Retrospective observational study on real world use of the Minimed™ 780G automated insulin delivery system: Impact of the settings on autocorrection and omitted meal boluses.

INTRODUCTION: The Medtronic MiniMed™ 780G (MM780G) system uses an algorithm that includes autocorrection bolus (AB) delivery. This study evaluates the impact of omitted meal boluses and the system settings, glucose target and active insulin time (AIT), on the AB. METHOD: Retrospective observational study on data uploaded by all MiniMed 780G users in our healthcare area, obtained through the remote monitoring platform Care Connect, from April to August 2023. Downloads with a sensor usage time <95% were excluded. RESULTS: 235 downloads belonging to 235 users were analysed. AB delivery was significantly higher at 2 h AIT (36.08 ±â€¯13.17%) compared to the rest of settings (2.25-4 h) (26.43 ±â€¯13.2%) (p < 0.001). AB differences based on the glucose target were not found. Patients with <3 meal boluses per day had higher AB delivery (46.91 ±â€¯19.00% vs 27.53 ±â€¯11.54%) (p < 0.001) and had more unfavourable glucometric parameters (GMI 7.12 ±â€¯0.45%, TIR 67.46 ±â€¯12.89% vs GMI 6.78 ±â€¯0.3%, TIR 76.51 ±â€¯8.37%) (p < 0.001). However, the 2-h AIT group presented similar TAR, TIR and GMI regardless of the number of meal boluses. CONCLUSION: The fewer user-initiated boluses, the greater the autocorrection received. The active insulin time of 2 h entails a more active autocorrection pattern that makes it possible to more effectively compensate for the omission of meal boluses without increasing hypoglycaemias.

Changes in NMDA Receptor Function in Rapid Ischemic Tolerance: A Potential Role for Tri-Heteromeric NMDA Receptors.

In this study, we characterize biophysical changes in NMDA receptor function in response to brief non-injurious ischemic stress (ischemic preconditioning). Electrophysiological studies show NMDA receptor function is reduced following preconditioning in cultured rat cortical neurons. This functional change is not due to changes in the reversal potential of the receptor, but an increase in desensitization. We performed concentration-response analysis of NMDA-evoked currents, and demonstrate that preconditioned neurons show a reduced potency of NMDA to evoke currents, an increase in Mg2+ sensitivity, but no change in glycine sensitivity. Antagonists studies show a reduced inhibition of GluN2B antagonists that have an allosteric mode of action (ifenprodil and R-25-6981), but competitive antagonists at the GluR2A and 2B receptor (NVP-AMM077 and conantokin-G) appear to have similar potency to block currents. Biochemical studies show a reduction in membrane surface GluN2B subunits, and an increased co-immunoprecipitation of GluN2A with GluN2B subunits, suggestive of tri-heteromeric receptor formation. Finally, we show that blocking actin remodeling with jasplakinolide, a mechanism of rapid ischemic tolerance, prevents NMDA receptor functional changes and co-immunoprecipitation of GluN2A and 2B subunits. Together, this study shows that alterations in NMDA receptor function following preconditioning ischemia are associated with neuroprotection in rapid ischemic tolerance.

Role of miR-2392 in driving SARS-CoV-2 infection.

MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation that have a major impact on many diseases and provide an exciting avenue toward antiviral therapeutics. From patient transcriptomic data, we determined that a circulating miRNA, miR-2392, is directly involved with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) machinery during host infection. Specifically, we show that miR-2392 is key in driving downstream suppression of mitochondrial gene expression, increasing inflammation, glycolysis, and hypoxia, as well as promoting many symptoms associated with coronavirus disease 2019 (COVID-19) infection. We demonstrate that miR-2392 is present in the blood and urine of patients positive for COVID-19 but is not present in patients negative for COVID-19. These findings indicate the potential for developing a minimally invasive COVID-19 detection method. Lastly, using in vitro human and in vivo hamster models, we design a miRNA-based antiviral therapeutic that targets miR-2392, significantly reduces SARS-CoV-2 viability in hamsters, and may potentially inhibit a COVID-19 disease state in humans.

The Great Deceiver: miR-2392's Hidden Role in Driving SARS-CoV-2 Infection.

MicroRNAs (miRNAs) are small non-coding RNAs involved in post-transcriptional gene regulation that have a major impact on many diseases and provides an exciting avenue towards antiviral therapeutics. From patient transcriptomic data, we have discovered a circulating miRNA, miR-2392, that is directly involved with SARS-CoV-2 machinery during host infection. Specifically, we show that miR-2392 is key in driving downstream suppression of mitochondrial gene expression, increasing inflammation, glycolysis, and hypoxia as well as promoting many symptoms associated with COVID-19 infection. We demonstrate miR-2392 is present in the blood and urine of COVID-19 positive patients, but not detected in COVID-19 negative patients. These findings indicate the potential for developing a novel, minimally invasive, COVID-19 detection method. Lastly, using in vitro human and in vivo hamster models, we have developed a novel miRNA-based antiviral therapeutic that targets miR-2392, significantly reduces SARS-CoV-2 viability in hamsters and may potentially inhibit a COVID-19 disease state in humans.

Whole Blood Transcriptome Analysis in Children with Sickle Cell Anemia.

Whole transcriptome RNA-sequencing was performed to quantify RNA expression changes in whole blood samples collected from steady state sickle cell anemia (SCA) and control subjects. Pediatric SCA and control subjects were recruited from Atlanta (GA)-based hospital(s) systems and consented for RNA sequencing. RNA sequencing was performed on an Ion Torrent S5 sequencer, using the Ion Total RNA-seq v2 protocol. Data were aligned to the hg19 reference genome and analyzed in the Partek Genomics studio package (v7.0). 223 genes were differentially expressed between SCA and controls (± 1.5 fold change FDR p < 0.001) and 441 genes show differential transcript expression (± 1.5 fold FDR p < 0.001). Differentially expressed RNA are enriched for hemoglobin associated genes and ubiquitin-proteasome pathway genes. Further analysis shows higher gamma globin gene expression in SCA (33-fold HBG1 and 49-fold HBG2, both FDR p < 0.05), which did not correlate with hemoglobin F protein levels. eQTL analysis identified SNPs in novel non-coding RNA RYR2 gene as having a potential regulatory role in HBG1 and HBG2 expression levels. Gene expression correlation identified JHDM1D-AS1(KDM7A-DT), a non-coding RNA associated with angiogenesis, enhanced GATA1 and decreased JAK-STAT signaling to correlate with HBG1 and HBG2 mRNA levels. These data suggest novel regulatory mechanisms for fetal hemoglobin regulation, which may offer innovative therapeutic approaches for SCA.

Enhancing Base Excision Repair of Mitochondrial DNA to Reduce Ischemic Injury Following Reperfusion.

We hypothesize that enhancing mitochondrial base excision repair (BER) capability in brain will reduce reperfusion-associated ischemic brain injury. Post-stroke reperfusion was modeled in mice via transient filament occlusion of the middle cerebral artery (60 min) (transient MCAO). Administration of a TAT-modified form of a DNA glycosylase (EndoIII) following reperfusion of the brain reduced resultant brain infarct volume. Protection was dose-dependent, BER enzyme specific, and regionally specific (more effective via the jugular vein). EndoIII is compatible with tissue plasminogen activator (tPA). The time window of a single dose of EndoIII effect is 3 h following reperfusion onset. These data suggest a novel approach to enhance protection of reperfused brain in the setting of revascularization procedures (thrombectomy or thrombolytic therapy) following stroke.

Online Reputation Management and Patient Satisfaction.

Online reputation management is critical in orthopaedic practice. All orthopaedic surgeons have an online reputation. Some aspects of an orthopaedic surgeon's online reputation can be controlled and other aspects of an orthopaedic surgeon's online reputation cannot be controlled. Online reputation management involves enhancing patient-surgeon communication and, ultimately, patient satisfaction. Patient-reported outcome measures are increasingly drivers of physician behavior, and potential untoward consequences must be monitored. In the future, patient-experience data are very likely to be among the most prominent forms of quality data on the Internet.

Assessing the accuracy of blood RNA profiles to identify patients with post-concussion syndrome: A pilot study in a military patient population.

Mild traumatic brain injury (mTBI) is a complex, neurophysiological condition that can have detrimental outcomes. Yet, to date, no objective method of diagnosis exists. Physical damage to the blood-brain-barrier and normal waste clearance via the lymphatic system may enable the detection of biomarkers of mTBI in peripheral circulation. Here we evaluate the accuracy of whole transcriptome analysis of blood to predict the clinical diagnosis of post-concussion syndrome (PCS) in a military cohort. Sixty patients with clinically diagnosed chronic concussion and controls (no history of concussion) were recruited (retrospective study design). Male patients (46) were split into a training set comprised of 20 long-term concussed (> 6 months and symptomatic) and 12 controls (no documented history of concussion). Models were validated in a testing set (control = 9, concussed = 5). RNA_Seq libraries were prepared from whole blood samples for sequencing using a SOLiD5500XL sequencer and aligned to hg19 reference genome. Patterns of differential exon expression were used for diagnostic modeling using support vector machine classification, and then validated in a second patient cohort. The accuracy of RNA profiles to predict the clinical diagnosis of post-concussion syndrome patients from controls was 86% (sensitivity 80%; specificity 89%). In addition, RNA profiles reveal duration of concussion. This pilot study shows the potential utility of whole transcriptome analysis to establish the clinical diagnosis of chronic concussion syndrome.

Blood transcriptome changes after stroke in an African American population.

OBJECTIVE: Molecular diagnostic medicine holds much promise to change point of care treatment. An area where additional diagnostic tools are needed is in acute stroke care, to assist in diagnosis and prognosis. Previous studies using microarray-based gene expression analysis of peripheral blood following stroke suggests this approach may be effective. Next-generation sequencing (NGS) approaches have expanded genomic analysis and are not limited to previously identified genes on a microarray chip. Here, we report on a pilot NGS study to identify gene expression and exon expression patterns for the prediction of stroke diagnosis and prognosis. METHODS: We recruited 28 stroke patients and 28 age- and sex-matched hypertensive controls. RNA was extracted from 3 mL blood samples, and RNA-Seq libraries were assembled and sequenced. RESULTS: Bioinformatical analysis of the aligned RNA data reveal exonic (30%), intronic (36%), and novel RNA components (not currently annotated: 33%). We focused our study on patients with confirmed middle cerebral artery occlusion ischemic stroke (n = 17). On the basis of our observation of differential splicing of gene transcripts, we used all exonic RNA expression rather than gene expression (combined exons) to build prediction models using support vector machine algorithms. Based on model building, these models have a high predicted accuracy rate >90% (spec. 88% sen. 92%). We further stratified outcome based on the improvement in NIHss scores at discharge; based on model building we observe a predicted 100% accuracy rate. INTERPRETATION: NGS-based exon expression analysis approaches have a high potential for patient diagnosis and outcome prediction, with clear utility to aid in clinical patient care.

Dynamic changes in DNA methylation in ischemic tolerance.

Epigenetic mediators of gene expression are hypothesized to regulate transcriptomic responses to preconditioning ischemia and ischemic tolerance. Here, we utilized a methyl-DNA enrichment protocol and sequencing (ChIP-seq) to identify patterns of DNA methylation in an established model of ischemic tolerance in neuronal cultures (oxygen and glucose deprivation: OGD). We observed an overall decrease in global DNA methylation at 4 h following preconditioning ischemia (30 min OGD), harmful ischemia (120 min OGD), and in ischemic tolerant neuronal cultures (30 min OGD, 24 h recovery, 120 min OGD). We detected a smaller cohort of hypermethylated regions following ischemic conditions, which were further analyzed revealing differential chromosomal localization of methylation, and a differential concentration of methylation on genomic regions. Together, these data show that the temporal profiles of DNA methylation with respect to chromatin hyper- and hypo-methylation following various ischemic conditions are highly dynamic, and may reveal novel targets for neuroprotection.

Investigating the role of the actin regulating complex ARP2/3 in rapid ischemic tolerance induced neuro-protection.

Neuronal morphology is highly sensitive to ischemia, although some re-organization may promote neuroprotection. In this study we investigate the role of actin regulating proteins (ARP2, ARP3 and WAVE-1) and their role in rapid ischemic tolerance. Using an established in vitro model of rapid ischemic tolerance, we show that WAVE-1 protein levels are stabilized following brief tolerance inducing ischemia (preconditioning). The stabilization appears to be due to a reduction in the ubiquitination of WAVE-1. Levels of ARP2, ARP3 and N-WASP were not affected by ischemic preconditioning. Immunocytochemical studies show a relocalization of ARP2 and ARP3 proteins in neurons following preconditioning ischemia, as well as a re-organization of actin. Blocking the protein kinase CK2 using emodin blocks ischemic tolerance, and our data suggests CK2 binds to WAVE-1 in neurons. We observe an increase in binding of the ARP2 subunit with WAVE-1. The neuroprotection observed following preconditioning is inhibited when cells are transduced with an N-WASP CA domain that blocks the activation of ARP2/3. Together these data show that ischemia affects actin regulating enzymes, and that the ARP2/3 pathway plays a role in rapid ischemic tolerance induced neuroprotection.

Suppression of TNF receptor-1 signaling in an in vitro model of epileptic tolerance.

Tumor necrosis factor-α (TNFα) is a pleiotropic cytokine that can regulate cell survival, inflammation or, under certain circumstances, trigger cell death. Previous work in rat seizure models and analysis of temporal lobe samples from epilepsy patients has suggested seizures activate TNF receptor 1 (TNFR1). Here we explored the activation and functional significance of TNFR1 signaling in the mouse hippocampus using in vitro and in vivo models of seizure-induced neuronal injury. Focal-onset status epilepticus in mice upregulated TNFR1 levels and led to formation of TNFR1-TNFR-associated death domain (TRADD) and TRADD-Fas-associated death domain (FADD) binding. Seizure-like injury modeled in vitro by removal of chronic excitatory blockade in mouse hippocampal neurons also activated this TNFR1 signaling pathway. Prior exposure of hippocampal neurons to a non-harmful seizure episode, via NMDA receptor blockade, 24 h prior to injurious seizures significantly reduced cell death and modeled epileptic tolerance in vitro. TNFR1 complex formation with TRADD and TRADD-FADD binding were reduced in tolerant cells. Finally, TNFR1 signaling and cell death were reduced by PKF-242-484, a dual matrix metaloproteinase/TNFα converting enzyme inhibitor. The present study shows that TNFR1 signaling is activated in mouse seizure models and may contribute to neuropathology in vitro and in vivo while suppression of this pathway may underlie neuroprotection in epileptic tolerance.

Identification of a novel Bcl-2-interacting mediator of cell death (Bim) E3 ligase, tripartite motif-containing protein 2 (TRIM2), and its role in rapid ischemic tolerance-induced neuroprotection.

We have previously shown that the cell death-promoting protein Bcl-2-interacting mediator of cell death (Bim) is ubiquitinated and degraded following a neuroprotection-conferring episode of brief ischemia (preconditioning). Here, we identify the E3 ligase that ubiquitinates Bim in this model, using a proteomics approach. Using phosphorylated GST-Bim as bait, we precipitated and identified by mass spectrometry tripartite motif protein 2 (TRIM2), a RING (really interesting new gene) domain-containing protein. The reaction between TRIM2 and Bim was confirmed using co-immunoprecipitation followed by immunoblotting. We show that TRIM2 binds to Bim when it is phosphorylated by p42/p44 MAPK but does not interact with a nonphosphorylatable Bim mutant (3ABim). 12-O-tetradecanoylphorbol-13-acetate activation of p42/p44 MAPK drives Bim ubiquitination in mouse embryonic fibroblast cells and is associated with an increased interaction between TRIM2 and Bim. One hour following preconditioning ischemia, the binding of Bim to TRIM2 increased, consistent with the time window of enhanced Bim degradation. Blocking p42/p44 MAPK activation following preconditioning ischemia with U0126 or using the nonphosphorylatable 3ABim reduced the binding between Bim and TRIM2. Immunodepletion of TRIM2 from cell lysates prepared from preconditioned cells reduced Bim ubiquitination. Finally, suppression of TRIM2 expression, using lentivirus transduction of shRNAmir, stabilized Bim protein levels and blocked neuroprotection observed in rapid ischemic tolerance. Taken together, these data support a role for TRIM2 in mediating the p42/p44 MAPK-dependent ubiquitination of Bim in rapid ischemic tolerance.

Inducible cutaneous inflammation reveals a protumorigenic role for keratinocyte CXCR2 in skin carcinogenesis.

Transgenic mice that overexpress PKCalpha in the epidermis (K5-PKCalpha mice) exhibit acute CXCR2-mediated intraepidermal neutrophilic inflammation and a strong epidermal hyperplasia in response to application of 12-O-tetradecanoylphorbol-13-acetate (TPA). We now show that hyperplasia is independent of infiltrating neutrophils. Furthermore, when K5-PKCalpha mice were initiated with 7,12-dimethylbenz(a)anthracene (DMBA) and promoted with a low dose of TPA, 58% of K5-PKCalpha mice developed skin papillomas that progressed to carcinoma, whereas wild-type mice did not develop tumors. We confirmed that CXCR2 is expressed by keratinocytes and showed that transformation by oncogenic ras (a hallmark of DMBA initiation) or TPA exposure induced all CXCR2 ligands. Ras induction of CXCR2 ligands was mediated by autocrine activation of epidermal growth factor receptor and nuclear factor-kappaB, and potentiated by PKCalpha. Oncogenic ras also induced CXCR2 ligands in keratinocytes genetically ablated for CXCR2. However, ras transformed CXCR2 null keratinocytes formed only small skin tumors in orthotopic skin grafts to CXCR2 intact hosts, whereas transformed wild-type keratinocytes produced large tumors. In vitro, CXCR2 was essential for CXCR2 ligand-stimulated migration of ras-transformed keratinocytes and for ligand activation of the extracellular signal-regulated kinase (ERK) and Akt pathways. Both migration and activation of ERK and Akt were restored by CXCR2 reconstitution of CXCR2 null keratinocytes. Thus, activation of CXCR2 on ras-transformed keratinocytes has both promigratory and protumorigenic functions. The up-regulation of CXCR2 ligands after initiation by oncogenic ras and promotion with TPA in the mouse skin model provides a mechanism to stimulate migration by both autocrine and paracrine pathways and contribute to tumor development.

CXCR2 ligands and G-CSF mediate PKCalpha-induced intraepidermal inflammation.

Transgenic mice overexpressing PKCalpha in the epidermis (K5-PKCalpha mice) exhibit an inducible severe intraepidermal neutrophilic inflammation and systemic neutrophilia when PKCalpha is activated by topical 12-O-tetradecanoylphorbol-13-acetate (TPA). This inducible model of cutaneous inflammation was used to define mediators of skin inflammation that may have clinical relevance. Activation of cutaneous PKCalpha increased the production of the chemotactic factors cytokine-induced neutrophil chemoattractant (KC) and macrophage inflammatory protein 2 (MIP-2) in murine plasma. TPA treatment of cultured K5-PKCalpha keratinocytes also released KC and MIP-2 into culture supernatants through an NF-kappaB-dependent pathway. MIP-2 and KC mediated the infiltration of neutrophils into the epidermis, since this was prevented by ablating CXCR2 in K5-PKCalpha mice or administering neutralizing antibodies against KC or MIP-2. The neutrophilia resulted from PKCalpha-mediated upregulation of cutaneous G-CSF released into the plasma independent of CXCR2. These responses could be inhibited by topical treatment with a PKCalpha-selective inhibitor. Inhibiting PKCalpha also reduced the basal and TNF-alpha- or TPA-induced expression of CXCL8 in cultured psoriatic keratinocytes, suggesting that PKCalpha activity may contribute to psoriatic inflammation. Thus, skin can be the source of circulating factors that have both local and systemic consequences, and these factors, their receptors, and possibly PKCalpha could be therapeutic targets for inhibition of cutaneous inflammation.

Transport of galectin-3 between the nucleus and cytoplasm. I. Conditions and signals for nuclear import.

Galectin-3, a factor involved in the splicing of pre-mRNA, shuttles between the nucleus and the cytoplasm. We have engineered a vector that expresses the fusion protein containing the following: (a) green fluorescent protein as a reporter of localization, (b) bacterial maltose-binding protein to increase the size of the reporter polypeptide, and (c) galectin-3, whose sequence we wished to dissect in search of amino acid residues vital for nuclear localization. In mouse 3T3 fibroblasts transfected with this expression construct, the full-length galectin-3 (residues 1-263) fusion protein was localized predominantly in the nucleus. Mutants of this construct, containing truncations of the galectin-3 polypeptide from the amino terminus, retained nuclear localization through residue 128; thus, the amino-terminal half was dispensable for nuclear import. Mutants of the same construct, containing truncations from the carboxyl terminus, showed loss of nuclear localization. This effect was observed beginning with truncation at residue 259, and the full effect was seen with truncation at residue 253. Site-directed mutagenesis of the sequence ITLT (residues 253-256) suggested that nuclear import was dependent on the IXLT type of nuclear localization sequence, first discovered in the Drosophila protein Dsh (dishevelled). In the galectin-3 polypeptide, the activity of this nuclear localization sequence is modulated by a neighboring leucine-rich nuclear export signal.

Protein kinase C alpha-mediated chemotaxis of neutrophils requires NF-kappa B activity but is independent of TNF alpha signaling in mouse skin in vivo.

Protein kinase C (PKC) isoforms are major regulators of cutaneous homeostasis and mediate inflammation in response to 12-O-tetradecanoylphorbol-13-acetate (TPA). We have previously reported that transgenic mice overexpressing PKCalpha in the skin exhibit severe intraepidermal neutrophilic inflammation and keratinocyte apoptosis when treated topically with TPA. Activation of PKCalpha increases the production of TNFalpha and the transcription of chemotactic factors (MIP-2, KC, S100A8/A9), vascular endothelial growth factor, and GM-CSF in K5-PKCalpha keratinocytes. In response to PKCalpha activation, NF-kappaB translocates to the nucleus and this is associated with IkappaB phosphorylation and degradation. Preventing IkappaB degradation reduces both the expression of inflammation-associated genes and chemoattractant release. To determine whether TNFalpha mediated NF-kappaB translocation and subsequent expression of proinflammatory factors, K5-PKCalpha mice were treated systemically with a dimeric soluble form of p75 TNFR (etanercept) or crossed with mice deficient for both TNFR isoforms, and keratinocytes were cultured in the presence of TNFalpha-neutralizing Abs. The in vivo treatment and TNFR deficiency did not prevent inflammation, and the in vitro treatment did not prevent NF-kappaB nuclear translocation after TPA. Together these results implicate PKCalpha as a regulator of a subset of cutaneous cytokines and chemokines responsible for intraepidermal inflammation independent of TNFalpha. PKCalpha inhibition may have therapeutic benefit in some human inflammatory skin disorders.

Evaluation of donor-specific transfusion sources: unique failure of bone marrow cells to induce prolonged skin allograft survival with anti-CD154 monoclonal antibody.

BACKGROUND: Treatment with anti-CD154 monoclonal antibody (mAb) plus a donor-specific transfusion (DST) of spleen cells prolongs skin allograft survival in mice through a mechanism involving deletion of host alloreactive CD8(+) T cells. It is unknown if other lymphohematopoietic cell populations can be used as a DST. METHODS: Murine recipients of allogeneic skin grafts on day 0 were either untreated or given a DST on day -7 plus 4 doses of anti-CD154 mAb on days -7, -4, 0, and +4. Deletion of CD8(+) alloreactive cells was measured using "synchimeric" CBA recipients, which circulate trace populations of TCR transgenic alloreactive CD8(+) T cells. RESULTS: Transfusion of splenocytes, thymocytes, lymph node cells, or buffy coat cells led to prolonged skin allograft survival in recipients treated with anti-CD154 mAb. In contrast, bone marrow DST failed to delete host alloreactive CD8(+) T cells and was associated with brief skin allograft survival. Transfusions consisting of bone marrow-derived dendritic cells or a mixture of splenocytes and bone marrow cells were also ineffective. CONCLUSIONS: Donor-specific transfusions of splenocytes, thymocytes, lymph node cells, or buffy coat cells can prolong skin allograft survival in recipients treated with costimulation blockade. Bone marrow cells fail to serve this function, in part by failing to delete host alloreactive CD8(+) T cells, and they may actively interfere with the function of a spleen cell DST. The data suggest that transplantation tolerance induction protocols that incorporate bone marrow cells to serve as a DST may not be effective.