21 research outputs found

    Modulation of aggression in male mice: influence of group size and cage size

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    Aggression in group-housed male mice is known to be influenced by both cage size and group size. However, the interdependency of these two parameters has not been studied yet. In this study, the level of aggression in groups of three, five, or eight male BALB/c mice housed in cages with a floor size of either 80 or 125 cm2/animal was estimated weekly after cage cleaning for a period of 14 weeks. Furthermore, urine corticosterone levels, food and water intake, body weight, and number of wounds were measured weekly. At the end of the experiment, tyrosine hydroxylase (TH) activity, testosterone levels, and weight of spleen, thymus, testes, and seminal vesicles were determined. Results indicate a moderate increase of intermale aggression in larger cages when compared to the smaller cages. Aggression in groups of eight animals was considerably higher than in groups of three animals. The increase of agonistic behavior was observed both in dominant and subordinate animals. Physiological parameters indicate differences in stress levels between dominant and subordinate animals. It is concluded that aggressive behavior in group-housed male BALB/c mice is best prevented by housing the animals in small groups of three to five animals, while decreasing floor size per animal may be used as a temporary solution to decrease high levels of aggression in an existing social group.

    Buparvaquone is active against Neospora caninum in vitro and in experimentally infected mice.

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    The naphthoquinone buparvaquone is currently the only drug used against theileriosis. Here, the effects of buparvaquone were investigated in vitro and in an experimental mouse model for Neospora caninum infection. In 4-day proliferation assays, buparvaquone efficiently inhibited N. caninum tachyzoite replication (IC50 = 4.9 nM; IC100 = 100 nM). However, in the long term tachyzoites adapted and resumed proliferation in the presence of 100 nM buparvaquone after 20 days of cultivation. Parasiticidal activity was noted after 9 days of culture in 0.5 µM or 6 days in 1 µM buparvaquone. TEM of N. caninum infected fibroblasts treated with 1 µM buparvaquone showed that the drug acted rather slowly, and ultrastructural changes were evident only after 3-5 days of treatment, including severe alterations in the parasite cytoplasm, changes in the composition of the parasitophorous vacuole matrix and a diminished integrity of the vacuole membrane. Treatment of N. caninum infected mice with buparvaquone (100 mg/kg) either by intraperitoneal injection or gavage prevented neosporosis symptoms in 4 out of 6 mice in the intraperitoneally treated group, and in 6 out of 7 mice in the group receiving oral treatment. In the corresponding controls, all 6 mice injected intraperitoneally with corn oil alone died of acute neosporosis, and 4 out of 6 mice died in the orally treated control group. Assessment of infection intensities in the treatment groups showed that, compared to the drug treated groups, the controls showed a significantly higher parasite load in the lungs while cerebral parasite load was higher in the buparvaquone-treated groups. Thus, although buparvaquone did not eliminate the parasites infecting the CNS, the drug represents an interesting lead with the potential to eliminate, or at least diminish, fetal infection during pregnancy

    In Vitro and In Vivo Effects of the Bumped Kinase Inhibitor 1294 in the Related Cyst-Forming Apicomplexans Toxoplasma gondii and Neospora caninum.

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    We report on the in vitro effects of the bumped kinase inhibitor 1294 (BKI-1294) in cultures of virulent Neospora caninum isolates Nc-Liverpool (Nc-Liv) and Nc-Spain7 and in two strains of Toxoplasma gondii (RH and ME49), all grown in human foreskin fibroblasts. In these parasites, BKI-1294 acted with 50% inhibitory concentrations (IC50s) ranging from 20 nM (T. gondii RH) to 360 nM (N. caninum Nc-Liv), and exposure of intracellular stages to 1294 led to the nondisjunction of newly formed tachyzoites, resulting in the formation of multinucleated complexes similar to complexes previously observed in BKI-1294-treated N. caninum beta-galactosidase-expressing parasites. However, such complexes were not seen in a transgenic T. gondii strain that expressed CDPK1 harboring a mutation (G to M) in the gatekeeper residue. In T. gondii ME49 and N. caninum Nc-Liv, exposure of cultures to BKI-1294 resulted in the elevated expression of mRNA coding for the bradyzoite marker BAG1. Unlike in bradyzoites, SAG1 expression was not repressed. Immunofluorescence also showed that these multinucleated complexes expressed SAG1 and BAG1 and the monoclonal antibody CC2, which binds to a yet unidentified bradyzoite antigen, also exhibited increased labeling. In a pregnant mouse model, BKI-1294 efficiently inhibited vertical transmission in BALB/c mice experimentally infected with one of the two virulent isolates Nc-Liv or Nc-Spain7, demonstrating proof of concept that this compound protected offspring from vertical transmission and disease. The observed deregulated antigen expression effect may enhance the immune response during BKI-1294 therapy and will be the subject of future studies

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    In vitro treatment of Besnoitia besnoiti with the naphto-quinone buparvaquone results in marked inhibition of tachyzoite proliferation, mitochondrial alterations and rapid adaptation of tachyzoites to increased drug concentrations.

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    We here assessed the in vitro efficacy of the naptho-quinone buparvaquone (BPQ) against Besnoitia besnoiti tachyzoites in vitro. BPQ is currently licensed for the treatment of theileriosis in cattle in many countries, but not in the EU. In 4-day treatment assays, BPQ massively impaired tachyzoite proliferation with an IC50 of 10 ± 3 nm, and virtually complete inhibition was obtained in the presence of nm BPQ. Exposure to 1 µm BPQ leads to ultrastructural changes affecting initially the mitochondrial matrix and the cristae. After 96 h, most parasites were largely distorted, filled with cytoplasmic amylopectin granules and vacuoles containing components of unknown composition. Host cell mitochondria did not appear to be notably affected by the drug. However, upon prolonged exposure (14-16 days) to increased BPQ concentrations, B. besnoiti tachyzoites exhibited the capacity to adapt, and they resumed proliferation at dosages of up to 10 µm BPQ, albeit at a lower rate. These BPQ-adapted parasites maintained this lower susceptibility to BPQ treatment after freeze-thawing, and inspection by the transmission electron microscopy revealed that they underwent proliferation in the absence of structurally intact mitochondria

    Validation of the Swiss Monte Carlo Plan for a static and dynamic 6 MV photon beam

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    Monte Carlo (MC) based dose calculations can compute dose distributions with an accuracy surpassing that of conventional algorithms used in radiotherapy, especially in regions of tissue inhomogeneities and surface discontinuities. The Swiss Monte Carlo Plan (SMCP) is a GUI-based framework for photon MC treatment planning (MCTP) interfaced to the Eclipse treatment planning system (TPS). As for any dose calculation algorithm, also the MCTP needs to be commissioned and validated before using the algorithm for clinical cases. Aim of this study is the investigation of a 6 MV beam for clinical situations within the framework of the SMCP. In this respect, all parts i.e. open fields and all the clinically available beam modifiers have to be configured so that the calculated dose distributions match the corresponding measurements. Dose distributions for the 6 MV beam were simulated in a water phantom using a phase space source above the beam modifiers. The VMC++ code was used for the radiation transport through the beam modifiers (jaws, wedges, block and multileaf collimator (MLC)) as well as for the calculation of the dose distributions within the phantom. The voxel size of the dose distributions was 2mm in all directions. The statistical uncertainty of the calculated dose distributions was below 0.4%. Simulated depth dose curves and dose profiles in terms of [Gy/MU] for static and dynamic fields were compared with the corresponding measurements using dose difference and γ analysis. For the dose difference criterion of ±1% of D(max) and the distance to agreement criterion of ±1 mm, the γ analysis showed an excellent agreement between measurements and simulations for all static open and MLC fields. The tuning of the density and the thickness for all hard wedges lead to an agreement with the corresponding measurements within 1% or 1mm. Similar results have been achieved for the block. For the validation of the tuned hard wedges, a very good agreement between calculated and measured dose distributions was achieved using a 1%/1mm criteria for the γ analysis. The calculated dose distributions of the enhanced dynamic wedges (10°, 15°, 20°, 25°, 30°, 45° and 60°) met the criteria of 1%/1mm when compared with the measurements for all situations considered. For the IMRT fields all compared measured dose values agreed with the calculated dose values within a 2% dose difference or within 1 mm distance. The SMCP has been successfully validated for a static and dynamic 6 MV photon beam, thus resulting in accurate dose calculations suitable for applications in clinical cases

    Repurposing of antiparasitic drugs: the hydroxy-naphthoquinone buparvaquone inhibits vertical transmission in the pregnant neosporosis mouse model.

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    The three anti-malarial drugs artemiside, artemisone, and mefloquine, and the naphthoquinone buparvaquone known to be active against theileriosis in cattle and Leishmania infections in rodents, were assessed for activity against Neospora caninum infection. All four compounds inhibited the proliferation of N. caninum tachyzoites in vitro with IC50 in the sub-micromolar range, but artemisone and buparvaquone were most effective (IC50 = 3 and 4.9 nM, respectively). However, in a neosporosis mouse model for cerebral infection comprising Balb/c mice experimentally infected with the virulent isolate Nc-Spain7, the three anti-malarial compounds failed to exhibit any activity, since treatment did not reduce the parasite burden in brains and lungs compared to untreated controls. Thus, these compounds were not further evaluated in pregnant mice. On the other hand, buparvaquone, shown earlier to be effective in reducing the parasite load in the lungs in an acute neosporosis disease model, was further assessed in the pregnant mouse model. Buparvaquone efficiently inhibited vertical transmission in Balb/c mice experimentally infected at day 7 of pregnancy, reduced clinical signs in the pups, but had no effect on cerebral infection in the dams. This demonstrates proof-of-concept that drug repurposing may lead to the discovery of an effective compound against neosporosis that can protect offspring from vertical transmission and disease

    In vitro effects of new artemisinin derivatives in Neospora caninum-infected human fibroblasts.

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    From a panel of 34 artemisinin derivatives tested in vitro, artemisone, GC007 and GC012 were most efficacious at inhibiting Neospora caninum replication (IC50 values of 3-54nM), did not notably impair the invasiveness of tachyzoites and were non-toxic for human foreskin fibroblasts (HFFs). Transmission electron microscopy of drug-treated N. caninum-infected HFFs demonstrated severe alterations in the parasite cytoplasm, changes in the composition of the matrix of the parasitophorous vacuole (PV) and diminished integrity of the PV membrane. To exert parasiticidal activity, parasites had to be cultured continuously in the presence of 5μM artemisone or GC007 for 3 weeks. N. caninum tachyzoites readily adapted to a stepwise increase in concentrations (0.5-10μM) of GC012, but not to artemisone or GC007. Drugs induced the expression of elevated levels of NcBAG1 and NcSAG4 mRNA, but only NcBAG1 could be detected by immunofluorescence. Thus, artemisinin derivatives represent interesting leads that should be investigated further

    N-terminal fusion of a toll-like receptor 2-ligand to a Neospora caninum chimeric antigen efficiently modifies the properties of the specific immune response

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    Immunoprophylactic products against neosporosis during pregnancy should induce an appropriately balanced immune response. In this respect, OprI, a bacterial lipoprotein targeting toll like receptor (TLR)2, provides promising adjuvant properties. We report on the manipulation of the innate and the T-cell immune response through the fusion of OprI with the Neospora caninum chimeric protein Mic3-1-R. In contrast to Mic3-1-R, OprI-MIC3-1-R significantly activated bone-marrow dendritic cells from naïve mice. Mice immunized with OprI-Mic3-1-R induced an immune response with mixed T helper (Th)1 and Th2 properties (high levels of both immunoglobulin (Ig)G1 and IgG2a and of interleukin (IL)-10, IL-12(p70) and interferon-γ responses) whereas Mic3-1-R+saponin induced a clear Th2-biased response (low IgG2a and high IL-4 and IL-10). After mating and challenge with N. caninum, increased expression of interferon-γ was only found in placentas from OprI-Mic3-1-R immunized dams. However, no protection against vertical transmission and neonatal mortality was observed in either of the two groups. These results indicated that more exhaustive studies must be done to elucidate the immune mechanisms associated with transplacental transmission. Antigen linkage to TLR2-ligands, such as OprI, is a useful tool to investigate this enigma by reorienting the innate and adaptive immune responses against other candidate antigens in future studies
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