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1.
Mucosal Immunol ; 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38901764

ABSTRACT

Exaggeration of type 2 immune responses promotes lung inflammation and altered lung development; however, eosinophils, despite expansion in the postnatal lung, have not been specifically assessed in the context of neonatal lung disease. Furthermore, early-life factors including prematurity and respiratory infection predispose infants to chronic obstructive pulmonary disease later in life. To assess eosinophils in the developing lung and how they may contribute to chronic lung disease, we generated mice harboring eosinophil-specific deletion of the negative regulatory enzyme SHIP-1. This increased the activity and number of pulmonary eosinophils in the developing lung, which was associated with impaired lung development, expansion of activated alveolar macrophages (AMφ), multinucleated giant cell formation, enlargement of airspaces, and fibrosis. Despite regression of eosinophils following completion of lung development, AMφ-dominated inflammation persisted, alongside lung damage. Bone marrow chimera studies showed that SHIP-1-deficient eosinophils were not sufficient to drive inflammatory lung disease in adult steady-state mice but once inflammation and damage was present, it could not be resolved. Depletion of eosinophils during alveolarization alleviated pulmonary inflammation and lung pathology, demonstrating an eosinophil-intrinsic effect. These results show that the presence of activated eosinophils during alveolarization aggravates AMφs and promotes sustained inflammation and long-lasting lung pathology.

2.
Crit Care Med ; 52(3): 396-406, 2024 03 01.
Article in English | MEDLINE | ID: mdl-37889228

ABSTRACT

OBJECTIVE: Terminal extubation (TE) and terminal weaning (TW) during withdrawal of life-sustaining therapies (WLSTs) have been described and defined in adults. The recent Death One Hour After Terminal Extubation study aimed to validate a model developed to predict whether a child would die within 1 hour after discontinuation of mechanical ventilation for WLST. Although TW has not been described in children, pre-extubation weaning has been known to occur before WLST, though to what extent is unknown. In this preplanned secondary analysis, we aim to describe/define TE and pre-extubation weaning (PW) in children and compare characteristics of patients who had ventilatory support decreased before WLST with those who did not. DESIGN: Secondary analysis of multicenter retrospective cohort study. SETTING: Ten PICUs in the United States between 2009 and 2021. PATIENTS: Nine hundred thirteen patients 0-21 years old who died after WLST. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: 71.4% ( n = 652) had TE without decrease in ventilatory support in the 6 hours prior. TE without decrease in ventilatory support in the 6 hours prior = 71.4% ( n = 652) of our sample. Clinically relevant decrease in ventilatory support before WLST = 11% ( n = 100), and 17.6% ( n = 161) had likely incidental decrease in ventilatory support before WLST. Relevant ventilator parameters decreased were F io2 and/or ventilator set rates. There were no significant differences in any of the other evaluated patient characteristics between groups (weight, body mass index, unit type, primary diagnostic category, presence of coma, time to death after WLST, analgosedative requirements, postextubation respiratory support modality). CONCLUSIONS: Decreasing ventilatory support before WLST with extubation in children does occur. This practice was not associated with significant differences in palliative analgosedation doses or time to death after extubation.


Subject(s)
Airway Extubation , Ventilator Weaning , Child , Adult , Humans , Infant, Newborn , Infant , Child, Preschool , Adolescent , Young Adult , Retrospective Studies , Respiration, Artificial , Withholding Treatment
3.
Cells ; 12(20)2023 10 15.
Article in English | MEDLINE | ID: mdl-37887298

ABSTRACT

The effects of hypothermia on neonatal encephalopathy may vary topographically and cytopathologically in the neocortex with manifestations potentially influenced by seizures that alter the severity, distribution, and type of neuropathology. We developed a neonatal piglet survival model of hypoxic-ischemic (HI) encephalopathy and hypothermia (HT) with continuous electroencephalography (cEEG) for seizures. Neonatal male piglets received HI-normothermia (NT), HI-HT, sham-NT, or sham-HT treatments. Randomized unmedicated sham and HI piglets underwent cEEG during recovery. Survival was 2-7 days. Normal and pathological neurons were counted in different neocortical areas, identified by cytoarchitecture and connectomics, using hematoxylin and eosin staining and immunohistochemistry for RNA-binding FOX-1 homolog 3 (Rbfox3/NeuN). Seizure burden was determined. HI-NT piglets had a reduced normal/total neuron ratio and increased ischemic-necrotic/total neuron ratio relative to sham-NT and sham-HT piglets with differing severities in the anterior and posterior motor, somatosensory, and frontal cortices. Neocortical neuropathology was attenuated by HT. HT protection was prominent in layer III of the inferior parietal cortex. Rbfox3 immunoreactivity distinguished cortical neurons as: Rbfox3-positive/normal, Rbfox3-positive/ischemic-necrotic, and Rbfox3-depleted. HI piglets had an increased Rbfox3-depleted/total neuron ratio in layers II and III compared to sham-NT piglets. Neuronal Rbfox3 depletion was partly rescued by HT. Seizure burdens in HI-NT and HI-HT piglets were similar. We conclude that the neonatal HI piglet neocortex has: (1) suprasylvian vulnerability to HI and seizures; (2) a limited neuronal cytopathological repertoire in functionally different regions that engages protective mechanisms with HT; (3) higher seizure burden, insensitive to HT, that is correlated with more panlaminar ischemic-necrotic neurons in the somatosensory cortex; and (4) pathological RNA splicing protein nuclear depletion that is sensitive to HT. This work demonstrates that HT protection of the neocortex in neonatal HI is topographic and laminar, seizure unmitigating, and restores neuronal depletion of RNA splicing factor.


Subject(s)
Hypothermia , Hypoxia-Ischemia, Brain , Neocortex , Animals , Male , Swine , Hypothermia/pathology , Animals, Newborn , Neocortex/metabolism , Hypoxia/pathology , Neurons/metabolism , Ischemia/pathology , Hypoxia-Ischemia, Brain/pathology , Seizures
4.
J Exp Clin Cancer Res ; 42(1): 165, 2023 Jul 12.
Article in English | MEDLINE | ID: mdl-37438818

ABSTRACT

BACKGROUND: The majority of women with epithelial ovarian cancer (OvCa) are diagnosed with metastatic disease, resulting in a poor 5-year survival of 31%. Obesity is a recognized non-infectious pandemic that increases OvCa incidence, enhances metastatic success and reduces survival. We have previously demonstrated a link between obesity and OvCa metastatic success in a diet-induced obesity mouse model wherein a significantly enhanced tumor burden was associated with a decreased M1/M2 tumor-associated macrophage ratio (Liu Y et al. Can, Res. 2015; 75:5046-57). METHODS: The objective of this study was to use pre-clinical murine models of diet-induced obesity to evaluate the effect of a high fat diet (HFD) on response to standard of care chemotherapy and to assess obesity-associated changes in the tumor microenvironment. Archived tumor tissues from ovarian cancer patients of defined body mass index (BMI) were also evaluated using multiplexed immunofluorescence analysis of immune markers. RESULTS: We observed a significantly diminished response to standard of care paclitaxel/carboplatin chemotherapy in HFD mice relative to low fat diet (LFD) controls. A corresponding decrease in the M1/M2 macrophage ratio and enhanced tumor fibrosis were observed both in murine DIO studies and in human tumors from women with BMI > 30. CONCLUSIONS: Our data suggest that the reported negative impact of obesity on OvCa patient survival may be due in part to the effect of the altered M1/M2 tumor-associated macrophage ratio and enhanced fibrosis on chemosensitivity. These data demonstrate a contribution of host obesity to ovarian tumor progression and therapeutic response and support future combination strategies targeting macrophage polarization and/or fibrosis in the obese host.


Subject(s)
Ovarian Neoplasms , Standard of Care , Humans , Female , Animals , Mice , Tumor Microenvironment , Ovarian Neoplasms/drug therapy , Obesity/complications , Carcinoma, Ovarian Epithelial
5.
Front Immunol ; 14: 1125260, 2023.
Article in English | MEDLINE | ID: mdl-37063825

ABSTRACT

Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are chronic relapsing diseases that affect the gastrointestinal tract, most commonly the colon. A link between the gut and the lung is suggested since patients with IBD have an increased susceptibility for chronic inflammatory lung disease. Furthermore, in the absence of overt lung disease, IBD patients have worsened lung function and more leukocytes in sputum than healthy individuals, highlighting a conduit between the gut and lung in disease. To study the gut-lung axis in the context of IBD, we used TCRδ-/- mice, which are highly susceptible to dextran sulfate sodium (DSS) due to the importance of γδ T cells in maintenance of barrier integrity. After induction of experimental colitis using DSS, the lungs of TCRδ-/- mice exhibited signs of inflammation and mild emphysema, which was not observed in DSS-treated C57BL/6 mice. Damage to the lung tissue was accompanied by a large expansion of neutrophils in the lung parenchyma and an increase in alveolar macrophages in the lung wash. Gene expression analyses showed a significant increase in Csf3, Cxcl2, Tnfa, and Il17a in lung tissue in keeping with neutrophil infiltration. Expression of genes encoding reactive oxygen species enzymes and elastolytic enzymes were enhanced in the lungs of both C57BL/6 and TCRδ-/- mice with colitis. Similarly, surfactant gene expression was also enhanced, which may represent a protective mechanism. These data demonstrate that severe colitis in a susceptible genetic background is sufficient to induce lung inflammation and tissue damage, providing the research community with an important tool for the development of novel therapeutics aimed at reducing co-morbidities in IBD patients.


Subject(s)
Colitis , Inflammatory Bowel Diseases , Pneumonia , Mice , Animals , Disease Models, Animal , Mice, Inbred C57BL , Colitis/metabolism , Inflammatory Bowel Diseases/metabolism
6.
Am J Respir Cell Mol Biol ; 69(1): 99-112, 2023 07.
Article in English | MEDLINE | ID: mdl-37014138

ABSTRACT

The epidemiological patterns of incident chronic obstructive pulmonary disease (COPD) and lung adenocarcinoma are changing, with an increasing fraction of disease occurring in patients who are never-smokers or were not exposed to traditional risk factors. However, causative mechanism(s) are obscure. Overactivity of Src family kinases (SFKs) and myeloid cell-dependent inflammatory lung epithelial and endothelial damage are independent candidate mechanisms, but their pathogenic convergence has not been demonstrated. Here we present a novel preclinical model in which an activating mutation in Lyn, a nonreceptor SFK that is expressed in immune cells, epithelium, and endothelium-all strongly implicated in the pathogenesis of COPD-causes spontaneous inflammation, early-onset progressive emphysema, and lung adenocarcinoma. Surprisingly, even though activated macrophages, elastolytic enzymes, and proinflammatory cytokines were prominent, bone marrow chimeras formally demonstrated that myeloid cells were not disease initiators. Rather, lung disease arose from aberrant epithelial cell proliferation and differentiation, microvascular lesions within an activated endothelial microcirculation, and amplified EGFR (epidermal growth factor receptor) expression. In human bioinformatics analyses, LYN expression was increased in patients with COPD and was correlated with increased EGFR expression, a known lung oncogenic pathway, and LYN was linked to COPD. Our study shows that a singular molecular defect causes a spontaneous COPD-like immunopathology and lung adenocarcinoma. Furthermore, we identify Lyn and, by implication, its associated signaling pathways as new therapeutic targets for COPD and cancer. Moreover, our work may inform the development of molecular risk screening and intervention methods for disease susceptibility, progression, and prevention of these increasingly prevalent conditions.


Subject(s)
Adenocarcinoma of Lung , Emphysema , Lung Neoplasms , Pulmonary Disease, Chronic Obstructive , Pulmonary Emphysema , Humans , Adenocarcinoma of Lung/genetics , ErbB Receptors/metabolism , Lung Neoplasms/genetics , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Emphysema/genetics , src-Family Kinases/metabolism
7.
Gynecol Oncol ; 172: 106-114, 2023 05.
Article in English | MEDLINE | ID: mdl-37004303

ABSTRACT

OBJECTIVE: A quality improvement initiative (QII) was conducted with five community-based health systems' oncology care centers (sites A-E). The QII aimed to increase referrals, genetic counseling (GC), and germline genetic testing (GT) for patients with ovarian cancer (OC) and triple-negative breast cancer (TNBC). METHODS: QII activities occurred at sites over several years, all concluding by December 2020. Medical records of patients with OC and TNBC were reviewed, and rates of referral, GC, and GT of patients diagnosed during the 2 years before the QII were compared to those diagnosed during the QII. Outcomes were analyzed using descriptive statistics, two-sample t-test, chi-squared/Fisher's exact test, and logistic regression. RESULTS: For patients with OC, improvement was observed in the rate of referral (from 70% to 79%), GC (from 44% to 61%), GT (from 54% to 62%) and decreased time from diagnosis to GC and GT. For patients with TNBC, increased rates of referral (from 90% to 92%), GC (from 68% to 72%) and GT (81% to 86%) were observed. Effective interventions streamlined GC scheduling and standardized referral processes. CONCLUSION: A multi-year QII increased patient referral and uptake of recommended genetics services across five unique community-based oncology care settings.


Subject(s)
Ovarian Neoplasms , Triple Negative Breast Neoplasms , Female , Humans , Quality Improvement , Triple Negative Breast Neoplasms/genetics , Genetic Testing , Ovarian Neoplasms/genetics , Ovarian Neoplasms/therapy , Genetic Counseling
8.
Pediatr Res ; 93(1): 56-62, 2023 01.
Article in English | MEDLINE | ID: mdl-35568732

ABSTRACT

BACKGROUND: Measurement of neonatal team resuscitation performance is critical to identify opportunities for improvement and to target education. An effective tool to measure team performance during infant resuscitations is lacking. METHODS: We developed an in-hospital infant resuscitation performance tool (Infa-RePT) using the modified Delphi method. We employed a QI framework and targeted interventions, including the use of role responsibility checklists, mock codes, and an educational video. We tracked Infa-RePT scores, mock code team attendance, and confidence surveys. Our specific aim was to improve Infa-RePT score from a baseline of 7.4 to <5 (lower is better) over a 26-month period. RESULTS: Twenty-five elements reached >80% consensus as essential components to include on the Infa-RePT. Independent observation showed 86% concordance on checklist items. Simulation (n = 26) and unit-based code (n = 10) Infa-RePT scores showed significant improvement after project start from 7.4 to 4.2 (p < 0.01) with special cause variation noted on control chart analysis. No significant difference was observed between simulations and in-unit codes. Staff confidence self-reports improved over the study period. CONCLUSIONS: Use of a novel scoring tool can help monitor team progress over time and identify areas for improvement. Focused interventions can improve resuscitation team performance. IMPACT: We developed and used a novel, comprehensive measurement tool for team infant resuscitation performance in both simulation and in-unit settings. Using QI methodology, team performance improved after the enhancement of a mock code simulation program. Review of team performance scores can highlight key areas to target interventions and monitor progress over time.


Subject(s)
Clinical Competence , Patient Care Team , Humans , Infant , Infant, Newborn , Resuscitation/methods , Surveys and Questionnaires
9.
J Cell Biol ; 222(1)2023 01 02.
Article in English | MEDLINE | ID: mdl-36239632

ABSTRACT

Membrane trafficking is essential for sculpting neuronal morphology. The GARP and EARP complexes are conserved tethers that regulate vesicle trafficking in the secretory and endolysosomal pathways, respectively. Both complexes contain the Vps51, Vps52, and Vps53 proteins, and a complex-specific protein: Vps54 in GARP and Vps50 in EARP. In Drosophila, we find that both complexes are required for dendrite morphogenesis during developmental remodeling of multidendritic class IV da (c4da) neurons. Having found that sterol accumulates at the trans-Golgi network (TGN) in Vps54KO/KO neurons, we investigated genes that regulate sterols and related lipids at the TGN. Overexpression of oxysterol binding protein (Osbp) or knockdown of the PI4K four wheel drive (fwd) exacerbates the Vps54KO/KO phenotype, whereas eliminating one allele of Osbp rescues it, suggesting that excess sterol accumulation at the TGN is, in part, responsible for inhibiting dendrite regrowth. These findings distinguish the GARP and EARP complexes in neurodevelopment and implicate vesicle trafficking and lipid transfer pathways in dendrite morphogenesis.


Subject(s)
Dendrites , Multiprotein Complexes , Vesicular Transport Proteins , trans-Golgi Network , Animals , Carrier Proteins , Dendrites/metabolism , Drosophila , Drosophila Proteins , Golgi Apparatus/metabolism , Multiprotein Complexes/metabolism , Receptors, Steroid , Sterols/metabolism , Vesicular Transport Proteins/metabolism , trans-Golgi Network/metabolism
11.
Parasit Vectors ; 15(1): 59, 2022 Feb 18.
Article in English | MEDLINE | ID: mdl-35180893

ABSTRACT

BACKGROUND: A subset of Australians who have been bitten by ticks experience a complex of chronic and debilitating symptoms which cannot be attributed to the known pathogenic species of bacteria present in Australia. As a result, there has been a renewed effort to identify and characterise viruses in Australian terrestrial ticks. Recent transcriptome sequencing of Ixodes and Amblyomma ticks has revealed the presence of multiple virus sequences. However, without virus isolates our ability to understand the host range and pathogenesis of newly identified viruses is limited. We have established a successful method for high-throughput virus discovery and isolation in mosquitoes using antibodies to double-stranded RNA. In this study we sought to characterise five archival tick-borne viruses to adapt our virus discovery protocol for Australian ticks. METHODS: We performed virus characterisation using a combination of bioinformatic sequence analysis and in vitro techniques including replication kinetics, antigenic profiling, virus purification and mass spectrometry. RESULTS: Our sequence analysis of Nugget virus, Catch-me-Cave virus and Finch Creek virus revealed marked genetic stability in isolates collected from the same location approximately 30 years apart. We demonstrate that the Ixodes scapularis-derived ISE6 cell line supports replication of Australian members of the Flaviviridae, Nairoviridae, Phenuiviridae and Reoviridae families, including Saumarez Reef virus (SREV), a flavivirus isolated from the soft tick Ornithodoros capensis. While antibodies against double-stranded RNA could be used to detect replication of a tick-borne reovirus and mosquito-borne flavivirus, the tick-borne flaviviruses Gadgets Gully virus and SREV could not be detected using this method. Finally, four novel virus-like sequences were identified in transcriptome sequencing of the Australian native tick Ixodes holocyclus. CONCLUSIONS: Genetic and antigenic characterisations of archival viruses in this study confirm that three viruses described in 2002 represent contemporary isolates of virus species first identified 30 years prior. Our findings with antibodies to double-stranded RNA highlight an unusual characteristic shared by two Australian tick-borne flaviviruses. Finally, comparative growth kinetics analyses of Australian tick-borne members of the Flaviviridae, Nairoviridae, Phenuiviridae and Reoviridae families in ISE6 and BSR cells will provide a useful resource for isolation of Australian tick-borne viruses using existing cell lines.


Subject(s)
Flavivirus , Ixodes , RNA Viruses , Animals , Australia , DNA Viruses , Humans , Ixodes/genetics
12.
Resuscitation ; 170: 316-323, 2022 01.
Article in English | MEDLINE | ID: mdl-34718083

ABSTRACT

AIM: To examine the associations between ETCO2, ROSC, and chest compression quality markers in paediatric patients during active resuscitation. METHODS: This was a single-centre cohort study of data collected as part of an institutional prospective quality initiative improvement program that included all paediatric patients who received chest compressions of any duration from January 1, 2013, through July 10, 2018, in the Johns Hopkins Children's Center. Data was collected from Zoll R Series® defibrillators. Events were included if Zoll data files contained both chest compression and ETCO2 data. 2,746 minutes corresponding to 143 events were included in the analyses. RESULTS: The median event ETCO2 for all 143 events was 16.8 [9.3-26.3] mmHg. There was a significant difference in median event ETCO2 between events that achieved ROSC and those that did not (ROSC: 19.3 [14.4-26.6] vs. NO ROSC: 13.9 [6.6-25.5] mmHg; p < 0.05). When the events were based on patient age, this relationship held in adolescents (ROSC: 18.8 [15.5-22.3] vs. NO ROSC: 9.6 [4.4-15.9] mmHg; p < 0.05), but not in children or infants. Median event ETCO2 was significantly associated with chest compression rate less than 140 (p < 0.0001) and chest compression fraction 90-100 (p < 0.0001). CONCLUSIONS: This represents the largest collection of ETCO2 and chest compression data in paediatric patients to date and unadjusted analyses suggests an association between ETCO2 and ROSC in some paediatric patients.


Subject(s)
Carbon Dioxide , Cardiopulmonary Resuscitation , Adolescent , Carbon Dioxide/analysis , Child , Cohort Studies , Humans , Infant , Pressure , Prospective Studies
14.
PLoS One ; 16(11): e0256908, 2021.
Article in English | MEDLINE | ID: mdl-34847164

ABSTRACT

This article describes our experience developing a novel mobile health unit (MHU) program in the Detroit, Michigan, metropolitan area. Our main objectives were to improve healthcare accessibility, quality and equity in our community during the novel coronavirus pandemic. While initially focused on SARS-CoV-2 testing, our program quickly evolved to include preventive health services. The MHU program began as a location-based SARS-CoV-2 testing strategy coordinated with local and state public health agencies. Community needs motivated further program expansion to include additional preventive healthcare and social services. MHU deployment was targeted to disease "hotspots" based on publicly available SARS-CoV-2 testing data and community-level information about social vulnerability. This formative evaluation explores whether our MHU deployment strategy enabled us to reach patients from communities with heightened social vulnerability as intended. From 3/20/20-3/24/21, the Detroit MHU program reached a total of 32,523 people. The proportion of patients who resided in communities with top quartile Centers for Disease Control and Prevention Social Vulnerability Index rankings increased from 25% during location-based "drive-through" SARS-CoV-2 testing (3/20/20-4/13/20) to 27% after pivoting to a mobile platform (4/13/20-to-8/31/20; p = 0.01). The adoption of a data-driven deployment strategy resulted in further improvement; 41% of the patients who sought MHU services from 9/1/20-to-3/24/21 lived in vulnerable communities (Cochrane Armitage test for trend, p<0.001). Since 10/1/21, 1,837 people received social service referrals and, as of 3/15/21, 4,603 were administered at least one dose of COVID-19 vaccine. Our MHU program demonstrates the capacity to provide needed healthcare and social services to difficult-to-reach populations from areas with heightened social vulnerability. This model can be expanded to meet emerging pandemic needs, but it is also uniquely capable of improving health equity by addressing longstanding gaps in primary care and social services in vulnerable communities.


Subject(s)
Mobile Health Units , Pandemics , Public Health , Adult , COVID-19 Testing , Female , Geography , Health Services , Humans , Male , Michigan , Middle Aged , Pandemics/prevention & control , Referral and Consultation , SARS-CoV-2/isolation & purification , Social Work
15.
Resusc Plus ; 8: 100174, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34820656

ABSTRACT

AIM: To evaluate an algorithm that uses an end-tidal carbon dioxide (ETCO2) target of ≥ 30 torr to guide specific changes in chest compression rate and epinephrine administration during cardiopulmonary resuscitation (CPR) in paediatric swine. METHODS: Swine underwent asphyxial cardiac arrest followed by resuscitation with either standard or ETCO2-guided algorithm CPR. The standard group received chest compressions at a rate of 100/min and epinephrine every 4 min during advanced life support consistent with the American Heart Association paediatric resuscitation guidelines. In the ETCO2-guided algorithm group, chest compression rate was increased by 10 compressions/min for every minute that the ETCO2 was < 30 torr, and the epinephrine administration interval was decreased to every 2 min if the ETCO2 remained < 30 torr. Short-term survival and physiologic data during active resuscitation were compared. RESULTS: Short-term survival was significantly greater in the ETCO2-guided algorithm CPR group than in the standard CPR group (16/28 [57.1%] versus 4/28 [14.3%]; p = 0.002). Additionally, the algorithm group had higher predicted mean ETCO2, chest compression rate, diastolic and mean arterial pressure, and myocardial perfusion pressure throughout resuscitation. Swine in the algorithm group also exhibited significantly greater improvement in diastolic and mean arterial pressure and cerebral perfusion pressure after the first dose of epinephrine than did those in the standard group. Incidence of resuscitation-related injuries was similar in the two groups. CONCLUSIONS: Use of a resuscitation algorithm with stepwise guidance for changes in the chest compression rate and epinephrine administration interval based on a goal ETCO2 level improved survival and intra-arrest hemodynamics in this porcine cardiac arrest model.

16.
Cells ; 10(8)2021 08 18.
Article in English | MEDLINE | ID: mdl-34440889

ABSTRACT

Cerebral hypoxia-ischemia (HI) compromises the proteasome in a clinically relevant neonatal piglet model. Protecting and activating proteasomes could be an adjunct therapy to hypothermia. We investigated whether chymotrypsin-like proteasome activity differs regionally and developmentally in the neonatal brain. We also tested whether neonatal brain proteasomes can be modulated by oleuropein, an experimental pleiotropic neuroprotective drug, or by targeting a proteasome subunit gene using recombinant adeno-associated virus-9 (AAV). During post-HI hypothermia, we treated piglets with oleuropein, used AAV-short hairpin RNA (shRNA) to knock down proteasome activator 28γ (PA28γ), or enforced PA28γ using AAV-PA28γ with green fluorescent protein (GFP). Neonatal neocortex and subcortical white matter had greater proteasome activity than did liver and kidney. Neonatal white matter had higher proteasome activity than did juvenile white matter. Lower arterial pH 1 h after HI correlated with greater subsequent cortical proteasome activity. With increasing brain homogenate protein input into the assay, the initial proteasome activity increased only among shams, whereas HI increased total kinetic proteasome activity. OLE increased the initial neocortical proteasome activity after hypothermia. AAV drove GFP expression, and white matter PA28γ levels correlated with proteasome activity and subunit levels. However, AAV proteasome modulation varied. Thus, neonatal neocortical proteasomes can be pharmacologically activated. HI slows the initial proteasome performance, but then augments ongoing catalytic activity. AAV-mediated genetic manipulation in the piglet brain holds promise, though proteasome gene targeting requires further development.


Subject(s)
Iridoid Glucosides/pharmacology , Proteasome Endopeptidase Complex/drug effects , Proteasome Endopeptidase Complex/metabolism , Animals , Animals, Newborn , Blotting, Western , Brain/drug effects , Brain/metabolism , Disease Models, Animal , Hypothermia/metabolism , Hypoxia-Ischemia, Brain/metabolism , Mice , Swine
17.
J Gen Virol ; 102(7)2021 07.
Article in English | MEDLINE | ID: mdl-34236957

ABSTRACT

Mosquito-borne flaviviruses are significant contributors to the arboviral disease burdens both in Australia and globally. While routine arbovirus surveillance remains a vital exercise to identify known flaviviruses in mosquito populations, novel or divergent and emerging species can be missed by these traditional methods. The MAVRIC (monoclonal antibodies to viral RNA intermediates in cells) system is an ELISA-based method for broad-spectrum isolation of positive-sense and double-stranded RNA (dsRNA) viruses based on detection of dsRNA in infected cells. While the MAVRIC ELISA has successfully been used to detect known and novel flaviviruses in Australian mosquitoes, we previously reported that dsRNA could not be detected in dengue virus-infected cells using this method. In this study we identified additional flaviviruses which evade detection of dsRNA by the MAVRIC ELISA. Utilising chimeric flaviviruses we demonstrated that this outcome may be dictated by the non-structural proteins and/or untranslated regions of the flaviviral genome. In addition, we report a modified fixation method that enables improved detection of flavivirus dsRNA and inactivation of non-enveloped viruses from mosquito populations using the MAVRIC system. This study demonstrates the utility of anti-dsRNA monoclonal antibodies for identifying viral replication in insect and vertebrate cell systems and highlights a unique characteristic of flavivirus replication.


Subject(s)
Culicidae/virology , Flavivirus/isolation & purification , Flavivirus/physiology , RNA, Double-Stranded/analysis , RNA, Viral/analysis , Aedes/virology , Animals , Antibodies, Monoclonal , Australia , Cell Line , Dengue Virus/genetics , Dengue Virus/isolation & purification , Dengue Virus/physiology , Enzyme-Linked Immunosorbent Assay , Flavivirus/genetics , RNA, Double-Stranded/immunology , RNA, Viral/immunology , Viral Envelope Proteins/analysis , Viral Envelope Proteins/metabolism , Viral Nonstructural Proteins/analysis , Viral Nonstructural Proteins/metabolism , Virus Replication
18.
Genes Dev ; 35(7-8): 449-469, 2021 04 01.
Article in English | MEDLINE | ID: mdl-33861720

ABSTRACT

Our cells are comprised of billions of proteins, lipids, and other small molecules packed into their respective subcellular organelles, with the daunting task of maintaining cellular homeostasis over a lifetime. However, it is becoming increasingly evident that organelles do not act as autonomous discrete units but rather as interconnected hubs that engage in extensive communication through membrane contacts. In the last few years, our understanding of how these contacts coordinate organelle function has redefined our view of the cell. This review aims to present novel findings on the cellular interorganelle communication network and how its dysfunction may contribute to aging and neurodegeneration. The consequences of disturbed interorganellar communication are intimately linked with age-related pathologies. Given that both aging and neurodegenerative diseases are characterized by the concomitant failure of multiple cellular pathways, coordination of organelle communication and function could represent an emerging regulatory mechanism critical for long-term cellular homeostasis. We anticipate that defining the relationships between interorganelle communication, aging, and neurodegeneration will open new avenues for therapeutics.


Subject(s)
Cellular Senescence , Neurodegenerative Diseases/physiopathology , Organelles/pathology , Animals , Humans , Neurodegenerative Diseases/therapy , Organelles/physiology , Signal Transduction
19.
J Surg Case Rep ; 2021(2): rjab014, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33628421

ABSTRACT

We present the case of a 16-year-old female with systemic lupus erythematosus who presented with shock of unclear etiology, refractory to fluid resuscitation and triple vasopressors. She suffered pulseless electrical activity and underwent cannulation onto veno-arterial extracorporeal membrane oxygenation (ECMO). After cannulation, it was discovered she had intentionally overdosed on her home medication, amlodipine, a calcium channel blocker (CCB). She was supported on ECMO, treated with IV calcium and insulin, and was able to be weaned off ECMO after 4 days. She developed oligoanuric acute kidney injury, treated with continuous renal replacement therapy followed by intermittent hemodialysis. At discharge, she was neurologically intact and did not require dialysis. Herein, we review the treatment of CCB overdose, review the literature on the use of ECMO in refractory shock due to cardiovascular medication overdose, and highlight the utility of ECMO in pediatric refractory shock and/or cardiac arrest of unclear etiology.

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