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Biomedical subjects

C L Yeager

Publications and source records attributed to C L Yeager.

At least 19 recordsLinked to original sources

Immunologic responses to vaccinia vaccines administered by different parenteral routes.

To develop a less reactogenic but equally immunogenic vaccine, this study of 91 human volunteers compared the safety and immunogenic potency of a new, cell culture-derived vaccinia virus vaccine administered intradermally and intramuscularly with the licensed vaccinia vaccine administered by scarification. Cutaneous pox lesions developed in a higher proportion of scarification vaccinees. Scarification and intradermal vaccine recipients who developed cutaneous pox lesions had more local reactions but also achieved significantly higher cell-mediated and neutralizing antibody responses than those who did not develop pox lesions. Although less reactogenic, intradermal or intramuscular administration of vaccinia vaccine without the concomitant development of a cutaneous pox lesion induced lower immune responses.

Antibodies, Viral↗

A national minority organ/tissue transplant education program: the first step in the evolution of a national minority strategy and minority transplant equity in the USA.

1. These successful education programs initially aimed at the AA community are being expanded into other minority groups such as Native American (Alaskan and American Indian), Hispanic (Latino), and Asian-Pacific Islander populations; and if the same modus operandus, ie, a minority-targeted message delivered by ethnically and culturally similar and sensitive messengers is used, this will have equal applicability to the majority population. MOTTEP, the first grass roots national transplant education program, while directed first to the minority population, can when presented to the majority population help all groups address the number one problem in transplantation today--the shortage of donors. 2. Active inclusion and involvement of minorities at all levels of problem resolution (resource allocation, research, and education), emphasizing community participation, education, and empowerment are the important next steps to allow for minority transplant equity in America. 3. The emergence of ASMHTP as the responsible brain trust for future minority-related efforts along with MOTTEP, a community based, empowering transplant education program, highlights the importance of a national strategy necessary for the survival of minority communities. This will enhance the interaction between minority transplant health professionals and the minority community and requires minority inclusion at all decision making levels of problem resolution within the transplant community.

Black or African American↗

Human aminopeptidase N is a receptor for human coronavirus 229E.

Human coronaviruses (HCV) in two serogroups represented by HCV-229E and HCV-OC43 are an important cause of upper respiratory tract infections. Here we report that human aminopeptidase N, a cell-surface metalloprotease on intestinal, lung and kidney epithelial cells, is a receptor for human coronavirus strain HCV-229E, but not for HCV-OC43. A monoclonal antibody, RBS, blocked HCV-229E virus infection of human lung fibroblasts, immunoprecipitated aminopeptidase N and inhibited its enzymatic activity. HCV-229E-resistant murine fibroblasts became susceptible after transfection with complementary DNA encoding human aminopeptidase N. By contrast, infection of human cells with HCV-OC43 was not inhibited by antibody RBS and expression of aminopeptidase N did not enhance HCV-OC43 replication in mouse cells. A mutant aminopeptidase lacking the catalytic site of the enzyme did not bind HCV-229E or RBS and did not render murine cells susceptible to HCV-229E infection, suggesting that the virus-binding site may lie at or near the active site of the human aminopeptidase molecule.

Aminopeptidases↗

Renal transplantation in heroin addicts.

On the basis of our experience, therefore, we believe that the reformed heroin addict is a good candidate for cadaveric donor renal transplantation if he can be discouraged from returning to heroin use. The fact that the majority of the patients in our study returned to marijuana smoking after transplantation has raised the issue of its role as a possible immunosuppressant.

Adult↗

Electrical potentials in human brain during cognition: new method reveals dynamic patterns of correlation.

A new technique has been developed for identifying, in humans, dynamic spatiotemporal electrical patterns of the brain during purposive behaviors. In this method, single-trial time-series correlations between brain macropotentials recorded from different scalp sites are analyzed by distribution-independent mathematical pattern recognition. Dynamic patterns of correlation clearly distinguished two brief visuomotor tasks differing only in type of mental judgement required (spatial or numeric). These complex patterns shifted in the anterior-posterior and left-right axes between successive 175-millisecond intervals, indicating that many areas in both cerebral hemispheres were involved even in these simple judgements. These patterns were not obtainable by conventional analysis of averaged evoked potentials or by linear analysis of correlations, suggesting that the new technique will advance the study of human brain activity related to cognition and goal-directed behaviors.

Adult↗

Electroencephalogram correlates of higher cortical functions.

By means of two-stage, nonlinear multivariate pattern recognition, electroencephalograms (EEG's) were analyzed during performance of verbal and spatial tasks. Complex scalp distributions of theta-, beta-, and, to a lesser extent, alpha-band spectral intensities discriminated between the two members of a pair of tasks, such as writing sentences and Koh's block design. Small EEG asymmetries were probably attributable to limb movements and other uncontrolled noncognitive aspects of tasks. Significant EEG differences beteeen cognitive tasks were eliminated when controls for inter-task differences in efferent activity, stimulus characteristics, and performance-related factors were introduced. Each controlled task was associated with an approximately 10 percent reduction, as compared with visual fixation, in the magnitude of alpha- and beta-band spectral intensity. This effect occurred bilaterally and was approximately the same over occipital, parietal, and central regions, with some minor difference over the frontal region in the beta band. With these controls, no evidence for lateralization of different cognitive functions was found in the EEG.

Adult↗

EEG patterns during 'cognitive' tasks. I. Methodology and analysis of complex behaviors.

This paper presents a methodology which uses nonlinear pattern recognition to study the spatial distribution of EEG patterns accompanying higher cortical functions. The multivariate decision rules reveal the essential EEG patterns which differentiate performance of two tasks. Cross-validation classification accuracy measures the generality of the findings. Using this method, EEG patterns were derived from a group of 23 adults during performance of several complex tasks, including Koh's block design, writing sentences, mental paper folding, and reading silently. These patterns discriminate between the tasks, are consistent with, and extend the results of, visual EEG interpretations and univariate analysis of spectral intensities. Since writing sentences could not be distinguished from mere scribbling, it is unclear whether the EEG patterns found to distinguish complex behaviors were related to the cognitive components of tasks, or to sensory-motor and performance-related factors.

Adult↗

Computer rejection of EEG artifact. II. Contamination by drowsiness.

As part of an effort to automatically measure a background EEG baseline against which changes due to therapy or experimental manipulations may be measured, algorithms to detect EEG patterns associated with drowsiness have been developed and objectively evaluated. The decision of drowsiness is tentatively based upon changes in simple signal features, including increased ratios of both delta-band to alpha-band and theta-band to alpha-band spectral intensity as compared to thresholds automatically determined from a waking calibration period. Several heuristic criteria are then required to reach a final decision. Thirty-one normal and abnormal, 3-minute, 8-channel clinical EEG recordings containing drowsiness were scored by 5 expert scorers. Out of a total of 106 events labeled drowsy by at least one judge, 85 were found by a consensus of 3 or more of the 5 experts. On the 20 recordings not used for training the decision thresholds (testing data set), the system found 84% for the 85 episodes found by the consensus, and 89% of the 62 episodes found by all 5 scorers. Only one event was found by the system which was not found by any scorer, or which did not border on a consensus-defined episode of drowsiness. This performance is adequate to justify inclusion of these algorithms into a previously described real time EEG analysis system, ADI-EEG, allowing integration of the decisions of the separate subsystems for detection of artifact, sharp transients and drowsiness.

Computers↗