Viral and Bacterial Etiology of Acute Diarrhea among Children under 5 Years of Age in Wuhan, China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acute diarrhea remains the serious problem in developing countries, especially among children under 5 years of age. Currently, only two or three common diarrhea pathogens were screened at most hospitals in China. The aim of this study was to provide a wide variety of diarrhea pathogens and their antimicrobial resistance patterns in children under 5 years of age.</p><p><b>METHODS</b>Totally 381 stool samples collected from Tongji Hospital between July 1, 2014 and June 30, 2015 were tested by culture and/or polymerase chain reaction for eight kinds of bacteria and five kinds of viruses. An antimicrobial sensitivity test was performed using dilution method recommended by the Clinical and Laboratory Standards Institute.</p><p><b>RESULTS</b>Viral infections were mainly identified in infants (0-11 months), whereas bacterial infections were more prevalent in the age of 24-59 months. About 69.8% of samples were positive for at least one pathogen, 51.7% of samples were virus positive, followed by bacteria positive cases (19.4%), and 12.6% of cases displayed co-infections with two viruses or a virus and a bacterium. Rotavirus was the most prevalent pathogen, followed closely by norovirus, while Salmonella was the most commonly isolated bacteria, followed by diarrheagenic Escherichia coli (DEC) and Campylobacter. More than 40% of Salmonella spp. and DEC isolates were resistant to first-line antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and tetracycline). Around 10% of Salmonella spp. isolates were resistant to ceftriaxone and ciprofloxacin simultaneously. Campylobacter spp. displayed high resistance to ciprofloxacin but kept low resistance to azithromycin and doxycycline.</p><p><b>CONCLUSIONS</b>The etiology of acute diarrhea varies in children of different age groups. The high frequency of infection with viruses suggests the urgent demand for new viral vaccine development. Proper use of antibiotics in the treatment of acute diarrhea is crucial due to the high level of antibiotic resistance.</p>

Study on the influence of the configuration of porcine aortic root on the stentless valve design / 中华外科杂志

<p><b>OBJECTIVE</b>To provide the reference for the stentless aortic valve design with the study of the inner configuration of porcine aortic root.</p><p><b>METHODS</b>The orifice areas of porcine aortic root at 4 levels (OA1 to 4), the average area of leaflets (Sa), the area analogue of leaflets (AA, AA = 1/2PH), the average area analogue of leaflets (AAa), the value PH of the left, right, non coronary leaflets (PHl, PHr, PHn) and the sums of PHs of the left and non-coronary leaflets (PHln) in the fresh and glutaraldehyde and epichlorohydrin-treated porcine aortic valves (20 respectively) were measured and calculated. The linear correlation and regression analysis by SPSS 12.0 was used to analyze the correlation between Sa and AAa, OA and Sa, OA and AAa, PHl, PHr and PHn, PHln and PHr in both groups.</p><p><b>RESULTS</b>The coefficient correlation between Sa and AAa in fresh and treated groups were 0.886 and 0.872 respectively (P < 0.05). The coefficient correlation between OA1 to 4 and AAa were 0.810, 0.851, 0.900, and 0.815 respectively in fresh group (P < 0.05), and were 0.852, 0.888, 0.836, and 0.817 respectively in treated group (P < 0.05). This showed that the degree of correlation between the average area analogue of leaflets and the average area of leaflets, the orifice areas of aortic root were relatively large. Additionally, the equation of linear regression existed between PHln and PHr in treated group as follows: PHr = -1.665 + 0.688 PHln (r = 0.907, P < 0.05), thereby PHr could be predicted by PHln.</p><p><b>CONCLUSION</b>The value of PH of leaflets could represent the spatial configuration of the aortic root, which provided a referred index for the stentless bioprostheses design.</p>

Effects of intensive insulin therapy on plasma nitric oxide and endothelin-1 levels in patients undergoing cardiac surgery under cardiopulmonary bypass / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the effects of intensive insulin therapy on plasma nitric oxide (NO) and endothelin-1 (ET-1) levels in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).</p><p><b>METHODS</b>A total of 36 patients were randomly assigned to routine therapy (RT) group and intensive insulin therapy (IT) group, with 18 patients in each group. The blood glucose levels during surgery were maintained at 3.9 to 10.0 mmol/L and those after surgery at 3.9 to 6.1 mmol/L in IT group, whereas patients in RT group didn't undergo the treatment of controlling glucose levels during operation and maintained below 13.9 mmoVL after operation. Levels of plasma NO and ET-1 in both groups were respectively measured before surgical anesthesia, at the initiation of CPB, and 0 h, 4 h, 12 h, 24 h and 48 h after the termination of CPB.</p><p><b>RESULTS</b>In RT group, plasma NO concentration was decreased since the initiation of CPB [from (68.2 +/- 16.3) micromol/L to (67.8 +/- 8.4) micromol/L] and reached the trough at the termination of CPB [ (60.0 +/- 10.2) micromol/L, P < 0.05 compared with that before anesthesia]. Then it began to increase and neared to the preoperational level 48 h after the termination of CPB. In contrast, plasma ET-1 concentration was increased since the initiation of CPB [from (62.2 +/- 10.2) ng/L to (68.3 +/- 10.8) ng/L] and reached the peak at the termination of CPB [ (112.5 +/- 18.6) ng/L, P < 0.01 compared with that before anesthesia]. Then it began to decrease and reached the preoperational level 24 h after the termination of CPB. In IT group, however, the changes of NO and ET-1 levels at different time points during CPB and thereafter didn't reach the significance as compared with those before anesthesia.</p><p><b>CONCLUSIONS</b>Intensive insulin therapy may relieve the changes of CPB-induced NO and ET-1 levels during cardiovascular surgery, which suggests its protective effects on cardiovascular function.</p>

Research on application of modified polyethylene glycol hydrogels in the construction of tissue engineered heart valve / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the effect of the polyethylene glycol (PEG)-hydrogels to enhance the seeding-cells adhesion to the biomaterial scaffolds.</p><p><b>METHODS</b>Sixteen porcine aortic valves were decellularized with Triton X-100 and trypsin, then divided into A and B group, eight in each group. Group A: the donor goat's autologous bone marrow mesenchymal stem cells (BMSCs) Selected as the seeding-cells were encapsulated into the modified PEG-hydrogels to complete the process of the cells attaching to the acellular porcine aortic valves. Non-PEG but reservation of BMSCs was modified in Group B. After static culture for 7 d, the mono semilunar tissue engineering heart valve (TEHV) were implanted respectively into each donor goat's abdominal aortas. Gross and histology examination, ultrasonic scanning, electron microscopy observation and biomechanics detection were performed at 16 weeks after operation. The 8 native goat aortic valves from the donor goats were selected at the same time as control group (Group C).</p><p><b>RESULTS</b>There were much more improvements compared Group A to Group B (P < 0.05) in tensile strength [(12.9 +/- 1.3) MPa vs. (8.8 +/- 0.4) MPa], ratio of re-endothelial (84.6% vs. 14.8%) and mural thrombosis (0/8 vs. 8/8). The data illustrated the critical importance of BMSCs differentiation to endothelial and myofibroblast for remodeling into native tissue in microenvironment in vivo.</p><p><b>CONCLUSIONS</b>It is feasible to reconstruct TEHV efficiently by combining modified PEG-hydrogels with acellular biomaterial scaffold and autologous MSCs cells. It can improve the integration of the seeding-cells and scaffold. It can also protect the growth and differentiation of the BMSCs in the systemic circulation effectively.</p>

Experimental study of differentiation of canine bone marrow mesenchymal stem cell into fibroblasts in vitro / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the way of stably inducing canine bone marrow mesenchymal stem cells (BMSCs) to differentiate into fibroblasts and myofibroblasts in vitro, and provide seed cells for fabricating tissue engineering heart valves (TEHV).</p><p><b>METHODS</b>Adult canine BMSCs were separated by a gradient centrifugation on Percoll (density 1.073 g/ml), then the cells were incubated in low-glucose Dulbecco Eagle's minimum essential medium (LG-DMEM) with 10% bovine calf serum. Cell phenotype were identified by immunohistochemistry staining. The second and third generation of BMSCs were committedly induced by conditioning culture medium, which were detected by immunohistochemistry staining. The induced-BMSCs were freezed, preserved and resuscitated after 7 d to observe the cell growth, proliferation and function.</p><p><b>RESULTS</b>BMSCs deriving from the bone marrow mononuclear cells separated by a Percoll gradient were positive expression of alpha-smooth muscle antibody, vimentin and negative expression of CD34, laminin. About (50 +/- 3)% induced-BMSCs were positive expression of laminin. Approximately (85 +/- 3)% freezed induced-BMSCs could be resuscitated. And the growth, proliferation and function were well.</p><p><b>CONCLUSION</b>BMSCs could be committedly induced to differentiate into fibroblasts and myofibroblasts in vitro. It is suitable to be the seed cells.</p>

Construction of a tissue-engineered valve with decellular porcine aortic valve scaffold in the abdominal aorta of canine / 中华外科杂志

<p><b>OBJECTIVE</b>To explore an experimental method for construction of tissue-engineered heart valve (TEHV) in canine abdominal aorta.</p><p><b>METHODS</b>The decellular porcine aortic valve (PAV) leaflets seeded with canine vessel interstitial cells and endothelial cells (ECs) were implanted into 6 canine abdominal aortas. Valve specimens were obtained respectively at the end of 4, 6, 8 and 10 weeks after implantation were studied for morphology, histology and immunohistochemistry.</p><p><b>RESULTS</b>(1) After 4 weeks implantation, multiple layers of cells grew into peripheral portion of valve scaffold, while new extracellular matrix appeared, and original scaffold tissue was partially absorbed. (2) At the end of 10th week after implantation, the decellular PAV scaffold disappeared completely and was substituted by recipient cells and new extracellular matrix. The interstitial cells in matrix was mainly consisted of fibroblasts and myofibroblast. The matrix was mainly composed by type I, III collagen, some elastic fibers with neutral and acid mucopolysaccharide. (3) Surface of valve leaflets were covered with endothelial cells.</p><p><b>CONCLUSIONS</b>(1) TEHV is primarily constructed with recellularized PAV after implantation into canine abdominal aorta for 10 weeks. (2) Heterotopic implantation into the abdominal aorta is an alternative experimental procedure to study the TEHV.</p>

Fontan operation with extracardiac conduit on beating hearts / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the results of Fontan operation with extracardiac conduit on beating hearts.</p><p><b>METHODS</b>Forty-two patients (31 males and 11 females) age ranged from 3 to 19 years old included in this study. There were 19 double inlet-ventricle, 10 tricuspid atresia, and 3 patients with mitral atresia, 10 patients with other complex congenital cardiac malformations. Fontan operations with extracardiac conduit were performed in all patients with the help of cardiopulmonary bypass without hypothermia in this study. Atrial septal fenestration was performed in 8 patients. In one patient, bi-directional cardiopulmonary procedure was performed 2 years before Fontan operation.</p><p><b>RESULTS</b>There was one early death caused by acute hepatic function failure and one late death caused by repeated lung infections. The follow-up of 1 to 4.5 years showed that all patients' cardiac functions were grade I to II, and arterial oxygen saturation was 92% - 96%.</p><p><b>CONCLUSIONS</b>The early and mid-term outcome of Fontan operation with extracardiac conduit on beating hearts is good and the method can be used in the single ventricle repair.</p>

The Progress of Tissue Engineering Heart Valve / 中国胸心血管外科临床杂志

@#The currently used heart valve prosthesis are still far from the ideal one in anticoagulation and longevity. The construction of tissue engineering heart valve leaflets are carried out recently. This article reviews the progress of tissue engineering heart valve leaflets in implanting materials, seeded cells, animal experiment and basic research. It also discusses the benefits and feasibility of tissue engineering heart valve leaflets.