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Background Silica nanoparticles (SiNPs) enter the human body through respiratory tract, digestive tract, and skin, causing body damage. Lung is one of the main damaged organs. Objective To observe the expressions of complement activated fragment C3a and its receptor C3aR in the lungs of mice exposed to SiNPs through respiratory tract, and to explore the involvement of C3a/C3aR in lung injury induced by SiNPs exposure. Methods The ultrastructure of SiNPs (particle size 5-20 nm) was determined under a transmission electron microscope, and the hydrodynamic diameter and surface Zeta potential of SiNPs were determined using a nanoparticle size analyzer. A total of 88 SPF C57BL/6J mice were randomly divided into five groups: a blank control group without any treatment (14 mice), a vehicle control group treated with 50 μL stroke-physiological saline solution by intratracheal instillation (14 mice), and three SiNPs exposure groups (low-dose group, medium-dose group, and high-dose group with 20 mice in each group, who were given 50 μL SiNPs suspension of 7, 21, and 35 mg·kg−1 respectively and exposed once every 3 days for 5 times). The mice were anesthetized on day 1 (1-day model group) and day 15 (15-day model group) after exposure, then sacrificed after extraction of bronchoalveolar lavage fluid (BALF), and lung tissues were retained. The morphological changes of lung tissues were observed by HE staining, the expression level of C3a in BALF was detected by enzyme-linked immunosorbent assay, the deposition of C3a and C3aR in lung tissues were observed by immunohistochemistry, the protein expression level of C3aR was determined by Western blotting, and the localization and semi-quantitative detection of C3a and C3aR in lung tissues was observed by immunofluorescence. Results SiNPs agglomerated in stroke-physiological saline solution. The average hydrodynamic diameter was (185.60±7.39) nm and the absolute value of Zeta potential was (43.33±0.76) mV. The condition of mice in the 1-day model group and the 15-day model group was good, while 2 mice died in the medium-dose group of the 1-day model group due to misoperation. The autopsy results of the two mice showed congestion of the lung tissue, emphysema, and no imperfection of trachea integrity. No death was observed in other dose groups. The HE staining results showed pathological damage to the mouse lung, including alveolar wall thickening and inflammatory cell infiltration after SiNPs exposure. The pathological damage became more serious with the increase of dose. Regarding pathological changes, the 15-day model group was slightly relieved compared with the 1-day model group, but there were still pathological changes. The enzyme-linked immunosorbent assay results showed that there was no difference in the expression level of C3a between the blank control group and the vehicle control group (P＞0.05), the expression levels of C3a in the medium-dose group and the high-dose group were significantly higher than that in the vehicle control group (P<0.05). The immunohistochemistry results showed that C3a deposition was consistent with the enzyme-linked immunosorbent assay results. The Western blotting and the immunohistochemistry results showed that C3aR expression was low in the blank control group and the vehicle control group, while the expression in each dose group tended to increase with the increase of dose. The immunofluorescence results showed that the fluorescence signals of C3a and C3aR were weak in the blank control group and the vehicle control group in the 1-day model group and the 15-day model group, while the fluorescence signals in the lung tissues of mice in the SiNPs exposure groups tended to increase with the increase of dose. Conclusion The increased expressions of C3a and C3aR in complement activation may be related to lung injury induced by intratracheal instillation of SiNPs, suggesting that C3a/C3aR may be involved in lung injury induced by SiNPs exposure.
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@#Objective - To establish a new non exposed intratracheal instillation method for establishing a rat silicosis model. Methods ， The specific pathogen free SD rats were randomly divided into control group and experimental group with ten rats in ， each group. Rats in the control group were given 1.0 mL of 0.9% sodium chloride solution and rats in the experimental group - were given 1.0 mL of silica suspension with a mass concentration of 50 g/L adopting to the one time intratracheal instillation ， - ， method and then followed by ventilator assisted ventilation immediately. When the tidal volume stabilized at 2.0 mL the ventilator was removed and the tracheal intubation was pulled out. Five rats in each group were sacrificed after two and four ， - Results weeks after modeling and hematoxylin eosin staining and Masson staining of lung tissue were performed. There was ， ， no death in the two groups of rats during the experiment. After two and four weeks the control group had normal lung structure ， ， ， normal alveolar cavity size no inflammatory cell infiltration thin alveolar wall only a small amount of collagen distribution ， around the lung interstitium and bronchus. At the second week of modeling the alveolar wall of the rats in the experimental ， ， ， group was slightly thickened interstitial lymphocytes and macrophages were infiltrated slight hyperplasia was found and a ， small amount of fibroblasts were visible. At the 4th week of modeling the alveolar wall of the rats in the experimental group was ， ， ， ， significantly thickened fibrous nodules were formed and fibroblasts fibrocytes collagen fibers were significantly increased. Conclusion - The combination of ventilator and non exposed intratracheal instillation method can be used to successfully ， ， . establish a rat silicosis model which is simple safe and effective
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@#To investigate the effects of intratracheal instillation of PM2.5 suspension on bleomycin (BLM)-induced pulmonary fibrosis in mice and the intervention of neotuberostemonine (NTS), the BLM dose (1.5 or 3.0 U/kg) and PM2.5 frequency (1 or 2 times per week) were studied by factorial experiment design. After intratracheal instillation of BLM (1.5 or 3.0 U/kg) on day 0, PM2.5 (5 mg/kg) was intratracheally injected to mice once or twice a week from day 1 to day 21, and the mice in the treatment group were given 30 mg/kg NTS by gavage once a day from day 8 to day 21. The degree of pulmonary fibrosis was evaluated by lung coefficient, hydroxyproline (HYP) content, HE staining and Masson staining lung sections as well as their semi-quantitative index (HE inflammatory score and collagen volume fraction, CVF). The results showed that the HE scores increased significantly in mice singly given PM2.5 once a week, the HYP content and HE score increased in mice singly given PM2.5 twice a week, but their CVF values did not significantly increase. However, the CVF values increased significantly in mice treated with PM2.5 and BLM co-infusion. These results suggested that PM2.5 (administered singly) could significantly increase BLM-induced collagen deposition and greatly aggravate pulmonary fibrosis although it mainly caused pulmonary inflammation rather than pulmonary fibrosis. NTS could significantly reduce the CVF value and α-SMA protein level of the model mice. It can be concluded that PM2.5 has great influence on patients with respiratory diseases, while NTS can improve pulmonary fibrosis induced by the combination of PM2.5 and BLM.
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Objective The aim of this study was to establish a PM2.5air pollution-induced mouse model of pulmo-nary inflammation and investigate its pathogenetic mechanism. Methods 150 specific pathogen-free BALB/c mice were subjected to intratracheal instillation of 2.5,5,or 10 mg/kg PM2.5suspension to construct airborne inflammation models. The blank group and saline group were taken as a control group. Mice were euthanized after 3rd,7th,21st,35th and 49th days to assess the pathological changes in lung tissues using HE staining and ELISA. Results The success rate of tracheal instillation was 96%. With the time prolongation and increasing doses of intratracheal PM2.5instillation,the histopathologi-cal scores of lung tissue increased gradually,showing alveolar macrophages with engulfed particles and lymphocyte accumu-lation in bronchiole and widened inter-alveolar space. The levels of BALF IL-6 and TNF-α of lung tissue homogenate were significantly increased in the high dose PM2.5(10 mg/kg)group, compared with the control groups. Conclusions A mouse model of PM2.5air pollution-induced lung inflammation is successfully established by intratracheal instillation of PM2.5suspension.This method is proved to be simple,safe and reliable,and is useful for further study of air pollution-in-duced and other inflammatory mechanisms.
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Objective To compare the different methods of administration of diacetyl (DA)-established bronchiolitis obliterans (BO)murine model so as to establish a simple,easy-to-operate and stable BO murine model. Methods SPF grade C57BL/6 male mice (6 to 8 weeks)were randomly divided into four groups with 10 mice in each group:oropharyngeal aspiration group (OPR),intratracheal instillation group (ITI),and control groups (OPR-CON and ITI-CON).OPR group was treated with DA (400 mg/kg,327 mg/kg)by oropharyngeal aspiration;ITI group received DA (400 mg/kg,327 mg/mL)through intratracheal instillation;OPR-CON group and ITI-CON group were treated with sterilized distilled water instead of DA,while the other experimental conditions were the same as those in OPR and ITI groups.The mice were kept in SPF-class animal center for 7 d to collect specimens. Collected bronchoalveolar lavage fluid (BALF)and the left lung were examined pathologically.Results Male C57 BL/6 mice were treated with a single dose of DA (400 mg/kg,327 mg/kg)by OPR or ITI,which could establish BO model.The successful model was evaluated by pulmonary function,BALF counts and pathological examination. Airway hyperresponsiveness occurred with the two-method resulted BO.And two methods of instilling DA resulted in airway injury,lumen occlusion,infiltration of inflammatory cells in the airway and around the vessels.The mortality rate of mice was up to 60% and the success of model construction was only 20% in BO model by oropharyngeal aspiration of DA,while that in ITI group mortality was only 30%,the success of model construction was up to 60%.There was no death in control groups.Conclusion BO murine model could be successfully established by OPR or ITI of DA (400 mg/kg,327 mg/mL).However,the BO model was established well by ITI of DA with lower mortality rate.Therefore,ITI of DA-established BO murine model is recommended for use.
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Objective:To study the effects of SiO2 nanoparticles on the organs of mice in vivo after intratracheal instillation, and to provide the basis for safety evaluation of SiO2 nanoparticles. Methods:Forty female BALB/c mice aged 6-8 weeks were randomly divided into control group (saline), low dose of SiO2 group (7 mg·kg-1), middle dose of SiO2 group (21 mg·kg-1), and high dose of SiO2 group (35 mg·kg-1).1 and 15 d after five times of non-exposed intratracheal instilation infection (once every 3 d), the mice were sacrificed and the left lungs,the right kidneys, livers, hearts and spleens were collected and embedded in paraffin.The morphology of tissue sections was observed under light microscope after hematoxylin-eosin (HE) staining.The eyeball blood was obtained and the biochemical indicators of liver and kidndy functions were detected.Results:Compared with control group, there were alveolar interval thickening, inflammatory cell infiltration, and a small amount of small arterial thrombosis in the lungs;granulomatous inflammatory cell infiltration and a small amount of focal necrosis of liver cells in the livers;red pulp enlargement, hyperemia, and more visibly scattered megakaryocytes in the spleens in SiO2 nanoparticles groups in a dose-dependent manner, especially in middle and high doses of SiO2 groups.After 15 d of injection, the damages alleviated with the prolongation of time.There was some inflammatory cell infiltration in the kidney tissue of the mice in SiO2 nanoparticle groups.The biochemical indicator detection results showed that alanine aminotransferase(ALT) and aspartate transaminase(AST) levels in SiO2 nanoparticles groups varied, suggesting the liver cell damages were at different degrees;the changes of urea nitrogen(BUN) and creatinine(Cr) levels in SiO2 nanoparticle groups remindered the kidney function alteration, but there were no obvious dose-and time-dependent effects.Conclusion:Intratracheal instillation of SiO2 nanoparticles can influence the major organs of the mice and mainly displays in the inflammation and injuries in the lung, liver, and spleen.
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Objective To investigate the effect of intratracheal instillation of curosurf on neonatal respiratory distress syndrome ( NRDS ) in children with right ventricular function.Methods 52 patients with NRDS were retrospectively selected and divided into two groups according to different treatment.The patients in the conventional group were treated with nasal airway ventilation.Based on the conventional group, the curosurf group was taken with curosurf.26 cases were in each group.The blood gas index (PaCO2, PaO2, pH), inflammatory reaction (TNF-α, IL-10), SF of the two groups were compared, the complications and curative effect of the two groups before and after treatment were taken for statistics.Results There was no significant difference in pH value between the two groups at each time point.The PaO2 expression levels in the curosurf group at different time points after treatment were significantly lower than the conventional group (P<0.05).The levels of TNF-αand IL-10 in the curosurf group were more stable than those in the control group at different time points after treatment (P<0.05), and the degree of SF increasing at different time points were higher (P<0.05).The total effective rate 80.77% of the curosurf group was significantly higher than that of the conventional group 61.54%(P<0.05).The total complication rate 19.24% had no significant differences with the conventional group 23.08%.Conclusion Intratracheal instillation of CsA in the treatment of NRDS has the advantages of simple operation, little side effect, rapid recovery of blood gas index and inflammatory factors, so it is a feasible method for clinical treatment of NRDS.
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We report of a successfully treated case of fatal bronchospasm, which developed after N-acetylcysteine bolus intratracheal instillation in a 49-year-old female patient with bronchial asthma undergoing laparoscopic cholecystectomy. N-acetylcysteine has been widely used as a potent mucolytic agent since 1963, with few reported adverse reactions. Its mucolytic action is due to the breakage of disulfide bonds in mucus mucoproteins. Most adverse reactions to N-acetylcysteine are usually mild and respond to the termination of the medication and symptomatic treatment with antihistamine. However, several cases of fatal bronchospasm have been reported in asthmatic patients after inhaled or intravenous N-acetylcysteine. N-acetylcysteine induced bronchospasm could be avoided in most asthmatic patients if its concentration is not allowed to exceed 10%, and concomitant beta2-selective bronchodilators are utilized. Nevertheless, asthma is still a potent risk factor and requires special precautions, including careful risk-versus-benefit assessment, close observation and the immediate availability of resuscitation equipment and staff in the event of life-threatening bronchospasm.
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Female , Humans , Middle Aged , Acetylcysteine , Asthma , Bronchial Spasm , Bronchodilator Agents , Cholecystectomy, Laparoscopic , Mucoproteins , Mucus , Resuscitation , Risk FactorsABSTRACT
Objective To study the acute effects of PM2.5 on the heart rhythm of spontaneously hypertensive rats(SHR)and the mechanism.Methods Twenty-eight male spontaneously hypertensive rats(SHR)were randomly divided into four groups.PM2.5 was administered by intratracheal instillation at the doses of 0 mg/kg,7.5 mg/kg,15 mg/kg and 30 mg/kg respectively.ECGs were monitored at 30 min,1 h and 24 h later.Results The numbers of the rats with arrhythmia in all groups increased at 30 min after treatment.At 1 h after treatment,in control group the rats recovered,but in PM2.5 groups abnormal ECGs was still showed.However,ECGs of all groups became normal 24 h later.As shown by laser scanning confocal microscope(LSCM),the expression of Cx43 in the heart tissue of rats in 15 mg/kg and 30 mg/kg groups significantly decreased compared with the control group.There was no significant change in content of MDA and SOD in the heart tissue of PM2.5 treated rats.Conclusion PM2.5 exposure through inhalation may induce arrhythmia in SHR rats and the downregulated expression of Cx43 may play an important role in the pathogenesis.