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Background: Irritable bowel syndrome (IBS) is a common disease with intestinal dysmotility, whose mechanism remains elusive. TMEM16A is a calcium-activated chloride channel (CaCC) involved in intestinal slow-wave generation.Aims: To investigate whether TMEM16A is involved in colonic dysmotility in IBS.Methods: A rat model of IBS was established by chronic water avoidance stress (WAS). Colonic pathological alterations were evaluated histologically, and intestinal motility was assessed by intestinal transit time (ITT) and fecal water content (FWC). Visceral sensitivity was determined by visceromotor response (VMR) to colorectal distension (CRD). TMEM16A expression was evaluated by RT-PCR, Western blot, and immunofluorescence. Colonic muscle strip contractility was measured by isometric transducers, and the effect of niflumic acid (NFA), a CaCC antagonist, on colonic motility was examined.Results: After 10 days of WAS exposure, ITT was decreased and FWC was elevated. Furthermore, VMR magnitude of WAS rats in response to CRD was significantly enhanced. Protein and mRNA levels of TMEM16A in colon were considerably increased after WAS. The percentage of TMEM16A-positive neurons in myenteric plexus (MP) of WAS rats was significantly higher than controls. Pharmacological blockade of TMEM16A activity by NFA considerably enhanced ITT, with concentration-dependent declines in FWC and VMR magnitude in NFA-treated rats. Further, spontaneous contraction of colonic strips of NFA-treated rats was significantly ameliorated in a concentration-dependent manner in vitro.Conclusions: Upregulation of TMEM16A in MP neurons may play an important role in chronic stress-induced colonic hypermotility, making CaCC-blocking drugs a putatively effective treatment method for colonic hypermotility in IBS. [ABSTRACT FROM AUTHOR]

Infections with the metastrongyloid nematode Aelurostrongylus abstrusus in cats have been reported sporadically from Germany. To assess the occurrence and regional geographical distribution of A. abstrusus in Germany, faecal samples from 391 cats with symptoms of respiratory disease were collected from December 2009 to November 2011. The zinc chloride/sodium chloride flotation and Baermann funnel technique were used to examine the samples for the presence of lungworm larvae. The collected data were analyzed using a geographic information system (GIS). Infections with lungworms were diagnosed in 26 (6.6 %) of the examined cats. The infection rates did not show significant differences in the age groups up to 7 years. Only cats older than 7 were significantly less infected with lungworms than young cats. Sixteen of the 192 female cats examined and 7 of the 186 males were positive for A. abstrusus, but there were no significant differences for the variable 'gender infection rate'. Most of the A. abstrusus-positive cats were located in Baden-Wuerttemberg, followed by Lower Saxony, Bremen, North Rhine-Westphalia, Bavaria, Hesse, Mecklenburg-Western Pomerania, Saarland, Saxony and Schleswig-Holstein. The majority of infected cats showed severe clinical symptoms characterised by coughing and dyspnoea, increased breathing rate, weight loss, bronchopneumonia, generally poor condition, sneezing and nasal discharge. The high number of lungworm-positive cats and the severe clinical symptoms should encourage veterinarians in Germany to consider infections with A. abstrusus as a differential diagnosis in cats with symptoms of respiratory disease. [ABSTRACT FROM AUTHOR]

The objective of the present work was to elucidate the potential relationship between Mycoplasma hyopneumoniae infection and seroconversion dynamics and climatological conditions in four groups of pigs from the same farm born in different seasons of the year. Nasal swabs and blood samples were taken from 184 pigs at 1, 3, 6, 9, 12, 15, 18, 22 and 25 (slaughter age) weeks of age. Outside climatologic parameters, including temperature (°C), relative humidity (%), precipitation (l/m) and wind speed (m/s) were recorded weekly from January 2003 to June 2004. Percentage of nPCR detection of M. hyopneumoniae in nasal swabs was associated significantly with the weekly precipitation rate [ P = 0.0018, OR = 1.31 (IC = 1.11-1.55)]; the higher the precipitation rate, the higher the probability of being M. hyopneumoniae nPCR-positive. On the other hand, the percentage of seropositive pigs had a significant association with mean weekly temperature rate [ P = 0.0012, OR = 0.89 [IC = 0.84-0.95]); the lower the temperature, the higher the probability of being M. hyopneumoniae seropositive. Animals born in autumn (when higher precipitations rates were recorded), entering finishing units in winter (when lower temperatures were recorded), and reaching slaughter in spring, had the highest probability of being infected by M. hyopneumoniae and the highest probability of being M. hyopneumoniae seropositive. [ABSTRACT FROM AUTHOR]

CD4CD25 regulatory T cells (Treg), which are a specialized subset of T cells, play an important role in the prevention of autoimmune diseases, maintenance of immune system homeostasis and tolerance to self-antigens. Chinese rhesus macaques (CRMs) are widely used in preclinical research on potential therapeutic drugs, vaccines and mechanisms of human diseases. However, the basic immunological characterization of Treg cells of CRMs has not been well established. To characterize Treg cells, peripheral blood of 43 adult CRMs was analyzed for CD4+ T lymphocytes by flow cytometry. It was found that Treg cells ranged from 1.52% to 11.1% of CD4+ T cells, and the average value was 5.7%. With our SIV-infected CRM model, through further studies, it was found that Treg cells in peripheral blood increased both in relative and absolute quantities. Moreover, Treg cells maintained their functions by suppressing Th1 cytokine secretion of their target cells. The results show that Treg cells might render cellular immunity against SIV viruses dysfunctional during the early stage after infection. [ABSTRACT FROM AUTHOR]

Understanding how individuals modify their social interactions in response to infectious disease is of central importance for our comprehension of how disease dynamics operate in real-world populations. Whilst a significant amount of theoretical work has modelled disease transmission using network models, we have comparatively little understanding of how infectious disease impacts on the social behaviour of individuals and how these effects scale up to the level of the population. We experimentally manipulated the parasite load of female guppies ( Poecilia reticulata) and introduced fish either infected with the ectoparasites Gyrodactylus spp. (experimental) or uninfected (control) into replicated semi-natural populations of eight size-matched female guppies. We quantified the behaviour and social associations of both the introduced fish and the population fish. We found that infected experimental fish spent less time associating with the population fish than the uninfected control fish. Using information on which fish initiated shoal fission (splitting) events, our results demonstrate that the population fish actively avoided infected experimental fish. We also found that the presence of an infected individual resulted in a continued decline in social network clustering up to at least 24 h after the introduction of the infected fish, whereas in the control treatment, the clustering coefficient showed an increase at this time point. These results demonstrate that the presence of a disease has implications for both the social associations of infected individuals and for the social network structure of the population, which we predict will have consequences for infectious disease transmission. [ABSTRACT FROM AUTHOR]

Malaria infection leads to anemia in humans which generally occurs during the chronic phase of the infection. The role that erythropoietic molecules play for anemia during malaria at low parasitemia levels is still controversial due to the lack of suitable animal models which might mimic this condition. In this regard, α-tocopherol transfer protein knockout mice, with undetectable levels of vitamin E in circulation, were possibly used as a model to investigate the role that erythropoietic molecules such as erythropoietin (EPO), erythropoietin receptor (EPOR), and macrophage migration inhibitory factor (MIF) play on the outcome of anemia during uncomplicated malaria infection at low parasitemias. The results indicate that the degree of parasitemia unlikely plays any important effect on mRNA expression of EPO and EPOR in different organs. Moreover, even though EPO and EPOR productions are impaired in the kidney and bone marrow, respectively, other organs such as the liver and spleen intend to compensate production of these cytokines to prevent anemia in the infected animals. [ABSTRACT FROM AUTHOR]

ims: Post-infectious irritable bowel syndrome (PI-IBS) is a subset of IBS which occurs after an episode of acute gastrointestinal infections. The mechanisms of PI-IBS are not fully understood. Currently, numerous animal models have been used in the study of PI-IBS. This article reviews the strengths and weaknesses of these models. Methods: All relevant articles were identified by searching in Ovid SP from 1962, the year the term PI-IBS was coined, up to December 31, 2009. The types of model were categorized as either post-infectious or post-inflammatory, and the characteristics of each kind of model were listed. Results: Based on our literature search, 268 articles were identified. Of those articles, 50 were included in this review. The existing PI-IBS models include infection with bacteria (e.g., Campylobacter jejuni, Salmonella enterica, and Campylobacter rodentium), and infection with parasites (e.g., Trichinella spiralis, Nippostrongylus brasiliensis, and Cryptosporidium parvum). The post-inflammatory IBS models are commonly induced with chemical agents, such as acetic acid, deoxycholic acid, dextran sulfate sodium, mustard oil, zymosan, and trinitrobenzene sulfonic acid (TNBS). TNBS is the most commonly used agent for post-inflammatory IBS models, but the experimental protocol varies. These models have one or more aspects similar to IBS patients. Conclusions: Different methods have been used for the development of post-infectious or post-inflammatory IBS models. Each model has its weaknesses and strengths. More studies are needed to establish post-infection IBS models using more common pathogens. A standard protocol in developing TNBS-induced post-inflammatory IBS model is needed. [ABSTRACT FROM AUTHOR]

Blastocystis hominis is a ubiquitous enteric protozoan whose pathogenic potential is still controversial. This study was carried out to clarify the pathogenecity of B. hominis infection and to study the proper number of parasites for mice infection. A total of 15 albino mice were orally inoculated with B. hominis and divided according to the inoculums, 102, 105, and 4 × 107 B. hominis forms/100 μl saline, into three groups consisting of five mice each, GI, GII GIII, respectively. In addition with group IV (uninfected control) consisting of five mice. All mice were sacrificed 2 weeks post-infection. The results revealed that all mice of GIII and two mice of GII got the infection while all mice of GI showed a completely negative result. Histopathological examination of large intestine on highly infected group (GIII) showed that B. hominis infiltrated the lamina propria, the submucosa, and the muscle layers in the form of collection of vacuolar forms. This was accompanied by active colitis with infiltration of mixed inflammatory cells. In conclusion, this study revealed that large number of B. hominis is essential for oral infection of mice and that vacuolar forms of B. hominis can invade the lamina propria, the submucosa, and even the muscle layers. [ABSTRACT FROM AUTHOR]

Bacteria represent a threat to human health, especially in healthcare settings, and treatment options are limited due to increasingly common antibiotic resistance. It is, therefore, imperative that we continue to investigate the mechanisms of pathogenesis and host-pathogen interactions. Despite the fact that some bacterial pathogens are capable of infecting both humans and at least one laboratory animal species, the relevance and animal welfare implications of animal infection models are of concern. Here, we consider whether plants and lower organisms are suitable candidates to investigate certain aspects of bacterial pathogenicity. Indeed, many of the virulence factors employed by micro-organisms render the capacity to infect a range of hosts. The scope for using such models, together with 3D human “organoids”, to accelerate the development and screening of novel drugs and treatment combinations for bacterial infections is considered. [ABSTRACT FROM AUTHOR]

Over a 4-year period, we analyzed 128 fecal samples from free-living elk ( Alces alces L., 1758) to determine the prevalence of Eimeria infections and identify the species present. Two eimerian species were isolated including Eimeria alces and a morphotype resembling Eimeria catubrina. Overall, two samples from 128 samples collected were positive for Eimeria (prevalence = 1.6 %), and the oocyst per gram, estimated with the use of the conventional McMaster quantitative technique, ranged from 50 to 100. Also, E. alces has been found in Lithuania and Belarus and is the only known species of eimerian to infect elk. E. catubrina is a parasite typically infecting roe deer ( Capreolus capreolus L., 1758). This is the first report of Eimeria spp. in elk in Poland. Results of our investigation indicate that elk may become infected with an eimerian species that is typical for roe deer, but this requires further investigation. [ABSTRACT FROM AUTHOR]

The article discusses the multiphoton microscopy, a simulation technique used in studying infections as they happen the natural way. Developed by Mark Miller and later improved by Winfried Denk, this technology involves the excitation of fluorophore using the simultaneous arrival of two or more photons of longer-wavelength light. Since then, the technique has brought researchers to in-depth views of the brain, the T-cells and several ground-breaking studies. In a particular experiment by Vjollca Konjufca, the microscopy was used in studying how Salmonella causes food poisoning, as well as how the immunity cells perform their job. However it is noted that the microscopy also has limitations such as incomplete view of the infection process as well as of the infection scene.