Traumatic Atrial Septal Defect Repair via Primary Endovascular Suture Method: Case Report and Operative Technique

We report a case of a 20-year-old male with no prior medical history who was found to have an atrial septal defect on echocardiography following a motor vehicle accident (MVA). The patient underwent primary percutaneous defect closure using the NobleStitch EL (Heartstitch, Fountain Valley, California) cardiovascular suturing system with intra-operative Doppler echocardiogram showing no residual shunt or color flow. There were no operative complications. At five months follow-up, the patient reported no symptoms from the procedure. In the case of traumatic atrial septal defect repair, the NobleStitch EL system may be utilized as an alternative to open heart surgery

Surgical approach to pancreaticoduodenectomy for pancreatic adenocarcinoma: uncomplicated ends justify the means.

BACKGROUND: Pancreaticoduodenectomy (PD) remains the cornerstone of managing pancreatic ductal adenocarcinoma (PDAC) of the pancreas head/neck, but it is associated with high morbidity. We hypothesize that, in absence of pancreatectomy-specific morbidity (PSM), minimally invasive PD (MIPD) provides improved short-term outcomes compared to open PD (OPD). METHODS: NSQIP pancreatectomy-targeted database 2014-2019 was utilized. PSM was defined as the occurrence of delayed gastric emptying (DGE) and/or post-operative pancreatic fistula (POPF). The cohort was divided into No-PSM and PSM groups. Propensity score match was applied in each group to compare outcomes of MIPD vs. OPD. RESULTS: 8,121 patients were selected. Patients were divided into No-PSM (N = 6267) and PSM (N = 1854) groups. In No-PSM group, we matched 1656 OPD to 552 MIPD patients. MIPD had longer operations (423 vs. 359 min; p \u3c 0.001) but less overall morbidity (22.1% vs. 29.1%; p = 0.001) mostly attributed to less bleeding and sepsis. MIPD patients also had a one-day shorter median LOS (6 vs. 7 days; p = 0.005) and higher rates of home discharge (92.8% vs. 89.6%; p = 0.027). No difference was noted in mortality and 30-day readmission. In PSM group, 441 OPD were matched to 147 MIPD peers. MIPD had longer operations but without short-term benefits. General morbidity (61.2% vs. 61.9%), median LOS (12 vs. 12 days), mortality (2.7% vs. 1.8%), and readmission rates (32.7% vs. 26.5%) were similar. Same conclusions were drawn in the per-protocol analysis. CONCLUSION: PSM is common following PD for PDAC. In the absence of PSM, MIPD is associated with less postoperative morbidity and shorter LOS

Anatomic patterns of recurrence in biliary tract cancers: does primary tumor site matter?

BACKGROUND: Recommendations for postoperative surveillance and adjuvant therapy following curative-intent resection for biliary tract cancers-including intrahepatic and extrahepatic cholangiocarcinoma (IHCCA and EHCCA) and primary gallbladder cancer (GBC)-are uniform across primary tumor site. However, these tumors may have distinct patterns of recurrence. METHODS: A retrospective observational cohort study was performed at a specialty cancer center. Patients undergoing resection of IHCCA, EHCCA, and GBC were identified (2005-2020). Recurrence-free survival (RFS) was estimated using Kaplan-Meier and Cox proportional hazard methods. Anatomic patterns of initial site of recurrence were described and compared. RESULTS: There were 142 patients included; 50 IHCCA, 32 EHCCA, and 60 GBC. Median RFS was 30.8 months, which was not significantly different between IHCCA, EHCCA, or GBC in univariate analysis or after adjustment. Nodal positivity was significantly associated with poor RFS (HR 3.92, P≤0.001). The most common initial site of recurrence overall was intrahepatic (n=49/64, 77%), in isolation (n=32) or synchronous with other site of recurrence (n=17). Significant differences in anatomic pattern of recurrence were observed (P=0.049) with IHCCAs more commonly recurring with simultaneous hepatic-pulmonary disease (n=5/22, 23%; EHCCA n=2/19, 10%; GBC n=1/23, 4%), GBC more commonly recurring within the porta (n=7/23, 30%; IHCCA n=0; EHCCA n=1/19, 5%), and EHCCA more commonly recurring within the peritoneum (n=5/19, 26%; IHCCA n=2/22, 9%, GBC n=2/23, 9%). CONCLUSIONS: Patterns of initial recurrence appear to differ between primary tumor site, likely reflecting underlying differences in anatomy and biology. These data could help inform future studies for adjuvant therapy as well as timing and anatomic focus for surveillance imaging

A Scalable, Multiplexed Assay for Decoding GPCR-Ligand Interactions with RNA Sequencing.

G protein-coupled receptors (GPCRs) are central to how mammalian cells sense and respond to chemicals. Mammalian olfactory receptors (ORs), the largest family of GPCRs, mediate the sense of smell through activation by small molecules, though for most bonafide ligands, they have not been identified. Here, we introduce a platform to screen large chemical panels against multiplexed GPCR libraries using next-generation sequencing of barcoded genetic reporters in stably engineered human cell lines. We mapped 39 mammalian ORs against 181 odorants and identified 79 interactions that have not been reported to our knowledge, including ligands for 15 previously orphaned receptors. This multiplexed receptor assay allows the cost-effective mapping of large chemical libraries to receptor repertoires at scale

Structural and functional characterization of G protein-coupled receptors with deep mutational scanning.

The >800 human G protein-coupled receptors (GPCRs) are responsible for transducing diverse chemical stimuli to alter cell state- and are the largest class of drug targets. Their myriad structural conformations and various modes of signaling make it challenging to understand their structure and function. Here, we developed a platform to characterize large libraries of GPCR variants in human cell lines with a barcoded transcriptional reporter of G protein signal transduction. We tested 7800 of 7828 possible single amino acid substitutions to the beta-2 adrenergic receptor (β2AR) at four concentrations of the agonist isoproterenol. We identified residues specifically important for β2AR signaling, mutations in the human population that are potentially loss of function, and residues that modulate basal activity. Using unsupervised learning, we identify residues critical for signaling, including all major structural motifs and molecular interfaces. We also find a previously uncharacterized structural latch spanning the first two extracellular loops that is highly conserved across Class A GPCRs and is conformationally rigid in both the inactive and active states of the receptor. More broadly, by linking deep mutational scanning with engineered transcriptional reporters, we establish a generalizable method for exploring pharmacogenomics, structure and function across broad classes of drug receptors

Structural and functional characterization of G protein-coupled receptors with deep mutational scanning.

The >800 human G protein-coupled receptors (GPCRs) are responsible for transducing diverse chemical stimuli to alter cell state- and are the largest class of drug targets. Their myriad structural conformations and various modes of signaling make it challenging to understand their structure and function. Here, we developed a platform to characterize large libraries of GPCR variants in human cell lines with a barcoded transcriptional reporter of G protein signal transduction. We tested 7800 of 7828 possible single amino acid substitutions to the beta-2 adrenergic receptor (β2AR) at four concentrations of the agonist isoproterenol. We identified residues specifically important for β2AR signaling, mutations in the human population that are potentially loss of function, and residues that modulate basal activity. Using unsupervised learning, we identify residues critical for signaling, including all major structural motifs and molecular interfaces. We also find a previously uncharacterized structural latch spanning the first two extracellular loops that is highly conserved across Class A GPCRs and is conformationally rigid in both the inactive and active states of the receptor. More broadly, by linking deep mutational scanning with engineered transcriptional reporters, we establish a generalizable method for exploring pharmacogenomics, structure and function across broad classes of drug receptors

Reproducibility of fluorescent expression from engineered biological constructs in E. coli

We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.Peer reviewe