Novel portable hypothermic machine perfusion preservation device enhances cardiac viability of donated human hearts.

Introduction: Heart transplant remains the gold standard treatment for patients with advanced heart failure. However, the list of patients waiting for a heart transplant continues to increase. We have developed a portable hypothermic oxygenated machine perfusion device, the VP.S ENCORE®, to extend the allowable preservation time. The purpose of this study was to test the efficacy of the VP.S. ENCORE® using deceased donors derived hearts. Methods: Hearts from brain-dead donors not utilized for transplant (n = 11) were offered for research from the Texas Organ Sharing Alliance (TOSA), South and Central Texas' Organ Procurement Organization (OPO) and were preserved in the VP.S ENCORE® for 4 (n = 2), 6 (n = 3), and 8 (n = 3) hours or were kept in static cold storage (SCS) (n = 3). After preservation, the hearts were placed in an isolated heart Langendorff model for reperfusion and evaluated for cardiac function. Results: The mean donor age was 37.82 ± 12.67 with the youngest donor being 19 and the oldest donor being 58 years old. SCS hearts mean weight gain (%) was -1.4 ± 2.77, while perfused at 4 h was 5.6 ± 6.04, perfused at 6 h 2.1 ± 6.04, and 8 h was 7.2 ± 10.76. Venous and arterial lactate concentrations were less than 2.0 mmol/L across all perfused hearts. Left ventricular contractility (+dPdT, mmHg/s) for 4 h (1,214 ± 1,064), 6 (1,565 ± 141.3), and 8 h (1,331 ± 403.6) were within the range of healthy human heart function. Thus, not significant as compared to the SCS group (1,597 ± 342.2). However, the left ventricular relaxation (mmHg/s) was significant in 6-hour perfused heart (p < 0.05) as compared to SCS. Gene expression analysis of inflammation markers (IL-6, IL-1ß) showed no significant differences between SCS and perfused hearts, but a 6-hour perfusion led to a downregulated expression of these markers. Discussion: The results demonstrate that the VP.S ENCORE® device enhances cardiac viability and exhibits comparable cardiac function to a healthy heart. The implications of these findings suggest that the VP.S ENCORE® could introduce a new paradigm in the field of organ preservation, especially for marginal hearts.

Synthesis and evaluation of novel trifunctional chelating agents for pretargeting approach using albumin binder to improve tumor accumulation.

INTRODUCTION: The pretargeting approach consists of in vivo ligation between pre-injected antibodies and low-molecular-weight radiolabeled effectors. The advantage of the pretargeting approach is to improve a tumor-to-background ratio, but the disadvantage is to compromise tumor accumulation. In this study, we applied albumin binder (ALB) to the pretargeting approach to overcome low tumor accumulation. METHODS: We synthesized two novel trifunctional effectors containing an ALB moiety, a chelator, and a different tetrazine and two corresponding effectors without an ALB moiety. Albumin-binding assays and stability assays were performed using 111In-labeled effectors. Measurements of reaction rate constant were conducted using 111In-labeled effectors and anti-HER2 antibody trastuzumab modified by trans-cyclooctene, which drives the click reaction with tetrazine. Biodistribution studies using HER2-expressing tumor-bearing mice were performed with or without the pretargeting approach. RESULTS: In albumin-binding assays, ALB-containing effectors exhibited a marked binding to albumin. Two ALB-containing effectors showed the difference in the reactivity and the slight difference in the stability. In biodistribution studies without the pretargeting approach, two ALB-containing effectors showed different pharmacokinetics in blood retention. With the pretargeting approach, the tumor accumulation was improved by the introduction of ALB and the highest tumor accumulation was observed in using the ALB-containing effector with higher blood retention. CONCLUSION: These results suggest that the application of ALB to the pretargeting approach is effective to improve tumor accumulation, and the structure of tetrazine influences the utility of ALB-containing effectors.

HIV-Tocky system to visualize proviral expression dynamics.

Determinants of HIV-1 latency establishment are yet to be elucidated. HIV reservoir comprises a rare fraction of infected cells that can survive host and virus-mediated killing. In vitro reporter models so far offered a feasible means to inspect this population, but with limited capabilities to dissect provirus silencing dynamics. Here, we describe a new HIV reporter model, HIV-Timer of cell kinetics and activity (HIV-Tocky) with dual fluorescence spontaneous shifting to reveal provirus silencing and reactivation dynamics. This unique feature allows, for the first time, identifying two latent populations: a directly latent, and a recently silenced subset, with the latter having integration features suggestive of stable latency. Our proposed model can help address the heterogeneous nature of HIV reservoirs and offers new possibilities for evaluating eradication strategies.

Synthesis and biological evaluation of radioiodinated benzoxazole and benzothiazole derivatives for imaging myelin in multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that results from destruction of the myelin sheath. Due to heterogeneity of the symptoms and course of MS, periodic monitoring of disease activity is important for diagnosis and treatment. In the present study, we synthesized four radioiodinated benzoxazole (BO) and benzothiazole (BT) derivatives, and evaluated their utility as novel myelin imaging probes for single photon emission computed tomography (SPECT). In a biodistribution study using normal mice, three compounds ([125I]BO-1, [125I]BO-2, and [125I]BT-2) displayed moderate brain uptake (2.7, 2.9, and 2.8% ID/g, respectively) at 2 min postinjection. On ex vivo autoradiography using normal mice, [125I]BO-2 showed the most preferable ratio of radioactivity accumulation in white matter (myelin-rich region) versus gray matter (myelin-deficient region). In addition, the radioactivity of [125I]BO-2 was reduced in the lysophosphatidylcholine-induced demyelination region. In conclusion, [123I]BO-2 demonstrated the fundamental characteristics of a myelin imaging probe for SPECT.

[Radiotheranostics Based on Chemical Control of Radioactivity Pharmacokinetics].

Recently, radiotheranostics, which systematically combines diagnosis by nuclear medicine imaging and treatment by internal radiotherapy, constitutes a new modality in cancer treatment, with some clinical reports showing marked effects on cancer. We have been developing multifunctional chelates containing a target recognition unit, a radiation release unit, and a radioactivity pharmacokinetics control unit in the same molecule to develop efficient agents for cancer radiotheranostics based on chemical control of radioactivity pharmacokinetics. Using these compounds, we have achieved improved cancer accumulation and reduced renal accumulation in tumor-bearing mice, and have developed novel hybrid radiotheranostic agents that can be applied to simultaneously perform target-specific molecular imaging using γ-ray emitting radionuclides and internal radiotherapy using α-particle-emitting radionuclides. For example, 111In/225Ac-labeled PSMA-DA1, which targets prostate-specific membrane antigen (PSMA) for radiotheranostics, achieved clear in vivo imaging of PSMA in tumor-bearing mice and showed marked tumor growth inhibition. In addition to PSMA, this platform for radiotheranostics has also shown efficacy against various cancer target molecules, including carbonic anhydrase IX (CA-IX), which is highly expressed in hypoxic regions of cancer, and glucagon-like peptide-1 receptor (GLP-1R), which is highly expressed in insulinomas. This review presents these recent results of our studies on radiotheranostics for cancer.

Impact of moderate to vigorous intensity physical activity on change in renal function in patients after acute myocardial infarction.

Acute myocardial infarction (AMI) is associated with a decline in renal function. This study aimed to investigate the impact of engaging in moderate to vigorous intensity physical activity (MVPA) for more than 30 min per day on changes in renal function during the first 3 months after AMI onset. A prospective, observational study was conducted, enrolling 87 patients (75 men; average age, 65.2 ± 12.5 years) who had experienced AMI. The cystatin C-based estimated glomerular filtration rate (eGFRcys) was collected at and 3 months after discharge. Daily MVPA was measured using triaxial accelerometers at a threshold of 3.0 Metabolic equivalent of the task for 3 months. Generalized estimating equations (GEE) were applied to evaluate the longitudinal association between the number of days per week of MVPA for 30 min or more and within-patient changes in eGFRcys. The patients were categorized into three groups based on their MVPA engagement days: 0 days (n = 20), 1-2 days (n = 14), and 3-7 days (n = 53) groups. After adjusting for potential confounding variables, GEE analysis revealed that the eGFRcys slope over 3 months was significantly higher in the 3-7 days group than in 0 days group (B = 2.9, (95% confidence interval: 1.5-4.2), p < 0.001). Similar results were obtained when MVPA time thresholds were set to 40 and 60 min. These findings suggest a significant positive effect of engaging in MVPA for 30 min or more for 3-7 days per week in the improvement of renal function after AMI onset.

Synthesis and biological evaluation of novel 18F-labeled 2,4-diaminopyrimidine derivatives for detection of ghrelin receptor in the brain.

The ghrelin receptor (GHSR) is known to regulate various physiological processes including appetite, food intake, and growth hormone release. Its expression is mainly observed in the brain, pancreas, stomach, and intestine. However, the functions of the receptor have not been fully elucidated. GHSR imaging with positron emission tomography (PET) is expected to further understanding of the functions and pathologies of the receptor. In this study, we newly designed and synthesized diaminopyrimidine derivatives ([18F]BPP-1 and [18F]BPP-2) and evaluated their utility as novel PET probes targeting GHSR. In in vitro competitive binding assays, the binding affinity of BPP-2 for GHSR (Ki = 274 nM) was comparable to that of the diaminopyimidine lead compound Abb8a (Ki = 109 nM). In a biodistribution study using normal mice, [18F]BPP-2 displayed low uptake in the brain and moderate uptake in the pancreas, but high radioactivity accumulation in bone was observed due to its defluorination in vivo. Taken together, although further improvement of the pharmacokinetics is needed, the diaminopyrimidine scaffold has potential for the development of useful GHSR-targeting PET probes.

Synthesis and biological evaluation of bi-modal BODIPY-conjugated Hoechst applicable for Auger-electron and photodynamic cancer therapy.

Current therapeutic approaches to cancer are not fully effective, and so development of more effective treatment is needed. Auger-electron therapy and photodynamic therapy have attracted marked attentions as a promising strategy in cancer treatment. In this study, we synthesized [125I]BH-2/BH-2, which comprised Hoechst and 2,6-diiodo-substituted BODIPY, and evaluated its usefulness as a bi-modal agent for Auger-electron/photodynamic therapy by comparison with the previously reported compound [125I]BH/BH. [125I]BH-2 was obtained at a 13% radiochemical yield. [125I]BH-2 showed similar uptake into the nucleus to [125I]BH, suggesting that Hoechst can function as a nuclear localization tag. HeLa cell viabilities were reduced in both cells exposed to [125I]BH-2 and [125I]BH. γ-H2AX foci in HeLa cells exposed to [125I]BH-2 or [125I]BH were increased in a dose-dependent manner, indicating that DNA double-strand breaks may have occurred. No significant difference was observed between [125I]BH-2 and [125I]BH at these investigations. For PDT application, BH-2 showed a higher singlet oxygen quantum yield (ΦΔ) and caused superior photo-induced cytotoxicity in HeLa cells compared with BH. These results suggest that bi-modal [125I]BH-2/BH-2 can cause anti-tumor effects with Auger-electron and photodynamic therapy.

In Vivo Near-Infrared Fluorescence Imaging Selective for Soluble Amyloid ß Aggregates Using y-Shaped BODIPY Derivative.

Soluble amyloid ß (Aß) aggregates, suggested to be the most toxic forms of Aß, draw attention as therapeutic targets and biomarkers of Alzheimer's disease (AD). As soluble Aß aggregates are transient and diverse, imaging their diverse forms in vivo is expected to have a marked impact on research and diagnosis of AD. Herein, we report a near-infrared fluorescent (NIRF) probe, BAOP-16, targeting diverse soluble Aß aggregates. BAOP-16, whose molecular shape resembles "y", showed a marked selective increase in fluorescence intensity upon binding to soluble Aß aggregates in the near-infrared region and a high binding affinity for them. Additionally, BAOP-16 could detect Aß oligomers in the brains of Aß-inoculated model mice. In an in vivo fluorescence imaging study of BAOP-16, brains of AD model mice displayed significantly higher fluorescence signals than those of wild-type mice. These results indicate that BAOP-16 could be useful for the in vivo NIRF imaging of diverse soluble Aß aggregates.

Development of Novel Trifunctional Chelating Agents That Enhance Tumor Retention of Radioimmunoconjugates.

Chelator-containing radioimmunoconjugates (RICs) composed of monoclonal antibodies, chelators, and radiometals exhibit broad potential for cancer diagnosis or therapy. In this study, we developed novel trifunctional chelating agents that enhance the tumor retention of RICs, MDPEI2, and MDPEI4, which contain the metal chelator DOTA, a maleimide moiety, and diethylenetriamine (PEI2) or tetraethylenepentamine (PEI4), respectively, as a poly(ethylenimine) (PEI) scaffold for the addition of positive charges to the radiometabolites of RICs to reduce their release from tumor cells. Trastuzumab radiolabeled by [111In]In-MDPEI2 ([111In]In-TMDPEI2) or [111In]In-MDPEI4 ([111In]In-TMDPEI4) showed high immunoreactivity and lower rates of exportations of their radiometabolites from tumor cells than RICs without PEI scaffolds. The tumor uptake of [111In]In-TMDPEI2 and [111In]In-TMDPEI4 was enhanced compared with RICs without PEI scaffolds, and [111In]In-TMDPEI2 exhibited the highest tumor/blood ratio. These results indicate the utility of MDPEI2 to synthesize RICs with favorable tumor-targeting properties in vivo by controlling the radioactivity distribution in tumor cells.

Antitumor Effect of Galectin-9 on Cell Proliferation and Tumor Growth of Human Duodenal Adenocarcinoma Cells.

BACKGROUND/AIM: Galectin-9 (Gal-9) induces tumor cell apoptosis in lymphoma and other malignant cell types. Duodenal adenocarcinoma is a rare malignancy, and there are insufficient data to determine a standard therapeutic approach. Here, we investigated the antitumor effect of Gal-9 in HuTu-80 duodenal adenocarcinoma cells. MATERIALS AND METHODS: Cell proliferation was examined in HuTu-80 cells using a Cell Counting Kit-8 assay. Cell cycle analysis, apoptosis array, and microRNA expression analysis were performed to identify the effect of Gal-9 on HuTu-80 cells. The antitumor effect of Gal-9 was also examined using xenograft mouse models. RESULTS: Gal-9 suppressed the proliferation of HuTu-80 via blockade of the G0 to G1 cell cycle transition. This blockade was accompanied by a strong decrease in cyclin D1 and phosphorylated Rb, suggesting a G1 arrest. Additionally, Gal-9 induced apoptosis, and the expression of cleaved caspase-3 was increased in Gal-9-treated HuTu-80 cells according to the apoptosis array. MiRNA microarrays revealed that Gal-9 altered the expression of miRNAs in HuTu-80 cells. CONCLUSION: These data demonstrate the therapeutic potential of Gal-9 and provide molecular mechanistic insights into its antitumor effect in HuTu-80 cells.

Development of Novel 111In/225Ac-Labeled Agent Targeting PSMA for Highly Efficient Cancer Radiotheranostics.

Prostate-specific membrane antigen (PSMA) is a promising target for metastatic castration-resistant prostate cancer. We previously reported the effectiveness of PSMA-DA1 as a PSMA-targeting radiotheranostic agent containing an albumin binder moiety. To further enhance tumor uptake, we newly designed PSMA-NAT-DA1 (PNT-DA1) by the introduction of a lipophilic linker into PSMA-DA1. The PSMA affinity of [111In]In-PNT-DA1 was increased (Kd = 8.20 nM) compared with that of [111In]In-PSMA-DA1 (Kd = 89.4 nM). [111In]In-PNT-DA1 showed markedly high tumor accumulation (131.6% injected dose/g at 48 h post-injection), and [111In]In-PNT-DA1 enabled the visualization of the tumor clearly at 24 h post-injection with SPECT/CT imaging. The administration of [225Ac]Ac-PNT-DA1 (2.5 kBq) led to shrinkage of the tumor without marked toxicity, and the antitumor effects of [225Ac]Ac-PNT-DA1 were superior to those of [225Ac]Ac-PSMA-DA1 and [225Ac]Ac-PSMA-617, which is the current gold standard for PSMA-targeting 225Ac-endoradiotherapy. These results suggest that the combination of [111In]In-PNT-DA1 and [225Ac]Ac-PNT-DA1 comprises a promising method of PSMA-targeting radiotheranostics.

Synthesis and evaluation of 111 In-labeled tetrapeptide-based compounds as single-photon emission computed tomography imaging probes targeting granzyme B.

Granzyme B is an attractive target as a biomarker for contributing to improve the treatment with immune checkpoint inhibitor (ICI). In this study, we designed novel 111 In-labeled granzyme B-targeting single-photon emission computed tomography (SPECT) imaging probes, [111 In]IDT and [111 In]IDAT. Nonradioactive In-labeled granzyme B-targeting compounds ([nat In]IDT, [nat In]IDAT) showed the affinity for recombinant mouse granzyme B. [111 In]IDT and [111 In]IDAT were obtained with moderate radiochemical yield and high stability in mouse plasma (>95%). In a biodistribution experiment using tumor-bearing mice, [111 In]IDT and [111 In]IDAT showed moderate accumulation in tumor. Ex vivo autoradiography (ARG) indicated that the accumulation of radioactivity in tumor was correlated to expression of granzyme B confirmed by the immunohistochemical staining. These results indicated that [111 In]IDT and [111 In]IDAT showed the basic properties as granzyme B-targeting SPECT probes.

Use of endoscopic gallbladder stenting and biliary scintigraphy for diagnosis of gallbladder dyskinesia: a case report.

A 40-year-old woman visited our hospital with a several-year history of right hypochondriac pain and vomiting after eating. She had been treated for functional dyspepsia, with no improvement in her symptoms. No gallstones were detected on imaging tests, but papillary insufficiency or dyskinesia of the gallbladder was suspected and biliary scintigraphy was performed. Biliary scintigraphy showed delayed excretion of radionuclides from the gallbladder and bile ducts into the duodenum. We initially suspected papillary dysfunction and performed endoscopic sphincterotomy, but there was no improvement in her symptoms. Biliary scintigraphy also showed delayed excretion of radionuclides, especially stagnation of radionuclides in the gallbladder. We suspected gallbladder dyskinesia and performed endoscopic gallbladder stenting, after which her symptoms disappeared and biliary scintigraphy showed improved excretion of radionuclides into the duodenum. Endoscopic gallbladder stenting may be useful for the diagnosis of gallbladder dyskinesia and for determining the efficacy of cholecystectomy.

The G protein-coupled receptor neuropeptide receptor-15 modulates larval development via the transforming growth factor-ß DAF-7 protein in Caenorhabditis elegans.

G protein-coupled receptors (GPCRs) are a major class of membrane receptors that modulate a wide range of physiological functions. These receptors transmit extracellular signals, including secreted bioactive peptides, to intracellular signaling pathways. The nematode Caenorhabditis elegans has FMRFamide-like peptides, which are one of the most diverse neuropeptide families, some of which modulate larval development through GPCRs. In this study, we identified the GPCR neuropeptide receptor (NPR)-15, which modulates C. elegans larval development. Our molecular genetic analyses indicated the following: 1) NPR-15 mainly functions in ASI neurons, which predominantly regulate larval development, 2) NPR-15 interacts with GPA-4, a C. elegans Gα subunit, and 3) NPR-15, along with GPA-4, modulates larval development by regulating the production and secretion of the transforming growth factor-ß (TGF-ß)-like protein DAF-7. The present study is the first report to demonstrate the importance of a GPCR to the direct regulation of a TGF-ß-like protein.

Single center experience and early outcomes of Impella 5.5.

Background: Acute decompensated heart failure (HF) and cardiogenic shock (CS) frequently are refractory to conservative treatment and require mechanical circulatory support (MCS). We report our early clinical experience and evaluate patient outcomes with the newer generation surgical Impella 5.5. Methods: Seventy patients that underwent Impella 5.5 implantation between October 2019 and December 2021 at a single center were enrolled in this study. Pre-operative characteristics, peri-operative clinical course information, and post-operative outcomes were retrospectively collected. Results: Fifty-seven (81%) patients survived to discharge, and 51 (76%) patients survived at the time of the first 30 days post-discharge visit. Thirty-one patients (44%) received Impella support for a bridge to advanced surgical heart failure therapy (transplant or durable left ventricular assist device [LVAD]), 27 (39%) cases were used for a bridge to recovery/decision and 12 (17.1%) cases was used for planned perioperative support for high-risk cardiac surgery procedure. Conclusion: Our results suggest that Impella 5.5 provides favorable survival in the management of HF and CS, particularly used for a bridge to heart transplant or LVAD. Early extubation and mobilization with high flow circulatory support allowed effective tailoring of MCS approaches from peri-operative support for high-risk cardiac surgery, bridge to recovery, and to advanced surgical heart failure therapy.

Synthesis and Characterization of Novel Radioiodinated Triazole-Pyrolidine Derivative to Detect Orexin 2 Receptor in the Brain.

It is generally accepted that the orexin 2 receptor (OX2R) plays a critical role in the arousal-promoting function, and in vivo imaging of OX2R is expected to contribute to elucidation of orexin systems and the development of drugs to treat sleep disorder. In this study, we newly synthesized and characterized a radioiodinated triazole-pyrolidine derivative ([125I]TPI) to detect OX2R in the brain. In vitro studies using OX1R or OX2R expression cells showed selective binding of [125I]TPI to OX2R. In addition, in vitro autoradiography using rat brain sections showed high accumulation of radioactivity in the OX2R expression region. However, [125I]TPI showed low brain uptake in normal mice. These results suggest that [125I]TPI has a fundamental character to detect OX2R in vitro, but further structural modification to improve brain pharmacokinetics is required to use it for in vivo detection of OX2R.

Hoechst-tagged radioiodinated BODIPY derivative for Auger-electron cancer therapy.

Targeted radionuclide therapy using Auger electrons is a promising strategy in cancer treatment. A DNA-binding Hoechst-tagged radioiodinated BODIPY derivative ([125I]BH) has been prepared as an Auger therapeutic agent. [125I]BH showed high accumulation in the nucleus of HeLa cells and cytotoxicity caused by DNA double-strand breaks.

The FMRFamide-like peptide FLP-1 modulates larval development by regulating the production and secretion of the insulin-like peptide DAF-28 in Caenorhabditis elegans.

The FMRFamide-like peptides (FLPs) are conserved in both free-living and parasitic nematodes. This molecular genetic study verified the relevance of the flp-1 gene, which is conserved in many nematode species, to the larval development of the free-living soil nematode Caenorhabditis elegans. Using C. elegans as a model, we found that: (1) FLP-1 suppressed larval development, resulting in diapause; (2) the secretion of FLP-1, which is produced in AVK head neurons, was suppressed by the presence of food (Escherichia coli) as an environmental factor to continue larval development; (3) the FLP-1 reduced the production and secretion of DAF-28, which is produced in ASI head neurons and is the predominant insulin-like peptide (INS) present. FLP-1 is conserved in many species of plant-parasitic root-knot nematodes that cause severe damage to crops. Therefore, our findings may provide insight into the development of new nematicides that can disturb their infection and development.