[Protective effects of low dose nitric oxide inhalation on lung ischemia/reperfusion injury during cardiopulmonary bypass surgery].

OBJECTIVE: Out aim is to study the effects of inhaling nitric oxide(NO) on the pulmonary ischemia/reperfusion injury during cardiopulmonary bypass surgery. METHODS: Cardiac valve replacement was performed on twenty patients with chronic rheumatic heart valve disease under cardiopulmonary bypass, and they were randomly divided into two groups: control group(n = 10) and NO group(n = 10). We monitored the following: mean pulmonary arterial pressure(MPaP), pulmonary vascular resistance(PVR), peak airway pressure (PAP), cyclic guanosine monophosphate(cGMP), inter-cellular adhesion molecule-1(ICAM-1), xanthinoxidase (XOD), malondialdehyde(MDA), PaO2 and the duration of post-operative mechanical ventilation. RESULTS: The PAP, MPaP and PVR in the control group were much higher than those in NO group after reperfusion(P < 0.05). The durations of postoperative mechanical ventilation in NO group were shorter than those in the control group(P < 0.01). The cGMP and PaO2 after reperfusion in NO group were higher(P < 0.01), and the ICAM-1, XOD, MDA were lower(P < 0.05) than those in the control group. CONCLUSIONS: 1. If aortic clamp time is over 1 h, lung ischemia/reperfusion injury may occur during cardio-pulmonary bypass surgery. 2. Inhaling 20 ppm NO in the early phase of reperfusion has protective effects on the lung ischemia/reperfusion injury during cardio-pulmonary bypass surgery. 3. The mechanisms of the protective effects may be related with the increase of cGMP and the decrease of ICAM-1, XOD, MDA.

[Surgical treatment for mitral valve prolapse].

OBJECTIVE: To determine the excellent operative procedure to treat mitral valve prolapse (MVP). METHODS: Fifty seven patients with MVP were divided into three groups: Group I received traditional chordal reconstruction; Group II underwent chordal replacement using expanded polytetrafluorethylene(e-PTFE) sutures and artificial ring valvuloplasty reconstruction; Group III submitted mitral valve replacement. RESULTS: Mitral regurgitation volume was reduced significantly in Group II [(1.3 +/- 3.8) ml] and Group III [(1.2 +/- 3.4) ml] than that in Group I [(4.7 +/- 7.7) ml] (P < 0.05). CONCLUSION: The utilization of e-PTFE sutures as artificial chordae and artificial ring valvuloplasty for MVP is a more reliable and safe procedure than traditional mitral valve reconstruction, and can avoid the complications of long term anticoagulant therapy after mechanical valve replacement.

Improved biocompatibility of bovine pericardium using a new method of cross linking.

The authors used glycerol (Gly) as a cross linking agent to treat bovine pericardium (BP) and compared it mechanically (tensile test) and biologically (subcutaneous implantation in rats) with glutaraldehyde (Glu) fixed lonescu-Shiley BP (ISBP). Maximum tensile stress (Stmax) was the same in both groups (n = 12 each), while maximum strain (Snmax) was larger in Gly BP. Calcium content (Ca) was lower and water content of tissue (WC) was higher in implants of Gly BP versus ISBP (n = 9 each). Gly BP appeared more hydrated than ISBP in specimens studied by scanning electron microscopy (SEM). In addition, SEM of three Gly BP mitral valves in sheep showed good growth of endothelial (En) cells. These biomechanical advantages of Gly BP over ISBP suggest that Gly may be a useful substitute for Glu in cross linking bovine pericardial valves.

[Animal model and multiple trait BLUP applied in poultry genetic evaluation].

Best linear unbiased prediction (BLUP) is a powerful method to estimate genetic values of animals, and is widely applied in many animal species but poultry. Beijing White Leghorn nested data in 1986-1987 with 777 individuals were analysed by animal model and multiple trait BLUP. Two traits (40-week egg production and 36-week egg weight) and two fixed effects (house-pen effect and hatching batch effect) were considered. The way to calculate a large set of mixed model equations in micro-computer was studied. Only non-zero elements of the coefficient matrix of MME were stored on a disk. The iteration process was reduced by block iteration. It also simplified the multiple trait BLUP method, the dimension of equations is only 1/q (q is the number of traits) of regular method. So it saved a lot of compute time and cost, and BLUP became applicable in poultry. The significance of using BLUP in poultry are: (1) Eliminating some fixed effects; (2) Reducing the estimation error for unbalanced data; (3) Estimating breeding values of progeny, so we can shorten the generation interval; (4) It can estimate breeding values of individuals without records from the relatives' information; (5) The breeding value of sires and dams can be estimated from their progeny records, used for family selection; (6) Due to genetic and environmental correlation between traits and all relatives information were considered, it can increase the selection accuracy.