Thyroid hormones regulate cardiac repolarization and QT-interval related gene expression in hiPSC cardiomyocytes

Prolongation of cardiac repolarization (QT interval) represents a dangerous and potentially life-threatening electrical event affecting the heart. Thyroid hormones (THs) are critical for cardiac development and heart function. However, little is known about THs influence on ventricular repolarization and controversial effects on QT prolongation are reported. Human iPSC-derived cardiomyocytes (hiPSC-CMs) and multielectrode array (MEA) systems were used to investigate the influence of 3,3′,5-triiodo-l-Thyronine (T3) and 3,3′,5,5′-tetraiodo-l-Thyronine (T4) on corrected Field Potential Duration (FPDc), the in vitro analog of QT interval, and on local extracellular Action Potential Duration (APD). Treatment with high THs doses induces a significant prolongation of both FPDc and APD, with the strongest increase reached after 24 h exposure. Preincubation with reverse T3 (rT3), a specific antagonist for nuclear TH receptor binding, significantly reduces T3 effects on FPDc, suggesting a TRs-mediated transcriptional mechanism. RNA-seq analysis showed significant deregulation in genes involved in cardiac repolarization pathways, including several QT-interval related genes. In conclusion, long-time administration of high THs doses induces FPDc prolongation in hiPSC-CMs probably through the modulation of genes linked to QT-interval regulation. These results open the way to investigate new potential diagnostic biomarkers and specific targeted therapies for cardiac repolarization dysfunctions.

Influence of the Variability of Limestone and Fly Ash on the Setting and Mechanical Properties of a Moroccan Composite Cement

The Moroccan cement industry is looking for new processes to effectively minimize the high energy costs associated to cement manufacturing. This work presents the effect of three types of limestone with different chemical compositions and different CaCO3 contents on the physical and mechanical properties of resulting composite cements by the addition of fly ash in the proportions by weight of: 5 % and 10 %. The samples are studied in order to evaluate the interaction between different types of limestone and fly ash. Ternary cements based on fly ash-limestone-clinker induce a significant prolongation of the setting time compared to binary cements based on limestone-clinker. The substitution of clinker by limestone induces an improvement in mechanical strength compared to ternary cements in the first days; at 28 days, cements prepared with fly ashes reach significant strength due to their pozzolanic reaction.

The Grapefruit Flavonoid Naringenin Inhibits Multiple Cardiac Ion Channels

Drinking fresh grapefruit juice is associated with a significant prolongation of the QT segment on the electrocardiogram (ECG) in healthy volunteers. Among the prominent flavonoids contained in citrus fruits, the flavanone naringenin is known to be a blocker of the human ether-a-go-go related gene (hERG) potassium channel. We hypothesized that naringenin could interfere with other major ion channels shaping the cardiac ventricular action potential (AP). To this end, we examined the effects of naringenin on the seven currents comprising the Comprehensive in vitro Pro-Arrhythmia (CiPA) panel for early arrhythmogenic risk assessment in drug discovery and development. We used automated patch-clamp of human ion channels heterologously expressed in mammalian cell lines to evaluate half-maximal inhibitory concentrations (IC50). Naringenin blocked all CiPA currents tested with IC50 values in the 30 µM – 100 µM concentration-range. The rank-order of channel sensitivity was the following: hERG > Kir2.1 > NaV1.5 late > NaV1.5 peak > KV7.1 > KV4.3 > CaV1.2. This multichannel inhibitory profile of naringenin suggests exercising caution when large amounts of grapefruit juice or other citrus juices enriched in this flavanone are drunk in conjunction with QT prolonging drugs or by carriers of congenital long QT syndromes.

Acute neurological deterioration after surgical interruption of spinal dural arteriovenous fistulas: clinical characteristics, possible predictors, and treatment. Patient series

BACKGROUND Acute neurological deterioration develops paradoxically in some patients after obliteration of a spinal dural arteriovenous fistula (SDAVF), with thrombosis of the spinal cord veins as its primary cause. The authors aimed to clarify the clinical and radiological characteristics of acute deterioration to identify high-risk patients. They also discussed the optimal treatment for this complication. OBSERVATIONS Ten patients with SDAVF presenting with congestive myelopathy who received microsurgical interruption were retrospectively reviewed. Severe myelopathy developed in three patients on postoperative days 1 to 3. Anticoagulation therapy was effective; however, discontinuing anticoagulants under residual spinal cord congestion caused redeterioration. These patients were characterized by significantly extended transit time on angiography and significant prolongation of spinal cord congestion. Acute deterioration exhibited a strong correlation with transit time (coefficient, 0.825; p = 0.006) and a strong correlation with spinal cord edema before surgery (coefficient, 0.656; p = 0.040). LESSONS Acute deterioration after SDAVF treatment is likely to develop in patients with severe venous outflow impairment. Its pathology is prolonged spinal cord congestion caused by postoperative venous thrombosis and preexistent severe venous outflow impairment. Anticoagulation treatment should be continued for patients with acute deterioration until the resolution of spinal cord congestion is confirmed with magnetic resonance imaging.

Effect of the use of dexmedetomidine as a local anesthetic adjuvant to bupivacaine 0.125% in epidural labor analgesia: randomized controlled study

Background Multiple methods exist for the management of pain during normal labor. Epidural analgesia has been reported to be an effective method in that perspective. The current study was conducted to evaluate the efficacy of dexmedetomidine as an adjuvant to local anesthetics in epidural analgesia for pregnant females presented for normal delivery. Sixty pregnant females were included in this prospective randomized study, and they were divided into two equal groups: control group which received bupivacaine alone and dexmedetomidine group that received bupivacaine with dexmedetomidine. The primary outcome was the onset of analgesia, while the secondary outcomes included the duration of analgesia, hemodynamic changes, labor progress, neonatal outcomes, and maternal complications. Results Dexmedetomidine group was associated with earlier onset of analgesia (P ˂ 0.001), prolonged duration (P ˂ 0.001), and lower need for top-up doses (P ˂ 0.001) compared to control group. Also, sedation and maternal satisfaction were significantly better in the same group (P = 0.001, 0.025; respectively). Labor progress parameters and neonatal outcomes were comparable between the two groups. Dexmedetomidine group has lower heart rate and mean arterial blood pressure compared to the control group. Despite of dexmedetomidine group had higher incidence of hypotension and bradycardia, it was statistically insignificant when compared to control group. Conclusions Dexmedetomidine is a reliable and an effective adjuvant to the local anesthetics in epidural analgesia during normal delivery as it resulted in earlier onset and significant prolongation of the analgesic time with decrease in the top-up doses intake. Trial registration Pan African Clinical Trial Registry (PACTR201710002664704). Register on 3 October 2017.

IM-6 HVJ-E containing PD-L1 siRNA inhibits immunosuppressive activities and elicits antitumor immune responses in glioma

Inactivated Sendai virus particle, hemagglutinating virus of Japan-envelope (HVJ-E), is a non-replicating virus-derived vector, in which the genomic RNA of Sendai virus (HVJ) has been destroyed. HVJ-E is a promising vector that enables the highly efficient and safe introduction of enclosed molecules such as RNA into target cells. Moreover, HVJ-E provokes robust antitumoral immunity by activating natural killer (NK) cells and CD8+ T lymphocytes and their induction into the tumor periphery, and by suppressing regulatory T lymphocytes (Treg) locally in the tumor. In the present study, we investigated a novel combination of antitumor immunotherapy by the antitumor immune-activating effect of HVJ-E itself with the inhibition of tumor PD-L1 molecule expression. We confirmed that intratumoral injection of HVJ-E containing siRNA targeting PD-L1 (siPDL1/HVJ-E) inhibited tumor PD-L1 protein expression in a mouse subcutaneous tumor model using TS, a mouse glioma stem-like cell. We conducted treatment experiments in the mouse brain tumor model in three groups: control group (PBS), siNC/HVJ-E group (negative control siRNA + HVJ-E), and siPDL1/HVJ-E group. We obtained a significant prolongation of overall survival in the siPDL1/HVJ-E group. Flow cytometric analyses of brain tumor models showed that the proportions of brain-infiltrating CD8+ T lymphocytes and NK cells were significantly increased after giving siPDL1/HVJ-E; in contrast, the rate of Treg/CD4+ lymphocytes was significantly decreased in HVJ-E-treated tumors (siNC/HVJ-E and siPDL1/HVJ-E). No difference was observed in the proportions of macrophages or M2 macrophages. CD8 depletion abrogated the therapeutic effect of siPDL1/HVJ-E, indicating that CD8+ T lymphocytes mainly mediated this therapeutic effect. We believe that this non-replicating immunovirotherapy may be a novel therapeutic alternative to treat patients with glioblastoma. The full article has been published (Cancer Science. 2021 Jan;112(1):81–90).

The Effect of Intravenous Dexamethasone and Dexmedetomidine on Analgesia Duration of Supraclavicular Brachial Plexus Block: A Randomized, Four-Arm, Triple-Blinded, Placebo-Controlled Trial

Intravenous dexamethasone and dexmedetomidine, in conjunction with peripheral nerve blockade, have each been reported to prolong the duration of analgesia. This study tested whether combined use further prolongs analgesia duration after supraclavicular brachial plexus block (BPB) in patients undergoing orthopedic upper extremity surgery. One hundred twenty patients were randomized 1:1:1:1 to Control (saline bolus and midazolam infusion [0.05 mg/kg loading, 20 µg/kg/h thereafter]); DMED (saline bolus and dexmedetomidine infusion [1 μg/kg loading, 0.4 μg/kg/h thereafter]); DEXA (dexamethasone [10 mg] bolus and midazolam infusion); and DMED-DEXA (dexmedetomidine infusion and dexamethasone bolus) groups. The primary outcome was the duration of postoperative analgesia, defined as the time from the end of the BPB to the first dose of analgesia via a patient-controlled device. Median (interquartile range) times to first dose of analgesia in the Control, DMED, DEXA, and DMED-DEXA groups were 8.1 (6.2–11.6), 9.0 (8.1–11.3), 10.7 (8.1–20.5), and 13.2 (11.5–19.1) hours, respectively (p < 0.001). Pairwise comparisons showed significant prolongation of analgesia in the DEXA included groups compared with the non-DEXA included groups (DEXA vs. control, p = 0.045; DEXA vs. DMED, p = 0.045; DMED-DEXA vs. control, p < 0.001; DMED-DEXA vs. DMED, p < 0.001). A mixed effect model showed that dexamethasone was the only significant factor for the prolongation of analgesia (p < 0.001). Intravenous dexamethasone prolonged the analgesia duration of supraclavicular BPB after orthopedic upper extremity surgery. The concurrent use of mild to moderate sedation dose of intravenous dexmedetomidine in addition to intravenous dexamethasone showed no additional benefit to the prolongation of analgesia.

Impact of Graft-Resident Leucocytes on Treg Mediated Skin Graft Survival

The importance and exact role of graft-resident leucocytes (also referred to as passenger leucocytes) in transplantation is controversial as these cells have been reported to either initiate or retard graft rejection. T cell activation to allografts is mediated via recognition of intact or processed donor MHC molecules on antigen-presenting cells (APC) as well as through interaction with donor-derived extracellular vesicles. Reduction of graft-resident leucocytes before transplantation is a well-known approach for prolonging organ survival without interfering with the recipient’s immune system. As previously shown by our group, injecting mice with IL-2/anti-IL-2 complexes (IL-2cplx) to augment expansion of CD4 T regulatory cells (Tregs) induces tolerance towards islet allografts, and also to skin allografts when IL-2cplx treatment is supplemented with rapamycin and a short-term treatment of anti-IL-6. In this study, we investigated the mechanisms by which graft-resident leucocytes impact graft survival by studying the combined effects of IL-2cplx-mediated Treg expansion and passenger leucocyte depletion. For the latter, effective depletion of APC and T cells within the graft was induced by prior total body irradiation (TBI) of the graft donor. Surprisingly, substantial depletion of donor-derived leucocytes by TBI did not prolong graft survival in naïve mice, although it did result in augmented recipient leucocyte graft infiltration, presumably through irradiation-induced nonspecific inflammation. Notably, treatment with the IL-2cplx protocol prevented early inflammation of irradiated grafts, which correlated with an influx of Tregs into the grafts. This finding suggested there might be a synergistic effect of Treg expansion and graft-resident leucocyte depletion. In support of this idea, significant prolongation of skin graft survival was achieved if we combined graft-resident leucocyte depletion with the IL-2cplx protocol; this finding correlated along with a progressive shift in the composition of T cells subsets in the grafts towards a more tolerogenic environment. Donor-specific humoral responses remained unchanged, indicating minor importance of graft-resident leucocytes in anti-donor antibody development. These results demonstrate the importance of donor-derived leucocytes as well as Tregs in allograft survival, which might give rise to new clinical approaches.

Endobronchial Therapy With Gentamicin and Dexamethasone After Airway Clearance by Bronchoscopy in Exacerbation of Non-Cystic Fibrosis Bronchiectasis: A Real-World Observational Study

Background: The exacerbation of non-cystic fibrosis bronchiectasis (NCFB) may lead to poor prognosis. The objective of this study was to retrospectively analyze the clinical efficacy and safety of endobronchial therapy with gentamicin and dexamethasone after airway clearance by bronchoscopy in the exacerbation of NCFB.Methods: We retrospectively reviewed 2,156 patients with NCFB between January 2015 and June 2016 and 367 consecutive patients with exacerbation of bronchiectasis who had complete data and underwent airway clearance (AC) by bronchoscopy. The final cohort included 181 cases of intratracheal instillation with gentamicin and dexamethasone after AC (a group with airway drugs named the drug group) and 186 cases of AC only (a group without airway drugs named the control group). The last follow-up was on June 30, 2017.Results: The total cough score and the total symptom score in the drug group were improved compared to those in the control group during 3 months after discharge (p &lt; 0.001). Re-examination of chest HRCT within 4–6 months after discharge revealed that the improvements of peribronchial thickening, the extent of mucous plugging, and the Bhalla score were all significantly improved in the drug group. Moreover, the re-exacerbations in the drug group were significantly decreased within 1 year after discharge. Univariate analysis showed a highly significant prolongation of the time to first re-exacerbation in bronchiectasis due to treatment with airway drugs compared with that of the control group. Multivariate Cox regression analysis showed that the risk of first re-exacerbation in the drug group decreased by 29.7% compared with that of the control group.Conclusion: Endobronchial therapy with gentamicin and dexamethasone after AC by bronchoscopy is a safe and effective method for treating NCFB.

Preclinical Evaluation of a Novel Orally Bioavailable Menin-MLL Interaction Inhibitor, DSP-5336, for the Treatment of Acute Leukemia Patients with MLL-Rearrangement or NPM1 Mutation

Background: The 11q23 abnormalities involving mixed lineage leukemia (MLL) gene are frequently found in adult and pediatric patients with acute leukemia. MLL rearrangements (MLL-r) are often associated with a poor prognosis and show poor response to currently available therapies, thus developing more effective therapy is urgently required. The leukemogenic activity of MLL fusion proteins, the products of the chimeric genes of MLL and its fusion partners generated by MLL-r, is critically dependent on direct interaction with MENIN, the product of the MEN1 gene. Interaction of MLL fusion proteins with MENIN plays an important role to enhance the proliferation and to block the differentiation of hematopoietic cells by maintaining high expression of hematopoietic stem cell program genes, such as HOXA9 and MEIS1. It has also been reported that the MENIN interaction with wild-type MLL, is required to induce HOXA9 and MEIS1 expression and also crucial for the development of acute leukemia with nucleophosmin (NPM1) mutations. Therefore, the MENIN-MLL interaction inhibitor is expected to have anti-leukemogenic activity against acute leukemia with MLL-r or NPM1 mutation by suppressing the expression of HOXA9 and MEIS1 and inducing terminal differentiation. Results: We generated DSP-5336, a novel, potent, and orally bioavailable MENIN-MLL interaction inhibitor for the treatment of acute leukemia patients with MLL-r or NPM1 mutation. DSP-5336 directly bound to the MENIN protein (Kd = 6.0 nM) and inhibited the MENIN-MLL interaction (IC 50 = 1.4 ± 0.058 nM). DSP-5336 selectively inhibited the cell growth of human leukemia cell lines including MV-4-11, MOLM-13, KOPN-8, and OCI-AML3 (IC 50 = 10, 15, 31 and 15 nM, respectively). These DSP-5336-sensitive cell lines possess a MLL-r or NPM1 mutation. On the other hand, DSP-5336 did not affect the cell growth of human leukemia cell lines such as HL-60, MOLT-4, and Reh (IC 50 &gt; 10 μM), which do not have MLL-r or NPM1 mutations. In a mouse xenograft model using MV-4-11 cells, which express MLL-AF4, DSP-5336 exhibited a significant antitumor activity at the doses of 25 mg/kg and 50 mg/kg, administered twice daily (BID) for 20 days. There were no dose related changes in general condition or body weight. The effects of DSP-5336 on the expression of MENIN-MLL-regulated genes and differentiation marker genes were evaluated using MV-4-11 cells as pharmacodynamics markers in vitro and in vivo. In both cases, DSP-5336 significantly reduced the gene expression of MEIS1 and HOXA9, representative leukemic genes regulated by the MENIN-MLL complex. On the contrary, DSP-5336 significantly increased the gene expression level of ITGAM, a terminal differentiation marker. The efficacy of DSP-5336 was further assessed in acute leukemia patient samples and in mouse AML models. DSP-5336 strongly inhibited blast colony formation and changed the gene expression of the pharmacodynamics markers (HOXA9, MEIS1 and ITGAM ) in an AML patient sample carrying the MLL-AF6 fusion. In patient-derived xenograft (PDX) model with NPM1 mutation, human CD45 positive cells in peripheral blood progressively decreased during and beyond the 28 day period of DSP-5336 administration at doses of 25, 50, and 100 mg/kg BID and achieved a complete remission with no relapse at the doses of 50 and 100 mg/kg BID. At these three dose levels, DSP-5336 also induced a significant prolongation of survival compared to the vehicle control. Similarly, in a PDX model with MLL-AF4, DSP-5336 induced complete remission and significant prolongation of survival at the doses of 100 mg/kg BID compared to the vehicle control. In mouse AML models wherein MLL-ENL- or MLL-AF10-transduced bone marrow cells are transplanted in syngeneic mice, DSP-5336 induced a significant prolongation of survival at the doses of 200 mg/kg once daily (QD) compared to the vehicle control and the standard chemo therapy (cytarabine+daunorubicin) group. Summary: DSP-5336 has a potential as an antitumor drug that provides survival advantages in acute leukemia patients with MLL rearrangement or NPM1 mutation. Currently, a Phase 1/2 clinical study of DSP-5336 is planned in AML and ALL patients. Disclosures Eguchi: Sumitomo Dainippon Pharma: Current Employment. Shimizu: Sumitomo Dainippon Pharma: Current Employment. Kato: Sumitomo Dainippon Pharma: Current Employment. Furuta: Sumitomo Dainippon Pharma: Current Employment. Kamioka: Sumitomo Dainippon Pharma: Current Employment. Ban: Sumitomo Dainippon Pharma: Current Employment. Ymamoto: Sumitomo Dainippon Pharma: Current Employment. Yokoyama: Sumitomo Dainippon Pharma: Research Funding. Kitabayashi: Sumitomo Dainippon Pharma: Research Funding.