Formation of neurofibrillary tangles in P301l tau transgenic mice induced by Abeta 42 fibrils

beta-Amyloid plaques and neurofibrillary tangles (NFTs) are the defining neuropathological hallmarks of Alzheimer's disease, but their pathophysiological relation is unclear. Injection of beta-amyloid Abeta42 fibrils into the brains of P301L mutant tau transgenic mice caused fivefold increases in the numbers of NFTs in cell bodies within the amygdala from where neurons project to the injection sites. Gallyas silver impregnation identified NFTs that contained tau phosphorylated at serine 212/threonine 214 and serine 422. NFTs were composed of twisted filaments and occurred in 6-month-old mice as early as 18 days after Abeta42 injections. Our data support the hypothesis that Abeta42 fibrils can accelerate NFT formation in vivo.     

Use of Trichosporon mycotoxinivorans to suppress the effects of ochratoxicosis on the immune system of broiler chicks

(1) The objective of this study was to determine whether the dietary inclusion of Trichosporon mycotoxinivorans (TRM) could suppress the detrimental effects of ochratoxin A (OTA) on the immune system of broiler chicks. (2) Six experimental treatments were tested in 300 1-d-old broiler chicks. Treatments included addition to a standard broiler ration of neither OTA nor TRM (Diet 1), OTA alone (500 microg/kg), OTA plus TRM at three inclusion rates (10(4) CFU/g of feed, 10(5) CFU/g, 10(6) CFU/g) and TRM alone at 10(5) CFU/g of feed. The ration was fed to chicks for 42 d. (3) Blood samples were collected at d 10, 20, 30 and 40 and macrophages and heterophils were isolated. The following variables were determined in macrophages and heterophils activated by phorbol myristate acetate (65 microM): cell viability, total cell-associated urokinase-plasminogen activator (u-PA), membrane-bound u-PA, free u-PA binding sites and superoxide production. (4) There was a decrease in the viability of macrophages and heterophils from chicks receiving OTA-contaminated feed compared to the viability of cells from control birds at d 40. Dietary TRM completely blocked the effect of OTA on cell viability; all three inclusion rates were equally effective. There was a decrease in total cell-associated and membrane-bound u-PA in macrophages and heterophils of chicks receiving OTA-contaminated feed compared to the corresponding values in control birds for heterophils at d 30 and 40 and for the macrophages at d 40. (5) Similarly, dietary TRM abolished the effect of OTA on total cell-associated and membrane-bound u-PA activity. All three inclusion rates of yeast were equally effective. Heterophils, but not macrophages, isolated from chicks receiving OTA-contaminated diet produced less superoxide anion compared to all other diet groups at d 30 and 40. (6) The immune system is a primary target of OTA toxicity in broilers: several functional properties of macrophages and heterophils were depressed in chicks fed OTA-contaminated feed. There was a delay of 30d before the immunosuppressive effect became apparent. The dietary inclusion of TRM completely blocked the detrimental effects of OTA on several immune properties in broilers.     

Flower Induction in Japanese Chrysanthemums with Gibberellic Acid

Gibberellic acid, when applied in lanolin to apices of three Japanese varieties of Chrysanthemum morifolium, induced bolting and flowering. These varieties are not sensitive to photoperiod but require a cold treatment in order to flower. On the other hand, the varieties of Chrysanthemum which belong to the short-day group are not induced to flower by gibberellic acid.     

Nitrate estimates using the Nitrachek Test for precise N-fertilization during plant growth and,after harvest,for quality testing potato tubers

Summary The effect of various levels, timing, and form of inorganic and organic nitrogenous fertilizers on the variation in nitrate content of stem bases over time was measured by means of the Nitrachek test in experiments carried out on sandy soils in Bremerv?rde, Germany (1985–7) and Helsinki, Finland (1987). There were good correlations between fertilizer use and nitrate content in the stem sap, and it was shown to be feasible to derive standard nitrate values which varied with growth stage. Splitting the application of N gave higher yields than applying all the N in the seedbed. The nitrate contents of tubers at harvest were correlated with the intensity of fertilizer use and was influenced by season. Soil N balances showed that splitting the N dressings reduced the soil N content more than applying all the nitrogen at the time of planting.     

Haploid plants from pollen grains

A method is presented by which hundreds of haploid plants of various species of Nicotiana can be raised from pollen grains. Stamens should be excised when pollen grains have been individualized, but are still uninucleate and free of starch. When grown in vitro on a relatively simple medium, some pollen grains proliferate into embryo-liké, structures which develop in stages similar to those of zygotic embryos. The plantlets mature and flower profusely, but do not set seed.     

Invasive pressure measuring for the determination of the aortic opening surface in normal and stenotic left ventricular outflow tracts

A method of evaluation of the aortic opening area in healthy dogs and dogs with aortic stenosis is described. Through right and left heart catheterisation intraventricular and intravascular pressures were measured. For the determination of cardiac output the thermodilution technique is used. The aortic opening area is calculated by using the GORLIN-formula. Values of normal and stenotic left ventricular outflow opening area are given.     

The legitimacy of the agricultural extension service

Traditionally, the Swedish Agricultural Extension Service has delivered technical information to farmers with the aim of increasing productivity and efficiency in farming. Present problems with overproduction of food and the negative social and environmental consequences of present farm practices has brought this traditional mission in question. In a situation of budgetary constraints it has been suggested that the funding of the governmental Agricultural Extension Service should be cut down or even discontinued altogether The article argues that this would be a mistake. The various negative consequences of modern agriculture indicate that we are far from an ideal mode of agricultural production. Instead, public opinion and new guidelines for agricultural and environmental policies call for substantial changes in Swedish agriculture with respect to pollution, preservation of non-renewable resources, maintaining an open rural landscape, ethical aspects of animal production, rural development etc. This reorientation of Swedish agriculture presumes that decision-makers, farmers, and the public at large get an opportunity to learn more about the complexities of agricultural production. In contributing to this learning process the Agricultural Extension Service would have an important mission. To be able to fulfill this mission, extension professionals must be provided an opportunity to learn a broader concept of productivity and efficiency in agriculture, for instance, how to extend cost-benefit analyses and technical criteria of efficiency to include social, environmental, and ethical aspects. Our present extension staff has not received adequate training for this task. It is suggested that all agricultural colleges need to create departments of Rural Sociology and Agricultural Humanities to provide agricultural students and professionals an opportunity to develop a better understanding of agriculture and make them prepared to take on the challenges and responsibilities they confront in developing our future agriculture.