AF) often undergo a blood test to measure troponin, but interpretation of the result is impeded by uncertainty about its clinical importance. We investigated the relationship between troponin level, coronary angiography, and all‐cause mortality in real‐world patients presenting with AF.Patients presenting with atrial fibrillation  days, there were 586 deaths (18.8%). The adjusted hazard ratio for mortality associated with a positive troponin  was 1.20 . Higher troponin levels were associated with higher risk of mortality, reaching a maximum hazard ratio of 2.6  at ≈250 multiples of the upper limit of normal. There was an exponential relationship between higher troponin levels and increased odds of coronary angiography. The mortality risk was 36% lower in patients undergoing coronary angiography than in those who did not .We used National Institute of Health Research Health Informatics Collaborative data to identify patients admitted between 2010 and 2017 at 5 tertiary centers in the United Kingdom with a primary diagnosis of AF. The lower hazard ratio in patients undergoing invasive management raises the possibility that the clinical importance of troponin release in AF may be mediated by coronary artery disease, which may be responsive to revascularization.Increased troponin was associated with increased risk of mortality in patients presenting with  Elevated troponin levels in patients presenting to the hospital with atrial fibrillation are associated with a high risk of mortality, with higher levels associated with worse prognosis.The risk of mortality associated with troponin increase was lower in patients who underwent coronary angiography than in those who did not undergo coronary angiography.Even troponin elevations mildly above the upper limits of normal should be taken seriously in patients presenting with atrial fibrillation.Consideration should be given to investigate for underlying coronary artery disease in patients presenting with atrial fibrillation and an increased troponin level.Patients presenting to the hospital with atrial fibrillation (AF), the most prevalent tachyarrhythmia,The aims of our study were to explore the relationship between troponin level and mortality in patients presenting to the hospital with AF, to understand the pattern of referral for coronary angiography in relation to troponin level, and to determine the role of coronary angiography in the relationship between troponin and mortality in these patients.The National Institute of Health Research Health Informatics Collaborative database consists of routinely collected electronic health record data from patients attending 5 large UK tertiary care centers with emergency departments  between 2010  and 2017. The data acquisition and analysis plan is found in Data International Classification of Diseases, Tenth Revision (ICD‐10), discharge codes and were therefore established by the clinical team after inpatient investigations and management were complete. Patients meeting the eligibility criteria were followed up using routinely collected data, until death or censoring on April 1, 2017.We identified patients from the National Institute of Health Research Health Informatics Collaborative database who were admitted to the hospital with a primary diagnosis of AF and underwent at least one troponin measurement. Patients with a concomitant secondary diagnosis of AF were not eligible for inclusion in the study. Diagnoses were established from routinely recorded All analyses on troponin were performed using the peak troponin level. For patients who had a single troponin measurement, the peak troponin was based on this measurement. In the remainder of the patients who had >1 troponin test in the same hospital episode of care, the peak troponin value was defined as the highest of all measurements. For patients with multiple episodes of care for which troponin was tested, the first episode of care was used.In clinical practice, troponin levels are frequently dichotomized into “positive”  or “negative.” Furthermore, troponin levels may have a progressive relationship with prognosis, too, but the shape of this relationship is not known across the full spectrum of values; and making the assumption of a linear relationship of mortality with troponin (or log troponin) may not be secure in our study participants.For these reasons, we treated the data in 2 ways. First, we dichotomized the results as being either positive or negative. Second, we used troponin on a continuous scale by standardizing the many troponin assays, by scaling the results using the ratio of the observed troponin value divided by the ULN for that particular troponin assay.Patients undergoing coronary angiography, or revascularization with either percutaneous coronary intervention or coronary artery bypass grafting, during the follow‐up period were identified. To account for outpatient procedures, patients were categorized as having angiography or intervention if performed within 3 months of the peak troponin level.Using a retrospective cohort study design, all patients were followed up until death or censoring on April 1, 2017. Life status was ascertained using routinely collected data on the National Health Service Spine Application, which was linked to the Office of National Statistics, and thereby to the national registry of deaths.U test or χ2 test.Descriptive statistics are displayed as median (interquartile range) for continuous variables and number (percentage) for categorical variables. Comparisons of baseline characteristics between patients who did and did not undergo angiography were explored by Mann‐Whitney The relationship between dichotomous troponin level (above ULN or not), or continuous troponin, and all‐cause mortality was performed using Cox proportional hazards regression modeling, using log transformation because of the positive skew of troponin values. The proportional hazard assumption was supported by a nonsignificant relationship between the Schoenfeld residuals and time. This test was not statistically significant for each of the covariates included in the Cox regression model.Using Martingale residuals, nonlinearity was detected in the relationship between the log hazard and all continuous covariates . To model nonlinear relationships, we used restricted cubic splines for Cox regression and logistic regression analyses to calculate mortality hazard ratio and odds of angiography outcomes, respectively. Preliminary analyses suggested that 4 unforced knots should be used to model troponin level in the restricted cubic spline analyses. Splines were adjusted for demographic characteristics, hematological and biochemical blood results, cardiovascular risk factors, and comorbidities. Subgroup analyses were performed in angiography and no angiography subgroups. Kaplan‐Meier survival curves were plotted according to angiography status.P<0.05 was considered significant. Statistical analyses were performed using the R 3.5.0 statistical package . Survival analyses were performed using the Survminer and Survival R packages.ICD‐10 discharge codes, underwent troponin measurement during the study period. Their baseline characteristics are displayed in Table A total of 3121 patients admitted to the hospital with a primary diagnosis of AF, according to A total of 216 patients (6.9%) underwent coronary angiography, with 78 (36.1%) of these patients subsequently undergoing coronary revascularization by percutaneous coronary intervention (93.6%), coronary artery bypass grafting (2.6%), or both (3.8%). A total of 39 patients (1.2%) had a secondary diagnosis of ACS. Most coronary angiograms  after adjustment for key demographic and baseline clinical factors. The relationship between continuous troponin level and mortality was demonstrated using restricted cubic spline Cox regression analysis, adjusted for the same demographic and baseline clinical factors  months, there were 586 deaths (18.8%), with a 1‐year mortality rate of 4.8%. The hazard ratio for mortality associated with a positive troponin result  was 1.20 . For those patients who were referred for angiography, there was a nonsignificant trend toward revascularization being associated with a reduction in mortality during follow‐up . The relationship between troponin and mortality in patients who underwent angiography without revascularization and the relationship in those who did not undergo angiography are shown in Figure Figure This is the first study investigating the relationship between troponin level, coronary angiography, and mortality in patients admitted to the hospital with a primary diagnosis of AF. This is also the largest study to report the association between troponin level and all‐cause mortality in this group.In 3121 patients presenting with AF, whose troponin was measured, there was a significant association between troponin levels (above the ULN) and higher mortality, even after adjusting for key demographic and clinical factors. Associations derived from dichotomizing continuous variables, such as troponin, can be driven by extreme values. However, even low‐level troponin elevations above the normal range (1–10 xULN) were associated with higher mortality risk. Abnormal troponin levels, at any level, appear to have prognostic importance in AF; and higher troponin levels appear to confer worse prognosis.The relationship between troponin level and adjusted hazard ratio for mortality in patients presenting with AF is nonlinear when considering the entire spectrum of troponin values, including detectable troponin within the normal range. Below the ULN of troponin, there does not appear to be any relationship between higher troponin levels and increased hazard ratio for mortality. A similar nonlinear pattern between troponin level and mortality has previously been observed in an unselected group of patients without ACS.Coronary angiography was performed in <7% of patients presenting with AF who had troponin measured. Below the ULN for troponin, higher troponin levels were not associated with an increased likelihood of coronary angiography. Above the ULN, there was an exponential relationship between troponin level and likelihood of coronary angiography. However, even at the highest troponin levels, less than half of patients underwent coronary angiography. This is consistent with typical clinical practice; small troponin increases in AF presentations are not deemed to be a useful marker of CAD by clinicians and even when troponin increases to high values, alternative explanations are often invoked. Other factors also influenced the likelihood of coronary angiography in this population: understandably, patients with malignancies were less likely to undergo coronary angiography and patients with prior infarcts were more likely to undergo coronary angiography. However, women were also less likely to undergo coronary angiography than men, despite other variances being accounted for in the multivariate analysis. This reflects a growing understanding that women with cardiac disease present, and are managed, in different ways to men, potentially to the detriment of women's health outcomes.In patients who underwent coronary angiography, higher troponin levels above ULN were associated with higher mortality, but the relationship was weak, with a shallow gradient, and not statistically significant. In patients who did not undergo coronary angiography, there was a clear, direct relationship between higher troponin levels (above ULN) and higher risk of mortality. Coronary angiography appeared to be associated with a 36% reduction in mortality across the spectrum of troponin values. One possible explanation for this is that we may be selecting a relatively low‐risk group of patients for coronary angiography compared with those we choose to treat medically. An alternative explanation is that invasive management may improve the prognosis of patients presenting with AF and abnormal troponin elevations, with greater improvement at higher troponin levels. Coronary angiography at higher troponin levels is more likely to reveal clinically important CAD that is amenable to prognosis‐improving treatment. Data on the rate of medical therapy for CAD were not available in this analysis, but coronary revascularization was performed in 36.1% of patients who underwent coronary angiography and there was a trend toward improved mortality with revascularization, although this did not reach statistical significance. The utility of routinely investigating for CAD in these patients requires testing in clinical trials.background of AF, rather than patients presenting to the hospital with a primary diagnosis of AF. In stable patients diagnosed with AF previously, increased troponin will inevitably be predictive of poor prognosis but troponin screening for patients in a stable phase of AF is rare and not a clinically relevant problem. How to interpret troponin increases in short‐term presentations with AF is an extremely common clinical dilemma, which is addressed in this study.This is the largest study to assess the relationship between troponin and mortality in patients presenting to the hospital with AF. Other studies have assessed the effects on revascularization, stroke, cardiovascular death, and other clinically important outcomes. However, all such diagnoses, including fatal stroke and cardiovascular death, risk inaccuracy and bias to varying extents. All‐cause mortality is the only outcome where the diagnosis is free from such bias. Larger subanalyses of randomized controlled trials comparing direct oral anticoagulants with warfarin have assessed the relationship between troponin and mortality in patients with AFConti et al prospectively enrolled 3627 patients presenting with recent‐onset <48‐hours) AF, but excluded patients with ACS, clinical instability, or severe comorbidity,8‐hours ATroponin I and T bind to tropomyosin in the intracellular sarcomeric contraction complex, but they are also found in the cytosol.We cannot directly infer, from our analysis, a mechanism for troponin release nor the mechanism via which troponin increases are associated with worse prognosis, but our findings raise the possibility that the clinical importance of troponin release in AF may mediated by CAD.Although this study benefits from having been conducted using real‐world clinical data in a large number of patients from multiple centers, there are some limitations. This study was retrospective, with data extracted from electronic medical records and subject to the limitations of this approach, including difficulty in accounting for all potential confounding factors. Bias may be introduced because of inaccuracies in routine data collection. In routine clinical practice, patients with larger troponin increases are more likely to be given a primary diagnosis of ACS on discharge, even if their presentation was with AF, altering the overall risk status of the patients with AF as the primary diagnosis. The data set also includes only those patients who had a troponin measurement potentially altering the overall risk profile. Furthermore, the subtype of AF  was not recorded, preventing analysis by chronicity of AF, and the role of stress testing was not available in the data set.We could not directly infer mechanisms for the importance of troponin increases in AF. Routinely collected data from electronic health records lack resolution for fine details of clinical encounters. For this reason, we could not analyze the data for the effect of troponin on cardiovascular outcomes and compare this with all‐cause mortality. However, as previously discussed, all‐cause mortality is the only outcome to be free from bias, which is of particular relevance in observational analyses.Abnormally elevated troponin at any level is associated with increased risk of mortality in patients presenting with AF, and higher troponin levels confer worse prognosis. Coronary angiography is rarely performed unless AF is associated with large troponin increases, but when it is performed, it is associated with lower mortality. This raises the question of whether the prognostic significance of troponin could be mediated by CAD and may be responsive to revascularization. Clinical trials are warranted to clarify the role of investigating and treating CAD in patients presenting with AF with elevated troponin levels.This article reports independent research led and funded by the National Institute for Health Research (NIHR) Imperial Biomedical Research Centre (BRC), as part of the NIHR Health Informatics Collaborative with the NIHR Oxford BRC, the NIHR University College London Hospitals BRC, the NIHR Guy's and St Thomas’ BRC, and the NIHR Cambridge BRC. The views expressed in this publication are those of the authors and not necessarily those of the National Health Service, the National Institute for Health Research, or the Department of Health. Dr Elliott and H. Hemingway received Health Data Research funding.None.Data S1. Data acquisition and analysis plan.Table S1. Odds Ratio of Undergoing Coronary AngiographyFigure S1. Odds ratio of undergoing coronary angiography.Figure S2. Odds ratio of undergoing coronary revascularisation according to troponin level.Figure S3. Multivariate* restricted cubic spline modelling of association between troponin level and hazard ratio for patients who underwent angiography without revascularisation (left) and those who did not undergo angiography (right).Click here for additional data file.


Perillyl alcohol (POH) has been extensively studied for the treatment of peripheral and primary brain tumors. The intranasal route of administration has been preferred for dosing POH in early-stage clinical trials associated with promising outcomes in primary brain cancer. However, it is unclear how intranasal POH targets brain tumors in these patients. Multiple studies indicate that intranasally applied large molecules may enter the brain and cerebrospinal fluid (CSF) through direct olfactory and trigeminal nerve-associated pathways originating in the nasal mucosa that bypass the blood–brain barrier. It is unknown whether POH, a small molecule subject to extensive nasal metabolism and systemic absorption, may also undergo direct transport to brain or CSF from the nasal mucosa. Here, we compared CSF and plasma concentrations of POH and its metabolite, perillic acid (PA), following intranasal or intravascular POH application. Samples were collected over 70 min and assayed by high-performance liquid chromatography. Intranasal administration resulted in tenfold higher CSF-to-plasma ratios for POH and tenfold higher CSF levels for PA compared to equal dose intravascular administration. Our preclinical results demonstrate POH undergoes direct transport from the nasal mucosa to the CSF, a finding with potential significance for its efficacy as an intranasal chemotherapeutic for brain cancer. In particular, the nasal route possesses distinct advantages when local effects are needed  or when non-invasive access to the systemic circulation is required for fast drug onset and/or to avoid extensive hepatic first-pass elimination . Multiple clinical studies show that intranasally applied small molecules  and low molecular weight peptide drugs , can achieve improved systemic exposure and therapeutically relevant concentrations in peripheral tissues3. Improved systemic exposure for these molecules is likely due to greater paracellular permeability across the nasal epithelia and more efficient absorption into the bloodstream through the extensive nasal vasculature present in the underlying lamina propria4. In contrast, intranasal delivery results in improved central exposure to the brain or CSF for only a subset of small molecules12. Mechanistic studies indicate that intranasally applied large molecules can directly access the central nervous system (CNS) through olfactory or trigeminal nerve-associated pathways that originate within the nasal mucosa17. Collectively, these findings have increased clinical interest in using the intranasal route for enhanced central delivery of small molecules. One such small molecule is perillyl alcohol (POH), a 152 Da plant-derived monocyclic terpene and chemotherapeutic agent. In vitro studies have demonstrated that both POH and its most stable metabolite, perillic acid (PA), may inhibit inflammation and cell proliferation by inducing apoptosis and inhibiting protein prenylation, a post-translational modification that ensures membrane-bound proteins are transported from the cytoplasm to the cell membrane to exert their function18. Importantly, POH is being actively investigated in clinical trials for the treatment of recurrent forms of primary brain cancers, particularly low-grade glioma (NCT02704858)22. POH was initially studied as an orally applied chemotherapeutic that showed efficacy in hepatic and mammary tumor-bearing rodents24. However, toxicity findings in multiple phase I clinical trials indicated that orally applied POH was associated with dose-limiting gastrointestinal toxicity28. Intranasally applied POH, alternatively, minimized these toxicity issues and sensitized the lesions to standard chemotherapeutic treatments such as surgical excision, radiotherapy, or chemotherapy21. Moreover, chronic intranasal application of POH blocks cell proliferation and migration pathways in cell cultures and significantly reduces tumor volumes in brain tumor xenograft-bearing mouse models31. More recent preclinical studies have also suggested that intranasally and intra-arterially applied POH may reversibly open the blood–brain barrier to some degree, resulting in improved CNS exposure of chemotherapeutics such as bortezomib, temozolomide, methotrexate, anti-PD-1, and CAR-T in xenograft-derived tumor-bearing rodents33. In clinical trials, primary brain cancer patients receiving intranasal POH every week for over 16 months have significantly reduced tumor volumes compared to tumor volumes at baseline (i.e. scans performed at week 0) 21.The intranasal (IN) route of administration has long been appreciated as an option for local and systemic delivery for certain small molecules, peptides, and protein drugs34. Here, we compared pharmacokinetic profiles for POH and its major metabolite following intranasal and intravascular POH administration in female, wild-type Sprague–Dawley rats. Our study demonstrates that the intranasal route is associated with a unique CSF exposure advantage compared to intravascular dosing for POH, a finding of importance for the clinical application of the intranasal route with POH, POH-drug conjugates and chemically modified POH analogs in the treatment of primary brain cancer patients.Despite this surge in interest in utilizing POH as an intranasally delivered chemotherapeutic for brain cancers, the question of whether this dosing route is important for its clinical use is limited by several unknowns. First, POH concentrations in brain and/or CSF following intranasal administration have not been reported in the literature. Second, it is yet unclear how intranasally applied POH achieves therapeutically relevant concentrations within the CNS. Third, it is not known whether intranasally applied POH gains access to the brain and/or CSF from the systemic circulation after crossing the blood–brain and blood-CSF interfaces or, alternatively, if POH may reach the brain and/or CSF through direct olfactory and trigeminal nerve associated pathways originating in the nasal mucosan = 5) or intravascular (n = 4) administration. The fixed dose administered to animals in both groups (4.745 mg) was chosen to represent: (i) the lowest POH dose described in previous preclinical studies and (ii) the allometrically-scaled dose corresponding to the intranasal POH formulation from an ongoing clinical trial examining its safety and efficacy in glioma patients (NCT02704858)38 (see “Methods” for further description). The intranasal POH formulation was directed to a region near the olfactory mucosa to increase the likelihood of CNS delivery since the olfactory mucosa has relatively lower vascular permeability and mucociliary clearance compared to the nasal respiratory mucosa13. CSF and plasma samples were processed to precipitate residual proteins  and to allow for total (bound and unbound) POH in each compartment to be analyzed. CSF concentration of POH was below the lower limit of detection (LLOD) for the assay in 1 out of 5 animals in the intravascular POH cohort; these values were therefore excluded from data analysis. POH and PA concentrations in the plasma and CSF were above LLOD for all other cases  resulted in a mean POH plasma concentration of 33.11 ± 15.78 µM Fig.  and a me resultedAUC70 value of 165.9 ± 18.9 µM.min , the major POH metabolite, was also assessed in both CSF and plasma taken from the same animals. Intravascularly applied POH resulted in a mean PA plasma concentration of 2.37 ± 0.27 µM  resulted in a mean POH plasma concentration of 7.57 ± 1.77 µM Fig.  and a me70 value of 1674.4 ± 276.5 µM min  intranasally applied POH results in a tenfold higher CSF-to-plasma ratio for POH compared to intravascular controls, (ii) intranasally applied POH results in tenfold higher PA concentrations in the CSF and plasma compared to intravascular delivery, and (iii) intranasal and intravascular application of POH resulted in similar CSF-to-plasma ratios for PA. Taken together, our results suggest intranasal POH application is more suited to obtain greater CSF exposure for POH and PA than intravascular POH application. Most importantly, our results provide new evidence supporting significant direct transport from the nasal mucosa to the CSF for POH, suggesting a strong advantage for the intranasal route in the central delivery of POH.40. Briefly, intranasally applied molecules may transit through the olfactory and/or respiratory nasal epithelia via intracellular or extracellular pathways to reach the underlying connective tissue40. Once within the lamina propria, molecules may experience several different fates: (i) systemic absorption into the nasal vasculature to enter the systemic circulation, (ii) lymphatic absorption into draining nasal lymphatic vessels and downstream cervical lymph nodes, and/or (iii) direct transport along pathways associated with the olfactory and trigeminal nerves  to enter the CSF and brain. More detailed mechanistic studies by our group have shown that macromolecules enter the CNS by direct transport pathways at the level of the olfactory bulbs (via olfactory pathways) or the brainstem  40. Subsequent widespread distribution from these regions may then occur within the perivascular spaces around cerebral blood vessels via convective transport or dispersion potentially down to the capillary level41.Our group has previously described how intranasally applied macromolecules access the CNS via potential pathways originating in the nasal mucosa42. POH also has a high binding affinity for albumin (Kd = 0.19 M) that results in a relatively low unbound drug fraction within albumin-rich fluid compartments such as plasma or CSF 43. Albumin-POH interactions may therefore affect passive diffusion of POH across the blood–brain and blood-CSF barriers. Interestingly, the distribution of POH and its metabolites between the blood and CSF compartments has not been carefully examined.Based on its molecular weight, POH (152 Da) belongs to a subset of non-polar small molecules that in theory may passively diffuse through the phospholipid bilayers of intact brain capillary endothelial cells to enter the CNSIn the present study, intranasally applied POH resulted in approximately fivefold lower POH concentrations in the CSF than that in plasma sampled from the same animals, indicating that POH is more likely to enter the systemic circulation following intranasal delivery. However, intravascularly applied POH at the same dose resulted in ~ 200-fold lower POH concentrations in the CSF than that in the plasma, indicating that a markedly higher relative POH CSF exposure was obtained with the intranasal route. These findings suggest that the intranasal route provides direct and elevated central exposure to POH.32. In contrast, an increase in blood–brain barrier permeability was not observed following POH application to intravascular sites other than to the carotid artery32. In our study, we administered a ~ 34-fold smaller dose (23 mg/kg) via the abdominal aorta and observed that POH concentrations in the CSF were 200-fold lower than POH concentrations in the plasma. Based on these findings, we do not believe that POH administration at the dose used in our study resulted in any significant effect on blood–brain barrier permeability.Wang et al. recently reported a blood–brain barrier permeability increase following intracarotid POH application at doses down to ~ 800 mg/kg in 3-week-old C57BL/6 tumor-bearing mice, resulting in elevated CNS exposure for bloodborne molecules33. Collectively, these findings from our study and Wang et al. suggest significant and rapid metabolism of POH to PA occurs following intranasal POH administration. Significant POH metabolism following intranasal application may be due to rapid POH-to-PA conversion at the nasal mucosa as well as along olfactory and trigeminal nerve-associated pathways into the CNS. POH is sequentially metabolized to perillaldehyde by alcohol dehydrogenases and then to perillic acid by aldehyde dehydrogenases. Prior studies have established that POH can also be sequentially altered to PA by cytochrome P450 and aldehyde dehydrogenases46. Interestingly, multiple reports indicate that these transmembrane enzymes are highly expressed in the olfactory mucosa at levels that exceed those within the respiratory mucosa51. Furthermore, significant alcohol dehydrogenase immunoreactivity appears to be associated with the perivascular compartment of systemic blood vessels, particularly smooth muscle cells of the tunica media52. High mRNA expression levels of alcohol and aldehyde dehydrogenases have also been detected at brain-CSF interfaces such as the leptomeninges, choroid plexus, and ependyma, as well as within the brain parenchyma55. The prominent presence of these biotransformative enzymes at the site of nasal administration, particularly the nasal region associated with brain delivery pathways (e.g. the olfactory epithelium), as well as at downstream sites that have been implicated in direct nose-to-brain biodistribution  is consistent with the significant POH-to-PA conversion we and others have observed following intranasal dosing.We further observed that measured PA concentrations were greater than POH concentrations in all physiological compartments assessed  following intranasal dosing. This pattern of higher PA than POH levels was also observed for brain lysate following intranasal dosing of POH in a recent study57, for which PA may well be a substrate. Further work will be needed to validate this hypothesis. Clarification of the regional biodistribution of both POH and PA in the brain following intranasal and intravascular dosing may reveal important sites for POH metabolism and PA transport; however, this was beyond the scope of the present study.Despite marked differences in POH CSF exposure, we observed that both intranasal and intravascular POH application resulted in similar CSF-to-plasma ratios for PA. One explanation for this result would be if PA were a substrate for specific transporters at the blood-CSF and blood–brain interfaces. This might lead to some degree of PA equilibration between blood and CSF irrespective of the delivery route and differences in metabolism. Indeed, immunohistochemical staining in the mouse has shown that brain microvessels, choroid plexus, and the glia limitans are highly immunoreactive for monocarboxylate transporters (MCT-1 and MCT-2)Our study has some limitations. Effects on POH biodistribution related to gender, species-differences, and pathology (e.g. tumor) will require further study. CSF and plasma samples were pooled over 70 min to obtain sufficiently large injection volumes for our HPLC setup. Investigating POH concentrations with more sophisticated detection systems may be able to yield more detailed kinetic information not provided in the present study. We also observed relatively high variability in measured POH plasma concentrations after intravascular dosing; the reasons for this variability were not entirely clear. Finally, the use of tracheotomized rats was necessary to ensure more consistent tolerance for the highly viscous POH formulation and to better allow for targeting to the olfactory mucosal area with tracer dosing. While unlikely, this experimental preparation may have had some effect on the resulting transport and central biodistribution observed following intranasal POH. Nevertheless, our results provide among the first evidence supporting intranasal enhancement of central POH exposure by a direct path that bypasses the blood–brain barrier. Our findings support further use of the intranasal route for the delivery of POH, POH-derived analogs, and possibly other similar chemotherapeutic agents to the CSF and brain for neuro-oncology applications.57. Acetonitrile  and methanol  were obtained from Fisher Scientific . Commercially available Sprague–Dawley rat plasma  and artificial cerebrospinal fluid  were used for assay calibration and validation. POH and PA were dissolved in methanol at a stock concentration of 10 µg/mL and 1000 µg/mL respectively and stored as one-time-use aliquots at -20 °C. POH standards were prepared in plasma and/or artificial CSF by serially diluting stock solutions . PA standards were prepared in a similar manner as mentioned above at 5.0, 4.0, 3.0, 2.0, 1.0, 0.75, 0.5, and 0.25 µg/mL final concentrations. Quality controls were prepared at 0.8, 0.45, and 0.25 µg/mL final concentrations for POH and 4.5, 2.5, and 0.65 µg/mL final concentrations for PA respectively.S-(−)-Perillyl alcohol  was obtained from Millipore-Sigma . Perillic acid (PA) was synthesized by Dr. Gould and colleagues based on methods described previously35 with slight modifications. Briefly, a 50 µL volume of sample/standard/quality control was supplemented with 100 µL acetonitrile and vortexed vigorously for 3 min (POH) or 1 min (PA). Samples were then centrifuged . Following centrifugation, 20 µL of supernatant was injected into the HPLC system. For PA analysis, 120 µL of supernatant was carefully transferred to a clean tube and dehydrated under a stream of nitrogen. Pellets were then resuspended in 100 µL diluted mobile phase , and 80 µL of this resuspension was injected into the HPLC system.HPLC assay design was based on a previously described pharmacokinetic study by Hua and colleaguesThe chromatography setup comprised of Shimadzu Prominence HPLC system modules, a degasser, an auto-sampler, a UV detector (wavelengths set to 210 nm and 217 nm for POH and PA detection respectively), and a column oven . The separation was performed using a Zorbax Eclipse XDB-C18 column  and a Zorbax C18 guard . Mobile phase composition for both analytes was isocratic, comprising of water–acetonitrile mixture  for POH analysis and 0.05 M ammonium acetate (pH 5)–acetonitrile mixture  for PA analysis. Both phases were passed through 0.45 µm filters  before use.37 to determine doses for rats based on the smallest daily dose received by a human subject in the clinical trial i.e. 4.745 mg (i.e. 23.75 mg/kg). Formulations were refrigerated as one-time-use aliquots  at 4 °C. The volume (54 µL) was considered safe for intranasal administration based on experiences with similar volumes for intranasal study paradigms in rats in our lab39.POH formulation used for this study was adapted from the nasal formulation recipe used in an ongoing clinical trial that examines the safety and efficacy of perillyl alcohol in recurrent grade IV glioma patients (NCT02704858). Briefly, intranasal POH formulation consisted of 10% v/v (9.4% w/w) POH, 55% v/v glycerin USP and 35% v/v dehydrated alcohol. Dose for in vivo experiments was determined by allometric scaling based on body weightA dedicated CSF withdrawal system was used for POH experiments Fig. . This syAll animal experiments were conducted at the University of Wisconsin-Madison as per the NIH Guide for the Care and Use of Laboratory Animals , the ARRIVE guidelines, and following the approval of the Institutional Animal Care and Use Committee regulations at the University of Wisconsin-Madison. Animals were housed under 12 h light/12 h dark cycles and climate-controlled conditions with ad libitum access to food and water. All experiments were terminal, and efforts were made to ensure minimal pain and distress during anesthesia and cannulations.Adult female Sprague Dawley rats  were anesthetized under urethane  with boosters to effect. Atropine sulfate  was given every 2 h to avoid fluid accumulation in the lungs. Animals were maintained at physiological body temperature using a generic homeothermic monitoring system throughout the experiment.2, glycerin: 0.95 N s/m2) that resulted in breathing issues and low survival rate of animals at the experimental endpoint (70 min). Hence, animals subjected to intranasal POH administration underwent a brief tracheotomy procedure before cisternal puncture. Briefly, an incision was made parallel to rings of hyaline cartilage in the anterior tracheal region; a short piece (5 cm) of PE-205 tubing (outer diameter: 2 mm) was then inserted into this opening. Tubing was secured by 2–3 surgical knots with a general-purpose thread, followed by sealing the skin with cyanoacrylate. In our experience, tracheotomy prior to intranasal administration increased the survival rate and time for rats. Tracheotomy was not performed for intravascular POH experiments.Preliminary experiments indicated that glycerin was increasing the viscosity of POH formulation  was applied as a local anesthetic at the scalp before positioning the animals in a stereotaxic frame. A 5 cm midline incision was then made from the base of the neck 2 cm anterior to the bregma. The skin was laterally secured with hemostats and muscle layers were sequentially retracted using vannas scissors and cotton tip applicators. Once the atlanto-occipital layer was exposed, gentle incisions were made by alternating between a goniotomy knife and forceps to avoid dural puncture. When the cisterna magna was visible beneath the intact dura, a small dural hole was made using a dental needle at a 60° angle from the vertical. PEEK tubing was then inserted with the help of a microelectrode holder and stereotaxic frame’s manipulator arm. Excess CSF flowing out from the hole was absorbed using cotton tip applicators and tubing was sealed to the cranial opening with cyanoacrylate; sealed setup was then dried until cured.Intracisternal cannulation was the first procedure conducted on animals undergoing intravascular POH dosing. Cannulation was performed after the tracheotomy procedure for intranasal POH administration experiments. Cisternal cannulation procedure was adapted from a recently reported setup for intrathecal delivery in rats at our laboratoryIntracisternal cannulation preceded abdominal aortic cannulation for both treatment groups. Briefly, animals were carefully flipped over to the ventral side without displacing the tubing from its position. An incision was made below the xiphoid process along the abdominal midline. Skin and visceral organs were sequentially retracted to obtain a clear view of the aorta. Aorta was separated from the vena cava by cotton tip applicators and curved sharp forceps. The fascia between the two abdominal vessels was broken the opening was widened. Next, a 6-inch long piece of general-purpose thread was tied to the bottom of this opening to cut off blood supply to the lower body. Another piece of thread (~ 12 in) was loosely held at the top of this opening to secure a 20 GA, 1.25-inch cannula attached to a 3-way stop cock.Aliquots of 54 µL of POH formulation were intranasally applied using 200 µL gel loading pipette tips. Briefly, 17 mm of a gel loading pipette tip was inserted into one naris . Once the tip was 5 mm inside the nasal cavity, it was aligned parallel to the nasal septum bone and inserted 12 mm further into the cavity. The formulation was pipetted close to the olfactory nasal mucosa, avoiding any tissue damage. Within the first 2 min, 2 bolus drops of intranasal POH formulation (27 µL each) were administered to each naris of the animal.For intravascular application, the POH formulation was diluted to 0.5 mL  prior to administration. Briefly, 54 µL of POH formation was diluted with 445 µL of physiological saline  and injected into the abdominal aorta using a 3-way stop-cork. Another round of 500 µL saline was injected to flush the entire formulation from the cannula into the artery.CSF was withdrawn at 0–12 min, 14–26 min, 28–40 min, 40–54 min, and 56–70 min at 5 µL/min. After each withdrawal, CSF samples were ejected from the tubing into clean microcentrifuge tubes over a 2-min interval. Tubes were pre-cooled on ice. Blood sampling (300 µL) was performed every 14 min. Blood was collected in 1.5 mL microcentrifuge tubes containing 3 µL sodium heparin . Tubes were centrifuged  to separate red blood cells from the CSF and plasma at the end of the experiment. Samples were further spun  to remove additional contamination. Samples were stored (− 80 °C) until ready for analysis. Before HPLC analysis, samples from each animal were thawed and pooled across all time points to run HPLC assays in triplicates.Animals were euthanized by injecting 1 mL KCl (1 M) into the pericardium.For each HPLC analysis, LLOD were determined before sample analysis. Pure samples used for standard curves were dissolved in artificial CSF (aCSF) and commercially available rat plasma. POH concentrations in the CSF and plasma were each estimated by linear regression analysis. The CSF concentration of POH was below the LLOD for the assay in 1 out of 5 animals in the intravascular POH cohort; these values were therefore excluded from statistical analysis. POH and PA concentrations in the plasma and CSF were above LLOD for all other cases. Treatment groups were compared using the Student’s t-test when the two groups exhibited normal distribution and equal variance. In the absence of a normal distribution, groups were compared using the Mann–Whitney rank-sum test. Both analyses were performed using SigmaPlot  to identify statistical significance.


Charcot spinal arthropathy, also known as Charcot spine and neuropathic spinal arthropathy, is a progressive and destructive condition that affects an intervertebral disc and the adjacent vertebral bodies following loss of spinal joint innervation. We report the first case of Charcot spinal arthropathy (CSA) associated with cerebrospinal fluid (CSF)-cutaneous fistula.A 54-year-old male who underwent T10-L2 posterior instrumented spinal fusion seven years prior for treatment of T11 burst fracture and accompanying T11 complete paraplegia visited our department complaining of leakage of clear fluid at his lower back. The patient had also undergone various types of skin graft and myocutaneous flap surgeries for treatment of repetitive pressure sores around his lumbosacral area. The patient presented with persistent CSF leakage from a cutaneous fistula (CSF-cutaneous fistula) formed in a lumbosacral pressure sore. The CSF-cutaneous fistula arose from the L5 post-traumatic CSA. Surgery was planned for management of CSF-cutaneous fistula and post-traumatic L5 CSA. We successfully treated the CSF-cutaneous fistula with ligation and transection of the dural sac and cauda equina at the L2-L3 level. In addition, the post-traumatic L5 CSA was successfully treated with a posterior four-rod spinopelvic fixation from T9 to ilium and S2 foramina. After surgery, the CSF leakage stopped and no other adverse neurological changes were found. The four-rod spinopelvic construct was well maintained five years later.CSA associated with CSF-cutaneous fistula is a very rare disorder. Only surgical treatment for both CSA and CSF-cutaneous fistula with ligation and transection of the dural sac and posterior four-rod spinopelvic fixation can bring satisfactory results. Charcot spinal arthropathy (CSA), also known as Charcot spine and neuropathic spinal arthropathy, is a progressive and destructive condition that affects an intervertebral disc and the adjacent vertebral bodies following loss of spinal joint innervation for any reason , 2. The Until mid-twentieth century, patients sustaining catastrophic traumatic spinal cord injury might have died of injury-related complications , 25, 26.Irrespective of non-traumatic or post-traumatic CSA, considerable advances in spinal surgery techniques and technology during the past few decades have altered treatment paradigms from conservative management to surgery , 13, 27.Because of its slow progression and sensory denervation, diagnosis of post-traumatic CSA is delayed and presents as a late complication of traumatic spinal cord injury , 6, 29.We report a post-traumatic CSA associated with CSF-cutaneous fistula case of a male patient treated with ligation and transection of the dural sac and posterior four-rod spinopelvic fixation.Consultation was requested from the department of plastic surgery for a 54-year-old male who developed leakage of clear fluid in a lumbosacral pressure sore. He had previously suffered T11 burst fracture and resultant complete paraplegia in a motorcycle accident seven years prior. At the time of the injury, he had received a T9-L2 posterior instrumented spinal fusion at another hospital. Being in a paraplegic state, pressure sore soon developed thereafter. The patient also underwent various types of skin graft and myocutaneous flap surgeries to treat for the repetitive pressure sores around his lumbosacral area. On physical exam, clear, colorless, tap water-like fluid leaked from a small, deep, fibrotic opening formed at a lumbosacral pressure sore. Based on the nature of the fluid and the depth of the opening, we suspected that the liquid from the persistent leakage might be CSF. In addition, although completely paraplegic, the patient reported a sense of lumbosacral instability and kyphosis when in a sitting position and he heard cracking noises in his lumbosacral region upon movement. These symptoms were not associated with pain.Lateral plain radiograph showed a horizontal split of the L5 vertebral body and complete posterior dissociation of the upper spinal segment with respect to the lower one Fig. . ComputePseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. After surgery, vancomycin and imipenem were administered to the patient to cover the two bacterial organisms. The CSF leakage stopped and no adverse neurological changes were found. One iliac screw inserted into the right ilium was removed at postoperative one year due to skin protrusion. The four-rod spinopelvic construct was well maintained five years later  of the origin of the CSF-cutaneous fistula.Because of the low incidence of CSA, it has been difficult to establish a consensus as to its optimal treatment . HoweverIn conclusion, to our knowledge, this is the first reported case of CSA associated with CSF-cutaneous fistula. We believe that disruption of the intact spinal muscles and skin overlying the dural tear site led to CSF leakage, consequently leading to a CSF-cutaneous fistula at the level of L5 post-traumatic CSA.We recommend ligation and transection of the dural sac and posterior four-rod spinopelvic fixation for a successful treatment of post-traumatic CSA with CSF-cutaneous fistula.Additional file 1. Timeline.


Furthermore, a large bathochromic shift in the onset wavelength of the UV-Vis absorbance spectra from 367 nm in G1PPT to 674 nm in G1PPT-co-PEDOT further attests of successful copolymerization. The electrochemical analysis of G1PPT-co-PEDOT achieved a highest occupied molecular orbital (HOMO) energy level value of 5.3 eV, which is reminiscent of the value for an ideal electron-donor material. Photoluminescence quenching of up to 82% was observed in solution blends of the G1PPT-co-PEDOT star copolymer and N,N′-diisopropyl naphthalene diimide (NDI). This demonstrates the occurrence of photoinduced intermolecular charge transfer (PICT) from the electron-donating G1PPT-co-PEDOT to the electron accepting NDI, a good property, beneficial for optoelectronic and photovoltaic applications.A generation 1 poly(propylene thiophenoimine)-co-poly(ethylenedioxy thiophene) (G1PPT-co-PEDOT) star copolymer, which exhibits a strong optical absorption over a broad range in the ultraviolet–visible (UV-Vis) region and with good electro/conductive properties, was chemically prepared for the first time. Synthesis of the star copolymer, G1PPT-co-PEDOT was confirmed by spectroscopic studies. Indeed, the disappearance of the very high intensity bands, C–H bending at α-position (687 cm The discovery of electrical conductivity in chemically doped polyacetylene, has prompted a lot of research in the area of modelling, fabrication, and detailed studies of the properties and applications of π-conjugated polymers ,2. Conjun-type over p-type semiconductors [n-type (electron-transporting) semiconductors in organic photovoltaics and optoelectronics lies in their compact and electron deficient cores [On the other hand, more materials with electron-accepting properties are also being investigated in order to replace fullerene and its derivatives. Among them, the class of molecules called rylenes has been the focus of extensive research . In thisnductors ,29,30. Anductors ,32 and tnductors . In addinductors . As NDIsnductors ,36. Naphnt cores ,38,39, ant cores ,41.N,N′-diisopropyl naphthalene diimide in different ratios of solution blends of both materials, was also investigated. The electron donating properties of the material were ascertained by evaluating its molecular orbital levels via cyclic voltammetry and by studying its propensity to induce photoluminescence quenching when mixed with N,N′-diisopropyl naphthalene diimide.Dendrimers based on PEDOT have been mostly prepared electrochemically and studied for applications in bio/sensors or in supramolecular chemistry on substrates ,43. HereN,N-dimethylsulfoxide, analytical grade; N,N-dimethyl formamide anhydrous, 99.8%; dichloromethane chromasol plus HPLC, ≥99.9%; methanol, analytical grade; and tetrabutyl ammonium hexafluorophosphate, ≥99.0%; were all purchased from Sigma-Aldrich, Johannesburg, South Africa.Generation 1 poly(propylene imine) tetramine (DAB-Am4) dendrimer (G1PPI); 1,4,5,8-naphthalene tetracarboxylic dianhydride; 2-thiophene carboxaldhyde, 98%; 3,4-ethylenedioxythiophene, ammonium persulfate, 97%; lithium perchlorate anhydrous; chloroform, 99.9% HPLC grade; 2) gas [0.3863 g (1.2205 mmol) of generation 1 poly (propylene imine) tetramine dendrimer, G1PPI was dissolved in 25 mL of methanol, to which 472.55 µL (4.8821 mmol) of 2-thiophene carbaldehyde was added. The mixture was allowed to stir for 48 h under nitrogen (N2) gas . Upon co4)2S2O8 and the mixture was allowed to stir for 2 h at room temperature. Copolymerization is believed to have happened at the interface between the aqueous and the organic phases considering both materials were solely soluble in the respective solvents in which they were prepared. Both solvents were removed by evaporation upon completion of the reaction, which was quenched by addition of methanol. The material was then washed with water and acetone, sonicated, and centrifuged. The star-copolymer G1PPT-co-PEDOT (see structure in 495 mg (0.71424 mmol) of G1PPT was dissolved in 10 mL of chloroform. Then, 318 µL (2.8570 mmol) of the monomer EDOT was then added with 29.75 mL of 0.1 M  equivalences of isopropylamine  were added and the mixture was stirred at 110 °C overnight [2.25 g (8.3900 mmol) of 1,4,5,8- naphthalene tetracarboxylic dianhydride (NTCDA) was introduced in the 2-neck round bottom flask containing 25 mL of vernight . FiltratTM 3-22-TRIAX spectrofluorometer  with double grating excitation, and emission monochromators with a slit width of 5 nm, respectively. Surface morphology and elemental characterization were by scanning electron microscopy (SEM) using a ZEISS ULTRA scanning electron microscope, equipped with an energy dispersive spectrometer (EDS), and a Tecnai G2F2O X-Twin MAT 200 kV field emission transmission electron microscope from Field Electron and Ion Company (FEI), Eindhoven, Netherlands). X-ray diffraction patterns of the material was obtained using a D8 advance diffractometer  employing copper Ka radiation with a wavelength of 0.154 nm, operating at a voltage of 40 kV and current of 40 mA. Cyclic voltammetry (CV) studies were conducted on a BAS 100 B electrochemical analyzer from Bioanalytical Systems Incorporated . Electrochemical measurements of drop-coated films of G1PPT-co-PEDOT and NDI were performed at ambient air in aqueous solutions of 0.1 M lithium perchlorate (LiClO4) and 0.1 M tetrabutylammonium hexafluorophosphate (Bu4NPF6), respectively. A three-electrode system with gold (Au) and platinum (Pt) working electrodes for G1PPT-co-PEDOT and NDI, respectively, a Pt wire as the counter electrode and Ag/AgCl as reference electrode, was used for these analyses. The sweeping scan rate used was 50 mV/s.Various analytical techniques were used in order to characterize the prepared materials. Fourier-transform infra-red (FTIR) spectroscopy, used for structural characterization, enabled confirming the presence of the functional groups characterizing the polymeric materials. The analyses were carried out on PerkinElmer model Spectrum 100 series equipment . Optical and photo–physical investigation, in the form of ultraviolet–visible (UV-Vis) and photoluminescence (PL) spectroscopy measurements were performed in a DMSO containing quartz cuvette using a Nicolet Evolution 100 UV-Visible spectrometer  and a NanoLog0.01 M of G1PPT-co-PEDOT was prepared by dissolving 0.06930 g of the star-copolymer in 10 mL of DMSO and sonicated for 1 h. Meanwhile, 0.01 M of NDI was also prepared by dissolving 0.0350 g of NDI in 10 mL of DMSO. Three solution blends of G1PPT-co-PEDOT:NDI were made by mixing one equivalent volume (in mL) of G1PPT-co-PEDOT with different volumes NDI in the ratio 1:1, 1:2, and 1:3, respectively.−1. Out-of-plane bending of the C–H bond located at the α-position to the thiophene ring was observed at 705 cm−1. At 1435 cm−1, the medium-weak multiple band accounts for the C=C stretching in the 5-membered aromatic ring of thiophene. The sharp band at 1632 cm−1 stretching is attributed to the C=N bond, formed during the functionalization of G1PPI. The bands at 2830 and 2938 cm−1 in G1PPT indicate the presence of the –CH2 stretching in the dendrimer moiety. In the G1PPT-co-PEDOT spectrum  was used to investigate the crystal structure and/or phase purity of the star copolymer, G1PPT-co-PEDOT, and small electron accepting material, NDI. Graphs A and B in 4− for G1PPT-co-PEDOT, and 0.1 M Bu4NPF6 for NDI at a scan rate of 50 mV/s with gold (Au) and platinum (Pt) electrodes used as working electrodes for G1PPT-co-PEDOT and NDI, respectively. The materials were drop-coated on the electrodes. A Pt wire served as the counter electrode and an Ag/AgCl electrode was used as the reference electrode. pa1i and pa2i at 595 mV and −148 mV and two reduction peaks pc1i and pc2i at −51 mV and −503 mV. The persistence of those peaks when sweeping over the potential range at 50 mV/s during five cycles therefore confirmed the obtained peaks. The redox process in the copolymer (see 4- anion penetrates into the copolymer matrix and interacts with the oxidation site of the polymer as counter ion. The first redox couple (pa1i and pc1i) can be attributed to the introduction and release of the Li+ cation while the other redox couple (pa2i and pc2i) is associated with the insertion and release of the ClO4− anions, respectively [4NPF6 prepared in dichloromethane, within a potential range of (−1600)–(−500) mV, at a scan rate of 50 mV/s, revealed two distinct redox couples: two oxidations pa1i and pa2i at −700 mV and −1110 mV, and two reduction peaks pc1i and pc2i at −768 mV and −1182 mV. This can be explained by a first reduction from NDI to NDI−, and a second one from NDI− to the dianion NDI2−, giving rise to the two redox couples NDI/NDI− and NDI−/NDI2− [The electrochemical behaviors of the polymer G1PPT-co-PEDOT and small molecule, NDI were investigated by cyclic voltammetry (CV) . CV scanymer see , is as aectively . VoltammI−/NDI2− .EIP, and oxidation potential and the electron affinity, EA, and reduction potential derived by Bredas et al. [Using the linear correlation between the ionization potential energy, s et al.  the elec(HOMO)E, (LUMO)E, and Based on the data from the voltammetric analyses of G1PPT-co-PEDOT, the HOMO and LUMO and energy band gap, aterials . Since iaterials , confirmλmax= 269 nm, whose area under the curve overlaps the two absorption peaks present in G1PPT. This maximal absorption peak is assigned to the absorption by the chromophores within the thiophene moiety. Indeed, according to the literature, reported UV-Vis absorption for thiophene-functionalized dendrimer is between 250–400 nm [λmax = 380 nm; characteristics of the absorbance of the chromophores C=O and C=C, whose peaks are as a result of π−π∗ transitions, which in is agreement with the already reported absorption of NDI [n–σ* transition within the C–N chromophore. The optical band gap of NDI was determined to be 3.16 eV, reflecting the small conjugated core [The optical and photophysical results of the investigated materials were obtained in dimethylsulfoxide (DMSO) as depicted in 0–400 nm . One imp0–400 nm . The bro0–400 nm ,55. Withted core .The photoluminescence spectra of pristine G1PPT-co-PEDOT and NDI when excited at their respective absorption wavelengths are also shown in UV-Vis spectroscopic analysis of G1PPT-co-PEDOT:NDI solution blends was conducted with reference to pristine G1PPT-co-PEDOT , to inve6 CPS. Upon addition of one equivalent volume of NDI, prepared at the same concentration (0.01 M), and excitation at the same wavelength, solution blend of G1PPT-co-PEDOT and NDI (1:1) exhibited approximately 35% fluorescence quenching, characterized by a decrease in intensity to around 3 × 106 CPS. The quenching in G1PPT-co-PEDOT:NDI blend is believed to be due to photoinduced electron transfer [6 CPS and 1.3 × 106 CPS, the in 1:2 and 1:3 solution blends, respectively. Two main types of PL quenching phenomena have been reported to occur in polymers, namely static and dynamic quenching. An interaction between a fluorophore (G1PPT-co-PEDOT) and a quencher (NDI) remains the pillar of this process. When a non-fluorescent complex is formed between a fluorophore and a quencher, regardless of the population of the excited state, a static quenching occurs. On the other hand, diffusion of the quencher to the fluorophore during the lifetime of the excited state results in the occurrence of a dynamic or collisional quenching. Such diffusion will cause the fluorophore to return to the ground state without photon emission. The collisional quenching is optimally described by the Stern–Volmer law [Among other characteristics, polymeric nanocomposites are usually required to exhibit high photoluminescence quenching in order to meet the need for optoelectronic and/or photovoltaic applications . The photransfer . Indeed,transfer . Moreovetransfer . It is atransfer , as obselmer law . FurtherN,N′-diisopropyl naphthalene diimide (NDI) were synthesized and evaluated for their potential application in optoelectronics as electron donating polymers. The UV-Vis absorption spectra of the star copolymer revealed a broad absorption band in the visible-near infrared (Vis-NIR) region, with an optical band gap as low as 1.84 eV, and a red-shift to higher wavelength in its solution blend with NDI. Effective photoinduced charge transfer was confirmed by photoluminescence quenching of up to 82%, when increasing amount of NDI was added to a solution of pristine G1PPT-co-PEDOT. The content of NDI in the solution blend played a significant role in the photoluminescence (PL) quenching. High NDI contents resulted in improved PL quenching. Characteristics such as high Vis-NIR region absorption, HOMO energy level below oxygen HOMO level (−5.3 eV), propensity to effectively donate electrons to electron accepting materials, and band gap below 2.0 eV (as found in G1PPT-co-PEDOT) are of primary importance for electron donating materials in optoelectronics. Thus, the blending of electroconductive G1PPT-co-PEDOT star copolymer with air-stable NDI may afford optoelectronic and photovoltaic devices with desirable properties, and hence holds promise for such applications.Novel G1PPT-co-PEDOT star copolymer and its blends with


Objective: TNFAIP2 is a novel gene induced by TNF-α and participates in inflammatory reaction and tumor angiogenesis. This study aims to understand the correlation between TNFAIP2 gene polymorphism and prediction as well as prognosis of gastric cancer (GC) in a Chinese population.Methods: One thousand two hundred seventy-nine cases were enrolled, including 640 GC and 639 non-cancer cases. The functional tagSNPs of the TNFAIP2 gene were screened by Haploview software and NIH Snpinfo website. Human whole-blood genomic DNA was extracted by phenol chloroform method and analyzed by KASP SNP typing and sequencing method. ELISA was used to determine the expression of TNFAIP2 protein in serum samples. The miRNAs bound to TNFAIP2 3′ UTR rs8126 were predicted by MirSNP and TargetScan database. SPSS 22.0 software was used for statistical analysis, and P < 0.05 showed statistical difference.Results: Four functional TNFAIP2 tagSNPs were found by bioinformatics analysis. TNFAIP2 rs8126 T>C polymorphism increased GC risk, and the risk in TC genotype cases was higher than that in TT genotype cases . In the dominant model, the TNFAIP2 rs8126 polymorphic carrier was 1.419 times higher (P = 0.007). TNFAIP2 rs710100 C>T polymorphism, TNFAIP2 rs3759571 G>A polymorphism, and TNFAIP2 rs3759573 A>G polymorphism were not correlated with GC risk. In the subgroup analysis, TNFAIP2 rs8126 TC genotype cases had a higher GC risk in male, aged 60 years or older, Helicobacter pylori-negative, non-smoking, and non-drinking. However, there was no correlation between TNFAIP2 SNPs and GC prognosis. The TNFAIP2 protein concentration in GC patients was significantly different from that in healthy persons (P = 0.029), but it was not associated with GC prognosis. The high or low expression of TNFAIP2 protein had no significant difference with gender, age, H. pylori infection, smoking, and drinking in GC patients. The serum TNFAIP2 protein expression in rs8126 TT genotype carriers was significantly higher than that in rs8126 CC genotype carriers (P < 0.001).Conclusion: TNFAIP2 3′ UTR rs8126 T>C polymorphism was associated with GC risk in a Chinese population, especially in cases with males aged 60 years or older, H. pylori negative, non-smoking and non-drinking. Compared with healthy persons, serum TNFAIP2 protein expression was higher in Chinese GC patients, and TNFAIP2 3′ UTR rs8126 T>C polymorphism might affect TNFAIP2 protein expression. Gastric cancer (GC) is considered to be one of the most common malignant tumors in the world . It is uin vitro studies, TNFAIP2 is believed to have differential expression during angiogenesis , also known as B94 and EXOC3L3, is a member of tumor necrosis factor alpha-induced proteins (TNFAIPs). It is located on human chromosome 14q32.32 and contains 14 exons, which has a genomic DNA span of 13.45 kDa and can encode a protein with 654 amino acids and a molecular weight of 72.6 kDa. TNFAIP2 interacts with EXOC1, EXOC2, EXOC4, EXOC7, and EXOC8 and participates in the formation and the development of human organs . In in vogenesis . In addiogenesis . Previouogenesis , 18, 19.However, the correlation between TNFAIP2 gene polymorphism and prediction or prognosis of GC is rarely reported, especially in Asian or Chinese populations. At present, only one study from an American population reported that, compared with TT + TC genotype, the TNFAIP2 3′ UTR rs8126 CC genotype significantly increased GC risk, especially in the drinking population .This study aims to understand the correlation between TNFAIP2 gene polymorphism and prediction or prognosis of GC in a Chinese population, explore the effect of TNFAIP2 gene polymorphism on the expression of TNFAIP2 protein, and attempt to provide a theoretical basis for molecular target prediction, disease diagnosis, and individualized treatment of GC.This was a case–control study from multiple medical centers in Liaoning Province, northern China, and 640 patients with GC and 639 non-GC cases were enrolled between December 1997 and December 2013. The inclusion criteria included the following: all participants had a clear pathological diagnosis and typing by electronic gastroscopy. The exclusion criteria included the following: (A) The participants had a major organ dysfunction; (B) The participants had autoimmune diseases; (C) The participants had other malignant tumors; and (D) The participants had infectious diseases. The fasting venous blood and serum of all participants were isolated and saved under the condition of 20°C below zero. The epidemiological information and the clinicopathological parameters of the cases were recorded, and the GC patients were followed up by telephone every 6 months. The main follow-up contents were overall survival, and the deadline for data collection was June 30, 2017 . This sthttps://snpinfo.niehs.nih.gov/). The F-SNP website (http://compbio.cs.queensu.ca/F-SNP/) and the NIH Snpinfo website were used to predict the functional tagSNPs, respectively. The parameters were set as: Chinese Han population, minimum allele frequency >5%, and frequency distribution r2 > 0.8 , SNP genotyping was performed by Bio Miao Biological Technology . In addition, we randomly selected 10% of the samples for repeated analysis and found that the consistency rate of all the duplicated samples was 100%.H. pylori-IgG titer was also detected by ELISA , and the details were described in our published study (Enzyme-linked immunosorbent assay (ELISA) was used to determine the expression of the TNFAIP2 protein in the serum samples. Double-antibody sandwich method was used for ELISA, and the ELISA kit was purchased from Shanghai Enzyme-linked Biotechnology Co., Ltd. The absorbance  was measured by Multiskan Ascent  at 450 nm, and the TNFAIP2 concentration was calculated by a standard curve. Serum ed study .T-test could be used for statistical analysis. If it did not conform to the normal distribution, non-parametric test should be used for statistical analysis. The counting units were statistically analyzed by chi-square test. Multivariate logistic regression model was used to compare TNFAIP2 SNPs genotypes between the GC group and the non-GC group, and OR value and confidence interval (95% CI) were calculated to represent the relative risk. Logistic regression model was used to evaluate the interaction relationship between TNFAIP2 SNPs and H. pylori infection, smoking, and drinking. Adjusting for gender and age, a full-factor model was used to calculate the P-value of the interaction relationship between TNFAIP2 SNPs genotypes and H. pylori infection, smoking, and drinking. Cox proportional risk model was used for univariate and multivariate analysis to calculate the relationship between the clinical parameters and the prognosis of GC patients. P < 0.05 was considered as statistically significant.SPSS 20.0 software  was used for statistical analysis. Firstly, we tested the normal distribution for units of measurement. If it conformed to the normal distribution, H. pylori infection between the two groups was statistically significant (P < 0.001), but there were no significant differences in smoking and drinking  and 58.53 ± 8.17 (26–89), respectively. The difference in drinking .Haploview software and NIH Snpinfo website were used to screen for functional tagSNPs, respectively. We found four functional TNFAIP2 SNPs and used them as candidate SNPs for further genotyping and statistical analysis, including miRNA binding sites (rs8126 and rs710100) and transcription factor binding sites (rs3759571 and rs3759573).P = 0.001, OR = 1.557). In the dominant model, the GC risk in TNFAIP2 rs8126 polymorphic carriers was 1.419 times higher (P = 0.007). However, TNFAIP2 rs710100 C>T polymorphism, TNFAIP2 rs3759571 G>A polymorphism, and TNFAIP2 rs3759573 A>G polymorphism were not associated with GC risk. In particular, TNFAIP2 rs3759573 A>G polymorphism was not consistent with Hardy–Weinberg's genetic linkage balance (PHWE < 0.05) and was excluded in the subsequent analysis , and GC risk was 1.443 times higher in TNFAIP2 rs8126 polymorphic carriers in the dominant model (P = 0.018). In subjects aged over 60 years, TNFAIP2 rs8126 TC genotype cases had a higher GC risk than TT genotype cases , and GC risk was 1.693 times higher in TNFAIP2 rs8126 polymorphic carriers in the dominant model (P = 0.010). In subjects younger than 60 years old, TNFAIP2 rs8126 TC genotype cases had a higher GC risk than TT genotype cases . In subjects without H. pylori infection, TNFAIP2 rs8126 TC genotype cases had a higher GC risk than TT genotype cases , and GC risk was 1.440 times higher in TNFAIP2 rs8126 polymorphic carriers in the dominant model (P = 0.017). In non-smoking subjects, TNFAIP2 rs8126 TC genotype cases had a higher GC risk than TT genotype cases , and GC risk was 1.643 times higher in TNFAIP2 rs8126 polymorphic carriers in the dominant model (P = 0.038). In non-drinking subjects, TNFAIP2 rs8126 TC genotype cases had a higher GC risk than TT genotype cases   .H. pylori infection, smoking, and drinking) on GC risk were analyzed, and the results showed that there was no significant correlation between them  and environmental factors (P > 0.05), suggesting that TNFAIP2 SNPs had nothing to do with GC prognosis in this group   .P = 0.029; ELISA was performed on 202 serum samples randomly selected from the GC group and the healthy control group, including 103 GC patients and 99 healthy persons. There was no statistical difference in age, gender, and TNFAIP2 rs8126 genotypes between the two groups. The average age of the GC group and the healthy control group was 56.57 ± 7.656 (29–67) years old and 54.45 ± 7.737 (43–81) years old, respectively. The TNFAIP2 protein concentration in GC patients was significantly different from that in healthy persons  and lymph node metastasis . The multivariate analysis with depth of invasion and lymph node metastasis as covariables confirmed that there was no significant difference in GC prognosis between the two groups . The results suggested that serum TNFAIP2 protein expression was not associated with the prognosis of GC patients in this group   .TNFAIP2 is a novel gene induced by TNF-α and can regulate inflammatory and tumor angiogenesis . In receP = 0.001, OR = 1.557), and the GC risk in polymorphic carriers of TNFAIP2 rs8126 was increased to 1.419 times in the dominant model (P = 0.007). These results were consistent with the American study and confirmed the correlation between TNFAIP2 rs8126 polymorphism and GC risk  (Pinteraction > 0.05), suggesting that the interaction effects between H. pylori infection and TNFAIP2 SNPs could not affect GC risk in this group, and no other similar results had been reported so far. In addition, we analyzed the interaction effects between smoking and drinking and TNFAIP2 SNPs on GC risk and found that there was no interaction between smoking and drinking and TNFAIP2 SNPs on GC risk (Pinteraction > 0.05). This result was different from that of the American population .The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: dbSNP (The studies involving human participants were reviewed and approved by Medical Science Research Ethics Committee of the First Affiliated Hospital of China Medical University. The patients/participants provided their written informed consent to participate in this study.YY and FG: conceived and designed the experiments. FG: performed the experiments. FG, QX, ZL, H-XD, Z-DZ, and L-PS: collected the samples and analyzed the data. YY: contributed reagents, materials, and analysis tools. FG and YY: wrote and revised the paper. All authors: read and approved the final manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


GDF8 levels were higher in patients with in-hospital ventricular tachycardia or fibrillation (VT/VF) than those without in-hospital VT/VF. GDF8 was positively correlated with troponin I peak . In multivariate linear regression analysis, log GDF8  was an independent predictor of troponin I peak. Conclusions: These results suggest that GDF8 levels could reflect the extent of myocardial damage during AMI, similar to peak troponin I, which is currently used to estimate infarct size. Further studies are needed to elucidate the underlying mechanisms linking the GDF8 cytokine with troponin I levels.Objective: Growth differentiation factor-8 (GDF8), also known as myostatin, is a member of the transforming growth factor-β superfamily that inhibits skeletal muscle growth. We aimed to investigate the association between GDF8 and peak troponin I levels after acute myocardial infarction (AMI). Methods: All consecutive patients admitted from June 2016 to February 2018 for type 1 AMI in the Coronary Care Unit of University Hospital of Dijon Bourgogne (France) were included in our prospective study. Blood samples were harvested on admission, and serum levels of GDF8 were measured using a commercially available enzyme-linked immunosorbent assay kit. Results: Among the 296 patients with type 1 AMI, median age was 68 years and 27% were women. GDF8 levels (median (IQR) = 2375 ng/L) were negatively correlated with age, sex and diabetes ( Patients with acute myocardial infarction (AMI) have a high rate of mortality, and the risk of fatal events is highest in the first hours following onset. The severity of AMI, which is usually determined early on with the measurement of circulating troponins, has a major impact on the development of late AMI consequences such as heart failure. Therefore, precise and rapid assessment of the severity of AMI critically affects treatment choices and patient prognoses. Recently, there has been interest in the potential role of new biomarkers for the assessment of severity in the early stages of AMI, with a particular focus on NT-pro-natriuretic peptide (NT-proBNP), heart-type fatty acid binding protein (hFABP) and circulating cytokines such as growth differentiation factor-15 [Growth differentiation factor-8 (GDF8), also known as myostatin, is a member of the transforming growth factor-β (TGF-β) superfamily. GDF8 shares many structural similarities with other members such as growth differentiation factor-11 ,3. GDF8 The aim of our study was to evaluate GDF8/myostatin levels in patients admitted for AMI, and to investigate the associations between GDF8 and markers of AMI severity such as troponin.The methods and design of the French Regional Observatoire des Infarctus de Côte-d’Or (RICO) survey have been previously described . From JuPatient characteristics were obtained at hospital admission. These included cardiovascular risk factors and history, and clinical and biological data. Risk scores were calculated (GRACE score and SYNTAX score). Blood samples were collected on admission to measure serum C-reactive protein (CRP), creatinine, creatine kinase peak, troponin Ic peak, NT-proBNP, blood lipids, glucose and hemoglobin. eGFR was calculated using Chronic Kidney Disease-EPIdemiology Collaboration formula (CKD-EPI). Echocardiographic data such as left ventricular ejection fraction (LVEF) were recorded. Finally, in-hospital events were documented, including death, cardiovascular death, re-infarction, stroke, development of heart failure and ventricular tachycardia or fibrillation (VT/VF).Blood samples were collected on admission from a vein in the arm, centrifuged at 4 °C to isolate the serum, and samples were stored at −80 °C until use. Median (IQR) time from symptom onset to blood sampling was 16(8–30) hours. Serum GDF8 was measured in duplicate using a commercially available Quantitine kit . The minimum detectable concentration was 2.25 ng/L, and the coefficient of variation between duplicates did not exceed 10%.n (%) and continuous variables as mean ± SD or median (interquartile range). A Kolmogorov–Smirnov test was performed to test the normality of continuous variables. For non-normally distributed variables , they were log transformed. The Mann-Whitney test or Student’s t test was used to compare continuous data, and the Chi 2 test or Fisher’s test was used for dichotomous data, as appropriate.Dichotomous variables are expressed as Pearson correlation analyses  or Spearman correlation analyses (one or two non-Gaussian variables) were performed. The threshold for significance was set at 5%.Bivariate linear regression analyses were used to adjust GDF8 with age.Multivariate logistic regression models were built to estimate in-hospital VT/VF and troponin Ic peak based on significant variables in univariate analysis. The inclusion threshold was set at 5%.SPSS version 12.0.1  was used for all of the statistical tests.The baseline characteristics of the study population are shown in Among the 296 included patients, eighty-one (27%) were female. The median age was 68 years, 178 (60%) had hypertension, 117 (40%) had hypercholesterolemia, 75 (25%) had diabetes and 85 (29%) are active smokers. Median GDF8 was 2375 (1640–3347) ng/L.p = 0.034, p = 0.034) and the sensitivity and specificity were good . Among patients with GDF8 > 2800 ng/L (112/296), the risk of developing in-hospital VT/VF was higher than in patients with GDF8 < 2800 ng/L (184/296) (p = 0.046). The other relevant biomarkers (CK and peak troponin Ic) showed similar associations with the outcome (VT/VF): the respective AUC were 0.717 (p = 0.027) and 0.698 (p = 0.034), and the cut-off values were 400.5 UI/L and 7.6 ng/mL. Sensitivity and specificity were respectively 100% and 44% for CK and 100% and 43% for peak troponin IC. Both CK and troponin Ic were significantly associated with VT/VF in logistic regression analysis (CK peak: OR (95% CI): 6.034 (1.684–21.621) and troponin Ic peak: OR (95% CI): 2.751 (1.079–7.019)).Ten patients (3%) developed VT/VF during their hospital stay. GDF8 levels were higher in these patients than in those who did not experience VT/VF . Patients with high  GDF8 levels had a trend toward an increased risk of TV/FV compared with patients who had lower  GDF8 levels (4.8% vs. 2%). Moreover, the troponin peak was much higher (X3) in patients with a supramedian GDF8 level, as shown in p = 0.095), smoking , left ventricular ejection fraction <40% , GRACE risk score , and time to admission  and log GDF8  were associated with the prediction of troponin Ic peak. In multivariable analysis, log GDF8 remained associated to the prediction of troponin Ic peak, after adjustment for confounding factors , occurrence of complicating heart failure, GRACE risk score, CK peak, NT-proBNP, and troponin levels. In multivariable analysis, log GDF8 was associated with the prediction of troponin I peak, even after adjustment for age. Moreover, among patients with the highest GDF8 levels >2800 ng/L), the risk of developing in-hospital VT/VF was higher. To our knowledge, this is the first time that GDF8 has been associated with clinical severity in the acute phase of MI. Previous studies in sheep found that GDF8 was expressed in the fetal and adult heart and was localized in the cardiomyocytes and Purkinje fibers . Further00 ng/L, n = 10), limiting statistical power. The second limitation is the monocentric nature of the study with a subsequent selection bias. However, the strong association between GDF8 and the prediction of troponin I peak was supported by results of univariate regression analysis (p < 0.001) and the enduring significance after adjustment for determinants (p < 0.001). In future, these preliminary results need to be confirmed in larger studies.The first limitation of our study is the small number of patients who developed VT/VF (To conclude, our original results suggest that GDF8 levels could reflect the extent of myocardial damage during AMI, similar to peak troponin I, which is currently used to estimate infarct size. Further studies are needed to elucidate the underlying mechanisms linking the GDF8 cytokine with troponin I levels.


BackgroundPosterior fossa craniotomies can be complicated by cerebrospinal fluid (CSF) leaks, infection, meningitis, neurologic deficits, and intracranial hypotension caused by defective closure of the dura. Secondary dural closures such as pericranial graft, muscle graft, glue, sealants, or fat graft are used. However, there have been few studies examining the use of sealants with a polyethylene glycol and polyethylenimine component.ObjectiveWe studied the effect of one such sealant, Adherus® , as an adjunct to secondary closure methods in the reduction of the use of abdominal fat grafting and lumbar puncture/drains.MethodsWe retrospectively reviewed the surgical records of all patients undergoing posterior fossa cranial surgery during a two-year period at a tertiary university affiliated medical center.ResultsOverall, data a total of 122 patients (62 in the no Adherus and 60 in the Adherus group) were collected. There was no statistically significant difference in the 30-day incisional CSF leak rate , 30-day non-incisional CSF leak rate , and 30-day pseudomeningocele rate  in the no Adherus and Adherus groups, respectively. However, there was a significant reduction in the use of abdominal fat grafting  and intraoperative CSF diversion techniques . Every instance of the use of Adherus saved on average, $809.36.ConclusionsA statistically significant reduction in the use of CSF shunting procedures during posterior fossa craniotomy/craniectomy was achieved after the introduction of Adherus with no increase in CSF leak rate. Posterior fossa craniotomies can be complicated by cerebrospinal fluid (CSF) leak, infection, meningitis, neurologic deficits, and intracranial hypotension, which may be caused by defective closure of the dura. The standard method of dural closure involves the use of interrupted and/or running suture to appose the edges of the dura together to create a watertight seal. In addition, if a dural defect is noted with too much tension required for apposition of the dura, secondary dural closure with the use of pericranium, muscle, glue, sealants, or fat graft has been performed to augment the closure. In addition, biologic and synthetic compounds such as fibrin glue or polyethylene glycol (PEG) sealants can be used.There is evidence to suggest that PEG sealants reduce CSF leak rates -3. HowevA previous study reported on the use of Adherus in 11 cases of intraoperative CSF leak treated with transphenoidal endoscopic surgery. There were no major complications, no postoperative CSF leaks, and no infections or other complications . In addiThe aim of this study was to report on the use of Adherus as an adjunct to primary closure methods, specifically to reduce the need for the use of abdominal fat grafting and lumbar puncture/drains and on CSF leak rates after posterior fossa cranial surgery.PopulationWe retrospectively reviewed the surgical records of all patients undergoing posterior fossa cranial surgery during a two-year period at a tertiary academic medical center. Institutional Review Board (IRB) approval from the University of California San Francisco (UCSF) was obtained. Patient consent for the study was not obtained due to the purely observational nature of the study. The senior author proposed the use of the dural sealant for eliminating a secondary surgical procedure for the harvesting of abdominal fat graft. Posterior fossa cases were divided into two groups: a group in which Adherus dural sealant was used for dural closure and a control group in which Adherus was not used. During the second year of the two-year period, Adherus was used in all posterior fossa craniotomies and therefore the two groups were split based on whether the surgery was performed during the first or second year of the two-year period. There were three surgeons who operated on patients in both groups of this study. We retrospectively selected a total of 122 posterior fossa surgeries. Adherus dural sealant was used in 60 (49.2%) of these cases.Additional demographic data were collected, including age, sex, smoking history, etiology of craniotomy, prior surgery, and the presence of diabetes. Other variables collected included the posterior fossa craniotomy approach and whether the patient required intraoperative CSF diversion, postoperative CSF diversion, and intraoperative abdominal fat grafting for dural closure. Outcome variables included 30-day postoperative incidence of incisional CSF leak, non-incisional CSF leak , and pseudomeningocele, as well as length of stay postoperatively.CostsSince the use of the dural sealant was proposed instead of harvesting of abdominal fat graft, an estimate of costs for the sealant was compared with that of the fat graft Table . The cosOutcomesIncisional CSF leak was defined as fluid leakage from the surgical incision within 30 days after surgery that required clinical intervention. Non-incisional CSF leak was defined as otorrhea or rhinorrhea within 30 days after surgery that necessitated clinical intervention. Pseudomeningoceles were defined as clinically symptomatic fluid collections under the skin surrounding the surgical site, also within 30 days after surgery. Sub-clinical pseudomeningoceles identified by radiology were not included in the analysis. Re-admissions secondary to abdominal wound infections at abdominal graft site were also included.Statistical analysisDescriptive variables were presented using means and standard deviations (SDs). Demographic characteristics and outcome measures between the Adherus and control groups were compared using bivariate analysis. A chi-square test of independence was used to determine whether significant differences in means existed in categorical demographic and outcome variables between the Adherus and control groups. For continuous demographics or outcomes, an independent-samples t-test was used to compare means between the two groups. There were no significant differences found in any of the primary outcomes when compared between groups using bivariate analysis, and thus multivariate analysis was not performed.Demographic data are summarized in Table Outcomes of the study are summarized in Table Cost analysis is summarized in Table This case-control retrospective analysis explores the effects of the use of dural sealant on the operative techniques and subsequent outcomes of patients undergoing posterior fossa craniotomy. At our institution, Adherus was introduced with the intent of providing a cost-saving measure with a conscious decision to decrease the use of intra- and postoperative CSF diversion procedures and abdominal fat grafting. Until recently, the use of abdominal fat at the site of surgical defect has been considered the standard of care method for the reduction of postoperative CSF leaks after retrosigmoid, retrolabyrinthine, and translabyrinthine procedures in the posterior fossa. Despite its use, the CSF leak rate in the literature remains to be 6 to 17% -7. With In addition to abdominal fat grafting, the use of intraoperative CSF diversion is an adjunct technique to posterior fossa craniotomy intended to provide relaxation of neural structures for better surgical corridors and also to reduce the pressure of CSF to aid in dural closure and reduction of CSF leaks. It is a commonly used procedure for the reduction of intraoperative fluid leak rates not only in posterior fossa surgery but also in surgery for pituitary adenomas . As withSpecifically, we performed a cost-of-use analysis, finding that the use of Adherus resulted in cost savings of $809.36 per case in billable charges to the patient. This was driven by the reduced need for abdominal fat grafting and also the prevention of any wound complications and further admissions required for abdominal wound breakdown. However, in addition to the modest savings of approximately $809.36 of billable charges per case, we believe that a more significant benefit is the avoidance of the complications related to an additional incision in the abdominal area and the additional time under anesthesia and complications that accompany an additional incision, which are not trivial should they occur. Additionally, the use of adjunct CSF diversion methods, such as lumbar drain and EVD, add costs related to length of hospital stay were not included in the analysis. Typically, the protocol with respect to lumbar drains and EVD involves continuous volume drainage over the course of at least three days, which adds at least two days of hospital stay to patient admissions.Our study has several limitations. First, it was a retrospective study using patient chart review for the abstraction of data and outcomes. Data gathering and patient recruitment were not performed with a prospective study design in mind; rather, a case series of consecutive patients undergoing posterior fossa craniotomies before and after the introduction of Adherus was collected and represents a convenience sample. However, we believe that we have reduced bias by selecting all patients who were treated with Adherus (n=60) after April 20, 2016, and simply including all consecutive patients within the same time duration before the introduction of Adherus (n=62). Second, patients were not assessed at definite time points for the outcomes of interest. Surveillance for the outcomes of interest was determined from a pragmatic clinical standpoint by abstracting from the patient’s chart daily progress notes, imaging results, and clinic notes for CSF leak, pseudomeningocele, and need for permanent CSF diversion. This may have resulted in an underreporting of complications, which may have been present and detected using standardized research assessments but may not have risen to clinical significance. Additionally, patients lost to follow-up and those who may have received treatment for complications at external hospitals may have been underreported. However, we do not believe that there should have been a systematic bias with respect to underreporting of complications.Despite these limitations, we present the first study to assess the effect of Adherus on the rates of CSF leak and pseudomeningocele after posterior fossa surgery. While we found no difference in these outcomes, a large and statistically significant reduction in adjunctive procedures including lumbar puncture, LSAD, and abdominal fat grafting for CSF leak reduction was achieved. Our study was not powered to detect differences in complication rates resulting from adjunctive procedures, but larger prospective studies should be performed to quantify these differences. It seems safe to conclude, however, that the use of Adherus allows the reduction of abdominal fat graft, lumbar puncture, and LSAD procedures, with no change in CSF leak or pseudomeningocele rates after posterior fossa craniotomy/craniectomy.A retrospective analysis of posterior fossa craniotomy/craniectomies for various pathologies was performed to determine whether there were statistically significant differences in CSF leak rates and associated factors after the introduction of Adherus dural sealant along with its impact on complication rates and cost-effectiveness. A statistically significant reduction in the use of intraoperative abdominal fat graft, lumbar puncture, and LSAD procedures during posterior fossa craniotomy/craniectomy was achieved after the introduction of Adherus for all procedures, with no increase in the 30-day CSF leak or pseudomeningocele rates.