Perivascular CLICK-gelatin delivery of thrombospondin-2 small interfering RNA decreases development of intimal hyperplasia after arterial injury.

Bypass graft failure occurs in 20%-50% of coronary and lower extremity bypasses within the first-year due to intimal hyperplasia (IH). TSP-2 is a key regulatory protein that has been implicated in the development of IH following vessel injury. In this study, we developed a biodegradable CLICK-chemistry gelatin-based hydrogel to achieve sustained perivascular delivery of TSP-2 siRNA to rat carotid arteries following endothelial denudation injury. At 21 days, perivascular application of TSP-2 siRNA embedded hydrogels significantly downregulated TSP-2 gene expression, cellular proliferation, as well as other associated mediators of IH including MMP-9 and VEGF-R2, ultimately resulting in a significant decrease in IH. Our data illustrates the ability of perivascular CLICK-gelatin delivery of TSP-2 siRNA to mitigate IH following arterial injury.

The impact of heparin and direct thrombin inhibitors on cell-penetrating polymer siRNA transfection.

Gene therapy using siRNA has become a promising strategy to achieve targeted gene knockdown for treatment of cardiovascular pathologies. However, efficient siRNA transfection often relies on cationic delivery vectors such as synthetic cell-penetrating polymers which are susceptible to interference by negatively charged molecules. Anticoagulants such as heparin, which is negatively charged and widely used in cardiovascular applications, may pose a significant barrier to effective siRNA delivery. We therefore conducted in vitro studies utilizing human smooth muscle and endothelial cells transfected with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and ß2-microglobulin (B2M) siRNA in the presence of heparin, argatroban, and bivalirudin in order to determine which anticoagulant therapy is most compatible for siRNA delivery. We observed that while heparin, at clinical doses, decreases the efficiency of siRNA targeted mRNA knockdown, mRNA knockdown is not inhibited in the presence of either argatroban or bivalirudin. Our data suggests that heparin should be avoided during siRNA therapy with cationic transfection agents, and argatroban and bivalirudin should be used in its stead.

Utility of Torso Imaging for Elderly Patients Sustaining Ground-Level Falls.

INTRODUCTION: Computed tomography (CT) of the torso has become increasingly common for assessment of fall patients in the emergency department. Some data suggest that older adults (≥65) may benefit from torso imaging more than younger patients. We sought to evaluate the usage and utility of CT imaging for elderly patients presenting after ground-level falls (GLFs) from 1 meter or less at our level 1 trauma center. METHODS: Patients ≥18 presenting with GLF in 2015-2019 were included. Data were obtained through chart and trauma registry review. Descriptive statistics were used to summarize the use of CT imaging for patients younger than versus older than 65 y old. Three multivariate logistic regression models with age as a continuous, binary (<65 versus ≥65), or categorical (in multiples of 5) variable were used to investigate whether age is associated with an increased identification of traumatic injury not previously suspected or known based on physical exam (PE) or plain radiograph after GLF. RESULTS: A total of 522 patients <65 and 673 patients ≥65 y old were included. Older patients were significantly more likely to receive screening chest radiograph, screening pelvic radiograph, brain CT, and neck CT (all P < 0.001), but not torso (chest, abdomen, and pelvis) CT (P = 0.144). On multivariate logistic regression, age was not significantly associated with an increased odds of identification of traumatic injury after torso CT (continuous: adjusted odds ratio [aOR] = 1.01, 95% confidence interval [CI] = 0.99-1.03, P = 0.379; binary: aOR = 0.86, 95% CI = 0.46-1.58, P = 0.619; categorical: aOR = 1.03, 95% CI = 0.94-1.14, P = 0.453). A positive PE was the only variable associated with significantly increased odds of having an abnormal torso CT scan in all models. Only two patients ≥65 y old had injuries identified on torso CT in the context of a negative PE and negative screening imaging. CONCLUSIONS: The rate of torso injury identification in patients sustaining GLF is not associated with age, but is strongly associated with positive PE findings. In the subset of elderly GLF patients without positive torso PE findings, more conservative use of CT imaging could decrease health-care utilization costs without compromising patient care.

Patients Experience Significant Long-term Social and Health Challenges after Major Lower Extremity Amputation.

OBJECTIVES: Major lower extremity amputation is a significant life-changing event that can have long-term implications. The goal of this study was to assess long-term medical outcomes and social determinants of health (SDH) challenges in this population. METHODS: A retrospective review of major lower extremity (above ankle) amputations (2018-2022) was performed at a safety-net tertiary care center. Patients who participated in a SDH survey between 6-months to 1.5 years postoperatively were included for survey analysis. Patient demographics, comorbidities, and perioperative and long-term outcomes were analyzed. RESULTS: There were 100 patients included. Mean age was 61.5 years and 23% were of female gender. The majority (57%) were Black race, 20% White race, and 21% Hispanic ethnicity. Comorbidities included diabetes (78%), chronic kidney disease (51%), coronary artery disease (31%), congestive heart failure (23%), previous cerebrovascular events (19%), and 37% used opioids preadmission. At baseline, the majority (62%) lived at home. Guillotine amputation was performed in 24%, with definitive amputation below and above knee in 67% and 33%, respectively. Median length of stay was 7 days. Readmission at 30, 90 days, and 1-year was 13%, 30%, and 43% respectively. The average follow-up was 839 days. At long-term follow-up, 55% lived at home, 25% used opioids, and only 25% were independently ambulatory. In the SDH survey at follow-up, 32% identified at least one SDH challenge, with younger patients more often affected (58 vs. 63 years, P=.031). SDH challenges consisted of food insecurity (17%), housing insecurity (13%), transportation challenges (13%), seeking employment (8%), difficulty paying for utilities (5%) and medications (4%), seeking further education (5%), and difficulty caring for family/friends (4%). On multivariable analysis, having at least one SDH challenge was independently associated with 1-year readmission (OR 6.7, 95% CI 1.3-35.8, P<.001). Older age was associated with lower long-term independent ambulation (OR 0.92, 95% CI 0.85-0.99, P=.025). CONCLUSION: After major lower extremity amputation, patients have significant medical and social challenges with fewer living at home, the majority were not independently ambulatory, and one third having at least one SDH challenge. Improvements in long-term support including medical, social, and rehabilitation services are required for this vulnerable population.

Early Kidney Transplantation or Conversion to Peritoneal Dialysis after First-Time Arteriovenous Access Creation.

BACKGROUND: After autogenous arteriovenous (AV) access creation for end-stage renal disease, a majority of patients will continue on hemodialysis (HD), a minority will receive definitive treatment with kidney transplantation, and a subset of patients will convert to peritoneal dialysis (PD). Our goal was to identify patient factors associated with early transition from HD to either kidney transplantation or PD. METHODS: This is a case-control study of all patients with first-time AV access creation in the Vascular Quality Initiative (2011-2022) who had long-term follow-up. Patients who remained on HD after AV access creation were the control group while patients who received early kidney transplant or who converted to PD were the 2 case groups. Relationship among demographics, comorbidities, neighborhood social disadvantage, and functional status as they relate to renal replacement therapy modality was assessed. RESULTS: There were 19,782 patients included; the average age was 62 ± 15 years and 57% were male. During the follow-up period of a median 306 (71-403) days, 1.3% underwent a kidney transplantation and 2.3% underwent conversion to PD. On univariable analysis, rates of kidney transplantation or conversion to PD varied with race (P < 0.001), insurance status (P < 0.001), area deprivation index (ADI) quintile (P < 0.001), and several medical comorbidities. On multivariable analysis, impaired ambulation, current smoking, Medicaid or Medicare insurance, Black race, heart failure, body mass index, and older age were associated with decreased transplantation rates. Conversion to PD was associated with ADI Q5, Q4, and Q3. Decreased conversion to PD was associated with impaired ambulation, Hispanic ethnicity, Black race, former smoking, medication-controlled diabetes, and older age. CONCLUSIONS: Decreased kidney transplantation was associated with Black race and noncommercial health insurance but not ADI quintile, suggesting disparities exist beyond community-level access to care. Early kidney transplantation conveyed a 3-year survival benefit compared with HD and PD, which had similar survival. Furthermore work is required to increase access to kidney transplantation and PD.

High Prevalence of Adverse Social Determinants of Health in Dialysis Access Creation Patients in a Safety-Net Setting.

BACKGROUND: Patients receiving dialysis access surgery are often exposed to adverse social determinants of health (SDH) that negatively impact their care. Our goal was to characterize these factors experienced by our arteriovenous dialysis access patients and identify differences in health outcomes based on their SDH. METHODS: We performed a retrospective cohort study of all patients who underwent dialysis access creation (2017-2021) and were screened for SDH at a clinical visit (using THRIVE survey) implemented at an urban, safety-net hospital institution within 1 year of access creation. Demographics, procedural details, early postoperative outcomes, survey responses, and referral to our hospital's preventive food pantry were recorded. Univariable analysis and multivariable analyses were performed to assess for associations with key health outcomes. RESULTS: There were 190 patients who responded to the survey within 1 year of their operation. At least 1 adverse SDH was identified in 42 (22%) patients. Normalized to number of respondents for each question, adverse SDH identified were difficulty obtaining transportation to medical appointments (18%), food insecurity (16%), difficulty affording utilities (13%), difficulty affording medication (12%), unemployed and seeking employment (9%), unstable housing (7%), difficulty caring for family/friends (6%), and desiring more education (5%). There were 71 (37%) patients who received food pantry referrals. Mean age was 60 years and 38% of patients were female and 64% were Black. More than half of patients (57%) had a tunneled dialysis catheter (TDC) at the time of access creation. Dialysis accesses created were brachiocephalic (39%), brachiobasilic (25%), radiocephalic fistulas (16%), and arteriovenous grafts (14%). Thirty-day emergency department (ED) visits, 30-day readmissions, and 90-day mortality occurred in 23%, 21%, and 2%, respectively. On univariable and multivariable analyses, any adverse SDH determined on survey and food pantry referral were not associated with preoperative dialysis through TDCs, receiving nonautogenous dialysis access, 30-day ED visits and readmissions, or 90-day mortality. CONCLUSION: Nearly a quarter of dialysis access surgery patients at a safety-net hospital experienced adverse SDH and more than one-third received a food pantry referral. Most common difficulties experienced include difficulty obtaining transportation to medical appointments, food insecurity, and difficulty paying for utilities and medication. Although there were no differences in postoperative outcomes, the high prevalence of these adverse SDH warrants prioritization of resources in this population to ensure healthy equity and further investigation into their effects on health outcomes.

Impact of neighborhood social disadvantage on the presentation and management of peripheral artery disease.

OBJECTIVE: Studies examining the relationship between socioeconomic disparities and peripheral artery disease (PAD) often focus on individual social health determinants and fail to account for the complex interplay between factors that ultimately impact disease severity and outcomes. Area deprivation index (ADI), a validated measure of neighborhood adversity, provides a more comprehensive assessment of social disadvantage. Therefore, we examined the impact of ADI on PAD severity and its management. METHODS: We identified all patients who underwent infrainguinal revascularization (open or endovascular) or amputation for symptomatic PAD in the Vascular Quality Initiative registry between 2003 and 2020. An ADI score of 1 to 100 was assigned to each patient based on their residential zip code, with higher ADI scores corresponding with increasing adversity. Patients were categorized by ADI quintiles (Q1-Q5). The outcomes of interest included indication for procedure (claudication, rest pain, or tissue loss) and rates of revascularization (vs primary amputation). Multinomial logistic regression was used to evaluate for an independent association between ADI quintile and these outcomes. RESULTS: Among the 79,973 patients identified, 9604 (12%) were in the lowest ADI quintile (Q1), 14,961 (18.7%) in Q2, 19,800 (24.8%) in Q3, 21,735 (27.2%) in Q4, and 13,873 (17.4%) in Q5. There were significant trends toward lower rates of claudication (Q1: 39% vs Q5: 34%, P < .001), higher rates of rest pain (Q1: 12.4% vs Q5: 17.8%, P < .001) as the indication for intervention, and lower rates of revascularization (Q1: 80% vs Q5: 69%, P < .001) with increasing ADI quintiles. In adjusted analyses, there was a progressively higher likelihood of presenting with rest pain vs claudication, with patients in Q5 having the highest probability when compared with those in Q1 (relative risk: 2.0; 95% confidence interval: 1.8-2.2; P < .001). Patients in Q5, when compared with those in Q1, also had a higher likelihood of presenting with tissue loss vs claudication (relative risk: 1.4; 95% confidence interval: 1.3-1.6; P < .001). Compared with patients in Q1, patients in Q2-Q5 had a lower likelihood of undergoing any revascularization procedure. CONCLUSIONS: Among patients who underwent infrainguinal revascularization or amputation in the Vascular Quality Initiative, those with higher neighborhood adversity had more advanced disease at presentation and lower rates of revascularization. Further work is needed to better understand neighborhood factors that are contributing to these disparities in order to identify community-level targets for improvement.

The impact of neighborhood social disadvantage on presentation and management of first-time hemodialysis access surgery patients.

OBJECTIVES: The impact of social determinants of health on the presentation, management, and outcomes of patients requiring hemodialysis (HD) arteriovenous (AV) access creation have not been well-characterized. The Area Deprivation Index (ADI) is a validated measure of aggregate community-level social determinants of health disparities experienced by members living within a community. Our goal was to examine the effect of ADI on health outcomes for first-time AV access patients. METHODS: We identified patients who underwent first-time HD access surgery in the Vascular Quality Initiative between July 2011 to May 2022. Patient zip codes were correlated with an ADI quintile, defined as quintile 1 (Q1) to quintile 5 (Q5) from least to most disadvantaged. Patients without ADI were excluded. Preoperative, perioperative, and postoperative outcomes considering ADI were analyzed. RESULTS: There were 43,292 patients analyzed. The average age was 63 years, 43% were female, 60% were of White race, 34% were of Black race, 10% were of Hispanic ethnicity, and 85% received autogenous AV access. Patient distribution by ADI quintile was as follows: Q1 (16%), Q2 (18%), Q3 (21%), Q4 (23%), and Q5 (22%). On multivariable analysis, the most disadvantaged quintile (Q5) was associated with lower rates of autogenous AV access creation (OR, 0.82; 95% confidence interval [CI], 0.74-0.90; P < .001), preoperative vein mapping (OR, 0.57; 95% CI, 0.45-0.71; P < .001), access maturation (OR, 0.82; 95% CI, 0.71-0.95; P = .007), and 1-year survival (OR, 0.81; 95% CI, 0.71-0.91; P = .001) compared with Q1. Q5 was associated with higher 1-year intervention rates than Q1 on univariable analysis, but not on multivariable analysis. CONCLUSIONS: The patients undergoing AV access creation who were most socially disadvantaged (Q5) were more likely to experience lower rates of autogenous access creation, obtaining vein mapping, access maturation, and 1-year survival compared with the most socially advantaged (Q1). Improvement in preoperative planning and long-term follow-up may be an opportunity for advancing health equity in this population.

Structural features of human DJ-1 in distinct Cys106 oxidative states and their relevance to its loss of function in disease.

DJ-1 (PARK7) is a multifunctional protein linked to the onset and progression of a number of diseases, most of which are associated with high oxidative stress. The Cys106 of DJ-1 is unusually reactive and thus sensitive to oxidation, and due to high oxidative stress it was observed to be in various oxidized states in disease condition. The oxidation state of Cys106 of DJ-1 is believed to determine the specific functions of the protein in normal and disease conditions. Here we report molecular dynamics simulation and biophysical experimental studies on DJ-1 in reduced (Cys106, S-), oxidized (Cys106, SO2-), and over-oxidized (Cys106, SO3-) states. To simulate the different oxidation states of Cys106 in DJ-1, AMBER related force field parameters were developed and reported for 3-sulfinoalanine and cysteine sulfonic acid. Our studies found that the overall structure of DJ-1 in different oxidation states was similar globally, while it differed locally significantly, which have implications on its stability, function and its link to disease on-set. Importantly, the results suggest that over-oxidation may trigger loss of functions due to local structural modification in the Cys106 containing pocket of DJ-1 and structurally destabilize the dimeric state of DJ-1, which is believed to be its bioactive conformation. Such loss of functions would result in reduced ability of DJ-1 to protect from oxidative stress insults and may lead to increased progression of disease.

Re-thinking the value of cross-sectional torso imaging for ground-level fall patients with altered mental status: Outcomes from a level 1 trauma center.

INTRODUCTION: Patients with altered mental status (AMS) are often excluded from studies evaluating the utility of computed tomography of the torso (CTT) after ground level falls (GLF). It is not known whether CTT identifies otherwise undetectable injuries in patients with AMS after GLF. We sought to describe the value of performing CTT in patients with AMS after GLF, and hypothesized that CTT would not identify new, clinically significant injuries in patients with a normal torso physical exam (PE) and normal chest and pelvic radiographs (CXR/PXR). METHODS: Single-institution retrospective cohort study of GLF patients (≤1 m) with and without AMS (GCS <15, blood alcohol level >150 mg/dL, intubation prior to hospital evaluation), 2015-2019. Traumatic injury identification on CTT was evaluated in the context of normal/abnormal torso PE (based on provider documentation) and normal CXR/PXR. RESULTS: 1195 patients met inclusion criteria; 344 had AMS, of which 129 (37.5 %) underwent CTT. A further 851 patients had normal mental status, of which 180 (21.2 %) underwent CTT. Patients with a normal PE with AMS (N = 79) and without AMS (N = 38) had a similar rate of new injury discovery on CTT (6.3% vs. 7.9 %, p = 1.00). Negative PE had a negative predictive value (NPV) for identification of a new, acute traumatic injury of 92.4 % (95 % CI: 0.84-0.96) in patients with AMS while normal PE, CXR, and PXR had a NPV of 96.0 % (95 % CI: 0.80-0.99). Among patients with CTT, patients with AMS had a significantly lower rate of acute traumatic injury on CTT compared to alert patients (26.4 % vs. 48.9 %, p < 0.001). On multivariate analysis, AMS was not positively associated with likelihood of identifying acute traumatic injury on CTT. CONCLUSIONS: In patients sustaining GLFs who present with AMS and who otherwise have a negative PE, CXR, and PXR, CTT is very unlikely to identify new traumatic injuries. Strong consideration should be given to forego cross-sectional imaging in this patient population.

Utilization of torso computed tomography for the evaluation of ground level falls: More imaging does not equal better care.

INTRODUCTION: Computed tomography (CT) of the chest (CTC), abdomen, and pelvis (CTAP) is common when assessing trauma patients in the emergency department. However, unnecessary imaging can expose patients to unneeded radiation and increase healthcare costs. Here, we characterize the use of torso CT imaging for the evaluation of ground level falls (GLF) at a single level 1 trauma center. PATIENTS AND METHODS: We conducted a retrospective review of all patients ≥18 years old presenting to a single level 1 trauma center with a GLF (1m or less) in 2015-2019. Data were obtained through chart review. Descriptive statistics were used to summarize patient characteristics. Multivariable logistic regression was used to assess factors leading to patients obtaining torso CT imaging. The utility of CT imaging in identifying injuries that changed management was also evaluated. RESULTS: Of the 1,195 patients captured during the study period, 492 patients had a positive torso physical exam (PE), and 703 had a negative torso PE. Of patients with a negative torso PE, 127 CTC and 142 CTAP were obtained, with only 5.5% CTC identifying traumatic injuries not previously diagnosed on chest radiograph (CXR), and only 0.7% CTAP identifying new injuries not identified on pelvic radiograph (PXR). Multivariable logistic regression demonstrated that only a positive PE was significantly associated with the identification of abnormal imaging findings on torso CT. A negative PE, CXR, and PXR have a negative predictive value of 98%. DISCUSSION: These data suggest that patients with a negative PE, even if intoxicated, intubated, or with a decreased GCS, are highly unlikely to have new, clinically relevant findings on torso CT imaging. CONCLUSION: Using PE, CXR, and PXR as a screening tool in patients sustaining GLF, which if negative close to obviates the need for torso CT, may reduce healthcare costs and radiation exposure without compromising patient care.

Preparation of photothermal palmitic acid/cholesterol liposomes.

Indocyanine green (ICG) is the only FDA-approved near-infrared dye and it is currently used clinically for diagnostic applications. However, there is significant interest in using ICG for triggered drug delivery applications and heat ablation therapy. Unfortunately, free ICG has a short half-life in vivo and is rapidly cleared from circulation. Liposomes have been frequently used to improve ICG's stability and overall time of effectiveness in vivo, but they have limited stability due to the susceptibility of phospholipids to hydrolysis and oxidation. In this study, nonphospholipid liposomes were used to encapsulate ICG, and the resulting liposomes were characterized for size, encapsulation efficiency, stability, and photothermal response. Using the thin-film hydration method, an ICG encapsulation efficiency of 54% was achieved, and the liposomes were stable for up to 12 weeks, with detectable levels of encapsulated ICG up to week 4. Additionally, ICG-loaded liposomes were capable of rapidly producing a significant photothermal response upon exposure to near-infrared light, and this photothermal response was able to induce changes in the mechanical properties of thermally responsive hydrogels. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1384-1392, 2019.

Structural Basis of Small Molecule Targetability of Monomeric Tau Protein.

The therapeutic targeting of intrinsically disordered proteins (IDPs) by small molecules has been a challenge due to their heterogeneous conformational ensembles. A potential therapeutic strategy to alleviate the aggregation of IDPs is to maintain them in their native monomeric state by small molecule binding. This study investigates the structural basis of small molecule druggability of native monomeric Tau whose aggregation is linked to the onset of Tauopathies such as Alzheimer's disease. Initially, two available monomeric conformational ensembles of a shorter Tau construct K18 (also termed Tau4RD) were analyzed which revealed striking structural differences between the two ensembles, while similar number of hot spots and small molecule binding sites were identified on monomeric Tau ensembles as on tertiary folded proteins of similar size. Remarkably, some critical fibril forming sequence regions of Tau (V306-K311, V275-K280) participated in hot spot formation with higher frequency compared to other regions. As an example of small molecule binding to monomeric Tau, it was shown that methylene blue (MB) bound to monomeric K18 and full-length Tau selectively with high affinity (Kd = 125.8 nM and 86.6 nM, respectively) with binding modes involving Cys291 and Cys322, previously reported to be oxidized in the presence of MB. Overall, our results provide structure-based evidence that Tau can be a viable drug target for small molecules and indicate that specific small molecules may be able to bind to monomeric Tau and influence the way in which the protein interacts among itself and with other proteins.