Do corticosteroids have a role in treating Ebola virus disease?

<正>Dear Editor,Humans have been fighting Ebola virus disease(EVD)since its first outbreak in 1976 in Yambuku village in the Democratic Republic of the Congo(previously Zaire).EVD is part of the Filoviridae family of viruses that includes Ebola and Marburg viruses.To date,EVD,one of the most deadly communicable diseases known to humans,has had15 outbreaks in Africa.In 2014,the most severe and complicated outbreak yet swept through the West African countries of Guinea,Liberia,Nigeria,Senegal and Sierra Leone,     

Do eosinophils have a role in the killing of helminth parasites?

Eosinophils have been shown to be potent effector cells for the killing of helminth parasites in in vitro cultures. However, an in vivo role for eosinophils has been more difficult to establish. Early data showed close associations between eosinophils and damaged or dead parasites in histological sections, and significant correlations between resistance to parasites and the capacity to induce eosinophilia after infection. However, more recent studies, using mice that have reduced or increased eosinophil levels through targeting of the eosinophil-specific cytokine interleukin 5, have not unanimously supported an in vivo role for eosinophils in resistance to parasites. Here, Els Meeusen and Adam Balic review these studies and suggest a major role for the innate immune response in unnatural mouse-parasite models to explain some of the findings. They conclude that the data so far are consistent with a role for eosinophils in the killing of infective larval stages, but not adults, of most helminth parasites.     

Do facts have a place in science?

The use of the word ‘fact’ in science is discussed. It is suggested that the everyday meaning of the term is assumed when it is used in science and that this can create problems. Some possible ways of overcoming these difficulties are indicated.     

Do helminths play a role in carcinogenesis?

Chronic helminthiasis is recognized as a significant factor in cancer development in humans. However, the mechanisms by which helminths initiate and promote malignant transformation of host cells are still not understood fully. Human helminthiasis can cause genetic instability and affect inter- and intracellular communication, ultimately leading to tumour development through inflammation, modulation of the host immune system, and secretion of soluble factors that interact with host cells.     

Does carnitine have a role in fat absorption?

The effect of D-carnitine and tetradecylglycidic acid (TDGA), an inhibitor of carnitine palmitoyltransferase, on intestinal absorption of palmitic acid was determined. The proximal intestinal segment was ligated in adult male rats and filled with 0.5 microCi of 14C-palmitic acid alone or with either D-carnitine or TDGA. Thirty minutes later the radioactivity was determined in the intestinal lumen, intestinal wall and plasma. The absorption of palmitic acid was decreased in the presence of D-carnitine (10 mg/ml) as evidenced by significantly lower levels of radioactivity in the gut wall and the plasma and by significantly greater residual radioactivity in the lumenal contents. L-carnitine had no effect on plasma radioactivity but if D- and L-carnitine were given together the effect of D-carnitine was still in evidence. TDGA also inhibited intestinal absorption of palmitic acid.     

Do you have a probiotic in your future?

The possibility of using microbes to maintain health, and to prevent or treat disease is a topic as old as microbiology. However, one factor impeding the introduction of effective probiotics has been our very limited understanding of the composition of the human microbiome, as well as the biological requirements for these organisms. With advances in understanding the microbiome and its metagenome in humans and other mammals, we now can build a more robust scientific basis to develop probiotic strategies. Increasing knowledge of intramicrobial competition and cooperation, as well as host-microbe cross-signaling, will facilitate design of new probiotics and the modeling of their deployment, leading to eventual clinical trials.     

Is there a role for CEA in innate immunity in the colon?

Carcinoembryonic antigen (CEA) is a well known tumor marker associated with the progression of colorectal tumors. The CEA family of glycoproteins has been fully characterized and the function of some of its members is now beginning to be understood. Here, we advance the hypothesis that, rather than functioning in cell adhesion as has been suggested previously, CEA plays a role in protecting the colonic mucosa from microbial invasion. This hypothesis is based on new microscopic, molecular, phylogenetic and microbiological evidence.     

Does Rbmy have a role in sperm development in mice?

The Y(d1) deletion in mice removes most of the multi-copy Rbmy gene cluster that is located adjacent to the centromere on the Y short arm (Yp). XY(d1) mice develop as females because Sry is inactivated, probably because it is now juxtaposed to centromeric heterochromatin. We have previously produced XY(d1)Sry transgenic males and found that they have a substantially increased frequency of abnormal sperm. Staining of testis sections with a polyclonal anti-RBMY antibody appeared to show a marked decrease of RBMY protein in the spermatids of XY(d1)Sry males compared to control males, which led us to suggest that this may be responsible for the increase in sperm anomalies. In the current study we sought to determine whether augmenting Rbmy expression specifically in the spermatids of XY(d1)Sry males would ameliorate the sperm defects. An expressing Rbmy transgene driven by the spermatid-specific mouse protamine 1 promotor (mP1Rbmy) was therefore introduced into XY(d1)Sry males. This failed to reduce the frequency of abnormal sperm. In the course of this study, a new RBMY antibody was generated that, in contrast to the original antibody, failed to detect RBMY in spermatid stages by immunostaining. The lack of RBMY was confirmed by western blotting of lysates from purified round spermatids and elongating spermatids. The implications of these results for the proposed role for RBMY in sperm development are discussed.     

Do tastants have a smell?

The stimuli used in taste research are usually considered to be odourless. This was tested in two experiments with aqueous solutions of two representative compounds for each of the five taste qualities including umami. In the first experiment elderly and young subjects rated the intensity and pleasantness of three concentrations of the stimuli, while wearing or not wearing a noseclip. Saliva production was also measured. Blocking olfaction only influenced salivation for umami. It reduced taste intensity ratings, but as in an earlier experiment with the same compounds in food products, this effect was stronger in the young, who also liked the stimuli better wearing the noseclip. In the second experiment, another group of young people tried to detect the odours of the tastants dissolved in demineralized, double-distilled or Evian water. A considerable number of subjects could regularly detect seven of the ten tastants by olfaction and the extent to which they did correlated significantly with the reduction in taste intensity ratings for the different tastants found in the first experiment. We suggest that most tastants can be smelled and that this smell contributes to taste intensity ratings.     

Do hemoglobin and hemocyanin impair schistosoma killing by no?

Nitric oxide (NO) possesses antiparasitic effects on both Protozoa and Metazoa in definitive and intermediate hosts as well as in vectors. Here, we postulate that hemoglobin and hemocyanin may impair Schistosoma killing by NO in the definitive and intermediate hosts. Interestingly, hemoglobin, myoglobin, and neuroglobin may protect Plasmodium and Trypanosoma from the antiparasitic effects of NO.     

Do basophils play a role in immunity against parasites?

The link between parasites and eosinophilia has been known for more than a century, although the role of eosinophils in host protection is still an open issue. Much less appreciated, however, is the concurrent systemic induction of a related cell type, the basophil, in parasitized hosts. To date, little is known about the role of basophils in immunity against parasites, but recent evidence points to a possible crucial role in the initiation of T-helper type 2 responses in the host. In this article, we review the current understanding of parasitic infections and basophils and discuss their putative role in immunity.     

Do antioxidants play a role in schistosome host-parasite interactions?

Schistosoma mansoni, an intravascular parasite, lives in a hostile environment in close contact with host humoral and cellular cytotoxic factors. To establish itself in the host, the schistosome has evolved a number of immune evasion mechanisms. Here, Philip LoVerde discusses evidence suggesting that antioxidant enzymes provide one such mechanism used by adult schistosomes. Antioxidant enzymes may thus represent a target for immune elimination of adult worms.     

Do small animals have a biogeography?

It has been stated that small organisms do not have barriers for distribution and will not show biogeographic discreteness. General models for size-mediated biogeographies establish a transition region between ubiquitous dispersal and restricted biogeography at about 1–10 mm. We tested patterns of distribution versus size with water mites, a group of freshwater organisms with sizes between 300 μm and 10 mm.We compiled a list of all known water mite species for Sierra del Guadarrama (a mountain range in the centre of the Iberian Peninsula) from different authors and our own studies in the area. Recorded habitats include lotic, lentic and interstitial environments. Species body size and world distribution were drawn from our work and published specialized taxonomic literature. The null hypothesis was that distribution is size-independent. The relationship between distribution and size was approached via analysis of variance and between size and habitat via logistic regression. Contrary to expectations, there is no special relationship between water mite size and area size distribution. On the other hand, water mite size is differentially distributed among habitats, although this ecological sorting is very weak. Larger water mites are more common in lentic habitats and smaller water mites in lotic habitats. Size-dependent distribution in which small organisms tend to be cosmopolitan breaks down when the particular biology comes into play. Water mites do not fit a previously proposed size-dependent biogeographical distribution, and are in accordance with similar data published on Tardigrada, Rotifera, Gastrotricha and the like.     

Does fructan have a functional role in physiological traits? Investigation by quantitative trait locus mapping

* The role of fructan in growth and drought-stress responses of perennial ryegrass (Lolium perenne) was investigated in an F(2) mapping family that segregates for carbohydrate metabolism. * A quantitative trait locus approach was used to compare the genetic control of traits. * Growth and drought-stress traits were extremely variable within the family. Most traits had high broad-sense heritability. Quantitative trait loci (QTL) were identified for most traits; the maximum number of QTL per trait was four. Between 11% and 75% of total phenotypic variation was explained. Few growth-trait QTL coincided with previously identified fructan QTL. A cluster of drought-trait QTL was close to two previously identified regions of the genome with tiller base fructan QTL in repulsion. * The high sugar parent contributed few alleles that increased 'reserve-driven' growth or performance during drought-stress. Correlation of growth and drought-stress traits with fructan content was low and increasing fructan content per se would not appear to improve drought resistance. Complex patterns of carbohydrate partitioning and metabolism within the cell may explain contradictory relationships between carbohydrate content and growth/stress-resistance traits.     

Do predators have a role to play in wetland ecosystem functioning? An experimental study in New England salt marshes

The historical ecological paradigm of wetland ecosystems emphasized the role of physical or “bottom‐up” factors in maintaining functions and services. However, recent studies have shown that the loss of predators in coastal salt marshes can lead to a significant reduction in wetland extent due to overgrazing of vegetation by herbivores. Such studies indicate that consumers or “top‐down” factors may play a much larger role in the maintenance of wetland ecosystems than was previously thought. The objective of this study was to evaluate whether altering top‐down control by manipulating the presence of predators can lead to measurable changes in salt marsh ecosystem properties. Between May and August of 2015 and 2016, we established exclosure and enclosure cages within three New England coastal wetland areas and manipulated the presence of green crab predators to assess how they and their fiddler and purple marsh crab prey affect changes in ecosystem properties. Predator presence was associated with changes in soil nitrogen and aboveground biomass at two of the three field sites, though the magnitude and direction of these effects varied from site to site. Further, path analysis results indicate that across field sites, a combination of bottom‐up and top‐down factors influenced changes in measured variables. These results challenge the growing consensus that consumers have strong effects, indicating instead that predator impacts may be highly context‐dependent.