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Intravascular ultrasound can provide clear real-time cross-sectional images, including lumen and plaque. In practice, to identify the plaques tissues in different pathological changes is very important. However, the grayscale differences of them are not so apparent. In this paper a new textural characteristic space vector was formed by the combination of Co-occurrence Matrix and fraction methods. The vector was projected to the new characteristic space after multiplied by a projective matrix which can best classify those plaques according to the Fisher linear discriminant. Then the classification was completed in the new vector space. Experimental results found that the veracity of this classification could reach up to 88%, which would be an accessorial tool for doctors to identify each plaque.  相似文献   

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本研究以灰度共生矩阵描述乳腺钼靶X线影像中结构扭曲的纹理特征.对学习样本(乳腺结构扭曲样本44个,正常样本78个),计算五个反映纹理性质的特征参数,根据相应的Fisher系数,确定最适合作为分类依据的特征参数或特征参数组合.用线性判别分析对测试样本(乳腺结构扭曲样本43个,正常样本78个)进行分类.分类结果表明本研究确定的纹理特征熵(ENT)是识别乳腺结构扭曲的最佳统计参数(分类正确率达78.5%、ROC曲线下的面积为0.786).  相似文献   

5.
The conventional way to estimate functional networks is primarily based on Pearson correlation along with classic Fisher Z?test. In general, networks are usually calculated at the individual-level and subsequently aggregated to obtain group-level networks. However, such estimated networks are inevitably affected by the inherent large inter-subject variability. A joint graphical model with Stability Selection (JGMSS) method was recently shown to effectively reduce inter-subject variability, mainly caused by confounding variations, by simultaneously estimating individual-level networks from a group. However, its benefits might be compromised when two groups are being compared, given that JGMSS is blinded to other groups when it is applied to estimate networks from a given group. We propose a novel method for robustly estimating networks from two groups by using group-fused multiple graphical-lasso combined with stability selection, named GMGLASS. Specifically, by simultaneously estimating similar within-group networks and between-group difference, it is possible to address inter-subject variability of estimated individual networks inherently related with existing methods such as Fisher Z?test, and issues related to JGMSS ignoring between-group information in group comparisons. To evaluate the performance of GMGLASS in terms of a few key network metrics, as well as to compare with JGMSS and Fisher Z?test, they are applied to both simulated and in vivo data. As a method aiming for group comparison studies, our study involves two groups for each case, i.e., normal control and patient groups; for in vivo data, we focus on a group of patients with right mesial temporal lobe epilepsy.  相似文献   

6.
Two rapid real-time RT-PCR assays, specific for respiratory syncytial virus (RSV) and influenza A and B, were evaluated for the detection of these viruses in clinical respiratory samples. The RSV assay was applied to 100 samples and the Influenza A and B assay applied to 96 samples all of which had been tested previously by an “in-house” multiplex real-time PCR assay. Forty-three samples were negative for RSV by both methods and 56 samples were positive by both methods. One sample was negative by the new RSV assay although it was positive for RSV A by the “in-house” test. Thirty-nine samples were negative for influenza virus by both methods and 55 samples were positive by both assays. Two samples were negative by the new influenza assay however they were positive by the “in-house” influenza assay. The new assays did not cross react with samples containing other viruses including parainfluenza 1, 2, and 4; human metapnuemovirus; coronavirus 229E, NL63, OC43; rhinovirus; adenovirus; bocavirus and had a specificity of 100% and a sensitivity of 98.2% for RSV and 96.5% for influenza respectively. The results of this study demonstrate that the new assays are specific and sensitive for the detection of RSV and influenza viruses in clinical samples.  相似文献   

7.
We have isolated and sequenced cDNA clones corresponding to the polymorphic and β chains encoded by the DR and DQ subregions of two HLA-DR4 haplotypes, LD“KT2” and LD“TAS”. These two haplotypes are distinguished on the basis of mixed lymphocyte culture typing. The data indicate that the designation of LD“TAS” as a distinct subtype from Dw13 is very likely due to amino acid differences in the DQβ chain. In contrast, LD“KT2” differs from TAS and Dw13 by a single amino acid substitution at position 37 of the DRβ1 chain. The functional and evolutionary significance of these polymorphisms is discussed.  相似文献   

8.
Due to molecular mimicry, Campylobacter jejuni lipo-oligosaccharides can induce a cross-reactive antibody response to nerve gangliosides, which leads to Guillain–Barré syndrome (GBS). Cross-reactive antibodies to ganglioside GQ1b are strongly associated with oculomotor weakness in GBS and its variant, Miller Fisher syndrome (MFS). Antigen recognition is a crucial first step in the induction of a cross-reactive antibody response, and it has been shown that GQ1b-like epitopes expressed on the surface of C. jejuni are recognized by sialic acid-binding immunoglobulin-like lectin-7 (Siglec-7). We aimed to determine the epitope specificity of C. jejuni binding to Siglec-7, and correlate the outcome to disease symptoms in GBS and MFS patients. Using a well-defined GBS/MFS-associated C. jejuni strain collection, which included three sialic acid knockout strains, we found that Siglec-7 exclusively binds to C. jejuni strains that express terminal disialylated ganglioside mimics. When serological and diagnostic patient records were correlated with the Siglec-7-binding properties, we observed an association between Siglec-7 binding and the presence of anti-GQ1b antibodies in patient serum. In addition, Siglec-7 binding was associated with oculomotor weakness in GBS and MFS patients. Lipo-oligosaccharide-specific binding of C. jejuni to Siglec-7 may be an initiating event in immune recognition and presentation, and lead to anti-GQ1b antibody production and the development of ocular weakness in GBS or MFS.  相似文献   

9.
Reported herein is an adult case of Fisher syndrome (FS) that occurred as a complication during the course of community-acquired pneumonia caused by Mycoplasma pneumoniae. A 38-yr-old man who had been treated with antibiotics for serologically proven M. pneumoniae pneumonia presented with a sudden onset of diplopia, ataxic gait, and areflexia. A thorough evaluation including brain imaging, cerebrospinal fluid examination, a nerve conduction study, and detection of serum anti-ganglioside GQ1b antibody titers led to the diagnosis of FS. Antibiotic treatment of the underlying M. pneumoniae pneumonia was maintained without additional immunomodulatory agents. A complete and spontaneous resolution of neurologic abnormalities was observed within 1 month, accompanied by resolution of lung lesions.  相似文献   

10.
Body surface potential mapping (BSPM) is an electrocardiographic measureing technique which produces the data as a series of three-dimensional maps. These maps are assumed to contain information which may help classify subjects for diagnostic purposes more effectively than standard ECGs. As quantitative classification of the complete sequences of maps is complex and cumbersome, the present study uses extracted features which characterise the data. The features, which have been presented and evaluated in a recent work, have been extracted after the maps were processed by a compression technique which conserved the spatial details of the maps. The compression by two-level thresholding converted the sequences of maps into sequences of annuli, from which the following features were extracted: time indices, velocity vector magnitude, loci in three-dimensional space of the centres of mass and cross-correlation coefficients between successive annuli in the sequence. Here, three different classification methods are applied to these features: statistical methods, the Fisher linear discriminant method and visual inspection. BSPMs from 54 subjects are used: 25 normal, 11 WPW syndrome and 18 CAD cases. It is found completely accurate classification of the subjects to their groups. The three-dimensional centre of mass is found to be the single best classifier; sucessfully categorising 20/25 of the normals 17/18 of the CAD patients and 11/11 of the WPW patients.  相似文献   

11.
基于最佳小波包的表面肌电信号分类方法   总被引:1,自引:0,他引:1  
针对表面肌电信号的分类问题,采用最佳小波包分解构造最能体现分类能力的小波包基。用Fisher线性判别分析对肌电信号各个子空间的相对能量特征进行降维处理,然后利用BP神经网络进行分类识别。实验表明该方法能够有效地从伸肌和屈肌采集的两道肌电信号中识别前臂内旋、前臂外旋、握拳和展拳四种运动模式,是一种稳定、有效的特征提取方法,为非平稳生理信号的分析提供了新的手段。  相似文献   

12.
HLA typing by molecular genotyping methods has become routine for class II typing and is now being pursued for class I typing. However, a deficiency in the DNA-based methodologies is the absence of information about cellular expression of the HLA molecule. This may be important in clinical HLA matching as we have identified two families with an HLA-A allele (A*2402 and A*0301 respectively) detected by DNA techniques but inherited as a serological “blank”. In an effort to determine the frequency of such HLA-blanks we have retrospectively analysed the HLA-A gene by PCR-SSO techniques from 200 serological HLA-A “homozygotes”.

In the 200 samples, 24 HLA-A heterozygotes were identified by PCR-SSO. These discrepancies were explained by: Two new alleles, A*3004 and A*24New were detected in this study. Another potential new allele, ??A*7401 is under further investigation.

Overall, the study yielded no further examples of serologically “blank” HLA-A alleles and suggests that this is a relatively low frequency event. However, the results indicate that A2 subtypes and resolution of the A19 CREG are high priority targets for HLA-A genotyping.  相似文献   


13.
We compared two correction methods for simultaneous 201Tl/99mTc dual-isotope single-photon emission computed tomography (SPECT). Both approaches use the information from the third energy window placed between the photopeak windows of the 201Tl and 99mTc. The first approach, described by Moore et al, corrects only for the contribution of the 99mTc to the 201Tl primary 70 keV window. We developed the three-window transformation dual isotope correction method, which is a simultaneous cross-talk correction. The two correction methods were compared in a simultaneous 201Tl/99mTc sestamibi cardiac dog study. Three separate acquisitions were performed in this dog study: two single-isotope and one dual-isotope acquisition. The 201Tl single-isotope images were used as references. The total number of counts, and the contrast between the left ventricular cavity (LVC) and the myocardium, were used in 70 keV short axis slices as parameters for evaluating the results of the dual-isotope correction methods. Three consecutive short-axis slices were used to calculate averaged contrast and the averaged total number of counts. The total number of the counts was 667000+/-500 and 414500+/-400 counts for the dual isotope (201Tl+/-99mTc) and single-isotope (201Tl-only) 70 keV images, respectively. The corrected dual-isotope images had 514700+/-700 and 368000+/-600 counts for Moore's correction and our approach, respectively. Moore's method improved contrast in the dual isotope 70 keV image to 0.14+/-0.03 from 0.11+/-0.02, which was the value in the 70 keV non-corrected dual-isotope image. Our method improved the same contrast to 0.22+/-0.03. The contrast in the 201Tl single-isotope 70 keV image was 0.28+/-0.02. Both methods improved the 70 keV dual-isotope images. However, our approach provided slightly better images than Moore's correction when compared with 201Tl-only 70 keV images.  相似文献   

14.
The infrastructure of a feminizing testicular Leydig cell tumor was analytically compared with that of the five reported feminizing neoplasms and with that of the eight published masculinizing or hormonally inactive tumors. Certain observations were noteworthy but of uncertain significance. In the current case, nuclear outlines tended to be irregular, nuclear pores were relatively few, chromatin was often uniformly dispersed, and nucleoli were frequently multiple. Membranous whorls and “myelin figures” were common. Collectively, the nuclear aberrations were noted only in the two feminizing neoplasms studied by us.

Other findings in the present case included abundant endoplasmic reticulum, swollen pleomorphic mitochondria, numerous lysosomes, “dark” and “light” Leydig cell nuclei, and specialized modifications of the plasma membrane. These observations were inconstantly present in the group as a whole, irrespective of hormonal activity.

Employing present methods it is not feasible to correlate the fine anatomy of testicular Leydig cell tumors with their capability of hormonal function.  相似文献   

15.
The aim of the present study was to evaluate the ability of Tl-201 abdominal SPECT to differentiate between chronic focal pancreatitis and pancreatic malignancy. Seventeen patients (12 men, 5 women; mean age, 56 years; 9 pancreatic cancer, 8 chronic pancreatitis) with pancreatic mass were prospectively investigated with Tl-201 abdominal SPECT. In all patients, CT and/or US could not clarify the nature of the pancreatic mass. Focal hot uptake was present in 8 of 9 patients with pancreatic cancer, while it was present in 2 of 8 patients with chronic pancreatitis. Therefore, the sensitivity and specificity of the present study were 89% and 75%, respectively. A significant difference of Tl-201 uptakes was noted between benign and malignant masses (p < 0.05). Therefore, we concluded that Tl-201 abdominal SPECT was a useful test in differentiation of malignant from benign pancreatic mass, especially when the differentiation could not be made by other imaging modalities.  相似文献   

16.
Results of cytogenetic studies, performed in a group of 201 institutionalized mentally retarded males, are presented. At least two cytogenetic methods for eliciting the Xq27.3 fragile site, recommended by the Fourth International Workshop on the Fra X Syndrome were used. A subgroup of 67 out of 201 studied males was also examined using molecular methods. In 6 (2.9%) males fra X syndrome was diagnosed. All cytogenetic positive results were confirmed by molecular analysis. Five patients had full expansion CGG repeats and one had both premutation and full mutation. Postulated frequency of fra X syndrome in Polish population being 0.2–0.4/1,000 males seems to be lower than it could be expected on the basis of previous literature data. © 1996 Wiley-Liss, Inc.  相似文献   

17.
Primary tumors of the heart are exceedingly rare with a prevalence rate of around 0.01% in autopsy studies. A majority of primary cardiac tumors are benign. Rhabdomyomas are the most common of benign pediatric cardiac tumors. A newborn female infant presented with perioral cyanosis and respiratory distress. She deteriorated progressively. The infant expired, and at autopsy, dissection of the heart revealed a large tumor mass in the interventricular septum. Histologically, the mass showed the classic “spider cells,” and a diagnosis of cardiac rhabdomyoma of childhood was established.  相似文献   

18.
The response to a Brucella melitensis purEK deletion mutant, delta purE201 (referred to as strain 201), was compared with the response to its parental strain, 16M, in juvenile goats. Proliferative responses to gamma-irradiated bacteria were detected earlier in strain 201-infected goats. Lymphocytes from strain 16M- or 201-infected goats proliferated in response to one-dimensional polyacrylamide gel electrophoresis-separated proteins of similar mass isolated from strain 16M or Brucella abortus RB51. Data from this study suggest that some antigens stimulating cell-mediated responses are conserved among Brucella species, as 201- and 16M-infected goats recognized similar proteins expressed by RB51 and 16M.  相似文献   

19.
蛛网膜下腔出血继发癫痫发作临床分析   总被引:1,自引:0,他引:1  
目的:探讨蛛网膜下腔出血(SAH)继发癫痫的临床特点。方法:回顾性分析近17年来经CT证实的134例SAH患者中18例继发性癫痫患者的临床资料,重点观察癫痫发作类型与SAH之Fisher分级间的关系。全组均采用脱水降颅压、止血、抗感染等综合治疗,对于癫痫发作2次及以上的病人同时给予抗癫痫治疗。结果:于SAH72 h内继发癫痫发作12例,于病程第4~15天继发癫痫发作6例。18例中,全身性强直-阵挛发作(强直组)10例,简单部分性运动发作(简单组)4例,复杂部分性运动发作(复杂组)4例;除强直组与简单组Fisher分级比较,差异有统计学意义(P〈0.05)外,其余组间比较差异无统计学意义(P〉0.05)。根据GOS量表评定疗效,本组优9例,良2例,中2例,死亡5例。结论:SAH继发癫痫多发生在SAH早期,且以强直-阵挛发作为多见;其发作类型与SAH出血量和出血波及大脑皮质的范围密切相关。  相似文献   

20.
An electron microscopic study of peripheral blood and lymph node from a patient with chronic lymphocytic leukemia revealed ribosome-lamella complexes in 11-16% of the peripheral lymphocytes and in 14% of the nodal lymphocytes. Annulate lamellae were seen in 2-8% of the peripheral lymphocytes and in 8% of the nodal lymphocytes. One peripheral blood specimen revealed coexistent annulate lamellae and ribosome-lamella complexes within the same cells in an additional 4% of the lymphocytes. The two structures were connected by continuous strands of apparent endoplasmic reticulum. Although annulate lamellae and ribosome-lamella complexes have each been described in chronic lymphocytic leukemia, albeit uncommonly, their unusual association with one another has not previously been documented and might offer a clue as to the origin and role of these interesting structures. The possible ramifications of these observations include relationship of the structures to endoplasmic reticulum and protein synthesis, to in vitro and possible clinical induction by drugs including “antitubulins”, and to induction in vitro by viral infection.  相似文献   

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