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41.
Linkage of the MHC to familial multiple sclerosis suggests genetic heterogeneity. The Multiple Sclerosis Genetics Group 总被引:5,自引:0,他引:5
Haines JL; Terwedow HA; Burgess K; Pericak-Vance MA; Rimmler JB; Martin ER; Oksenberg JR; Lincoln R; Zhang DY; Banatao DR; Gatto N; Goodkin DE; Hauser SL 《Human molecular genetics》1998,7(8):1229-1234
Multiple sclerosis (MS) is a demyelinating autoimmune disease of the
central nervous system. While its etiology is not well understood, genetic
factors are clearly involved. Until recently, most genetic studies in MS
have been association studies using the case-control design testing
specific candidate genes and studying only sporadic cases. The only
consistently replicated finding has been an association with the HLA-DR2
allele within the major histocompatibility complex (MHC) on chromosome 6.
Using the genetic linkage design, however, evidence for and against linkage
of the MHC to MS has been found, fostering suggestions that sporadic and
familial MS have different etiologies. Most recently, two of four genomic
screens demonstrated linkage to the MHC, although specific allelic
associations were not tested. Here, a dataset of 98 multiplex families was
studied to test for an association to the HLA-DR2 allele in familial MS and
to determine if genetic linkage to the MHC was due solely to such an
association. Three highly polymorphic markers (HLA-DR, D6S273 and TNFbeta)
in the MHC demonstrated strong genetic linkage (parametric lod scores of
4.60, 2.20 and 1.24, respectively) and a specific association with the
HLA-DR2 allele was confirmed (TDT; P < 0.001). Stratifying the results
by HLA-DR2 status showed that the linkage results were limited to families
segregating HLA-DR2 alleles. These results demonstrate that genetic linkage
to the MHC can be explained by the HLA-DR2 allelic association. They also
indicate that sporadic and familial MS share a common genetic
susceptibility. In addition, preliminary calculations suggest that the MHC
explains between 17 and 62% of the genetic etiology of MS. This
heterogeneity is also supported by the minority of families showing no
linkage or association with loci within the MHC.
相似文献
42.
Based on the dissection of 30 hemi-mandibles, the authors report a study of the inferior alveolar artery in its intraosseous course. On morphologic considerations they propose a classification of the collaterals into two groups: the principal collaterals destined for the teeth and the bony alveolar tissue and the secondary collaterals destined for the sheath and the nerve as well as the bony tissue around the canal. Loss of the teeth and absorption of the alveolar bone modify the caliber of the inferior alveolar arterial axis, the distribution of its collaterals and possibly its mode of termination. These facts suggest a consideration of the vascularization of the mandible in terms of four sectors. They arrive at practical conclusions that may be drawn from this study in stomatology. 相似文献
43.
44.
ALLISON A. YATES PhD RD SANDRA A. SCHLICKER PhD CAROL W. SUITOR ScD RD 《Journal of the American Dietetic Association》1998,98(6):699-706
Dietary Reference Intakes (DRIs) represent the new approach adopted by the Food and Nutrition Board to providing quantitative estimates of nutrient intakes for use in a variety of settings, replacing and expanding on the past 50 years of periodic updates and revisions of the Recommended Dietary Allowances (RDAs). The DRI activity is a comprehensive effort undertaken to include current concepts about the role of nutrients and food components in long-term health, going beyond deficiency diseases. The DRIs consist of 4 reference intakes: the RDA, which is to be used as a goal for the individual; the Tolerable Upper Intake Level (UL), which is given to assist in advising individuals what levels of intake may result in adverse effects if habitually exceeded; the Estimated Average Requirement (EAR), the intake level at which the data indicate that the needs for 50% of those consuming it will not be met; and the Adequate Intake (AI), a level judged by the experts developing the reference intakes to meet the needs of all individuals in a group, but which is based on much less data and substantially more judgment than that used in establishing an EAR and subsequently the RDA. When an RDA cannot be set, an AI is given. Both are to be used as goals for an individual. Two reports have been issued providing DRIs for nutrients and food components reviewed to date: these include calcium and its related nutrients: phosphorus, magnesium, vitamin D, and fluoride; and most recently, folate, the B vitamins, and choline. The approaches used to determine the DRIs, the reference values themselves, and the plans for future nutrients and food components are discussed. J Am Diet Assoc. 1998;98: 699–706. 相似文献
45.
A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern. 相似文献
46.
The effects of section separation on image contrast and calculated T1 relaxation times were investigated in healthy volunteers and a phantom using an early commercial version magnetic resonance imaging system. The effects are explained qualitatively on the basis of side lobes of excitation occurring outside the selected section resulting in reduction of the time permitted for T1 relaxation. The options for dealing with imperfect section selection, including separation of the sections (i.e., leaving gaps) and nonsequential excitation, are illustrated and the trade-offs involved in each explained. 相似文献
47.
ALLISON ROSE JONATHAN OSBORNE GORDON WRIGHT VIRGINIA BILLSON 《Journal of Medical Imaging and Radiation Oncology》1991,35(2):145-147
Specimen radiography is already established as an essential adjunct to excisional biopsy of mammographically detected abnormalities. Two methods of specimen sectioning following the initial specimen radiograph are described. The techniques were devised to identify the lesion accurately in the specimen for subsequent pathological analysis. They have been tailored to suit the differing facilities at two Breast Screening Centres. The methods highlight the desirability of a cooperative multidisciplinary approach to the management of breast disease. They underline the importance of radiological localization of the lesion; not only for the surgeon, but also for the pathologist. 相似文献
48.
49.
Perforation of the inferior vena cava with aortic and vertebral penetration by a suprarenal Greenfield filter 总被引:1,自引:0,他引:1
Various complications have been reported after insertion of the Greenfield filter. This report describes an unusual complication after suprarenal placement of this filter: spreading of the filter struts, with perforation of the inferior vena cava, and penetration of the aorta and a vertebral body, followed by fracture of one of the struts. 相似文献
50.