Research progress of plant cytogenetics in Jiangsu province.

Cytogenetics was established based on the "Chromosome theory of inheritance", proposed by Boveri and Sutton and evidenced by Morgan's lab in early stage of the 20 th centrary. With rapid development of related research areas, especially molecular genetics, cytogenetics developed from traditional into a new era, molecular cytogenetics in late 1960s. Featured by an established technique named DNA in situ hybridization (ISH), molecular cytogenetics has been applied in various research areas. ISH provids vivid and straightforward figures showing the virtual presence of DNA, RNA or proteins. In combination with genomics and cell biology tools, ISH and derived techniques have been widely used in studies of the origin, evolution, domestication of human, animal and plant, as well as wide hybridization and chromosome engineering. The physical location and order of DNA sequences revealed by ISH enables the detection of chromosomal re-arrangments among related species and gaps of assembled genome sequences. In addition, ISH using RNA or protein probes can reveal the location and quantification of transcripted RNA or translated protein. Since the 1970s, scientists from universities or institutes belonging to the Jiangsu Society of Genetics have initiated cytogenetics researches using various plant species. In recent years, research platforms for molecular cytogenetics have also been well established in Nanjing Agricultural University, Yangzhou University, Nanjing Forestry University, Jiangsu Xuhuai Academy of Agricultural Sciences, and Jiangsu Normal University. The application of molecular cytogenetics in plant evolution, wide hybridization, chromosome engineering, chromosome biology, genomics has been successful. Significant progresses have been achieved, both in basic and applied researches. In this paper, we will review main research progresses of plant cytogenetics in Jiangsu province, and discuss the potential development of this research area.

Optimal Timing of Surgical Revascularization for Myocardial Infarction and Left Ventricular Dysfunction.

BACKGROUND: The optimal timing of surgical revascularization for patients presenting with ST-segment elevation myocardial infarction (STEMI) and impaired left ventricular function is not well established. This study aimed to examine the timing of surgical revascularization after STEMI in patients with ischemic heart disease and left ventricular dysfunction (LVD) by comparing early and late results. METHODS: From January 2003 to December 2013, there were 2276 patients undergoing isolated coronary artery bypass grafting (CABG) in our institution. Two hundred and sixty-four (223 male, 41 females) patients with a history of STEMI and LVD were divided into early revascularization (ER, <3 weeks), mid-term revascularization (MR, 3 weeks to 3 months), and late revascularization (LR, >3 months) groups according to the time interval from STEMI to CABG. Mortality and complication rates were compared among the groups by Fisher's exact test. Cox regression analyses were performed to examine the effect of the time interval of surgery on long-term survival. RESULTS: No significant differences in 30-day mortality, long-term survival, freedom from all-cause death, and rehospitalization for heart failure existed among the groups (P > 0.05). More patients in the ER group (12.90%) had low cardiac output syndrome than those in the MR (2.89%) and LR (3.05%) groups (P = 0.035). The mean follow-up times were 46.72 ± 30.65, 48.70 ± 32.74, and 43.75 ± 32.43 months, respectively (P = 0.716). Cox regression analyses showed a severe preoperative condition (odds ratio = 7.13, 95% confidence interval 2.05-24.74, P = 0.002) rather than the time interval of CABG (P > 0.05) after myocardial infarction was a risk factor of long-term survival. CONCLUSIONS: Surgical revascularization for patients with STEMI and LVD can be performed at different times after STEMI with comparable operative mortality and long-term survival. However, ER (<3 weeks) has a higher incidence of postoperative low cardiac output syndrome. A severe preoperative condition rather than the time interval of CABG after STEMI is a risk factor of long-term survival.

[Surgical ventricular restoration versus isolated coronary artery bypass grafting for left ventricular aneurysm: comparison of mid- to long-term outcomes].

OBJECTIVE: To compare the mid- to long-term outcomes of patients receiving isolated coronary artery bypass grafting (CABG) versus surgical ventricular restoration (SVR) plus CABG for left ventricular aneurysms. METHODS: The clinical data were retrospectively analyzed in 205 patients with left ventricular aneurysms admitted to our hospital between January, 1997 and December, 2012, including 115 patients receiving SVR plus CABG and 90 undergoing isolated CABG. By matching preoperative echocardiographic parameters including aneurysm size, left ventricular ejection fraction (LVEF), left ventricular end-systolic volume index (LVESVI) and EuroSCORE risk factors, 32 patients receiving SVR plus CABG and another 32 with isolated CABG were enrolled in this study. The patients were compared for survival rates, major adverse cardiac or cerebrovascular events (MACCEs), left ventricular geometry and function at 1, 3 and 5 years of follow-up. RESULTS: Compared with the patients receiving isolated CABG, those receiving SVR and CABG showed greater improvements in echocardiographic parameters and NYHA functional class. The differences in the echocardiographic parameters between the two groups gradually reduced with time and became comparable at 5 years after the operation (P>0.05). No significant difference was found in the mid- to long-term survival or the incidence of MACCEs between the two groups (P>0.05). CONCLUSION: Compared with isolated CABG, SVR plus CABG does not reduce the incidence of MACCEs or improve the mid- to long-term survival rate of patients with left ventricular aneurysm with a LVESVI <60 mL/m(2).

[Different approaches to revascularization for complex coronary artery disease and left ventricular dysfunction: analysis of perioperative outcomes].

OBJECTIVE: To compare the perioperative outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for treatment of complex coronary artery disease and left ventricular dysfunction. METHDOS: The clinical data of 966 patients admitted to our hospital from January 2003 to December 2013 with coronary artery disease and left ventricular dysfunction (ejection fraction ≤50%) were retrospectively reviewed. Among the patients, 386 underwent CABG and 580 received PCI. After matching for EuroSCORE risk factors and preoperative echocardiographic parameters, 135 patients with CABG and 135 with PCI were enrolled in this study. With hospital mortality and perioperative major complications as the endpoints, the early outcomes of the procedures were evaluated. Perioperative echocardiography was performed to evaluate the change of left ventricular geometry and function. RESULTS: Compared with CABG group, PCI group had significantly higher incidences of chronic lung disease (8.1% vs 0.7%, P=0.003) and recent myocardial infarction (64.4% vs 31.9%, P=0.000) but significantly lower left-main disease (12.6% vs 23.7%, P=0.018); the other baseline characteristics were comparable between the two groups. Patients with CABG had a greater number of treated target vessels than those with PCI (2.90±0.81 vs 1.67±0.73, P=0.000), and complete revascularization was more common in CABG group (94.8% vs 51.8%, P=0.000). No significant difference was found in perioperative variations of LVEF between the two groups, but patients with CABG had a greater variation in LVEDD than those with PCI. The hospital mortality and other major complications were similar between the two groups. CONCLUSION: Both CABG and PCI are safe and reliable revascularization strategies for complex coronary artery disease and left ventricular dysfunction, but CABG can achieve a higher rate of complete revascularization and better improves the left ventricular function.

[Acute kidney injury early after cardiac surgery with cardiopulmonary bypass: clinical analysis].

OBJECTIVE: To explore the occurrence of acute kidney injury (AKI) in early stage after cardiac surgery under cardiopulmonary bypass (CPB) and discuss the perioperative risk factors and its impact on clinical outcome. METHODS: Retrospective analysis was performed among 1472 adult patients undergoing cardiac surgery with CPB between January 2008 and April 2011. The postoperative occurrence of AKI following cardiac surgery was stratified according to the RIFLE criteria. And the perioperative risk factors of AKI and its impact on clinical outcome were analyzed. RESULTS: AKI occurred in 437 patients (29.7%) within 72 hours postoperation. Of these, 292 (19.8%) fulfilled AKI-Risk, 110 (7.5%) AKI-Injury and 35 (2.4%) AKI-Failure. Logistic regression analysis showed that age, hypertension, chronic renal insufficiency, reoperation, aortic surgery, CPB duration, intraoperative transfused erythrocyte volume and perioperative use of intra-aortic balloon pump were independent risk factors for AKI. A postoperative elevation of AKI level was associated with a prolonged duration of mechanical ventilation, intensive care unit stay, postoperative hospital stay, delayed extubation, extubation failure and death. Receiver operator characteristic (ROC) curve showed that AKI classification was a postoperative predictor of delayed extubation, extubation failure and death. CONCLUSION: As a common complication after cardiac surgery, AKI is associated with many perioperative risk factors. And the AKI classification is predicator of delayed extubation, extubation failure and death.

[The use of recombinant activated factor VII for blood loss after cardiovascular surgery].

OBJECTIVE: To describe the early experiences with rFVIIa in the management of bleeding after cardiovascular surgery. METHODS: From May 2006 through December 2007, 16 patients received rFVIIa during or after surgery despite conventional medical therapy and transfusion of blood products. There were 15 male patients and 1 female patients, aged from 36 to 77 years old with a mean of 52 years old. The surgical procedures include aortic procedures for 8 cases, valve replacement for 6 cases, pulmonary thromboendarterectomy for 1 case and atrial septal defect repair for 1 case. The data of these patients were reviewed and the safety and efficacy of rFVIIa after cardiovascular surgery were evaluated. RESULTS: rFVIIa was administered as a first dose of 27.6 to 54.5 microg/kg with a mean of 40.2 microg/kg. Six patients achieved hemostasis after the first dose. Nine patients received a second administration within 30 min, with a cumulative dose of 59.3 to 90.9 microg/kg, a mean of 80.3 microg/kg. Eight patients achieved hemostasis and 1 patient went to exploration. One patient received four doses of rFVIIa with a cumulative dose of 203.4 microg/kg and the bleeding stopped. Mean amount of chest drain loss and the amount of red blood cell, fresh frozen plasma, cryoprecipitate, and platelet transfusions decreased significantly after rFVIIa administration. The total amount of chest drain losses, transfusions of red blood cell and cryoprecipitate within 12 h postoperatively was positively correlated with the time from the end of bypass to administration of rFVIIa. No thromboembolic complications and other adverse reactions were noted. CONCLUSIONS: The use of rFVIIa is associated with reduced blood loss, rapid improvement of coagulation variables, and decreased need for blood products. rFVIIa is safe and efficacious in the management of refractory postcardiotomy bleeding.

[Isolation and characterization of the centromeric BAC clones from different genomes in genus Oryza].

Centromeres play an important role in ensuring the correct segregation and transmission of chromosome during mitosis and meiosis in eukaryotes. In this research, we constructed five BAC libraries for diploid wild rice with different genomes. Together with the technique of colony blot hybridization and fluorescence in situ hybridization (FISH), centromere-related BAC clones were screened and characterized from different genomes. Meanwhile, co-hybridization was detected between these clones and the five genomes. The results from this study demonstrated that: (1) there were centromere-specific satellite repeat in Oryza officinalis (CC genome) and O. brachyantha (FF genome), respectively, and centromere-specific CRR-related sequence was found in O. brachyantha; (2) homology sequences of CentO and CRR of O. sativa (AA genome) were detected on all centromeres of O. glaberrima (AA genome), O. punctata (BB genome) and O. australiensis (EE genome); And (3) the two somatic chromosomes of O. officinalis comprised of homology sequences of CentO satellites as revealed FISH analysis probed with RCS2. Homology sequences of CRR of O. sativa were also detected on all centromeres of O. officinalis. The results provided a foundation toward cloning the centromeric sequences from different genomes of genus Oryza, studying centromere organization and evolution of different genome, analyzing the relationship between centromeric structure and function among different genome.

[Expression of the GUS fusion gene controlled by the tomato rbcS3A promoter in transgenic rice].

To use different types of promoters in transgenic rice research, the 1.1 kb 5'-upstream regulation region of one of the tomato (Solanum tuberosum L.) Rubisco small subunit gene, rbcS3A, was cloned and its sequences were confirmed by comparison with the known sequences in GenBank. The cloned rbcS3A promoter was fused to the 5'-upstream of GUS (beta-glucuronidase) coding region in a binary vector, and introduced into an elite japonica rice variety by Agrogacterium-mediated transformation. The integration of the GUS fusion gene into the genome of transgenic rice was confirmed by both PCR and Southern blot analysis. The results of both histochemical staining and quantitative analysis of GUS activity showed that the expression level of GUS fusion gene was significantly stronger in stem, leaf blade and sheath than in other organs of transgenic rice plants, and showed highest in the stem, which implies that the tomato rbcS3A promoter can make tissue-specific, in particular in the stem, expression of foreign genes in transgenic rice. The results present here also demonstrate that light induction had no effect on the expression of the foreign gene when regulated by the tomato rbcS3A promoter in transgenic rice. Our results show that the cloned tomato rbcS3A promoter might be very useful for the expression of target genes in transgenic rice, with particularly high efficiency in stem tissues.

[Experimental study of degradable chitin long fiber reinforced polycaprolactone for reconstruction of chest wall defects].

OBJECTIVE: To investigate the application of a novel degradable biomaterial as a chest wall prosthesis and provide valuable scientific basis for clinical application. METHODS: Preparation of chitin long fiber reinforced polycaprolactone (PCL) by means of melt blending and modeling. Full-thickness chest wall defects of 10 cm x 8 cm was created in 10 dogs and then repaired with long chitin fiber reinforced PCL artificial rib in 8 dogs (tested group) and Marlex mesh in 2 dogs (control group). It was dynamically observed that the situation of the implanted chest wall prosthesis and the progress of the regeneration of the chest wall tissue postoperatively. RESULTS: No operative and perioperative deaths were observed in all experimental dogs. In tested group, slight paradoxical respiration occurred in 2 dogs and could not be seen in 2 weeks. No chest wall subsidence and infection occurred. New bone tissue obviously regenerated around both resection ends of the ribs and integrated tightly with artificial ribs. In control group, there were evidently paradoxical respiration and chest wall subsidence. Marlex mesh folded and was enveloped by fibrous tissue. CONCLUSION: Degradable chitin long fiber reinforced PCL can provide effective support to chest walls and is a practicable material for chest wall reconstruction.

[Agrobacterium-mediated transformation of rice mature embryos and regeneration of transgenic plants with Metr gene].

The mature embryos of a Japonica rice, Guanglingxiangnuo, were used for the study on optimization of Agrobacterium-mediated transformation. Several factors affecting the transformation were investigated and a suitable transformation system was set up. For this transformation system, the HRM medium, based on the MS medium, was suitable for inducing callus from rice mature embryos. The suitable time span of initial culture in this medium was 7-8 days before co-culturing with Agrobacterium and suitable medium for selection was CC medium. Using this transformation system, the Metr gene was introduced into Guanglingxiangnuo, and many transgenic plants were obtained. Most of these transgenic rice plants were confirmed by PCR technique and basta resistance, indicating the T-DNA had been integrated into the genome of transgenic rice plants.

[Physical mapping of the 45S rDNA and 5S rDNA to rice prometaphase chromosome].

Rice (Oryza sativa L.) is one of the most important cereal crops in the world. The chromosomes of rice are relatively small in size. With the help of fluorescence in situ hybridization (FISH), several rice DNAs have been localized on rice chromosomes. 45S rDNA and 5S rDNA are encoding sequences for ribosomal RNA synthesis. For detecting the chromosomes related to 45S rDNA and 5S rDNA, the digoxigenin-dUTP labeled probe DNA was probed to the prometaphase chromosomes which were prepared from the root tips harvested from an indica rice variety, Zhongxian 3037. For identification of the chromosomes, slides were stained with Giemsa before FISH. With the improved FISH protocol 45S rDNA was clearly detected on two pairs of chromosomes which are usually found to be attached to nucleolus. The signal size between two pairs of the chromosomes was different. According to the characteristics of the chromosomes, the chromosomes with bigger signal were chromosome 9 and the other pair were chromosome 10. They were also discriminated from arm ratio. The signals of 5S rDNA were relatively small but clear. According to the size and arm ratio of the chromosome with FISH signals, the 5S rDNA was mapped on the short arm of chromosome 11, very close to the centromere region.