospondin 1 (TSP1) has the ability to bind to HL-60 cells and to reversibly inhibit human neutrophil elastase (HNE). Human factor V (FV) can be cleaved by HNE thereby providing FV with cofactor activity (FVa HNE ). Experiments were performed to evaluate the ability of HNE expressed on the surface of HL-60 cells to generate FVa HNE to support thrombin generation, and to determine the effect of TSP1 on this reaction. Results Western blot analysis showed TSP1 forming a complex with FVa HNE within a region corresponding to the heavy chain of FV. Enzymatic reactions were performed to determine the role of TSP1–HNE–FVa HNE on the surface of HL-60 cells, namely the assembly of the prothrombinase complex. Thrombin generation was measured by the chromogenic substrate S2238. Exposure of factor V to HL-60 cells prior to the addition of prothrombin and activated factor X provided FV with cofactor activity. HL-60 cells were found capable of synthesizing factor V with cofactor activity, but HL-60 cells failed to synthesize and/or to provide factor X with enzymatic activity. The ability of HL-60 cells to synthesize FV and TSP1 was demonstrated. The addition of exogenous TSP1 enhanced both the rate and amount of thrombin generated on the HL-60 cell surface. Conclusion Despite the ability of TSP1 to reversibly inhibit HNE in a purified system, TSP1 expression favors the reactions leading to thrombin generation on the HL-60 cell surface. These observations are relevant to clinical conditions where there is a prothrombotic state such as malignant tumors.

SummaryPlatelets contain two cAMP phosphodiesterases (PDEs) which regulate intracellular cAMP levels, cGMP-inhibited cAMP PDE (PDE3A) and cGMP-stimulated PDE (PDE2A). Using the PDE3 inhibitor, milrinone and the PDE2 inhibitor, erythro-9-(2-hydroxyl-3-nonyl)adenine (EHNA), we have explored the contribution of each PDE to the regulation of platelet function. Inhibition of PDE2 resulted in higher levels of intracellular cAMP than inhibition of PDE3A suggesting this PDE may be the more important regulator of cAMP in human platelets. However, a concentration-dependent inhibition of agonist-induced aggregation was observed with milrinone while little effect was seen with EHNA. In addition, we observed a concentration-dependent inhibition in the increase of intracellular Ca2+ with PDE3 inhibition and significantly less with PDE2 inhibition. PDE3 inhibition also resulted in a concentration-dependent increase in cAMP-mediated phosphorylation of the vasodilator-stimulated phospho-protein (VASP) whereas there was no significant increase with PDE2 inhibition. In each of these experiments, synergism was noted with the combination of milrinone and EHNA. These results suggest that cAMP pools may be localized and the various PDEs regulate specific pools. These data also suggest that inhibitors of PDE3A may be more effective antiplatelet agents.

The thrombospondin-1 (TSP1) structural requirements within its heparin-binding domain (HBD)(30 kd) or within the other domains of the molecule (450 kd) that interact with neutrophils (PMNs) have not been delineated. Synthetic peptides based on the HBD, a TSP1 proteolytic fragment lacking the HBD, a large C-terminal domain of TSP1 (210 kd), a TSP1 recombinant fragment (rTSP1 784-932 ), and a monoclonal antibody directed against the TSP1 type 3 repeats (mAb D4.6) were utilized to map such structural requirements on TSP1. Synthetic peptides containing a heparin-binding motif and encompassing residues F16-G33 or A74-S95 of TSP1 competed quantitatively with iodine 125–labeled TSP1 for binding to heparin-agarose beads. However, only F16-G33 was a competitor of TSP1 binding to PMNs, suggesting that the sequence F16-G33 within the HBD plays a role in PMN binding. The interaction site within the 450-kd fragment was further narrowed. A TSP1-derived proteolytic fragment (210 kd), a recombinant TSP1 fragment (rTSP1 784-932 ), and a type 3 repeat anti-TSP1 monoclonal antibody (mAb D4.6) competed for the binding of 125 I-labeled TSP1 to PMNs. The N-terminal of rTSP1 784-932 and C-terminal sequence analysis of TSP1–210 kd delineated the structural requirements for the second binding region for PMNs—namely, residues A784-N823. (J Lab Clin Med 2000;136:292-302)

This study evaluated the application of ultrasound (US) guidance in the percutaneous placement of gastric feeding tubes in patients in whom endoscopic placement of a nutrition tube is not possible.Thirty-eight patients with upper gastrointestinal obstruction were entered in a prospective study with US-guided nutrition tube application. Feasibility of placement, side effects, and nutritional states were monitored for a mean follow-up of 4 months.Ultrasound allowed rapid puncture after filling of the stomach with water through a nasal tube in 34/38 cases. In four cases a total upper gastrointestinal obstruction required an initial stomach insufflation through a direct puncture. Puncture-related major complications were not observed. Minor complications during the observation time were one late dislocation, five cases with broken material after about 6 months (four could be changed by using the Seldinger technique), and two minor local infections. The nutrition through feeding tubes stabilized body weight and body composition parameters.The percutaneous sonographic gastrostomy (PSG) is a safe and minimally invasive procedure for enteral nutrition in all cases with upper gastrointestinal obstruction when endoscopic placement of a feeding tube is not possible. Percutaneous sonographic gastrostomy may help to stabilize the nutritional parameters and general condition in patients with malignant diseases.

With the approval of boceprevir and telaprevir the standard treatment of chronic hepatitis C virus (HCV) genotype 1 infection will be the triple therapy of a HCV protease inhibitor together with pegylated interferon alfa and ribavirin. In clinical studies a significant increase of sustained virological response rates from 38 - 44 % to 63 - 75 % for treatment-naïve and from 17 - 21 % to 59 - 66 % in treatment-experienced patients in comparison to the dual combination therapy with pegylated interferon alfa and ribavirin alone has been demonstrated. In addition, a large number of treatment-naïve patients and relapsers benefit from shorten treatment durations to 24 - 28 weeks. However, important differences exist between the administration of boceprevir and telaprevir in terms of a pegylated interferon alfa/ribavirin lead-in phase, the duration of dosing of the protease inhibitor, the overall treatment duration, HCV RNA measurements for response guided treatment durations and stopping rules. Furthermore, triple therapies with boceprevir and telaprevir may be associated with selection of resistant viral variants, new adverse events and clinically relevant drug-drug interactions. The present review gives an overview on the results of underlying clinical studies together with a guideline for the practical management of boceprevir- and telaprevir-based triple therapies.

Electrophoresis is a method by which a complex mixture of proteins can be separated. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is a technique used to move charged molecules through a gel matrix by means of an electric current. This procedure is used to determine protein subunit composition, verify homogeneity of the protein sample, and purify proteins for use in other applications. The migration rate of the proteins during SDS-PAGE is determined by the pore size of the gel matrix and charge, size, and shape of the protein. In this unit, the protocol covers the casting of gels, preparation of the protein samples, staining and drying of the gels, and calculation of molecular mass of the proteins based on electrophoretic mobility. Curr. Protoc. Microbiol. 22:A.3M.1-A.3M.13. © 2011 by John Wiley & Sons, Inc. Keywords: protein; electrophoresis; separation; SDS-PAGE; polyacrylamide

Objective: To evaluate the effect of a thrombospondin 1 (TSP1)-derived peptide on inflammation and angiogenesis in an animal model of erosive arthritis and to assess the relationship between TSP1 and connective tissue growth factor (CTGF) in the pathophysiology of rheumatoid arthritis. Methods: Erosive arthritis in Lewis rats was induced by peptidoglycan-polysaccharide (PG-PS). Animals were divided into four groups: (1) negative control and groups receiving, (2) no treatment, (3) treatment with a TSP1-derived peptide, and (4) treatment with a scrambled peptide. Samples obtained from ankle joint, spleen and liver were studied using histology, histomorphometry, immunohistochemistry and RT-PCR. Results: Histological data indicated that the TSP1-derived peptide treatment decreased neovascularization, leukocyte infiltration and thickening of the synovial lining of the joint, and reduced granuloma formation in the spleen and liver when compared to control groups. Higher concentrations of CTGF and TSP1 proteins were observed in the affected areas of animals which did not receive TSP1-derived peptide treatment. Also, immunofluorescence and RT-PCR analyses showed an increase in CTGF protein expression and regulation, respectively, in the tissues of untreated animals when compared to the TSP1-derived peptide treated animals. By immunofluorescence, TSP1 expression was decreased in the TSP1-derived peptide treated animals. Moreover, macrophage/monocyte-specific staining revealed a decrease in cell infiltration in the articular tissue of the TSP1-derived peptide treated animals. Conclusion: Both inflammation and angiogenesis were decreased after TSP1-derived peptide treatment indicating a potential pathway by which TSP1 interaction with neutrophils induces CTGF in RA affected tissues. J. Cell. Physiol. 211: 504–512, 2007. © 2007 Wiley-Liss, Inc.

Objective Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with leukocyte adhesion to and extravasation through vascular endothelium into synovial tissue. Recent evidence indicates that the thrombospondin 1 gene is up-regulated in patients with RA. We have identified a region within the TSP-1 type 3 repeats that inhibits human neutrophil elastase (HNE) and binds to human neutrophils. The present study was undertaken to investigate the therapeutic benefit of this TSP-1-derived peptide sequence and its effect on connective tissue growth factor (CTGF), a protein involved in fibrotic disorders and in neovascularization, which is a hallmark of RA. Methods CTGF gene and protein expression, as well as protein levels of CTGF in the synovium, after treatment with the TSP-1-derived peptide were studied in the peptidoglycan-polysaccharide animal model of erosive arthritis. Results Peptide treatment prevented joint infiltration and inflammation and was associated with reduced circulating antigen levels of HNE and TSP-1. Additionally, CTGF was up-regulated in this experimental model of RA. Treatment with the TSP-1-derived peptide was associated with down-regulation of the message and protein levels of CTGF. Immunofluorescence studies showed that the mean area fraction of CTGF immunoreactivity in the peptide-treated group of animals was significantly less than that in the untreated group. Conclusion These results document a role for TSP-1 in regulating CTGF gene and protein expression in synovial tissue, suggesting a link with the disease course in this model of RA. This TSP-1-derived synthetic peptide may represent an important template for drug development in RA and other inflammatory conditions associated with neutrophil activation.

Ultrasound education improves by simulator training, however, the acceptance of ultrasound simulator training has not been investigated. Therefore we evaluated the participants response to simulator education during an ultrasound course of abdominal emergencies at an international ultrasound congress, at a regular ultrasound course and during courses at a regional hospital and an university hospital. Altogether, 62.3% of the participants judged the simulator image quality to be good. 84.3% considered the case selection to be good and 92.7% of the participants viewed the educational benefit to be good. 98.5% whished to have further ultrasound simulator courses to be developed and 95.3% of the participants opted for the integration of simulator training into the conventional ultrasound education.

Platelet-rich plasma (PRP) harbors growth factors identified in bone. It has been suggested that these factors enhance osteogenesis. The objective of this study was to conduct a radiographic evaluation on local bone formation following surgical implantation of a PRP preparation using a critical-size rat calvaria defect model.Thirty 22-week-old male Sprague-Dawley rats were used. The PRP preparation was obtained from 10 ml of whole blood drawn from one age-matched donor rat. The preparation was processed by gradient density centrifugation and stored at -80 degrees C until use. Using aseptic techniques, the PRP preparation soak-loaded onto an absorbable collagen sponge (ACS) carrier or ACS alone was surgically implanted into contralateral critical-size 6 mm rat calvaria osteotomies in 18 animals. Twelve animals received ACS alone versus sham surgery in contralateral defects. Animals were sacrificed at 4 and 8 weeks when biopsies were collected and radiographs were obtained using a standardized protocol. Three masked examiners independently evaluated the radiographic images of the defect sites. Examiner reproducibility was examined by repeat evaluation of all defect sites (r=0.6; P0.0001).The animals were maintained without adverse events. Defect sites in two animals receiving ACS versus sham surgery (4-week healing interval) were not evaluated due to specimen damage. Seventy-five percent of the sites (PRP/ACS or ACS) exhibited partial closure at 4 weeks; one site (ACS) exhibited full closure without significant differences between protocols (P=0.1797). Fifty percent of the sites receiving PRP/ACS exhibited full closure and 20% partial closure at 8 weeks versus 20% and 80%, respectively, for the ACS control (P=0.7532). There were no noteworthy differences between sites receiving ACS versus sham surgery at 4 or 8 weeks.The results suggest that the PRP preparation does not have a significant effect on osteogenesis.

Ultrasound education is complicated by varying quantities and qualities of specific pathologies resulting from distinct patient collectives. Furthermore, under current clinical conditions ultrasound educators as well as trainees frequently lack the time necessary for a sufficient ultrasound education. Finally, current ultrasound education materials including "gold standard" images are not ideally suited for teaching scanning three-dimensional pathologies. An improvement of ultrasound education is feasible by training ultrasound trainees on an ultrasound simulator we developed. By using this simulator as well in the classical beginner and advanced level courses as in focused courses of abdominal emergencies or general practice for instance, ultrasound trainees are able to practice scanning of numerous well defined pathologies under realistic conditions.

Ultrasound is one of the most important imaging methods in medicine. However, ultrasound education is complicated by varying quantities and qualities of specific pathologies resulting from distinct patient collectives. Furthermore, under current clinical conditions ultrasound educators as well as trainees frequently lack the time necessary for a sufficient ultrasound education. Finally, current ultrasound education materials including "gold standard" images are not ideally suited for teaching scanning three-dimensional pathologies. In a direct cross over study we recently proved, that the ultrasound simulator we developed simulated the real patient examination reliably and reproducibly. By using this simulator as well in the classical beginner and advanced level courses as in focused courses of abdominal emergencies for instance, ultrasound trainees are able to practice scanning of well defined pathologies under realistic conditions, which has not been possible before. Furthermore, the ultrasound simulator is well suited for a structured ultrasound training in single hospitals as well as in continuous medical education. Finally, objective, standardized ultrasound quality control has become possible with the simulator.

Ultrasound is an important tool in the diagnosis of acute abdominal pain, which is mainly caused by gastrointestinal diseases. This article gives an overview on the important differential diagnosis related to pain localization. Sonomorphological signs and their sensitivity and specificity are discussed. In contrast to other imaging methods ultrasound is hand guided. The present article differentiates the diagnostic capability of ultrasonic diagnosis depending on technical equipment and sonographer's educational level. These facts are important to stabilize the position of ultrasound in the ensemble of other imaging methods. The use of mobile ultrasound machines and an improved training (e.g. by computer assisted sonosimulator systems) will lead to an increasing importance of ultrasound.

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The avian isthmic nuclei are constituted by a group of structures reciprocally connected with the tectum opticum and considered to play a role in the modulation of intratectal processes. Although the two larger isthmic nuclei, the n. isthmi pars parvocellularis (Ipc) and the n. isthmi pars magnocellularis (Imc), have been studied in detail previously, the third and smallest of this group, the n. isthmi pars semilunaris (SLu), has been largely neglected. The present study demonstrates this isthmic component to be characterized by a unique connectivity and immunohistochemical pattern: 1) SLu receives tectal afferents and projects back onto the outer retinorecipient tectal layers; 2) it projects bilaterally onto the nucleus rotundus and thus modulates the ascending tectofugal system; 3) in addition, previous studies have demonstrated SLu projections onto the lateral spiriform nucleus (SpL), which mediates basal ganglia output onto the tectum. In that SpL projects onto the deep layers of the tectum, SLu indirectly modulates descending tectal output patterns. Taken together, the role of SLu goes far beyond a local modulation of intratectal processes. Instead, this isthmic structure is likely to play a key role in the topographically organized modulation of the ascending and, at least indirectly, also the descending projections of the optic tectum.

This study was undertaken in order to assess the main features of hepatocellular carcinoma in Germany, a country with low incidences of this tumor.Two hundred and eighty consecutive patients with hepatocellular carcinomas admitted to the Medical School Hannover between 1993-1997 were retrospectively studied.Reliable data for the assessment of the etiology and the tumor stage of HCC were available for 268 patients. The female/male ratio was 1/4. In 51.9% of the patients, HCC was associated with hepatitis virus B or C (HBV, HCV) infection: 35.1% with HBV, 26.9%) with HCV and 10% coinfection with HBV/HCV This result emphasizes the major impact of HBV and HCV infection in liver cancer in Germany. Of all patients with HCC 74.6%) had liver cirrhosis. The predominant majority of the HCC (87%) were restricted to the liver: in only 5.9% could regional lymph node metastases as well as 8.5%) metastases in other organs be clinically diagnosed by chest X-ray, computed tomography scan or sonography. Data to asses the Okuda tumor stage were available for 166 patients: 47% were classified as stage I, 47% as stage II and only 6% as stage III. Serum AFP were determined in 195 patients. In 66% of the patients, the AFP value was elevated, but only in 30% did the AFP level reach the value of 500 microg/l, which is considered to be significant for HCC diagnosis in patients with liver cirrhosis. The proportion of liver cirrhosis was higher in HCV (97.8%) versus HBV (80.6%) associated HCC, which was the only significant (p0.05) difference in the characteristics of HCC according to the etiology.Our study shows that liver cirrhosis is the prime risk factor for hepatocarcinogenesis in Germany. However, the very high proportion of hepatitis virus related HCC, in particular the high proportion of HBV infections, contradicts the common view that alcohol is by far the most important etiological factor for hepatocarcinogenesis in low hepatitis virus endemic areas such as Germany.