Comparison and Utility of Intravenous Iodinated Contrast in Chest, Abdomen, Pelvis Computerized Tomography for Trauma Patients With Blunt Mechanism of Injury Before and After the May 9, 2022 Global Contrast Shortage at a Level II Trauma Center

Background: Intravenous (IV) contrast improves the sensitivity and specificity of injury detection in computerized tomography (CT). Its use is recommended in the workup of trauma patients by the American College of Surgeons and American College of Radiology. On May 9, 2022, the Food and Drug Administration declared a shortage of iodinated contrast due to the COVID-19 pandemic. Although the shortage has ended, the temporary lack of IV contrast forced physicians to be prudent in ordering CT scans with IV contrast. We sought to determine if there was a change in the percentage of CT contrast studies performed during the contrast shortage and if this change affected patient outcomes.Methods: Retrospective chart review was performed on all adult tier 2 trauma patients at a 619-bed community-based level II trauma center who received CT chest, abdomen, and pelvis imaging as initial workup for blunt trauma from 5/9/2021-6/30/2021 (pre-shortage) and 5/9/2022-6/30/2022 (during shortage).Results: Patients were predominantly male with median age of 31-52 and of White or Hispanic ethnicity. Before the contrast shortage, all 110 trauma patients were scanned with contrast. During the shortage, 29 of 114 patients were scanned with contrast (P < 0.001). Injuries were identified in 59% of patients scanned with contrast (P < 0.001). There were no significant differences in blood transfusion needs, repeat CT, disposition, or mortality when comparing pre-shortage to during shortage or when comparing between non-contrast and contrast studies during the shortage.Discussion: There was a decrease in the percentage of CT contrast studies performed during the shortage. A higher percentage of injuries were identified in the patients scanned with contrast. However, there were no significant differences in patient outcomes. Certain trauma patients may be safely scanned without contrast.

Role of β3 subunit of the GABA type A receptor in triple negative breast cancer proliferation, migration, and cell cycle progression

Triple negative breast cancer (TNBC) is known for its heterogeneous nature and aggressive onset. The unresponsiveness to hormone therapies and immunotherapy and the toxicity of chemotherapeutics account for the limited treatment options for TNBC. Ion channels have emerged as possible therapeutic candidates for cancer therapy, but little is known about how ligand gated ion channels, specifically, GABA type A ligand-gated ion channel receptors (GABAAR), affect cancer pathogenesis. Our results show that the GABAA β3 subunit is expressed at higher levels in TNBC cell lines than non-tumorigenic cells, therefore contributing to the idea that limiting the GABAAR via knockdown of the GABAA β3 subunit is a potential strategy for decreasing the proliferation and migration of TNBC cells. We employed pharmacological and genetic approaches to investigate the role of the GABAA β3 subunit in TNBC proliferation, migration, and cell cycle progression. The results suggest that pharmacological antagonism or genetic knockdown of GABAA β3 subunit decreases TNBC proliferation and migration. In addition, GABAA β3 subunit knockdown causes cell cycle arrest in TNBC cell lines via decreased cyclin D1 and increased p21 expression. Our findings suggest that membrane bound GABAA receptors containing the β3 subunit can be further developed as a potential novel target for the treatment of TNBC.

Caverno-saphenous shunt for recurrent priapism

We present a case of medication-induced priapism that was refractory to conventional urologic methods and required treatment with a caverno-saphenous bypass. The patient had been misusing an injectable erectile dysfunction medication consisting of alprostadil, papaverine, and phentolamine (Trimix), resulting in multiple episodes of priapism. His initial episodes of priapism were successfully treated with the traditional urologic algorithm, including phenylephrine, aspiration, and distal shunting. However, due to his continued medication misuse, these became ineffective, requiring proximal shunt surgery. Priapism requiring an extra-anatomic bypass is exceedingly rare. Following our proximal shunt surgery, he maintained partial sexual function, and his bypass remained patent.

Protocol in a Day: An Educational Institutional Workshop for Protocol Development

PURPOSE/OBJECTIVE(S)

The Protocol-in-a-Day (PIAD) workshop was developed to support junior faculty and residents with clinical trial protocol design, with the main goal of providing initial feedback during development to reduce time for review and approval from institutional oversight committees. Our objectives are to mentor and educate participants and to evaluate the time to institutional approval by oversight committees.

MATERIALS/METHODS

PIAD provided concurrent educational feedback on 6 key elements of trial design. These included: (1) regulatory aspects; (2) institutional scientific review committee (SRC) and institutional review board (IRB); (3) clinical research and data coordination (including nursing); (4) statistics; (5) correlatives including imaging, biospecimens, and health services research/patient-reported outcomes; and (6) operations. The average number of days from submission to IRB approval or study activation for PIAD protocols was compared to other protocols submitted between January 2018 - January 2022 within the Division of Radiation Oncology. Participants were also given a 15-question survey to assess their perspective of the impact of the workshop.

RESULTS

A total of 25 protocols went through the PIAD workshop between January 2018-January 2022. Of the 25 protocols, 7 (28%) were excluded from this study due to not being submitted possibly after participants benefited from education on the limitations of their design. Eighteen protocols were included in our final analyses. These protocols included phase II (n = 11), phase 1 (n = 5), and phase III (n = 2). At the time of this report, all protocols (n = 18) have received IRB approval and have been activated. Protocol elements that could impact study activation included protocols requiring investigational new drug (IND) approval (n = 8) and multicenter studies (n = 1). Analyzing the time of submission to request for activation showed a decrease in time for protocols that went through PIAD vs those that did not [PIAD protocols, 254 days vs All other protocols, 262 days]. Likewise, those who attended PIAD had a lower average time from submission to IRB Approval [ PIAD protocols, 40 days vs All other protocols, 59 days]. All participants (100%) of the PIAD workshop responded that the educational program "improved the overall quality of the study design." The most commonly cited changes were protocol language (n = 17), statistics (n = 15), consent language (n = 8), and study design (n = 8). Aspects participants identified as the most educational included mentorship from regulatory, clinical research finance, and IRB review.

CONCLUSION

PIAD from participant surveys provided high educational value in the areas of improving trial quality, language and statistical design. When analyzing the average time, from 'submission to IRB initial approval' and 'submission to activation', PIAD protocols had a shorter time for approval, and thus suggests PIAD is effective in improving the overall design of protocols.

Predictors of Mortality in Trauma patients Receiving massive Transfusion Protocol

INTRODUCTION

Massive transfusion protocol (MTP) is often defined as the transfusion of ≥10 units of packed red blood cells (PRBCs) in 24 hours. The purpose of this study is to determine which factors most significantly contribute to mortality in patients receiving MTP after trauma.

METHODS

An initial database search followed by retrospective chart review was performed on patients treated at four trauma centers in Southern California. Data were collected on all patients who received MTP, defined as at least 10 units PRBCs within the first 24 hours of admission, between January 2015 and December 2019. Patients with isolated head injuries were excluded. Univariate and multivariate analyses were used to determine which factors most significantly influenced mortality.

RESULTS

Of 1278 patients who met our inclusion criteria in the database, 596 (46.6%) survived and 682 (53.4%) died. On univariate analysis initial vitals and labs, except for initial hemoglobin and initial platelet count were significant predictors of mortality. A multivariate regression model showed the strongest predictors of mortality were pRBC transfusions at 4 hours (OR 1.073, CI 1.020-1.128, P = .006) and 24 hours (OR 1.045, CI 1.003-1.088, P = .036), and FFP transfusion at 24 hours (OR 1.049, CI 1.016-1.084, P = .003).

CONCLUSION

Our data indicates that several factors may contribute to mortality in patients receiving MTP. In particular age, mechanism, initial GCS, and PRBC transfusions at 4 and 24 hours provided the strongest correlation. Further multicenter trials are indicated to provide further guidance in deciding when to discontinue massive transfusion.

Abstract 6148: Disulfide isomerases AGR2, ERp44, and PDIA1 maintain death receptor 5 in an auto-inhibited, monomeric form

Previous studies indicated that compounds termed Disulfide bond Disrupting Agents (DDAs) exhibit anti-cancer activity that is associated with downregulation of EGFR/HER1, HER2, and HER3, and activation of Death Receptors 4 and 5 (DR4/5). DDA-induced HER1-3 downregulation is preceded by disulfide-mediated oligomerization. In contrast, DDA-mediated DR4/5 oligomerization results in DR5 upregulation, and activation of DR4/5 pro-apoptotic signaling through Caspases 8 and 3. However, the precise mechanisms by which altered disulfide bonding stabilizes and activates DR5 are unknown. A recent report indicated that the extracellular domain of DR5 acts in an auto-inhibitory manner to prevent DR5 oligomerization and pro-apoptotic signaling in the absence of its ligand, TRAIL. A subsequent paper showed that the DR5 auto-inhibitory domain is a positive patch consisting of three basic residues. Importantly, the structure of the auto-inhibitory loop is formed by two disulfide bonds. We hypothesize that DDAs disrupt the disulfide bonds that make up the auto-inhibitory loop, resulting in DR5 oligomerization, and activation of Caspase 8/3-driven apoptosis in a TRAIL-independent manner. Due to their novel mechanisms of action, DDAs may overcome the pharmacological liabilities that have limited the efficacy of TRAIL analogs and DR5 agonist antibodies. Another unanswered question is how precisely DDAs alter DR5 and EGFR disulfide bonding. The direct targets of DDA action were revealed through affinity purification studies with biotinylated-DDA analogs. These studies identified the protein disulfide isomerases AGR2, ERp44, and PDIA1 as DDA target proteins, explaining how DDAs alter DR5 and EGFR disulfide bonding patterns. Consistent with this interpretation, knockdown of AGR2 or ERp44, or expression of catalytically null AGR2 or ERp44 mutants, mimicked DDAs in inducing disulfide-mediated DR5 oligomerization and Caspase 8 activation. Together, these results demonstrate a fundamentally novel, ligand-independent mechanism for activation of DR5 through DDA-mediated inhibition of the PDIs AGR2, ERp44, and PDIA1. Significantly, DDAs are the first identified active site inhibitors of AGR2 and ERp44.

Citation Format: Brian K. Law, Mary E. Law, Elham Yaaghubi, Amanda Ghilardi, Brad J. Davis, Renan Ferreira, Samantha Eggleston, Jade Nguyen, Grace Alexandrow, Jin Koh, Sixue Chen, Chi-Wu Chiang, Coy Heldermon, Peter Norgaard, Ronald K. Castallano, Zaafir M. Dulloo. Disulfide isomerases AGR2, ERp44, and PDIA1 maintain death receptor 5 in an auto-inhibited, monomeric form. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6148.

A combined exercise and cognitive training intervention induces fronto-cingulate cortical plasticity in first-episode psychosis patients

OBJECTIVE

Schizophrenia (SZ) is characterized by neurobiological and associated cognitive and functional deficits, including pronounced cortical thinning, that lead to acute and long-term functional impairment. Research with older adults supports the role of non-pharmacological interventions, such as exercise (E) and cognitive training (CT), for cognitive impairments. This literature influenced the development of combined CT&E treatments for individuals with SZ. However, the impact of longer combined treatment duration (6 months) on neuroanatomy has yet to be explored in patients in the early course of the illness. The impact of adding exercise to cognitive training for key brain regions associated with higher-order cognition was examined here using magnetic resonance imaging (MRI) in first-episode psychosis (FEP) patients.

METHODS

UCLA Aftercare Research Program patients with a recent first episode of schizophrenia were randomly assigned to either combined cognitive and exercise training (CT&E) (N = 20) or cognitive training alone (CT) (N = 17) intervention. Cortical thickness was measured longitudinally and analyzed for two regions of interest using FreeSurfer.

RESULTS

Compared to patients in the CT group, those in the CT&E group demonstrated an increase in cortical thickness within the left anterior cingulate cortex over the six-month treatment period (ACC: F_{(1, 35)} = 4.666, P < .04). Directional tendencies were similar in the left dorsolateral prefrontal cortex (DLPFC: F_(1,35) = 4.132, P < .05).

CONCLUSIONS

These findings suggest that exercise and cognitive training may synergistically increase fronto-cingulate cortical thickness to mitigate progressive neural atrophy in the early course of SZ. This combined intervention appears to be a valuable adjunct to standard pharmacologic treatment in FEP patients.

Resectability of bilobar liver tumours after simultaneous portal and hepatic vein embolization versus portal vein embolization alone: meta-analysis

BACKGROUND

Many patients with bi-lobar liver tumours are not eligible for liver resection due to an insufficient future liver remnant (FLR). To reduce the risk of posthepatectomy liver failure and the primary cause of death, regenerative procedures intent to increase the FLR before surgery. The aim of this systematic review is to provide an overview of the available literature and outcomes on the effectiveness of simultaneous portal and hepatic vein embolization (PVE/HVE) versus portal vein embolization (PVE) alone.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, and Embase up to September 2022. The primary outcome was resectability and the secondary outcome was the FLR volume increase.

RESULTS

Eight studies comparing PVE/HVE with PVE and six retrospective PVE/HVE case series were included. Pooled resectability within the comparative studies was 75 per cent in the PVE group (n = 252) versus 87 per cent in the PVE/HVE group (n = 166, OR 1.92 (95% c.i., 1.13-3.25)) favouring PVE/HVE (P = 0.015). After PVE, FLR hypertrophy between 12 per cent and 48 per cent (after a median of 21-30 days) was observed, whereas growth between 36 per cent and 67 per cent was reported after PVE/HVE (after a median of 17-31 days). In the comparative studies, 90-day primary cause of death was similar between groups (2.5 per cent after PVE versus 2.2 per cent after PVE/HVE), but a higher 90-day primary cause of death was reported in single-arm PVE/HVE cohort studies (6.9 per cent, 12 of 175 patients).

CONCLUSION

Based on moderate/weak evidence, PVE/HVE seems to increase resectability of bi-lobar liver tumours with a comparable safety profile. Additionally, PVE/HVE resulted in faster and more pronounced hypertrophy compared with PVE alone.

New Ameloblastoma Cell Lines Enable Preclinical Study of Targeted Therapies

Ameloblastoma (AB) is an odontogenic tumor that arises from ameloblast-lineage cells. Although relatively uncommon and rarely metastatic, AB tumors are locally invasive and destructive to the jawbone and surrounding structures. Standard-of-care surgical resection often leads to disfigurement, and many tumors will locally recur, necessitating increasingly challenging surgeries. Recent genomic studies of AB have uncovered oncogenic driver mutations, including in the mitogen-activated protein kinase (MAPK) and Hedgehog signaling pathways. Medical therapies targeting those drivers would be a highly desirable alternative or addition to surgery; however, a paucity of existing AB cell lines has stymied clinical translation. To bridge this gap, here we report the establishment of 6 new AB cell lines-generated by "conditional reprogramming"-and their genomic characterization that reveals driver mutations in FGFR2, KRAS, NRAS, BRAF, PIK3CA, and SMO. Furthermore, in proof-of-principle studies, we use the new cell lines to investigate AB oncogene dependency and drug sensitivity. Among our findings, AB cells with KRAS or NRAS mutation (MAPK pathway) are exquisitely sensitive to MEK inhibition, which propels ameloblast differentiation. AB cells with activating SMO-L412F mutation (Hedgehog pathway) are insensitive to vismodegib; however, a distinct small-molecule SMO inhibitor, BMS-833923, significantly reduces both downstream Hedgehog signaling and tumor cell viability. The novel cell line resource enables preclinical studies and promises to speed the translation of new molecularly targeted therapies for the management of ameloblastoma and related odontogenic neoplasms.

Dragon 1 Protocol Manuscript: Training, Accreditation, Implementation and Safety Evaluation of Portal and Hepatic Vein Embolization (PVE/HVE) to Accelerate Future Liver Remnant (FLR) Hypertrophy

STUDY PURPOSE

The DRAGON 1 trial aims to assess training, implementation, safety and feasibility of combined portal- and hepatic-vein embolization (PVE/HVE) to accelerate future liver remnant (FLR) hypertrophy in patients with borderline resectable colorectal cancer liver metastases.

METHODS

The DRAGON 1 trial is a worldwide multicenter prospective single arm trial. The primary endpoint is a composite of the safety of PVE/HVE, 90-day mortality, and one year accrual monitoring of each participating center. Secondary endpoints include: feasibility of resection, the used PVE and HVE techniques, FLR-hypertrophy, liver function (subset of centers), overall survival, and disease-free survival. All complications after the PVE/HVE procedure are documented. Liver volumes will be measured at week 1 and if applicable at week 3 and 6 after PVE/HVE and follow-up visits will be held at 1, 3, 6, and 12 months after the resection.

RESULTS

Not applicable.

CONCLUSION

DRAGON 1 is a prospective trial to assess the safety and feasibility of PVE/HVE. Participating study centers will be trained, and procedures standardized using Work Instructions (WI) to prepare for the DRAGON 2 randomized controlled trial. Outcomes should reveal the accrual potential of centers, safety profile of combined PVE/HVE and the effect of FLR-hypertrophy induction by PVE/HVE in patients with CRLM and a small FLR.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT04272931 (February 17, 2020). Toestingonline.nl: NL71535.068.19 (September 20, 2019).

Presentation, clinical course and complications in trauma patients with concomitant COVID-19 infection

BACKGROUND

This study investigated the impact of COVID-19 infection on hospitalized trauma patients.

METHODS

A retrospective review of hospitalized trauma patients at a level I trauma center was performed from March-December 2020. Data pertaining to patient demographics, presentation and hospital course was compared between COVID positive and negative trauma patients.

RESULTS

There were 4,912 patients and 179 (3.64%) were COVID-19 positive. Demographics and clinical presentation did not differ significantly between those with and without concomitant COVID-19. However, COVID positive trauma patients had higher rates of acute kidney injury (p = 0.016), sepsis (p = 0.016), unplanned intubation (p = 0.002) and unplanned return to the ICU (p = 0.01). The COVID positive cohort also had longer hospital stays (p < 0.01) with no significant difference in mortality.

CONCLUSIONS

In the setting of an ongoing pandemic, awareness of the complications COVID positive trauma patients are predisposed to is important for providers.

Surveillance de la bronchiolite à Mayotte : dynamique des épidémies en temps de Covid-19

Introduction

La bronchiolite est une affection virale fréquente chez les enfants de moins de deux ans, atteignant les petites voies aériennes avec une inflammation aiguë des bronchioles, pouvant évoluer vers des difficultés respiratoires importantes. Le virus respiratoire syncitial (VRS) est responsable de plus de 70 % des infections. Le virus se transmet par la salive, les éternuements, la toux et les mains

A Mayotte, la recrudescence saisonnière des cas de bronchiolite débute habituellement en janvier avec le plus souvent un pic épidémique en février et une épidémie qui se termine à la fin de l'été austral. Depuis la survenue de l'épidémie de Covid-19 dont les premiers cas ont été détectés à Mayotte en mars 2020, la saisonnalité des pathologies respiratoires a été fortement modifiée.

Matériels et méthodes

La surveillance épidémiologique de la bronchiolite à Mayotte repose sur deux sources de données. Le réseau de médecins sentinelles, instauré en 2009, rapporte la proportion de consultations pour bronchiolite parmi l'ensemble des consultations en ville et dans les centres de soins rattachés à l'hôpital. Le dispositif de surveillance des passages dans le service d'urgence de l'hôpital de Mayotte, mis en place depuis 2010, suit la proportion de passages pour bronchiolite parmi l'ensemble des passages. Toute l'année, les médecins hospitaliers assurent des prélèvements nasopharyngés et le laboratoire réalise un panel respiratoire permettant de détecter la présence des virus influenza, VRS, rhinovirus et entovirus et metapneumovirus

Résultats

En 2020 l'épidémie de bronchiolite est survenue selon la saisonnalité habituelle entre janvier et mars, avant la première vague de Covid de mai à juin 2020. La seconde vague de Covid-19 est survenue entre janvier et mars 2021 suivie de l'épidémie de bronchiolite qui est survenue avec trois mois de retard et une durée plus longue qu'habituellement de mai à septembre. La période inter-épidémique a été marquée par une circulation plus élevée du VRS chez les moins de deux ans par rapport aux niveaux de base habituellement observés. En 2021-2022 l'épidémie de bronchiolite a débuté dès le mois de décembre de manière précoce et s'est déroulée de manière concomitante avec la troisième vague épidémique de Covid-19 (fin décembre-janvier 2022). Fin février 2022, l'épidémie de bronchiolite 2022 est encore en cours.

Conclusion

Les mesures de prévention de la bronchiolite sont similaires à celles du Covid-19. Le retard de survenue de l'épidémie de 2021 laisse supposer une bonne adhésion de la population aux mesures de prévention lors des premières vagues de Covid-19 sur l'île. En revanche l'étendue de l'épidémie de bronchiolite de 2021 et la survenue de l'épidémie 2022 simultanément à la troisième vague de Covid-19 laissent supposer une lassitude de la population et une moindre application des mesures de protection nécessitant une adaptation de la stratégie de communication.

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Modulation of Subcellular Redox Homeostasis with Trialkylphosphines

Redox homeostasis is essential for cell function and its disruption is associated with multiple pathologies. Redox balance is largely regulated by the relative concentrations of reduced (GSH) and oxidized (GSSG) glutathione. In eukaryotic cells, this ratio is different in each cell compartment. There is a lack of chemical probes able to modulate GSH/GSSG in order to study the impact of redox stress in an organelle specific manner. Here, we highlight the importance of trialkylphosphines to induce reductive stress and how it can be targeted to a specific organelle. Our probe is selectively activated by endogenous nitroreductases, and releases tributylphosphine to trigger redox stress in mitochondria. Mechanistic studies revealed that the induced stress activates a cellular response orchestrated by transcription factor ATF4, which upregulates genes involved in glutathione catabolism.

Vestibular testing in children - The suppression head impulse (SHIMP) test

INTRODUCTION

The incidence of vestibular disorders and vertigo during childhood is increasing and pediatric clinicians have become more sensitive to children's balance disorders; thus, there is a need for appropriate detection test procedures for peripheral vestibular hypofunction. In order to ensure a reliable diagnosis and minimize misdiagnosis, a standardized clinical procedure via careful history and clinical examination is recommended. However, children, especially, are often unable to verbalize "vertigo" in a concrete manner, which often necessitates a consultation with a pediatrician holding nonspecific symptoms. The so-called suppression of the head impulse test (SHIMPs) represents a modification of the video head impulse test (HIMP) and is used for a more sensitive assessment of residual vestibular functions. In adults, SHIMPs are already an established diagnostic method. Nevertheless, to date, nothing is known about the applicability and standard values in childhood.

MATERIAL AND METHODS

In this monocentric, prospective study, we investigated whether SHIMPs enable a sensitive functional analysis of the vestibular system in healthy children of different ages. For this purpose, SHIMPs were performed in 40 children aged 3-18 years.

RESULTS

In this study, we demonstrated that SHIMPs can be easily performed in children (3-18 years). It is vital that the test be appropriately explained for children to ensure sufficient test tolerance and compliance.

CONCLUSION

SHIMPs are a helpful supplement to clinically established vestibular tests such as the HIMP in pediatric vestibular balance disorder diagnostics and can be integrated into the clinical routine, especially in children who have minimal verbal abilities or understanding of the instructions for HIMP. Similar to the HIMP, SHIMPs are characterized by a short test duration and a high tolerance.

Identifying microplastic litter with Laser Induced Breakdown Spectroscopy: A first approach

The broad diversity of microplastic litter requires a selection of analytical techniques to reliably determine the particle's chemical composition. This study demonstrates that Laser Induced Breakdown Spectroscopy (LIBS) can identify microplastic particles based on their spectral fingerprints. By studying the spectral features of polymer reference spectra, microplastic litter can be distinguished from non-plastic materials. The results show that LIBS can be used as a fast in-situ technique for pre-characterization of the microparticle's material and is a possible tool for environmental studies on microplastics.

Antidiuretic hormone inhibits osteogenic differentiation of dental follicle stem cells via V1a receptors and the PLC-IP3 pathway

OBJECTIVE

The aim of this study was to elucidate the molecular mechanism by which antidiuretic hormone (ADH) inhibited osteogenesis in dental follicle stem cells.

DESIGN

Rat dental follicle stem cells were cultured in osteogenic differentiation medium supplemented with ADH. Alkaline phosphatase enzyme activity, Alizarin Red S staining, MTT assay and RT-qPCR was used to examine ADH's impact on cell mineralization, viability, and osteogenic gene expression. Real-time calcium imaging analysis was performed to identify the ADH receptor and its mechanism of action.

RESULTS

ADH supplementation to the osteogenic differentiation medium inhibited cell mineralization without compromising cell viability and downregulated the expression of key osteogenic genes: DCN (Decorin), RUNX2 (Runt-related transcription factor 2) and BSP (Bone sialoprotein). Real-time calcium imaging analysis revealed that ADH (1-1000 nM) increased intracellular calcium in a concentration-dependent manner. Pretreatment of cells with V2255, a V1a receptor blocker, inhibited the calcium signals, but not with the V1b (Nelivaptan) or V2 (Tolvaptan). V2255 also reversed the inhibitory effect of ADH on osteogenesis. Furthermore, U73122, a Phospholipase C (PLC) inhibitor, 2-APB, an Inositol Triphosphate (IP₃) receptor blocker, and depletion of endoplasmic reticulum calcium stores abolished the calcium signals by ADH.

CONCLUSIONS

Our results demonstrated that ADH activates V1a receptors and the PLC-IP₃ pathway to stimulate intracellular calcium signals, which inhibits cell mineralization and osteogenic gene expression. These findings uncovered a novel function for ADH as a negative regulator of osteogenesis in dental follicle stem cells. The role of ADH in the pathogenesis of bone diseases remains to be determined.

Early versus late tube feeding initiation after PEG tube placement: Does time to feeding matter?

BACKGROUND

Variation exists in the timing of tube feed initiation after percutaneous endoscopic gastrostomy (PEG) tube placement. The aim of our study was to review outcomes of early tube feed (ETF) versus late tube feed (LTF) initiation after PEG tube placement.

METHODS

We performed a retrospective review of all trauma patients who underwent PEG tube placement from 1/2014 to 12/2018. ETF was defined as initiation < 24 h and LTF > 24 h after placement. The primary outcome measure was feeding intolerance and secondary outcomes included post-operative complications. All statistical analyses were performed using standard statistical methods (e.g. Pearson's Chi-squared, Fisher's exact and Mann Whitney-U tests).

RESULTS

There were 295 patients (164 ETF and 131 LTF) that received a PEG tube at our level 1 trauma center. There was no difference with feeding intolerance at 12 h (5% vs. 4%; p = 0.88), 24 h (1% vs. 2%; p = 1.00), and 48 h (4% vs. 4%; p = 1.00). There was no difference when comparing intolerance symptoms such as nausea and vomiting (1% vs. 2%; p = 0.79), abdominal tenderness (2% vs. 3%; p = 0.76), high gastric residuals (2% vs. 2%; p = 1.00) and aspiration (0% vs. 2%; p = 0.39). There was no difference when comparing post-operative complications (4% vs. 8%; p = 0.21).

CONCLUSIONS

Early tube feeding after PEG placement is safe and equivalent to late tube feeding in the adult trauma population. Future prospective studies are warranted to establish the optimal timing for initiation of tube feeds after PEG tube placement.

Disruption of mitochondrial redox homeostasis by enzymatic activation of a trialkylphosphine probe

Redox homeostasis is essential for cell function and its disruption is associated with multiple pathologies. Redox balance is largely regulated by the relative concentrations of reduced and oxidized glutathione. In eukaryotic cells, this ratio is different in each cell compartment, and disruption of the mitochondrial redox balance has been specifically linked to metabolic diseases. Here, we report a probe that is selectively activated by endogenous nitroreductases, and releases tributylphosphine to trigger redox stress in mitochondria. Mechanistic studies revealed that, counterintuitively, release of a reducing agent in mitochondria rapidly induced oxidative stress through accumulation of superoxide. This response is mediated by glutathione, suggesting a link between reductive and oxidative stress. Furthermore, mitochondrial redox stress activates a cellular response orchestrated by transcription factor ATF4, which upregulates genes involved in glutathione catabolism.

How oscillating aerodynamic forces explain the timbre of the hummingbird's hum and other animals in flapping flight

How hummingbirds hum is not fully understood, but its biophysical origin is encoded in the acoustic nearfield. Hence, we studied six freely hovering Anna’s hummingbirds, performing acoustic nearfield holography using a 2176 microphone array in vivo, while also directly measuring the 3D aerodynamic forces using a new aerodynamic force platform. We corroborate the acoustic measurements by developing an idealized acoustic model that integrates the aerodynamic forces with wing kinematics, which shows how the timbre of the hummingbird’s hum arises from the oscillating lift and drag forces on each wing. Comparing birds and insects, we find that the characteristic humming timbre and radiated power of their flapping wings originates from the higher harmonics in the aerodynamic forces that support their bodyweight. Our model analysis across insects and birds shows that allometric deviation makes larger birds quieter and elongated flies louder, while also clarifying complex bioacoustic behavior.

Anyone walking outdoors has heard the whooshing sound of birdwings flapping overhead, the buzzing sound of bees flying by, or the whining of mosquitos seeking blood. All animals with flapping wings make these sounds, but the hummingbird makes perhaps the most delightful sound of all: their namesake hum. Yet, how hummingbirds hum is poorly understood.

Bird wings generate large vortices of air to boost their lift and hover in the air that can generate tones. Further, the airflow over bird wings can be highly turbulent, meaning it can generate loud sounds, like the jets of air coming out of the engines of aircraft. Given all the sound-generating mechanisms at hand, it is difficult to determine why some wings buzz whereas others whoosh or hum.

Hightower, Wijnings et al. wanted to understand the physical mechanism that causes animal wings to whine, buzz, hum or whoosh in flight. They hypothesized that the aerodynamic forces generated by animal wings are the main source of their characteristic wing sounds. Hummingbird wings have the most features in common with different animals’ wings, while also featuring acoustically complex feathers. This makes them ideal models for deciphering how birds, bats and even insects make wing sounds.

To learn more about wing sounds, Hightower, Wijnings et al. studied how a species of hummingbird called Anna’s hummingbird hums while drinking nectar from a flower. A three-dimensional ‘acoustic hologram’ was generated using 2,176 microphones to measure the humming sound from all directions. In a follow-up experiment, the aerodynamic forces the hummingbird wings generate to hover were also measured. Their wingbeat was filmed simultaneously in slow-motion in both experiments. Hightower, Wijnings et al. then used a mathematical model that governs the wing’s aeroacoustics to confirm that the aerodynamic forces generated by the hummingbirds’ wings cause the humming sound heard when they hover in front of a flower. The model shows that the oscillating aerodynamic forces generate harmonics, which give the wings’ hum the acoustic quality of a musical instrument.

Using this model Hightower, Wijnings et al. found that the differences in the aerodynamic forces generated by bird and insect wings cause the characteristic timbres of their whines, buzzes, hums, or whooshes. They also determined how these sounds scale with body mass and flapping frequency across 170 insect species and 80 bird species. This showed that mosquitos are unusually loud for their body size due to the unusual unsteadiness of the aerodynamic forces they generate in flight.

These results explain why flying animals’ wings sound the way they do – for example, why larger birds are quieter and mosquitos louder. Better understanding of how the complex forces generated by animal wings create sound can advance the study of how animals change their wingbeat to communicate. Further, the model that explains how complex aerodynamic forces cause sound can help make the sounds of aerial robots, drones, and fans not only more silent, but perhaps more pleasing, like the hum of a hummingbird.

Reconnaissance of tumor immune microenvironment spatial heterogeneity in metastatic renal cell carcinoma and correlation with immunotherapy response

A clearer understanding of the tumor immune microenvironment (TIME) in metastatic clear cell renal cell carcinoma (ccRCC) may help to inform precision treatment strategies. We sought to identify clinically meaningful TIME signatures in ccRCC. We studied tumors from 39 patients with metastatic ccRCC using quantitative multiplexed immunofluorescence and relevant immune marker panels. Cell densities were analyzed in three regions of interest (ROIs): tumor core, tumor-stroma interface and stroma. Patients were stratified into low- and high-marker density groups using median values as thresholds. Log-rank and Cox regression analyses while controlling for clinical variables were used to compare survival outcomes to patterns of immune cell distributions. There were significant associations with increased macrophage (CD68⁺ CD163⁺ CD206⁺ ) density and poor outcomes across multiple ROIs in primary and metastatic tumors. In primary tumors, T-bet⁺ T helper type 1 (Th1) cell density was highest at the tumor-stromal interface (P = 0·0021), and increased co-expression of CD3 and T-bet was associated with improved overall survival (P = 0·015) and survival after immunotherapy (P = 0·014). In metastatic tumor samples, decreased forkhead box protein 3 (FoxP3)⁺ T regulatory cell density correlated with improved survival after immunotherapy (P = 0·016). Increased macrophage markers and decreased Th1 T cell markers within the TIME correlated with poor overall survival and treatment outcomes. Immune markers such as FoxP3 showed consistent levels across the TIME, whereas others, such as T-bet, demonstrated significant variance across the distinct ROIs. These findings suggest that TIME profiling outside the tumor core may identify clinically relevant associations for patients with metastatic ccRCC.

Hirschsprung’s Disease: Two Cases of Total Intestinal Aganglionosis

Introduction/Objective

Hirschsprung’s disease is a disorder associated with an absence of ganglion cells in a segment of the bowel. Total colonic and small bowel aganglionosis occurs in less than 1% of all Hirschsprung’s disease patients. Even rarer is the finding of Haddad syndrome, the coexistence of congenital central hypoventilation syndrome and Hirschsprung’s disease. Congenital central hypoventilation syndrome has approximately 1,000 reported cases, with colonic aganglionosis being associated with 15-20% of those cases. The prevalence of Hirschsprung’s disease with congenital renal anomalies may be another underreported finding.

Methods

Here, we report two rare cases of Hirschsprung’s disease with significant extension in the small bowel. One case involves a 38-week gestational age male infant admitted for apnea and another case involves 39-week gestational age female infant admitted for vomiting.

Results

Both infants had rectal suction biopsies confirming the absence of ganglion cells. The male infant had mapping biopsies which histologically showed hypertrophic nerve fibers and an absence of ganglion cells in the colon extending up to 70 cm proximal to the ileocecal valve. Calretinin immunostaining confirmed aganglionsis. Genetic testing showed a PHOX2B gene mutation carrying 32 polyalanine repeat mutations, confirming a diagnosis of congenital central hypoventilation syndrome coexisting with Hirschsprung’s disease. The female infant had intraoperative frozen sections that identified ganglion cells throughout the colon. On permanent sections, there was an absence of ganglion cells in the upper rectum extending up to 65 cm proximal to the ileocecal valve. She also was noted to have agenesis of the left kidney and a urachal remnant. Genetic testing was negative for RET mutations.

Conclusion

Overall, these cases provide further information on a rare variant of Hirschsprung’s disease that includes significant portions of the small bowel. Additionally, this study adds to the documented reports of Haddad syndrome and the connections between renal anomalies with Hirschsprung’s disease. Last, this series alludes to the difficulties of frozen section diagnosis of this disease.

0017 Transmembrane TNF- Soluble TNF Receptor Reverse Signal to Induce a Wake-Like State in Vitro

Introduction

Tumor necrosis factor (TNF) has sleep regulatory roles. Neuronal action potentials enhance TNF expression. Neuron/glia co-cultures exhibit more intense local sleep-like states after TNF administration in vitro. Both TNF and TNF receptors (Rs) are produced as transmembrane (tm) proteins that can subsequently be cleaved to produce soluble (s) forms. With immunocytes, sTNFR can bind tmTNF and induce reverse signaling within the cell expressing the tmTNF. This is opposite of conventional signaling induced by soluble ligands (e.g. sTNF) binding to transmembrane receptors. Having previously shown sleep inhibition after sTNFR administration in vivo, we hypothesized that tmTNF-sTNFR binding would induce wake-like states in vitro through reverse signaling.

Methods

Somatosensory cortical neurons/glia, from wildtype (WT) mice and mice lacking either TNF (TNF-KO) or both TNFRs (TNFR-KO), were co-cultured on multi-electrode arrays. Daily one-hour recordings were taken consecutively on incubation days 4 - 13 for development analyses. On day 14, a one-hour baseline was recorded prior to treatment with sTNFR (0.0 ng/μL-120 ng/μL). Immediately after treatment, recordings resumed for one hour. Synchronization of electrical activity (SYN), action potentials, slow wave power (SWP; 0.25–3.75 Hz), and burstiness index (measures used to define sleep in vivo) were used to characterize the ontological emergence of these electrophysiological properties and sTNFR-induced changes in vitro.

Results

Development rates were reduced in TNF-KO cells and increased in TNFR-KO cells relative to each other and to WT mice. Additionally, after sTNFR treatments, cells from TNFR-KO mice, which still express TNF, exhibited dose-dependent decreased SYN and SWP, indicative of a wake-like state. In contrast, cells from TNF-KO mice lacked a response to sTNFR treatment.

Conclusion

To our knowledge, this is the first demonstration of reverse TNF signaling with respect to sleep/wake states. As such, it provides a new way of viewing state regulation and associated potential clinical applications.

Support

This work was supported by grant NS096250 awarded to JK by NIH/NINDS.

Genetically Encoded Activators of Small Molecules for Imaging and Drug Delivery

Chemical biologists have developed many tools based on genetically encoded macromolecules and small, synthetic compounds. The two different approaches are extremely useful, but they have inherent limitations. In this Minireview, we highlight examples of strategies that combine both concepts to tackle challenging problems in chemical biology. We discuss applications in imaging, with a focus on super-resolved techniques, and in probe and drug delivery. We propose future directions in this field, hoping to inspire chemical biologists to develop new combinations of synthetic and genetically encoded probes.