Serum Thyroid Hormone Concentrations Fluctuate in Cats with Hyperthyroidism

We measured serum thyroxine (T4) and 3,3',5-triiodothyronine (T3) concentrations in hyperthyroid cats (hourly for 10 hours in 14 cats, and daily for 15 days in seven cats) to assess fluctuation in thyroid hormone levels. Over the 10-hour study period the coefficient of variation (CV) for serum T4 and T3 concentrations ranged from 6.4-22.6% (mean = 12.0 +/- 4.8%) and from 9.6-33.1% (mean = 17.5 +/- 6.3%), respectively. During the 15-day study period, CV for serum T4 ranged from 6.6-34.8% (mean = 18.4 +/- 9.3%), while CV for serum T3 ranged from 7.8-31.0% (mean = 20.1 +/- 8.6%). These CV values were significantly higher than the expected intra-assay CVs (T4 assay, 5.1%; T3 assay, 7.7%). In addition, some of the cats with mild hyperthyroidism showed one or more normal serum T4 and T3 values during the course of the respective study periods. There was no specific time during the 10-hour study period at which the cats consistently showed peak serum T4 or T3 concentrations. These results suggest that serum thyroid hormone concentrations are subject to a degree of fluctuation that exceeds the usual assay variation, and that cats with mild hyperthyroidism can, at a given time, exhibit normal serum T4 and T3 values. Therefore, a diagnosis of feline hyperthyroidism should not be excluded on the basis of the finding of a single normal serum T4 or T3 value in a cat with clinical signs and physical examination findings consistent with the disease.     

Canine hemangiopericytoma: 23 cases (1967-1984)

The medical records of 23 histopathologically confirmed cases of canine hemangiopericytoma were reviewed. Ninety-one percent (21/23) of the dogs were 7 years old or older, and 70% (16/23) were female. Seventy-four percent (20/27) of the tumors developed on the extremities. Recurrence rates were 31% (5/16) with surgical excision only, and 60% (3/5) with surgical excision combined with radiotherapy. Tumor recurrence did not appear to be related to mitotic index. Metastasis was suspected in one of the dogs, but was not confirmed.     

Landscape-scale modelling of agroforestry ecosystems services in Swiss orchards: a methodological approach

Context

Agroforestry systems in temperate Europe are known to provide both, provisioning and regulating ecosystem services (ES). Yet, it is poorly understood how these systems affect ES provision at a landscape scale in contrast to agricultural practises.

Objectives

This study aimed at developing a novel, spatially explicit model to assess and quantify bundles of provisioning and regulating ES provided by landscapes with and without agroforestry systems and to test the hypothesis that agroforestry landscapes provide higher amounts of regulating ES than landscapes dominated by monocropping.

Methods

Focussing on ES that are relevant for agroforestry and agricultural practices, we selected six provisioning and regulating ES—“biomass production”, “groundwater recharge”, “nutrient retention”, “soil preservation”, “carbon storage”, “habitat and gene pool protection”. Algorithms for quantifying these services were identified, tested, adapted, and applied in a traditional cherry orchard landscape in Switzerland, as a case study. Eight landscape test sites of 1 km?×?1 km, four dominated by agroforestry and four dominated by agriculture, were mapped and used as baseline for the model.

Results

We found that the provisioning ES, namely the annual biomass yield, was higher in landscape test sites with agriculture, while the regulating ES were better represented in landscape test sites with agroforestry. The differences were found to be statistically significant for the indicators annual biomass yield, groundwater recharge rate, nitrate leaching, annual carbon sequestration, flowering resources, and share of semi-natural habitats.

Conclusions

This approach provides an example for spatially explicit quantification of provisioning and regulating ES and is suitable for comparing different land use scenarii at landscape scale.

     

Isolation and Culture of Ovine and Bubaline Small and Large Pre-antral Follicles: Effect of Cyclicity and Presence of a Dominant Follicle

Studies were conducted to examine the effects of the cyclicity and the presence of a dominant follicle (DF) in ovary on the recovery and in vitro growth of pre-antral follicles (PFs) in sheep and buffalo. Small pre-antral follicles (SPFs, 100–250 μm) and large pre-antral follicles (LPFs, 250–450 μm) were isolated from slaughterhouse ovaries in the breeding seasons by a mechanical and enzymatic method. The sheep and buffalo PFs were cultured in vitro for 6 and 15 days, respectively, and examined for their growth, survival and antrum formation rates and growth rates of oocytes in cultured pre-antral follicles. The follicles of the sheep and buffalo were recovered and cultured simultaneously within replicates. The recovery rates (number per ovary) of both SPFs and LPFs were significantly (p < 0.05) higher in cyclic ewes (SPFs: 22.0 ± 3.3 vs 12.1 ± 2.6 and LPFs: 16.0 ± 3.6 vs 9.2 ± 1.8) and buffaloes (SPFs: 9.2 ± 1.3 vs 4.1 ± 1.0 and LPFs: 10.3 ± 2.7 vs 5.4 ± 0.7) compared with those recovered from acyclic ones. Presence of a DF in ovary significantly (p < 0.05) reduced the recovery rates of LPFs in ewes (9.06 ± 2.7 vs 16.4 ± 3.8) but had no effect in buffalo. Cyclicity of animals or follicular dominance had no effects on in vitro growth, survival and antrum formation rates and growth rates of oocytes in cultured PFs of SPFs and LPFs in both sheep and buffalo. The in vitro growth, survival and antrum formation rates of LPFs and growth rates of oocytes in cultured LPFs were significantly (p < 0.05) higher than those observed in SPFs in both sheep and buffalo. The overall recovery and growth rates of the PFs were lower in buffaloes compared with ewes.     

Gonadotropin releasing hormone receptor gene and protein expression and immunohistochemical localization in bovine uterus and oviducts

Recently GnRH, GnRH-R systems has been demonstrated in various extrahypothalamic and extrapituitary reproductive tissues in different mammalian species, where GnRH acts in an autocrine and or paracrine manner and modulates different biological processes. GnRH-R mRNA has also been demonstrated in bovine ovaries (follicle and corpus luteum) and normal and carcinogenic human endometrium/endometrial cells. This is the first study elucidating presence of GnRH-R mRNA and GnRH-R protein in bovine uterus and oviducts in follicular and luteal phases of the estrous cycle and further localizing the receptors to endometrial and oviductal epithelial cells. To our knowledge this is the first report demonstrating GnRH-R mRNA and protein in mammalian oviducts. We used gene-specific primers and monoclonal GnRH-R antibody to test GnRH-R mRNA and GnRH-R protein through RT-PCR and immunobloting. Immunohistochemistry was employed to localize these receptors to endometrial and oviductal epithelial cells. GnRH-R mRNA and receptor protein were expressed at expected molecular weights of 920bp and 60kD, respectively. Densitometry analysis revealed that expression levels for GnRH-R protein in uterus and oviducts were similar to bovine pituitary. The presence of GnRH receptors in bovine uterus and oviducts is intriguing and it would be imperative to examine the functional role of this system in the regulation of reproductive processes.     

Glucocorticoids in the cat

Glucocorticoids are one of the two main classes of hormones, along with mineralocorticoids, which are secreted from the adrenal cortex. Since the discovery of the anti‐inflammatory properties of the natural glucocorticoid hydrocortisone, a large number of artificial glucocorticoids have been synthesized to attempt to increase efficacy and decrease side effects. These drugs are now considered one of the most commonly prescribed agents in veterinary practice. The effect of these drugs has been shown to vary significantly between species. Cats appear to tolerate glucocorticoids well, resulting in these drugs being recommended for a wide variety of conditions; however, there are few studies on the effects of glucocorticoids in cats. In this paper we review some of the available literature on glucocorticoid use in the cat.     

Development and in vitro characterization of canine CD40-Ig

We recently reported that blockade of the CD40-CD154 ligand interaction with the cross-reacting mouse anti-human CD154 antibody, 5c8, together with donor-specific transfusion led to enhanced but not completely successful engraftment in a canine model of DLA-identical marrow transplantation after 100cGy total body irradiation (TBI). In order to improve the transplantation outcomes, we sought to develop a canine-specific reagent. To that end, we fused the extracellular domain of the canine CD40 with a mouse IgG2a Fc tail and tested the immunosuppressive effectiveness of the fusion protein in mixed leukocyte reactions. The extracellular domain of canine CD40 was fused with the Fc portion of mouse IgG2a in a pcDNA3.1+vector. Dhfr-deficient CHO cells were co-transfected with the CD40-Ig vector and a dhfr-containing vector. Stable, high producing clones were selected under increasing methotrexate concentrations. The fusion protein was purified, tested in mixed leukocyte reactions, and its immunosuppressive effect compared to that of the anti-CD154 antibody 5c8. The transfected cell line produced a CD40-Ig dimer whose identity was confirmed by mass spectroscopy. The purified canine CD40-Ig blocked mixed leukocyte reactions at a concentration of 1nM, which was 10 times more effective than the anti-CD154 antibody. Canine CD40-Ig is more immunosuppressive than the anti-human CD154 antibody 5c8 in canine mixed leukocyte reactions and may be more effective in vivo in a model of marrow transplantation.