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Biomedical subjects

R Ader

Publications and source records attributed to R Ader.

At least 73 records · Page 4Linked to original sources
PubMed1980

Immediate and sustained hemodynamic and clinical improvement in chronic heart failure by an oral angiotensin-converting enzyme inhibitor.

The hemodynamic effects of an oral angiotensin-converting enzyme inhibitor, captopril, were evaluated in 10 symptomatic patients with chronic congestive heart failure. In all patients there was a significant increase in cardiac output (average 28%), stroke volume (49%), and stroke work index (26%), along with a decrease in pulmonary capillary wedge pressure (48%), indicating improved left ventricular function. Modest decreases in heart rate and arterial pressure were also observed. In seven patients maintained on captopril therapy, repeat hemodynamic studies at 2 months revealed sustained effects. These beneficial hemodynamic effects were accompanied by clinical improvement and improved exercise tolerance during maintenance therapy. These findings suggest that captopril may be a useful therapeutic adjunct for the long-term management of patients with chronic congestive heart failure.

Administration, Oral↗
PubMed1979

Conditioned suppression of a thymus-independent antibody response.

An illness-induced taste aversion was conditioned in mice by pairing cyclophosphamide, an immunosuppressive drug, with the consumption of saccharin, a novel drinking solution. Two weeks after conditioning, animals were injected with the hapten trinitrophenyl (TNP) coupled to the thymus-independent carrier, lipopolysaccharide. Serum antibodies to TNP were titered 6 days later by passive hemagglutination. Relative to control groups, conditioned animals provided with saccharin at the time of antigenic stimulation and, again, 3 days later showed a significant attenuation of their anti-TNP antibody response. In a second experiment, the conditioned stimulus (CS) consisted of the novel saccharin drinking solution plus the noxious internal effects of an injection of LiCl. Conditioned animals reexposed to the CS again showed the lowest antibody titers, but differed significantly from only one of the control groups. Taken together, the results of these experiments confirm previous reports of conditioned immunosuppression and suggest that the effects of conditioning on a primary humoral antibody response can be observed in response to a T-cell independent antigen in the mouse.

Antibody Formation↗
PubMed1977

Early learning and retention of a conditioned taste aversion.

Weanling rats were trained on a taste aversion task and tested 60 days later using the single bottle and preference methods for assessing the retention of a taste aversion, and a competitive situation in which the CS was eventually substituted for plain water. Only the competitive situation showed the effects of the early taste aversion training. The results are discussed in terms of the conditioning and reactivation of adrenocortical steroid elevations and how these might affect subsequent retrieval.

Age Factors↗
PubMed1976

Conditioned adrenocortical steroid elevations in the rat.

An illness-induced taste aversion paradigm was used to condition an elevation in plasma corticosterone level. Rats were injected with cyclophosphamide 30 min after consuming a novel saccharin drinking solution. Plasma corticosterone levels were measured before conditioning to determine unconditioned steroid levels and 3 and 6 days after training when conditioned and nonconditioned animals were provided with the saccharin solution or plain water, or were left deprived. The pairing of saccharin and cyclophosphamide was effective in inducing a passive avoidance response. There were no differences between the steroid levels of conditioned and nonconditioned animals supplied with plain water or those that remained deprived, although deprivation increased corticosterone levels. Nonconditioned rats presented with saccharin had steroid levels that did not differ from control values. Conditioned animals presented with saccharin showed an elevation in steroid level which was significantly greater than that observed in any other group. Comparable results were obtained when LiCl was used as the unconditioned stimulus.

Animals↗