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Biomedical subjects

T G Bolwig

Publications and source records attributed to T G Bolwig.

At least 109 records · Page 6Linked to original sources
PubMed1983

The Hamilton Anxiety Scale. Evaluation of homogeneity and inter-observer reliability in patients with depressive disorders.

In the present study the Hamilton Anxiety Scale (HAS), originally constructed for patients with neurotic anxiety, has been applied to patients with diagnosis of depressive disorders. The inter-rater reliability and homogeneity are evaluated and total scale score has been correlated to the Bech-Rafaelsen Melancholia Scale (BRMES). Twenty-two patients entered the study, 13 with endogenous depressions, and 9 with non-endogenous depressions when classified according to the ICD-8. For both scales the inter-rater reliability was found statistically significant. Concerning the homogeneity of the HAS, statistical significance was obtained for 7 items reflecting psychic anxiety, whereas in the BRMES statistical significance was found in all items apart from 2. Total scale score on HAS correlated positively with total score on BRMES for all 2 patients. However, when the patients were classified according to the ICD-8 this correlation seemed to be due to the endogenously depressed group as no significant correlation was seen for the group of non-endogenous depression. On the other hand, when the patients were classified according to the MULTI-CLAD system no significant intercorrelation of the HAS and BRMES scores was found within the subtypes of depression.

Adjustment Disorders↗
PubMed1983

Electroconvulsive therapy and intracranial aneurysm. Prevention of blood pressure elevation in a normotensive patient by hydralazine and propranolol.

A 42-year-old normotensive woman developed a severe mental depression 6 months after an operation for intracranial aneurysm. The use of electroconvulsive therapy (ECT) was judged to be of vital importance. By concurrent administration of intravenous hydralazine and propranolol before induction of anaesthesia the normally occurring ECT-induced blood pressure elevation was completely prevented, and the patient received a series of ten ECTs without complications.

Adult↗
PubMed1983

Effect of diazoxide-induced hypotension on cerebral blood flow in hypertensive rats.

The effect on cerebral blood flow of acute diazoxide-induced hypotension was studied in rats with renal and spontaneous hypertension. Diazoxide (5 mg/kg, i.v. bolus), caused arterial pressure to fall rapidly to that of normotensive rats, i.e. c. 75 mmHg. There was a concomitant fall in cerebral blood flow of about 35% (P less than 0.01) in renal hypertensive rats and 25% (P less than 0.05) in spontaneously hypertensive rats; the greater fall in flow in the former corresponded to a greater drop in pressure. Flow remained at these reduced levels during a 2 h observation period. Histological examination revealed small areas of ischaemic damage in the brains of five of the twelve animals. In control hypertensive rats not given diazoxide, cerebral blood flow and blood pressure were stable during a 2 1/2 h period and there was no evidence of ischaemic damage to the brains. The diazoxide-induced reduction in cerebral blood flow was interpreted as being secondary to a blood pressure fall to below the lower limit of cerebral blood flow autoregulation. No evidence was found of direct effects on the cerebral circulation such as seen with ganglionic blockers, alpha-blockers and cerebral vasodilators.

Animals↗
PubMed1983

The Melancholia Scale and the Newcastle Scales. Item-combinations and inter-observer reliability.

The reliability of the total scores on three rating scales (Melancholia Scale and the two Newcastle Scales) and the algorithms leading to the Feighner, Research Diagnostic Criteria, and the DSM-III subtypes of depression have been compared. The degree of inter-observer agreements for the various item-combinations was significantly higher than would be expected by chance. The average agreement for each assessment system ranged from 80 to 93 per cent. This 7 to 20 per cent lack of total agreement probably reflects the limitation of clinical assessments including the influence of halo effects.

Adult↗
PubMed1982

Cerebral blood flow in rats with renal and spontaneous hypertension: resetting of the lower limit of autoregulation.

The effect of chronic hypertension on cerebral blood flow (CBF) was studied in anaesthetised rats. CBF was measured with the intracarotid 133Xe injection method. Rats with spontaneous and renal hypertension were compared with normotensive controls. The lower limit of autoregulation was determined during controlled haemorrhage. In the normotensive rats, CBF remained constant until mean arterial pressure (MAP) had decreased to the range of 50-69 mm Hg. Thereafter, CBF decreased with each further decrease in MAP. In both types of hypertensive rats, CBF remained constant until MAP had decreased to the range of 70-89 mm Hg. Thus, a 20-mm Hg shift of the lower limit of CBF autoregulation was found in both spontaneous and renal hypertensive rats. A neuropathological study revealed ischaemic brains lesions in half of the hypertensive rats following hypotension, whereas only a single lesion was found in one of six normotensive rats. No ischaemic brain lesions were found in a control study in which CBF was shown to be stable over a 21/2-h period. In conclusion, hypertensive rats showed a shift of the lower limit of CBF autoregulation as well as an increased susceptibility to ischaemic brain damage during hypotension. These findings presumably reflect hypertensive structural changes in the cerebral circulation.

Animals↗
PubMed1982

Lithium treatment: does the kidney prefer one daily dose instead of two?

Renal structure and function were investigated in two groups of long-term lithium treated patients. Lithium was administered in two different ways either in a one-dose per day schedule where the whole dose of lithium was given between 8 and 10 p.m. or in a schedule where the lithium dose was given, divided into two or three doses, during the day. Kidney biopsy was performed, and structural changes in the kidney tissue were determined together with 24-h urine volume in the individual patients. The functional as well as the structural changes were most pronounced in patients given their lithium in divided doses during the day. Lithium may be more harmful to the kidney when the lithium administration gives a relatively constant serum lithium level than when the administration causes greater variations including peak values and low minimum levels in serum lithium. The reason for this might be that a number of regenerative processes only occur in periods with low lithium concentrations.

Adult↗
PubMed1981

Blood-brain barrier permeability of L-dopa in man.

The permeability of L-dopa across the blood-brain barrier was studied in twelve patients by means of the indicator dilution method. The extraction of [1-14C]L-dopa and [3-14C]L-dopa was 11.7% and 10.4%, respectively. After pretreatment with carbidopa the extraction was unchanged (13.5% and 11.6%). The permeability coefficient (P) was calculated to 0.9 x 10(-5) cm s-1.

Adult↗
PubMed1981

Lead poisoning and the blood-brain barrier.

Lead exposure may produce varying degrees of neuropsychiatric manifestations from discrete phenomena, quite often seen in children and as an occupational disease, to the rate fulminant lead encephalopathy. It was determined whether or not damage of the blood-brain barrier permeability in adult rats, as has been demonstrated in neonatal animals exposed to lead, could also play a role. Massive lead exposure did not induce any change in the transfer (facilitated diffusion) of phenylalanine any tyrosine measured by means of the indicator dilution technique. Ultrastructural examination, after application of horseradish peroxidase, did not reveal any pathological changes in the permeability to the tracer. It is concluded that in adult rats, in contrast to neonatal animals, the observed pathological signs clearly seen in the chronically exposed animals must be ascribed to a noxious influence of lead on the extravascular side of the blood-brain barrier.

Animals↗
PubMed1981

Comparison of peripheral anticholinergic effects of antidepressants: dry mouth.

Twenty-one healthy volunteers were given single doses of placebo or antidepressants corresponding to average daily doses of patient medications. Spontaneous whole mouth and parotid salivation was measured two, six, and ten hours after drug administration in session 1; in session 2 after ten hours. The results indicate that a subdivision of antidepressants into four groups can be made according to inhibitory effect on salivation: (a) isocarboxazide and lithium citrate with no effect, (b) zimelidine and nomifensine with slight effect, (c) imipramine oxide and mianserin with moderate effect and (d) maprotiline, nortriptyline, clomipramine, imipramine, and amitriptyline with pronounced effect. Research implications and predictive value for new antidepressants are discussed.

Adult↗
PubMed1981

Electroconvulsive therapy: a comparison of seizure duration as monitored with electroencephalograph and electromyograph.

EEG and EMG were monitored simultaneously at 72 ECT sessions in 18 patients. When EMG was recorded from the leg the duration of EMG curve convulsions varied between 43 and 89% of the EEG recorded seizure duration of the same fit. The EMG/EEG seizure ratio varied widely among different patients as well as within the single patient during a series of ECT sessions. EMG recording from the masseter muscles showed EMG seizure duration to be more in accordance with the EEG seizure duration than EMG recordings from the leg. The EMG/EEG seizure ratio (masseter) varied from 65 to 100%, which was significantly higher than the EMG/EEG seizure ratio obtained with EMG recorded from the calf muscles. The use of EEG monitoring of ECT is advocated in order to obtain the most precise evaluation of the cerebral seizure activity. If EEG monitoring is not available EMG recorded from the masseter muscles provides a reasonably accurate and easily applicable method of monitoring the presence and duration of the ECT-induced seizure.

Depressive Disorder↗
PubMed1980

Synaptic proteins after electroconvulsive stimulation: reversibility and regional differences in the brain.

The pattern of changes in brain-specific proteins mainly related to the synapses were studied in rats given electroconvulsive stimuli (ECS). One group was studied after three ECS per week for 4 weeks, another was further allowed a recovery period of 12 weeks. The experimental animals were compared with adequate controls. Brain-specific proteins were analyzed using crossed immunoelectrophoresis. The changes in the protein pattern after 4 weeks of ECS differed in the regions studied and are interpreted as follows: in the hypothalamus the amount of synapses seem to have increased, in the forebrain synaptic remodelling is under way and in the occipital cortex a delay in the neuronal development has been induced. The results further indicate an overall increased preparedness to meet the glycolytic demands accompanying seizure. Following 12 weeks of recovery a partial reversion of the induced changes was observed. The implication of the findings in relation to newer concepts of the working action of electroconvulsive therapy is discussed.

Animals↗
PubMed1979

Synaptic proteins after electroconvulsive stimulation.

Quantitative immunoelectrophoresis of rat brain synaptic proteins following a series of electroconvulsive stimulations demonstrated changes suggestive of an increase in the number of synaptic vesicles, in a preparedness for glycolytic demands, and a delayed development of a certain area in the brain. The increased synaptic remodeling may be important for the action of electroconvulsive therapy.

Animals↗