Level of agreement and biopsy correlation using two- and three-tier systems to grade cervical dyskaryosis

At present, a three-tier system is used to grade cervical dyskaryosis in the UK, although the two-tier Bethesda system is used in the United States, and the British Society for Clinical Cytology has recommended that a two-tier system be implemented here. In this study, we have retrospectively re-graded 117 conventional cervical smears using both systems to determine the intra- and interobserver variation and compare the cytology grading in both systems with the final histology. The intra and interobserver agreement was moderate using both grading systems, but the agreement between cytology grade and final histology was poor in both the two- and three-tier systems, and slightly worse using two-tier grading. However, when each of the three histological categories is considered separately the two-tier system appears to work better. Therefore, changing the way in which cervical dyskaryosis is graded in the UK may result in poorer agreement between the cervical smear result and the final histological diagnosis if introduced without proper training, monitoring and assessment.     

The phylogenetic affinities of the chaetognaths: a molecular analysis

The chaetognaths, or arrowworms, constitute a small and enigmatic phylum of marine invertebrates whose phylogenetic affinities have long been uncertain. A popular hypothesis is that the chaetognaths are the sister group of the major deuterostome phyla: chordates, hemichordates, and echinoderms. Here we attempt to determine the affinities of the chaetognaths by using molecular sequence data. We describe the isolation and nucleotide sequence determination of 18S ribosomal DNA from one species of chaetognath and one acanthocephalan. Extensive phylogenetic analyses employing a suite of phylogenetic reconstruction methods (maximum parsimony, maximum likelihood, evolutionary parsimony, and two distance methods) suggest that the hypothesized relationship between chaetognaths and the deuterostomes is incorrect. In contrast, we propose that the lineage leading to the chaetognaths arose prior to the advent of the coelomate metazoa.      

Effect of 1-aminocyclopropane-1-carboxylic acid on maize kernel development in vitro

Pollination stimulates ethylene production in maize ears, and the application of ethephon during the pollination period can cause kernel abortion. The objective of this study was to determine if kernel abortion could be induced in vitro by the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC). Adding ACC to the culture medium resulted in the evolution of ethylene which caused abortion and reduced mature kernel mass. The effect of ethylene on kernel abortion and dry matter accumulation was partially negated by the addition of the ethylene-binding site inhibitor, 2,5-norbornadiene (NBD). The effect of ethylene on kernel abortion was greatest during the early stage of kernel development and was intensified by an increase in media sucrose concentration. These data suggest that ethylene could regulate kernel abortion in maize.Contribution of the Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108. Paper No. 17,088, Scientific Journal Series, Minnesota Agriculture Experimental Station.     

Relationship between Climatic Variables during Early Flowering of Sorghum and the Incidence of Sugary Disease caused by Sphacelia sorghi

The relationship between sugary disease incidence and six climatic variables during the early stages of flowering was determined in field trials conducted over three seasons. Daily maximum temperature was highly significantly correlated with sugray disease incidence and accounted for 83 % of the variation observed in disease incidence. The critical period for infection was limited to 5 days after commencement of pollen shed. Deviations from the temperature × sugary disease model occurred in late flowering plots. These were correlated with low temperatures during the 2 weeks prior to pollen shed and, thus, possibly, a reduction in pollen vigour.     

正常人左心室功能指标的参考值及其预计公式的初步研究报告*

目的: 当前评估左心室容量和功能仍常用正常值范围,个体化分析也仅使用体表面积进行校正。尚缺少个体化因素相关的大样本参考值和预计公式。方法: 本研究纳入美国加州洛杉矶县南湾地区1200名健康志愿者,其中男807女393,年龄20岁-94岁,心脏CT造影（CTA）,经过高精度三维成像技术处理,计算左心室容积在收缩和舒张过程中的连续动态变化,测定左心室（LV）容量和功能指标：舒张末期容积（EDV)、收缩末期容积(ESV)、每搏输出量(SV)、射血分数(EF)和心输出量(CO)。将以上指标与一般特征指标进行多因素相关分析,以探索正常人预计值计算公式。结果: 男性除LVEF小于女性外（P<0.001）,其余各指标均大于女性（P<0.001）。多元线性回归分析提示, 性别、年龄、身高和体质量均为EDV、ESV、SV的独立影响因子(P<0.001); 而CO仅受年龄、性别、体质量显著影响(P<0.001),但与身高无关(P>0.05)。CO的预测公式CO (L·min^-1)= 6.963+0.446(Male) -0.037×年龄(yr)+0.013×体质量(kg)。结论: 性别、年龄、身高、体质量均影响左心室容量和功能,建立预测值计算公式,对心血管疾病的无创评估和个体化精准医疗具有重要参考价值。