一种高比放 DNA 探针的制备方法及其应用

随机引物法标记 DNA 探针是一种高比放、高灵敏度的 DNA 探针标记法。DNA 标记比放可达9.0×10~8cpm/μg DNA,比缺口平移法标记的比放高约9倍。因此法标记的 DNA 探针在分子杂交试验中均获得良好的结果。     

三钾合剂中总钾含量测定的不同方法比较

目的三钾合剂中总钾含量测定的不同方法比较,寻找钾含量测定的最佳方法。方法采用中和法、四苯硼钠重量法、火焰原子吸收分光光度法（FAAS）及电感耦合等离子体发射光谱法（ICP-AES）等测定三钾合剂中总钾的含量,并对方法的精密度、线性范围及加标回收率等进行比较。结果 4种方法在测定范围内呈现良好线性关系,回收率均在95%~105%范围内,RSD均小于0.1%。结论 FAAS法为测定三钾合剂中总钾含量的较优方法。     

原发性肝癌不同介入治疗方法疗效的比较研究：（附468例分析）

本文对468例原发性肝癌的不同介入治疗方法的疗效进行了比较研究。分单纯化疗(A)组,化疗碘油栓塞(B)组和化疗、碘油、明胶海绵栓塞(C)组,三者的有效率分别为20.29％、41.18％和44.77％。1、3年生存率,A组为20.53±3.62％、1.95±2.39％,B组51.34±4.36％、10.11±4.92％,C组62.99±3.89％、13.92±4.65％。A、B、C三组的平均生存期分别为9.57月,16.07月和17.93月。A与B、C组之间有明显差别,以化疗,碘油和明胶海绵复合栓塞的疗效最好。对栓塞的分类提出了:远、中、近三段分类法。     

静脉注射人免疫球蛋白（pH4）不溶性微粒检测方法的建立

目的建立静脉注射人免疫球蛋白（pH4）不溶性微粒检测的方法。方法光阻法;溶剂：微粒检查用水。结果测定了4个生产企业生产的12批静脉注射人免疫球蛋白（pH4）样品,平均微粒加样回收率为101.2%。结论本方法简便、灵敏、准确,可用于静脉注射人免疫球蛋白（pH4）的质量控制。     

高原低氧不同适应水平群体（4850m）MEFV指标测定的分析──对急性高原病易感人群预测价值初步探讨

本文对进入４８５０ｍ高原后连续半年１１４名体力劳动者ＭＥＦＶ进行了动态观察。按进住时间梯度，通过对高原低氧不同适应水平群体的肺功能变化的演变进程的观察。结果表明：在低海拔同一条件下，发病组ＭＥＦＶ有关指标参数明显低于未发病组，机体在低氧应激下发病组各指标参数波动较大，且无规律性，低氧反应严重，恢复慢。这种改变也许对高原病易感人群预测的研究提供了一个新线索。而且揭示有高原适应衰退现象。     

BioSunLAMP:一个用于环介导等温扩增的引物设计软件

目的环介导等温扩增法(loop-mediated isothermal amplification,LAMP)是一种新型等温核酸扩增方法。由于其具有简便、高效、特异性高和成本低等优点,在甲型H1N1流感和肺结核等流行病检测中得到了广泛应用。在LAMP技术中,关键的起始步骤是设计合适的引物序列。为了让引物设计更加方便与高效,我们开发了LAMP引物设计软件BioSunLAMP。方法采用Delphi程序设计语言开发了界面友好、便于使用的软件系统。结果经甲型H1N1流感、结核分枝杆菌实验验证,BioSunLAMP软件设计的引物达到了预期效果。此外,与同类软件相比,BioSunLAMP还具有如下特点:①集引物设计与引物特异性分析于一体,可以通过本地数据库或远程调用NCBI的相关数据库来检查引物特异性;②支持针对多序列的通用引物与特异引物设计。结论 BioSunLAMP软件的开发,为LAMP技术的普及提供了很好的生物信息学支持。     

A sensitive PARACEST contrast agent for temperature MRI: Eu3+-DOTAM-glycine (Gly)-phenylalanine (Phe).

Tissue temperature is a fundamental physiological parameter that can provide insight into pathological processes. The purpose of this study was to develop and characterize a novel paramagnetic chemical exchange saturation transfer (CEST) agent suitable for in vivo temperature mapping at 9.4T. The CEST properties of the europium (Eu(3+)) complex of the DOTAM-Glycine (Gly)-Phenylalanine (Phe) ligand were studied in vitro at 9.4T as a function of temperature, pH, and agent concentration. The transfer of magnetization (CEST effect) from the bound water to bulk water pools was approximately 75% greater for Eu(3+)-DOTAM-Gly-Phe compared to Eu(3+)-DOTAM-Gly at physiologic temperature (38 degrees C) and pH (7.0 pH units) when using power level sufficiently low for in vivo imaging. Unlike Eu(3+)-DOTAM-Gly, whose CEST effect decreased with increasing temperature in the physiologic range, the CEST effect of Eu(3+)-DOTAM-Gly-Phe was optimal at body temperature. A strong linear dependence of the chemical shift of the bound water pool on temperature was observed (0.3 ppm/ degrees C), which was insensitive to pH and agent concentration. Temperature maps with SDs < 1 degrees C were acquired at 9.4T in phantoms containing: 1) phantom A, an aqueous solution of 10 mM Eu(3+)-DOTAM-Gly-Phe; 2) phantom B, 5% bovine serum albumin (BSA) with 15 mM Eu(3+)-DOTAM-Gly-Phe; and 3) phantom C, mouse brain tissue with 4 mM Eu(3+)-DOTAM-Gly-Phe. The temperature sensitivity combined with the high CEST effect observed at low concentration using low saturation power (B(1)) suggests this compound may be a good choice for in vivo temperature mapping at 9.4T.     

A comparison of four methods for PCR inhibitor removal

Biological samples collected from the crime scenes often contain some compounds that can inhibit the polymerase chain reaction (PCR). The removal of PCR inhibitors from the extracts prior to the PCR amplification is vital for successful forensic DNA typing. This paper aimed to evaluate the ability of four different methods (PowerClean^® DNA Clean-Up kit, DNA IQ™ System, Phenol–Chloroform extraction and Chelex^®-100 methods) to remove eight commonly encountered PCR inhibitors including: melanin, humic acid, collagen, bile salt, hematin, calcium ions, indigo and urea. Each of these PCR inhibitors was effectively removed by the PowerClean^® DNA Clean-Up kit and DNA IQ™ System as demonstrated by generating more complete short tandem repeat (STR) profiles from the cleaned up inhibitor samples than from the raw inhibitor samples. The Phenol–Chloroform extraction and Chelex^®-100 methods, however, could only remove some of eight PCR inhibitors. Our results demonstrated that the PowerClean^® DNA Clean-Up kit and DNA IQ™ System were very effective for the removal of known PCR inhibitors that are routinely found in DNA extracts from forensic samples.     

A comparison of methods to calculate biological effectiveness (RBE) from Monte Carlo simulations.

The relative biological effectiveness (RBE) of radiation is assessed and easily calculated by Monte Carlo simulations of the passage of radiation through matter. The expression to calculate the RBE provided by microdosimetry requires the use of the energy spectrum of charged particles. This paper compares the RBE values obtained for Palladium-103 (103Pd) and iodine-125 (125I) when calculated with 2 different spectra: the electron slowing-down spectrum and the ejection spectrum. The former yields a value of 10.6%, twice the value obtained with the latter (4.5%). Which spectrum to use is an open question. A theoretical argument is presented in favor of the ejection spectrum.     

Evaluation of marker selection methods and statistical models for chronological age prediction based on DNA methylation

In forensic investigation, retrieving biological information from DNA evidence is a promising field of interest. One of the applications is on the estimation of the age of the donor based on DNA methylation. A large number of studies focused on age prediction using the 450 K Human Methylation Beadchip. Various marker selection methods and prediction models have been considered. However, there is a lack of research evaluating different high-dimensional variable selection methods of CpG sites with various models for age prediction. The aim of this study is to evaluate four variable selection methods (forward selection, LASSO, elastic net and SCAD) combined with a classical statistical model and sophisticated machine learning models based on the mean absolute deviation (MAD) and the root-mean-square error (RMSE). We used publicly available 450 K data set containing 991 whole blood samples (age 19–101 years). We found that the multiple linear regression model with 16 markers selected from the forward selection method performed very well in age prediction (MAD = 3.76 years and RMSE = 5.01 years). On the other hand, the highly advanced ultrahigh dimensional variable selection methods and sophisticated machine learning algorithms appeared unnecessary for age prediction based on DNA methylation.     

Competition of nitroxyl contrast agents as an in vivo tissue redox probe: comparison of pharmacokinetics by the bile flow monitoring (BFM) and blood circulating monitoring (BCM) methods using X-band EPR and simulation of decay profiles.

Nitroxyl radicals used as tissue redox-sensitive contrast agents in electron paramagnetic resonance (EPR) and/or NMR imaging should satisfy the following two conditions: 1) the molecules disperse into tissues rapidly, and 2) paramagnetic loss occurs by simple reduction of the radical. The pharmacokinetic trends of several nitroxyl contrast agents were compared with the results obtained by bile flow monitoring (BFM) and blood circulation monitoring (BCM) methods using X-band EPR. The nitroxyl radicals (TEMPO, TEMPONE (oxo-TEMPO), and amino-TEMPO) showed additional EPR signals in the bile that were attributed to metabolites formed during transport from blood to bile through the liver. However, the highly hydrophilic CAT-1 (trimethylammonium-TEMPO), which has low membrane permeability, showed minimal concentration in the bile. Probes that have carboxyl moiety, such as carboxy-TEMPO and carboxy-PROXYL, can be transported via anion transporter into hepatic cells. The EPR signal decay profiles of the nitroxyl radicals were simulated based on the experimental data. The simulation, which we previously applied to mouse blood, was modified to simultaneously fit the experimental results of BFM and BCM obtained with rats. The simulation data showed the simplicity/complexity of the pharmacokinetic mechanisms and that carbamoyl-PROXYL and TEMPOL (hydroxy-TEMPO) are suitable contrast agents for assessing tissue redox status.     

A comparison in monkeys of (99m)Tc labeled to a peptide by 4 methods.

Although a number of different strategies for labeling peptides with (99m)Tc have been developed, only a few studies have compared the in vivo properties of (99m)Tc when attached to different chelators. Furthermore, these comparisons are usually in mice, whereas results obtained in nonhuman primates may be expected to be more relevant to the clinical situation. METHODS: We evaluated the influence of 4 common chelators on the biodistribution in monkeys of (99m)Tc-labeled HNE-2, a 6.7-kDa peptide being investigated as an inflammation/infection imaging agent. The peptide was conjugated with the N-hydroxysuccinimide ester of mercaptoacetyltriglycine (MAG3), mercaptoacetyltriserine (MAS3), hydrazinonicotinamide (HYNIC), and the cyclic anhydride of diethylenetriaminepentaacetic acid (DTPA). After radiolabeling, each peptide was administered intravenously to rhesus monkeys with a Staphylococcus aureus-induced focal inflammation/infection. RESULTS: Quantification of radioactivity accumulation by regions of interest over 3 h after administration in monkeys showed important differences among labeling methods: For example, at 3 h, kidney accumulation varied in percentage injected dose per organ (%ID per organ) from 31 %ID per organ (HYNIC) to 18 %ID per organ (MAG3), whereas liver varied from 7.8 %ID per organ (MAG3) to 2.8 %ID per organ (MAS3). Radioactivity accumulation in the lesion was independent of labeling method. These organ accumulations were compared with that obtained earlier in mice by sacrifice and dissection also at 3 h and at the same administered dosage. In the rodent, kidney levels varied from 45 %ID per organ (HYNIC) to 12 %ID per organ (MAS3) and liver levels varied from 6.5 %ID per organ (DTPA) to 2.0 %ID per organ (MAS3). CONCLUSION: In agreement with previous work from this laboratory and elsewhere, the method of radiolabeling had an important effect on the biodistribution of (99m)Tc. Furthermore, although biodistribution results in mice should be used with caution to predict biodistributions in primates, in major organs, these results in mice and monkeys were similar.     

Single-leg mechanical performance and inter-leg asymmetries during bilateral countermovement jumps: A comparison of different calculation methods

BackgroundThe possibility to selectively assess the force exerted by each leg during bilateral jumps has allowed sport scientists to explore inter-leg asymmetries, this metric being a rich source of research due to its potential applications to improve sports performance and reduce the risk of injury. The purpose of this study was to explore the reliability and agreement of single-leg mechanical performance and inter-leg asymmetry variables obtained by two procedures of analysis (Synchronous [simultaneous jump detection for both legs] and Asynchronous [specific jump detection for each leg]) during bilateral countermovement jumps (CMJs).MethodDuring a single testing session, 74 participants performed 5 maximal height bilateral CMJs on dual force platforms (Kistler, model 9260AA6, Winterthur, Switzerland), and the 2 trials that differed the least in terms of squat depth and jump height were considered for statistical analyses. The following mechanical variables were calculated separately for each leg using the Synchronous and Asynchronous procedures: mean force, peak force, and propulsive impulse.ResultsThe procedures showed comparable reliability, except for mean force and propulsive impulse of the left leg (higher for the Asynchronous procedure). The agreement between the procedures was very high, while the most reliable mechanical variable was mean force (CV≈2.9%, ICC≈0.98), followed by peak force (CV≈4.4%, ICC≈0.96) and propulsive impulse (CV≈6.4%, ICC≈0.91). Reliability of inter-leg asymmetries was greater using mean and peak force (ICC range=0.74–0.82) than using propulsive impulse (ICC range = 0.65–0.66).SignificanceBoth Synchronous and Asynchronous procedures can be used to evaluate single-leg mechanical performance (mean force, peak force, and propulsive impulse) and asymmetries, whereas mean force should be used to evaluate single-leg mechanical performance and mean or peak force to assess asymmetries.     

A comparison of three methods to determine the radiochemical purity of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO)

Determining the radiochemical purity of 99Tcm-HMPAO using the standard method suggested by the manufacturer of the HMPAO kit is slow, consuming much of the 30 min useful shelf-life of the radiopharmaceutical. We have compared two new methods (a solvent extraction technique and a method involving a disposable, pre-packed reverse phase chromatography cartridge) with the standard method for determining the radiochemical purity of 99Tcm-HMPAO. There were no significant differences (F test, p less than 0.05) in the results obtained by all three methods. However, the reversed phase chromatography method gave better agreement (correlation coefficient of 0.877) with results obtained using the standard method than did the solvent extraction technique (correlation coefficient of 0.693). The solvent extraction technique took about 10 min to perform whereas the reversed phase chromatography method took only 5 min. Both of the new methods did not achieve complete separation of the secondary, less lipophilic 99Tcm-HMPAO complex from the primary, lipophilic 99Tcm-HMPAO complex but the error introduced was small (typically only 3-5%). The new methods offer the capability of determining the radiochemical purity of 99Tcm-HMPAO quickly, reliably and accurately, prior to administration of the radiopharmaceutical to the patient.