Maple syrup urine disease in calves: a clinical, pathological and biochemical study

The clinical, pathological and biochemical findings of a study of 30 Poll Hereford, Hereford, Poll Hereford cross or Hereford cross calves affected with branched chain ketoacid dehydrogenase (BCKAD) complex deficiency or maple syrup urine disease (MSUD) are presented. In breeding studies, 6 of 21 calves from obligate heterozygote matings were affected with MSUD, suggesting the disease is inherited in an autosomal recessive manner. Calves were clinically affected from birth, but there were variations in the subsequent course of progressive deterioration of central nervous system function. Concentrations of the branched chain amino acids and keto acids were elevated in pre-suckle plasma and cerebellar water content was higher in affected calves. Activity of BCKAD complex was minimal in fibroblasts cultured from an affected calf. Spongiform encephalopathy and elevated ratios of the branched to straight chain amino acids in formalin fixed cerebral tissue were found in a stillborn foetus and a 3-month-old Hereford calf. These findings suggest the disease occurs prenatally and that a delayed form may exist.     

Hormonal calcium regulation and calcium setpoint in offspring of bitches with different calcium intakes during pregnancy

High maternal calcium (Ca) intake may lead to alterations in development and differentiation of fetal tissues and may result in altered 'programming' of Ca homeostasis, with eventual effects on Ca handling and skeletal development in the offspring during later life. In bitches fed a diet with a Ca intake three times above recommendations (3.27 g/100 g vs 1.14 g/100 g dry matter) during the second half of pregnancy, the plasma concentration of 1,25 dihydroxy cholecalciferol (1,25 (OH)₂ vit D) appeared to decrease, while plasma Ca, phosphorus (P), parathyroid hormone (PTH) and calcitonin (CT) concentrations remained unchanged. High maternal Ca intake did not result in altered basal or stimulated plasma concentrations of Ca, P, PTH, CT and 1,25 (OH)₂ vit D in the offspring (n = 7) when compared with pups from bitches fed a normal Ca diet during the entire pregnancy (controls, n = 7). The Ca setpoint for PTH secretion (^Ca S_for PTH) was therefore not different from controls. From this pilot study it may be concluded that excessive Ca intake during late pregnancy in the bitch has no deleterious effects on hormonal Ca homeostasis in the offspring.     

Meningeal carcinomatosis in a dog: magnetic resonance imaging features and pathological correlation

A six-year-old cross breed dog was presented with a four-month history of seizure activity, which was unresponsive to anticonvulsive therapy and an acute deterioration in neurological status, evident as central blindness. Cyst-like structures and nodular enhancement within the subarachnoid space were shown on a magnetic resonance image (MRI) scan. Histopathological examination of brain tissue was consistent with meningeal carcinomatosis.     

Comparison of carbon-stock changes,eddycovariance carbon fluxes and model estimates in coastal Douglas-fir stands in British Columbia

Background: The global network of eddy-covariance(EC) flux-towers has improved the understanding of the terrestrial carbon(C) cycle, however, the network has a relatively limited spatial extent compared to forest inventory data and plots. Developing methods to use inventory-based and EC flux measurements together with modeling approaches is necessary evaluate forest C dynamics across broad spatial extents.Methods: Changes in C stock change(ΔC) were computed based on repeated measurements of forest inventory plots and compared with separate measurements of cumulative net ecosystem productivity(ΣNEP) over four years(2003 – 2006) for Douglas-fir(Pseudotsuga menziesii var menziesii) dominated regeneration(HDF00), juvenile(HDF88and HDF90) and near-rotation(DF49) aged stands(6, 18, 20, 57 years old in 2006, respectively) in coastal British Columbia. ΔC was determined from forest inventory plot data alone, and in a hybrid approach using inventory data along with litter fall data and published decay equations to determine the change in detrital pools. These ΔC-based estimates were then compared with ΣNEP measured at an eddy-covariance flux-tower(EC-flux) and modelled by the Carbon Budget Model- Canadian Forest Sector(CBM-CFS3) using historic forest inventory and forest disturbance data.Footprint analysis was used with remote sensing, soils and topography data to evaluate how well the inventory plots represented the range of stand conditions within the area of the flux-tower footprint and to spatially scale the plot data to the area of the EC-flux and model based estimates.Results: The closest convergence among methods was for the juvenile stands while the largest divergences were for the regenerating clearcut, followed by the near-rotation stand. At the regenerating clearcut, footprint weighting of CBM-CFS3 ΣNEP increased convergence with EC flux ΣNEP, but not for ΔC. While spatial scaling and footprint weighting did not increase convergence for ΔC, they did provide confidence that the sample plots represented site conditions as measured by the EC tower.Conclusions: Methods to use inventory and EC flux measurements together with modeling approaches are necessary to understand forest C dynamics across broad spatial extents. Each approach has advantages and limitations that need to be considered for investigations at varying spatial and temporal scales.     

Upregulation of the PI3K/Akt Pathway in the Tumorigenesis of Canine Thyroid Carcinoma

Background

Information on the genetic events leading to thyroid cancer in dogs is lacking.

Hypothesis/Objectives

Upregulation of the PI3K/Akt pathway has an important role in the tumorigenesis of thyroid carcinoma in dogs.

Animals

Fifty‐nine dogs with thyroid carcinoma and 10 healthy controls.

Methods

Quantitative RT‐PCR was performed for VEGFR‐1, VEGFR‐2, EGFR, PIK3CA, PIK3CB, PDPK1, PTEN, AKT1, AKT2, COX‐2, and CALCA. Mutation analysis was performed for known hotspots of RAS (N, K, H), PIK3CA, BRAF, RET, and for the entire coding region of PTEN.

Results

Forty‐three dogs (73%) had follicular cell thyroid carcinoma (FTC) and 16 dogs (27%) had medullary thyroid carcinoma (MTC). The relative mRNA expressions of VEGFR‐1 (P < .001), VEGFR‐2 (P = .002), PDPK1 (P < .001), AKT1 (P = .009), and AKT2 (P < .001) were increased in FTC, and those of EGFR (P < .001), VEGFR‐1 (P = .036), and PIK3CA (P = .019) were increased in MTC when compared to normal thyroid glands. Mutation analysis of K‐RAS identified 2 activating missense mutations, which also have been described in thyroid cancer of humans. A G12R substitution was present in 1 FTC and an E63K substitution was present in 1 MTC. No functional mutations were found in the sequenced regions of H‐RAS, N‐RAS, PIK3CA, BRAF, RET, and PTEN.

Conclusions and Clinical Importance

The increased expression of several genes associated with PI3K/Akt signaling suggests the involvement of this pathway in the pathogenesis of thyroid carcinoma in dogs, warranting further research on pathway activation and gene amplification. The mutations most frequently associated with thyroid cancer in humans are rare in dogs.     

Identification of Apoptotic Bodies in Equine Semen

Apoptosis in the testis is required to ensure an efficient spermatogenesis. However, sometimes, defective germ cells that are marked for elimination during this process escape elimination in the testes, giving rise to ejaculates with increased percentages of abnormal and apoptotic spermatozoa and a high percentage of apoptotic bodies. Apoptosis markers in the ejaculate have been associated with low fertility, either in animals or humans. Therefore, the goal of this study was to investigate whether fresh equine semen contains apoptotic bodies [initially named Merocyanine 540 (M540) bodies] and to study the relationship between the quantity of these bodies and cell concentration, the volume of ejaculate, viability and motility. Moreover, we also studied whether the presence apoptotic bodies in fresh semen was related to the resistance of the stallion spermatozoa to being incubated at 37°C or being frozen and thawed. Fresh equine semen was stained with fluorescent dyes such as M540 and Annexin‐V. Active Caspase 3 was studied in fresh semen through Western blotting and immunofluorescence with a specific antibody. Sperm kinematics was assessed in fresh, incubated and thawed samples using computer‐assisted semen analysis, and viability was evaluated with the LIVE/DEAD Sperm Viability Kit. Overall, our results demonstrate for the first time the presence of apoptotic bodies in equine semen. The quantity of apoptotic bodies was highly variable among stallions and was positively correlated with Caspase 3 activity in fresh samples and negatively correlated with the viability and motility of stallion spermatozoa after the cryopreservation process.     

Anti‐Mullerian Hormone Concentration and Antral Ovarian Follicle Population in Murrah Heifers Compared to Holstein and Gyr Kept Under the Same Management

This study was performed to evaluate plasma concentrations of anti‐Mullerian hormone (AMH) and the ovarian antral follicle population (AFP) in different genetic groups. Cyclic heifers (13 Bubalus bubalis [Murrah]; 15 Bos taurus [Holstein] and 10 Bos indicus [Gyr]) were maintained under the same management and were synchronized with two doses of 150 μg IM d‐cloprostenol administered 14 days apart. After the second d‐cloprostenol treatment, heifers had their ovaries scanned daily by ultrasound to define the day of ovulation. On the same day, the AFP was determined and a plasma sample was collected to measure AMH. Murrah heifers had less AFP (25.6 ± 2.1 follicles; p = 0.01) and plasma AMH concentration (0.18 ± 0.03 ng/ml; p < 0.001) than Gyr (60.0 ± 12.2 follicles and 0.60 ± 0.12 ng/ml of AMH); however, data were similar when compared to Holstein (35.9 ± 6.8 follicles and 0.24 ± 0.06 ng/ml of AMH) heifers. Regardless of genetic background, there was a positive relationship between the AFP and plasmatic AMH concentration (Murrah [r = 0.62; p < 0.01], Holstein [r = 0.66; p < 0.001] and Gyr [r = 0.88; p < 0.001]). Also, when heifers were classified according to high‐ or low‐AMH concentration based on the average within each genetic group, high‐AMH heifers had greater (p < 0.0001) AFP than low‐AMH heifers. In conclusion, both Murrah and Holstein heifers presented lower plasma AMH concentration and AFP when compared to Gyr.     

Capture of atmospheric ammonium by grassland canopies

Air pollution can cause a decline in species through acidification of the habitat. New data suggest that the decline may be due to eutrophication rather than acidification. In Western Europe, eutrophication largely results from atmospheric ammonium deposition. The amount deposited on vegetation is a function of its canopy structure. Deposition on grasslands has been underestimated, and a significant amount of the deposited ammonium appears to be assimilated by the plant canopy. These quantities are sufficient to initiate changes in the competitive relations among the plant species.     

Reconstruction of Current Flow and Imaging of Current-Limiting Defects in Polycrystalline Superconducting Films

Magneto-optical imaging was used to visualize the inhomogeneous penetration of magnetic flux into polycrystalline TlBa2Ca2Cu3Ox films with high critical current densities, to reconstruct the local two-dimensional supercurrent flow patterns and to correlate inhomogeneities in this flow with the local crystallographic misorientation. The films have almost perfect c-axis alignment and considerable local a- and b-axis texture because the grains tend to form colonies with only slightly misaligned a and b axes. Current flows freely over these low-angle grain boundaries but is strongly reduced at intermittent colony boundaries of high misorientation. The local (<10-micrometer scale) critical current density Jc varies widely, being up to 10 times as great as the transport Jc (scale of approximately 1 millimeter), which itself varies by a factor of about 5 in different sections of the film. The combined experiments show that the magnitude of the transport Jc is largely determined by a few high-angle boundaries.