Right ventricular systolic and diastolic function assessed by two-dimensional speckle tracking echocardiography in dogs with myxomatous mitral valve disease

Pulmonary hypertension (PH) is a common comorbidity in dogs with myxomatous mitral valve disease (MMVD), and can induce various changes in the right heart, such as right ventricular (RV) hypertrophy, dilatation, and dysfunction. We hypothesized that RV function, not only systolic function but also diastolic function, could be worsened with PH progression. We aimed to compare RV systolic and diastolic function in dogs with MMVD. Twenty healthy dogs and sixty-eight dogs with MMVD were enrolled. Dogs with MMVD were classified into the probability of PH. Two-dimensional and Doppler echocardiographic indices for right heart and two-dimensional speckle tracking echocardiography indices were measured. The morphological indicators of the right heart were significantly higher only in the high probability of PH group. The RV strain, early-diastolic and systolic strain rates were significantly lower in the high probability of PH group than those in the low and intermediate probability of PH groups. Multivariate analysis showed that increased RV internal dimension normalized by body weight and RV myocardial performance index were significantly associated with the presence of right-sided congestive heart failure. Speckle tracking echocardiography-derived RV systolic and diastolic function were activated in the low and intermediate probability of PH groups. However, dogs with high probability of PH showed RV myocardial dysfunction and dilatation. Increased RV myocardial performance index and end-diastolic RV internal dimension normalized by body weight were significantly associated with the presence of right-sided congestive heart failure in dogs with MMVD.     

Seasonal variations in and effect of incubation water temperature on vertebral number in naturally spawning chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>

Seasonal variations and reaction norms for vertebral number (V _N) in response to incubation water temperature were estimated in adult and juvenile naturally spawning chum salmon Oncorhynchus keta. The mean V _N of adults varied according to spawning time; the early-spawning population had higher V _N values than the late-spawning population. Moreover, the mean V _N values in the early-spawning population decreased with seasonal changes, whereas V _N values in the late-spawning population remained stable. Chum salmon embryos in three full-sib families were incubated at five different temperatures until hatching, and the V _N values of the resulting juveniles were analyzed. The V _N reaction norm to incubation water temperature showed a V-shaped curve that was lowest at an intermediate temperature. The mean V _N at the same incubation temperature varied among the three families. These results suggest that V _N values in chum salmon are influenced by genetic components and incubation water temperatures. V _N may be a useful parameter for estimating the environmental conditions during ontogenesis and the genetic background by detecting population changes.     

A case of juvenile form of dilated cardiomyopathy in a 6-month-old Shiba Inu dog

A 6-month-old Shiba Inu dog was brought to the Veterinary Medical Teaching Hospital because of a cough, exercise intolerance, and pulmonary edema. The dog had a Levine 2/6 systolic murmur. Transthoracic echocardiography revealed left atrial and ventricular dilatation (left atrium to aortic ratio: 2.8), mitral and tricuspid valve regurgitation, and severe left ventricular myocardial hypokinesia (fractional shortening was 11.8%). Bubble contrast echocardiography did not reveal a congenital shunt; therefore, the dog was clinically diagnosed with early onset dilated cardiomyopathy. From the first visit, the dog was treated with pimobendan, taurine, torasemide, and isosorbide dinitrate. After 435 days, echocardiography revealed that systolic function had not improved. On Day 465, atrial fibrillation was confirmed via electrocardiogram, and treatment with diltiazem hydrochloride was initiated. The dog continued to appear clinically stable thereafter, until it died suddenly 1087 days after the initial visit. A postmortem histopathological examination identified severe enlargement of the left atrial and ventricular chambers as well as attenuated wavy fibers in the ventricular myocardium, which confirmed dilated cardiomyopathy in a juvenile. This is the first report of a juvenile form of dilated cardiomyopathy in a Shiba Inu dog. This case report provides evidence that the extended prognosis of this dog differed from that in previously reported cases of dilated cardiomyopathy in young dogs.Key clinical message:This is the first reported case of a juvenile form of dilated cardiomyopathy in a Shiba Inu dog. This report provides evidence that the prognosis of this dog differed from that in previously reported cases of dilated cardiomyopathy in young dogs.     

Expression and subcellular localization of E-cadherin, alpha-catenin, and beta-catenin in 8 feline mammary tumor cell lines

Protein expression and subcellular localization of E-cadherin, alpha-catenin, and beta-catenin in 8 feline mammary tumor cell lines were examined by western blot analysis and fluorescence immunocytochemistry. A low E-cadherin expression was observed in FNN-m cells. Furthermore, compared to other cell lines, two E-cadherin bands existed in FMC-p1 cells and were localized in the perinuclear region; distinct radial lines were observed in the cytoplasm. A low alpha-catenin expression was observed in FON-m cells, but there were no apparent abnormalities in its localization. In contrast, similar levels of beta-catenin expression and cytoplasmic localization were observed in all cell lines.     

Weed dynamics during the change of a degraded pasture to agroforestry system

This study evaluates weed dynamics during the first 4 years (2008–2011) of the implementation of an agroforestry system in the municipality of Tomé-açu in the state of Pará, Brazil. The study was conducted in a degraded pasture of Brachiaria humidicola, and treatments (T) included mixed plantations of oil palm with short-cycle leguminous species (T1) with the inclusion of manioc in T2 and forest species and palm trees in T3. In 2008, a floristic survey was conducted in 12 plots of 2 × 2 m per treatment. In 2009, herbicide was applied to one half of the area in each treatment. A total of 19,367 individuals of height <1.5 m were surveyed, of which 51 % were B. humidicola and 21 % were leguminous species that had been planted. Overall, an increase in plant density was observed between 2009 and 2010, followed by a decrease over the following year in areas without herbicide and a tendency for high densities to persist in areas with herbicide. Species richness increased over the study period in all areas (with or without herbicide), which might be related to habitat availability resulting from the reduced density of B. humidicola due to the effects of the herbicide, the leguminous species planted and the development of the agroforestry system. The association of short-cycle leguminous plants with afforestation appears to be an effective method for controlling weeds in the absence of herbicides.     

ErbB2 copy number gain is associated with adverse outcome in canine mammary carcinoma

Copy number gain (CNG) and/or protein overexpression of ErbB2 have been observed in human breast cancer patients and are associated with poor prognosis. Similarly, ErbB2 overexpression has also been observed in canine mammary carcinoma; however, data on ErbB2 copy number is limited. The purposes of this study were to evaluate ErbB2 copy number in dogs with mammary carcinoma and to investigate associations of ErbB2 CNG with ErbB2 expression, histological and clinical characteristics, and survival. DNA samples were isolated from 59 formalin-fixed paraffin-embedded canine mammary gland tissues (34 carcinoma, 14 adenoma, and 11 normal). Using a digital PCR assay, the ErbB2 copy number in these samples was determined as compared to a reference gene on canine chromosome 8. ErbB2 CNG was detected in 14/34 (41%) carcinomas and 2/14 (14%) adenomas. ErbB2 overexpression was observed in 3/34 (9%) carcinomas but not in adenomas. Neither ErbB2 CNG nor ErbB2 overexpression were detected in the normal controls. There was no significant association of the ErbB2 CNG with histological and clinical characteristics such as age, neutered status, histological grade, tumor size, lymph node involvement, distant metastasis, and clinical stage in the dogs with mammary carcinoma. The presence of ErbB2 CNG, but not ErbB2 overexpression, was significantly related to the shorter overall survival. These findings suggest that ErbB2 CNG is a prognostic factor in dogs with mammary carcinoma.