Biomedical subjects

M H Rock

Publications and source records attributed to M H Rock.

3 recordsLinked to original sources

PubMed1994

Effect of intracoronary infusions of amrinone and dobutamine on segment shortening, blood flow, and oxygen consumption in in situ canine hearts.

Previous in vivo studies assessing the effects of amrinone on myocardial contractility used intravenous infusions, and thus were complicated by varying cardiac loading conditions. Accordingly, the present study was performed in 15 open-chest, anesthetized (fentanyl and midazolam) dogs using infusions of amrinone and dobutamine directly into the left anterior descending artery (LAD). In the LAD bed, percentage of segment shortening (%SS), an index of local myocardial contractility, was assessed with ultrasonic crystals. Coronary blood flow was measured electromagnetically and used to calculate myocardial oxygen consumption and infused drug concentrations. Amrinone and dobutamine were infused separately into the LAD at rates yielding calculated arterial blood concentrations in the clinical range (100, 150, and 200 micrograms/min, and 2.5, 5.0, and 7.5 micrograms/min, respectively). A mixture of amrinone and dobutamine was also infused into LAD and changes in %SS compared with the sum of the their individual effects. In six of the dogs, an extracorporeal system was used to maintain constant coronary blood flow during amrinone infusions. Amrinone and dobutamine caused individually increases in %SS that were comparable (range, 20%-45%). Myocardial oxygen consumption increased in parallel with %SS for both amrinone and dobutamine. For amrinone, coronary blood flow increased more than myocardial oxygen consumption, resulting in a modest (at highest dose approximately 10%) decrease in oxygen extraction; whereas for dobutamine, coronary blood flow increased in proportion to myocardial oxygen consumption, resulting in no change in oxygen extraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Amrinone↗

PubMed1981

Level of ego development and psychotherapy outcome in phobic patients.

forty male and 86 female phobic outpatients were randomly assigned to three treatment conditions (behaviour therapy with Imipramine: behaviour therapy with placebo; and supportive therapy with Imipramine) and seen in therapy for a 26-week period. They were initially assessed for level of ego development on Loevinger's Sentence Completion measure and evaluated for initial level of pathology and therapy outcome. A stepwise multiple regression analysis, performed separately for the female and male groups, yielded results as follows: (1) patients at the preconformist level improved significantly less than the patients at the other levels; (2) an interaction between the use of medication and level of ego development was also found, with postconformist patients reporting the least benefit from the drug. These findings were significant only for the female patients.

Adult↗

PubMed1978

Relationship between agoraphobia and field dependence.

In recent years agoraphobia has been viewed by clinicians as etiologically distinct from other phobic disorders, with conflicts over the developmentally early issue of separation and individuation (self-other differentiation) playing a central role. In an effort to adduce quantitative evidence for this clinical observation, three groups of phobic patients (totaling 166 outpatients in all) were distinguished on the basis of their symptomatology (agoraphobia, simple phobias, and mixed phobias) and were individually administered the Group Embedded Figures Test as a measure of field dependence, a cognitive style dimension that according to Witkin is, at least in part, a manifestation of self-other differentiation. A one-way analysis of variance, performed separately for men and women for differences among the three phobic groups on field dependence, showed significance (rho less than .05) for the females, with the famale agoraphobic being more field dependent than the female simple phobic groups, but not for the males. Implications for the understanding of agoraphobia are discussed.

Adult↗