Cells and viruses with mutations affecting viral entry are selected during persistent infections of L cells with mammalian reoviruses

Previous studies demonstrated that both cellular and viral mutants are selected during maintenance of persistent infections established in murine L cells with high-passage stocks of mammalian reoviruses. In particular, when one culture was cured of persistent infection, the resulting cells were found to support the growth of viruses isolated from persistently infected cultures (termed PI viruses here) better than that of wild-type (wt) viruses (R. Ahmed, W. M. Canning, R. S. Kauffman, A. H. Sharpe, J. V. Hallum, and B. N. Fields, Cell 25:325-332, 1981). To address the nature of cellular and viral mutations selected during maintenance of persistent reovirus infections, we established independent, persistently infected cultures with L cells and high-passage stocks of wt reovirus. These cultures served as sources of new PI viruses and cured cells for study. We found that although wt viruses grew poorly in cured cells when infection was initiated with intact virions, they grew well in cured cells when infection was initiated with infectious subvirion particles generated from virions by in vitro treatment with chymotrypsin. This finding indicates that the block to growth of wt viruses in cured cells involves an early step that is unique to infection by virions, such as proteolytic processing in an endocytic compartment. We also found that PI viruses grew better than wt viruses in L cells treated with ammonium chloride, a weak base that inhibits the pH decrease in endosomes and lysosomes. Because ammonium chloride blocks an early step in infection by intact virions, probably the proteolytic processing of viral outer capsid proteins by acid-dependent cellular proteases in late endosomes or lysosomes, this finding indicates that PI viruses differ from wt viruses with respect to viral entry into cells. Therefore, these results indicate that both cells and viruses evolve mutations that affect one or more early steps in the viral growth cycle during maintenance of L-cell cultures persistently infected with reoviruses.     

The quantity and quality of aftercare services: Relationship with recidivism in mental hospital patients.

Studied 79 16–88 yr old mental patients who were released to a 3-county area and received aftercare services. Patient information on prehospital, inhospital, and posthospital variables was collected from existing records to determine the relationship between the community support system available to the patient and 3 criteria of subsequent recidivism. Current situational factors were found to be the most important single predictors of recidivism, while the magnitude of aftercare services received was not related to recidivism. However, when variables associated with self-selection into the aftercare program were partialled out, the patient's living situation was the best predictor of recidivism, and greater aftercare costs indicating a greater amount of contact were found to be associated with a higher recidivism rate. Results suggest that aftercare services need to be directed at prevention and skill building and that aftercare should not be relied on as an intervention strategy. (French summary) (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An empirical study of some election systems.

Uses presidential election data of the American Psychological Association for 5 yrs to compare a number of election systems in frequency of selecting Condorcet winners, consistency over subslates, and the effect of relevant and irrelevant candidates. The results from each system could be scaled in 1 dimension for each of the 5 elections, using the Kemeny metric. These scales were closely related to the weighting given to the variance of the candidates' rankings. An interpretation is given in terms of the polarizing effect of a candidate on an electorate. Election systems are discussed as strategies for the accumulation of subelectorates to reach a decisive set of voters. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morse-code-controlled computer aid for the nonvocal quadriplegic

A computer-based communications system was established for a quadriplegic patient who suffered a brainstem infarction that left him with normal intelligence, but without speech and without functional motor control except for the thumb of his right hand. An arm brace was developed to support the hand and thumb so it could control two switches that generated Morse code signals. An interface was also devised to translate Morse code into ASCII characters to access a personal computer. Additional codes were added to represent keyboard control functions. This device allows the patient to communicate with others and control, to some extent, his environment.     

Microsystems Macro-Assemblers and Macro-Based Languages in Microprocessor Software Development

Using a conventional macro-assembler as a multi-target cross-assembler and cross-compiler, the authors developed portable algorithmic code for microprocessor controllers.     

Informational social influence and product evaluation.

Describes a class marketing research project in which 144 undergraduates, in 4 groups, were asked to evaluate a new product. 2 groups of ss were exposed to 16 scaled product evaluations (supposedly from peers). High uniformity and low uniformity conditions were determined by degree of dispersion, and ss expected their evaluations to be visible to others. 2 remaining groups were given no information regarding others' evaluations, and one of these groups expected their evaluations to be visible to others. It was found that ss' subsequent evaluations were significantly influenced by others' ratings, the greatest influence occurring under the high uniformity-visibility condition. There was, however, no significant difference due to ss' expectations that their ratings would be visible to others. Individual differences in interpersonal response orientations were not significantly related to the acceptance of information from others, although the direction of results was in accord with predictions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A symposium on psychologists in schools of medicine in 1977.

Introduces a series of 4 articles reporting the results of a survey of organizational structure, career status, and satisfaction of psychologists in medical schools, the range and pattern of graduate programs offered, and a general overview. (5 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)