Nonstructural proteins NS2-3 and NS4A of classical swine fever virus: essential features for infectious particle formation

The nonstructural protein NS2-3 of pestiviruses undergoes tightly regulated processing. For bovine viral diarrhea virus it was shown that uncleaved NS2-3 is required for infectious particle formation while cleaved NS3 is essential for genome replication. To further investigate the functions of NS2-3 and NS4A in the pestivirus life cycle, we established T7 RNA polymerase-dependent trans-complementation for p7-NS2-3-4A of classical swine fever virus (CSFV). Expression of NS2-3 and NS4A in trans restored the production of infectious particles from genomes lacking NS2-3 expression. Co-expression of cleaved NS4A was essential. None of the enzymatic activities harbored by NS2-3 were required for infectious particle formation. Importantly, expression of uncleavable NS2-3 together with NS4A rescued infectious particles from a genome lacking NS2, demonstrating that cleaved NS2 per se has no additional essential function. These data indicate that NS2-3 and NS3, each in association with NS4A, have independent functions in the CSFV life cycle.

Hepatoblastoma with a low serum alpha-fetoprotein level at diagnosis: The SIOPEL group experience

AIM OF THE STUDY: To investigate the characteristics of patients with hepatoblastoma and low serum alpha-fetoprotein (AFP) at diagnosis. PATIENTS AND METHODS: Inclusion of all 21 patients accrued onto SIOPEL trials, whose serum AFP was <100ng/ml at diagnosis. Slides of all 15 patients with available histological material were centrally reviewed. RESULTS: Median age: 10 months. Disease extension at diagnosis: PRETEXT group: II (3 patients), III (10 patients) and IV (8 patients). Extra-hepatic extension: 8 patients. Multifocal tumour: 8 patients. Histology at review: wholly epithelial subtype: 11/15 patients including nine with a small-cell undifferentiated histology. Outcome: only 9 patients achieved a partial response and 16 died. Median survival: 4.4 months. Two-year overall survival: 24% (confidence interval 10-45%). CONCLUSION: This study clearly identifies patients with hepatoblastoma and low serum AFP at diagnosis as a high-risk subgroup with extensive disease at diagnosis, poor response to chemotherapy and a poor outcome.

Confidence Bands for Convex Median Curves using Sign-Tests

Suppose that one observes pairs (x1,Y1), (x2,Y2), ..., (xn,Yn), where x1 < x2 < ... < xn are fixed numbers while Y1, Y2, ..., Yn are independent random variables with unknown distributions. The only assumption is that Median(Yi) = f(xi) for some unknown convex or concave function f. We present a confidence band for this regression function f using suitable multiscale sign tests. While the exact computation of this band seems to require O(n4) steps, good approximations can be obtained in O(n2) steps. In addition the confidence band is shown to have desirable asymptotic properties as the sample size n tends to infinity.

Marshall's Lemma for Convex Density Estimation

Marshall's (1970) lemma is an analytical result which implies root-n-consistency of the distribution function corresponding to the Grenander (1956) estimator of a non-decreasing probability density. The present paper derives analogous results for the setting of convex densities on [0,\infty).

Recurrent rearrangements of chromosome 1q21.1 and variable pediatric phenotypes

BACKGROUND: Duplications and deletions in the human genome can cause disease or predispose persons to disease. Advances in technologies to detect these changes allow for the routine identification of submicroscopic imbalances in large numbers of patients. METHODS: We tested for the presence of microdeletions and microduplications at a specific region of chromosome 1q21.1 in two groups of patients with unexplained mental retardation, autism, or congenital anomalies and in unaffected persons. RESULTS: We identified 25 persons with a recurrent 1.35-Mb deletion within 1q21.1 from screening 5218 patients. The microdeletions had arisen de novo in eight patients, were inherited from a mildly affected parent in three patients, were inherited from an apparently unaffected parent in six patients, and were of unknown inheritance in eight patients. The deletion was absent in a series of 4737 control persons (P=1.1x10(-7)). We found considerable variability in the level of phenotypic expression of the microdeletion; phenotypes included mild-to-moderate mental retardation, microcephaly, cardiac abnormalities, and cataracts. The reciprocal duplication was enriched in nine children with mental retardation or autism spectrum disorder and other variable features (P=0.02). We identified three deletions and three duplications of the 1q21.1 region in an independent sample of 788 patients with mental retardation and congenital anomalies. CONCLUSIONS: We have identified recurrent molecular lesions that elude syndromic classification and whose disease manifestations must be considered in a broader context of development as opposed to being assigned to a specific disease. Clinical diagnosis in patients with these lesions may be most readily achieved on the basis of genotype rather than phenotype.

No surgical innovation without evaluation: the IDEAL recommendations

Surgery and other invasive therapies are complex interventions, the assessment of which is challenged by factors that depend on operator, team, and setting, such as learning curves, quality variations, and perception of equipoise. We propose recommendations for the assessment of surgery based on a five-stage description of the surgical development process. We also encourage the widespread use of prospective databases and registries. Reports of new techniques should be registered as a professional duty, anonymously if necessary when outcomes are adverse. Case series studies should be replaced by prospective development studies for early technical modifications and by prospective research databases for later pre-trial evaluation. Protocols for these studies should be registered publicly. Statistical process control techniques can be useful in both early and late assessment. Randomised trials should be used whenever possible to investigate efficacy, but adequate pre-trial data are essential to allow power calculations, clarify the definition and indications of the intervention, and develop quality measures. Difficulties in doing randomised clinical trials should be addressed by measures to evaluate learning curves and alleviate equipoise problems. Alternative prospective designs, such as interrupted time series studies, should be used when randomised trials are not feasible. Established procedures should be monitored with prospective databases to analyse outcome variations and to identify late and rare events. Achievement of improved design, conduct, and reporting of surgical research will need concerted action by editors, funders of health care and research, regulatory bodies, and professional societies.

Challenges in evaluating surgical innovation

Research on surgical interventions is associated with several methodological and practical challenges of which few, if any, apply only to surgery. However, surgical evaluation is especially demanding because many of these challenges coincide. In this report, the second of three on surgical innovation and evaluation, we discuss obstacles related to the study design of randomised controlled trials and non-randomised studies assessing surgical interventions. We also describe the issues related to the nature of surgical procedures-for example, their complexity, surgeon-related factors, and the range of outcomes. Although difficult, surgical evaluation is achievable and necessary. Solutions tailored to surgical research and a framework for generating evidence on which to base surgical practice are essential.

Evaluation and stages of surgical innovations

Surgical innovation is an important part of surgical practice. Its assessment is complex because of idiosyncrasies related to surgical practice, but necessary so that introduction and adoption of surgical innovations can derive from evidence-based principles rather than trial and error. A regulatory framework is also desirable to protect patients against the potential harms of any novel procedure. In this first of three Series papers on surgical innovation and evaluation, we propose a five-stage paradigm to describe the development of innovative surgical procedures.

Cisplatin versus cisplatin plus doxorubicin for standard-risk hepatoblastoma

BACKGROUND: Preoperative cisplatin alone may be as effective as cisplatin plus doxorubicin in standard-risk hepatoblastoma (a tumor involving three or fewer sectors of the liver that is associated with an alpha-fetoprotein level of >100 ng per milliliter). METHODS: Children with standard-risk hepatoblastoma who were younger than 16 years of age were eligible for inclusion in the study. After they received one cycle of cisplatin (80 mg per square meter of body-surface area per 24 hours), we randomly assigned patients to receive cisplatin (every 14 days) or cisplatin plus doxorubicin administered in three preoperative cycles and two postoperative cycles. The primary outcome was the rate of complete resection, and the trial was powered to test the noninferiority of cisplatin alone (<10% difference in the rate of complete resection). RESULTS: Between June 1998 and December 2006, 126 patients were randomly assigned to receive cisplatin and 129 were randomly assigned to receive cisplatin plus doxorubicin. The rate of complete resection was 95% in the cisplatin-alone group and 93% in the cisplatin-doxorubicin group in the intention-to-treat analysis (difference, 1.4%; 95% confidence interval [CI], -4.1 to 7.0); these rates were 99% and 95%, respectively, in the per-protocol analysis. Three-year event-free survival and overall survival were, respectively, 83% (95% CI, 77 to 90) and 95% (95% CI, 91 to 99) in the cisplatin group, and 85% (95% CI, 79 to 92) and 93% (95% CI, 88 to 98) in the cisplatin-doxorubicin group (median follow-up, 46 months). Acute grade 3 or 4 adverse events were more frequent with combination therapy (74.4% vs. 20.6%). CONCLUSIONS: As compared with cisplatin plus doxorubicin, cisplatin monotherapy achieved similar rates of complete resection and survival among children with standard-risk hepatoblastoma. Doxorubicin can be safely omitted from the treatment of standard-risk hepatoblastoma. (ClinicalTrials.gov number, NCT00003912.)

Chondrocyte mechanotransduction: effects of compression on deformation of intracellular organelles and relevance to cellular biosynthesis

OBJECTIVE: The effects of mechanical deformation of intact cartilage tissue on chondrocyte biosynthesis in situ have been well documented, but the mechanotransduction pathways that regulate such phenomena have not been elucidated completely. The goal of this study was to examine the effects of tissue deformation on the morphology of a range of intracellular organelles which play a major role in cell biosynthesis and metabolism. DESIGN: Using chemical fixation, high pressure freezing, and electron microscopy, we imaged chondrocytes within mechanically compressed cartilage explants at high magnification and quantitatively and qualitatively assessed changes in organelle volume and shape caused by graded levels of loading. RESULTS: Compression of the tissue caused a concomitant reduction in the volume of the extracellular matrix (ECM), chondrocyte, nucleus, rough endoplasmic reticulum, and mitochondria. Interestingly, however, the Golgi apparatus was able to resist loss of intraorganelle water and retain a portion of its volume relative to the remainder of the cell. These combined results suggest that a balance between intracellular mechanical and osmotic gradients govern the changes in shape and volume of the organelles as the tissue is compressed. CONCLUSIONS: Our results lead to the interpretive hypothesis that organelle volume changes appear to be driven mainly by osmotic interactions while shape changes are mediated by structural factors, such as cytoskeletal interactions that may be linked to extracellular matrix deformations. The observed volume and shape changes of the chondrocyte organelles and the differential behavior between organelles during tissue compression provide evidence for an important mechanotransduction pathway linking translational and post-translational events (e.g., elongation and sulfation of glycosaminoglycans (GAGs) in the Golgi) to cell deformation.

Empowering Interactions. Political Cultures and the Emergence of the State. in Europe 1300-1900

The emergence of the state in Europe is a topic that has engaged historians since the establishment of the discipline of history. Yet the primary focus of has nearly always been to take a top-down approach, whereby the formation and consolidation of public institutions is viewed as the outcome of activities by princes and other social elites. Yet, as the essays in this collection show, such an approach does not provide a complete picture. By investigating the importance of local and individual initiatives that contributed to state building from the late middle ages through to the nineteenth century, this volume shows how popular pressure could influence those in power to develop new institutional structures. By not privileging the role of warfare and of elite coercion for state building, it is possible to question the traditional top-down model and explore the degree to which central agencies might have been more important for state representation than for state practice. The studies included in this collection treat many parts of Europe and deal with different phases in the period between the late middle ages and the nineteenth century. Beginning with a critical review of state historiography, the introduction then sets out the concept of 'empowering interactions' which is then explored in the subsequent case studies and a number of historiographical, methodological and theoretical essays. Taken as a whole this collection provides a fascinating platform to reconsider the relationships between top-down and bottom-up processes in the history of the European state.