Acquired resistance in Arabidopsis.

Acquired resistance is an important component of the complex disease resistance mechanism in plants, which can result from either pathogen infection or treatment with synthetic, resistance-inducing compounds. In this study, Arabidopsis, a tractable genetic system, is shown to develop resistance to a bacterial and a fungal pathogen following 2,6-dichloroisonicotinic acid (INA) treatment. Three proteins that accumulated to high levels in the apoplast in response to INA treatment were purified and characterized. Expression of the genes corresponding to these proteins was induced by INA, pathogen infection, and salicylic acid, the latter being a putative endogenous signal for acquired resistance. Arabidopsis should serve as a genetic model for studies of this type of immune response in plants.     

A CMA position. Acquired immunodeficiency syndrome.

The following general principles serve as guidelines for various bodies, health care professionals and the general public. Specific aspects of infection with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) that relate to physicians'' ethical responsibilities as well as society''s moral obligations are discussed. Such matters include the need for education, research and treatment resources; the patient''s right to investigation and treatment and to refusal of either; the need to obtain the patient''s informed consent; the right to privacy and confidentiality; the importance of infection control; and the right to financial compensation in the case of occupational exposure to HIV.     

Electronmicroscopical localization of nitric oxide synthase-containing nerve elements in cat pylorus.

Intrinsic nitric oxide synthase (NOS)-containing nerve cells and fibers were studied in the wall of the pylorus of cat at the ultrastructural level using ABC immunocytochemistry. Large numbers of NOS immunoreactive (IR) nerve cell bodies were observed in the myenteric and in the submucous plexuses, and few in the tunica propria mucosa. The NOS IR nerve fibers were most abundant in the inner circular muscle layer and in the tunica mucosa. They were found in very close vicinity to the smooth muscle cells of the inner circular muscular layer as well as to the blood vessels and the epithelial lining. The gap between the NOS IR nerve fibers and the membrane of the target cells was 20 to 250nm. Apparent synaptic contacts were observed between the IR nerve fibers and unlabelled nerve processes and other non IR nerve cell body. It is confirmed that NO might influence smooth muscle cell activity, regulate blood flow and modulate the function of the epithelial cells. Our ultrastructural study suggested that some of the NOS containing neurons belong to the intrinsic interneurons and have a regulatory effect on other intrinsic nerve elements involved in local neuronal reflexes.     

Acquired myopia in 11-year-old children.

Children who had acquired myopia by the age of 11 years were identified from a nationally representative sample. There were no overall sex differences in its occurrence but myopia was more common in children from non-manual families than in those from manual families. Short-sighted children were more likely to come from small families and to be of higher birth order than children with normal vision, and these associations held within each social class. At 11 years myopic children showed striking advantages in educational performance over their normal-sighted peers, as judged by tests of reading, arithmetic, and general ability. After adjustments had been made for social background, this age gain still amounted to over one year. Findings obtained at 7 years of age showed that superior educational attainments were already apparent before the onset of myopia. Children with myopia read in their leisure time more often than normally sighted children, but despite the visual impairment, they participated in outdoor sports as often as other children.