[The Feasibility and Repeatability of Ultrasound Microbubble Angiography in the Determination of Pulmonary Blood Volume in Animal Models].

OBJECTIVE: To investigate the feasibility of measuring pulmonary blood volume (PBV) by ultrasound microbubble angiography, which may provide a feasible method for further detection of PBV changes. METHODS: Ultrasound microbubble angiography was used to calculate the PBV by detecting pulmonary transit time (PTT) and heart rate-normalized pulmonary transit time (nPTT). To evaluate the consensus degree based on the intra-, inter-observer and within-day variation in order to determine the repeatability. The method was used for acute left ventricular dysfunction models to determine the feasibility as well. RESULTS: The Bland-Atlman plots showed good intra-observer, within-day, and inter-observer consistency of measurement results. Application in acute left ventricular dysfunction models showed that, compared with the control, left heart failure models had higher PTT, nPTT and PBV ( P<0.05). CONCLUSION: Detection of PTT/nPTT to calculate PBV by ultrasound microbubble angiography is simple and feasible, it is not easy to produce miscarriage of justice, with good intra- and inter-observer consistency of repeatability test results. The method has certain feasibility.

[Correlation of Krebs Von Den Lungen-6（KL-6） Expression and Perioperative Pulmonary Function in Adults Receiving Continuing Low-volume Ventilation during Valve Surgery].

OBJECTIVE: To investigate the influence of continuous low-volume ventilation in cardiopulmonary bypass (CPB) on the expression of krebs von den lungen-6 (KL-6) and perioperative pulmonary function in adults undergoing valve surgery. METHODS: From 2017 Sept. to 2018 Jan., 60 patients who received valve replacement surgery were prospectively comprised in this study. We randomly allocated these patients into control group ( n=30, non-ventilation) and experimental group ( n=30, continuous low-volume ventilation during CPB). At different perioperative time points, we identified the dynamic changes of pulmonary function and biomarkers which expressed in serum and bronchoalveolar lavage fluid (BALF). Meanwhile, we also compared perioperative clinical outcomes of the two groups. RESULTS: The expression of serum KL-6 and BALF KL-6 in the two groups were both statistically significant（ P＜0.05）. The oxygenation index increased with time and reached to the top point at T 1, then subsequently decreased with time ( P＜0.05). The alveolar-arterial oxygen tension difference (P A-aO 2) in the two groups fluctuate with time, the differences have no statistical significance. According to linear correlation, the serum KL-6 level was negatively correlated with oxygenation indexes ( r=－0.525, P=0.003), while it was positively correlated with P A-aO 2 ( r=0.489, P=0.006). There were no significant differences between the two groups in clinical outcomes. CONCLUSION: Continuing low-volume ventilation during CPB could decrease the expression level of KL-6, while it has no significant influence on perioperative outcomes.

[Risk Factors for Adverse Aortic Remodeling in Post-TEVAR Patients with Acute Stanford B Aortic Dissection].

OBJECTIVES: To assess morphological changes of distal aorta and the risk factors for adverse aortic remodeling inpost-TEVAR（thoracic endovascular aortic repair） patients with acute Stanford B aortic dissection. METHODS: We retrospectively investigated the patients who underwent TEVAR for a type B dissection between October 2005 and December 2015. CT angiogram (CTA) was obtained for each patients preoperatively, postoperatively and during the post-operational follow-up. Based on Criadol partition principle, we divided the aorta into descending thoracic aorta area, suprarenal abdominal aorta area, infrarenal abdominal aorta area and iliac artery area, and evaluated the distribution of aortic tears and the form of true and false lumen in different aortic partition. Univariate and multivariate logistic regression analyses were used to analyze the risk factors affecting distal aortic remodeling. RESULTS: Of 216 patients (mean follow-up (3.9±2.1) years) who were regularly followed up in our center, 47 patients (21.8%) occurred adverse remodeling in distal aorta. Univariate logistic regression indicated that abnormal aortic wall structure (Marfan's syndrome) and patent false lumen (existence of distal tears, decreased complete false lumen thrombosis) were associated with distal aortic adverse remodeling. Multivariate logistic regression showed that more tears in descending thoracic aorta area ( OR=1.36, 95% CI=1.12-1.58, P=0.005) and less tears in infrarenal abdominal aorta area ( OR=0.49, 95% CI=0.22-0.71, P<0.001) were independent risk factors affecting remodeling in distal aorta after TEVAR. CONCLUSIONS: Aortic wall structure abnormalities, a patent false lumen, more tears in descending thoracic aorta area, less tears in infrarenal abdominal aorta area are independent risk factors for adverse aortic remodeling in post-TEVAR patients with acute Stanford B aortic dissection.

Aortoesophageal fistula and arch pseudoaneurysm after removing of a swallowed chicken bone: a case report of one-stage hybrid treatment.

BACKGROUND: Aortoesophageal fistula (AEF) and arch pseudoaneurysm are rare complications induced by a foreign body, and considerable controversy remains regarding the appropriate management strategies. We herein report a successful one-stage hybrid treatment in a patient with AEF and arch pseudoaneurysm. CASE PRESENTATION: The patient, a 40-year-old man, presented to the emergency room because of intense retrosternal discomfort for 3 days and hematemesis for 3 h. The esophagoscopy and thoracic enhanced computed tomography (CT) showed two irregular mural ulcers in the esophagus and a large saccular pseudoaneurysm at the aortic isthmus, respectively. The laboratory examinations confirmed no widespread inflammation and infection. We have successfully performed a successful one-stage hybrid treatment for this patient. Six-month follow-up shows the patient is in good condition and the esophagoscopy reveals the two mural ulcers had completely healed. CONCLUSION: The treatment decision-making process should depend upon the patients' specific situations. Our case suggest the one-stage hybrid treatment could be an valuable alternative in some selected patients.

[Effects of Restrictive Transfusion on the Outcome of Mitral Valve Replacement].

OBJECTIVE: To investigate effects of restrictive transfusion on the outcome of mitral valve replacement. METHODS: We selected 120 continuous patients of mitral valve replacement from June 2011 to June 2016. Based on the different blood transfusion strategy,the patients were divided into two groups: liberal blood transfusion group and restrictive blood transfusion strategy group. The blood routine test,liver and kidney function,coagulation function,full examination before blood transfusion,blood types,echocardiography and so on were examined when the patients were admitted to hospital,also the clinical data of perioperative patients were recorded,and blood transfusion volume,major complication and mortality were compared between the two groups. RESULTS: The transfusion volume of red blood cells decreased from (3.2±1.1) to (1.8±1.5) U with restrictive transfusion,the difference was statistically significant (P=0.01),while plasma volume increased from (325.7±96.5) mL to (385.2±86.2) mL (P=0.04). There were differences in major complications between the two groups (39.2% vs. 31.7%,P=0.04),especially for respiratory-related complications such as the proportion of using ventilator >24 h (P=0.03),total time using ventilator (P=0.03),lung infection rate (P=0.04). The restrictive transfusion group had better outcome with less cost of hospitalization. The mortality was not different (P>0.05). CONCLUSION: Restrictive transfusion strategy reduces the incidence of major complications in patients of mitral valve replacement with less cost.

[The Clinical Evaluation of Prosthetic Valve in Patients with Dysfunction Valve Endocarditis].

OBJECTIVE: To evaluate the outcomes of valve replacement of endocarditis using bioprothetic and mechanical valves. METHODS: This study comprised 52 patients [mean age (47±18) yr.,mean follow-up time (6.2±3.8) years] underwent valve endocarditis with bioprotheses,The control group were matched (3∶1) with 156 patients of endocarditis underwent mechanical valves replacement using the following variables: age±5 yr.,body mass index (BMI)±20%,time of operation±1 year,replacement position and sex ratio. And evaluate the effects of using bioprothetic and mechanical valves on perioperative and long-term outcomes of valve replacement of endocarditis. RESULTS: The perioperative mortality of the patients receiving bioprothetic and mechanical valves were 17.3%±2.2% and 19.9%±1.8%,respectively,which was independent of valve type (P=0.27). Long-term survival were 56.1%±5.2% and 61.2%±8.1%,respectively (P=0.58). Meanwhile,long-term complication-free survival were 75.0%±3.2% and 82.3%±4.4%,respectively (P=0.29). For the patients younger than or equal to 60 yr.,long-term reoperation rates for bioprothetic and mechanical valves were 41.4%±7.2% and 30.5%±5.4% (P=0.02). For the patients older than 60 yr.,however,reoperation rates were 24.1%±8.5% and 14.7%±5.7% (P=0.36). CONCLUSION: Perioperative mortality and long-term survival are independent to valve types in patients with endocarditis. Mechanical valve shows potential advantage compared with bioprothetic valve in the patients younger than 60-year-old.

[Application of Biological Heart Valves (BHV) and Mechanical Heart Valves (MHV) in the Female Patients of Childbearing Age: a Matched Paired Study].

OBJECTIVE: To observe the efficacy and safety of biological heart valves (BHV) and mechanical heart valves (MHV) in childbearing age women (CAW) during the perinatal and short-moderate term postoperative (SMTP) periods. METHODS: There were 33 patients [(25.2±7.1) yr.] undergoing BHV replacement from September 2009 to December 2014 had completely followed-up,whose data were retrospectively collected. A 1∶4 matching study was conducted,therefore there were 132 patients undergoing MHV were included. The collected date included the clinical outcomes in the perioperative, perinatal,and SMTP period event-free survival (EFS) was determined using the Kaplan-Meier method and compared using the log-rank test. RESULTS: The average follow-up time was (5.8±3.6) years,and the two groups had similar baseline . The clinical outcomes difference of perinatal and SMTP between the two groups were not significant. There were 17 patients in BHV group and 60 in MHV group with pregnancy and birth experiences (PBE),which also showed no significant difference for adverse events both in the maternity and in the fetus. The rates of valve-related adverse events of BHV replacement patients with and without PBE were 5.9% and 0% at 3 years after the operation, and 11.8% and 5.9% after 5 years. PBE was not identified as an adverse prognostic factor for EFS (P=0.43). CONCLUSION: Either artificial BHV or MHV replacement can achieve ideal SMTP effect in CAW. BHV seems not superior to MHV. Pregnancy and birth experience will not increase the risk of BHV relevant adverse events.

[Risk Factors Associated with the Outcomes of Heart Valve Replacement].

OBJECTIVE: To determine risk factors associated with the outcomes of heart valve replacement,especially in the patients with rheumatic heart disease (RHD). METHODS: Data were extracted from 2 696 patients who received valve replacement from August 2012 to January 2015. Spearman correlation analyses were performed to identify potential risk factors. Logistic regression models were established to determine risk factors associated with deaths and complications. RESULTS: Duration of cardiopulmonary bypass (CPB) [standard partial regression coefficient ( B')=0.418],heart function ( B'=0.344) and pulmonary hypertension ( B'=0.285) were significant predictors of deaths in hospitals. The prevalence of complications was associated with heart function ( B'=0.520),pulmonary hypertension ( B'=0.365),CPB duration ( B'=0.306),diabetes ( B'=0.129),left ventricular diameter ( B'=0.118) and pulmonary regurgitation B'=0.071). For patients with RHD,significant predictors of complications included heart function ( B'=0.578),pulmonary hypertension ( B'=0.401),CPB duration ( B'=0.305) and diabetes ( B'=0.143). Left ventricular ejection fraction was not significant in the regression models. CONCLUSION: Chronic renal failure,heart function and CPB duration are associated with postoperative deaths in patients with heart valve replacement,while diabetes,heart function and pulmonary hypertension are significant predictors of postoperative complications. For RHD patients,diabetes,heart function and pulmonary hypertension are major risk factors associated with postoperative complications.

[Correlation Between Serum Concentrations of Catecholamines and Oxygen Index in Acute Aortic Dissection].

OBJECTIVES: To explore whether the serum concentration of adrenaline (AD) and noradrenaline (NA) elevate and its correlation with oxygenation index (OI) in the patients of acute aortic dissection (AAD). METHODS: From April 2013 to December 2013, clinical data were collected from three groups of patients (38 cases of AAD in Group A, 28 cases of ascending aortic aneurysm in Group B, and 22 cases of angina in Group C). All patients received the measurement of serum concentrations of AD, NA and endotoxin (ET). Linear correlation was used to analyze the relationships between catecholamines (including AD and NA), ET and OI. RESULTS: The baseline of the three groups showed no significant difference. The serum concentrations of AD, NA and ET in Group A were higher than those in Group B and Group C ( P<0.01), white OI was lower than that in Group B and Group C ( P<0.001). In the patients with AAD, the serum concentrations of AD and NA were positively correlated with ET, while both were negatively correlated with OI. CONCLUSIONS: Higher serum concentrations of AD and NA correlated with more severe acute lung injury in AAD patients.

[The Role of Bone Morphogenic Protein-4 in the Progression of Vein Graft Hyperplastic Remodeling under Hyperglycemic Condition].

OBJECTIVE: This study was designed to assess the vessel wall characteristics and the expression levels of bone morphogenic protein4(BMP4) and proliferating cell antigen Ki67 in vein grafts harvested from diabetic rats,and to investigate the role of BMP4 in progression of vein graft hyperplastic remodeling under hyperglycemic condition. METHODS: 48 male SpragueDawky rats [body mass (194±16) g] aged 8 weeks were randomly divided into diabetes mellitus (DM) group ( n=24) and nondiabetes mellitus (NDM) group ( n=24). The DM rats were induced by streptozotocin in combination with highsugar and highfat diet. The unilateral external jugular vein was interposition grafted into the common carotid arteries in the two groups. The vein grafts were harvested at preoperatively and 1,2 and 4 weeks postoperatively ( n=6) in each group. The morphological characteristics of the venous graft wall were evaluated by hematoxylineosin staining,and the expression levels and the distribution of Ki67 and BMP4 were assessed by immunohistochemistry analysis,then the expression of BMP4 gene and protein was measured by realtime polymerase chain reaction (RTPCR) and Western blot assay respectively. RESULTS: In the progression of rats vein grafts hyperplastic remodeling,the venous wall thickness of rats thickened with time increasing,and the intimal and medial thickness of the vein grafts harvested from DM rats were significantly higher than those from NDM rats at the same time postoperatively ( P<0.05). Ki-67 was highly xpressed in smooth muscle cells nucleus located in the rats vein grafts,and its expression level was up-regulated gradually in the progression of vein graft failure,and the Ki 67 positive cells of vein grafts from DM rats were significantly higher than those from NDM controls at the same period ( P<0.05). Immunohistochemistry analysis showed that BMP4 was expressed in smooth muscle cells cytoplasmof the rats vein grafts,combined with the results of RT-PCR and Western blot assay,there was a little BMP4 expression could be seen in venous wall of NDM rats,while BMP4 positive cells and the expression level of BMP4 gene and protein from DM rats vein grafts was increasing with obvious time dependence and significantly higher than the NDM rats ( P<0.05). CONCLUSION: The morphological and pathological changes within the venous wall were significantly correlated with the high expression levels of BMP4 in vein grafts harvested from diabetic rats,implying a potential role of BMP4 in the progression of accelerated vein graft failure under hyperglycemic condition.

Sternal fractures and delayed cardiac tamponade due to a severe blunt chest trauma.

Sternal fractures caused by blunt chest trauma are associated with an increased incidence of cardiac injury. Reports of the incidence of cardiac injury associated with sternal fracture range from 18% to 62%. Delayed cardiac tamponade is a rare phenomenon that appears days or weeks after injury. Moreover, after nonpenetrating chest trauma, cardiac tamponade is very rare and occurs in less than 1 of 1000. This case describes a patient who had delayed cardiac tamponade 17 days after a severe blunt chest trauma.

[Epigallocatechin-3-gallate Attenuates Myocardial Reperfusion Injury in Rats Through Activation of PI3K/Akt Signaling Pathway].

OBJECTIVE: This study was designed to investigate whether epigallocatechin-3-gallate (EGCG) postconditioning protects the heart against ischemic-reperfusion injury (IRI), and to explore its potential mechanisms in a rat model. METHODS: Male Wistar rats were subjected to myocardial ischemia (30 min) and reperfusion (up to 2 h) and the rats were divided into sham group (SO) group, ischemia-reperfusion (I/R) model group and EGCG group. EGCG group were treated with EGCG (10 mg/kg) via intravenous infusion 5 min before reperfusion. Electrocardiogram were applied to record ventricular arrhythmia frequency. The severity of myocardial injury [serum level of lactate dehydrogenase (LDH) and creatine kinase (CK), hematoxylineosin (HE) staining] and ventricular arrhythmia, and the serum levels of inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukins-6 (IL-6) and IL-8] were assessed with ELISA, electrocardiogram and Western blot respectively. RESULTS: EGCG given before reperfusion could effectively reduce the serum level of LDH and CK and the incidence of ventricular arrhythmia (P < 0.05, respectively), improved the pathological damage. Meanwhile, EGCG could down-regulate the expression levels of TNF-α, IL-6, IL-8 in the myocardial tissue after IRI (P < 0.05, repectively). The expression levels of p-p85 and p-Akt in the EGCG group were significantly up-regulated compared to those in I/R group (P < 0.05, repectively). CONCLUSION: EGCG-related anti-inflammatory action could attenuate rat myocardial IRI and this cardioprotective effect might be activated through the PI3K/Akt pathway.

[The Association Between Bone Morphogenic Protein-4 and in-situ Saphenous Vein Graft Pathology in Diabetic Patients Undergoing Coronary Revascularization].

OBJECTIVES: This study was designed to assess the expression levels of bone morphogenic protein-4 (BMP4) in saphenous veins harvested from diabetic patients undergoing coronary artery bypass grafting (CABG), and to investigate its association with in-situ morphological and pathological changes within the venous wall. METHODS: From January 2013 to December 2014, forty patients with type 2 diabetes mellitus (DM) and risk factors matched non-DM controls (n =40) were enrolled prospectively. Of the 40 DM patients, 24 had noninsulin-dependent diabetes (NIDM) and the remaining 16 had insulin-dependent diabetes (IDM). Segments of saphenous vein without surgical dilatation from these 80 patients were obtained. Vessel wall characteristics were evaluated by hematoxylin-eosin (HE) staining, and the expression and distribution of BMP4 was assessed by Western blot assay and immunohistochemistry analysis. RESULTS: The intimal and medial thickness of the saphenous veins harvested from DM patients were higher than those from non-DM controls. Compared with non-DM patients, the expression level of BMP4 was significantly elevated in diabetic veins ( P<0.05), and BMP4 was highly expressed in smooth muscle cells located in the medial layer. Moreover, the expression levels of BMP4 in diabetic veins were significantly correlated with intimal thickness (r =0.655, P<0.01), intimal area (r =0.684, P<0.01), medial thickness (r =0.642, P<0.01) and medial area (r =0.692, P<0.01). CONCLUSIONS: The pre-existing intimal and medial hyperplasia were significantly correlated with the high expression levels of BMP4 in saphenous veins harvested from diabetic patients, implying a potential role of BMP4 in the progression of vein graft stenotic diseases in this cohort of post-CABG patients. Future studies were warranted in investigating novel therapeutic strategy targeting at BMP4 for improving long-term vein graft patency.

[Clinical significances of plasma interleukin-6,C-reaction protein and tumor necrosis factor-alpha in patients with aortic dissection].

OBJECTIVE: To investigate the clinical significances of plasma IL-6, CRP and TNF-alpha concentration changes in aortic dissection. METHODS: Plasma concentrations of IL-6, TNF-alpha and CRP were determined in 68 aortic dissection patients,50 patients with essential hypertensionand 50 healthy volunteers. The changes of plasma IL-6, CRP and TNF-alpha concentration were analyzed in aortic group along with the progression of the disease which was divided into 9 differenttime courses. RESULTS: Compared with essential hypertension and healthy control group, significantly elevated CRP, IL-6 and TNF-alpha concentrations were detected in aortic dissection patients (P<0.05, respectively). All the concentrations of CRP, IL-6 and TNF-alpha reached the peak in acute phase of aortic dissection and then gradually declined in subacute and chronic phase. CONCLUSION: Increased plasma inflammatory factors were significantly associated with aortic dissection.

[Proximal Aorta Reconstruction for Type A Aortic Dissection Patients without Intimal Tear in Aortic Arch: the Early and Mid-outcomes].

OBJECTIVE: To evaluate the early and mid-outcomes of proximal aorta reconstruction for type A aortic dissection (AAD) patients without intimal tear in aortic arch, and assess the safety and efficacy of this surgical strategy. METHODS: From January 2010 to February 2013, there were 23 AAD patients without intimal tear in the aortic arch received proximal aorta reconstruction surgery. Clinical data of these patients were analyzed retrospectively, the mean age was (48.04 ± 12.37) years old (21-73 yr.). Twelve cases were acute aortic dissection, the others were chronic dissection. Bentall surgery was performed for 13 cases, Cabrol surgery for 2 cases, Wheat surgery for 1 case, ascending aorta replacement and aortic valve repair was employed for 1 patient, simple ascending aorta replacement for 6 cases. The patients received follow-up every 3 to 6 months after the surgery. RESULTS: The duration of CPB time was (182.83 ± 36.98) min, cardiac arrest time was (111.87 ± 18.82) min, circulatory arrest time was (24.22 ± 6.38) min. The complications were lung infection (4 cases, 17.4%), tracheotomy (2 cases), peritoneal dialysis (1 case), 2 cases suffered transient neurological dysfunction. None stroke, paralysis, and permanent neurological dysfunction occurred. All the patients were discharged. Mean time of follow-up was (38.35 ± 11.95) months (18-56 months). All patients were alive and return to normal life, the proportion of false lumen closure was 65.22% (15 cases). None patients need secondary surgery. CONCLUSION: Proximal aorta reconstruction is safe and effective for AAD patient without intimal tear in aortic arch, the operation strategy can be used individually.

[Mid-long-term clinical results and hemodynamic evaluation of aortic valve replacement with 17 mm St. Jude medical regent valve].

OBJECTIVE: To investigate the mid-long-term clinical results of aortic valve replacement with 17 mm St. Jude medical regent valve with hemodynamic evaluation including the measurement of effective orifice area, the occurrence of prosthesis-patient mismatch (PPM) and its affect on heart function. METHODS: There were 44 patients accepted aortic valve replacement with 17 mm St. Jude medical regent valve because of small aortic annulus. Before the operation and during the postoperative follow-up, color doppler echocardiography was used to measure the hemodynamic parameters, such as left ventricular mass (LVmass), effective orifice area (EOA) and effective orifice area index (EOAI), etc. RESULTS: Transthoracic echocardiographic data were obtained from 39 of 44 patients (88.6%) at 12-55 months after surgery. One (2.27%) died of heart failure in 1 year. According to the current standard of PPM (EOAI < or = 0.85 cm2/m2), 33 cases (82.1%) had PPM, 13 cases (30.8%) had severe PPM with an EOAI < or = 0.65 cm2/m2. After the operation, there were significant decreases in LVAo-PG (19 +/- 8) mmHg and left ventricular mass index (LVmass I) (86.6 +/- 23.3) g/m2 (P < 0.05). The assessment for physical capacity according to NYHA classification: 41 patients improved to class II or better and 2 patients improved to class III (P < 0.05). CONCLUSION: The patients with small aortic annulus may obtain satisfactory clinical results after AVR with 17 mm St. Jude medical regent valve, PPM seems not affect the mid-long-term results.

Anticancer mechanism of peptide P18 in human leukemia K562 cells.

Studies on the anticancer mechanism of peptide P18 in human leukemia K562 cells revealed that P18 causes the death of most K562 cells by depolarizing plasma membrane potential and enhancing membrane permeability, rather than activating the classical apoptosis pathway. The mechanistic studies indicate that disrupting plasma membrane is an effective approach to kill cancer cells and help design more effective peptide analogues in future cancer therapies.

Chest injuries associated with earthquakes: an analysis of injuries sustained during the 2008 Wen-Chuan earthquake in China.

PURPOSE: The goal of this study was to analyze the patterns, therapeutic modalities, and short-term outcomes of patients with chest injuries in the aftermath of the Wen-Chuan earthquake, which occurred on May 12, 2008 and registered 8.0 on the Richter scale. METHODS: Of the 1522 patients who were referred to the West China Hospital of Sichuan University from May 12 to May 27, 169 patients (11.1%) had suffered major chest injuries. The type of injury, the presence of infection, Abbreviated Injury Score (AIS 2005), New Injury Severity Score (NISS), treatment, and short-term outcome were all documented for each case. RESULTS: Isolated chest injuries were diagnosed in 129 patients (76.3%), while multiple injuries with a major chest trauma were diagnosed in 40 patients (23.7%). The mean AIS and the median NISS of the hospitalized patients with chest injuries were 2.5 and 13, respectively. The mortality rate was 3.0% (5 patients). CONCLUSIONS: Most of the chest injuries were classified as minor to moderate trauma; however, coexistent multiple injuries and subsequent infection should be carefully considered in medical response strategies. Coordinated efforts among emergency medical support groups and prior training in earthquake preparedness and rescue in earthquake-prone areas are therefore necessary for efficient evacuation and treatment of catastrophic casualties.

Fluorescence studies on a designed self-assembling peptide of RAD16-II as a potential carrier for hydrophobic drug.

The self-assembling peptide, RAD16-II (Ac-RARADADARARADADA-NH2), has been shown to have many great applications in nanotechnology and tissue engineering. But few studies have been carried out to study the application of self-assembling peptides as a drug carrier. We used hydrophobic drug pyrene as a model and liposome vesicles to mimic bilayer membranes to study the ability of RAD16-II in drug encapsulation and transfer to lipid vesicles. It was found that this designed self-assembling peptide was able to stabilize hydrophobic drug in aqueous solution and deliver it into lipophilic environment. Analysis of the fluorescence excitation spectra showed that pyrene was present in the crystalline form when stabilized by RAD16-II and was able to be dispersed in egg phosphatidylcholine vesicles. This suggested that pyrene was completely released from RAD-Py mixture into the bilayer membranes. Furthermore, the concentration of pyrene transferred into the vesicles was quantified and its transfer rate was determined. The scanning electron micrograph image showed that pyrene microcrystals and peptide were absorbed by each other and the size of the pyrene-peptide complexes was larger than 10 microm. These data further demonstrated that this type of ionic complementary oligopeptides was able to significantly encapsulate hydrophobic drug and provide a new type of nanomaterials for delivering drugs.