Effects of training multiple form classes on acquisition,generalization and maintenance of word retrieval in a single subject

Abstract

A study by McNeil et al. reported no generalization effects in two individuals with aphasia following application of a word finding treatment in which subjects were trained sequentially on lexical items arranged by form class. The present investigation examined, in one of the two subjects from the original study, whether training on lexical items from a variety of form classes concurrently would result in greater response generalization than was observed previously in this subject. Results replicated earlier findings with positive acquisition and maintenance effects and little evidence of generalization to untrained items within or across form classes.     

Excitatory actions of GABA in developing chick vestibular afferents: Effects on resting electrical activity

The aim of this study was to characterize the effect of γ-aminobutyric acid (GABA) in the resting multiunit activity of the vestibular afferents during development using the isolated inner ear of embryonic and postnatal chickens (E15-E21 and P5). GABA (10⁻³ to 10⁻⁵ M; n = 133) and muscimol (10⁻³M) elicited an increase in the frequency of the basal discharge of the vestibular afferents. We found that GABA action was dose-dependent and inversely related to animal age. Thus, the largest effect was observed in embryonic ages such as E15 and E17 and decreases in E21 and P5. The GABA_A receptor antagonists, bicuculline (10⁻⁵M; n = 10) and picrotoxin (10⁻⁴M; n = 10), significantly decreased the excitatory action of GABA and muscimol (10⁻³M). Additionally, CNQX 10⁻⁶M, MCPG 10⁻⁵M and 7ClKyn 10⁻⁵M (n = 5) were co-applied by bath substitution (n = 5). Both the basal discharge and the GABA action significantly decreased in these experimental conditions. The chloride channel blocker 9-AC 0.5 mM produced an important reduction in the effect of GABA 10⁻³ (n = 5) and 10⁻⁴M (n = 5). Thus, our results suggest an excitatory role of GABA in the resting activity of the vestibular afferents that can be explained by changes in the gradient of concentration of Cl⁻ during development. We show for the first time that the magnitude of this GABA effect decreases at later stages of embryonic and early postnatal development. Taking into account the results with glutamatergic antagonists, we conclude that GABA has a presynaptic action but is not the neurotransmitter in the vestibular afferent synapses, although it could act as a facilitator of the spontaneous activity and may regulate glutamate release. Synapse 67:374–381, 2013. © 2013 Wiley Periodicals, Inc.     

The influence of master cast technique on the cast precision of implant-retained fixed prostheses

The aim of this study was to evaluate the precision of three different mold filling techniques in order to obtain a cast simulating a three-unit, implant-retained, fixed prosthesis. Thirty casts (n = 10) were obtained using three different mold filling techniques. Group 1 used a unique fulfillment technique, Group 2 used a two-step fulfillment technique, and Group 3 used a latex cylinder technique. Using a metallic matrix, a titanium substructure was created to simulate a three-unit fixed prosthesis used as reference to evaluate the marginal misfit and tension forces in each cast. The vertical misfit was measured by an optical microscope with an increase of 120X and by an analysis unit using the one-screw test. The tension was quantified using strain gauges. The strain results showed a statistical difference between Group 3 and the other groups. The Tukey test showed no difference between the different treatment groups (p = 0.05). All three techniques were deemed efficient; however, considering that the cylinder latex technique induced less force toward the implants, it is the preferable technique for daily clinical practice.     

Relationships Between Health Care Disparities and Coverage Policies for Breast,Colon, and Lung Cancer Screening

Disparities in outcomes exist for breast, colon, and lung cancer among diverse populations, particularly racial and ethnic underrepresented minorities (URMs) and individuals from lower socioeconomic status. For example, blacks experience mortality rates up to about 42% higher than whites for these cancers. Furthermore, although overall death rates have been declining, the differential access to screening and care has aggravated disparities. Our purpose is to assess how the coverage policies of CMS and the United States Preventive Services Task Force (USPSTF) influence these disparities. Additionally, barriers are often encountered in accessing screening tests and receiving prompt treatment. To narrow, and potentially eliminate, outcomes disparities, CMS and USPSTF could consider revising their decision-making processes regarding coverage. Some options include (1) extending their evidence base to include observational studies that involve groups at higher risk; (2) lowering the threshold ages for screening to encompass differences in incidence; (3) CMS approving screening CT colonography coverage, which can even increase compliance with other screening tests; (4) clarifying and streamlining guidelines; (5) supporting research on improving access to screening; and (6) encouraging the development of more navigation services for URMs.     

Hypothetical protein Cpn0308 is localized in the Chlamydia pneumoniae inclusion membrane

The hypothetical protein encoded by Chlamydia pneumoniae open reading frame cpn0308 was detected in inclusion membranes of C. pneumoniae-infected cells using antibodies raised with Cpn0308 fusion proteins. The anti-Cpn0308 antibodies did not cross-react with IncA, a known C. pneumoniae inclusion membrane protein, although the anti-Cpn0308 antibody staining overlapped with the anti-IncA antibody labeling. The labeling of the inclusion membrane by the anti-Cpn0308 antibody was specifically blocked by the Cpn0308 but not IncA fusion proteins. The Cpn0308 antigen was detectable 24 h after infection and remained in the inclusion membrane throughout the infection course.