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1.
Philip D. Fernsten Jan K. Czyzyk Toshihide Mimura John B. Winfield 《Molecular biology reports》1994,20(2):85-95
Patients with SLE develop IgM autoantibodies to different isoforms of CD45, the major surface membrane protein tyrosine phosphatase on lymphocytes and other nucleated hemopoietic cells. Because such autoantibodies could have a potential role in the development of immune dysfunction in this disorder, we performed a series of experiments to characterize their antigenic specificity further. Blots of recombinantE. coli fusion proteins encoded by exons 3–7 of the p220 and p180 isoforms were uniformly non-reactive with SLE IgM, suggesting that anti-CD45 autoantibodies in SLE are directed against conformational and/or carbohydrate epitopes, rather than linear polypeptide epitopes. This issue was examined further using chemically and enzymatically modified CD45 purified from T cells by lectin affinity chromatography as substrates. Treatment of CD45 with 25 mM sodium-m-periodate, sufficient to abrogate binding to various lectins, abolished the reactivity with SLE anti-CD45 autoantibodies. On the other hand, digestion of CD45 with neuraminidase enhanced the binding of anti-CD45 autoantibodies from some of the SLE sera. This result probably reflects decreased steric hindrance or charge repulsion because the binding of mouse monoclonal antibodies directed against linear polypeptide epitopes of CD45 was similarly enhanced. Digestion of CD45 with N-glycosidase F had no effect on autoantibody staining. Taken together, these data suggest that IgM anti-CD45 autoantibodies in SLE recognize non-sialylated carbohydrate determinants in the highly O-glycosylated polymorphic domains of CD45.Abbreviations SLE
systemic lupus erythematosus
- SBA
soybean agglutinin
- RCAI
Ricinus communis agglutinin
- SNL
Sambucus nigra lectin
- MBP
maltose binding protein
- mAb
monoclonal antibody
- WGA
wheat germ agglutinin 相似文献
2.
mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
相似文献
3.
4.
Muma JB Lund A Siamudaala VM Munang'andu HM Munyeme M Matope G Nielsen K DJønne B Godfroid J Tryland M Skjerve E 《Journal of wildlife diseases》2010,46(4):1063-1069
One of the diseases of veterinary and public health importance affecting the Kafue lechwe (Kobus leche kafuensis) on the Kafue flats is brucellosis, for which only scant information is available. During the 2003 (October), 2004 (December), and 2008 (July-December) hunting seasons in the Kafue flats, we conducted a study to determine the seroprevalence of Brucella spp. in the Kafue lechwe and to evaluate serologic tests for detection of Brucella spp. antibodies in lechwe. The Rose Bengal Test (RBT), competitive enzyme-linked immunosorbent assay (cELISA), and fluorescence polarization assay (FPA) were used. A total of 121 Kafue lechwe were hunted for disease investigations in 2003, 2004, and 2008 in the Kafue Flat Game Management Area. Of these, 21.6%, (95% confidence interval [CI]: 14.2-29.1%) had detectable antibodies to Brucella spp. The Kafue lechwe in Lochnivar National Park had higher antibody results than those in Blue Lagoon National Park (odds ratio=3.0; 95% CI: 0.94-9.4). Infection levels were similar in females (21.6%) and males (21.7%). Results were similar among RBT, FPA, cELISA tests, suggesting that these could effectively be used in diagnosing brucellosis in the Kafue lechwe. Our study demonstrates the presence of Brucella infections in the Kafue lechwe in two national parks located in the Kafue flats and further highlights the suitability of serologic assays for testing the Kafue lechwe. Because the Kafue lechwe is the most hunted wildlife species in Zambia, hunters need to be informed of the public health risk of Brucella spp. infection. 相似文献
5.
Deletion of peptide amidation enzymatic activity leads to edema and embryonic lethality in the mouse
Czyzyk TA Ning Y Hsu MS Peng B Mains RE Eipper BA Pintar JE 《Developmental biology》2005,287(2):301-313
Peptidylglycine alpha-amidating monooxygenase (PAM) catalyzes the COOH-terminal amidation of peptide hormones. We previously had found high expression of PAM in several regions of the developing rodent. To determine the function of PAM during mouse embryogenesis, we produced a null mutant of the PAM gene. Homozygous mutants die in utero between e14.5 and e15.5 with severe edema that is likely due to cardiovascular deficits. These defects include thinning of the aorta and carotid arteries and are very similar to those of the recently characterized adrenomedullin (AM) gene KO despite the presence of elevated immunoreactive AM in PAM KO embryos. No peptide amidation activity was detected in PAM mutant embryos, and there was no moderation of the AM-like phenotype that could be expected if any alternative peptide amidation mechanism exists in the mouse. Despite the proposed contribution of amidated peptides to neuronal cell proliferation, no alteration in neuroblast proliferation was observed in homozygous mutant embryos prior to lethality. Mice heterozygous for the mutant PAM allele develop normally and express wildtype levels of several amidated peptides despite having one half the wildtype levels of PAM activity and PAM protein. Nonetheless, both an increase in adiposity and a mild glucose intolerance developed in aged (>10 months) heterozygous mice compared to littermate controls. Ablation of PAM thus demonstrates an essential function for this gene during mouse development, while alterations in PAM activity in the adult may underlie more subtle physiologic effects. 相似文献
6.
Susan DJ Chapple Anna M Crofts S Paul Shadbolt John McCafferty Michael R Dyson 《BMC biotechnology》2006,6(1):49-15
Background
A variety of approaches to understanding protein structure and function require production of recombinant protein. Mammalian based expression systems have advantages over bacterial systems for certain classes of protein but can be slower and more laborious. Thus the availability of a simple system for production and rapid screening of constructs or conditions for mammalian expression would be of great benefit. To this end we have coupled an efficient recombinant protein production system based on transient transfection in HEK-293 EBNA1 (HEK-293E) suspension cells with a dot blot method allowing pre-screening of proteins expressed in cells in a high throughput manner. 相似文献7.
Study design
A prospective treatment study with a new brace was conducted Objective. To evaluate radiological and subjective clinical results after one year conservative brace treatment with pressure onto lordosis at the thoracolumbar joint in children with scoliosis and kyphosis.Summary of background data
Conservative brace treatment of adolescent scoliosis is not proven to be effective in terms of lasting correction. Conservative treatment in kyphotic deformities may lead to satisfactory correction. None of the brace or casting techniques is based on sagittal forces only applied at the thoracolumbar spine (TLI= thoracolumbar lordotic intervention). Previously we showed in patients with scoliosis after forced lordosis at the thoracolumbar spine a radiological instantaneous reduction in both coronal curves of double major scoliosis.Methods
A consecutive series of 91 children with adolescent scoliosis and kyphosis were treated with a modified symmetric 30 degrees Boston brace to ensure only forced lordosis at the thoracolumbar spine. Scoliosis was defined with a Cobb angle of at least one of the curves [greater than or equal to] 25 degrees and kyphosis with or without a curve <25 degrees in the coronal plane. Standing radiographs were made i) at start, ii) in brace at beginning and iii) after one year treatment without brace.Results
Before treatment start ??in brace?? radiographs showed a strong reduction of the Cobb angles in different curves in kyphosis and scoliosis groups (sagittal n = 5 all p < 0.001, pelvic obliquity p < 0.001). After one year of brace treatment in scoliosis and kyphosis group the measurements on radiographs made without brace revealed an improvement in 3 Cobb angles each.Conclusion
Conservative treatment using thoracolumbar lordotic intervention in scoliotic and kyphotic deformities in adolescence demonstrates a marked improvement after one year also in clinical and postural criteria. An effect not obtained with current brace techniques. 相似文献8.
9.
The ITS sequences of Acropora spp. are the shortest so far identified in
any metazoan and are among the shortest seen in eukaryotes; ITS1 was 70-80
bases, and ITS2 was 100-112 bases. The ITS sequences were also highly
variable, but base composition and secondary structure prediction indicate
that divergent sequence variants are unlikely to be pseudogenes. The
pattern of variation was unusual in several other respects: (1) two
distinct ITS2 types were detected in both A. hyacinthus and A. cytherea,
species known to hybridize in vitro with high success rates, and a putative
intermediate ITS2 form was also detected in A. cytherea; (2) A. valida was
found to contain highly (29%) diverged ITS1 variants; and (3) A.
longicyathus contained two distinct 5.8S rDNA types. These data are
consistent with a reticulate evolutionary history for the genus Acropora.
相似文献
10.