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Biomedical subjects

M Peet

Publications and source records attributed to M Peet.

At least 55 records · Page 3Linked to original sources
PubMed1985

Blood levels of vanadium, caesium, and other elements in depressive patients.

Levels of vanadium and 29 other elements were measured in whole blood of 25 depressive patients, 13 recovered depressive, and 24 control subjects. Vanadium levels were normal in depressive patients, and did not change on recovery. Changes of doubtful significance were found in blood levels of copper, strontium and chromium on recovery from depressive illness. The depressive patients had reduced blood levels of caesium which increased towards normal on recovery. This finding is discussed in relation to pertinent neurochemical and behavioural effects of caesium.

Adult↗
PubMed1981

Half-of-the-sites reactivity in the malate thiokinase reaction.

Malate thiokinase catalyzes the reversible formation of malyl-CoA or succinyl-CoA from ATP, CoA, and malate or succinate, respectively. Incubation of the enzyme with succinyl-CoA results in the formation of a tight complex in which 4 succinyl-CoA molecules are bound/alpha 4 beta 4 tetramer. Denaturation of the enzyme with urea or sodium dodecyl sulfate releases succinyl-CoA from the enzyme. Enzyme-bound succinyl-CoA is also released by reaction with ADP + Pi (reverse reaction) or by reaction with arsenate (arsenolysis reaction). Addition of ATP to enzyme containing 4 mol of bound succinyl-CoA/mol of enzyme leads to the loss of 2 of the molecules of bound succinyl-CoA with the concomitant incorporation of 2 molecules of phosphate into the enzyme. In a single turnover experiment in which enzyme containing 2 mol of bound succinyl-CoA and 2 mol of phosphate/mol of alpha 4 beta 4 tetramer was incubated with succinate plus CoA, only phosphate was released from the enzyme. Isolation of the enzyme from a reaction mixture undergoing catalysis showed 2 mol of succinyl-CoA bound/enzyme tetramer. These results suggest that, during steady state catalysis, approximately 2 molecules of succinyl-CoA are bound/tetramer, and that malate thiokinase exhibits half-of-the-sites reactivity.

Acyl Coenzyme A↗
PubMed1981

The effect of level of depression on the use of visual analogue scales by normal volunteers.

1 In two separate studies, 102 normal male volunteers were screened for level of depression using the Zung Self-Rating Depression Scale (Zung, 1965). Eight high scorers and eight low scorers were selected for inclusion in each study. 2 There were marked differences in scores on the visual analogue mood scales of Bond & Lader (1974) between the high depressed (HD) and low depressed (LD) groups. 3 In the first study, subjects were given single doses of imipramine 50 mg and 100 mg, diazepam 10 mg, and placebo in a double-blind randomized crossover design with 1 week between treatments. Drug effects as assessed on visual analogue scales were significantly more marked in the LD than in the HD group, to the extent that the sedative effects of imipramine 50 mg and diazepam 10 mg were minimal or absent in the HD groups whereas these effects were clear and highly significant in the LD group. 4 In a second study, LD and HD volunteers were given more objective items to rate using visual analogue scales. Ratings of the size of each of a series of ten circles, and of the weight of a 'black box', were consistently and significantly lower in the LD than in the HD group. Significant differences between LD and HD groups were also found on a series of visual analogue scales expressing attitudes not directly related to mood. 5 It is concluded that normal volunteers with varying levels of depression cannot be considered as homogeneous in their mode of expression on visual analogue scales, and that this should be taken into account in the design and interpretation of studies involving the use of such scales.

Adolescent↗
PubMed1981

Beta-blockers in the treatment of neurological and psychiatric disorders.

Beta-blockers, originally introduced into clinical practice for the treatment of cardiovascular disorders, are being increasingly advocated in the treatment of diverse neurological and psychiatric conditions. Thus, propranolol and certain other beta-blockers have been shown to be effective, and may be the drugs of choice, in the treatment of benign essential tremor and the prevention of recurrent migraine attacks. These drugs also have a useful role to play in the treatment of anxiety and alcohol withdrawal states, although beta-blockers have not come into general use in these conditions. The action of propranolol and related drugs in these neurological and psychiatric conditions is generally considered to be mediated by blockade of peripheral beta-adrenergic receptors, although other effects, either central or peripheral, may also be involved. The use of beta-blockers in the treatment of psychosis remains controversial. Current evidence does not support the use of propranolol in schizophrenia, but further studies in mania are warranted.

Adrenergic beta-Antagonists↗
PubMed1981

Propranolol in schizophrenia. I. Comparison of propranolol, chlorpromazine and placebo.

Fifty-three hospitalized chronic schizophrenic patients were treated with either propranolol, chlorpromazine or placebo in a double-blind randomized trials for up to three months. Propranolol in a usual dose of 640 mg/day, produced marked cardiovascular effects but no improvement in schizophrenic symptomatology relative to placebo. The effects of chlorpromazine were small and inconsistent.

Blood Pressure↗
PubMed1981

Propranolol in schizophrenia. II. Clinical and biochemical aspects of combining propranolol with chlorpromazine.

Ten hospitalized chronic schizophrenic patients were given chlorpromazine alone and chlorpromazine plus high dose propranolol in two 7-week treatment periods according to a randomized crossover design. In the six patients who completed the whole study, plasma levels of chlorpromazine and chlorpromazine sulphoxide, total serum levels of neuroleptic and serum levels of prolactin were consistently and significantly elevated during treatment with chlorpromazine plus propranolol relative to levels during treatment with chlorpromazine alone. These effects are sufficient to explain previously reported clinical improvement in schizophrenic patients given propranolol in addition to neuroleptics.

Adult↗
PubMed1979

Controlled studies of the acute antidepressant effects of lithium.

In two randomized double-blind controlled trials on 63 depressed female in-patients subject to recurrent affective disorder (bipolar and unipolar manic-depressive psychosis) lithium was shown to have major acute antidepressant effects. At the end of three weeks lithium produced more uniform improvement than did imipramine; lithium in combination with tryptophan (in the form of Optimax) was superior to tryptophan alone--the latter drug having no discernible antidepressant activity in this group of patients. Lithium did not produce an antidepressant effect until the second and third week of both trials.

Adult↗
PubMed1978

Mianserin and lithium in the prophylaxis of depression.

Forty-one out-patients with a history of at least three attacks of depressive illness were randomly allocated to treatment on a double-blind basis for one year with either mianserin 20 mg three times daily plus placebo lithium tablets, or to lithium tablets once daily plus placebo mianserin tablets. After one year, the dosage of mianserin was increased to 30 mg t.d.s. for a further six months. All but three of the patients had previously been stabilized on prophylactic lithium therapy. Lithium was found to be significantly superior to mianserin in avoiding admission to hospital or ECT. The overall affective morbidity index, calculated from global rating, showed no significant difference between drugs, but the index of the mianserin group was higher in the second six months than in the first. The lithium group showed no such change. Lithium remains the choice for the prophylaxis of unipolar recurrent depressive illness.

Administration, Oral↗
PubMed1978

Mianserin: a decade of scientific development.

1 Mianserin is a tetracyclic piperazino-azepine compound synthesized in 1966 for its peripheral anti 5-hydroxytryptamine properties. Animal screening showed that mianserin was centrally active, but the profile did not indicate possible antidepressant activity. Following clinical observations of sedative and possible mood-lifting effects, a quantitative electroencephalogram (EEG) study showed that the EEG effects of mianserin are similar to those of amitriptyline. 2 Subsequent clinical and pharmacological studies have indicated that mianserin is an effective antidepressant which differs from the tricyclic antidepressants not only chemically but also in its pharmacological and clinical profile. Mianserin seems to lack anticholinergic and cardiotoxic properties, and has unusual effects on monoamine metabolism. 3 On the basis of the initial profile a series of clinical and pharmacological studies has been carried out, and the results of many of these studies are presented in these Proceedings.

Amines↗