191 research outputs found
The application of immunocytochemistry to direct smears in the diagnosis of effusions
Metastatic malignancy represents a common cause of effusions. Immunocytochemistry (ICC) is useful in confirming malignancy and gaining insight into the site of origin. Cell blocks are commonly utilized for this purpose; nonetheless, when the malignant cells are sparse, they may not be represented in cell blocks thereby precluding immunophenotypic characterization. Thus, we sought to investigate the utility of direct smear preparations as a platform for ICC in the diagnosis of effusions. Airâdried, unstained direct smears were prepared from 49 malignant effusions and 17 reactive effusions for comparison. ICC for EMA and MOCâ31 highlighted the tumor cells in 91 and 98% of the malignant effusions tested, respectively. EMA immunoreactivity was focally observed within the calretininâpositive mesothelial cell population in 1 (6%) of the 17 reactive effusions. ICC for MOCâ31 was negative in all reactive effusions. Siteâspecific immunomarkers were also evaluated. Immunoreactivity for NapsinâA and TTFâ1 were observed in 78 and 67% of metastatic lung adenocarcinomas, respectively. ICC for PAX8 highlighted metastatic MĂŒllerian and thyroid carcinomas in 100% of cases tested. CDXâ2 immunoreactivity was observed in 25, 60, and 100% of metastatic gastric, pancreatic, and colorectal adenocarcinomas, respectively. Positivity for p63 was observed in 75% of metastatic urothelial cell carcinomas and the one case of pulmonary squamous cell carcinoma examined. Calretinin ICC highlighted the tumor cells in both malignant mesothelioma cases tested as well as the benign mesothelial cells in the reactive effusions. In conclusion, direct smears represent an effective platform for the performance of ICC in the diagnosis of malignant effusions. Diagn. Cytopathol. 2013. © 2012 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97537/1/22852_ftp.pd
Epidermal Growth Factor Receptor Expression and Mutational Analysis in Synovial Sarcomas and Malignant Peripheral Nerve Sheath Tumors
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140003/1/onco0459.pd
Histologic Alterations from Neoadjuvant Chemotherapy in HighâGrade Extremity Soft Tissue Sarcoma: Clinicopathological Correlation
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139918/1/onco0451.pd
Retroperitoneal Compared to Transperitoneal Approach for Open Abdominal Aortic Aneurysm Repair Is Associated with Reduced Systemic Inflammation and Postoperative Morbidity
Background âIn the United Kingdom, the most common surgical approach for repair of open abdominal aortic aneurysms (AAAs) is transperitoneal (TP). However, retroperitoneal (RP) approach is favored in those with more complex vascular anatomy often requiring a cross-clamp on the aorta superior to the renal arteries. This study compared these approaches in patients matched on all major demographic, comorbid, anatomic, and physiological variables. Methods âFifty-seven patients (TP: n â=â24; RP: n â=â33) unsuitable for endovascular aneurysm repair underwent preoperative cardiopulmonary exercise testing prior to open AAA repair. The surgical approach undertaken was dictated by individual surgeon preference. Postoperative mortality, complications, and length of hospital stay (LoS) were recorded. Patients were further stratified according to infrarenal (IR) or suprarenal/supraceliac (SR/SC) surgical clamping. Systemic inflammation (C-reactive protein) and renal function (serum creatinine and estimated glomerular filtration rate) were recorded. Results âTwenty-three (96%) of TP patients only required an IR clamp compared with 12 (36%) in the RP group. Postoperative systemic inflammation was lower in RP patients ( p â=â0.002 vs. TP) and fewer reported pulmonary/gastrointestinal complications whereas renal impairment was more marked in those receiving SR/SC clamps ( p â<â0.001 vs. IR clamp). RP patients were defined by lower LoS ( p â=â0.001), while mid-/long-term mortality was low/comparable with TP, resulting in considerable cost savings. Conclusion âDespite the demands of more complicated vascular anatomy, the clinical and economic benefits highlighted by these findings justify the more routine adoption of the RP approach for complex AAA repair
Land use not litter quality is a stronger driver of decomposition in hyperdiverse tropical forest
In hyperdiverse tropical forests, the key drivers of litter decomposition are poorly understood despite its crucial role in facilitating nutrient availability for plants and microbes. Selective logging is a pressing land use with potential for considerable impacts on plant-soil interactions, litter decomposition, and nutrient cycling. Here, in Borneo's tropical rainforests, we test the hypothesis that decomposition is driven by litter quality and that there is a significant "home-field advantage," that is positive interaction between local litter quality and land use. We determined mass loss of leaf litter, collected from selectively logged and old-growth forest, in a fully factorial experimental design, using meshes that either allowed or precluded access by mesofauna. We measured leaf litter chemical composition before and after the experiment. Key soil chemical and biological properties and microclimatic conditions were measured as land-use descriptors. We found that despite substantial differences in litter quality, the main driver of decomposition was land-use type. Whilst inclusion of mesofauna accelerated decomposition, their effect was independent of land use and litter quality. Decomposition of all litters was slower in selectively logged forest than in old-growth forest. However, there was significantly greater loss of nutrients from litter, especially phosphorus, in selectively logged forest. The analyses of several covariates detected minor microclimatic differences between land-use types but no alterations in soil chemical properties or free-living microbial composition. These results demonstrate that selective logging can significantly reduce litter decomposition in tropical rainforest with no evidence of a home-field advantage. We show that loss of key limiting nutrients from litter (P & N) is greater in selectively logged forest. Overall, the findings hint at subtle differences in microclimate overriding litter quality that result in reduced decomposition rates in selectively logged forests and potentially affect biogeochemical nutrient cycling in the long term
A proofreading mutation with an allosteric effect allows a cluster of SARS-CoV-2 viruses to rapidly evolve
The RNA-dependent RNA polymerase of the severe acute respiratory syndrome coronavirus 2 virus is error prone, with errors being corrected by the exonuclease (NSP14) proofreading mechanism. However, the mutagenesis and subsequent evolutionary trajectory of the virus is mediated by the delicate interplay of replicase fidelity and environmental pressures. Here, we have shown that a single, distal mutation (F60S) in NSP14 can have a profound impact upon proofreading with an increased accumulation of mutations and elevated evolutionary rate being observed. Understanding the implications of these changes is crucial, as these underlying mutational processes may have important implications for understanding the population-wide evolution of the virus. This study underscores the urgent need for continued research into the replicative mechanisms of this virus to combat its continued impact on global health, through the re-emergence of immuno-evasive variants
A clinical study of kuru patients with long incubation periods at the end of the epidemic in Papua New Guinea
Kuru is so far the principal human epidemic prion disease. While its incidence has steadily declined since the cessation of its route of transmission, endocannibalism, in Papua New Guinea in the 1950s, the arrival of variant CreutzfeldtâJakob disease (vCJD), also thought to be transmitted by dietary prion exposure, has given kuru a new global relevance. We investigated all suspected cases of kuru from July 1996 to June 2004 and identified 11 kuru patients. There were four females and seven males, with an age range of 46â63 years at the onset of disease, in marked contrast to the age and sex distribution when kuru was first investigated 50 years ago. We obtained detailed histories of residence and exposure to mortuary feasts and performed serial neurological examination and genetic studies where possible. All patients were born a significant period before the mortuary practice of transumption ceased and their estimated incubation periods in some cases exceeded 50 years. The principal clinical features of kuru in the studied patients showed the same progressive cerebellar syndrome that had been previously described. Two patients showed marked cognitive impairment well before preterminal stages, in contrast to earlier clinical descriptions. In these patients, the mean clinical duration of 17 months was longer than the overall average in kuru but similar to that previously reported for the same age group, and this may relate to the effects of both patient age and PRNP codon 129 genotype. Importantly, no evidence for lymphoreticular colonization with prions, seen uniformly in vCJD, was observed in a patient with kuru at tonsil biopsy
The crystal sructure of Bacillus cereus HblL1
The Hbl toxin is a three-component haemolytic complex produced by Bacillus cereus sensu lato strains and implicated as a cause of diarrhoea in B. cereus food poisoning. While the structure of the HblB component of this toxin is known, the structures of the other components are unresolved. Here, we describe the expression of the recombinant HblL1 component and the elucidation of its structure to 1.36 Ă
. Like HblB, it is a member of the alpha-helical pore-forming toxin family. In comparison to other members of this group, it has an extended hydrophobic beta tongue region that may be involved in pore formation. Molecular docking was used to predict possible interactions between HblL1 and HblB, and suggests a head to tail dimer might form, burying the HblL1 beta tongue region
Glycosylation increases active site rigidity leading to improved enzyme stability and turnover
Glycosylation is the most prevalent protein postâtranslational modification, with a quarter of glycosylated proteins having enzymatic properties. Yet, the full impact of glycosylation on the protein structureâfunction relationship, especially in enzymes, is still limited. Here, we show that glycosylation rigidifies the important commercial enzyme horseradish peroxidase (HRP), which in turn increases its turnover and stability. Circular dichroism spectroscopy revealed that glycosylation increased holoâHRP's thermal stability and promoted significant helical structure in the absence of haem (apoâHRP). Glycosylation also resulted in a 10âfold increase in enzymatic turnover towards oâphenylenediamine dihydrochloride when compared to its nonglycosylated form. Utilising a naturally occurring siteâspecific probe of active site flexibility (Trp117) in combination with redâedge excitation shift fluorescence spectroscopy, we found that glycosylation significantly rigidified the enzyme. In silico simulations confirmed that glycosylation largely decreased protein backbone flexibility, especially in regions close to the active site and the substrate access channel. Thus, our data show that glycosylation does not just have a passive effect on HRP stability but can exert longârange effects that mediate the ânativeâ enzyme's activity and stability through changes in inherent dynamics
No difference in penetrance between truncating and missense/aberrant splicing pathogenic variants in mlh1 and msh2: A prospective lynch syndrome database study
Background. Lynch syndrome is the most common genetic predisposition for hereditary cancer. Carriers of pathogenic changes in mismatch repair (MMR) genes have an increased risk of developing colorectal (CRC), endometrial, ovarian, urinary tract, prostate, and other cancers, depending on which gene is malfunctioning. In Lynch syndrome, differences in cancer incidence (penetrance) according to the gene involved have led to the stratification of cancer surveillance. By contrast, any differences in penetrance determined by the type of pathogenic variant remain unknown. Objective. To determine cumulative incidences of cancer in carriers of truncating and missense or aberrant splicing pathogenic variants of the MLH1 and MSH2 genes. Methods. Carriers of pathogenic variants of MLH1 (path_MLH1) and MSH2 (path_MSH2) genes filed in the Prospective Lynch Syndrome Database (PLSD) were categorized as truncating or missense/aberrant splicing according to the InSiGHT criteria for pathogenicity. Results. Among 5199 carriers, 1045 had missense or aberrant splicing variants, and 3930 had truncating variants. Prospective observation years for the two groups were 8205 and 34,141 years, respectively, after which there were no significant differences in incidences for cancer overall or for colorectal cancer or endometrial cancers separately. Conclusion. Truncating and missense or aberrant splicing pathogenic variants were associated with similar average cumulative incidences of cancer in carriers of path MLH1 and path_MSH2.Fil: Dominguez Valentin, Mev. St Markâs Hospital; Reino Unido. The Norwegian Radium Hospital; Noruega. European Hereditary Tumour Group; Reino UnidoFil: Plazzer, John Paul. St Markâs Hospital; Reino Unido. The Royal Melbourne Hospital; AustraliaFil: Sampson, Julian R.. European Hereditary Tumour Group; Reino Unido. Cardiff University; Reino UnidoFil: Engel, Christoph. European Hereditary Tumour Group; Reino Unido. Universitat Leipzig; AlemaniaFil: Aretz, Stefan. Universitat Bonn; AlemaniaFil: Jenkins, Mark A.. University of Melbourne; AustraliaFil: Sunde, Lone. Aalborg University; DinamarcaFil: Bernstein, Inge. Aalborg University; DinamarcaFil: Capella, Gabriel. European Hereditary Tumour Group; Reino Unido. St Markâs Hospital; Reino Unido. Institut CatalĂ dâOncologia; EspañaFil: Balaguer PrunĂ©s, Francesc. Universidad de Barcelona; EspañaFil: Macrae, Finlay. European Hereditary Tumour Group; Reino Unido. The Royal Melbourne Hospital; AustraliaFil: Winship, Ingrid M.. University of Melbourne; AustraliaFil: Thomas, Huw. Imperial College London; Reino UnidoFil: Evans, Dafydd Gareth. University of Manchester; Reino UnidoFil: Burn, John. Universidad de Newcastle; Australia. The Royal Melbourne Hospital; Australia. St Markâs Hospital; Reino UnidoFil: Greenblatt, Marc. University of Vermont; Estados UnidosFil: de Vos tot Nederveen Cappel, Wouter H.. Isala Clinics; PaĂses BajosFil: Sijmons, Rolf H.. University of Groningen; PaĂses Bajos. St Markâs Hospital; Reino Unido. European Hereditary Tumour Group; Reino UnidoFil: Nielsen, Maartje. Leids Universitair Medisch Centrum; PaĂses BajosFil: Bertario, Lucio. Fondazione IRCCS Istituto Nazionale dei Tumori; ItaliaFil: Bonanni, Bernardo. Fondazione IRCCS Istituto Nazionale dei Tumori; ItaliaFil: Tibiletti, Maria Grazia. UniversitĂ dellâInsubria; ItaliaFil: Cavestro, Giulia Martina. Vita-Salute San Raffaele University; ItaliaFil: Lindblom, Annika. Karolinska Huddinge Hospital; SueciaFil: Della Valle, Adriana. Hospital Fuerzas Armadas; UruguayFil: Lopez Kostner, Francisco. ClĂnica Universidad de los Andes; ChileFil: Alvarez, Karin. ClĂnica Universidad de los Andes; ChileFil: Gluck, Nathan. Universitat Tel Aviv; IsraelFil: Katz, Lior. Sheba Medical Center; IsraelFil: Heinimann, Karl. University Hospital Basel; SuizaFil: Piñero, Tamara Alejandra. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica - Hospital Italiano. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica; ArgentinaFil: Pavicic, Walter Hernan. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica - Hospital Italiano. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e IngenierĂa BiomĂ©dica; Argentin
- âŠ