Extracellular matrix‐based hydrogels such as Matrigel are easy‐to‐use, commercially available, and offer environments for three‐dimensional (3‐D) cell culture that mimic native tissue. However, manipulating small volumes of these materials to produce thin‐layer 3‐D culture systems suitable for analysis is difficult because of air–liquid‐substrate interfacial tension effects and evaporation. Here, we demonstrate two simple techniques that use standard liquid‐handling tools and nontreated 96‐well plates to produce uniform, thin‐layer constructs for 3‐D culture of cells in Matrigel. The first technique, the floating 3‐D cell culture method, uses phase‐separating polymers to form a barrier between the dispensed Matrigel, air, and cultureware surface to generate consistently thin hydrogels from volumes as low as 5 μL. These unanchored gels provide a useful assay for investigating airway smooth muscle cell contraction and may have future applications in studying asthma pathophysiology. The second technique, the fixed 3‐D cell culture method, provides an anchored gel system for culturing noncontractile cells (e.g., neurons) where 20 μL of Matrigel is dispensed into the bottom of a well filled with culture medium to form a thin gel containing embedded cells. This technique has potential widespread applications as an accessible 3‐D culture platform for high‐throughput production of disease models for evaluation of novel drug therapies. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2733, 2019

No abstract

Background Melanoma is one of the most common cancers in Canada, 1 with the highest incidence in Nova Scotia (NS). Objectives To describe the demographics, lesion characteristics, and diagnostic accuracy of suspected melanomas excised at the largest center in NS. Methods The dermatopathology database was interrogated for cases of possible melanoma from 2015 through 2019. Age, gender, site of lesion, pathologic diagnosis, Breslow depth, and equivocal pathology were assessed. Results 984 lesions had a clinical diagnosis of possible melanoma, identifying 301 melanomas. Of these, 142 (47%) were melanoma in situ (MIS) which in females occurred mostly on the extremities, while in males the head predominated. For invasive melanoma (IM), the extremities remained predominant for women, while the back was most common in men. Lower extremity lesions were more likely to be invasive and female patients were more likely to present with them at a younger age compared to males. The pathology was challenging for 23.94% of MIS, and 16.18% of IM. A mean of 3.1 lesions were excised for every melanoma identified. Conclusions Early diagnosis of melanoma is challenging clinically and pathologically. Our melanoma detection rate was 31%, with an increasing trend in the proportion of MIS, and decreasing trend in the proportion of IM over the years. Almost 50% of melanomas were detected in early stages, supporting positive outcomes. Melanomas were more common on extremities in females and the back in males. Melanomas on the lower limbs were more likely to be invasive regardless of gender.

Primary outcome was the incidence of PEP. The diagnosis and severity of PEP were defined by the ASGE lexicon for endoscopic adverse events. Patient-related factors, operator-related factors, procedure-related factors and preventive measures were accumulated. The risk factors and preventive measures for PEP were examined by using univariate and multivariate analyses. Results: A total of 16,032 ERCP procedures were performed in the 36 centers during the period, 3,739 ERCPs were enrolled in this study. The average of age was 72.5 years and 43.7% of patients were women. PEP developed in 258 cases (6.9%); 201 mild, 39 moderate, 17 severe, and 1 fatal. Multivariate analysis was performed using 20 risk factors and 8 preventive measures. On multivariate analysis, the significant factors were women under 50 years old, ASA-PS 3, normal serum bilirubin level, obstruction of main pancreatic duct at the pancreatic head, guidewire insertion for the pancreatic duct, total procedure time >60 minutes, prophylactic pancreatic stenting, rectal administration of NSAIDs after ERCP, and spraying saline-epinephrine (Table 1, 2). Conclusions: The extracted risk factors for PEP were young women, normal serum bilirubin level, guidewire insertion for pancreatic duct and prolonged procedure time. Prophylactic pancreatic stenting and spraying saline-epinephrine were suggested to be effective as preventive measures for PEP. The administration of NSAIDs after ERCP was considered a risk factor rather than a preventive measure. However, since the operators decided to administer NSAIDs based on the patient conditions during and after the procedures, then we have to consider what factors were hidden behind the post-ERCP NSAIDs administration.

No abstract