A pilot study on the pulmonary anthracosis in stray dogs of Kathmandu Valley, Nepal: A potential public health threat for future.

Background and Aim: Kathmandu is a densely populated metropolitan city in Nepal. In recent years, however, the metropolis has been ranked as one of the most polluted cities worldwide. Both humans and animals are susceptible to various respiratory diseases due to chronic exposure to polluted air. Due to the relative similarities in the anatomical structure and physiological functions of the respiratory system between humans and dogs, polluted environments may lead to respiratory illness in similar ways in both species living in the valley. On the basis of information on the air quality in the valley, this study was conceived to assess pulmonary illness in street dogs to discern the health hazards caused by polluted air. Materials and Methods: A total of 76 dogs with clinical signs of tachypnea, dyspnea, sneezing, coughing, mucopurulent discharge, moderate hyperthermia, and anorexia admitted from July 2020 to November 2020 in Animal Nepal for treatment were included in this study. Among them, 24 animals responded to treatment, and 52 dogs died during their stay in the hospital. The 52 dead animals were necropsied, and the lesions that resembled pulmonary anthracosis were further studied grossly and histologically in a blinded fashion by trained veterinary pathologists. Results: Significant morphological alterations were observed in the lungs and associated lymph nodes of 25 animals, indicating pulmonary anthracosis. Gross morphological changes included multiple black foci with hemorrhage, congestion, nodular, and emphysema on the parietal and visceral surfaces of the lungs. The alveolar septa and visceral pleura exhibited deposition of black particles. Congestion, emphysema, and inflammatory exudates were also detected in the lung tissues and lymph nodes. Conclusion: The clinical, gross, and microscopic findings accurately resembled those of pulmonary anthracosis. This life-threatening condition in stray canines may be caused by a critical level of air pollution from different sources and carbon emissions from vehicles. To protect animals and humans living in the Kathmandu Valley, concerned government and non-government agencies should work toward reducing air pollution levels as soon as possible.

Early Antibiotic Exposure Alters Intestinal Development and Increases Susceptibility to Necrotizing Enterocolitis: A Mechanistic Study.

Increasing evidence suggests that prolonged antibiotic therapy in preterm infants is associated with increased mortality and morbidities, such as necrotizing enterocolitis (NEC), a devastating gastrointestinal pathology characterized by intestinal inflammation and necrosis. While a clinical correlation exists between antibiotic use and the development of NEC, the potential causality of antibiotics in NEC development has not yet been demonstrated. Here, we tested the effects of systemic standard-of-care antibiotic therapy for ten days on intestinal development in neonatal mice. Systemic antibiotic treatment impaired the intestinal development by reducing intestinal cell proliferation, villi height, crypt depth, and goblet and Paneth cell numbers. Oral bacterial challenge in pups who received antibiotics resulted in NEC-like intestinal injury in more than half the pups, likely due to a reduction in mucous-producing cells affecting microbial-epithelial interactions. These data support a novel mechanism that could explain why preterm infants exposed to prolonged antibiotics after birth have a higher incidence of NEC and other gastrointestinal disorders.

Complement C5 inhibition protects against hemolytic anemia and acute kidney injury in anthrax peptidoglycan-induced sepsis in baboons.

Late-stage anthrax infections are characterized by dysregulated immune responses and hematogenous spread of Bacillus anthracis, leading to extreme bacteremia, sepsis, multiple organ failure, and, ultimately, death. Despite the bacterium being nonhemolytic, some fulminant anthrax patients develop a secondary atypical hemolytic uremic syndrome (aHUS) through unknown mechanisms. We recapitulated the pathology in baboons challenged with cell wall peptidoglycan (PGN), a polymeric, pathogen-associated molecular pattern responsible for the hemostatic dysregulation in anthrax sepsis. Similar to aHUS anthrax patients, PGN induces an initial hematocrit elevation followed by progressive hemolytic anemia and associated renal failure. Etiologically, PGN induces erythrolysis through direct excessive activation of all three complement pathways. Blunting terminal complement activation with a C5 neutralizing peptide prevented the progressive deposition of membrane attack complexes on red blood cells (RBC) and subsequent intravascular hemolysis, heme cytotoxicity, and acute kidney injury. Importantly, C5 neutralization did not prevent immune recognition of PGN and shifted the systemic inflammatory responses, consistent with improved survival in sepsis. Whereas PGN-induced hemostatic dysregulation was unchanged, C5 inhibition augmented fibrinolysis and improved the thromboischemic resolution. Overall, our study identifies PGN-driven complement activation as the pathologic mechanism underlying hemolytic anemia in anthrax and likely other gram-positive infections in which PGN is abundantly represented. Neutralization of terminal complement reactions reduces the hemolytic uremic pathology induced by PGN and could alleviate heme cytotoxicity and its associated kidney failure in gram-positive infections.

Acceleration of Small Intestine Development and Remodeling of the Microbiome Following Hyaluronan 35 kDa Treatment in Neonatal Mice.

The beneficial effects of human milk suppressing the development of intestinal pathologies such as necrotizing enterocolitis in preterm infants are widely known. Human milk (HM) is rich in a multitude of bioactive factors that play major roles in promoting postnatal maturation, differentiation, and the development of the microbiome. Previous studies showed that HM is rich in hyaluronan (HA) especially in colostrum and early milk. This study aims to determine the role of HA 35 KDa, a HM HA mimic, on intestinal proliferation, differentiation, and the development of the intestinal microbiome. We show that oral HA 35 KDa supplementation for 7 days in mouse pups leads to increased villus length and crypt depth, and increased goblet and Paneth cells, compared to controls. We also show that HA 35 KDa leads to an increased predominance of Clostridiales Ruminococcaceae, Lactobacillales Lactobacillaceae, and Clostridiales Lachnospiraceae. In seeking the mechanisms involved in the changes, bulk RNA seq was performed on samples from the terminal ileum and identified upregulation in several genes essential for cellular growth, proliferation, and survival. Taken together, this study shows that HA 35 KDa supplemented to mouse pups promotes intestinal epithelial cell proliferation, as well as the development of Paneth cells and goblet cell subsets. HA 35 KDa also impacted the intestinal microbiota; the implications of these responses need to be determined.

Factor XII plays a pathogenic role in organ failure and death in baboons challenged with Staphylococcus aureus.

Activation of coagulation factor (F) XI promotes multiorgan failure in rodent models of sepsis and in a baboon model of lethal systemic inflammation induced by infusion of heat-inactivated Staphylococcus aureus. Here we used the anticoagulant FXII-neutralizing antibody 5C12 to verify the mechanistic role of FXII in this baboon model. Compared with untreated control animals, repeated 5C12 administration before and at 8 and 24 hours after bacterial challenge prevented the dramatic increase in circulating complexes of contact system enzymes FXIIa, FXIa, and kallikrein with antithrombin or C1 inhibitor, and prevented cleavage and consumption of high-molecular-weight kininogen. Activation of several coagulation factors and fibrinolytic enzymes was also prevented. D-dimer levels exhibited a profound increase in the untreated animals but not in the treated animals. The antibody also blocked the increase in plasma biomarkers of inflammation and cell damage, including tumor necrosis factor, interleukin (IL)-1ß, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, nucleosomes, and myeloperoxidase. Based on clinical presentation and circulating biomarkers, inhibition of FXII prevented fever, terminal hypotension, respiratory distress, and multiorgan failure. All animals receiving 5C12 had milder and transient clinical symptoms and were asymptomatic at day 7, whereas untreated control animals suffered irreversible multiorgan failure and had to be euthanized within 2 days after the bacterial challenge. This study confirms and extends our previous finding that at least 2 enzymes of the contact activation complex, FXIa and FXIIa, play critical roles in the development of an acute and terminal inflammatory response in baboons challenged with heat-inactivated S aureus.

CD14 inhibition improves survival and attenuates thrombo-inflammation and cardiopulmonary dysfunction in a baboon model of Escherichia coli sepsis.

BACKGROUND: During sepsis, gram-negative bacteria induce robust inflammation primarily via lipopolysacharride (LPS) signaling through TLR4, a process that involves the glycosylphosphatidylinositol (GPI)-anchored receptor CD14 transferring LPS to the Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD-2) complex. Sepsis also triggers the onset of disseminated intravascular coagulation and consumptive coagulopathy. OBJECTIVES: We investigated the effect of CD14 blockade on sepsis-induced coagulopathy, inflammation, organ dysfunction, and mortality. METHODS: We used a baboon model of lethal Escherichia (E) coli sepsis to study two experimental groups (n = 5): (a) E coli challenge; (b) E coli challenge plus anti-CD14 (23G4) inhibitory antibody administered as an intravenous bolus 30 minutes before the E coli. RESULTS: Following anti-CD14 treatment, two animals reached the 7-day end-point survivor criteria, while three animals had a significantly prolonged survival as compared to the non-treated animals that developed multiple organ failure and died within 30 hours. Anti-CD14 reduced the activation of coagulation through inhibition of tissue factor-dependent pathway, especially in the survivors, and enhanced the fibrinolysis due to strong inhibition of plasminogen activator inhibitor 1. The treatment prevented the robust complement activation induced by E coli, as shown by significantly decreased C3b, C5a, and sC5b-9. Vital signs, organ function biomarkers, bacteria clearance, and leukocyte and fibrinogen consumption were all improved at varying levels. Anti-CD14 reduced neutrophil activation, cell death, LPS levels, and pro-inflammatory cytokines (tumor necrosis factor, interleukin (IL)-6, IL-1ß, IL-8, interferon gamma, monocyte chemoattractant protein-1), more significantly in the survivors than non-surviving animals. CONCLUSIONS: Our results highlight the crosstalk between coagulation/fibrinolysis, inflammation, and complement systems and suggest a protective role of anti-CD14 treatment in E coli sepsis.

Systemic levels of iron, phosphorus, and total protein in normocyclic versus repeat breeder Holstein Friesian crossbred cows of Kesharbag, Chitwan, Nepal.

BACKGROUND AND AIM: In repeat breeding, a sexually mature cow fails to conceive even after three or more consecutive inseminations despite being without any clinically detectable reproductive anomalies. This is a major cause of economic loss in livestock farms, particularly in developing countries, where humans and livestock directly compete for food, and the mineral content of animal feed is rarely checked. This study investigated the association between systemic iron, phosphorus, and total protein and estrous cyclicity in crossbred Holstein Friesian cows. MATERIALS AND METHODS: Blood samples were collected from 10 normal cyclic and 10 repeat breeder cows 12 h after the onset of estrus. Serum was separated, and iron, phosphorus, and total protein were quantified with spectrophotometry, using standard controls for all three measurement parameters (iron, phosphorus, and total protein). RESULTS: Iron and phosphorus levels were significantly (p<0.05) lower in the repeat breeders group than in the normocyclic group, but no significant differences were found in total protein levels. CONCLUSION: Repeat breeding is associated with systemic iron and phosphorus levels but is independent of total protein level.

Inhibition of contact-mediated activation of factor XI protects baboons against S aureus-induced organ damage and death.

Staphylococcus aureus infections can produce systemic bacteremia and inflammation in humans, which may progress to severe sepsis or septic shock, even with appropriate antibiotic treatment. Sepsis may be associated with disseminated intravascular coagulation and consumptive coagulopathy. In some types of mouse infection models, the plasma coagulation protein factor XI (FXI) contributes to the pathogenesis of sepsis. We hypothesize that FXI also contributes to the pathogenesis of sepsis in primates, and that pharmacological interference with FXI will alter the outcome of Staphylococcus aureus-induced lethality in a baboon model. Pretreatment of baboons with the anti-FXI antibody 3G3, a humanized variant of the murine monoclonal 14E11 that blocks FXI activation by FXIIa, substantially reduced the activation of coagulation, as reflected by clotting times and plasma complexes of coagulation proteases (FXIIa, FXIa, FIXa, FXa, FVIIa, and thrombin) with serpins (antithrombin or C1 inhibitor) following infusion of heat-inactivated S aureus 3G3 treatment reduced fibrinogen and platelet consumption, fibrin deposition in tissues, neutrophil activation and accumulation in tissues, cytokine production, kininogen cleavage, cell death, and complement activation. Overall, 3G3 infusion protected the structure and function of multiple vital organs, including lung, heart, liver, and kidney. All treated animals reached the end point survival (7 days), whereas all nontreated animals developed terminal organ failure within 28 hours. We conclude that FXI plays a role in the pathogenesis of S aureus-induced disseminated intravascular coagulation and lethality in baboons. The results provide proof of concept for future therapeutic interventions that may prevent sepsis-induced organ failure and save lives in certain forms of sepsis.

Role of ADTRP (Androgen-Dependent Tissue Factor Pathway Inhibitor Regulating Protein) in Vascular Development and Function.

Background The physiological function of ADTRP (androgen-dependent tissue factor pathway inhibitor regulating protein) is unknown. We previously identified ADTRP as coregulating with and supporting the anticoagulant activity of tissue factor pathway inhibitor in endothelial cells in vitro. Here, we studied the role of ADTRP in vivo, specifically related to vascular development, stability, and function. Methods and Results Genetic inhibition of Adtrp produced vascular malformations in the low-pressure vasculature of zebrafish embryos and newborn mice: dilation/tortuosity, perivascular inflammation, extravascular proteolysis, increased permeability, and microhemorrhages, which produced partially penetrant lethality. Vascular leakiness correlated with decreased endothelial cell junction components VE -cadherin and claudin-5. Changes in hemostasis in young adults comprised modest decrease of tissue factor pathway inhibitor antigen and activity and increased tail bleeding time and volume. Cell-based reporter assays revealed that ADTRP negatively regulates canonical Wnt signaling, affecting membrane events downstream of low-density lipoprotein receptor-related protein 6 ( LRP 6) and upstream of glycogen synthase kinase 3 beta. ADTRP deficiency increased aberrant/ectopic Wnt/ß-catenin signaling in vivo in newborn mice and zebrafish embryos, and upregulated matrix metallopeptidase ( MMP )-9 in endothelial cells and mast cells ( MCs ). Vascular lesions in newborn Adtrp -/- pups displayed accumulation of MCs , decreased extracellular matrix content, and deficient perivascular cell coverage. Wnt-pathway inhibition reversed the increased mmp9 in zebrafish embryos, demonstrating that mmp9 expression induced by Adtrp deficiency was downstream of canonical Wnt signaling. Conclusions Our studies demonstrate that ADTRP plays a major role in vascular development and function, most likely through expression in endothelial cells and/or perivascular cells of Wnt-regulated genes that control vascular stability and integrity.