UW Neurological Surgery Recent PubMed Publications

The potassium channel Kv4.2 regulates dendritic spine morphology, electroencephalographic characteristics and seizure susceptibility in mice.

Exp Neurol. 2020 Aug 18;:113437

Authors: Tiwari D, Schaefer TL, Schroeder-Carter LM, Krzeski JC, Bunk AT, Parkins EV, Snider A, Danzer R, Williams MT, Vorhees CV, Danzer SC, Gross C

Abstract
The voltage-gated potassium channel Kv4.2 is a critical regulator of dendritic excitability in the hippocampus and is crucial for dendritic signal integration. Kv4.2 mRNA and protein expression as well as function are reduced in several genetic and pharmacologically induced rodent models of epilepsy and autism. It is not known, however, whether reduced Kv4.2 is just an epiphenomenon or a disease-contributing cause of neuronal hyperexcitability and behavioral impairments in these neurological disorders. To address this question, we used male and female mice heterozygous for a Kv.2 deletion and adult-onset manipulation of hippocampal Kv4.2 expression in male mice to assess the role of Kv4.2 in regulating neuronal network excitability, morphology and anxiety-related behaviors. We observed a reduction in dendritic spine density and reduced proportions of thin and stubby spines but no changes in anxiety, overall activity, or retention of conditioned freezing memory in Kv4.2 heterozygous mice compared with wildtype littermates. Using EEG analyses, we showed elevated theta power and increased spike frequency in Kv4.2 heterozygous mice under basal conditions. In addition, the latency to onset of kainic acid-induced seizures was significantly shortened in Kv4.2 heterozygous mice compared with wildtype littermates, which was accompanied by a significant increase in theta power. By contrast, overexpressing Kv4.2 in wildtype mice through intrahippocampal injection of Kv4.2-expressing lentivirus delayed seizure onset and reduced EEG power. These results suggest that Kv4.2 is an important regulator of neuronal network excitability and dendritic spine morphology, but not anxiety-related behaviors. In the future, manipulation of Kv4.2 expression could be used to alter seizure susceptibility in epilepsy.

PMID: 32822706 [PubMed - as supplied by publisher]

Insulin-like growth factor 1-receptor signaling stimulates GRP78 expression through the PI3K/AKT/mTOR/ATF4 axis.

Cell Signal. 2020 Aug 14;:109736

Authors: Ha DP, Lee AS

Abstract
GRP78, a major molecular chaperone, is critical for the folding and maturation of membrane and secretory proteins and serves as the master regulator of the unfolded protein response. Thus, GRP78 is frequently upregulated in highly proliferative cells to cope with elevated protein synthesis and metabolic stress. IGF-1 is a potent regulator of cell growth, metabolism and survival. Previously we discovered that GRP78 is a novel downstream target of IGF-1 signaling by utilizing mouse embryonic fibroblast model systems where the IGF-1 receptor (IGF-1R) was either overexpressed (R+) or knockout (R-). Here we investigated the mechanisms whereby GRP78 is upregulated in the R+ cells. Our studies revealed that suppression of PI3K/AKT/mTOR downstream of IGF-1R signaling resulted in concurrent decrease in GRP78 and the transcription factor ATF4. Through knock-down and overexpression studies, we established ATF4 as the essential downstream nodal of the PI3K/AKT/mTOR signaling pathway critical for GRP78 transcriptional upregulation mediated by IGF-1R.

PMID: 32805346 [PubMed - as supplied by publisher]

Anatomic Gradients in the Microbiology of Spinal Fusion Surgical Site Infection and Resistance to Surgical Antimicrobial Prophylaxis.

Spine (Phila Pa 1976). 2020 Aug 12;:

Authors: Long DR, Bryson-Cahn C, Pergamit R, Tavolaro C, Saigal R, Chan JD, Lynch JB

Abstract
STUDY DESIGN: Retrospective hospital-registry study.
OBJECTIVE: To characterize the microbial epidemiology of surgical site infection (SSI) in spinal fusion surgery and the burden of resistance to standard surgical antibiotic prophylaxis.
SUMMARY OF BACKGROUND DATA: SSI persists as a leading complication of spinal fusion surgery despite the growth of enhanced recovery programs and improvements in other measures of surgical quality. Improved understandings of SSI microbiology and common mechanisms of failure for current prevention strategies are required to inform the development of novel approaches to prevention relevant to modern surgical practice.
METHODS: Spinal fusion cases performed at a single referral center between January 2011 and June 2019 were reviewed and SSI cases meeting National Healthcare Safety Network criteria were identified. Using microbiologic and procedural data from each case, we analyzed the anatomic distribution of pathogens, their differential time to presentation, and correlation with methicillin-resistant Staphylococcus aureus screening results. Susceptibility of isolates cultured from each infection were compared with the spectrum of surgical antibiotic prophylaxis administered during the index procedure on a per-case basis. Susceptibility to alternate prophylactic agents was also modeled.
RESULTS: Among 6727 cases, 351 infections occurred within 90 days. An anatomic gradient in the microbiology of SSI was observed across the length of the back, transitioning from cutaneous (gram-positive) flora in the cervical spine to enteric (gram-negative/anaerobic) flora in the lumbosacral region (correlation coefficient 0.94, p < 0.001). The majority (57.5%) of infections were resistant to the prophylaxis administered during the procedure. Cephalosporin-resistant gram-negative infection was common at lumbosacral levels and undetected methicillin-resistance was common at cervical levels.
CONCLUSIONS: Individualized infection prevention strategies tailored to operative level are needed in spine surgery. Endogenous wound contamination with enteric flora may be a common mechanism of infection in lumbosacral fusion. Novel approaches to prophylaxis and prevention should be prioritized in this population.
LEVEL OF EVIDENCE: 3.

PMID: 32796459 [PubMed - as supplied by publisher]

Direct Quantification of Single Red Blood Cell Hemoglobin Concentration with Multiphoton Microscopy.

Anal Chem. 2020 09 15;92(18):12235-12241

Authors: Francis AT, Shears MJ, Murphy SC, Fu D

Abstract
Blood disorders, diseases, and infections often affect the shape, number, and content of red blood cells (RBCs) dramatically. To combat these pathologies, many therapies target RBCs and their contents directly. Mean corpuscular hemoglobin concentration (MCHC) is an important pathological metric in both identification and treatment. However, current methods for RBC analysis and MCHC quantification rely on bulk measurements. Single RBC measurements could provide necessary insight into the heterogeneity of RBC health and improve therapeutic efficacy. In this study, we present a novel multimodal multiphoton approach for quantifying hemoglobin concentration at single RBC resolution. We achieve this by collecting two images simultaneously that allows us to excite water with stimulated Raman scattering and hemoglobin with transient absorption. This multimodal imaging is enabled by a newly designed orthogonal modulation theme for dual-channel lock-in detection. By leveraging water as an internal standard, we quantify MCHC of healthy RBCs and RBCs infected with Plasmodium yoelii, a commonly studied rodent parasite model.

PMID: 32786430 [PubMed - indexed for MEDLINE]

Aggression subtypes relate to distinct resting state functional connectivity in children and adolescents with disruptive behavior.

Eur Child Adolesc Psychiatry. 2020 Aug 13;:

Authors: Werhahn JE, Mohl S, Willinger D, Smigielski L, Roth A, Hofstetter C, Stämpfli P, Naaijen J, Mulder LM, Glennon JC, Hoekstra PJ, Dietrich A, Kleine Deters R, Aggensteiner PM, Holz NE, Baumeister S, Banaschewski T, Saam MC, Schulze UME, Lythgoe DJ, Sethi A, Craig MC, Mastroianni M, Sagar-Ouriaghli I, Santosh PJ, Rosa M, Bargallo N, Castro-Fornieles J, Arango C, Penzol MJ, Zwiers MP, Franke B, Buitelaar JK, Walitza S, Brandeis D

Abstract
There is increasing evidence for altered brain resting state functional connectivity in adolescents with disruptive behavior. While a considerable body of behavioral research points to differences between reactive and proactive aggression, it remains unknown whether these two subtypes have dissociable effects on connectivity. Additionally, callous-unemotional traits are important specifiers in subtyping aggressive behavior along the affective dimension. Accordingly, we examined associations between two aggression subtypes along with callous-unemotional traits using a seed-to-voxel approach. Six functionally relevant seeds were selected to probe the salience and the default mode network, based on their presumed role in aggression. The resting state sequence was acquired from 207 children and adolescents of both sexes [mean age (standard deviation) = 13.30 (2.60); range = 8.02-18.35] as part of a Europe-based multi-center study. One hundred eighteen individuals exhibiting disruptive behavior (conduct disorder/oppositional defiant disorder) with varying comorbid attention-deficit/hyperactivity disorder (ADHD) symptoms were studied, together with 89 healthy controls. Proactive aggression was associated with increased left amygdala-precuneus coupling, while reactive aggression related to hyper-connectivities of the posterior cingulate cortex (PCC) to the parahippocampus, the left amygdala to the precuneus and to hypo-connectivity between the right anterior insula and the nucleus caudate. Callous-unemotional traits were linked to distinct hyper-connectivities to frontal, parietal, and cingulate areas. Additionally, compared to controls, cases demonstrated reduced connectivity of the PCC and left anterior insula to left frontal areas, the latter only when controlling for ADHD scores. Taken together, this study revealed aggression-subtype-specific patterns involving areas associated with emotion, empathy, morality, and cognitive control.

PMID: 32789793 [PubMed - as supplied by publisher]

Economic Impact of COVID-19 on a High-Volume Academic Neurosurgical Practice.

World Neurosurg. 2020 11;143:e561-e566

Authors: Sivakanthan S, Pan J, Kim L, Ellenbogen R, Saigal R

Abstract
BACKGROUND: Coronavirus disease-2019 (COVID-19) is a novel disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that rapidly spread around the globe. The dramatic increase in the number of cases and deaths have placed tremendous strain on health care systems worldwide. As health care workers and society adjust to focus treatment and prevention of COVID-19, other facets of the health care enterprise are affected, particularly surgical volume and revenue. The purpose of this study was to describe the financial impact of COVID-19 on an academic neurosurgery department.
METHODS: A retrospective review of weekly average daily work relative value units (wRVUs) were compared before and after COVID-19 in the fiscal year 2020. A comparative time period of the same months in the year prior was also included for review. We also review strategies for triaging neurosurgical disease as needing emergent, urgent, or routine operative treatment.
RESULTS: Daily average wRVU after COVID-19 dropped significantly with losses in all weeks examined. Of the 7 weeks in the current post-COVID period, the weekly daily average wRVU was 173 (range, 128-363). The mean decline was 51.4% compared with the pre-COVID era. Both inpatient and outpatient revenue was affected.
CONCLUSIONS: COVID-19 had a profound detrimental effect on surgical productivity and revenue generation.

PMID: 32791222 [PubMed - indexed for MEDLINE]

Optimizing the management of castration-resistant prostate cancer patients: A practical guide for clinicians.

Prostate. 2020 10;80(14):1159-1176

Authors: Shore ND, Drake CG, Lin DW, Ryan CJ, Stratton KL, Dunshee C, Karsh LI, Kaul S, Kernen K, Pieczonka C, Sieber P, Stewart C, Williams M, Concepcion RS

Abstract
BACKGROUND: Advanced prostate cancer (PC) patients, especially those with metastatic prostate cancer (mPC), often require complex management pathways. Despite the publication of clinical practice guidelines by leading urological and oncological organizations that provide a substantial and comprehensive framework, there are numerous clinical scenarios that are not always addressed, especially as new treatments become available, new imaging modalities are developed, and advances in genetic testing continue.
METHODS: A 14-member expert review panel comprised of urologists and medical oncologists were chosen to provide guidance on addressing specific topics and issues regarding metastatic castration-resistant prostate cancer (mCRPC) patients. Panel members were chosen based upon their experience and expertise in the management of PC patients. Four academic members (two urologists and two medical oncologists) of the panel served as group leaders; the remaining eight panel members were from Large Urology Group Practice Association (LUGPA) practices with proven experience in leading their advanced PC clinics. The panel members were assigned to four separate working groups, each assigned a specific mCRPC topic to review and discuss with the entire panel.
RESULTS: This article describes the practical recommendations of an expert panel on the management of mCRPC patients. The target reading audience for this publication is all providers (urologists, medical oncologists, radiation oncologists, or advanced practice providers) who evaluate and manage advanced PC patients, regardless of their practice setting.
CONCLUSION: The panel has provided recommendations for managing mCRPC with regard to specific issues: (a) biomarker monitoring and the role of genetic and molecular testing; (b) rationale, current strategies, and optimal sequencing of the various approved therapies, including hormonal therapy, cytotoxic chemotherapy, radiopharmaceuticals and immunotherapy; (c) adverse event management and monitoring; and (d) imaging advanced PC patients. These recommendations seek to complement national guidelines, not replace them, and a discussion of where the panel agreed or disagreed with national guidelines is included.

PMID: 32779781 [PubMed - indexed for MEDLINE]

Health-related quality of life and opioid use disorder pharmacotherapy: A secondary analysis of a clinical trial.

Drug Alcohol Depend. 2020 Aug 05;215:108221

Authors: Jalali A, Ryan DA, Jeng PJ, McCollister KE, Leff JA, Lee JD, Nunes EV, Novo P, Rotrosen J, Schackman BR, Murphy SM

Abstract
OBJECTIVE: To examine the health-related quality-of-life (HRQoL) of persons with opioid use disorder (OUD) seeking treatment in an inpatient detoxification or short-term residential setting; continuing treatment as outpatients.
METHODS: We conducted a secondary analysis of data from a clinical trial (N = 508) where participants were randomized to extended-release naltrexone or buprenorphine-naloxone for the prevention of opioid relapse. We used a generalized structural equation regression mixture model to identify associations of HRQoL (EQ-5D) trajectories, including latent characteristics, over the 24-week trial and 36-week follow-up period, among participants who reported HRQoL beyond baseline. This novel framework accounted for baseline and time-varying characteristics, while simultaneously identifying latent classes.
RESULTS: We identified two subpopulations: HRQoL "pharmacotherapy responsive" (82.3 %) and HRQoL "characteristic sensitive" (17.7 %). The pharmacotherapy responsive subpopulation was characterized by a shortterm HRQoL improvement and then stable HRQoL over time, and by a positive association between HRQoL and receiving pharmacotherapy in the past 30 days. The characteristic sensitive subpopulation was characterized by an initial improvement in HRQoL with a gradual decline over time, and no significant HRQoL response to pharmacotherapy. HRQoL changes over time in this subpopulation were more influenced by baseline demographic, socioeconomic, and psychosocial characteristics.
CONCLUSION: Our findings suggest that while HRQoL may be improved and sustained through targeted efforts to promote use of pharmacotherapy for many persons with OUD, an identifiable subpopulation may require additional services that address socioeconomic and psychosocial issues to achieve HRQoL benefits. Our analysis provides insight for improving individualized care for persons with opioid use disorder seeking treatment.

PMID: 32777692 [PubMed - as supplied by publisher]

A National Analysis of Temporal Changes in Prescribing of Testosterone Replacement Therapy Considering Methods of Delivery and Government Regulation.

World J Mens Health. 2020 Jul 30;:

Authors: Morton A, Williams M, Perera M, Ranasinghe S, Teloken PE, Williams M, Chung E, Roberts MJ

Abstract
PURPOSE: Testosterone replacement therapy (TRT) is commonly used for various causes of androgen deficiency and subsidized by the Pharmaceutical Benefits Scheme (PBS) in Australia when appropriate. In response to a sharp increase in the prescribing of subsidized TRT, the Australian government instituted new, stricter prescription criteria in April 2015. We aim to demonstrate longitudinal changes in the prescription patterns of subsidized TRT over time.
MATERIALS AND METHODS: The publicly available PBS database was accessed for TRT prescription data between 1992-2018. Population estimate data was collected from the Australian Bureau of Statistics for population-adjustment. Data analysis was performed according to class and specific formulation of TRT. Total and population-adjusted trends were considered, as was indexation to 2015 when restrictions were implemented.
RESULTS: Longitudinal trends in subsidized TRT prescription demonstrated a progressive overall increase since 2000, according to total prescriptions and population-adjusted estimates, with greater use of topical formulations (gel, patch, cream/spray) and injections. Since 2015, a 37% decline in total population-adjusted prescriptions was observed (1,399-883 per 100,000 persons). Since 2015, relatively increased use of injections (50%) and 1% gel (30%) comprise the majority of contemporary TRT. Annual financial burden due to TRT was $AU16,768 per 100,000 persons prior to 2000 (mean cost 1992-2000), increasing to $AU112,539 in 2018 (due to use of injections). The rate of change in costs slowed after the restrictions were introduced in 2015.
CONCLUSIONS: The restrictions in subsidized TRT eligibility enforced by the PBS have reduced overall TRT prescriptions and slowed the cumulative financial burden.

PMID: 32777869 [PubMed - as supplied by publisher]

Risk Factors for Suicidal Ideation Following Mild Traumatic Brain Injury: A TRACK-TBI Study.

J Head Trauma Rehabil. 2020 Jul 22;:

Authors: Campbell-Sills L, Jain S, Sun X, Fisher LB, Agtarap SD, Dikmen S, Nelson LD, Temkin N, McCrea M, Yuh E, Giacino JT, Manley GT, Stein MB, TRACK-TBI Investigators

Abstract
OBJECTIVE: To identify risk factors for suicidal ideation (SI) following mild traumatic brain injury (mTBI).
SETTING: Eleven US level 1 trauma centers.
PARTICIPANTS: A total of 1158 emergency department patients with mTBI (Glasgow Coma Scale score = 13-15) enrolled in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study.
DESIGN: Prospective observational study; weights-adjusted multivariable logistic regression models (n's = 727-883) estimated associations of baseline factors and post-TBI symptoms with SI at 2 weeks and 3, 6, and 12 months postinjury.
MAIN MEASURES: Patient Health Questionnaire, Rivermead Post-Concussion Symptoms Questionnaire.
RESULTS: Preinjury psychiatric history predicted SI at all follow-ups (adjusted odds ratios [AORs] = 2.26-6.33, P values <.05) and history of prior TBI predicted SI at 2 weeks (AOR = 2.36, 95% confidence interval [CI] = 1.16-4.81, P = .018), 3 months (AOR = 2.62, 95% CI = 1.33-5.16, P = .005), and 6 months postinjury (AOR = 2.54, 95% CI = 1.19-5.42, P = .016). Adjusting for these baseline factors, post-TBI symptoms were strongly associated with SI at concurrent (AORs = 1.91-2.88 per standard deviation unit increase in Rivermead Post-Concussion Symptoms Questionnaire score; P values <.0005) and subsequent follow-up visits (AORs = 1.68-2.53; P values <.005). Most of the associations between post-TBI symptoms and SI were statistically explained by co-occurring depression.
CONCLUSION: Screening for psychiatric and prior TBI history may help identify patients at risk for SI following mTBI. Awareness of the strong associations of post-TBI symptoms with SI may facilitate interventions to prevent suicide-related outcomes in patients with mTBI.

PMID: 32769835 [PubMed - as supplied by publisher]

The Stigma of Sexually Transmitted Infections.

Nurs Clin North Am. 2020 09;55(3):295-305

Authors: Lee ASD, Cody SL

Abstract
Evidence-based guidelines have improved diagnosis and treatment of sexually transmitted infections (STI). Social stigma remains a barrier to STI testing and is associated with underutilization of prevention services. Alternatives for STI testing (eg, in-home testing) are convenient. However, some individuals decline follow-up treatment in fear of unintentional disclosure of their diagnosis. This article reviews STI treatment guidelines and examines the impact of stigma and ethical issues on testing, adherence, partner notification, and transmission rates. An understanding of STI-associated ethical issues and controversies is an important step toward eliminating stigma and reducing STI prevalence and morbidity.

PMID: 32762851 [PubMed - indexed for MEDLINE]

Rhinovirus Infection Drives Complex Host Airway Molecular Responses in Children With Cystic Fibrosis.

Front Immunol. 2020;11:1327

Authors: Ling KM, Garratt LW, Gill EE, Lee AHY, Agudelo-Romero P, Sutanto EN, Iosifidis T, Rosenow T, Turvey SE, Lassmann T, Hancock REW, Kicic A, Stick SM

Abstract
Early-life viral infections are responsible for pulmonary exacerbations that can contribute to disease progression in young children with cystic fibrosis (CF). The most common respiratory viruses detected in the CF airway are human rhinoviruses (RV), and augmented airway inflammation in CF has been attributed to dysregulated airway epithelial responses although evidence has been conflicting. Here, we exposed airway epithelial cells from children with and without CF to RV in vitro. Using RNA-Seq, we profiled the transcriptomic differences of CF and non-CF airway epithelial cells at baseline and in response to RV. There were only modest differences between CF and non-CF cells at baseline. In response to RV, there were 1,442 and 896 differentially expressed genes in CF and non-CF airway epithelial cells, respectively. The core antiviral responses in CF and non-CF airway epithelial cells were mediated through interferon signaling although type 1 and 3 interferon signaling, when measured, were reduced in CF airway epithelial cells following viral challenge consistent with previous reports. The transcriptional responses in CF airway epithelial cells were more complex than in non-CF airway epithelial cells with diverse over-represented biological pathways, such as cytokine signaling and metabolic and biosynthetic pathways. Network analysis highlighted that the differentially expressed genes of CF airway epithelial cells' transcriptional responses were highly interconnected and formed a more complex network than observed in non-CF airway epithelial cells. We corroborate observations in fully differentiated air-liquid interface (ALI) cultures, identifying genes involved in IL-1 signaling and mucin glycosylation that are only dysregulated in the CF airway epithelial response to RV infection. These data provide novel insights into the CF airway epithelial cells' responses to RV infection and highlight potential pathways that could be targeted to improve antiviral and anti-inflammatory responses in CF.

PMID: 32765492 [PubMed - as supplied by publisher]

Bayesian priors in estimates of object location in virtual reality.

Psychon Bull Rev. 2020 Aug 06;:

Authors: Sampaio C, Jones M, Engelbertson A, Williams M

Abstract
We investigated the category bias in spatial memory, which reveals the influence of a region (i.e., a spatial category) on memory for specific locations within the region's bounds. The standard approach to investigating the category bias employs a static dot-in-circle task, in which observers indicate the location of a single dot from memory after a brief interval. The agreement in the literature is that these location estimates result from Bayesian principles; however, the priors in the dot-in-circle task are geometric prototypes (the central angular value of each quadrant and two-thirds of the radius from the center of the circle to its circumference). These geometric prototypes are not "true" priors in that they are not pre-existing statistical likelihoods of a target's location before other evidence is considered. In this paper, we tested the category bias with items for which informative priors exist (e.g., a vase, which is expected to be in the center of a table) and found that people favor them over geometric prototypes for estimating angular but not radial target positions. Our work contributes to the literature by showing that localizing common everyday objects in a circular space is not restricted to the use of cues intrinsic to the space. This is important because the majority of the empirical data on the category bias derives from locating targets that have little to no semantic information.

PMID: 32767045 [PubMed - as supplied by publisher]

Guidelines for the Management of Severe Traumatic Brain Injury: 2020 Update of the Decompressive Craniectomy Recommendations.

Neurosurgery. 2020 09 01;87(3):427-434

Authors: Hawryluk GWJ, Rubiano AM, Totten AM, O'Reilly C, Ullman JS, Bratton SL, Chesnut R, Harris OA, Kissoon N, Shutter L, Tasker RC, Vavilala MS, Wilberger J, Wright DW, Lumba-Brown A, Ghajar J

Abstract
When the fourth edition of the Brain Trauma Foundation's Guidelines for the Management of Severe Traumatic Brain Injury were finalized in late 2016, it was known that the results of the RESCUEicp (Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension) randomized controlled trial of decompressive craniectomy would be public after the guidelines were released. The guideline authors decided to proceed with publication but to update the decompressive craniectomy recommendations later in the spirit of "living guidelines," whereby topics are updated more frequently, and between new editions, when important new evidence is published. The update to the decompressive craniectomy chapter presented here integrates the findings of the RESCUEicp study as well as the recently published 12-mo outcome data from the DECRA (Decompressive Craniectomy in Patients With Severe Traumatic Brain Injury) trial. Incorporation of these publications into the body of evidence led to the generation of 3 new level-IIA recommendations; a fourth previously presented level-IIA recommendation remains valid and has been restated. To increase the utility of the recommendations, we added a new section entitled Incorporating the Evidence into Practice. This summary of expert opinion provides important context and addresses key issues for practitioners, which are intended to help the clinician utilize the available evidence and these recommendations. The full guideline can be found at: https://braintrauma.org/guidelines/guidelines-for-the-management-of-severe-tbi-4th-ed#/.

PMID: 32761068 [PubMed - indexed for MEDLINE]

Estimation of Fractional Extracellular Space at CT for Predicting Chemotherapy Response and Survival in Pancreatic Ductal Adenocarcinoma.

AJR Am J Roentgenol. 2020 09;215(3):610-616

Authors: Wang ZJ, Zhang TT, An C, Ko AH, Tempero M, Collisson E, Yeh BM

Abstract
OBJECTIVE. The purpose of this study was to investigate the association between primary pancreatic ductal adenocarcinoma fractional extracellular space (fECS) estimated from pretreatment CT and tumor response to chemotherapy and patient outcome. MATERIALS AND METHODS. A database search identified the records of patients with locally advanced or metastatic pancreatic ductal adenocarcinoma treated with systemic therapies who had undergone pretreatment CT that included both unenhanced and equilibrium phase images. An ROI was placed on the primary tumor and aorta, and the tumor fECS was calculated as follows: (tumor attenuation in the equilibrium phase - tumor attenuation in the unenhanced phase) / (aortic attenuation in the equilibrium phase - aortic attenuation in the unenhanced phase) × (1 - hematocrit). Response to therapy was assessed in subsequent CT examinations according to the Response Evaluation Criteria in Solid Tumors version 1.1. Relevant clinical variables, including carbohydrate antigen 19-9 level, chemotherapy regimen, and survival were recorded. Multivariate analyses were performed to determine the predictors of treatment response and patient survival. RESULTS. The median primary tumor fECS was 0.41 (range, 0.02-0.69). When dichotomized to high (> 0.41) versus low fECS (≤ 0.41) values, a larger proportion of patients with high tumor fECS values achieved disease control after chemotherapy than did those with low tumor fECS values: full cohort, 27 of 30 versus 19 of 30 (p = 0.030); cohort with locally advanced disease, 23 of 24 versus 10 of 15 (p = 0.024). The mean progression-free survival among patients with high primary tumor fECS values was significantly longer than that among those with low fECS values (191 versus 115 days, p = < 0.0001). Primary tumor fECS was an independent predictor of progression-free survival (p = 0.003) in multivariate analysis. CONCLUSION. High primary tumor fECS value estimated from staging CT was associated with chemotherapy response and progression-free survival of patients with advanced pancreatic ductal adenocarcinoma.

PMID: 32755156 [PubMed - indexed for MEDLINE]

Both Small and Large Infrarenal Aortic Size is Associated with an Increased Prevalence of Ischaemic Heart Disease.

Eur J Vasc Endovasc Surg. 2020 10;60(4):594-601

Authors: Jones GT, Drinkwater B, Blake-Barlow A, Hill GB, Williams MJA, Krysa J, van Rij AM, Coffey S

Abstract
OBJECTIVE: Past studies have suggested a potential "J shaped" relationship between infrarenal aortic diameter and both cardiovascular disease (CVD) prevalence and all cause mortality. However, screening programmes have focused primarily on large (aneurysmal) aortas. In addition, aortic diameter is rarely adjusted for body size, which is particularly important for women. This study aimed to investigate specifically the relationship between body size adjusted infrarenal aortic diameter and baseline prevalence of CVD.
METHODS: A retrospective analysis was performed on a total of 4882 elderly (>50 years) participants (mean age 69.4 ± 8.9 years) for whom duplex ultrasound to assess infrarenal abdominal aortic diameters had been performed. History of CVDs, including ischaemic heart disease (IHD), and associated risk factors were collected at the time of assessment. A derivation cohort of 1668 participants was used to select cut offs at the lower and upper 12.5% tails of the aortic size distributions (aortic size index of <0.84 and >1.2, respectively), which was then tested in a separate cohort.
RESULTS: A significantly elevated prevalence of CVD, and specifically IHD, was observed in participants with both small and large aortas. These associations remained significant following adjustment for age, sex, diabetes, hypertension, dyslipidaemia, obesity (body mass index), and smoking.
CONCLUSION: The largest and smallest infrarenal aortic sizes were both associated with prevalence of IHD. In addition to identifying those with aneurysmal disease, it is hypothesised that screening programmes examining infrarenal aortic size may also have the potential to improve global CVD risk prediction by identifying those with small aortas.

PMID: 32753305 [PubMed - indexed for MEDLINE]

The Stringent Stress Response Controls Proteases and Global Regulators under Optimal Growth Conditions in Pseudomonas aeruginosa.

mSystems. 2020 Aug 04;5(4):

Authors: Pletzer D, Blimkie TM, Wolfmeier H, Li Y, Baghela A, Lee AHY, Falsafi R, Hancock REW

Abstract
The bacterial stringent stress response, mediated by the signaling molecule guanosine tetraphosphate, ppGpp, has recently gained attention as being important during normal cellular growth and as a potential new therapeutic target, which warrants detailed mechanistic understanding. Here, we used intracellular protein tracking in Pseudomonas aeruginosa PAO1, which indicated that RelA was bound to the ribosome, while SpoT localized at the cell poles. Transcriptome sequencing (RNA-Seq) was used to investigate the transcriptome of a ppGpp-deficient strain under nonstressful, nutrient-rich broth conditions where the mutant grew at the same rate as the parent strain. In the exponential growth phase, the lack of ppGpp led to >1,600 transcriptional changes (fold change cutoff of ±1.5), providing further novel insights into the normal physiological role of ppGpp. The stringent response was linked to gene expression of various proteases and secretion systems, including aprA, PA0277, impA, and clpP2 The previously observed reduction in cytotoxicity toward red blood cells in a stringent response mutant appeared to be due to aprA Investigation of an aprA mutant in a murine skin infection model showed increased survival rates of mice infected with the aprA mutant, consistent with previous observations that stringent response mutants have reduced virulence. In addition, the overexpression of relA, but not induction of ppGpp with serine hydroxamate, dysregulated global transcriptional regulators as well as >30% of the regulatory networks controlled by AlgR, OxyR, LasR, and AmrZ. Together, these data expand our knowledge about ppGpp and its regulatory network and role in environmental adaptation. It also confirms its important role throughout the normal growth cycle of bacteria.IMPORTANCE Microorganisms need to adapt rapidly to survive harsh environmental changes. Here, we showed the broad influence of the highly studied bacterial stringent stress response under nonstressful conditions that indicate its general physiological importance and might reflect the readiness of bacteria to respond to and activate acute stress responses. Using RNA-Seq to investigate the transcriptional network of Pseudomonas aeruginosa cells revealed that >30% of all genes changed expression in a stringent response mutant under optimal growth conditions. This included genes regulated by global transcriptional regulators and novel downstream effectors. Our results help to understand the importance of this stress regulator in bacterial lifestyle under relatively unstressed conditions. As such, it draws attention to the consequences of targeting this ubiquitous bacterial signaling molecule.

PMID: 32753509 [PubMed]

Heart Failure With Reduced Ejection Fraction: A Review.

JAMA. 2020 Aug 04;324(5):488-504

Authors: Murphy SP, Ibrahim NE, Januzzi JL

Abstract
Importance: Worldwide, the burden of heart failure has increased to an estimated 23 million people, and approximately 50% of cases are HF with reduced ejection fraction (HFrEF).
Observations: Heart failure is a clinical syndrome characterized by dyspnea or exertional limitation due to impairment of ventricular filling or ejection of blood or both. HFrEF occurs when the left ventricular ejection fraction (LVEF) is 40% or less and is accompanied by progressive left ventricular dilatation and adverse cardiac remodeling. Assessment for heart failure begins with obtaining a medical history and physical examination. Also central to diagnosis are elevated natriuretic peptides above age- and context-specific thresholds and identification of left ventricular systolic dysfunction with LVEF of 40% or less as measured by echocardiography. Treatment strategies include the use of diuretics to relieve symptoms and application of an expanding armamentarium of disease-modifying drug and device therapies. Unless there are specific contraindications, patients with HFrEF should be treated with a β-blocker and one of an angiotensin receptor-neprilysin inhibitor, angiotensin-converting enzyme inhibitor, or angiotensin receptor blocker as foundational therapy, with addition of a mineralocorticoid receptor antagonist in patients with persistent symptoms. Ivabradine and hydralazine/isosorbide dinitrate also have a role in the care of certain patients with HFrEF. More recently, sodium-glucose cotransporter 2 (SGLT2) inhibitors have further improved disease outcomes, significantly reducing cardiovascular and all-cause mortality irrespective of diabetes status, and vericiguat, a soluble guanylate cyclase stimulator, reduces heart failure hospitalization in high-risk patients with HFrEF. Device therapies may be beneficial in specific subpopulations, such as cardiac resynchronization therapy in patients with interventricular dyssynchrony, transcatheter mitral valve repair in patients with severe secondary mitral regurgitation, and implantable cardiac defibrillators in patients with more severe left ventricular dysfunction particularly of ischemic etiology.
Conclusions and Relevance: HFrEF is a major public health concern with substantial morbidity and mortality. The management of HFrEF has seen significant scientific breakthrough in recent decades, and the ability to alter the natural history of the disease has never been better. Recent developments include SGLT2 inhibitors, vericiguat, and transcatheter mitral valve repair, all of which incrementally improve prognosis beyond foundational neurohormonal therapies. Disease morbidity and mortality remain high, with a 5-year survival rate of 25% after hospitalization for HFrEF.

PMID: 32749493 [PubMed - indexed for MEDLINE]

Early-Onset Familial Alzheimer's Disease Variant PSEN2 N141I Heterozygosity is Associated with Altered Microglia Phenotype.

J Alzheimers Dis. 2020 Jul 24;:

Authors: Fung S, Smith CL, Prater KE, Case A, Green K, Osnis L, Winston C, Kinoshita Y, Sopher B, Morrison RS, Garden GA, Jayadev S

Abstract
BACKGROUND: Early-onset familial Alzheimer disease (EOFAD) is caused by heterozygous variants in the presenilin 1 (PSEN1), presenilin 2 (PSEN2), and APP genes. Decades after their discovery, the mechanisms by which these genes cause Alzheimer's disease (AD) or promote AD progression are not fully understood. While it is established that presenilin (PS) enzymatic activity produces amyloid-β (Aβ), PSs also regulate numerous other cellular functions, some of which intersect with known pathogenic drivers of neurodegeneration. Accumulating evidence suggests that microglia, resident innate immune cells in the central nervous system, play a key role in AD neurodegeneration.
OBJECTIVE: Previous work has identified a regulatory role for PS2 in microglia. We hypothesized that PSEN2 variants lead to dysregulated microglia, which could further contribute to disease acceleration. To mimic the genotype of EOFAD patients, we created a transgenic mouse expressing PSEN2 N141I on a mouse background expressing one wildtype PS2 and two PS1 alleles.
RESULTS: Microglial expression of PSEN2 N141I resulted in impaired γ-secretase activity as well as exaggerated inflammatory cytokine release, NFκB activity, and Aβ internalization. In vivo, PS2 N141I mice showed enhanced IL-6 and TREM2 expression in brain as well as reduced branch number and length, an indication of "activated" morphology, in the absence of inflammatory stimuli. LPS intraperitoneal injection resulted in higher inflammatory gene expression in PS2 N141I mice brain relative to controls.
CONCLUSION: Our findings demonstrate that PSEN2 N141I heterozygosity is associated with disrupted innate immune homeostasis, suggesting EOFAD variants may promote disease progression through non-neuronal cells beyond canonical dysregulated Aβ production.

PMID: 32741831 [PubMed - as supplied by publisher]

Anaplastic Transformation in Myxopapillary Ependymoma: A Report of 2 Cases and Review of the Literature.

J Neuropathol Exp Neurol. 2020 Aug 02;:

Authors: Gitto L, Serinelli S, Galbraith K, Williams M, Mirchia K, Galgano MA, Krishnamurthy S, de la Roza G, Viapiano MS, Walker JM, Jour G, Serrano J, DeLorenzo M, Snuderl M, Richardson TE

Abstract
Myxopapillary ependymoma (MPE) is a relatively common neoplasm arising primarily in the filum terminale/lumbosacral region of the spinal cord. It is designated as a grade I tumor in the most recent WHO Classification of Tumours of the CNS, although aggressive clinical behavior can be observed, especially in cases arising in an extradural location. Anaplastic transformation in MPE is exceedingly rare with <20 examples reported in the English literature, and consensus on diagnostic features and definitive grading remain to be determined. Here, we present 2 cases of recurrent MPE with anaplastic features, both of which had histology consistent with conventional MPE as well as areas with significant atypia, frequent mitotic figures, elevated Ki-67 proliferation indices (>10%-50%), necrosis, and focal vascular proliferation. Targeted next-generation sequencing panels revealed no definitive pathogenic mutations or fusion proteins in either case. Copy number profiling, methylation profiling, and t-Distributed Stochastic Neighbor Embedding were performed to investigate the molecular characteristics of these tumors. To the best of our knowledge, these are the first reported cases of MPE with anaplastic features with methylation profiling data. In addition, we review the literature and discuss common histologic and molecular findings associated with anaplastic features in MPE.

PMID: 32743660 [PubMed - as supplied by publisher]