Effects of dietary-fiber levels on RANK/RANKL/OPG expression in the appendix of weanling rabbits.

BACKGROUND/PURPOSE: The dietary fiber can regulate the intestinal mucosal immunity, and the M cell is the portal for initiating mucosal immunity. We investigated the effects of dietary fiber on the transport of Escherichia coli to assess the function of microfold (M) cells in the appendix. METHOD: A total of 150 New Zealand rabbits were fed three diets (high fiber (HF): 31.72%; control: 37.36%; low dietary fiber (LF): 41.84%; neutral detergent fiber (NDF). An infection model was established in vivo using E. coli containing green fluorescent protein as the indicator in appendix loops. Samples were collected before and after inoculation with indicator for 10, 30, or 60 min. The M cells number, differentiation-related genes and proteins were monitored by respectively using immunofluorescence, Q-PCR and Western-blot. RESULTS: The number of M cells in HF group was significantly higher than that of LF group before and at 10 min, 30 min post injection with E.coli (P < 0.01), which has an opposite at 60 min. The number of fluorescent E. coli transported across the appendix was significantly increased in the HF group (P < 0.01) compared with the LF group at 30 min (P < 0.001); expression of RANKL gene and protein levels were no difference between HF and LF group. The variation tendency of RANK, OPG genes and proteins were consistent with the change of M cell transport indicator number in different time points. CONCLUSION: Our study showed that a high-fiber diet can increase number of M cells and speed up antigen transfer under regulation of ANKL/OPG/RANK system.

Effect of dietary fiber levels on bacterial composition with age in the cecum of meat rabbits.

This study investigated the influence of dietary fiber levels on the growth performance, digestion, metabolism, and cecal microbial community of rabbits with different diets at different age. The different levels of dietary natural detergent fiber (NDF) were formulated accordingly: 400(A), 350(B), 300(C), 250(D) g/kg original matter basis, respectively; the different ages were 52, 62, and 72 days. With NDF increasing, the average daily feed intake (ADFI) and feed conversion rate (FCR) were increased, whereas average daily gain (ADG) and mortality were decreased (p < 0.05). The stomach relative weight, stomach content relative weight, cecal relative weight, and cecal content weight increased with increasing NDF (p < 0.05). The NH3 -N concentration of cecum dropped when the dietary NDF increased (p < 0.05). The diversity of the total microbiota increased significantly in Diets B, C (p = 0.011), and reached the lowest in 52 days for all diet groups. The richness index was decreased significantly in Diet A, D (p < 0.05) and in 62 days (p < 0.001), respectively. The phylum Firmicutes was higher (p < 0.01) in rabbits fed Diets B, C than Diets A, D and Bacteroidetes was highest in Diets C, D, and Proteobacteria was the highest in Diet A (p < 0.001). Among the classified genera, there were 14 that had levels of abundance of more than 1% and were commonly shared by all samples. Ruminococcus spp. that produced volatile fatty acid (VFA) abundance was highest from Diets B, C at 52 and 62 days. It is interesting to note that Bifidobacterium from Diet C was the most abundant genus during the entire experimental period (p < 0.01). The data from Venn diagrams, principal component analysis (PCA), and heat map plots of the bacterial communities showed that there were more groups of shared microbiota with aging. The above results indicate the cecal microbiota controlled by the 350 g/kg NDF diet can prevent gastrointestinal distress and exhibit good production performance.

Early- and intermediate-term results of surgical correction in 122 patients with total anomalous pulmonary venous connection and biventricular physiology.

BACKGROUND: We retrospectively reported our 26-year experience with operative repair of total anomalous pulmonary venous connection (TAPVC) with biventricular physiology. METHODS: Between December 1982 and December 2008, 122 TAPVC patients with biventricular heart underwent surgical repair in our department. Moderate or deep hypothermia was induced at the time of cardiopulmonary bypass (CPB). Follow-up was conducted for 5 postoperative years. Surgical outcomes of early and intermediate deaths after TAPVC repair were retrospectively analyzed. RESULTS: Six deaths occurred operatively; and three deaths, during follow-up. The 5-year survival rates after TAPVC repair was 92.6 %, without gradient across the anastomosis. The survival rate of the patients who were younger was 78.8 %, significantly lower than those older than 1 year. It was also lower in those who were less than 6 kg in weight. Three patients died during follow-up. Three patients died of ventricular arrhythmia, right heart failure, and pneumonia, respectively, during follow-up. If the left atrium pressure was higher than 15 mm Hg, the snare of the vertical vein was loosened after CPB ceased in the patients with supracardiac connection. It decreased from 21 ± 5 to 13 ± 3 mm Hg. The vertical vein was ligated in 57 cases and left open in 20 cases. A patient with an intact vertical vein had a large shunt and was cured by intervention afterward. Supraventricular arrhythmia occurred in 19 patients with the supercardiac type repaired through a biatrial incision. One patient died of ventricular arrhythmia, and none of the remaining patients had arrhythmias. CONCLUSION: Surgical treatment of TAPVC carried a low operative risk and had satisfactory immediate and intermediate results. Age younger than 1 year and weight less than 6 kg were risk factors. It was a good choice to leave the vertical vein open in the patients with a left atrial pressure higher than 15 mm Hg.

[The anatomy features and surgical significance of the pulmonary circuits of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries].

OBJECTIVES: To analyze the anatomy features of the pulmonary circuits in the patients with pulmonary atresia (PA) with ventricular septal defect (VSD) and major aortopulmonary collateral arteries (MAPCA), and discuss the clinical significance. METHODS: From April 2002 to June 2010, the anatomy features of pulmonary circuits in 33 patients with PA/VSD/MAPCA were examined and analyzed. There were 21 male and 12 female patients. The age ranged from 11 months to 29 years. The anatomic types of PA/VSD included group B for 22 cases, group C for 11 cases. Thirty-one patients of them underwent 33 operative procedures. The operations included aorta-pulmonary shunt in 8 cases, one stage unifocalization with VSD open in 2 cases, complete repair in 23 cases. RESULTS: Twenty-nine (87.9%) patients had native pulmonary arteries, 6 of them were normal size and 23 were hypoplastic size. Four patients (12.1%) had no native pulmonary arteries. The postoperative oxygen saturation of the patients undergone shunt and one stage unifocalization was increased to 83% to 90%. There was one early death after complete repair because of multiorgan function failure. There were 4 cases of severe low cardiac output and 3 cases of respiratory function failure. Sixteen patients after complete repair were followed up more than one year. The postoperative right ventricular pressure was 41 to 99 mmHg (1 mmHg = 0.133 kPa). The ejection fraction value was more than 50% in 14 patients and less than 50% in 2 patients. Two patients had medium pulmonary insufficiency. CONCLUSIONS: An individualized approach based on the anatomy of the pulmonary circuits permits achievement in the patients with PA/VSD/MAPCA. The surgical strategy for PA/VSD/MAPCA mainly depends on the anatomy features of native pulmonary arteries, confluent pulmonary arteries and MAPCA.

Effective pulmonary artery perfusion mode during cardiopulmonary bypass.

AIM: Reducing lung injury during cardiopulmonary bypass (CPB) is important for patients' recovery. The present study was designed to research convenient and effective pulmonary artery perfusion mode during CPB in an animal model. METHODS: Twelve healthy mongrel dogs were randomly divided into 2 groups: a control group and a perfusion group designed to simulate clinical CPB-induced lung injury. During CPB, pulmonary artery perfusion with modified low-potassium dextran (LPD) solution was performed immediately after the initiation of ischemia and before reperfusion for 3 to 4 minutes each time, with pressure maintained at 15 to 20 mmHg; animals in the control group were not perfused. After pulmonary reperfusion, the changes in pulmonary function and tissue biochemical data were determined. RESULTS: Compared with the control group, lung compliance, oxygenation, and vascular resistance after reperfusion were significantly improved in the perfusion group. The malonaldehyde concentration, neutrophil sequestration ratio, and tissue water content also decreased significantly in the perfusion group. CONCLUSION: The pulmonary artery perfusion mode used in this experiment could relieve CPB-induced lung injury effectively. Improving cellular tolerance to hypoxia and decreasing inflammatory reaction may be the important mechanisms. Moreover, this mode is convenient and does not interfere with the intended operations, which is promising for clinical use.

Half rotation of the truncus arteriosus plus arterial switch for transposition of the great arteries with ventricular septal defect and pulmonary outflow tract obstruction.

OBJECTIVE: The goal of our study was to report our experience of using half rotation of the truncus arteriosus plus arterial switch, as a modification of the Nikaidoh procedure, for anatomic repair of transposition of the great arteries (TGA) with ventricular septal defect (VSD) and pulmonary outflow tract obstruction (pulmonary stenosis (PS)). METHODS: From December 2006 to December 2009, 11 patients (six male, five female) underwent half rotation of the truncus arteriosus plus arterial switch for repair of TGA, VSD, and PS or double-outlet right ventricle (DORV) at our heart center. RESULTS: There was no operative death. All patients had relief of left ventricular outflow tract obstruction (LVOTO) as determined by direct pressure measurements intraoperatively. Echocardiography was performed for all patients intraoperatively and before discharge. Two patients had mild aortic regurgitation and two patients had mild pulmonary regurgitation. For a median follow-up of 15 months (range 6-42 months), all patients were alive. Echocardiography was performed at 3, 6, 12, 24 and 36 postoperative months. All patients have normal ventricular function. No evidence of LVOTO was founded in all patients. Two patients had mild aortic regurgitation and three patients had mild to medium pulmonary regurgitation. CONCLUSIONS: Half rotation of the truncus arteriosus plus arterial switch, as a modification of the Nikaidoh procedure, is a good alternative treatment for complete anatomic repair for TGA, VSD, and PS or DORV with malposition of great arteries and PS. The technique might allow to reconstruct biventricular outflow tract, preserve competence and growth potential of the pulmonary root with valves and decrease the probability of reoperation. Its long-term benefits need to be evaluated with a large number of patients and longer follow-up.

[Clinical analysis of surgical procedures and outcomes for corrected transposition of great arteries with heart anomaly].

OBJECTIVE: To determine the outcome of anatomically corrective repair and traditional repair of corrected transposition of great arteries (c-TGA) with heart anomaly. METHODS: From April 2002 to December 2006, nineteen patients including fourteen male and five female with c-TGA, underwent operations, age ranged from 2 to 22 years old and weight ranged from 10 to 48 kg. Fifteen of them received anatomically corrective repair and the other four received traditional repair. Eighteen patients were referred to SLL (segmental anatomy) in situs solitus while fifteen of them with levocardia and three with dextrocardia. One patient was referred to IDD (segmental anatomy) in situs inversus with levocardia. Associated cardiac lesions included ventricular defect in eighteen patients, double outlet of right ventricle in one patient, pulmonary stenosis in seventeen patients and pulmonary hypertension in two patients. The operative procedures to anatomically correct atrioventricular discordance included an atrial switch plus a ventricle-arterial switch. The atrial switch was performed using the modified Senning procedure (n=13), Senning procedure (n=1) and Mustard procedure (n=1). The ventricle-arterial switch was performed using a Rastelli procedure (n=13) or an arterial switch (n=2). The patients underwent Mustard and Rastelli procedure had received bi-direct Gleen shunt due to postoperative high pressure of superior vena cava. Three patients underwent traditional cardiac repair because of small ventricular septal defect and one patient was reoperated to undergo traditional cardiac repair because of left ventricular failure after received anatomically corrective repair. RESULTS: In the patients received anatomically corrective repair, there was one early operative death received a modified Senning atrial switch and an arterial switch. The cause of death was acute myocardial failure due to imperfect coronary transfer. The postoperative complications included severe low cardiac output syndrome (n=1), temporary atrioventricular block (n=1) and thorax cavity fluidify (n=1). The survivors were followed up for 6 months to 4 years. All were sinus cardiac rhythm and in NYHA class I or II. There was no death in the patients received traditional repair. Four patients were followed up for 1 year. Three patients were in NYHA I or II class and one patient in class II. CONCLUSIONS: Anatomically corrective repair of c-TGA can be performed with good operative survival and intermediate-term outcome. The patients with good right ventricular function and well developed tricuspid valve who were difficult to undergo anatomically corrective repair might be fit to receive traditional repair.

Role of nitric oxide during early phase myocardial ischemic preconditioning in rats.

BACKGROUND: To date, there have been no reports on altered nitric oxide (NO) content in ischemia/reperfusion with regard to in vivo preconditioning procedures. These studies are important for understanding the mechanisms of NO during early myocardial ischemic preconditioning. The aim of the present study was to investigate the mechanisms of NO during early myocardial ischemic preconditioning by measuring levels of NO and cyclic guanosine monophosphate (cGMP), as well as activity of nitric oxide synthase (NOS) in ischemia/reperfusion with respect to preconditioning in rats. METHODS: Sixty-six female Sprague-Dawley rats were randomly divided into four groups: ischemic preconditioning group (IP), ischemia/reperfusion group (I/R), control group (CON), and preconditioning procedure group (PC). In the PC group, rats were further divided into PC1-, PC1 +, PC2-, PC2 +, PC3-, and PC3 + subgroups. Rats underwent left coronary artery occlusion and reperfusion, and subsequently, NOS activity and levels were assessed with spectrophotometric analysis. cGMP contents were measured with radioimmunoassay. RESULTS: The level of NO and cGMP, as well as the activity of NOS, were significantly higher in the IP group compared to the I/R and CON groups (P < 0.05). During preconditioning prior to prolonged ischemia, NO and cGMP levels varied markedly with ischemia and reperfusion. The levels of NO repeatedly increased when the heart was exposed to three episodes of 5-minute ischemia, and were almost completely reversed during each reperfusion period. NO and cGMP levels were significantly different between the 5-minute period of ischemia and the same period of reperfusion during preconditioning. CONCLUSIONS: NO plays an important role during early phase myocardial ischemic preconditioning in rats. NO and cGMP could be triggers and mediators of early phase myocardial ischemic preconditioning. Altered NOS activity following ischemic stress could be the primary inducer of higher NO levels detected. NO and cGMP fluctuations might be the trigger for protection during early phase myocardial ischemic preconditioning.

[Study of cardiopulmonary adaptation during exercise in patients after extracardiac conduit total cavopulmonary connection].

OBJECTIVE: To study cardiopulmonary physiology during exercise in patients after extracardiac total cavopulmonary connection (ECTCPC). METHODS: Twenty-six patients were studied after ECTCPC by exercise testing with bicycle treadmill protocol. Heart rate (HR), blood pressure (BP), respiratory frequency (RF) and pulse oxygen saturation (SpO(2)) were measured continuously; twenty-six patients suffered from Fallot 4 underwent biventricular repair were also studied as control group. RESULTS: In ECTCPC group, HR, BP, SpO(2) and RF all increased with exercise below 3 grade; when exceed 4 grade, BP, SpO(2) decreased and RF kept increasing. Compared with control group, HR, RF were higher (t = 2.13, P < 0.05; t = 2.31, P < 0.05), SpO(2) was lower (t = 2.46, P < 0.05) under the quiescent condition; When exceed 3 grade, HR, BP, SpO(2) decreased more significantly, but RF increased continuously. In fenestration group after ECTCPC, HR reached the top at 5 grades, but in group without fenestration it reached the top at 3 grades; In the whole process of exercising, RF kept higher and SpO(2) kept lower in fenestration group. CONCLUSIONS: The ECTCPC patients showed obviously exercise limitation. Totally bypass of sinoatrial node in this operation may have some adverse effects on the integer regulation of HR.

[The effects of inhaled nitric oxide on pulmonary vascular resistance in patients after total cavopulmonary connection].

OBJECTIVE: To study the effects of inhaled nitric oxide (NO) on pulmonary vascular resistance in patients after total cavopulmonary connection (TCPC). METHODS: Fifty-two patients after TCPC were evaluated, of them 24 patients were administered with inhaled nitric oxide in the early postoperative period. The cardiac index (CI) and pulmonary vascular resistance (PVR) were compared before and after inhaled NO. RESULTS: In experimental group, after inhaled NO, partial pressure of oxygen in artery/fraction of inspired oxygen increased from 161 +/- 17 to 193 +/- 23 (t = 2.75, P < 0.01); CI from (2.86 +/- 0.24) L.min(-1).m(-2) to (3.13 +/- 0.22) L.min(-1).m(-2) (t = 2.25, P < 0.05); PVR decreased from (4.2 +/- 0.5) U/m(2) to (3.8 +/- 1.4) U/m(2) (t = 2.29, P < 0.05); central venous pressure (CVP) from (17.0 +/- 1.8) mm Hg to (15.0 +/- 1.1) mm Hg, decreased 11.7%. Compared with the control group, respirator time decreased from (86 +/- 27) h to (54 +/- 18) h (t = 2.29, P < 0.05); ICU time from (6 +/- 2) d to (4 +/- 2) d (t = 2.32, P < 0.05); But hydrothorax drainage and length of stay had no significant difference. CONCLUSIONS: Though inhaled NO, there is no significant long-term effects in patients after TCPC, but it may play an important role in the management of low cardiac output syndrome and high cava pressure caused by reactive elevated pulmonary vascular resistance in the early postoperative period of TCPC.