RNA interference in plant parasitic nematodes: a summary of the current status

SUMMARYRNA interference (RNAi) has emerged as an invaluable gene-silencing tool for functional analysis in a wide variety of organisms, particularly the free-living model nematode Caenorhabditis elegans. An increasing number of studies have now described its application to plant parasitic nematodes. Genes expressed in a range of cell types are silenced when nematodes take up double stranded RNA (dsRNA) or short interfering RNAs (siRNAs) that elicit a systemic RNAi response. Despite many successful reports, there is still poor understanding of the range of factors that influence optimal gene silencing. Recent in vitro studies have highlighted significant variations in the RNAi phenotype that can occur with different dsRNA concentrations, construct size and duration of soaking. Discrepancies in methodology thwart efforts to reliably compare the efficacy of RNAi between different nematodes or target tissues. Nevertheless, RNAi has become an established experimental tool for plant parasitic nematodes and also offers the prospect of being developed into a novel control strategy when delivered from transgenic plants.     

Hyperhidrosis: a review of current management

Primary hyperhidrosis is a troublesome disorder of excessive perspiration that affects as much as 1 percent of the population. Sufferers are usually young and are often affected by related social, professional, and psychological problems. Many methods for treating hyperhidrosis exist; however, no single treatment is without its weakness or complications. This article aims to clarify the issues related to the use of each treatment modality, including the most recently proposed method using botulinum toxin.     

Recent developments in genomewide association scans: a workshop summary and review

With the imminent availability of ultra-high-volume genotyping platforms (on the order of 100,000-1,000,000 genotypes per sample) at a manageable cost, there is growing interest in the possibility of conducting genomewide association studies for a variety of diseases but, so far, little consensus on methods to design and analyze them. In April 2005, an international group of >100 investigators convened at the University of Southern California over the course of 2 days to compare notes on planned or ongoing studies and to debate alternative technologies, study designs, and statistical methods. This report summarizes these discussions in the context of the relevant literature. A broad consensus emerged that the time was now ripe for launching such studies, and several common themes were identified--most notably the considerable efficiency gains of multistage sampling design, specifically those made by testing only a portion of the subjects with a high-density genomewide technology, followed by testing additional subjects and/or additional SNPs at regions identified by this initial scan.     

Biological effects of oxidized phytosterols: a review of the current knowledge

The cholesterol-lowering effect of phytosterols has been extensively studied, and consumption of phytosterols is among the recommendations to lower LDL-cholesterol concentrations. Due to their structural similarity with cholesterol, phytosterols may undergo oxidative processes comparable to those involved in cholesterol oxidation. Consumption of phytosterols could therefore lead to increased systemic concentrations of oxidized phytosterols (oxyphytosterols) via increased dietary intake or in vivo formation from non-oxidized phytosterols. While the biological effects of oxidized cholesterol (oxycholesterol) have been well studied, the amount of biological research on oxyphytosterols is scarce. Most reports on oxyphytosterols cover their quantitative analysis. Whether oxyphytosterols may play similar biological roles as compared to oxycholesterol has not been fully elucidated. The usual perception about oxyphytosterols is that these components present a concern in terms of food quality and health. This perception originates from the parallel that is made with oxycholesterol. Yet, in line with results for oxycholesterol, recent data suggest that oxyphytosterols--depending on the type of oxidation product--may also have beneficial biological properties. Therefore, the objective of this review is to summarise the current understanding of the biological effects, next to identifying future research needs that will help to clarify the possible impact of oxyphytosterols on human health.     

Xanthelasma palpebrarum: a review and current management principles

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Describe the differential diagnosis of xanthelasma palpebrarum. 2. Discuss the various nonsurgical and surgical treatment options and their advantages and disadvantages. 3. Describe the circumstances in which recurrence is most likely after treatment. Xanthelasma palpebrarum is the most common cutaneous xanthoma. It typically presents in middle-aged and older adults, most often around the eyelids. The diagnosis can often be made on clinical grounds alone. For the plastic surgeon, it is important to apply an algorithmic approach to the treatment of these lesions. Depending on the size and location, several different methods can be used to address this problem, ranging from simple excision, to laser treatment, to chemical peeling. This article addresses the underlying pathophysiology of xanthelasma and the currently accepted modes of treatment.     

Theorizing transnational immigration: a critical review of current efforts

During the past decade, transnationalism has entered the lexicon of migration scholars. As with other terms used in the study of immigration and ethnicity, this concept suffers from ambiguity as a result of competing definitions that fail to specify the temporal and spatial parameters of the term and to adequately locate it vis-à-vis older concepts such as assimilation and cultural pluralism. This article offers a review and critique of the ways the term has come to be employed at the hands of key spokespersons that have articulated the most sustained theoretical rationales to date for transnationalism as a conceptual construct to account for new immigrant identities and communities. The conclusion of the essay offers in schematic form an alternative assessment of transnationalism that locates it as one potential subset of assimilation theory, rather than as an alternative to it.     

Connecting cytokines and brain: a review of current issues

Cytokines have been a multi-disciplinary research focus for over 2 decades. To date, there have been more than 15,000 articles published concerning the relationship between cytokines and the central nervous system (CNS). Over half of these articles have been published in the last 5 years. From such vast number of studies, two major topics emerge as the critical issues: 1) how do cytokines modulate the functions of the CNS? 2) what is the role of cytokines in the pathogenesis of neurological diseases? Thus far, it has been clearly established that cytokines can alter the functions of the CNS in specific manners, invoking CNS-controlled autonomic, neuroendocrine, and behavioral responses. Induced expression of cytokines has also been found in the CNS during brain injury and infection, contributing to the immunological processes at this "immunologically privileged" site. Furthermore, increasing evidence points to the potential involvement of cytokines in the induction and modulation of an array of neurological diseases ranging from Alzheimer's disease to chronic fatigue syndrome. Despite such progress, however, substantial obstacles remain for both the basic understanding and the potential clinical exploitation of how cytokines interact with CNS. In this review, we will attempt to synopsize the current theories and evidence regarding the answers to the above-mentioned critical questions. These issues will be reviewed not only in isolation, as most of the original reports focused on only one of the questions, but also in parallel such that inter-issue insights may be gained.     

Cryopreservation of hepatocytes: a review of current methods for banking

Cryopreservation, the freezing of hepatocytes in liquid nitrogen for storage, has been investigated for many years, as a method of long-term storage for hepatocytes. Unfortunately an agreed acceptable protocol has been elusive, in part due to the susceptibility of hepatocytes to the freeze thaw process involved. A method for long-term storage (months, possibly years) of human hepatocytes, in particular, is desirable for the development of a clinically applicable bioartificial liver, hepatocyte transplantation and for pharmacotoxicological research. The sources of human liver tissue from which hepatocytes can be derived are limited. Many groups have modified and improved the process of cryopreservation and many new techniques have been published, including the incorporation of such cryopreserved cells in clinically based studies. Further evaluation is still required to develop a universally acceptable protocol. This article reviews the difficulties involved in cryopreserving hepatocytes for banking and examines recent technical advances within this field.     

Fibrinolysis standards: A review of the current status

Biological standards are used to calibrate measurements of components of the fibrinolytic system, either for assigning potency values to therapeutic products, or to determine levels in human plasma as an indicator of thrombotic risk. Traditionally WHO International Standards are calibrated in International Units based on consensus values from collaborative studies. The International Unit is defined by the response activity of a given amount of the standard in a bioassay, independent of the method used. Assay validity is based on the assumption that both standard and test preparation contain the same analyte, and the response in an assay is a true function of this analyte. This principle is reflected in the diversity of source materials used to prepare fibrinolysis standards, which has depended on the contemporary preparations they were employed to measure. With advancing recombinant technology, and improved analytical techniques, a reference system based on reference materials and associated reference methods has been recommended for future fibrinolysis standards. Careful consideration and scientific judgement must however be applied when deciding on an approach to develop a new standard, with decisions based on the suitability of a standard to serve its purpose, and not just to satisfy a metrological ideal.     

NPY receptors in human cancer: a review of current knowledge

Many peptide hormone receptors are over-expressed in human cancer, permitting an in vivo targeting of tumors for diagnostic and therapeutic purposes. NPY receptors are novel and promising candidates in this field. Using in vitro receptor autoradiography, Y1 and Y2 receptors have been found to be expressed in breast carcinomas, adrenal gland and related tumors, renal cell carcinomas, and ovarian cancers in both tumor cells and tumor-associated blood vessels. Pathophysiologically, tumoral NPY receptors may be activated by endogenous NPY released from intratumoral nerve fibers or tumor cells themselves, and mediate NPY effects on tumor cell proliferation and tumoral blood supply. Clinically, tumoral NPY receptors may be targeted with NPY analogs coupled with adequate radionuclides or cytotoxic agents for a scintigraphic tumor imaging and/or tumor therapy.     

Alzheimer's dementia: current data review

The review focuses on current data on Alzhemier's dementia, a clinical syndrom characterised with acquired deterioration of cognitive functioning and emotional capacities, which impaires everyday activity and quality of life. Alzheimer's dementia is the most common type of dementia in clinical surveys. The diagnosis of Alzheimer's dementia is primarily based on symptoms and signs and memory impairment is clinically most significant. Cholinesterase inhibitors -donepezil, rivastigmine and galantamine are considered to be the first line pharmacotherapy for mild to moderate Alzheimer's disease. Currently, no effective pharmacologic interventions have been researched enough to support their use in prevention of Alzheimer's dementia. Studies suggest that healthy lifestyle, ongoing education, regular physical activity, and cholesterol control, play a role in prevention of Alzheimer's dementia.     

Testing solutions in grass-dominated landscapes: a review of current research

In this paper we review the experimental development of agri-environment measures for use on grasslands. Sward structure has been shown to have a strong influence on birds' ability to forage in grasslands, but the effects of food abundance on foraging behaviour are poorly understood and this hinders development of grassland conservation measures. The experiments described have a dual purpose: to investigate the foraging ecology of birds on grasslands and to test candidate management measures. Most of the work featured focuses on increasing invertebrate food resources during the summer by increasing habitat heterogeneity. We also identify important gaps in the habitats provided by existing or experimental measures, where similar dual-purpose experiments are required.