Identification of novel antiviral drug candidates using an optimized SARS-CoV-2 phenotypic screening platform.

Reliable, easy-to-handle phenotypic screening platforms are needed for the identification of anti-SARS-CoV-2 compounds. Here, we present caspase 3/7 activity as a readout for monitoring the replication of SARS-CoV-2 isolates from different variants, including a remdesivir-resistant strain, and of other coronaviruses in numerous cell culture models, independently of cytopathogenic effect formation. Compared to other models, the Caco-2 subline Caco-2-F03 displayed superior performance. It possesses a stable SARS-CoV-2 susceptibility phenotype and does not produce false-positive hits due to drug-induced phospholipidosis. A proof-of-concept screen of 1,796 kinase inhibitors identified known and novel antiviral drug candidates including inhibitors of phosphoglycerate dehydrogenase (PHGDH), CDC like kinase 1 (CLK-1), and colony stimulating factor 1 receptor (CSF1R). The activity of the PHGDH inhibitor NCT-503 was further increased in combination with the hexokinase II (HK2) inhibitor 2-deoxy-D-glucose, which is in clinical development for COVID-19. In conclusion, caspase 3/7 activity detection in SARS-CoV-2-infected Caco-2-F03 cells provides a simple phenotypic high-throughput screening platform for SARS-CoV-2 drug candidates that reduces false-positive hits.

Initial in-human experience with the conveyor cardiovascular system for the delivery of large profile transcatheter valve devices.

OBJECTIVES: To determine the safety and efficacy of the conveyor cardiovascular system (CCS) to facilitate the delivery of large profile transcatheter valve devices. BACKGROUND: Transcatheter valve devices rely on force provided by the operator to be delivered to their intended position. This delivery may be challenging in a variety of anatomic scenarios. The ability to provide steering from the tip of the device by forming an arterial venous loop may help overcome these challenges. METHODS: Between May, 2019 and October, 2020, five patients were recruited for delivery of transcatheter valve devices with the CCS. These patients were deemed by the operators to have challenging anatomy which could make conventional valve delivery difficult or impossible. These patients were recruited as part of an FDA approved early feasibility study or through an institutional review board approved compassionate use protocol. RESULTS: Three patients underwent transcatheter mitral valve replacement with a SAPIEN-3 valve. One patient each underwent transcatheter aortic valve (TAVR) implantation with a SAPIEN 3 and 1 patient underwent TAVR implantation with a Lotus valve. All patients underwent successful implantation of the valve and removal of the CCS and valve delivery systems. There was no more than trivial mitral regurgitation post procedure in any patient and there was no more than trivial paravavular leak. There were no major in-hospital complications. CONCLUSIONS: The CCS facilitates the delivery of large profile transcatheter valve devices in challenging anatomic scenarios. Further studies are needed with additional valve technologies.

Comparative differences of mitral valve-in-valve implantation: A new mitral bioprosthesis versus current mosaic and epic valves.

OBJECTIVE: Evaluate transcatheter mitral valve replacement (TMVR) valve-in-valve (VIV) outcomes in three different mitral bioprostheses (of comparable measured internal diameters) under stable hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography (CT), and autopsy comparisons pre- and post-valve implantation in a porcine model under matched controlled conditions. BACKGROUND: Impact of surgical bioprosthesis design on TMVR VIV procedures is unknown. METHODS: Fifteen similar-sized Yorkshire pigs underwent pre-procedural CT screening. Twelve had consistent anatomic features and underwent implantation of mitral bioprostheses. Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris, followed by TMVR VIV with 26 Edwards Sapien3. Post-VIV, suprasternal TEE studies were performed to assess hemodynamic function, followed by a gated contrast CT. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful VIV implantation with no study deaths. The post vivMitris (3.77 ± 0.36)/(2.2 ± 0.25 mmHg) had the lowest peak/mean trans-mitral gradient and the vivEpic the highest (15.5 ± 2.55)/(7.09 ± 1.13 mmHg). All THVs (transcatheter heart valves) had greatest deformation within the center of the THV frame; with the smallest waist opening area in the vivEpic (329 ± 35.8 mm2 ) and greatest in the vivMitris (414 ± 33.12 mm2 ). Bioprosthetic frames without obvious radiopaque markers resulted in the most ventricular implantation of the THV's anteroseptal frame (Epic: -4.52 ± 0.76 mm), versus the most radiopaque bioprosthesis (Mitris: -1.18 ± 2.95 mm), and higher peak LVOT gradients (Epic: 4.82 ± 1.61 mmHg; Mitris: 2.91 ± 1.47 mmHg). CONCLUSIONS: The current study demonstrates marked variations in hemodynamics, THV opening area, and anatomic dimensions among measured similarly sized mitral bioprostheses. These data suggest a critical need for understanding the potential impact of variations in bioprosthesis design on TMVR VIV clinical outcomes.

Comparison of a new bioprosthetic mitral valve to other commercially available devices under controlled conditions in a porcine model.

BACKGROUND/AIM: To evaluate three mitral bioprostheses (of comparable measured internal diameters) under controlled, stable, hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography and autopsy comparisons pre- and postvalve implantation. METHODS: Fifteen similar-sized Yorkshire pigs underwent preprocedural computerized tomography anatomic screening. Of these, 12 had consistent anatomic features and underwent implantation of a mitral bioprosthesis via thoracotomy on cardiopulmonary bypass (CPB). Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris bioprostheses. After CPB, epicardial echocardiographic studies were performed to assess hemodynamic function and define any paravalvular leaks, followed by postoperative gated contrast computerized tomography. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful valve implantation with no study deaths. Postoperative echocardiographic trans-valve gradients varied among bioprosthesis manufacturers. The 25-mm Mitris (5.1 ± 2.7)/(2.6 ± 1.3 torr) had the lowest peak/mean gradient and the 27-mm Epic bioprosthesis had the highest (9.2 ± 3.7)/(4.6 ± 1.9 torr). Surgical valve opening area (SOA) varied with the 25-mm Mitris having the largest SOA (2.4 ± 0.15 cm2 ) followed by the 27-mm Mosaic (2.04 ± 0.23 cm2 ) and the 27-mm Epic (1.8 ± 0.27 cm2 ) valve. Bench device orthogonal internal diameter measurements did not match manufacturer device size labeling: 25-mm Mitris (23 × 23 mm), 27-mm Mosaic (23 × 22 mm), 27-mm Epic (21 × 21 mm). CONCLUSIONS: Current advertisement/packaging of commercial surgical mitral valves is not uniform. This study demonstrates marked variations in hemodynamics, valve opening area and anatomic dimensions between similar sized mitral bioprostheses. These data suggest a critical need for standardization and close scientific evaluation of surgical mitral bioprostheses to ensure optimal clinical outcomes.

Local iontophoretic administration of cytotoxic therapies to solid tumors.

Parenteral and oral routes have been the traditional methods of administering cytotoxic agents to cancer patients. Unfortunately, the maximum potential effect of these cytotoxic agents has been limited because of systemic toxicity and poor tumor perfusion. In an attempt to improve the efficacy of cytotoxic agents while mitigating their side effects, we have developed modalities for the localized iontophoretic delivery of cytotoxic agents. These iontophoretic devices were designed to be implanted proximal to the tumor with external control of power and drug flow. Three distinct orthotopic mouse models of cancer and a canine model were evaluated for device efficacy and toxicity. Orthotopic patient-derived pancreatic cancer xenografts treated biweekly with gemcitabine via the device for 7 weeks experienced a mean log2 fold change in tumor volume of -0.8 compared to a mean log2 fold change in tumor volume of 1.1 for intravenous (IV) gemcitabine, 3.0 for IV saline, and 2.6 for device saline groups. The weekly coadministration of systemic cisplatin therapy and transdermal device cisplatin therapy significantly increased tumor growth inhibition and doubled the survival in two aggressive orthotopic models of breast cancer. The addition of radiotherapy to this treatment further extended survival. Device delivery of gemcitabine in dogs resulted in more than 7-fold difference in local drug concentrations and 25-fold lower systemic drug levels than the IV treatment. Overall, these devices have potential paradigm shifting implications for the treatment of pancreatic, breast, and other solid tumors.

Suprasternal direct aortic approach transcatheter aortic valve replacement avoids sternotomy and thoracotomy: first-in-man experience†.

OBJECTIVES: Direct aortic deployment of a transcatheter aortic valve eliminates the need to traverse the aortic arch with the valve delivery system, enables placement of large sheaths in the aorta and innominate artery, provides maximal precision during deployment and ensures a safe, conventional surgical aortotomy closure. We describe the initial experience with the Suprasternal Aortic Access System (SuprAA System, Aegis Surgical Ltd, Dublin, Ireland) for direct transaortic/innominate valve delivery. METHODS: Patients with severe, symptomatic aortic stenosis who were candidates for transcatheter aortic valve replacement (TAVR) via a direct transaortic approach were enrolled in the SuprAA-TAVR First-in-Man Study. Under general anaesthesia, the innominate artery and aortic arch were exposed in each patient, using the SuprAA System via a 2.5-cm incision directly above the sternal notch. The TAVR delivery sheath was positioned and the transcatheter valve deployed routinely under fluoroscopic guidance. Upon sheath removal, haemostasis at the aortotomy site was confidently secured using a double purse-string suture closure. All were extubated immediately. A meta-analysis of the direct aortic approach was done for comparison. RESULTS: Four male patients (mean 82.5 years) underwent SuprAA-TAVR (2 CoreValve; 2 SAPIEN). Anatomical visualization was excellent and suprasternal valve deployment was accurate regardless of sheath size with 100% Valve Academic Research Consortium-2 procedural success. The average total procedure time was 109.5 min without perioperative wound or vascular complications. CONCLUSIONS: The SuprAA System provides direct aortic/innominate access without sternal or thoracotomy incision. Patient recovery to normal activity is maximized, sheath size limitations are eliminated and valve deployment is precise. This innovative system creates a new and exciting minimally invasive approach for high-risk patients with aortic stenosis.

Biomedical innovation: a risky business at risk.

Regulatory and financial challenges conspire to stall the development and market approval of breakthrough medical products. Inconsistent parameters are used to assess the safety and efficacy of drugs, biologics, and devices; this glitch in the system introduces uncertainty, slows or blocks product approvals, and increases the costs of product development. Here, we consider how to balance the benefits and risks to the public in the assessment of innovative medical products. We also discuss the Institute of Medicine's recent report on the medical device approval process.

Deployment and operation of a transportable burn intensive care unit in response to a burn multiple casualty incident.

In many hospitals, intensive care units (ICUs) operate at or above capacity on a daily basis. Multiple casualty incidents will create a sudden need for additional ICU beds and hospital planning for disaster response must anticipate the need for rapid ICU expansion. In this article, the authors describe the management of 6 patients who were burned in Guam and successfully transported a distance of 7,268 miles to San Antonio, TX, for tertiary burn center care. The mission required creation of a temporary burn ICU at Tripler Army Medical Center in Hawaii, approximately midway between the referring hospital and the receiving burn center. A method of creating a temporary burn center is described. Lessons learned, including the need to standardize equipment, and to cross-train and cross-credential medical personnel, are applicable to both military and civilian mass casualty management.

Use of step-section histopathology to evaluate 18F-fluorocholine PET sextant localization of prostate cancer.

To assess positron emission tomography (PET) with fluorine-18 fluorocholine for sextant localization of malignant prostate tumors. Histopathologic analysis was performed on step-sectioned whole-mounted prostate specimens from 15 patients who underwent PET with fluorocholine prior to radical prostatectomy. The maximum standardized uptake value (SUVmax) corresponding to prostate sextants on PET was measured by region of interest analysis and compared with histopathologic results. Histopathology demonstrated malignant involvement in 61 of 90 prostate sextants. The mean total tumor volume per specimen was 4.9 mL (range 0.01-28.7 mL). Mean SUVmax was 6.0+/-2.0 in malignant sextants and 3.8+/-1.4 in benign sextants (p<.0001). The area under the receiver operating characteristic curve was 0.82 for sextant detection of malignancy based on SUVmax measurement. Tumor diameter directly correlated with sextant SUVmax in malignant sextants (r=.54, p<.05). In 13 subjects, the largest tumor in the specimen corresponded to the sextant with the highest SUVmax. Fluorocholine PET can serve to localize dominant areas of malignancy in patients with prostate cancer. However, PET with fluorocholine may fail to identify sextants with smaller volumes of malignancy.

Case report: Endoscopic laser lithotripsy of seminal-vesicle stones.

A 25-year-old man presented with painful ejaculation, an ejaculate volume of 0.75, and complaints of passing "granules" in the semen. Transrectal ultrasonography showed bilateral seminal vesicle enlargement. The patient underwent transurethral resection of the ejaculatory duct. The entry point of duct was resected using pure cutting current, resulting in the passage of multiple proteinaceous-appearing stones. Approximately 10 months later, the patient reported recurrent painful ejaculation and passage of granules in his semen. At cystoscopy, the ejaculatory duct openings were intubated with a cone-tipped catheter to perform bilateral seminal vesiculograms, which showed numerous mobile filling defects and a Steinstrasse appearance at the ejaculatory ducts. A 7F semirigid ureteroscope entered the lumen without difficulty over a guidewire, and the stones were fragmented with a 270-microm holmium laser fiber. The ejaculatory ducts were balloon dilated to 18F. To our knowledge, this is the first reported case where a ureteroscope was utilized to treat seminal-vesicle stones. The seminal vesiculogram proved to be extremely valuable in the diagnosis.

Renal artery stenosis is not associated with the development of acute renal failure following coronary artery bypass grafting.

BACKGROUND: Acute renal failure (ARF) is a frequent complication of coronary artery bypass grafting (CABG) surgery and is strongly associated with perioperative morbidity and mortality. We hypothesized that renal artery stenosis (RAS), causing occult renal ischemia, may be an important factor contributing to development of ARF after CABG surgery. METHODS: Preoperative and intraoperative data on 798 consecutive adult patients undergoing CABG surgery with cardiopulmonary bypass from February 1, 1995 to February 1, 1997 (who had also undergone an abdominal aortogram for the evaluation of RAS) were recorded and entered into a computerized database. The development of ARF was defined as a rise in serum creatinine of 1 mg/dL (88.4 micromol/L) above baseline postoperatively. The association between the presence of renal artery stenosis together with preoperative and intraoperative variables and the development of ARF was assessed by multivariate logistic regression. RESULTS: A total of 798 patients underwent isolated coronary bypass grafting, of which 18.7% demonstrated 50% or more RAS. ARF developed in 82 patients (10.2%), of which three (0.3%) required dialysis support. The mortality for patients who developed ARF was 14% (OR 15, P=0.0001) compared to 0.2% among those who did not develop ARF. The presence of renal artery stenosis of any severity ranging from unilateral 50% RAS to bilateral 95% RAS was not associated with the subsequent development of ARF. CONCLUSIONS: The development of ARF following CABG surgery is associated with high mortality. The presence of RAS does not appear to increase the risk for developing ARF.

Relationship between activated clotting time during percutaneous intervention and subsequent bleeding complications.

BACKGROUND: Approximately 50% of percutaneous coronary interventions in the United States are performed with unfractionated heparin and no IIb/IIIa agent. The operator must weigh the risks and benefits of more intensive anticoagulation during these percutaneous interventions. This study helps clarify the relationship between patient and procedural factors, such as the intensity of heparin anticoagulation as measured by activated clotting time (ACT), and the risk of blood loss and bleeding complications. METHODS: Four hundred twenty-nine patients undergoing elective or urgent percutaneous coronary intervention were followed up prospectively for 72 hours after intervention for clinical bleeding complications. Blood loss, defined as the difference between preprocedural and nadir postprocedural hematocrit adjusted for interval transfusions, was also tracked. In-laboratory ACTs, as well as other potential clinical and procedural predictors of blood loss and bleeding risk, were collected and analyzed. RESULTS: Maximum in-laboratory ACT was significantly related to blood loss as measured by the change in hematocrit (P =.017) and to the risk of major bleeding complications (P =.002). In multivariate analysis, patient age (P =.004), sex (P =.014), procedure length (P <.001), and additional interventions (P <.001) were significant, independent predictors of blood loss. Major bleeding complications were significantly, independently predicted by patient age (P <.001), additional interventions (P =.015), and maximum in-laboratory ACT (P <.001). CONCLUSIONS: Compared with the other clinical and procedural predictors of bleeding complications, maximum in-laboratory ACT was second only to patient age in significance as a multivariate predictor of postprocedural bleeding complications. Maximum in-laboratory ACT was found to be the most significant modifiable univariate and multivariate predictor of clinical bleeding complications after percutaneous coronary intervention. Particularly in patients with nonmodifiable risk factors for blood loss and bleeding complications such as advanced age, female sex, and multiple and prolonged procedures, avoiding high intensity anticoagulation with unfractionated heparin is associated with lower bleeding risk.