Trends of Trauma Admissions in a Rural Trauma Center During Coronavirus Disease 2019 Pandemic.

INTRODUCTION: The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to implementing strict social distancing mandates nationwide. This study evaluates the trauma trends during the pandemic at a rural level II trauma center in Pennsylvania. METHODS: A retrospective review of all trauma registries between 2018 and 2021 was performed overall and on a 6-month basis. Injury severity score, injury types-blunt versus penetrating, and mechanisms of injury were compared across the years. RESULTS: A total of 3056 patients in 2018-2019 and 2506 patients in 2020-2021 were evaluated as the historic control and study group, respectively. The median age of the patients was 63 and 62 years in the control and the study group, respectively (P = 0.616). There was an overall significant decline in blunt injuries and an increase in penetrating injuries (Blunt: 2945 versus 2329, Penetrating: 89 versus 159, P < 0.001). Injury severity score was not different across the eras. Falls, motorcycle accidents, motor vehicle accidents, and all-terrain vehicles comprised most of the blunt traumas. Penetrating injuries secondary to assault with firearms and sharp weapons had an increasing trend. CONCLUSIONS: There was no association between trauma numbers and the beginning of the pandemic. Overall, there was a decline in trauma numbers during the second 6 mo of the pandemic. There was an increase in injuries involving firearms and stabbing. Rural trauma centers have a unique demographic and admission trend that should be considered while advising regulatory changes during pandemics.

Identification of core allosteric sites through temperature- and nucleus-invariant chemical shift covariance.

Allosteric regulation is essential to control biological function. In addition, allosteric sites offer a promising venue for selective drug targeting. However, accurate mapping of allosteric sites remains challenging since allostery relies on often subtle, yet functionally relevant, structural and dynamical changes. A viable approach proposed to overcome such challenge is chemical shift covariance analysis (CHESCA). Although CHESCA offers an exhaustive map of allosteric networks, it is critical to define the core allosteric sites to be prioritized in subsequent functional studies or in the design of allosteric drugs. Here, we propose two new CHESCA-based methodologies, called temperature CHESCA (T-CHESCA) and CLASS-CHESCA, aimed at narrowing down allosteric maps to the core allosteric residues. Both T- and CLASS-CHESCAs rely on the invariance of core inter-residue correlations to changes in the chemical shifts of the active and inactive conformations interconverting in fast exchange. In T-CHESCA the chemical shifts of such states are modulated through temperature changes, while in CLASS-CHESCA through variations in the spin-active nuclei involved in pairwise correlations. T- and CLASS-CHESCAs, as well as complete-linkage CHESCA, were applied to the cAMP-binding domain of the exchange protein directly activated by cAMP (EPAC), which serves as a prototypical allosteric switch. Residues consistently identified by the three CHESCA methods were found in previously identified EPAC allosteric core sites. Hence, T-, CLASS-, and CL-CHESCA provide a toolset to establish allosteric site hierarchy and triage allosteric sites to be further analyzed by mutations and functional assays. Furthermore, the core allosteric networks selectively revealed through T- and CLASS-CHESCA are expected to facilitate the mechanistic understanding of disease-related mutations and the design of selective allosteric modulators.

A systematic review of primary ileostomy site malignancies.

BACKGROUND: This paper aimed to elucidate the etiologies of all primary ileostomy site malignancies published in the literature. METHODS: A review of the literature was conducted following PRISMA guidelines by querying PubMed, Global Health, and Web of Science for articles published before November 2020. Search criteria contained broad terminology for ileostomy site neoplasms without language, date, or publication limitations. A full-text review of the abstracts confirmed primary malignant pathologies and was evaluated for study inclusion. RESULTS: Literature search discovered 858 publications, with 76 meeting eligibility criteria. The final sample contained 91 patients, with equal males and females. The mean age of patients with ileostomy site malignancy was 62.0 ± 12.2, with an average ileostomy age of 29.4 ± 12.4. The most common indications for ileostomy creation were inflammatory bowel disease (IBD) (73.6%) and familial adenomatous polyposis (FAP) (20.9%). There was a total of eight ileostomy malignant pathologies reported, with adenocarcinoma being the most common (76.9%), followed by squamous cell carcinoma (SCC) (11.0%). Adenocarcinoma was diagnosed at a younger age than SCC (59.7 vs. 72.3) and developed over a shorter time (28.8 vs. 37.0). Patients with FAP almost exclusively developed adenocarcinoma (94.4%) at a younger stoma age (25.8 vs. 31.4) than those with IBD who developed seven diverse pathologies. With a median follow-up of 0.75 years, four patients developed disease recurrence and received oncologic resection of their cancer less often than the 55 negative patients (p = 0.04). CONCLUSION: Ileostomy site malignancies are late-appearing complications that require curative surgery. Their presentation is associated with ileostomy duration and creation indication, such as FAP or IBD. We recommend screening at a stoma age ≥ 20 or patient age ≥ 50 for patients with FAP, while stoma age ≥ 25 or patient age ≥ 60 for IBD patients.

Cellular cholesterol accumulation modulates high fat high sucrose (HFHS) diet-induced ER stress and hepatic inflammasome activation in the development of non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH), is the form of non-alcoholic fatty liver disease posing risk to progress into serious long term complications. Human and pre-clinical models implicate cellular cholesterol dysregulation playing important role in its development. Mouse model studies suggest synergism between dietary cholesterol and fat in contributing to NASH but the mechanisms remain poorly understood. Our laboratory previously reported the primary importance of hepatic endoplasmic reticulum cholesterol (ER-Chol) in regulating hepatic ER stress by comparing the responses of wild type, Ldlr-/-xLcat+/+ and Ldlr-/-xLcat-/- mice, to a 2% high cholesterol diet (HCD). Here we further investigated the roles of ER-Chol and ER stress in HFHS diet-induced NASH using the same strains. With HFHS diet feeding, both WT and Ldlr-/-xLcat+/+ accumulate ER-Chol in association with ER stress and inflammasome activation but the Ldlr-/-xLcat-/- mice are protected. By contrast, all three strains accumulate cholesterol crystal, in correlation with ER-Chol, albeit less so in Ldlr-/-xLcat-/- mice. By comparison, HCD feeding per se (i) is sufficient to promote steatosis and activate inflammasomes, and (ii) results in dramatic accumulation of cholesterol crystal which is linked to inflammasome activation in Ldlr-/-xLcat-/- mice, independent of ER-Chol. Our data suggest that both dietary fat and cholesterol each independently promote steatosis, cholesterol crystal accumulation and inflammasome activation through distinct but complementary pathways. In vitro studies using palmitate-induced hepatic steatosis in HepG2 cells confirm the key roles by cellular cholesterol in the induction of steatosis and inflammasome activations. These novel findings provide opportunities for exploring a cellular cholesterol-focused strategy for treatment of NASH.

Lecithin:Cholesterol Acyltransferase (LCAT) Deficiency Promotes Differentiation of Satellite Cells to Brown Adipocytes in a Cholesterol-dependent Manner.

Our laboratory previously reported that lecithin:cholesterol acyltransferase (LCAT) and LDL receptor double knock-out mice (Ldlr(-/-)xLcat(-/-) or DKO) spontaneously develop functioning ectopic brown adipose tissue (BAT) in skeletal muscle, putatively contributing to protection from the diet-induced obesity phenotype. Here we further investigated their developmental origin and the mechanistic role of LCAT deficiency. Gene profiling of skeletal muscle in DKO newborns and adults revealed a classical lineage. Primary quiescent satellite cells (SC) from chow-fed DKO mice, not in Ldlr(-/-)xLcat(+/+) single-knock-out (SKO) or C57BL/6 wild type, were found to (i) express exclusively classical BAT-selective genes, (ii) be primed to express key functional BAT genes, and (iii) exhibit markedly increased ex vivo adipogenic differentiation into brown adipocytes. This gene priming effect was abrogated upon feeding the mice a 2% high cholesterol diet in association with accumulation of excess intracellular cholesterol. Ex vivo cholesterol loading of chow-fed DKO SC recapitulated the effect, indicating that cellular cholesterol is a key regulator of SC-to-BAT differentiation. Comparing adipogenicity of Ldlr(+/+)xLcat(-/-) (LCAT-KO) SC with DKO SC identified a role for LCAT deficiency in priming SC to express BAT genes. Additionally, we found that reduced cellular cholesterol is important for adipogenic differentiation, evidenced by increased induction of adipogenesis in cholesterol-depleted SC from both LCAT-KO and SKO mice. Taken together, we conclude that ectopic BAT in DKO mice is classical in origin, and its development begins in utero. We further showed complementary roles of LCAT deficiency and cellular cholesterol reduction in the SC-to-BAT adipogenesis.

A tool set to map allosteric networks through the NMR chemical shift covariance analysis.

Allostery is an essential regulatory mechanism of biological function. Allosteric sites are also pharmacologically relevant as they are often targeted with higher selectivity than orthosteric sites. However, a comprehensive map of allosteric sites poses experimental challenges because allostery is driven not only by structural changes, but also by modulations in dynamics that typically remain elusive to classical structure determination methods. An avenue to overcome these challenges is provided by the NMR chemical shift covariance analysis (CHESCA), as chemical shifts are exquisitely sensitive to redistributions in dynamic conformational ensembles. Here, we propose a set of complementary CHESCA algorithms designed to reliably detect allosteric networks with minimal occurrences of false positives or negatives. The proposed CHESCA toolset was tested for two allosteric proteins (PKA and EPAC) and is expected to complement traditional comparative structural analyses in the comprehensive identification of functionally relevant allosteric sites, including those in otherwise elusive partially unstructured regions.