Biomedical subjects

D Friedman

Publications and source records attributed to D Friedman.

At least 253 records · Page 14Linked to original sources

PubMed1978

Immune reactivity during aging. II. Analysis of the cellular mechanisms involved in the deficient antibody response in old mice.

Analysis was made of the cellular basis of decline in the antibody immune response with advancing age. Employing the cell transfer system, it was found that spleen cells of aged mice have a limited capacity to react to SRBC when transferred into young irradiated recipients. Partial reconstitution was achieved when thymus cells from young untreated donors were applied together with the spleen cells, suggesting that deficiency in T helper cell function is responsible in part for the limited response. Similar studies using the T helper-independent antigen PVP also resulted in low levels of antibodies in the irradiated recipients. Treatment of the spleen cells with anti-theta serum before transfer did not lead to an increased response. Hence, it is suggested that the reduced response is related to limited function in the B cell compartment, and not to function of T suppressor cells. Transfer of bone marrow cells from aged into young irradiated recipients indicated that cells capable of differentiation into antibody-producing cells are available during aging. It is thus maintained that the defect at the B cell level is of a developmental nature.

Aging↗

PubMed1977

A new technique for the treatment of guilt.

A behavioural technique is described suitable for the treatment of patients with high levels of guilt who attempt to relieve their depression by risk-taking activities which reflect their individual wishes and fears, or who suffer anxiety due to unacceptable past behaviour. It is recommended as an alternative brief method of treatment to psychoanalysis and is based on the application of behaviour therapy to a patient's psychopathology. Three case histories are described to illustrate the principles of the technique.

Adult↗

PubMed1975

Activation of immune competence by thymus factors.

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Aging↗

PubMed1975

Cortical evoked potentials elicited by real speech words and human sounds.

Averaged evoked potentials were recorded from PZ and left and right temporo-parietal electodes to real speech words and human sounds in 8 right-handed subjects. Stimuli were presented in a "no task" condition where the subject was instructed to listen attentively, and a vigilance condition where the subject responded to a particular word or sound during a run of such stimuli. The vigilance condition produced two classes of stimuli:signals and non-signals. Evoked potentials to physically identical words or sounds were examined when they were "no task", non-signal and signal stimuli. P300 amplitude increased significantly as a function of increasing task demands going from "no task" to non-signal to signal. When a strict statistical criterion for multiple comparisons (Bonferroni test) was applied in looking for asymmetries between hemispheres, only 2 isolated left greater than right differences turned out to be significant. Review of the literature concerning evoked potential correlates of differential hemispheric processing pointed up flaws in design, statistical technique, and inconsistencies in reported findings which suggested that while evoked potentials may sometimes reflect differences in hemispheric functioning, this effect is marginal at best.

Adult↗

PubMed1975

The late positive component (P300) and information processing in sentences.

Averaged visual evoked potentials to sequentially flashed words comprising a sentence were recorded from vertex and left and right temporoparietal electrodes in 8 right-handed subjects. In condition 1 the sentence took the form: The -eel is on the shoe, in which the first grapheme was omitted from the second word, so that the subject did not know the meaning of the second word until he viewed the last word. In condition 2, the sentence took the form: The heel is on the shoe, in which the second word was given and the last word provided no further information. P300 latency to words which delivered information (last word of condition 1, second word of condition 2) were significantly longer than P300 latency to any of the other words in the sentence, as well as to the same position word in the other condition. Comparisons of P300 latencies to redundant words (the, is, on) within and between conditions showed no significant differences. P300 amplitude to the last word was significantly larger than P300 amplitude to any of the other words within the sentence, even in condition 2 where the second word delivered information. The major effect of information delivery was on P300 latency, while "syntactic closure" had its major effect on P300 amplitude. The fact that evoked potentials to all words had P300 components was attributed to the engagement of the P300 system whenever task-related language stimuli are used.

Adolescent↗

PubMed1975