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11.
D Barbut J S Borer A Gharavi D Wallerson R B Devereux P Supino N D Suite 《The American journal of cardiology》1992,70(9):901-905
Anticardiolipin antibodies (acLa) are associated with a thrombotic tendency (often involving cerebral ischemic events), are frequently present with systemic lupus erythematosus and have been found together with cardiac valve abnormalities. Previous studies evaluated patients characterized by the presence of acLa or lupus, precluding assessment of the frequency of acLa in those with valvular disease. This study aims to establish the prevalence of acLa in patients with valve disease in the absence of lupus and, furthermore, to determine the influence of acLa on the risk of cerebral events in valve disease. Eighty-seven consecutive patients with mitral or aortic regurgitation, or both, prospectively underwent enzyme-linked immunosorbent assay testing for immunoglobulin G (IgG) and M acLa, as did 24 normal subjects. AcLa values greater than or equal to 3 SD above the normal mean were considered "positive." Prior cerebral events were defined retrospectively. Of 87 patients with valvular disease, 26 had positive IgG acLa levels compared with 0 of 24 normal subjects (p less than 0.01). AcLa values did not vary with valve disease etiology. Focal cerebral events had occurred in 8 patients and were embolic or probably embolic in 7, including 7 of 26 IgG acLa-positive and 1 of 60 IgG acLa-negative patients (p less than 0.001). In the absence of lupus, IgG acLa is highly prevalent among patients with aortic or mitral regurgitation, or both; this association may indicate a relatively high risk for cerebral emboli. 相似文献
12.
Relative carriage rates of nuclear dehydrogenating clostridia in two populations of different colorectal cancer risk 下载免费PDF全文
Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer. 相似文献
13.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
14.
Variability of skin temperature in the waking monkey 总被引:3,自引:0,他引:3
15.
MRL/lpr-->severe combined immunodeficiency mouse allografts produce autoantibodies, acute graft-versus-host disease or a wasting syndrome depending on the source of cells. 下载免费PDF全文
D Ashany J J Hines A E Gharavi J Mouradian J Drappa K B Elkon 《Clinical and experimental immunology》1992,90(3):466-475
MRL/lpr (lpr) mice spontaneously develop a lupus-like illness as well as massive lymphadenopathy. Attempts to transfer autoimmunity by adoptive transfer or radiation bone marrow chimeras have been unsuccessful. Since severe combined immunodeficiency (SCID) mice have been engrafted with human and rat xenografts without apparent graft-versus-host disease (GVHD), we subjected SCID mice to low-dose irradiation and reconstituted the mice with spleen cells from young or old lpr mice or with lpr bone marrow. Fourteen out of twenty (70%) of SCID mice engrafted with spleen cells from old lpr mice produced autoantibodies (anti-DNA and anti-Sm) without evidence of the severe lymphoid atrophy previously described for lpr spleen-->+/+ chimeras. SCID mice engrafted with spleen cells from young lpr mice developed acute GVHD and 5/6 (83%) died within 4 weeks post-transfer. Although 8/11 (73%) of lpr-->SCID bone marrow allografts survived for at least 4 months, these mice developed a wasting disease characterized by lymphoid atrophy and fibrosis without the production of autoantibodies. None of the lpr-->SCID grafts resulted in the transfer of double negative T cells or the lymphoproliferative syndrome characteristic of MRL/lpr mice. These findings indicate that SCID mice can be engrafted with splenocytes from old MRL/lpr mice and that B cells continue to secrete autoantibodies for several months in the SCID recipients. This study also demonstrates that, unlike i.p. transplant of xenogeneic cells, acute GVHD is a consistent feature of i.p. transplants of normal allogeneic mononuclear cells into SCID mice. 相似文献
16.
Permeation of human ovarian tissue with cryoprotective agents in preparation for cryopreservation 总被引:18,自引:10,他引:18
Newton H; Fisher J; Arnold JR; Pegg DE; Faddy MJ; Gosden RG 《Human reproduction (Oxford, England)》1998,13(2):376-380
The recent improvements in the treatment of cancer by chemo- and
radiotherapy have led to a significant increase in the survival rates of
patients with malignant disease, but at the expense of distressing side
effects. One major problem, especially for younger patients, is that
aggressive therapy destroys a significant proportion of the follicular
population, which can result in either temporary or permanent infertility.
Freeze-banking pieces of ovarian cortex prior to treatment is one strategy
for preserving fecundity. When the patient is in remission, fertility
could, theoretically, be restored by autografting the thawed tissue at the
orthotopic site or by growing isolated follicles to maturity in vitro.
Recent studies have found good follicular survival in frozen-thawed human
ovarian tissue but to optimize the process an effective cryopreservation
method needs to be developed. An essential part of such a technique is to
permeate the tissue with a cryoprotectant to minimize ice formation and the
extent of this equilibration is an important determinant of post-thaw
cellular survival. In the current study, we have investigated the diffusion
of four cryoprotective agents into human tissue at both 4 degrees C and 37
degrees C. We have also studied the effect of adding different
concentrations of the non penetrating cryoprotective agent, sucrose, to the
freezing media using the release of lactate dehydrogenase as a measure of
its protective effect. At 4 degrees C propylene glycol and glycerol
penetrated the tissue significantly slower than either ethylene glycol or
dimethyl sulphoxide. At the higher temperature of 37 degrees C all four
cryoprotectants penetrated at a faster rate, however concern about enhanced
toxicity prevents the use of these conditions in practice. Thus, the
results suggest that the best method of preparing tissue for freezing is
exposure for 30 min to 1.5 M solutions of ethylene glycol or dimethyl
sulphoxide at 4 degrees C; this achieved a mean tissue concentration that
was almost 80% that of the bathing solution. We also report that the
addition of low concentrations of sucrose to the freezing medium does not
have a significant protective effect against freezing injury.
相似文献
17.
Stein TP; Oram-Smith JC; Leskiw MJ; Wallace HW; Long LC; Leonard JM 《The American journal of physiology》1976,230(5):1321-1325
18.
19.
Vaughan JR; Farrer MJ; Wszolek ZK; Gasser T; Durr A; Agid Y; Bonifati V; DeMichele G; Volpe G; Lincoln S; Breteler M; Meco G; Brice A; Marsden CD; Hardy J; Wood NW 《Human molecular genetics》1998,7(4):751-753
A mutation in exon 4 of the human alpha-synuclein gene was reported
recently in four families with autosomal dominant Parkinson's disease (PD).
In order to examine whether mutations in this exon or elsewhere in the gene
are common in familial PD, all seven exons of the alpha- synuclein gene
were amplified by PCR from index cases of 30 European and American
Caucasian kindreds affected with autosomal dominant PD. Each product was
sequenced directly and examined for mutations in the open reading frame. No
mutations were found in any of the samples examined. We conclude that the
A53T change described in the alpha- synuclein gene is a rare cause of PD or
may even be a rare variant. Mutations in the regulatory or intronic regions
of the gene were not excluded by this study.
相似文献
20.
Rigor and resistance to stretch in vertebrate smooth muscle 总被引:2,自引:0,他引:2