Early cutaneous inflammatory response at different degree of burn and its significance for clinical diagnosis and management.

A complete characterization of the burn wound based on cutaneous architectural changes and inflammatory response is extremely important to provide evidence for progressive changes in the burn wound. Burn wounds are highly susceptible to conversion into deeper wounds, which need special care and attention; thereby, the complete characterization of burn wound type and their subsequent inflammatory status in the cutaneous system at the earliest is of paramount importance. Inflammatory markers at different degrees will help clinicians devise better and more specific treatment strategies for each burn type. The present study is carried out to profile pro-inflammatory gene expression along with immune cell quantification, vascular perfusion, and histopathological assessment in the cutaneous system of murine models. The study revealed that burn injury caused an immediate increase in vascular perfusion in superficial and partial-thickness burns, whereas there was a decrease in vascular perfusion in full-thickness burns. An influx of lymphocytes at the edges of burn wounds in each type of burn injury was well-orchestrated with the event of vascular perfusion. Further, pro-inflammatory gene expression profiling revealed significant upregulation vis-à-vis upregulation of TNF-α and MCP-1 genes, with an increase in the number of neutrophils following 72 h of injury that evidently cemented the conversion of superficial burn into partial-thickness burn. The molecular findings were profoundly supported by the histopathological changes. Thus, our foundational studies show distinct characteristic cutaneous changes correlated with the expression of key pro-inflammatory genes in three different types of burn injuries. Characterization of these cutaneous inflammatory responses provides a promising future for medical interventions involved with different degrees of burn injury, and it will also help in the pre-clinical testing of therapies for burn injury.

Herb-drug interactions: a mechanistic approach.

In India, traditional herbal medicines have been an essential part of therapy for the last centuries. However, a large portion of the general populace is using these therapies in combination with allopathy lacking a proper understanding of possible interactions (synergistic or antagonistic) between the herbal product and the allopathic drug. This is based on the assumption that herbal drugs are relatively safe, i.e. without side effects. We have established a comprehensive understanding of the possible herb-drug interactions and identified interaction patterns between the most common herbs and drugs currently in use in the Indian market. For this purpose, we listed common interactors (herbs and allopathic drugs) using available scientific literature. Drugs were then categorized into therapeutic classes and aligned to produce a recognizable pattern present only if interactions were observed between a drug class and herb in the scientific literature. Interestingly, the top three categories (with highest interactors), antibiotics, oral hypoglycemics, and anticonvulsants, displayed synergistic interactions only. Another major interactor category was CYP450 enzymes, a natural component of our metabolism. Both activation and inhibition of CYP450 enzymes were observed. As many allopathic drugs are known CYP substrates, inhibitors or inducers, ingestion of an interacting herb could result in interaction with the co-administered drug. This information is largely unavailable for the Indian population and should be studied in greater detail to avoid such interactions. Although this information is not absolute, the systematic literature review proves the existence of herb-drug interactions in the literature and studies where no interaction was detected are equally important.

Combined radiation burn injuries: A note.

Combined radiation injury occurs when radiation is accompanied by any other form of trauma. The past experiences of Hiroshima, Nagasaki, and Chernobyl have revealed that a large number of victims of such nuclear accidents or attacks suffer from combined radiation injuries. The possibility of a nuclear attack seems very far-fetched, but the destruction that would occur in such an event would be massive, with a huge lossof lives. Therefore, preparedness for the same should be done beforehand. The severity of combined radiation depends upon various factors, such as radiation dose, type, tissues affected, and traumas. The article focuses on combined radiation burn injury (CRBI) which may arise due to the combination of ionising radiation with thermal burns. CRBI can have varied effects on different organs like the hematopoietic, digestive, lymphatic, cardiovascular, and respiratory systems. Some of the most profound lethal effects are hematopoietic dysfunction, gastrointestinal leakage, bacterial translocation to other organ sites, pulmonary fibrosis, and pneumonitis. In this article, we have attempted to accumulate the knowledge of ongoing research on the functioning of different organ systems, which are affected due to CRBI and possible countermeasures to minimize the effects, thus improving survival.

A chemical-genetic screen identifies ABHD12 as an oxidized-phosphatidylserine lipase.

Reactive oxygen species (ROS) are transient, highly reactive intermediates or byproducts produced during oxygen metabolism. However, when innate mechanisms are unable to cope with sequestration of surplus ROS, oxidative stress results, in which excess ROS damage biomolecules. Oxidized phosphatidylserine (PS), a proapoptotic 'eat me' signal, is produced in response to elevated ROS, yet little is known regarding its chemical composition and metabolism. Here, we report a small molecule that generates ROS in different mammalian cells. We used this molecule to detect, characterize and study oxidized PS in mammalian cells. We developed a chemical-genetic screen to identify enzymes that regulate oxidized PS in mammalian cells and found that the lipase ABHD12 hydrolyzes oxidized PS. We validated these findings in different physiological settings including primary peritoneal macrophages and brains from Abhd12-/- mice under inflammatory stress, and in the process, we functionally annotated an enzyme regulating oxidized PS in vivo.

Sphingosine kinases negatively regulate the expression of matrix metalloproteases (MMP1 and MMP3) and their inhibitor TIMP3 genes via sphingosine 1-phosphate in extravillous trophoblasts.

PURPOSE: Extracellular matrix remodeling is essential for extravillous trophoblast (EVT) cell migration and invasion during placental development and regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteases (TIMPs). Sphingosine kinases (SPHK1 and SPHK2) synthesize sphingosine-1-phosphate (S1P), which works either intracellularly or extracellularly via its receptors S1PR1-5 in an autocrine or paracrine manner. The role of SPHKs/S1P in regulating the expression of MMPs and TIMPs in EVT is mostly unknown and forms the primary objective of the study. METHODS: HTR-8/SVneo cells were used as a model of EVT. To inhibit the expression of SPHKs, cells were treated with specific inhibitors, SK1-I and SKI-II, or gene-specific siRNAs. The expressions of MMPs and TIMPs were estimated by qPCR. RESULTS: We demonstrated that SPHK1, MMP1-3, and TIMP1-3 were highly expressed in HTR-8/SVneo cells. We found that treatment of cells with SK1-I, SKI-II, and knockdown of SPHK1 or SPHK2 increased the expression of MMP1, MMP3, and TIMP3. The addition of extracellular S1P inhibits the upregulation of MMPs and TIMPs in treated cells. CONCLUSIONS: SPHKs negatively regulate the expression of MMP1, MMP3, and TIMP3. The level of intracellular S1P acts as a negative feedback switch for MMP1, MMP3, and TIMP3 expression in EVT cells.

Urological implications of SARS CoV-19.

INTRODUCTION: The novel coronavirus disease 2019 (COVID-19), pandemic has afflicted > 3.3 million people around the world since December 2019. Though, more than 1000 publications have appeared in scientific journals addressing a plethora of questions, there is a considerable hiatus in understanding of the behavior and natural history of the virus and its impact on urology. Also, a modified approach is the need of hour in taking care of patients as urologists should safeguard their teams, families, and patients. MATERIAL AND METHODS: The authors have used guidelines from USA, Canada, UK, Europe and India for making recommendations to help urologist define their own policies that may have to be fine-tuned on the basis of continued and evolving challenges they would encounter and the local resources at their disposal. RESULTS: COVID-19 do effect genitourinary system from kidney to testis. The authors provide scientific basis to urologists to help identify patients by remote consultation who are likely to be harmed by coming to the hospital, and not to miss those who need hospitalization for diagnostic or therapeutic interventions. There is uncompromised need of specific precautions during surgery to safe guard the surgeon and his team along with the patient. CONCLUSIONS: Urological operations during COVID-19 pandemic should be limited to emergency cases during the acute phase with an exit strategy planned in a staggered manner, based on the scientific risk stratification. Telemedicine (e-clinics or virtual clinics) would help achieve the goal of risk stratification.

Vascular perfusion: A predictive tool for thermal burn injury.

Damage to the blood vascular system and their altered permeability is a prominent pathological event in case of dermal injury, particularly in burn trauma situations. Prediction of vascular perfusion at the site of damage could be an attractive tool in the estimation of thermal burn injury. A very few reports are available with reference to this tool in defining the thermal injury status. We have used the vascular perfusion estimation method as a tool in assessing the severity of thermal damage to the animal skin. To validate this tool, the mice were subjected to the thermal burn at 90 °C for 10, 20 & 30 s and excised burned skin samples were analyzed for vascular perfusion 24hr post-burn treatment. The vascular perfusion was significantly altered in a time-dependent fashion. This method also provided information regarding blood vessel damage at varied time points. The results of this study clearly indicate the severity of skin damage by the thermal burn. The finding of the present study could have greater implications in predicting the degree of burn. This method is very simple and cost-effective compared to other available modalities used for the estimation of thermal burn injury. The method certainly has the benefit of the estimation of burn injury in the animal models.

Polystyrene-Supported Palladium (Pd@PS)-Catalyzed Carbonylative Annulation of Aryl Iodides Using Oxalic Acid as a Sustainable CO Source for the Synthesis of 2-Aryl Quinazolinones.

An efficient and convenient strategy for the synthesis of diversely substituted quinazolinones from o-carbamoyl/cyano aniline and aryl iodides using oxalic acid as a CO source under polystyrene supported palladium (Pd@PS) nanoparticles (NPs) catalyzed conditions has been developed. In this study, oxalic acid has been employed as safe, economic, environmentally benign, sustainable and bench-stable, solid CO surrogate under Double-Layer-Vial (DLV) system for the synthesis of 2-aryl quinazolinones. This methodology does not require any special high-pressure equipment like autoclaves, microwaves, etc. Moreover, a simple procedure for catalyst preparation, catalyst recyclability, easy handling of reaction, additive and base-free generation of CO, excellent to good yields and vast substrate scope are the additional features of developed protocol.

Pharmacological control of inflammation in wound healing.

Wound inflammation is a rapid and highly orchestrated process that significantly impacts the wound healing cascade. Consequent to injury, a series of events set off that include inflammatory, proliferation and maturation phases leading to wound closure and restoration of normal skin integrity. Stimuli causing stress to host immune system or induce inflammatory response include tissue damage and pathogenic microbial infection.Several evidences points towards the positive role of inflammation as it essential to fight against the attack of invading pathogens and to remove dead tissues from the site of injury. Besides its positive role, prolonged inflammation is injurious and may result in deregulated stages of the wound healing which may lead to excessive scarring. Achieving balance in inflammatory cascade is one of the challenging tasks for development of a wound healing drug. This review mainly focuses on the pharmacological control of inflammation by agents which critically balance the inflammatory cascade. However, none of the agent is available in the healthcare market which exclusively plays a role in wound repair. In this review we shall explore different factors or agents affecting inflammation in wound healing. This information might be helpful in designing and development new process, technologies or drugs for better management of wound care. In addition, understanding the effect of inflammation on the outcome of the healing process will serve as a significant milestone in the area of pathological tissue repair.

Redox-guided small molecule antimycobacterials.

The emergence of drug resistance has posed a major challenge to treatment of tuberculosis worldwide. The new drug candidates in the pipeline are few and therefore there is an urgent need to develop antimycobacterials with novel mechanisms of action. Maintenance of redox homeostasis is integral to mycobacterial survival and growth. Therefore, perturbation of this equilibrium can result in irreversible stress induction and inhibition of growth. Herein, we review a number of small molecules that have either been designed to induce redox stress or were found to do so after their discovery. A number of these small molecules are quite effective against drug-resistant mycobacterial strains and thus offer scope for exploration of potentially new mechanism of action. The progress in redox-guided antimycobacterial compounds and the challenges towards clinical applications are reviewed. © 2018 IUBMB Life, 70(9):826-835, 2018.

Kinetics of Interferon gamma and Interleukin-21 response following foot and mouth disease virus infection.

Foot and mouth disease (FMD) is one of the most contagious diseases of cloven footed animals causing significant economic impediment in livestock production system. The immune response to FMD virus (FMDV) infection is regulated by a complex interplay between various cells, cytokines and other immune components. Based on the well established role of Interferon-gamma (IFN-γ) and Interleukin-21 (IL-21) in viral infections, this study aimed to determine expression level of these cytokines in clinically infected adults and calves; and the results were compared with those in the subclinically infected animals up to 120 days post outbreak (DPO) in a vaccinated cattle herd. The expression level of IFN-γ and IL-21 was assayed on 0, 7, 14, 28, 60, 90, and 120 DPO by enzyme linked immunosorbent assay (ELISA) with simultaneous assessment of FMDV structural protein-antibody titer against serotype 'O' by liquid phase blocking ELISA (LPBE) and nonstructural protein-antibody, a differential marker of infection, using r3AB3 indirect ELISA (r3AB3 I-ELISA). Although, the peak expression of IFN-γ was observed on 14 DPO across all categories of animals, the clinically infected animals registered a significant increase in IFN-γ level as compared to the subclinically infected population possibly due to the difference in the extent of virus replication and inflammation. The IL-21 level increased significantly during 14-28 DPO and highest expression was noticed on 28 DPO. The increase in the expression level of IFN-γ and IL-21 at 28 DPO correlated with the increase in antibody titer as determined by LPBE suggesting the role of these cytokines in augmenting immune response to FMDV infection.

Dissipation pattern, safety evaluation, and generation of processing factor (PF) for pyraclostrobin and metiram residues in grapes during raisin preparation.

A residue analysis method was validated for trace level estimation of pyraclostrobin by liquid chromatography-mass spectrometry and metiram (analyzed as CS2) by gas chromatography mass spectrometry in grapes and raisin matrix. Dissipation of their residues and processing factors (PFs) during raisin making were evaluated through field studies with applications at single dose (SD) and double dose (DD). Residue data during drying process were best fitted to first + first-order kinetics model giving half-life ranging between 6 and 7 days for pyroclostrobin and 4 days for metiram. PFs for metiram and pyraclostrobin related to washing and oil dipping were 0.47 and 0.41, and 0.78 and 0.63 at single dose (SD) and double dose (DD), respectively. PF value of >1 for drying (1.01 and 1.31 for metiram and 1.34 and 1.10 for pyraclostrobin) indicates concentration of the residues during the drying process. The dietary exposure corresponding to average daily consumption of 0.0043 kg raisin per day on each sampling day was less than the respective maximum permissible intake at both the doses.

Knockdown and repellent effect of permethrin-impregnated army uniform cloth against Aedes aegypti after different cycles of washings.

Personnel protection is one of the methods for protection from bites of mosquitoes and other arthropod vectors transmitting many dreadful diseases. Insect repellents and other plant products are normally used to ward off mosquitoes. Application of synthetic pyrethroid permethrin on cloth is adopted for repelling arthropod vectors in many countries for military and civil purposes. In the present study, attempt has been made to impregnate permethrin in the army uniform cloth and to evaluate for its knockdown and repellency against unfed female Aedes aegypti mosquitoes in laboratory condition. WHO protocols were adopted for impregnation of permethrin on cloth and evaluation for its knockdown and repellency after different cycles of washing. Results showed that 93.33% of mosquitoes were knocked down within 1 h after the first washing while its efficacy reduced gradually till the fifty-fifth washing. Landing of mosquitoes on the permethrin-treated cloth was found to increase with respect to number of washings as compared to the untreated cloth. Within 24 h, 100% mortality of all the mosquitoes exposed to permethrin-impregnated cloth was observed. SEM-EDX studies on the texture of untreated cloth and permethrin-treated cloth after different cycles of washing also revealed presence of permethrin on treated cloth.

Fission Yeast as a Platform for Antibacterial Drug Screens Targeting Bacterial Cytoskeleton Proteins.

Bacterial cytoskeletal proteins such as FtsZ and MreB perform essential functions such as cell division and cell shape maintenance. Further, FtsZ and MreB have emerged as important targets for novel antimicrobial discovery. Several assays have been developed to identify compounds targeting nucleotide binding and polymerization of these cytoskeletal proteins, primarily focused on FtsZ. Moreover, many of the assays are either laborious or cost-intensive, and ascertaining whether these proteins are the cellular target of the drug often requires multiple methods. Finally, the toxicity of the drugs to eukaryotic cells also poses a problem. Here, we describe a single-step cell-based assay to discover novel molecules targeting bacterial cytoskeleton and minimize hits that might be potentially toxic to eukaryotic cells. Fission yeast is amenable to high-throughput screens based on microscopy, and a visual screen can easily identify any molecule that alters the polymerization of FtsZ or MreB. Our assay utilizes the standard 96-well plate and relies on the ability of the bacterial cytoskeletal proteins to polymerize in a eukaryotic cell such as the fission yeast. While the protocols described here are for fission yeast and utilize FtsZ from Staphylococcus aureus and MreB from Escherichia coli, they are easily adaptable to other bacterial cytoskeletal proteins that readily assemble into polymers in any eukaryotic expression hosts. The method described here should help facilitate further discovery of novel antimicrobials targeting bacterial cytoskeletal proteins.

Fate of multi-residue insecticides and their metabolites in the process of vinification: Analytical method validation, dissipation kinetics, processing factor, and risk assessment.

In viticulture, the use of synthetic chemical formulations introduces insecticide residues into harvested grapes and further into processed grape products, posing a safety concern to consumers. This study investigated the fate of ten insecticide residues and their metabolites from vine to wine. A rapid validated multi-residue approach using QuEChERS extraction and LC-MS/MS configuration was employed for targeted analysis in grape, pomace, and wine. The targeted insecticides showed satisfactory mean recoveries (76.03-111.95%) and precision (RSD = 0.75-7.90%) across the three matrices, with a matrix effect ranging from -16.88 to 35.18%, particularly higher in pomace. Preliminary grape washing effectively removed 15.52-61.31% of insecticide residues based on water solubility and systemic nature. Residue dissipation during fermentation ranged from 73.19% to 87.15% with a half-life spanning from 1 to 5.5 days. The mitigation rate was observed at 12.85-26.81% for wine and 17.76-51.55% for pomace, with the highest transfer rate for buprofezin (51.55%) to pomace and fipronil (25.72%) to wine. Calculated processing factors (PF) for final wine ranged from 0.16 to 0.44, correlating strongly with the octanol-water partition ratio of targeted insecticides. The reported PF, calculated hazard quotient (HQ) (0.003-5.800%), and chronic hazard index (cHI) (2.041-10.387%) indicate reduced residue concentrations in wine and no potential chronic risk to consumers, ensuring a lower dietary risk to wine consumers.

Alleviation of radiation combined skin injury in rat model by topical application of ascorbate formulation.

PURPOSE: This research endeavor was undertaken to elucidate the impact of an innovative ascorbate formulation on the regeneration process of full-thickness excision wounds in a rat model exposed to whole-body gamma irradiation, replicating conditions akin to combat or radiation emergency scenarios. MATERIALS AND METHODS: We established a comprehensive rat model by optimizing whole body γ-radiation doses (5-9 Gy) and full-thickness excision wound sizes (1-3 cm2) to mimic radiation combined injury (RCI). The developed RCI model was used to explore the healing potential of ascorbate formulation. The study includes various treatment groups (i.e., sham control, radiation alone, wound alone, radiation + wound, and radiation + wound + formulation). The ascorbate formulation was applied twice daily, with a 12-hour gap between each application, starting 1 hour after the initiation of the wound. The healing potential of the formulation in the RCI context was evaluated over 14 days through hematological, molecular, and histological parameters. RESULTS: The combination of a 5 Gy radiation dose and a 1 cm2 wound was identified as the optimal setting to develop the RCI model for subsequent studies. The formulation was used topically immediately following RCI, and then twice daily until complete healing. Treatment with the ascorbate formulation yielded noteworthy outcomes and led to a substantial reduction (p < .05) in the wound area, accelerated epithelialization periods, and an increased wound contraction rate. The formulation's localized healing response improved organ weights, normalized blood parameters, and enhanced hematopoietic and immune systems. A gene expression study revealed the treatment up-regulated TGF-ß and FGF, and down-regulated PDGF-α, TNF-α, IL-1ß, IL-6, MIP-1α, and MCP-1 (p < .05). Histopathological assessments supported the formulation's effectiveness in restoring cellular architecture and promoting tissue regeneration. CONCLUSION: Topical application of the ascorbate formulation in RCI resulted in a significant improvement in delayed wound healing, leading to accelerated wound closure by mitigating the expression of inflammatory responses.

Understanding innate and adaptive responses during radiation combined burn injuries.

The occurrence of incidents involving radiation-combined burn injuries (RCBI) poses a significant risk to public health. Understanding the immunological and physiological responses associated with such injuries is crucial for developing care triage to counter the mortality that occurs due to the synergistic effects of radiation and burn injuries. The core focus of this narrative review lies in unraveling the immune response against RCBI. Langerhans cells, mast cells, keratinocytes, and fibroblasts, which induce innate immunity, have been explored for their response to radiation, burns, and combined injuries. In the case of adaptive immune response, exploring behavioral changes in T regulatory (Treg) cells, T helper cells (Th1, Th2, and Th17), and immunoglobulin results in delayed healing compared to burn and radiation injury. The review also includes the function of complement system components such as neutrophils, acute phase proteins (CRP, C3, and C5), and cytokines for their role in RCBI. Combined insults resulting in a reduction in the cell population of immune cells display variation in response based on radiation doses, burn injury types, and their intrinsic radiosensitivity. The lack of approved countermeasures against RCBI poses a significant challenge. Drug repurposing might help to balance immune cell alteration, resulting in fast recovery and decreasing mortality, which gives it clinical significance for its implication on the site of such incidence. However, the exact immune response in RCBI remains insufficiently explored in pre-clinical and clinical stages, which might be due to the non-availability of in vitro models, standard animal models, or human subjects, warranting further research.

In the realm of public health, RCBI presents significant risks and obstacles. This hazard is quite serious, and it might get worse in the future as evidenced by incidents like nuclear meltdowns and medical mistakes. Diagnosis and treatment become more challenging when serious injuries, particularly burns, are combined with radiation exposure. Features like early shock, poor wound healing, and hematopoietic instability call for advancements in both diagnosis and therapy. Furthermore, the immune system's response to RCBI is complicated and involves changes in cytokine concentrations, immune cell activity, and adaptive immune responses compared to single injuries. Immune cell radiosensitivity varies depending on the type of cell, radiation dose, and length of exposure, so it's important to understand. Repurposing drugs is one of the potential techniques to reduce mortality and speed up healing which are discussed in the manuscript. Still, more research is needed. To effectively tackle RCBI, more investigation into molecular processes, treatment strategy optimization, and information gap closure are essential.

Exosomes: A new perspective for radiation combined injury as biomarker and therapeutics.

Radiation Combined Injuries (RCI) pose formidable public health risks, particularly in the context of nuclear incidents, necessitating specialized treatments and development of biomarkers. RCI encompasses instances where ionizing radiation exposure coincides with burns, wounds, or trauma. However, the limited understanding of cellular responses hinders progress in developing effective therapies. This article underscores the pivotal role of exosomes, nano-sized particles (30-120 nm) actively secreted by cells, in addressing the intricate challenges posed by RCI. Exosomes serve as vehicles for the transportation of bioactive molecules, including proteins, lipids, and miRNA, thereby facilitating processes critical to radiotherapy, burn injury, and wound healing. Exosomes hold significant promise for the transformation of RCI management by reducing inflammation, promoting wound healing, managing sepsis, altering immunological responses, and modulating signal transduction pathways. Moreover, exosomes are also being explored as biomarker for various diseases and stress conditions including radiation exposure and associated injuries. This comprehensive review highlights the burgeoning potential of exosomes in advancing the management of RCI, thereby enhancing public health preparedness and response.

Intracellular peroxynitrite perturbs redox balance, bioenergetics, and Fe-S cluster homeostasis in Mycobacterium tuberculosis.

The ability of Mycobacterium tuberculosis (Mtb) to tolerate nitric oxide (•NO) and superoxide (O2•-) produced by phagocytes contributes to its success as a human pathogen. Recombination of •NO and O2•- generates peroxynitrite (ONOO-), a potent oxidant produced inside activated macrophages causing lethality in diverse organisms. While the response of Mtb toward •NO and O2•- is well established, how Mtb responds to ONOO- remains unclear. Filling this knowledge gap is important to understand the persistence mechanisms of Mtb during infection. We synthesized a series of compounds that generate both •NO and O2•-, which should combine to produce ONOO-. From this library, we identified CJ067 that permeates Mtb to reliably enhance intracellular ONOO- levels. CJ067-exposed Mtb strains, including multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical isolates, exhibited dose-dependent, long-lasting oxidative stress and growth inhibition. In contrast, Mycobacterium smegmatis (Msm), a fast-growing, non-pathogenic mycobacterial species, maintained redox balance and growth in response to intracellular ONOO-. RNA-sequencing with Mtb revealed that CJ067 induces antioxidant machinery, sulphur metabolism, metal homeostasis, and a 4Fe-4S cluster repair pathway (suf operon). CJ067 impaired the activity of the 4Fe-4S cluster-containing TCA cycle enzyme, aconitase, and diminished bioenergetics of Mtb. Work with Mtb strains defective in SUF and IscS involved in Fe-S cluster biogenesis pathways showed that both systems cooperatively protect Mtb from intracellular ONOO- in vitro and inducible nitric oxide synthase (iNOS)-dependent growth inhibition during macrophage infection. Thus, Mtb is uniquely sensitive to intracellular ONOO- and targeting Fe-S cluster homeostasis is expected to promote iNOS-dependent host immunity against tuberculosis (TB).

CD38-Specific Gallium-68 Labeled Peptide Radiotracer Enables Pharmacodynamic Monitoring in Multiple Myeloma with PET.

The limited availability of molecularly targeted low-molecular-weight imaging agents for monitoring multiple myeloma (MM)-targeted therapies has been a significant challenge in the field. In response, a first-in-class peptide-based radiotracer, [68Ga]Ga-AJ206, is developed that can be seamlessly integrated into the standard clinical workflow and is specifically designed to noninvasively quantify CD38 levels and pharmacodynamics by positron emission tomography (PET). A bicyclic peptide, AJ206, is synthesized and exhibits high affinity to CD38 (KD: 19.1 ± 0.99 × 10-9 m) by surface plasmon resonance. Further, [68Ga]Ga-AJ206-PET shows high contrast within 60 min and suitable absorbed dose estimates for clinical use. Additionally, [68Ga]Ga-AJ206 detects CD38 expression in cell line-derived xenografts, patient-derived xenografts (PDXs), and disseminated disease models in a manner consistent with flow cytometry and immunohistochemistry findings. Moreover, [68Ga]Ga-AJ206-PET successfully quantifies CD38 pharmacodynamics in PDXs, revealing increased CD38 expression in the tumor following all-trans retinoic acid (ATRA) therapy. In conclusion, [68Ga]Ga-AJ206 exhibits the salient features required for clinical translation, providing CD38-specific high-contrast images in multiple models of MM. [68Ga]Ga-AJ206-PET could be useful for quantifying total CD38 levels and pharmacodynamics during therapy to evaluate approved and new therapies in MM and other diseases with CD38 involvement.