Inhibition of viability of human retinal microvascular endothelial cells by vialinin A under high glucose condition

AIM:To investigate the effects of vialinin A on viability of human retinal endothelial cells(HRECs)under high glucose condition and its potential mechanism.METHODS:The HRECs were divided into four groups:normal glucose control group(NG,5 mmol/L D-glucose),high glucose group(HG,30 mmol/L D-glucose),HG+1μmol/L vialinin A group,and HG+5μmol/L vialinin A group.The cell viabilities were measured with cell counting kit-8(CCK-8)assay for proliferation,with scratch assay for migration,and tube formation,for evaluation of the impact of vialinin A on cellular behaviour.Real-time PCR and Western blotting were used to determine the expression level of vascular endothelial growth factor(VEGF).RESULTS:The proliferative capacity and migration of HRECs was reduced by 5μmol/L vialinin A in high glucose environment(both P<0.05).Vialinin A also inhibited highglucose-induced tube formation of HRECs.The expression level of VEGF and PI3K in HRECs was also significantly decreased by vialinin A(P<0.05).CONCLUSION:Vialinin A inhibits the cell viability of HRECs.It may serve as a potential target for anti-angiogenic therapy.

Clinical validation of the early embryo viability assessment system: Analysis for the blastocyst morphology and pregnancy outcomes

Objective:To determine the relationship between the early embryo viability assessment(EEVA)and blastocyst morphological parameters and pregnancy outcomes.Methods:This retrospective cohort study was conducted on 291 intracytoplasmic sperm injection cycles including 2522 embryos with indications of prolonging embryo culture to the blastocyst stage in the Genea embryo review incubator,and 511 single vitrified-warmed blastocyst transfer cycles from January 2020 to June 2023.The EEVA system produced an EEVA score from E1(best)to E5(worse)for the potential of blastocyst formation.Blastocyst morphology was evaluated.The association between the EEVA score and each type of blastocyst morphology,implantation rate,clinical pregnancy,and ongoing pregnancy were assessed using generalized estimating equations.Results:The inner cell mass A(ICM A),trophectoderm A(TE A),blastocoele expansion degree of 3,4,5,6,7 rates were higher with lower the EEVA score.The adjusted odd ratio(aOR)(E5 vs E1)was 0.3 for ICM A,0.174 for TE A and 0.210 for BL3,4,5,6,7(all P<0.001),suggesting a significant association between lower EEVA scores and improved embryo quality.The implantation,clinical pregnancy,and ongoing pregnancy rate were also higher with lower the EEVA score.The aOR of E5 vs E1 was 0.245 for implantation,0.185 for clinical pregnancy and 0.200 for ongoing pregnancy rate(P<0.001).Conclusions:There were associations between blastocyst morphology,pregnancy outcome and EEVA scores.The good blastocyst morphology and pregnancy outcomes are higher with lower the EEVA score.

Visible Light and Its Influence on the Embryonic Viability of the Cricket Acheta domesticus

During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.

A review on cell damage,viability,and functionality during 3D bioprinting

Three-dimensional(3D)bioprinting fabricates 3D functional tissues/organs by accurately depositing the bioink composed of the biological materials and living cells.Even though 3D bioprinting techniques have experienced significant advancement over the past decades,it remains challenging for 3D bioprinting to artificially fabricate functional tissues/organs with high post-printing cell viability and functionality since cells endure various types of stress during the bioprinting process.Generally,cell viability which is affected by several factors including the stress and the environmental factors,such as pH and temperature,is mainly determined by the magnitude and duration of the stress imposed on the cells with poorer cell viability under a higher stress and a longer duration condition.The maintenance of high cell viability especially for those vulnerable cells,such as stem cells which are more sensitive to multiple stresses,is a key initial step to ensure the functionality of the artificial tissues/organs.In addition,maintaining the pluripotency of the cells such as proliferation and differentiation abilities is also essential for the 3D-bioprinted tissues/organs to be similar to native tissues/organs.This review discusses various pathways triggering cell damage and the major factors affecting cell viability during different bioprinting processes,summarizes the studies on cell viabilities and functionalities in different bioprinting processes,and presents several potential approaches to protect cells from injuries to ensure high cell viability and functionality.

Viability and hatchability of brine shrimp Artemia franciscana cysts after passing through the digestive system of eared grebes Podiceps nigricollis

Brine shrimp Artemia franciscana provide food for many migrating and staging birds that spend summer and fall on Great Salt Lake,Utah,USA.Artemia produce live young and cysts(hard-walled eggs);these cysts are commercially harvested on Great Salt Lake and support a large industry in Utah.It is unclear the impact that millions of hungry birds have on the Artemia population in the lake.To help assess that,this study evaluated cyst viability(percentage of cysts that contain an embryo)and hatchability(percent of cysts that hatch)from cysts that had passed through the digestive tract of eared grebes Podiceps nigricollis and cysts obtained directly from Great Salt Lake at the same site where each grebe was collected.Hatchability was significantly higher for cysts collected from the water column(19%)than from the stomach(0.3%)or intestines(3%)of eared grebes.Viability also was significantly different for cysts collected from the water column(29%),stomach(0.7%),and intestines(5%).These results indicate that eared grebes nutritionally benefit from eating cysts and that they may be an important food source for grebes in late fall after the adult population of Artemia dies off due to the water becoming too cold.Also,enough cysts survive their passage through the digestive system that grebes can vector hatchable cysts to other waterbodies.

甲醛固定对Live/Dead BacLight Bacterial Viability Kit死活细菌染液荧光显微计数海洋细菌的影响

利用Live/Dead BacLight Bacterial Viability Kit死活细菌染液对采自湛江东海大堤海水、沉积物细菌和大型海藻拟刚毛藻(Cladophoropsis zollingeri)内生细菌数量进行了甲醛固定处理前后的荧光显微计数对比分析。结果表明,新鲜样品(不加甲醛固定)、甲醛刚固定样品、甲醛固定1周样品和甲醛固定2周样品中海洋细菌数量差异不显著(p>0.05)。甲醛固定对Live/Dead BacLight Bacterial Viability Kit死活细菌染液荧光显微计数海洋细菌数量无显著影响,固定后的样品可在2周内完成计数。

Synthesis and characterization of arginine-modified and europium-doped hydroxyapatite nanoparticle and its cell viability

The arginine-modified and europium-doped hydroxyapatite nanoparticles（HAP-Eu） were synthesized by hydrothermal synthesis.The prepared nanoparticles were characterized by transmission electron microscopy（TEM）,X-ray diffractometry（XRD）,Fourier transform infrared（FTIR） and zeta potential analyzer.The cell viability of HAP-Eu was tested by image flow cytometry.The results indicated that HAP-Eu is short column shapes and its size is approximately 100 nm,its zeta potential is about 30.10 mV at pH of 7.5,and shows no cytotoxicity in human epithelial cells and endothelial cells.

Track Monitoring on Viability of Rice Germplasm Resources and Regeneration under Low Temperature Storage

53 rice germplasm resources warehoused during 1981-1984 were regarded as materials to monitor the viability at warehouse time and different years after warehoused. The results showed that seed germination rates of different rice germplasm resources assumed descending trend in storage, with annual decreasing rate between 0.12%-3.05% ; the seed germination rates of most cultivars were above 75% after stored for 26 years; forecasting analysis based on the germination rate of 75% as reference showed a huge difference of safe storage life for different rice germplasm resources, ranging from 12 to 50 years, even longer time. The results suggest that track monitoring on viability and regeneration of rice cultivars is of great importance for germplasm resources conservation.

Determination of A canthopanax senticosus ＇ s Seed Viability

以6个产地的刺五加种子为试验材料，采用四唑染色法（TTC法）、红墨水染色法、溴麝香草酚蓝法（BTB法）、炒种法及纸上荧光法测定种子生活力，筛选最佳的刺五加种子生活力测定方法。结果显示：溴麝香草酚蓝法是测定刺五加种子生活力的最佳方法。

Effects of Low Temperature and Ultra-low Temperature on Pollen Viability of Tomato(Lycopersicon esculentum Mill.)

The pollen of two tomato varieties, Ryau961721 and Ryau9327D, was adopted in our research. The two tomato varieties were bred by College of Land- scape and Horticulture, Yunnan Agricultural University. The collected pollen was stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circumstances. Then it was inoculated to the medium and cultured at 28 ℃ in thermostat incubator. The pollen viability was determined by electron microscope. The results showed that compared to that of pollen stored in control （25 ℃） circumstance, the viability of pollen stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circum- stances for 1 -3 d did not change significantly. In addition, pollen viability trended to decrease with the increase of freeze-thaw cycle and storage time. The pollen lost basically the viability by the 7th d in the storage.

Study on Pollen Viability and Stigma Receptivity of Very Later-ripening ‘Dongxing' Apricot

[Objective] The primary aims of this study were to understand the characteristic of floralorgan development in ‘Dongxing＇, and analyze its differences with other apricot varieties. [Method] Floral organ morphology, pollen quantity, pollen viability and stigma receptivityof ‘Dongxing＇ and other apricot varieties were observed and measured. [Result] The ratio between the medium style and long style of‘Dongxing＇ was 82.4%, and the ratio of pistillode was lower than that in the other apricot varieties. Its pollen quantity was 32 183.2 grains per flower, and was fewer than the others. The pollen germination of ‘Dongxing＇ in optimum medium（1% agar ＋15% sucrose ＋ 0.01% boric acid） was 53.0%, i.e. its pollen viability was low. The pollen viability increased at first and then decreased following the period of the bud stage to flowering stage, and pollen viability reached maximum value at the 1st d after flowering. Meanwhile the stored pollen viability continuously decreased with the extension of storage time, and pollen viability of the both vivo or vitro stored was decreased to the half of the maximum value at the 3rdd after flowering or storage.The stigma receptivity of ‘ongxing＇ enhanced at first then weakened, maximum stigma receptivity was found at the period of 2 h to 4 h after flowering. The optimum time for artificial pollination was 1 h to 8 h after flowering and it was shorter than the other apricot varieties was. [Conclusion] The ratio between the medium style and long style of ‘Dongxing＇ was higher than the other apricot varieties, while the pollen viability of ‘Dongxing＇ on the contrary. Its pollen viability reached maximum value at the 1st d after flowering and the optimum time for artificial pollination was1 h to 8h after flowering.

Effects of primary PCI and facilitated PCI on myocardial viability and ventricular systolic synchrony in acute myocardial infarction patients

Objective To evaluate short time effects of primary percutaneous coronary intervention (pPCI) and rtPA thrombolysis+PCI (rtPA+PCI) on myocardial viability and ventricular systolic synchrony in AMI patients.Methods Eighty seven patients with first AMI were divided into two groups: group A ( n =42), pPCI group, the patients underwent PCI within 6h after onset of AMI; group B ( n =45), rtPA+PCI group, the patients underwent PCI after thrombolysis within 6h after onset of AMI; Myocardial viability was measured by 99m Tc MIBI SPECT. While, the parameters of cardiac function LVEF and ventricular systolic synchrony LVPS were measured by 99m Tc gated cardiac blood pool image on the first and the fourth weekend. Results (1) The peak CK MB was significantly lower in group A than that in group B( P <0.01 ). (2) Myocardial infarction area (MIA) was decreased and radioactivity counts in MIA was significantly increased in group A and B on the 4th weekend compared with that on the first weekend ( P <0.01 ), but there were no significant difference between group A and group B. (3) LVEF, LVPS were no significant difference between group A and group B.Conclusions (1)pPCI in acute myocardial infartion can limit infarct area, maintain ventricular systolic synchrony and improve ventricular function; (2) but, in those hospitals that there were no any condition for PCI, they should transfer the patients to central hospital for PCI after thrombolysis at the first time. It is beneficial to improve myocardial viability and ventricular systolic synchrony of AMI patients in short time.

Aniracetam attenuates H_2O_2-induced deficiency of neuron viability, mi-tochondria potential and hippocampal long-term potentiation of mice in vitro

Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer＇s disease （AD） and aging. The present study examines the protective effects of aniracetam against H2O2- induced toxicity to neuron viability, mitochondria potential and hippocampal long-term potentiation （LTP）. Methods Tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide （MTT） was used to detect neuronal viability. MitoTracker Red （CMX Ros）, a fluorescent stain for mitochondria, was used to measure mitochondria potential. Electrophysiological technique was carried out to record hippocampual LTE Results H2O2 exposure impaired the viability of neurons, reduced mitochondria potential, and decreased LTP in the CA region of hippocampus. These deficient effects were significantly rescued by pre-treatment with aniracetam （10 ～100μmol/L）. Conclusion These results indicate that aniracetam has a strong neuroprotective effect against H2O2-induced toxicity, which could partly explain the mechanism of its clinical application in neurodegenerative diseases.

Influence of perfusate on liver viability during hypothermic machine perfusion

AIM: To optimize the perfusates used for hypothermicmachine perfusion(HMP).METHODS: Sprague-Dawley rats were assigned randomly to three groups(n = 12 per group) that received either saline, University of Wisconsin coldstorage solution(UW) or histidine-tryptophan-ketoglutarate solution(HTK) as the perfusate. Each group was divided into two subgroups: static cold storage(SCS) and HMP(n = 6 per subgroup). The liver graft was retrieved according to the method described by Kamada. For the SCS group, the graft was directly placed into cold perfusate(0-4?℃) for 6 h after liver isolation while the portal vein of the graft was connected to the perfusion machine for the HMP group. Then the perfusates were collected at different time points for analysis of aspartate aminotransferase(AST), alanine transaminase(ALT) and lactate dehydrogenase(LDH) levels. Liver tissues were obtained for evaluation of histology, dry/wet weight(D/W) ratio, and malondialdehyde(MDA) and adenosine-triphosphate(ATP) levels. The portal vein pressure and velocity were monitored in real time in all HMP subgroups.RESULTS: Comparison of HMP and SCS: Regardless of the perfusate, HMP improved the architecture of donor graft in reducing the congestion around sinusoids and central vein and maintaining sinusoid lining in morphology; HMP improved liver function in terms of ALT, AST and LDH, especially during the 3-6 h period(SCS vs HMP using saline: ALT3, 225.00 ± 105.62 vs 49.50 ± 18.50, P = 0.047; LDH3, 1362.17 ± 563.30 vs 325.75 ± 147.43, P = 0.041; UW: LDH6, 2880.14 ± 948.46 vs 2135.00 ± 174.27, P = 0.049; HTK, AST6, 307.50 ± 52.95 vs 185.20 ± 20.46, P = 0.041); HMP decreased MDA level(saline, 2.79 ± 0.30 vs 1.09 ± 0.09, P = 0.008; UW, 3.01 ± 0.77 vs 1.23 ± 0.68, P = 0.005; HTK, 3.30 ± 0.52 vs 1.56 ± 0.22, P = 0.006). Comparison among HMP subgroups: HTK showed less portal vein resistance than UW and saline(vs saline, 3.41 ± 0.49 vs 5.00 ± 0.38, P < 0.001; vs UW, 3.41 ± 0.49 vs 4.52 ± 0.63, P = 0.007); UW reduced edema most efficiently(vs saline, 0.68 ± 0.02 vs 0.79 ± 0.05, P = 0.013), while HTK maintained ATP levels best(vs saline, 622.60 ± 29.11 vs 327.43 ± 44.66, P < 0.001; vs UW, 622.60 ± 29.11 vs 301.80 ± 37.68, P < 0.001).CONCLUSION: HMP is superior to SCS in maintaining both architecture and function of liver grafts. Further, HTK was found to be the optimal perfusate for HMP.

Protective Effects of Trimetazidine on Bone Marrow Mesenchymal Stem Cells Viability in an ex vivo Model of Hypoxia and in vivo Model of Locally Myocardial Ischemia

Bone marrow mesenchymal stem cells (MSCs) have shown potential for cardiac repair following myocardial injury,but this approach is limited by their poor viability after transplantation.The present study was to investigate whether trimetazidine (TMZ) could improve survival of MSCs in an ex vitro model of hypoxia,as well as survival,differentiation,and subsequent activities of transplanted MSCs in rat hearts with acute myocardial infarction (AMI).MSCs at passage 3 were examined for their viability and apoptosis under a transmission electron microscope,and by using flow cytometry following culture in serumfree medium and exposure to hypoxia (5% CO2,95% N2) for 12 h with or without TMZ.Thirty Wistar rats were divided into 3 groups (n=10 each group),including groupⅠ(AMI control),groupⅡ (MSCs transplantation alone),and group Ⅲ (TMZ+MSCs).Rat MSCs (4×107) were injected into peri-infarct myocardium (MSCs group and TMZ+MSCs group) 30 min after coronary artery ligation.The rats in TMZ+MSCs group were additionally fed on TMZ (2.08 mg?kg-1?day-1) from day 3 before AMI to day 28 after AMI.Cardiac structure and function were assessed by echocardiography at 28th day after transplantation.Blood samples were collected before the start of TMZ therapy (baseline),and 24 and 48 h after AMI,and inflammatory cytokines (CRP,TNF-α) were measured.Then the sur-vival and differentiation of transplanted cells in vivo were detected by immunofluorescent staining.The cellular apoptosis in the peri-infarct region was detected by using TUNEL assay.Furthermore,apoptosis-related proteins (Bcl-2,Bax) within the post-infarcted myocardium were detected by using Western blotting.In hypoxic culture,the TMZ-treated MSCs displayed a two-fold decrease in apoptosis under serumfree medium and hypoxia environment.In vivo,cardiac infarct size was significantly reduced,and cardiac function significantly improved in MSCs and TMZ+MSCs groups as compared with those in the AMI control group.Combined treatment of TMZ with MSCs implantation demonstrated further decreased MSCs apoptosis,further increased MSCs viability,further decreased infarct size,and further improved cardiac function as compared with MSCs alone.The baseline levels of inflammatory cyto-kines (CRP,TNF-α) had no significant difference among the groups.In contrast,all parameters at 24 h were lower in TMZ+MSCs group than those in MSCs group.Furthermore,Western blotting indicated that the expression of antiapoptotic protein Bcl-2 was upregulated,while the proapoptotic protein Bax was down-regulated in the TMZ+MSCs group,compared with that in the MSCs group.It is suggested that implantation of MSCs combined with TMZ treatment is superior to MSCs monotherapy for MSCs viability and cardiac function recovery.

Effects of different drying methods on quality,bacterial viability and storage stability of probiotic enriched apple snacks

Effects of four different drying methods on the colour, texture, sensory quality, microstructure, bacterial viability and storage stability of probiotic-enriched apple snacks were assessed. The drying methods were air drying （AD）, freeze drying （FD）, freeze drying followed by microwave vacuum drying （FD＋MVD） and air drying followed by explosion puffing drying （AD＋EPD）. Overall, FD＋MVD can be used as a suitable drying method for the development of probiotic enriched apple snacks in consideration of colour, texture, sensory quality, bacterial viability and storage stability. Probiotic bacteria in FD＋MVD-dried samples remained above 1×106 CFU g 1 for 120 days at 25℃C. Interestingly, bacterial viability in FD＋MVD-dried samples turned out to be significantly higher than FD-dried samples during storage for 120 days.

Effect of human autologous serum and fetal bovine serum on human corneal epithelial cell viability,migration and proliferation in vitro

AIM： To analyze the concentration-dependent effects of autologous serum （AS） and fetal bovine serum （FBS） on human corneal epithelial cell （HCEC） viability, migration and proliferation. METHODS： AS was prepared from 13 patients with non- healing epithelial defects Dulbecco＇s modified eagle medium/ Ham＇s F12 （DMEM/F12） with 5% FBS, 0.5% dimethyl sulphoxide （DMSO）, 10 ng/mL human epidermal growth factor, 1% insulin-transferrin-selenium, then were incubated in serum media： DMEM/F12 supplemented by 5%, 10%, 15% or 30% AS or FBS. HCEC viability was analyzed using cell proliferation kit XTI＇, migration using a wound healing assay, proliferation by the cell proliferation enzyme-linked immunosorbent assay （ELISA） BrdU kit. Statistical analysis was performed using the generalized linear model, the values at 30% AS or 30% FBS were used as the baselines. RESULTS： HCEC viability was the highest at 30% AS or 15% FBS and the lowest at 10% AS or 30% FBS application. HCEC migration was the quickest through 30% AS or 30% FBS and the slowest through 5% AS or 5% FBS concentrations. Proliferation was the most increased through 15% AS or 5% FBS and the least increased through 30% AS or 30% FBS concentrations. HCEC viability at 10% and 15% AS was significantly worse （P=0.001, P=0.023） compared to baseline and significantly better at 15% FBS （P=0.003） concentrations. HCEC migration was significantly worse （P〈0.007） and HCEC proliferation significantly better （P〈0.001） in all concentration groups compared to baseline. CONCLUSION： For the best viability of HCEC 30% AS or 15% FBS, for HCEC migration 30% AS or 30% FBS, for proliferation 15% AS or 5% FBS should be used. Therefore, we suggest the use of 30% AS in clinical practice.

Impact of crosslinking/riboflavin-UVA-photodynamic inactivation on viability,apoptosis and activation of human keratocytes in vitro

Riboflavin-UVA photodynamic inactivation is a potential treatment altemative in therapy resistant infectious keratitis. The purpose of our study was to determine the impact of riboflavin-UVA photodynamic inactivation on viability, apop- tosis and activation of human keratocytes in vitro. Primary human keratocytes were isolated from human corneal buttons and cultured in DMEM/Ham＇s F12 medium supplemented with 10% fetal calf serum. Keratocytes underwent UVA light illumination （375 nm） for 4.10 minutes （2 J/cm2） during exposure to different concentrations of riboflavin. Twenty-four hours after treatment, cell viability was evaluated photometrically, whereas apoptosis, CD34 and alpha-smooth muscle actin （α-SMA） expression were assessed using flow cytometry. We did not detect significant changes in cell viability, apoptosis, CD34 and α-SMA expression in groups only treated with riboflavin or UVA light. In the group treated with riboflavin-UVA-photodynamic inactivation, viability of keratocytes decreased significantly at 0.1% riboflavin （P〈0.01） while the percentage of CD34 （P〈0.01 for both 0.05% and 0.1% riboflavin） and alpha-SMA positive keratocytes （P〈0.01 and P〈0.05 for 0.05% and 0.1% riboflavin, respectively） increased significantly compared to the controls. There was no significant change in the percentage of apoptotic keratocytes compared to controls at any of the used ribo- flavin concentrations （P=0.09 and P=0.13）. We concluded that riboflavin-UVA-photodynamic-inactivation decreases viability of myofibroblastic transformation and multipotent haematopoietic stem cell transformation; however, it does not have an impact on apoptosis of human keratocytes in vitro.

Effect of recombinant human platelet-derived growth factor B on cat corneal endothelial cell viability mediated by adeno-associated virus

AIM: To transduce recombinant human platelet-derived growth factor B (PDGF-B) gene adeno-associated virus(AAV) to in vitro cultured cat corneal endothelial cell (CEC) and observe the effect of the expressed PDGF-BB protein on the viability of cat CEC. METHODS: Cat cornea endothelium was torn under microscope and rapidly cultivated in DMEM to form single layer CEC and the passage 2 endothelial cells were used in this study. The recombinant human PDGF-B gene AAV was constructed and transduced into cat CEC directly. Three groups were as following: blank control group, AAV control group and recombinant AAV group. At 24 hours, 48 hours, and 5 days after transduction, total RNA was extracted from the CEC by Trizol and the expression of PDGF-B gene was detected by fluorescence quantitative polymerase chain reaction. Viability of the transduced CEC was detected at 48 hours after transduction by MTT assay. Cell morphology was observed under inverted phase contrast microscope. RESULTS: With the torn endothelium culture technique, we rapidly got single layer cat CEC. At 24 hours, 48 hours and 5 days after transduction, fluorescence quantitative polymerase chain reaction showed there was no significant difference of the expressed PDGF-B gene mRNA between blank control group and AAV control group (P>0.05). In contrast, there were significant differences between two control groups and recombinant AAV group (P<0.05). MTT assay showed that in recombinant AAV group, the expressed PDGF-BB protein could promote the viability of cat CEC. Morphology observation showed at 48 hours after transduction, cells in CEC-AAV-PDGF-B group proliferated into bigger scales in regular triangle to hexagon shape with distinct boundary, while the number of cells was significantly less in the two control groups. CONCLUSION: The recombinant AAV-PDGF-B expresses biological active PDGF-BB protein in cat CEC, which promotes the viability and proliferation of cells.

Characteristics and Warning Indexes of Rice Seeds Viability Loss During Storage at 45℃ Constant Temperature

Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor during aging process were measured to study seed viability-losing characteristic and to determine warning index for seed viability loss. As a result, seed viability survival curves were obtained across different rice accessions at 45℃ constant temperature. The curves appeared to be contra-sigmoid survival curves. The loss of seed viability in the aging process consisted of two phases. The first phase took a long duration, in which the viability of vigorous seeds declined slowly. In the second phase, seed viability declined rapidly. It was obvious that seed viability declined inconsistently during storage. It also showed that seed germination was prolonged and the seedling was significantly weakened before the coming of the rapid declining phase of seed viability. These two parameters could be used to indicate seed quality during storage. The rate of compatibility of tests (RCT), coefficient of variation (CV), vigor of seedling, the day the seeds start to germinate could be used as warning indexes to indicate overall quality of a mass of accessions. These warning indexes could also be used in monitoring the viability of seeds stored in the seed genebank.