Effect of light Sr doping on the spin-state transition in LaCoO_3

We present an inelastic neutron scattering study of the low energy crystal-field excitations in the lightly doped cobalt perovskite La_0.998Sr_0.002CoO_3. In contrast to the parent compound LaCoO_3 an inelastic peak at energy transfer ~0.75 meV was found at temperatures below 30 K. This excitation apparently corresponds to a transition between a ground state orbital singlet and a higher excited orbital doublet, originating from a high-spin triplet split by a small trigonal crystal field. Another inelastic peak at an energy transfer ~0.6 meV was found at intermediate temperatures starting from T > 30 K. This confirms the presence of a thermally induced spin-state transition from the low-spin Co^3+ to a magnetic high-spin state in the non-disturbed LaCoO_3 matrix. We suggest that hole doping of LaCoO_3 leads to the creation of a magnetic polaron and hence to the low-to-high spin state transition on the relevant Co sites.Comment: 4 pages, 2 figures; based on a talk given at ICM'06, Kyoto; to appear in JMM

Bacterial Cholangitis, Cholecystitis, or both in Dogs

BACKGROUND: Bacterial cholangitis and cholecystitis are rarely reported, poorly characterized diseases in the dog. OBJECTIVES: To characterize the clinical features of these conditions. ANIMALS: Twenty‐seven client‐owned dogs with bacterial cholangitis, cholecystitis, or both. METHODS: Multicenter, retrospective cases series of dogs with bacterial cholangitis, cholecystitis, or both, presenting January 2000 to June 2011 to 4 Veterinary Schools in Ireland/United Kingdom. Interrogation of hospital databases identified all cases with the inclusion criteria; histopathologically confirmed cholangitis or cholecystitis and bile culture/cytology results supporting a bacterial etiology. RESULTS: Twenty‐seven dogs met the inclusion criteria with approximately 460 hepatitis cases documented over the same study period. Typical clinical pathology findings were increases in liver enzyme activities (25/26), hyperbilirubinemia (20/26), and an inflammatory leukogram (21/24). Ultrasound findings, although nonspecific, aided decision‐making in 25/26 cases. The most frequent hepatobiliary bacterial isolates were Escherichia coli (n = 17; 16 cases), Enterococcus spp. (n = 8; 6 cases), and Clostridium spp. (n = 5; 5 cases). Antimicrobial resistance was an important feature of aerobic isolates; 10/16 E. coli isolates resistant to 3 or more antimicrobial classes. Biliary tract rupture complicated nearly one third of cases, associated with significant mortality (4/8). Discharged dogs had a guarded to fair prognosis; 17/18 alive at 2 months, although 5/10 re‐evaluated had persistent liver enzyme elevation 2–12 months later. CONCLUSION AND CLINICAL SIGNIFICANCE: Bacterial cholangitis and cholecystitis occur more frequently than suggested by current literature and should be considered in dogs presenting with jaundice and fever, abdominal pain, or an inflammatory leukogram or with ultrasonographic evidence of gallbladder abnormalities

Comparative pharmacokinetic and cytotoxic analysis of three different formulations of mitoxantrone in mice.

Two liposomal formulations of mitoxantrone (MTO) were compared with the aqueous solution (free MTO) in terms of their pharmacokinetic behaviour in ICR mice and cytotoxic activity in a nude mouse xenograft model. The three different formulations of MTO [free MTO, phosphatidic acid (PA)-MTO liposomes, pH-MTO liposomes] were administered intravenously (three mice per formulation and time point) at a dose of 4.7 micromol kg(-1) for free MTO, 6.1 micromol kg(-1) for PA-MTO and 4.5 micromol kg(-1) for pH-MTO. The concentrations of MTO were determined using high-performance liquid chromatography (HPLC) in blood, liver, heart, spleen and kidneys of the mice. Additionally, the toxicity and anti-tumour activity of MTO was evaluated in a xenograft model using a human LXFL 529/6 large-cell lung carcinoma. The dose administered was 90% of the maximum tolerated dose (MTD) of the corresponding formulation (8.1 micromol kg(-1) for free MTO, 12.1 micromol kg(-1) for PA-MTO and pH-MTO). The pharmacokinetic behaviour of PA-MTO in blood was faster than that of free MTO, but the cytotoxic effect was improved. In contrast, pH-MTO showed a tenfold increased area under the curve (AUC) in blood compared with free MTO, without improvement of the cytotoxic effect. This discrepancy between the pharmacokinetic and cytotoxic results could be explained by the fact that MTO in pH-MTO liposomes remains mainly in the vascular space, whereas MTO in PA-MTO liposomes is rapidly distributed into deep compartments, even more so than free MTO

Genome-wide association studies of inflammatory bowel disease in German shepherd dogs

Canine Inflammatory Bowel Disease (IBD) is considered a multifactorial disease caused by complex interactions between the intestinal immune system, intestinal microbiota and environmental factors in genetically susceptible individuals. Although IBD can affect any breed, German shepherd dogs (GSD) in the UK are at increased risk of developing the disease. Based on previous evidence, the aim of the present study was to identify single nucleotide polymorphisms (SNPs), which may confer genetic susceptibility or resistance to IBD using a genome-wide association study (GWAS). Genomic DNA was extracted from EDTA blood or saliva samples of 96 cases and 98 controls. Genotyping of cases and controls was performed on the Canine lllumina HD SNP array and data generated was analyzed using PLINK. Several SNPs and regions on chromosomes 7,9,11 and 13 were detected to be associated with IBD using different SNP-by-SNP association methods and F-ST windows approach. Searching one Mb up-and down-stream of the most significant SNPs, as identified by single SNP analysis as well as 200Kb before and after the start and the end position of the associated regions identified by F-ST windows approach, we identified 63 genes. Using a combination of pathways analysis and a list of genes that have been reported to be involved in human IBD, we identified 16 candidate genes potentially associated with IBD in GSD

Hypovitaminosis D is associated with negative outcome in dogs with protein losing enteropathy: a retrospective study of 43 cases

Abstract Background Hypovitaminosis D has previously been shown to be prevalent amongst dogs with protein losing enteropathy (PLE). The hypothesis of this study was that Low 25-hydroxyvitamin D (25(OH) D) serum concentrations could be a risk factor for negative outcome in dogs with PLE. Forty-three dogs diagnosed with PLE (2005–2014) and which serum Vitamin D serum concentrations were collected and archived at −80 Degrees C were analyzed. Post-diagnostic communication with referring veterinarians was made to determine outcome of PLE dogss: Dogs which died due to PLE within 4 months after diagnosis (negative outcome group, n = 22) and dogs alive or which died due to another disease at the end point of the study (1 year after diagnosis, good outcome group, n = 21). Serum samples taken at the time of diagnosis were analysed for ionized calcium (iCa) concentrations and serum 25(OH) D concentration. Results Clinical (CCECAI) scores, age at PLE diagnosis, and iCa concentrations were not significantly different between dog groups. A significantly greater (p < 0.001) number of PLE dogs treated with hydrolyzed or elimination diet alone showed good outcome as compared to the PLE negative outcome group. Median serum 25(OH) D concentration was significantly (p = 0.017) lower in dogs with negative outcome versus PLE dogs with good outcome. Using logistic regression analysis, 25(OH) D serum concentration was shown to be a statistically significant factor for outcome determination. Cox regression analysis yielded a hazard ratio of 0.974 (95% CI 0.949, 0.999) per each one nmol/l increase in serum 25(OH) D concentration. Conclusions Low serum 25(OH) D concentration in PLE dogs was significantly associated with poor outcome. Further studies are required to investigate the clinical efficacy of Vitamin D (cholecalciferol) as a potential therapeutic agent for dogs with PLE

Spin-filter effect of the europium chalcogenides: An exactly solved many-body model

A model Hamiltonian is introduced which considers the main features of the experimental spin filter situation as s-f interaction, planar geometry and the strong external electric field. The proposed many-body model can be solved analytically and exactly using Green functions. The spin polarization of the field-emitted electrons is expressed in terms of spin-flip probabilities, which on their part are put down to the exactly known dynamic quantities of the system. The calculated electron spin polarization shows remarkable dependencies on the electron velocity perpendicular to the emitting plane and the strength of s-f coupling. Experimentally observed polarization values of about 90% are well understood within the framework of the proposed model.Comment: accepted (Physical Review B); 10 pages, 11 figures; http://orion.physik.hu-berlin.de

4f-spin dynamics in La(2-x-y)Sr(x)Nd(y)CuO(4)

We have performed inelastic magnetic neutron scattering experiments on La(2-x-y)Sr(x)Nd(y)CuO(4) in order to study the Nd 4f-spin dynamics at low energies. In all samples we find at high temperatures a quasielastic line (Lorentzian) with a line width which decreases on lowering the temperature. The temperature dependence of the quasielastic line width Gamma/2(T) can be explained with an Orbach-process, i.e. a relaxation via the coupling between crystal field excitations and phonons. At low temperatures the Nd-4f magnetic response S(Q,omega) correlates with the electronic properties of the CuO(2)-layers. In the insulator La(2-y)Nd(y)CuO(4) the quasielastic line vanishes below 80 K and an inelastic excitation occurs. This directly indicates the splitting of the Nd3+ ground state Kramers doublet due to the static antiferromagnetic order of the Cu moments. In La(1.7-x)Sr(x)Nd(0.3)CuO(4) with x = 0.12, 0.15 and La(1.4-x)Sr(x)Nd(0.6)CuO(4) with x = 0.1, 0.12, 0.15, 0.18 superconductivity is strongly suppressed. In these compounds we observe a temperature independent broad quasielastic line of Gaussian shape below T about 30 K. This suggests a distribution of various internal fields on different Nd sites and is interpreted in the frame of the stripe model. In La(1.8-y)Sr(0.2)Nd(y)CuO(4) (y = 0.3, 0.6) such a quasielastic broadening is not observed even at lowest temperature.Comment: 8 pages, 10 figures included, to appear in Phys. Rev.

Oral chondroitin sulfate and prebiotics for the treatment of canine Inflammatory Bowel Disease: a randomized, controlled clinical trial

BACKGROUND Canine inflammatory bowel disease (IBD) is a chronic enteropathy of unknown etiology, although microbiome dysbiosis, genetic susceptibility, and dietary and/or environmental factors are hypothesized to be involved in its pathogenesis. Since some of the current therapies are associated with severe side effects, novel therapeutic modalities are needed. A new oral supplement for long-term management of canine IBD containing chondroitin sulfate (CS) and prebiotics (resistant starch, β-glucans and mannaoligosaccharides) was developed to target intestinal inflammation and oxidative stress, and restore normobiosis, without exhibiting any side effects. This double-blinded, randomized, placebo-controlled trial in dogs with IBD aims to evaluate the effects of 180 days administration of this supplement together with a hydrolyzed diet on clinical signs, intestinal histology, gut microbiota, and serum biomarkers of inflammation and oxidative stress. RESULTS Twenty-seven client-owned biopsy-confirmed IBD dogs were included in the study, switched to the same hydrolyzed diet and classified into one of two groups: supplement and placebo. Initially, there were no significant differences between groups (p > 0.05) for any of the studied parameters. Final data analysis (supplement: n = 9; placebo: n = 10) showed a significant decrease in canine IBD activity index (CIBDAI) score in both groups after treatment (p < 0.001). After treatment, a significant decrease (1.53-fold; p < 0.01) in histologic score was seen only in the supplement group. When groups were compared, the supplement group showed significantly higher serum cholesterol (p < 0.05) and paraoxonase-1 (PON1) levels after 60 days of treatment (p < 0.01), and the placebo group showed significantly reduced serum total antioxidant capacity (TAC) levels after 120 days (p < 0.05). No significant differences were found between groups at any time point for CIBDAI, WSAVA histologic score and fecal microbiota evaluated by PCR-restriction fragment length polymorphism (PCR-RFLP). No side effects were reported in any group. CONCLUSIONS The combined administration of the supplement with hydrolyzed diet over 180 days was safe and induced improvements in selected serum biomarkers, possibly suggesting a reduction in disease activity. This study was likely underpowered, therefore larger studies are warranted in order to demonstrate a supplemental effect to dietary treatment of this supplement on intestinal histology and CIBDAI