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101.
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α-l-Iduronidase has been purified 25,000-fold from the soluble proteins of human kidney by chromatography on heparin-Sepharose, hydroxylapatite, and Bio-Gel P-100. The α-l-iduronidase activity is associated with 80% of the protein in the most purified preparation. It has a molecular weight of 60,000 ± 6500, determined by sedimentation equilibrium, and can be dissociated by reduction into subunits of molecular weight 31,000 ± 6500 determined by polyacrylamide gel electrophoresis in sodium dodecyl sulfate in the presence of dithiothreitol. It contains glucosamine and binds to concanavalin A. The pH optimum, Km and Vmax for two substrates, phenyl iduronide and [3H]anhydromannitol iduronide, were found to be 4.0, 1.05 mm, 16 μmol/mg protein/min, and 4·5, 9 mm and 270 μmol/mg protein/min, respectively. The enzyme is of the low uptake, noncorrective form with respect to fibroblasts cultured from the skin of patients with Hurler syndrome. It is inhibited by 106 m p-chloromercuribenzoate and 10?3 m Cu2+, but is not significantly affected by other divalent cations, EDTA, or sulfhydryl compounds. Antibodies to α-l-iduronidase have been raised in goats.  相似文献   
104.
We have used heterologous probes to investigate the degree of sequence conservation in the plastid genome ofConopholis americana, a totally achlorophyllous angiosperm which exists as a root parasite on red oaks. AlthoughConopholis is completely nonphotosynthetic, it retains a plastid genome in which certain regions, including that which contains the ribosomal RNA genes, are highly conserved. Other regions, including those containing the genes for numerous photosynthesis proteins, are either absent or highly divergent. We also find that the 16S and 23S ribosomal genes of theConopholis plastid are transcribed and processed, implying a potentially functional genetic apparatus. These results are in agreement with findings reported recently for a related root parasite,Epifagus virginiana (de Pamphilis and Palmer, 1990). Furthermore, the plastid genome is maintained in high copy number in fruit tissue, whereas mature seeds have an approximately 10-fold lower copy number.  相似文献   
105.

Background

The wild grass Brachypodium distachyon has emerged as a model system for temperate grasses and biofuel plants. However, the global analysis of miRNAs, molecules known to be key for eukaryotic gene regulation, has been limited in B. distachyon to studies examining a few samples or that rely on computational predictions. Similarly an in-depth global analysis of miRNA-mediated target cleavage using parallel analysis of RNA ends (PARE) data is lacking in B. distachyon.

Results

B. distachyon small RNAs were cloned and deeply sequenced from 17 libraries that represent different tissues and stresses. Using a computational pipeline, we identified 116 miRNAs including not only conserved miRNAs that have not been reported in B. distachyon, but also non-conserved miRNAs that were not found in other plants. To investigate miRNA-mediated cleavage function, four PARE libraries were constructed from key tissues and sequenced to a total depth of approximately 70 million sequences. The roughly 5 million distinct genome-matched sequences that resulted represent an extensive dataset for analyzing small RNA-guided cleavage events. Analysis of the PARE and miRNA data provided experimental evidence for miRNA-mediated cleavage of 264 sites in predicted miRNA targets. In addition, PARE analysis revealed that differentially expressed miRNAs in the same family guide specific target RNA cleavage in a correspondingly tissue-preferential manner.

Conclusions

B. distachyon miRNAs and target RNAs were experimentally identified and analyzed. Knowledge gained from this study should provide insights into the roles of miRNAs and the regulation of their targets in B. distachyon and related plants.  相似文献   
106.

Introduction

Serious infection, cardiovascular disease, and mortality are increased in rheumatoid arthritis (RA). Whether RA affects the risk for these complications after total joint arthroplasty (TJA) is unknown, we hypothesize that it does. We compared the occurrence of 30-day postoperative complications and mortality in a large cohort of RA and osteoarthritis (OA) patients undergoing hip or knee TJA.

Methods

Analyses included 7-year data from the Veterans Affairs Surgical Quality Improvement Program. The 30-day complications were compared by diagnosis by using logistic regression, and long-term mortality was examined by using Cox proportional hazards regression. All analyses were adjusted for age, sex, and clustering by surgical site. Additional covariates included sociodemographics, comorbidities, health behaviors, and operative risk factors.

Results

The 34,524 patients (839 RA, 33,685 OA) underwent knee (65.9%) or hip TJA. Patients were 95.7% men with a mean (SD) age of 64.4 (10.7) years and had 3,764 deaths over a mean follow-up of 3.7 (2.3) years. Compared with OA patients, those with RA were significantly more likely to require a return to the operating room (odds ratio (OR), 1.45 (95% CI, 1.08 to 1.94), but had similar rates of 30-day postoperative infection, OR 1.02 (0.72 to 1.47), cardiovascular events, OR 0.69 (0.37 to 1.28), and mortality, OR 0.94 (0.38 to 2.33). RA was associated with a significantly higher long-term mortality; hazard ratio (HR), 1.22 (1.00 to 1.49).

Conclusion

In this study of US veterans, RA patients were not at an increased risk for short-term mortality or other major complications after TJA, although they returned to the operating room more often and had increased long-term mortality.  相似文献   
107.
Sex estimation from the skull is commonly performed by physical and forensic anthropologists using a five‐trait scoring system developed by Walker. Despite the popularity of this method, validation studies evaluating its accuracy across a variety of samples are lacking. Furthermore, it remains unclear what other intrinsic or extrinsic variables are related to the expression of these traits. In this study, cranial trait scores and postcranial measurements were collected from four diverse population groups (U.S. Whites, U.S. Blacks, medieval Nubians, and Arikara Native Americans) following Walker's protocols (total n = 499). Univariate and multivariate analyses were utilized to evaluate the accuracy of these traits in sex estimation, and to test for the effects of population, age, and body size on trait expressions. Results revealed significant effects of population on all trait scores. Sample‐specific correct sex classification rates ranged from 74% to 94%, with an overall accuracy of 85% for the pooled sample. Classification performance varied among the traits (best for glabella and mastoid scores and worst for nuchal scores). Furthermore, correlations between traits were weak or nonsignificant, suggesting that different factors may influence individual traits. Some traits displayed correlations with age and/or postcranial size that were significant but weak, and within‐population analyses did not reveal any consistent relationships between these traits across all groups. These results indicate that neither age nor body size plays a large role in trait expression, and thus does not need to be incorporated into sex estimation methods. Am J Phys Anthropol 154:259–269, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
108.
From June through August in 1999 and 2000, we conducted an avian serosurvey for eastern equine encephalomyelitis (EEE) virus at Killbuck Marsh Wildlife Area (KMWA), a focus of infection in central Ohio. We also monitored abundance of the suspected enzootic vector, Culiseta melanura Coquillett, in Brown's Lake Bog, an adjacent wetland. Of the 363 birds of 30 species sampled in 1999, three gray catbirds (Dumetella carolinensis) were positive for antibodies to EEE virus, representing 1.2% of the avian samples and 4.2% of the gray catbirds sampled. Given these results and the abundance of gray catbirds at this site, this species became the focus of our sampling efforts in 2000. However, none of the 109 samples collected from 98 catbirds in 2000 was positive for the virus. Culiseta melanura adults were monitored using resting boxes and CDC CO, light traps at both sites in 1999. Culiseta melanura larvae were monitored in 1999 and 2000 at Brown's Lake Bog, the closest known source of this species, approximately 5km from the avian serosurvey site. We suggest that dry conditions reduced the breeding and abundance of Cs. melanura in 2000 and possibly the transmission of EEE virus at KMWA.  相似文献   
109.
While it has been proposed in several taxa that the mitochondrial genome is associated with adaptive evolution to different climatic conditions, making links between mitochondrial haplotypes and organismal phenotypes remains a challenge. Mitonuclear discordance occurs in the small brown planthopper (SBPH), Laodelphax striatellus, with one mitochondrial haplogroup (HGI) more common in the cold climate region of China relative to another form (HGII) despite strong nuclear gene flow, providing a promising model to investigate climatic adaptation of mitochondrial genomes. We hypothesized that cold adaptation through HGI may be involved, and considered mitogenome evolution, population genetic analyses, and bioassays to test this hypothesis. In contrast to our hypothesis, chill‐coma recovery tests and population genetic tests of selection both pointed to HGII being involved in cold adaptation. Phylogenetic analyses revealed that HGII is nested within HGI, and has three nonsynonymous changes in ND2, ND5 and CYTB in comparison to HGI. These molecular changes likely increased mtDNA copy number, cold tolerance and fecundity of SBPH, particularly through a function‐altering amino acid change involving M114T in ND2. Nuclear background also influenced fecundity and chill recovery (i.e., mitonuclear epistasis) and protein modelling indicates possible nuclear interactions for the two nonsynonymous changes in ND2 and CYTB. The high occurrence frequency of HGI in the cold climate region of China remains unexplained, but several possible reasons are discussed. Overall, our study points to a link between mtDNA variation and organismal‐level evolution and suggests a possible role of mitonuclear interactions in maintaining mtDNA diversity.  相似文献   
110.
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