Cigarette smoking associates with body weight and muscle mass of patients with rheumatoid arthritis: a cross-sectional,observational study

Introduction  

Rheumatoid arthritis (RA) is associated with altered metabolism leading to muscle wasting. In the general population, cigarette smoking is known to affect body composition by reducing fat and inhibiting muscle synthesis. Even though smoking has been implicated in the pathophysiology and progression of RA, its possible effects on body composition of such patients have not been studied. This cross-sectional study aimed to identify potential associations of smoking with body weight and composition of RA patients.     

Characterization of 16 microsatellite marker loci in the Maasai giraffe (Giraffa camelopardalis tippelskirchi)

Sixteen polymorphic microsatellite markers with an average allele size of k = 4.3 are identified from a genomic plasmid library constructed for giraffe (Giraffa camelopardalis ssp.). Primer sequences and marker data are reported in tabular form. The markers were screened in a population of 25 Maasai giraffe (G. c. tippelskirchi) collected near the Athi River, Kenya. The average observed heterozygosity for each marker was 0.36 with an average expected heterozygosity of 0.535. Hardy–Weinberg deviations are reported from this population, which is suspected to be inbred. The markers will be used to screen the captive giraffe population for subspecific or hybrid classification.     

A Second Quorum-Sensing System Regulates Cell Surface Properties but Not Phenazine Antibiotic Production in Pseudomonas aureofaciens

The root-associated biological control bacterium Pseudomonas aureofaciens 30-84 produces a range of exoproducts, including protease and phenazines. Phenazine antibiotic biosynthesis by phzXYFABCD is regulated in part by the PhzR-PhzI quorum-sensing system. Mutants defective in phzR or phzI produce very low levels of phenazines but wild-type levels of exoprotease. In the present study, a second genomic region of strain 30-84 was identified that, when present in trans, increased β-galactosidase activity in a genomic phzB::lacZ reporter and partially restored phenazine production to a phzR mutant. Sequence analysis identified two adjacent genes, csaR and csaI, that encode members of the LuxR-LuxI family of regulatory proteins. No putative promoter region is present upstream of the csaI start codon and no lux box-like element was found in either the csaR promoter or the 30-bp intergenic region between csaR and csaI. Both the PhzR-PhzI and CsaR-CsaI systems are regulated by the GacS-GacA two-component regulatory system. In contrast to the multicopy effects of csaR and csaI in trans, a genomic csaR mutant (30-84R2) and a csaI mutant (30-84I2) did not exhibit altered phenazine production in vitro or in situ, indicating that the CsaR-CsaI system is not involved in phenazine regulation in strain 30-84. Both mutants also produced wild-type levels of protease. However, disruption of both csaI and phzI or both csaR and phzR eliminated both phenazine and protease production completely. Thus, the two quorum-sensing systems do not interact for phenazine regulation but do interact for protease regulation. Additionally, the CsaI N-acylhomoserine lactone (AHL) signal was not recognized by the phenazine AHL reporter 30-84I/Z but was recognized by the AHL reporters Chromobacterium violaceum CV026 and Agrobacterium tumefaciens A136(pCF240). Inactivation of csaR resulted in a smooth mucoid colony phenotype and formation of cell aggregates in broth, suggesting that CsaR is involved in regulating biosynthesis of cell surface components. Strain 30-84I/I2 exhibited mucoid colony and clumping phenotypes similar to those of 30-84R2. Both phenotypes were reversed by complementation with csaR-csaI or by the addition of the CsaI AHL signal. Both quorum-sensing systems play a role in colonization by strain 30-84. Whereas loss of PhzR resulted in a 6.6-fold decrease in colonization by strain 30-84 on wheat roots in natural soil, a phzR csaR double mutant resulted in a 47-fold decrease. These data suggest that gene(s) regulated by the CsaR-CsaI system also plays a role in the rhizosphere competence of P. aureofaciens 30-84.     

建立正常人肺血管容量的无创精确测量方法的初步报告*

目的: 由于传统呼吸调控环路忽略了对血液循环的决定性作用,肺（静脉）血管容量相关研究甚少,亟需建立肺血管容量测量方法。方法: 选择正常志愿者完成CT全肺扫描,图像数据经过计算机软件分析处理,从肺尖到肺底以40~50层进行肺野手工切划,相邻层间由计算机自动模拟连接,在去除干扰后进行全肺血管（≥0.6 mm）高精度三维立体成像技术处理,进而计算全肺和肺血管容积。结果: 12例正常志愿者从肺尖到肺底CT扫描图片层数为530±98（431~841）张。全肺和肺血管的总容积是3705±857（2398~5383）ml ,肺血管血液总的容积是125±32（94~201）ml。按肺静脉系统血管容量约为全肺血管血液容量一半计算,应该是63±16（47~100）ml。结论: 肺CT扫描数据分析三维立体成像建立肺血管容量无创测量方法精确可行。     

Fertilizer and manure equivalent rates on forage corn production (<i>Zea mays</i>)

An experiment with increasing rates of fertilizer and manure in silage corn was established to evaluate the agronomic crop response and to estimate the manure nitrogen availability. The treatments were designed to deliver 0, 67, 100 and 133% of the crop nitrogen requirements (CNR), using ammonium sulphate and manure as N source. Dry matter (DM) yield was similar among treatments receiving N, but those values were greater than those found in the control. Nitrogen extraction at harvest was not statistically different in treatments with fertilizer or manure, but it was higher in these treatments than in the control without N (p≤ 0.05). With both sources of N, crop N extraction was adjusted to a quadratic regression equation, as a function of N rates. According to the fertilizer equivalence (EF) methodology, the rate of 231.3 kg/ha of inorganic fertilizer N, and 752.9 kg/ha of total N in manure, had 129.5 kg/ha of N extracted by the crop. The ratio of the above rates, fertilizer N/ manure total N, represents the crop available manure N; in the present study, it was 30.7% of total N in the manure. Since no differences in yield were observed between N sources, it is concluded that N fertilizer can be substituted by manure, at a rate estimated to provide the crop N requirements. The estimation of the manure available N is important to adjust manure rates, thereafter avoiding excessive applications and pollution risks.     

Functional enucleation of bovine oocytes: effects of centrifugation and ultraviolet light

Functional enucleation is removal or denaturation of an oocytes DNA without piercing the zona pellucida. Two experiments were conducted in this study to determine the effects of centrifugation, and ultraviolet (UV) light on metaphase II bovine oocytes. Experiment 1 evaluated the effects of centrifugation (12,000 x g for 4 min) on the cleavage rate of in vitro matured oocytes. Centrifugation decreased (P < 0.05) the cleavage rate of oocytes (79.5 vs 70.4%). In addition, it was noted that there were two types of ooplasm after centrifugation, stratified and granular. Developmental potential, as represented by cleavage percent, of the two types of ooplasm was not significantly different. Experiment 2 was conducted to determine the interactive effects of centrifugation (as above) and UV light (254 nm) on cleavage rate of oocytes exposed as metaphase II oocytes. The UV light decreased (P < 0.07) oocyte cleavage rates (35.4 vs 25.2%). Centrifuging metaphase II oocytes also decreased (P < 0.07) cleavage rates (34.1 vs 26.5%). In addition, we determined the fate of chromosomes of oocytes centrifuged and(or) exposed to UV light. Both centrifugation and UV light alone affected (P < 0.05) chromosome placement at 42 +/- 3 h after fertilization. Furthermore, centrifugation and UV light interactively increased (P < 0.05) the percentage of non-cleaved oocytes with their DNA located in the perivitelline space (17.4, 15.5, 13.1, and 49.2, respectively, for control, UV exposed, centrifuged, and UV *centrifuged). Collectively, these data indicate that bovine oocytes at the metaphase II stage can be functionally enucleated with centrifugation and exposure to UV light; however, developmental potential may be diminished by those techniques.     

Impacts of degraded DNA on restriction enzyme associated DNA sequencing (RADSeq)

Degraded DNA from suboptimal field sampling is common in molecular ecology. However, its impact on techniques that use restriction site associated next‐generation DNA sequencing (RADSeq, GBS) is unknown. We experimentally examined the effects of in situDNA degradation on data generation for a modified double‐digest RADSeq approach (3RAD). We generated libraries using genomic DNA serially extracted from the muscle tissue of 8 individual lake whitefish (Coregonus clupeaformis) following 0‐, 12‐, 48‐ and 96‐h incubation at room temperature posteuthanasia. This treatment of the tissue resulted in input DNA that ranged in quality from nearly intact to highly sheared. All samples were sequenced as a multiplexed pool on an Illumina MiSeq. Libraries created from low to moderately degraded DNA (12–48 h) performed well. In contrast, the number of RADtags per individual, number of variable sites, and percentage of identical RADtags retained were all dramatically reduced when libraries were made using highly degraded DNA (96‐h group). This reduction in performance was largely due to a significant and unexpected loss of raw reads as a result of poor quality scores. Our findings remained consistent after changes in restriction enzymes, modified fold coverage values (2‐ to 16‐fold), and additional read‐length trimming. We conclude that starting DNA quality is an important consideration for RADSeq; however, the approach remains robust until genomic DNA is extensively degraded.     

N-acyl-homoserine lactone-mediated regulation of phenazine gene expression by Pseudomonas aureofaciens 30-84 in the wheat rhizosphere.

Pseudomonas aureofaciens 30-84 is a soilborne bacterium that colonizes the wheat rhizosphere. This strain produces three phenazine antibiotics which suppress take-all disease of wheat by inhibition of the causative agent Gaeumannomyces graminis var. tritici. Phenazines also enhance survival of 30-84 within the wheat rhizosphere in competition with other organisms. Expression of the phenazine biosynthetic operon is controlled by the phzR/phzI N-acyl-homoserine lactone (AHL) response system (L. S. Pierson III et al., J. Bacterial 176:3966-3974, 1994; D. W. Wood and L. S. Pierson III, Gene 168:49-53, 1996). By using high-pressure liquid chromatography coupled with high-resolution mass spectrometry, the AHL produced by PhzI has now been identified as N-hexanoyl-homoserine lactone (HHL). In addition, the ability of HHL to serve as an interpopulation signal molecule in the wheat rhizosphere has been examined by using isogenic reporter strains. Disruption of phzI reduced expression of the phenazine biosynthetic operon 1,000-fold in the wheat rhizosphere. Coinoculation of an isogenic strain which produced the endogenous HHL signal restored phenazine gene expression in the phzI mutant to wild-type levels in situ. These results demonstrate that HHL is required for phenazine expression in situ and is an effective interpopulation signal molecule in the wheat rhizosphere.