BACKGROUND: We previously demonstrated that continuous exposure to nitrous acid gas (HONO) for 4 weeks, at a concentration of 3.6 parts per million (ppm), induced pulmonary emphysema-like alterations in guinea pigs. In addition, we found that HONO affected asthma symptoms, based on the measurement of respiratory function in rats exposed to 5.8 ppm HONO. This study aimed to investigate the dose-response effects of HONO exposure on the histopathological alterations in the respiratory tract of guinea pigs to determine the lowest observed adverse effect level (LOAEL) of HONO. METHODS: We continuously exposed male Hartley guinea pigs (n = 5) to four different concentrations of HONO (0.0, 0.1, 0.4, and 1.7 ppm) for 4 weeks (24 h/day). We performed histopathological analysis by observing lung tissue samples. We examined samples from three guinea pigs in each group under a light microscope and measured the alveolar mean linear intercept (Lm) and the thickness of the bronchial smooth muscle layer. We further examined samples from two guinea pigs in each group under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). RESULTS: We observed the following dose-dependent changes: pulmonary emphysema-like alterations in the centriacinar regions of alveolar ducts, significant increase in Lm in the 1.7 ppm HONO-exposure group, tendency for hyperplasia and pseudostratification of bronchial epithelial cells, and extension of the bronchial epithelial cells and smooth muscle cells in the alveolar duct regions. CONCLUSIONS These histopathological findings suggest that the LOAEL of HONO is < 0.1 ppm.
Alveolar Epithelial Cells ; drug effects ; Animals ; Bronchi ; drug effects ; Dose-Response Relationship, Drug ; Emphysema ; chemically induced ; Epithelial Cells ; drug effects ; Guinea Pigs ; Hyperplasia ; chemically induced ; Inhalation Exposure ; adverse effects ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Myocytes, Smooth Muscle ; drug effects ; Nitrous Acid ; toxicity

The aim of the present study was to investigate the role of ferroptosis in acute lung injury (ALI) mouse model induced by oleic acid (OA). ALI was induced in the mice via the lateral tail vein injection of pure OA. The histopathological score of lung, lung wet-dry weight ratio and the protein content of bronchoalveolar lavage fluid (BALF) were used as the evaluation indexes of ALI. Iron concentration, glutathione (GSH) and malondialdehyde (MDA) contents in the lung tissues were measured using corresponding assay kits. The ultrastructure of pulmonary cells was observed by transmission electron microscope (TEM), and the expression level of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA was detected by quantitative polymerase chain reaction (q-PCR). Protein expression levels of glutathione peroxidase 4 (GPX4), ferritin and transferrin receptor 1 (TfR1) in lung tissues were determined by Western blot. The results showed that histopathological scores of lung tissues, lung wet-dry weight ratio and protein in BALF in the OA group were higher than those of the control group. In the OA group, the mitochondria of pulmonary cells were shrunken, and the mitochondrial membrane was ruptured. The expression level of PTGS2 mRNA in the OA group was seven folds over that in the control group. Iron overload, GSH depletion and accumulation of MDA were observed in the OA group. Compared with the control group, the protein expression levels of GPX4 and ferritin in lung tissue were down-regulated in the OA group. These results suggest that ferroptosis plays a potential role in the pathogenesis of ALI in our mouse model, which may provide new insights for development of new drugs for ALI.
Acute Lung Injury ; chemically induced ; pathology ; Animals ; Apoptosis ; Bronchoalveolar Lavage Fluid ; chemistry ; Cyclooxygenase 2 ; metabolism ; Ferritins ; metabolism ; Glutathione ; analysis ; Glutathione Peroxidase ; metabolism ; Iron ; analysis ; Iron Overload ; physiopathology ; Lung ; cytology ; pathology ; Malondialdehyde ; analysis ; Mice ; Microscopy, Electron, Transmission ; Mitochondrial Membranes ; ultrastructure ; Oleic Acid

OBJECTIVEThe effect of the silica nanoparticles (SNs) on lungs injury in rats was investigated to evaluate the toxicity and possible mechanisms for SNs.

METHODSMale Wistar rats were instilled intratracheally with 1 mL of saline containing 6.25, 12.5, and 25.0 mg of SNs or 25.0 mg of microscale SiO2 particles suspensions for 30 d, were then sacrificed. Histopathological and ultrastructural change in lungs, and chemical components in the urine excretions were investigated by light microscope, TEM and EDS. MDA, NO and hydroxyproline (Hyp) in lung homogenates were quantified by spectrophotometry. Contents of TNF-α, TGF-β1, IL-1β, and MMP-2 in lung tissue were determined by immunohistochemistry staining.

RESULTSThere is massive excretion of Si substance in urine. The SNs lead pulmonary lesions of rise in lung/body coefficients, lung inflammation, damaged alveoli, granuloma nodules formation, and collagen metabolized perturbation, and lung tissue damage is milder than those of microscale SiO2 particles. The SNs also cause increase lipid peroxidation and high expression of cytokines.

CONCLUSIONThe SNs result into pulmonary fibrosis by means of increase lipid peroxidation and high expression of cytokines. Milder effect of the SNs on pulmonary fibrosis comparing to microscale SiO2 particles is contributed to its elimination from urine due to their ultrafine particle size.

Air Pollutants ; toxicity ; Animals ; Dose-Response Relationship, Drug ; Lung ; drug effects ; pathology ; ultrastructure ; Male ; Microscopy, Electron, Transmission ; Nanoparticles ; toxicity ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Random Allocation ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Specific Pathogen-Free Organisms ; Spectrometry, X-Ray Emission ; Urine ; chemistry

OBJECTIVETo analyze the clinical characteristic of Kartagener syndrome in Chinese and foreign children.

METHODFour cases of Kartagener syndrome diagnosed in our hospital were analyzed with literature review. The differences between Chinese and foreign children in clinical manifestations and diagnosis were compared.

RESULTAll of the cases had the following clinical manifestations: recurrent productive cough, nasosinusitis, dextrocardia, total situs inversus and bronchiectasia. Situs inversus of the airway structure was visible under the bronchoscope, and electron microscopy of the respiratory mucosa showed an abnormal ciliary ultrastructure. By using "Kartagener syndrome" and "child" as the key words, reports on 55 Chinese cases and 61 foreign cases in children were retrieved from CNKI and PubMed databases. The average age of diagnosis was 9.16 ± 3.67 years in China, which was significantly later than 7.07 ± 4.92 years in foreign countries (t=2.642, P<0.01). The main clinical manifestations were recurrent productive cough, nasosinusitis or rhinopolyp, recurrent pulmonary infection, recurrent wheezing and otitis media. Sinus imaging showed maxillary sinusitis. Dextrocardia, total situs inversus and bronchiectasia were found on thoracic and abdominal CT. The ciliary ultrastructural analysis showed shorter and missing dynein arm (6/6 cases in China and 25/27 cases in foreign) .

CONCLUSIONThe clinical manifestations are recurrent upper and lower respiratory tract infection combined with dextrocardia or other situs inversus in both China and other countries. The diagnosis abroad relied more on abnormal ciliary ultrastructure observed under electron microscopy, but in China mainly relied on its typical clinical manifestations.

Asian Continental Ancestry Group ; Child ; China ; Cilia ; ultrastructure ; Humans ; Kartagener Syndrome ; diagnosis ; ethnology ; Lung ; pathology ; ultrastructure ; Microscopy, Electron ; Respiratory Tract Infections ; diagnosis ; Situs Inversus ; diagnosis

OBJECTIVETo establish an animal model of sulfur mustard (SM)-induced acute lung injury in rats through different routes and compare the morphological changes in lung tissue and cells.

METHODSOne hundred and thirty-six male rats were selected and randomly divided into 5 groups, namely peritoneal cavity SM group (n=32), trachea SM group (n=32), peritoneal cavity propylene glycol group (n=32), trachea propylene glycol group (n=32), and normal control group (n=8). The rats in peritoneal cavity SM group were injected intraperitoneally with diluted SM (0.1 ml, 8 mg/kg), and the rats in trachea SM group were injected intratracheally with diluted SM (0.1 ml, 2 mg/kg). Once the rats were sacrificed at 6, 24, 48, and 72 h after SM treatment, morphological changes in lung tissue and cells were observed by light and electron microscopy.

RESULTSIn the peritoneal cavity SM group, the epithelial cells of bronchioles maintained intact with increased exudate and bleeding in alveolar cavity and large areas of pulmonary consolidation under the light microscope. In the tracheal SM group, focal ulcer formed in the epithelial cells of bronchioles with increased exudate and bleeding in alveolar cavity, partial pulmonary consolidation, and compensatory emphysema in peripheral alveolar space under the light microscope. The alveolar interval areas were widened obviously in both groups in a time-dependent manner. Under the electron microscope, we observed local loss of cellular membrane in type I alveolar epithelium, broken or lost microvilli in cells of typeⅡalveolar epithelium and fuzzy mitochondrial crista as well as the appearance of ribosome detached from rough endoplasmic reticulum in both two groups. Compared with those in the trachea SM group and the control group, the ratio of the alveolar septum average area to the visual field area in the peritoneal cavity SM group at 6, 24, 48, and 72 h was significantly higher (P<0.05).

CONCLUSIONThe lung tissue injury through the intraperitoneal route is more severe than that through the tracheal route, while focal ulceration of bronchioles epithelial cells appears in the case of tracheal route. The degree of injury increases over time in both groups, and the cellular damage is approximately the same in both groups.

Acute Lung Injury ; chemically induced ; pathology ; Animals ; Disease Models, Animal ; Lung ; pathology ; Male ; Mustard Gas ; toxicity ; Peritoneum ; Pulmonary Alveoli ; pathology ; ultrastructure ; Rats ; Trachea

Humans ; Lung ; ultrastructure ; Paraquat ; toxicity ; Pulmonary Edema ; pathology ; Research Report

OBJECTIVETo document ultrastructural changes of brain, spinal cord, skeletal muscle, jejunum and lung of EV71 infection mouse model, and to explore the myotropism and pathogenesis of EV71 in nervous system.

METHODSTen-day-old suckling mice were infected with EV71 strain via the intraperitoneal route. Mice with paralysis were scarified on day 4 post infection and the brain, spinal cord, skeletal muscle, jejunum and lung were sampled for transmission electron microscopy and light microscopy.

RESULTSLesions in brain were generally mild with inner chamber swelling in some of mitochondria. Myelin sheaths of medullated fibers were split with vacuolated changes. The Nissl bodies in anterior motor neurons disappeared along with mitochondria swelling, rough endoplasmic reticulum swelling and degranulation. Cytoplasm of anterior motor neurons showed cribriform appearance accompanied by neuronophagia. The bands of skeletal muscle in the infected group disappeared with degeneration and karyopyknosis in myocytes, in addition to mitochondrial swelling. Microvilli of epithelium in jejunum became loosely arranged along with formation of spiral medullary sheath structure and mitochondria swelling. Interstitial pneumonia was observed in lungs with type II pneumocyte proliferation and evacuation of the multilamellar bodies.

CONCLUSIONSEV71 infection causes severe myositis in the mouse model suggesting a strong myotropism of EV71 virus. The presence of lesions of various degrees in central nervous system and changes in anterior motor neurons may be associated with limb paralysis.

Animals ; Brain ; ultrastructure ; virology ; Disease Models, Animal ; Enterovirus A, Human ; Enterovirus Infections ; pathology ; virology ; Jejunum ; ultrastructure ; virology ; Lung ; ultrastructure ; virology ; Mice ; Mice, Inbred BALB C ; Microscopy, Electron, Transmission ; Muscle, Skeletal ; ultrastructure ; virology ; Spinal Cord ; ultrastructure ; virology

OBJECTIVETo observe the lung injury in rats induced by SiO₂ nanoparticles.

METHODSOne hundred and fifty SD rats were divided into five groups: the control group, the nanosized SiO₂ groups of 6.25, 12.5, 25 mg/ml, and the microsized SiO₂ group of 25 mg/ml, 30 rats each group. On the 7th, 15th, 30th, 60th and 90th day after exposure, six rats were sacrificed at each time point and the lung viscera coefficient, the pathological morphology and ultrastructure of lung were observed.

RESULTSAt each time point, the rat lung viscera coefficient of 25 mg/ml microsized SiO₂ and nanosized SiO₂ group were higher than the physiological saline group (P < 0.05), 25 mg/ml microsized SiO₂ group was higher than the same dose of nanosized SiO₂ group (P < 0.05); With longer duration of dye dust, lung viscera coefficient of 25 mg/ml microsized SiO₂ group and each dose of nanosized SiO₂ group were in time-effect relationship. Under light microscope we can see microsized SiO₂ group gradually formed cellularity nodules, and fused into fibrous nodules; At the early stage 25 mg/ml nanosized SiO₂ group occured focal alveolar macrophages and fibroblast proliferation and later fibrous connective tissue proliferated. Under TEM osmium lamellar corpuscle of type II alveolar epithelial cells were abnormal, and collagen and elastic fiber proliferated in mesenchyme of microsized and nanosized SiO₂ group.

CONCLUSIONNanosized SiO₂ particles after exposure can cause lung tissue injury in rat, and at the early stage it is showed inflammation, and later mainly characterized by pulmonary interstitial fibrosis differing from nodular lung fibrosis caused by microsized SiO₂, its ability to fibrosis is weaker compared with the same concentration of microsized SiO₂.

Animals ; Lung ; drug effects ; pathology ; ultrastructure ; Lung Injury ; chemically induced ; Male ; Nanoparticles ; toxicity ; Pulmonary Fibrosis ; chemically induced ; pathology ; Rats ; Rats, Sprague-Dawley ; Silicon Dioxide ; toxicity

OBJECTIVETo investigate the mechanism of how curcumin improves pulmonary vascular remodeling associated with chronic pulmonary arterial hypertension.

METHODSThe model of chromic hypoxia hypercapniapulmoary remodeling was made. Twenty-four male rats were randomly divided into 4 groups (n = 6): group I (normoxia control group), group II (hypxia and hypercapnia model group), group II (disodium cromoglycate control group), group IV (curcumin treated group). The last 3 group rats were put in a hypoxia cabin where the concentrate of O2 was 8% - 11% and the concentrate of CO2 was 3% - 5%, for 8 h a day and lasting 4 w in total. Group III rats were intraperitoneally injected with disodium cromoglycate (20 mg/kg) and group IV rats were administrated with curcumin by gavage (150 mg/kg). The morphological changes of pulmonary vessel walls and the ultrastructure of mast cells were observed by the optics microscope and the transmission electron microscope. Mast cells and its degranulation state were measured by toluidine blue staining and immunohistochemistry. Data were expressed as means ± SD (standard deviation) and analyzed with SPSS17.0 software.

RESULTS(1) By optics microscopy observation, the value of WA/TA was significantly higher in II group than other groups (P < 0.05). (2) Electron microscope showed that the endothelial cells of pulmonary arterioles in III and IV group were near to I group and the proliferation of pulmonary arterial media smooth cell layer and collagen fibers in adventitia was much lighter than those in II group. The membrane of mast cells was more intact in I, III, IV group than II group. (3) The number of mast cells, the degranulation rate of master cells and the number of positive tryptase stained cells in II group were significantly more than those in other groups. (P < 0.05).

CONCLUSIONCurcumin may inhibit the remodeling of pulmonary vessel induced by chronic hypoxia hypercapnia by mast cell regulation.

Animals ; Cell Degranulation ; Curcumin ; pharmacology ; Hypercapnia ; physiopathology ; Hypertension, Pulmonary ; drug therapy ; Hypoxia ; physiopathology ; Lung ; pathology ; Male ; Mast Cells ; physiology ; ultrastructure ; Pulmonary Artery ; drug effects ; Rats ; Rats, Sprague-Dawley ; Vascular Remodeling ; drug effects

Acute Lung Injury ; chemically induced ; metabolism ; pathology ; Animals ; CDC2 Protein Kinase ; genetics ; metabolism ; Cell Cycle ; drug effects ; Checkpoint Kinase 1 ; Female ; Lung ; metabolism ; pathology ; ultrastructure ; Male ; Malondialdehyde ; metabolism ; Microscopy, Electron, Transmission ; Organometallic Compounds ; toxicity ; Oxidative Stress ; Protein Kinases ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley