Differential protein profiling as a potential multi-marker approach for TSE diagnosis

Rona Barron - ORCID: 0000-0003-4512-9177 https://orcid.org/0000-0003-4512-9177This "proof of concept" study, examines the use of differential protein expression profiling using surface enhanced laser desorption and ionisationtime of flight mass spectrometry (SELDI-TOF) for the diagnosis of TSE disease. Spectral output from all proteins selectively captured from individual murine brain homogenate samples, are compared as "profiles" in groups of infected and non-infected animals. Differential protein expression between groups is thus highlighted and statistically significant protein "peaks" used to construct a panel of disease specific markers. Studies at both terminal stages of disease and throughout the time course of disease have shown a disease specific protein profile or "disease fingerprint" which could be used to distinguish between groups of TSE infected and uninfected animals at an early time point of disease. Results Our results show many differentially expressed proteins in diseased and control animals, some at early stages of disease. Three proteins identified by SELDI-TOF analysis were verified by immunohistochemistry in brain tissue sections. We demonstrate that by combining the most statistically significant changes in expression, a panel of markers can be constructed that can distinguish between TSE diseased and normal animals. Conclusion Differential protein expression profiling has the potential to be used for the detection of disease in TSE infected animals. Having established that a "training set" of potential markers can be constructed, more work would be required to further test the specificity and sensitivity of the assay in a "testing set". Based on these promising results, further studies are being performed using blood samples from infected sheep to assess the potential use of SELDI-TOF as a pre-mortem blood based diagnostic.https://doi.org/10.1186/1471-2334-9-1889pubpub

Gastrointestinal perforation after bevacizumab: a multi-site, single-institution study with a focus on survival

Abstract Background Bevacizumab-induced gastrointestinal perforation is a rare but potentially devastating adverse event that has generated limited data on overall survival. Yet, such survival data are critical in guiding management. Methods This multi-site, single-institution retrospective study focused on all cancer patients who had received bevacizumab and who had suffered a well-documented gastrointestinal perforation from January 1, 2004 through January 20, 2022.The main goal was to report survival outcomes; Kaplan Meier curves and Cox survival models were used for this purpose. Results Eighty-nine patients are included in this report with a median age of 62 years (range 26–85). Colorectal cancer was the most common malignancy (n = 42). Thirty-nine patients underwent surgery for the perforation. Seventy-eight were deceased at the time of reporting with an overall median survival of all patients of 2.7 months (range 0–45 months), and 32 (36%) died within 30 days of perforation. In univariable survival analyses, no statistically significant associations were observed for age, gender, corticosteroid use, and time since last bevacizumab dose. However, surgically treated patients manifested a better survival (hazard ratio (HR) 0.49 (95% CI 0.31–0.78); p = 0.003). In multivariable analyses, surgery continued to be associated with improved survival (HR 0.47 (95% CI 0.29–0.74); p = 0.002), and corticosteroid use was associated with worse survival (HR 1.75 (95% CI 1.02–2.99); p = 0.04). Conclusion Although gastrointestinal perforation after bevacizumab should be managed on a case-by-case basis, these descriptive survival data can help inform patients, their families, and healthcare providers as challenging management decisions arise

Systematic review and meta-analysis on the influence of surgeon specialization on outcomes following appendicectomy in children

The aim of this study is to assess the influence of surgeon specialization on outcomes following appendicectomy in children.General surgeons and pediatric surgeons manage appendicitis in children; however, the influence of subspecialization on outcomes remains unclear.Two authors searched Medline and Embase to identify relevant studies. Eligible studies were comparative and provided data on children who had appendicectomy while under the care of general or pediatric surgical teams. Two authors initially screened titles and abstracts and then full text manuscripts were evaluated. Data were extracted by 2 authors using an electronic spreadsheet. Pooled risk ratios and pooled mean differences were used in analyses.We identified 9 relevant studies involving 50,963 children who were managed by general surgery teams and 15,032 children who were managed by pediatric surgery teams. A normal appendix was removed in 4660/48,105 children treated by general surgery units and in 889/14,760 children treated by pediatric units (pooled risk ratio 1.79; 95% confidence interval [CI] 1.26-2.54; P=0.001). Children managed in general units had shorter mean hospital stays compared with children managed in pediatric units (pooled mean difference -0.70 days; 95%CI -1.09 to -0.30; P=0.0005). There were no significant differences regarding wound infections, intra-abdominal abscesses, readmissions, or mortality.We found that children who were managed by specialized pediatric surgery teams had lower rates of negative appendicectomy although mean length of stay was longer. Our article is based upon a group of heterogeneous and mostly retrospective studies and therefore there is little external validity. Further studies are needed

Measuring prions causing bovine spongiform encephalopathy or chronic wasting disease by immunoassays and transgenic mice

There is increasing concern over the extent to which bovine spongiform encephalopathy (BSE) prions have been transmitted to humans, as a result of the rising number of variant Creutzfeldt-Jakob disease (vCJD) cases. Toward preventing new transmissions, diagnostic tests for prions in livestock have been developed using the conformation-dependent immunoassay (CDI), which simultaneously measures specific antibody binding to denatured and native forms of the prion protein (PrP). We employed high-affinity recombinant antibody fragments (recFab) reacting with residues 95-105 of bovine (Bo) PrP for detection and another recFab that recognizes residues 132-156 for capture in the CDI. We report that the CDI is capable of measuring the disease-causing PrP isoform (PrP(Sc)) in bovine brainstems with a sensitivity similar to that of end-point titrations in transgenic (Tg) mice expressing BoPrP. Prion titers were approximately 10(7) ID(50) units per gram of bovine brainstem when measured in Tg(BoPrP) mice, a figure approximately 10 times greater than that determined by bioassay in cattle and approximately 10,000x greater than in wild-type mice. We also report substantial differences in BoPrP(Sc) levels in different areas of the obex region, where neuropathology has been consistently observed in cattle with BSE. The CDI was able to discriminate between PrP(Sc) from BSE-infected cattle and Tg(BoPrP) mice as well as from chronic wasting disease (CWD)-infected deer and elk. Our findings argue that applying the CDI to livestock should considerably reduce human exposure to animal prions