Axial forces and bending moments in the loaded rabbit tibia in vivo

Background

Different animal models are used as fracture models in orthopaedic research prior to implant use in humans, although biomechanical forces can differ to a great extend between species due to variable anatomic conditions, particularly with regard to the gait. The rabbit is an often used fracture model, but biomechanical data are very rare. The objective of the present study was to measure axial forces, bending moments, and bending axis directly in the rabbit tibia in vivo. The following hypothesis was tested: Axial forces and bending moments in the mid-diaphysis of rabbit tibia differ from other experimental animals or indirectly calculated data.

Methods

A minifixateur system with 4 force sensors was developed and attached to rabbit tibia (n = 4), which were subsequently ostectomised. Axial forces, bending moments and bending angles were calculated telemetrically during weight bearing in motion between 6 and 42 days post operation.

Results

Highest single values were 201% body weight [% bw] for axial forces and 409% bw cm for bending moments. Whereas there was a continous decrease in axial forces over time after day 10 (P = 0.03 on day 15), a decrease in bending moments was inconsistent (P = 0.03 on day 27). High values for bending moments were frequently, but not consistently, associated with high values for axial forces.

Conclusion

Axial forces in rabbit tibia exceeded axial forces in sheep, and differed from indirectly calculated data. The rabbit is an appropriate fracture model because axial loads and bending moments in rabbit tibia were more closely to human conditions than in sheep tibia as an animal model.     

Gene expression of selected signature cytokines of T cell subsets in duodenal tissues of dogs with and without inflammatory bowel disease

Inflammatory bowel disease (IBD) is a common cause of chronic diarrhoea in dogs. In people, specific cytokine patterns attributed to T cell subsets, especially T helper cell [Th]1, Th17 and regulatory T(reg) cells have emerged in IBD. In contrast, no specific involvement of a distinct T cell subset has been described so far in canine IBD. Thus, the aim of the present study was to assess gene expression of signature cytokines in duodenal tissues from 18 German shepherd dogs with IBD (group 1), 33 dogs of other breeds with IBD (group 2) and 15 control dogs (group 3). Relative quantification of IL-17A, IL-22, IL-10, IFNy and TGFβ was performed. Expression of IL-17A was significantly lower in groups 1 and 2 compared to group 3 (p=0.014), but no difference in the expression of IL-22 (p=0.839), IFNγ (p=0.359), IL-10 (p=0.085) or TGFβ (p=0.551) across groups was detected. Thus, no clear evidence for the involvement of Th-17 signature cytokines in canine IBD at the mRNA level could be shown. The contribution of specific T cell subsets to the pathogenesis of canine IBD warrants further investigation.     

Effects of sanitation processes on survival of Synchytrium endobioticum and Globodera rostochiensis

The two quarantine pests Synchytrium endobioticum, the causal agent of potato wart disease and Globodera rostochiensis, the yellow potato cyst nematode are currently present in Germany. Winter sporangia of Synchytrium endobioticum and cysts of Globodera rostochiensis can be spread with waste from potato processing industries, if infected tubers are processed. The German Biowaste Ordinance prescribes sanitation of organic waste before it can be used on arable land as fertilizer or filling material. Sanitation parameters prescribed by the German Biowaste Ordinance include composting for 7 days at 65°C or 14 days at 55°C or pasteurisation for 60 min at 70°C. The effect of composting and pasteurisation processes on winter sporangia of Synchytrium endobioticum and cysts of Globodera rostochiensis was tested with varying time-temperature relations. Cysts of Globodera rostochiensis were killed by composting for 7 days at 50–55°C and by pasteurisation for 30 min at 70°C. In contrast, viable winter sporangia of Synchytrium endobioticum could be extracted from sample material after composting for 70 days at 30–45°C, composting for 21 days at 50–55°C and after composting for 12 days at 60–65°C. Likewise viable winter sporangia could be extracted after pasteurisation for 90 min at 70°C and heating in a water bath at 80°C and in a dry oven at 90°C for 8 h. The parameters prescribed in the German Biowaste Ordinance are sufficient to kill cysts of Globodera rostochiensis but not sufficient to kill winter sporangia of Synchytrium endobioticum in organic waste.     

Soluble and bound phenolic compounds in different Bolivian purple corn ( Zea mays L.) cultivars

In nine Bolivian purple corn ( Zea mays L.) varieties the content of phenolic compounds as well as the anthocyanin composition has been determined. The phenotypes under investigation included four red and five blue varieties (Kulli, Ayzuma, Paru, Tuimuru, Oke, Huaca Songo, Colorado, Huillcaparu, and Checchi). In purple corn, phenolic compounds were highly concentrated in cell walls. Thus, simultaneous determination of soluble and bound-form phenolics is essential for analysis, extraction, and quantification. The present study reports the determination of soluble and insoluble-bound fraction of phenolic compounds by HPLC-DAD and HPLC-ESI-MS(n) in Bolivian purple corn varieties. Enzymatic, thermal, and alkaline hydrolyses were used to obtain the cell wall-linked phenolic compounds. Ferulic acid values ranged from 132.9 to 298.4 mg/100 g, and p-coumaric acid contents varied between 251.8 and 607.5 mg/100 g dry weight (DW), respectively, and were identified as the main nonanthocyanin phenolics. The total content of phenolic compounds ranged from 311.0 to 817.6 mg gallic acid equivalents (GAE)/100 g DW, and the percentage contribution of bound to total phenolics varied from 62.1 to 86.6%. The total monomeric anthocyanin content ranged from 1.9 to 71.7 mg cyanidin-3-glucoside equivalents/100 g DW. Anthocyanin profiles are almost the same among the different samples. Differences are observed only in the relative percentage of each anthocyanin. Cyanidin-3-glucoside and its malonated derivative were detected as major anthocyanins. Several dimalonylated monoglucosides of cyanidin, peonidin, and pelargonidin were present as minor constituents.     

Non-starch polysaccharides alter interactions between Heterakis gallinarum and Histomonas meleagridis

Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p<0.001). An interaction between effects of diet and dimetridazole treatment on worm burden (p<0.001) indicated that the S-NSP diet resulted in lowest worm burden in dimetridazole un-treated birds, whereas it caused the highest worm burden in the treated birds (p<0.05). Furthermore, the treatment resulted in higher worm burdens when compared to un-treated birds on the corresponding diets (p<0.05). Infection with H. gallinarum impaired body weight (BW) of the chicks (p<0.05) and H. meleagridis aggravated this effect (p<0.05). Dimetridazole treated and un-treated uninfected birds developed similar BW (p>0.05). Both NSP supplemented diets resulted in lower (p<0.05) BW when compared with the CON diet, S-NSP being inferior to I-NSP (p<0.05). It is concluded that H. meleagridis harms the definitive host as well as H. gallinarum. Both insoluble and soluble NSP supplemented diets favor H. gallinarum infection while S-NSP additionally intensifies histomonas infection, which then impairs establishment and development of H. gallinarum.     

Effects of dietary non-starch polysaccharides on establishment and fecundity of Heterakis gallinarum in grower layers

It was hypothesized that the establishment and fecundity of Histomonas meleagridis free Heterakis gallinarum may be affected by dietary non-starch polysaccharides (NSPs). One-day-old female layer chicks (N=670) were fed ad libitum for 11wk one of the following diets in a three-times repeated experiment: basal diet (CON), basal diet plus pea bran rich in insoluble NSP (I-NSP), basal diet plus chicory root meal as a source of inulin rich soluble NSP (S-NSP). At the end of wk three, each feeding group was subdivided into an uninfected and an infected group of birds each being inoculated with a placebo or with 200 H. meleagridis free eggs of H. gallinarum. The birds were slaughtered 8wk post infection and their worm burdens, the nematode egg excretion, caeca sizes and weights as well as intracaecal pH and volatile fatty acid (VFA) concentrations were determined. The NSP supplemented diets and also infection led to reduced body weights (BWs) of birds and impaired the feed conversion rate (P<0.001). The NSP supplemented diets increased average length of caecum (P<0.001) with S-NSP exerting a stronger effect than I-NSP (P<0.05). Full caeca weight was increased by S-NSP (P<0.001). Feeding S-NSP lowered intracaecal pH and molar proportion of acetate and increased that of butyrate compared to CON and I-NSP (P<0.001). Caecal pool of VFA was increased with S-NSP (P<0.001). The NSP-diets elevated incidence of infection (P<0.01), average number of larvae (P<0.009) and total worm burden (P<0.001) compared to CON. The daily amount of faeces increased in NSP-fed birds (P<0.001). Number of eggs per gram of faeces (EPG), number of eggs excreted per worm population of a bird within 24h (EPD) and female worm fecundity (EPD/female worm) were elevated after feeding S-NSP (P≤0.002), whereas I-NSP led to lower EPG/female worm (P<0.05). The EPD increased in the sequence of CON相似文献   

Clinical and imaging findings in five dogs with intracranial blastomycosis (Blastomyces dermatiditis)

Fungal infections affecting the central nervous system are rare. The purpose of this study was to describe clinical and imaging findings in dogs with intracranial blastomycosis (Blastomyces dermatiditis). The radiology database was searched retrospectively for patients with a diagnosis of intracranial blastomycosis which had computed tomography performed as part of their diagnostic work-up. Medical records and imaging studies were reviewed. Five dogs met the inclusion criteria. Major presenting complaints were stertor/nasal discharge (n=2), exophthalmos (n=1), and seizures (n=2). Clinical and laboratory findings were variable. Computed tomographic examination revealed a single contrast-enhancing intra-axial mass (n=1), a nasal mass disrupting the cribriform plate (n=3), and an intracranial mass extending into the orbit and nasal cavity (n=1). Findings in intracranial blastomycosis in dogs are variable, and the disease may mimic other inflammatory disorders or neoplasia.     

Interactive effects of plant growth–promoting rhizobacteria and organic fertilization on P nutrition of Zea mays L. and Brassica napus L.

The organic matter supply can promote the dispersal and activity of applied plant growth–promoting rhizobacteria (PGPR), but the complementary effect of organic fertilization and PGPR application on the turnover of P is scarcely known. The effects of the application of two PGPR strains (Pseudomonas fluorescens strain DR54 and Enterobacter radicincitans sp. nov. strain DSM 16656) alone and in combination with organic fertilization (cattle manure and biowaste compost) on growth and P uptake of maize (Zea mays L.) and oilseed rape (Brassica napus L.) were investigated under semi–field conditions. Furthermore, P pools and phosphatase activities in soil and the arbuscular mycorrhizal colonization of maize were examined. The organic‐fertilizer amendments increased the growth and P uptake of both plant species and the soil P pools. The application of the E. radicincitans strain increased P uptake of oilseed rape when no organic fertilizer was added. Furthermore, the application of both bacterial strains increased the activities of phosphatases under both plant species. Here, the effect of the PGPR application even exceeded the effect of organic fertilization. The magnitude of this effect varied between the different fertilizing treatments and between the two bacterial strains. Phosphatase activities were increased to the greatest extent after application of P. fluorescens in the unfertilized soil. Under rape increases of 52% for acid phosphatase activities (ACP), 103% for alkaline phosphatase activities (ALP), and 133% for phosphodiesterase (PDE) were observed therewith. In the unfertilized soil, the application of P. fluorescens also resulted in a strong increase of the arbuscular mycorrhizal colonization of maize. We conclude that application of PGPR can promote the P mobilization and supply of crops in P‐deficient soils, however, in combination with organic fertilization these effects might be masked by a general improved P supply of the crops. Interactive effects of applied bacterial strains and organic fertilization depend on the sort of organic fertilizer and crop species used.     

Pharmacokinetics and bioavailability after intramuscular injection of the 5‐HT1A serotonin agonist R‐8‐hydroxy‐2‐(di‐n‐propylamino) tetralin (8‐OH‐DPAT) in domestic goats (Capra aegagrus hircus)

To determine the bioavailability and pharmacokinetic properties of the serotonin 5‐HT_1A receptor agonist R‐8‐OH‐DPAT in goats, and 0.1 mg kg^?1 R‐8‐OH‐DPAT hydrobromide was administered intramuscularly (i.m.) and intravenously (i.v.) to six goats in a two‐phase cross‐over design experiment. Venous blood samples were collected from the jugular vein 2, 5, 10, 15, 20, 30, 40 and 60 min following treatment and analysed by liquid chromatography tandem mass spectrometry. Bioavailability and pharmacokinetic parameters were determined by a one‐compartment analysis. Mean bioavailability of R‐8‐OH‐DPAT when injected i.m. was 66%. The mean volume of distribution in the central compartment was 1.47 L kg^?1. The mean plasma body clearance was 0.056 L kg^?1 min^?1. All goats injected i.v. and two of six goats injected i.m. showed signs of serotonin toxicity. In conclusion, R‐8‐OH‐DPAT is well absorbed following i.m. injection and the observed pharmacokinetics suggest that administration via dart is feasible. Administration of R‐8‐OH‐DPAT hydrobromide, at a dosage of 0.1 mg kg^?1, resulted in the observation of clinical signs of serotonin toxicity in the goats. It is suggested that dosages for the clinical use of the compound should be lower in order to achieve the desired clinical effect without causing serotonin toxicity.