126 research outputs found
The effect of communication between the right and left liver on the outcome of surgical drainage for jaundice due to malignant obstruction at the hilus of the liver
Debate continues regarding the optimal management of irresectable malignant proximal biliary obstruction. Controversy exists concerning the ability of unilateral drainage to provide adequate biliary decompression with tumors that have occluded the communication between the right and left hepatic ductal systems. Between October 1986 and October 1989, 18 patients with malignant proximal biliary obstruction were treated by an intrahepatic biliary enteric bypass. Patients were divided into two groups based on the presence or absence of a communication between the right and left biliary systems. In Group I (n = 9), there was free communication; and in Group II (n = 9) there was no communication. There were two perioperative deaths (11%) one due to persistent cholangitis and the other to myocardial insufficiency both with one death in each group. The median survival (excluding perioperative deaths) was 5.6 months. Comparison of pre- and postoperative serum levels of bilirubin and alkaline phosphatase showed a significant decrease in each group, but no difference between the groups in the size of the reduction. Sixteen patients survived at least three months and the palliation was judged as excellent in eight, fair in five, and unchanged in three. These results demonstrate the effectiveness of biliary enteric bypass regardless of communication between the left and right biliary ductal systems.H. U. Baer, M. Rhyner, S. C. Stain, P. W. Glauser, A. R. Dennison, G. J. Maddern, and L. H. Blumgar
Transport on percolation clusters with power-law distributed bond strengths: when do blobs matter?
The simplest transport problem, namely maxflow, is investigated on critical
percolation clusters in two and three dimensions, using a combination of
extremal statistics arguments and exact numerical computations, for power-law
distributed bond strengths of the type .
Assuming that only cutting bonds determine the flow, the maxflow critical
exponent \ve is found to be \ve(\alpha)=(d-1) \nu + 1/(1-\alpha). This
prediction is confirmed with excellent accuracy using large-scale numerical
simulation in two and three dimensions. However, in the region of anomalous
bond capacity distributions () we demonstrate that, due to
cluster-structure fluctuations, it is not the cutting bonds but the blobs that
set the transport properties of the backbone. This ``blob-dominance'' avoids a
cross-over to a regime where structural details, the distribution of the number
of red or cutting bonds, would set the scaling. The restored scaling exponents
however still follow the simplistic red bond estimate. This is argued to be due
to the existence of a hierarchy of so-called minimum cut-configurations, for
which cutting bonds form the lowest level, and whose transport properties scale
all in the same way. We point out the relevance of our findings to other scalar
transport problems (i.e. conductivity).Comment: 9 pages + Postscript figures. Revtex4+psfig. Submitted to PR
An Experimental Analysis of RowHammer in HBM2 DRAM Chips
RowHammer (RH) is a significant and worsening security, safety, and
reliability issue of modern DRAM chips that can be exploited to break memory
isolation. Therefore, it is important to understand real DRAM chips' RH
characteristics. Unfortunately, no prior work extensively studies the RH
vulnerability of modern 3D-stacked high-bandwidth memory (HBM) chips, which are
commonly used in modern GPUs.
In this work, we experimentally characterize the RH vulnerability of a real
HBM2 DRAM chip. We show that 1) different 3D-stacked channels of HBM2 memory
exhibit significantly different levels of RH vulnerability (up to 79%
difference in bit error rate), 2) the DRAM rows at the end of a DRAM bank (rows
with the highest addresses) exhibit significantly fewer RH bitflips than other
rows, and 3) a modern HBM2 DRAM chip implements undisclosed RH defenses that
are triggered by periodic refresh operations. We describe the implications of
our observations on future RH attacks and defenses and discuss future work for
understanding RH in 3D-stacked memories.Comment: To appear at DSN Disrupt 202
Novel in vitro diagnosis of equine allergies using a protein array and mathematical modelling approach: a proof of concept using insect bite hypersensitivity
Insect bite hypersensitivity (IBH) is a seasonal recurrent skin allergy of horses caused by IgE-mediated reactions to allergens present in the saliva of biting insects of the genus Culicoides, and possibly also Simulium and Stomoxys species. In this work we show that protein microarrays containing complex extracts and pure proteins, including recombinant Culicoides allergens, can be used as a powerful technique for the diagnosis of IBH. Besides the obvious advantages such as general profiling and use of few microliters of samples, this microarray technique permits automation and allows the generation of mathematical models with the calculation of individual risk profiles that can support the clinical diagnosis of allergic diseases. After selection of variables on influence on the projection (VIP), the observed values of sensitivity and specificity were 1.0 and 0.967, respectively. This confirms the highly discriminatory power of this approach for IBH and made it possible to attain a robust predictive mathematical model for this disease. It also further demonstrates the specificity of the protein array method on identifying a particular IgE-mediated disease when the sensitising allergen group is known
Stateâofâtheâart in marketed adjuvants and formulations in Allergen Immunotherapy: a position paper of the European Academy of Allergy and Clinical Immunology (EAACI)
Since the introduction of allergen immunotherapy (AIT) over 100 years ago, focus has been on standardization of allergen extracts, with reliable molecular composition of allergens receiving the highest attention. While adjuvants play a major role in European AIT, they have been less well studied. In this Position Paper we summarize current unmet needs of adjuvants in AIT citing current evidence. Four adjuvants are used in products marketed in Europe: aluminium hydroxide (Al(OH)3) is the most frequently used adjuvant, with microcrystalline tyrosine (MCT), monophosphoryl lipid A (MPLA) and calcium phosphate (CaP) used less frequently. Recent studies on humans, and using mouse models, have characterized in part the mechanisms of action of adjuvants on preâexisting immune responses. AIT differs from prophylactic vaccines that provoke immunity to infectious agents, as in allergy the patient is preâsensitized to the allergen. The intended mode of action of adjuvants is to simultaneously enhance the immunogenicity of the allergen, while precipitating the allergen at the injection site to reduce the risk of anaphylaxis. Contrasting immune effects are seen with different adjuvants. Aluminium hydroxide initially boosts Th2 responses, while the other adjuvants utilised in AIT redirect the Th2 immune response toward Th1 immunity. After varying lengths of time, each of the adjuvants supports tolerance. Further studies of the mechanisms of action of adjuvants may advise shorter treatment periods than the current threeâtoâfiveâyear regimens, enhancing patient adherence. Improved lead compounds from the adjuvant pipeline are under development and are explored for their capacity to fill this unmet need
Atopic dermatitis: Correlation of distinct risk factors with age of onset in adulthood compared to childhood
Background: Atopic dermatitis (AD) has long been regarded as a primarily pediatric disease. However, there is growing evidence for a high rate of adult-onset AD. We aimed to characterize factors associated with adult-onset versus childhood-onset AD and controls.
Methods: We analyzed cross-sectional data of the CK-CARE-ProRaD cohorts Bonn, Augsburg, Davos, ZĂŒrich of 736 adult patients stratified by age of AD onset (childhood-onset <18 years: 76.4% (subsets: 0 to 2; â„2 to 6; â„7 to 11; â„12 to 18); adult-onset â„18 years: 23.6% (subsets: â„18 to 40; â„41 to 60; â„61) and 167 controls (91 atopic, 76 non-atopic)).
Results: We identified active smoking to be associated with adult-onset AD versus controls (adjusted Odds Ratio (aOR) = 5.54 [95% Confidence Interval: 1.06-29.01] vs. controls , aOR = 4.03 [1.20-13.45] vs. controls ). Conjunctivitis showed a negative association versus controls (aOR = 0.36 [0.14-0.91]). Food allergy (aOR = 2.93 [1.44-5.96]), maternal food allergy (aOR = 9.43 [1.10-80.95]), palmar hyperlinearity (aOR = 2.11 [1.05-4.25]), and academic background (aOR = 2.14 [1.00-4.54]) increased the odds of childhood-onset AD versus controls. Shared AD-associated factors were maternal AD (4-34x), increased IgE (2-20x), atopic stigmata (2-3x) with varying effect sizes depending on AD onset and control group. Patients with adult-compared to childhood-onset had doubled odds of allergic rhinitis (aOR = 2.15 [1.12-4.13]), but reduced odds to feature multiple (3-4) atopic comorbidities (aOR = 0.34 [0.14-0.84]). Adult-onset AD, particularly onset â„61 years, grouped mainly in clusters with low contributions of personal and familial atopy and high frequencies of physical inactivity, childhood-onset AD, particularly infant-onset, mainly in "high-atopic"-clusters.
Conclusions: The identified associated factors suggest partly varying endo- and exogeneous mechanisms underlying adult-onset versus childhood-onset AD. Our findings might contribute to better assessment of the individual risk to develop AD throughout life and encourage prevention by non-smoking and physical activity as modifiable lifestyle factors
Componentâresolved microarray analysis of IgE sensitization profiles to Culicoides recombinant allergens in horses with insect bite hypersensitivity
Background: Allergy to bites of blood sucking insects, including biting midges can affect both human and veterinary patients. Horses are often suffering from an IgEâmediated allergic dermatitis caused by bites of midges (Culicoides spp) . With the aim to improve allergen immunotherapy (AIT) numerous Culicoides allergens have been produced as recombinant (râ) proteins. This study aims to test a comprehensive panel of differently expressed Culicoides râallergens on a cohort of IBHâaffected and control horses using an allergen microarray.
Methods: IgE levels to 27 Culicoides râallergens, including 8 previously unpublished allergens, of which 11 were expressed in more than one expression system, were determined in sera from 347 horses. ROC analyses were carried out, cutâoffs selected using a specificity of 95% and seroâpositivity rates compared between horses affected with insect bite hypersensitivity (IBH) and control horses. The combination of râallergens giving the best performing test was determined using logistic regression analysis.
Results: Seroâpositivity was significantly higher in IBH horses compared to controls for 25 râallergens. Nine Culicoides râallergens were major allergens for IBH with seven of them binding IgE in sera from >70% of the IBHâaffected horses. Combination of these top seven râallergens could diagnose >90% of IBHâaffected horses with a specificity of >95%. Correlation between differently expressed râallergens was usually high (mean = 0.69, range 0.28â0.91).
Conclusion: This microarray will be a powerful tool for development of componentâresolved, patientâtailored AIT for IBH and could be useful for the study of allergy to biting midges in humans and other species
Loss and damage livelihood resilience
Climate change Loss and Damage has emerged as a key challenge of the 21st century. This Policy Brief first frames the challenge and then introduces the Resilience Academy, highlighting 5 key insights that both feed the debate and inform action. Finally, it provides 5 recommendations to the Executive Committee of the Warsaw International Mechanism (WIM ExCom) for its 5-year work plan
Interrater Reliability of NI-RADS on Posttreatment PET/Contrast-enhanced CT Scans in Head and Neck Squamous Cell Carcinoma
Purpose: To evaluate the interrater reliability among radiologists examining posttreatment head and neck squamous cell carcinoma (HNSCC) fluorodeoxyglucose PET/contrast-enhanced CT (CECT) scans using Neck Imaging Reporting and Data System (NI-RADS). Materials and Methods: In this retrospective study, images in 80 patients with HNSCC who underwent posttreatment surveillance PET/CECT and immediate prior comparison CECT or PET/CECT (from June 2014 to July 2016) were uploaded to the American College of Radiology's cloud-based website, Cortex. Eight radiologists from seven institutions with variable NI-RADS experience independently evaluated each case and assigned an appropriate prose description and NI-RADS category for the primary site and the neck site. Five of these individuals were experienced readers (> 5 years of experience), and three were novices (< 5 years of experience). In total, 640 lexicon-based and NI-RADS categories were assigned to lesions among the 80 included patients by the eight radiologists. Light generalization of Cohen Îș for interrater reliability was performed. Results: Of the 80 included patients (mean age, 63 years ± 10 [standard deviation]), there were 58 men (73%); 60 patients had stage IV HNSCC (75%), and the most common tumor location was oropharynx (n = 32; 40%). Light Îș for lexicon was 0.30 (95% CI: 0.23, 0.36) at the primary site and 0.31 (95% CI: 0.24, 0.37) at the neck site. Light Îș for NI-RADS category was 0.55 (95% CI: 0.46, 0.63) at the primary site and 0.60 (95% CI: 0.48, 0.69) at the neck site. Percent agreement between lexicon and correlative NI-RADS category was 84.4% (540 of 640) at the primary site and 92.6% (593 of 640) at the neck site. There was no significant difference in interobserver agreement among the experienced versus novice raters. Conclusion: Moderate agreement was achieved among eight radiologists using NI-RADS at posttreatment HNSCC surveillance imaging
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