Volume loading-related changes in tissue Doppler images derived from the tricuspid valve annulus in dogs

OBJECTIVE: To investigate the relationship between preload and tricuspid valve annulus-derived tissue Doppler imaging (TDI) as an index of right ventricular (RV) filling in dogs. ANIMALS: 7 Beagles. PROCEDURES: Peak systolic RV pressure and RV end-diastolic pressure (RVEDP) were measured in anesthetized dogs. Pulsed Doppler was used to measure tricuspid valve inflow and pulmonary valve outflow velocities. The TDI velocities were measured at the lateral corner of the tricuspid valve annulus. Lactated Ringer's solution was infused at 200 mL/kg/h for 60 minutes via the cephalic vein. RESULTS: IV infusion significantly increased heart rate, RV pressure, and RVEDP. Early diastolic flow (E-wave) and ejection time significantly increased. The myocardial performance index (MPI) significantly decreased. Intravenous infusion significantly increased the ratio of the E'-wave (peak myocardial velocity during early diastole) to the A'-wave (peak myocardial velocity during late diastole; E':A' ratio) and myocardial velocity during systole (S'), early diastole (E'), and late diastole (A'). The TDI-isovolumic relaxation time and TDI-MPI decreased significantly. The RVEDP was correlated with late diastolic flow (A-wave), ratio of the E-wave to the A-wave (E:A ratio), E'-wave, A'-wave, S'-wave (peak myocardial velocity during systole), TDI-isovolumic relaxation time, TDI-MPI, and ratio of the E-wave to the E'-wave (E: E' ratio). The A-wave and E:A ratio and TDI-derived isovolumic relaxation time, S' duration, and E'-wave could predict the RVEDP. CONCLUSIONS AND CLINICAL RELEVANCE: The TDI velocities were affected by RV filling pressure in healthy dogs, whereas other TDI profiles, such as MPI and E':A' ratio, were independent of acute filling abnormalities.     

Effects of ammonia and hydrogen sulfide on physical and biochemical properties of the claw horn of Holstein cows

The effects of ammonia and hydrogen sulfide on the physical and biochemical properties of the claw horn of Holstein cows were evaluated. Significant (P < 0.05, 0.01) decreases in hardness and elasticity were found in claw horns soaked in ammonia (NH₃) and hydrogen sulfide (H₂S) solutions compared with those that were soaked in water for 12, 24, and 48 h. Water absorption rate, as a indicator of permeability barrier function, increased significantly (P < 0.05) over time during the soaking period and was found to be dependent on the concentrations of NH₃ and H₂S in the solutions. The contents of ceramide, the main lipid component for the permeability barrier system of the stratum corneum, were significantly decreased in claw horns soaked in NH₃ and H₂S solutions compared with the values before soaking. Quantities of eluted protein released from claw horns treated with NH₃ and H₂S solutions were approximately 20 times and 30 to 40 times greater than those released from claw horns treated with water alone. Interestingly, the quantities of cytokeratin 10, the main cytoskeletal protein of the stratum corneum, eluted from claw horns treated with NH₃ and H₂S solutions were markedly greater than the quantity released from horns soaked in water. Our results suggest that abnormal changes in the physical property of claw horn caused by NH₃ and H₂S treatment are due to disruption of the biochemical property of the claw horn induced by these chemical agents derived from slurry.     

Changes of blood biochemical values in ponies recovering from hyperlipemia in Japan

Hyperlipemia in horses is a disorder of lipid metabolism peculiar to ponies. This study reports changes of blood biochemical values from the acute to the postconvalescent phases in 3 Shetland ponies with hyperlipemia in Japan. Diseased ponies (all 7 to 9 years old, in late pregnancy, and obese) were fed in the same farm. The periods of their hospitalizations ranged from 30 to 45 days. Twelve well-conditioned ponies (3 to 13 years old) around parturition were used to establish baseline values for blood test results. Main clinical findings in the affected ponies were depression, dysphagia, anorexia, ventral edema and milky-appearing plasma. Hypertriglyceridemia (40- to 70-fold rise of controls) was found in the acute phase of the disease in the affected ponies, and was derived from increased very-low density lipoproteins. Aspartate transaminase and gamma-glutamyl transpeptidase activities, blood urea nitrogen, and creatinin concentrations were increased in acute ponies compared to controls, suggesting impairment of liver and kidney functions. However, these values gradually recovered until the end of postconvalescent phase. Hyperinsulinemia was observed in the acute phase of the hyperlipemia of all affected ponies. And an exaggerated insulin response to intravenous glucose was observed in the 2 ponies given intravenous glucose tolerance tests. These findings suggest decreased insulin sensitivity in hyperlipemic ponies.     

Changes in peripheral lymphocyte subsets in the type 1 diabetic dogs treated with insulin injections

Plasma metabolites and peripheral lymphocyte subsets were measured in ten diabetic and ten control dogs to investigate their significances as indicators to evaluate immune states in the diabetic dogs. Diabetic dogs were treated with insulin injections, however their plasma glucose and fructosamine concentrations were significantly higher than those of the controls. There were no significant differences in counts of total white blood cells (WBC) and lymphocyte CD8(+) cells (cytotoxic T cells) between the control and the diabetic dogs. In the diabetic dogs, the counts of CD3(+) (T cells), CD4(+) (Helper T cells) and CD21(+) (B cells) cells and the peripheral lymphocytes CD4/CD8 ratio were significantly lower than those in the control dogs. We confirmed abnormality of lymphocyte subsets in insulin treated diabetic dogs and it may relate to depression of immunocompetence and high susceptibility to common infectious diseases.     

Controlling highly prevalent Staphylococcus aureus mastitis from the dairy farm

In 57 Holstein cows where the dairy farm uses a milking parlor system, the somatic cell count (SCC) increased persistently in the bulk milk (monthly mean 52.3 x 10(4) cells/ml; range 21 to 94 x 10(4) cells/ml). We detected S. aureus in 24 (41.2%) of the 54 lactating cows and in 29 (12.8%) of 227 quarters of the 57 milking cows in the herd. A control program was implemented in an effort to eradicate S. aureus mastitis from this dairy farm. The control plan established improved handling of the lactating cows, improved milking procedures, dry-cow therapy, and culling of infected cows. The program was monitored for 3.5 years by frequent checkups on the rate of S. aureus infection, the SCC, and the changes in milk composition. Eighteen months after the control program was started, the rate of S. aureus infection in the quarter milk decreased dramatically, and no S. aureus isolates were found in the milk of the remaining cows. The SCC in the bulk milk of the herd dropped to a monthly mean of <20 x 10(4) cells/ml. In conclusion, the control program was effective for controlling persistent S. aureus mastitis in this dairy herd.     

Cultivar variation for seed development in white clover (Trifolium repens L.)

Summary A controlled environment study was undertaken to clarify the factors responsible for poor seed set and to study seed development, ovule degeneration and seed abortion, both morphologically and cytologically, in three Japanese cultivars of white clover. Although the mean number of ovules per floret was 4.2–5.1, the average number of seeds per floret was found to be only 2.3–2.7. Microscopic examination of carpels from 0 to 28 days following floret maturity and pollination showed that 26–33% and 8–17% of the total seeds lost occurred within the first three days and the third through fifth day following pollination, respectively. Beyond this period occasional seed abortion was observed at all stages of seed development, but this represented a very small proportion (2–7%) of the total seeds lost.A stain clearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilized, mature ovules and embryos of the ovules at 3 and 5-day periods following pollination. It was found that 20–22% of unfertilized and matured ovules were sterile, suggesting that ovule degeneration before fertilization was the major cause for the high percentage of seeds lost within a 0 to 3-day period following pollination. Cytological observations revealed that abortion of developing seed was due to a sudden arrest in embryo growth and that the early development of the embryo of such aborting seed was normal. Either nutrient shortage or meiotic irregularities may be the cause for high ovule sterility or post-fertilization abortion of developing seeds.     

Biochemical properties of the cell wall in the Arabidopsis mutant bor1‐1 in relation to boron nutrition

We examined concentrations of boron (B) and dimerization of rhamnogalacturonan II (RG‐II), a B‐binding polysaccharide, in the cell wall of a low‐B sensitive mutant of Arabidopsis thaliana, bor1‐1, to investigate possible effects of the bor1‐1 mutation on the biochemical form of pectins in the cell wall. In the bor1‐1 mutant, B concentrations in the cell wall from shoots were lower than those in the wild type at low B supply, whereas they were similar at sufficient B supply. The amount of B present as borate ester of the RG‐II dimer (dRG‐II‐B) in the bor1‐1 mutant was lower than that in the wild type at low B supply. In the wild type, about 90 % of RG‐II was present as dRG‐II‐B, both, at low and sufficient B supply. In the bor1‐1 mutant, about 60 % of RG‐II was in its monomeric form (mRG‐II) at low B supply, whereas more than 85 % of it was present as dRG‐II‐B at sufficient B supply. However, similar as the wild type, mRG‐II derived from the bor1‐1 mutant was able to form dRG‐II‐B in vitro in the presence of borate and lead. Sugar composition of cell wall fractions was similar in both genotypes. These results suggest that the polysaccharide composition in the cell wall was not strongly affected by the bor1‐1 mutation. The observed difference in dimerization of RG‐II at low B supply is most likely due to a reduced B concentration in the shoots of the bor1‐1 mutant.     

Method to quantify root border cells in sandy soil

Root border cells are cells that detach from the growing root cap, and serve both physical and biological roles in the rhizosphere. Most work on border cells has been confined to agar, or hydroponic culture, because of the difficulty in separating them from soil particles. We present a new method to separate the root border cells from soil, and quantify border cell numbers in non-sterile sandy loam soil at contrasting matric potentials (−20 and −300 kPa). Recovery rates of 90±1% were achieved using a combination of surfactants, sonication, and centrifugation. Root border cell numbers in the dry soil (1.4×10³ after 24 h) were significantly decreased as compared with those in the wetter soil (1.7×10³ after 24 h). Possible reasons for the decreased release of border cells are discussed.