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1.
Anal Chem ; 96(21): 8406-8415, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38728057

ABSTRACT

In this study, we present a simple, highly sensitive, and selective colorimetric method for detecting sulfur mustard (SM) and its simulants. This method relies on a nucleophilic substitution reaction between derivatives of 4-(p-nitrobenzyl)pyridine (NBP) and SM and subsequent treatment with an external base, resulting in a visible response. This reaction exhibits an impressively low detection threshold by the naked eye, as low as 10 ppm at room temperature. In contrast to the conventional use of NBP for detecting other alkylating agents, such as nitrogen mustard, our approach eliminates the need for prolonged heating or intricate extraction processes. Both computational and experimental investigations underscore the significance of water within our detection medium as it stabilizes crucial episulfonium cation intermediates. Furthermore, we demonstrate the practical applicability of this sensor by incorporating it onto cellulose and silica surfaces, which may provide guidance for the design and development of solid-state SM detectors.

2.
J Vet Intern Med ; 38(2): 1092-1100, 2024.
Article in English | MEDLINE | ID: mdl-38240116

ABSTRACT

BACKGROUND: Evidence-based recommendations for antiepileptic drug selection in cats beyond phenobarbital are limited, and additional studies are needed for cats where seizures remain inadequately controlled by administration of phenobarbital alone or for cats that cannot safely receive phenobarbital. OBJECTIVE: To compare seizure frequency in cats before and after oral administration of zonisamide and describe adverse clinical or clinicopathologic effects in this cohort. ANIMALS: Fifty-seven cats with a history of seizures. METHODS: Multicenter, retrospective study. Median number of seizures per month and number of seizure days per month were compared before and after administration of zonisamide in all cats, a subgroup of cats with idiopathic epilepsy (IE), and a subgroup of cats receiving zonisamide as sole therapy. Clinical and clinicopathologic adverse effect data were also reported. RESULTS: A median decrease of 1 (P = .001, 95% confidence interval (CI) [-1.0, -0.5]) seizure per month, and 1 (P = .003, 95% CI [-1.5, -0.2]) seizure days per month was found across all cats after oral administration of zonisamide. The subgroup with IE showed median decreases of 1 (P = .03, 95% CI [-2.0, -0.5]) and 2 (P = .01, 95% CI [-2.5, -1.0]), respectively. The most common clinical adverse effects were sedation (17%), ataxia (11%), hyporexia (17%), and emesis (5%). One cat developed mild nonregenerative anemia, 2 cats developed mild metabolic acidosis, and 6 cats showed mild increases in ALT and ALP. CONCLUSION: Zonisamide was well tolerated and efficacious in controlling seizure activity in most cats.


Subject(s)
Cat Diseases , Epilepsies, Partial , Epilepsy , Animals , Cats , Anticonvulsants/therapeutic use , Cat Diseases/drug therapy , Epilepsies, Partial/veterinary , Epilepsy/drug therapy , Epilepsy/veterinary , Phenobarbital/therapeutic use , Retrospective Studies , Seizures/drug therapy , Seizures/veterinary , Zonisamide/therapeutic use
3.
J Intensive Care Med ; 39(7): 628-635, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38190576

ABSTRACT

Background: The likelihood of a patient being preload responsive-a state where the cardiac output or stroke volume (SV) increases significantly in response to preload-depends on both cardiac filling and function. This relationship is described by the canonical Frank-Starling curve. Research Question: We hypothesize that a novel method for phenotyping hypoperfused patients (ie, the "Doppler Starling curve") using synchronously measured jugular venous Doppler as a marker of central venous pressure (CVP) and corrected flow time of the carotid artery (ccFT) as a surrogate for SV will refine the pretest probability of preload responsiveness/unresponsiveness. Study Design and Methods: We retrospectively analyzed a prospectively collected convenience sample of hypoperfused adult emergency department (ED) patients. Doppler measurements were obtained before and during a preload challenge using a wireless, wearable Doppler ultrasound system. Based on internal jugular and carotid artery Doppler surrogates of CVP and SV, respectively, we placed hemodynamic assessments into quadrants (Qx) prior to preload augmentation: low CVP with normal SV (Q1), high CVP and normal SV (Q2), low CVP and low SV (Q3) and high CVP and low SV (Q4). The proportion of preload responsive and unresponsive assessments in each quadrant was calculated based on the maximal change in ccFT (ccFTΔ) during either a passive leg raise or rapid fluid challenge. Results: We analyzed 41 patients (68 hemodynamic assessments) between February and April 2021. The prevalence of each phenotype was: 15 (22%) in Q1, 8 (12%) in Q2, 39 (57%) in Q3, and 6 (9%) in Q4. Preload unresponsiveness rates were: Q1, 20%; Q2, 50%; Q3, 33%, and Q4, 67%. Interpretation: Even fluid naïve ED patients with sonographic estimates of low CVP have high rates of fluid unresponsiveness, making dynamic testing valuable to prevent ineffective IVF administration.


Subject(s)
Carotid Arteries , Fluid Therapy , Jugular Veins , Ultrasonography, Doppler , Humans , Pilot Projects , Male , Female , Fluid Therapy/methods , Middle Aged , Jugular Veins/diagnostic imaging , Prospective Studies , Carotid Arteries/diagnostic imaging , Aged , Resuscitation/methods , Central Venous Pressure/physiology , Retrospective Studies , Adult , Stroke Volume/physiology , Cardiac Output/physiology , Emergency Service, Hospital , Hemodynamics
4.
Ultrasound J ; 15(1): 32, 2023 Jul 28.
Article in English | MEDLINE | ID: mdl-37505318

ABSTRACT

Providing intravenous (IV) fluids to a patient with signs or symptoms of hypoperfusion is common. However, evaluating the IV fluid 'dose-response' curve of the heart is elusive. Two patients were studied in the emergency department with a wireless, wearable Doppler ultrasound system. Change in the common carotid arterial and internal jugular Doppler spectrograms were simultaneously obtained as surrogates of left ventricular stroke volume (SV) and central venous pressure (CVP), respectively. Both patients initially had low CVP jugular venous Doppler spectrograms. With preload augmentation, only one patient had arterial Doppler measures indicative of significant SV augmentation (i.e., 'fluid responsive'). The other patient manifested diminishing arterial response, suggesting depressed SV (i.e., 'fluid unresponsive') with evidence of ventricular asynchrony. In this short communication, we describe how a wireless, wearable Doppler ultrasound simultaneously tracks surrogates of cardiac preload and output within a 'Doppler Starling curve' framework; implications for IV fluid dosing are discussed.

5.
J Intensive Care ; 11(1): 7, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36793079

ABSTRACT

BACKGROUND: Little data exist on the time spent by emergency department (ED) personnel providing intravenous (IV) fluid to 'responsive' versus 'unresponsive' patients. METHODS: A prospective, convenience sample of adult ED patients was studied; patients were enrolled if preload expansion was indicated for any reason. Using a novel, wireless, wearable ultrasound, carotid artery Doppler was obtained before and throughout a preload challenge (PC) prior to each bag of ordered IV fluid. The treating clinician was blinded to the results of the ultrasound. IV fluid was deemed 'effective' or 'ineffective' based on the greatest change in carotid artery corrected flow time (ccFT∆) during the PC. The duration, in minutes, of each bag of IV fluid administered was recorded. RESULTS: 53 patients were recruited and 2 excluded for Doppler artifact. There were 86 total PCs included in the investigation comprising 81.7 L of administered IV fluid. 19,667 carotid Doppler cardiac cycles were analyzed. Using ccFT∆ ≥ + 7 ms to discriminate 'physiologically effective' from 'ineffective' IV fluid, we observed that 54 PCs (63%) were 'effective', comprising 51.7 L of IV fluid, whereas, 32 (37%) were 'ineffective' comprising 30 L of IV fluid. 29.75 total hours across all 51 patients were spent in the ED providing IV fluids categorized as 'ineffective.' CONCLUSIONS: We report the largest-known carotid artery Doppler analysis (i.e., roughly 20,000 cardiac cycles) in ED patients requiring IV fluid expansion. A clinically significant amount of time was spent providing physiologically ineffective IV fluid. This may represent an avenue to improve ED care efficiency.

6.
Nat Commun ; 14(1): 321, 2023 01 19.
Article in English | MEDLINE | ID: mdl-36658158

ABSTRACT

IFNγ is an immune mediator with concomitant pro- and anti-tumor functions. Here, we provide evidence that IFNγ directly acts on intra-tumoral CD8 T cells to restrict anti-tumor responses. We report that expression of the IFNγ receptor ß chain (IFNγR2) in CD8 T cells negatively correlates with clinical responsiveness to checkpoint blockade in metastatic melanoma patients, suggesting that the loss of sensitivity to IFNγ contributes to successful antitumor immunity. Indeed, specific deletion of IFNγR in CD8 T cells promotes tumor control in a mouse model of melanoma. Chronic IFNγ inhibits the maintenance, clonal diversity and proliferation of stem-like T cells. This leads to decreased generation of T cells with intermediate expression of exhaustion markers, previously associated with beneficial anti-tumor responses. This study provides evidence of a negative feedback loop whereby IFNγ depletes stem-like T cells to restrict anti-tumor immunity. Targeting this pathway might represent an alternative strategy to enhance T cell-based therapies.


Subject(s)
Melanoma , T-Lymphocytes, Cytotoxic , Mice , Animals , T-Lymphocytes, Cytotoxic/metabolism , CD8-Positive T-Lymphocytes , Melanoma/therapy , Melanoma/drug therapy , Clone Cells/metabolism
7.
BMJ Open ; 12(9): e063583, 2022 09 29.
Article in English | MEDLINE | ID: mdl-36175104

ABSTRACT

INTRODUCTION: Multimodal prehabilitation, an emerging field within the Perioperative Medicine specialty, requires close multidisciplinary team coordination. The goal is to optimise the patient's health status in the 4-8 weeks before elective surgery to withstand surgical stress. Most patients are unfamiliar with the concept of prehabilitation but are interested in participating in such a programme after explanation. The objective of this randomised controlled trial is to evaluate the effect of prehabilitation (patient education video and multimodal prehabilitation) on the preoperative patient-centred coordinated care experience. METHOD AND ANALYSIS: One hundred patients undergoing major elective surgery (cardiac, colorectal, hepatobiliary-pancreatic and urology) will be recruited into a two-group, parallel, superiority, single-blinded randomised controlled trial. Patients will be randomised to receive either preoperative patient education comprising of a video and prehabilitation programme with standard care (intervention) or standard care (control). The primary outcome measure will be the quality of preoperative patient care experience using the 11-item Chinese version of the Person-Centred Coordinated Care Experience Questionnaire (P3CEQ) before surgery. Secondary outcomes will include the change in Hospital Anxiety and Depression Scale (HADS) score from trial enrolment to before surgery, Quality of Recovery Score (QoR-15) on third day after surgery and Days Alive and At Home within 30 days after surgery (DAH30). Intention-to-treat and per-protocol analyses will be performed. ETHICS AND DISSEMINATION: The Joint CUHK-NTEC Clinical Research Ethics Committee approved the study protocol (CREC Ref. No. 2021.518-T). The findings will be presented at scientific meetings, in peer-reviewed journals and to study participants. TRIAL REGISTRATION NUMBER: ChiCTR2100053637.


Subject(s)
Communications Media , Preoperative Exercise , Elective Surgical Procedures , Humans , Patient Education as Topic , Preoperative Care , Randomized Controlled Trials as Topic
8.
PLoS One ; 17(6): e0270640, 2022.
Article in English | MEDLINE | ID: mdl-35771891

ABSTRACT

BACKGROUND: Patients with colorectal cancer have a high risk of iron deficiency anaemia (IDA) due to chronic tumour induced blood loss, a reduced dietary iron intake from poor nutrition or gastrointestinal malabsorption. This pilot, double blinded, randomised controlled trial (RCT) examined the effect and feasibility of using preoperative iron isomaltoside for treating iron deficiency anaemia. METHODS: Forty eligible adults with IDA were randomised to receive either intravenous iron isomaltoside (20 mg.kg-1 up to 1000 mg over 30 minutes) or usual preoperative care (control) three weeks before scheduled colorectal surgery. The primary outcomes were perioperative changes in haemoglobin and ferritin concentrations. RESULTS: The recruitment rate was 78% of all eligible referred patients (1.9 patients/month). The haemoglobin and ferritin concentrations were higher in the iron isomaltoside group than the control group over the perioperative period (group*time interaction P = 0.042 and P < 0.001 respectively). Mean haemoglobin change from baseline to before surgery was higher in the iron isomaltoside group (7.8, 95% CI: 3.2 to 12.3 g.l-1) than the control group (1.7, 95% CI: -1.9 to 5.3 g.l-1) [mean difference 6.1, 95% CI: 0.3 to 11.8 g.l-1; P = 0.040]. The ferritin change from baseline to before surgery between groups was large in favour of the iron isomaltoside group (mean difference 296.9, 95% CI: 200.6 to 393.2 µg.l-1; P < 0.001]. There were no differences between groups in packed red blood cell transfusions needed, surgical complications, quality of recovery and days (alive and) at home within 30 days after surgery. CONCLUSION: Iron isomaltoside therapy was safe and had a minimal effect on perioperative changes in haemoglobin concentration. Given the slow recruitment and new evidence emerging during the conduct of this study, conducting a multi-centre RCT based on the current pilot trial protocol is unlikely to be feasible. TRIAL REGISTRATION: ClinicalTrials.gov NCT03565354.


Subject(s)
Anemia, Iron-Deficiency , Colorectal Neoplasms , Iron Deficiencies , Adult , Anemia, Iron-Deficiency/complications , Anemia, Iron-Deficiency/drug therapy , Colorectal Neoplasms/complications , Colorectal Neoplasms/surgery , Disaccharides , Ferric Compounds/therapeutic use , Ferritins , Hemoglobins/analysis , Humans , Iron/therapeutic use , Iron, Dietary , Pilot Projects , Prospective Studies
9.
BMJ Simul Technol Enhanc Learn ; 7(4): 199-206, 2021.
Article in English | MEDLINE | ID: mdl-37534688

ABSTRACT

Introduction: In the face of a rapidly advancing pandemic with uncertain pathophysiology, pop-up healthcare units, ad hoc teams and unpredictable personal protective equipment supply, it is difficult for healthcare institutions and front-line teams to invent and test robust and safe clinical care pathways for patients and clinicians. Conventional simulation-based education was not designed for the time-pressured and emergent needs of readiness in a pandemic. We used 'rapid cycle system improvement' to create a psychologically safe learning oasis in the midst of a pandemic. This oasis provided a context to build staff technical and teamwork capacity and improve clinical workflows simultaneously. Methods: At the Department of Anaesthesia and Intensive Care in Prince of Wales Hospital, a tertiary institution, in situ simulations were carried out in the operating theatres and intensive care unit (ICU). The translational simulation design leveraged principles of psychological safety, rapid cycle deliberate practice, direct and vicarious learning to ready over 200 staff with 51 sessions and achieve iterative system improvement all within 7 days. Staff evaluations and system improvements were documented postsimulation. Results/Findings: Staff in both operating theatres and ICU were significantly more comfortable and confident in managing patients with COVID-19 postsimulation. Teamwork, communication and collective ability to manage infectious cases were enhanced. Key system issues were also identified and improved. Discussion: To develop readiness in the rapidly progressing COVID-19 pandemic, we demonstrated that 'rapid cycle system improvement' can efficiently help achieve three intertwined goals: (1) ready staff for new clinical processes, (2) build team competence and confidence and (3) improve workflows and procedures.

10.
Toxicol Lett ; 332: 36-41, 2020 Oct 10.
Article in English | MEDLINE | ID: mdl-32629075

ABSTRACT

The study examined the degradation of riot control agents (RCAs): 2-chloroacetophenone (CN), 2-chlorobenzalmalononitrile (CS), and capsaicin, using the Reactive Skin Decontamination Lotion Kit (RSDL®) lotion and evaluated the the direct liquid phase reactivity of the RSDL lotion component with each RCA. RSDL lotion was mixed with the selected RCAs at different molar ratios. Reactivity of the active ingredient potassium 2,3-butanedione monoximate (KBDO) with the RCA was observed for one hour. Samples of 10 µL were taken and quenched, analyzed for residual RCA using LC-MS. CN, was degraded at molar ratios of two and above in less than 2 min. At a molar ratio of 1:1 KBDO:CN, ∼90 % of CN was degraded within 2 min, the remaining 10 % residual CN was observed for one hour without any change. CS, degradation of more than 68 % of CS was achieved at 20:1 M ratio of KBDO:CS within 1 h of reaction time. For capsaicin, no degradation was observed regardless of the higher molar ratios of up to 20:1 and longer reaction times of up to one hour. This study provides evaluation of neutralizing action of the RSDL lotion without assessment of the physical removal component by the RSDL Kit.


Subject(s)
Capsaicin/chemistry , Chlorobenzenes/chemistry , Decontamination/methods , Irritants/chemistry , Sensory System Agents/chemistry , Skin Cream/chemistry , Tear Gases/chemistry , omega-Chloroacetophenone/chemistry , Calibration , Capsaicin/analysis , Chlorobenzenes/analysis , Chromatography, High Pressure Liquid , Humans , Irritants/analysis , Sensory System Agents/analysis , Skin , Tear Gases/analysis , omega-Chloroacetophenone/analysis
11.
Sci Signal ; 13(634)2020 06 02.
Article in English | MEDLINE | ID: mdl-32487715

ABSTRACT

The dysregulation of multiple signaling pathways, including those through endosomal Toll-like receptors (TLRs), Fc gamma receptors (FcγR), and antigen receptors in B cells (BCR), promote an autoinflammatory loop in systemic lupus erythematosus (SLE). Here, we used selective small-molecule inhibitors to assess the regulatory roles of interleukin-1 receptor (IL-1R)-associated kinase 4 (IRAK4) and Bruton's tyrosine kinase (BTK) in these pathways. The inhibition of IRAK4 repressed SLE immune complex- and TLR7-mediated activation of human plasmacytoid dendritic cells (pDCs). Correspondingly, the expression of interferon (IFN)-responsive genes (IRGs) in cells and in mice was positively regulated by the kinase activity of IRAK4. Both IRAK4 and BTK inhibition reduced the TLR7-mediated differentiation of human memory B cells into plasmablasts. TLR7-dependent inflammatory responses were differentially regulated by IRAK4 and BTK by cell type: In pDCs, IRAK4 positively regulated NF-κB and MAPK signaling, whereas in B cells, NF-κB and MAPK pathways were regulated by both BTK and IRAK4. In the pristane-induced lupus mouse model, inhibition of IRAK4 reduced the expression of IRGs during disease onset. Mice engineered to express kinase-deficient IRAK4 were protected from both chemical (pristane-induced) and genetic (NZB/W_F1 hybrid) models of lupus development. Our findings suggest that kinase inhibitors of IRAK4 might be a therapeutic in patients with SLE.


Subject(s)
Dendritic Cells/metabolism , Endosomes/metabolism , Interleukin-1 Receptor-Associated Kinases/metabolism , Membrane Glycoproteins/metabolism , Plasma Cells/metabolism , Signal Transduction , Toll-Like Receptor 7/metabolism , Agammaglobulinaemia Tyrosine Kinase , Animals , Endosomes/genetics , Humans , Interleukin-1 Receptor-Associated Kinases/genetics , Membrane Glycoproteins/genetics , Mice , Toll-Like Receptor 7/genetics
12.
Mol Ther Oncolytics ; 17: 278-292, 2020 Jun 26.
Article in English | MEDLINE | ID: mdl-32368616

ABSTRACT

Tumor-targeted chimeric antigen receptor (CAR)-engineered T lymphocytes (CAR-T cells) have demonstrated striking clinical success, but their use has been associated with a constellation of toxicities. A better understanding of the pathogenesis of these toxicities is required to improve the safety profile of CAR-T cells. Herein, we describe a xenograft model of off-tumor CAR-T cell-associated toxicity. Human CAR-T cells targeted against HER2 using a small-protein binding domain induced acute, dose-dependent toxicities in mice. The inclusion of a CD28 or 4-1BB co-stimulatory domain in the CAR was required to produce toxicity; however, co-stimulation through CD28 was most toxic on a per-cell basis. CAR-T cell activation in the lungs and heart was associated with a systemic cytokine storm. The severity of observed toxicities was dependent upon the peripheral blood mononuclear cell (PBMC) donor used as a T cell source and paralleled the CD4+-to-CD8+ T cell ratio in the adoptive transfer product. CD4+ CAR-T cells were determined to be the primary contributors to CAR-T cell-associated toxicity. However, donor-specific differences persisted after infusion of a purified CD4+ CAR-T cell product, indicating a role for additional variables. This work highlights the contributions of CAR-T cell-intrinsic variables to the pathogenesis of off-tumor toxicity.

13.
Cancer Immunol Res ; 8(5): 685-697, 2020 05.
Article in English | MEDLINE | ID: mdl-32205315

ABSTRACT

Epitopes derived from mutated cancer proteins elicit strong antitumor T-cell responses that correlate with clinical efficacy in a proportion of patients. However, it remains unclear whether the subcellular localization of mutated proteins influences the efficiency of T-cell priming. To address this question, we compared the immunogenicity of NY-ESO-1 and OVA localized either in the cytosol or in mitochondria. We showed that tumors expressing mitochondrial-localized NY-ESO-1 and OVA proteins elicit significantdly higher frequencies of antigen-specific CD8+ T cells in vivo. We also demonstrated that this stronger immune response is dependent on the mitochondrial location of the antigenic proteins, which contributes to their higher steady-state amount, compared with cytosolic localized proteins. Consistent with these findings, we showed that injection of mitochondria purified from B16 melanoma cells can protect mice from a challenge with B16 cells, but not with irrelevant tumors. Finally, we extended these findings to cancer patients by demonstrating the presence of T-cell responses specific for mutated mitochondrial-localized proteins. These findings highlight the utility of prioritizing epitopes derived from mitochondrial-localized mutated proteins as targets for cancer vaccination strategies.


Subject(s)
Antigens, Neoplasm/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cancer Vaccines/immunology , Epitopes/immunology , Mitochondrial Proteins/immunology , Neoplasms/immunology , Animals , Cell Line, Tumor , Disease Models, Animal , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Mitochondrial Proteins/metabolism , Neoplasms/metabolism , Neoplasms/therapy
14.
AEM Educ Train ; 4(1): 36-42, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31989069

ABSTRACT

INTRODUCTION: Traditional simulation debriefing is both time- and resource-intensive. Shifting the degree of primary learning responsibility from the faculty to the learner through self-guided learning has received greater attention as a means of reducing this resource intensity. The aim of the study was to determine if video-assisted self-debriefing, as a form of self-guided learning, would have equivalent learning outcomes compared to standard debriefing. METHODS: This randomized cohort study consisting of 49 PGY-1 to -3 emergency medicine residents compared performance after video self-assessment utilizing an observer checklist versus standard debriefing for simulated emergency department procedural sedation (EDPS). The primary outcome measure was performance on the second EDPS scenario. RESULTS: Independent-samples t-test found that both control (standard debrief) and intervention (video self-assessment) groups demonstrated significantly increased scores on Scenario 2 (standard-t(40) = 2.20, p < 0.05; video-t(45) = 3.88, p < 0.05). There was a large and significant positive correlation between faculty and resident self-evaluation (r = 0.70, p < 0.05). There was no significant difference between faculty and residents self-assessment mean scores (t(24) = 1.90, p = 0.07). CONCLUSIONS: Residents receiving feedback on their performance via video-assisted self-debriefing improved their performance in simulated EDPS to the same degree as with standard faculty debriefing. Video-assisted self-debriefing is a promising avenue for leveraging the benefits of simulation-based training with reduced resource requirements.

15.
Proc Natl Acad Sci U S A ; 116(21): 10214-10222, 2019 05 21.
Article in English | MEDLINE | ID: mdl-31076556

ABSTRACT

While study in the field of polymer mechanochemistry has yielded mechanophores that perform various chemical reactions in response to mechanical stimuli, there is not yet a triggering method compatible with biological systems. Applications such as using mechanoluminescence to generate localized photon flux in vivo for optogenetics would greatly benefit from such an approach. Here we introduce a method of triggering mechanophores by using high-intensity focused ultrasound (HIFU) as a remote energy source to drive the spatially and temporally resolved mechanical-to-chemical transduction of mechanoresponsive polymers. A HIFU setup capable of controlling the excitation pressure, spatial location, and duration of exposure is employed to activate mechanochemical reactions in a cross-linked elastomeric polymer in a noninvasive fashion. One reaction is the chromogenic isomerization of a naphthopyran mechanophore embedded in a polydimethylsiloxane (PDMS) network. Under HIFU irradiation evidence of the mechanochemical transduction is the observation of a reversible color change as expected for the isomerization. The elastomer exhibits this distinguishable color change at the focal spot, depending on ultrasonic exposure conditions. A second reaction is the demonstration that HIFU irradiation successfully triggers a luminescent dioxetane, resulting in localized generation of visible blue light at the focal spot. In contrast to conventional stimuli such as UV light, heat, and uniaxial compression/tension testing, HIFU irradiation provides spatiotemporal control of the mechanochemical activation through targeted but noninvasive ultrasonic energy deposition. Targeted, remote light generation is potentially useful in biomedical applications such as optogenetics where a light source is used to trigger a cellular response.


Subject(s)
Elastomers/chemistry , High-Intensity Focused Ultrasound Ablation/methods , Light , Ultrasonics/methods
16.
J Am Chem Soc ; 141(5): 1898-1902, 2019 02 06.
Article in English | MEDLINE | ID: mdl-30676738

ABSTRACT

The development of a multicolor mechanochromic polymer/silica composite is achieved by using two distinct types of mechanochromophores. The multicolor mechanochromism of the composite containing diarylbibenzofuranone in silica-rich domains and naphthopyran in the polymer-rich domain is observed. The obtained composite shows blue, green, and orange colors according to the intensity of applied mechanical stimuli, solvent addition, and lapse of time. This unique multicolor mechanochromic behavior is evaluated by solid-state UV-vis absorption spectroscopy, ab initio steered molecular dynamics simulations, and computed minimum energy paths on force-modified potential energy surfaces. The unique mechanochromism is attributed to the difference in properties, activated colors, and domain locations between the two mechanochromophores.

17.
ACS Macro Lett ; 8(5): 535-539, 2019 May 21.
Article in English | MEDLINE | ID: mdl-35619357

ABSTRACT

The ability of nanosegregated polymerized ionic liquids (PILs) to dissipate shockwave energy is investigated for a series of imidazolium-based PILs with varying alkyl spacer length. The PILs are designed to have similar glass transition temperatures but different structures. X-ray scattering analysis reveals that each of the amorphous PILs exhibit distinct nanoscale structural heterogeneity, depending on the length of the chain spacer. We find that a higher structural heterogeneity, determined from the intensity of the intercluster scattering peak, in the PILs with longer alkyl spacers results in greater shockwave energy dissipation. In addition, we observe the crystalline phase is less effective at dissipating shockwave energy than the amorphous phase due to the close packed morphology and slow kinetics.

18.
Nat Commun ; 9(1): 3049, 2018 08 03.
Article in English | MEDLINE | ID: mdl-30076299

ABSTRACT

Engineering T cells with chimeric antigen receptors (CARs) is an effective method for directing T cells to attack tumors, but may cause adverse side effects such as the potentially lethal cytokine release syndrome. Here the authors show that the T cell antigen coupler (TAC), a chimeric receptor that co-opts the endogenous TCR, induces more efficient anti-tumor responses and reduced toxicity when compared with past-generation CARs. TAC-engineered T cells induce robust and antigen-specific cytokine production and cytotoxicity in vitro, and strong anti-tumor activity in a variety of xenograft models including solid and liquid tumors. In a solid tumor model, TAC-T cells outperform CD28-based CAR-T cells with increased anti-tumor efficacy, reduced toxicity, and faster tumor infiltration. Intratumoral TAC-T cells are enriched for Ki-67+ CD8+ T cells, demonstrating local expansion. These results indicate that TAC-T cells may have a superior therapeutic index relative to CAR-T cells.


Subject(s)
Receptors, Antigen/immunology , Receptors, Chimeric Antigen/immunology , Recombinant Proteins/immunology , T-Cell Antigen Receptor Specificity/immunology , T-Lymphocytes/immunology , Adoptive Transfer , Animals , CD28 Antigens/immunology , Cell Line, Tumor , Cytokines/blood , Cytokines/metabolism , Cytotoxicity, Immunologic , Female , Genetic Engineering , HEK293 Cells , Humans , Immunotherapy, Adoptive/methods , Lentivirus/genetics , Lymphocyte Activation , Male , Mice , Mice, Inbred NOD , Protein Engineering , Receptor, ErbB-2/immunology , Receptors, Antigen/genetics , Receptors, Chimeric Antigen/genetics , Single-Domain Antibodies , T-Cell Antigen Receptor Specificity/genetics , T-Lymphocytes, Cytotoxic/immunology , Vision, Ocular , Xenograft Model Antitumor Assays
19.
Brain Behav ; 8(5): e00972, 2018 05.
Article in English | MEDLINE | ID: mdl-29761021

ABSTRACT

Introduction: Stroke is the leading cause of disability in the United States but current therapies are limited with no regenerative potential. Previous translational failures have highlighted the need for large animal models of ischemic stroke and for improved assessments of functional outcomes. The aims of this study were first, to create a post-stroke functional outcome assessment scale in a porcine model of middle cerebral artery occlusion (MCAO) and second, to use this scale to determine the effect of human-induced-pluripotent-cell-derived neural progenitor cells (iNPCs) on functional outcome in this large animal stroke model. Materials and Methods: Eight 6-month-old Landrace mix pigs underwent permanent MCAO. Five days following MCAO, pigs received intraparenchymal injections of either iNPCs or PBS. A post-stroke assessment scale was developed to measure functional outcome. Evaluations were performed at least 1-3 days prior to MCAO and repeated 1 day, 3 days, and 5 days post-stroke as well as 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks, 9 weeks, and 12 weeks post-injection. Comparisons of scores between animals receiving iNPCs or PBS only were compared using a two-way ANOVA and a Tukey's post-hoc t test. Results: The developed scale was able to consistently determine differences between healthy and stroked pigs at all time points. iNPC-treated pigs showed a significantly faster recovery in their overall scores relative to PBS-only treated pigs with the parameters of appetite and body posture exhibiting the most improvement in the iNPC-treated group. Conclusions: We developed a robust and repeatable functional assessment tool that can reliably detect stroke and recovery, while also showing for the first time that iNPC therapy leads to functional recovery in a translational pig ischemic stroke model. These promising results suggest that iNPCs may 1 day serve as a first in class cell therapeutic for ischemic stroke.


Subject(s)
Induced Pluripotent Stem Cells/transplantation , Infarction, Middle Cerebral Artery , Outcome Assessment, Health Care/methods , Recovery of Function/physiology , Animals , Appetite/physiology , Disease Models, Animal , Humans , Infarction, Middle Cerebral Artery/diagnostic imaging , Infarction, Middle Cerebral Artery/physiopathology , Infarction, Middle Cerebral Artery/therapy , Magnetic Resonance Imaging/methods , Male , Neurologic Examination/methods , Posture/physiology , Reproducibility of Results , Swine , Treatment Outcome
20.
Am J Vet Res ; 79(1): 73-82, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29287157

ABSTRACT

OBJECTIVE To determine the physiochemical properties and pharmacokinetics of 3 midazolam gel formulations following buccal administration to dogs. ANIMALS 5 healthy adult hounds. PROCEDURES In phase 1 of a 2-phase study, 2 gel formulations were developed that contained 1% midazolam in a poloxamer 407 (P1) or hydroxypropyl methylcellulose (H1) base and underwent rheological and in vitro release analyses. Each formulation was buccally administered to 5 dogs such that 0.3 mg of midazolam/kg was delivered. Each dog also received midazolam hydrochloride (0.3 mg/kg, IV). There was a 3-day interval between treatments. Blood samples were collected immediately before and at predetermined times for 8 hours after drug administration for determination of plasma midazolam concentration and pharmacokinetic analysis. During phase 2, a gel containing 2% midazolam in a hydroxypropyl methylcellulose base (H2) was developed on the basis of phase 1 results. That gel was buccally administered such that midazolam doses of 0.3 and 0.6 mg/kg were delivered. Each dog also received midazolam (0.3 mg/kg, IV). All posttreatment procedures were the same as those for phase 1. RESULTS The H1 and H2 formulations had lower viscosity, greater bioavailability, and peak plasma midazolam concentrations that were approximately 2-fold as high, compared with those for the P1 formulation. The mean peak plasma midazolam concentration for the H2 formulation was 187.0 and 106.3 ng/mL when the midazolam dose administered was 0.6 and 0.3 mg/kg, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that buccal administration of gel formulations might be a viable alternative for midazolam administration to dogs.


Subject(s)
Anticonvulsants/pharmacokinetics , Dogs/metabolism , Midazolam/pharmacokinetics , Administration, Buccal , Animals , Anticonvulsants/administration & dosage , Area Under Curve , Biological Availability , Cross-Over Studies , Female , Gels/administration & dosage , Gels/pharmacokinetics , Half-Life , Male , Midazolam/administration & dosage
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