Gamma Irradiation of Embryogenic Callus Cultures and In vitro Selection for Salt Tolerance in Sugarcane (Saccharum officinarum L.)

Radiation induced mutagenesis followed by in vitro selection was employed for salt tolerance in popular Indian sugarcane （Saccharum officinarum L.） cv. CoC-671. Embryogenic calli were gamma irradiated and exposed to different levels of NaCl （42.8, 85.6, 128.3, 171.1,213.9, 256.7, 299.5, or 342.2 mM）. The relative growth rate （RGR） decreased progressively with increasing salt stress and was the least with a salt stress of 256.7 mM （0.25±0.009）, almost 10 fold lesser than the control. The RGR was significantly lower in 85.6 mM and higher salt stressed calli than the control. The survival percent also decreased, with an increase in NaCl concentration. In case of 10 and 20 Gy irradiated calli, regeneration was observed up to 85.6 mM NaCl selection, medium, whereas, higher treatments （128.3 mM and beyond） exhibited browning initially. However, in the subsequent subcultures, regeneration was obtained in the case of 10 and 20 Gy irradiated calli on 128.3 and 171.1 mM NaCl selections. Higher dose of gamma irradiation （40 Gy） also showed regeneration, but only with 85.6 mM NaCI selection. The unirradiated calli regenerated the highest number of plantlets followed by 10 and 20 Gy irradiated calli on salt selection. A total of 147 plantlets were selected from different salt levels. The salt selected plants are being tested for their field performance.

In Vitro Selection and Identification of Drought-Tolerant Mutants in Sweetpotato

In vitro selection of drought-tolerant mutants in sweetpotato cv. Lizixiang was studied by using PEG6000 as selection stress. Embryogenic suspension cultures were cultured in MS medium containing 035% PEG6000 and 2 mg L 1 2,4-dichlorophenoxyacetic acid (2,4-D). The results indicated that 30% PEG6000 can be used for the optimal selection stress of drought-tolerance. Embryogenic suspension cultures irradiated with 80 Gy gamma-ray were cultured in MS medium containing 30% PEG6000 and 2 mg L 1 2,4-D and 20 drought-tolerant cell aggregates were obtained. These cell aggregates were transferred to solid MS me- dium supplemented with 2 mg L 1 2,4-D and formed embryogenic callus with somatic embryos. The embryogenic callus with somatic embryos was further transferred to MS medium supplemented with 1 mg L 1 abscisic acid (ABA), resulting in the germination of somatic embryos. In this study a total of 18 regenerated plants were obtained. The regenerated plants were transplanted in a greenhouse and 11 lines were formed. The analysis on drought treatment of seedlings, water retaining capacity of leaves and coefficient of drought-tolerance showed that 3 lines had significant drought-tolerance in comparison with the control plants.

Effect of Gamma Irradiation and Selection with Fungus Filtrate(Rhizoctonia solani Kuhn)on the in Vitro Culture of Common Bean(Phaseolus vulgaris)

The present investigation was undertaken to study the effect of gamma irradiation (dose from 10 to 100 Gy) and in vitro selection with fungus filtrate as selecting agent (concentration from 20% to 100%) on the susceptibility of the common bean to Rhizoctonia solani. The best results were found with a dose of 20 Gy or a concentration of 20% of fungus filtrate applied separately. These conditions were used to evaluate the combined effect of both approaches in a second experiment. The combined effect of irradiation and then selection adversely affected growth (height and roots) and survival of the in vitro plants. It may not be necessary to combine the variation generated by irradiation with the selection technique. For future assays we propose the application of: 1) gamma radiation, thereby inducing not only mutants with pathogen resistance, but also with other agronomic traits of interest. Later in the subculture MV4 potential fungus-resistant mutants will be evaluated in the field;or 2) selection pressure using fungus filtrate during three subcultures, which may be sufficient to induce the variation necessary to obtain in vitro plants resistant to fungus.

Insight into the preformed albumin corona on in vitro and in vivo performances of albumin-selective nanoparticles

Preformed albumin corona of albumin-nonselective nanoparticles(NPs)is widely exploited to inhibit the unavoidable protein adsorption upon intravenous administration.However,very few studies have concerned the preformed albumin corona of albumin-selective NPs.Herein,we report a novel type of albumin-selective NPs by decorating 6-maleimidocaproyl polyethylene glycol stearate(SA)onto PLGA NPs(SP NPs)surface,taking albuminnonselective PLGA NPs as control.PLGA NPs and SP NPs were prepared by emulsion-solvent evaporation method and the resultant NPs were in spherical shape with an average diameter around 180 nm.The corresponding albumin-coating PLGA NPs(PLGA@BSA NPs)and albumin-coating SP NPs(SP@BSA NPs)were formulated by incubating SP NPs or PLGA NPs with bovine serum albumin solution,respectively.The impact of albumin corona on particle characteristics,stability,photothermal effect,cytotoxicity,cell uptake,spheroid penetration and pharmacokinetics was investigated.In line with previous findings of preformed albumin coating,PLGA@BSA NPs exhibited higher stability,cytotoxicity,cell internalization and spheroid penetration performances in vitro,and longer blood circulation time in vivo than those of albumin-nonselective PLGA NPs,but albumin-selective SP NPs is capable of achieving a comparable in vitro and in vivo performances with both SP@BSA NPs and PLGA@BSA NPs.Our results demonstrate that SA decorated albumin-selective NPs pave a versatile avenue for optimizing nanoparticulate delivery without preformed albumin corona.

SELECTIVE TOXICITY OF RHODAMINE 123 ON CARCINOMA CELL IN VITRO

The selective toxicity of the mitochondria-specific cationic fluorescent dye rhodamine 123 (Rh-123) on He La cells in culture was studied. In this report, we demonstrate that with continuous exposure, Rh-123 markedly inhibited the growth of HeLa cells but had little effect on normal human kidney fibroblasts. With continuous exposure to Rh-123, the growth rate, colony forming ability, anl mitotic index of HeLa cells were decreased. The mechanism of toxicity of Rh-123 on HeLa cells was investigated by EM and enzyme cytochemistry stain. The mitochondria of carcinoma cells were the main targets for the inhibitory action of Rh-123, since they selectively accumulated the dye. At the dosage of Rh-123 which was toxic to HeLa cells, the structure and function of mitochondria were disrupted, as the mitochondria-related enzymes, i.e., ATPase, LDH and SDH were inhibited. The possible mechanism of the action of Rh-123 on HeLa cells is briefly discussed.

北京医院临床检验体外诊断试剂的遴选与优化管理实践

目的形成临床检验体外诊断试剂(in vitro diagnostic reagents,IVD)遴选与优化的管理方案和管理数据库,优化IVD管理工作。方法对政策背景和北京医院临床检验IVD的管理现状进行分析,基于临床需求,制定已开展和新申请检验项目IVD的遴选与优化管理方案,通过梳理项目、公开招标、创新报价方式、现场评审等步骤,对全院IVD进行遴选和优化,形成北京医院IVD管理数据库和资质数据库,并从合规性、工作效率和成本管控方面进行效果评估。结果按照制定的IVD遴选与优化管理方案完成全院1737项IVD的遴选和优化工作,管理方案的实施提高了工作效率,平均一次会议评审的内容增加10倍以上,加快了新申请IVD准入频率;降低了IVD成本,全院采购金额平均降幅约15%,重点IVD产品遴选后较遴选前价格降低,且差异具有统计学意义(t=2.493,P=0.034)。结论IVD遴选与优化的管理方案切实可行,可以达到“保合规,提效率,降成本”的目标。

Evolution of chemistry and selection technology for DNA-encoded library

DNA-encoded chemical library(DEL)links the power of amplifiable genetics and the nonself-replicating chemical phenotypes,generating a diverse chemical world.In analogy with the biological world,the DEL world can evolve by using a chemical central dogma,wherein DNA replicates using the PCR reactions to amplify the genetic codes,DNA sequencing transcripts the genetic information,and DNA-compatible synthesis translates into chemical phenotypes.Importantly,DNA-compatible synthesis is the key to expanding the DEL chemical space.Besides,the evolution-driven selection system pushes the chemicals to evolve under the selective pressure,i.e.,desired selection strategies.In this perspective,we summarized recent advances in expanding DEL synthetic toolbox and panning strategies,which will shed light on the drug discovery harnessing in vitro evolution of chemicals via DEL.

基于综合评分的体外诊断试剂遴选与准入机制

面对医疗技术快速发展和体外诊断试剂需求增长带来的挑战,为确保试剂质量和安全并有效控制成本,避免传统采购工作存在的遴选方式主观化、效率低、质量安全难以保证及频繁更换产品、成本控制不佳等问题,医院建立了基于综合评分的体外诊断试剂遴选与准入机制。该机制通过明确采购需求、编制磋商公告和磋商文件、公开邀请供应商参与磋商、试用样品经临床实验室性能验证、现场二次磋商等步骤,并由专家评审团队根据综合评分表对供应商投标产品进行评分,以实现对产品和供应商的严格筛选,使筛选标准更具象化、客观化。该机制实际实施过程中确保了磋商过程公平竞争,增强了体外诊断试剂采购的透明度,提升了体外诊断试剂遴选过程的竞争性,帮助医院精准选择符合需求的体外诊断试剂产品和供应商。

Development of peanut varieties with high oil content by in vitro mutagenesis and screening

Peanut (Arachis hypogaea L.) is an important oil crop globally and high oil content is one of the major targets in peanut breeding programs. Previous studies indicated that the osmotic pressure (OP) of the leaves of peanut plants subjected to drought stress was negatively correlated with kernel oil content. Based on this knowledge, we established a practical and reliable method for creating new peanut varieties with high oil content using in vitro mutagenesis and directional OP-based selection. Using embryonic leaflets of peanut variety Huayu 20 as explants, pingyangmycin (PYM) as the mutagen, and hydroxyproline (HYP) as the OP regulator, we developed 15 HYP-tolerant regenerated plants. For each regenerated plant, we selected offspring with oil content>55% (relative to 49.5% for Huayu 20). We developed and released three new peanut varieties with high yield and high oil content from the offspring of the HYP-tolerant regenerated plants. The three new varieties were named as Yuhua 4, Yuhua 9 and Yuhua 14 and their oil contents were 57.7, 61.1 and 59.3%, respectively. The results indicate that in vitro mutagenesis with PYM followed by directed screening with HYP is a useful approach for breeding peanut varieties with high oil contents.

深度学习在体外受精胚胎优选中的应用

挑选移植胚胎对提高体外受精-胚胎移植周期成功率至关重要。当前最常用的挑选胚胎方法是胚胎形态学评估,其高度依赖于实验室技术人员的主观视觉印象和个人经验,影响胚胎优选的准确性和一致性。近年有学者尝试将深度学习算法引入移植胚胎的选择,基于大量人工标记的胚胎图像/视频建立质量评估和结局预测模型,发现深度学习模型具备客观、准确、高效及稳定等优点。综述深度学习模型优选胚胎研究现状,并与人工胚胎形态学评估和经典机器学习算法的性能进行比较,进一步探讨其在辅助生殖中的应用价值。

In vitro Selection for Fusarium Wilt Resistance in Gladiolus

Cormels pieces of four Fusarium susceptible Gladiolus cultivars （Friendship, Peter Pears, Victor Borge and Novalux） formed friable calli when cultured in vitro on Murashige and Skoog basal medium containing various concentrations of auxin and cytokinin. The friable calli established cell suspensions. Plantlet regeneration was obtained from the control callus, control cell suspension derived callus and in vitro selected Fusarium oxysporum Schlecht. resistant cell-lines of Friendship. The in vitro cormlets showed 85-95% germination after breaking dormancy of 8 weeks at 4℃. Cell suspensions of all four Gladiolus cultivars were found to be highly sensitive to fusaric acid. Gradual increase in fusaric acid concentrations to the cell-suspension cultures decreased cell growth considerably. One albino plant was found from the second generation of the in vitro selected cell line of Friendship. The albino plant was found to be highly susceptible to F. oxysporum. The cormlets of all in vitro selected cell lines of Friendship were inoculated with a conidial suspension of the F. oxysporum before planting and were also sprayed with the same spore suspension for further characterization when the height of plants was about 6cm. The four selected cell lines showed the same response whether or not they were inoculated with conidia of the F. oxysporum. Plantlets of all of the selected cell lines exhibited significant growth as compared with the control after application of conidia of the F. oxysporum.

浮游器优选精子方法对体外受精胚胎发育结局的影响

目的探讨密度梯度离心结合上游法和浮游器上游法优化精子对两种体外受精IVF/ICSI胚胎发育的影响。方法回顾性分析2021年3月~2022年2月在海南省妇女儿童医学中心生殖医学中心行IVF/ICSI治疗周期的病例。分为密度梯度离心结合上游法(IVF周期:n=276;ICSI周期:n=79)和浮游器上游法(IVF周期:n=126;ICSI周期:n=78),比较两组精子优化方法在IVF/ICSI治疗周期中的受精率、卵裂率、优质胚胎率、囊胚形成率及可利用囊胚率等指标之间的差异。结果IVF周期浮游器上游法组的双原核受精率为(72.2±19.9)%显著高于密度梯度离心结合上游法组(68.0±18.0)%,差异有统计学意义(P<0.05)。浮游器上游法组多原核受精率显著低于密度梯度离心结合上游法组(5.3±9.1)%vs(7.4±9.9)%;浮游器上游法组优质囊胚率(62.6±33.0)%显著高于密度梯度离心结合上游法组:(53.2±34.0)%,差异均有统计学意义(P<0.01)。ICSI周期的浮游器上游法组D3优质胚胎率为(38.0±27.7)%,显著高于密度梯度离心结合上游法组(28.2±25.3)%;浮游器上游法组优质囊胚率为(52.6±37.0)%,显著高于密度梯度离心结合上游法组(40.2±38.3)%,差异均有统计学意义(P<0.05)。结论浮游器上游法优化精子后可获得更高的正常受精率和优质胚胎率,降低多原核受精率,减少精子损伤,提高胚胎质量。

茄子抗黄萎病突变体离体筛选 Ⅱ.突变体筛选

针对茄子黄萎病育种中缺乏高抗材料,作者利用生物技术和理化诱变技术,开展了茄子抗黄萎病突变体的离体筛选,并获得得一株黄萎病抗性为中抗(病情指数为23 0)、农艺性状较好的"三月茄"突变体(142 E),其自交群体的染色体也与三月茄野生型相同。

甘薯耐旱突变体的离体筛选与鉴定

以甘薯品种栗子香为材料 ,用PEG6 0 0 0作为耐旱性突变体离体筛选的选择剂 ,将栗子香胚性悬浮细胞培养在含有 0～ 35 % (w/v)PEG6 0 0 0和 2 .0mg·L-12 ,4 D的液体MS培养基中。结果表明 ,甘薯耐旱性离体筛选的适宜选择压为 30 %PEG6 0 0 0。采用多步选择法 ,在含有 30 %PEG6 0 0 0和 2 .0mg·L-12 ,4 D的液体MS培养基中对经 80Gyγ射线辐照的栗子香胚性悬浮细胞进行离体筛选 ,获得了 2 0个耐旱性小细胞团。将这些小细胞团转移到添加2 .0mg·L-12 ,4 D的固体MS培养基上 ,获得了耐旱胚性愈伤组织 ,并形成体细胞胚。将具有体细胞胚的胚性愈伤组织进一步转移到添加 1.0mg·L-1ABA的MS培养基上 ,体细胞胚发芽形成完整植株 ,共获得 18株再生植株。将获得的 18株再生植株移栽到温室 ,获得 11个株系。用苗期干旱处理、叶片保水力及耐旱系数等指标对这 11个株系进行耐旱性分析 ,其中 3个株系的耐旱性显著高于对照。

利用细胞工程技术筛选小麦抗根腐病突变体的研究

以小麦根腐病菌002号菌株产生的致病培养滤液为选择剂,选用春、冬小麦品种、品系以及杂种的花药和幼德进行离体培养,并结合物理诱变技术,已获得抗根腐病的植株,用根腐病菌分生孢子接种鉴定,再生植株50株中有12株抗病。

番茄耐盐体细胞变异体的离体筛选

以上海主要栽培番茄品种“鲜丰”的下胚轴作为外植体诱导愈伤组织 ,用 Na Cl进行直接高盐胁迫和逐渐加大盐浓度胁迫筛选。研究结果表明 ,逐渐加大 Na Cl浓度胁迫筛选获得的耐盐性大多属生理适应性 ,直接高盐胁迫筛选才有可能获得真正的耐盐突变体。直接高盐胁迫筛选再生出的 1 2株耐盐植株 ,在 1 5 0 mmol/L Na Cl的盐胁迫下 ,幼苗的成活率可达6 6 % ,而未经胁迫筛选过的原始株成活率则为零。其中 ,2株耐盐突变株能正常开花、结果。其后代在盐胁迫培养基中芽体的生根率。

体外诱导嗜水气单胞菌对喹诺酮类耐药及其耐药机制研究

【目的】探讨在亚抑菌浓度喹诺酮类药物培养后,嗜水气单胞菌Aeromonas hydrophila对喹诺酮类的药物敏感性变化及其耐药机制.【方法】以对喹诺酮类敏感的临床分离嗜水气单胞菌菌株和标准菌ATCC7966为研究对象,分别在含亚抑菌浓度萘啶酸(NAL)和环丙沙星(CIP)的培养基上逐步诱导培养.提取诱导菌的DNA,PCR扩增其gryA和parC基因,测序分析其喹诺酮类耐药决定区(QRDR)突变情况;测定诱导菌对诱导药物和11种非诱导药物的最小抑菌浓度(MIC)及添加外排泵抑制剂羰基氰化氯苯腙(CCCP)后的MIC,分析其敏感性变化与基因突变、外排作用的关系.【结果和结论】诱导后菌株对萘啶酸和环丙沙星的MIC分别提高了1 024和64 000倍,对非诱导药物也有不同程度提高;当萘啶酸和环丙沙星诱导浓度分别达到16和32μg/mL或以上后,诱导菌株gyrA基因编码的氨基酸分别发生Asp87→Tyr和Ser83→Arg的变化,但两者parC基因编码的氨基酸均没有发生突变;添加CCCP后,只有氟喹诺酮类药物的MIC值略有下降,提示嗜水气单胞菌对喹诺酮类耐药存在靶基因突变及主动外排作用等多种耐药机制.

节瓜抗枯萎病变异体离体筛选研究初报

利用镰刀菌酸（FA）为胁迫剂，以节瓜不定芽为筛选材料，进行节瓜抗枯萎病变异体离体筛选技术的研究，初步试验结果表明FA胁迫的适宜浓度为75～100mg／L。经过筛选的细胞系对FA的抗性较未经筛选的细胞系明显增强。初步建立了节瓜抗性变异体离体筛选体系，获得了抗FA变异体再生植株的自交种子。

杜鹃抗盐突变体的筛选

利用杜鹃的离体叶片诱导不定芽 ,发现MS +BA2 0ppm +ZT0 1ppm培养基不定芽分化率最高。用γ射线作诱变剂 ,对离体叶片产生的不定芽进行了耐盐筛选 ,得到了耐 0 5%、0 7%和 1 %NaCl的变异株系 ,并对变异株系进行了初步鉴定。

节丛孢属真菌抗反刍动物消化菌株的体外筛选

利用食线虫真菌对动物寄生线虫病进行生物防治是寄生虫学当今的研究热点之一。获得能够通过动物消化道的食线虫菌株是取得成功的前提。本文采用模拟反刍动物瘤胃和真胃的消化道作用，对８４株节丛孢属的食线虫真菌进行了体外抗消化筛选。结果表明：共有２３株通过了２４ｈ瘤胃液的处理，通过率为２７．３８％；１６株同时还通过了４ｈ盐酸－胃蛋白酶的处理，通过率为１９０４％。