脂蛋白脂酶多态性对郑州地区汉族糖尿病合并冠心病发病的影响

目的　探讨脂蛋白脂酶 (lipoproteinlipase ,LPL )对 2型糖尿病和糖尿病合并冠心病发病的影响。方法　测定 2型糖尿病 (10 5例 )和糖尿病合并冠心病 (10 8例 )患者和对照组 (10 1例 )外周血白细胞LPL内含子 6的PvuⅡ和内含子 8的HindⅢ多态性 ,以及血清胆固醇 (TC)、甘油三酯 (TG)、高密度脂蛋白胆固醇 (HDL C)等水平。结果　①LPL基因PvuⅡ的等位基因P +和P -频率对照组分别为 0 .6 9与 0 .31,2型糖尿病组为 0 .6 3和 0 .37,糖尿病合并冠心病组为 0 .5 9与 0 .4 1,3组相比其差异无统计学意义。HindⅢ等位基因H +和H -频率对照组分别为 0 .6 8和 0 .32 ,2型糖尿病组为 0 .6 7和 0 .33,糖尿病合并冠心病组为 0 .6 8与 0 .32 ,3组间的差异无统计学意义。② 2型糖尿病LPL基因PvuⅡ基因表型P - /P -患者血清TG [(1.5± 0 .5 )mmol/L]、TC [(5 .0± 1.2 )mmol/L]、LDL C [((3.8±0 .9)mmol/L]及糖尿病合并冠心病P - /P -患者的TG[(2 .1± 1.1)mmol/L]、TC[(5 .3± 1.9)mmol/L]和LDL C[(4 .0± 1.9)mmol/L]的水平均低于同组内非P - /P -表型 (P <0 .0 5 ) ,而P - /P -表型 2型糖尿病患者HDL C[(1.0± 0 .4 )mmol/L]水平则高于同组非P - /P -表型患者 (P <0 .0 5 )。 3组中HindⅢ基因型H - /H -患者血清TG、TC     

The Irish potato famine pathogen Phytophthora infestans originated in central Mexico rather than the Andes

Phytophthora infestans is a destructive plant pathogen best known for causing the disease that triggered the Irish potato famine and remains the most costly potato pathogen to manage worldwide. Identification of P. infestan’s elusive center of origin is critical to understanding the mechanisms of repeated global emergence of this pathogen. There are two competing theories, placing the origin in either South America or in central Mexico, both of which are centers of diversity of Solanum host plants. To test these competing hypotheses, we conducted detailed phylogeographic and approximate Bayesian computation analyses, which are suitable approaches to unraveling complex demographic histories. Our analyses used microsatellite markers and sequences of four nuclear genes sampled from populations in the Andes, Mexico, and elsewhere. To infer the ancestral state, we included the closest known relatives Phytophthora phaseoli, Phytophthora mirabilis, and Phytophthora ipomoeae, as well as the interspecific hybrid Phytophthora andina. We did not find support for an Andean origin of P. infestans; rather, the sequence data suggest a Mexican origin. Our findings support the hypothesis that populations found in the Andes are descendants of the Mexican populations and reconcile previous findings of ancestral variation in the Andes. Although centers of origin are well documented as centers of evolution and diversity for numerous crop plants, the number of plant pathogens with a known geographic origin are limited. This work has important implications for our understanding of the coevolution of hosts and pathogens, as well as the harnessing of plant disease resistance to manage late blight.The potato pathogen Phytophthora infestans, the causal agent of potato late blight, is the plant pathogen that has most greatly impacted humanity to date. This pathogen is best known for its causal involvement in the Irish potato famine after introduction of the HERB-1 strain to Ireland from the Americas in the 19th century (1). To this day, potato late blight remains a major threat to food security and carries a global cost conservatively estimated at more than $6 billion per year (2). In the 1980s, a single asexual lineage named US-1, possibly derived from the same metapopulation as HERB-1 (1), dominated global populations, whereas a genetically diverse and sexual population of P. infestans in central Mexico led to formulation of the hypothesis identifying Mexico as this pathogen’s center of origin (3, 4). A competing hypothesis argues that the center of origin of the potato, the South American Andes, is the center of origin of P. infestans (5). This hypothesis recently gained prominence after an analysis demonstrated ancestral variation in Andean lineages of P. infestans (5). Other evidence supporting this hypothesis includes infection of native Solanum hosts and an Andean distribution for Phytophthora andina, a phylogenetic relative of P. infestans (6).Evidence supporting a Mexican center of origin is substantial, but inconclusive (4). Two close relatives of P. infestans, Phytophthora ipomoeae and Phytophthora mirabilis, are endemic to central Mexico (7, 8). P. ipomoeae and P. mirabilis cause disease on two endemic plant host groups, Ipomoea spp. and Mirabilis jalapa, respectively. Populations of P. infestans in the Toluca Valley, southwest of Mexico City, are genetically diverse, are in Hardy–Weinberg equilibrium, and contain mating types A1 and A2 in the expected 1:1 ratio for sexual populations (9, 10). Before a migration event from Mexico to Europe in the 1970s (11, 12), only A1 mating types of P. infestans were found worldwide outside of central Mexico, limiting other populations to asexual reproduction (13). Tuber-bearing native Solanum species occur throughout the Toluca Valley (14). Of the R genes that have been used to confer resistance to strains of P. infestans in potato, the majority described to date originated from Solanum demissum or Solanum edinense in the Toluca Valley, with some discovered in South America (15).Support for the alternate hypothesis that P. infestans originated in the Andes is based on a coalescent analysis conducted by Gómez-Alpizar et al. (5). This analysis used the nuclear RAS locus and the mitochondrial P3 and P4 regions to infer rooted gene genealogies that showed ancestral lineages rooted in the Andes. Furthermore, the Mexico sample harbored less nucleotide diversity than the Andean population. P. andina was identified as the ancestral lineage for the mitochondrial genealogy; however, P. mirabilis and P. ipomoeae were not included in that study. P. andina has since been shown to be a hybrid species derived from P. infestans and a Phytophthora sp. unknown to science (16). Surprisingly, populations of P. infestans and P. andina are clonal in South America and are not in Hardy–Weinberg equilibrium (6, 17–19). Thus, the question of whether P. infestans originated in the Andes or central Mexico remained unresolved.Powerful approaches for determining the demographic and evolutionary history of organisms are now available (20). Many of these approaches rely on the power of coalescent theory for inferring the genealogical history of a species based on a representative population sample (21–23). Bayesian phylogeography uses geographic information in light of phylogenetic uncertainty to provide model-based inference of geographic locations of ancestral strains (24). The isolation with migration (IM) model and associated software uses likelihood-based inference to infer divergence time between evolutionary lineages (25). Approximate Bayesian computation (ABC) makes use of coalescent simulations and likelihood-free inference to contrast complex demographic scenarios. Each of these methods has proven useful in reconstructing the demography of pests and pathogens (24, 26–29).The objective of the present study was to reconcile the two competing hypotheses on the origin of P. infestans using Bayesian phylogenetics and ABC. We sampled key populations of P. infestans from central Mexico and the Andes and expanded on the analysis of Gómez-Alpizar et al. (5) by sequencing additional nuclear loci to assess support for the center of origin across multiple loci. To determine ancestral state, we added sequences from the sister taxa P. andina, P. mirabilis, P. ipomoeae, and Phytophthora phaseoli, all of which belong to Phytophthora clade 1c (30, 31). Finally, we aimed to reconcile the biology of P. infestans in Mexico with the findings of Gómez-Alpizar et al. (5) of ancestral variation in the Andes.     

INAUGURAL ARTICLE by a Recently Elected Academy Member:Natural history-driven,plant-mediated RNAi-based study reveals CYP6B46’s role in a nicotine-mediated antipredator herbivore defense

Manduca sexta (Ms) larvae are known to efficiently excrete ingested nicotine when feeding on their nicotine-producing native hostplant, Nicotiana attenuata. Here we describe how ingested nicotine is co-opted for larval defense by a unique mechanism. Plant-mediated RNAi was used to silence a midgut-expressed, nicotine-induced cytochrome P450 6B46 (CYP6B46) in larvae consuming transgenic N. attenuata plants producing MsCYP6B46 dsRNA. These and transgenic nicotine-deficient plants were planted into native habitats to study the phenotypes of larvae feeding on these plants and the behavior of their predators. The attack-behavior of a native wolf spider (Camptocosa parallela), a major nocturnal predator, provided the key to understanding MsCYP6B46’s function: spiders clearly preferred CYP6B46-silenced larvae, just as they had preferred larvae fed nicotine-deficient plants. MsCYP6B46 redirects a small amount (0.65%) of ingested nicotine from the midgut into hemolymph, from which nicotine is exhaled through the spiracles as an antispider signal. CYP6B46-silenced larvae were more susceptible to spider-attack because they exhaled less nicotine because of lower hemolymph nicotine concentrations. CYP6B46-silenced larvae were impaired in distributing ingested nicotine from midgut to hemolymph, but not in the clearing of hemolymph nicotine or in the exhalation of nicotine from hemolymph. MsCYP6B46 could be a component of a previously hypothesized pump that converts nicotine to a short-lived, transportable, metabolite. Other predators, big-eyed bugs, and antlion larvae were insensitive to this defense. Thus, chemical defenses, too toxic to sequester, can be repurposed for defensive functions through respiration as a form of defensive halitosis, and predators can assist the functional elucidation of herbivore genes.Plants produce a pharmacopeia of potent chemical defenses that prevent the attack of unadapted herbivores and thwart the growth of adapted ones. Frequently, lepidopteran herbivores co-opt these diet-acquired toxins for their own defensive purposes. The eastern tent caterpillar (Malacosoma americanum) regurgitates hydrogen cyanide and benzaldehyde ingested from their cyanogenic hostplants when attacked by ants (1). The Atala butterfly (Eumaeus atala) acquires a toxic azoxyglycoside from its cycad hosts and becomes unpalatable to bird and ant predators (2). Similarly, rattlebox moths (Utetheisa ornatrix) co-opt pyrrolizidine alkaloids that their larvae sequester while feeding on rattlebox legume hostplants (Crotalaria spp.) to deter predatory spiders (3). Prey frequently advertise their toxic status with warning colorations, odors, and behaviors, and predators readily learn these aposematic signals to avoid consuming toxic prey (4). The molecular mechanisms of how herbivores co-opt plant defenses for their own defense remain largely unexplored.The pyridine alkaloid nicotine is a defense metabolite of several Nicotiana spp. Nicotine is extremely effective against herbivores because of its ability to poison the essential neuromuscular junction common to all animals that use muscles to move: the acetylcholine receptor (5, 6). Nicotiana spp. hostplants respond to the herbivore attack with large increases in nicotine accumulation (7). However, the tobacco hornworm (Manduca sexta, Ms), a specialist lepidopteran herbivore that feeds on nicotine-producing Nicotiana plants, tolerates doses of nicotine that are lethal for unadapted herbivores (8). More endoparasitoid wasps (Cotesia congregata) emerged as adults from parasitized M. sexta larvae fed on low nicotine varieties of cultivated tobacco than from larvae fed on nicotine-rich varieties (9). The generalist predatory argentine ant (Iridomyrmex humilis) also preferred M. sexta larvae reared on artificial diets (AD) without nicotine over those reared on high nicotine diets, and were deterred by topical nicotine treatments (10). These results suggest that M. sexta larvae might be able to use this diet-derived toxin for their own protection. How this happens remains a mystery, as the larvae’s resistance of ingested nicotine does not appear to include sequestration and storage of this toxin.The exact mechanisms responsible for M. sexta’s nicotine resistance remain unclear, but both efficient excretion and metabolism appear to be involved. Some researchers have focused on the polar metabolites of nicotine, such as cotinine and the N-oxides of both nicotine and cotinine, which are commonly found in the urine and blood of human smokers (8, 11, 12); cytochrome P450s (CYPs) are thought to mediate nicotine’s oxidation to these metabolites (8, 11, 13–15), but other researchers have been unable to find the oxides in M. sexta’s excretions and propose that nicotine is rapidly excreted without modification (16–18). Although this theory is widely accepted, most studies have not been able to recover all of the ingested nicotine in the frass and nicotine can be found in the hemolymph of larvae feeding on nicotine-containing diets. Hence, within these physiological limits of M. sexta’s excretory-based tolerance lie opportunities for the defensive use of nicotine. Whether nicotine-resistance and co-option are regulated by a common mechanism remains unknown.Here we examine how M. sexta larvae co-opt diet-ingested nicotine for their own defense. In a previous unbiased microarray study, we found that a midgut-expressed cytochrome P450 (CYP6B46) was strongly down-regulated in larvae that were fed genetically modified hostplants with suppressed nicotine production (19, 20). To evaluate if this CYP6B46 is involved in nicotine resistance and co-option, we used a reverse genetics approach, plant-mediated RNA interference (PMRi) (20, 21), to silence this gene in larvae feeding on nicotine-containing, native coyote tobacco (Nicotiana attenuata) hostplants transformed to harbor the silencing construct. Lepidopteran herbivores appear to lack the RNA-dependent RNA polymerase required to sustain gene silencing by RNAi; however, a continuous supply of double-stranded (ds)RNA administered via the hostplant (or diet) effectively silences genes in these herbivores (21, 22).N. attenuata plants were transformed with an expression vector containing a 300-bp fragment of CYP6B46 in an inverted repeat (ir) orientation. Continuous dsRNA ingestion efficiently silenced CYP6B46 in the midguts of larvae feeding on these plants in a highly target-sequence–specific manner, as the most similar CYP expressed in larval midguts, CYP6B45, was not cosilenced (20). These PMRi plants were planted into the native habitat of both hostplant and larvae, the Great Basin Desert, Utah, which teems with larval predators—such as bugs, mantids, ants, antlions, spiders, and lizards—but lacks the Argentine ants and C. congregata endoparasitoids previously reported to be nicotine-sensitive. One of these predators, a wolf spider [Camptocosa parallela (Lycosidae)], selectively attacked CYP6B46-silenced larvae just as it did larvae feeding on nicotine-free hostplants. The particular predatory behavior of these spiders revealed the function of MsCYP6B46 in externalizing ingested nicotine for defensive use. The combination of natural history studies and the plant- and herbivore-reverse genetic procedures can fruitfully dissect the molecular mechanisms governing the tritrophic interactions.     

Autism spectrum disorder severity reflects the average contribution of de novo and familial influences

Autism spectrum disorders (ASDs) are a highly heterogeneous group of conditions—phenotypically and genetically—although the link between phenotypic variation and differences in genetic architecture is unclear. This study aimed to determine whether differences in cognitive impairment and symptom severity reflect variation in the degree to which ASD cases reflect de novo or familial influences. Using data from more than 2,000 simplex cases of ASD, we examined the relationship between intelligence quotient (IQ), behavior and language assessments, and rate of de novo loss of function (LOF) mutations and family history of broadly defined psychiatric disease (depressive disorders, bipolar disorder, and schizophrenia; history of psychiatric hospitalization). Proband IQ was negatively associated with de novo LOF rate (P = 0.03) and positively associated with family history of psychiatric disease (P = 0.003). Female cases had a higher frequency of sporadic genetic events across the severity distribution (P = 0.01). High rates of LOF mutation and low frequencies of family history of psychiatric illness were seen in individuals who were unable to complete a traditional IQ test, a group with the greatest degree of language and behavioral impairment. These analyses provide strong evidence that familial risk for neuropsychiatric disease becomes more relevant to ASD etiology as cases become higher functioning. The findings of this study reinforce that there are many routes to the diagnostic category of autism and could lead to genetic studies with more specific insights into individual cases.The set of conditions diagnosed as autism spectrum disorders (ASDs) vary enormously in their presentation (1). The most severely impaired individuals—often those with intellectual disabilities, limited speech, and severe behavioral problems—can require lifelong care. At the other end of the functional spectrum, people diagnosed with ASDs can be verbally fluent and academically gifted and can achieve independence in adulthood (2, 3). The broad range of cognitive and behavioral profiles seen in diagnosed ASDs has been long viewed as a challenge by the research community (4). Although it is well established that (i) the cognitive/behavioral profile of people diagnosed with ASDs varies widely and (ii) the set of genetic factors related to ASDs varies widely (5, 6), the degree to which phenotype can be used to predict patterns in disease architecture remains unclear.Recent insights into the genetic influences on ASDs offer an opportunity to investigate this question through the lens of de novo vs. familial effects. On average, ASDs run in families. The siblings of children with ASDs are 10–20 times more likely to receive a diagnosis of ASD themselves (7, 8); the parents of children with ASDs are more likely to manifest autistic features, as well as a variety of other neuropsychiatric conditions, such as schizophrenia and bipolar disorder (9, 10). These epidemiologic observations are consistent with analyses suggesting that ASDs are influenced by thousands of common genetic variants transmitted between generations. It has been estimated that common, genotyped SNPs account for 20–60% of variation in ASD risk, although the effect of any individual SNP is likely very small (11–13). Many of these influences are shared with other psychiatric disorders (12, 14), which at least in part explains the familial clustering of different types of behavior problems.However, statistics about ASD heritability reflect an average. For example, there are likely many affected families for whom sibling recurrence risk is less than 10–20%. The strongest evidence toward this claim comes from studies of rare, severely deleterious genetic events that are associated with ASDs (15–20). Events of this type, for example copy number variants and loss of function (LOF) mutations, are often de novo (not seen in an affected individual’s parents). Although cases of ASDs involving a de novo mutation could reflect a concert of spontaneous and inherited genetic events, de novo events of large effect may reduce the likelihood of seeing psychiatric problems in an affected individual’s family members.     

定量RT—PCR分析穿孔素基因在无症状乙型肝炎病毒携带者中的表达及意义

目的：验证无症状乙型肝炎病毒携带者（ASCs）与正常对照组消减文库中的差异基因穿孔素（perforin）在相应人群中的差异表达。方法：采集43例ASCs和41例正常对照者的外周静脉血，分离外周血单个核细胞（PBMC）并提取RNA，做定量RT—PCR（Real—timeRT—PCR）。结果：穿孔素在HBV携带者中表达水平是正常对照的3．58倍。结论：通过定量RT—PCR首次证实了穿孔素基因在ASCs较正常对照表达增高，因穿孔索与免疫抑制有关，该基因在ASCs的高表达对于阐明ASCs的发病机制有首要意义。     

ACE基因多态性对新诊断T2DM患者颈动脉内中膜厚度进展的预测作用

目的：探讨多因素强化干预条件下,血管紧张素转换酶（ACE）基因多态性对新诊断T2DM患者颈总动脉内中膜厚度（CCA-IMT）进展的预测作用。方法：采用限制性片段长度多形态多聚酶链式反应（PCR-RFLP）技术检测100例新诊断T2DM患者ACE基因内含子16 I/D多态性,利用B超检测新诊断T2DM患者CCA-IMT,并对其进行多因素强化干预治疗,探讨ACE基因多态性对新诊断T2DM患者CCA-IMT进展的预测作用。结果：携带ACE DD基因型者CCA-IMT、hs-CRP高于携带II及ID基因型者（P〈0.05）;强化干预后,携带ACE DD基因型者CCA-IMT、hs-CRP与携带II及ID基因型者差异无显著性（P〉0.05）,干预前后自身比较CCA-IMT值、hs-CRP水平较干预前显著下降（P〈0.05）,CCA-IMT非进展组与进展组患者ACE基因型、等位基因携带者比例均差异无显著性（P〉0.05）;Logistic回归分析显示,ACE DD基因型不是新诊断T2DM患者CCA-IMT进展的危险因素。结论：多危险因素强化干预条件ACE DD基因型不能预测CCA-IMT的进展,多危险因素强化干预延缓了携带ACE DD基因型者CCA-IMT的进展。     

Forensic nursing educational development: an integrated review of the literature

The forensic area of practice has been a popular career choice and area of study for many of the health science disciplines. Forensic nursing is a nursing specialty with subspecialties that focus on nursing practice who care for victims and offenders, living and deceased at the clinical legal interface. This integrated review of the literature overviewed the historical development of each of the forensic nursing subspecialties and identified gaps in specialty nursing educational development. Although multiple studies for the last 30 years identified the need for forensic nursing education, recommendations did not soon translate into educational curriculum development. The literature showed that role development was not concurrent with educational development in all forensic nursing subspecialties.     

家族性2型糖尿病遗传方式及血糖血脂代谢的研究

目的 :探索家族性 2型糖尿病的遗传方式及家族性 2型糖尿病家系一级亲属正常糖耐量同胞的血糖血脂代谢变化。方法 :按WHO1980标准 ,收集江苏苏南地区 2型糖尿病多发家系 99个 ,进行 3代家族史和血统成员的调查研究。检查血糖、血脂、葡萄糖耐量及胰岛素C肽释放试验。在排除糖尿病和糖耐量减低 (IGT)的前提下 ,选择先证者的正常糖耐量同胞为观察组 (5 4例 ) ,同胞的正常配偶为对照组 (5 6例 ) ,进行血糖血脂代谢分析。结果 :先证者的同胞患病率为 46 7%。同胞患病率是其配偶的 6.6倍 ;而同胞及其配偶的IGT患病率均为 11%左右。病系谱分析显示 ,至少双亲之一为糖尿病患者的家系达5 0 .5 % ,先证者同胞患糖尿病者达 1/ 2。与配偶组比较同胞的TG、LDL水平升高 ,空腹血糖升高 ,而胰岛素、C肽水平无差异。结论 :有家族史的 2型糖尿病患者有明显的家族聚集性 ,其发病与遗传密切相关 ,其遗传方式不完全支持多基因遗传 ,而支持孟德尔的常染色体显性遗传。同胞在糖耐量正常的情况下血糖、血脂已开始变化 ,对该糖尿病高危人群应进行血糖血脂监测以利早期防治。     

神经营养因子-3质粒转染失神经肌肉的表达

目的:观察外源性神经营养因子-3(neurotrophin-3,NT-3)基因直接转染失神经肌肉的表达及治疗效果。方法:SD大鼠40只,制成腓肠肌失神经支配模型。实验组术后胖肠肌内注射人NT-3质粒10μl(1μg/μl),对照组注射等量生理盐水10μl/d,不同时间点取材采用免疫组化检测蛋白的表达,并进行肌湿重、肌纤维横截面积和运动终板检测。结果:实验组2d后肌细胞出现外源性NT-3免疫组化染色阳性,7 d时达到高峰,14 d和 28 d时有所下降,但与 2 d相比,仍维持在较高水平。而对照组免疫组化染色结果为阴性。实验组与对照组检测指标比较差异有显著性。结论:NT-3基因直接转染可在肌细胞内表达蛋白,为失神经肌肉萎缩的基因治疗提供了初步的理论和实验依据。