ZFP148 (Zinc-Finger Protein 148) Binds Cooperatively With NF-1 (Neurofibromin 1) to Inhibit Smooth Muscle Marker Gene Expression During Abdominal Aortic Aneurysm Formation.

Objective- The goal of this study was to determine the role of ZFP148 (zinc-finger protein 148) in aneurysm formation. Approach and Results- ZFP148 mRNA expression increased at day 3, 7, 14, 21, and 28 after during abdominal aortic aneurysm formation in C57BL/6 mice. Loss of ZFP148 conferred abdominal aortic aneurysm protection using ERTCre+ ZFP148 flx/flx mice. In a third set of experiments, smooth muscle-specific loss of ZFP148 alleles resulted in progressively greater protection using novel transgenic mice (MYH [myosin heavy chain 11] Cre+ flx/flx, flx/wt, and wt/wt). Elastin degradation, LGAL3, and neutrophil staining were significantly attenuated, while α-actin staining was increased in ZFP148 knockout mice. Results were verified in total cell ZFP148 and smooth muscle-specific knockout mice using an angiotensin II model. ZFP148 smooth muscle-specific conditional mice demonstrated increased proliferation and ZFP148 was shown to bind to the p21 promoter during abdominal aortic aneurysm formation. ZFP148 smooth muscle-specific conditional knockout mice also demonstrated decreased apoptosis as measured by decreased cleaved caspase-3 staining. ZFP148 bound smooth muscle marker genes via chromatin immunoprecipitation analysis mediated by NF-1 (neurofibromin 1) promote histone H3K4 deacetylation via histone deacetylase 5. Transient transfections and chromatin immunoprecipitation analyses demonstrated that NF-1 was required for ZFP148 protein binding to smooth muscle marker genes promoters during aneurysm formation. Elimination of NF-1 using shRNA approaches demonstrated that NF-1 is required for binding and elimination of NF-1 increased BRG1 recruitment, the ATPase subunit of the SWI/SWF complex, and increased histone acetylation. Conclusions- ZFP148 plays a critical role in multiple murine models of aneurysm formation. These results suggest that ZFP148 is important in the regulation of proliferation, smooth muscle gene downregulation, and apoptosis in aneurysm development.

Ileal perforation in the setting of atezolizumab immunotherapy for advanced bladder cancer.

Atezolizumab is a promising immunotherapy for advanced urothelial carcinoma. Like other immune checkpoint inhibitors, it can produce rare immune-related adverse events (IRAEs). Here we present the recent case of a patient with metastatic bladder cancer who developed diarrhea and abdominal pain months after beginning atezolizumab therapy. He presented to our institution with an ileal perforation secondary to atezolizumab-induced enterocolitis. After surgical repair, the patient's condition improved, and he was discharged. We discuss the management of atezolizumab-induced enterocolitis, including the importance of early recognition and intervention to prevent more devastating complications.

A novel chronic advanced stage abdominal aortic aneurysm murine model.

OBJECTIVE: The purpose of this study was to establish a reliable, chronic model of abdominal aortic aneurysm (AAA). METHODS: Wild-type 8-week-old C56BL/6 male mice (n = 120) were equally divided into three groups: (1) BAPN group: 0.2% 3-aminopropionitrile fumarate salt (BAPN) drinking water was provided to mice 2 days before surgery until the end of study. Sham aneurysm induction surgery was performed using 5 µL of heat deactivated elastase. (2) Elastase group: mice were given regular drinking water without BAPN. During aneurysm induction surgery, 5 µL of the active form of elastase (10.3 mg protein/mL, 5.9 U/mg protein) was applied on top of the infrarenal abdominal aorta adventitia for 5 minutes. (3) BAPN+elastase group: mice were given BAPN drinking water and the active form of elastase application, as above. On postoperative days 7, 14, 21, 28, and 100, aortic samples were collected for histology, cytokine array, and gelatin zymography after aortic diameter measurement. RESULTS: Compared with the elastase group, the BAPN+elastase group had a higher AAA formation rate (93% vs 65%; P < .01) with more advanced AAAs (25 of 42 vs 1 of 40 for stage II and III; P < .001). Aneurysms from the BAPN+elastase group demonstrated persistent long-term growth (221.5% ± 36.6%, 285.8% ± 78.6%, and 801% ± 160% on days 21, 28, and 100, respectively; P < .001), with considerable thrombus formation (54%) and rupture (31%) at the advanced stages of AAA development. Cytokine levels (pro-matrix metalloproteinase 9, interleukin-1ß, interleukin-6, chemokine [C-C motif] ligand 5, triggering receptor expressed on myeloid cells 1, monocyte chemotactic protein 1, and tissue inhibitor of metalloproteinase 1) in the BAPN+elastase group were higher than in the elastase group on day 7. After day 7, cytokine levels returned to baseline, with the exception of elevated matrix metalloproteinase 2 activity. By histology, CD3-positive T cells in the BAPN+elastase group were elevated on days 28 and 100. CONCLUSIONS: A combination of oral BAPN administration and periaortic elastase application induced a chronic, advanced-stage AAA with characteristics of persistent aneurysm growth, thrombus formation, and spontaneous rupture. Future studies should use this model, especially for examining tissue remodeling during the late stages of aneurysm development.

Sarcopenia in emergency abdominal surgery.

BACKGROUND: Sarcopenia, a loss of skeletal muscle mass associated with aging, is a practical measure of frailty and has been previously identified as a predictor of outcomes in surgical cohorts including cancer resection and elderly patients. We hypothesized that sarcopenia, as measured by preoperative computerized tomography (CT) scan, predicts mortality and morbidity in emergent laparotomy. METHODS: Institutional American College of Surgeons National Surgical Quality Improvement Program data were queried for adult patients who underwent open emergency abdominal surgery between 2008 and 2013. Patients with abdominal CT scans within 30 d before surgery were included, and cross-sectional areas of the psoas muscles at vertebral level L4 were summed, normalized by patient height, and stratified by sex. The influence of this total psoas area (TPA) on postoperative morbidity and mortality was evaluated using univariate and multivariate analysis. RESULTS: Of 781 surgeries, 593 (75.9%) had appropriate preoperative CT scans. Median patient age was 61 years old, median TPA was 1719 mm2, and median body mass index was 26.7. Univariate analysis demonstrated a significant association between TPA and total postoperative morbidity (P = 0.0133), increased length of stay (<0.0001), and 90-d mortality (P = 0.0008) but not 30-d mortality (P = 0.26). In multivariate analysis, TPA lost its significance compared to more influential predictors of mortality, including American Society of Anesthesiologists classification. CONCLUSIONS: Sarcopenia, as measured by TPA, significantly predicted mortality in univariate analysis but lost significance in multivariate analysis when factors such as American Society of Anesthesiologists score were included. Because TPA is readily available at no additional risk or cost, it is a convenient additional tool for preoperative risk assessment and counseling.

B-Cell Depletion Promotes Aortic Infiltration of Immunosuppressive Cells and Is Protective of Experimental Aortic Aneurysm.

OBJECTIVE: B-cell depletion therapy is widely used for treatment of cancers and autoimmune diseases. B cells are abundant in abdominal aortic aneurysms (AAA); however, it is unknown whether B-cell depletion therapy affects AAA growth. Using experimental models of murine AAA, we aim to examine the effect of B-cell depletion on AAA formation. APPROACH AND RESULTS: Wild-type or apolipoprotein E-knockout mice were treated with mouse monoclonal anti-CD20 or control antibodies and subjected to an elastase perfusion or angiotensin II infusion model to induce AAA, respectively. Anti-CD20 antibody treatment significantly depleted B1 and B2 cells, and strikingly suppressed AAA growth in both models. B-cell depletion resulted in lower circulating IgM levels, but did not affect the levels of IgG or cytokine/chemokine levels. Although the total number of leukocyte remained unchanged in elastase-perfused aortas after anti-CD20 antibody treatment, the number of B-cell subtypes was significantly lower. Interestingly, plasmacytoid dendritic cells expressing the immunomodulatory enzyme indole 2,3-dioxygenase were detected in the aortas of B-cell-depleted mice. In accordance with an increase in indole 2,3-dioxygenase+ plasmacytoid dendritic cells, the number of regulatory T cells was higher, whereas the expression of proinflammatory genes was lower in aortas of B-cell-depleted mice. In a coculture model, the presence of B cells significantly lowered the number of indole 2,3-dioxygenase+ plasmacytoid dendritic cells without affecting total plasmacytoid dendritic cell number. CONCLUSIONS: The present results demonstrate that B-cell depletion protects mice from experimental AAA formation and promotes emergence of an immunosuppressive environment in aorta.

Cost analysis of endovascular versus open repair in the treatment of thoracic aortic aneurysms.

OBJECTIVE: For descending thoracic aortic aneurysms (TAAs), it is generally considered that thoracic endovascular aortic repairs (TEVARs) reduce operative morbidity and mortality compared with open surgical repair. However, long-term differences in survival of patients have not been demonstrated, and an increased need for aortic reintervention has been observed. Many assume that TEVAR becomes less cost-effective through time because of higher rates of reintervention and surveillance imaging. This study investigated midterm outcomes and hospital costs of TEVAR compared with open TAA repair. METHODS: This was a retrospective, single-institution review of elective TAA repairs between 2005 and 2012. Patient demographics, operative outcomes, reintervention rates, and hospital costs were assessed. The literature was also reviewed to determine commonly observed complication and reintervention rates for TEVAR and open repair. Monte Carlo simulation was used to model and to forecast hospital costs for TEVAR and open TAA repair up to 3 years after intervention. RESULTS: Our cohort consisted of 131 TEVARs and 27 open repairs. TEVAR patients were significantly older (67.2 vs 58.7 years old; P = .02) and trended toward a more severe comorbidity profile. Operative mortality for TEVAR and open repair was 5.3% and 3.7%, respectively (P = 1.0). There was a trend toward more complications in the TEVAR group, although not statistically significant (all P > .05). In-hospital costs were significantly greater in the TEVAR group ($52,008 vs $37,172; P = .001). However, cost modeling by use of reported complication and reintervention rates from the literature overlaid with our cost data produced a higher cost for the open group in-hospital ($55,109 vs $48,006) and at 3 years ($58,426 vs $52,825). Interestingly, TEVAR hospital costs, not reintervention rates, were the most significant driver of cost in the TEVAR group. CONCLUSIONS: Our institutional data showed a trend toward lower mortality and complication rates with open TAA repair, with significantly lower costs within this cohort compared with TEVAR. These findings were likely, at least in part, to be due to the milder comorbidity profile of these patients. In contrast, cost modeling by Monte Carlo simulation demonstrated lower costs with TEVAR compared with open repair at all time points up to 3 years after intervention. Our institutional data show that with appropriate selection of patients, open repair can be performed safely with low complication rates comparable to those of TEVAR. The cost model argues that despite the costs associated with more frequent surveillance imaging and reinterventions, TEVAR remains the more cost-effective option even years after TAA repair.

Derlin-dependent retrograde transport from endosomes to the Golgi apparatus.

Cells have to maintain stable plasma membrane protein and lipid compositions under normal conditions and to remodel their plasma membranes in response to stimuli. This maintenance and remodeling require that integral membrane proteins at the plasma membrane that become misfolded, because of the relatively harsher extracellular milieu or carbohydrate and amino acid sequence changes, are degraded. We had previously shown that Derlin proteins, required for quality control mechanisms in the endoplasmic reticulum, also localize to endosomes and function in the degradation of misfolded integral membrane proteins at the plasma membrane. In this study, we show that Derlin proteins physically associate with sorting nexins that function in retrograde membrane transport from endosomes to the Golgi apparatus. Using genetic studies in Caenorhabditis elegans and ricin pulse-chase analyses in murine RAW264.7 macrophages, we show that the Derlin-sorting nexin interaction is physiologically relevant. Our studies suggest that at least some integral membrane proteins that are misfolded at the plasma membrane are retrogradely transported to the Golgi apparatus and ultimately to the endoplasmic reticulum for degradation via resident quality control mechanisms.

Outcomes and Management of Peripheral Intravenous Infiltration Injuries.

Background: Although intravenous (IV) infiltration is relatively common, data regarding complications and outcomes of this problem remain limited. In addition, there is wide variation in institutional protocols for the management of IV infiltrations. Through retrospective review, we aim to delineate complications and outcomes, and propose an algorithm for the management of these injuries. Methods: We performed a retrospective review of all patients who had an IV infiltration at a tertiary care center's inpatient and outpatient facilities between January 1, 2016, and December 31, 2018. Results: In all, 479 patients with 495 infiltrations were included, with a mean age of 36.7 years. The upper extremity was involved in 89.6% of events. Of all the events, 8.6% led to a superficial soft tissue infection, 3.2% led to necrosis or eschar formation, and 1.9% led to ulceration or full-thickness wound formation. There were zero cases of compartment syndrome. Only 5.1% resulted in any long-term defects; none resulted in a functional defect of the extremity. Patients with vascular disease did not experience worse outcomes compared with healthy individuals. Plastic or orthopedic surgery was consulted in 25.3% of events. No emergent surgical intervention was required, 7 (1.4%) required bedside procedures, and 7 (1.4%) patients underwent nonacute operations. Conclusions: A specialist was consulted in about one-quarter of IV infiltrations, yet none were surgical emergencies. Instead, most complications could be monitored and managed by a primary team. Therefore, we propose algorithms involving nursing staff, wound care teams, and primary physicians with limited specialist consultation to manage these injuries.

Endocytosis function of a ligand-gated ion channel homolog in Caenorhabditis elegans.

Ligand-gated ion channels are transmembrane proteins that respond to a variety of transmitters, including acetylcholine, gamma-aminobutyric acid (GABA), glycine, and glutamate [1 and 2]. These proteins play key roles in neurotransmission and are typically found in the nervous system and at neuromuscular junctions [3]. Recently, acetylcholine receptor family members also have been found in nonneuronal cells, including macrophages [4], keratinocytes [5], bronchial epithelial cells [5], and endothelial cells of arteries [6]. The function of these channels in nonneuronal cells in mammals remains to be elucidated, though it has been shown that the acetylcholine receptor alpha7 subunit is required for acetylcholine-mediated inhibition of tumor necrosis factor release by activated macrophages [4]. We show that cup-4, a gene required for efficient endocytosis of fluids by C. elegans coelomocytes, encodes a protein that is homologous to ligand-gated ion channels, with the highest degree of similarity to nicotinic acetylcholine receptors. Worms lacking CUP-4 have reduced phosphatidylinositol 4,5-bisphosphate levels at the plasma membrane, suggesting that CUP-4 regulates endocytosis through modulation of phospholipase C activity.

Extracorporeal life support for adult cardiopulmonary failure.

The use of extracorporeal life support (ECLS) or extracorporeal membrane oxygenation (ECMO), as it is also known, has rapidly expanded over the past decade. The increase in ECMO use is a consequence of multiple factors including significant advancements in extracorporeal technology, the emergence of data supporting its use, and a growing number of potential clinical applications. This review focuses on the various modes of ECLS as well as the clinical indications and available evidence for the use of extracorporeal support.

Derlin-dependent accumulation of integral membrane proteins at cell surfaces.

Quality-control mechanisms of protein folding of transmembrane and secreted proteins is mediated by endoplasmic-reticulum-associated degradation (ERAD), which is used to detect and to degrade misfolded proteins in the ER. The ERAD machinery consists of chaperones, transmembrane proteins and ubiquitin-associated enzymes that detect, modify, and retro-translocate the misfolded proteins to the cytoplasm for degradation by the proteasome. In contrast to ERAD, little is known about the fates of integral membrane and secreted proteins that become misfolded at the plasma membrane or in the extracellular space. Derlin proteins are a family of proteins that are conserved in all eukaryotes, where they function in ERAD. Here, we show that loss of Derlin function in Caenorhabditis elegans and in mouse macrophages results in the accumulation of integral membrane proteins at the plasma membrane. Induction of LDL receptor misfolding at the plasma membrane results in a sharp decrease in its half-life, which can be rescued by proteasomal inhibitors or by reduction of Derlin-1 levels. We also show that Derlin proteins localize to endosomes as well as to the ER. Our data are consistent with a model where Derlin proteins function in a spatially segregated quality control pathway that is used for the recognition and degradation of transmembrane proteins that become misfolded at the plasma membrane and/or in endosomes.