The concept of compensation in cognitive aging: the case of prose processing in adulthood.

Although the rule of cognitive aging appears to be one of generalized decline with advancing age, much recent theoretical and empirical work has addressed a variety of potential exceptions to this rule. One mechanism through which decline might not be experienced is known as compensation. We describe a conceptualization of compensation that applies to lifespan cognitive development, in general, and the aging of prose processing skills, in particular. Our model of the forms and processes of compensation directs attention to the developing dynamics of cognitive skills and compensatory mechanisms. We outline three main approaches to research on compensation in cognitive aging: a) the logical experimental, b) on-line observation and manipulation, and c) several verbal report procedures. In summarizing our own research program, we emphasize that a) each of these approaches can render valuable information, b) each have some limitations, and c) there are potential theoretical benefits from employing more than one of them in a given study.     

Discordant repeat size and phenotype in Kennedy syndrome

Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease.     

Tissue homogenization with sterile reinforced polyethylene bags for quantitative culture of Candida albicans.

A simple method of tissue homogenization with sterile reinforced polyethylene bags for quantitative fungal cultures was evaluated with mice infected with Candida albicans. This new method correlated well with standard methods (P less than or equal to 0.01) for quantifying viable fungus in homogenates of brain, kidney, spleen, liver, and lungs and may be applicable in clinical and experimental mycology laboratories.