PubMed Health⌕ Search

Biomedical subjects

E Winograd

Publications and source records attributed to E Winograd.

33 records · Page 2Linked to original sources
PubMed1987

Expression of senescent antigen on erythrocytes infected with a knobby variant of the human malaria parasite Plasmodium falciparum.

Erythrocytes infected with a knobby variant of Plasmodium falciparum selectively bind IgG autoantibodies in normal human serum. Quantification of membrane-bound IgG, by use of 125I-labeled protein A, revealed that erythrocytes infected with the knobby variant bound 30 times more protein A than did noninfected erythrocytes; infection with a knobless variant resulted in less than a 2-fold difference compared with noninfected erythrocytes. IgG binding to knobby erythrocytes appeared to be related to parasite development, since binding of 125I-labeled protein A to cells bearing young trophozoites (less than 20 hr after parasite invasion) was similar to binding to uninfected erythrocytes. By immunoelectron microscopy, the membrane-bound IgG on erythrocytes infected with the knobby variant was found to be preferentially associated with the protuberances (knobs) of the plasma membrane. The removal of aged or senescent erythrocytes from the peripheral circulation is reported to involve the binding of specific antibodies to an antigen (senescent antigen) related to the major erythrocyte membrane protein band 3. Since affinity-purified autoantibodies against band 3 specifically bound to the plasma membrane of erythrocytes infected with the knobby variant of P. falciparum, it is clear that the malaria parasite induces expression of senescent antigen.

Animals↗
PubMed1985

Reminding as a basis for temporal judgments.

In the normal course of events, some events bring to mind earlier events. This reminding or, in the context of list learning experiments, study-phase retrieval can serve as a basis for the accurate judgment of the relative recencies of the two events in question. In this article, evidence for this position is presented in three experiments. By manipulations of encoding using visual imagery instructions and word associations, appropriate conditions were arranged for reminding to occur. The results of all three studies support the position that reminding provides a direct basis for later judgments of the relative recency of events.

Association↗
PubMed1984

Voice recognition: effects of orienting task, and a test of blind versus sighted listeners.

Three experiments on memory for unfamiliar voices are reported. In the first two experiments, the type of encoding was manipulated by orienting tasks. In each study, one group rated the pleasantness of the voices, another group made judgments of pitch, and a third group performed no orienting task. Recognition memory was not correlated with encoding condition in either experiment. In Experiment 2, voice memory was better when the message remained constant from study to test than when it was changed. In Experiment 3, a group of blind adults was tested with no orienting task. The blind subjects' memory was equivalent to that of the appropriate sighted group of Experiment 2. It is proposed that voices represent a psychologically unitary stimulus that cannot be encoded with differing degrees of elaboration; therefore, voices are not sensitive to orienting tasks in the way that other classes of events, such as words and faces, are.

Adult↗
PubMed1982

Aging and the picture superiority effect in recall.

One recurrent theme in the literature on aging and memory is that the decline of memory for nonverbal information is steeper than for verbal information. This research compares verbal and visual encoding using the picture superiority effect, the finding that pictures are remembered better than words. In the first experiment, an interaction was found between age and type of material; younger subjects recalled more pictures than words while older subjects did not. However, the overall effect was small and two further experiments were conducted. In both of these experiments, the picture superiority effect was found in both age groups with no interaction. In addition, performing a semantic orienting task had no effect on recall. The finding of a picture superiority effect in older subjects indicates that nonverbal codes can be effectively used by subjects in all age groups to facilitate memory performance.

Adult↗
PubMed1981

Elaboration and distinctiveness in memory for faces.

This research attempts to account for the finding that faces that have been judged with reference to traits such as honesty or friendliness are better remembered than faces judged with respect to a physical feature. Four experiments are reported in which the orienting task engaged in by the subjects was controlled. The first two experiments support an elaboration hypothesis that it is the amount rather than the type of information encoded that accounts for the observed effect. Experiments 3 and 4 provide evidence that elaborative encoding is effective because the likelihood of a distinctive feature being encoded increases with the degree of elaboration. The role of distinctiveness is emphasized.

Discrimination Learning↗
PubMed1966

List differentiation with varied trials on both lists.

Differentiation, defined as the discrimination of list membership, was studied with a recognition procedure. In each of the two studies, the number of learning trials was varied for one list and the trials on the other list were held constant. Differentiation was a U-shaped function of trials, passing through a minimum when both lists were shown equally often.

Discrimination Learning↗
PubMedDate not supplied

Indirect assessment of memory for music during anesthesia.

STUDY OBJECTIVE: To obtain evidence for intraoperative registration of auditory information in patients undergoing elective surgery. DESIGN: Within-subject design with three levels of frequency of exposure to music. SETTING: A university hospital and a university language laboratory. PATIENTS: Thirty-four patients scheduled for elective surgery and 20 healthy undergraduate psychology students. INTERVENTIONS: Selections of instrumental ethnic music were played to patients for 0, 3, or 12 exposures in one experiment and for 0, 6, or 24 exposures in another study. The undergraduates heard 0, 3, or 12 exposures of the music while awake. MEASUREMENTS AND MAIN RESULTS: Forty-eight hours after hearing the music, all subjects were tested on their preference for the selections they had heard as well as selections they had not heard. For the patients, the mean preference ratings (in millimeters, mm) on a visual analog scale following 0, 3, and 12 exposures were 73.3 mm, 74.0 mm, and 65.1 mm, respectively, a nonsignificant difference. For the patients who were exposed to the music 0, 6, and 24 times, the mean preference ratings were 64.4 mm, 66.1 mm, and 70.6 mm, respectively, a nonsignificant difference. For the waking participants, the mean preference ratings following 0, 3, and 12 exposures were 55 mm, 66.2 mm, and 62.5 mm, respectively, a significant difference (p less than 0.05). CONCLUSIONS: The anesthetized patients did not exhibit indirect memory for music played intraoperatively, at least to the extent required to demonstrate an exposure effect.

Adult↗
PubMedDate not supplied

Identification of novel membrane structures in Plasmodium falciparum infected erythrocytes.

Little is known about the molecular mechanisms underlying the release of merozoites from malaria infected erythrocytes. In this study membranous structures present in the culture medium at the time of merozoite release have been characterized. Biochemical and ultrastructural evidence indicate that membranous structures consist of the infected erythrocyte membrane, the parasitophorous vacuolar membrane and a residual body containing electron dense material. These are subcellular compartments expected in a structure that arises as a consequence of merozoite release from the infected cell. Ultrastructural studies show that a novel structure extends from the former parasite compartment to the surface membrane. Since these membrane modifications are detected only after merozoites have been released from the infected erythrocyte, it is proposed that they might play a role in the release of merozoites from the host cell.

Animals↗