A STUDY OF THE EFFECTS OF ALCOHOL ON MENTAL FUNCTIONS

In the case of a legal defence of drunkenness, it is common practice to call a psychiatrist to examine the accused and to give an opinion of his mental state at the time of the commission of the alleged offence. While clinical experience indicates that impairment may occur at relatively low concentrations of alcohol in the bloodstream, and that mental functions are not uniformly affected, there is surprisingly little experimental work to support this observation.

The present study was undertaken to determine the effects of a blood alcohol concentration of approximately 1.0 parts per 1,000 on mental functions. The subjects were eight non-psychotic males of average intelligence referred to the Forensic Services for mental examination. All were volunteers. The amount of alcohol in the bloodstream was measured by the Breathalyzer, and equivalent tests of general orientation and personal history; attention (digit span); abstract thinking (similarities test); learning efficiency (paired verbal associates) were administered before the intake of alcohol and when the blood alcohol concentration had reached 1.0 parts per 1,000. A test of retention was given, consisting of having the subjects identify and repeat the titles of TAT cards 24 hours after having described and titled them in an alcohol-free state and at the 1.0 level of blood alcohol respectively.

It was found that the experimental condition, i.e. a mean blood alcohol concentration of 1.0 parts per 1,000, had no effect upon the subjects' accuracy of information relating to personal identity and orientation in time and place.

The subjects' performances on the tests of attention, abstract thinking; and learning efficiency were adversely affected by the alcohol condition. Of the two retention measures, recognition and recall, only the latter was affected to a statistically significant degree.

A subsequent matching of a complete log of actual events occurring during the alcohol condition, with the subjects' recall of them 24 hours later, revealed vagueness; and of three subjects taken to the 2.0 parts per 1,000 level, two could not recall quite significant events occurring at higher concentration than 1.2 and 1.5 parts per 1,000. One of these subjects related the content of a conversation with the experimentor in a highly confabulatory manner.

The findings are taken to support the clinical observation that mental functions are not uniformly affected by alcohol, and that impairment can occur at relatively low concentrations of blood alcohol.

EXCESS LACTATE: AN INDEX OF REVERSIBILITY OF SHOCK IN HUMAN PATIENTS

"Excess lactate," an indicator of oxygen debt, has been studied as a metabolic index of severity of the shock state in human patients. The levels of excess lactate correspond to severity of circulatory failure, and an excess of more than 4 millimoles per liter prognosticates a fatal outcome. The validity of this index was confirmed by studies on experimental hemorrhagic shock in dogs. It provides a parameter for measurement of "reversibility" and serves as an objective clinical guide.

SPURIOUS HYPERKALAEMIA

In a patient with acute lymphoblastic leukaemia, the plasma was found to have a potassium level of 10.4 mEq./1. Investigations showed that plasma from patients with leukaemia may be found to have falsely high potassium levels because of breakdown of leucocytes between the venepuncture and separation of the plasma.

CHANGES IN SERUM ALPHA-2 GLOBULINS IN RETICULOSES

The total concentrations of alpha(2) globulin and two of its components, haptoglobin and caeruloplasmin, have been determined in the sera from 78 patients with primary malignant diseases of lympho-reticular tissue (reticuloses). The total alpha(2) globulin fraction was significantly raised only in Hodgkin's disease. The serum haptoglobin was also significantly increased in Hodgkin's disease and some other reticuloses, including acute leukaemia, lymphosarcoma, and reticulum cell sarcoma. The serum level of caeruloplasmin was raised in all reticuloses. There was possibly some correlation between the rise in haptoglobin and caeruloplasmin concentrations and the total alpha(2) globulin in Hodgkin's disease but this was not statistically significant. The significance of these results is discussed, and it is concluded that the increase in alpha(2) globulin which occurs in Hodgkin's disease is due to an increase in several of its components and not to a single component.

A COLORIMETRIC METHOD FOR SERUM CHYMOTRYPSIN DETERMINATION

A colorimetric method for serum chymotrypsin determination is presented. A specific substrate, N-acetyl-L-tyrosine hydrazide, is hydrolyzed by chymotrypsin, liberating hydrazine. This hydrazine is determined colorimetrically with Ehrlich's reagent. The procedure is suitable for the routine assay of serum chymotrypsin and its inhibitors.

IRON ABSORPTION: THE EFFECT OF AN IRON-DEFICIENT DIET

A diet deficient in iron causes a rapid, marked increase in iron absorption in rats. The increased absorption occurs in the absence of a significant change in iron stores as judged by the effect of an equivalent change in stores produced by phlebotomy, and in the absence of increased erythropoietic activity as judged by the rate of removal of iron-59 from the plasma.

PLASMA VASOCONSTRICTOR ACTIVITY IN PATIENTS WITH RENAL, MALIGNANT, AND PRIMARY HYPERTENSION

Polypeptide vasoconstrictor activity was assayed in the peripheral venous blood of 45 hypertensive patients and 20 normal subjects. The average activity was significantly increased in all hypertensive groups, and activity tended to be much higher in patients with renovascular and malignant hypertension than in primary hypertension.

In confirmation of previously reported results by Helmer and Judson, there was no correlation between vasoconstrictor activity and renal excretory function. The plasma level of vasoconstrictor activity did not correlate with mean arterial pressure except when malignant or renovascular hypertension was present.

A significant inverse relationship was found between the serum potassium concentration and vasoconstrictor activity: as activity levels increased, the potassium fell. The data suggest that a renin-like substance may be present in various hypertensive states in amounts sufficient to depress serum potassium, presumably by activation of the renin-angiotensin-aldosterone mechanism.

SERUM BILE ACID LEVELS IN HYPERCHOLESTEROLAEMIC PATIENTS

A shortened method of estimating serum bile acids is described, based on extraction and the measurement of fluorescence in sulphuric acid solution at 37 degrees C. The cholate and dihydroxy bile acid fractions are determined separately by measurements made one hour and 24 hours after preparing the solution. About 1% of the serum cholesterol escapes separation and appears in the sulphuric acid solution; in its fluorescent properties it behaves in a manner almost identical with dihydroxy bile acids. As a result, the normal serum bile acids are overestimated by about 2 mg./100 ml. This effect is unimportant in cases of jaundice. In non-jaundiced cases with hypercholesterolaemia, the apparently raised serum bile acid levels are accounted for by the interference from cholesterol and there is no evidence that a raised serum cholesterol level is usually associated with raised serum bile acids.