Aptamer-functionalized quantum dots as theranostic nanotools against cancer and bacterial infections: A comprehensive overview of recent trends

Aptamers (Apts) are synthetic nucleic acid ligands that can be engineered to target various molecules, including amino acids, proteins, and pharmaceuticals. Through a series of adsorption, recovery, and amplification steps, Apts are extracted from combinatorial libraries of synthesized nucleic acids. Using aptasensors in bioanalysis and biomedicine can be improved by combining them with nanomaterials. Moreover, Apt-associated nanomaterials, including liposomes, polymeric, dendrimers, carbon nanomaterials, silica, nanorods, magnetic NPs, and quantum dots (QDs), have been widely used as promising nanotools in biomedicine. Following surface modifications and conjugation with appropriate functional groups, these nanomaterials can be successfully used in aptasensing. Advanced biological assays can use Apts immobilized on QD surfaces through physical interaction and chemical bonding. Accordingly, modern QD aptasensing platforms rely on interactions between QDs, Apts, and targets to detect them. QD-Apt conjugates can be used to directly detect prostate, ovarian, colorectal, and lung cancers or simultaneously detect biomarkers associated with these malignancies. Tenascin-C, mucin 1, prostate-specific antigen, prostate-specific membrane antigen, nucleolin, growth factors, and exosomes are among the cancer biomarkers that can be sensitively detected using such bioconjugates. Furthermore, Apt-conjugated QDs have shown great potential for controlling bacterial infections such as Bacillus thuringiensis, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Campylobacter jejuni, Staphylococcus aureus, and Salmonella typhimurium. This comprehensive review discusses recent advancements in the design of QD-Apt bioconjugates and their applications in cancer and bacterial theranostics.     

山东省假性肥大型肌营养不良的RFLP分析 Ⅰ．可疑携带者的基因型确定

本文选用10个DMD基因内部和桥探针,对山东省9个地区的21个DMD／BMD家系的173名成员进行RFLP分析,其中可疑携带者55人,多数家系应用1－3个探针,有基因重组家庭选用4－5个探针,便可完成多态分析,RFLP分析可以确定85．45％的可疑携带者（≥95％可信限）,即13人确定为携带者,30人排除携带者,另有4人风险大幅提高,通过这些探针的群体多态检测和不同家庭结构和类型的应用分析,我们提出了在中国人群中DMD／SMD基因诊断的基本程序。     

肺炎支原体肺炎患儿血清sB7-H3含量与细胞因子水平及病情严重程度的相关性研究

摘要 目的：研究肺炎支原体肺炎（mycoplasma pneumoniae pneumonia, MPP）患儿血清可溶性共刺激分子B7-H3（soluble co-stimulatory molecule B7-H3, sB7-H3）含量与细胞因子水平及病情严重程度的相关性。方法：收集2019年3月至2020年6月期间我院收治的MPP患儿共96例,根据患儿病情严重程度分为轻症MPP组和重症MPP组,另选取同期于我院体检中心体检的健康儿童50例作为对照组。收集所有受试者的一般资料、主要临床表现、临床指标及细胞因子水平,对各指标进行Pearson相关性分析和多元逐步回归分析。结果：与对照组相比,MPP组患儿的白细胞计数（white blood cell, WBC）、中性粒细胞计数（neutrophil, NE）、红细胞沉降率（erythrocyta sedimentation rate, ESR）、C反应蛋白（C-reactive protein,CRP）、sB7-H3、粒细胞-巨噬细胞集落刺激因子（granulocyte-macrophage colony stimulating factor, GM-CSF）、干扰素-γ（interferon-γ, IFN-γ）、白介素-10（interleukin-10,IL-10）和白介素-17A（interleukin-17A,IL-17A）均较高（P＜0.05）;与轻症MPP组患儿相比,重症MPP组患儿的WBC、NE、ESR、CRP、sB7-H3、GM-CSF、IFN-γ、IL-10和IL-17A均较高（P＜0.05）。Pearson相关性分析结果表明,sB7-H3与WBC、NE、ESR、CRP、GM-CSF、IFN-γ、IL-10和IL-17A呈正相关（P＜0.05）。多元线性回归分析显示,GM-CSF（β=0.103,P＜0.001）、IFN-γ（β=0.121,P＜0.001）、IL-10（β=0.026,P＜0.001）和IL-17A（β=0.093,P＜0.001）是sB7-H3的独立影响因素。结论：MPP患儿血清sB7-H3、GM-CSF、IFN-γ、IL-10和IL-17A与MPP的病情严重程度密切相关,且sB7-H3的表达水平与GM-CSF、IFN-γ、IL-10和IL-17A的水平呈正相关。     

Epidemiology of apple proliferation (AP) in northwestern Italy: evaluation of the frequency of AP-positive psyllids in naturally infected populations of Cacopsylla melanoneura (Homoptera: Psyllidae)

Adults of Cacopsylla melanoneura, vector of the apple proliferation (AP) phytoplasma, were collected every 2 weeks from January until May in 2000 and 2001 by the beating tray method in eight apple orchards of the Aosta Valley (northwestern Italy). Total DNA was extracted from batches of five insects and amplified with the universal phytoplasma primers P1/P7 in direct PCR. A nested PCR assay was then performed on P1/P7 amplicons using the primers fO1/rO1, specific for the AP‐ phytoplasma group. The digestion of fO1/rO1 amplicons with Ssp I restriction endonuclease confirmed that C. melanoneura adults harboured the AP phytoplasma. The data obtained with PCR were used to estimate the proportion of AP‐positive insects in over wintered and offspring adults. Percentages of AP‐positive insects of 3.6% and 0.8% were estimated in 2000 among over wintered and offspring psyllids respectively. In 2001 only the over wintered insects were found infected, with an estimated proportion of 2.8%. The seasonal abundance of the vector was measured using yellow sticky traps. C. melanoneura was always present at a low population level, and the highest density was recorded from mid‐February until mid‐March in both years. The results show that the overwintered population is higher and spends a longer period in apple orchards, suggesting the crucial role of the overwintered adults in vectoring AP.     

细菌巨大质粒的快速检测

本文报道了一种快速检测微生物巨大质粒的方法．该方法是通过对Ｅｃｋｈａｒｄｔ所报道的方法加以改进,使之能对根瘤菌、大肠杆菌、甚至链霉菌的大质粒进行快速检测．     

Oligozymes

The simple use of nonisotopic hybridization probes to detect complementary sequences provides valuable information in a large number of research and commercial applications. In hybridization assays, the four ‘S’s (speed, simplicity, sensitivity, and specificity) are important criteria for determining the choice of probe and label. The direct chemical combination of synthetic oligonucleotide probes and enzyme labels offer advantages unmatched by other approaches, with the oligonucleotide providing rapid hybridization and high specificity, and the direct enzyme label providing simple and sensitive detection. Such oligonucleotide-enzyme conjugates (“oligozymes”) can be used in a variety of hybridization and detection formats, including dot blots, Southern/northern blots,in situ, and solution hybridization/capture schemes. The practical synthesis and use of such oligozymes are summarized.     

用Ciprofloxacin去除传代细胞株中的支原体污染的研究

在应用细胞培养手段的生物学研究和生物工程产品中,支原体污染仍是一个非常棘手的问题。对Ｖｅｒｏ和ＳＰ２／０－Ａｇ１４等细胞,应用Ｃｉｐｒｏｆｌｏｘａｃｉｎ,１０μｇ／ｍｌ处理１４天,支原体检测全部转阴,经４个月的培养、传代、冻存、复苏,每次支原体检测均保持阴性。对去除了支原体的Ｖｅｒｏ和ＩＳＣ－１１６细胞株,测试了其生长特征和功能,均未见受影响。     

28s rDNA group-I introns: a powerful tool for identifying strains of Beauveria brongniartii

The nuclear ribosomal DNA of the entomopathogenic fungus Beauveria brongniartii is polymorphic in terms of both restriction site and length. Insertions of 350–450 bp long, identified as group-I introns, were detected in the 28 s rDNA. A panel of 47 strains of B. brongniartii , two B. bassiana and one Metarhizium anisopliae of various geographical and biological origins were found to contain 14 variant forms of intron differing in size and restriction pattern, at four different positions. Twelve types of ribosomal large subunit were defined on the basis of variant distribution and compared with strain clustering based on internal transcribed spacers analysis. There was a correlation between the characteristic introns and isolates collected from the sugar cane pest Hoplochelus marginalis . Primers for polymerase chain reaction amplification were chosen from these variants, and used to develop a specific method for detecting strains pathogenic towards Hoplochelus .     

The membrane topology of the amino-terminal domain of the red cell calcium pump.

A systematic study of the membrane-associated regions in the plasma membrane Ca2+ pump of erythrocytes has been performed by hydrophobic photolabeling. Purified Ca2+ pump was labeled with 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)-diazirine ([125I]TID), a generic photoactivatable hydrophobic probe. These results were compared with the enzyme labeled with a strictly membrane-bound probe, [3H]bis-phosphatidylethanolamine (trifluoromethyl) phenyldiazirine. A significant light-dependent labeling of an M(r) 135,000-140,000 peptide, corresponding to the full Ca2+ pump, was observed with both probes. After proteolysis of the pump labeled with each probe and isolation of fragments by SDS-PAGE, a common pattern of labeled peptides was observed. Similarly, labeling of the Ca2+ pump with [125I]TID, either in isolated red blood cell membranes or after the enzyme was purified, yields a similar pattern of labeled peptides. Taken together, these results validate the use of either probe to study the lipid interface of the membrane-embedded region of this protein, and sustain the notion that the conformation of the pump is maintained throughout the procedures of solubilization, affinity purification, and reconstitution into proteoliposomes. In this work, we put special emphasis on a detailed analysis of the N-terminal domain of the Ca2+ pump. A labeled peptide of M(r) 40,000 belonging to this region was purified and further digested with V8 protease. The specific incorporation of [125I]TID to proteolytic fragments pertaining to the amino-terminal region indicates the existence of two transmembrane stretches in this domain. A theoretical analysis based on the amino acid sequence 1-322 predicts two segments with high probability of membrane insertion, in agreement with the experimental data. Each segment shows a periodicity pattern of hydrophobicity and variability compatible with alpha-helical structure. These results strongly suggest the existence of a transmembrane helical hairpin motif near the N-terminus of the Ca2+ pump.     

鼠脑微透析液痕量氨基酸的激光诱导荧光检测

使用自制微透析探针和活动体位生化取样装置以及自行组装的毛细管电泳-增强型电荷耦合器件-激光诱导荧光系统,对鼠脑透析液中的痕量氨基酸以异硫氢酸荧光黄(FITC)进行柱前衍生后进行了分离和检测. 鼠脑海马CA₃区微透析液中游离氨基酸的浓度为10^-8～10^-6 mol/L, 并将其用于学习与记忆的研究, 为无损伤研究活体脑内神经递质和其他痕量生化物质的动态变化提供了一种新方法.