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Biomedical subjects

T G Bolwig

Publications and source records attributed to T G Bolwig.

At least 91 records · Page 5Linked to original sources
PubMed1989

Long-term effects of lithium on the kidney: functional-morphological correlations.

Correlations between quantitative kidney biopsy findings and clinical renal function in 46 unselected patients treated with lithium for an average of eight years were studied. A significant relationship between maximum renal concentrating capacity and degree of tubular atrophy was found. GFR correlated significantly with sclerotic glomeruli as well as atrophic tubules in patients on a multiple dosage schedule, whereas no relationship was seen in patients receiving lithium in a single daily dose. Thus, renal dysfunction may have a structural basis in a subgroup of lithium-treated patients on a multiple dosage schedule.

Adult↗
PubMed1989

Personality characteristics and epilepsy.

Patients with a long history of temporal lobe epilepsy or primary generalized epilepsy entered a questionnaire study of personality characteristics, based on a modification of the Bear-Fedio inventory for temporal lobe behavioural syndrome. Psoriasis patients and healthy volunteers served as controls. Four clinical meaningful dimensions of included personality traits were identified: ixoide, ideational, obsessive-compulsive and affective features. Analyses based on the Rasch model approved of all dimensions except for affective features. The epilepsy group obtained the highest scores on all 3 dimensions, healthy volunteers the lowest, while the psoriasis group repeatedly held an intermediate position in all sets of assessment (subjects, interviewers and relatives). A logistic regression analysis showed ixoide features being most important when the entire epilepsy group was compared with other study groups, while the dimension ideational features was significant when the temporal lobe epilepsy group was entered as target group and opposed to primary generalized epilepsy. The intermediate position of the psoriasis group, however, suggests that in addition to the presence of a cerebral dysfunction in the epilepsy group, the mere presence of a chronic disorder with potential social stigmatization influences personality.

Adult↗
PubMed1988

Local cerebral glucose consumption during ethanol withdrawal in the rat: effects of single and multiple episodes and previous convulsive seizures.

Local cerebral glucose consumption (l-CMRgl) was studied using [14C]2-deoxyglucose autoradiography in minimally restrained rats during acute (12 or 18 h postwithdrawal (p.w.] and late (14 days p.w.) ethanol withdrawal, as well after 10 previous, weekly withdrawal episodes as after a similar period of isocalorical feeding. A period of two days of intoxication was established by gastric intubation. Spontaneous incomplete convulsive seizures were observed during the 8th to 10th withdrawal episode. Audiogenic seizures occurred following stimulation during the 6th and 10th withdrawal episode. Animals with previous spontaneous or audiogenic seizure were distributed randomly and evenly among the groups. l-CMRgl values were adjusted to a temperature of 38 degrees C. During acute withdrawal, l-CMRgl was significantly reduced by 18-32% in cortical and most limbic regions, but unchanged in cerebellum and subcortical structures as compared with the neutral state (late withdrawal and control groups). l-CMRgl was relatively more lowered in the amygdala in animals with previous spontaneous withdrawal seizures and in structures belonging to the auditory system in animals with previous audiogenic seizures. l-CMRgl did not differ among neutral groups. The lowered l-CMRgl in cortical and limbic regions during withdrawal contrasts to the results of previous studies. This difference may be attributed to the minimal restraint of animals in this study. The pattern of l-CMRgl in acute and late withdrawal animals with previous spontaneous withdrawal seizures is consistent with a mechanism comparable to electrical amygdala kindling contributing to seizure genesis.

Animals↗
PubMed1988

Ego functions in epilepsy.

Two groups of epilepsy patients (28 patients with temporal lobe epilepsy and 15 patients with primary generalized epilepsy) entered a study of personality traits related to epilepsy, based on a modification of Bellak's semistructured interview for assessment of ego strength. Two groups of subjects served as controls: 15 patients with a non-neurological but relapsing disorder, psoriasis, and 15 healthy volunteers. Compared with the group of healthy volunteers, a decreased adaptive level of ego functioning was found in the epilepsy groups, regardless of seizure types and EEG findings, and, to a lesser extent, compared with the psoriasis group. Areas of ego functioning most affected were "reality testing", "cognitive functioning", "integrative functioning" and "regulation and control of drives". Patients with more than one type of seizure were the most affected, as were patients who were younger than 15 years when the disease began. The number of anticonvulsants administered did not influence the results. No difference on adaptive level of ego functioning was found between the group with primary generalized epilepsy and the group with temporal lobe epilepsy. Similarly, the temporal lobe epilepsy group with predominantly right-sided and left-sided EEG changes, respectively, showed similar adaptive levels of ego functioning.

Adult↗
PubMed1988

Blood-brain barrier studies with special reference to epileptic seizures.

A review is given of the structure and function of the blood-brain barrier (BBB) with special reference to the situation during and after epileptic seizures including electroconvulsive therapy (ECT). Based on the literature describing different models of epilepsy the development of the theories concerning the early observations of a BBB dysfunction in connection with seizure activity is given, and gross morphology, ultrastructural and dynamic findings are briefly reviewed.

Animals↗
PubMed1988

Cerebral blood flow during delirium tremens and related clinical states studied with xenon-133 inhalation tomography.

The regional cerebral blood flow of 12 patients with severe alcohol withdrawal reactions (delirium tremens or impending delirium tremens) was measured during the acute state before treatment and after recovery. Greater cerebral blood flow was significantly correlated with visual hallucinations and agitation during the acute withdrawal reaction. The results suggest that delirium tremens and related clinical states represent a type of acute brain syndrome mainly characterized by CNS hyperexcitability.

Adult↗
PubMed1987

Brain marker protein changes after short- and long-term ethanol intoxication and withdrawal in the rat.

The brain marker proteins, D1, D2, and D3, localised to neuronal membranes, and mitochondrial and cytoplasmic marker proteins (MM and CM), were studied during 1-6 days (short term) intragastrically-induced severe ethanol intoxication and during 1 month (long-term) ethanol intoxication established by a liquid diet regimen. The concentrations of the same brain proteins were also measured during withdrawal from the ethanol intoxication periods. Three categories of effect were encountered: decreased concentration of brain marker proteins during severe short-term intoxication the effect being most marked for D3, possibly indicating degradation of mature synapses; increased concentration of proteins D2 and MM during withdrawal, the D2 changes possibly indicating formation of new synapses; increased concentration of D1 protein and MM during long-term intoxication. We suggest that the changes in brain marker proteins reflect dynamic changes of subcellular neuronal structures which may form a part of the basis of functional tolerance to and physical dependence upon ethanol or the reversion of these states after withdrawal of ethanol.

Alcohol Withdrawal Delirium↗
PubMed1987

Grafted noradrenergic neurons suppress seizure development in kindling-induced epilepsy.

Norepinephrine-rich cell suspensions, prepared from the locus coeruleus region of rat fetuses, were grafted bilaterally into the hippocampus of rats made hypersensitive to hippocampal kindling by a neurotoxic lesion of the central catecholamine system. The animals with grafts showed a marked suppression of the onset and progression of kindling-induced epilepsy, and this effect was correlated with the degree of graft-derived noradrenergic innervation of the host hippocampal formation. We conclude that grafted neurons can modulate the excitability of epileptic brain regions.

Adrenergic Fibers↗
PubMed1986

Lithium: long-term effects on the kidney. I. Renal function in retrospect.

46 patients treated with lithium for an average of 8 years participated in a functional-morphological follow-up study based on a 12-day hospitalization and involving a kidney biopsy. The functional part of the study showed that tubular function was markedly influenced, leading to increased urine volume (average 3 1/24 h) and a decreased renal concentration capacity in 85% of the patients. Glomerular function was generally not influenced, and only 10% of the patients had glomerular filtration rates below their age-corrected normal ranges. Both urine volume and glomerular filtration rates showed significant correlations with dosage schedule. Urine volume was lower and glomerular filtration rate higher on a one-dose schedule than when lithium was given in divided doses during the day. It is concluded that discontinuity in lithium treatment minimizes lithium effects on kidney function.

Adult↗
PubMed1985

Convulsive and non-convulsive ethanol withdrawal behaviour in rats with lesions of the noradrenergic locus coeruleus system.

The ascending noradrenergic pathways from the locus coeruleus were lesioned bilaterally in 10 rats by intracerebral 6-hydroxydopamine injections. Ten rats were sham-operated. All animals were subjected to a 4-day ethanol intoxication period using intragastric intubation. Intoxication and withdrawal assessments were performed blindly. The 6-hydroxydopamine lesions did not appear to affect tolerance to ethanol. During withdrawal, however, lesioned animals showed minor, but statistically significant changes in scores of certain non-convulsive withdrawal signs, but incidence and intensity of spontaneous and audiogenic convulsive seizures were not different between the groups.

Acoustic Stimulation↗
PubMed1984

Assessment of the anticholinergic effects of antidepressants in a single-dose cross-over study of salivation and plasma levels.

In order to evaluate the anticholinergic effect of antidepressant drugs, 11 healthy volunteers were given single oral doses of reference drug, test drugs or placebo on a double-blind basis at weekly intervals. The doses corresponded to average daily patient medications. Spontaneous whole mouth and parotid salivation, and plasma levels of drug and possible metabolites were measured 2, 6 and 10 h after drug administration. Moderate, statistically significant inhibition of salivation was found when nortriptyline, imipramine-N-oxide and mianserin were given. Less pronounced, but still statistically significant inhibition occurred after ingestion of nomifensine and zimelidine. The zimelidine effect was exclusively due to the metabolite norzimelidine, and the inhibition after imipramine-N-oxide was mainly due to the metabolite imipramine, but imipramine-N-oxide itself also had slight activity. Isocarboxazide and lithium had no effect on salivation. From these results and reported values of pharmacokinetic variables, the average level of anticholinergic activity during long-term treatment may be predicted: for mianserin and (nor-)zimelidine moderate inhibition of salivation, although less pronounced than with nortriptyline; for nomifensine no clinically significant effect; and for imipramine-N-oxide a negligible contribution from the unmetabolized drug.

Adult↗
PubMed1984

Salivation after single-doses of the new antidepressants femoxetine, mianserin and citalopram. A cross-over study.

Twelve healthy volunteers were given oral single doses of a reference drug (nortriptyline), test drugs, and placebo on a randomised single-blind basis at weekly intervals. The doses corresponded to average daily patient medication. Spontaneous whole mouth salivation was measured before (at 10 p.m.) and 10 hours after drug administration (at 8 a.m.). Drug plasma levels were determined after 4 and 10 hours. When analysing the salivations 10 hours after drug administration adjusted for the effects of the pre-treatment salivations, statistically significant inhibition of salivation was found after nortriptyline (56%), femoxetine (34%), and mianserin (29%) when compared with placebo, while for citalopram and cis- and trans-flupenthixol no significant inhibition of salivation was demonstrated (Fig. 1, Table 5). From the estimated log linear regression coefficients, relating adjusted salivation rates and drug plasma levels 10 hours after drug administration (Table 6), and reported average steady-state plasma drug levels (Table 7), semiquantitative predictions of the average level of anticholinergic activity during long-term treatment may be made: For femoxetine and mianserin, moderate anticholinergic activity, less pronounced than with nortriptyline, are predicted, while for citalopram no such activity can be predicted (Table 7).

Adolescent↗
PubMed1984

The intracarotid 133xenon injection method for measurement of cerebral blood flow (CBF) in rats: evaluation of the effect of bolus volume.

It is assumed that the cerebral microcirculation is not perturbed by the intraarterial injection used in determination of cerebral blood flow (CBF) with the intraarterial 133Xenon technique (and in various assessments of blood brain barrier (BBB) permeability). The application of these techniques to the rat, where the injectate is large compared to normal blood flow, places this problem is focus and it has been claimed that since large intracarotid injections increased cerebral venous outflow, the CBF must also increase. We investigated this problem in the rat by means of the intraarterial 133Xenon injection technique, using a saline bolus injected in less than 1 sec and found that CBF was unaltered at bolus volumes between 10 and 100 microliters. Furthermore, injection of 100-200 microliters saline during washout detection did not change the slope of the semilogarithmic wash-put curves. It is concluded that in spite of large intracarotid injections the CBF remained constant and that the hemodilution produced by the saline bolus is not sufficient to influence CBF. Consequently, estimations of CBF yield valid results in the present rat preparation.

Animals↗