A novel brominated chalcone derivative as a promising multi-target inhibitor against multidrug-resistant Listeria monocytogenes.

Foodborne pathogens continue to challenge public health due to their ability to cause severe illness and their increasing resistance to current antimicrobial treatments. Listeria monocytogenes is a resilient foodborne pathogen that poses significant risks to vulnerable populations, leading to severe infections and high hospitalization rates. The emergence of antimicrobial-resistant (AMR) strains of L. monocytogenes underscores the need for novel therapeutic strategies. In this study, we investigated the antimicrobial efficacy of the (2E)-3-(3,5-dibromo-2-hydroxylphenyl)-1-(5-methylfuran-2-yl) prop-2-en-1-one (DK06) against multidrug-resistant L. monocytogenes. DK06 exhibited a significant dose-dependent inhibition of L. monocytogenes growth, achieving a maximum inhibition of 92.9% at 320 µM. Molecular docking and dynamics simulations revealed high binding affinities for key virulence proteins PlcB and ArgA, with stable protein-ligand interactions maintained despite conformational changes. DK06 also disrupted biofilm formation at sub-MIC levels, reducing extracellular polymeric substances (EPS) and biofilm mass, as observed by scanning electron microscopy (SEM) analysis. Furthermore, DK06 downregulated the expression of virulence genes (plcB, argA, and hly) and decreased hemolytic activity. In vivo zebrafish studies confirmed the safety of DK06 up to 80 µM, demonstrating its efficacy in reducing mortality and oxidative stress associated with L. monocytogenes infection. DK06 also attenuated inflammation by downregulating key inflammatory markers (tnfa, il1b, il6, and nfkb). These findings indicate that DK06 is a promising multi-target inhibitor with potential application in treating infections and combating antimicrobial resistance.

Toxicity and therapeutic property of dioxopiperidin derivative SKT40 demonstrated in-vivo zebrafish model due to inflammatory bowel disease.

Inflammatory bowel disease (IBD) encompasses chronic disorders that cause severe inflammation in the digestive tract. This study evaluates (E)-3-(3,4-dichlorophenyl)-N-(2,6-dioxopiperidin-3-yl) acrylamide (named SKT40), a derivative of dioxopiperidinamide, as a potential novel treatment for IBD. The pharmacological activity of SKT40 indicated positive interactions using network pharmacology and molecular docking in silico. In vivo, adult and larval zebrafish were tested to evaluate the effectiveness of SKT40 at different concentrations (7.5 µM, 10 µM, 15 µM) in preventing dextran sulfate sodium (DSS)-induced intestinal inflammation. The administration of SKT40 resulted in positive effects by reducing reactive oxygen species (ROS), lipid peroxidation, and cell apoptosis in zebrafish larvae. SKT40 demonstrated a significant reduction in intestinal damage in adult zebrafish by increasing antioxidant enzymes that combat the causes of IBD, such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and glutathione peroxidase (GPx). It also reduces cellular damage and inflammation, as indicated by decreased levels of lactate dehydrogenase (LDH) and malondialdehyde (MDA). Gene expression analysis identified downregulation in gene expression of inflammatory mediators such as TNF-α, IL-1ß, COX-2, and IL-6. Histopathological analysis showed tissue repair from DSS-induced damage and indicated reduced hyperplasia of goblet cells. These findings suggest that SKT40 effectively treats intestinal damage, highlighting its potential as a promising candidate for IBD therapy.

Indole-3-acetic acid exposure leads to cardiovascular inflammation and fibrosis in chronic kidney disease rat model.

Indole-3-acetic acid (IAA), a protein-bound uremic toxin, has been linked to cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. This study explores the influence of IAA (125 mg/kg) on cardiovascular changes in adenine sulfate-induced CKD rats. HPLC analysis revealed that IAA-exposed CKD rats had lower excretion and increased circulation of IAA compared to both CKD and IAA control groups. Moreover, echocardiography indicated that CKD rats exposed to IAA exhibited heart enlargement, thickening of the myocardium, and cardiac hypertrophy in contrast to CKD or IAA control group. Biochemical analyses supported the finding that IAA-induced CKD rats had elevated serum levels of c-Tn-I, CK-MB, and LDH; there was also evidence of oxidative stress in cardiac tissues, with a significant decrease in SOD and CAT levels, as well as an increase in MDA levels. The gene expression analysis found significant increases in ANP, BNP, ß-MHC, TNF-α, IL-1ß, and NF-κB levels in IAA-exposed CKD groups in contrast to the CKD or IAA control group. In addition, higher cardiac fibrosis markers, including Col-I and Col-III. The findings of this study indicate that IAA could trigger cardiovascular inflammation and fibrosis in CKD conditions.

Bisphenol A-induced ovarian damage countered by luteolin: Experiments in in vitro CHO cells and in vivo PCOS phenotype zebrafish.

Bisphenol-A (BPA) is a widely used chemical that can harm the human body, including the reproductive system. BPA accumulates in the body and is found in 95 % of individuals due to everyday exposure through food, water, and skin absorption. BPA can impair female fertility by interfering with ovarian folliculogenesis, inhibiting follicular growth, and inducing atresia, leading to polycystic ovary syndrome (PCOS). PCOS is a prevalent endocrine disorder that affects many reproductive-aged women. While current treatments can help manage symptoms, they do not entirely prevent complications. Luteolin, a natural flavonoid with medicinal properties, is commonly used to treat metabolic and inflammatory disorders. Therefore, we evaluated Luteolin's properties against PCOS in Network pharmacology and molecular docking studies; further, the antioxidant and anti-inflammatory properties in protecting the Chinese Hamster ovarian (CHO) cells from Reactive Oxygen Species, cellular damage, and negative mitochondrial membrane potential were evaluated. Additionally, an in-vivo PCOS-like model was developed using zebrafish, and the localization of Luteolin was identified using fluorescein isothiocyanate (FITC). Luteolin protected the CHO cells from cellular damage, ROS, and negative mitochondrial membrane potential. Luteolin alleviated the total SOD levels in the Zebrafish ovary, induced follicular maturation, and altered the key genes in ovarian proliferation and pro-inflammatory cytokines TNF-α and IL-1ß expression. Natural Phyto-oxidants such as Luteolin may protect follicular development and early PCOS in adult zebrafish to prevent oxidative stress and inflammation. This study suggests using Luteolin as a phytomedicine to alleviate ovarian function decline.

Co-occurrence of azorubine and bisphenol A in beverages increases the risk of developmental toxicity: A study in zebrafish model.

The prevalent use of Azorubine (E122) and the unintentional food additive, Bisphenol A (BPA), in ready-to-drink (RTD) beverages raises significant health concerns, especially for children. The combined impact on embryonic development must be explored despite individual safety assessments. Our investigation revealed that the combined exposure of E122 and BPA at beverage concentration significantly induces mortality and morphological deformities, including reduced growth, pericardial edema, and yolk sac edema. The co-exposure triggers oxidative stress, impairing antioxidant enzyme responses and resulting in lipid and cellular damage. Notably, apoptotic cells are observed in the neural tube and notochord of the co-exposed larvae. Critical genes related to the antioxidant response elements (nrf2, ho1, and nqo1), apoptosis activation (bcl2, bax, and p53), and pro/anti-inflammatory cytokines (nfkb, tnfa, il1b, tgfb, il10, and il12) displayed substantial changes, highlighting the molecular mechanisms. Behavior studies indicated hypo-locomotion with reduced thigmotaxis and touch response in co-exposed larvae, distinguishing it from individual exposures. These findings underscore the neurodevelopmental impacts of E122 and BPA at reported beverage concentrations, emphasizing the urgent need for comprehensive safety assessments, particularly for child consumption.

Indole-3-acetic acid induced cardiogenesis impairment in in-vivo zebrafish via oxidative stress and downregulation of cardiac morphogenic factors.

Plant growth regulators (PGRs) are increasingly used to promote sustainable agriculture, but their unregulated use raises concerns about potential environmental risks. Indole-3-acetic acid (IAA), a commonly used PGR, has been the subject of research on its developmental toxicity in the in-vivo zebrafish model. IAA exposure to zebrafish embryos caused oxidative stress, lipid peroxidation, and cellular apoptosis. The study also revealed that critical antioxidant genes including sod, cat, and bcl2 were downregulated, while pro-apoptotic genes such as bax and p53 were upregulated. IAA exposure also hampered normal cardiogenesis by downregulating myl7, amhc, and vmhc genes and potentially influencing zebrafish neurobehavior. The accumulation of IAA was confirmed by HPLC analysis of IAA-exposed zebrafish tissues. These findings underscore the need for further study on the potential ecological consequences of IAA use and the need for sustainable agricultural practices.

Prophylactic effects of apigenin against hyperglycemia-associated amnesia via activation of the Nrf2/ARE pathway in zebrafish.

The escalating focus on ageing-associated disease has generated substantial interest in the phenomenon of cognitive impairment linked to diabetes. Hyperglycemia exacerbates oxidative stress, contributes to ß-amyloid accumulation, disrupts mitochondrial function, and impairs cognitive function. Existing therapies have certain limitations, and apigenin (AG), a natural plant flavonoid, has piqued interest due to its antioxidant, anti-inflammatory, and anti-hyperglycemic properties. So, we anticipate that AG might be a preventive medicine for hyperglycemia-associated amnesia. To test our hypothesis, naïve zebrafish were trained to acquire memory and pretreated with AG. Streptozotocin (STZ) was administered to mimic hyperglycemia-induced memory dysfunction. Spatial memory was assessed by T-maze and object recognition through visual stimuli. Acetylcholinesterase (AChE) activity, antioxidant enzyme status, and neuroinflammatory genes were measured, and histopathology was performed in the brain to elucidate the neuroprotective mechanism. AG exhibits a prophylactic effect and improves spatial learning and discriminative memory of STZ-induced amnesia in zebrafish under hyperglycemic conditions. AG also reduces blood glucose levels, brain oxidative stress, and AChE activity, enhancing cholinergic neurotransmission. AG prevented neuronal damage by regulating brain antioxidant response elements (ARE), collectively contributing to neuroprotective properties. AG demonstrates a promising effect in alleviating memory dysfunction and mitigating pathological changes via activation of the Nrf2/ARE mechanism. These findings underscore the therapeutic potential of AG in addressing memory dysfunction and neurodegenerative changes associated with hyperglycemia.

Indole-3 acetic acid induced cardiac hypertrophy in Wistar albino rats.

Indole-3-acetic acid (IAA) is the most widely utilized plant growth regulator. Despite its extensive usage, IAA is often overlooked as an environmental pollutant. Due to its protein-binding nature, it also functions as a uremic toxin, contributing to its association with chronic kidney disease (CKD). While in vitro and epidemiological research have demonstrated this association, the precise impact of IAA on cardiovascular disease in animal models is unknown. The main objective of this study is to conduct a mechanistic analysis of the cardiotoxic effects caused by IAA using male Wistar albino rats as the experimental model. Three different concentrations of IAA (125, 250, 500 mg/kg) were administered for 28 days. The circulating IAA concentration mimicked previously observed levels in CKD patients. The administration of IAA led to a notable augmentation in heart size and heart-to-body weight ratio, indicating cardiac hypertrophy. Echocardiographic assessments supported these observations, revealing myocardial thickening. Biochemical and gene expression analyses further corroborated the cardiotoxic effects of IAA. Dyslipidemia, increased serum c-Troponin-I levels, decreased SOD and CAT levels, and elevated lipid peroxidation in cardiac tissue were identified. Moreover, increased expression of cardiac inflammatory biomarkers, including ANP, BNP, ß-MHC, Col-III, TNF-α, and NF-κB, was also found in the IAA-treated animals. Histopathological analysis confirmed the cardiotoxic nature of IAA, providing additional evidence of its adverse effects on cardiovascular health. These results offer insights into the potential negative impact of IAA on cardiovascular function, and elucidating the underlying mechanisms of its cardiotoxicity.

Neuroprotective potential of pyrazole benzenesulfonamide derivative T1 in targeted intervention against PTZ-induced epilepsy-like condition in in vivo zebrafish model.

Epilepsy is a chronic neurological disease characterized by a persistent susceptibility to seizures. Pharmaco-resistant epilepsies, impacting around 30 % of patients, highlight the urgent need for improved treatments. Neuroinflammation, prevalent in epileptogenic brain regions, is a key player in epilepsy, prompting the search for new mechanistic therapies. Hence, in this study, we explored the anti-inflammatory potential of pyrazole benzenesulfonamide derivative (T1) against pentylenetetrazole (PTZ) induced epilepsy-like conditions in in-vivo zebrafish model. The results from the survival assay showed 79.97 ± 6.65 % at 150 µM of T1 compared to PTZ-group. The results from reactive oxygen species (ROS), apoptosis and histology analysis showed that T1 significantly reduces cellular damage due to oxidative stress in PTZ-exposed zebrafish. The gene expression analysis and neutral red assay results demonstrated a notable reduction in the inflammatory response in zebrafish pre-treated with T1. Subsequently, the open field test unveiled the anti-convulsant activity of T1, particularly at a concentration of 150 µM. Moreover, both RT-PCR and immunohistochemistry findings indicated a concentration-dependent potential of T1, which inhibited COX-2 in zebrafish exposed to PTZ. In summary, T1 protected zebrafish against PTZ-induced neuronal damage, and behavioural changes by mitigating the inflammatory response through the inhibition of COX-2.

Toxic ties: Unraveling the complex relationship between endocrine disrupting chemicals and chronic kidney disease.

Environmental pollution is inherently linked to several metabolic diseases and high mortality. The kidney is more susceptible to environmental pollutants compared to other organs as it is involved in concentrating and filtering most of these toxins. Few epidemiological studies revealed the intrinsic relationship between exposure to Endocrine Disrupting Chemicals (EDCs) and CKD development. Though EDCs have the potential to cause severe pathologies, the specific molecular mechanisms by which they accelerate the progression of CKD remain elusive. In particular, our understanding of how pollutants affect the progression of chronic kidney disease (CKD) through the gut-kidney axis is currently limited. EDCs modulate the composition and function of the gut microbial community and favor the colonization of harmful gut pathogens. This alteration leads to an overproduction of uremic toxin and membrane vesicles. These vesicles carry several inflammatory molecules that exacerbate inflammation and renal tissue damage and aggravate the progression of CKD. Several experimental studies have revealed potential pathways by which uremic toxin further aggravates CKD. These include the induction of membrane vesicle production in host cells, which can trigger inflammatory pathways and insulin resistance. Reciprocally, CKD can also modulate gut bacterial composition that might further aggravate CKD condition. Thus, EDCs pose a significant threat to kidney health and the global CKD burden. Understanding this complicated issue necessitates multidisciplinary initiatives such as strict environmental controls, public awareness, and the development of novel therapeutic strategies targeting EDCs.

Furan based synthetic chalcone derivative functions against gut inflammation and oxidative stress demonstrated in in-vivo zebrafish model.

Inflammatory Bowel Disease (IBD) is a group of persistent intestinal illnesses resulting from bowel inflammation unrelated to infection. The prevalence of IBD is rising in industrialized countries, increasing healthcare costs. Whether naturally occurring or synthetic, chalcones possess a broad range of biological properties, including anti-inflammatory, anti-microbial, and antioxidant effects. This investigation focuses on DKO7 (E)-3-(4-(dimethylamino)phenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one, a synthesized chalcone with potential anti-inflammatory effects in a zebrafish model of intestinal inflammation induced by Dextran sodium sulfate (DSS). The in vitro study displayed dose-dependent anti-inflammatory as well as antioxidant properties of DKO7. Additionally, DKO7 protected zebrafish larvae against lipid peroxidation, reactive oxygen stress (ROS), and DSS-induced inflammation. Moreover, DKO7 reduced the expression of pro-inflammatory genes, including TNF-α, IL-1ß, IL-6, and iNOS. Further, it reduced the levels of nitric oxide (NO) and lactate dehydrogenase (LDH) in the intestinal tissues of adult zebrafish and increased the levels of antioxidant enzymes such as Catalase (CAT) and superoxide dismutase (SOD). The protective effect of DKO7 against chemically (or DSS) induced intestinal inflammation was further verified using histopathological techniques in intestinal tissues. The furan-based chalcone derivative, DKO7, displayed antioxidant and anti-inflammatory properties. Also, DKO7 successfully reverses the DSS-induced intestinal damage in zebrafish. Overall, this study indicates the ability of DKO7 to alleviate DSS-induced gut inflammation in an in-vivo zebrafish.

Expanding germ-organ theory: Understanding non-communicable diseases through enterobacterial translocation.

Diverse microbial communities colonize different habitats of the human body, including gut, oral cavity, nasal cavity and tissues. These microbial communities are known as human microbiome, plays a vital role in maintaining the health. However, changes in the composition and functions of human microbiome can result in chronic low-grade inflammation, which can damage the epithelial cells and allows pathogens and their toxic metabolites to translocate into other organs such as the liver, heart, and kidneys, causing metabolic inflammation. This dysbiosis of human microbiome has been directly linked to the onset of several non-communicable diseases. Recent metabolomics studies have revealed that pathogens produce several uraemic toxins. These metabolites can serve as inter-kingdom signals, entering the circulatory system and altering host metabolism, thereby aggravating a variety of diseases. Interestingly, Enterobacteriaceae, a critical member of Proteobacteria, has been commonly associated with several non-communicable diseases, and the abundance of this family has been positively correlated with uraemic toxin production. Hence, this review provides a comprehensive overview of Enterobacterial translocation and their metabolites role in non-communicable diseases. This understanding may lead to the identification of novel biomarkers for each metabolic disease as well as the development of novel therapeutic drugs.

Luteolin, a promising quorum quencher mitigates virulence factors production in Pseudomonas aeruginosa - In vitro and In vivoapproach.

Pseudomonas aeruginosa (PA) is an opportunistic pathogen that causes healthcare-associated infection and high mortality in immunocompromised patients. It produces several virulence factors through quorum sensing (QS) mechanisms that is essential for subverting host immune system. Even front-line antibiotics are unable to control PA pathogenicity due to the emergence of antibiotic resistance. Luteolin is a naturally derived compound that has proven to be the effective drug to annihilate pathogens through quorum quenching mechanism. In this study, the protective effect of luteolin against the PA-mediated inflammation was demonstrated using zebrafish model. Luteolin protects zebrafish from PA infection and increases their survival rate. It was found that PA-mediated ROS, lipid peroxidation, and apoptosis were also significantly reduced in luteolin-treated zebrafish larvae. Open field test (OFT) reveals that luteolin rescued PA-infected zebrafish from retarded swimming behavior. Furthermore, luteolin increases SOD and CAT levels and decreases LDH and NO levels in PA-infected zebrafish compare to control group. Histological and gene expression analysis reveals that luteolin protects PA-infected zebrafish by decreasing gut inflammation and altering the expression of inflammatory (TNF-α, IL-1ß, IL-6) and antioxidant markers (iNOS, SOD, CAT). Thus, luteolin was found to have dual effect in protecting PA-infected zebrafish by decreasing virulence factors production in PA and stimulating host immune system. This is the first study demonstrating the protective effect of luteolin using animal model. Hence, luteolin could be used as a future therapeutic drug to control multi-drug resistant PA.

Gut Enterobacteriaceae and uraemic toxins - Perpetrators for ageing.

Ageing is a complex process that is associated with changes in the composition and functions of gut microbiota. Reduction of gut commensals is the hallmarks of ageing, which favours the expansion of pathogens even in healthy centenarians. Interestingly, gut Enterobacteriaceae have been found to be increased with age and also consistently observed in the patients with metabolic diseases. Thus, they are associated with all-cause mortality, regardless of genetic origin, lifestyle, and fatality rate. Moreover, Enterobacteriaceae are also implicated in accelerating the ageing process through telomere attrition, cellular senescence, inflammasome activation and impairing the functions of mitochondria. However, acceleration of ageing is likely to be determined by intrinsic interactions between Enterobacteriaceae and other associated gut bacteria. Several studies suggested that Enterobacteriaceae possess genes for the synthesis of uraemic toxins. In addition to intestine, Enterobacteriaceae and their toxic metabolites have also been found in other organs, such as adipose tissue and liver and that are implicated in multiorgan dysfunction and age-related diseases. Therefore, targeting Enterobacteriaceae is a nuance approach for reducing inflammaging and enhancing the longevity of older people. This review is intended to highlight the current knowledge of Enterobacteriaceae-mediated acceleration of ageing process.

Nitroimidazooxazoles(#) Part xxiv, Search for Antileishmanial Agents: 2,3-Dihydro-6-nitroimidazo[2,1-b]oxazoles as Potential Antileishmanial Agents.

A number of mono and bicyclic nitroimidazoles were screened for in vitro antileishmanial activity. Among these, compounds belonging to the class of nitroimidazo[2,1-b]oxazoles showed moderate to good activity. This class of compounds had been reported previously to have pronounced antitubercular activity, particularly CGI17341 (5a). In the present study (5a) and (5d) and (7) were found to be more potent antileishmanials in vitro than the standard and less toxic in relation to a reference compound. (7) Was earlier formulated to have the phenyl group located on C-2(5b).

Ontogeny and tissue-specific expression of innate immune related genes in rohu, Labeo rohita (Hamilton).

The innate immune response in fish represents an early and rapid defense against pathogens. The present study aims at looking into ontogeny of innate immune system in the teleost, Labeo rohita using RT-PCR based approach. Total RNA extracted from unfertilized and fertilized eggs, and hatchlings (hatched at 28 ± 2 °C) at 0, 1, 3, 6, 12, 24 h, and 3, 7, 16, 21, 31 days post-fertilization were subjected to RT-PCR using self-designed or earlier published primers to amplify some innate immune relevant genes (lysozyme C, lysozyme G, beta-2 microglobulin, toll-like receptor 22-like and transferrin). The constitutive expression of ß-actin was detected in unfertilized eggs and further developmental stages. Transferrin and TLR22-like mRNA transcripts were detected by RT-PCR from 6 h post-fertilization to 31 day post-fertilization, whereas ß-2 microglobulin transcripts were detected only from 7 day post-fertilization onwards. Lysozyme C mRNA transcripts were detected from 24 h post-fertilization to 31 day post-fertilization. Lysozyme G mRNA transcripts were detected early from unfertilized egg stage onwards. Similarly, tissues viz. intestine, heart, ovary, gill, spleen, muscle, liver, brain, skin, anterior kidney, posterior kidney, and blood collected from juveniles of rohu were subjected to detection of all above mentioned gene transcripts by RT-PCR. ß2-microglobulin mRNA transcript was expressed in all tissues. Lysozyme C mRNA expression is confined to blood and posterior kidney only whereas lysozyme G mRNA is expressed in all tissues. TLR22-like mRNA is expressed in all tissues except ovary and liver whereas transferrin mRNA transcript is detected only in liver. Finally, all these information taken are likely to shed light on the ontogeny of innate immunity in L. rohita, which offers new insights to developmental biology when compared to higher vertebrates and also helpful in the development of preventive measures against problems concerning infectious diseases.

Management of supernumerary testis in an adult: case report and review.

Polyorchidism is a rare congenital anomaly. Approximately 100 cases have been published to date. We report a case of triorchidism in a 20-year-old man who presented to us with inguinal hernia. There is more than 30% incidence of histological abnormalities in polyorchid testes and 4-7% present with malignancy. The management of polyorchidism is controversial. Some authors prefer conservative approach to increase the chances of spermatogenesis and others suggest excision to prevent malignancy. In our case, a biopsy of the testes was performed and was found to be normal. This patient was placed on follow-up with regular self examination, six monthly clinical examination and yearly scrotal sonogram.

Methemoglobin to cumulative nitric oxide ratio and response to inhaled nitric oxide in PPHN.

BACKGROUND: One-third of infants with persistent pulmonary hypertension of the newborn (PPHN) do not respond to inhaled nitric oxide (iNO). If iNO is not delivered to the pulmonary vasculature because of parenchymal lung disease, it cannot interact with hemoglobin to form methemoglobin (MHb). OBJECTIVE: To study the correlation between oxygenation response to iNO in infants with PPHN secondary to parenchymal lung disease and initial MHb% to cumulative NO exposure (ppm x hours) ratio (MHb/SigmaNO). STUDY DESIGN: Retrospective chart review of neonates with PPHN secondary to parenchymal lung disease treated with iNO comparing non-responders (PaO(2)/FiO(2) ratio<10 change with iNO) with responders (>or=10 change). RESULT: Non-responders (n=16) had a PaO(2)/F(iO2) of 83+/-48 (mean+/-s.d.) and decreased to 74+/-44 after iNO. PaO(2)/FiO(2) increased from 70+/-48 to 151+/-63 with iNO among responders (n=36). The MHb/SigmaNO ratio was low (0.024+/-0.012) among non-responders compared with responders (0.07+/-0.053, P<0.005). CONCLUSION: Inadequate oxygenation response to iNO is associated with lower MHb/SigmaNO, suggesting suboptimal delivery of iNO to the pulmonary vasculature.