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Biomedical subjects

J Davidson

Publications and source records attributed to J Davidson.

At least 271 records · Page 15Linked to original sources
PubMed1981

MAO inhibition and control of anxiety following amitriptyline therapy. A pilot study.

In a pilot study, 32 patients with mixed states of anxiety, depression, somatization and panic received amitriptyline for 4 weeks, the dose ranging from 50 to 300 mg/day. Steady-state plasma levels of the drug and activity of platelet monoamine oxidase were measured after 4 weeks. Clinical change was rated, using the SCL-90. Amitriptyline produced a small but significant inhibition of platelet monoamine oxidase activity (range 1.4--82%). A significant positive correlation was noted between MAO inhibition and improvement on somatization, and psychological and panic-phobic components of anxiety, but not for depression. No significant correlations were observed between improvement and combined or separate ami- + nortriptyline plasma levels.

Adult↗
PubMed1981

Relationship between response to phenelzine and MAO inhibition in a clinical trial of phenelzine, amitriptyline and placebo.

This report examines the hypothesis that for phenelzine to be more effective than placebo it is necessary to achieve at least 80% inhibition of platelet MAO activity. This hypothesis was examined in the context of a double-blind comparison of phenelzine, amitriptyline and placebo in depressed patients. When phenelzine became significantly more effective than placebo at 4 weeks, the average MAO inhibition was 85%. By the 5th week, with MAO inhibition greater than 90%, phenelzine was significantly more effective than amitriptyline. A highly significant correlation was noted between improvement and MAO inhibition within the phenelzine group.

Amitriptyline↗
PubMed1981

Heterozygote advantage in Tay-Sachs carriers?

Chi-square analyses of new data as well as data previously reported by Myrianthopoulos have shown that grandparents of Tay-Sachs carriers die from proportionally the same causes as grandparents of noncarriers. It is unlikely that there is any advantage to being a Tay-Sachs carrier insofar as resistance to tuberculosis is concerned. Our results are further evidence to support Fraikor's claim that the high carrier frequency of the allele in Ashkenazi Jews is probably caused by a combination of founder effect, genetic drift, and differential immigration patterns.

Alleles↗
PubMed1981

The effect of hyperbaric oxygen on infarct size in the conscious animal.

The effect of hyperbaric oxygen (HBO) on infarct size associated with myocardial infarction remains uncertain. Accordingly, the present study was performed in 46 conscious dogs with experimental infarction to determine the effect of HBO on enzymatic estimates of infarct size. Since HBO may affect plasma creatine kinase (CK) release or disappearance, parameters used to calculate enzymatic estimates of infarct size from plasma CK, we assessed infarct size by directly measuring myocardial CK depletion. Twenty-three animals were given HBO (2 atm of pressure) for 3 h immediately after coronary occlusion and results of infarct size compared to those in 23 dogs with occlusion who remained in room air. In 10 other animals CK release was measured after coronary occlusion in 5 controls and compared to 5 treated. In 5 normal animals the CK disappearance rate of purified canine CK was determined before and after HBO. Infarct size was determined 24 h after coronary occlusion and in the treated animals averaged 25.4 +/- 1.3% of LV (mean +/- SEM), and being similar to controls (26.7 +/- 1.4, P greater than 0.25). The plasma CK disappearance rate before and after HBO was the same being 0.0072 +/- 0.0022 (min-1) and 0.0073 +/- 0.0021, respectively. Total CK released into the plasma was also the same in treated and controls (2232 +/- 210 IU and 2011 +/- 232), as was the ratio of CK released to that depleted from the myocardium (0.15 +/- 2% vs 0.15 +/- 3%). Our results indicate: (1) HBO does not reduce infarct size produced experimentally in the conscious dog; (2) HBO does not affect CK release or disappearance; and (3) estimates of infarct size by plasma CK remain valid despite administration of HBO.

Animals↗
PubMed1980

A comparison of inpatients with primary unipolar depression and depression secondary to anxiety.

Retrospective comparisons between primary unipolar depression and depression secondary to anxiety in 65 inpatients revealed a number of differences. Secondary depression was associated with a significantly higher incidence of neurotic traits in childhood, chronic unhappiness, and unsupportive family. Tricyclic antidepressants and ECT were both more effective in primary depression, and some secondary depressives became worse on ECt. When primary depression was sub-divided into familial, nonfamilial and spectrum types, the greatest differences were noted between familial and secondary depressions. In the former group a more stable life style was noted. Secondary and spectrum types differed on only two variables and several similarities were noted. Platelet monoamine oxidase activity was significantly higher in secondary depression.

Adult↗
PubMed1980

Results of treatment of acetabular fractures.

If it is not possible to achieve a satisfactory position by conservative methods, surgical treatment is indicated in displaced fractures of the acetabulum in order to restore and stabilize both the hip joint structure and the integrity of the pelvic ring. Restoration of the joint surfaces to as near normal as possible offers the best chance for a symptom-free hip. The postoperative recovery time is not hastened, but the conditions for early activity and restoration of function are improved. As demonstrated in 270 cases reported here, and as is well recognized in the past, a significant proportion of patients will require secondary or salvage surgery, i.e., total hip arthroplasty. Such treatment may not be possible if there is extensive residual disorganization of the hip joint. Preparation for future reconstructive surgery is important as an indication for operative reduction of the acetabulum.

Acetabulum↗
PubMed1979

Single case study. Complementary effects of phenelzine and psychotherapy in long term treatment of depression.

A case report is described wherein the monoamine oxidase inhibitor phenelzine was administered for 10 months at different doses. Drug treatment in the initial part of the study was double blind. Weekly psychotherapy was instituted at the point of symptomatic recovery. At a reduced dose, in month 3, the patient experienced a relapse in depression. While platelet monoamine oxidase inhibition was greater than 80 per cent the patient was well, but at the point of relapse, inhibition was 14 per cent. Clinical ratings at relapse (Beck and SCL-90 scales) revealed greater readiness by the patient to report psychological discomfort compared with the original interview. The combined effects of psychotherapy and pharmacotherapy were felt to be responsible for this change. However, psychotherapy in this form and duration did not prevent relapse, which depended upon maintaining an adequate dose of phenelzine.

Adult↗