Effect of the US3 protein of bovine herpesvirus 5 on the actin cytoskeleton and apoptosis

The US3 protein is a unique protein kinase only present in the Alphaherpesvirinae subfamily of the herpesviruses. Studies performed with several alphaherpesviruses demonstrated that the US3 protein is involved in cytoskeleton modifications during viral infection and displays anti-apoptotic activity. However, the US3 protein of BoHV-5 has not been studied up to now. As reported for other alphaherpesviruses, our results showed that BoHV-5 US3 confers resistance against apoptosis and induces cytoskeletal reorganization leading to cell rounding, actin stress fiber breakdown and cell projections that interconnect cells. The expression of a kinase-dead version of BoHV-5 US3 showed that the anti-apoptotic activity and the induction of cell projections are kinase-dependent whereas kinase activity is not absolutely required for actin stress fiber breakdown. Besides, the kinase-dead version of US3, but not the wild type protein, was found excluded from the nucleus. These results constitute the first report on the BoHV-5 US3 functions, and highlight that there are functional differences and similarities among US3 proteins of different alphaherpesviruses.     

Phytochemical, antioxidant, and antiproliferative properties of seed oil and flour extracts of Maryland-grown tobacco cultivars

To determine the possible alternative use of tobacco, the seeds representing seven Maryland tobacco cultivars were investigated for their phytochemical, antioxidant, and antiproliferative properties. Tobacco seed oils were extracted by the Soxhlet method, and analyzed for their yield, density, refractive index, fatty acid profiles, and tocopherol profile. The defatted flours were extracted in 50% acetone and 80% ethanol. The tobacco seed oil and flour extracts were analyzed for total phenolic contents (TPC) and scavenging capacities against peroxyl, hydroxyl and 2,2-diphenyl-1-picryhydrazyl (DPPH) radicals. The fatty acid compositions of phospholipids and the protein content of the flours were also analyzed. In addition, oil and flour extracts of varieties MD609 and MD609LA were evaluated for their antiproliferative effects on HT-29 human colon cancer cells. All of the tested extracts significantly inhibited HT-29 cell proliferation except that from MD609 oil. The data from this study suggest the potential alternative use of tobacco seeds in developing natural antioxidants and antiproliferative agents for improving human health.     

Reliability of pelvimetry is affected by observer experience but not by breed and sex: A cross-sectional study in beef cattle

Pelvis size plays an important role to prevent dystocia in cattle caused by the foeto-maternal disproportion in commonly primiparous females. The reproducibility and repeatability are two important aspects for the reliability of the measurements to use in the selection of cattle for culling. Pelvic measures were taken with a Rice pelvimeter from 224 young cattle (180 females and 44 males) of four beef breeds in South Africa. One experienced and two inexperienced observers each measured pelvic height and width twice. The proportion measurements with a maximum difference of 0.5 cm within animal compared with the first measurement by the experienced observer are around 80% and by the inexperienced observers around 50% for pelvic height and around 60% for pelvic width. Breed and sex do not affect the reliability of pelvimetry by an experienced observer. Under- and overestimation of pelvis size were observed in inexperienced observers, which seems to be unrelated to breed and sex.     

Effect of root temperature on carob growth: Nitrate versus ammonium nutrition

The response of carob (Ceratonia siliqua L.) seedlings grown at different root zone temperatures affected by nitrate and ammonium nutrition was studied. When root temperatures ranged from 10 to 35°C, ammonium‐fed plants were significantly larger than nitrate‐fed plants. Ammonium‐fed plants displayed toxicity symptoms and were much smaller at 40°C root temperature in comparison with the nitrate‐fed plants grown at the same root temperature. Root/shoot ratio slightly increase with root temperature in ammonium‐ and nitrate‐fed plants in a similar way, and shoot demand per root unit decreased with root temperature between 15 and 25°C. There was a general increase in net photosynthesis with root temperature, though nitrate‐fed plants were more sensitive to low and ammonium‐fed plants to high temperatures. Increasing the root temperature of ammonium fed plants from 10 to 40°C leads to a 30% increase in the amount of photosynthates sent to the roots. The presence of ammonium resulted in the distribution of newly fixed carbon away from carbohydrates and into nitrogen compounds. Potassium, calcium, and nitrogen content of the plants also increased with increasing root temperature.     

Nitrate assay by multiple wavelength spectroscopy and analysis of kinetic parameters of net nitrate uptake by barley seedlings

A method for determination of nitrate concentration and estimation of kinetic parameters of nitrate uptake by spectroscopy based on absorbances at multiple wavelengths has been developed to estimate nitrate uptake by barley (Hordeum vulgare L. cv. Steptoe) seedlings. Nitrate concentration in the nutrient solution was determined from the slope of the linear regression line of the absorbances to nitrate absorption coefficients at 12 wavelengths. Interference by root exudates was only due to an absorption component changing with wavelength in correlation with nitrate absorption. The standard error of the determination decreased in reverse proportion to the square root of the number of the wavelengths. A linear form of the net uptake equation, NUR = I_maxC/K_m+C‐E, could be expressed as NUR = (I_max ‐ E) ‐ K_m NUR/C ‐ K_mE I/C where NUR is net uptake rate, Imax is maximum influx, C is concentration, Km is the Michaelis constant, and E is an efflux constant. The method described here was used to determine the time course of nitrate depletion by barley seedlings from their nutrient solution. The isotherm of net nitrate uptake rates derived from the time course was analyzed after modifications based on the linear form of the net uptake equation. The analysis yielded highly significant results (P<0.0001).     

Cell size in Russet Burbank potato tubers with various levels of nitrogen and soil moisture tensions

Russet Burbank potatoes were grown at levels of added nitrogen of 0, 135, and 270 kg/ha and soil moisture tensions (SMT) of 0.5 and 1.0 atm. With all combinations, there was a consistent gradient of larger to smaller starch-storage parenchyma cells from stem end to bud end of mature tubers. Stem and bud ends of tubers grown at a SMT of 0.5 atm with N had smaller cortical and pith (innermost medullary or water-core) cells than did ends of tubers grown without N. Perimedullary tissues of bud ends of tubers receiving N likewise contained smaller cells than did corresponding tissues of tubers grown without N. No pronounced differences in cell size were found in tissues from the midsections. In bud-end tissue of tubers grown at a SMT of 1.0 atm, there were no consistent differences in cell size with respect to N levels. However, pith, perimedullary, and cortical tissues of the midsections and stem ends of tubers receiving N had smaller cells than did corresponding tissues from tubers without N. The different patterns of cell size in tubers grown at different SMT indicate that the effects of N may be influenced by soil moisure.     

Disentangling the effect of environmental factors on yield and nitrogen uptake of irrigated rice in Asia

Rice yield is the result of the interaction between genotype (cultivar characteristics), environment (climate and soil conditions), and management. Few studies have attempted to isolate the contribution of each of these factors. Here the rice growth model ORYZA2000 was used to analyse the variation in yield, nitrogen (N) uptake, and internal N use efficiency (INUE, grain yield per unit total crop N uptake) of rice in different environments. First, ORYZA2000 was calibrated and evaluated using an empirical data set that spanned three varieties, three years, and eight locations in Asia. Next, we used the model to investigate the relative contribution of indigenous soil N and external N supply and of the weather factors temperature and radiation to observed variation in yield.     

Enhanced cutaneous hypersensitivity reactions are associated with ovine high and low cortisol responsiveness to acute endotoxin challenge

Inbred rodent studies have demonstrated that cutaneous hypersensitivity reactions are exacerbated in stress-susceptible, and attenuated in stress-resistant strains of mice. This physiological response was, in part, mediated by activation of the hypothalamic-pituitary-adrenal axis during the acute restraint stress. A study was conducted to examine whether or not cutaneous hypersensitivity reactions are also associated with variable cortisol responsiveness to inflammatory stress in an outbred ovine population. High (H), medium (M), and low (L) cortisol responsive sheep were identified from a population of 110 females based on their estimated breeding values for cortisol concentration measured 4 h post-systemic challenge with Escherichia coli endotoxin (400 ng kg(-1)). Cutaneous hypersensitivity reactions to phytohaemagglutinin (PHA), 1-chloro-2, 4-dinitrobenzene (DNCB), and Candida albicans cellular antigen (CAA) were measured in these variable cortisol-responding sheep, in addition to serum interleukin (IL)-6, interferon (IFN)-gamma, and ovalbumin (OVA)-specific IgG concentrations. When compared to the M cortisol responders, both H and L cortisol responders had significantly greater cutaneous swelling during the elicitation phase in response to DNCB (P < 0.05) and CAA (P < 0.05); a similar but not significant trend was observed during the PHA challenge. The primary, but not the secondary, IgG response to OVA was significantly lower in the H and L cortisol responders when compared to the M cortisol responders. Differences in serum IL-6 or IFN-gamma concentration were not observed across variable cortisol-responsive groups. Together, these results demonstrate that cutaneous hypersensitivity reactions are enhanced in outbred H and L cortisol-responding sheep, independent of systemic modulation by IL-6 and IFN-gamma.     

Isolation and characterization of the heat stable enterotoxin from a pathogenic bovine strain of Escherichia coli

A heat-stable enterotoxin secreted by a pathogenic strain of Escherichia coli of calf origin was purified to homogeneity by a procedure involving acetone fractionation, DEAE cellulose chromatography, Biogel P2 chromatography and size exclusion high pressure liquid chromatography. The purity of the product was ascertained by amino-acid analyses and amino acid sequence using manual degradation with 4-N, N dimethylaminoazobenzene-4' isothiocyanate (DABITC) and an automatic gas phase sequenator. The following amino acid sequence is proposed: Asn-Thr-Phe-Tyr-Cys-Cys-Glu-Leu-Cys-Cys-Asn-Pro-Ala-Cys-Ala-Gly-Cys-Tyr. It is identical to a similar active peptide isolated from strains of porcine origin. Antibodies to ST were successfully produced in rabbits using a conjugate with bovine serum albumin. The ultraviolet absorption and circular dichroism spectra of the active product were recorded and discussed.