Lung Histopathological Changes Research Articles

Myeloid-Derived Suppressor Cells Dampen Airway Inflammation Through Prostaglandin E2 Receptor 4.

Emerging evidence suggests a mechanistic role for myeloid-derived suppressor cells (MDSCs) in lung diseases like asthma. Previously, we showed that adoptive transfer of MDSCs dampens lung inflammation in murine models of asthma through cyclooxygenase-2 and arginase-1 pathways. Here, we further dissected this mechanism by studying the role and therapeutic relevance of the downstream mediator prostaglandin E2 receptor 4 (EP4) in a murine model of asthma. We adoptively transferred MDSCs generated using an EP4 agonist in a murine model of asthma and studied the consequences on airway inflammation. Furthermore, pegylated human arginase-1 was used to model MDSC effector activities. We demonstrate that the selective EP4 agonist L-902,688 increased the number and suppressive activity of MDSCs through arginase-1 and nitric oxide synthase-2. These results showed that adoptive transfer of EP4-primed MDSCs, EP4 agonism alone or arginase-1 administration ameliorated lung inflammatory responses and histopathological changes in asthmatic mice. Collectively, our results provide evidence that MDSCs dampen airway inflammation in murine asthma through a mechanism involving EP4.

A safe and effective mucosal RSV vaccine in mice consisting of RSV phosphoprotein and flagellin variant.

Respiratory syncytial virus (RSV) is a major cause of serious acute lower respiratory tract infection in infants and the elderly. The lack of a licensed RSV vaccine calls for the development of vaccines with other targets and vaccination strategies. Here, we construct a recombinant protein, designated P-KFD1, comprising RSV phosphoprotein (P) and the E.-coli-K12-strain-derived flagellin variant KFD1. Intranasal immunization with P-KFD1 inhibits RSV replication in the upper and lower respiratory tract and protects mice against lung disease without vaccine-enhanced disease (VED). The P-specific CD4+ Tcells provoked by P-KFD1 intranasal (i.n.) immunization either reside in or migrate to the respiratory tract and mediate protection against RSV infection. Single-cell RNA sequencing (scRNA-seq) and carboxyfluorescein succinimidyl ester (CFSE)-labeled cell transfer further characterize the Th1 and Th17 responses induced by P-KFD1. Finally, we find that anti-viral protection depends on either interferon-γ (IFN-γ) or interleukin-17A (IL-17A). Collectively, P-KFD1 is a promising safe and effective mucosal vaccine candidate for the prevention of RSV infection.

A systematic approach to evaluate plausible modes of actions for mouse lung tumors in mice exposed to 4-methylimidozole

The National Toxicology Program (NTP) reported that chronic dietary exposure to 4-methylimidazole (4-MeI) increased the incidence of lung adenomas/carcinomas beyond the normally high spontaneous rate in B6C3F1 mice. To examine plausible modes of action (MoAs) for mouse lung tumors (MLTs) upon exposure to high levels of 4-MeI, and their relevance in assessing human risk, a systematic approach was used to identify and evaluate mechanistic data (in vitro and in vivo) in the primary and secondary literature, along with high-throughput screening assay data. Study quality, relevance, and activity of mechanistic data identified across the evidence-base were organized according to key characteristics of carcinogens (KCCs) to identify potential key events in known or novel MLT MoAs. Integration of these evidence streams provided confirmation that 4-MeI lacks genotoxic and cytotoxic activity with some evidence to support a lack of mitogenic activity. Further evaluation of contextual and chemical-specific characteristics of 4-MeI was consequently undertaken. Due to lack of genotoxicity, along with transcriptomic and histopathological lung changes up to 28 and 90 days of exposure, the collective evidence suggests MLTs observed following exposure to high levels of 4-MeI develop at a late stage in the mouse chronic bioassay, albeit the exact MoA remains unclear.

Evaluation of aromatase inhibitor on radiation induced pulmonary fibrosis via TGF- β/Smad 3 and TGF- β/PDGF pathways in rats

Radiation-induced pulmonary fibrosis (RIPF) is a known complication in cancer patients after getting thoracic radiotherapy. Aromatase inhibitors (AIs) as anastrozole have been used instead of tamoxifen for adjuvant endocrine treatment of postmenopausal women with hormone sensitive breast cancer. This study is to evaluate the concurrent treatment of anastrozole and RIPF in rats. Twenty four female Wistar rats were distributed into 4 groups: Control (C), Radiation group (R) (total dose 30 Gy in 10 fractions, 5 fractions/week), anastrozole group (A) (0.003 mg/200 g body weight) orally for 14 consecutive days, and Radiation + anastrozole group (R + A). Radiation exposure resulted in a significant increase (p < 0.05) in pulmonary Transforming growth factor-beta 1 (TGF-β), SMAD family member 3 (Smad3), Platelet-derived growth factor (PDGF), malondialdehyde (MDA), Total nitrate/nitrite (NO), interleukin 1β (IL-1β) and interleukin 6 (IL-6) compared to the control group. While, significant decreases (p < 0.05) in superoxide dismutase (SOD) activity, reduced glutathione (GSH) and connective tissue growth factor (CTGF) were observed in lung tissue. These alterations were minimized by anastrozole intervention. Also, anastrozole markedly hindered the lung histopathological changes observed after radiation. Concomitant use of anastrozole with radiation seems to attenuate radiation-induced pulmonary toxicity via TGF-β/Smad 3 and TGF-β/PDGF pathways in rats.

Immunoprotective inference of experimental chronic Trichinella spiralis infection on house dust mites induced allergic airway remodeling

Allergic bronchial asthma is characterized by chronic inflammation of the respiratory airways mediated by T-helper 2 (Th2), Th17 and their cytokines. Although most asthmatic patients suffer from allergic airway remodeling (AAR), aggressive anti-allergic treatment failed to reverse it. The hygiene hypothesis illuminated the counter relationship between allergy and helminthic infections. The immune system is modulated by Trichinella spiralis (T. spiralis) infection to maintain homeostasis. Therefore, this work aimed to investigate the impact of chronic T. spiralis infection on induced AAR in C57BL/6 mice sensitized by house dust mites (HDM) allergens. Forty mice were divided into 3 groups: I (10 healthy mice), IΙ (15 HDM sensitized mice), and ΙΙI (15 T. spiralis chronically infected mice and sensitized with HDM allergens). The assessment aimed to evaluate the effects of regulatory CD4+CD25+FOXP3+ cells (Tregs) and their cytokines comparative to hypersensitivity mediated cytokines. Chronic T. spiralis infection effectively prevented the host's AAR. This result was evidenced by upregulated Tregs in blood by flow cytometric analysis and increased interleukin-10 (IL-10) levels in bronchoalveolar lavage (BAL) by Enzyme linked immunosorbent assay (ELISA) as well as improved lung histopathological changes. Also, serum HDM specific immunoglobulin E (IgE), BAL eosinophils, BAL IL-5 levels, and IL-17 gene expression in lung tissues were significantly reduced in T. spiralis chronically infected mice. In conclusion, the immune response in chronic T. spiralis infection could provide a promising mechanistic tool for protection against AAR, which paves the way for innovative preventive measures of other immunological disorders.

Prenatal developmental toxicity studies on fumes from oxidised asphalt (OA) in the rat

The prenatal developmental toxicity of the fumes of oxidised asphalt (OA) was tested by nose-only inhalation in the rat. The test material was generated by collecting fumes from the headspace of storage tanks filled with OA. The composition of these fumes was matched to fumes sampled at a workplace where the same OA was applied in a pour-and-roll operation, representing occupational exposure with high concentrations of fumes to not underestimate the possible hazard. In the main study, dams were exposed to 0, 53, 158 and 536 mg/m3 of fume (as total organic mass), for 6 h/day for 19 days p.c. The maternal NOAEC was 53 mg/m³ (lowest dose tested). In the high-dose group treatment-related effects on body weight gain were seen. In the mid- and high-dose groups treatment-related effects on food consumption, lung weights, and histopathological changes in lungs and the upper respiratory tract were observed. The NOAEC for prenatal developmental toxicity was 536 mg/m³ since no exposure-related effects were found in any of the exposure groups for any of the investigated reproductive endpoints. Furthermore, nose-only exposure to OA fumes in concentrations up to 536 mg/m³ from days 1–19 p.c. did not induce any significant fetal abnormalities.

Pulmonary toxicity and gene expression changes after short-term inhalation exposure to surface-modified copper oxide nanoparticles

Copper oxide nanoparticles (CuO NPs) have previously been shown to cause dose-dependent pulmonary toxicity following inhalation. Here, CuO NPs (10 nm), coated with polyethylenimine (PEI) or ascorbate (ASC) resulting in positively or negatively charged NPs, respectively, were evaluated. Rats were exposed nose-only to similar exposure dose levels of ASC or PEI coated CuO NPs for 5 consecutive days. On day 6 and day 27 post-exposure, pulmonary toxicity markers in bronchoalveolar lavage fluid (BALF), lung histopathology and genome-wide transcriptomic changes in lungs, were assessed. BALF analyses showed a dose-dependent pulmonary inflammation and cell damage, which was supported by the lung histopathological findings of hypertrophy/hyperplasia of bronchiolar and alveolar epithelium, interstitial and alveolar inflammation, and paracortical histiocytosis in mediastinal lymph nodes for both types of CuO NPs. Transcriptomics analysis showed that pathways related to inflammation and cell proliferation were significantly activated. Additionally, we found evidence for the dysregulation of drug metabolism-related genes, especially in rats exposed to ASC-coated CuO NPs. Overall, no differences in the type of toxic effects and potency between the two surface coatings could be established, except with respect to the (regional) dose that initiates bronchiolar and alveolar hypertrophy. This disproves our hypothesis that differences in surface coatings affect the pulmonary toxicity of CuO NPs.

Graphene oxide induces dose-dependent lung injury in rats by regulating autophagy.

Graphene is a two-dimensional structured material with a hexagonal honeycomb lattice composed of carbon atoms. The biological effects of graphene oxide (GO) have been extensively investigated, as it has been widely used in biological research due to its increased hydrophilicity/biocompatibility. However, the exact mechanisms underlying GO-associated lung toxicity have not yet been fully elucidated. The aim of the present study was to determine the role of GO in lung injury induction, as well as its involvement in oxidative stress, inflammation and autophagy. The results revealed that lower concentrations of GO (5 and 10 mg/kg) did not cause significant lung injury, but the administration of GO at higher concentrations (50 and 100 mg/kg) induced lung edema, and increased lung permeability and histopathological lung changes. High GO concentrations also induced oxidative injury and inflammatory reactions in the lung, demonstrated by increased levels of oxidative products [malondialdehyde(MDA) and 8-hydroxydeoxyguanosine (8-OHdG)] and inflammatory factors (TNF-α, IL-6, IL-1β and IL-8). The autophagy inhibitors 3-methyladenine (3-MA) and chloroquine (CLQ) inhibited autophagy in the lung and attenuated GO-induced lung injury, as demonstrated by a reduced lung wet-to-dry weight ratio, lower levels of protein in the bronchoalveolar lavage fluid, and a reduced lung injury score. Furthermore, 3-MA and CLQ significantly reduced the levels of MDA, 8-OHdG and inflammatory factors in lung tissue, suggesting that autophagy also mediates the development of oxidative injury and inflammation in the lung. Finally, autophagy was directly inhibited in BEAS-2B cells by short hairpin RNA-mediated autophagy protein 5 (ATG5) knockdown, which were then treated with GO. Cell viability, as well as the extent of injury (indicated by lactate dehydrogenase level) and oxidative stress were determined. The results revealed that ATG5 knockdown-induced autophagic inhibition significantly decreased cellular injury and oxidative stress, suggesting that autophagy induction is a key event that leads to lung injury during exposure to GO. In conclusion, the findings of the present study indicated that GO causes lung injury in a dose-dependent manner by inducing autophagy.

MNK as a potential pharmacological target for suppressing LPS-induced acute lung injury in mice

Acute lung injury (ALI) or its more severe form, known as acute respiratory distress syndrome (ARDS), is characterized by an initial exudative phase, expression of proinflammatory mediators, activation of inflammatory leukocytes, and impairment of the lung endothelium and epithelium. Despite numerous, novel therapeutic strategies have been developed regarding the pathophysiology of ALI, current treatment is mainly supportive, as specific therapies have not been established in the past few decades. The MAP kinase-interacting kinases (MNK1 and MNK2) are serine threonine kinases which are activated by mitogen-activated protein kinases (MAPKs), regulate protein synthesis by phosphroylating eukaryotic translation initiation factor 4E (eIF4E). Although studies have shown that MAPKs pathway is involved in anti-inflammatory and preventing tissue injury processes, the role of MNKs in ALI has, until now, remained relatively unexplored. Here, we investigated whether partial inhibition of MAPKs pathway by targeting MNKs was effective in the prevention and treatment of ALI. C57BL6 mice were pretreated with MNK1 and MNK2 inhibitor (CGP57380, 30 mg/kg) for 30 min and then challenged with 5 mg/kg LPS for 6 h. The results showed that pretreatment with CGP57380 not only significantly attenuated LPS-induced lung wet/dry ratio, as well as protein content, total cells and neutrophils in bronchoalveolar lavage fluid (BALF), but also decreased the production of pro-inflammatory mediators such as interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α) and keratinocyte-derived chemoattractant (KC). In addition, CGP57380 was observed to significantly suppress LPS-stimulated phosphorylation of eIF4E and MAPKs in the mouse bone marrow-derived macrophages (BMDMs). The involvement of MNK2 in lung injury was further evident by MNK2 knockout mice. MNK2 deficiency resulted in the attenuated lung histopathological changes, as also reflected by reductions in neutrophil counts, and the less LPS-induced the production of IL-6, TNF-α and KC in mouse BALF. Taken together, these findings demonstrated for the first time that MNK inhibition could effectively reduce the LPS-induced ALI in mice, suggesting a novel and potential application for MNK-based therapy to treat this serious disease.

GYY4137 alleviates sepsis-induced acute lung injury in mice by inhibiting the PDGFRβ/Akt/NF-κB/NLRP3 pathway

AimsGYY4137 [GYY, morpholin-4-ium-4-methoxyphenyl (morpholino) phosphinodithioate] is a novel and perfect hydrogen sulfide (H2S) donor that is stable in vivo and in vitro. H2S, along with CO and NO, has been recognized as the third physiological gas signaling molecule that plays an active role in fighting various lung infections. However, the mechanism by which GYY4137 affects cecal ligation and puncture (CLP)-induced acute lung injury (ALI) is not understood. This study aimed to investigate whether GYY4137 inhibits the activation of the pyrin domain-containing protein 3 (NLRP3) inflammasome by inhibiting the PDGFRβ/Akt/NF-κB pathway. Main methodsThe model of CLP-induced ALI was established in vivo. The mice were subsequently treated with GYY4137 (25 μg/g and 50 μg/g) to simulate the realistic conditions of pathogenesis. Western blotting and immunohistochemical staining were used to examine protein expression, hematoxylin and eosin staining was used for the histopathological analysis, and the levels of inflammatory factors were determined using enzyme-linked immunosorbent assays (ELISAs). Key findingsGYY4137 significantly increased the 7-day survival of mice with septic peritonitis and protected against CLP-induced ALI, including decreasing neutrophil infiltration, improving sepsis-induced lung histopathological changes, diminishing lung tissue damage, and attenuating the severity of lung injury in mice. The protective effect of GYY4137 was undoubtedly dose-dependent. We discovered that GYY4137 reduced the levels of the p-PDGFRβ, p-NF-κB, ASC, NLRP3, caspase-1, and p-Akt proteins in septic mouse lung tissue. Akt regulates the generation of proinflammatory cytokines in endotoxemia-associated ALI by enhancing the nuclear translocation of NF-κB. SignificanceThese results indicate a new molecular mechanism explaining the effect of GYY4137 on the treatment of CLP-induced ALI in mice.

Non-muscle myosin II knockdown improves survival and therapeutic effects of implanted bone marrow-derived mesenchymal stem cells in lipopolysaccharide-induced acute lung injury.

BackgroundBone marrow-derived mesenchymal stem cells (BMSCs) have been shown to have some beneficial effects in acute lung injury (ALI), but the therapeutic effects are limited due to apoptosis or necrosis after transplantation into injured lungs. Here, we aim to explore whether Non-muscle myosin II (NM-II) knockdown could enhance BMSCs survival and improve therapeutic effects in ALI.MethodsMSCs, isolated from rat bone marrow, were transfected with the small interfering RNA (siRNA) targeted to NM-II mRNA by a lentivirus vector. Rats were equally randomized to four groups: the control group was given normal saline via tail vein; the other three groups underwent intratracheal lipopolysaccharide (LPS) instillation followed by administration with either normal saline, BMSCs transduced with lentivirus-enhanced green fluorescent protein (eGFP) empty vector, or BMSCs transduced with lentivirus-eGFP NM-II siRNA. Hematoxylin and eosin staining was used to evaluate lung histopathologic changes and Masson trichrome staining was used to assess lung fibrosis. The myeloperoxidase activity was also tested in lung tissues. The mRNA expression of inflammatory cytokines in lung tissues was determined via quantitative reverse transcription PCR. Sex-determining region of the Y chromosome gene expression was measured by fluorescence in situ hybridization (FISH) assay. The expression of self-renewal activity and apoptosis-associated proteins were measured by Western blot.ResultsTransplantation of NM-II siRNA-modified BMSCs could improve histopathological morphology, decrease inflammatory infiltrates, down-regulate the expression levels of inflammatory cytokines, and reduce pulmonary interstitial edema. NM-II siRNA-modified BMSCs showed antifibrotic properties and alleviated the degrees of pulmonary fibrosis induced by endotoxin. In addition, NM-II knockdown BMSCs showed slightly better therapeutic effect on lung inflammation when compared with control BMSCs. The beneficial effects of NM-II siRNA-modified BMSCs may be attributed to enhanced self-renewal activity and decreased apoptosis.ConclusionsNM-II knockdown could inhibit the apoptosis of implanted BMSCs in lung tissues and improve its self-renewal activity. NM-II siRNA-modified BMSCs have a slightly enhanced ability to attenuate lung injury after LPS challenge.

MSC-NTF (NurOwn\xae) exosomes: a novel therapeutic modality in the mouse LPS-induced ARDS model

BackgroundOne of the most severe complications of the current COVID-19 pandemic is acute respiratory distress syndrome (ARDS). ARDS is caused by increased amounts of pro-inflammatory cytokines, leading to lung damage and loss of lung function. There are currently no effective therapies for combatting ARDS. Mesenchymal stem cells (MSCs) have been suggested as a potential treatment for ARDS due to their significant immunomodulatory properties. MSC small extracellular vesicles (sEVs), including exosomes, modulate the immune response as effectively as MSCs themselves, with the added advantages of increased safety and tissue penetration.MethodsWe isolated sEVs from MSCs induced to secrete increased levels of neurotrophic and immunomodulatory factors, termed Exo MSC-NTF, and compared their ability to treat ARDS, in a lung injury LPS mouse model, to sEVs isolated from naïve MSCs (Exo MSC). Measurments of lung histopathological changes and neutrophil infiltration, blood oxygen saturation, and bronchoalveolar lavge fluid (BALF) proinflammatory cytokines and coagulation related factors were performed.ResultsWe found that Exo MSC-NTF was superior to Exo MSC in reducing LPS-induced ARDS markers, including physiological lung damage such as alveolar wall thickness, fibrin presence, and neutrophil accumulation, as well as increasing oxygenation levels. Furthermore, Exo MSC-NTF reversed the imbalance in the host immune response, seen as decreased IFN-γ, IL-6, TNF-α, and RANTES levels in the bronchoalveolar lavage fluid.ConclusionsThese positive preclinical results suggest that Exo MSC-NTF may be suitable as a therapy for COVID-19-induced ARDS and are more effective at combatting ARDS physiological, pathological, and biochemical symptoms than sEVs isolated from non-induced MSCs.

Histopathological Effects of Prazosin Drug on Lung of Rats

This study was conducted at the laboratory of histology and anatomy, Faculty of Medical and Health Techniques/Kufa, and laboratory of post Graduate/ Department of biology, Faculty of Science/University of Kufa, The present study was conducted to investigate the effect of Prazosin hydrochloride on some organs in male rats (Rattus norvegicus), about 25 mature male rats with the average body weight of 210-290gram and three months age were randomly divided into four groups (5rats / group). The first group was given orally with distilled water as a control group and the other groups (second, third, and fourth) were also given orally with three doses of Prazosin (25, 50,75 mg /kg. b.wt.) daily for a period of eight weeks. At the end of the treatment period (eight weeks), rats were sacrificed, blood samples obtained, and organs lung, and spleen. The histopathological changes of lungs in the rats treated with prazosin at dose 25 mg/kg.b.wt for 8-weeks showed emphysema and dilation in some of the alveoli, hemorrhage distributed inside the tissue of the lung, polymorphic nuclear infiltration due to pneumonia, the pulmonary artery revealed degenerative changes in the tunica media structure (smooth muscle) and hyperplasia in the connective tissue around pulmonary artery and alveoli. These symptoms which occur in rats treated with prazosin at dose 50 and 75 mg/kg b.wt. as well as the histopathological changes of rat lung demonstrate severe hemorrhage, emphysema, thickening in the wall of some alveoli, pneumocyte necrosis (pneumocyte type 1 and pneumocyte type 2), and showed exudate among lung tissue. Histopathological changes of Spleen in the rats treated with prazosin at doses(50 and75)mg/kg b.w. for 8-weeks revealed histopathological changes, which represented by proliferation in the white pulp lead to fused white pulp together and destruction of some components of red pulp, stenosis in many splenic venous sinuses, the germinal artery show thickening in the tunica media and stenosis occurs, degenerative change in many nuclei of lymphocytes, and proliferation in the component of the white pulp.

Inhibition of MicroRNA-214 Alleviates Lung Injury and Inflammation via Increasing FGFR1 Expression in Ventilator-Induced Lung Injury.

Ventilator-induced lung injury (VILI) is an additional inflammatory injury caused by mechanical ventilation (MV). This study aimed to determine the effects of microRNA-214 (miR-214) on VILI and its underlying mechanism of action. To develop a VILI mouse model, mice were subjected to MV. The expression of miR-214 was detected by qRT-PCR. The macrophages, fibroblasts, epithelial cells, and endothelial cells were isolated from lung tissues by fluorescence-activated cell sorting. The histopathological changes of lung, lung wet/dry weight (W/D) ratio, and myeloperoxidase (MPO) activity were used to evaluate the degree of lung injury. The levels of pro-inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter assay was performed to determine the interactions between miR-214 and FGFR1. Western blot was used to detect the protein expression of FGFR1, p-AKT, and p-PI3K. The expression of miR-214 was increased in lung tissues and macrophages, fibroblasts, epithelial cells, and endothelial cells isolated from lung tissues in VILI mice. MiR-214 inhibition decreased the histopathological changes of lung, lung W/D ratio, MPO activity, and pro-inflammatory cytokines levels in BALF in VILI mice. FGFR1 was targeted by miR-214. The protein expression of FGFR1 was decreased in VILI mice. Ponatinib (FGFR1 inhibitor) reversed the suppressive effects of miR-214 inhibition on lung injury and inflammation of VILI mice. MiR-214 increased the activity of PI3K/AKT pathway by regulating FGFR1. Inhibition of miR-214 attenuated lung injury and inflammation in VILI mice by increasing FGFR1 expression, providing a novel therapeutic target for VILI.

Pulmonary histopathology in fatal paraquat poisoning.

ABSTRACTParaquat is a potent herbicide widely used in the Indian agriculture industry. Human fatality due to paraquat poisoning is not uncommon in this country. The primary effect of paraquat is on the lungs, and the resultant pulmonary damage leads to the patient's demise. There is a high mortality rate in paraquat poisoning as the treatment is usually supportive with no known antidote. There are limited human studies that have observed the histopathological changes in lungs in paraquat poisoning. The authors have discussed the time-related histopathological changes in lungs in paraquat poisoning on autopsy subjects. The role of anticoagulants and fibrinolytic agents in the treatment of this poisoning has also been discussed.

Molecular Characterization, Pathogenesis and Immunological Effect of Avian Influenza H9N2 Virus Isolated From Broiler Chickens in Egypt During 2019

Many commercial flocks in Egypt were infected with the low pathogenic avian influenza virus (LPAIV) subtype H9N2, resulting in severe economic losses, particularly when combined with other viral and bacterial diseases. The current study aimed to investigate the genetic evolution of LPAIV (H9N2) in broiler farms in Egypt during 2019 and evaluate its effect on the viral pathogenesis, cytokine response, innate immunity and oxidative state in specific pathogen free (SPF) chicks. Sixty tracheal swabs were collected from broilers and tested by RRT-PCR and the HA gene were sequenced for the genetic evolution. Then this isolated virus was experimentally studied in a total of 20 SPF chicks (21 days old) that were divided into two equal groups. Group-1(G1) was negative control and group-2 (G2) was experimentally infected with the isolated LPAIV (H9N2). The obtained results revealed that all isolated LPAIV (H9N2) in this study were belong to G1-like Eurasian sub-lineages (A/quail/Hong Kong/G1/97-like) and clustered with Israeli strains in group B with specific mutation specific for Egyptian AIV-H9N2 isolated in 2018-2019 forming new subgroup-I. The experimental infection with LPAIV (H9N2) (G2) in SPF chickens, induced mild clinical signs, moderate histopathological changes in lung and spleen, shedding of higher mean LPAIV (H9N2) titre in trachea, up regulation of both the pro-inflammatory (IL-6) and the anti-viral (IFN-γ) cytokines, significant decrease of the serum levels of lysozyme and disturbance of the oxidative state where the serum nitric oxide (NO) and the malondialdehyde (MDA) levels were significantly increased and the antioxidants glutathione (GSH) and superoxide dismutase (SOD) were significantly decreased. In conclusion, the LPAIV (H9N2) was continually circulated in broiler chicken farms and highly evolved. The induced oxidative stress in LPAIV (H9N2) infection could be contributed to the viral pathogenesis, up-regulation of pro-inflammatory and anti-viral cytokines and down-regulation of the innate immune response.

Histopathological changes in lungs, liver and kidneys in cases of death due to agricultural poisoning in a tertiary care centre: A cross sectional study

Medico legal deaths due to agricultural poisoning claim a substantial number of lives in Andaman and Nicobar Islands. Respiratory failure is the most common complication of OP poisoning leading to death. Histopathological studies of viscera in organophosphate poisoning cases help the autopsy surgeon in ascertaining out the secondary causes of death. Microscopy of three visceral organs-lungs, liver and kidneys of 40 cases of organophosphate poisoning were studied and the changes were correlated with the duration of survival post consumption. By knowing the exact histopathological changes in these organs, it is easier to attribute death to a failure of one of these organs as a consequence of organophosphate consumption. Knowing the rapidity of involvement of an organ is beneficial to the treating physician as well thereby helping him reduce the morbidity and hence mortality.

Effects of mechanical ventilation with different tidal volumes on right ventricular hemodynamics in acute respiratory distress syndrome rats

To explore the effect of different tidal volumes (VT) on the hemodynamics of right heart in acute respiratory distress syndrome (ARDS) rats induced by oleic acid (OA). Sixty adult male Sprague-Dawley (SD) rats were divided into control group (n = 20), ARDS model group (n = 20), low VT (LVT) group (n = 10) and high VT (HVT) group (n = 10) by random number table. ARDS model was reproduced by injecting OA 0.15 mL/kg through a jugular vein. The control group was given the same amount of normal saline. The success of modeling was judged by the oxygenation index (PaO2/FiO2) 2 hours after modeling, at the same time, the lung tissues were collected, the wet/dry weight (W/D) ratio was determined, and the lung histopathological changes were measured by lung injury score. The rats in the LVT group and HVT group were given mechanical ventilation with VT of 6 mL/kg or 20 mL/kg for 4 hours, respectively at 2 hours after modeling. The rats in the control group and the ARDS model group maintained spontaneous breathing. After mechanical ventilation for 4 hours, the heart rate (HR), right ventricular systolic pressure (RVSP), the maximum rate of rising of right ventricular pressure (dp/dt max), and the blood pressure (BP) were measured. Meanwhile, arterial blood samples were collected for blood gas analysis, including pH value, arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2) and PaO2/FiO2. The rats in the ARDS model group showed symptoms of respiratory distress 1 hour after modeling, and the lung tissue samples showed obvious patchy bleeding 2 hours after modeling, while the control group showed no such changes. The PaO2/FiO2 in the ARDS model group was significantly lower than that in the control group [mmHg (1 mmHg = 0.133 kPa): 294.3±5.9 vs. 459.0±4.4, P < 0.01], and the lung W/D ratio and lung injury score were significantly higher (lung W/D ratio: 8.24±0.25 vs. 4.48±0.13, lung injury score: 0.60±0.03 vs. 0.12±0.02, both P < 0.01). It indicated that ARDS model was successfully reproduced. The arterial blood gas analysis and hemodynamic parameters of the ARDS model group were significantly worse than those of the control group. After 4-hour mechanical ventilation, the blood gas parameters of the LVT group were better than those of the ARDS model group and the HVT group [pH value: 7.36±0.02 vs. 7.24±0.02, 7.13±0.01; PaO2 (mmHg): 92.4±2.1 vs. 61.8±2.3, 76.6±2.2; PaCO2 (mmHg): 49.6±1.7 vs. 61.8±1.8, 33.6±1.3; PaO2/FiO2 (mmHg): 440.0±10.2 vs. 274.3±21.4, 364.7±10.5; all P < 0.05]. HR, BP and dp/dt max in the LVT group were significantly higher than those in the ARDS model group and the HVT group [HR (bpm): 346.9±5.4 vs. 302.3±10.1, 265.5±12.2; BP (mmHg): 125.4±2.2 vs. 110.0±2.5, 89.2±2.8; dp/dt max (mmHg/s): 1 393.3±30.3 vs. 1 236.4±20.5, 896.1±19.5; all P < 0.05], and RVSP was significantly lower than that in the ARDS model group and the HVT group (mmHg: 31.3±0.4 vs. 34.0±1.0, 38.8±0.9, both P < 0.05). Mechanical ventilation with low VT can improve the hemodynamic parameters of the right ventricle and protect the function of the right heart in ARDS rats.

The mechanism underlying hypaconitine-mediated alleviation of pancreatitis-associated lung injury through up-regulating aquaporin-1/TNF-α.

Acute pancreatitis-associated lung injury (APALI) is one of the most common and most dangerous form of extra-pancreatic organ damage in severe acute pancreatitis (SAP). The treatment options for SAP were limited thus far; as a result, approximately 60%-80% of patients with SAP would die within a week. Hypaconitine (HC), one of the most important active ingredients in a Mongolian traditional medicine Radix Aconiti Kusnezoffii has an excellent anti-inflammatory effect. To ascertain whether HC has a protective effect against APALI, we investigated the therapeutic effects and the underlying mechanisms in vivo and in vitro and attempted to elucidate the mechanism in detail. In this study, APALI rats and human pulmonary microvascular endothelial cells were treated with therapeutic doses of HC after establishing a model with sodium taurocholate and lipopolysaccharide, respectively. Serum amylase and lipase activity, lung wet/dry weight ratio, lung myeloperoxidase activity, and pancreatic and lung histopathological changes showed that HC alleviated APALI in a dose-dependent way, which can be abolished by an aquaporin-1 (AQP-1) knockdown. The results of the reverse transcriptase polymerase chain reaction, Western blot, and immunohistochemical staining confirmed the expression of AQP-1, a kind of transmembrane protein that mainly distributed in the membranes of pulmonary cells and contributed to maintain water balance in the body by interacting with tumor necrosis factor-alpha (TNF-α), is negatively associated with APALI. On the contrary, HC treatment up-regulated AQP-1 expression and down-regulated the TNF-α expression as a consequence in APALI. These results suggest that HC has a good anti-inflammatory therapeutic effect on APALI with a possible underlying mechanism that affects the AQP-1/TNF-α pathway.

Exposure of calcium carbide induces apoptosis in mammalian fibroblast L929 cells

Inspite of various health warnings from Government and health organizations, Calcium carbide (CaC2) is still the most commonly and widely used artificial fruit ripener, probably due to its easy availability, low cost and convenience of usage. Assessment of the hazardous effects of the CaC2 applications for fruit ripening has been a matter of interest since long. Several in vivo studies have reported the toxicological outcomes such as histopathological changes in lungs and kidneys, haematological and immunological responses, upon exposure with CaC2. However, a well-controlled study investigating the effects of CaC2 under in-vitro setup was lacking. Hence, this study has been conducted to explore the toxicity associated cellular events in L929 cells exposed with varying concentrations of CaC2 (0.00312–0.2 μg/μl) for 24 h exposure time. A 23.14% reduction in cell viability was observed at the highest dose of CaC2. A similar trend in cellular stress levels at 0.2 μg/μl dose was observed in terms of rounded cellular morphology and decreased adherence as compared to the control. Furthermore, Annexin V FITC/PI staining and subsequent confocal imaging revealed a similar trend of CaC2 induced apoptosis in a dose dependent manner. A gradual elevation of intracellular ROS has also been observed up to 0.025 μg/μl dose. Thus, the study concludes that short term CaC2 exposure may increase the cellular oxidative stress and disturb the redox balance of the cell which then undergoes apoptosis. The study concludes that the exposure of CaC2 can be associated with severe diseases and suggests to stop the uses of CaC2 as fruit ripening agent.