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41.
Twin studies provide estimates of genetic and environmental contributions to cognitive ability differences, but could be based
on biased samples. Here we report whole-population estimates using twins from unique mental surveys in Scotland. The Scottish
Mental Surveys of 1st June 1932 (SMS1932) and 4th June 1947 (SMS1947), respectively, administered the same validated verbal
reasoning test to almost everyone born in 1921 or 1936 and attending school in Scotland. There were 572 twin pairs from the
SMS1932, and 517 pairs from the SMS1947. Information on zygosity was unavailable. A novel application of a mixture distribution
was used to estimate genetic and environmental components of verbal reasoning variation by maximum likelihood. We found consistent
heritability (~0.70) and shared environment (~0.21) estimates. The estimates did not change substantially when additional
quantitative traits (height and weight) were added in a multivariate analysis. More generally for studies in genetics, the
methodological innovation developed here implies that large (national) data collections can provide sufficient information
on twin pairs to estimate genetic parameters, even without zygosity. 相似文献
42.
Immunoassay targeting nonstructural protein 5 to differentiate West Nile virus infection from dengue and St. Louis encephalitis virus infections and from flavivirus vaccination 下载免费PDF全文
Wong SJ Boyle RH Demarest VL Woodmansee AN Kramer LD Li H Drebot M Koski RA Fikrig E Martin DA Shi PY 《Journal of clinical microbiology》2003,41(9):4217-4223
West Nile virus (WNV) is an emerging flavivirus that has caused frequent epidemics since 1996. Besides natural transmission by mosquitoes, WNV can also be transmitted through blood transfusion and organ transplantation, thus heightening the urgency of development of a specific and rapid serologic assay of WNV infection. The current immunoassays lack specificity because they are based on detection of antibodies against WNV structural proteins and immune responses to structural proteins among flaviviruses cross-react to each other. Here, we describe microsphere immunoassays that detect antibodies to nonstructural proteins 3 and 5 (NS3 and NS5). In contrast to immunoassays based on viral envelope and NS3 proteins, the NS5-based assay (i) reliably discriminates between WNV infections and dengue virus or St. Louis encephalitis virus infections, (ii) differentiates between flavivirus vaccination and natural WNV infection, and (iii) indicates recent infections. These unique features of the NS5-based immunoassay will be very useful for both clinical and veterinary diagnosis of WNV infection. 相似文献
43.
44.
Rapid expansion and IL-4 expression by Leishmania-specific naive helper T cells in vivo 总被引:2,自引:0,他引:2
CD4 T cells are pivotal for effective immunity, yet their initial differentiation into effector subsets after infection remains poorly defined. We examined CD4 T cells specific for the immunodominant Leishmania major LACK antigen using MHC/peptide tetramers and IL-4 reporter mice. Comprising approximately 15 cells/lymph node in naive mice, LACK-specific T cells expanded over 100-fold, and 70% acquired IL-4 expression by 96 hr. Despite their pathogenic role in susceptible mice, LACK-specific precursor frequency, expansion, and IL-4 expression were comparable between susceptible and resistant mice. When injected with unrelated antigen, Leishmania efficiently activated IL-4 expression from naive antigen-specific T cells. CD4 subset polarization in this highly characterized model occurs independently from IL-4 expression by naive T cells, which is activated indiscriminately after parasitism. 相似文献
45.
Sam Tsemberis Gregory McHugo Valerie Williams Patricia Hanrahan Ana Stefancic 《Journal of community psychology》2007,35(1):29-42
Reliable and valid longitudinal residential histories are needed to assess interventions to reduce homelessness and increase community tenure. This study examined the test‐retest reliability, sensitivity to change, and concurrent validity of the Residential Time‐Line Follow‐Back (TLFB) Inventory, a method used to record residential histories in the Collaborative Program to Prevent Homelessness (n = 1,381). The Residential TLFB Inventory yielded temporally stable aggregate measures of duration in residential categories, and it revealed significant differences in change over time when contrasting study groups. A comparison of agency and participant data at one site. 相似文献
46.
Suzanne Lombard-Platet Valerie Meyer Rhodri Ceredig 《Clinical & developmental immunology》1997,5(2):115-120
Pro-B cells are early B-cell progenitors that retain macrophage potential. We have studied
MHC class II molecules and invariant chain inducibility on four class II negative mouse pro-
B-cell clones. We analyzed the effects of IL-4 and IFN-γ, which represent the major inducers
of class II in the B-lymphoid and monocytic/macrophage lineages, respectively. After 48 h of
treatment with either cytokine, three pro-B-cell clones (C2.13, A1.5, and F2.2) expressed intracellular
invariant chain and cell-surface class II molecules. One clone (D2.1) remained negative.
As already reported, more differentiated 70Z/3 pre-B cells were inducible by IL-4 only.
These data suggest that the induction of class II and invariant-chain genes are subject to regulation
throughout B-cell differentiation. 相似文献
47.
Christine R. Bryke Valerie Lindgren Julie S. Fryburg Teresa L. Yang-Feng 《American journal of medical genetics. Part A》1990,36(2):247-250
A previously unreported isodicentric chromosome 18 was discovered in an abnormal infant boy whose mosaic karyotype was 46, XY/46,XY,–18, + idic(18)(q12.2). His constellation of congenital anomalies was typical of the 18q-syndrome. The clinical and cytogentic characteristics of this patient are reported, and the literature concerning isochromosomes of 18 is reviewed. 相似文献
48.
49.
Summary Isatin -thiosemicarbazone (ITSC) is well known for its chemoprophylactic activity against certain poxvirus infections. The influence of 20 M ITSC on the development of neurovaccinia virus particles in infected embryo rabbit kidney cells has been studied by electron microscopy. It is shown that ITSC exerts an intracellular effect, permitting the formation of immature and abnormal forms, but preventing the normal development of these to give mature infective virus particles. The effects are compared with the normal development of mature virus particles as observed by us and as described by other authors from their electron microscopy studies. 相似文献
50.
Transgenic Mice as an in vivo Model for Self-Reactivity 总被引:1,自引:0,他引:1
Davto A. Ferrick Pamela S. Ohashi Valerie A. Wallace Marco Schilham Tak W. Mak 《Immunological reviews》1990,118(1):257-283