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Biomedical subjects

T G Bolwig

Publications and source records attributed to T G Bolwig.

At least 19 recordsLinked to original sources
PubMed1992

[Electric stimulation (ECT) in Parkinson disease].

A case report and a review of the literature concerning electroconvulsive therapy (ECT) in the treatment of Parkinson's disease with special reference to the therapy of "on-off" phenomena is given. The first report of positive effect appeared in 1959 and, with a single exception, all published articles on this topic point to a positive outcome of ECT. There seems to be a specific anti-Parkinsonian effect alongside the well-known effect on various psychotic conditions. ECT thus must be considered a valuable intervention when drug therapy is insufficient, when prolonged medication leads to decreased efficacy, or when patients develop neuro-psychiatric manifestations. A short review of the pathophysiological mechanisms which may underly the effect of ECT in Parkinson's disease is given.

Electroconvulsive Therapy↗
PubMed1992

Kidney functioning during lithium treatment: a prospective study of patients treated with lithium for up to ten years.

A cohort of 53 patients with affective disorders who originally carried through renal functional tests before start of prophylactic lithium treatment were followed up prospectively after an average period of 8.5 years (range 7-10 years). Ten patients who had continued lithium treatment were re-examined. In this subgroup, the glomerular function was unaffected by the treatment, whereas the average urine volume increased during lithium treatment (NS). Polyuria and low renal concentrating abilities were also found before start of treatment and these findings underline the importance of access to renal baseline information prior to lithium treatment.

Adult↗
PubMed1991

Hippocampal kindling in the rat is associated with time-dependent increases in the concentration of glial fibrillary acidic protein.

The effect of hippocampal kindling on the regional brain concentration of total glial fibrillary acidic protein (GFAP), a marker of reactive astrocytes, was studied in partially kindled rats, and in fully kindled rats after a post-kindling period of 24 h, 1 week, and 2 months. GFAP concentration was measured in arbitrary units by dot-blots. In the hippocampus, dentate gyrus, basolateral amygdala, pyriform cortex, and entorhinal cortex, limbic structures which are known to be involved in the kindling process, there was an increase in GFAP concentration which was maximal in the fully kindled animals studied after 24 h. In most brain areas, GFAP concentration was still elevated 1 week post-kindling, but had declined to control level 2 months post-kindling. A significant increase in GFAP was also found in septum, ventral pallidum/accumbens nucleus, and primary motor cortex of kindled rats with a post-kindling period of 24 h, whereas in several other brain regions GFAP was unchanged. These results suggest that astrocyte activation, indicative of degenerative changes in nearby neurons, is a transient and regional phenomenon in kindling occurring only during the development of the kindled state.

Animals↗
PubMed1991

Lithium: long-term effects on the kidney. A prospective follow-up study ten years after kidney biopsy.

Forty-six patients with recurrent affective disorders, who began prophylactic treatment with lithium an average of 20 years previously, were followed up prospectively after a ten-year observation period to assess renal function. Nineteen patients had maintained lithium therapy, and eight patients had died. Tubular function was almost unchanged and patients who had continued lithium had not shown increasing urine volumes, but patients who had received lithium in a single daily dosage at night had a significantly lower urinary output than those on a multiple-dosage schedule. The GFR decreased significantly, but the decline was essentially dependent on increasing age, except in two patients who had developed renal insufficiency. Renal function during chronic lithium treatment is related to age, lithium intoxication episodes, pre-existing renal disease, and treatment schedule rather than to duration of prophylactic lithium therapy.

Adult↗
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↗
PubMed1979

The Bech-Rafaelsen Mania Scale and the Hamilton Depression Scale.

In a study of 18 patients with manic symptomatology and 31 patients with melancholic symptomatology the Bech-Rafaelsen Mania Scale (BRMS) and the Hamilton Depression Scale (HDS) have been compared. The results showed that the inter-observer reliability of the BRMS was adequate compared with the HDS. Both scales are constructed for assessing the severity of manic or melancholic states, and no difference was found in the total BRMS or HDS score between the various diagnostic groups, when the patients were classified by an index of the course and symptomatology otive disorder, using the Multi-axial Classificetion System for Affective Disorders (MULTI-CLAD). The homogeneity of the BRMS seemed more adequate than that of the HDS, when each item was correlated to the corresponding total score. Although the homogeneity of the BRMS needs to be evaluated by other statistical models than correlation analysis, our results seem to indicate that the improvement in assessing manic-melancholic states quantitatively is a matter of redefining items or incorporating new items in the melancholic rather than the manic part of these rating scales.

Adult↗
PubMed1978

Increased permeability to horseradish peroxidase across cerebral vessels, evoked by electrically induced seizures in the rat.

Under normal conditions a slight vesicular transfer of intravenously injected horseradish peroxidase (HRP) occurs across the endothelium of cerebral vessels, especially short segments of arterioles. The vesicular transport can be notably increased by chemically induced acute hypertension. In the present investigation 4 groups of animals received HRP, and the permeability of the cerebral endothelium was studied semimacroscopically, light microscopically and electron microscopically. The rats in group 1 were given 10 electroshocks. This caused a significant rise in the blood pressure (BP). Furthermore, a noticeable extravasation of HRP was observed, especially across the endothelium in cerebral arterioles. From the basement membranes of the vessels reaction product could be followed into the extracellular spaces of the neighbouring neuropil. Group 2 comprises rats that were given 10 electroshocks preceded by transection of the cervical part of the spinal cord. The BP remained at normal level and the permeability was unaltered. The animals in group 3 received only 1 electroshock. Usually, the BP was markedly increased and this was accompanied by enhanced permeability across the vessels of the brain. Group 4 consists of control animals, injected with HRP and treated as groups 1 and 3 with the difference that electrical stimulation was not performed. A general feature was that no endothelial damage was observed and that reaction product was not found between neighbouring endothelial cells from the first luminal to the first abluminal tight junction. Based on the observations it seems reasonable to assume that the increased permeability of tracer that occurs after 10 electroshocks or only one is caused by the acute hypertension evoked by the electrical stimulation; furthermore, the transfer is concluded to be vesicular transport.

Animals↗
PubMed1977

The permeability of the blood-brain barrier during electrically induced seizures in man.

The blood-brain barrier (BBB) in man was studied during various conditions using the indicator dilution method of Crone [8]. Using 113m In-DTPA as reference substance the extraction, E, of the small test substances 24Na+, 36Cl-, 14C-urea and 14C-thiourea was estimated from the areas under the venous outflow curves following intracarotid slug injection of tracers. Interlaminar diffusion and red cell carriage were taken into consideration when calculating E. Cerebral blood flow (CBF) was measured using the intra-arterial 133Xe-injection method. Twenty-two patients receiving electroconvulsive therapy (ECT) were studied before and during seizures and during hypercapnia. Before seizures the extraction values in % were as follows: ENa+ 1.6, ECl- 1.9, Eurea 3.9 and Ethiourea 7.8; the corresponding values for the permeability-surface area products (PS) in ml/100 g x min were 0.5, 0.3, 0.7, 4.1, respectively. During seizure a decrease of Ethiourea and an increase of PSurea were significant. During hypercapnia PSNa and PSthiourea rose significantly. Due to the similarity of the findings in those two high flow situations it is suggested that the changes of CBF and not the epileptic activity are responsible for the changes in permeability. The mechanism of action may be a stretching of endothelial cells in the cerebral vessels or an opening up of new capillaries, or a combination of both.

Adult↗
PubMed1977

Blood-brain barrier during electroshock seizures in the rat.

The effect of electrically induced seizures on the permeability of the rat blood-brain barrier was investigated. The small radioactive tracers sodium (24Na+), chloride (36Cl-) carbon labelled thiourea (14C-thiourea) and glucose (14C-D-glucose) were studied in indicator dilution experiments with indium labelled diethylenetriaminepenta-acetic acid (113mIn-DTPA) as reference substance. This method allows a quantitative estimate of the transcapillary loss of solutes, the extraction (E), during a single passage through the brain. Passage of macromolecules was studied using as marker substance Evans Blue which binds to plasma albumin. In the resting state ENa, ECl, Ethiourea and Eglucose were 2.9, 4.8, 9.3 and 12.5%, respectively. During seizures and during shortlasting hypercapnia E glucose decreased while E for the other tracers was unchanged. As cerebral blood flow increased, there must be an increased transfer of test substances into the brain. This finding is in agreement with recent human studies [15]. When Evans Blue was injected intravenously prior to electroshock, there was no staining of brain tissue after one electroshock but following repeated electroshocks some staining was observed. In an attempt quantify this transcapillary loss of albumin by means of indicator dilution, 51Cr-labelled erythrocytes were used as intravascular reference substance against 113mIn-DTPA (a plasma tracer). However, the albumin loss (by pinocytosis or otherwise) occurring after ten electroshocks could not be detected during a single passage through the brain.

Animals↗
PubMed1977

Acute hypertension causing blood-brain barrier breakdown during epileptic seizures.

The influence of shortlasting (less than 1 min) epileptic seizures on the permeability to protein of the blood-brain barrier (BBB) was studied in rats. The protein tracer, horseradish peroxidase (HRP) was used as marker substance. Monitoring arterial blood pressure (BP) and electroencephalogramme (EEG) seizures were induced electrically after HRP was given intravenously. Following a single electroshock seizure slight staining of brain tissue was seen, while after 10 electroshock stimuli followed by sustained seizure activity, this phenomenon was more pronounced. If 10 electroshock stimuli were preceded by transsection of the spinal cord, blood pressure increase was abolished and no tissue staining was seen in spite of epileptic seizure activity recorded on EEG. This means that the acute hypertension and not the seizure activity per se is the mechanism behind the breakdown of the BBB during epileptic seizures. Electron microscopy revealed an increased vesicular transport (pinocytosis) across the endothelial cells, while the vascular structure remained intact.

Acute Disease↗