国内有关肿瘤标志物诊断性研究存在的实验设计缺陷

目的对比国内外肿瘤标志物诊断性试验类论文,寻找国内论文存在的差距,为提高论文写作质量提供参考。方法通过电子数据库全文检索,国外论文30篇,国内40篇。对比两者在样本量、对照组选择、统计方法等方面的差异。结果国内外论文在病例组样本量、对照组构成等方面差异均有统计学意义(P<0.05);多数(78%)国外论文采用非参数检验方法(P<0.001);多数(87%)国内论文采用参数检验方法(P<0.001)。结论总体上看,国内论文样本量偏少,对照组构成不够科学,统计学方法不正确。     

Identification of the chromosome 14 origin of a C-negative marker associated with a 14q32 deletion by chromosome painting

A constitutional chromosome 14 rearrangement was observed in a female with a psychodevelopmental disorder. Karyotype analysis using a variety of chromosome techniques, QFQ, GTG, CBG, Ag-NOR and DA-DAPI, showed a deletion of chromosome 14q32.1-qter region in association with a supernumerary marker chromosome. The marker, resembling a submetacentric, approximately half the size of a G group chromosome is C band and Ag-NOR negative. The heteromorphism of the satellites showed that the deleted chromosome 14 is paternal in origin. Chromosome painting using an Alu-PCR probe specific for the human chromosome 14 and fluorescent in situ hybridization (FISH) showed that the marker contains chromosome 14q32 sequences. It is likely that the marker was generated from the deleted chromosome 14 region through a complex rearrangement.     

识别正常人类G带染色体的标准与鉴别检索表——Ⅱ.Prometaphase haploid 500带期

<正> 4.染色体最大。P上有9个深色带.其中第1带(P21)最宽,其次为第3带(P31.1),其余带均窄。P端部为浅色带。q远端的4个带的宽窄大小由近至远的顺序为窄宽窄宽(即q32.2q42.2相似文献   

Alcohol Abuse, Alcoholism, and Damage to the Immune System—A Review

Chronic alcohol abuse exacts a major social and medical toll in the United States and other Western countries. One of the least appreciated medical complications of alcohol abuse is altered immune regulation leading to immunodeficiency and autoimmunity. The consequences of the immunodeficiency include increased susceptibility to bacterial pneumonia, tuberculosis, and other infectious diseases. In addition, the chronic alcoholic often has circulating autoantibodies, and recent investigations indicate that the most destructive complications of alcoholism, such as liver disease and liver failure, may have a component of autoimmunity. Current research on altered cytokine balance produced by alcohol is leading to new insights on the regulation of the immune system in the chronic alcoholic. There is also recent development of exciting new techniques designed to improve or restore immune function by manipulation of cytokine balance. Although much remains to be learned, both in the abnormalities produced by alcohol and in the techniques to reverse those abnormalities, current progress reflects a rapidly improving understanding of the basic immune disorders of the alcoholic.     

A novel high molecular weight metalloproteinase cleaves fragment F1 of activated human prothrombin.

A hemorrhagic proteinase, jerdohagin, was purified from Trimeresurus jerdonii venom by gel filtration and ion-exchange chromatographies. It was a single chain polypeptide with an apparent molecular weight of 96 kDa as estimated by SDS-PAGE under the non-reducing and reducing conditions. Internal peptide sequencing indicated that it consisted of metalloproteinase, disintegrin-like and cysteine-rich domains and belonged to the class III snake venom metalloproteinases (class P-III SVMPs). Like other typical metalloproteinases, hemorrhagic activities of jerdohagin were completely inhibited by EDTA, but not by PMSF. Jerdohagin preferentially degraded alpha-chain of human fibrinogen. Interestingly, jerdohagin did not activate human prothrombin, whereas it cleaved human prothrombin and fragment F1 of activated human prothrombin.     

Caffeine effects on resting-state arousal.

OBJECTIVE: This study examined the use of caffeine to manipulate arousal level without the confounds associated with task-related activation. From previous work in our laboratory, an increase in skin conductance level (SCL) and EEG alpha frequency, together with a global decrease in alpha power, were used as markers of arousal increase, and we sought to identify these effects with caffeine ingestion. METHODS: We examined the effect of a single oral dose of caffeine (250 mg) in a randomised double-blind placebo-controlled repeated-measures cross-over study. Eighteen healthy university students (mean age 21 years; 13/18 females) participated in two sessions 1 week apart. EEG and autonomic data (SCL, heart rate, systolic and diastolic blood pressure, and respiration rate) from a 2 min eyes-closed epoch, commencing approximately 30 min after ingestion of caffeine or placebo, were examined. RESULTS: Caffeine was associated with increased SCL, a global reduction in EEG power in the alpha band, and a global increase in alpha frequency. There were no cardiovascular effects. CONCLUSIONS: The positive results are consistent with recent electrodermal and EEG studies of arousal and suggest that caffeine may be utilised as a task-free means of manipulating arousal in future investigations. Further work is necessary to clarify the absence of cardiovascular effects, and to integrate those data with emerging conceptualisations of arousal and activation. SIGNIFICANCE: The present data support the use of caffeine as a simple tool to explore the role of arousal in both normal and atypical functioning, and this may be useful in determining the validity and importance of supposed hyper- or hypo-arousal in such syndromes as attention-deficit/hyperactivity disorder (AD/HD).     

GC-MS detection and characterization of thebaine as a urinary marker of opium use

The differentiation between legal and illegal opiate product use through the detection of marker compounds in urine is one of the most important subjects in forensic toxicology. Thebaine, an opium alkaloid, can be detected by gas chromatography-mass spectrometry (GC-MS) and has been suggested as a good marker of poppy seed use in differentiation from that of illicit heroin. In the present study, thebaine was targeted as a urinary marker of opium use because it is a major constituent of opium. Although thebaine lacks the conventional functional group, it was found to form a trimethylsilyl (TMS) derivative. This has made it possible to simultaneously detect thebaine together with morphine and codeine in the same urine sample to confirm opium use, thus saving time and cost of analysis while using less material. The TMS derivatization was found to enhance the stability and chromatographic properties of thebaine and to increase the sensitivity of its detection about 50-fold in comparison with that of the underivatized compound. Using the present method, thebaine was analyzed for a number of actual urine samples obtained from users of opium, illicit heroin, or codeine preparation. The results showed that thebaine is a useful opium-use marker subject to its oral administration.     

Multiple activation currents can be evoked inXenopus laevis eggs when cortical granule exocytosis is inhibited by weak bases

The fertilization potential inXenopus eggs under normal circumstances is considered to be a unique event. It is associated with a concomitantly occurring cortical granule exocytosis. If eggs were exposed to weak bases, exocytosis was inhibited but the fertilization potential could still be evoked. After recovery from this first transient increase in membrane conductance, a second could be elicited by a further stimulus. A fertilization potential could be triggered either before or after the egg had undergone an electrically induced activation potential. This suggests that sperm receptors and sperm activated ionic channels in the egg membrane remain functional following the conductance change, at least when the exocytotic event was prevented.A transient conductance increase could only be induced by NH ₄ ⁺ (pH 9.0) in unactivated eggs that had not undergone cortical granule exocytosis.Tremendous variation was noticed between successive activation currents elicited in the same egg. Under voltageclamp at 0 mV holding potential, the current often changed from inward to outward. Although cortical granule exocytosis may only play a minor role in the transient conductance change triggered at fertilization, it may well be involved in subsequent modifications of membrane conductance.     

Blood samples drawn for culture as a surrogate marker for case-mix adjustment of hospital antibiotic use

Hospital antibiotic consumption is generally adjusted to occupancy. This study hypothesised that the number of blood culture samples could be a surrogate marker for case-mix adjustment. Antibiotic consumption was compared over 16 consecutive trimesters in one medical ward in terms of patient-days or blood culture samples. Compared with patient-days, measurement adjusted to blood culture samples detected three trimesters with an unusually high consumption, and one trimester with consumption falsely classified as high because of a high incidence of infections. Blood culture numbers enabled easy and accurate identification of periods with a drift in antibiotic consumption ina medical ward.     

小鼠SRS-82细胞系和SAC-ⅡB_2、SAC一ⅡC_3克隆细胞株的染色体组型比较

本文研究结果表明,SRS-82细胞系的干系细胞染色体数是43,SAC-IIB_2细胞株的染色体数为多倍体,分布在75～91之间,SAC-IIC_3的干系细胞染色体数是41。三种细胞中均可看到A、B和M三种标记染色体,三种细胞的G显带核型也有差异。