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31.

Introduction

Increased frequencies of hyperuricemia and gout have been associated with primary hyperparathyroidism, and recent clinical trials of parathyroid hormone (PTH) have reported hyperuricemic adverse events. We evaluated the potential population impact of PTH on serum uric acid (SUA) levels by using a nationally representative sample of United States adults.

Methods

By using data from 8,316 participants aged 18 years and older in the National Health and Nutrition Examination Survey 2003 to 2006, we examined the relation between serum PTH and SUA levels with weighted linear regression. Additionally, we examined the relation with hyperuricemia by using weighted logistic regression.

Results

SUA levels increased with increasing serum PTH concentration. After adjusting for age, sex, dietary factors, glomerular filtration rate (GFR), and other potentially related biomarkers (calcium, phosphorus, alkaline-phosphatase, 25-hydroxyvitamin D), the SUA level differences from the bottom (referent) to top quintiles of serum PTH levels were 0, 8, 13, 14, and 19 ??M (95% CI, 12 to 26; P for trend, < 0.001). These estimates were larger among renally impaired individuals (multivariate SUA difference between the extreme quintiles of PTH, 26 versus 15 ??M among those with GFR ?? 60 versus < 60 ml/min per 1.73 m2, respectively) (P for interaction = 0.004). The odds of hyperuricemia by various definitions increased with increasing PTH levels as well (multivariate P values for trend, < 0.05).

Conclusions

These nationally representative data indicate that serum PTH levels are independently associated with serum uric acid levels and the frequency of hyperuricemia at the population level.  相似文献   
32.
Objectives: The aim of this study was to assess persistence and tissue invasion of Candida albicans strains isolated from a 65 year‐old patient with chronic hyperplastic candidosis (CHC), that subsequently developed into squamous cell carcinoma (SCC). Materials and Methods: C. albicans (n=7) were recovered from the oral cavity of the patient over seven years. Confirmation of CHC and SCC in this patient was achieved by histopathological examination of incisional biopsy tissue. DNA fingerprinting was performed on the seven isolates from the CHC patient together with a further eight isolates from patients with normal oral mucosa (n=2), chronic atrophic candidosis (n=1), SCC (n=1) and CHC (n=4). Genotyping involved the use of inter‐repeat PCR using the eukaryotic repeat primer 1251. Characterisation of the tissue invasive abilities of the isolates was achieved by infecting a commercially available reconstituted human oral epithelium (RHE; SkinEthic, Nice, France). After 24 h. C. albicans tissue invasion was assessed by histopathological examination. Results: DNA fingerprinting demonstrated strain persistence of C. albicans in the CHC patient over a seven year period despite provision of systemic antifungal therapy. The strain of C. albicans isolated from this patient was categorised as a high invader within the RHE compared to other isolates. Conclusions: Candidal strain persistence was evident in a patient with CHC over seven years. This persistence may be due to incomplete eradication from the oral cavity following antifungal therapy or subsequent recolonisation from other body sites or separate exogenous sources. The demonstration of enhanced in vitro tissue invasion by this particular strain may, in part, explain the progression to carcinoma.  相似文献   
33.
The paleoecologist must be able to distinguish a transported assemblage from an in situ one. A method is proposed to assess whether the post-mortem transport of individuals affected their observed spatial (horizontal) distribution. The spatial distribution of a species can be random or contagious. The spatial distribution of individuals of a species in the death assemblage produced by the cumulation of many temporally discrete inputs will be random if the individual inputs are random and contagious if the inputs are contagious. The spatial distribution patterns of several species should not covary in the absence of physical disturbance regardless of their own distributions, however. The degree of covariance between individuals of several species of similar hydrodynamic propensity is dependent on the amount and intensity of postmortem movement. The more species that covary, and the larger the size classes that covary, the more likely that transportation played an important role in the species' distribution patterns. Conversely, the absence of covariance suggests that, for at least some species, biological factors determined the species' spatial distributions. Similarly, covariance of vertical distribution patterns might suggest homogenization. by bioturbational or physical mixing.  相似文献   
34.
Smirnova I  Poltorak A  Chan EK  McBride C  Beutler B 《Genome biology》2000,1(1):research002.1-research00210

Background  

Differences in responses to bacterial surface lipopolysaccharides (LPSs) are apparent between and within mammalian species. It has been shown in mice that resistance to LPS is caused by defects in the Toll-like receptor 4 gene (Tlr4), the product of which is thought to bind LPS and mediate LPS signal transduction in immune system cells.  相似文献   
35.

Background  

Paedocypris, a highly developmentally truncated fish from peat swamp forests in Southeast Asia, comprises the world's smallest vertebrate. Although clearly a cyprinid fish, a hypothesis about its phylogenetic position among the subfamilies of this largest teleost family, with over 2400 species, does not exist. Here we present a phylogenetic analyses of 227 cypriniform taxa, including 213 cyprinids, based upon complete mitochondrial DNA cytochrome b nucleotide sequences in order to determine the phylogenetic position of Paedocypris and to study the evolution of miniaturization among cyprinids.  相似文献   
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Climate change and overfishing may lead to ecosystem instability and may benefit nonexploited organisms such as jellyfish. In the Irish Sea, an increase in jellyfish abundance was evident (r2=0.29, P=0.03) in a 16‐year time‐series (1994–2009) collected during juvenile fish surveys. Jellyfish abundance correlated positively with sea surface temperature (SST) over the preceding 18 months (r=0.65, pACF<0.001) and copepod biomass in the previous year (r=0.56, pACF=0.03) and negatively with spring (February–May) precipitation (r=?0.57, pACF=0.02). Principal components regression indicated that climatic indices explained 68% of the interannual variability in jellyfish abundance (P=0.003), where the components were based on the North Atlantic Oscillation Index, SST and precipitation. The frequency of cnidarian material present in Continuous Plankton Recorder (CPR) samples has also increased since 1970, with a period of frequent outbreaks between 1982 and 1991. Before this period, the herring stock in the northern Irish Sea declined rapidly to a low level, potentially stimulating structural change in the ecosystem. In 1985, there was a step decrease in CPR copepod biomass and in 1989, a step increase in the phytoplankton colour index, suggesting a cascading regime shift during the 1980s. Subsequent overexploitation of gadids, coupled with warm temperatures and the poor recruitment of cod, led to the rapid decline in cod biomass from 1990. While the biomass of sprat has decreased in the last decade, the herring stock has recovered partially. Reductions in demersal fishing pressure since 2000, intended to stimulate cod recovery, appear to have facilitated further rises in haddock biomass. Since the 1980s regime shift, sea temperatures have increased, the fish community has altered and jellyfish abundance has risen such that jellyfish and haddock may now play an increasingly important role in the ecosystem.  相似文献   
39.

Background  

Polarised gene expression is thought to lead to the graded distribution of signaling molecules providing a patterning mechanism across the embryonic eye. Bone morphogenetic protein 4 (Bmp4) is expressed in the dorsal optic vesicle as it transforms into the optic cup. Bmp4 deletions in human and mouse result in failure of eye development, but little attempt has been made to investigate mammalian targets of BMP4 signaling. In chick, retroviral gene overexpression studies indicate that Bmp4 activates the dorsally expressed Tbx5 gene, which represses ventrally expressed cVax. It is not known whether the Tbx5 related genes, Tbx2 and Tbx3, are BMP4 targets in the mammalian retina and whether BMP4 acts at a distance from its site of expression. Although it is established that Drosophila Dpp (homologue of vertebrate Bmp4) acts as a morphogen, there is little evidence that BMP4 gradients are interpreted to create domains of BMP4 target gene expression in the mouse.  相似文献   
40.
Natural selection can favor songbirds that desert nests containingeggs of the parasitic brown-headed cowbird (Molothrus ater).However, the high variability in desertion of parasitized nestswithin species is perplexing in light of the typically highcosts of parasitism. Because nest desertion can also be a responseto partial clutch predation, we first asked if Bell's vireos(Vireo bellii) deserted nests in response to the presence ofcowbird eggs (antiparasite response hypothesis) or to egg removalby predators and female cowbirds (egg predation hypothesis).Second, we asked whether variation in nest desertion was dueto intrinsic differences among individuals or to variation innest contents. We monitored a large number of nests (n = 494)and performed a clutch manipulation experiment to test thesehypotheses. The number of vireo eggs that remained in a nestwas a strong predictor of desertion both within and among pairs.Neither the presence of a single cowbird egg, which leads tonest failure for this host, nor the number of cowbird eggs receivedin a vireo nest influenced nest desertion. Furthermore, vireosdid not desert experimental nests when we immediately exchangedcowbird eggs for vireo eggs but deserted if we removed vireoeggs and replaced them with cowbird eggs the following morning.Desertion of parasitized nests by Bell's vireos can be almostentirely explained as a response to partial or complete clutchloss and does not appear to have been altered by selection frombrood parasitism.  相似文献   
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