滇金丝猴(Rhinopithecus bieti)子宫颈的大体和显微形态学

本文研究了滇金丝猴子宫颈的形态结构。结果表明,滇金丝猴的子宫颈不发达,呈扁平状结构。不存在子宫颈丘,子宫颈管基本上是直的或稍弯曲;粘膜平滑,腺体和隐窝贫乏。子宫颈外口为较薄的腹侧唇和较厚的背侧唇所包围。背侧穹窿深于腹侧穹窿。复层鳞状上皮与柱状上皮的连接位于子宫颈外口处。子宫颈上皮由纤毛细胞和分泌细胞组成。     

Solvation Energy and Thermal Stability of Hydrophilization-Modified α-Chymotrypsin

As reported in the literature [Mozhaev et al. (1988), Eur. J. Biochem. 173, 147–154], when a series of modifiers, especially the cyclic anhydrides of pyromellitic and mellitic acids, are introduced into each lysine located in the -chymotrypsin (CT) surface, a substantial hydrophilization of the enzyme surface can occur and remarkable stabilization effects of modified enzymes can be obtained. In this paper, four models are applied to calculate the solvation energy of native and the modified CT based on their tertiary structures, which can be built by the CVFF force field. Analyzing the relationship between the solvation energy and the thermal stability in detail, we find that the results of three solvation energy models (Ooi model, WE-1 model, and WE-2 model) can be used to illustrate the relative stability among these enzymes qualitatively. The present study should be of practical value as well as of some theoretical interest.     

Effects of enhanced atmospheric ammonia on photosynthetic characteristics of two maize (<Emphasis Type=Italic>Zea mays</Emphasis> L.) cultivars with various nitrogen supply across long-term growth period and their diurnal change patterns

We investigated the effect of enhanced atmospheric ammonia (NH₃) in combination with low and high nitrogen (LN and HN, respectively) growth medium on photosynthetic characteristics of two maize (Zea mays L.) cultivars (NE5 with high- and SD19 with low N-use efficiency) across long-term growth period and their diurnal change patterns exposed to 10 nl l⁻¹ and 1,000 nl l⁻¹ NH₃ fumigation in open-top chambers (OTCs). Regardless of the level of N in medium, increased NH₃ concentration promoted maximum net photosynthetic rate (P _max) and apparent quantum yield (AQY) of both cultivars at earlier growth stages, but inhibited P _max of NE5 from silking to maturity stage and that of SD19 at maturity stage only above the ambient concentration. Greater positive/less negative responses were predominant in the LN than in the HN treatment, especially for SD19. Dark respiration rate (R _D) remained more enhanced in the LN than in the HN treatment for SD19 as well as increased in the LN while decreased in the HN treatment for NE5 at their silking stage, following exposure to elevated NH₃ concentration. Additionally, enhanced atmospheric NH₃ increased net photosynthetic rate (P _N) and stomatal conductance (g _s) but reduced intercellular CO₂ concentration (C _i) of both cultivars with either the LN or HN treatment during the diurnal period at tasseling stage. The diurnal change patterns of P _N and g _s showed bimodal curve type and those of C _i presented single W-curve type for NE5, when NH₃ concentration was enhanced. As for SD19, single-peak curve type was showed for both P _N and g _s while single V-curve type for C _i. All results supported the hypothesis that appropriately enhanced atmospheric NH₃ can increase assimilation of CO₂ by improving photosynthesis of maize plant, especially at earlier growth stages and after photosynthetic “noon-break” point. These impacts of elevated NH₃ concentration were more beneficial for SD19 as compared to those for NE5, especially in the LN supply environment.     

Wintersweet accumulates apoplastic chitinase with a dual role in petals

Most monocotyledons like cereals accumulate antifreeze proteins in the apoplast during cold acclimation, but it is still uncertain whether dicotyledons do. Here we report the isolation and characterisation of a 33-kD apoplastic chitinase extracted from the corolla of wintersweet (Chinmonanthus praecox communis L.), which was purified using successive column chromatography on Phenyl-Sepharose, DEAE-Sepharose, and CM-Sepharose. Antifreezing activity of chitinase was confirmed in terms of the formation of bipyramidal ice crystals and high thermal-hysteresis values. Interestingly, chitinase was also found to affect germination of fungal spores of four major plant pathogens. From these data, we hypothesize that, under natural conditions, wintersweet as one of the overwintering dicotyledons also accumulates apoplastic antifreeze proteins like monocotyledons. To our knowledge, this is the first report on the isolation of dicotyledon apoplastic chitinase with high-level antifreeze and antifungal activities.     

Plasma Neutrophil Elastase and Elafin Imbalance Is Associated with Acute Respiratory Distress Syndrome (ARDS) Development

Background

We conducted an exploratory study of genome-wide gene expression in whole blood and found that the expression of neutrophil elastase inhibitor (PI3, elafin) was down-regulated during the early phase of ARDS. Further analyses of plasma PI3 levels revealed a rapid decrease during early ARDS development. PI3 and secretory leukocyte proteinase inhibitor (SLPI) are important low-molecular-weight proteinase inhibitors produced locally at neutrophil infiltration site in the lung. In this study, we tested the hypothesis that an imbalance between neutrophil elastase (HNE) and its inhibitors in blood is related to the development of ARDS.

Methodology/Principal Findings

PI3, SLPI, and HNE were measured in plasma samples collected from 148 ARDS patients and 63 critical ill patients at risk for ARDS (controls). Compared with the controls, the ARDS patients had higher HNE, but lower PI3, at the onset of ARDS, resulting in increased HNE/PI3 ratio (mean = 14.5; 95% CI, 10.9–19.4, P<0.0001), whereas plasma SLPI was not associated with the risk of ARDS development. Although the controls had elevated plasma PI3 and HNE, their HNE/PI3 ratio (mean = 6.5; 95% CI, 4.9–8.8) was not significantly different from the healthy individuals (mean = 3.9; 95% CI, 2.7–5.9). Before the onset (7-days period prior to ARDS diagnosis), we only observed significantly elevated HNE, but the HNE-PI3 balance remained normal. With the progress from prior to the onset of ARDS, the plasma level of PI3 declined, whereas HNE was maintained at a higher level, tilting the balance toward more HNE in the circulation as characterized by an increased HNE/PI3 ratio. In contrast, three days after ICU admission, there was a significant drop of HNE/PI3 ratio in the at-risk controls.

Conclusions/Significance

Plasma profiles of PI3, HNE, and HNE/PI3 may be useful clinical biomarkers in monitoring the development of ARDS.     

Transgene Expression Is Associated with Copy Number and Cytomegalovirus Promoter Methylation in Transgenic Pigs

Transgenic animals have been used for years to study gene function, produce important proteins, and generate models for the study of human diseases. However, inheritance and expression instability of the transgene in transgenic animals is a major limitation. Copy number and promoter methylation are known to regulate gene expression, but no report has systematically examined their effect on transgene expression. In the study, we generated two transgenic pigs by somatic cell nuclear transfer (SCNT) that express green fluorescent protein (GFP) driven by cytomegalovirus (CMV). Absolute quantitative real-time PCR and bisulfite sequencing were performed to determine transgene copy number and promoter methylation level. The correlation of transgene expression with copy number and promoter methylation was analyzed in individual development, fibroblast cells, various tissues, and offspring of the transgenic pigs. Our results demonstrate that transgene expression is associated with copy number and CMV promoter methylation in transgenic pigs.     

Ecological restoration design of a stream on a college campus in central Ohio

Straightened stream channels and altered and drained wetlands have adversely impacted streams and rivers throughout Midwestern USA, where some of the most dense drainage and riparian ecosystem alteration in the world have occurred. A segment of Grave Creek on The Ohio State University's Marion (OSU Marion) campus in Ohio, USA, with its lack of riparian ecosystems, illustrates the transformation of a natural fluvial ecosystem to an unstable and “simplified” aquatic environment that requires continued maintenance and provides little value to the surrounding landscape or to the university. However, the straight ditch, available adjacent riparian land and existing hydric soil give OSU Marion a great opportunity to demonstrate a project of stream and wetland restoration on a college campus. To restore the natural ecological stability of OSU Marion's “back yard” and to provide habitat improvement to Grave Creek and its surrounding landscape on the OSU Marion campus, we have designed a restoration of 1.1 km of Grave Creek meandering to the east of the existing sewer, using the two-stage channel techniques, and about 0.6–0.8 ha of adjacent wetland. We estimate that restoration on this scale will cost about US$ 200,000–300,000, not including monitoring of the results. To fulfill this project, it is likely that an opportunity for using this restoration in a stream/wetland loss mitigation will present itself in this region of Ohio while a long-term pre- and post-construction monitoring plan and more detailed design would be expected as the next step.     

NaCl胁迫对PSII光能利用和耗散的影响

用荧光动力学的方法研究了不同浓度的ＮａＣｌ 处理对ＰＳＩＩ光能利用和耗散的影响。结果表明,在较低的光强下,与对照、１００ｍ ｍｏｌ／Ｌ 和２００ｍ ｍｏｌ／Ｌ ＮａＣｌ 处理相比,经３００ｍ ｍｏｌ／Ｌ 和４００ｍ ｍｏｌ／Ｌ ＮａＣｌ 处理的小麦,其荧光光化学淬灭效率较低,荧光非光化学淬灭效率较高,Ｆｏ 淬灭系数较大,ＱＢ － 非还原性ＰＳＩＩ反应中心含量较大; 而在较高光强下, 其荧光非光化学淬灭效率和Ｆｏ 淬灭系数则相对较低。