Detection of DNA Sequence with Enhanced Sensitivity and Higher FRET Efficiency Using a Light-Emitting Polymer,Peptide Nucleic Acid Probe and Anionic Surfactant System

An improved strategy has been developed for detection of DNA sequence by using water-soluble cationic conjugated polymer (PFP)/single-strand (ss) DNA and peptide nucleic acid labeled with fluorescent dye (PNAC*), where an anionic surfactant (sodium dodecyl sulphate, SDS) system has been used to improve the sensitivity of the sensor. The method of detection is simple to use, fast and cost-effective. This method uses the phenomenon of Forester Resonance Energy Transfer (FRET). The detection sensitivity of the biosensor has been improved by about ten times by using the anionic surfactant. It is observed that the effect of surfactant is to increase the photoluminescence (PL) intensity of the PNAC* when the sequence of the DNA is complementary (to that of PNA probe). On the other hand when the two sequences are non-complementary, the PL intensity of the PNAC* is further reduced as compared to the case when surfactant was absent.     

以压迫阻滞针效定位的方法测试人体体表心包经的循行路线

以心功能和心电图为指标,以机械压迫阻滞针效为手段,比较压迫心包经穴位、经线上非穴位点和该穴点两侧对照点对针刺内关穴针效的影响,检测心包经在体表的循行轨迹。结果,压迫经上穴点针后各项指标变化微小,针效显著降低;压迫两侧对照点则对针效无明显影响。两者比较,差异非常显著。证明上肢屈侧确有一条与心包经一致的机能路线,并与心脏机能活动调节密切相关。     

Pain from Rectal Distension in Women with Irritable Bowel Syndrome (Relationship to Sexual Abuse)

The aims of this study were to determine whetherincreased pain sensitivity in patients with irritablebowel is due to physiological differences in perceptualsensitivity or psychological influences on perception, and whether prior sexual abuseaccounts for increased pain sensitivity. Seventeensexually abused and 15 nonabused women with irritablebowel were compared to 13 sexually abused and 14nonabused women without irritable bowel. Among thenonabused subjects, the volume of rectal distension thatproduced moderate pain was lower in IBS patients than incontrols, replicating earlier studies, but these thresholds were correlated with psychologicalmeasures of anxiety and somatization. The ability todiscriminate between painful distensions (perceptualsensitivity) was not different between groups. Sexual abuse was not associated with lower painthresholds. Thus, differences in pain sensitivity appearto be due to psychological influences on perception, buta history of sexual abuse does not contributesignificantly to this pain sensitivity.     

Limits of detection for time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS): detection of low amounts of adsorbed protein

Characterization of biomaterial surfaces requires analytical techniques that are capable of detecting a wide concentration range of adsorbed protein. This range includes detection of low amounts of adsorbed protein (<10 ng/cm²) that may be present on non-fouling biomaterials. X-ray Photoelectron Spectroscopy (XPS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) are surface sensitive techniques capable of detecting adsorbed proteins. We have investigated the lower limits of detection of both XPS and ToF-SIMS on four model substrates each presenting unique challenges for analysis by XPS and ToF-SIMS: mica, poly(tetrafluoroethylene), allyl amine plasma polymer and heptyl amine plasma polymer. The detection limit for XPS ranged from 10 ng/cm² of fibrinogen (on mica) to 200 ng/cm² (on allyl amine plasma polymers). The detection limit for ToF-SIMS ranged from 0.1 ng/cm² of fibrinogen to 100 ng/cm², depending on the substrate and data analysis. Optimal conditions provided detection limits between 0.1 ng/cm² and 15 ng/cm² on all of the substrates used in this study. While both techniques were shown to be effective in detecting protein, the sensitivity of both XPS and ToF-SIMS was shown to be dependent on substrate surface chemistry and the organization of the adsorbed protein film. This study specifically highlights the applicability of ToF-SIMS in the characterization of low level protein adsorption.     

人乳头瘤病毒感染量测定对宫颈癌前病变预测意义的探讨

【目的】探讨采用第二代杂交捕获法(hybrid captureⅡ,HC2)检测高危型人乳头瘤病毒DNA(HPV-DNA)的含量与宫颈癌前病变的关系。【方法】2003年9月至2005年1月就诊于广东省中医院妇科门诊的妇女433例,采用HC2法定量检测其宫颈HPV-DNA的含量,对于阳性患者行膜式薄层液基细胞学(TCT)检查,若细胞学异常,则行阴道镜下宫颈多点活检和宫颈颈管搔刮术。【结果】128例HPV-DNA阳性患者中,细胞学异常者[包括不典型鳞状细胞(ASCUS)、低度鳞状上皮内病变(LSIL)、高度鳞状上皮内病变(HSIL)]为98例(占76.56%),比细胞学为良性反应性细胞(占23.44%)者多,并且细胞学异常者的宫颈组织中的HPV-DNA含量也高于良性反应性细胞者(P<0.05)。对慢性宫颈炎和宫颈上皮内瘤样病变(CIN)者的HPV-DNA含量测定结果显示,两者的HPV-DNA含量无显著性差异(P>0.05),即随着宫颈病变程度的增加,HPV-DNA含量无上升趋势。【结论】HPV-DNA的定性和定量测定对宫颈癌前病变发生的可能性有预测意义,即HPV-DNA阳性并且HPV-DNA含量高者发生宫颈癌的可能性较大,但HPV-DNA的含量测定还不能作为宫颈病变程度的判别指标。     

大鼠经脉体表循行线表皮结构特征的形态计量学研究

用电镜与光镜的形态计量学方法研究了大鼠胃经胸腹段和膀胱经背部段体表循行线表皮的结构特征。结果表明，经脉线表皮细胞缝隙连接的面数密度、数密度、平均外径和平均面积均明显大于邻近对照表皮。经线上每个表皮细胞膜上的缝隙连接面积为其邻近对照表皮细胞的１２倍以上，而表皮厚度、角质层厚度、表皮细胞层数、细胞间隙体密度和桥粒体密度等参数在经脉线与对照表皮间均未见显著差异。     

痤疮患者的耳穴探测及耳针疗效观察

应用ＳＷＤ－９００１型信息治疗仪，对９６例青年痤疮患者和４０例健康青年作了耳穴敏感点测定。结果，痤疮患者阳性例数在７０％以上的有内分泌、肾上腺、大肠、肺、胃等５点，而健康青年上述５点阳性例数明显减少。经统计学处理，两组有显著性差异。同时将９６名患者随机分成耳针加中药组和中药组，进行对照观察。结果耳针加中药组基本治愈率、显效率明显优于中药组。     

Evaluation of Two String Tests for Obtaining Gastric Juice for Culture, Nested-PCR Detection, and Combined Single- and Double-Stranded Conformational Polymorphism Discrimination of Helicobacter pylori

We have compared two gastric string tests forobtaining gastric juice for culture of Helicobacterpylori and for nested-PCR detection and PCR-basedcombined single- and double-stranded conformationalpolymorphism (SDSCP) discrimination of infecting strains.String test specimens were obtained from oneseropositive volunteer for 13 consecutive weeks. Thedistal 10 cm of each string was suspended in 1 ml salineand quantitatively cultured. An additional ninevolunteers with histories of upper-gastrointestinalcomplaints were given a string test for culture andnested-PCR assay. H. pylori isolates and/or gastricjuice from each volunteer were extracted for DNA andanalyzed by PCR-based SDSCP. Quantitative culture showedthat the Entero-test was four times as sensitive as theGastro-test but was more prone to contamination by oral flora. However, the two string testsare equally sensitive by PCR assays. Thus, theGastro-test is more suitable for culture detection of H.pylori, since it is less prone to oral contamination and its shorter length is better tolerated.SDSCP analysis of H. pylori DNA from four PCR-positivevolunteers without requiring culture showed fourdistinct profiles, indicating different infectingstrains. SDSCP analysis of strains isolated before andafter treatment of one volunteer had the same SDSCPprofile, suggesting endogenous reinfection by the samestrain.     

Natural Polysaccharides as Active Biomaterials in Nanostructured Films for Sensing

The search for natural, biocompatible and degradable materials amenable to be used in biomedical/analytical applications has attracted attention, either from the environmental or medical point of view. Examples are the polysaccharides extracted from natural gums, which have found applications in the food and pharmaceutical industries as stabilizers or thickening agent. In a previous paper, however, it was shown that a Brazilian natural gum, chicha (Sterculia striata), is suitable for application as building block for nanostructured film fabrication in conjunction with phthalocyanines. The films displayed electroactivity and could be used in sensing. In the present paper, we introduce the use of two different natural gums, viz., angico (Anadenanthera colubrina) and caraia (Sterculia urens), as active biomaterials to be used to modification layers, in the form of nanostructured thin films, including the study of dopamine detection. The multilayer films were assembled in conjunction with nickel tetrasulfonated phthalocyanines (NiTsPC) and displayed good chemical and electrochemical stability, allowing their use as transducer elements in sensors for detection of specific neurotransmitters. It is suggested here that nanoscale manipulation of new biodegradable natural polymers opens up a variety of new opportunities for the use of these materials in advanced biomedical and analytical devices.     

Screening and Clinical Implications for BRCA1 and BRCA2 Mutation Carriers

In this article, we review the history oftesting for mutations in breast cancer susceptibilitygenes and discuss the current state of testing formutations in BRCA1 and BRCA2 in different clinicalsettings including at-risk individuals and cancerpatients. The risk of breast cancer, other associatedmalignancies and prognosis in carriers of thesemutations are reviewed. A final section includesdiscussion of current recommendations for surveillance andthe need for further research to identify environmentaland genetic factors which modify the risk of developingcancer in mutation carriers.