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21.
Frederick L. Datz MD Charles Rosenberg Frank V. Gabor Paul E. Christian Grant T. Gullberg Raj Ahluwalia Kathryn A. Morton 《Journal of digital imaging》1993,6(2):67-80
Computer-assisted diagnosis (CAID) is commonly used to evaluate cardiac nuclear medicine studies such as thallium perfusion scans. Part 1 of this series (Journal of Digital Imaging, 5:209–222, 1992) reviewed the basic theory underlying CAID in nuclear medicine and its use in planar thallium imaging. Part 2 discussed the application of CAID to SPECT perfusion studies (Journal of Digital Imaging, 6:1–15, 1993). This article reviews new variations of CAID programs for SPECT imaging and the application of expert systems and neural networks to CAID of nuclear medicine perfusion studies. 相似文献
22.
Mallikarjuna Rao GN Hussain T Geetha Devi N Jain S Chandak GR Ananda Raj MP 《Indian journal of medical sciences》2003,57(1):1-6
66 unrelated patients from Southern India with Duchenne Muscular Dystrophy (DMD) were studied for intragenic deletion in 18 exons and Pm region of the DMD gene using multiplex PCR. Of these 41 (62.1%) showed intragenic deletions. 78% of the deletions were located at the distal hotspot region (44-55 exons) and 22% of the deletions were located at the proximal region (exon 2-19). Exon 50 is most frequently deleted. Deletions in isolated cases were significantly more compared to familial cases. The lower incidence reported from South India compared to North India, is suggestive of variations in the Southern and Northern population. 相似文献
23.
Nagarkatti R Kumar R Sharma SK Ghosh B 《International archives of allergy and immunology》2004,134(3):206-212
BACKGROUND: Asthma is a complex airway disorder, and a number of genetic loci have been found to be associated with asthma. The 5q31-33 region is one of the most important loci linked to asthma and atopic disorders. However, association studies with candidate genes in this region, such as IL4, were inconclusive, as both positive and negative results were obtained in several populations studied. The aim of our case-control study was to determine the association between IL4 and asthma in North Indians. PATIENTS AND METHODS: Polymorphisms in the promoter and a dinucleotide repeat in the 2nd intron in IL4 were genotyped by sequencing and GeneScan analysis, respectively, in ethnically matched, unrelated patients (n = 171) and controls (n = 128), following the guidelines of the American Thoracic Society. RESULTS: The proximal promoter region of the IL4 gene was found to be invariant. Previously reported polymorphisms, -590 C/T and +33 C/T, were found to be absent in our population. The chi2 test using only large expected cell counts (more than 5% of the sample size) showed a significant association between allele size and disease status (chi2 = 38.08, d.f. = 6, p < 0.05). In addition, a significant difference was observed for the allele and genotype frequencies (p < 0.0005 and p = 0.0009, respectively) in the patient and the control groups using the Fisher-Freeman-Halton test. CONCLUSION: Our studies indicate that the promoter of the IL4 gene is invariant in our population. The case-control studies on the CA repeat polymorphism in the 2nd intron of the IL4 gene have shown interesting results and indicate the need for further family-based studies. 相似文献
24.
A model for susceptibility artefacts from respiration in functional echo-planar magnetic resonance imaging 总被引:1,自引:0,他引:1
Respiration causes variations in the signals acquired during magnetic resonance imaging (MRI) and therefore is a significant source of noise in functional brain imaging. A primary component of respiratory noise may arise from variations of bulk susceptibility or air volume in the chest. Here we investigate the nature of the image artefacts that can be caused by such changes. We develop a simple model which attempts to mimic the effects of variations in susceptibility and volume during respiration. Theoretical calculations, computer simulations and imaging experiments with this model show that small variations in susceptibility within the thorax from alterations in the paramagnetism of cavity gas may lead to a shift of the image on the order of 0.1 pixels as well as a shading of the intensity by +/-1%. These effects are observed to be predominant in the phase-encoding direction. They may lead to the production of spurious activations in functional MRI and are likely to be of more importance at higher field strengths. 相似文献
25.
Sarin H Nigam S Chaturvedi UK Tripathi V Raj A 《Indian journal of pathology & microbiology》2003,46(1):97-99
A rare case of malignant nasal paraganglioma is described. A 30 year old female patient presented with a one year history of bilateralnasal obstruction, nasal deformity and recurrent epistaxis. CT scan demonstrated an enhancing mass occupying both nasal cavities, right maxillary antrum and anterior ethmoid sinus. Histopathologic diagnosis was malignant paraganglioma. A total maxillectomy with excision of growth was performed. Post-operative radiotherapy and chemotherapy was given but patient expired before the completion of therapy. Nose being a rare site for paragangliomas, these lesions present a diagnostic challenge to histopathologists and clinicians alike. A review of the four previously described malignant nasal paragangliomas is also presented. 相似文献
26.
The effect of dietary supplementation with Vitamin E was studied in sensitized guinea pigs. After measurement of baseline airway reactivity and sensitization with ovalbumin, the animals were randomized into two groups: Group A, on a commercial feed and Group B, on dietary supplementation with oral Vitamin E (0.7 IU/kg). These were challenged with inhaled ovalbumin after 4 weeks. The following outcomes were studied: airway responses to ovalbumin inhalation, airway reactivity, sodium and calcium ion influx in isolated tracheal cells, Na+ K+ ATPase and Ca2+ ATPase activity in tracheal homogenate and plasma malonaldehyde. Sensitization increased airway reactivity in Group A but not in Group B. The tracheal cells of animals in Group B showed significantly lower rates of 45Ca and 22Na influx and lower activities of tracheal Na+ K+ ATPase and Ca2+ ATPase as compared to Group A. Plasma malonaldehyde was similar between two groups. We concluded that Vitamin E suppresses the increase in airway reactivity following sensitization and has membrane stabilizing actions. 相似文献
27.
Mohan D Rolston R Pal R Swalsky PA Sasatomi E Lee RE Finkelstein SD 《Human pathology》2004,35(4):482-487
The genetic diagnosis of Gaucher disease by molecular methods is complicated by the existence of a highly homologous transcribed pseudogene (96% identity) that is found in close proximity to the true gene on chromosome 1q21. In addition, the pseudogene sequence can mimic disease-causing mutations in the true gene. Selective polymerase chain reaction (PCR) amplification of the true gene can be accomplished in extracted DNA from fresh-frozen samples by designing oligonucleotide primers to hybridize to defined regions that are not present in the pseudogene. This standard molecular approach, which entails amplification of relatively long segments of intact DNA, is not feasible in archival, paraffin-embedded, solid-tissue specimens in which the negative effects of chemical fixation result in DNA strand scission and breakdown of nucleic acid. A novel approach, specifically created for use with archival, fixative-treated tissue specimens, was developed for detection and characterization of common mutations of Gaucher disease. Three separate robust PCR reactions were formulated, 2 for selective amplification of portions of only the true gene exons 2 and 9, with a third reaction targeting exon 10, wherein both the true and pseudogene were coamplified. In the latter, DNA sequencing was used to determine the presence of true and pseudogene allele content in addition to identification of base sequence alterations. This method, requiring a single, 4-microm-thick histologic section, was successfully applied to archival paraffin block tissue specimens that had been in storage for up to 75 years. It was capable of accurately genotyping common Gaucher disease mutations as well as discovering a novel mutation and genetic polymorphism. We recommend our approach when only fixative-treated tis sue is available for molecular genotyping. 相似文献
28.
Miksch S Lumsden A Guenther UP Foernzler D Christen-Zäch S Daugherty C Ramesar RK Lebwohl M Hohl D Neldner KH Lindpaintner K Richards RI Struk B 《Human mutation》2005,26(3):235-248
Pseudoxanthoma elasticum (PXE) is a systemic heritable disorder that affects the elastic tissue in the skin, eye, and cardiovascular system. Mutations in the ABCC6 gene cause PXE. We performed a mutation screen in ABCC6 using haplotype analysis in conjunction with direct sequencing to achieve a mutation detection rate of 97%. This screen consisted of 170 PXE chromosomes in 81 families, and detected 59 distinct mutations (32 missense, eight nonsense, and six likely splice-site point mutations; one small insertion; and seven small and five large deletions). Forty-three of these mutations are novel variants, which increases the total number of PXE mutations to 121. While most mutations are rare, three nonsense mutations, a splice donor site mutation, and the large deletion comprising exons 23-29 (c.2996_4208del) were identified as relatively frequent PXE mutations at 26%, 5%, 3.5%, 3%, and 11%, respectively. Chromosomal haplotyping with two proximal and two distal polymorphic markers flanking ABCC6 demonstrated that most chromosomes that carry these relatively frequent PXE mutations have related haplotypes specific for these mutations, which suggests that these chromosomes originate from single founder mutations. The types of mutations found support loss-of-function as the molecular mechanism for the PXE phenotype. In 76 of the 81 families, the affected individuals were either homozygous for the same mutation or compound heterozygous for two mutations. In the remaining five families with one uncovered mutation, affected showed allelic compound heterozygosity for the cosegregating PXE haplotype. This demonstrates pseudo-dominance as the relevant inheritance mechanism, since disease transmission to the next generation always requires one mutant allelic variant from each parent. In contrast to other previous clinical and molecular claims, our results show evidence only for recessive PXE. This has profound consequences for the genetic counseling of families with PXE. 相似文献
29.
The UL41 gene of the HSZP strain of herpes simplex virus type 1 (HSV-1) defective with respect to the early shutoff of host
protein synthesis was sequenced and compared with the corresponding HSV-1 strain KOS and 17 gene sequences. In comparison
with strain 17, nine mutations (base changes) were HSZP specific, five KOS specific and four were common for both strains.
Nine mutations caused codon changes. Three of these mapped to the nonconserved regions and the others to the conserved regions
of the functional map of UL4l gene. One KOS specific mutation mapped to the region responsible for the binding of the virion
host shutoff (vhs) protein to the alpha-transinducing factor (VP16). The possible relationship between mutations and host
shutoff function is discussed. The nucleotide sequence data of the UL41 gene of HSZP and KOS have been submitted to the Genbank
nucleotide database and have been assigned the accesion numbers Z72337 and Z72338.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
30.
Law CL Hayden-Ledbetter M Buckwalter S McNeill L Nguyen H Habecker P Thorne BA Dua R Ledbetter JA 《International immunology》2002,14(4):389-400
The TCR-CD3 complex consists of the clonotypic disulfide-linked TCRalphabeta or TCRdeltagamma heterodimers, and the invariant CD3delta, epsilon, gamma and zeta chains. We generated plasmid constructs expressing the extracellular domains of the CD3delta, epsilon or gamma subunits fused to human IgG1 Fc. Recombinant fusion proteins consisting of individual CD3delta, epsilon or gamma subunits reacted poorly with anti-CD3 mAb including G19-4, BC3, OKT3 and 64.1. Co-expression of the CD3epsilon-Ig with either the CD3delta-Ig (CD3epsilondelta-Ig) or the CD3gamma-Ig (CD3epsilongamma-Ig) resulted in fusion proteins with much increased binding to G19-4. A brief acid treatment of the purified CD3epsilondelta-Ig fusion protein substantially improved its binding to BC3, OKT3 and 64.1. Surface plasmon resonance analysis revealed that the dissociation constants for CD3epsilondelta-Ig and anti-CD3 mAb ranged from 10(-8) to 10(-9) M. Based on these results, a single-chain (sc) construct encoding the CD3delta chain linked to the CD3epsilon chain with a flexible linker followed by human IgG1 Fc was expressed. The sc CD3deltaepsilon-scIg reacted with anti-CD3 mAb without requiring acid treatment. Moreover, anti-CD3 mAb bound CD3epsilondelta-Ig at a higher affinity than CD3epsilongamma-Ig, suggesting potential structural differences between the CD3epsilondelta and CD3epsilongamma subunits. In summary, we report the expression of soluble recombinant CD3 proteins that demonstrate structural characteristics of the native CD3 complex expressed on the T cell surface. These CD3 fusion proteins can be used to further analyze the structure of the TCR-CD3 complex, and to identify molecules that can interfere with TCR-CD3-mediated signal transduction by disrupting the interaction between CD3 and TCR subunits. 相似文献