Clonal isolation of endothelial colony-forming cells from early gestation chorionic villi of human placenta for fetal tissue regeneration

BACKGROUND Endothelial colony-forming cells(ECFCs)have been implicated in the process of vascularization,which includes vasculogenesis and angiogenesis.Vasculogenesis is a de novo formation of blood vessels,and is an essential physiological process that occurs during embryonic development and tissue regeneration.Angiogenesis is the growth of new capillaries from pre-existing blood vessels,which is observed both prenatally and postnatally.The placenta is an organ composed of a variety of fetal-derived cells,including ECFCs,and therefore has significant potential as a source of fetal ECFCs for tissue engineering.AIM To investigate the possibility of isolating clonal ECFCs from human early gestation chorionic villi(CV-ECFCs)of the placenta,and assess their potential for tissue engineering.METHODS The early gestation chorionic villus tissue was dissociated by enzyme digestion.Cells expressing CD31 were selected using magnetic-activated cell sorting,and plated in endothelial-specific growth medium.After 2-3 wks in culture,colonies displaying cobblestone-like morphology were manually picked using cloning cylinders.We characterized CV-ECFCs by flow cytometry,immunophenotyping,tube formation assay,and Dil-Ac-LDL uptake assay.Viral transduction of CVECFCs was performed using a Luciferase/tdTomato-containing lentiviral vector,and transduction efficiency was tested by fluorescent microscopy and flow cytometry.Compatibility of CV-ECFCs with a delivery vehicle was determined using an FDA approved,small intestinal submucosa extracellular matrix scaffold.RESULTS After four passages in 6-8 wks of culture,we obtained a total number of 1.8×107 CV-ECFCs using 100 mg of early gestational chorionic villus tissue.Immunophenotypic analyses by flow cytometry demonstrated that CV-ECFCs highly expressed the endothelial markers CD31,CD144,CD146,CD105,CD309,only partially expressed CD34,and did not express CD45 and CD90.CV-ECFCs were capable of acetylated low-density lipoprotein uptake and tube formation,similar to cord blood-derived ECFCs(CB-ECFCs).CV-ECFCs can be transduced with a Luciferase/tdTomato-containing lentiviral vector at a transduction efficiency of 85.1%.Seeding CV-ECFCs on a small intestinal submucosa extracellular matrix scaffold confirmed that CV-ECFCs were compatible with the biomaterial scaffold.CONCLUSION In summary,we established a magnetic sorting-assisted clonal isolation approach to derive CV-ECFCs.A substantial number of CV-ECFCs can be obtained within a short time frame,representing a promising novel source of ECFCs for fetal treatments.

Hierarchy of mesenchymal stem cells: Comparison of multipotentmesenchymal stromal cells with fibroblast colony forming units

The organization of the compartment of mesenchymal stem cells is still obscure. Two types of human stromal precursor cells are known. Both of them are analyzed in in vitro system: mesenchymal multipotent stromal cells (MMSC) and fibroblast colony forming units (CFU-F). The aim of this study was to compare the main characteristics of MMSC and CFU-F derived from the bone marrow of 24 healthy donors. Growth and differentiation parameters, as well as relative expression levels of different genes were analyzed in MMSC and CFU-F. MMSC were cultivated for 5 passages. CFU-F concentration was determined for each bone marrow sample. The data obtained demonstrated the heterogeneity and hierarchical organization of both studied populations of stromal precursor cells-MMSC and CFU-F. These two types of stromal precursor cells turned to be different in most parameters studied. Altogether MMSC seemed to be more immature cells than CFU-F and took up the higher position in hierarchical tree of mesenchymal stem cells. The rate of differentiation and proliferative potential decreased with the donor’s age in both populations MMSC and CFU-F.

Direct Infection of Colony Forming Unit-Megakaryocyte by Human Cytomegalovirus Contributes the Pathogenesis of Idiopathic Thrombocytopenic Purpura

Human cytomegalovirus （HCMV） late mRNA expression in megakaryoblast and in turn the pathogenesis of idiopathic thrombocytopenic purpura （ITP） patients with HCMV infection, and effectiveness of ganciclovir were investigated. Colony forming unit-megakaryocytes （CFU-MK） of 46 ITP patients with HCMV infection were incubated from patients＇ bone marrow mononuclear cells （MNC）. Reverse transcriptase-polymerase chain reaction （RT-PCR） was subsequently used for CFU-MK for HCMV-late mRNA detection, Ganciclovir therapy was given to both HCMV-late mRNA positive and negative groups for comparison of therapeutic effectiveness, The results in 19 of 46 CFU-MK culture cells specimens with positive HCMV-DNA by PCR or positive CMV-IgM by enzyme linked immunosorbent assay （ELISA） in the correspondent serum of peripheral blood were positive for HCMV-late mRNA, Sixteen out of 19 patients with positive HCMV-late mRNA CFU-MK had a positive response to ganciclovir. Amongst 27 patients with negative HCMV-late mRNA CFU-MK, only 4 positive responders to ganciclovir therapy were observed. Curative effectiveness of ganciclovir in HCMV-late mRNA positive group was significantly higher than that in HCMV-late mRNA negative group （P〈0.01）, It was suggested that HCMV could directly infect CFU-MK, which might be one of the mechanisms responsible for HCMV related ITE The ganci- clovir is an effective therapy in resulting in the increases in thrombocyte in the ITP patients whose HCMV- late mRNA was positive in their CFU-MK.

Machine learning for enumeration of cell colony forming units

As one of the most widely used assays in biological research,an enumeration of the bacterial cell colonies is an important but time-consuming and labor-intensive process.To speed up the colony counting,a machine learning method is presented for counting the colony forming units(CFUs),which is referred to as CFUCounter.This cellcounting program processes digital images and segments bacterial colonies.The algorithm combines unsupervised machine learning,iterative adaptive thresholding,and local-minima-based watershed segmentation to enable an accurate and robust cell counting.Compared to a manual counting method,CFUCounter supports color-based CFU classification,allows plates containing heterologous colonies to be counted individually,and demonstrates overall performance(slope 0.996,SD 0.013,95%CI:0.97–1.02,p value<1e-11,r=0.999)indistinguishable from the gold standard of point-and-click counting.This CFUCounter application is open-source and easy to use as a unique addition to the arsenal of colony-counting tools.

METTL3调控miR-301a促进缺氧环境下内皮集落形成细胞血管生成

目的:探讨缺氧环境对内皮集落形成细胞(ECFCs)血管生成能力的影响及甲基转移酶样3(METTL3)的调控作用。方法:分离、培养犬外周血ECFCs。实验分为正常对照组与缺氧实验组。缺氧实验组分别使用含50μmol/L、100μmol/L和200μmol/L氯化钴(CoCl_(2))的培养基处理细胞24 h,对照组CoCl_(2)浓度为0。CCK-8检测不同浓度CoCl_(2)对ECFCs增殖的影响,实时荧光定量PCR(RT-qPCR)检测缺氧诱导因子-1α(HIF-1α)的表达,筛选适宜浓度的CoCl_(2)用于缺氧环境构建。Transwell实验和管形成实验分别检测ECFCs迁移和血管生成能力。RT-qPCR和western blotting检测血管内皮生长因子(VEGF)、CD31、METTL3、miR-301a的表达情况。构建沉默METTL3慢病毒转染ECFCs,将ECFCs分为NC-shRNA组和METTL3-shRNA组。RT-qPCR和western blotting检测ECFCs细胞中VEGF、CD31、METTL3、miR-301a表达水平的变化。结果:与正常对照组比较,50μmol/L和100μmol/L的CoCl_(2)培养ECFCs 24 h后可促进细胞增殖(均P<0.0001),HIF-1α随着CoCl_(2)浓度升高而高表达(P<0.01)。100μmol/L CoCl_(2)组中ECFCs迁移能力和血管生成能力提高(均P<0.01),VEGF、CD31、METTL3、miR-301a mRNA水平表达升高(均P<0.01),VEGF、CD31、METTL3蛋白表达升高(均P<0.01)。与NC-shRNA组比较,METTL3-shRNA组中VEGF、CD31、METTL3、miR-301a mRNA表达降低(均P<0.05),VEGF、CD31、METTL3蛋白表达降低(均P<0.05)。结论:适宜的缺氧干预可提高ECFCs增殖、迁移和血管生成能力,METTL3/miR-301a轴可能参与调控血管生成。

金属桶生产线中凸轮运动规律曲线的优化设计

针对凸轮运动规律曲线优化设计中描述线型单一导致的优化幅度有限和普适性差的问题,提出一种将分段曲线应用于优化设计的方法,该分段曲线由七次多项式线型和傅里叶线型组成。利用凸轮机构的设计参数构建多项式型或傅里叶型运动规律曲线,在较优曲线周围以一定分度生成点阵解集;以整体跃度最小化为目标,通过蚁群算法从解集中选取最优位移约束点,确定各段曲线描述方式;将所有条件代入分段曲线模型,计算出最优凸轮运动规律曲线。该方法应用于金属桶提手成型装置优化设计的效果良好。以5组随机设计参数的凸轮机构为例,通过该运动学分析结果表明,相比单一线型,该方法可降低10%以上的整体跃度,并具有普适性。

基于改进蚁群算法优化神经网络的焊缝成形预测研究

为了控制焊接机器人焊缝成形的质量,提出了一种基于改进蚁群算法(ACO)优化BP神经网络的焊缝成形预测模型,实现对焊缝成形尺寸的控制。首先通过Otsu优化Canny算子的方法提取焊接过程中熔池图像的数据样本,然后用BP神经网络来进行训练预测。为了优化初始权阈值,引入ACO优化BP;针对蚁群陷入局部最优的情况,引入遗传算法(GA)中的交叉变异,利用适应度值来确定选择概率的特性,从而加快迭代速度,避开蚁群初期的收敛慢问题,提升预测模型的性能。最后通过与传统BP、GA-BP和ACO-BP的预测实验对比,发现改进后的预测模型准确度高、稳定性好。

Difference between resistant and susceptible maize to systematic colonization as revealed by DsRed-labeled Fusarium verticillioides

Fusarium verticillioides was labeled with DsRed via Agrobacterium tumefaciens-mediated transformation to examine differences in colonization and reactions of resistant and susceptible inbred lines of maize(Zea mays L.). The extent of systemic colonization of F. verticillioides in roots from maize lines either resistant or susceptible to the fungus was studied by visualizing the red fluorescence produced by the fungus expressing DsRed. The difference in quantities of colony forming units(CFU) in roots and basal stems, production of fumonisin B1, and pH of root were determined. Although F. verticillioides colonized both resistant and susceptible lines, differences were observed in the pattern and extent of fungal colonization in the two types of maize lines. The fungus colonized the susceptible lines producing mosaic patterns by filling the individual root cells with hyphae. Such a pattern of colonization was rarely observed in resistant lines, which were less colonized by the fungus than the susceptible lines in terms of CFUs. The production of mycotoxin fumonisin B1 in roots from different lines was closely correlated with the amount of F. verticillioides colonization, rather than the pH or amylopectin concentrations in the root. The findings from this study contribute to a better understanding of the defense mechanism in resistant maize lines to F. verticillioides.

缺氧环境中犬内皮集落形成细胞成血管能力及自噬水平观察

目的观察缺氧环境中犬内皮集落形成细胞(ECFCs)成血管能力及自噬水平。方法取对数生长期的ECFCs,分为缺氧组和常氧组,缺氧组在缺氧环境中培养,常氧组在常氧环境中培养,比较两组成血管能力(细胞OD值、细胞迁移数、细胞迁移率、管分支数及VEGF mRNA、FGF mRNA、VEGF蛋白、FGF蛋白相对表达量)和自噬水平(细胞LC3 mRNA、P62 mRNA、LC3Ⅱ/Ⅰ、P62蛋白、LC3平均荧光强度、P62平均荧光强度)。结果与常氧组比较,缺氧组培养48、72、96 h的OD值及细胞迁移数、细胞迁移率、管分支数和VEGF mRNA、FGF mRNA、VEGF蛋白、FGF蛋白相对表达量增加(P均<0.05)。与常氧组比较,缺氧组LC3 mRNA、LC3Ⅱ/Ⅰ表达增加及LC3平均荧光强度增强,P62 mRNA、P62蛋白表达减少及P62平均荧光强度减弱(P均<0.05)。结论缺氧环境中犬ECFCs成血管能力增强,自噬水平升高。

改良水胶体敷料对无痛结肠镜检查病人造口周围皮肤的影响

目的:探讨改良水胶体敷料(hydrocolloid dressing,HCD)对无痛结肠镜检查(painless colonoscopy)病人造口周围皮肤(peristomal skin)的影响。方法:选取2022年1月—2022年12月在郑州大学第一附属医院行无痛结肠镜检查的64例造口病人作为研究对象,采用随机数字表法分为改良HCD应用组(H组)和对照组(C组)各32例。在结肠镜检查前,C组实施常规护理,使用无纺布洞巾覆盖病人腹部;H组在C组基础上采用改良HCD(3M)粘贴于造口周围皮肤,实施结肠镜检查。观察两组病人造口周围性皮炎分级(采用国际伤口创面评价标准评估)、造口周围皮肤水分百分比、造口周围黏膜酸碱度(pH值)和造口周围皮肤菌落计数。结果:干预后,H组病人造口周围性皮炎分级明显优于C组,菌落计数明显少于C组,造口周围皮肤水分百分比明显低于C组(均P<0.001);干预后两组病人造口周围皮肤黏膜酸碱度和温度比较差异无统计学意义(P>0.05)。结论:在无痛结肠镜检查期间,改良HCD可为病人提供可靠的造口周围皮肤保护作用。

Microbiological Quality of Freshly Prepared, Packaged Fruit and Milk Juices Sold in Cafés, Shops, and Supermarkets in Hargeisa, Somaliland

Background: Due to their delicious taste, high nutritional content, and health benefits, fruit juices are well-known drinks in many countries and are now an essential component of the modern diet. Objective: Determining the microbiological quality of both packaged and freshly made fruit and milk juices. Method: The spread-plate approach was employed to isolate and count the bacteria. 90 ml of sterile peptone water were blended with 10 ml of well-mixed, packed, and freshly made fruit juices. The samples were sequentially diluted (101 - 105) in accordance with the Indian Manual of Food Microbiological Testing Methods. Results: From eight samples of imported packaged fruit and milk juice, the average of total coliform, staphylococci, and viable bacterial counts were zero, 1.39 × 102, and 2 × 102 CFU/ml, respectively. In contrast, from three samples of locally produced fruit and milk juice, the average of total coliform, staphylococci, and viable bacterial counts were zero, 5.83 × 102, and 2.73 × 103 CFU/ml, respectively. Four samples of handmade prepared fruit and milk juices had a mean of total coliform, staphylococci, and viable bacterial count of 1.441 × 104, 4.1 × 103, and 2.35 × 105 CFU/ml, respectively. Conclusion: 33.3% of the results from microbiological analysis of freshly made fruit and milk juices met the permissible range of the Revised Microbiological Standards for Fruit and Vegetables and Their Products, which were published in 2018 and as well as the Hong Kong Center for Food Safety, whereas 66.7% of the microbiological analyses of freshly prepared fruit and milk juices were above the permissible reference range of GSO standard 2000. 12.5% of the investigated imported and packed fruits and milk juices had one failed test (TSC), which was above the acceptable limit, 87.5% of the tested samples of fruit and milk juices fulfilled the necessary standards of TCC, TVBC, and TSC. 100% of the tested locally manufactured fruit and milk juices complied with TSC, TCC, and TVBC requirements. All investigations showed that freshly made fruit and milk juices were heavily contaminated (Total viable bacterial count, total coliform count, and total staphylococcus count). .

Clonogenic colony-forming ability of hepatic stem cells in the spleens of mice

To confirm the existence of hepatic stem cells (HSCs), fetal liver cells isolated from mice on embryonic day 13 (ED13) were long-term cultured in vitro. Growth of the cells was observed intensively and characteristics were iden-tified by immunocytochemistry. The results showed that some of the cells grew as colonies, in which some cells ex-pressed AFP, CD34 and Albumin. Then the cells were trans-planted intravenously into irradiated syngeneic mice. At day 12 a number of small hyperplasia nodules were seen in the apparently enlarged spleens of recipient mice. Moreover, some nodules were positive for AFP and CD34 and consisted of various types of cells, suggesting the very existence of he-patic stem cells in the mouse fetal liver.

Evaluation of the relationship between two different methods for enumeration fecal indicator bacteria: Colony-forming unit and most probable number

Most probable number （MPN） and colony-forming unit （CFU） estimates of fecal indicator bacteria （FIB） concentration are common measures of water quality in aquatic environments. Thus, FIB intensively monitored in Yeongsan Watershed in an attempt to compare two different methods and to develop a statistical model to convert from CFU to MPN estimates or vice versa. As a result, the significant difference was found in the MPN and CFU estimates. The enumerated Escherichia coli concentrations in MPN are greater than those in CFU, except for the measurement in winter. Especially in fall, E. coli concentrations in MPN are one order of magnitude greater than that in CFU. Contrarily, enterococci bacteria in MPN are lower than those in CFU. However, in general, a strongly positive relationship are found between MPN and CFU estimates. Therefore, the statistical models were developed, and showed the reasonable converting FIB concentrations from CFU estimates to MPN estimates. We expect this study will provide preliminary information towards future research on whether different analysis methods may result in different water quality standard violation frequencies for the same water sample.

地黄低聚糖对快速老化模型小鼠造血功能的影响

目的：研究地黄低聚糖（ＲＧＯＳ）对快速老化模型小鼠（ＳＡＭＰ８）造血功能的影响。方法：采用造血祖细胞体外克隆培养等实验血液学方法。结果：ＲＧＯＳ１０，２０ｍｇ·ｋｇ－１可使ＳＡＭＰ８小鼠的ＣＦＵ－Ｓ、ＣＦＵ－ＧＭ、ＣＦＵ－Ｅ和ＢＦＵ－Ｅ明显增多，并可使外周血中降低的ＷＢＣ数明显增加。提示ＲＧＯＳ可刺激ＳＡＭＰ８小鼠造血干细胞、祖细胞的增殖分化。集落刺激活性实验显示ＲＧＯＳ可使小鼠体内的集落刺激因子产生明显增多。小鼠骨髓组织学研究结果也进一步证实了ＲＧＯＳ增强ＳＡＭＰ８小鼠造血功能的作用。结论：ＲＧＯＳ可以增强ＳＡＭＰ８小鼠的造血功能。

胰酶对皮肤角质细胞分离和传代的影响

考察不同的胰酶浓度及其作用时间对角质细胞分离和传代的影响。实验发现在胰酶浓度 0 2 5 %时作用5min可获得的总活细胞量和有克隆形成能力的细胞量均优于其它培养条件 ;而在胰酶浓度 0 0 5 %时作用 5min可获得最大的原代角质细胞贴壁率。随着胰酶浓度的提高 ,传代角质细胞的贴壁率和贴壁速率常数以及克隆形成率均随之增加 ,因此在传代培养时使用 0 2 5

黄芪注射液对人巨细胞病毒感染的粒-单系祖细胞体外增殖的影响

目的 探讨黄芪注射液对人巨细胞病毒 (HCMV)感染的粒—单系祖细胞 (CFU GM )体外增殖的影响。方法 采用造血祖细胞体外培养技术 ,用黄芪干预HCMV感染的CFU GM ,观察计数CFU GM的产率 ,大小 ,峰期及维持时间。结果 ①黄芪组每 2× 10 5个细胞中CFU GM簇和集落的产率分别为 333.33± 12 .6 9和81.2 3± 4 .93,病毒组每 2× 10 5个细胞中簇和集落的产率分别为 16 7.80± 16 .6 3,5 3.70± 1.6 7,两者相比差异有显著性 (P <0 .0 1)。②黄芪组大集落的比例占 (9.5± 0 .8) % ,明显高于病毒组 (2 .7± 1.0 ) % ,P <0 .0 1。③黄芪组大集落峰期出现早 ,集落和大集落维持时间长。结论 在体外黄芪注射液可以促进HCMV感染的CFU GM增殖。

基于感性意象的产品造型优化设计

针对当前消费者感性需求的提高,运用组合思想提出基于感性意象的产品造型优化设计方法.首先应用感性工学类目层次法得到产品的设计要素,再应用数量化一类理论建立感性意象和造型特征元素之间的对应关系,作为优化产品造型时的评判依据.然后应用蚁群算法对造型特征元素进行组合优化,实现了以少量的产品属性形态构建多样的产品造型方案,从而快速设计出满足消费者感性意象需求的产品.最后以电热水壶设计进行实例研究,结果表明运用该方法可有效地进行产品意象造型优化设计.

鲜切菠萝片加工工艺的研究

以菌落总数和感官评价为指标,研究了鲜切菠萝片的合理工艺条件。结果表明:鲜切菠萝片经1.0%Vc-Na和1.0%柠檬酸处理,通过紫外灭菌(30W,照射高度40cm)30min,贮存于5℃,使货架期达到8d左右;菌落总数控制在105以内,符合鲜切果蔬的食品卫生要求,产品感官品质优良。

充气和搅动对球形棕囊藻生长及囊体形成的影响

球形棕囊藻生活史中包含游离单细胞和球形囊体两种生活形态,但是实验室中培养的球形棕囊藻经常无法形成囊体。研究通过向培养基中泵入过滤空气,以及给培养基提供不同程度的搅动,研究了充气和搅动对球形棕囊藻生长及囊体形成的影响。充气和搅动均显著提高了囊体的数量,并且提高了囊体内细胞的生长速率。但是充气对于囊体直径及囊体内细胞密度并无显著影响。搅动则明显的提高了囊体直径和囊体内细胞数量。然而,尽管充气以及搅动有利于球形棕囊藻囊体的形成,但是培养的囊体直径依然小于自然海区中囊体的大小。

人参总皂甙诱导人内皮细胞和单核细胞表达GM-CSF的实验研究

目的:研究人参总皂甙(TSPG)对人内皮细胞和单核细胞表达粒细胞巨噬细胞集落刺激因子(GM-CSF)的影响,及其与人粒单系血细胞发生调控的关系。方法:采用造血祖细胞体外培养、造血生长因子生物学活性检测、免疫细胞化学和核酸分子原位杂交等技术,检测内皮细胞和单核细胞中GM-CSF的表达。结果:经TSPG诱导制备的内皮细胞和单核细胞条件培养液中富含GM-CSF样活性,能显著促进人粒单系造血祖细胞的增殖分化;TSPG能显著促进内皮细胞与单核细胞的GM-CSF蛋白和mRNA表达。结论:TSPG可能通过直接和间接途径促进造血诱导微环境中的内皮细胞和单核细胞合成和分泌GM-CSF,进而促进血细胞生成。