共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
A simple method to design a polymerase chain reaction (PCR) primer for parasites of interest was developed using Dirofilaria immitis as a test sample. The method involved the cloning and sequencing of randomly amplified DNA of the parasite, and designing a primer based on the resulting DNA sequence. Using the primer, DNA fragments of the expected length were amplified by a regular PCR with genomic DNA of Dirofilaria immitis. 相似文献
3.
A method combining the advantages of electrophoretic DNA fractionation and autoradiography is described for the qualitative and quantitative analysis of internucleosomal DNA fragmentation that occurs during apoptosis, or "programmed cell death." This procedure utilizes terminal transferase enzyme to uniformly add one molecule of [alpha 32P]-dideoxynucleotide to the 3'-end of DNA fragments. Following gel electrophoresis and autoradiographic analysis, the total amount of radiolabel incorporated into the low molecular weight DNA fraction can be quantitated and used to estimate the degree of apoptotic DNA fragmentation in any given sample. This method requires as little as 15 ng of total cellular DNA and increases the sensitivity of apoptotic DNA detection by at least 100-fold over the widely used ethidium bromide staining method. The procedure should prove valuable for the analysis of apoptosis in minute quantities of tissues and cultured cells. 相似文献
4.
By using computer cytophotometric analysis, aneuploid as well as other 12 parameters of tissue DNA content were measured in 28 cases of small bowel cancer, 5 cases of intestinal adenoma, 6 cases of normal intestinal tissues. The number of aneuploid tumors in intestinal cancer was much higher than in intestinal adenoma. 7 DNA parameters (Entropy of DNA, 2CDI, DNA- grade of neoplasia, 5C Exceeding Rate, 9C Exceeding Rate, Diploid Deviation Quotient and Mean Ploidy) were the valuable indexes that could determine the quality of intestinal lesions, benign or malignant. DNA content didn't correlate with the clinically differentiated degree of pathological tissues, but aneuploid intestinal cancers had a higher malignant degree than non-aneuploid ones, and were more liable to invade and metastasize with low postoperative survival-rate and poor prognosis. 5 DNA parameters (DNA-Index, Medal Value, DNA-grade of neoplasia, Stemline Ploid and 9C Exceeding Rate) had close relation to the prognosis of intestinal cancer, possessing important value to the prognostic analysis of intestinal cancer. 相似文献
5.
A single synthesis cycle of the amplification refractory mutation system (ARMS) was applied to the analysis of K-ras alleles amplified by polymerase chain reaction and immobilized in streptavidin-coated microtiter plates. The ARMS cycle provided the specificity and molecular switch characteristics of a conventional ARMS assay. This allowed linear extension from an allele-specific primer and the incorporation of digoxigenin-labeled deoxyuridine monophosphate from digoxigenin-11-deoxyuridine triphosphate in the presence of the appropriate K-ras allele. Any digoxigenin-labeled deoxyuridine monophosphate substitution was then demonstrated by enzyme-linked immunoassay with colorimetric endpoint. This method is capable of detecting underrepresented acquired mutations, and this has been shown by the unambiguous detection of specific K-ras mutations in cell line DNA/normal human genomic DNA admixtures. The characterization of K-ras mutations in frozen colorectal tumor samples and histologic material is also described. 相似文献
6.
为实现高分辨率与小方差的小子样频谱分析,在快速傅立叶变换算法基础上,引入最大熵算法,给出计算原理和算例,并与常用的FFT和BFFT软件的相应计算结果进行比较.计算实例表明,应用最大熵算法分析计算诸如海浪一类平稳各态历经的随机过程是有效的. 相似文献
7.
T Miki 《Canadian Metallurgical Quarterly》1998,46(10):1008-1014
The pathogenesis of Alzheimer's disease (AD) remains unclear. We ascertained 57 Japanese families with early onset familial Alzheimer's disease (EOFAD; mean onset age < 65 years). Screening the known beta/A4 amyloid precursor protein (APP) mutations in familial AD by a simplified PCR product detection system disclosed only one EOFAD with the APP717Val-Ile mutation (AD1 locus). Four of 6 families showing a positive linkage to AD3 locus had four different mutations on the presenilin 1 gene. These mutations were Val 96 Phe, Ile223Thr, His163Arg and splicing mutation with an AG-AA substitution at the acceptor site of intron 9. The allele frequency of APOE-e4 of late-onset and early-onset AD was significantly higher than that of age-matched controls (p < 0.0001). These results suggest that APOE-e4 (AD2 locus) is a susceptibility gene for AD in the Japanese population, regardless of the age at onset. It is probable that the risk for AD in most subjects is likely to arise from the cumulative effects of environmental factors along with various genetic factors. Advances in molecular biology and molecular genetics have enabled us to more easily understand these genetic factors. 相似文献
8.
Rohrer Doug; Wixted John T.; Salmon David P.; Butters Nelson 《Canadian Metallurgical Quarterly》1995,21(5):1127
In 3 experiments, participants generated category exemplars (e.g., kinds of fruits) while a voice key and computer recorded each response latency relative to the onset of responding. In Experiment 1, mean response latency was faster when participants generated exemplars from smaller categories, suggesting that smaller mental search sets result in faster mean latencies. In Experiment 2, a concurrent secondary task increased mean response latency, suggesting that slowed mental processing results in slower mean latencies. In Experiment 3, the mean response latency of Alzheimer's participants was faster than that of elderly controls, which is consistent with the idea that the semantic memory impairments of Alzheimer's disease patients stem primarily from a reduction in available items (as in Experiment 1) rather than retrieval slowing (as in Experiment 2). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
9.
MF Weiner RC Risser CM Cullum L Honig C White S Speciale RN Rosenberg 《Canadian Metallurgical Quarterly》1996,153(10):1269-1273
OBJECTIVE: The authors compared clinical findings of Alzheimer's disease and the so-called Lewy body variant of Alzheimer's disease. METHOD: Available data were analyzed on the clinical features of 58 patients with Alzheimer's disease and 24 patients with the Lewy body variant of Alzheimer's disease who underwent postmortem examination. RESULTS: The proportion of men was significantly larger in the Lewy body variant group than in the Alzheimer's disease group (66.7% versus 34.5%), and, concordantly, the Lewy body variant group was slightly taller. The prevalence of hallucinations and delusions was significantly higher in Lewy body variant subjects than the Alzheimer's disease subjects, but there were no significant differences between the two groups in educational attainment, family history of dementia, age at onset, duration of illness, cognitive impairment, overall severity of illness, or neuropsychological findings. Patients with the Lewy body variant of Alzheimer's disease tended to experience more frequent extrapyramidal side effects of neuroleptics than did the patients with Alzheimer's disease, but for patients in the two groups who were not exposed to neuroleptics, there was little difference in frequency of extrapyramidal side effects. CSF concentration of homovanillic acid (HVA) was significantly lower in the Lewy body variant patients, even when correction was made for height. CONCLUSIONS: The Lewy body variant of Alzheimer's disease may be suspected in elderly male dementia patients who otherwise meet criteria for Alzheimer's disease but who manifest significant psychiatric symptoms and neuroleptic-induced extrapy-ramidal side effects and have low levels of CSF HVA. 相似文献
10.
J Zedenius T Dwight BG Robinson L Delbridge M B?ckdahl G Wallin C Larsson G Weber 《Canadian Metallurgical Quarterly》1998,22(6):544-548
In 22 consecutive patients with tetralogy of Fallot (TF), a total correction was attempted without the use of a homologous blood transfusion from September 1995 to March 1997. The 22 patients were divided into two groups according to their surgical procedures; namely, either a simple correction (group I: n = 14) or a complex correction including the relief of peripheral pulmonary stenosis and/or the division of a previous systemic-pulmonary shunt (group II: n = 8). In 77% of all patients, surgery was performed without a homologous blood transfusion. No differences were found in the non-transfusion rate and the hematocrit (Ht) values between the two groups and, as a result, we thus confirm that this additional procedure is not a risk factor for surgery without a homologous blood transfusion. According to the correlation of the red blood cell volume before and after surgery, the preoperative Ht value corresponding to the postoperative Ht of 30% could be accurately predicted. The calculated Ht values were 41.0% in the patient weighing 15 kg, 42.5% in those weighing 10 kg, and 46.9% in those weighing 5 kg. These data suggest that a surgical correction without a homologous blood transfusion can therefore be safely performed in almost all patients with TF. 相似文献
11.
LOTOS(Language of Temporal Ordering Dpecification)是一种基于进程代数CCS的协议描述语言,这里提出LOTOS的实时扩展ET-LOTOS,是Timed LOTOS的增强版.它增加了时间控制的操作器,对LOTOS的操作语义进行了实时的扩充,支持定量时间的观点,提高了形式方法的表达力. 相似文献
12.
13.
JA Hanley 《Canadian Metallurgical Quarterly》1996,15(14):1575-1585
The binormal model is widely used for parametric receiver operating characteristic (ROC) analyses of data concerning the accuracy of medical diagnostic tests. Empirical evaluation of the performance of this model in the face of departures from binormality has been limited to interpretations of radiology-type examinations recorded on a rating scale. This paper extends the investigation to the performance of the model with biochemical and other tests recorded on an interval scale. In order to describe non-binormal pairs of distributions, a useful standardized graphical display is developed; this display also illustrates several features of ROC curves. We consider non-binormal pairs of distributions with or without a monotone likelihood ratio and show that by transformation of the underlying scale, one can make many such pairs resemble closely the binormal model. These findings justify Metz's use of the binormal model in the 'LABROC' software for ROC analyses of laboratory type data even when the raw data may 'look' decidedly non-Gaussian. 相似文献
14.
SM Azarian CF Megarity J Weng DH Horvath GH Travis 《Canadian Metallurgical Quarterly》1998,102(6):699-705
In order to evaluate the effect of thyroid replacement therapy on bone metabolism in congenital hypothyroid children, we studied 23 (10 girls and 13 boys) consecutive patients. Their age ranged from 3 to 8 weeks. One of these patients had familiar dyshormonogenesis, 21 had ectopic glands and one hemiagenesis. As a control group, we studied 46 sex- and age-matched healthy newborns. Before the beginning of therapy, the hypothyroid patients showed higher values of calcium (2.78 +/- 0.04 vs 2.65 +/- 0.07 mmol/l; p < 0.05) and of 1,25-dihydroxy-vitamin D (159.7 +/- 31.6 vs 90.5 +/- 33.1 ng/l; p < 0.01), while they showed lower values of osteocalcin (1.9 +/- 0.8 vs 2.9 +/- 0.9 ng/ml; p < 0.01) than controls. After 3 months of therapy, we found a complete normalization of all these parameters and a progressive increase of osteocalcin. Our data show that in congenital hypothyroid children there are abnormalities in calcium metabolism which seem to be transient and reversible after L-thyroxine replacement therapy. 相似文献
15.
Y Wu VM Hayes J Osinga IM Mulder MW Looman CH Buys RM Hofstra 《Canadian Metallurgical Quarterly》1998,26(23):5432-5440
Denaturing gradient gel electrophoresis (DGGE) is one of the most powerful methods for mutation detection currently available. For successful application the appropriate selection of PCR fragments and PCR primers is crucial. The sequence of interest should always be within the domain with the lowest melting temperature. When more than one melting domain is present the fragment is generally divided into several smaller ones. This, however, is not always necessary. We found that simple modifications of PCR fragments and primer sequences may substantially reduce the number of amplicons required. Furthermore, by plotting the (natural) melting curves of fragments without a GC-clamp, we could explain why fragments theoretically perfect for DGGE in practice failed to reveal mutations. Alternative fragment selection and the use of modified primers (addition of T/A or G/C tails) result in the detection of mutations that originally remained undetected. Our studies extend the utility of DGGE by using a minimum of PCR fragments and achieving a maximum of mutation detection. 相似文献
16.
在一定条件下,用方波极谱法研究了Au(Ⅲ)和Au(Ⅰ)与4-(2-吡啶偶氮)-间苯二酚(PAR)络合时,Au(HI)和PAR络合物在-0.35V和-0.42V处有两个明晰的还原峰,其中第二个还原峰的电流(IP)与Au(Ⅲ)的质量浓度在0.50~4.0μg/mL范围内呈线性关系,检出限为0.010μg/mL;Au(Ⅰ)与PAR络合物在-0.38V处有-个明晰的还原峰,峰电流(IP)与Au(Ⅰ)的质量浓度在0.050—2.0μg/mL范围内呈线性关系,检出限为0.0030μg/mL。用该方法成功地分析了金矿粉处理后滤液中金的价态和含量。 相似文献
17.
RE Patterson 《Canadian Metallurgical Quarterly》1996,3(4):334-341
This article reviews selected literature that can be useful for analysis of cost-effectiveness (CE) of diagnostic procedures in patients with known or suspected coronary artery disease. First, a clinical example illustrates some of the issues involved. Four questions are used to organize the material: (1) What is CE analysis? (2) Why should we use CE analysis? (3) Who should perform CE analysis? and (4) How should CE analysis be performed? (1) What is CE analysis? CE analysis differs from cost-reduction or cost-benefit analysis but may encompass cost-utility analysis. Marginal CE emphasizes differences in CE between different strategies. (2) Why should we use CE analysis? Nuclear cardiology depends on the fruits of medical technology, and many policy makers blame technology for escalating costs of health care. This situation requires us to reduce the absolute cost or the increment in cost, as well as to assess the true value of the technology we use. (3) Who should perform CE analysis? A team approach is the best answer to combine the expertise from clinicians and economists. A team approach and detailed definitions of assumptions can help minimize potential bias. (4) How should CE analysis be performed? CE analysis requires formulating important questions, designing alternative scenarios or strategies, selecting values for the numeric variables and including the probability that an event will occur, calculating cost per outcome, and sensitivity analysis of the model. The appropriate goal of CE analysis of the clinical use of cardiac imaging procedures is, first, to help improve patient outcome and, second, to limit costs. 相似文献
18.
19.
The uptake of serotonin (14C-5-hydroxytryptamine, 5HT) in platelets and its kinetic characteristics were investigated in a group of women (n = 20) with probable Alzheimer's Disease (mean age = 76.0, years, SD = 8.27, range = 63-88) and in healthy normal women (n = 18, mean age = 72.6 years, SD = 7.24, range = 61-84). Both the apparent affinity of binding of 5HT to the platelet membrane (Km) and the maximum velocity (Vmax) of the rate of transport of 14C-5HT into platelets were significantly higher in the Alzheimer's Disease group than in the normal comparison group. Initial velocity of 14C-5HT uptake not passive diffusion (nonspecific uptake of 14C-5HT at 4 degrees C) differed significantly in the two groups. Our findings suggest abnormalities in the kinetic mechanisms involved in the uptake of 14C-5HT by platelets in women with Alzheimer's Disease. 相似文献
20.
N Howell I Kubacka R Smith F Frerman JK Parks WD Parker 《Canadian Metallurgical Quarterly》1996,46(1):219-222
We report previously undescribed or atypical clinical and biochemical manifestations of the mitochondrial DNA MERRF mutation at nucleotide 8344 in members of a multigenerational family with maternally inherited, highly variable neurodegenerative disorder. The more profound neurologic abnormalities include Leigh disease, spinocerebellar degeneration, and atypical Charcot-Marie-Tooth disease. 相似文献