Perforated gastric ulcer causing mediastinal emphysema: A case report

BACKGROUND Mediastinal emphysema is a condition in which air enters the mediastinum between the connective tissue spaces within the pleura for a variety of reasons.It can be spontaneous or secondary to chest trauma,esophageal perforation,medi-cally induced factors,etc.Its common symptoms are chest pain,tightness in the chest,and respiratory distress.Most mediastinal emphysema patients have mild symptoms,but severe mediastinal emphysema can cause respiratory and circulatory failure,resulting in serious consequences.CASE SUMMARY A 75-year-old man,living alone,presented with sudden onset of severe epigastric pain with chest tightness after drinking alcohol.Due to the remoteness of his residence and lack of neighbors,the patient was found by his nephew and brought to the hospital the next morning after the disease onset.Computed tomography(CT)showed free gas in the abdominal cavity,mediastinal emph-ysema,and subcutaneous pneumothorax.Upper gastrointestinal angiography showed that the esophageal mucosa was intact and the gastric antrum was perforated.Therefore,we chose to perform open gastric perforation repair on the patient under thoracic epidural anesthesia combined with intravenous anesthesia.An operative incision of the muscle layer of the patient's abdominal wall was made,and a large amount of subperitoneal gas was revealed.And a continued incision of the peritoneum revealed the presence of a perforation of approx-imately 0.5 cm in the gastric antrum,which we repaired after pathological examination.Postoperatively,the patient received high-flow oxygen and cough exercises.Chest CT was performed on the first and sixth postoperative days,and the mediastinal and subcutaneous gas was gradually reduced.CONCLUSION After gastric perforation,a large amount of free gas in the abdominal cavity can reach the mediastinum through the loose connective tissue at the esophageal hiatus of the diaphragm,and upper gastrointestinal angiography can clarify the site of perforation.In patients with mediastinal emphysema,open surgery avoids the elevation of the diaphragm caused by pneumoperitoneum compared to laparoscopic surgery and avoids increasing the mediastinal pressure.In addition,thoracic epidural anesthesia combined with intravenous anesthesia also avoids pressure on the mediastinum from mechanical ventilation.

Life-threatening delayed mediastinal and subcutaneous emphysema after general anesthesia in a rheumatoid arthritis patient: a case report

Background:Delayed mediastinal emphysema with subcutaneous emphysema after extubation is rarely reported in current literature.Symptomatic treatment is considered effective for management.Case presentation:We report a case of a 56-year-old female with longstanding rheumatoid arthritis under corticosteroid therapy who developed mediastinal emphysema with subcutaneous emphysema 2 days after recovering from general anesthesia for orthopedic surgery treating a femoral neck fracture.The patient received aggressive subcutaneous decompression and symptomatic management.Results:The patient’s condition improved after treatment.Based on computed tomography scan results,we hypothesize that the longstanding rheumatoid arthritis may have resulted in fragile lung tissue.Violent postoperative coughing likely caused rupture of small airways,leading to mediastinal emphysema.Conclusions:It is crucial to preoperatively assess the risk of airway injury in high-risk patients with longstanding rheumatoid arthritis.Delayed postoperative mediastinal emphysema should be carefully evaluated and managed aggressively to avoid exacerbation or life-threatening scenarios.Further research is warranted to elucidate the pathology and guide perioperative management in these patients.

Successful treatment of a rare subcutaneous emphysema after a blow-out fracture surgery using needle aspiration:A case report

BACKGROUND Many cases of emphysema associated with blow-out fractures occur before surgery due to trauma.However,emphysema can occur even after surgery,and most of such cases are managed conservatively and allowed to resolve.Swelling in the periorbital area due to emphysema that occurs after surgery can make early recovery difficult.CASE SUMMARY Herein,we describe a case of postoperative subcutaneous emphysema that was treated using a simple needle aspiration method.A 48-year-old male patient visited the hospital with a blow-out fracture of the left medial orbital wall and nasal bone fracture.One day postoperatively,swelling and crepitus in the left periorbital area were observed,and follow-up computed tomography showed emphysema in the left periorbital subcutaneous area.Needle aspiration using an 18-gauge needle and syringe was used to relieve the emphysema.The symptoms of sudden swelling improved immediately,and no recurrence was observed.CONCLUSION We conclude that needle aspiration is a useful method that could help in relieving symptom,resolving discomfort,and enabling early return to daily life in patients with postoperative subcutaneous emphysema.

With two episodes of right retromandibular angle subcutaneous emphysema during right upper molar crown preparation:A case report

BACKGROUND Subcutaneous emphysema is a well-known complication of oral surgery,especially during mandibular wisdom tooth extraction.However,subcutaneous emphysema secondary to dental procedures such as crown preparation is rare.The main symptom of emphysema is swelling and crepitus on palpation.Uncontrolled emphysema may spread along the fascial planes and cause deep space infections or a pneumomediastinum.CASE SUMMARY In this paper,we report a 34-year-old female who underwent upper molar tooth preparation for crowns and subsequently developed extensive subcutaneous emphysema on the retromandibular angle on two different occasions.The treatment plan for this patient involved close observation of the airway,and administration of dexamethasone and antibiotics via intravenous drip or orally.Ice bag compression was quickly applied and medication was prescribed to alleviate discomfort and promote healing.Although the main reason is unclear,the presence of a fissure in the molar is an important clue which may contribute to the development of subcutaneous emphysema during crown preparation.It is imperative for dental professionals to recognize such pre-disposing factors in order to minimize the risk of complications.CONCLUSION This case highlights the need for prompt diagnosis and management of subcutaneous emphysema because of the risk of much more serious complications.Awareness of relatively“benign”subcutaneous emphysema during any dental procedure is critical not only for inexperienced dentists,but also for those who work in rural and remote settings as members of surgical teams.In this study,we review the clinical presentation,mechanism,and differential diagnosis of subcutaneous emphysema.

Pneumomediastinum and subcutaneous emphysema secondary to dental extraction:Two case reports

BACKGROUND Dental extraction is a common operation in oral surgery and is usually accompanied by pain,swelling,and local infection.The application of high-speed air turbines increases the comfort of alveolar surgery and makes it more minimally-invasive.However,high-speed gas can enter the subcutaneous tissue of the face and neck or even the chest and mediastinum,which is a serious iatrogenic complication.CASE SUMMARY We describe two cases of severe subcutaneous and mediastinal emphysema caused by high-speed turbine splitting during dental extraction.The first case involved a 34-year-old man who complained of swelling of the face,mild chest tightness,and chest pain after dental extraction.Computed tomography(CT)scan showed a large amount of gas in the neck,chest wall,and mediastinum.The second case involved a 54-year-old woman who complained of swelling and pain of the neck after dental extraction.CT showed a large amount of gas collected in the neck and mediastinum.Both of them used high-speed turbine splitting during dental extraction.CONCLUSION High-speed turbine splitting during dental extraction may lead to severe subcutaneous and mediastinal emphysema.Dentists should carefully operate to avoid emphysema.If emphysema occurs,CT can be used to improve the diagnosis.The patient should be informed,and the complications dealt with carefully.

Facial and Orbital Emphysema after a Violent Nose-Blowing

Subcutaneous orbital and facial emphysema is a rare condition that may occur after a direct or indirect sinus trauma. A case report of a 25-year-old female complaining of bilateral swelling of the eyelid, orbital area, and facial puffiness, secondary to a violent nose-blowing. Computed tomography (CT) confirmed the diagnosis of subcutaneous emphysema. The initial treatment plan was puncture-suction and prophylactic intravenous antibiotic therapy. The patient was advised to not blow her nose. There has been no improvement in the patient’s condition on the tenth day, so we performed a bilateral nasal packing by two Merocels (R), maintained for five days. After two weeks, the condition had completely resolved.

Carbon dioxide insufflation in esophageal endoscopic submucosal dissection reduces mediastinal emphysema: A randomized, double-blind, controlled trial

AIM To assess the efficacy of CO2 insufflation for reduction of mediastinal emphysema(ME) immediately after endoscopic submucosal dissection(ESD).METHODS A total of 46 patients who were to undergo esophageal ESD were randomly assigned to receive either CO2 insufflation(CO2 group, n = 24) or air insufflation(Air group, n = 22). Computed tomography(CT) was carried out immediately after ESD and the next morning. Pain and abdominal distention were chronologically recorded using a 100-mm visual analogue scale(VAS). The volume of residual gas in the digestive tract was measured using CT imaging. RESULTS The incidence of ME immediately after ESD in the CO2 group was significantly lower than that in the Air group(17% vs 55%, P = 0.012). The incidence of ME the next morning was 8.3% vs 32% respectively(P= 0.066). There were no differences in pain scores or distention scores at any post-procedure time points. The volume of residual gas in the digestive tract immediately after ESD was significantly smaller in the CO2 group than that in the Air group(808 m L vs 1173 m L, P = 0.013).CONCLUSION CO2 insufflation during esophageal ESD significantly reduced postprocedural ME. CO2 insufflation also reduced the volume of residual gas in the digestive tract immediately after ESD, but not the VAS scores of pain and distention.

Apoptosis of Alveolar Wall Cells in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Emphysema Is Involved in Emphysematous Changes

This study explored the role of apoptosis of alveolar wall cells of chronic obstructive pulmonary disease （COPD） patients with pulmonary emphysema in the pathogenesis of emphysema. The subjects were divided into three groups： COPD patients with pulmonary emphysema （COPD group）, asymptomatic smokers and non-smokers. Lung tissues were harvested and histologically assessed. TUNEL assay was employed to determine the ap＇optotic cells. The expression of PCNA, Bax and SP-C in the lung alveolar wall cells were immunohistochemically determined. SP-C immunofluorescence staining was used to identify type Ⅱ alveolar cells in the TUNEL-positive cells. The mean linear interval （MLI）, mean alveoli number （MAN） and mean alveoli area （MAA） in COPD group were significantly different as compared with those in asymptomatic smokers and non-smokers, respectively （P〈0.01）. The proliferation index （PI）, apoptosis index （AI） and the percentage of Bax-positive cells in COPD group were significantly greater than those of asymptomatic smokers and non-smokers （P〈0.01）. However, the percentage of SP-C-positive cells was significantly lower in COPD group than in asymptomatic smokers and non-smokers （P〈0.01）. Most of the TUNEL-positive cells expressed SP-C. In COPD group, the apoptosis of alveolar wall cells, especially apoptosis of type- Ⅱ cells, may take part in the pathogenesis of emphysema. Up-regulation of Bax expression may be responsible for the apoptosis of alveolar wall cells in the COPD patients with pulmonary emphysema.

Prophylactic Anti-inflammation Inhibits Cigarette Smoke-induced Emphysema in Guinea Pigs

In this study, the effect of prophylactic anti inflammation on the development of smoke induced emphysema was investigated. Young male guinea pigs aged 1.5 - 2 months (weighing 198.3±26.9 g) were randomly divided into 4 groups: group A (cigarette smoke exposure only), group B (cigarette smoke exposure plus pentoxifylline rich (PTX, 10 mg/d) forage feeding), group C (cigarette smoke exposure plus intermittent cortical steroid injection (Triamcinolone acetonide, 3 mg, im, every three weeks) and control group (group D: animals with sham smoke exposure, raised under the same conditions). Animals in group A, B and C were exposed to smoke of cigarettes for 1 to 1.5 h twice a day, 5 days a week. All animals were killed at the 16th week and followed by morphometrical analysis of the midsagittal sectioned lung slices. Smoke exposure of 16 weeks resulted in visible emphysematous development in Group A but not in Group B and C. It was evidenced by the indicator of air space size, mean linear intercept (L m): 120.6±16.0 μm in Group A; 89.8±9.2 μm in Group B and 102.4±17.7 μm in Group C. The average L m in either group B or group C was shorter than that in Group A (ANOVA and Newman Keuls test, F=8.80, P =0.0002) but comparable to that (94.8±13.2 μm) in group D ( P >0.05). It is concluded that long term prophylactic anti inflammation inhibits pulmonary emphysema induced by cigarette smoking in the guinea pigs.

Single-lung transplantation in emphysema:Retrospective study analyzing survival and waiting list mortality

AIM: To performed remains a subject of debate and is the principal aim of the study. METHODS: This retrospective analysis included 73 patients with emphysema(2000-2012). The outcomes of patients undergoing single-lung transplantation(SL)(n = 40) or double-lung transplant(DL)(n = 33) were compared in a Cox multivariate analysis to study the impact of the technique, postoperative complications and acute and chronic rejection on survival rates. Patients were selected for inclusion in the waiting list according to the International Society of Heart Lung Transplantation criteria. Pre and postoperative rehabilitation and prophylaxis, surgical technique and immunosuppressive treatment were similar in every patients. Lung transplantation waiting list information on a national level and retrospective data on emphysema patient survival transplanted in Spain during the study period, was obtained from the lung transplantation registry managed by the National Transplant Organization(ONT). RESULTS: Both groups were comparable in terms of gender and clinical characteristics. We found significant differences in the mean age between the groups, the DL patients being younger as expected from the inclusion criteria. Perioperative complications occurred in 27.6% SL vs 54% DL(P = 0.032). Excluding perioperative mortality, median survival was 65.3 mo for SL and 59.4 mo for DL(P = 0.96). Bronchiolitis obliterans and overall 5-year survival were similar in both groups. Bacterialrespiratory infection, cytomegalovirus and fungal infection rates were higher but not significant in SL. No differences were found between type of transplant and survival(P = 0.48). To support our results, national data on all patients with emphysema in waiting list were obtained(n = 1001). Mortality on the waiting list was 2.4% for SL vs 6.2% for DL. There was no difference in 5 year survival between 235 SL and 430 DL patients transplanted(P = 0.875).CONCLUSION: Our results suggest that SL transplantation in emphysema produce similar survival than DL with less postoperative complication and significant lower mortality in waiting list.

Pneumomediastinum, pneumorachis, subcutaneous emphysema: An unusual complication of leukemia in a child

Pneumorrhachis(PR), or epidural emphysema, denotes the presence of air in the spinal epidural space. It can be associated with a variety of etiologies, including trauma; recent iatrogenic manipulations during surgical, anesthesiological and diagnostic interventions;malignancy and its associated therapy. It usually represents an asymptomatic epiphenomenon but also can be symptomatic by itself, as well as by its underlying pathology, and rarely can be fatal. The pathogenesis and etiology of PR are varied and can sometimes be a diagnostic challenge. As such, there are no standard guidelines for the management of symptomatic PR and its treatment is often individualized. Here, we present a case of a 14-year-old boy treated for leukemia who developed this complication and whether chemotherapy related or not, it proved to be fatal for him. To our knowledge, this is the first case in the literature of this complication with acute lymphoblastic leukemia.

Pulmonary fibrosis and emphysema: Is the emphysema type associated with the pattern of fibrosis?

AIM: To investigate whether the predominant emphysema type is associated with the high resolution computed tomography(HRCT) pattern of fibrosis in combined pulmonary fibrosis and emphysema(CPFE).METHODS: Fifty-three smokers with upper lobe emphysema and lower lobe pulmonary fibrosis on- HRCT-were retrospectively evaluated. Patients were stratified into 3 groups according to the predominant type of emphysema: Centrilobular(CLE), paraseptal(PSE), CLE = PSE. Patients were also stratified into 3 other groups according to the predominant type of fibrosis on HRCT: Typical usual interstitial pneumonia(UIP), probable UIP and nonspecific interstitial pneumonia(NSIP). HRCTs were scored at 5 predetermined levels for the coarseness of fibrosis(Coarseness), extent of emphysema(emphysema), extent of interstitial lung disease(Tot Ext ILD), extent of reticular pattern not otherwise specified(Ret NOS), extent of ground glass opacity with traction bronchiectasis(extG GOBx), extent of pure ground glass opacity and extent of honeycombing. HRCT mean scores, pulmonary function tests, diffusion capacity(DLCO) and systolic pulmonary arterial pressure were compared among the groups.RESULTS: The predominant type of emphysema was strongly correlated with the predominant type of fibrosis. The centrilobular emphysema group exhibited a significantly higher extent of emphysema(P < 0.001) and a lower extent of interstitial lung disease(P < 0.002), reticular pattern not otherwise specified(P < 0.023), extent of ground glass opacity with traction bronchiectasis(P < 0.002), extent of honeycombing(P < 0.001) and coarseness of fibrosis(P < 0.001) than the paraseptal group. The NSIP group exhibited a significantly higher extent of emphysema(P < 0.05), total lung capacity(P < 0.01) and diffusion capacity(DLCO)(P < 0.05) than the typical UIP group. The typical UIP group exhibited a significantly higher extent of interstitial lung disease, extent of reticular pattern not otherwise specified, extent of ground glass opacity with traction bronchiectasis, extent of honeycombing and coarseness of fibrosis(0.039 > P > 0.000). Although the pulmonary arterial pressure was higher in typical UIP group relative to the NSIP group, the difference was not statistically significant.CONCLUSION: In CPFE patients, paraseptal emphysema is associated more with UIP-HRCT pattern and higher extent of fibrosis than centrilobular emphysema.

Massive surgical emphysema following transanal endoscopic microsurgery

We describe an impressive and rare case of surgical emphysema after minimally invasive rectal surgery. This case reports on a patient who developed mas-sive retroperitoneal, intraperitoneal and subcutaneous emphysema directly following a transanal endoscopic microsurgery(TEM) procedure for a rectal intramuco-sal carcinoma. Free intra-abdominal air after gastro-intestinal surgery can be a sign of a bowel perforation or anastomotic leakage. This is a serious complication often requiring immediate surgery. In our patient an abdominal computed tomography-scan with rectal con-trast showed no signs of a rectal perforation. Therefore this emphysema was caused by the insufflation of CO2 gas in the rectum during the TEM-procedure. Conserva-tive treatment resulted in an uneventful recovery. With the increasing usage of TEM for rectal lesions we ex-pect this complication to occur more often. After ruling out a full thickness rectal wall perforation in patients with surgical emphysema following TEM, conservative treatment is the treatment of choice.

Use of a mathematical model of autopoietic maintenance of pulmonary alveolar integrity to show a possible relationship between epithelial-mesenchymal transition and the genesis of emphysema and fibrosis

Rationale: There is accumulating evidence that a group of stem/progenitor cells (SPCs) maintain alveolar epithelial integrity. Pulmonary emphysema is characterized by the histological finding of the loss of alveolar epithelial integrity along with corresponding bronchiolar fibrosis. Objectives: Based on the concept of autopoiesis (the capacity to produce oneself), we proposed a mathematical model in the maintenance of alveolar epithelial integrity as related to the genesis of pulmonary emphysema and fibrosis. Methods: A tessellation automaton model was used to describe the autopoietic dynamics of the bronchiolo-alveolar epithelial surface. The alveolar septal volume en-closed by the epithelial surface is a distributed system of discrete elements, which move by random walk in the manner of Brownian motion. Assuming that the numbers of components and events in the automaton are large, an approximate theoretical treatment in terms of differential equations is possible, allowing a set of partial differential equations to be produced. Results: 1) Assuming the loss of progenitor cells through the epithelial-mesenchymal transition (EMT), a sharp bifurcation between two qualitatively distinct regions of the phase space (one that is repaired completely, and another that has disappeared entirely) clearly appeared. 2) Thus, from the system of discrete and spatial partial differential equations, we obtained a system of ordinary differential equations in equilibrium conditions that defined a close relationship between the degree of emphysema, the density of alveolar septal fibroblasts, and the mean concentration of SPCs. Conclusions: A mathematical model of the autopoietic maintenance of the alveolar epithelial surface suggested a close relationship between alveolar emphysema and fibrosis and EMT in lungs affected by chronic obstructive pulmonary disease.

Influence of tidal-volume setting, emphysema and ARDS on human alveolar sacs mechanics

Mechanical ventilation (MV) devices help patients with lung disorders to breathe.Improper setting for MV devices lead to further lung injuries.Therefore,investigating influence of ventilator device settings on healthy and diseased alveolar sacs mechanics could prevent injuries while in use.To this aim,three-dimensional (3D) models for healthy and emphysematous alveolar sacs with and without acute respiratory distress syndrome (ARDS) were developed,and computational fluid dynamics (CFD) analysis and fluid-solid interaction (FSI) approach were employed to study the influence of alveolar sacs wall motion,tidal volume (TV) setting and disease on alveolar sac mechanics.The recirculation region was only monitored in alveolar sacs with rigid wall.Observations demonstrated an increase in compliance during air inhalation into the emphysematous alveolar sacs.Induced air penetrated deeper into healthy alveolar sacs compared to the emphysematous model and recommended TV for chronic obstructive pulmonary disease (COPD) increased applied strain,stress and wall shear stress (WSS) on emphysematous alveolar sacs.In addition,recommended TVs for patients with ARDS decreased strain and stress,but did not influence applied WSS significantly.In general,increasing TV raised stress and strain level and led to deeper air penetration into the alveolar sacs.Afterwards,lower TV decreased strain,stress and WSS for patients who had both ARDS and emphysema.This study can provide invaluable insights about diseased alveolar sacs mechanics and evaluate importance of ventilator devices setting in different disease conditions.

Emphysematous Complications Following Third Molars Removal: Incidence among 10779 Surgeries and Report of Two Cases

Subcutaneous emphysema is a condition that results from introduction of air into soft tissues. In head and neck, it is commonly observed following fractures of paranasal sinuses. Less frequently, it may occur during surgical procedures for tooth removal, when air from dental hand-pieces is forced into surgical site. Depending on its extension, it may involve vital spaces such as mediastinum. This specific finding may induce life-threatening situations. The aim of this article is to establish the incidence of subcutaneous emphysema among 10,779 impacted third molar surgical procedures and report the cases in which such complications had occurred. In this retrospective study, data collected from 10,779 third molar extraction procedures performed at Piracicaba School of Dentistry were evaluated for the occurrence of subcutaneous emphysema. Two cases of subcutaneous emphysema (0.018%) occurred following extraction of impacted third molars. Both were associated with mandibular tooth and related to the use of dental air hand-piece. One of the cases involved submandibular and buccal spaces while the other involved buccal and canine spaces. Regression of emphysema occurred spontaneously and postoperative recovery was uneventful. Subcutaneous emphysema following impacted third molar extractions is rare and strongly associated with the use of air turbines. Follow-up and preservation are the treatments of choice, but clinicians should be aware about the possibility of microbial spreading through facial spaces.

Dynamic Expression of Tumor Necrosis Factor-α and Vascular Endothelial Growth Factor in Rat Model of Pulmonary Emphysema Induced by Smoke Exposure

In order to explore the roles of tumor necrosis factor-α （TNF-α） and vascular endothelial growth factor （VEGF） in the pathogenesis of pulmonary emphysema, male Wistar rats were randomized into group At, group A2.5 and group A4, each with smoke exposure for 1 month, 2.5 months or 4 months, respectively. Group B t, group B2.5 and group B4 were used as non smoking controls at corresponding time points. TNF-α in bronchoalveolar lavage fluid （BALF） and expression of VEGF in lung tissue was determined by ELISA or by SABC immunohistochemistry assay either. Lung slices were stained with hematoxylin and eosin （HE）. Results showed that in animal with smoke exposure the mean linear interceptor （Lm）, an index of pulmonary emphysema and the content of TNF-α in BALF increased gradually, on contrary, the expression of VEGF in lung tissue decreased （P〈0.05）. This phenomenon was not obvious in animals without smoke exposure. Lm was negatively correlated to the VEGF expression （7=--0.81, P〈0.01） and positively correlated to TNF-α concentration （7 = 0.52, P〈0.004）, which implies that smoke exposure decreased the expression of VEGF and increased the expression of TNF-α. It is plausible to speculate that the imbalance of TNF-α and VEGF may play an important role in the pathogenesis of smoke-induced pulmonary emphysema.

Effects of Bilirubin on Alveolar Macrophages in Rats with Emphysema and Expression of iNOS and NO in Them

To explore the effects of bilirubin on alveolar macrophages (AM) and expression of iNOS and NO in them in emphysema model, the rats were pretreated with bilirubin before exposed to smoke. AM were isolated from bronchoalveolar lavage fluid (BALF) and cultured. Pathological microscopic examination of AM and immunohistochemical analysis of iNOS were performed. Nitric oxide (NO) content in the samples was determined by nitrate reductase technique. The results showed both alveoli and alveolar septum appeared normal in size and shape in normal group. AM showed kidney-shaped nucleus and were rich in Golgi complexes and primary lysosomes in the cytoplasm. The inner membrane of mitochondrion was continuous. Most cristae of the mitochondria were intact. In model group, the alveoli were expanded, ruptured and bullaes were formed. Both the population and sizes of AM increased significantly. Secondary lysosomes were rich in the cytoplasm. Deformation and pyknosis of the nucleus, swelling of the mitochondrions and rupture of the inner mitochondrial membrane could also be seen. At high magnification, most of the mitochondrial cristae were broken, or completely lost at certain points. In bilirubin group, alveoli partly expanded and the population of AM also increased, with morphological changes being slighter than that in model group. Both NO contents and expression of iNOS in model group were higher than those in normal group (P<0.05). In bilirubin group the two indice were lower than those in model group (P<0.05). Our findings suggested that high expression of iNOS and high NO content in AM accelerate the development of emphysema associated with smoking in rats. Bilirubin may exert protective effects on AM and retards the development of emphysema in rats.

Investigation of the Effects of Emphysema and Influenza on Alveolar Sacs Closure through CFD Simulation

Emphysema and influenza directly affect alveolar sacs and cause problems in lung performance during the breathing cycle. In this study, the effects of Emphysema and Influenza on alveolar sac’s air flow characteristics are investigated through Computational Fluid Dynamics (CFD) simulation. Both normal and Emphysemic alveolar sac models with varying collapsed volumes resulting from influenza virus replication were developed. Maximum, area average pressure, and wall shear stress (WSS) in collapsed and open alveolar sacs models were compared. It was found that a collapse at half of the volume at the bottom of the alveolar sacs’ models would cause a decrease in average and maximum pressure values and yield higher WSS values for fluid flow during the breathing cycle. On the other hand, a quarter volume collapse at the bottom and side of the model resulted in higher values for average and maximum pressure and WSS. Additionally, results also showed that a combination of alveolar sacs closure and Emphysema would generally lead to an increase in fluid pressure and average WSS during breathing. Maximum WSS was observed during exhalation and maximum WSS decrease occurred during inhalation. Findings are in good agreement with previous studies and suggest that emphysema and influenza virus affect fluid flow and may contribute to alveolar sac closure. However, more realistic simulations should include the fluid-solid interaction studies.

Effects of Shenmai and Aminophylline on Apoptosis of Small Airway Smooth Muscle Cells and the Expression of Relevant Genes in Rats with Emphysema

The effects of Shenmai injection (SMI) and am inophylline on apoptosis of sm all airway smooth muscle cells (SASMC) and the Fas/ Fas L expression in rats with papain- induced em physe- ma were investigated.Rat emphysema model was established by a single intratracheal instillation of papain.Apoptosis and Fas/Fas L expression of SASMC were detected by im munohistochemistry SABC and TU NEL assay at day1,3,5 ,7,15 ,30 after modeling,and the effect of SMI and am inophylline on them were observed.The results indicated that the Fas/Fas L expression positive rate in SASMC was2 .31± 0 .5 5 /1.2 8± 0 .4 7respectively.After a single intratracheal instillation of papain,the expression of Fas/Fas L positive rate in the placebo group was increased in a tim e- dependent manner.SMI could inhibit the expression of Fas/ Fas L ,but aminophylline couldn't. The positive rate of apoptosis in the control group was 0 .87± 0 .32 .After a single intratracheal in- stillation of papain,the SASMC apoptosis positive rate in the placebo group was increased in a tim e- dependent manner.The SASMC apoptosis rate in all groups was declined after treatment with SMI,but the effect of am inophylline was notobvious.Itwas dem onstrated thatin the patho- genesis of emphysem a Fas/Fas L played an important role in the regulation of SASMC apoptosis. SMI influenced the expression of Fas/ Fas L and declined SASMC apoptosis by inhibiting the releas- ing of inflamm atory m edia and played an im portant role in the therapy of em physema.