构建siRNA慢病毒载体抑制A549细胞株VEGF受体KDR基因的表达

目的构建针对血管内皮生长因子(VEGF)受体KDR基因的siRNA慢病毒载体,鉴定其对肺癌细胞株A549基因干扰效果。方法设计合成针对KDR编码区的三条siRNA序列及阴性对照序列,克隆到PGCL-GFP载体,构建重组质粒,行PCR鉴定、DNA测序分析;转染人肺癌细胞株A549,Real-Time PCR及Western blot分别检测KDR mRNA、蛋白水平变化;细胞计数法绘制细胞生长曲线,流式细胞仪检测细胞周期。结果成功构建pGCL/KDR-siRNA重组质粒。A549干扰组KDR mRNA表达率下降,KDR蛋白表达量明显减少,细胞周期改变。结论构建的pGCL/KDR-siRNA表达载体可在mRNA和蛋白水平上有效抑制A549细胞株KDR基因的表达。     

Gene silencing of Tead3 abrogates radiation-induced adaptive response in cultured mouse limb bud cells

There is a crucial need to better understand the effects of low-doses of ionizing radiation in fetal models. Radiation-induced adaptive response (AR) was described in mouse embryos pre-exposed in utero to low-doses of X-rays, which exhibited lower apoptotic levels in the limb bud. We previously described AR-specific gene modulations in the mouse embryo. In this study, we evaluated the role of three candidate genes in the apoptotic AR in a micromass culture of limb bud cells: Csf1, Cacna1a and Tead3. Gene silencing of these three genes abrogated AR. Knowing that TEAD3 protein levels are significantly higher in adapted cells and that YAP/TAZ/TEAD are involved in the control of cell proliferation and apoptosis, we suggest that modulation of Tead3 could play a role in the induction of AR in our model, seen as a reduction of radiation-induced apoptosis and a stimulation of proliferation and differentiation in limb bud cells.     

Seasonal influenza vaccine delivered by intradermal microinjection: A randomised controlled safety and immunogenicity trial in adults

Influenza vaccines remain largely underused. A promising alternative to current intramuscular vaccines is a trivalent inactivated influenza vaccine (TIV) delivered using a microinjection system to offer a less invasive and possibly more acceptable vaccination. A phase II, multicentre, randomised open-label study in 978 healthy adults (18-57 years) evaluated the immunogenicity and safety of intradermal TIV. Subjects received a 0.1 ml injection of intradermal TIV, containing 9 microg of haemagglutinin (HA) per strain (n = 588) or a conventional 0.5 ml intramuscular vaccine (15 microg of HA/strain; n = 390). Intradermal TIV induced non-inferior humoral immune responses against all three strains and superior responses against both A strains (H1N1, H3N2) compared with the control. Both vaccines were well tolerated.     

Evidence-based care in nursing: reforms versus research, rhetoric versus reality.

The new evidence-based health care culture, together with nurses' demands for enhanced professional status, has embedded within its strategy the imperative to develop a corpus of nursing-specific research. These apparently compatible aims were intended to meet the need for enhanced professional status while at the same time enabling clinical nursing practice to be justified on scientific grounds. While the dual reform agendas brought with them the resistance that always accompanies radical amendments to the status quo, they also seem to have created an unanticipated reciprocal antagonism which has impeded the development of nursing research. The policy changes that were necessary to meet the prerequisites for professional status have had a detrimental effect on the potential for generating an adequate body of nursing research. This second paper discusses some of the key reforms to nursing that have been implemented over the last decade and their impact on nursing's progress towards creating its own esoteric research knowledge base that could inform clinical care. It is suggested that policy and research may be diametrically opposed, and that nursing, if it is committed to professionalization, may have to reconsider its allegiance to the scientific research culture in favor of achieving some of the other objectives on its agenda.     

Analysis of the Microbiome Based on 16S rRNA Gene Signature in Women with Preterm versus Term Birth

Objective::To characterize and compare the microbiome signature in the maternal, intrauterine, and fetal environments and the associated bacterial species in wo...     

Homologous recombination in bovine pestiviruses: Phylogenetic and statistic evidence

Bovine pestiviruses (Bovine Viral Diarrea Virus 1 (BVDV 1) and Bovine Viral Diarrea Virus 2 (BVDV 2)) belong to the genus Pestivirus (Flaviviridae), which is composed of positive stranded RNA viruses causing significant economic losses world-wide. We used phylogenetic and bootstrap analyses to systematically scan alignments of previously sequenced genomes in order to explore further the evolutionary mechanisms responsible for variation in the virus. Previously published data suggested that homologous crossover might be one of the mechanisms responsible for the genomic rearrangements observed in cytopathic (cp) strains of bovine pestiviruses. Nevertheless, homologous recombination involves not just homologous crossovers, but also replacement of a homologous region of the acceptor RNA. Furthermore, cytopathic strains represent dead paths in evolution, since they are isolated exclusively from the fatal cases of mucosal disease. Herein, we report evidence of homologous inter-genotype recombination in the genome of a non-cytopathic (ncp) strain of Bovine Viral Diarrea Virus 1, the type species of the genus Pestivirus. We also show that intra-genotype homologous recombination might be a common phenomenon in both species of Pestivirus. This evidence demonstrates that homologous recombination contribute to the diversification of bovine pestiviruses in nature. Implications for virus evolution, taxonomy and phylogenetics are discussed.     

Renal tubular handling of 203Hg2+ in the dog: A microinjection study

²⁰³HgCl₂ in trace amounts was injected together with [methoxy-³H]inulin into the proximal convoluted tubules of the dog kidney superficial nephrons. Of the injected inulin, 97.3 ± 5.7% was recovered in the urine from the injected kidney. From the injected ²⁰³Hg only 8.2 ± 1.0% was recovered in the urine from the injected kidney and 0.4 ± 0.7% from the contralateral kidney. These results were not significantly influenced by intrarterial infusion of KCN, ouabain, or 2,4-dinitrophenol, indicating that there occurred no active tubular reabsorption of mercury. Of the injected ²⁰³Hg, 88.2–93.5% was recovered in the kidney whose tubules were punctured. When ²⁰³Hg was injected into peritubular capillary, only 1.2 ± 0.7% was recovered in the urine from the injected and 0.91 ± 0.2% from the contralateral kidney, this difference being not significant. Results are interpreted as lacking evidence for active transport mechanism of Hg²⁺ in the dog kidney under conditions of microinjection experiment.     

Morbidity in primary health care: patients versus visits

The introduction of the Family and Community Medicine specialist in Spain implied the beginning of an epidemiological approach in the activities of primary care, and the publication of the first studies on cared morbidity. Variations in tolerance threshold to illness by patients, differences in perception of health problems by physicians, the lack of a consensus on the definition of events that should be registered, together with the lack of a census of the eligible population are important problems for the development of such studies. The majority of studies published in our country have not overcome all these problems in an acceptable way.     

Re-thinking accountability: trust versus confidence in medical practice

In seeking to prevent a reoccurrence of scandals such as that involving cardiac surgery in Bristol, the UK government has adopted a model of regulation that uses rules and surveillance as a way of both improving the quality of care delivered and increasing confidence in healthcare institutions. However, this approach may actually act to reduce confidence and trust while also reducing the moral motivation of practitioners. Accountability in health care is discussed, and it is suggested that openness about the difficult dilemmas that arise when practitioners have a duty to be accountable to more than one audience may be an alternative means of restoring trust. A greater emphasis on the sharing of information between individual health professionals and their patients would increase trust and would allow patients to hold their doctors to account for the quality of care they receive. Concentrating more on developing trust by the sharing of information and less on the futile search for complete confidence in systems and rules may improve the quality of care delivered while also nurturing the moral motivation of professionals upon which the delivery of high quality health care depends.     

Oat fiber: composition versus physiological function in rats

The effect of processing on the ability of oat fiber to lower plasma and liver cholesterol concentrations in rats was studied. Male Sprague-Dawley rats were fed diets containing 6% dietary fiber as cellulose, oat bran, high fiber oat flour or one of four processed high fiber oat flours for 3 wk. All diets also contained 1.0% cholesterol and 0.2% cholic acid. At the conclusion plasma and liver concentrations of cholesterol and triglycerides were measured. All of the oat products significantly lowered plasma and liver cholesterol without depressing food intake or weight gain. As little as 4% dietary fiber in a processed oat flour significantly lowered cholesterol concentrations. Detailed fiber analysis of all of the oat fiber products revealed that processing increased the proportion of the total fiber that was soluble. The proportions recovered as total beta-glucans and total neutral sugars also increased, in part because the proportion recovered as Klason lignin decreased in all of the processed oat flours except the one prepared by a high pressure extrusion process.     

Voice recognition in clinical medicine: process versus technology

Large-vocabulary, continuous voice recognition technology, as well as the voice recognition industry, have matured to the point that the available tools are affordable and powerful enough to provide clinicians with an alternative to keyboard data entry. However, use of voice recognition technology in clinical medicine faces several practical process-oriented hurdles that may restrict the use of this technology to certain types of activities. For example, the use of voice recognition technology for dictation raises practical issues of privacy, security, and confidentiality. However, the same economic pressures that forced many clinicians to learn the keyboard instead of relying on a secretary may push clinicians from the keyboard to the microphone.     

Food preferences in human obesity: Carbohydrates versus fats

A large clinical sample of obese men and women were asked for a self-generated list of ten favorite foods. The lists were characterized by frequent instances of foods that are major nutrient sources of fat in the American diet. While obese men listed mainly protein/fat sources (meat dishes) among their favorite foods, obese women tended to list predominantly carbohydrate/fat sources (doughnuts, cookies, cake) and foods that were sweet. There was no evidence that selective preferences for a single macronutrient, carbohydrate, were a standard feature of human obesity. Rather, preferences for major nutrient sources of fat as opposed to carbohydrate may be a primary characteristic of human obesity syndromes.     

Reproductive inequality in sub-Saharan Africa: differentials versus concentration

Within developing countries, our understanding of reproductive inequality-how fertility is distributed within a population-has been shaped largely by studies of fertility differentials, a practical but partial-information measure. In this study, we examine whether exclusive reliance on differentials biases this understanding. Findings based on recent data from sub-Saharan Africa show bias. We find that historical and especially cross-country comparisons can yield substantially different conclusions about the magnitude and even the direction of inequality patterns and trends, depending on whether differentials or fuller-information measures are used. For instance, the fertility differentials associated with education have remained relatively stable as national fertility has fallen, but inequality (as calculated by a fuller measure) has increased. Such results underscore the value of complementing existing studies of fertility differentials with analyses based on fuller-information measures. The analyses also show how change in differential fertility behavior and in the educational composition of national populations has shaped recent variations in reproductive inequality in the region.     

Toxicity of 4-chloroaniline in early life-stages of zebrafish (Brachydanio rerio): I. Cytopathology of liver and kidney after microinjection

In addition to survival and hatching parameters, cytological alterations in liver and kidney of 4- and 6-d old zebrafish larvae (Brachydanio rerio) following single microinjection of fertilized eggs at the germ-ring stage with 5, 12.5, and 25 ng 4-chloroaniline/egg were investigated by means of electron microscopy. Whereas survival remained unaffected, microinjection with 4-chloroaniline disturbed hatching of larvae. Hatching was delayed by microinjection of 12.5 ng 4-chloroaniline/egg and above when compared to controls. Cytological investigations revealed ultrastructural changes in both liver and kidney in a dose- and time-dependent fashion. In the liver, major cytopathological changes included fenestration, fragmentation, and vesiculation of the rough endoplasmic reticulum, proliferation of atypical mitochondria, and atypical lysosomes. Furthermore, myelin whorls, lipid inclusions, and cholesterol crystals were increased, whereas glycogen stores were reduced. Renal tubular cells displayed altered brush borders, proliferation of nucleoli, atypical mitochondria, fenestrated, fragmented, and vesiculated RER cisternae, as well as giant lysosomes. Most of these effects indicate cellular dysfunction (e.g., disturbance of lipid metabolism in the liver), whereas others illustrate general cellular stress-responses to chemical aggression. Comparisons of results with those of previous studies based on conventional fish exposure prove the suitability and sensitivity of microinjection bioassays with zebrafish eggs as an alternative to conventional early life-stage tests.     

Empowerment versus power: consumer participation in mental health services

Consumer participation is regarded as increasingly important in the effective delivery of mental health services and for the empowerment of mental health consumers. In a qualitative study, 17 consumers and 10 occupational therapists discussed their perceptions of consumer participation in mental health services. These included the advantages and benefits of consumer participation, the barriers to participation and how health workers can facilitate participation. The research brought to light an uncertain relationship between empowerment and power. While empowerment was universally considered to be desirable, opinions about the transfer of power were more ambivalent. It is argued that consumers and health workers need to work together to find creative ways of addressing concerns relating to power so that real power can be shared to benefit all consumers. Limitations of the study included the small sample size and the sampling method, which restricted access to potential participants. Further research is suggested into consumer participation and consumer power. Copyright © 1999 Whurr Publishers Ltd.     

Custom-made versus ready-to-wear treatments: behavioral propensities in physicians' choices

To customize treatments to individual patients entails costs of coordination and cognition. Thus, providers sometimes choose treatments based on norms for broad classes of patients. We develop behavioral hypotheses explaining when and why doctors customize to the particular patient, and when instead they employ "ready-to-wear" treatments. Our empirical studies examining length of office visits and physician prescribing behavior find evidence of norm-following behavior. Some such behavior, from our studies and from the literature, proves sensible; but other behavior seems far from optimal.