Objective Platelet aggregation, activation induced by bubbles is the main cause of decompression sick-ness.Clopidogrel(Clo) can decrease platelet aggregation through inhibiting the bind of fibrinogen and ADP .This study is designed to find if Clopidogrel can paly a protective role in decompression sickness and explore the intervention mechanism . Methods Totally 111 male SD rats divided into 3 groups:normal control group (n=20), decompression sickness(DCS) group(n=46), and DCS+Clo(Clopidogrel)treated decompression sickness (DCS+Clo)group(n=45).The rats in DCS and DCS+Clo group were placed in chamber and compressed to 1.5 MPa at speed of 2t/4 , the time of compression and res-idence was 4.5 min totally, then decompressed to surface at a speed of 3 m/s.The mortality and behavioral of rats were ob-served within 30 min post decompression .The pathology and the wet/dry ratio of lung , WBC and platelet counts in periph-eral blood, the expression of activated platelets , and immunohistochemical detection of lung tissue CD 41 expression were also been tested .Results We found Clo reduces the DCS mortality risk ( mortality rate:11/45 in DCS+Clo group vs 28/46 in DCS group, P<0.01).Clo reduced the lung injury, the wet/dry ratio of lung, the accumulation of platelet and leu-kocyte in lung , the WBC counts and activated platelets in peripheral blood .Conclusion Clo can play a protective role in decompression sickness through reducing post-decompression platelet consumption and activation , decreasing the activation of leukocytes .

Objective To study the expression levels of microRNA (miR)-16 and miR-146a in rat lungs of decompres-sion sickness (DCS) caused by fast buoyancy ascent escape or diving .Methods At 0.5 h after fast buoyancy ascent es-cape or diving, the pathological changes in rat lungs and expression levels of miR-16,and miR-146a were detected by re-verse transcription-quantitive polymerase chain reaction and compared with normal control group .Results The pathological characteristics of lungs in two DCS groups were tissue damage .At 0.5 h after DCS caused by fast buoyancy ascent escape , the lung tissue expression levels of miR-16 and miR-146a did not significantly change compared with normal control and diving DCS groups ,but the rat lung tissue expression level of miR-146 a in diving DCS group was obviously increased , com-pared with normal control group .Conclusion miR-146a may play a role in post-transcriptional regulation in the process of diving DCS .

Objective To study the pathological changes of lung tissues during fast floating escape-induced decompres-sion sickness.Methods Eighty male SD rats were randomly divided into 2 groups, 60 in fast floating escape group (escape group) , and 20 in control group .Rats in the control group were only put in a cabin under the same atmospheric pressure (ATM).Rats in escape group were pressurized to 1.5 MPa by pressure air at the 2t/7 exponential rate and stayed for 4 min till decompression.Then the rats′survival rate was observed after 0.5 h, lung tissue specimens were collected from each rat, the pathological score was taken , according to the degree of lung injury and the R language was used for statistical analysis.Results The mortality rate was 50%.Lung tissues of these rats were pathologically characterized by stromal lung thickening, edema, and hyperemia.Kruskal non-parametric test analysis found a significant difference (P=0.0016) between the two groups .Nemenyi test was used in pairwise comparison .The death and survival animals in escape group compared with the control group, the scores were significantly different (P<0.05).The scores had no significant difference between the deach and survival animal in escape group .Conclusion Decompression sickness caused by fast floating es-cape can significantly damage the blood-lung barrier to cause pulmonary edema .

Objective To establish a closed-chest pulmonary embolism-reperfusion animal model by Swan-Ganz catheter and to explore the mechanisms of pulmonary embolism(PE)-reperfusion injury(RI). Methods Experiments were made on 14 mongrel dogs,ranging in weight from 15 to 18 kg,anesthetized with 3% pentobarbital sodium.The dogs were intubated with I.D.7 endotracheal tubes.Under sterile conditions,a 7 F Swan-Ganz catheter via the external jugular vein was positioned in the unilateral pulmonary diaphragmatic lobe(DL)artery.Occlusion/reperfusion of the DL artery was controlled with 1.2 ml diluted contrast agent filled into/drawn from the balloon.After the 24 h PE,the balloon was deflated to result in 4 h reperfusion of the DL.Measurements of blood gases and tumor necrosis factor-?(TNF-?)were made at normal condition,at 24 h PE and at 4 h reperfusion.Thin-section CT scans were performed at normal condition,24 h PE,30 min,1,2,3 and 4 h reperfusion,respectively.At the end of each experiment, tissue specimens of bilateral diaphragmatic lobes were obtained for both wet/dry(W/D)weight ratio and for pathological study.Results Reperfusion pulmonary edema(RPE)was an acute,mixed,noncardiogenic edema that was observed in all 14 dogs who had been successfully established as PE/RI animal models.RPE demonstrated heterogeneous ground-glass opacifications that predominated in the areas distal to the recanalized vessels.It manifested pathologically as an edematous lung infiltrated by inflammatory cells.The mean ofPaO_2 and TNF-? of 4 h reperfusion was(81?4)mm Hg(l mm Hg=0.133 kPa)and(16.0? 2.5)pg/ml,which were significantly different(P

Objective To study the effect of nicardipine on fast floating escape induced lung injury in animal models with decompression sickness .Methods Sixty male SD rats were randomly and evenly divided into three groups:blank control, control and nicardipine groups .The nicardipine group was given nicardipine 50 mg/kg orally 0.5 h before entrance.In the control group, rats were given an equal volume of saline 0.5 h before entrance.The blank control group only stayed in the vehicle without any pressurized procedure .The air was pressurized at the 2t/7 exponential rate to 1.5 Mpa which was maintained for 4 min, and then uniformly decompressed to atmospheric pressure .The extravehicular survival and lung pathology were observed in rats after 0.5 h, IL1-βand TNF-αexpression levels were detected by ELISA , and the Caspase 3 expression in lung tissue was detected by Western blot .Results The incidence and mortality rate were 80%and 50%respectively in control group ,and 100%and 80%in the experimental group .The surviving animals in the two groups suffered from alveolar and interstitial lung hemorrhage , with widened interstitial lung .IL1-βin the experimental group was significantly higher than in the normal control group , while TNF-αhad no significant change .After nicardipine treatment pro-caspase 3 did not change significantly , but cleaved-caspase 3 increased significantly .Conclusion Nicardipine can aggravate lung injury caused by fast floating escape-induced decompression sickness if used before decompression.

OBJECTIVETo investigate the effect of different pressure oxygen pre-breathing in preventing decompression sickness of rats.

METHODSForty male SD rats were randomly divided into 4 groups: decompression sickness (DCS) group and three oxygen pre-breathing groups with 1 ATA, 2 ATA and 3 ATA pressure respectively. The rats of DCS group were placed in the hyperbaric chamber and the chamber was compressed evenly within 3 minutes to depths of 7 absolute atmosphere(ATA) and held at the designated depth for 60 min, then decompressed (3 min) at constant speed to the surface pressure. After that, the rats were taken out for further detection. While the rats of oxygen pretreatment groups pre-breathed different pressure oxygen for 20 min before entering into chamber. The mortality and behavioral of rats were observed with 30 min post decompression. The dry/wet ratio of the lung, protein levels in the bronchoalveolar lavage fluid (BALF), and the inflammatory cytokine tumor necrosis factor (TNF-alpha) expression were also tested.

RESULTSCompared with that of the DCS group, the mortality and morbidity of oxygen pre-breathe groups didn't change obviously. But the total BALF protein level and the inflammatory cytokine TNF-alpha expression of 1 ATA oxygen pre-breathe group were obviously decreased, while the dry/wet ratio of lung as obviously increased instead (P < 0.05).

CONCLUSIONAlthough preoxygenation can' t obviously change the mortality and mobidity of rats, normal pressure oxygen pre-breathing can mitigate the protein infiltration in BALF and the expression of inflammatory cytokine in lung tissue.

Animals ; Bronchoalveolar Lavage Fluid ; chemistry ; Decompression Sickness ; Diving ; Lung ; pathology ; Oxygen ; physiology ; Pressure ; Rats ; Rats, Sprague-Dawley ; Tumor Necrosis Factor-alpha ; metabolism

Objective To investigate the effect of N-acetylcysteine ( NAC) on lung and heart injury of rats with a fast floating escape induced decompression sickness .Methods Eighty male Sprague-Dawley rats were randomly and evenly divided into four groups:control group and three NAC prevention groups .The NAC groups were treated with different doses of NAC(250, 500 or 1000 mg/kg)by intraperitoneal injection 1 h before entrance.In the control group, rats were given an equal volume of saline1h before entrance.The air was pressurized at the 2t/7 exponential rate to 1.5 MPa which was maintained for 4 min and then uniformly decompressed to atmospheric pressure .The extravehicular survival and pathological changes in the lung and heart tissue were detected 0.5 h after rat egress.Results The survival rate of rats treated with NAC 500 mg/kg(90%) was significantly higher than that of those treated with saline (65%)alone (P<0.05).There was large break and fusion in the structure of pulmonary alveolus of control group besides obvious erythrocyte exudation , cardiac muscle fibers edema ,and obvious denaturation and break .Conclusion NAC can play a protective role in rats with a fast floating escape induced decompression sickness by mitigating the injury to and inflammation of lung and heart tissue .

A system analysis about the microbial flora of normal and abnormal soybean sauce liquor from the high-salt-level watery state fermentation was made and the dominant bacteria and yeasts were identified.On the other hand,a discussion of effect of temperature on microbial flora was made.The results indicated that there were no obvious differences about the count of aerobe,spore-producing bacteria,enterobacteriaceae,lactic acid bacteria and anaerobe between the normal and abnormal soybean sauce liquor and there were marked differences about the count of yeasts and salt-tolerant bacteria.The predominant yeasts in normal soybean sauce were Torulopsis and Saccharomyces,accounting for 55.9% and 35.3% of the total yeasts separately,and in abnormal soybean sauce were Pichia,candida and Saccharomyces,accounting for 62.8%,17.9% and 9.0% respectively.

These years with industrial antiseptics and disinfectants widely used, especially unscientifically used, the resistance of microorganisms is more and more serious, which brought much more difficulties to industrial producing. The developments on the resistance of microorganisms to industrial antiseptics and disinfectants, their resistant mechanisms and the control strategies are reviewed, which aids us to reasonably use industrial organic antiseptics and disinfectants in existence and provides academic and scientific basis.

Objective To evaluate the clinical outcome of external bracket fixation in the treat- ment of complex tibia diaphysis fracture involving intra-articular fractures.Methods Forty-two cases of complex tibia diaphysis fracture with proximal and distal intra-articular fractures treated surgically in our hospital from January 1999 to January 2004 were analyzed.The complex tibia diaphysis fractures were categorized according to the AO classification as type C2 (multiple segments fracture) and type C3 (ir- regular fracture),proximal and distal intra-articular fractures in 23 and 19 cases,respectively.Definite operation was done within one week.Twenty-two cases were treated with simple external fixator,and 20 cases treated with screws and external fixator.Results All the 42 cases were followed-up regularly. According to AO evaluation of the knee and ankle joint movement,83% (35/42 cases) of the cases gained satisfactory functional outcome,14% (6/42 cases) had quite satisfactory results and 2% (1/42 case) had unsatisfactory functional outcome.Conclusion External bracket fixation can obtain outcome of relative length of the tibia and fibula,tube structure reconstruction,smoothness of the articular surface and the parallel and symmetric relation of knees and ankles for complex tibia diaphysis fracture with proxi- mal and distal intra-articular fracture.The arthritis resulting in pain in movement and restriction of func- tion is considered to be the most important factor affecting the joint function.Early functional exercise is important for best recovery of knee and ankle function.