Molecular signatures that can be transferred across different omics platforms.

MOTIVATION: Molecular signatures for treatment recommendations are well researched. Still it is challenging to apply them to data generated by different protocols or technical platforms. RESULTS: We analyzed paired data for the same tumors (Burkitt lymphoma, diffuse large B-cell lymphoma) and features that had been generated by different experimental protocols and analytical platforms including the nanoString nCounter and Affymetrix Gene Chip transcriptomics as well as the SWATH and SRM proteomics platforms. A statistical model that assumes independent sample and feature effects accounted for 69-94% of technical variability. We analyzed how variability is propagated through linear signatures possibly affecting predictions and treatment recommendations. Linear signatures with feature weights adding to zero were substantially more robust than unbalanced signatures. They yielded consistent predictions across data from different platforms, both for transcriptomics and proteomics data. Similarly stable were their predictions across data from fresh frozen and matching formalin-fixed paraffin-embedded human tumor tissue. AVAILABILITY AND IMPLEMENTATION: The R-package 'zeroSum' can be downloaded at https://github.com/rehbergT/zeroSum . Complete data and R codes necessary to reproduce all our results can be received from the authors upon request. CONTACT: rainer.spang@ur.de.

Preoperative chemoradiotherapy for esophageal or junctional cancer.

BACKGROUND: The role of neoadjuvant chemoradiotherapy in the treatment of patients with esophageal or esophagogastric-junction cancer is not well established. We compared chemoradiotherapy followed by surgery with surgery alone in this patient population. METHODS: We randomly assigned patients with resectable tumors to receive surgery alone or weekly administration of carboplatin (doses titrated to achieve an area under the curve of 2 mg per milliliter per minute) and paclitaxel (50 mg per square meter of body-surface area) for 5 weeks and concurrent radiotherapy (41.4 Gy in 23 fractions, 5 days per week), followed by surgery. RESULTS: From March 2004 through December 2008, we enrolled 368 patients, 366 of whom were included in the analysis: 275 (75%) had adenocarcinoma, 84 (23%) had squamous-cell carcinoma, and 7 (2%) had large-cell undifferentiated carcinoma. Of the 366 patients, 178 were randomly assigned to chemoradiotherapy followed by surgery, and 188 to surgery alone. The most common major hematologic toxic effects in the chemoradiotherapy-surgery group were leukopenia (6%) and neutropenia (2%); the most common major nonhematologic toxic effects were anorexia (5%) and fatigue (3%). Complete resection with no tumor within 1 mm of the resection margins (R0) was achieved in 92% of patients in the chemoradiotherapy-surgery group versus 69% in the surgery group (P<0.001). A pathological complete response was achieved in 47 of 161 patients (29%) who underwent resection after chemoradiotherapy. Postoperative complications were similar in the two treatment groups, and in-hospital mortality was 4% in both. Median overall survival was 49.4 months in the chemoradiotherapy-surgery group versus 24.0 months in the surgery group. Overall survival was significantly better in the chemoradiotherapy-surgery group (hazard ratio, 0.657; 95% confidence interval, 0.495 to 0.871; P=0.003). CONCLUSIONS: Preoperative chemoradiotherapy improved survival among patients with potentially curable esophageal or esophagogastric-junction cancer. The regimen was associated with acceptable adverse-event rates. (Funded by the Dutch Cancer Foundation [KWF Kankerbestrijding]; Netherlands Trial Register number, NTR487.).

Strong reduction of AGO2 expression in melanoma and cellular consequences.

BACKGROUND: Processing of microRNAs (miRNAs) is a highly controlled process. Deregulation of miRNA expression was observed in several types of cancer but changes in the miRNA-processing enzymes have not been analysed until today. In this study, we analysed Argonaute2 (AGO2, EIF2C2), as one main factor of the miRNA processing ensemble, in the context of cancer development, especially in melanoma. METHODS: We determined the AGO2 expression level in melanoma, as well as in other cancers, with biochemical approaches (qRT-PCR, western blot and immunofluorescence studies) and analysed the cell behaviour in migration assays. RESULTS: Specifically in melanoma, we revealed a strong reduction of AGO2 expression compared with primary melanocytes. The reduction of AGO2 expression was only found on protein level, whereas the mRNA level stayed unchanged hinting to post-transcriptional regulation. We could show that re-expression of AGO2 in melanoma leads to a strong improvement of regulatory effects due to increased functionality of small-interfering RNAs and short hairpin RNAs. CONCLUSION: We identified melanoma-specific downregulation of AGO2 and corresponding reduced RNAi efficiency. These findings will help to understand the molecular basis of malignant melanoma and can potentially lead to an improvement of therapeutic strategies.

[Metal ion concentrations in patients with metal-metal bearings in prostheses]. / Metallkonzentrationen bei Patienten mit Metall-Metall-Gleitpaarungs-Prothese.

Increased wear leads to elevated systemic and local metal ion concentrations for patients treated with metal-on-metal bearings. The local metal ion content in the close environment of the joint replacement (e.g. joint aspirate or tissue) is several times higher compared to the systemic metal content (e.g. in blood or serum). As a result of increased metal ion levels, local and systemic effects, such as osteolysis, pseudotumors, sensitization or in rare cases toxicity may occur. Although the definition of a specific threshold to define clinical problems is difficult due to a lack of sensitivity, the systemic metal concentration is frequently measured clinically. Currently a threshold for cobalt and chromium between 4 µg/l and 7 µg/l is under debate. Very high levels (≥ 20 µg/l) or a steady increase over time should be a warning sign; however, metal ion levels should not be interpreted as a single diagnostic tool but rather in the entire context of the clinical, radiological and cross-sectional imaging, metal artefact reduction sequence (MARS) magnetic resonance imaging (MRI), ultrasound and computed tomography (CT) findings.

[Principles of tribological analysis of endoprostheses]. / Grundlagen zur tribologischen Analyse von Endoprothesen.

For the tribological characterization of artificial joints, various experimental methods are currently available. However, the in vitro test conditions applied are only comparable in a limited way and transferability to the in vivo situation is also restricted. This is due to the different wear simulation concepts used and partly insufficient simulation of clinical worst case situations. In the present paper current scientific methods and procedures for tribological testing of artificial joints are presented. In addition, the biological effects of wear products are described enabling clinicians to challenge tribological studies and to facilitate specific interpretation of scientific results taking the clinical situation into account.

[The collaboration between dentists and dental hygienists: from paradox to resolution]. / De samenwerking tussen tandartsen en mondhygiënisten: van paradox naar oplossing.

The occupation of dental hygienist has changed since the introduction of vertical task redistribution. However, this change has not yet resulted in an optimal collaboration between dentists and dental hygienists. Four typical characteristics of vertical task redistribution are considered to be influentialfactors with respect to collaboration and the acceptance of vertical task redistribution: the transition from a hierarchical work relation to a more functional work relation, educational level as related to competence and social status, the relation between vertical task redistribution and professional identity and the perceived usefulness of interprofessional collaboration and task redistribution. Implications for educational development are based on scientific literature and are illustrated by an example from the dental curriculum in the Dutch city of Groningen. Even though interprofessional collaboration does not seem to be optimal at the present time, there are insights that suggest ways of improving interprofessional collaboration between dentists and dental hygienists. However, more clues are needed. In particular, the paradox between professional identity and interprofessional collaboration has not yet received much scientific attention.

Incidence of bactobilia increases over time after endoscopic sphincterotomy.

Patients with choledochocystolithiasis are usually treated by endoscopic retrograde cholangiography with endoscopic sphincterotomy (ES) followed by laparoscopic cholecystectomy (LC). LC after ES is more difficult than in uncomplicated gallstone disease, possibly due to bacterial colonization of the common bile duct. The goal of this study was to evaluate if bactobilia influences the peri- and postoperative outcomes. Data were obtained from a randomized trial on the timing of LC after ES. Ninety-six patients were randomized after ES to LC either within 72 h (early LC [ELC]) or in 6-8 weeks (delayed LC [DLC]). In 64 of 96 patients bile samples were obtained peroperatively. The overall prevalence of bactobilia was 62.5% [40/64; 50% of ELC patients (n = 13) vs. 71.1% in the DLC group (n = 27); p = 0.088]. Age and group (i.e. ELC/DLC) were independent and significant predictors for the presence of bactobilia. The presence of bactobilia did not influence operating time and difficulty or conversion rate. Patients with bactobilia developed more biliary events in the period between ES and LC (44 vs. 28%). After ES for choledochocystolithiasis, 62.5% of patients have bactobilia at the time of surgery. The prevalence of bactobilia increases with age and time. Patients with bactobilia tend to develop more biliary-related complications awaiting surgery.

Cardiac tamponade following post-pericardiotomy syndrome.

SUMMARY: Subxyphoid pericardial window (SPW) is performed as both a diagnostic and therapeutic intervention in patients presenting with a penetrating cardiac injury (PCI). Post-pericardiotomy syndrome (PPS) with cardiac tamponade has been reported after penetrating cardiac trauma and after transdiaphragmatic pericardial window. We describe the first PPS with acute tamponade, weeks after diagnostic SPW for a PCI.

Progress on the development of human in vitro dendritic cell based assays for assessment of the sensitizing potential of a compound.

Allergic contact dermatitis is the result of an adaptive immune response of the skin to direct exposure to an allergen. Since many chemicals are also allergens, European regulations require strict screening of all ingredients in consumer products. Until recently, identifying a potential allergen has completely relied on animal testing (e.g.: Local Lymph Node Assay). In addition to the ethical problems, both the 7th Amendment to the Cosmetics Directive and REACH have stimulated the development of alternative tests for the assessment of potential sensitizers. This review is aimed at summarising the progress on cell based assays, in particular dendritic cell based assays, being developed as animal alternatives. Primary cells (CD34(+) derived dendritic cells, monocyte derived dendritic cells) as well as dendritic cell-like cell lines (THP-1, U-937, MUTZ-3, KG-1, HL-60, and K562) are extensively described along with biomarkers such as cell surface markers, cytokines, chemokines and kinases. From this review, it can be concluded that no single cell based assay nor single marker is yet able to distinguish all sensitizers from non-sensitizers in a test panel of chemicals, nor is it possible to rank the sensitizing potential of the test chemicals. This suggests that sensitivity and specificity may be increased by a tiered assay approach. Only a limited number of genomic and proteomic studies have been completed until now. Such studies have the potential to identify novel biomarkers for inclusion in future assay development. Although progress is promising, this review suggests that it may be difficult to meet the up and coming European regulatory deadlines.

Perturbation of human endothelial cells by thrombin or PMA changes the reactivity of their extracellular matrix towards platelets.

In this study we have examined the influence of perturbation of endothelial cells on the amounts of fibronectin and von Willebrand factor in their extracellular matrix and the consequences of a changed composition of the matrix on platelet adhesion. For this purpose, we have used an in vitro perfusion system with which we can investigate the interactions of platelets in flowing blood with cultured endothelial cells and their extracellular matrix (Sakariassen, K. S., P. A. M. M. Aarts, P. G. de Groot, W. P. M. Houdgk, and J. J. Sixma, 1983, J. Lab. Clin Med. 102:522-535). Treatment of endothelial cells with 0.1-1.0 U/ml thrombin for 2 h increased the reactivity of the extracellular matrix, isolated after the thrombin treatment, towards platelets by approximately 50%. The increased reactivity did not depend on de novo protein synthesis but was inhibited by 3-deazaadenosine, an inhibitor of phospholipid methylation, which also inhibits the stimulus-induced instantaneous release of von Willebrand factor from endothelial cells. However, no changes in the amounts of von Willebrand factor and fibronectin in the matrix were detected. Thrombin may change the organization of the matrix proteins, not the composition. When endothelial cells were perturbed with the phorbol ester PMA or thrombin for 3 d, the adhesion of platelets to the extracellular matrix of treated cells was strongly impaired. This impairment coincided with a decrease in the amounts of von Willebrand factor and fibronectin present in the matrix. These results indicate that, after perturbation, endothelial cells regulate the composition of their matrix, and that this regulation has consequences for the adhesion of platelets.

[Seven means of measuring fear of treatment: reliability and convergent validity]. / Zeven instrumenten voor het meten van behandelangst. Betrouwbaarheid en convergente validiteit.

Fear of dental treatment sometimes already begins during childhood. Different kinds of diagnostic instruments can measure children's dental anxiety. In this study the reliability and convergent validity of 7 instruments are compared. Results show that there is no 'gold standard' with which convergent validity can be established unambiguously. Furthermore, self report measures are investigated more often than observational measures even though the latter are more commonly used. Generally, the compared measures are satisfactory in respect to their reliability. Nevertheless, sufficient interest coherence is sometimes lacking. This could be explained by the multidimensional character of the construct 'fear' and, in some cases, the type of measuring-method. In almost none of the compared studies were norms defined prior to the study by means of which statistical indicators could be unambiguously interpreted. In the present study, such norms were established.

[Familial schwannomatosis, a new entity distinct from neurofibromatosis type 1 and 2]. / Familiaire schwannomatose, een nieuwe entiteit te onderscheiden van neurofibromatose 1 en 2.

A Dutch family was diagnosed with familial schwannomatosis, a disorder that is distinct from neurofibromatosis (NF) type 1 and 2. The proband and 4 relatives had schwannomas on spinal roots, cranial nerves, plexuses, and peripheral nerves; no vestibular schwannomas were found. One of the affected relatives was later diagnosed with intracerebral glioma; schwannomas were not found. None of the living affected relatives had genomic defects affecting the NF2 gene. Large deletions in the proximal region of chromosome 22 were found in all resected schwannomas. Schwannomatosis can occur sporadically or be inherited. Pain is often the clinical manifestation of schwannomas. Resection should be reserved for tumours that are symptomatic or threaten to cause spinal cord compression.

Comparison of secretion and subcellular localization of von Willebrand protein with that of thrombospondin and fibronectin in cultured human vascular endothelial cells.

Cultured human vascular endothelial cells synthesize von Willebrand protein, thrombospondin and fibronectin. These proteins are secreted in the culture medium and incorporated into the extracellular matrix. We have compared the subcellular localization and the secretion of these proteins in response to stimulants in cultured human umbilical vein endothelial cells. Density gradient centrifugation using colloidal silica showed that the storage and secretion organelle with von Willebrand protein did not contain thrombospondin or fibronectin. Indirect immunofluorescence microscopy indicated that thrombospondin and fibronectin are not located in the rod-shaped organelles containing von Willebrand protein. Thrombin, ionophore A23187 and phorbol myristate acetate did not affect secretion of thrombospondin and fibronectin, while von Willebrand protein secretion was stimulated upon incubation of cells with these agents for 30 min. Prolonged incubation of cultured endothelial cells after a 1-h treatment with phorbol myristate acetate resulted in an increased secretion of von Willebrand protein into the conditioned medium; in contrast, accumulation of thrombospondin and fibronectin in endothelial cell-conditioned medium was decreased. These findings indicate that, unlike in platelets, these major endothelial proteins are not located in the same subcellular compartments. Von Willebrand protein is distinguished from thrombospondin and fibronectin both by its unique subcellular localization and its secretion rate in response to stimuli.

Polar secretion of von Willebrand factor by endothelial cells.

Human umbilical vein endothelial cells cultured on a collagen lattice were used to study the polarity of von Willebrand factor (vWF) secretion. Endothelial cells cultured under these conditions allow direct measurements of substances released at both the apical and basolateral surface. The constitutive secretion of vWF was compared to the release of vWF from their storage granules after stimulation (regulated secretion). The basal, constitutive release of vWF occurs into both the apical and subendothelial direction. The rate of accumulation of vWF to the subendothelial direction is about three times higher than the amount of vWF secreted into the lumenal medium per unit of time. However, upon stimulation of confluent endothelial cell monolayers with phorbol myristate acetate, endothelial cells predominantly secrete vWF at the lumenal surface. Under these conditions, vWF does not accumulate in the collagen matrix. Thus, endothelial cells are able to organize themselves into a polarized monolayer, in such a way that vWF secreted by the regulated pathway accumulates at the lumenal site, whereas resting endothelial cells release vWF predominantly at the opposite, basolateral surface.

Isolation of a storage and secretory organelle containing Von Willebrand protein from cultured human endothelial cells.

Von Willebrand protein was synthesized and secreted by human endothelial cells in culture. Ca2+ ionophore A23187 and phorbol myristate acetate stimulated the release of Von Willebrand protein from the cultured cells. Stimulated release was accompanied by the disappearance of rod-like structures from the cultured endothelial cells immunostained for Von Willebrand protein, suggesting the existence of a storage organelle for Von Willebrand protein in these cells (Loesberg, C., Gonsalves, M.D., Zandbergen, J., Willems, C., Van Aken, W.G., Stel, H.V., Van Mourik, J.A. and De Groot, P.G. (1983) Biochim. Biophys. Acta 763, 160-168). Cultured human endothelial cells were fractionated on a density gradient of colloidal silica. Von Willebrand protein was found in two organelle populations: a buoyant one sedimenting with a variety of cell organelle marker enzymes, including those of the Golgi apparatus, mitochondria, lysosomes, peroxisomes, endoplasmic reticulum and plasma membrane fragments (peak density of this fraction: 1.08 g X ml-1), and a dense one with a peak density of 1.12 g X ml-1. The dense organelles containing Von Willebrand protein were apparently free of other organelles. Stimulating Von Willebrand protein release with phorbol myristate acetate or Ca2+ ionophore A23187 resulted in a decrease or even complete disappearance of Von Willebrand protein from the high-density organelle fraction, implying a role of this organelle in the stimulus-induced release of Von Willebrand protein. The Von Willebrand protein content of the buoyant fraction was lowered to some extent or did not change upon incubation of the cells with ionophore A23187 and phorbol myristate acetate. Restoration of Von Willebrand protein content of the dense organelle fraction after stimulation occurred within 2 days; this was accompanied by recurrence of immunostaining of rod-shaped structures in cells and an increase in cellular Von Willebrand protein. The excretion of restored Von Willebrand protein could be stimulated again.

[Palliative treatment of esophageal cancer with dysphagia: more favourable outcome from single-dose internal brachytherapy than from the placement of a self-expanding stent; a multicenter randomised study]. / Palliatieve behandeling voor slokdarmkanker met passageklachten: gunstiger uitkomsten van eenmalige inwendige brachytherapie dan van plaatsing van een zelfexpanderende stent; multicentrisch, gerandomiseerd onderzoek.

OBJECTIVE: To compare the results of single-dose internal irradiation (brachytherapy) and self-expanding metal stent placement in the palliation of oesophageal obstruction due to cancer of the oesophagus. DESIGN: Randomised trial. METHOD: In the period from December 1999-Jun 2002, 209 patients with dysphagia due to inoperable carcinoma of the oesophagus were randomised to placement of an Ultraflex stent (n = 108) or single-dose (12 Gy) brachytherapy (n = 101). Primary outcome was relief of dysphagia; secondary outcomes were complications, persistent or recurrent dysphagia, health-related quality of life, and costs. Patients were followed up by monthly home visits from a specialised nurse. RESULTS: Dysphagia improved more rapidly after stent placement than after brachytherapy, but long-term relief of dysphagia was better after brachytherapy. Stent placement resulted in more complications than did brachytherapy (36/108 (33%) versus 21/101 (21%); p = 0.02), due mainly to an increased incidence of late haemorrhage in the stent group (14 versus 5; p = 0.05). The groups did not differ with regard to the incidence of persistent or recurrent dysphagia or median survival (p > 0.20). In the long term, quality-of-life scores were higher in the brachytherapy group. Total medical costs were also similar for both treatments: Euro 8,215 for stent placement and Euro 8,135 for brachytherapy. CONCLUSION: Brachytherapy provided better long-term relief of dysphagia than did stent placement and also produced fewer complications. Brachytherapy is therefore recommended as the preferred treatment for the palliation of dysphagia due to oesophageal cancer.

Review of anal cancer patients at the Ottawa hospital.

BACKGROUND: Anal cancer is uncommon. We reviewed the treatment and outcomes of anal cancer patients in a population referred to the Ottawa Hospital Cancer Centre (TOHCC) over a 12-year period. METHODS: A chart review was conducted with patient data collected from hospital records, including: demographic, treatment and outcome information. Outcomes of interest included: overall survival (OS), disease free survival (DFS), and colostomy free survival (CFS). RESULTS: 180 patients were included in the study population. 72% (n = 130) female and 28% (n = 50) male. 6.7% (n = 12 males) of patients were HIV positive - all were on anti-retroviral therapy. 60% (n = 108) of patients were ever-smokers, mean patient age was 62 [range 35-90] years. The most frequent presenting symptoms were blood per rectum and anal pain. Treatment intent was curative in 87%. Treatment included radiotherapy (94%), brachytherapy (26%), chemotherapy (73%). Among patients treated with curative-intent, 72% had a complete response, 31% had local/regional recurrence, 16% required salvage surgery and 21% had distant recurrence. The colostomy rate was 23%. 5 year overall survival (OS) was not significantly different for patients by HIV status. Survival was superior if MMC-FU was used first vs. CIS-FU; OS HR 0.47 (0.24-0.94), p < 0.033. CONCLUSIONS: The outcomes of patients in this large retrospective cohort study are similar to the outcomes of patients in highly selective clinical trials. Five year overall survival and colostomy free survival are encouraging. MMC-FU was found to be superior to CIS-FU.

[Bearing selection in total hip arthroplasty]. / Wahl der richtigen Gleitpaarung in der Hüftendoprothetik.

Different bearing materials are available in total hip arthroplasty and it's the surgeon who has the choice between hard-on-soft, hard-on-hard and alternative materials. Ideally, the material selection should rely on evidence-based data regarding the wear performance, the incidence of revision surgery and other potential bearing-associated risk factors for the corresponding combinations of materials in the individual patient. While there are high-quality studies available for some materials, adequate data is lacking for other materials. Therefore, the current article aims to provide bearing selection criteria for the surgeon and to review the current literature regarding different combinations of bearing materials in total hip arthroplasty.

von Willebrand factor in cultured human vascular endothelial cells from adult and umbilical cord arteries and veins.

Endothelial cells were cultured from various human arteries and veins, obtained from adult individuals and from umbilical cords. We compared the storage and secretion of von Willebrand factor by endothelial cells from umbilical veins with that of endothelial cells cultured from a number of adult vessels, including aorta, arteria iliaca, vena saphena magna and vena cava. There were no differences in the way the cultured endothelial cells handled the von Willebrand factor they synthesized. Endothelial cells from the various vessels responded to stimuli in secreting stored von Willebrand factor. The cells also responded to thrombin and ionophore A23187 in producing enhanced amounts of prostacyclin. Thus, cultured umbilical vein endothelial cells have properties that are very similar to those of cultured endothelial cells of various other origins. It is concluded that foetal venous cells provide a representative model for studies of endothelial cell von Willebrand factor biosynthesis and prostacyclin production.