Animal Efficacy Studies Research Articles

The Development of Animal Models for Respiratory Syncytial Virus (RSV) Infection and Enhanced RSV Disease

The development of immunoprophylactic products against respiratory syncytial virus (RSV) has resulted in notable advancements, leading to an increased demand for preclinical experiments and placing greater demands on animal models. Nevertheless, the field of RSV research continues to face the challenge of a lack of ideal animal models. Despite the demonstration of efficacy in animal studies, numerous RSV vaccine candidates have been unsuccessful in clinical trials, primarily due to the lack of suitable animal models. The most commonly utilized animal models for RSV research are cotton rats, mice, lambs, and non-human primates. These animals have been extensively employed in mechanistic studies and in the development and evaluation of vaccines and therapeutics. However, each model only exemplifies some, but not all, aspects of human RSV disease. The aim of this study was to provide a comprehensive summary of the disease symptoms, viral replication, pathological damage, and enhanced RSV disease (ERD) conditions across different RSV animal models. Furthermore, the advantages and disadvantages of each model are discussed, with the intention of providing a valuable reference for related RSV research.

Combination therapy is it in the future for successfully treating peripheral diabetic neuropathy?

In 2022, the Center for Disease Control and Prevention reported that 11.3% of the United States population, 37.3 million people, had diabetes and 38% of the population had prediabetes. A large American study conducted in 2021 and supported by many other studies, concluded that about 47% of diabetes patients have peripheral neuropathy and that diabetic neuropathy was present in 7.5% of patients at the time of diabetes diagnosis. In subjects deemed to be pre-diabetes and impaired glucose tolerance there was a wide range of prevalence estimates (interquartile range (IQR): 6%-34%), but most studies (72%) reported a prevalence of peripheral neuropathy ≥10%. There is no recognized treatment for diabetic peripheral neuropathy (DPN) other than good blood glucose control. Good glycemic control slows progression of DPN in patients with type 1 diabetes but for patients with type 2 diabetes it is less effective. With obesity and type 2 diabetes at epidemic levels the need of a treatment for DPN could not be more important. In this article I will first present background information on the "primary" mechanisms shown from pre-clinical studies to contribute to DPN and then discuss mono- and combination therapies that have demonstrated efficacy in animal studies and may have success when translated to human subjects. I like to compare the challenge of finding an effective treatment for DPN to the ongoing work being done to treat hypertension. Combination therapy is the recognized approach used to normalize blood pressure often requiring two, three or more drugs in addition to lifestyle modification to achieve the desired outcome. Hypertension, like DPN, is a progressive disease caused by multiple mechanisms. Therefore, it seems likely as well as logical that combination therapy combined with lifestyle adjustments will be required to successfully treat DPN.

Abstract 4183: Utility of the highly immunodeficient SRG rat for combined drug efficacy, pharmacokinetics, and toxicology studies in tumor-bearing animals

Abstract Immunodeficient rodents are vital pre-clinical disease models. Historically, immunodeficient mice have been standard for hosting human cell and tissue xenografts, enabling cancer drug efficacy and tolerability testing. However, an immunodeficient rat that supports a variety of human cancer types provides a larger model for easier surgical manipulation and serial blood and tumor tissue sampling, allowing for efficacy, pharmacokinetics, and toxicology testing in the same animal. We created a Sprague Dawley Rag2 -/-, Il2rg -/- rat (SRG Rat®; SRG) that is highly supportive of human cell and tissue engraftment. The SRG rat lacks B, T, and NK cells and is more immunodeficient than the Nude rat. Here we show comparative pathology between the SRG rat and its parental strain, the CRL Sprague Dawley (CD). We also present data from an efficacy study in tumor bearing SRG rats, demonstrating that serial blood draws and tumor biopsies can be performed in tumor bearing animals to assess drug pharmacokinetics and pharmacodynamics within a single study. First, we assessed 10 SRG (5/sex) and 10 CD (5/sex) at 8-10 weeks of age. Body weight, hematology, and clinical chemistry parameters were measured. Microscopic examinations were performed on routine H&E slide preparations. Male and female SRG displayed lower mean body weight when compared to sex- and age-matched CD. Compared to CD, SRG had reduced lymphoid tissue and circulating monocytes, and highly reduced circulating lymphocytes, neutrophils, eosinophils, and basophils; expected phenotypes for this severely immunodeficient rat. Thymus was not present in SRG rats, spleens were grossly smaller, and bone marrow cellularity was decreased compared to CD. Microscopically, mandibular lymph nodes and lymphoid tissue in spleen, lung, and intestine were not observed in SRG rats, consistent with the 92% decrease in circulating lymphocytes. To demonstrate the utility of the SRG for tumor inhibition, pharmacokinetics, and pharmacodynamics, we inoculated rats with human VCaP prostate cancer cell-derived tumors, then treated these animals and collected serial blood samples and tumor biopsies to assess tumor biomarkers. Treatment led to decreased PSA and AR, two key proteins expressed in prostate cancer, correlating to decreased tumor growth. These data demonstrate that the SRG rat is suitable for toxicology studies and has comparable pathology to the CD rat, except for reduced lymphoid tissue and WBCs, which are expected phenotypes. In addition, the SRG rat supports the growth of human cancer tissue for treatment studies. The large size of the SRG rat and comparative pathology to the CD rat support its value as an immunodeficient model for assessing toxicity during efficacy testing for de-risking safety concerns in the presence of the human target tissue. Citation Format: Diane Begemann, Cynthia Dunn, Darrell Robertson, Lauren Keach, Emily Baldwin, R. Grace Walton, Alex Van Engelenburg, Jessica Durrant, Laura Healy, Koh Meng Aw Yong, Michael J. Schlosser, Fallon K. Noto. Utility of the highly immunodeficient SRG rat for combined drug efficacy, pharmacokinetics, and toxicology studies in tumor-bearing animals [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4183.

Animal efficacy study of a plant extract complex (BEN815) as a potential treatment for COVID-19.

In a short time, several types of injectable and oral therapeutics have been developed and used to effectively manage patients with coronavirus disease 2019 (COVID-19). BEN815 is an improved mixture of three extracts (Psidium guajava, Camellia sinensis, and Rosa hybrida) recognized by the Ministry of Food and Drug Safety of Korea as a health food ingredient that alleviates allergic rhinitis. The current animal efficacy study was performed to assess its probability of improving COVID-19 symptoms. BEN815 treatment significantly increased the survival of K18-hACE2 transgenic mice and reduced viral titers in the lungs at 5 days post infection (DPI). Furthermore, the lungs of the treated mice showed mild tissue damage at 5 DPI and nearly complete recovery from COVID-19 at 14 DPI. BEN815 appears to be an effective and minimally toxic anti-SARS-CoV-2 agent in mice and has potential for clinical applications.

Recent updates on medical management of Glaucoma.

Glaucoma is the leading cause of irreversible blindness worldwide. It is estimated to affect more than 110 million people globally by the year 2040. The disease is characterised by progressive loss of the retinal ganglion cells resulting in characteristic visual field defects. Modulating intraocular pressure is the widely accepted and practiced strategy in managing glaucoma. While most of the available drugs either suppressed aqueous formation or shunted it across the uveo-scleral pathways, rho kinase inhibitors have been introduced targeting the trabecular meshwork. Latanoprostene Bunod and its combination with Latanoprost, and Omidenepeg Isopropyl are new additions soon to be available in India. Durysta, a sustained release Bimatoprost implant is already approved in United States and other implants involving Travoprost are in pipeline. Neuroprotection is the ultimate goal in glaucoma management and recent trials with neurotrophic factors, glutamate antagonists, stem cells and antioxidant therapy have been encouraging. Coenzyme Q10 with vitamin E combination (Coqun) eye drops have demonstrated efficacy as an adjunct antiglaucoma therapy. While Brain Derived Neurotrophic factor have demonstrated efficacy in animal studies, experimental study with Nerve Growth Factor eye drops have shown promising results in humans. Stem cell research has a great potential in neuroprotection but still is in infancy. Concerns such as mode of delivery, graft survival and potential side effects remain to be known before stem cell therapy comes to the fore of clinical management of glaucoma. The present provides an overview of the recent developments in the wide arena of medical management of glaucoma.

Acute toxicity of a new antiseptic for veterinary dentistry

The development steps of new drugs require consistent safety and efficacy studies in animals. This article reflects the research of a new antiseptic for veterinary dentistry containing active ingredients such as chlorhexidine bigluconate and propolis. Acute toxicity studies were carried out following the “Guidelines for the experimental (preclinical) study of new pharmacological substances” (2005), according to GOST 32644-2014 and taking into account the requirements of the Order of the Ministry of Agriculture of the Russian Federation of March 6, 2018 No. 101. rats with an average live weight of 250-280 grams, from which one experimental group of three animals was formed (for the first stage of the study), after receiving the results of the first stage, a second experimental group of three animals was formed for the second stage. The rats of the experimental groups were injected with the studied antiseptic once into the inside of the stomach using a special club-shaped needle at a dose of 2000 mg/kg. As a result of the experiment, it was found that the investigated new antiseptic containing chlorhexidine bigluconate and propolis, intended for the treatment of inflammatory processes in the oral cavity in animals, belongs to substances of hazard class V according to GOST 32644-2014. There were no deaths of animals during the experiment.

Abstract 6339: BCA101, a novel tumor-targeted bifunctional fusion antibody simultaneously inhibiting EGFR and TGF-β signaling with potential for durable tumor growth inhibition

Abstract Introduction: The suboptimal clinical efficacy EGFR-targeting therapeutics is attributed to both tumor intrinsic and tumor microenvironment (TME) derived acquired (extrinsic) resistance mechanisms. Intrinsic factors include activation of other receptor tyrosine kinases and key extrinsic resistance mechanism include the enhanced secretion of immunosuppressive factors such as IL-10 and TGF-β1. Here, we describe a first-in-class bifunctional monoclonal antibody fusion designed to simultaneously target EGFR and sequester TGF-β in the TME. Experimental Procedures: Functional activity of BCA101 was evaluated in multiple in vitro assays such as ELISA, inhibition of proliferation, antibody-dependent cellular toxicity, SMAD-reporter assay. Neutralization of TGF-β by BCA101 was demonstrated by epithelial-to-mesenchymal transition and tumor cell/immune cell co-culture assays. BCA101 tumor targeting was evaluated in a whole animal imaging study and efficacy studies were performed in nude xenograft models while combination studies with immune checkpoint inhibitors were performed in B16-EGFR syngeneic models. Results: BCA101 is an anti-EGFR IgG1 monoclonal antibody linked to an extracellular domain of human TGF-βRII. The TGF-β “trap” fused to light chain in BCA101 did not sterically interfere with its ability to bind EGFR, inhibit cell proliferation, or mediate antibody-dependent cellular cytotoxicity in vitro. BCA101 increased production of proinflammatory cytokines and key markers associated with T and NK cell activation, while suppressing VEGF secretion. Additionally, BCA101 inhibited differentiation of naïve CD4+ T cells to inducible T-regulatory (iTreg) cells when compared to cetuximab. In vivo, biodistribution studies showed that BCA101 localized to tumor tissues in xenograft mouse models, with comparable kinetics as cetuximab. TGF-β in tumors was neutralized to about 90% in animals dosed with 10 mg/kg of BCA101 compared to 54% in animals dosed with equimolar TGF-βRII-Fc. BCA101 had longer tumor tissue retention compared to cetuximab, further confirming improved tumor localization. In patient-derived xenograft mouse models of head and neck squamous cell carcinoma, BCA101 showed durable response post dose cessation as compared to cetuximab. In FaDu xenografts, BCA101 displayed early and durable response to cetuximab/cetuximab plus TGF-βRII-Fc combination. The combination of BCA101 and anti-PD1 antibody improved tumor inhibition in both B16-hEGFR expressing syngeneic mouse and in humanized HuNOG-EXL mice bearing human PC-3 xenograft models. Conclusion: These results support clinical development of BCA101, either as a monotherapy or in combination with immune checkpoint therapy. Citation Format: Srinivas Reddy Boreddy, Reshmi Nair, Prashant Kumar Pandey, Anshu Kuriakose, Arindam Banerjee, Chaitali Dey, Madhukara A R, Bhadravathi Marigowda Shivakumar, Hanumant Kulkarni, Milind Sagar, Prashantha Kumar M. V, Shiv Ram Krishn, Jaya Bhatnagar, Moni Abhram Kuriakose, Ram Bhupal Reddy, Amritha Suresh, Praveen Reddy Moole, Usha Bughani, Seng-Lai Tan, Pradip Nair, Rachel Salazar. BCA101, a novel tumor-targeted bifunctional fusion antibody simultaneously inhibiting EGFR and TGF-β signaling with potential for durable tumor growth inhibition. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6339.

Effects of different remote ischemia perconditioning methods on cerebral infarct volume and neurological impairment in rats

Remote ischemic perconditioning (RIPerC) is a novel neuroprotective method against cerebral infarction that has shown efficacy in animal studies but has not been consistently neuroprotective in clinical trials. We focused on the temporal regulation of ischemia–reperfusion by RIPerC to establish an optimal method for RIPerC. Rats were assigned to four groups: 10 min ischemia, 5 min reperfusion; 10 min ischemia, 10 min reperfusion; 5 min ischemia, 10 min reperfusion; and no RIPerC. RIPerC interventions were performed during ischemic stroke, which was induced by a 60-min left middle cerebral artery occlusion. Infarct volume, sensorimotor function, neurological deficits, and cellular expressions of brain-derived neurotrophic factor (BDNF), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and caspase 3 were evaluated 48 h after the induction of ischemia. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) was also performed. RIPerC of 10 min ischemia/10 min reperfusion, and 5 min ischemia/10 min reperfusion decreased infarct volume, improved sensorimotor function, decreased Bax, caspase 3, and TUNEL-positive cells, and increased BDNF and Bcl-2 expressions. Our findings suggest RIPerC with a reperfusion time of approximately 10 min exerts its neuroprotective effects via an anti-apoptotic mechanism. This study provides important preliminary data to establish more effective RIPerC interventions.

Lethal action of Licarin A derivatives in Leishmania (L.) infantum: Imbalance of calcium and bioenergetic metabolism

Natural metabolites present an extraordinary chemo-diversity and have been used as the inspiration for new drugs. Considering the need for new treatments against the neglected parasitic disease leishmaniasis, three semi-synthetic derivatives of natural neolignane licarin A were prepared: O-acetyl (1a), O-allyl (1b), and 5-allyl (1c). Using an ex vivo assay, compounds 1a, 1b, and 1c showed activity against the intracellular amastigotes of Leishmania (L.) infantum, with IC50 values of 9, 13, and 10 μM, respectively. Despite no induction of hemolytic activity, only compound 1b resulted in mammalian cytotoxicity (CC50 = 64 μM). The most potent compounds (1a and 1c) resulted in selectivity indexes >18. The mechanism of action of compound 1c was evaluated by fluorescent/luminescent based techniques and MALDI-TOF/MS. After a short incubation period, increased levels of the cytosolic calcium were observed in the parasites, with alkalinization of the acidocalcisomes. Compound 1c also induced mitochondrial hyperpolarization, resulting in decreased levels of ATP without altering the reactive oxygen species (ROS). Neither plasma membrane damages nor DNA fragmentation were observed after the treatment, but a reduction in the cellular proliferation was detected. Using MALDI-TOF/MS, mass spectral alterations of promastigote proteins were observed when compared to untreated and miltefosine-treated groups. This chemically modified neolignan induced lethal alterations of the bioenergetic and protein metabolism of Leishmania. Future PKPD and animal efficacy studies are needed to optimize this promising natural-derived compound.

Targeting CD89 on tumor-associated macrophages overcomes resistance to immune checkpoint blockade

BackgroundDespite the survival benefits observed with immune checkpoint blockade (ICB) treatment—programmed cell death-1/programmed cell death ligand-1 (PD-1/PD-L1), many patients with cancer have not benefited from these agents because of impaired...

Pre- and Postlicensure Animal Efficacy Studies Comparing Anthrax Antitoxins.

The deliberate use of Bacillus anthracis spores is believed by the US government to be a high bioweapons threat. The first line of defense following potential exposure to B. anthracis spores would be postexposure prophylaxis with antimicrobials that have activity against B. anthracis. Additional therapies to address the effects of toxins may be needed in systemically ill individuals. Over the last 2 decades, the United States government (USG) collaborated with the private sector to develop, test, and stockpile 3 antitoxins: anthrax immunoglobulin intravenous (AIGIV), raxibacumab, and obiltoxaximab. All 3 products target protective antigen, a protein factor common to the 2 exotoxins released by B. anthracis, and hamper or block the toxins' effects and prevent or reduce pathogenesis. These antitoxins were approved for licensure by the United States Food and Drug Administration based on animal efficacy studies compared to placebo. We describe USG-sponsored pre- and postlicensure studies that compared efficacy of 3 antitoxins in a New Zealand White rabbit model of inhalation anthrax; survival following a lethal aerosolized dose of B. anthracis spores was the key measure of effectiveness. To model therapeutic intervention, intravenous treatments were started following onset of antigenemia. In pre- and postlicensure studies, all 3 antitoxins were superior to placebo; in the postlicensure study, raxibacumab and obiltoxaximab were superior to AIGIV, but neither was superior to the other. These data illustrate the relative therapeutic benefit of the 3 antitoxins and provide a rationale to prioritize their deployment.

Determination of probiotic properties of lactic acid bacteria and yeasts isolated from three lacto‐fermented cereals mixed with whey, citrus, and tomato pomace

This study tested the probiotic activities of bacteria and yeast isolates from three lacto-fermented cereal (LFC) products which were earlier shown high probiotic efficacy in farm animals. LFC products were freshly produced by solid-state fermentation using fresh whey without a starter culture. LFCa is a mixture of barley, whey, citrus pomace, LFCb of rye, whey, citrus pomace, and tomato pomace and LFCc of LFCb with an addition of ground thyme leaves at the end of fermentation. Six bacteria and two yeast species were isolated from LFC products and tested for probiotic activities. Candida spp and Saccharomyces spp exhibited low probiotic activities. However, lactic acid bacteria (LAB) isolates, namely, Lactobacillus plantarum O33, Pediococcus pentosaceus 10, Lactobacillus paracasei spp. paracasei O54, Enterococcus spp., Lactococcus lactis spp. lactis O3, and Lactobacillus curvatus O32 had overall high survival rates of 76% at pH 4.0, 95% at pH 5.0, 70% at 0.30% of bile salt, high exopolysaccharide production of 85 to 150 mg/L, acceptable aggregation rates of 19% of 4 h co-aggregation with E. coli and 25% auto-aggregation, high inhibition zones of 11 to 20 mm in diameter of pathogens and resistance to three antibiotics. Multivariate tests showed that Enterococcus spp. was the one with the highest probiotic efficacy. In conclusion, these LFC products can be used as probiotic supplements. Novelty impact statement This study determined the probiotic activity of bacteria and yeasts isolated from lacto-fermented cereals, previously shown to have high efficacy in animal studies. Yeast isolates exhibited low probiotic abilities, while six lactic acid bacteria isolated exhibited strong probiotic properties. Enterococcus spp. was found with the highest probiotic activities. The results showed that the products or isolated bacteria strains can safely be used in food and feed applications for health benefits.

Clinical Use of Tecovirimat (Tpoxx) for Treatment of Monkeypox Under an Investigational New Drug Protocol - United States, May-August 2022.

Currently, no Food and Drug Administration (FDA)-approved treatments for human monkeypox are available. Tecovirimat (Tpoxx), however, is an antiviral drug that has demonstrated efficacy in animal studies and is FDA-approved for treating smallpox. Use of tecovirimat for treatment of monkeypox in the United States is permitted only through an FDA-regulated Expanded Access Investigational New Drug (EA-IND) mechanism. CDC holds a nonresearch EA-IND protocol that facilitates access to and use of tecovirimat for treatment of monkeypox.§ The protocol includes patient treatment and adverse event reporting forms to monitor safety and ensure intended clinical use in accordance with FDA EA-IND requirements. The current multinational monkeypox outbreak, first detected in a country where Monkeypox virus infection is not endemic in May 2022, has predominantly affected gay, bisexual, and other men who have sex with men (MSM) (1,2). To describe characteristics of persons treated with tecovirimat for Monkeypox virus infection, demographic and clinical data abstracted from available tecovirimat EA-IND treatment forms were analyzed. As of August 20, 2022, intake and outcome forms were available for 549 and 369 patients, respectively; 97.7% of patients were men, with a median age of 36.5 years. Among patients with available data, 38.8% were reported to be non-Hispanic White (White) persons, 99.8% were prescribed oral tecovirimat, and 93.1% were not hospitalized. Approximately one half of patients with Monkeypox virus infection who received tecovirimat were living with HIV infection. The median interval from initiation of tecovirimat to subjective improvement was 3 days and did not differ by HIV infection status. Adverse events were reported in 3.5% of patients; all but one adverse event were nonserious. These data support the continued access to and treatment with tecovirimat for patients with or at risk for severe disease in the ongoing monkeypox outbreak.

Accurate and Early Metastases Diagnosis in Live Animals With Multimodal X-ray and Optical Imaging

In vivo optical imaging systems are essential to track disease progression and evaluate therapeutic efficacy in animal studies. However, current approaches are limited by their inability to accurately capture 3-dimensional (3-D) image information. To overcome this hindrance, we adopted x-ray computed tomography (CT) as a prior for 3-D optical image reconstruction and further challenged the multimodal imaging performance with a metastasis model. The iSMAART system, an integrated small animal research platform, features coregistered high-quality quantitative optical tomography and CT. In the synergistic dual-modality imaging, CT provides both 3-D anatomy information and animal structure mesh for optical tomography reconstruction, which is performed using bioluminescence projections acquired from 4 orthogonal angles. The multimodal imaging system was challenged with a prostate cancer metastasis model, and a double-blind histopathology diagnosis was obtained to validate the imaging results. The iSMAART located, visualized, and quantified early tumor metastases at the millimeter scale, and can accurately track deep tumors as small as 1.5 mm in live animals. Tumors metastasized into the liver, diaphragm, and tibia in 4 mice were all successfully diagnosed by the integrated tomographic imaging. Instead of roughly comparing surface-light intensities, as traditionally performed in 2-dimensional optical imaging, iSMAART provides accurate tumor imaging and quantitative assessment capabilities with integrated CT and optical tomography for cancer metastasis research. With the powerful 3-D optical/CT imaging capability, iSMAART has the potential to tackle more complex research needs with higher targeting accuracy.

Abstract 5988: Intra-carotid artery brain metastasis models for evaluation of lung and breast cancer drugs

Abstract Non-CNS metastatic brain cancer is about 10 times more common than CNS cancer. Lung cancer and breast cancer account for most brain metastasis. KRAS-mutant NSCLC compose a third lung adenocarcinoma, among which 17% to 55% will develop brain metastases. Likewise, more than a third HER2-positive breast cancer will develop brain metastasis. Among existing animal models, the ectopic injection in brain cannot reflect the mechanism of tumor invasion and metastasis, while tail vein and intra-cardiac injection usually produces extra-cerebral metastatic disease and the animals have to be sacrificed before brain metastases appeared. Here we developed several metastasis models injected by intra-carotid artery (ICA) to address these problems. Two KRAS-mutant lung cancer cells and two HER2-positive breast cancer cells selected by their metastasize potential were luciferase labeled for in vivo imaging and drug evaluation. The tumor pathology in brain was evaluated by H&E staining. Compared to ectopic models, these ICA models have natural dissemination and progression in the brain, which recapitulate the different pattern of metastatic lesions in the clinic. With synchronized growth rate and little variation compared to tail vein and intra-cardiac models, these tumor growth kinetics allow for more appropriate animal efficacy study. Both KRAS-sensitive and insensitive models have been developed and validated for the next generation drug development; HER-2 positive breast models with ICA method also showed a good discriminative power on anti-HER2 modalities including antibodies, small molecules and ADC. Meanwhile, ICA models with human immune cell reconstitution were also developed to support immune therapies in pre-clinical stage. In summary, we have developed a panel of intra-carotid artery brain metastatic models for drug evaluation, and demonstrated their superiority in growth kinetics, brain microenvironment, drug selectivity and immune component. These models can be a promising predictive tool for novel drug/modality discovery to target brain metastasis. Citation Format: Fuyang Wang, Yuying Yang, Haoxia Zhao, Chunlei Dai, Bingrui Han, Mengyao Zhang, Xia Xiong, Chao Zhang, Xuzhen Tang, Qunsheng Ji. Intra-carotid artery brain metastasis models for evaluation of lung and breast cancer drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5988.

The Impact of Supplements on Recovery After Peripheral Nerve Injury: A Review of the Literature.

Peripheral nerve injury (PNI) can result from trauma, surgical resection, iatrogenic injury, and/or local anesthetic toxicity. Damage to peripheral nerves may result in debilitating weakness, numbness, paresthesia, pain, and/or autonomic instability. As PNI is associated with inflammation and nerve degeneration, means to mitigate this response could result in improved outcomes. Numerous nutrients have been investigated to prevent the negative sequelae of PNI. Alpha-lipoic acid, cytidine diphosphate-choline (CDP Choline), curcumin, melatonin, vitamin B12, and vitamin E have demonstrated notable success in improving recovery following PNI within animal models. While animal studies show ample evidence that various supplements may improve recovery after PNI, similar evidence in human patients is limited. The goal of this review is to analyze supplements that have been used successfully in animal models of PNI to serve as a reference for future studies on human patients. By analyzing supplements that have shown efficacy in animal studies, healthcare providers will have a resource from which to guide decision-making regarding future human studies investigating the role that supplements could play in PNI recovery. Ultimately, establishing a comprehensive understanding of these supplements in human patients following PNI may significantly improve post-surgical outcomes, quality of life, and peripheral nerve regeneration.

The development of broad-spectrum antiviral medical countermeasures to treat viral hemorrhagic fevers caused by natural or weaponized virus infections.

The Joint Program Executive Office for Chemical, Biological, Radiological, and Nuclear Defense (JPEO-CBRND) began development of a broad-spectrum antiviral countermeasure against deliberate use of high-consequence viral hemorrhagic fevers (VHFs) in 2016. The effort featured comprehensive preclinical research, including laboratory testing and rapid advancement of lead molecules into nonhuman primate (NHP) models of Ebola virus disease (EVD). Remdesivir (GS-5734, Veklury, Gilead Sciences) was the first small molecule therapeutic to successfully emerge from this effort. Remdesivir is an inhibitor of RNA-dependent RNA polymerase, a viral enzyme that is essential for viral replication. Its robust potency and broad-spectrum antiviral activity against certain RNA viruses including Ebola virus and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) led to its clinical evaluation in randomized, controlled trials (RCTs) in human patients during the 2018 EVD outbreak in the Democratic Republic of the Congo (DRC) and the ongoing Coronavirus Disease 2019 (COVID-19) pandemic today. Remdesivir was recently approved by the US Food and Drug Administration (FDA) for the treatment of COVID-19 requiring hospitalization. Substantial gaps remain in improving the outcomes of acute viral infections for patients afflicted with both EVD and COVID-19, including how to increase therapeutic breadth and strategies for the prevention and treatment of severe disease. Combination therapy that joins therapeutics with complimentary mechanisms of action appear promising, both preclinically and in RCTs. Importantly, significant programmatic challenges endure pertaining to a clear drug and biological product development pathway for therapeutics targeting biodefense and emerging pathogens when human efficacy studies are not ethical or feasible. For example, remdesivir’s clinical development was facilitated by outbreaks of Ebola and SARS-CoV-2; as such, the development pathway employed for remdesivir is likely to be the exception rather than the rule.The current regulatory licensure pathway for therapeutics targeting rare, weaponizable VHF agents is likely to require use of FDA’s established Animal Rule (21 CFR 314.600–650 for drugs; 21 CFR 601.90–95 for biologics). The FDA may grant marketing approval based on adequate and well-controlled animal efficacy studies when the results of those studies establish that the drug is safe and likely to produce clinical benefit in humans. In practical terms, this is anticipated to include a series of rigorous, well-documented, animal challenge studies, to include aerosol challenge, combined with human safety data. While small clinical studies against naturally occurring, high-consequence pathogens are typically performed where possible, approval for the therapeutics currently under development against biodefense pathogens will likely require the Animal Rule pathway utilizing studies in NHPs. We review the development of remdesivir as illustrative of the effort that will be needed to field future therapeutics against highly lethal, infectious agents.

Anti-Tuberculosis Activity of Pediococcus acidilactici Isolated from Young Radish Kimchi against Mycobacterium tuberculosis.

Tuberculosis is a highly contagious disease caused by Mycobacterium tuberculosis. It affects about 10 million people each year and is still one of the leading causes of death worldwide. About 2 to 3 billion people (equivalent to 1 in 3 people in the world) are infected with latent tuberculosis. Moreover, as the number of multidrug-resistant, extensively drug-resistant, and totally drug-resistant strains of M. tuberculosis continues to increase, there is an urgent need to develop new anti-tuberculosis drugs that are different from existing drugs to combat antibiotic-resistant M. tuberculosis. Against this background, we aimed to develop new anti-tuberculosis drugs using probiotics. Here, we report the anti-tuberculosis effect of Pediococcus acidilactici PMC202 isolated from young radish kimchi, a traditional Korean fermented food. Under coculture conditions, PMC202 inhibited the growth of M. tuberculosis. In addition, PMC202 inhibited the growth of drug-sensitive and -resistant M. tuberculosis- infected macrophages at a concentration that did not show cytotoxicity and showed a synergistic effect with isoniazid. In a 2-week, repeated oral administration toxicity study using mice, PMC202 did not cause weight change or specific clinical symptoms. Furthermore, the results of 16S rRNA-based metagenomics analysis confirmed that dysbiosis was not induced in bronchoalveolar lavage fluid after oral administration of PMC202. The anti-tuberculosis effect of PMC202 was found to be related to the reduction of nitric oxide. Our findings indicate that PMC202 could be used as an anti-tuberculosis drug candidate with the potential to replace current chemicalbased drugs. However, more extensive toxicity, mechanism of action, and animal efficacy studies with clinical trials are needed.

Evaluation of antileishmanial potential of the antidepressant escitalopram in Leishmania infantum

Neglected tropical diseases (NTDs) such as visceral leishmaniasis (VL) present a limited and toxic therapeutic arsenal, and drug repositioning represents a safe and cost-effective approach. In this work, we investigated the antileishmanial potential and the mechanism of lethal action of the antidepressant escitalopram. The efficacy of escitalopram was determined ex-vivo using the intracellular Leishmania (L.) infantum amastigote model and the mammalian cytotoxicity was determined by the colorimetric MTT assay. The cellular and molecular alterations induced by the drug were investigated using spectrofluorimetry, a luminescence assay and flow cytometry. Our data revealed that escitalopram was active and selective against L. infantum parasites, with an IC50 value of 25 µM and a 50% cytotoxic concentration (CC50) of 184 µM. By using the fluorescent probes SYTOX® Green and DiSBAC2(3), the drug showed no alterations in the plasma membrane permeability nor in the electric potential of the membrane (∆ψp); however, after a short-time incubation, the drug caused a dose-dependent up-regulation of the calcium levels, leading to the depolarization of the mitochondrial membrane potential (∆ψm) and a reduction of the ATP levels. No up-regulation of reactive oxygen (ROS) was observed. In the cell cycle analysis, escitalopram induced a dose-dependent increase of the parasites at the sub G0/G1 stage, representing fragmented DNA. Escitalopram presented a selective antileishmanial activity, with disruption of single mitochondrion and interference in the cell cycle. Approved drugs such as escitalopram may represent a promising approach for NTDs and can be considered in future animal efficacy studies.

Infections @ Trauma/Orthopedic Implants: Recent Advances on Materials, Methods, and Microbes-A Mini-Review.

Implants and materials are indispensable in trauma and orthopedic surgery. The continuous improvements of implant design have resulted in an optimized mechanical function that supports tissue healing and restoration of function. One of the still unsolved problems with using implants and materials is infection. Trauma and material implantation change the local inflammatory situation and enable bacterial survival and material colonization. The main pathogen in orthopedic infections is Staphylococcus aureus. The research efforts to optimize antimicrobial surfaces and to develop new anti-infective strategies are enormous. This mini-review focuses on the publications from 2021 with the keywords S. aureus AND (surface modification OR drug delivery) AND (orthopedics OR trauma) AND (implants OR nails OR devices). The PubMed search yielded 16 original publications and two reviews. The original papers reported the development and testing of anti-infective surfaces and materials: five studies described an implant surface modification, three developed an implant coating for local antibiotic release, the combination of both is reported in three papers, while five publications are on antibacterial materials but not metallic implants. One review is a systematic review on the prevention of stainless-steel implant-associated infections, the other addressed the possibilities of mixed oxide nanotubes. The complexity of the approaches differs and six of them showed efficacy in animal studies.