The art of simplicity: Water-soluble porphyrin-like carbon dots self-assemble into mesmerizing red glow

In this new study, we present an intriguing development in the field of theranostics: the simplistic self-assembly of red-emissive amphiphilic porphyrin-like carbon dots (P-CDs). By harnessing their exceptional photophysical properties, we have revealed a strong candidate as the ideal photosensitizer (PS) for applications, particularly in the realm of imaging. Spanning a remarkable size average between 1-4 nm, these particles exhibit both highly stable and unparalleled emission characteristics between 650 and 715 nm in water in comparison to current carbon dots (CDs) available. Lastly, these CDs were fairly non-toxic when tested against normal human cell lines as well as were found to have favorable imaging capabilities in zebrafish embryo.

Advancing glioblastoma imaging: Exploring the potential of organic fluorophore-based red emissive carbon dots

Over time, the interest in developing stable photosensitizers (PS) which both absorb and emit light in the red region (650 and 950 nm) has gained noticeable interest. Recently, carbon dots (CDs) have become the material of focus to act as a PS due to their high extinction coefficient, low cytotoxicity, and both high photo and thermal stability. In this work, a Federal and Drug Association (FDA) approved Near Infra-Red (NIR) organic fluorophore used for photo-imaging, indocyanine green (ICG), has been explored as a precursor to develop water-soluble red emissive CDs which possess red emission at 697 nm. Furthermore, our material was found to yield favorable red-imaging capabilities of glioblastoma stem-like cells (GSCs) meanwhile boasting low toxicity. Additionally with post modifications, our CDs have been found to have selectivity towards tumors over healthy tissue as well as crossing the blood-brain barrier (BBB) in zebrafish models.

Carbon Dots in Treatment of Pediatric Brain Tumors: Past, Present, and Future Directions

Pediatric brain tumors remain a significant source of morbidity and mortality. Though developments have been made in treating these malignancies, the blood-brain barrier, intra- and inter-tumoral heterogeneity, and therapeutic toxicity pose challenges to improving outcomes. Varying types of nanoparticles, including metallic, organic, and micellar molecules of varying structures and compositions, have been investigated as a potential therapy to circumvent some of these inherent challenges. Carbon dots (CDs) have recently gained popularity as a novel nanoparticle with theranostic properties. This carbon-based modality is highly modifiable, allowing for conjugation to drugs, as well as tumor-specific ligands in an effort to more effectively target cancerous cells and reduce peripheral toxicity. CDs are being studied pre-clinically. The ClinicalTrials.gov site was queried using the search terms: brain tumor and nanoparticle, liposome, micelle, dendrimer, quantum dot, or carbon dot. At the time of this review, 36 studies were found, 6 of which included pediatric patients. Two of the six studies investigated nanoparticle drug formulations, whereas the other four studies were on varying liposomal nanoparticle formulations for the treatment of pediatric brain tumors. Here, we reviewed the context of CDs within the broader realm of nanoparticles, their development, promising pre-clinical potential, and proposed future translational utility.

DDEL-12. QUADRUPLE CARBON DOT NANO MODEL FOR ENHANCED TUMOR TARGETING AND DUAL DRUG DELIVERY FOR THE TREATMENT OF PEDIATRIC HIGH-GRADE GLIOMAS

High-grade gliomas remain among the most lethal neoplasms. Nanotechnology aims to Improve drug targeting and efficacy. Here we developed a quadruple nano-model (QNM) that specifically targets pediatric high-grade glioma cells and delivers chemotherapies to the cell nucleus. This carbon dot based QNM were fabricated by covalently attaching two drugs (epirubicin and temozolomide) and two targeting peptides. ShPep-1 peptide binds to the IL-13Rα2 receptors allowing for cellular import while lnPep-1h peptide delivers the DNA damaging drugs to the nucleus. Despite demonstrating the lowest measurable drug content (23.3%), the dual peptide linked QNM induced significantly greater cell death than single peptide linked conjugates suggesting enhanced cell uptake. Greatest effect was observed in glioblastoma (SJ-GBM2) and diffuse intrinsic pontine glioma (NP53) cells with IC50s of approximately 60 nM, 3-6-fold lower than single peptide conjugates. Imaging studies using FITC-conjugated carbon dots confirmed the dual peptide conjugate demonstrated greatest cellular uptake and nuclear localization.

Prevalence of pulmonary embolism among patients presenting to emergency department for hemoptysis

Background

Although hemoptysis is a well known symptom of presentation of pulmonary embolism (PE), and it is included in different diagnostic scores for PE, the prevalence of PE in patients with hemoptysis and the yield of evidence based PE diagnostic pathway in these patients has not been specifically investigated.

Objectives

To determine the prevalence of PE and the yield (n° of positive tests/n° of tests), the efficiency (the proportion of patients in whom PE could be considered to be excluded) and the failure rate (the false negative rate) of the classic diagnostic algorithm for PE in patients with hemoptysis.

Methods

Unselected patients presenting with hemoptysis to 7 italian EDs were prospectively enrolled in a diagnostic multicenter study. Pre-test clinical probability for PE was assessed using the 2-level Wells score and the results of D-dimer testing using age-adjusted cutoffs. Presence of PE was evaluated by CT pulmonary angiogram (CTPA), when ordered as part of the clinical assessment by the treating ED physician, or by one month follow-up data.

Results

Out of 327 adult patients presenting to ED with hemoptysis, 15 (4.6%) were excluded because of diagnostic protocol violation and absence of one month follow-up. Among 312 included patients, PE was detected at presentation in 15 patients (4.8%; 95% confidence interval [CI]: 2.72–7.81%). During follow-up, 5 patients died (1.6%; 95% CI: 0.52%-3.7%) not due to PE. Among 165 patients with a “likely” score or a high D-dimer, 13 (7.9%; 95% CI: 4.72–13.8%) had PE. The efficiency was 32.8% and the failure rate was 1.7% in patients tested by D-dimer.

Conclusions

PE seems an uncommon cause of hemoptysis among patients presenting to the ED and the yield of classic diagnostic algorithm is low. PE-screening in patients with hemoptysis deserves further investigation aimed at improving the diagnostic yield.

Funding Acknowledgement

Type of funding sources: None.

Dropped head syndrome in a patient with Parkinson's disease and inflammatory myopathy, treated with sternocleidomastoid release and circumferential cervical fusion

BACKGROUND

Dropped head syndrome (DHS) is a recently recognised cause of cervical spinal deformity and disability. The combination of Parkinson's disease (PD) and inflammatory myopathy in the genesis of DHS has not been previously reported. Furthermore, the optimal surgical treatment of progressive DHS remains undefined.

CASE DESCRIPTION

We report the case of a 64-year-old patient with severe DHS and coronal plane deformity secondary to underlying PD, precipitated by a focal paraspinal myositis, successfully corrected using asymmetric sternocleidomastoid (SCM) release and circumferential cervical fusion. The nuances of decision-making in this challenging patient population are highlighted, including the benefits of intraoperative traction, anterior column reconstruction and bicortical screw fixation. Postoperatively, significant reductions in pain and disability were achieved, along with restoration of cervical lordosis (CL), C2-7 sagittal vertical axis (CSVA) and chin-brow vertical angle (CBVA).

CONCLUSIONS

Circumferential cervical fusion with concomitant SCM release is a useful option in the treatment of recalcitrant DHS with biplanar deformity, addressing the unique biomechanical and endocrinological challenges posed by patients with underlying PD.

Surface modification of carbon nitride dots by nanoarchitectonics for better drug loading and higher cancer selectivity

Carbon Dots (CDs) have recently attracted a considerable amount of attention thanks to their well-documented biocompatibility, tunable photoluminescence, and excellent water solubility. However, CDs need further analysis before their potential use in clinical trials. Previously, we reported a new type of carbon nitride dot (CND) that displayed selective cancer uptake traits attributed to structural resemblances between CNDs and glutamine. Here, the effects of surface structural differences on the cellular uptake of CNDs are further investigated to understand their selective cancer cell uptake trend. Beyond enhanced drug loading on modified CNDs, our cytotoxicity, western blotting and bioimaging studies proposed that modified CNDs' cellular uptake mechanism is thoroughly linked with ASCT2 and LAT1 transporters. Therefore, CNDs have a promising trait of selective cancer cell targeting by utilizing highly expressed transporters on cancer cells. Additionally, drug loaded CNDs exhibited improved anti-cancer efficacies towards cancer cells along with good non-tumor biocompatibilities.

DFMO Carbon Dots for Treatment of Neuroblastoma and Bioimaging

Neuroblastoma (NB) is a pediatric malignancy affecting the peripheral nervous system. Despite recent advancements in treatment, many children affected with NB continue to submit to this illness, and new therapeutic strategies are desperately needed. In recent years, studies of carbon dots (CDs) as nanocarriers have mostly focused on the delivery of anticancer agents because of their biocompatibility, good aqueous dissolution, and photostability. Their fluorescence properties, surface functionalities, and surface charges differ on the basis of the type of precursors used and the synthetic approach implemented. At present, most CDs are used as nanocarriers by directly linking them either covalently or electrostatically to drug molecules. Though most modern CDs are synthesized from large carbon macromolecules and conjugated to anticancerous drugs, constructing CDs from the anticancerous drugs and precursors themselves to increase antitumoral activity requires further investigation. Herein, CDs were synthesized using difluoromethylornithine (DFMO), an irreversible ornithine decarboxylase inhibitor commonly used in high-risk neuroblastoma treatment regiments. In this study, NB cell lines, SMS-KCNR and SK-N-AS, were treated with DFMO, the newly synthesized DFMO CDs, and conventional DFMO conjugated to black carbon dots. Bioimaging was done to determine the cellular localization of a fluorescent drug over time. The mobility of DNA mixed with DFMO CDs was evaluated by gel electrophoresis. DFMO CDs were effectively synthesized from DFMO precursor and characterized using spectroscopic methods. The DFMO CDs effectively reduced cell viability with increasing dose. The effects were dramatic in the N-MYC-amplified line SMS-KCNR at 500 μM, which is comparable to high doses of conventional DFMO at a 60-fold lower concentration. In vitro bioimaging as well as DNA electrophoresis showed that synthesized DFMO CDs were able to enter the nucleus of neuroblastoma cells and neuronal cells and interact with DNA. Our new DFMO CDs exhibit a robust advantage over conventional DFMO because they induce comparable reductions in viability at a dramatically lower concentration.

NAMPT Inhibition Induces Neuroblastoma Cell Death and Blocks Tumor Growth

High-risk neuroblastoma (NB) portends very poor prognoses in children. Targeting tumor metabolism has emerged as a novel therapeutic strategy. High levels of nicotinamide-adenine-dinucleotide (NAD+) are required for rapid cell proliferation. Nicotinamide phosphoribosyl transferase (NAMPT) is the rate-limiting enzyme for NAD+ salvage and is overexpressed in several cancers. Here, we determine the potential of NAMPT as a therapeutic target for NB treatment. NAMPT inhibition cytotoxicity was determined by trypan blue exclusion and LDH assays. Neuroblastoma stem cell self-renewal was evaluated by neurosphere assay. Protein expression was evaluated via Western blot. The effect of targeting NAMPT in vivo was determined using an NB1691-xenografted mouse model. Robust NAMPT expression was demonstrated in multiple N-MYC amplified, high-risk neuroblastoma cell lines. NAMPT inhibition with STF-118804 (STF) decreased ATP, induced apoptosis, and reduced NB stem cell neurosphere formation. STF treatment down-regulated N-MYC levels and abrogated AKT activation. AKT and glycolytic pathway inhibitors in combination with NAMPT inhibition induced robust, greater-than-additive neuroblastoma cell death. Lastly, STF treatment blocked neuroblastoma tumor growth in mouse xenograft models. NAMPT is a valid therapeutic target as inhibition promoted neuroblastoma cell death in vitro and prevented tumor growth in vivo. Further investigation is warranted to establish this therapy’s role as an adjunctive modality.

Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

Implantable brain-computer interface for neuroprosthetic-enabled volitional hand grasp restoration in spinal cord injury

Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in one 21-year-old male subject with complete cervical quadriplegia (C5 American Spinal Injury Association Impairment Scale A) using a portable fully implanted brain-computer interface within the home environment. The brain-computer interface consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic activity. Movement-intent was used to trigger functional electrical stimulation of the dominant hand during an initial 29-weeks laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement-intent information could be decoded consistently throughout the 29-weeks in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy of various upper extremity tasks, including lifting small objects and transferring objects to specific targets. At-home decoding accuracy during open-loop trials reached an accuracy of 91.3% (range 80-98.95%) and an accuracy of 88.3% (range 77.6-95.5%) during closed-loop trials. Importantly, the temporal stability of both the functional outcomes and decoder metrics were not explored in this study. A fully implanted brain-computer interface can be safely used to reliably decode movement-intent from motor cortex, allowing for accurate volitional control of hand grasp.

Incidence and Clinical Outcomes of Hypothyroidism in Patients Undergoing Spinal Fusion

Background

Hypothyroidism has been independently associated with the development of several comorbidities and is known to increase complication rates in non-spinal surgeries. However, there are limited data regarding the effects of hypothyroidism in major spine surgery. Therefore, we present the largest retrospective analysis evaluating outcomes in hypothyroid patients undergoing spinal fusion.

Methods

A retrospective review of the National Inpatient Sample (NIS) from 2004-2014 was performed. Patients with an International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) procedure code indicating spinal fusion (81.04-81.08, 81.34-81.38, 81.0x, 81.3x) were included. Patients with an ICD-9-CM diagnosis code indicating hypothyroidism (244.x) were compared to those without. Cervical and lumbar fusions were evaluated independently. Significant covariates in univariable logistic regression were utilized to construct multivariable models to analyze the effect of hypothyroidism on perioperative morbidity and mortality.

Results

A total of 4,149,125 patients were identified, of which 9.4% were hypothyroid. Although, hypothyroid patients had a higher risk of hematologic complications (lumbar - odds ratio [OR] 1.176, p < 0.0001; cervical - OR 1.162, p < 0.0001), they exhibited decreased in-hospital mortality (lumbar - OR .643, p < 0.0001; cervical - OR .606, p < 0.0001). Hypothyroid lumbar fusion patients also demonstrated decreased rates of perioperative myocardial infarction (MI) (OR .851, p < 0.0001). All these results were independent of patient gender.

Conclusions

Hypothyroid patients undergoing spinal fusion demonstrated lower rates of inpatient mortality and, in lumbar fusions, also had lower rates of acute MI when compared to their euthyroid counterparts. This suggests that hypothyroidism may offer protection against all-cause mortality and may be cardioprotective in the postoperative period for lumbar spinal fusions independent of patient gender.

Short lever arm, bipedicular handlebar construct for correction of acute angular kyphosis in spondylodiscitis-induced kyphotic deformity: illustrative case

BACKGROUND

Pyogenic spondylodiscitis diminishes spinal structural integrity via disruption of the anterior and middle column, sometimes further compounded by iatrogenic violation of the posterior tension band during initial posterior decompressive surgeries. Although medical management is typically sufficient, refractory infection or progressive deformity may require aggressive debridement and reconstructive arthrodesis. Although anterior debridement plus reconstruction with posterior stabilization is an effective treatment option, existing techniques have limited efficacy for correcting focal deformity, leaving patients at risk for long-term sagittal imbalance, pain, and disability.

OBSERVATIONS

The authors present a case of chronic lumbar pyogenic spondylodiscitis in a patient in whom initial surgical debridement failed and pronounced angular kyphosis and intractable low back pain developed. A novel bipedicular handlebar construct was used to achieve angular correction of the kyphosis through simultaneous anterior interbody grafting and posterior instrumentation with the patient in the lateral position.

LESSONS

Leveraging both pedicle screws at the same level to transmit controlled corrective distraction forces through the segment allows for kyphosis correction without relying on long posterior constructs for cantilever reduction. Simultaneous anterior reconstruction with a posterior short lever arm, bipedicular handlebar construct is an effective technique for achieving high angular correction during circumferential reconstructive approaches to postinfectious focal kyphotic deformities.

National Trends and Correlates of Dysphagia After Anterior Cervical Discectomy and Fusion Surgery

Objective

Anterior cervical discectomy and fusion (ACDF) is the most common performed surgery in the cervical spine. Dysphagia is one of the most frequent complications following ACDF. Several studies have identified certain demographic and perioperative risk factors associated with increased dysphagia rates, but few have reported recent trends. Our study aims to report current trends and factors associated with the development of inpatient postoperative dysphagia after ACDF.

Methods

The National Inpatient Sample was evaluated from 2004 to 2014 and discharges with International Classification of Diseases procedure codes indicating ACDF were selected. Time trend series plots were created for the yearly treatment trends for each fusion level by dysphagia outcome. Separate univariable followed by multivariable logistic regression analyses were performed to evaluate predictors of dysphagia.

Results

A total of 1,212,475 ACDFs were identified in which 3.3% experienced postoperative dysphagia. A significant increase in annual dysphagia rates was observed from 2004–2014. Frailty, intraoperative neuromonitoring, 4 or more level fusions, African American race, fluid/electrolyte disorders, blood loss, and coagulopathy were all identified as significant independent risk factors for the development of postoperative dysphagia following ACDF.

Conclusion

Postoperative dysphagia is a well-known postsurgical complication associated with ACDF. Our cohort showed a significant increase in the annual dysphagia rates independent of levels fused. We identified several risk factors associated with the development of postoperative dysphagia after ACDF.

pH and redox triggered doxorubicin release from covalently linked carbon dots conjugates

Tumor microenvironment responsive drug delivery systems are potential approaches to reduce the acute toxicity caused by high-dose cancer chemotherapy. Notwithstanding the conventional nano-drug delivery systems, the redox and pH stimuli drug delivery systems are currently gaining attention. Therefore, the current study was designed to compare three different covalent carbon dots (C-dots) systems based on doxorubicin (dox) release profiles and cancer cell viability efficacy under acidic and physiological conditions. The C-dots nanosystems that were examined in this study are directly conjugated (C-dots-dox), pH triggered (C-dots-HBA-dox), and the redox stimuli (C-dots-S-S-dox) conjugates. The drug loading content (DLC%) of the C-dots-S-S-dox, C-dots-HBA-dox, and C-dots-dox was 34.2 ± 0.4, 60.0 ± 0.3, and 70.0 ± 0.2%, respectively, that examined by UV-vis spectral analysis. The dox release paradigms were emphasized that all three conjugates were promisingly released the dox from C-dots faster in acidic pH than in physiological pH. The displayed highest dox released percentage in the acidic medium was 74.6 ± 0.8% obtained by the pH stimuli, C-dots-HBA-dox conjugate. When introducing the redox inducer, dithiothreitol (DTT), preferentially, the redox stimuli C-dot-S-S-dox conjugate demonstrated a faster dox release at acidic pH than in the pH 7.4. The SJGBM2 cell viability experiments revealed that the pH stimuli, C-dots-HBA-dox conjugate, displayed a significant cell viability drop in the artificially acidified pH 6.4 medium. However, in the physiological pH, the redox stimuli, C-dots-S-S-dox conjugate, was promising over the pH stimuli C-dots-HBA-dox, exhibiting cell viability of 60%, though its' efficacy dropped slightly in the artificially acidified pH 6.4 medium. Moreover, the current study illustrates the stimuli conjugates' remarkable efficacy on sustain drug release than direct amide linkage.

UCP2 as a Potential Biomarker for Adjunctive Metabolic Therapies in Tumor Management

Glioblastoma (GBM) remains one of the most lethal primary brain tumors in both adult and pediatric patients. Targeting tumor metabolism has emerged as a promising-targeted therapeutic strategy for GBM and characteristically resistant GBM stem-like cells (GSCs). Neoplastic cells, especially those with high proliferative potential such as GSCs, have been shown to upregulate UCP2 as a cytoprotective mechanism in response to chronic increased reactive oxygen species (ROS) exposure. This upregulation plays a central role in the induction of the highly glycolytic phenotype associated with many tumors. In addition to shifting metabolism away from oxidative phosphorylation, UCP2 has also been implicated in increased mitochondrial Ca²⁺ sequestration, apoptotic evasion, dampened immune response, and chemotherapeutic resistance. A query of the CGGA RNA-seq and the TCGA GBMLGG database demonstrated that UCP2 expression increases with increased WHO tumor-grade and is associated with much poorer prognosis across a cohort of brain tumors. UCP2 expression could potentially serve as a biomarker to stratify patients for adjunctive anti-tumor metabolic therapies, such as glycolytic inhibition alongside current standard of care, particularly in adult and pediatric gliomas. Additionally, because UCP2 correlates with tumor grade, monitoring serum protein levels in the future may allow clinicians a relatively minimally invasive marker to correlate with disease progression. Further investigation of UCP2’s role in metabolic reprogramming is warranted to fully appreciate its clinical translatability and utility.

Metformin derived carbon dots: Highly biocompatible fluorescent nanomaterials as mitochondrial targeting and blood-brain barrier penetrating biomarkers

Carbon dots (CDs) have been intensively studied since their discovery in 2004 because of their unique properties such as low toxicity, excellent biocompatibility, high photoluminescence (PL) and good water dispersibility. In this study metformin derived carbon dots (Met-CDs) were synthesized using a microwave assisted method. Met-CDs were meticulously characterized using ultra-violet spectroscopy (UV-vis), photoluminescence (PL), Fourier Transform Infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), atomic force (AFM) and transmission electron (TEM) microscopies. According to results of cytotoxicity studies, Met-CDs possess low-toxicity and excellent biocompatibility towards both non-tumor and tumor cell lines indicating that Met-CDs are outstanding candidates for living cell bioimaging studies. Furthermore, bioimaging studies have displayed that Met-CDs can penetrate the cell membrane and disperse throughout the cell structure including the nucleus and mitochondria. More specifically, Met-CDs tend to start localizing selectively inside the mitochondria of cancer cells, but not of non-tumor cells after 1 h of incubation. Finally, a zebrafish study confirmed that Met-CDs cross the blood-brain barrier (BBB) without the need of any other ligands. In summary, this study presents synthesis of Met-CDs which feature abilities such as mitochondrial and nucleus localizations along with BBB penetration.

Effects of Body Mass Index on Perioperative Outcomes in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgery

Objective

Obesity has become a public health crisis and continues to be on the rise. An elevated body mass index has been linked to higher rates of spinal degenerative disease requiring surgical intervention. Limited studies exist that evaluate the effects of obesity on perioperative complications in patients undergoing anterior cervical discectomy and fusion (ACDF). Our study aims to determine the incidence of obesity in the ACDF population and the effects it may have on postoperative inpatient complications.

Methods

The National Inpatient Sample was evaluated from 2004 to 2014 and discharges with International Classification of Diseases procedure codes indicating ACDF were identified. This cohort was stratified into patients with diagnosis codes indicating obesity. Separate univariable followed by multivariable logistic regression analysis were performed for the likelihood of perioperative inpatient outcomes among the patients with obesity.

Results

From 2004 to 2014, estimated 1,212,475 ACDFs were identified in which 9.2% of the patients were obese. The incidence of obesity amongst ACDF patients has risen dramatically during those years from 5.8% to 13.4%. Obese ACDF patients had higher inpatient likelihood of dysphagia, neurological, respiratory, and hematologic complications as well as pulmonary emboli, and intraoperative durotomy.

Conclusion

Obesity is a well-established modifiable comorbidity that leads to increased perioperative complications in various surgical specialties. We present one of the largest retrospective analyses evaluating the effects of obesity on inpatient complications following ACDF. Our data suggest that the number of obese patients undergoing ACDF is steadily increasing and had a higher inpatient likelihood of developing perioperative complications.

The Effects of Lockdown During the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Pandemic on Neurotrauma-Related Hospital Admissions

Background

The response to the global severe acute respiratory syndrome coronavirus 2 pandemic culminated in mandatory isolation throughout the world, with nationwide confinement orders issued to decrease viral spread. These drastic measures were successful in “flattening the curve” and maintaining the previous rate of coronavirus disease 2019 infections and deaths. To date, the effects of the coronavirus disease 2019 pandemic on neurotrauma has not been reported.

Methods

We retrospectively analyzed hospital admissions from Ryder Trauma Center at Jackson Memorial Hospital, during the months of March and April from 2016 to 2020. Specifically, we identified all patients who had cranial neurotrauma consisting of traumatic brain injury and/or skull fractures, as well as spinal neurotrauma consisting of vertebral fractures and/or spinal cord injury. We then performed chart review to determine mechanism of injury and if emergent surgical intervention was required.

Results

Compared with previous years, we saw a significant decline in the number of neurotraumas during the pandemic, with a 62% decline after the lockdown began. The number of emergent neurotrauma surgical cases also significantly decreased by 84% in the month of April. Interestingly, although the number of vehicular traumas decreased by 77%, there was a significant 100% increase in the number of gunshot wounds.

Conclusions

Population seclusion had a direct effect on the frequency of neurotrauma, whereas the change in relative proportion of certain mechanisms may be associated with the psychosocial effects of social distancing and quarantine.

Pediatric glioblastoma target-specific efficient delivery of gemcitabine across the blood-brain barrier via carbon nitride dots

Pediatric glioblastomas are known to be one of the most dangerous and life-threatening cancers among many others regardless of the low number of cases reported. The major obstacles in the treatment of these tumors can be identified as the lack of prognosis data and the therapeutic requirement to be able to cross the blood-brain barrier (BBB). Due to this lack of data and techniques, pediatric patients could face drastic side effects over a long-time span even after survival. Therefore, in this study, the capability of non-toxic carbon nitride dots (CNDs) to selectively target pediatric glioblastoma cells was studied in vitro. Furthermore, the nanocarrier capability and efficiency of CNDs were also investigated through conjugation of a chemotherapeutic agent and transferrin (T_f) protein. Gemcitabine (GM) was introduced into the system as a chemotherapeutic agent, which has never been successfully used for the treatment of any central nervous system (CNS) cancer. More than 95% of selective damage of SJGBM2 glioma cells was observed at 1 μM of CN-GM conjugate with almost 100% viability of non-cancerous HEK293 cells, although this ability was diminished at lower concentrations. However, further conjugation of T_f to obtain CN-GM-T_f allowed the achievement of selective targeting and prominent anti-cancer activity at a 100-fold lower concentration of 10 nM. Furthermore, both conjugates were capable of effectively damaging several other brain tumor cells, which were not well responsive towards the single treatment of GM. The capability of BBB penetration of the conjugates was observed using a zebrafish model, which confirms the CNDs' competence as an excellent nanocarrier to the CNS.

P6463Prognostic value of respiratory index (RI) in hemodinamically stable patients with acute pulmonary embolism: the RI-MODEL study

Background

The accuracy of the 2014 ESC model to predict 30-day mortality in hemodynamically stable patients with acute pulmonary embolism (PE) is relatively limited.

Purpose

The aims of this study in hemodynamically stable patients with acute PE were i) to evaluate the prognostic value of a novel respiratory index (RI) (oxygen saturation in air to respiratory rate ratio) and ii) to assess the accuracy of the RI-model (simplified Pulmonary Embolism Severity Index [sPESI] + RI), both in predicting 30-day mortality.

Methods

A collaborative database of hemodynamically stable patients with PE was divided into two cohorts (derivation and validation) with equal numbers of patients, based on a temporal criterion. Study outcome was 30-day all-cause-death. Discrimination and calibration were assessed in the derivation and validation cohorts by the c-statistics and by the Hosmer-Lemeshow test, respectively.

Results

30-day all-cause-death occurred in 7.5% of the 319 patients in the derivation cohort (mean age 72 years, females 53%). The RI was an independent predictor of 30-day mortality (p=0.004). A RI ≤3.8 was associated with an increased death rate compared to higher RI values (15.4% vs 5.0%, OR 3.4, 95% CI 1.5–8.1). When the RI≤3.8 was integrated in the sPESI, the novel RI-model showed a good discriminatory power (c-statistics 0.703, 95% CI 0.603–0.803).

In the 319 patients of the validation cohort (30-day mortality 6.9%, mean age 71 years, females 55%) the discriminatory power of the RI-model was confirmed (c-statistics 0.838, 95% CI 0.768–0.907).

The RI-model and the 2014 ESC model had a c-statistics of 0.772 (95% CI 0.709–0.834) and of 0.687 (95% CI 0.620–0.753) in the overall population, respectively.

Conclusion

In this study, the RI independently predicted 30-day mortality in hemodynamically stable patients with acute PE. A clinical model including RI showed a better discriminatory value than 2014 ESC model and could be used for risk stratification in these patients.

P5588Early versus delayed oral anticoagulation in patients with acute pulmonary embolism: determinants and outcome

Background

Whether early oral anticoagulant treatment is appropriate for patients with acute pulmonary embolism (PE) regardless of PE severity is undefined. The aim of this study in patients with acute PE at intermediate risk of death were: I) to assess the determinants for the use of early vs delayed vs no oral anticoagulants in patients with acute PE and II) to assess the association between timing of oral anticoagulation and in-hospital mortality.

Methods

Prospective cohorts of patients with acute PE at intermediate risk of death according to the European Society of Cardiology Guidelines 2014 were merged in a collaborative database. The initiation of oral anticoagulation was classified as early (≤3 days) or delayed (between day 3 and 10 from diagnosis). Patients treated with parenteral anticoagulants for longer than 10 days were also included. In-hospital death was the primary study outcome.

Results

Overall, 557 patients were included in the study, 23 received thrombolytic treatment during the hospital stay. The mean duration of parenteral anticoagulation was 7±8 days (5 median), 348 patients were initiated on a direct oral anticoagulant and 79 on a vitamin K antagonist during the hospital stay. Initiation of oral anticoagulants occurred early or delayed in 209 (37%) and 218 (39%) patients, respectively and never occurred during the first 30 days in 130 (23%).

Intermediate-low risk patients more commonly received early and intermediate high delayed oral anticoagulation. Simplified PESI score of zero (OR 1.9, 95% CI 1.3–2.7) was independently associated with early oral anticoagulation; among sPESI components absence of cancer (OR 5.9, 95% CI 3.3–10) and heart rate <110 (OR 1.8, 95% CI 1.01–3.16) were independent predictors of early initiation of oral anticoagulants. The presence of both right ventricle dysfunction and injury was associated with delayed initiation of oral anticoagulants.

The incidence of death was 5.5%. Death occurred in 32 patients and was not related to the duration of parenteral anticoagulation (OR 1.01 per day, 95% CI 0.98–1.06) nor to right ventricle dysfunction but to sPESI 1 (OR 3.32, 95% CI 1.14–9.66). These results were partially confirmed in the 435 intermediate risk patients without cancer (OR 1.03, 95% CI 0.99–1.08 for days of parenteral treatment; OR 4.17, 95% CI 0.95–18 for sPESI 1).

Conclusion

The clinical severity of PE and not the timing of initiation of oral anticoagulants are associated with in-hospital death in patients with intermediate risk PE. Randomized studies are needed to definitively assess the role of heparin lead-in in patients with PE at intermediate risk for death.

Exploiting metabolic susceptibilities in glioblastoma via glycolytic inhibition and ketogenic therapy

e13558

Background: Glioblastoma (GBM) remains one of the most lethal primary brain tumors in children and adults. Despite enormous efforts to elucidate the genetic and epigenetic drivers of this disease, the prognosis for patients diagnosed with GBM remains dismal. Because tumor cell metabolism differs greatly from that of normal non-cancerous cells, it is possible to develop therapies which more effectively target the cancer cell while sparing normal cells. Growing in popularity is the ketogenic diet, which is a high fat, very low carbohydrate diet resulting in the production of ketone bodies, acetoacetate (AA) and β-hydroxybutyrate (βHB) to generate ATP. Methods: Analysis conducted by open-access GBM patient database, mts assay, Western blot, neurosphere assay, and TEM. Results: Enzymes required for ketone metabolism (BDH1 and OXCT1) were significantly downregulated in GBM while glycolytic enzymes were significantly upregulated (HK2, HK1, SLC2A3, NAMPT, G6PD). GBM stem cell (GSC) markers (CD44, STAT3) positively correlated with glycolytic enzymes. Ultrastructural analysis of GSCs indicated that about half of the mitochondria were missing cristae, highly suggestive of an increased glycolytic dependency. Treatment of patient-derived GSC lines as well as non-stem cell lines SJGBM2 (pediatric) and U87 (adult) resulted in a dose-dependent decrease in viability in response to the glycolytic inhibitor 2-deoxy-D-glucose (2-DG). When cells were exposed to ketone bodies, AA but not βHB induced a dose-dependent decrease in cell viability with 10 mM reducing viability ranging from 20-80% of non-treated controls. Western blot analysis demonstrated robust caspase activation and PARP cleavage in response to AA. Furthermore, AA significantly reduced GSC neurosphere formation at 2.5 mM suggesting inhibition of GSC self-renewal pathways. Combined treatment of low dose 2-DG (50 μM) with increasing concentrations of AA resulted in more cell death than either treatment. The effect was more than additive at the low concentrations of AA (1- 5 mM) suggesting synergy. Conclusions: Glycolytic inhibition in conjunction with the ketogenic diet may be a promising therapeutic route for this difficult-to-treat cancer.

Triple conjugated carbon dots as a nano-drug delivery model for glioblastoma brain tumors

Most of the dual nano drug delivery systems fail to enter malignant brain tumors due to a lack of proper targeting systems and the size increase of the nanoparticles after drug conjugation. Therefore, a triple conjugated system was developed with carbon dots (C-dots), which have an average particle size of 1.5-1.7 nm. C-dots were conjugated with transferrin (the targeted ligand) and two anti-cancer drugs, epirubicin and temozolomide, to build the triple conjugated system in which the average particle size was increased only up to 3.5 nm. In vitro studies were performed with glioblastoma brain tumor cell lines SJGBM2, CHLA266, CHLA200 (pediatric) and U87 (adult). The efficacy of the triple conjugated system (dual drug conjugation along with transferrin) was compared to those of dual conjugated systems (single drug conjugation along with transferrin), non-transferrin C-dots-drugs, and free drug combinations. Transferrin conjugated samples displayed the lowest cell viability even at a lower concentration. Among the transferrin conjugated samples, the triple conjugated system (C-dots-trans-temo-epi (C-DT)) was more strongly cytotoxic to brain tumor cell lines than dual conjugated systems (C-dots-trans-temo (C-TT) and C-dots-trans-epi (C-ET)). C-DT increased the cytotoxicity to 86% in SJGBM2 at 0.01 μM while C-ET and C-TT reduced it only to 33 and 8%, respectively. Not only did triple conjugated C-DT increase the cytotoxicity, but also the two-drug combination in C-DT displayed a synergistic effect.

Targeting Glioblastoma Stem Cells with 2-Deoxy-D-Glucose (2-DG) Potentiates Radiation-Induced Unfolded Protein Response (UPR)

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, and despite optimized treatment options, median survival remains dismal. Contemporary evidence suggests disease recurrence results from expansion of a robustly radioresistant subset of GBM progenitor cells, termed GBM stem cells (GSCs). In this study, we utilized transmission electron microscopy to uncover ultrastructural effects on patient-derived GSC lines exposed to supratherapeutic radiotherapy levels. Elevated autophagosome formation and increased endoplasmic reticulum (ER) internal diameter, a surrogate for ER stress and activation of unfolded protein response (UPR), was uncovered. These observations were confirmed via protein expression through Western blot. Upon interrogating genomic data from an open-access GBM patient database, overexpression of UPR-related chaperone protein genes was inversely correlated with patient survival. This indicated controlled UPR may play a role in promoting radioresistance. To determine if potentiating UPR further can induce apoptosis, we exposed GSCs to radiation with an ER stress-inducing drug, 2-deoxy-D-glucose (2-DG), and found dose-dependent decreases in viability and increased apoptotic marker expression. Taken together, our results indicate GSC radioresistance is, in part, achieved by overexpression and overactivation of ER stress-related pathways, and this effect can be overcome via potentiation of UPR, leading to loss of GSC viability.

A systematic review of interventions and outcomes in lung cancer metastases to the spine

Seventy percent of cancer patients will have metastatic bone disease, most commonly in the vertebra. Prognosis of metastatic lung cancer is poor and treatment is mostly palliative. To-date, there is no systematic review on the ideal treatment for lung cancer with spinal metastases in regards to mortality. Literature searches were performed based on PRISMA guidelines for systematic review. Thirty-nine studies comprising 1925 patients treated for spinal metastases of lung cancer met inclusion criteria. All analyses were performed using SAS and SPSS. Data were analyzed for meaningful comparisons of baseline patient characteristics, primary cancer type, metastatic lesion characteristics, treatment modality, and clinical and radiologic outcomes. Significantly greater mean survival length was seen in the non-surgical group (8.5 months, SD 6.6, SEM 0.17) compared to the surgical group (7.5 months, SD 4.5, SEM 0.25; p = 0.013). There was no statistically significant survival difference between different types of primary lung cancer: NSCLC (8.3 months, SD 13.8, SEM 0.91) and SCLC (7.0 months, SD 4.6, SEM 0.46; p = 0.36). Number of vertebral levels involved per lesion also did not exhibit significant difference: single lesion (11.3 months, SD 6.8, SEM 2.2) and multiple lesions (13.8 months, SD 15.7, SEM 3.6; p = 0.64). For patients with symptomatic spinal metastases from lung cancer, non-operative approaches experience significantly better survival outcomes (p = 0.013). Future clinical studies are needed to determine the best treatment algorithm to help maximize outcomes and minimize mortality in metastatic lung cancer.

Treatment of posttraumatic lumbar interspinous ligament calcification with partial resection of spinous processes and calcified interspinous ligaments: case report

The authors report on the first surgical treatment for traumatic interspinous ligament calcification, with significant radiographic and symptomatic improvements at long-term follow-up. Heterotopic ossification occurs following traumatic injury but does not typically affect the interspinous ligaments. While these ligaments can calcify with age, this is rarely seen in patients younger than 50 years of age. The authors present the unusual case of a 31-year-old man who suffered traumatic fractures of thoracic and lumbar spinous processes. He developed progressive low-back pain that failed to respond to conservative treatments. At presentation, he was neurologically intact. CT scanning demonstrated partial calcification of the interspinous ligaments at L2-3, L3-4, and L4-5 with significant hypertrophy of the spinous processes at those levels. He did not have significant disc pathology, and his symptoms were attributed to the limited range of motion caused by the enlarged spinous processes. Partial resection of the spinous processes and calcified interspinous ligaments was performed to remove the heterotopic bone. The patient was seen in follow-up at 5 months postoperatively for imaging, and he was interviewed at 1 and 2 years postoperatively. He is doing well with significant pain relief and an improved range of motion. His Oswestry Disability Index improved from 25 preoperatively to 18 at 2 years postoperatively.

Carbon Nitride Dots: A Selective Bioimaging Nanomaterial

In contrast to the recent immense attention in carbon nitride quantum dots (CNQDs) as a heteroatom-doped carbon quantum dot (CQD), their biomedical applications have not been thoroughly investigated. Targeted cancer therapy is a prominently researched area in the biomedical field. Here, the ability of CNQDs as a selective bioimaging nanomaterial was investigated to assist targeted cancer therapy. CNQDs were first synthesized using four different precursor sets involving urea derivatives, and the characteristics were compared to select the best candidate material for bioapplications. Characterization techniques such as UV-vis, luminescence, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, and transmission electron microscopy were used. These CNQDs were analyzed in in vitro studies of bioimaging and labeling using pediatric glioma cells (SJGBM2) for possible selective biolabeling and nanodistribution inside the cell membrane. The in vitro cellular studies were conducted under long-wavelength emission without the interference of blue autofluorescence. Thus, excitation-dependent emission of CNQDs was proved to be advantageous. Importantly, CNQDs selectively entered SJGBM2 tumor cells, while it did not disperse into normal human embryonic kidney cells (HEK293). The distribution studies in the cell cytoplasm indicated that CNQDs dispersed into lysosomes within approximately 6 h after the incubation. The CNQDs exhibited great potential as a possible nanomaterial in selective bioimaging and drug delivery for targeted cancer therapy.

Oxygen saturation or respiratory rate to improve risk stratification in hemodynamically stable patients with acute pulmonary embolism

Essentials In acute pulmonary embolism (PE), risk stratification is essential to drive clinical management. Improving the 2014-ESC risk stratification strategy is crucial in hemodynamically stable patients. Oxygen saturation and respiratory rate improve risk stratification in hemodynamically stable PE. Simple and routine tests improve risk stratification of hemodynamically stable PE. SUMMARY: Background In patients with acute pulmonary embolism (PE), risk stratification for short-term death is recommended to drive clinical management. A risk stratification strategy combining the simplified Pulmonary Embolism Severity Index (PESI), echocardiography and troponin was proposed by the European Society of Cardiology (ESC) in 2014. The identification of hemodynamically stable patients at increased risk of death by this strategy needs improvement. Objective To assess whether further stratification by serial cut-off values of oxygen saturation or respiratory rate improves the accuracy of the ESC risk stratification strategy in hemodynamically stable PE patients. Methods Prospective cohorts of hemodynamically stable patients with PE were merged in a collaborative database. The accuracy of risk stratification for 30-day mortality by the original and a modified 2014 ESC strategy was assessed. Results Overall, 255 patients (27%) were categorized as low, 510 (54%) as intermediate-low and 181 (19%) as intermediate-high risk according to the original 2014 ESC strategy. Thirty-day mortality was 1.2% in low, 10% in intermediate-low and 11% in intermediate-high-risk patients. By adding oxygen saturation in air of < 88%, the discriminatory power of the 2014 ESC model improved for 30-day mortality (c-statistics, 0.71; 95% confidence interval [CI], 0.65-0.77 vs. 0.63, 95% CI, 0.56-0.69) and for PE-related death (c-statistics, 0.75; 95% CI, 0.69-0.81 vs. 0.63, 95% CI 0.56-0.69). Conclusions Simple and routine tests, such as oxygen saturation or respiratory rate, could be added to the 2014 ESC strategy for risk stratification to identify hemodynamically stable PE patients at increased risk of death who are potentially candidates for more aggressive treatment.

Fish-Mouth Thoracic Fracture Fixation with Minimally Invasive Percutaneous Reduction: A Technical Note

BACKGROUND

Surgical stabilization of thoracic spine fractures is recommended for unstable patterns, yet much debate exists regarding the best approach for reduction. The aim of this article was to report the outcome of a novel method for stabilization of a fish-mouth thoracic spine fracture.

METHODS

A retrospective patient chart review was conducted. Data collected included blood loss, operative time, length of stay, perioperative complications, neurologic deficits, and secondary procedures. The patient underwent percutaneous reduction of a hyperextension injury to the thoracic spine. Sufficient reduction was achieved through a percutaneous approach, followed by sequential distraction of 1 rod with sequential locking of the contralateral rod to maintain deformity correction. Electrophysiologic monitoring was used during the procedure.

RESULTS

Sufficient fracture reduction was achieved and evaluated on postoperative computed tomography. Operative time was 145 minutes, and estimated blood loss was 120 mL. There were no cerebrospinal fluid leaks, iatrogenic neurologic deficits, implant failures, other systemic events or revisions during the 8-month follow-up.

CONCLUSIONS

This article describes the feasibility of using a novel model for reduction and stabilization of fish-mouth thoracic spine fracture with minimal soft tissue violation.

Percutaneous Instrumentation of a Complex Lumbar Spine Fracture with Bilateral Pedicle Dissociation: Case Report and Technical Note

Background and Study Objective Complex traumatic lumbar spine fractures are difficult to manage and typically occur in younger patients. Surgical immobilization for unstable fractures is an accepted treatment but can lead to future adjacent-level disease. Furthermore, large variations in fracture morphology create significant difficulties when attempting fixation. Therefore, a surgical approach that considers both long-term outcomes and fracture type is of utmost importance. We present a novel technique for percutaneous fixation without interbody or posterolateral fusion in a young patient with bilateral pedicle dissociations and an acute-onset incomplete neurologic deficit.

Case Description A 20-year-old man involved in a motorcycle accident presented with unilateral right lower extremity paresis and sensory loss with intact rectal tone and no saddle anesthesia. Lumbar computed tomography (CT) demonstrated L2 and L3 fractures associated with bilateral pedicle dislocations. Lumbar magnetic resonance imaging showed draping of the conus medullaris/cauda equina anteriorly over the kyphotic deformity at L2 with minimal associated canal stenosis at L2 and L3. He was treated with emergent percutaneous fixation of the fracture segment without interbody or posterolateral fusion. Decompression was not performed because of the negligible amount of canal stenosis and high likelihood of cerebrospinal fluid leakage due to dural tears from the fractures. Surgical fixation of the L2 vertebra was achieved by cannulating the left pedicle with an oversized tap while holding the right pedicle in place with a normal tap and then driving screws into the left and right pedicles, respectively, thus reducing the free-floating fracture segment. At 18 months after surgery, a follow-up CT demonstrated good cortication across the prior pedicle fractures, and the instrumentation was removed without any obvious signs of instability or disruption of the alignment at the thoracolumbar junction.

Conclusion We present a novel technique for percutaneous reduction and fixation of bilateral pedicle fractures with significant dissociation from the vertebral body, associated neural compression from the kyphotic deformity, and minimal spinal canal stenosis. Furthermore, we argue that early fixation and reduction of the fracture prevented irreversible neurologic compromise, and the absence of interbody or posterolateral fusion ultimately preserved the spinal mobility of the patient once the hardware was removed.

Repair of giant postlaminectomy pseudomeningocele with fast-resorbing polymer mesh: technical report of 2 cases

Pseudomeningocele is a rare but well-known complication of lumbar spine surgery, which arises in 0.068%-0.1% of individuals in large series of patients undergoing laminectomy and in up to 2% of patients with postlaminectomy symptoms. In symptomatic pseudomeningoceles, surgical reexploration and repair of the dural defect are typically necessary. Whereas the goals of pseudomeningocele repair, which are extirpation of the pseudomeningocele cavity and elimination of extradural dead space, can typically be achieved by primary closure performed using nonabsorbable sutures, giant pseudomeningoceles (> 8 cm) can require more elaborate repair in which fibrin glues, dural substitute, myofascial flaps, or all of the above are used. The authors present 2 cases of postsurgical symptomatic giant pseudomeningoceles that were repaired using a fast-resorbing polymer mesh-supported reconstruction technique, which is described here for the first time.

Preoperative skin antisepsis with chlorhexidine gluconate versus povidone-iodine: a prospective analysis of 6959 consecutive spinal surgery patients

OBJECTIVE The aim of this study was to determine the efficacy of 2 common preoperative surgical skin antiseptic agents, ChloraPrep and Betadine, in the reduction of postoperative surgical site infection (SSI) in spinal surgery procedures. METHODS Two preoperative surgical skin antiseptic agents-ChloraPrep (2% chlorhexidine gluconate and 70% isopropyl alcohol) and Betadine (7.5% povidone-iodine solution)-were prospectively compared across 2 consecutive time periods for all consecutive adult neurosurgical spine patients. The primary end point was the incidence of SSI. RESULTS A total of 6959 consecutive spinal surgery patients were identified from July 1, 2011, through August 31, 2015, with 4495 (64.6%) and 2464 (35.4%) patients treated at facilities 1 and 2, respectively. Sixty-nine (0.992%) SSIs were observed. There was no significant difference in the incidence of infection between patients prepared with Betadine (33 [1.036%] of 3185) and those prepared with ChloraPrep (36 [0.954%] of 3774; p = 0.728). Neither was there a significant difference in the incidence of infection in the patients treated at facility 1 (52 [1.157%] of 4495) versus facility 2 (17 [0.690%] of 2464; p = 0.06). Among the patients with SSI, the most common indication was degenerative disease (48 [69.6%] of 69). Fifty-one (74%) patients with SSI had undergone instrumented fusions in the index operation, and 38 (55%) patients with SSI had undergone revision surgeries. The incidence of SSI for minimally invasive and open surgery was 0.226% (2 of 885 cases) and 1.103% (67 of 6074 cases), respectively. CONCLUSIONS The choice of either ChloraPrep or Betadine for preoperative skin antisepsis in spinal surgery had no significant impact on the incidence of postoperative SSI.

Abstract 5864: Targeting brain cancer stem cells by potentiating radiation-induced ER stress

Background. Glioblastoma (GBM) is one of the most malignant brain tumors occurring in both children and adults. Despite an aggressive treatment regimen consisting of surgical resection, radiation therapy and chemotherapy the five-year survival rate is less than 5%. This poor outcome has been attributed to the existence of therapy-resistant GBM stem-like cells (GSCs), which are believed to be responsible for tumor recurrence and patient relapse. Understanding the resistance mechanisms employed by brain tumor stem cells and developing novel methods to target these cells is necessary for prolonged patient survival. Recent evidence suggests that the endoplasmic reticulum stress response pathway may mediate therapeutic resistance in cancer. Here we sought to examine the ER stress response pathway of GSCs in response to ionizing radiation and to increase the extent of ER stress in an effort to promote cell death using the glycolytic inhibitor, 2-deoxy glucose (2-DG).

Methods. GSC lines were derived from resected tumor sections. GSCs were irradiated using the Rad Source 2000 Series Biological Irradiator. Transmission Electron Microscopy (TEM) was used to investigate the ultra-structural alterations of GSCs following exposure to 8 Gy radiation. Viability was determined using trypan blue exclusion, MTS and LDH assays. Cell signaling pathways were investigated by western blot analysis.

Results. Consistent with previous findings, minimal cell death was observed in GSCs exposed to 2-20 Gy radiation. TEM analysis revealed that exposure to 8 Gy significantly increased ER lumen dilation, suggestive of ER stress. Western blot analysis indicated an increase in ER stress markers GRP78, GRP94 and CHOP, confirming that radiation induces ER stress in GSCs. Treatment with 2-DG induced an increase in ER lumen diameter and ER stress markers. Combined 2-DG (0.5mM and 2mM) and radiotherapy (8 Gy) significantly increased ER luminal diameter and ER stress marker expression over radiation or 2-DG alone. In addition, combined radiation and 2-DG (0.1-2mM) significantly reduced GSC viability compared to radiation or 2-DG alone.

Conclusion. The ER stress response pathway is an adaptive mechanism and thought to mediate therapeutic resistance. Here we demonstrate that radiation induces ER stress response pathway including ER lumen dilation and an increase in molecular chaperone expression in GSCs. Potentiating ER stress can switch the pathway from one of adaptation to cell death. 2-DG increased radiation-induced ER stress and promoted cell death. Our data suggests that targeting this adaptive response could increase the efficacy of radiotherapy and prolong patient survival

Note: This abstract was not presented at the meeting.

Citation Format: Regina M. Graham, Sumedh S. Shah, Alexis J. Musick, Winston Walters, Ricardo J. Komotar, Jeffery S. Prince, Steven Vanni. Targeting brain cancer stem cells by potentiating radiation-induced ER stress [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5864. doi:10.1158/1538-7445.AM2017-5864

Museum samples could help to reconstruct the original distribution of Salmo trutta complex in Italy

Partial D-loop sequences of museum specimens of brown trout and marble trout (Salmo trutta species complex) collected from Mediterranean rivers in the late 19th century were analysed to help to describe the native distribution of these species. All the individuals studied carried native haplotypes, the geographic distribution of which is consistent with published data. These results indicate that museum specimens from the 19th century could represent an opportunity to get a picture of the original genetic diversity distribution of this species complex.

Transferrin conjugated nontoxic carbon dots for doxorubicin delivery to target pediatric brain tumor cells

Among various cancers, pediatric brain tumors represent the most common cancer type in children and the second most common cause of cancer related deaths. Anticancer drugs and therapies, such as doxorubicin (Dox), have severe side effects on patients during chemotherapy, especially for children as their bodies are still under development. These side effects are believed to be due to the lack of a delivery system with high efficacy and targeting selectivity, resulting in serious damages of normal cells. To improve the efficacy and selectivity, the transferrin (Trans) receptor mediated endocytosis can be utilized for drug delivery system design, as transferrin receptors are expressed on the blood brain barrier (BBB) and often over expressed in brain tumor cells. Carbon dots (C-Dots) have recently emerged as benign nanoparticles in biomedical applications owing to their good water solubility, tunable surface functionalities and excellent biocompatibility. The unique characteristics of C-Dots make them promising candidates for drug delivery development. In this study, carbon dots-transferrin-doxorubicin covalent conjugate (C-Dots-Trans-Dox) was synthesized, characterized by different spectroscopic techniques and investigated for the potential application as a drug delivery system for anticancer drug doxorubicin to treat pediatric brain tumors. Our in vitro results demonstrate greater uptake of the C-Dots-Trans-Dox conjugate compared to Dox alone presumably owing to the high levels of transferrin receptors on these tumor cells. Experiment showed that C-Dots-Trans-Dox at 10 nM was significantly more cytotoxic than Dox alone, reducing viability by 14-45%, across multiple pediatric brain tumor cell lines.

Abstract B41: Withaferin A promotes ROS-mediated differentiation of neuroblastoma

Background: Neuroblastoma (NB), the most common extra-cranial solid tumor in children, originates from the precursor neuroblasts of the sympathetic nervous system. NB accounts for approximately 7-10% of childhood cancers and 15% of childhood cancer death. Despite an aggressive treatment regimen, the 5-year survival for high risk NB remains less than 50%. The differentiation of NB cells into mature cells represents a promising strategy for NB therapy. Currently, retinoids are the most commonly used differentiating agents. However, their use can be limited due to intrinsic or acquired resistance, as well as toxicity. We sought to evaluate the potential of the natural product withaferin A (WA), a steroidal lactone derived from the medicinal plant Withania somnifera, to induce NB cell differentiation.

Methods: For differentiation studies NB cell lines (NB1691, SMS-KCNR, SH-SY5Y and the primary cell line SVBM15) were exposed to WA (100-500nM) for 7-10 days and evaluated by light microscopy, immunocytochemistry and western blot analysis. NB stem-like cell lines were generated by culturing NB1691 and SVBM15 cells in neurosphere media. To determine the IC50 (concentration needed to reduce viability by 50%), NB stem-like cell lines were exposed to increasing concentrations of WA and viability was assessed at 72 hours using MTS assay. Reactive oxygen species (ROS) were detected using CM-H2DFDA and ROS induction was inhibited with N-acetyl-L- Cysteine (NAC). To determine WA effect on neurosphere formation, NB cells were plated in 96-well plates at 50 cells/well. Cells were grown in increasing concentrations of WA and spheres were counted at 14 days.

Results: WA promoted morphologic alterations (neurite outgrowth) and growth inhibition in a dose dependent manner. Immunocytochemistry and western blot analysis indicated an increase in neuronal markers including neurofilament, β-tubulin and MAP2, as well as a decrease in the stem cell markers BMi-1 and musashi. WA promoted ROS induction, which could be prevented with NAC pretreatment. NAC prevented WA-induced morphological changes and inhibited WA-induced changes in stem cell and differentiation marker expression. WA induced NB stem-like cell death in a dose dependent manner (IC50 of NB1691=1.05 μM; SVBM15=1.06 μM), and significantly inhibited neurosphere formation at concentrations as low as 50nM, which did not exhibit cytotoxicity in regular cell culture conditions.

Conclusion: Withania somnifera has been used for centuries and is commonly used in ayurvedic medicine. WA has been shown to affect multiple pathways important for cancer progression and induce anti-cancer effects in breast, prostate and pancreatic cancers. Our data indicates that WA induces NB stem-like cell death, and promotes ROS-mediated NB cell differentiation. Differentiation therapy aims at reducing the risk of the tumor regrowth following high-dose chemotherapy and stem cell transplant in patients classified as high-risk. WA holds great promise as a novel alternative NB treatment strategy for children with persistent minimal residual disease.

Citation Format: Gregor A. Rodriguez, Claudia P. Zapata, Anthony Sanchez, Nicolas A. De Cordoba, Beatriz E. Hawkins, Nadia G. Myrthil, Sarah A. Samuels, Amelia Bahamonde, Steven Vanni, Regina M. Graham. Withaferin A promotes ROS-mediated differentiation of neuroblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B41.