HL-1 cells express an inwardly rectifying K+ current activated via muscarinic receptors comparable to that in mouse atrial myocytes

An inwardly rectifying K^+ current is present in atrial cardiac myocytes that is activated by acetylcholine (I_{KACh}). Physiologically, activation of the current in the SA node is important in slowing the heart rate with increased parasympathetic tone. It is a paradigm for the direct regulation of signaling effectors by the Gβγ G-protein subunit. Many questions have been addressed in heterologous expression systems with less focus on the behaviour in native myocytes partly because of the technical difficulties in undertaking comparable studies in native cells. In this study, we characterise a potassium current in the atrial-derived cell line HL-1. Using an electrophysiological approach, we compare the characteristics of the potassium current with those in native atrial cells and in a HEK cell line expressing the cloned Kir3.1/3.4 channel. The potassium current recorded in HL-1 is inwardly rectifying and activated by the muscarinic agonist carbachol. Carbachol-activated currents were inhibited by pertussis toxin and tertiapin-Q. The basal current was time-dependently increased when GTP was substituted in the patch-clamp pipette by the non-hydrolysable analogue GTPγS. We compared the kinetics of current modulation in HL-1 with those of freshly isolated atrial mouse cardiomyocytes. The current activation and deactivation kinetics in HL-1 cells are comparable to those measured in atrial cardiomyocytes. Using immunofluorescence, we found GIRK4 at the membrane in HL-1 cells. Real-time RT-PCR confirms the presence of mRNA for the main G-protein subunits, as well as for M2 muscarinic and A1 adenosine receptors. The data suggest HL-1 cells are a good model to study IKAch

Timing But Not Patterns of Recurrence Is Different Between Node-negative and Node-positive Resected Pancreatic Cancer

Objective:Our aim was to evaluate recurrence patterns of surgically resected PDAC patients with negative (pN0) or positive (pN1) lymph nodes.Summary Background Data:Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer death by 2030. This is mostly due to early local and distant metastasis, even after surgical resection. Knowledge about patterns of recurrence in different patient populations could offer new therapeutic avenues.Methods:Clinicopathologic data were collected for 546 patients who underwent resection of their PDAC between 2005 and 2016 from 2 tertiary university centers. Patients were divided into an upfront resection group (n = 394) and a neoadjuvant group (n = 152).Results:Tumor recurrence was significantly less common in pN0 patients as compared with pN1 patients, (upfront surgery: 55% vs. 77%, P < 0.001 and 64% vs. 78%, P = 0.040 in the neoadjuvant group). In addition, time to recurrence was significantly longer in pN0 versus pN1 patients in the upfront resected patients (median 16 mo pN0 vs. 10 mo pN1 P < 0.001), and the neoadjuvant group (pN0 21 mo vs. 11 mo pN1, P < 0.001). Of the patients who recurred, 62% presented with distant metastases (63% of pN0 and 62% of pN1, P = 0.553), 24% with local disease (27% of pN0 and 23% of pN1, P = 0.672) and 14% with synchronous local and distant disease (10% of pN0 and 15% of pN1, P = 0.292). Similarly, there was no difference in recurrence patterns between pN0 and pN1 in the neoadjuvant group, in which 68% recurred with distant metastases (76% of pN0 and 64% of pN1, P = 0.326) and 18% recurred with local disease (pN0: 22% and pN1: 15%, P = 0.435).Conclusion:Time to recurrence was significantly longer for pN0 patients. However, patterns of recurrence for pN0 vs. pN1 patients were identical. Lymph node status was predictive of time to recurrence, but not location of recurrence. © 2020 Lippincott Williams and Wilkins. All rights reserved

Properties of the Vacancy Statistic in the Discrete Circle Covering Problem

Holst (1985) introduced a discrete spacings model that is related to the Bose-Einstein distribution and obtained the distribution of the number of vacant slots in an associated circle covering problem. We correct his expression for its probability mass function, obtain the first two moments, and describe their limiting properties. We also discuss an application of our results to a study of contagion in banking networks

Nitric Oxide Mediates Stretch-Induced Ca2+ Release via Activation of Phosphatidylinositol 3-Kinase-Akt Pathway in Smooth Muscle

Hollow smooth muscle organs such as the bladder undergo significant changes in wall tension associated with filling and distension, with attendant changes in muscle tone. Our previous study indicated that stretch induces Ca(2+) release occurs in the form of Ca(2+) sparks and Ca(2+) waves in urinary bladder myocytes. While, the mechanism underlying stretch-induced Ca2+ release in smooth muscle is unknown.We examined the transduction mechanism linking cell stretch to Ca(2+) release. The probability and frequency of Ca(2+) sparks induced by stretch were closely related to the extent of cell extension and the time that the stretch was maintained. Experiments in tissues and single myocytes indicated that mechanical stretch significantly increases the production of nitric oxide (NO) and the amplitude and duration of muscle contraction. Stretch-induced Ca(2+) sparks and contractility increases were abrogated by the NO inhibitor L-NAME and were also absent in eNOS knockout mice. Furthermore, exposure of eNOS null mice to exogenously generated NO induced Ca(2+) sparks. The soluble guanylyl cyclase inhibitor ODQ did not inhibit SICR, but this process was effectively blocked by the PI3 kinase inhibitors LY494002 and wortmannin; the phosphorylation of Akt and eNOS were up-regulated by 204+/-28.6% and 258+/-36.8% by stretch, respectively. Moreover, stretch significantly increased the eNOS protein expression level.Taking together, these results suggest that stretch-induced Ca2+ release is NO dependent, resulting from the activation of PI3K/Akt pathway in smooth muscle

De-identification of primary care electronic medical records free-text data in Ontario, Canada

<p>Abstract</p> <p>Background</p> <p>Electronic medical records (EMRs) represent a potentially rich source of health information for research but the free-text in EMRs often contains identifying information. While de-identification tools have been developed for free-text, none have been developed or tested for the full range of primary care EMR data</p> <p>Methods</p> <p>We used <it>deid </it>open source de-identification software and modified it for an Ontario context for use on primary care EMR data. We developed the modified program on a training set of 1000 free-text records from one group practice and then tested it on two validation sets from a random sample of 700 free-text EMR records from 17 different physicians from 7 different practices in 5 different cities and 500 free-text records from a group practice that was in a different city than the group practice that was used for the training set. We measured the sensitivity/recall, precision, specificity, accuracy and F-measure of the modified tool against manually tagged free-text records to remove patient and physician names, locations, addresses, medical record, health card and telephone numbers.</p> <p>Results</p> <p>We found that the modified training program performed with a sensitivity of 88.3%, specificity of 91.4%, precision of 91.3%, accuracy of 89.9% and F-measure of 0.90. The validations sets had sensitivities of 86.7% and 80.2%, specificities of 91.4% and 87.7%, precisions of 91.1% and 87.4%, accuracies of 89.0% and 83.8% and F-measures of 0.89 and 0.84 for the first and second validation sets respectively.</p> <p>Conclusion</p> <p>The <it>deid </it>program can be modified to reasonably accurately de-identify free-text primary care EMR records while preserving clinical content.</p

Outcomes After Minimally-invasive Versus Open Pancreatoduodenectomy: A Pan-European Propensity Score Matched Study

OBJECTIVE: To assess short-term outcomes after minimally invasive (laparoscopic, robot-assisted, and hybrid) pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) among European centers. BACKGROUND: Current evidence on MIPD is based on national registries or single expert centers. International, matched studies comparing outcomes for MIPD and OPD are lacking. METHODS: Retrospective propensity score matched study comparing MIPD in 14 centers (7 countries) performing ≥10 MIPDs annually (2012-2017) versus OPD in 53 German/Dutch surgical registry centers performing ≥10 OPDs annually (2014-2017). Primary outcome was 30-day major morbidity (Clavien-Dindo ≥3). RESULTS: Of 4220 patients, 729/730 MIPDs (412 laparoscopic, 184 robot-assisted, and 130 hybrid) were matched to 729 OPDs. Median annual case-volume was 19 MIPDs (interquartile range, IQR 13-22), including the first MIPDs performed in 10/14 centers, and 31 OPDs (IQR 21-38). Major morbidity (28% vs 30%, P = 0.526), mortality (4.0% vs 3.3%, P = 0.576), percutaneous drainage (12% vs 12%, P = 0.809), reoperation (11% vs 13%, P = 0.329), and hospital stay (mean 17 vs 17 days, P > 0.99) were comparable between MIPD and OPD. Grade-B/C postoperative pancreatic fistula (POPF) (23% vs 13%, P < 0.001) occurred more frequently after MIPD. Single-row pancreatojejunostomy was associated with POPF in MIPD (odds ratio, OR 2.95, P < 0.001), but not in OPD. Laparoscopic, robot-assisted, and hybrid MIPD had comparable major morbidity (27% vs 27% vs 35%), POPF (24% vs 19% vs 25%), and mortality (2.9% vs 5.2% vs 5.4%), with a fewer conversions in robot-assisted- versus laparoscopic MIPD (5% vs 26%, P < 0.001). CONCLUSIONS: In the early experience of 14 European centers performing ≥10 MIPDs annually, no differences were found in major morbidity, mortality, and hospital stay between MIPD and OPD. The high rates of POPF and conversion, and the lack of superior outcomes (ie, hospital stay, morbidity) could indicate that more experience and higher annual MIPD volumes are needed

Surgical Outcome After Distal Pancreatectomy With and Without Portomesenteric Venous Resection in Patients with Pancreatic Adenocarcinoma:A Transatlantic Evaluation of Patients in North America, Germany, Sweden, and The Netherlands (GAPASURG)

BackgroundPancreatic adenocarcinoma located in the pancreatic body might require a portomesenteric venous resection (PVR), but data regarding surgical risks after distal pancreatectomy (DP) with PVR are sparse. Insight into additional surgical risks of DP-PVR could support preoperative counseling and intraoperative decision making. This study aimed to provide insight into the surgical outcome of DP-PVR, including its potential risk elevation over standard DP.MethodsWe conducted a retrospective, multicenter study including all patients with pancreatic adenocarcinoma who underwent DP +/- PVR (2018-2020), registered in four audits for pancreatic surgery from North America, Germany, Sweden, and The Netherlands. Patients who underwent concomitant arterial and/or multivisceral resection(s) were excluded. Predictors for in-hospital/30-day major morbidity and mortality were investigated by logistic regression, correcting for each audit.ResultsOverall, 2924 patients after DP were included, of whom 241 patients (8.2%) underwent DP-PVR. Rates of major morbidity (24% vs. 18%; p = 0.024) and post-pancreatectomy hemorrhage grade B/C (10% vs. 3%; p = 0.041) were higher after DP-PVR compared with standard DP. Mortality after DP-PVR and standard DP did not differ significantly (2% vs. 1%; p = 0.542). Predictors for major morbidity were PVR (odds ratio [OR] 1.500, 95% confidence interval [CI] 1.086-2.071) and conversion from minimally invasive to open surgery (OR 1.420, 95% CI 1.032-1.970). Predictors for mortality were higher age (OR 1.087, 95% CI 1.045-1.132), chronic obstructive pulmonary disease (OR 4.167, 95% CI 1.852-9.374), and conversion from minimally invasive to open surgery (OR 2.919, 95% CI 1.197-7.118), whereas concomitant PVR was not associated with mortality.ConclusionsPVR during DP for pancreatic adenocarcinoma in the pancreatic body is associated with increased morbidity, but can be performed safely in terms of mortality