Targeting KDM4A epigenetically activates tumor-cell-intrinsic immunity by inducing DNA replication stress.

Developing strategies to activate tumor-cell-intrinsic immune response is critical for improving tumor immunotherapy by exploiting tumor vulnerability. KDM4A, as a histone H3 lysine 9 trimethylation (H3K9me3) demethylase, has been found to play a critical role in squamous cell carcinoma (SCC) growth and metastasis. Here we report that KDM4A inhibition promoted heterochromatin compaction and induced DNA replication stress, which elicited antitumor immunity in SCC. Mechanistically, KDM4A inhibition promoted the formation of liquid-like HP1γ puncta on heterochromatin and stall DNA replication, which activated tumor-cell-intrinsic cGAS-STING signaling through replication-stress-induced cytosolic DNA accumulation. Moreover, KDM4A inhibition collaborated with PD1 blockade to inhibit SCC growth and metastasis by recruiting and activating CD8+ T cells. In vivo lineage tracing demonstrated that KDM4A inhibition plus PD1 blockade efficiently eliminated cancer stem cells. Altogether, our results demonstrate that targeting KDM4A can activate anti-tumor immunity and enable PD1 blockade immunotherapy by aggravating replication stress in SCC cells.

Quantitative turbidimetric characterization of stabilized complex coacervate dispersions.

Stabilizing complex coacervate microdroplets is desirable due to their various applications, such as bioreactors, drug delivery vehicles, and encapsulants. Here, we present quantitative characterization of complex coacervate dispersion stability inferred by turbidimetry measurements. The stability of the dispersions is shown to be modulated by the concentrations of comb polyelectrolyte (cPE) stabilizers and salt. We demonstrate cPEs as effective stabilizers for complex coacervate dispersions independent of the chemistry or length of the constituent polyelectrolytes, salts, or preparation routes. By monitoring the temporal evolution of dispersion turbidity, we show that cPEs suppress microdroplet coalescence with minimal change in microdroplet sizes over 48 hours, even at salt concentrations up to 300 mM. The number density and average microdroplet size are shown to be controlled by varying the cPE and salt concentrations. Lastly, turbidity maps, akin to binodal phase maps, depict an expansion of the turbid two-phase region and an increase in the salt resistance of the coacervates upon the introduction of cPEs. The coacervate salt resistance is shown to increase by >3×, and this increase is maintained for up to 15 days, demonstrating that cPEs impart higher salt resistance over extended durations.

Black patients referred to a lung cancer screening program experience lower rates of screening and longer time to follow-up.

BACKGROUND: Racial disparities are well-documented in preventive cancer care, but they have not been fully explored in the context of lung cancer screening. We sought to explore racial differences in lung cancer screening outcomes within a lung cancer screening program (LCSP) at our urban academic medical center including differences in baseline low-dose computed tomography (LDCT) results, time to follow-up, adherence, as well as return to annual screening after additional imaging, loss to follow-up, and cancer diagnoses in patients with positive baseline scans. METHODS: A historical cohort study of patients referred to our LCSP was conducted to extract demographic and clinical characteristics, smoking history, and lung cancer screening outcomes. RESULTS: After referral to the LCSP, blacks had significantly lower odds of receiving LDCT compared to whites, even while controlling for individual lung cancer risk factors and neighborhood-level factors. Blacks also demonstrated a trend toward delayed follow-up, decreased adherence, and loss to follow-up across all Lung-RADS categories. CONCLUSIONS: Overall, lung cancer screening annual adherence rates were low, regardless of race, highlighting the need for increased patient education and outreach. Furthermore, the disparities in race we identified encourage further research with the purpose of creating culturally competent and inclusive LCSPs.

Durability of the hepatitis B vaccination in pediatric renal transplant recipients.

Since hepatitis B virus (HBV) vaccine implementation, HBV infection has significantly decreased. However, adult renal transplant recipients show a higher rate of seroreversion compared to the general population, leading to HBV infection risk. Data are limited in pediatric renal transplant recipients. Retrospective data were collected to determine the seroprotection and durability of HBV vaccination in pediatric renal transplant patients from 2004 to 2014. One hundred subjects were categorized based on pre- and post-transplant hepatitis B surface antibody (HBsAb). Pretransplant, 85 recipients (85%) had a positive HBsAb compared to 15 (15%) with negative HBsAb. In univariable analyses, other than age (P < .05) no significant differences existed pretransplant by demographics, pretransplantation dialysis, or number of vaccinations. Of the 85 pretransplantation responders, 53 (62%) remained HBsAb positive post-transplantation, 28 (32%) seroreverted, and 4 developed indeterminate titers. All seroreversions occurred within 5 years post-transplant. Receipt of a living donor organ had higher risk of reversion (P = .005). No significant differences were found in demographics, pretransplantation dialysis, vaccination number, or acute rejection. Despite vaccination, 15% of pediatric renal transplant candidates were seronegative, and an additional 32% lost seroprotection within 5 years post-transplantation leaving nearly half of transplant recipients at risk for HBV infection.

Obtaining consensus regarding international transplantation continues to be difficult for pediatric centers in the United States.

Organ transplant is life-saving and any given organ may be valuable to a multitude of potential recipients. An allocation system must be used to reconcile the difference between supply and demand, and this system must take into account the impact that accepting international patients may have on the local system. The principles for allocation must be clear, equitable, provide utility and must be monitored so as to maintain public trust. The impact of the system on metrics deemed to be critical must be measured. Finally, strategies must take into account the local culture, size of the region to be supported, the number and experience of transplant centers, and the resources of the healthcare delivery system. Our focus is on the United States, recognizing that strategies and challenges may vary across countries.

A Case-Control Study on the Impact of Ventilator-Associated Tracheobronchitis in the PICU.

OBJECTIVES: Hospital-acquired infections increase morbidity, mortality, and charges in the PICU. We implemented a quality improvement bundle directed at ventilator-associated pneumonia in our PICU in 2005. We observed an increase in ventilator-associated tracheobronchitis coincident with the near-elimination of ventilator-associated pneumonia. The impact of ventilator-associated tracheobronchitis on critically ill children has not been previously described. Accordingly, we hypothesized that ventilator-associated tracheobronchitisis associated with increased length of stay, mortality, and hospital charge. DESIGN: Retrospective case-control study. PATIENTS: Critically ill children admitted to a quaternary PICU at a free-standing academic children's hospital in the United States. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We conducted a retrospective case control study, with institutional review board approval, of 77 consecutive cases of ventilator-associated tracheobronchitis admitted to our PICU from 2004-2010. We matched each case with a control based on the following criteria (in rank order): age range (< 30 d, 30 d to 24 mo, 24 mo to 12 yr, > 12 yr), admission Pediatric Risk of Mortality III score ± 10, number of ventilator days of control group (> 75% of days until development of ventilator-associated tracheobronchitis), primary diagnosis, underlying organ system dysfunction, surgical procedure, and gender. The primary outcome measured was PICU length of stay. Secondary outcomes included ventilator days, hospital length of stay, mortality, and PICU and hospital charges. Data was analyzed using chi square analysis and p less than 0.05 was considered significant. We successfully matched 45 of 77 ventilator-associated tracheobronchitis patients with controls. There were no significant differences in age, gender, diagnosis, or Pediatric Risk of Mortality III score between groups. Ventilator-associated tracheobronchitis patients had a longer PICU length of stay (median, 21.5 d, interquartile range, 24 d) compared to controls (median, 18 d; interquartile range, 17 d), although not statistically significant (p = 0.13). Ventilator days were also longer in the ventilator-associated tracheobronchitis patients (median, 17 d; IQR, 22 d) versus control (median, 10.5 d; interquartile range, 13 d) (p = 0.01). There was no significant difference in total hospital length of stay (54 d vs 36 d; p = 0.69). PICU mortality was higher in the ventilator-associated tracheobronchitis group (15% vs 5%; p = 0.14), although not statistically significant. There was an increase in both median PICU charges ($197,393 vs $172,344; p < 0.05) and hospital charges ($421,576 vs $350,649; p < 0.05) for ventilator-associated tracheobronchitis patients compared with controls. CONCLUSIONS: Ventilator-associated tracheobronchitis is a clinically significant hospital-acquired infection in the PICU and is associated with longer duration of mechanical ventilation and healthcare costs, possibly through causing a longer PICU length of stay. Quality improvement efforts should be directed at reducing the incidence of ventilator-associated tracheobronchitis in the PICU.

NMR probe of metallic states in nanoscale topological insulators.

A 125Te NMR study of bismuth telluride nanoparticles as a function of particle size revealed that the spin-lattice relaxation is enhanced below 33 nm, accompanied by a transition of NMR spectra from the single to the bimodal regime. The satellite peak features a negative Knight shift and higher relaxivity, consistent with core polarization from p-band carriers. Whereas nanocrystals follow a Korringa law in the range 140-420 K, micrometer particles do so only below 200 K. The results reveal increased metallicity of these nanoscale topological insulators in the limit of higher surface-to-volume ratios.

The investment case for preventing NICU-associated infections.

BACKGROUND: Nosocomial [hospital-associated or neonatal intensive care unit (NICU)-associated] infections occur in as many as 10 to 36% of very low-birth-weight infants cared for in NICUs. OBJECTIVE: To determine the potentially avoidable, incremental costs of care associated with NICU-associated bloodstream infections. STUDY DESIGN: This retrospective study included all NICU admissions of infants weighing 401 to 1500 g at birth in the greater Cincinnati region from January 1, 2005, through December 31, 2007. Nonphysician costs of care were compared between infants who developed at least one bacterial bloodstream infection prior to NICU discharge or death and infants who did not. Costs were adjusted for clinical and demographic characteristics that are present in the first 3 days of life and are known associates of infection. RESULTS: Among 900 study infants with no congenital anomaly and no major surgery, 82 (9.1%) developed at least one bacterial bloodstream infection. On average, the cost of NICU care was $16,800 greater per infant who experienced NICU-associated bloodstream infection. CONCLUSION: Potentially avoidable costs of care associated with bloodstream infection can be used to justify investments in the reliable implementation of evidence-based interventions designed to prevent these infections.

Bat teeth illuminate the diversification of mammalian tooth classes.

Tooth classes are an innovation that has contributed to the evolutionary success of mammals. However, our understanding of the mechanisms by which tooth classes diversified remain limited. We use the evolutionary radiation of noctilionoid bats to show how the tooth developmental program evolved during the adaptation to new diet types. Combining morphological, developmental and mathematical modeling approaches, we demonstrate that tooth classes develop through independent developmental cascades that deviate from classical models. We show that the diversification of tooth number and size is driven by jaw growth rate modulation, explaining the rapid gain/loss of teeth in this clade. Finally, we mathematically model the successive appearance of tooth buds, supporting the hypothesis that growth acts as a key driver of the evolution of tooth number and size. Our work reveal how growth, by tinkering with reaction/diffusion processes, drives the diversification of tooth classes and other repeated structure during adaptive radiations.

Ubiquitin-regulated nuclear-cytoplasmic trafficking of the Nipah virus matrix protein is important for viral budding.

Paramyxoviruses are known to replicate in the cytoplasm and bud from the plasma membrane. Matrix is the major structural protein in paramyxoviruses that mediates viral assembly and budding. Curiously, the matrix proteins of a few paramyxoviruses have been found in the nucleus, although the biological function associated with this nuclear localization remains obscure. We report here that the nuclear-cytoplasmic trafficking of the Nipah virus matrix (NiV-M) protein and associated post-translational modification play a critical role in matrix-mediated virus budding. Nipah virus (NiV) is a highly pathogenic emerging paramyxovirus that causes fatal encephalitis in humans, and is classified as a Biosafety Level 4 (BSL4) pathogen. During live NiV infection, NiV-M was first detected in the nucleus at early stages of infection before subsequent localization to the cytoplasm and the plasma membrane. Mutations in the putative bipartite nuclear localization signal (NLS) and the leucine-rich nuclear export signal (NES) found in NiV-M impaired its nuclear-cytoplasmic trafficking and also abolished NiV-M budding. A highly conserved lysine residue in the NLS served dual functions: its positive charge was important for mediating nuclear import, and it was also a potential site for monoubiquitination which regulates nuclear export of the protein. Concordantly, overexpression of ubiquitin enhanced NiV-M budding whereas depletion of free ubiquitin in the cell (via proteasome inhibitors) resulted in nuclear retention of NiV-M and blocked viral budding. Live Nipah virus budding was exquisitely sensitive to proteasome inhibitors: bortezomib, an FDA-approved proteasome inhibitor for treating multiple myeloma, reduced viral titers with an IC(50) of 2.7 nM, which is 100-fold less than the peak plasma concentration that can be achieved in humans. This opens up the possibility of using an "off-the-shelf" therapeutic against acute NiV infection.

Posttranslational modification of mammalian AP endonuclease (APE1).

A key issue in studying mammalian DNA base excision repair is how its component proteins respond to a plethora of cell-signaling mediators invoked by DNA damage and stress-inducing agents such as reactive oxygen species, and how the actions of individual BER proteins are attributed to cell survival or apoptotic/necrotic death. This article reviews the past and recent progress on posttranslational modification (PTM) of mammalian apurinic/apyrimidinic (AP) endonuclease 1 (APE1).

Reducing catheter-associated bloodstream infections in the pediatric intensive care unit: Business case for quality improvement.

OBJECTIVE: To determine whether catheter-associated bloodstream infections were associated with increased lengths of stay in pediatric intensive care units and hospitals and increased healthcare costs in critically ill children. Previous studies have shown that hospital-acquired bloodstream infections are associated with longer stays in pediatric intensive care units, increased hospital costs, and increased hospital mortality. Catheter-associated bloodstream infections comprise the vast majority of hospital-acquired bloodstream infections. DESIGN: Retrospective, case-matched, cohort study and financial analysis. SETTING: University-affiliated children's medical center. PATIENTS: Twenty-two critically ill children with catheter-associated bloodstream infections and their matched controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We compared the length of stay, mortality, and hospital costs in critically ill children with catheter-associated bloodstream infections and matched controls. The presence of catheter-associated bloodstream infections extended the entire hospital length of stay by 9 days (6.5 days while in the pediatric intensive care unit) and increased hospital costs by $33,039, primarily driven by the increase in length of stay days. Quality improvement efforts directed at reducing the prevalence of catheter-associated bloodstream infections during the period of study decreased total hospital days by 354, reduced total hospital costs by $1,298,271, and reduced total costs to payers by $1,415,676. CONCLUSION: The potential cost savings from reducing or eliminating catheter-associated bloodstream infections in the pediatric intensive care unit are significant. Elimination of catheter-associated bloodstream infections will directly reduce hospital costs, improve asset utilization, and most importantly, improve clinical care.

Dentoalveolar trauma in the pediatric population.

BACKGROUND: Dental alveolar trauma in pediatric patients is a challenge to health care professionals. It can lead to early tooth loss that can compromise oral function, aesthetics, and self-esteem and alter the long-term plan of care for the pediatric patient. METHODS: The authors reviewed the literature pertaining to pediatric dental and alveolar traumas. The current etiology, incidence, classifications of injury, and methods to diagnose and treat these patients were reviewed and outlined. CONCLUSIONS: Management of dental trauma is complex and requires a comprehensive and accurate diagnostic and treatment plan. It is also important to consider the biologic, functional, aesthetic, and economic aspects, as well as the patient's desire. Physicians who provide primary care for children have a unique position to provide diagnostic, triage, educational, and preventive dental care for patients. Several articles have been published regarding primary pediatricians' participation in the preventive dental health care of their patients. One publication, a survey of physicians in Alabama focusing on physicians' overall awareness of dental issues, concluded that most physicians believe they have a role in the oral health of their patients. Most were not aware of many of the American Academy of Pediatric Dentistry's recommendations.

The Case for Patient Navigation in Lung Cancer Screening in Vulnerable Populations: A Systematic Review.

Patient navigation has been proposed to combat cancer disparities in vulnerable populations. Vulnerable populations often have poorer cancer outcomes and lower levels of screening, adherence, and treatment. Navigation has been studied in various cancers, but few studies have assessed navigation in lung cancer. Additionally, there is a lack of consistency in metrics to assess the quality of navigation programs. The authors conducted a systematic review of published cancer screening studies to identify quality metrics used in navigation programs, as well as to recommend standardized metrics to define excellence in lung cancer navigation. The authors included 26 studies evaluating navigation metrics in breast, cervical, colorectal, prostate, and lung cancer. After reviewing the literature, the authors propose the following navigation metrics for lung cancer screening programs: (1) screening rate, (2) compliance with follow-up, (3) time to treatment initiation, (4) patient satisfaction, (5) quality of life, (6) biopsy complications, and (7) cultural competency.

The business case for preventing ventilator-associated pneumonia in pediatric intensive care unit patients.

BACKGROUND: A retrospective matched (1:1) case-control study was conducted to compare the financial impact and costs attributable to ventilator-associated pneumonia (VAP) in a 25-bed pediatric intensive care unit (PICU) in a 475-bed quaternary-care pediatric hospital from the perspective of multiple stakeholders, including the hospital and payors. METHODS: For PICU patients with VAP from January 1 2005, to December 31, 2005, 13 patients were matched to 13 control patients by age, sex, severity of illness, primary diagnosis, underlying illness, surgical procedures, and duration of mechanical ventilation. RESULTS: The mean hospital length of stay (LOS) for VAP patients was 26.5 +/- 13.1 days compared with 17.8 +/- 4.7 days for non-VAP patients (p = .032). The hospital LOS attributable to VAP was 8.7 days. The mean hospital costs for VAP patients was $156,110 +/- $80,688 compared with $104,953 +/- $59,191 for non-VAP patients (p = 0.026). The attributable VAP costs were $51,157. After implementation of the VAP prevention bundle, VAP rates decreased from 7.8 cases per 1,000 ventilator days in fiscal year (FY) 2005 to 0.5 cases per 1,000 ventilator days in FY 2007 (VAP infections: 24 in FY 2005, 9 in FY 2006, 2 in FY 2007; p < 0.001). This reduced hospital days by 400, reduced unreimbursed cost of care by $442,789, reduced hospital costs by $2,353,222, and reduced cost to payors by $2,653,710 for FY 2006 and FY 2007 combined. DISCUSSION: This study provides the first demonstration of significant, sustained reductions in pediatric VAP rates following the implementation of the VAP prevention bundle and the first business case analysis of this pediatric-specific intervention as described from the perspective of multiple stakeholders. A return on investment may speed health care organizations' investment in patient safety and quality improvement.

Targeted nanodiamonds for identification of subcellular protein assemblies in mammalian cells.

Transmission electron microscopy (TEM) can be used to successfully determine the structures of proteins. However, such studies are typically done ex situ after extraction of the protein from the cellular environment. Here we describe an application for nanodiamonds as targeted intensity contrast labels in biological TEM, using the nuclear pore complex (NPC) as a model macroassembly. We demonstrate that delivery of antibody-conjugated nanodiamonds to live mammalian cells using maltotriose-conjugated polypropylenimine dendrimers results in efficient localization of nanodiamonds to the intended cellular target. We further identify signatures of nanodiamonds under TEM that allow for unambiguous identification of individual nanodiamonds from a resin-embedded, OsO4-stained environment. This is the first demonstration of nanodiamonds as labels for nanoscale TEM-based identification of subcellular protein assemblies. These results, combined with the unique fluorescence properties and biocompatibility of nanodiamonds, represent an important step toward the use of nanodiamonds as markers for correlated optical/electron bioimaging.

Alterations of cell signaling pathways in pancreatic cancer.

Pancreatic ductal adenocarcinomas continue to have the worst prognosis of any adult malignancy with a five-year survival rate of less than 4%. One approach to improve patient survival from pancreatic cancer is to identify new biological targets that contribute to the aggressive pathogenecity of this disease and to develop reagents that will interfere with the function of these targets. Apart from the identification of the genetic profile of pancreatic cancer, a number of studies have focused on aberrant cell signaling pathways and their role in pancreatic cancer biology and response to therapy. This review, although not comprehensive, will discuss the salient features of several of these pathways. These include the roles of TGF beta signaling in both tumor suppression and tumor promotion and the effects of deregulation of phosphotyrosine kinase receptor signaling pathways in pancreatic cancer.

Nanodiamond landmarks for subcellular multimodal optical and electron imaging.

There is a growing need for biolabels that can be used in both optical and electron microscopies, are non-cytotoxic, and do not photobleach. Such biolabels could enable targeted nanoscale imaging of sub-cellular structures, and help to establish correlations between conjugation-delivered biomolecules and function. Here we demonstrate a sub-cellular multi-modal imaging methodology that enables localization of inert particulate probes, consisting of nanodiamonds having fluorescent nitrogen-vacancy centers. These are functionalized to target specific structures, and are observable by both optical and electron microscopies. Nanodiamonds targeted to the nuclear pore complex are rapidly localized in electron-microscopy diffraction mode to enable "zooming-in" to regions of interest for detailed structural investigations. Optical microscopies reveal nanodiamonds for in-vitro tracking or uptake-confirmation. The approach is general, works down to the single nanodiamond level, and can leverage the unique capabilities of nanodiamonds, such as biocompatibility, sensitive magnetometry, and gene and drug delivery.

Real-time maps of fluid flow fields in porous biomaterials.

Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, non-invasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.