Evaluation of 99mtechnetium stannous pyrophosphate as an imaging agent in acute myocardial infarction.

Serial 99mTc pyrophosphate scintigrams were obtained 7 hr to 15 days after experimental acute myocardial infarction produced by permanent or transient coronary occlusion. Scintigrams were interpreted visually and the increased radioactivity in the precordial image was quantitated and compared to extent of infarction found histologically. Results of these studies indicate: 1) 99mTc pyrophosphate imaging is an extremely sensitive for detection of acute myocardial infarction, i.e., infarction in excess of 1% of the left ventricular mass was detected. 2) Early detection of acute infarction is a function of blood flow since 7 hr after infarction scans were negative after permanent occlusion but were strongly positive after transient occlusion. 3) Radioactivity in the precordial image was inversely related to extent of infarction after permanent occlusion and directly related to extent of infarction after transient occlusion. 4) 99mTc pyrophosphate localized in areas with significant histologic infarction but the distribution of radioactivity was not proportional to extent of infarction.     

Temporal dynamics of age-related differences in auditory incidental verbal learning

Auditory response profiles for a group of ten healthy young and ten healthy elderly subjects, evoked by implicit memory and delayed verbal recognition tasks, were evaluated to determine if effects of stimulus repetition could be identified in the superior temporal gyrus (STG) and prefrontal cortical regions. We hypothesized that effects of stimulus repetition should occur both early in time and at early levels of the nervous system (STG) followed by later effects in prefrontal regions. Magnetoencephalographic (MEG) responses were recorded using a whole-head MEG system and automated, multi-start analysis methods were applied to the data in order to characterize the temporal response profiles from distributed but focal, cortical regions engaged in memory-related tasks. The findings revealed a main effect of age for early activity ( approximately 50 ms) in STG which appeared to be nonspecific for Old/New words and an Age x Task interaction for late activity ( approximately 100-800 ms) in STG which was specific to Old/New words. Although the behavioral performance measures did not reveal traditional effects of response priming, the MEG measures did reveal a reduction in amplitude with stimulus repetition in young subjects. The elderly did not reveal a reduction in amplitude concomitant with stimulus repetition for either the global attributes of words or for specific Old/New words. Long duration effects of stimulus repetition noted in the present study raise the possibility that results from sensory gating, mismatch negativity and P300 paradigms may represent a continuum of stimulus repetition effects. Two of these paradigms evoke greater enhancement to novel or infrequent stimuli, or rather, greater reduction of amplitude with repetition.     

Back to our future? The Consensus Conference and Combined-Integrated model of doctoral training in professional psychology

Is it possible and advisable for the profession of psychology to articulate and endorse a common, generalist, and integrative framework for the education and training of its students? At the Consensus Conference on Combined and Integrated Doctoral Training in Psychology, held at James Madison University in Harrisonburg, VA (USA), May 2 to 4, 2003, participants from across the spectrum of education and training in professional psychology ultimately answered "yes." This article, the first in this special series on the Consensus Conference and Combined-Integrated (C-I) model of doctoral training in professional psychology, essentially provides an overview of the conference rationale, participants, goals, proceedings, and results. Because the other 12 articles in this series all reference the Consensus Conference and C-I model, this overview provides a good starting point for understanding what occurred at the conference, what it means to educate and train from a C-I perspective, and what the potential implications of such a model might be for the profession of psychology.     

The effect of forefoot varus on postural stability

STUDY DESIGN: Counterbalanced experimental design study comparing a group of subjects with greater than or equal to 70 of forefoot varus (MFV) to a group with less than 70 of forefoot varus (LFV). OBJECTIVES: To investigate the effect of forefoot varus on single-limb stance postural stability (PS). BACKGROUND: Impaired PS has been implicated as a potential risk factor for sustaining acute foot and ankle injuries. The identification of variables that deleteriously affect PS may be important in the prevention of future injuries. METHODS AND MEASURES: Postural stability of the MFV group (n = 20) and the LFV group (n = 12) was assessed during right and left single-limb stance and eyes-open and eyes-closed conditions. Standard deviations of the x-axis and y-axis ground reaction forces measured via a force platform were used to represent anteroposterior (AP) and mediolateral (ML) PS, respectively. The mean of 3 successful 5-second trials of each testing condition was calculated and used for subsequent data analysis using 3-way mixed-model ANOVAs with 1 between-subject and 2 within-subject factors. RESULTS: The AP PS scores of the MFV group were significantly greater than those of the LFV group (P < .05). ML PS scores, although higher in the MFV group, were not significantly different from those of the LFV group. Both groups had significantly greater AP and ML PS scores during the eyes-closed versus the eyes-open condition (P < .05). CONCLUSIONS: The results suggest that the presence of greater than or equal to 70 of forefoot varus may significantly impair AP PS. The decreased stability associated with increased forefoot varus may be due to decreased joint congruity and consequently an increased reliance on soft tissue structures for stability.