Phenotypic Expression of ADAMTS13 in Glomerular Endothelial Cells

Background: ADAMTS13 is the physiological von Willebrand factor (VWF)-cleaving protease. The aim of this study was to examine ADAMTS13 expression in kidneys from ADAMTS13 wild-type (Adamts13+/+) and deficient (Adamts13-/-) mice and to investigate the expression pattern and bioactivity in human glomerular endothelial cells. Methodology/Principal Findings: Immunohistochemistry was performed on kidney sections from ADAMTS13 wild-type and ADAMTS13-deficient mice. Phenotypic differences were examined by ultramorphology. ADAMTS13 expression in human glomerular endothelial cells and dermal microvascular endothelial cells was investigated by real-time PCR, flow cytometry, immunofluorescence and immunoblotting. VWF cleavage was demonstrated by multimer structure analysis and immunoblotting. ADAMTS13 was demonstrated in glomerular endothelial cells in Adamts13+/+ mice but no staining was visible in tissue from Adamts13-/- mice. Thickening of glomerular capillaries with platelet deposition on the vessel wall was detected in Adamts13-/- mice. ADAMTS13 mRNA and protein were detected in both human endothelial cells and the protease was secreted. ADAMTS13 activity was demonstrated in glomerular endothelial cells as cleavage of VWF. Conclusions/Significance: Glomerular endothelial cells express and secrete ADAMTS13. The proteolytic activity could have a protective effect preventing deposition of platelets along capillary lumina under the conditions of high shear stress present in glomerular capillaries. © 2011 Tati et al.published_or_final_versio

In Vitro Characterization of Protein Effector Export in the Bradyzoite Stage of Toxoplasma gondii

Toxoplasma bradyzoites persist within tissue cysts and are refractory to current treatments, serving as a reservoir for acute complications in settings of compromised immunity. Much remains to be understood regarding how this life stage successfully establishes and maintains persistent infection. In this study, we investigated whether the export of parasite effector proteins into the host cell occurs during the development of in vitro tissue cysts. We quantified the presence of four previously described effectors in host cell nuclei at different time points after bradyzoite differentiation and found that they accumulated largely during the early stages of infection. Despite a decline in nuclear accumulation, we found that one of these effectors still mediated its function after prolonged infection with bradyzoites, and we provide evidence that this effector is exported beyond early infection stages. These findings suggest that effector export from within developing tissue cysts provides one potential mechanism by which this parasite achieves chronic infection.The ubiquitous parasite Toxoplasma gondii exhibits an impressive ability to maintain chronic infection of its host for prolonged periods. Despite this, little is known regarding whether and how T. gondii bradyzoites, a quasi-dormant life stage residing within intracellular cysts, manipulate the host cell to maintain persistent infection. A previous proteomic study of the cyst wall, an amorphous layer of proteins that forms underneath the cyst membrane, identified MYR1 as a putative cyst wall protein in vitro. Because MYR1 is known to be involved in the translocation of parasite-derived effector proteins into the host cell, we sought to determine whether parasites transitioning toward the bradyzoite life stage retain the capacity to translocate proteins via this pathway. By epitope tagging the endogenous loci of four known effectors that translocate from the parasitophorous vacuole into the host cell nucleus, we show, by immunofluorescence assays, that most effectors accumulate in the host nucleus at early but not late time points after infection, during the tachyzoite-to-bradyzoite transition and when parasites further along the bradyzoite differentiation continuum invade a new host cell. We demonstrate that the suppression of interferon gamma signaling, which was previously shown to be mediated by the effector TgIST, also occurs in the context of prolonged infection with bradyzoites and that TgIST export is a process that occurs beyond the early stages of host cell infection. These findings have important implications regarding how this highly successful parasite maintains persistent infection of its host

Evaluation of pro-carboxypeptidase A and carboxypeptidase A as serologic markers for adenocarcinoma of the pancreas

Background: A serological marker for pancreatic cancer may allow for early detection and potentially more effective treatments. Pro-carboxypeptidase A (pro-CPA) is produced exclusively in the pancreas and converted to its active form, CPA, in the intestinal lumen. We hypothesized that alterations in serum pro-CPA and/or CPA may be useful as a diagnostic test for pancreatic cancer. Patients and methods: Serum samples obtained from 34 patients with pancreatic adenocarcinoma prior to surgical intervention and 64 control patients were assayed for pro-CPA and CPA. A variety of statistical methods was used to evaluate the utility of these measurements individually and in combination to classify the samples with respect to the presence or absence of pancreatic adenocarcinoma. Results: Because of positive skewing of the data in some populations, transformation of the data to natural logarithmic scales was used and resulted in normal distributions. All pancreatic cancer patients had ln(CPA) levels within or below the normal range defined as two standard deviations from the control group mean (−2.714±0.413). Ln(pro-CPA) levels in 24 of 34 cancer patients were outside the normal range of the control group (0.306±0.33). Pancreatic cancer patients with ln pro-CPA values within the control range had low ln CPA, advanced stage and/or evidence of pancreatic insufficiency. While each of these individual values (ln pro-CPA or ln CPA) does not adequately separate all control from cancer patients, a bivariate classification rule is presented that uses both ln pro-CPA and ln CPA simultaneously to predict the presence of pancreatic cancer with a sensitivity of 91% and a specificity of 95%. Conclusions: The data presented suggest that abnormalities in serum pro-CPA and CPA levels are associated with the presence of pancreatic cancer

Provider preferences for postoperative analgesia in obese and non-obese patients undergoing ambulatory surgery

Abstract Background Few guidelines exist on safe prescription of postoperative analgesia to obese patients undergoing ambulatory surgery. This study examines the preferences of providers in the standard treatment of postoperative pain in the ambulatory setting. Methods Providers from five academic medical centers within a single US city were surveyed from May–September 2015. They were asked to provide their preferred postoperative analgesic routine based upon the predicted severity of pain for obese and non-obese patients. McNemar’s tests for paired observations were performed to compare prescribing preferences for obese vs. non-obese patients. Fisher’s exact tests were performed to compare preferences based on experience: > 15 years vs. ≤15 years in practice, and attending vs. resident physicians. Results A total of 452 providers responded out of a possible 695. For mild pain, 119 (26.4%) respondents prefer an opioid for obese patients vs. 140 (31.1%) for non-obese (p = 0.002); for moderate pain, 329 (72.7%) for obese patients vs. 348 (77.0%) for non-obese (p = 0.011); for severe pain, 398 (88.1%) for obese patients vs. 423 (93.6%) for non-obese (p  15 years in practice vs. 86 (74.5%) with ≤15 years (p = 0.047), and 177 (68.0%) attending physicians vs. 129 (83.0%) residents (p = 0.002). Conclusions While there is a trend to prescribe less opioid analgesics to obese patients undergoing ambulatory surgery, these medications may still be over-prescribed. Less experienced physicians reported prescribing opioids to obese patients more frequently than more experienced physicians