Mental and Physical Health-Related Quality of Life Following Military Polytrauma.

INTRODUCTION: The long-term impact of deployment-related trauma on mental and physical health-related quality of life (HRQoL) among military personnel is not well understood. We describe the mental and physical HRQoL among military personnel following deployment-related polytrauma after their discharge from the hospital and examine factors associated with HRQoL and longitudinal trends. MATERIALS AND METHODS: The U.S. military personnel with battlefield-related trauma enrolled in the Trauma Infectious Diseases Outcomes Study were surveyed using SF-8 Health Surveys at 1 month post-discharge (baseline) and at follow-up intervals over 2 years. Inclusion in the longitudinal analysis required baseline SF-8 plus responses during early (3 and/or 6 months) and later follow-up periods (12, 18, and/or 24 months). Associations of demographics, injury characteristics, and hospitalization with baseline SF-8 scores and longitudinal changes in SF-8 scores during follow-up were examined. Survey responses were used to calculate the Mental Component Summary score (MCS) and the Physical Component Summary score (PCS). The MCS focuses on vitality, mental health, social functioning, and daily activity limitations, whereas PCS is related to general health, bodily pain, physical functioning, and physical activity limitations. Longitudinal trends in SF-8 scores were assessed using chi-square tests by comparing the median score at each timepoint to the median 1-month (baseline) score, as well as comparing follow-up scores to the immediately prior timepoint (e.g., 6 months vs. 3 months). Associations with the 1-month baseline SF-8 scores were assessed using generalized linear regression modeling and associations with longitudinal changes in SF-8 were examined using generalized linear regression modeling with repeated measures. RESULTS: Among 781 enrollees, lower baseline SF-8 total scores and PCS were associated with spinal and lower extremity injuries (P < .001) in the multivariate analyses, whereas lower baseline MCS was associated with head/face/neck injuries (P < .001). Higher baseline SF-8 total was associated with having an amputation (P = .009), and lower baseline SF-8 total was also associated with sustaining a traumatic brain injury (TBI; P = .042). Among 524 enrollees with longitudinal follow-up, SF-8 scores increased, driven by increased PCS and offset by small MCS decreases. Upward SF-8 total score and PCS trends were associated with time post-hospital discharge and limb amputation (any) in the multivariate analyses (P < .05), whereas downward trends were independently associated with spinal injury and developing any post-discharge infection (P ≤ .001). Patients with lower extremity injuries had lower-magnitude improvements in PCS over time compared to those without lower extremity injuries (P < .001). Upward MCS trend was associated with higher injury severity (P = .003) in the multivariate analyses, whereas downward trends were independently associated with having a TBI (P < .001), time post-hospital discharge (P < .001), and occurrence of post-discharge infections (P = .002). CONCLUSIONS: Overall, HRQoL increased during the 2-year follow-up period, driven by PCS improvement. Increasing HRQoL was associated with time since hospital discharge and limb amputation, whereas a downward trend in HRQoL was associated with spinal injury and post-discharge infection. The longitudinal decline in MCS, driven by TBI occurrence, time since hospital discharge, and developing post-discharge infections, emphasizes the importance of longitudinal mental health care in this population.

DoD-VA Trauma Infection Research Collaboration.

BACKGROUND: In the aftermath of wars, there is a surge in the number of wounded service members who leave active duty and become eligible for healthcare through the Department of Veterans Affairs (VA). Collaborations between the Department of Defense (DoD) and VA are crucial to capture comprehensive data and further understand the long-term impact of battlefield trauma. We provide a summary of the development, methodology, and status of an effective collaboration between the Infectious Disease Clinical Research Program and the St. Louis VA Health Care System with the multicenter, observational Trauma Infectious Disease Outcomes Study (TIDOS), which examines the short- and long-term outcomes of deployment-related trauma. METHODS: As part of TIDOS, wounded service members who transitioned to participating military hospitals in the United States (2009-2014) were given the opportunity to enroll in a prospective follow-up cohort study to continue to capture infection-related data after their hospital discharge. Enrollees in the TIDOS cohort who left military service and received health care through the VA also had the option of consenting to have relevant VA medical records abstracted and included with the study data. Infections considered to be complications resulting from the initial trauma were examined. RESULTS: Among 1,336 TIDOS enrollees, 1,221 (91%) registered and received health care through the VA with 633 (47%) consenting to follow-up using VA records and comprising the TIDOS-VA cohort. Of the first 337 TIDOS-VA cohort enrollees, 38% were diagnosed with a new trauma-related infection following hospital discharge (median: 88 days; interquartile range: 18-351 days). Approximately 71% of the infections were identified through DoD sources (medical records and follow-up) and 29% were identified through VA electronic medical records, demonstrating the utility of DoD-VA collaborations. The TIDOS DoD-VA collaboration has also been utilized to assess intermediate and long-term consequences of specific injury patterns. Among 89 TIDOS-VA cohort enrollees with genitourinary trauma, 36% reported sexual dysfunction, 21% developed at least one urinary tract infection, 14% had urinary retention/incontinence, and 8% had urethral stricture. The rate of urinary tract infections was 0.05/patient-year during DoD follow-up time and 0.07/patient-year during VA follow-up time. CONCLUSIONS: Wider capture of infection-related outcome data through the DoD-VA collaboration provided a clearer picture of the long-term infection burden resulting from deployment-related trauma. Planned analyses include assessment of osteomyelitis among combat casualties with amputations and/or open fractures, evaluation of mental health and social factors related to injury patterns, and examination of health care utilization and cost in relation to infectious disease burdens.

Mitigating COVID-19 Vaccine Waste Through a Multidisciplinary Inpatient Vaccination Initiative.

ABSTRACT: A multidisciplinary team at a tertiary care Veterans Health Administration medical center created a standardized process to identify medically stable inpatients, to notify inpatient staff of available COVID-19 vaccine doses, and to coordinate inpatient vaccine administration. The team's goals were to mitigate vaccine waste while safely vaccinating as many patients as possible. Using a unique set of exclusion criteria and clinical judgment, a quality improvement team reviewed patients admitted to medicine teams to determine medical stability. Eligible, interested patients were listed in a secure shared file, and outpatient vaccine clinic staff communicated with inpatient nurse leaders regarding the availability of unadministered doses. Doses were transported to the hospital from the clinic and administered by inpatient nurses. Between January 8 and April 26, 2021, 105 patients were vaccinated with either the Moderna or the Pfizer-BioNTech COVID-19 vaccine during admission. Sixty-nine percent of the patients received a first dose, 27% received a second dose, and 4% received both doses. Forty-two percent of the patients vaccinated while inpatient identified as Black or African American compared with 28% of the vaccinated outpatients. No vaccine-related safety events were reported. This process demonstrates a viable approach to mitigating waste of COVID-19 vaccines and safely, efficiently, and equitably vaccinating an inpatient population.

Universal masking to control healthcare-associated transmission of severe acute respiratory coronavirus virus 2 (SARS-CoV-2).

OBJECTIVES: To assess extent of a healthcare-associated outbreak of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and to evaluate the effectiveness of infection control measures, including universal masking. DESIGN: Outbreak investigation including 4 large-scale point-prevalence surveys. SETTING: Integrated VA healthcare system with 2 facilities and 330 beds. PARTICIPANTS: Index patient and 250 exposed patients and staff. METHODS: We identified exposed patients and staff and classified them as probable and confirmed cases based on symptoms and testing. We performed a field investigation and an assessment of patient and staff interactions to develop probable transmission routes. Infection prevention interventions included droplet and contact precautions, employee quarantine, and universal masking with medical and cloth face masks. We conducted 4 point-prevalence surveys of patient and staff subsets using real-time reverse-transcriptase polymerase chain reaction for SARS-CoV-2. RESULTS: Among 250 potentially exposed patients and staff, 14 confirmed cases of coronavirus disease 2019 (COVID-19) were identified. Patient roommates and staff with prolonged patient contact were most likely to be infected. The last potential date of transmission from staff to patient was day 22, the day universal masking was implemented. Subsequent point-prevalence surveys in 126 patients and 234 staff identified 0 patient cases and 5 staff cases of COVID-19, without evidence of healthcare-associated transmission. CONCLUSIONS: Universal masking with medical face masks was effective in preventing further spread of SARS-CoV-2 in our facility in conjunction with other traditional infection prevention measures.

Inpatient versus outpatient intravenous diuresis for the acute exacerbation of chronic heart failure.

BACKGROUND: We established an IV outpatient diuresis (IVOiD) clinic and conducted a quality improvement project to evaluate safety, effectiveness and costs associated with outpatient versus inpatient diuresis for patients presenting with acute decompensated heart failure (ADHF) to the emergency department (ED). METHODS: Patients who were clinically diagnosed with ADHF in the ED, but did not have high-risk features, were either diuresed in the hospital or in the outpatient IVOiD clinic. The dose of IV diuretic was based on their home maintenance diuretic dose. The outcomes measured were the effects of diuresis (urine output, weight, hemodynamic and laboratory abnormalities), 30-90 day readmissions, 30-90 day death and costs. RESULTS: In total, 36 patients (22 inpatients and 14 outpatients) were studied. There were no significant differences in the baseline demographics between groups. The average inpatient stay was six days and the average IVOiD clinic days were 1.2. There was no significant difference in diuresis per day of treatment (1159 vs. 944 ml, p = 0.46). There was no significant difference in adverse outcomes, 30-90 day readmissions or 30-90 day deaths. There was a significantly lower cost in the IVOiD group compared to the inpatient group ($839.4 vs. $9895.7, p=<0.001). CONCLUSIONS: Outpatient IVOiD clinic diuresis may be a viable alternative to accepted clinical practice of inpatient diuresis for ADHF. Further studies are needed to validate this in a larger cohort and in different sites.

Regulation of pancreatic cancer TRAIL resistance by protein O-GlcNAcylation.

TRAIL-activating therapy is promising in treating various cancers, including pancreatic cancer, a highly malignant neoplasm with poor prognosis. However, many pancreatic cancer cells are resistant to TRAIL-induced apoptosis despite their expression of intact death receptors (DRs). Protein O-GlcNAcylation is a versatile posttranslational modification that regulates various biological processes. Elevated protein O-GlcNAcylation has been recently linked to cancer cell growth and survival. In this study, we evaluated the role of protein O-GlcNAcylation in pancreatic cancer TRAIL resistance, and identified higher levels of O-GlcNAcylation in TRAIL-resistant pancreatic cancer cells. With gain- and loss-of-function of the O-GlcNAc-adding enzyme, O-GlcNActransferase (OGT), we determined that increasing O-GlcNAcylation rendered TRAIL-sensitive cells more resistant to TRA-8-induced apoptosis, while inhibiting O-GlcNAcylation promoted TRA-8-induced apoptosis in TRAIL-resistance cells. Furthermore, we demonstrated that OGT knockdown sensitized TRAIL-resistant cells to TRA-8 therapy in a mouse model in vivo. Mechanistic studies revealed direct O-GlcNAc modifications of DR5, which regulated TRA-8-induced DR5 oligomerization. We further defined that DR5 O-GlcNAcylation was independent of FADD, the adapter protein for the downstream death-inducing signaling. These studies have demonstrated an important role of protein O-GlcNAcylation in regulating TRAIL resistance of pancreatic cancer cells; and uncovered the contribution of O-GlcNAcylation to DR5 oligomerization and thus mediating DR-inducing signaling.

After the Battlefield: Infectious Complications among Wounded Warriors in the Trauma Infectious Disease Outcomes Study.

INTRODUCTION: During recent wars in Iraq and Afghanistan, improved survivability in severe trauma corresponded with a rise in the proportion of trauma-related infections, including those associated with multidrug-resistant organisms (MDROs). Significant morbidity was reported in association with the infections. There is also concern regarding potential long-term impacts of the trauma-related infectious complications. Therefore, to meet the critical need of prospective collection of standardized infection-related data to understand the disease burden and improve outcomes of wounded personnel, the Trauma Infectious Disease Outcomes Study (TIDOS) was developed. Herein, we review accomplishments and key peer-reviewed findings of TIDOS. METHODS: The TIDOS project is a multicenter observational study of short- and long-term infectious complications following deployment-related trauma. Wounded military personnel medevac'd to Landstuhl Regional Medical Center (LRMC; Germany) before transfer to a participating US military hospital between June 2009 and December 2014 were eligible for inclusion. An infectious disease module to supplement the Department of Defense Trauma Registry by collecting infection-related data from all trauma patients admitted to participating hospitals was developed. Specimens from trauma patients were also collected and retained in a microbiological isolate repository. During the initial hospitalization, patients were given the opportunity to enroll in a prospective follow-up cohort study. Patients who received Department of Veterans Affairs (VA) care were also given the opportunity to consent to ongoing VA follow-up. RESULTS: A total of 2,699 patients transferred to participating military hospitals in the USA, of which 1,359 (50%) patients enrolled in the TIDOS follow-up cohort. In addition, 638 enrolled in the TIDOS-VA cohort (52% of TIDOS enrollees who entered VA healthcare). More than 8,000 isolates were collected from infection control surveillance and diagnostic evaluations and retained in the TIDOS Microbiological Repository. Approximately 34% of the 2,699 patients at US hospitals developed a trauma-related infection during their initial hospitalization with skin and soft-tissue infections being predominant. After discharge from the US hospitals, approximately one-third of TIDOS cohort enrollees developed a new trauma-related infection during follow-up and extremity wound infections (skin and soft-tissue infections and osteomyelitis) continued to be the majority. Among TIDOS cohort enrollees who received VA healthcare, 38% developed a new trauma-related infection with the incident infection being diagnosed a median of 88 days (interquartile range: 19-351 days) following hospital discharge. Data from TIDOS have been used to support the development of Joint Trauma System clinical practice guidelines for the prevention of combat-related infections, as well as the management of invasive fungal wound infections. Lastly, due to the increasing proportion of infections associated with MDROs, TIDOS investigators have collaborated with investigators across military laboratories as part of the Multidrug-Resistant and Virulent Organisms Trauma Infections Initiative with the objective of improving the understanding of the complex wound microbiology in order to develop novel infectious disease countermeasures. CONCLUSIONS: The TIDOS project has focused research on four initiatives: (1) blast-related wound infection epidemiology and clinical management; (2) DoD-VA outcomes research; (3) Multidrug- Resistant and other Virulent Organisms Trauma Infections Initiative; and (4) Joint Trauma System clinical practice guidelines and antibiotic stewardship. There is a continuing need for longitudinal data platforms to support battlefield wound research and clinical practice guideline recommendation refinement, particularly to improve care for future conflicts. As such, maintaining a research platform, such as TIDOS, would negate the lengthy time needed to initiate data collection and analysis.

Urinary Tract Infections after Combat-Related Genitourinary Trauma.

Background: We examined clinical outcomes among combat casualties with genitourinary injuries after blast trauma. Methods: Characteristics, clinical care, urologic complications, and infections for subjects enrolled in the Trauma Infectious Disease Outcomes Study (TIDOS) were collected from Department of Defense (DOD) and Department of Veterans Affairs (VA) sources. Logistic regression identified predictors for urinary tract infections (UTIs) after genitourinary trauma. Results: Among 530 TIDOS enrollees who entered VA care, 89 (17%) sustained genitourinary trauma. The majority of subjects (93%) were injured via a blast and 27% had a dismounted complex blast injury (DCBI). Sexual dysfunction was reported with 36% of subjects, whereas 14% had urinary retention/incontinence and 8% had urethral stricture. Urologic complications were comparable between patients with and without DCBIs. Nineteen (21%) subjects had one or more UTI with a total of 40 unique UTI events (25% during initial hospitalization and 75% during subsequent DOD or VA care). The UTI incidence rate was 0.89 per patient-year during initial hospitalization, 0.05 per patient-year during DOD follow-up, and 0.07 per patient-year during VA healthcare. Subjects with UTIs had a higher proportion of bladder injury (53% vs. 13%; p < 0.001), posterior urethral injury (26% vs. 1%; p = 0.001), pelvic fracture (47% vs. 4%; p < 0.001), soft-tissue infection of the pelvis/hip (37% vs. 4%; p = 0.001), urinary catheterization (47% vs. 11%; p < 0.001), urinary retention or incontinence (42% vs. 6%; p < 0.001), and stricture (26% vs. 3%; p = 0.004) compared with patients with genitourinary trauma and no UTI. Independent UTI risk factors were occurrence of a soft-tissue infection at the pelvis/hip, trauma to the urinary tract, and transtibial amputation. Conclusions: Among combat casualties with genitourinary trauma, UTIs are a common complication, particularly with severe blast injury and urologic sequelae. Episodes of UTIs typically occur early after the initial injury while in DOD care, however, recurrent infections may continue into long-term VA care.

Cytoplasmic PARP-1 promotes pancreatic cancer tumorigenesis and resistance.

The poly(ADP-ribose) polymerases (PARP) play important roles in repairing damaged DNA during intrinsic cell death. We recently linked PARP-1 to death receptor (DR)-activated extrinsic apoptosis, the present studies sought to elucidate the function of cytoplasmic PARP-1 in pancreatic cancer tumorigenesis and therapy. Using human normal and pancreatic cancer tissues, we analyzed the prevalence of cytoplasmic PARP-1 expression. In normal human pancreatic tissues, PARP-1 expression was present in the nucleus; however, cytoplasmic PARP-1 expression was identified in pancreatic cancers. Therefore, cytoplasmic PARP-1 mutants were generated by site-direct mutagenesis, to determine a causative effect of cytoplasmic PARP-1 on pancreatic cancer tumorigenesis and sensitivity to therapy with TRA-8, a humanized DR5 antibody. PARP-1 cytoplasmic mutants rendered TRA-8 sensitive pancreatic cancer cells, BxPc-3 and MiaPaCa-2, more resistant to TRA-8-induced apoptosis; whereas wild-type PARP-1, localizing mainly in the nucleus, had no effects. Additionally, cytoplasmic PARP-1, but not wild-type PARP-1, increased resistance of BxPc-3 cells to TRA-8 therapy in a mouse xenograft model in vivo. Inhibition of PARP enzymatic activity attenuated cytoplasmic PARP-1-mediated TRA-8 resistance. Furthermore, increased cytoplasmic PARP-1, but not wild-type PARP-1, was recruited into the TRA-8-activated death-inducing signaling complex and associated with increased and sustained activation of Src-mediated survival signals. In contrast, PARP-1 knockdown inhibited Src activation. Taken together, we have identified a novel function and mechanism underlying cytoplasmic PARP-1, distinct from nuclear PARP-1, in regulating DR5-activated apoptosis. Our studies support an innovative application of available PARP inhibitors or new cytoplasmic PARP-1 antagonists to enhance TRAIL therapy for TRAIL-resistant pancreatic cancers.

Infectious Complications After Deployment Trauma: Following Wounded US Military Personnel Into Veterans Affairs Care.

Background: Infectious complications related to deployment trauma significantly contribute to the morbidity and mortality of wounded service members. The Trauma Infectious Disease Outcomes Study (TIDOS) collects data on US military personnel injured in Iraq and Afghanistan in an observational cohort study of infectious complications. Patients enrolled in TIDOS may also consent to follow-up through the Department of Veterans Affairs (VA). We present data from the first 337 TIDOS enrollees to receive VA healthcare. Methods: Data were collected from the Department of Defense (DoD) Trauma Registry, TIDOS infectious disease module, DoD and VA electronic medical records, and telephone interview. Cox proportional hazard analysis was performed to identify predictors of post-discharge infections related to deployment trauma. Results: Among the first 337 TIDOS enrollees who entered VA healthcare, 111 (33%) had 244 trauma-related infections during their initial trauma hospitalization (2.1 infections per 100 person-days). Following initial discharge, 127 (38%) enrollees had 239 trauma-related infections (170 during DoD follow-up and 69 during VA time). Skin and soft-tissue infections and osteomyelitis were predominant during and after the initial trauma hospitalization. In a multivariate model, a shorter time to development of a new infection following discharge was independently associated with injury severity score ≥10 and occurrence of ≥1 inpatient infection during initial trauma hospitalization. Conclusions: Incident infections related to deployment trauma continue well after initial hospital discharge and into VA healthcare. Overall, 38% of enrolled patients developed a new trauma-related infection after their initial hospital discharge, with 29% occurring after the patient left military service.

The long non-coding RNA HOTAIR enhances pancreatic cancer resistance to TNF-related apoptosis-inducing ligand.

Pancreatic cancer is a malignant neoplasm with a high mortality rate. Therapeutic agents that activate TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis have shown promising efficacy, but many pancreatic cancers are resistant to TRAIL therapy. Epigenetic regulation plays important roles in tumor pathogenesis and resistance, and a recent study indicated that the long non-coding RNA HOX transcript antisense RNA (HOTAIR) is overexpressed in pancreatic cancer. However, the role of HOTAIR in pancreatic cancer resistance to anticancer agents is unknown. The present study determined the role of HOTAIR in pancreatic cancer TRAIL resistance and investigated the underlying molecular mechanisms. We observed that TRAIL-resistant pancreatic cancer cells had higher levels of HOTAIR expression, whereas TRAIL-sensitive pancreatic cancer cells had lower HOTAIR levels. Overexpressing HOTAIR in TRAIL-sensitive cells attenuated TRAIL-induced apoptosis, and shRNA-mediated HOTAIR knockdown in TRAIL-resistant PANC-1 cells sensitized them to TRAIL-induced apoptosis. These results support a causative effect of HOTAIR on TRAIL sensitivity. Mechanistically, we found that increased HOTAIR expression inhibited the expression of the TRAIL receptor death receptor 5 (DR5), whereas HOTAIR knockdown increased DR5 expression. We further demonstrated that HOTAIR regulates DR5 expression via the epigenetic regulator enhancer of zeste homolog 2 (EZH2) and that EZH2 controls histone H3 lysine 27 trimethylation on the DR5 gene. Taken together, these results demonstrate that high HOTAIR levels increase the resistance of pancreatic cancer cells to TRAIL-induced apoptosis via epigenetic regulation of DR5 expression. Our study therefore supports the notion that targeting HOTAIR function may represent a strategy to overcome TRAIL resistance in pancreatic cancer.

Tumor Necrosis Factor Inhibition and Head and Neck Cancer Recurrence and Death in Rheumatoid Arthritis.

The objective of this retrospective cohort study was to determine the effect of tumor necrosis factor inhibitor (TNFi) therapy on the risk of head and neck cancer (HNC) recurrence or HNC-attributable death in patients with rheumatoid arthritis (RA). RA patients with HNC were assembled from the US national Veterans' Affairs (VA) administrative databases, and diagnoses confirmed and data collected by electronic medical record review. The cohort was divided into those treated with non-biologic disease-modifying anti-rheumatic drugs (nbDMARDs) versus TNF inhibitors (TNFi) after a diagnosis of HNC. Likelihood of a composite endpoint of recurrence or HNC-attributable death was determined by Cox proportional hazards regression. Of 180 patients with RA and HNC, 31 were treated with TNFi and 149 with nbDMARDs after the diagnosis of HNC. Recurrence or HNC-attributable death occurred in 5/31 (16.1%) patients in the TNFi group and 44/149 (29.5%) patients in the nbDMARD group (p = 0.17); it occurred in 2/16 (13%) patients who received TNFi in the year prior to HNC diagnosis but not after. Overall stage at diagnosis (p = 0.03) and stage 4 HNC (HR 2.49 [CI 1.06-5.89]; p = 0.04) were risk factors for recurrence or HNC-attributable death; treatment with radiation or surgery was associated with a lower risk (HR 0.35 [CI 0.17-0.74]; p = 0.01 and HR 0.39 [CI 0.20-0.76]; p = 0.01 respectively). Treatment with TNFi was not a risk factor for recurrence or HNC-attributable death (HR 0.75; CI 0.31-1.85; p = 0.54). We conclude that treatment with TNFi may be safe in patients with RA and HNC, especially as the time interval between HNC treatment and non-recurrence increases. In this study, TNF inhibition was not associated with an increase in recurrence or HNC-attributable death.

Beyond Respiratory Depression and Constipation: Adverse Effects of Opioids.

The numbers of opioid presciptions have skyrocketed over the last two decades. Adverse effects of opioids are difficult to diagnose because the usual presenting complaints is persistence of severe pain and decreases function leading to chronic usage of medication with minimal benefit to patients. This concise review discusses the adverse effects of opioids to appropriately diagnose and treat patients on opioid therapy. We emphasize less commonly known adverse effects and the controversial use of opioids in non-cancer pain.

Calmodulin antagonists promote TRA-8 therapy of resistant pancreatic cancer.

Pancreatic cancer is highly malignant with limited therapy and a poor prognosis. TRAIL-activating therapy has been promising, however, clinical trials have shown resistance and limited responses of pancreatic cancers. We investigated the effects of calmodulin(CaM) antagonists, trifluoperazine(TFP) and tamoxifen(TMX), on TRA-8-induced apoptosis and tumorigenesis of TRA-8-resistant pancreatic cancer cells, and underlying mechanisms. TFP or TMX alone did not induce apoptosis of resistant PANC-1 cells, while they dose-dependently enhanced TRA-8-induced apoptosis. TMX treatment enhanced efficacy of TRA-8 therapy on tumorigenesis in vivo. Analysis of TRA-8-induced death-inducing-signaling-complex (DISC) identified recruitment of survival signals, CaM/Src, into DR5-associated DISC, which was inhibited by TMX/TFP. In contrast, TMX/TFP increased TRA-8-induced DISC recruitment/activation of caspase-8. Consistently, caspase-8 inhibition blocked the effects of TFP/TMX on TRA-8-induced apoptosis. Moreover, TFP/TMX induced DR5 expression. With a series of deletion/point mutants, we identified CaM antagonist-responsive region in the putative Sp1-binding domain between -295 to -300 base pairs of DR5 gene. Altogether, we have demonstrated that CaM antagonists enhance TRA-8-induced apoptosis of TRA-8-resistant pancreatic cancer cells by increasing DR5 expression and enhancing recruitment of apoptotic signal while decreasing survival signals in DR5-associated DISC. Our studies support the use of these readily available CaM antagonists combined with TRAIL-activating agents for pancreatic cancer therapy.

Characterization of calmodulin-Fas death domain interaction: an integrated experimental and computational study.

The Fas death receptor-activated death-inducing signaling complex (DISC) regulates apoptosis in many normal and cancer cells. Qualitative biochemical experiments demonstrate that calmodulin (CaM) binds to the death domain of Fas. The interaction between CaM and Fas regulates Fas-mediated DISC formation. A quantitative understanding of the interaction between CaM and Fas is important for the optimal design of antagonists for CaM or Fas to regulate the CaM-Fas interaction, thus modulating Fas-mediated DISC formation and apoptosis. The V254N mutation of the Fas death domain (Fas DD) is analogous to an identified mutant allele of Fas in lpr-cg mice that have a deficiency in Fas-mediated apoptosis. In this study, the interactions of CaM with the Fas DD wild type (Fas DD WT) and with the Fas DD V254N mutant were characterized using isothermal titration calorimetry (ITC), circular dichroism spectroscopy (CD), and molecular dynamics (MD) simulations. ITC results reveal an endothermic binding characteristic and an entropy-driven interaction of CaM with Fas DD WT or with Fas DD V254N. The Fas DD V254N mutation decreased the association constant (Ka) for CaM-Fas DD binding from (1.79 ± 0.20) × 10(6) to (0.88 ± 0.14) × 10(6) M(-1) and slightly increased a standard state Gibbs free energy (ΔG°) for CaM-Fas DD binding from -8.87 ± 0.07 to -8.43 ± 0.10 kcal/mol. CD secondary structure analysis and MD simulation results did not show significant secondary structural changes of the Fas DD caused by the V254N mutation. The conformational and dynamical motion analyses, the analyses of hydrogen bond formation within the CaM binding region, the contact numbers of each residue, and the electrostatic potential for the CaM binding region based on MD simulations demonstrated changes caused by the Fas DD V254N mutation. These changes caused by the Fas DD V254N mutation could affect the van der Waals interactions and electrostatic interactions between CaM and Fas DD, thereby affecting CaM-Fas DD interactions. Results from this study characterize CaM-Fas DD interactions in a quantitative way, providing structural and thermodynamic evidence of the role of the Fas DD V254N mutation in the CaM-Fas DD interaction. Furthermore, the results could help to identify novel strategies for regulating CaM-Fas DD interactions and Fas DD conformation and thus to modulate Fas-mediated DISC formation and thus Fas-mediated apoptosis.

Serious bleeding events due to warfarin and antibiotic co-prescription in a cohort of veterans.

BACKGROUND: Antibiotics may interact with warfarin, increasing the risk for significant bleeding events. METHODS: This is a retrospective cohort study of veterans who were prescribed warfarin for 30 days without interruption through the US Department of Veterans Affairs between October 1, 2002 and September 1, 2008. Antibiotics considered to be high risk for interaction with warfarin include: trimethoprim/sulfamethoxazole (TMP/SMX), ciprofloxacin, levofloxacin, metronidazole, fluconazole, azithromycin, and clarithromycin. Low-risk antibiotics include clindamycin and cephalexin. Risk of bleeding event within 30 days of antibiotic exposure was measured using Cox proportional hazards regression, adjusted for demographic characteristics, comorbid conditions, and receipt of other medications interacting with warfarin. RESULTS: A total of 22,272 patients met inclusion criteria, with 14,078 and 8194 receiving high- and low-risk antibiotics, respectively. There were 93 and 36 bleeding events in the high- and low-risk groups, respectively. Receipt of a high-risk antibiotic (hazard ratio [HR] 1.48; 95% confidence interval [CI], 1.00-2.19) and azithromycin (HR 1.93; 95% CI, 1.13-3.30) were associated with increased risk of bleeding as a primary diagnosis. TMP/SMX (HR 2.09; 95% CI, 1.45-3.02), ciprofloxacin (HR 1.87; 95% CI, 1.42-2.50), levofloxacin (HR 1.77; 95% CI, 1.22-2.50), azithromycin (HR 1.64; 95% CI, 1.16-2.33), and clarithromycin (HR 2.40; 95% CI, 1.16-4.94) were associated with serious bleeding as a primary or secondary diagnosis. International normalized ratio (INR) alterations were common; 9.7% of patients prescribed fluconazole had INR value >6. Patients who had INR performed within 3-14 days of co-prescription were at a decreased risk of serious bleeding (HR 0.61; 95% CI, 0.42-0.88). CONCLUSIONS: Warfarin users who are prescribed high-risk antibiotics are at higher risk for serious bleeding events. Early INR evaluation may mitigate this risk.

Myocardial infarction risk among patients with fractures receiving bisphosphonates.

OBJECTIVE: To determine if bisphosphonates are associated with reduced risk of acute myocardial infarction (AMI). PATIENTS AND METHODS: A cohort of 14,256 veterans 65 years or older with femoral or vertebral fractures was selected from national administrative databases operated by the US Department of Veterans Affairs and was derived from encounters at Veterans Affairs facilities between October 1, 1998, and September 30, 2006. The time to first AMI was assessed in relationship to bisphosphonate exposure as determined by records from the Pharmacy Benefits Management Database. Time to event analysis was performed using multivariate Cox proportional hazards regression. An adjusted survival analysis curve and a Kaplan-Meier survival curve were analyzed. RESULTS: After controlling for atherosclerotic cardiovascular disease risk factors and medications, bisphosphonate use was associated with an increased risk of incident AMI (hazard ratio, 1.38; 95% CI, 1.08-1.77; P=.01). The timing of AMI correlated closely with the timing of bisphosphonate therapy initiation. CONCLUSION: Our observations in this study conflict with our hypothesis that bisphosphonates have antiatherogenic effects. These findings may alter the risk-benefit ratio of bisphosphonate use for treatment of osteoporosis, especially in elderly men. However, further analysis and confirmation of these findings by prospective clinical trials is required.

PARP-1 regulates resistance of pancreatic cancer to TRAIL therapy.

PURPOSE: Activating extrinsic apoptotic pathways targeting death receptors (DR) using agonistic antibodies or TNF-related apoptosis-inducing ligand (TRAIL) is promising for cancer therapy. However, most pancreatic cancers are resistant to TRAIL therapy. The present studies aimed to identify combination therapies that enhance the efficacy of TRAIL therapy and to investigate the underlying mechanisms. EXPERIMENTAL DESIGN: A xenograft model in nude mice was used to determine pancreatic cancer tumorigenesis and therapeutic efficacy of TRA-8, a monoclonal agonistic antibody for DR5. Pancreatic cancer cells were used to characterize mechanisms underlying PARP-1 regulation of TRA-8-induced apoptosis in vitro. RESULTS: PARP-1 was found highly expressed in the TRA-8-resistant PANC-1 and Suit-2 cells, compared with TRA-8-sensitive BxPc-3 and MiaPaca-2. Inhibition of PARP-1 with a pharmacologic inhibitor sensitized PANC-1 and Suit2 cells to TRA-8-induced apoptosis in a dose-dependent manner. Furthermore, siRNAs specifically knocking down PARP-1 markedly enhanced TRA-8-induced apoptosis in vitro and augmented the efficacy of TRA-8 therapy on tumorigenesis in vivo. PARP-1 knockdown increased TRA-8-induced activation of caspase-8 in the death-induced signaling complex (DISC). Immunoprecipitation with DR5 antibody identified the recruitment of PARP-1 and PARP-1-mediated protein poly-ADP-ribosylation (pADPr) modification in the DR5-associated DISC. Further characterization revealed that PARP-1-mediated pADPr modification of caspase-8 inhibited caspase-8 activation, which may contribute to its function in regulating TRA-8 resistance. CONCLUSIONS: Our studies provide molecular insights into a novel function of PARP-1 in regulating the extrinsic apoptosis machinery and also support interventions combining PARP-1 inhibitors with DR agonists for pancreatic cancer therapy.

Structural insight for the roles of fas death domain binding to FADD and oligomerization degree of the Fas-FADD complex in the death-inducing signaling complex formation: a computational study.

Fas binding to Fas-associated death domain (FADD) activates FADD-caspase-8 binding to form death-inducing signaling complex (DISC) that triggers apoptosis. The Fas-Fas association exists primarily as dimer in the Fas-FADD complex, and the Fas-FADD tetramer complexes have the tendency to form higher order oligomer. The importance of the oligomerized Fas-FADD complex in DISC formation has been confirmed. This study sought to provide structural insight for the roles of Fas death domain (Fas DD) binding to FADD and the oligomerization of Fas DD-FADD complex in activating FADD-procaspase-8 binding. Results show Fas DD binding to FADD stabilized the FADD conformation, including the increased stability of the critical residues in FADD death effector domain (FADD DED) for FADD-procaspase-8 binding. Fas DD binding to FADD resulted in the decreased degree of both correlated and anticorrelated motion of the residues in FADD and caused the reversed correlated motion between FADD DED and FADD death domain (FADD DD). The exposure of procaspase-8 binding residues in FADD that allows FADD to interact with procaspase-8 was observed with Fas DD binding to FADD. We also observed different degrees of conformational and motion changes of FADD in the Fas DD-FADD complex with different degrees of oligomerization. The increased conformational stability and the decreased degree of correlated motion of the residues in FADD in Fas DD-FADD tetramer complex were observed compared to those in Fas DD-FADD dimer complex. This study provides structural evidence for the roles of Fas DD binding to FADD and the oligomerization degree of Fas DD-FADD complex in DISC formation to signal apoptosis.