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Prohemistomum azimi n. sp. is described from one out of four Egyptian slit-faced bats, Nycteris thebaica Geffroy, 1910 captured from Giza, Egypt. The new species is compared with other related species of the genus and its specific diagnosis is outlined. The new species is the first record of the genus Prohemistomum Odhner, 1913 from Chiroptera. 相似文献
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Survival of Male Patients with Incontinentia Pigmenti Carrying a Lethal Mutation Can Be Explained by Somatic Mosaicism or Klinefelter Syndrome 总被引:2,自引:0,他引:2
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The International IP Consortium 《American journal of human genetics》2001,69(6):1210-1217
Incontinentia pigmenti (IP), or "Bloch-Sulzberger syndrome," is an X-linked dominant disorder characterized by abnormalities of skin, teeth, hair, and eyes; skewed X-inactivation; and recurrent miscarriages of male fetuses. IP results from mutations in the gene for NF-kappaB essential modulator (NEMO), with deletion of exons 4-10 of NEMO accounting for >80% of new mutations. Male fetuses inheriting this mutation and other "null" mutations of NEMO usually die in utero. Less deleterious mutations can result in survival of males subjects, but with ectodermal dysplasia and immunodeficiency. Male patients with skin, dental, and ocular abnormalities typical of those seen in female patients with IP (without immunodeficiency) are rare. We investigated four male patients with clinical hallmarks of IP. All four were found to carry the deletion normally associated with male lethality in utero. Survival in one patient is explained by a 47,XXY karyotype and skewed X inactivation. Three other patients possess a normal 46,XY karyotype. We demonstrate that these patients have both wild-type and deleted copies of the NEMO gene and are therefore mosaic for the common mutation. Therefore, the repeat-mediated rearrangement leading to the common deletion does not require meiotic division. Hypomorphic alleles, a 47,XXY karyotype, and somatic mosaicism therefore represent three mechanisms for survival of males carrying a NEMO mutation. 相似文献
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The present study tested the hypothesis that action of sex steroids on the hypothalamus-pituitary-adrenal (HPA) axis is measurable in the hypothalamus. Late-gestation fetal sheep were treated (5 mg/21 days) with either estradiol, androstenedione, or tamoxifen and compared to age-matched control fetuses. Tamoxifen significantly increased hypothalamic corticotropin releasing factor (CRF) and arginine vasopressin (AVP) concentrations, and androstenedione significantly decreased hypothalamic CRF concentration. Adult sheep were treated with estrone (10 mg/21 days), and responded with significant increases in hypothalamic AVP concentration, but not in immunoreactive ACTH concentration or processing within the pituitary. The results demonstrate that the effect of estrogen on the HPA axis is measurable in the hypothalamus, and is therefore not primarily at the anterior pituitary. 相似文献
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We assessed the influence of schizophrenia on different olfactory tasks. Forty patients with schizophrenia (20 males and 20 females) and 40 control subjects (20 males and 20 females) were tested. The experiment included two sessions. Initially, 12 odorants were presented at a rate of one per minute. The subjects were asked to rate intensity, pleasantness, familiarity and edibility for each odour using linear rating scales. The odorants were then presented a second time and the subjects were asked to identify them. The results showed that the scores for pleasantness, familiarity, edibility and identification but not intensity were disturbed in patients when compared with control subjects. Furthermore, the familiarity judgement of male patients was more often deficient than that of female patients and they rated odorants as being inedible when the women judged them as neutral. Considered together, these data show that our olfactory test may be used in patients with schizophrenia for evidencing various dysfunctions specific to different types of olfactory processing that represent steps in the odour name identification process. 相似文献
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S. LUYSSAERT P. CIAIS S. L. PIAO E.‐D. SCHULZE M. JUNG S. ZAEHLE M. J. SCHELHAAS M. REICHSTEIN G. CHURKINA D. PAPALE G. ABRIL C. BEER J. GRACE D. LOUSTAU G. MATTEUCCI F. MAGNANI G. J. NABUURS H. VERBEECK M. SULKAVA G. R.
Van Der WERF I. A. JANSSENS members of the CARBOEUROPE‐IP SYNTHESIS TEAM 《Global Change Biology》2010,16(5):1429-1450
We present a new synthesis, based on a suite of complementary approaches, of the primary production and carbon sink in forests of the 25 member states of the European Union (EU‐25) during 1990–2005. Upscaled terrestrial observations and model‐based approaches agree within 25% on the mean net primary production (NPP) of forests, i.e. 520±75 g C m?2 yr?1 over a forest area of 1.32 × 106 km2 to 1.55 × 106 km2 (EU‐25). New estimates of the mean long‐term carbon forest sink (net biome production, NBP) of EU‐25 forests amounts 75±20 g C m?2 yr?1. The ratio of NBP to NPP is 0.15±0.05. Estimates of the fate of the carbon inputs via NPP in wood harvests, forest fires, losses to lakes and rivers and heterotrophic respiration remain uncertain, which explains the considerable uncertainty of NBP. Inventory‐based assessments and assumptions suggest that 29±15% of the NBP (i.e., 22 g C m?2 yr?1) is sequestered in the forest soil, but large uncertainty remains concerning the drivers and future of the soil organic carbon. The remaining 71±15% of the NBP (i.e., 53 g C m?2 yr?1) is realized as woody biomass increments. In the EU‐25, the relatively large forest NBP is thought to be the result of a sustained difference between NPP, which increased during the past decades, and carbon losses primarily by harvest and heterotrophic respiration, which increased less over the same period. 相似文献
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Nucleotide sequence of the genes for tryptophan synthase in Pseudomonas aeruginosa 总被引:17,自引:0,他引:17
We have determined the DNA sequence of the two adjacent genes for the alpha
and beta chains of tryptophan synthase in Pseudomonas aeruginosa, along
with 34 5'-flanking and 799 3'-flanking base pairs. The gene order is trpBA
as predicted from earlier genetic studies, and the two cistrons overlap by
4 bp; a ribosome binding site for the second gene is evident in the coding
sequence of the first gene. We have also determined the location of three
large deletions eliminating portions of each gene. A detailed comparison of
the deduced P. aeruginosa amino acid sequence with those published for E.
coli, Bacillus subtilis, and Saccharomyces cerevisiae shows much similarity
throughout the beta and most of the alpha subunit. Most of the residues
implicated by chemical modification or mutation as being critical for
enzymatic activity are conserved, along with many others, suggesting that
three-dimensional structure has remained largely constant during evolution.
We also report the construction of a recombinant plasmid that overproduces
a slightly modified alpha subunit from P. aeruginosa that can form a
functionally effective multimer with normal E. coli beta 2 subunit in vivo.
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Structure and regulation of the anthranilate synthase genes in Pseudomonas aeruginosa: II. Cloning and expression in Escherichia coli 总被引:7,自引:0,他引:7
Crawford IP; Wilde A; Yelverton EM; Figurski D; Hedges RW 《Molecular biology and evolution》1986,3(5):449-458
The genes for the large and small subunits of anthranilate synthase (trpE
and trpG, respectively) have been cloned from Pseudomonas aeruginosa PAC174
into E. coli by R-prime formation with the broad-host- range plasmid
R68.44. Sequential subcloning into plasmid vectors reduced the active
Pseudomonas DNA fragment to a length of 3.1 kb. We obtained evidence that
this region contains the promoter for its own expression and retains a
vestigial regulatory response to tryptophan scarcity or excess.
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ANSON V. KOEHLER JOHN M. PEARCE PAUL L. FLINT J. CHRISTIAN FRANSON HON S. IP 《Molecular ecology》2008,17(21):4754-4762
The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the northern pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses confirmed the genetic divergence between Asian and North American strains of LPAI, but also suggested inter-continental virus exchange and at a higher frequency than previously documented. In 38 isolates from Alaska, nearly half (44.7%) had at least one gene segment more closely related to Asian than to North American strains of LPAI. Additionally, sequences of several Asian LPAI isolates from GenBank clustered more closely with North American northern pintail isolates than with other Asian origin viruses. Our data support the role of wild birds in the intercontinental transfer of influenza viruses, and reveal a higher degree of transfer in Alaska than elsewhere in North America. 相似文献