Application of vaccines and dietary supplements in aquaculture: possibilities and challenges

The development of vaccines has proven essential for the development of a successful finfish aquaculture industry by preventing the occurrence of diseases like furunculosis and vibriosis in industrialised finfish farming. Further developments, like DNA vaccines, will aid in controlling even more diseases in the future. There are however many diseases where it is difficult to produce effective vaccines. Furthermore, many disease outbreaks may occur due to impaired animal welfare. Identifying factors associated with disease and optimizing health and welfare through biotechnological developments is likely to be an important research area in the future. The fact that dietary manipulation can affect fish gut microbiota thus improving disease resistance is well known from mammalian science, and is slowly gaining ground in finfish research. Both prebiotic and probiotic approaches have been used in fish, with particular focus on lactic acid bacteria. Positive effects include enhanced growth and feed efficiency, improved immunity and disease resistance. The synbiotic concept (using a combination of probiotics and prebiotics) is particularly promising and is gaining increased interest within the research community. Immunostimulants may also improve disease resistence via increase humoral and cellular immune responses. The most promising immunostimulants at present are β-glucans, alginate and Ergosan. Additionally, medical plant extracts and their products are receiving increased attention as immune modulators, but further studies are needed. There are also great expectations or the future usage of microalgae to control microbiota and optimize fish health.     

Leishmania vaccines: old and new

The approach to the development of a Leishmania vaccine has undergone a revolution since its early beginnings with the ancient practice of leishmazation: the inoculation of infectious parasites from an active lesion in order to produce a self-healing lesion in a healthy individual. Controlled infection has been followed by injection of killed parasites and has now progressed to subunit and naked DNA vaccines. Emanuela Handman here discusses the current studies and the future prospects for a Leishmania vaccine with a focus on cutaneous leishmaniasis. Unfortunately, what J.F. Williams said about antiparasite vaccines in 1987 (Ref. 1) is still true in 1997: 'the reasons for optimism are less evident than the reasons for enthusiasm'.     

Review the formation of adventitious roots: New concepts, new possibilities

Summary Considerable progress has recently been made in understanding adventitious root formation using physiological studies. It is recognized that rooting is a process consisting of distinct phases, each with its own requirements. In this review, the successive phases in the rooting process are described and the possible roles of wounding-related compounds, auxin, ethylene and phenolic compounds during these specific phases are discussed. Recent results are assisting the development of advanced rooting treatments. Molecular studies on rooting are underway and will be essential in revealing the mechanisms underlying adventitious root formation.     

Developmental biology: an array of new possibilities

Microarrays offer biologists comprehensive and powerful tools to analyze the involvement of genes in developmental processes at an unprecedented scale. Microarrays that employ defined sequences will permit us to elucidate genetic relationships and responses, while those that employ undefined DNA sequences (ESTs, cDNA, or genomic libraries) will help us to discover new genes, relate them to documented gene networks, and examine the way in which genes (and the process that they themselves control) are regulated. With access to broad new avenues of research come strategic and logistical headaches, most of which are embodied in the reams of data that are created over the course of an experiment. The solutions to these problems have provided interesting computational tools, which will allow us to compile huge data sets and to construct a genome-wide view of development. We are on the threshold of a new vista of possibilities where we might consider in comprehensive and yet specific detail, for example, the degree to which diverse organisms utilize similar genetic networks to achieve similar ends.     

Heterochromatin: new possibilities for the inheritance of structure

Significant portions of the eukaryotic genome are heterochromatic, made up largely of repetitious sequences and possessing a distinctive chromatin structure associated with gene silencing. New insights into the form of packaging, the associated histone modifications, and the associated nonhistone chromosomal proteins of heterochromatin have suggested a mechanism for providing an epigenetic mark that allows this distinctive chromatin structure to be maintained following replication and to spread within a given domain.     

Biomarkers in nutritional epidemiology: applications, needs and new horizons

Modern epidemiology suggests a potential interactive association between diet, lifestyle, genetics and the risk of many chronic diseases. As such, many epidemiologic studies attempt to consider assessment of dietary intake alongside genetic measures and other variables of interest. However, given the multi-factorial complexities of dietary exposures, all dietary intake assessment methods are associated with measurement errors which affect dietary estimates and may obscure disease risk associations. For this reason, dietary biomarkers measured in biological specimens are being increasingly used as additional or substitute estimates of dietary intake and nutrient status. Genetic variation may influence dietary intake and nutrient metabolism and may affect the utility of a dietary biomarker to properly reflect dietary exposures. Although there are many functional dietary biomarkers that, if utilized appropriately, can be very informative, a better understanding of the interactions between diet and genes as potentially determining factors in the validity, application and interpretation of dietary biomarkers is necessary. It is the aim of this review to highlight how some important biomarkers are being applied in nutrition epidemiology and to address some associated questions and limitations. This review also emphasizes the need to identify new dietary biomarkers and highlights the emerging field of nutritional metabonomics as an analytical method to assess metabolic profiles as measures of dietary exposures and indicators of dietary patterns, dietary changes or effectiveness of dietary interventions. The review will also touch upon new statistical methodologies for the combination of dietary questionnaire and biomarker data for disease risk assessment. It is clear that dietary biomarkers require much further research in order to be better applied and interpreted. Future priorities should be to integrate high quality dietary intake information, measurements of dietary biomarkers, metabolic profiles of specific dietary patterns, genetics and novel statistical methodology in order to provide important new insights into gene-diet-lifestyle-disease risk associations.     

Prospects for new viral vaccines

Animal virology has made outstanding contributions to preventive medicine by the development of vaccines for the control of infectious disease in man and animals. Cost-benefit analysis indicates substantial savings in health care costs from the control of diseases such as smallpox, poliomyelitis, yellow fever and measels. Areas for further development include vaccines for influenza (living, attenuated virus), the herpes group (varicella: cytomegalovirus), respiratory syncytial virus, rotavirus and hepatitis A, B, and non A/non B. The general options for vaccine formulation are discussed with particular emphasis on approaches with the use of viral genetics to 'tailor make' vaccine viruses with defined growth potential in laboratory systems, low pathogenicity, and defined antigens. Current progress with the development of an inactivated hepatitis B vaccine is reviewed as a case study in vaccine development. The impact of recent experiments in cloning hepatitis B virus DNA in E. coli on the production of a purified viral polypeptide vaccine is assessed.     

Preventing papillomavirus infectious and herpes zoster: new vaccines

Two new vaccines have been recently licensed : a quadrivalent vaccine against Human papillomavirus infections (HPV) 6, 11, 16 and 18, recommended to children from 9 years old and to young adults under the age of 26 years, and a vaccine against herpes zoster for adults from 60 years old onwards. A bivalent vaccine against HPV 16 and 18 will be shortly available. HPV vaccines are composed of the L1 structural proteins of 2 or 4 HPV genotypes, produced by genetic engineering and self-assembled. These inert vaccines are devoid of genetic materials and mimic the viral particle (virus-like particle, VLP). They allow, as suggested by the 4.5 to 5 years follow-up, to prevent HPV infections and the onset of pre-cancerous lesions associated with genotypes contained within the vaccine. They represent a major overhang in the vaccinology field, and, as anti-hepatitis B vaccine, will probably be effective in cancer prevention. Their use must be associated with the continued detection of cervix cancer by smears and also with the prevention of other sexually transmitted diseases. The herpes zoster vaccine is a living attenuated vaccine produced from the OKA/Merck strain already used in the vaccine against varicella. Its safety is good among persons 50 years old and over and its efficiency on lowering herpes zoster incidence, on the burden of illness and on post-herpetic neuralgia has been demonstrated in persons over 60 years old.     

Trends in US approvals: new biopharmaceuticals and vaccines

The efficient development and approval of new therapeutics and vaccines is vital to the health and welfare of patients. Tufts Center for the Study of Drug Development has collected and analyzed data for new protein therapeutics and vaccines approved in the USA during the past decade. Our results suggest trends toward longer clinical and approval phases for the therapeutics, particularly for oncology products. In this Opinion article, we discuss various legislative acts and FDA initiatives that might improve the efficiency of drug development and approval. Furthermore, few new vaccines have been approved in the past 10 years owing, at least in part, to the lack of incentives for the development of the products. We predict that this might change in the future as government and industry respond to the twin threats of the global spread of infectious diseases and potential bioterrorism.     

一种口腔康复治疗器设计

目的:设计一种既可用于口腔肌肉康复训练又可用于辅助治疗的口腔康复治疗器.方法:采用AUTOCAD设计出牙套,弹簧,支杆等部件,采用硅胶制作牙套,采用碳素弹簧钢丝制作菱形弹簧,采用不锈钢制作成支杆,最后组装成一个完整的口腔康复治疗器进行应用测试.结果:应用方便、感觉舒适,有效缓解了张口难度和提高张口的开启度、增加咬合力度和有效提高治疗体位稳定性.结论:该设计成果使用舒适,有效实现面肌康复和提高咬合力,减小和避免面肌纤维化和提高了治疗位置体位稳定性.