Developmental Regulation and Biological Functions of Root Border Cells in Higher Plants

Root border cells, previously referred to as sloughed root cap cells, is a special cell population which separates in large numbers from the periphery of the root cap and accumulates in the root tip. Recent evidence reveals that border cells, whose development is regulated by endogenous and exogenous signals, are biologically viable in the majority of higher plant species. As soon as border cells detach from root cap periphery, their metabolic activity dramatically increases in accordance with a differential gene expression from that in root cap cells. Recently, PsUGT1 and RCPME1, relevant to the early and late stage of border cell development, respectively, have been cloned and functionally identified. Border cells can synthesize specially and export a diverse array of chemicals including anthocyanins, antibiotics, special enzymes and other substances, that either inhibit or promote the growth of other entities in rhizosphere such as bacteria, fungi, viruses, and nematodes, and also antagonize some toxic chemicals around the root tip in soil such as aluminum toxicity. Therefore, there are multiple biological roles played by border cells during plant growth and development.

Developmental Characteristics and Cinnamic Acid Resistance of Root Border Cells in Cucumber and Figleaf Gourd Seedlings

Root border cells （RBCs） originate from the root tip epidermis and surround the root apices. In this study, we evaluated the developmental characteristics and the roles of RBCs in protection of root apices of cucumber and ifgleaf gourd seedlings from CA toxicity. The formation of RBCs and the emergence of the root tip occurred almost simultaneously in root apices of cucumber and ifgleaf gourd seedlings. CA ranging from 0 to 0.25 mol L-1 inhibited root elongation and decreased root cell viability in the root tip, moreover the inhibitory effects of CA were more signiifcant in the CA-sensitive cucumber than in the CA-tolerant ifgleaf gourd. Removal of RBCs from root tips led to more severe CA induced inhibition of root elongation and decline in root cell viability. Increasing CA levels and treatment time decreased the relative viability of attached and detached RBCs. CA also induced a thicker mucilage layer surrounding attached RBCs of both species. Additionally, a signiifcantly higher relative cell viability of attached RBCs and thicker mucilage layers were observed in ifgleaf gourd. These results suggest that RBCs play an important role in protecting root tips from CA toxicity.

Developmental characteristics and response to iron toxicity of root border cells in rice seedlings

To investigate the Fe^2＋ effects on root tips in rice plant, experiments were carried out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20---25 mm root length. This mortality was more pronounced at the first 1-12 h exposure to 250 mg/L Fe^2＋ than at the last 12-36 h. After 36 h, the cell viability exposed to 250 mg/L Fe^2＋ decreased to nought, whereas it was 46.5% at 0 mg/L Fe^2＋. Increased Fe^2＋ dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe^2＋ treatment, the cell viabilities were _〉80% at 0 and 50 mg/L Fe^2＋ treatment and were 〈62% at 150, 250 and 350 mg/L Fe^2＋ treatment; The viability of border cells decreased by 10% when the Fe^2＋ concentration increased by 100 mg/L. After 24 h Fe^2＋ treatment, the viabilities of border cells at all the Fe^2＋ levels were 〈65%; The viability of border cells decreased by 20% when the Fee＋ concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe^2＋ dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.

The leaf extract of crofton weed(Eupatorium adenophorum)inhibits primary root growth by inducing cell death in maize root border cells

The extract of crofton weed(Eupatorium adenophorum) inhibits seed germination and weed growth;however,the physiological mechanisms underlying the effect of crofton weed extract on the modulation of seedling growth and root system development remain largely unclear.In this study,we investigated the effects of the leaf extract of crofton weed(LECW) on primary root(PR) growth in maize seedlings.Treatment with LECW markedly inhibited seed germination and seedling growth in a dose-dependent manner.Physiological analysis indicated that the LECW induced reactive oxygen species(ROS) accumulation in root tips,thereby leading to cell swelling and deformation both in the root cap and elongation zone of root tips,finally leading to cell death in root border cells(RBCs) and PR growth inhibition.The LECW also inhibited pectin methyl esterase(PME) activity,thereby decreasing the RBC number.Taken together,our results indicated that the LECW inhibited PR growth by inducing ROS accumulation and subsequent cell death in RBCs.The present study provides a better understanding of how the LECW modifies root system development and provides insight for evaluating the toxicity of crofton weed extracts in plants.

ENHANCEMENT OF RADIATION-INDUCED APOPTOSIS IN RAJI CELL LINE BY BC1-2 ANTISENSE OLIGODEOXYNUCLEOTIDE

Objective: To investigate whether the Bc1-2 antisense oligonucleotide(ASODN) may enhance radiation-induced apoptosis in Raji cell line. Methods: Cell surviving fraction was determined using the trypan blue dye exclusion assay. The expression level of bc1-2 protein was assayed by immunofluorescence using fluoresce isothiocyanate label. Apoptosis was detected by Giemsa staining and flow cytomertric cell cycle analysis. Results: It was found that Bc1-2 ASODN combined with radiation had significantly reduced the number of viable cells (P<0.05). There was no difference on cell survival between mismatch Bc1-2 oligodeoxynucleotide/radiation combination and radiation-treated cells alone. Bc1-2 ASODN combined with radiation could significantly inhibit expression of Bc1-2 protein in Raji cells (P<0.05). Cells treated with Bc1-2 ASODN combined with radiation at 72 h displayed classic apoptotic changes. Apoptosis rates of Raji cells treated with Bc1-2 oligodeoxynucleotide/radiation combination and radiation-treated cells alone, respectively. Conclusion: Bc1-2 antisense oligonucleotide can enhance radiation-induced apoptosis in Raji cell line.

EXPRESSIONS OF P_(53), PROLIFERATING CELL NUCLEAR ANITIGEN,BCL-2 PROTEIN AND THEIR SIGNIFICANCE IN SALIVARY ADENOID CYSTIC CARCINOMA

Objective To study the effects of P53, PCNA, Bc1-2 protein and their relationship in salivary adenoid cystic carclnoma(SACC). Methods These protelns were examlned by lmmunohistochemistry. Results overexpressions of Ps, and PCNA were revealed in ACC samples, they were higher than those in (polymorphous adenomas) PA, but expression of Bc1-2 protein was not different between ACC and PA. In 3 subtypes of ACC, expressions of 3 proteins were different. Conciusion Mutations of P53, Bc1-2 may be involed in the occurrence of SACC, expression of PCNA and mutation of P53 may coexist in the development of the SACC.

迈瑞BC-6900血细胞分析仪在血幼稚粒细胞百分比检测中的应用效果

目的:评价迈瑞BC-6900血细胞分析仪检测血幼稚粒细胞百分比(IMG%)的效果.方法:选取2022年4月—2023年7月南京大学医学院附属苏州医院门诊、体检及住院患者141例,抽取其静脉血,分析迈瑞BC-6900血细胞分析仪与OLYMPUS-CX31RTSF显微镜检测IMG%的相关性,并对迈瑞BC-6900血细胞分析仪检测IMG%进行重复性验证.结果:共98例样本数据参与拟合分析,结果显示迈瑞BC-6900血细胞分析仪与显微镜检测IMG%具有高度相关性(R2=0.956,P<0.001).迈瑞BC-6900血细胞分析仪IMG%提示范围与显微镜检测IMG%相关性分析结果显示,当迈瑞BC-6900血细胞分析仪提示IMG%≤1%时,与显微镜检测符合率相对较低,可以不进行显微镜复查;当提示IMG%>1%,与显微镜检测符合率随之增高,迈瑞BC-6900血细胞分析仪IMG%提示范围与显微镜检测IMG%之间具有正向相关性(r=0.936,P<0.05).本研究选取的5份样本重复性变异系数均<10%.结论:迈瑞BC-6900血细胞分析仪检测IMG%能有效提高样本处理效率及检测结果准确性.

LDBC-Ⅰ全自动血细胞图像分析仪对外周血有核细胞分类能力的验证评价

目的对LD BC-Ⅰ型全自动血细胞图像分析仪的临床性能进行验证及评价。方法收集2016年10~12月福建医科大学附属协和医院门诊EDTA-Na_2抗凝血液样本202例,涂片经瑞氏染色后,分别进行人工镜检和血细胞图像分析仪扫描,比较人工镜检与自动分析仪检测效率及有核细胞分类结果的差异,进一步分析两种方法所测结果的相关性与一致性。结果自动分析仪分析每份标本所用平均时间较人工镜检缩短3.81±2.11min,差异具有统计学意义(t=25.626,P<0.01)。分析仪预分析原始细胞、早幼、中幼及晚幼粒细胞、异型淋巴细胞的符合率分别是71.4%,64.8%,28.8%,21.1%和71.6%。经人工复核后,五种有核细胞诊断符合率提高到87.7%,81.5%,38.1%,26.3%和86.2%。PassingBablok回归法显示,两种方法检测中性粒细胞、淋巴细胞、单核细胞、嗜酸性粒细胞,呈显著正相关(r=0.981,0.894,0.725,0.772,均P<0.01)。Bland-Altman分析显示,两种方法的中性粒细胞、淋巴细胞、单核细胞、嗜酸性粒细胞的符合率分别为96%,96%,91%和94%。结论 LD BC-Ⅰ型血细胞图像全自动分析仪能显著提高有核细胞的分析效率,对成熟的粒细胞、单核细胞及淋巴细胞分类结果与人工镜检一致性好,有一定的临床应用推广价值。

鸡BCs原代培养贴壁性影响因素分析

试验从鸡第X期胚胎中分离囊胚,使用含10%FBS、青霉素和链霉素的高糖DMEM培养基,对鸡X期BCs进行无饲养层培养。分别在6h、12h、24h对细胞贴壁性进行评价,探究分离方法、离散程度、培养细胞密度、离心损伤对细胞培养的影响。结果表明:滤纸环法在分离胚胎上效果最好;细胞离散程度上,吹打20下效果最好,与吹打30下差异不显著(P>0.05),二者与吹打40下差异均显著(P<0.05);接种密度上,1×103个/mL和5×103个/mL两组差异不显著(P>0.05),这两组与其它组,以及其它组之间差异均显著(P<0.05),密度为1×105个/mL时效果最好,5×104个/mL次之,但密度为5×104个/mL时更方便观察;离心处理上,都离心5 min的条件下,5 590×g和1 398×g组差异不显著(P>0.05),但其与224×g处理组差异显著(P<0.05),其中5 590×g组效果最佳。因此,滤纸环法分离胚胎,吹打20下离散细胞,使用5 590×g离心5min,稀释成5×104个/mL的密度,接种到96孔板培养,可以获得较好的结果。

胸腹腔积液及脑脊液标本细胞计数及分类计数中应用迈瑞BC5800仪的临床价值

目的探讨迈瑞BC5800仪在胸腹腔积液及脑脊液标本技术及分类计数中的应用及临床价值。方法取156份脑脊液及胸腹腔积液标本,在BC5800全自动血液分析仪上,以体液模式进行检测,同时取剩余标本进行手工法计数检测,对有核细胞的含量分为低浓度和高浓度2组标本,将获得的DIFF检测结果与手工显微镜计数结果进行比较。结果仪器检测和人工检测有核细胞携带污染率分别为0.02%和0.03%,差异无统计学意义(P>0.05)。仪器检测的胸腹腔积液和脑脊液的白细胞计数、单个核细胞、红细胞及多个核细胞的计数与传统的手工计数结果的相关性较高,对胸腹腔积液总浓度,低浓度,高浓度区间DIFF通道检测结果和手工检测结果的相关系数分别为:0.978、0.952、0.991。脑脊液BC5800检测结果与手工检测结果的相关系数为:0.935。结论 BC5800全自动血液分析仪的体液检测模式,在检测胸腹腔积液及脑脊液细胞计数方面能够满足临床检验的需求,与手工方法检测结果的相关性良好,BC5800可以适用于常规胸腹腔积液和脑脊液标本有核细胞的计数。

迈瑞BC-5500全自动血细胞分析仪的性能评价

目的对迈瑞BC-5500全自动血细胞分析仪进行系统评价。方法按照国际血液学标准化委员会(ICSH)制定的评价标准进行。结果各项指标线性良好(r>0.990),各参数的携带污染率低(<0.01%);在室温或4℃条件下至少可稳定48h,不精密度的CV均<5%;BC-5500与ICSH推荐的参考方法及ABX PENTER 120血细胞分析仪结果间相关性均较好(r>0.97);高胆红素及高血脂对各参数基本无干扰(P>0.05);600例标本的白细胞分类计数(DC)结果显示,BC-5500与参考方法比二者嗜中性粒细胞、淋巴细胞、嗜酸性粒细胞相关性较好,r分别为0.918、0.911、0.882,单核细胞r=0.665,而嗜碱性粒细胞相关性差(r<0.3)。结论BC-5500各方面性能良好,测定全血细胞计数(CBC)参数快速、准确、精密、过筛能力强,对大批量全血标本的CBC与DC进行快速而有效筛检的全自动血细胞分析仪。

BC-5500五分类血细胞分析仪性能评价

目的 对BC-5500全自动五分类血细胞分析仪的主要性能进行评价,并将其与XE-2100进行对比. 方法 依照ICSH、CLSI等标准对BC-5500的携带污染率、精密度、重复性、线性范围、可比性等项目进行评价. 结果 各参数携带污染率均小于1,所有的CBC参数具有较好的精密度与重复性,WBC、RBC、HGB、MCV、PLT的CV值均小于4%;WBC、RBC、HGB、PLT具有良好的线性(相关系数r>0.9998);与XE-2100进行对比,WBC、RBC、HGB、PLT、MCV的相关系数R均大于0.9800;白细胞分类与XE-2100比较,嗜中性粒细胞(Neu%)、淋巴细胞(Lym%)、单核细胞(Mon%)、嗜酸粒细胞(Eos%)、嗜碱性粒细胞(Bas%)的相关系数分别为0.9902、0.9901、0.9145、0.8907、0.5764. 结论 BC-5500具有良好的性能,与XE-2100具有较好的可比性.

BCOR基因敲除促进骨髓间充质干细胞成骨分化的研究

目的研究BCL6共抑制因子-BCOR对骨髓间充质干细胞成骨定向分化能力的影响。方法利用慢病毒载体的BCOR shRNA基因敲除BCOR,进行丧失性功能研究。通过检测ALP活性、茜素红染色、钙离子定量分析、成骨分化相关基因的表达,观察骨髓间充质干细胞体外成骨分化能力。结果 BCOR在牙源性间充质干细胞和骨髓间充质干细胞的表达无明显差异。基因敲除BCOR促进了骨髓间充质干细胞ALP活性、体外矿化能力及成骨分化相关基因骨涎蛋白、骨钙素的表达。结论 BCOR基因表达降低能促进骨髓间充质干细胞成骨分化,证实BCOR是骨髓间充质干细胞成骨分化的抑制基因。

BC-5800血细胞分析仪白细胞警示异常结果人工镜检分析

目的比较分析BC-5800血细胞分析仪白细胞警示异常结果与人工镜检结果。方法选取我院2015年8月至2016年8月采用BC-5800血细胞分析仪检测的380份白细胞合格血液标本,以人工镜检作为"金标准",分析BC-5800血细胞分析仪白细胞警示异常的灵敏度、特异性和准确性。结果 380份白细胞合格血液标本中,221份(58.16%)经人工镜检明确诊断为白细胞异常,BC-5800血细胞分析仪诊断白细胞异常223份(58.68%),比较差异无统计学意义(P>0.05);BC-5800血细胞分析仪检测的灵敏度为87.78%,特异性为81.76%。血细胞分析仪警示异常白细胞中的幼稚细胞、核左移、异常中性粒细胞、异常嗜酸性粒细胞、异常嗜碱性粒细胞经人工镜检复查均有统计学差异(P<0.05),异常单核细胞、异常淋巴细胞比较则无统计学差异(P>0.05)。结论 BC-5800血细胞分析仪在异常白细胞检测中具有较高灵敏度和特异性,对警示异常白细胞行人工镜检复查能提高检测准确性,降低误诊率和漏诊率,具有重要临床意义。

迈瑞BC-7500血细胞分析仪常见故障维修方法

迈瑞BC-7500血细胞分析仪是市场上血细胞计数主流设备之一,血液常规检查是疾病诊断依据,为临床的监测及疗效观察提供了有价值的指标。迈瑞BC-7500血细胞分析仪内部结构复杂,维修成本高,本文介绍了迈瑞BC-7500血细胞分析仪常见故障排除方法,通过分析有效的排除了该设备的常见故障,并介绍了分析故障的细节方法,通过自修,降低了医院维修成本。

BC-6800plus型全自动血细胞分析仪性能评价

目的:对迈瑞BC-6800plus型全自动血液细胞分析仪进行性能评价。方法:根据国家卫生行业标准《临床血液学检验常规项目分析质量要求》(WS/T406-2012)对全自动血液细胞分析仪的本底计数、携带污染、批内精密度、日间精密度、线性、正确度、不同吸样模式的结果可比性、实验室内的结果可比性和准确度进行测定评价。结果:全自动血液细胞分析仪的本底计数所有项目检测值均为0,白细胞计数(WBC)、红细胞计数(RBC)、血红蛋白(Hb)以及血小板计数(PLT)的携带污染均<1%。批内精密度和日间精密度均小于仪器说明书上的要求,远低于行业标准要求。仪器的线性范围很宽,线性回归方程的斜率在1±0.05范围内,相关系数r2均>0.95。与BC-6000plus的结果比对通过率为100%。实验室内结果比较仪器的正确度、不同吸样模式下的结果偏差和准确度均在允许范围内。结论:BC-6800plus全自动血液细胞分析仪性能良好,测定结果准确可靠,是一种理想的全自动血液细胞分析仪。

迈瑞BC-6800血细胞分析仪临床应用性能验证

目的:对迈瑞BC-6800血细胞分析仪进行临床应用性能评价。方法:根据中华人民共和国卫生卫生行业标准WS/T406-2012的要求,对迈瑞BC-6800血细胞分析仪白细胞(WBC)、红细胞(RBC)、血小板(PLT)、血红蛋白(HGB)、红细胞压积(HCT)、平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)、平均红细胞血红蛋白浓度(MCHC)八项参数进行批内精密度、批间精密度、正确度、携带污染率、线性范围检测。结果:BC-6800对八项参数WBC、RBC、HBG、HCT、MCV、MCH、MCHC、PLT批内精密度、批间精密度、正确度、携带污染率、线性范围均在允许范围内。结论:迈瑞BC-5800血细胞分析仪各项性能符合临床检验相关标准的要求,能够满足医院需求。

迈瑞BC-6800血细胞分析仪的临床性能评价

目的评价迈瑞BC-6800全自动血细胞分析仪的主要性能指标,确保临床检验的准确性。方法参照国际血液学标准化委员会(ICSH)公布的评价方案以及中华人民共和国卫生行业标准WS/T406-2012标准对仪器的精密度、线性范围、携带污染率、可比性等指标进行评价。结果迈瑞BC-6800血细胞分析仪WBC、RBC、HGB、HCT、PLT的精密度、线性范围良好,携带污染率小,不同进样模式检测结果的偏倚均在行业标准范围内。与XE-2100血细胞分析仪进行结果比对,显示与XE-2100具有良好的相关性(r2>0.98)。结论迈瑞BC-6800血细胞分析仪分析性能良好,能较好地满足临床血细胞分析的需求。

Successful Nitrogen Doping of 1.3 GHz Single Cell Superconducting Radio-Frequency Cavities

A high intrinsic quality factor （Q0） of a superconducting radio-frequency cavity is beneficial to reducing the oper- ation costs of superconducting accelerators. Nitrogen doping （N-doping） has been demonstrated as a aseful way to improve Q0 of the superconducting cavity in recent years. N-doping researches with 1.3 GHz single cell cavities are carried out at Peking University and the preliminary results are promising. Our recipe is slightly different from other laboratories. After 250μm polishing, high pressure rinsing and 3 h high temperature annealing, the cavities are nitrogen doped at 2.7-4.0Pa for 20rain and then followed by 15μm electropolishing. Vertical test results show that Q0 of a 1.3 GHz single cell cavity made of large grain niobium has increased to 4 ×10 10 at 2.0K and medium gradient.

BC-6900全自动血液细胞分析仪检测外周血有核红细胞的准确性分析

目的探讨BC-6900全自动血液细胞分析仪法(简称仪器法)检测外周血有核红细胞(NRBC)的方法学特点,评价其临床应用价值。方法同时用仪器法和显微镜检查法(简称镜检法)检测100例外周血标本中的NRBC,以镜检法为金标准,比较不同方法的计数结果,并从批内精密度、稳定性、携带污染率、人机比对方面分析BC-6900全自动血液细胞分析仪检测NRBC的效果。结果仪器法检测NRBC的灵敏度为97.959%(48/49),特异度为96.078%(49/51),假阳性率为3.922%(2/51),假阴性率为2.041%(1/49)。仪器法与镜检法检测结果有极好的相关性(r=0.9731),2种检测法比较,NRBC计数结果差异无统计学意义(P>0.05)。仪器法检测NRBC的重复性好,线性范围较宽,携带污染率小,比对试验中各项目变异系数(CV)均小于实验室允许的CV。结论BC-6900全自动血液细胞分析仪检测外周血NRBC性能良好,能满足临床医生对全血检测分析的需求。