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1.
BackgroundThe ectoparasitic mite, Varroa destructor, is considered to be one of the most significant threats to apiculture around the world. Chemical cues are known to play a significant role in the host-finding behavior of Varroa. The mites distinguish between bees from different task groups, and prefer nurses over foragers. We examined the possibility of disrupting the Varroa – honey bee interaction by targeting the mite''s olfactory system. In particular, we examined the effect of volatile compounds, ethers of cis 5-(2′-hydroxyethyl) cyclopent-2-en-1-ol or of dihydroquinone, resorcinol or catechol. We tested the effect of these compounds on the Varroa chemosensory organ by electrophysiology and on behavior in a choice bioassay. The electrophysiological studies were conducted on the isolated foreleg. In the behavioral bioassay, the mite''s preference between a nurse and a forager bee was evaluated.ConclusionsThese data indicate the potential of the selected compounds to disrupt the Varroa - honey bee associations, thus opening new avenues for Varroa control.  相似文献   

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Formalin has long been the standard fixative for clinical routines worldwide. After the Formaldehyde Standard became law in the US in 1987, as a result of increasing concerns about the potential carcinogenicity of formaldehyde, attempts have been made to find safer alternatives. Alcoholic formalin is a useful fixative, because in addition to fixation, dehydration also is begun. For centuries, honey has been known to be an antibacterial agent with the potential to preserve compounds without harmful effects on its users. We compared the effects of honey fixation with other routine fixatives using conventional histochemical and immunohistochemical staining methods. Our results demonstrated that tissues fixed in either honey or alcoholic formalin and 10% neutral buffered formalin (NBF) have similar histomorphology. Honey fixation showed minor histomorphological differences among the various tissues; however, it did not influence affect correct diagnostic conclusions. Our results suggested that honey can be used as a safe alternative to formalin in histopathology.  相似文献   

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Summary and conclusions In an important percentage of stools of healthy persons Shiga bacteriophage occurs.The Shiga bacteriophage occurs during some lapse of time in water which has been polluted by human faeces. The Shiga bacteriophage could be ascertained in water by means of the enrichment method ofNyberg.The Shiga bacteriophage method for indicating the pollution of strongly polluted water is as sensitive or sometimes less so than the methods ofEijkman and ofClemesha.For the examination of water in several stages of purification in water works the Shiga bacteriophage method is as sensitive or even more so than the other methods.The Shiga bacteriophage does not act strongly in the self-purification of polluted water.The Shiga bacteriophage may be used as indicator for a faecal pollution of water and this method may be applied along with the other bacteriological methods in water control. It may be advantageous to study more closely its limits and its benefits in the practice of water control  相似文献   

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The constant pressure posed by parasites has caused species throughout the animal kingdom to evolve suites of mechanisms to resist infection. Individual barriers and physiological defenses are considered the main barriers against parasites in invertebrate species. However, behavioral traits and other non-immunological defenses can also effectively reduce parasite transmission and infection intensity. In social insects, behaviors that reduce colony-level parasite loads are termed "social immunity." One example of a behavioral defense is resin collection. Honey bees forage for plant-produced resins and incorporate them into their nest architecture. This use of resins can reduce chronic elevation of an individual bee's immune response. Since high activation of individual immunity can impose colony-level fitness costs, collection of resins may benefit both the individual and colony fitness. However the use of resins as a more direct defense against pathogens is unclear. Here we present evidence that honey bee colonies may self-medicate with plant resins in response to a fungal infection. Self-medication is generally defined as an individual responding to infection by ingesting or harvesting non-nutritive compounds or plant materials. Our results show that colonies increase resin foraging rates after a challenge with a fungal parasite (Ascophaera apis: chalkbrood or CB). Additionally, colonies experimentally enriched with resin had decreased infection intensities of this fungal parasite. If considered self-medication, this is a particularly unique example because it operates at the colony level. Most instances of self-medication involve pharmacophagy, whereby individuals change their diet in response to direct infection with a parasite. In this case with honey bees, resins are not ingested but used within the hive by adult bees exposed to fungal spores. Thus the colony, as the unit of selection, may be responding to infection through self-medication by increasing the number of individuals that forage for resin.  相似文献   

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What Can Medicine Learn from the Human DNA Sequence?   总被引:1,自引:0,他引:1  
The cooperation of biochemistry with clinical medicine consists of two overlapping temporal phases. Phase 1 of the cooperation, which still is not finished, is characterized by joint work on the pathogenesis and diagnostics of systemic metabolic diseases, whereas in phase 2 the cooperation on tissue and cell specific as well as on molecular diseases is prevailing. In view of the conceptual revolution and shift in paradigm, which biochemistry and medicine are presently experiencing, the content of cooperation between the two disciplines will profoundly change. It will become deeply influenced by the results of the research into the human genome and human proteome. Biochemistry will strongly be occupied to relate the thousands of protein coding genes to the structure and function of the encoded proteins, and medicine will be concerned in finding new protein markers for diagnostics, to identify novel drug targets, and to investigate, for example, the proteomes of the variety of tumors to aid tumor classification, to mention only a few areas of interest which medicine will have in the progress of human genome research. The review summarizes the recent achievements in sequencing the human DNA as published in February 2001 by the International Human Genome Sequencing Consortium and Celera Genomics and discusses their significance in respect to the further development of molecular, in particular genetic, medicine as an interdisciplinary field of the modern clinical sciences. Only biochemistry can provide the conceptual and experimental basis for the causal understanding of biological mechanisms as encoded in the genome of an organism.  相似文献   

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The zebrafish has proven to be an excellent model for analyzing issues of vertebrate development. In this review we ask whether the zebrafish is a viable model for analyzing the neurodevelopmental causes of autism. In developing an answer to this question three topics are considered. First, the general attributes of zebrafish as a model are discussed, including low cost maintenance, rapid life cycle and the multitude of techniques available. These techniques include large-scale genetic screens, targeted loss and gain of function methods, and embryological assays. Second, we consider the conservation of zebrafish and mammalian brain development, structure and function. Third, we discuss the impressive use of zebrafish as a model for human disease, and suggest several strategies by which zebrafish could be used to dissect the genetic basis for autism. We conclude that the zebrafish system could be used to make important contributions to understanding autistic disorders.  相似文献   

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Efforts to increase affinity in the design of new therapeutic molecules have tended to lead to greater lipophilicity, a factor that is generally agreed to be contributing to the low success rate of new drug candidates. Our aim is to provide a structural perspective to the study of lipophilic efficiency and to compare molecular interactions created over evolutionary time with those designed by humans. We show that natural complexes typically engage in more polar contacts than synthetic molecules bound to proteins. The synthetic molecules also have a higher proportion of unmatched heteroatoms at the interface than the natural sets. These observations suggest that there are lessons to be learnt from Nature, which could help us to improve the characteristics of man-made molecules. In particular, it is possible to increase the density of polar contacts without increasing lipophilicity and this is best achieved early in discovery while molecules remain relatively small.  相似文献   

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SYNOPSIS. The Ediacaran fossils of the latest Precambrian haveat one time or another been grouped with almost every extantkingdom, and also lumped into separate kingdom-level taxa. Thishas often been based on the facile use of a few characters,or on some sort of "overall similarity." This has not been avery fruitful approach; if anything, it has held back understandingof the Ediacaran organisms and of their significance for laterhistory. While many of the simpler forms remain problematic,careful study of the more complex forms gives good reasons toplace at least some of them with the Animalia. A complementaryapproach is to use sources of information such as the distributionof fossils across space, time, and paleoenvironments. The resultsmay feed back into systematic work, allowing us to constructand test more robust hypotheses of these organisms' evolutionaryrelationships.  相似文献   

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Background

Due to an ageing population and demographic changes worldwide, a higher prevalence of heart disease is forecasted, which causes an even higher demand for cardiac implants in future. The increasing high incidence of clinical adverse events attributed especially to high-risk medical devices has led an advocated change from many stakeholders. This holds especially true for devices like cardiac implants, with their high-risk nature and high complication rates associated with considerable mortality, due to their frequent use in older populations with frequent co-morbidities. To ensure patients’ safety, the objective of this study is to analyze different cardiac implants recall reasons and different recall systems, based on an overview of the recalls of cardiac implant medical devices in the last decade. On the basis of the results from this structured analysis, this study provides recommendations on how to avoid such recalls from a manufacturer perspective, as well as how to timely react to an adverse event from a post-surveillance system perspective.

Methods and Findings

A systematic search of cardiac implant recalls information has been performed in the PubMed, ScienceDirect and Scopus databases, as well as data sources in regulatory authorities from 193 UN Member States. Data has been extracted for the years 2004-2014 with the following criteria applied: cardiac implant medical device recalls and reasons for recall, associated harm or risk to patients. From the data sources described above, eleven regulatory authorities and 103 recall reports have been included in this study. The largest cardiac implant categories include ICDs 40.8%, pacemakers 14.5% and stents 14.5%. Regarding the recall reasons, the majority of reports were related to device battery problems (33.0%) and incorrect therapy delivery (31.1%). From a total of 103 recall reports, five reported death and serious injuries. Our review highlights weaknesses in the current cardiac implant recall system, including data reporting and management issues and provides recommendations for the improvement of safety information and management.

Conclusion

Due to the mortality associated with the nature of cardiac implants, the traceability and transparency of safety hazards information is crucial. By a structured analysis of recall reasons and their efficient management, important knowledge is gained to inform an effective safety-reporting system for monitoring the safety of cardiac implanted patients, ideally by building up cardiac implant registries worldwide in the future.  相似文献   

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Low serum testosterone has been associated with obesity, type 2 diabetes, metabolic syndrome, and atherosclerosis. Individuals with these comorbidities are at increased risk of premature death and other adverse health effects. Clinical data portend low testosterone as a risk factor for developing these conditions which are supported by the hypogonadal-obesity-adipocytokine hypothesis. The authors support comprehensive evaluation for these comorbid conditions in men found to have low serum testosterone.Key words: Androgen deficiency, Aging male, Comorbidities, Diabetes, Cardiovascular diseaseTestosterone is a male sex hormone that affects sexual development and function and enhances muscle strength and bone density.1 Low testosterone levels have been associated with a variety of comorbid conditions, such as metabolic syndrome (MetS), obesity, type 2 diabetes (T2D), and cardiovascular disease (CVD).13 Each of these comorbid conditions is a strong risk factor that contributes to an increased risk of major adverse cardiovascular events.1 In addition, low serum testosterone is inversely associated with increased mortality.4,5This review explores the association between low serum testosterone and diseases that portend poor health, such as MetS, obesity, T2D, and CVD, and reviews current clinical studies and proposed mechanisms by which low testosterone is associated with these diseases.  相似文献   

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Magnetic resonance imaging (MRI) is an imaging technique with a rapidly expanding application range. This methodology, which relies on quantum physics and substance magnetic properties, is now being routinely used in the clinics and medical research. With the advent of measuring functional brain activity with MRI (functional MRI), this methodology has reached a larger section of the neuroscience community (e.g. psychologists, neurobiologists). In the past, the use of MRI as a biomarker or as an assay to probe tissue pathophysiological condition was limited. However, with the new applications of MRI: molecular imaging, contrast-enhanced imaging and diffusion imaging, MRI is turning into a powerful tool for in vivo characterization of tissue pathophysiology. This review focuses on the diffusion MRI. Although it only measures the averaged Brownian translational motion of water molecules, using different analysis schemes, one can extract a wide range of quantitative indices that represent tissue morphology and compartmentalization. Statistical and visualization routines help to relate these indices to biologically relevant measures such as cell density, water content and size distribution. The aim of this review is to shed light on the potential of this methodology to be used in biological research. To that end, this review is intended for the non-MRI specialists who wish to pursue biological research with this methodology. We will overview the current applications of diffusion MRI and its relation to cellular biology of brain tissue.  相似文献   

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This paper reports on the first test of the value of an online curriculum in social intelligence (SI). Built from current social and cognitive neuroscience research findings, the 50 session SI program was administered, with facilitation in Spanish by classroom instructors, to 207 students from Universidad Rey Juan Carlos in Madrid as part of their undergraduate classes. All materials were translated into Castilian Spanish, including outcome measures of SI that have been used in prior studies to provide valid estimates of two key components of social intelligence: 1) Sensitivity to others and 2) confidence in one’s capacity to manage social situations. Pre- and Posttest were administered to participants in the SI training, and also to 87 students in similar classes who did not receive the program who served as the control group. Gender and emotional intelligence levels at pretest also were examined as potential individual differences that might affect the impact of the program on study outcomes. Repeated measures ANOVAs on study outcomes revealed significant increases, from pre to post, in most measures of social intelligence for program participants in comparison to controls, with no effects of gender or age on program effectiveness. Prior scores on emotional intelligence were not a prerequisite for learning from the program. Some findings suggest ways the program may be improved to have stronger effects. Nonetheless, the findings indicate that the SI program tested here shows considerable promise as a means to increase the willingness of young adults to take the perspective of others and enhance their efficacy for initiating and sustaining positive social connections.  相似文献   

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Reebs SG 《Animal behaviour》2000,59(2):403-409
There is no information on whether the daily foraging movements of fish shoals are the result of chance, the collective will of all shoalmates, or the leadership of a few individuals. This study tested the latter possibility. Shoals of 12 golden shiners, Notemigonus crysoleucas, were trained to expect food around midday in one of the brightly lit corners of their tank. They displayed daily food-anticipatory activity by leaving the shady area of their tank and spending more and more time in the food corner up to the normal time of feeding. Past this normal time they remained in the shade, even on test days when no food was delivered. Most of these experienced individuals were then replaced by na?ve ones. The resulting ratio of experienced:na?ve fish could be 5:7, 3:9 or 1:11. On their own, na?ve individuals would normally spend the whole day in the shade, but in all tests the experienced individual(s) were able to entrain these more numerous na?ve fish out of the shade and into the brightly lit food corner at the right time of day. Entrainment was stronger in the 5:7 than in the 1:11 experiment. The test shoals never split up and were always led by the same fish, presumably the experienced individuals. These results indicate that in a strongly gregarious species, such as the golden shiner, a minority of informed individuals can lead a shoal to food, either through social facilitation of foraging movements or by eliciting following behaviour. Copyright 2000 The Association for the Study of Animal Behaviour.  相似文献   

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Aldosterone-producing adenoma (aldosteronoma)--the most frequent form of primary hyperaldosteronism (PH)--is considered a specific form of diabetes mellitus (DM). In a previous study we demonstrated insulin resistance in patients with PH. We have therefore undertaken a study to evaluate the incidence of abnormalities of glucose metabolism in patients with PH (36 subjects) compared to control subjects with essential hypertension (EH) (21 patients). The following parameters were measured in all studied subjects: office blood pressure (by mercury sphygmomanometer in the sitting position), body mass index (BMI), plasma potassium, plasma glucose and insulin levels during oral glucose tolerance test (OGTT) (0, 60, 120 min), plasma renin activity and plasma aldosterone. Although patients with PH tended to have higher stimulated plasma glucose levels after 60 and 120 min compared to EH, these differences did not attain statistical significance. Patients with EH tended to have higher insulin levels at each measured interval, but due to a high variability these differences were again not significant. There were no significant differences between PH and EH in the proportion of diabetics (20% vs. 14%) or patients with impaired glucose tolerance (18% vs. 10%). In conclusion, we have found the absence of significant differences in the frequency of diabetes mellitus, impaired glucose tolerance and insulin resistance in patients with EH and PH. Our data thus do not support the idea of primary hyperaldosteronism as a specific type of diabetes mellitus. Furthermore, our results indicate that glucose metabolic characteristics in essential hypertension and primary hyperaldosteronism tend to be similar. The definitive conclusion with respect to the possible causal relationship between DM and PH, however, can be obtained only on larger groups of subjects, in particular after the evaluation of the effect of surgical/pharmacological treatment of primary hyperaldosteronism.  相似文献   

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