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@#Objective To investigate the protective and cure effects of dexamethasone on bleomycin-induced pulmonary fibrosis.Methods32 rats were randomly divided into the control group (C-group, n=8), injury group (I-group, n=12) and dexamethasone group (D-group, n=12). The acute pulmonary model was established by intratracheal injection of bleomycin with rats of the I-group and D-group; while rats of the C-group injected with distilled water. After that, rats of the D-group were injected with dexamethasone sodium phosphate in intraperitoneal every day, those of the C-group and I-group were injected with saline. The animals were killed on the 3rd, 7th, 14th, and 27th days after treatment, and tests of bronchoalveolar lavage fluid (BALF), total lung collagen content and lung tissue processing were performed.ResultsPathological evidence of the I-group rats demonstrated that the alveolar compartment companied with massive inflammatory cell invasion and a number of myofibroblast proliferation became more thick. However, lung injury in the D-group rats got better than that in the I-group. Neutrophil percentage achieved peak in both I-group and D-group on the 7th day. But the neutrophil ratio in the D-group was significantly lower than that of the I-group on the 7th day ( P<0.05) and the 14th day ( P<0.01). Total lung collagen content achieved peak on the 14th day both in I-group and D-group, but that of the I-group was significantly higher than that of the C-group ( P<0.01) and the D-group was significantly lower than the I-group ( P<0.01).ConclusionDexamethasone plays a protective and cure role in lung fibrosis by efficiently inhibiting the gather and invasion of neutropils and restraining the increase of collagen secreted by proliferous fibroblasts.
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Objective To observe the pulmonary pathologic changes of endotoxin (ET)-induced acute lung injury (ALI) in rabbits and the potential protective effects of fructose-1,6-diphosphate (FDP) on the ET-induced ALI of rabbits. Methods 24 flap-eared albation rabbits were randomly assigned to 3 groups, 8 for each, as follows: control group (group A), ET-treated group (group B) and combination group (treated by ET and FDP, group C). ALI was induced by injection of ET at one time. Group A was only injected with placebo, normal saline. ET was given to the rest groups. In group C, FDP was given as an intervening measure after rabbits injured. Rabbits were sacrificed at 6h time point. The pulmonary pathologic changes were observed. Some markers of pulmonary tissues, including the content of lipid peroxide (LPO), thromboxane B2 (TXB2), 6-keto-prostaglandin F1α(6-keto-PGF1α), interleukin-13 (IL-13) and the activity of superoxide dismutase (SOD), were observed. Results Compared with group A, the contents of LPO and TXB2 of group B showed significant increase (P＜0.05, P＜0.01), the SOD activity of group B weakened obviously (P＜0.01), the contents of 6-keto-PGF1α and IL-13 showed no statistical differences. The LPO content and the SOD activity of group C were similar to those of group A, the contents of TXB2, 6-keto-PGF1α and IL-13 of group C were much higher than those of group A (P＜0.01). Estimated by light microscope and electron microscope, the structure of lung tissue of group A is basically normal, the pathologic injuries of lung tissue of group B were much more severer and that of group C were slighter. Conclusion In the progress of ET-induced ALI, the oxidative injury, imbalance of TXB2/6-keto-PGF1α ratio and the secretion deficiency of protective cytokines play important role in inducing pathologic injuries of lung tissues. FDP can inhibit oxidative injury, ameliorate TXB2/6-keto-PGF1α balance and promote the secretion of protective cytokines, which, in turn, can protect rabbits from ET-induced ALI to some extent.
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BACKGROUND:Contraction of three-dimensional collagen gels has been used as a model for the contraction which characterizes both normal wound healing and the development of fibrosis in the tissue. Several factors and cytokines,such as tumor necrosis factor alpha (TNF-α), interleukin-1, prostaglandin E2 and insulin have been proved to play important roles in collagen remodeling in vitro as well as serum extravasation during the fibrotic progress.OBJECTIVE: To observe extracellular collagen matrix contraction and apoptosis of fetal lung fibroblasts in TNF-α,interleukin-1, insulin, prostaglandin E2, albumin and globum under three-dimensional culture, and investigate the effects of cytokines, insuin, serum and serum protein on the remodeling and fibrotic formation of lung tissue.DESIGN: A randomized controlled experiment.SETTING: Department of Respiratory Medicine, Lanzhou General Hospital of Lanzhou Military Area Command of Chinese PLA.MATERIALS: The experiment was carried out The experiments were carried out in the respiratory laboratory of Lanzhou General Hospital of Lanzhou Military Area Command of Chinese PLA from August 2005 to January 2006. Human fetal lung fibroblasts (American Type Culture Collection), Dulbecco's modified Eagle's medium (DMEM) and fetal bovine serum, insulin, transforming growth factor (TGF) (R&D), prostaglandin E2, type Ⅰ collagen was extracted from rat-tail tendons.METHODS: In order to investigate the effect of initial collagen concentration in the gels on the contractility of fibroblasts,the appropriate amount of collagen was mixed with distilled water, four fold-concentrated DMEM, and cells were suspended so that the mass concentration was 0.75-2.0 g/L, with a physiological ionic strength and the desired cell concentration. In order to investigate the effect of cell number in the gels on the contraction, the cellular concentration fibroblasts in the gels were prepared to 0.2×107-4×107 L-1. The areas of floating gels were measured daily and the contraction was calculated by contrasting the initial size (％ of initial area). Different serum concentrations (0.01％-0.5％)in the medium were prepared, the serum albumin (0.1％) or globulin (0.1％) were added to the serum-free culture medium to observe the gel contraction. TGF (10 mg/L), interleukin-1 (10 mg/L), insulin (1 mg/L) and prostaglandin E2 (0.1 μmol/L) were added to observe the effects of cytokines and insulin on fibroblasts-mediated collagen gel contraction.The DNA content and cellular survivability in gels in collagen were determined.MAIN OUTCOME MEASURES: Effect of lung fibroblasts on collagen contraction with or without the presence of cytokines in three-dimensional culture; Effect of collagen with different concentration on the proliferation and apoptosis.RESULTS: ① Collagen gel contraction showed a dependence on the number of fibroblasts. ② Collagen gel contraction was augmented by increasing serum concentration in culture medium, and albumin increased the contraction dramatically. ③TGF and insulin significantly increased the contraction, whereas prostaglandin E2 and interleukin-1 significantly inhibited the gel contraction. ④ The lower the initial collagen concentration was, the more gel contracted and smaller final size were observed, and cell apoptosis increased.CONCLUSION: During the fibrotic process, fibroblast population migrated into the injured lung tissue may play an important role in the development of pulmonary fibrosis and serum infiltrating into injury lung tissue may play an role in stimulating the fibrotic progress. Infiltrating fluids and edema result in the dilution of the collagen concentration in the pulmonary interstitial which may lead to stronger contraction and serious fibrosis. In the dense fibrosis area, cells were hard to survive. In consequence, the final structure of fibrotic lung could not been changed and lung fibrosis progressed.
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Objective To study the changes in activity of phospholipase A2 (PLA2) in the course of endotoxin (ET) induced acute lung injury (ALI) inrabbits and the antagonizing effect of fructose-1, 6-diphosphate (FDP), in order to evaluate the therapeutic effect of FDP on ET-induced ALI. Methods Flapeared white rabbits were randomly assigned to three groups: control group (group A), ET challenge group (group B) and treatment group (ET challenged followedby FDP, group C). Group A animals were injected with saline (2ml/kg) as control. Group B animals were injected with ET (500μg/kg) solution followed by saline. Total amount of liquid was 2ml/kg. Group C animals were given the same amount of ET solution followed by injection of FDP (300mg/kg) solution. Total amount of liquid was also 2 ml/kg. During the experiment, respiratory rate, heart rate, blood pressure, arterial blood gases and the plasma PLA2 activity were determined at 0h, 0. 5h, 2h, 4h and 6h respectively. The rabbits were sacrificed at 6h, pulmonary PLA2 activity was assessed, and the pathologic changes in pulmonary tissues were examined with light microscope and transmission electron microscope. Results Compared with group A,rabbits of group B manifested the typical characters of ALI after ET injection, and the PLA2 activity in both serum and pulmonary tissue was much higher than those of group A (P＜0. 01).Values of the PLA2 activity in group C were between those of the two former groups. At the rame time, obvious pathological changes indicating lung injury were observed in group B and only mild pathological changes could be discerned in group C. Conclusion Activation of PLA2 activity is an important factor in pathogenesis of ET-induced ALI. FDP can antagonize the PLA2 activity and protect rabbits from early ET induced ALI to a certain extent.
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Objective To study the role the pathogenesis of early acute lung injury (ALI) of rabbits induced by intravascular injection of endotoxin (ET) with the intervening method of Chloroquine. Methods Rabbits were randomly assigned to three groups: control group, ET group, and ET+ chloroquine group. Acute lung injury was induced by intravascular injection of ET (500μg/kg). The arterial gas analyses, leucocyte and platelet counts in peripheral blood, PLA2 activity both in serum and lung tissue, lipid peroxide (LPO) and superoxide dismutase (SOD) in lung tissue were measured. Electron microscope and light microscope were used to observe the pathological injuries in pulmonary tissue. The protective effects of chloroquine in early ALI were evaluated. Results Compared with saline controls, rabbits treated with ET displayed the early lung injuries, such as the decrease of PaO2 (P＜0.05), the decrease of leucocytes and platelets in peripheral blood, the leukocytes sequestration in lung tissue. The PLA2 activity significantly increased in ET group compared with control group and chloroquine group both in serum and pulmonary tissue. In ET group, concentration of LPO increased in lung tissue (P＜0.05), while concentration of SOD decreased (P＜0.05). Severe histopathological injuries were presented in ET group, including pulmonary edema, lung tissue haemorrhage, inflammatory cells infiltration, asphyxial membrand formation, partial pulmonary closure and emphysema.Ultrastructural changes showed both type Ⅰ and type Ⅱ epithelial cells injury in ET group, the edema of endothelial cells, interalveolar septum thickening. In chloroquine group, PaO2 didn't decrease, PLA2 activities in serum and pulmonary tissue were lower than ET group (P＜0.05, P＜0.05), while the concentration of LPO in lung tissue decreased (P＜0.01) and SOD increased significantly (P＜0.01). Pathological examination showed slight pulmonary edema, inflammatory cells infiltration were extenuated, ultrastructural examination proved that the injuries were alleviated by chloroquine compared with ET group. Conclusion Intravascular injection of ET could successfully induce the early ALI models in rabbits. Chloroquine could inhibit the PLA2 activation and reduce the oxidative injury in lung tissue. The experiment result demonstrated PLA2 activation and oxidative stress played important roles in the pathophysiological process of early ET-induced ALI in rabbits.
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BACKGROUND: Fructose-1, 6-diphosphate (FDP) is an intermediate product in the course of cellular glycometabolism, and has many biological effects, such as improving cellular energy metabolism, stabilizing biological membrane, inhibiting inflammation intermedium release, antagonizing oxidation, and so on.OBJECTIVE: To observe the changes of oxidative stress reaction in the course of endotoxin (ET) induced acute lung injury (ALI) in flap-eared white rabbits and the antagonistic action of FDP, and to explore the therapeutic effects of FDP on ALI.DESIGN: Complete randomized group design, controlled experiment.SETTING: Department of Respiratory Medicine, General Hospital of Chinese PLA. MATERIALS: The experiment was conducted in the laboratory of Department of Respiratory Medicine, General Hospital of Chinese PLA between May and December 2003. Twenty-four cleaning male flap-eared white rabbits were selected and randomly assigned into control group, injured group and interventional group with 8 animals in each group.METHODS: ①Control group: The rabbits were injected with saline (2 mL/kg) through vein. Injured group: The rabbits were injected with ET (500 μg/kg) solution dissolved in 2 mL saline through cannulation in cervical vein once within 5 minutes, and then saline was injected once (Total amount of the solution was 2 mL/kg). Interventional group: The rabbits were injected with the same amounts of ET solution within 5 minutes as that in the injured group, but FDP (300 mg/kg) solution was injected later (Total amount of solution was also 2 ml/kg). ②Peripheral blood and arterial blood were collected at 0, 0.5, 2, 4 and 6 hours in each group. Peripheral blood cell count and arterial blood gas were measured with autoblood cell analyzer and blood gas analyzer, respectively. After rabbits were sacrificed through bloodletting at the 6th hour, content of lipid peroxide (LPO) and activity of superoxide dismutase (SOD) in the pulmonary tissues of rabbits were measured with barbituric acid colorimetry and pyrogallol auto-oxidizing suppression, respectively. In addition, some right lower lobes of pulmonary tissues were observed on pathology with transmission electron microscope (TEM). ③Data accorded with normal distribution and homogeneity of variance were compared by t-test, or by rank sum test.MAIN OUTCOME MEASURES: ① Comparison of result of arterial blood gas and blood cell count measured before experiment, after 0.5, 2, 4 and 6 hours experiment in rabbits of each group. ②Rabbits were sacrificed after 6 hours experiment, the pulmonary contents of LPO and the activities of SOD were measured, and the pathologic changes were also examined.RESULTS: ①At 0.5 hour after ET injected, arterial blood oxygen pressure and white blood cell count in peripheral blood were lower significantly in the rabbits of the injured group as compared with those of the control group (t=-4.27, P ＜ 0.01,z=2.64, P ＜ 0.01 ). Arterial blood oxygen pressure and white blood cell count in peripheral blood in the interventional group showed insignificant difference as compared with the control group (P ＞ 0.05). The arterial blood oxygen pressure in the interventional group was obviously higher than that in the injured group (t=4.32,P ＜ 0.01 ). ②At the 4th hour after experiment, the arterial blood oxygen pressure in the interventional group was distinctly higher than those of the control group and the injured group (t=4.98, 2.40, P ＜ 0.01, 0.05). The white blood cell count in the injured group was dramatically less than those of the control group (z=2.42,P ＜ 0.05). ③At the 6th hours after experiment, the arterial blood oxygen pressure in the interventional group was markedly higher than those of the control group (t=3.39,P ＜ 0.01), The white blood cell count in the injured group was remarkably less than those of the control group (z=2.16,P ＜ 0.05). Content of pulmonary LPO in the injured group was significantly higher than that in the control group (t=3.70,P ＜ 0.01)while the activity of SOD was obviously lower than that in the control group(t=-4.12,P<0.01).Markedly pathological lesion appeared in the pulmonary tissue. Six hours later, the content of pulmonary LPO and the activity of pulmonary SOD in the interventional group had no remarkable difference from those in the control group (P ＞ 0.05), and the pulmonary pathologic injury showed less obvious.CONCLUSION: The relative deficiency of oxidative stress reaction can aggravate oxidative injury, which is an important role in pathogenesis of ET-induced ALI. FDP can improve abilities of oxidative stress reaction, inhibit oxidative injury and protect rabbits from ET-induced ALI in flapeared rabbits to a certain extent.
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Objective To study the roles of phospholipase A 2 (PLA 2) and oxidative stress in the pathogenesis of acute lung injury(ALI) of rabbits induced by intravascular injection of endotoxin (ET), as well as the protective effects of chloroquine. Methods Rabbits were randomly assigned to three groups: control group, ET group, and ET+chloroquine group(n=8). Acute lung injury was induced by intravascular injection of ET (500?g/kg). The arterial blood gas analysis and serum PLA 2 activity were measured before and after the ET challenge. At the end of the experiment, PLA 2 activity, content of malodialdchyde (MDA), and superoxide dismutase (SOD) in lung tissue were assayed. Electron microscope and light microscope were used to observe the pathological injuries in the pulmonary tissue. Results Compared with saline controls, rabbits treated with ET manifested signs of ALI, such as the decrease of PaO 2(P
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Objective To study the clinical diagnosis of pulmonary sarcoidosis,in order to improve the diagnostic accuracy.Methods The clinical data of 20 patients with pulmonaty sarcoidosis was retrospectively analyzed .Results There were 7 males and 13 females in this group with 20 patients age 14～63 years old mean 41 6 years,main symptom was cough(n=16),wet cough(n=8),hard breathing(n=6),fever(n=6),erythema(n=4),visual change(n=3),fatigue(n=2),headache(n=1),X-ray and CT examination results were as followes:bilateral hilar hilifuge larger than normal 19 cases,single hilifuge larger than normal 1 cases,mediastinal lymphadenectasis 12 cases,interstial pulmonary fibrosis 6 cases,bilateral little quantity pleural effusion 3 cases.Bronchofiberoscopy diagnosis in 14 cases,live tissue examination of skin,mucosa and lymph node in 8 cases,Kveim test positive 3 cases,SACE 69 8?12 6?/L.Conclusions Clincal symptom of pulmonary sarcoidosis was not typical,high morbidity was occured among females.In combination of clinical symptom,X-ray examination and bronchofiberoscopy pathologic examination was required to improve diagnosis rate.The therapy of adrenocortical hormone could acquire good efficacy.
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Objective To study the changes in activity of phospholipase A_2 (PLA_2) in the course of endotoxin (ET)-induced acute lung injury (ALI) in rabbits and the antagonizing effect of fructose-1,6-diphosphate (FDP), in order to evaluate the therapeutic effect of FDP on ET-induced ALI. Methods Flap-eared white rabbits were randomly assigned to three groups: control group (group A), ET challenge group (group B) and treatment group (ET challenged followed by FDP, group C). Group A animals were injected with saline (2ml/kg) as control. Group B animals were injected with ET (500?g/kg) solution followed by saline. Total amount of liquid was 2ml/kg. Group C animals were given the same amount of ET solution followed by injection of FDP (300mg/kg) solution. Total amount of liquid was also 2 ml/kg. During the experiment, respiratory rate, heart rate, blood pressure, arterial blood gases and the plasma PLA_2 activity were determined at 0h, 0.5h, 2h, 4h and 6h respectively. The rabbits were sacrificed at 6h, pulmonary PLA_2 activity was assessed, and the pathologic changes in pulmonary tissues were examined with light microscope and transmission electron microscope. Results Compared with group A, rabbits of group B manifested the typical characters of ALI after ET injection, and the PLA_2 activity in both serum and pulmonary tissue was much higher than those of group A (P
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Objective To investigate the changes in interleukin-19(IL-19)in lungs of rabbits with acute lung injury(ALI)induced by endotoxin(ET),so as to study the mechanism of injury of ET to the lung and the protective mechanism of meloxicam.Methods Twenty four male Japanese flap-eared white rabbit was randomly assigned to three groups:control group,ET-treated group and treatment with meloxicam group.Rabbit ALI model was replicated with intravascular ET injection(700?g/kg),and meloxicam was intravenously injected(2.5mg/kg)for treatment group.The content of IL-19 was measured with ELSIA method and the changes in malondialdehyde(MDA)and superoxide dismutase(SOD)were determined in every group.Results IL-19 expression in ET challenged group was significantly higher than that in control group(P