Sexual conflict and indirect benefits

Recent work on sexual selection and sexual conflict has explored the influence of indirect effects on the evolution of female mating behaviour. It has been suggested that the importance of these effects has been underestimated and that the influence of indirect effects may actually be of relatively greater significance than direct effects. Additionally, it has also been suggested that all indirect effects, both good genes and sexy son, are qualitatively equivalent. Here a counterpoint to these suggestions is offered. We argue two main points: (1) it is unlikely that indirect effects will commonly outweigh direct effects, and (2) that there are important differences between good genes and sexy son indirect effects that must be recognized. We suggest that acknowledgement of these distinctions will lead to increased understanding of processes operating in both sexual conflict and sexual selection.     

ELF Noise Fields: A Review

The debate as to whether low-level electromagnetic fields can affect biological systems and in the long term cause health effects has been going on for a long time. Yet the interaction of weak electromagnetic fields (EMF) with living cells, undoubtedly a most important phenomenon, is still not well understood. The exact mechanisms by which the effects are produced have not been identified. Furthermore, it is not possible to clearly define which aspects of an EMF exposure that constitute the “dose.” One of the groups that contributed to solving this problem is the Bioelectromagnetics group at Catholic University of America (CUA), Washington, D.C. Their work has been devoted to investigating the physical parameters that are needed to obtain an effect of EMF exposure on biological systems, and also how to inhibit the effect. This is a review of their work on bioeffects caused by low-level EMF, their dependence on coherence time, constancy, spatial averaging, and also how the effects can be modified by an applied ELF noise magnetic field. The group has been using early chick embryos, and L929 and Daudi cells as their main experimental systems. The review also covers the work of other groups on low-level effects and the inhibition of the effects with an applied noise field. The group at CUA has shown that biological effects can be found after exposure to low-level ELF and RF electromagnetic fields, and when effects are observed, applying an ELF magnetic noise field inhibits the effects. Also, other research groups have tried to replicate the studies from the CUA group, or to apply EMF noise to suppress EMF-induced effects. Replications of the CUA effects have not always been successful. However, in all cases where the noise field has been applied to prevent an observed effect, it has been successful in eliminating the effect.     

Nontargeted effects of ionizing radiation: implications for low-dose exposures

The traditional thinking has been that the biological effects of ionizing radiation occur in irradiated cells as a consequence of the DNA damage they incur. This implies that: 1) biological effects occur only in irratiated cells, 2) radiation traversal through the nucleus of the cell is a prerequisite to produce a biological response, and 3) DNA is the target molecule in the cell. Evidence has been emerging, however, for non-DNA targeted effects of radiation; that is, effects including mutations, chromosomal aberrations, and changes in gene expression which occur in cells that in themselves receive no radiation exposure. Two of these phenomena will be described in this paper. The first is radiation-induced genomic instability whereby biological effects, including elevated frequencies of mutations and chromosomal aberrations, arise in the distant descendants of irradiated cells. The second phenomenon has been termed the "bystander effect", whereby in a mixed population of irradiated and nonirradiated cells, biological effects arise in those cells that receive no radiation exposure. The damage signals are transmitted from cell to cell through gap junction channels, and the genetic effects observed in bystander cells appear to result from an upregulation of oxidative stress. The possible influence of these non-targeted effects of radiation of the respounse to low-dose exposures is discussed.     

6-Shogaol,an active constituent of ginger,attenuates neuroinflammation and cognitive deficits in animal models of dementia

Recently, increased attention has been directed towards medicinal extracts as potential new drug candidates for dementia. Ginger has long been used as an important ingredient in cooking and traditional herbal medicine. In particular, ginger has been known to have disease-modifying effects in Alzheimer's disease (AD). However, there is no evidence of which constituents of ginger exhibit therapeutic effects against AD. A growing number of experimental studies suggest that 6-shogaol, a bioactive component of ginger, may play an important role as a memory-enhancing and anti-oxidant agent against neurological diseases. 6-Shogaol has also recently been shown to have anti-neuroinflammatory effects in lipopolysaccharide (LPS)-treated astrocytes and animal models of Parkinson’s disease, LPS-induced inflammation and transient global ischemia. However, it is still unknown whether 6-shogaol has anti-inflammatory effects against oligomeric forms of the Aβ (AβO) in animal brains. Furthermore, the effects of 6-shogaol against memory impairment in dementia models are also yet to be investigated. In this study, we found that administration of 6-shogaol significantly reduced microgliosis and astrogliosis in intrahippocampal AβO-injected mice, ameliorated AβO and scopolamine-induced memory impairment, and elevated NGF levels and pre- and post-synaptic marker in the hippocampus. All these results suggest that 6-shogaol may play a role in inhibiting glial cell activation and reducing memory impairment in animal models of dementia.     

Asthma induced by house dust mites: benefits resulting from a correct environmental hygienization

Summary The aim of the present work has been the determination of the effectiveness of a primary prevention in the allergopathy induced by house dust mites weighing its benefits as regards asthmatic symptomatology.A sample of 56 subjects, aged 6 to 30 years, monosensitive to house dust mites (DTP and DTF) and with a diagnosis of bronchial asthma has been examined. The patients have entered a study plan whose purpose has been the evaluation of the effects of an environmental improvement on symptomatology. The diagnosis of asthma induced by house dust mites has been confirmed both by in vivo (Prick-test) and in vitro (PRIST and RAST) investigations.A follow-up after 3 months has shown that the hygienic measures have produced beneficial effects on symptomatology in as many as 22 patients (52.4%) out of a total of 42 who have put into practice the environmental improvement. These results encourage to proceed on this path in the choice of the therapy for those subjects affected by respiratory allergopathy to house dust mites.     

The therapeutic potential of hydrogen sulfide: separating hype from hope

Hydrogen sulfide (H(2)S) has become the hot new signaling molecule that seemingly affects all organ systems and biological processes in which it has been investigated. It has also been shown to have both proinflammatory and anti-inflammatory actions and proapoptotic and anti-apoptotic effects and has even been reported to induce a hypometabolic state (suspended animation) in a few vertebrates. The exuberance over potential clinical applications of natural and synthetic H(2)S-"donating" compounds is understandable and a number of these function-targeted drugs have been developed and show clinical promise. However, the concentration of H(2)S in tissues and blood, as well as the intrinsic factors that affect these levels, has not been resolved, and it is imperative to address these points to distinguish between the physiological, pharmacological, and toxicological effects of this molecule. This review will provide an overview of H(2)S metabolism, a summary of many of its reported "physiological" actions, and it will discuss the recent development of a number of H(2)S-donating drugs that show clinical potential. It will also examine some of the misconceptions of H(2)S chemistry that have appeared in the literature and attempt to realign the definition of "physiological" H(2)S concentrations upon which much of this exuberance has been established.     

Neuropeptides and neuroendocrine hormones in ultraviolet radiation-induced immunosuppression

Exposure of the skin to ultraviolet radiation (UVR) can lead to deleterious effects such as sunburn, photoaging, and the development of skin cancer. UVR has also been shown to reduce local and systemic immune responses in humans and animals. In the recent past it has become clear that neuropeptides mediate some of the effects of UVR-induced immunosuppression. Among the neuropeptides released from cutaneous nerves after exposure to UVR, calcitonin gene-related peptide (CGRP) has been examined most extensively. It appears to lead to a reduction of contact hypersensitivity by inducing mast cells to degranulate and thus release tumor necrosis factor alpha (TNF-alpha) and, most likely, interleukin (IL)-10. Nitric oxide, which is coreleased with CGRP, seems to also play a role in immunosuppression through a yet undiscovered mechanism of action, while substance P may have counterregulatory effects. New evidence suggests that the release of neuropeptides from cutaneous sensory c-fibers after UVR is induced by keratinocyte-derived nerve growth factor. UVR can also induce epidermal and some dermal cells, such as melanocytes, keratinocytes, and dermal microvascular epithelial cells, to produce proopiomelanocortin (POMC) and its derivatives. The POMC product alpha-melanocyte-stimulating hormone (alpha-MSH) has been implicated in suppression of contact hypersensitivity and induction of hapten-specific tolerance, most likely by inducing keratinocytes and monocytes to produce the anti-inflammatory cytokine IL-10. Other POMC derivatives have not yet been investigated with regard to a possible role in UVR-induced effects on immunity.     

The embryotoxicity of phenytoin: an update on possible mechanisms

PHT has multiple effects in adult humans and animals, and there is no reason to assume that it will not have multiple effects in embryos and fetuses. Although one of the first associations between anticonvulsant therapy and an adverse development effect in humans was noted in 1964 (104), the mechanism(s) whereby these adverse effects occur has thus far eluded research efforts. In this review, I have focused on three possible mechanisms. Overall, the evidence does not appear to implicate folate deficiency in PHT-induced embryotoxicity. A role for glucocorticoids or interaction between PHT and the glucocorticoid receptor has not been ruled out. However, a significant amount of work remains to be done to examine the involvement of the arachidonic acid cascade in PHT-induced embryotoxicity in vivo. The bulk of the experimental evidence would seem to favor a role for the generation of a reactive intermediate and its subsequent binding to embryonic macromolecules. This metabolite(s) has not been identified. Additionally, the association between covalent binding of metabolites and embryotoxicity remains simply an association; a causal relationship has not been established. Much work remains to be done to determine whether any of these possibilities, some other possibility, or a combination of several mechanisms will explain the adverse development effects of this very important, therapeutically useful anticonvulsant.     

锂对造血干细胞和神经干细胞作用影响的研究进展

锂在现代精神病学中使用超过65年,其构成了双相情感障碍（BD）长期治疗的基础。锂的许多生物学特性已经被证实,包括抗病毒、血液系统和神经系统保护作用。本文系统综述了锂对造血干细胞（HSCs）、神经干细胞（NSCs）以及诱导多能干细胞（iPSCs）作用影响的研究进展及其目前已证实的分子机制。自20世纪70年代以来,锂对保持HSCs和生长因子高水平的作用已被报道。锂可以改善HSCs的归巢能力、形成菌落的能力和自我更新的能力。关于锂对神经发生影响的研究表明,锂可促进海马齿状回的干细胞增殖,并导致施旺氏细胞有丝分裂活性增强。锂被证实与神经保护和神经营养作用相关,具体作用反映在锂可改善突触的可塑性,促进细胞存活,抑制细胞凋亡等。在临床研究中发现,锂离子的治疗可增加大脑灰质的成分,尤其作用在额叶、海马和杏仁核等位置。锂对干细胞的作用涉及多条介质和信号通路,其中最重要的介质和信号通路被认为是糖原合成酶激酶-3（GSK-3）和Wnt/β-catenin通路,另外包括调节cAMP、蛋白激酶B、磷脂酰肌醇3-激酶（pi3k）和肌醇单磷酸酶（IMP）水平的信号通路等也与锂作用有紧密的联系。锂在现阶段被利用于治疗BD和降低痴呆症患病风险的临床实验中,并对神经退行性疾病发挥有益作用。除此之外,为了研究的发病机制和锂离子在其中的作用机制,从BD患者中获得的iPSCs也被广泛应用。     

Neuroprotective features of carnosine in oxidative driven diseases

Carnosine (β-alanyl-L-histidine) is a natural dipeptide widely and abundantly distributed in excitable tissues of several animal tissues. Although its physiological role has not been completely understood yet, many beneficial actions have been attributed to carnosine, such as being an antioxidant, antiglycating and ion-chelating agent, a wound healing promoter and a free-radical scavenger. The role of carnosine in the neuroprotection of oxidative stress-driven disorders has been reviewed. The effects of carnosine have been extensively studied both in vivo and in vitro models of cerebral damages, such as neurodegenerative disorders and hypoxia-ischemia injuries. Beside the classical sacrificial agent, carnosine has been reevaluated as a molecular chaperon and an inducer of antioxidant systems in oxidative stress conditions. Thus, beneficial effects on most of the common biochemical events that characterize neurological disorders make carnosine a very promising molecule among all the endogenous compounds in the treatment and/or prevention of oxidative driven diseases.     

Selenium prevents the growth stimulatory effects of cadmium on human prostatic epithelium

Cadmium has been implicated in the increase in prostate cancer incidence in men exposed to high levels. A decrease in zinc and a concomitant increase in cadmium levels in the human prostate has been shown. The role and mechanism of cadmium action in prostate carcinogenesis is not clear. Selenium, on the other hand, has been shown to inhibit carcinogenesis in several animal systems. Results show that cadmium stimulates the growth of human prostatic epithelium in vitro, between 10(-9) M and 10(-7) M concentrations. Selenium, at concentrations between 10(-12) M and 10(-7) M shows no growth stimulatory or inhibitory effects on these cells. However, when present at 10(-8) M level, selenium inhibits the growth stimulation induced by cadmium. These results suggest that selenium may be useful in counteracting the effects of cadmium in the human prostate and offer possibilities for investigations on the protective effects of selenium in cadmium-related carcinogenesis in man.     

Differential effects of metal-binding agents on the D-glucose-6-phosphate phosphohydrolase activity of the rat liver.

The metal-binding agents (citrate, oxalate, bicarbonate, EDTA) exert dual effects on D-glucose-6-phosphate phosphohydrolase activity in the homogenate as well as in the subcellular fractions. The important differences of the effects are associated with the concentration of the chelator and with time of its addition. The small (appropriate) concentrations of the metal-binding agents stimulate and stabilize the enzyme activity. However, chelators used in higher concentrations exert the inhibitory influence on the activity of glucose-6-phosphatase. Stimulation of the reaction was observed only if the chelator was added before the enzyme-substrate complex formation has been started. The formation of the ternary complex: the enzyme(metal)-chelator substrate exerting a protective influence on the active centre has been suggested. The hypothesis of a similar action of the metal-binding agents and Pi on the glucose-6-phosphatase as a metaloproteid has been proposed.     

UVA的辐射效应及其分子机理

在光量子血疗法治疗肿瘤及其它疾病中,紫外线已被广泛地用作辐照光源,并取得满意效果。本文综述了近几年关于ＵＶＡ的辐射效应和分子机制研究的某些进展。     

Co-transport of anions and neutral solutes with cations across charged biological membranes. Effects of surrface potential on uptake kinetics

General rate equations have been developed for the co-transport of an anion with one or two cations across a negatively charged biological membrane. The effects of surface potential on the kinetical parameters of co-transport of monovalent anions with monovalent cations have been investigated in more detail. The influence of changes in the surface potential on ion uptake kinetics appears to be markedly affected by the properties of the co-transport system. This can be shown by investigating boundary cases of the general model, namely (a) random order of binding of the ions, (b) anion binds before cations, (c) cations bind before anion. Since the effects of the surface potential are different for these three cases, these effects might serve as (additional) discrimination criteria.The effect of the surface potential on anion uptake kinetics via a co-transport system to which two cations can bind is rather complex: maxima or minima of the apparent affinity constant K_m of anion uptake may occur. Not only the magnitude of the effect of changes in the surface potential, but also its direction (stimulation, inhibition), is influenced by the co-substrate (cation) concentration. Such effects may also occur if only one cation can bind to the translocator, provided that OH^? ions compete for the anion transport site.In addition, the case of co-transport of a neutral solute with a monovalent cation has been investigated. It has been shown, that monovalent cation has been investigated. It has been shown, that also in this case, the effect of changes in the surfaces potential is affected by the order of binding of the substrates to the translocator.     

Evidence for an endogenous circannual component in the control of the annual gonadal cycle in spotted munia

Abstract

For the first time evidence has been provided for a circannual gonadal cycle in any avian species (male spotted munia Lonchura punctulata, Estrildidae) held on continuous light. A model has thus been rendered available in which the “entraining effects” of photoperiod could be clearly distinguished from its direct “driving effects”.     

Benthiocarb toxicity on rat brain AChE

Benthiocarb effect on rat brain acetylcholinesterase (AChE) has been studied to know the toxic effects of benthiocarb on mammalian cholinergic systems. From the study, it has been observed that the inhibition of AChE activity increased with increase in treatment period which is attributed to the cumulative effects of benthiocarb on AChE activity. The kinetic study revealed that there is a slight increase in Km and a marked decrease in Vmax which accounts for the non-competitive inhibition of enzyme during benthiocarb intoxication.     

Ecological effects of roads and traffic: a literature review

This survey of the literature on the ecological effects of roads and traffic revealed many articles published over many years in peer reviewed journals. There has also been a growing number of reports on the ecological effects of roads produced by government authorities. Whereas few reports have been published on assessing the ecological impacts, there has been a rapidly growing number of reports on methods for mitigation. Gaps in research include the effects of heavy metal accumulation and the processes and effects resulting from habitat fragmentation. There is a need to assess the effectiveness of underpasses and tunnels and the nature and functioning of buffer zones. A literature database has been assembled and is being updated.     

Trophic control of mesopredators in terrestrial ecosystems: top‐down or bottom‐up?

It has been argued that widespread extinctions of top predators have changed terrestrial ecosystem structures through mesopredator release, where increased abundances of medium-sized predators have detrimental effects on prey communities. This top-down concept has received much attention within conservation biology, but few studies have demonstrated the phenomenon. The concept has been criticized since alternative explanations involving bottom-up impacts from bioclimatic effects on ecosystem productivity and from anthropogenic habitat change are rarely considered. We analyse the response of a mesopredator (the red fox) to declines in top predators (wolf and Eurasian lynx) and agricultural expansion over 90 years in Sweden, taking bioclimatic effects into account. We show a top-down mesopredator release effect, but ecosystem productivity determined its strength. The impacts of agricultural activity were mediated by their effects on top predator populations. Thus, both top-down and bottom-up processes need to be understood for effective preservation of biodiversity in anthropogenically transformed ecosystems.     

Comparison of strategies to detect epistasis from eQTL data

Genome-wide association studies have been instrumental in identifying genetic variants associated with complex traits such as human disease or gene expression phenotypes. It has been proposed that extending existing analysis methods by considering interactions between pairs of loci may uncover additional genetic effects. However, the large number of possible two-marker tests presents significant computational and statistical challenges. Although several strategies to detect epistasis effects have been proposed and tested for specific phenotypes, so far there has been no systematic attempt to compare their performance using real data. We made use of thousands of gene expression traits from linkage and eQTL studies, to compare the performance of different strategies. We found that using information from marginal associations between markers and phenotypes to detect epistatic effects yielded a lower false discovery rate (FDR) than a strategy solely using biological annotation in yeast, whereas results from human data were inconclusive. For future studies whose aim is to discover epistatic effects, we recommend incorporating information about marginal associations between SNPs and phenotypes instead of relying solely on biological annotation. Improved methods to discover epistatic effects will result in a more complete understanding of complex genetic effects.